{"gene":"CX3CL1","run_date":"2026-04-28T17:28:53","timeline":{"discoveries":[{"year":2004,"finding":"CX3CL1 is synthesized in endothelial cells as a transmembrane protein; the N-terminal chemokine domain is proteolytically cleaved and secreted as a soluble chemoattractant, while the membrane-bound form acts as an adhesion molecule for CX3CR1-expressing leukocytes (monocytes and lymphocytes). Expression is induced by TNF-α, IL-1, LPS, and IFN-γ, and inhibited by soluble IL-6Rα, 15-deoxy-Δ(12,14)-PGJ2, and hypoxia.","method":"Cell stimulation assays, protein expression analysis, functional adhesion assays in endothelial cells","journal":"Journal of atherosclerosis and thrombosis","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods, replicated across labs","pmids":["15067194"],"is_preprint":false},{"year":2007,"finding":"CX3CL1 transmembrane chemokine is sequentially processed by α-secretase activity (ADAM10, cleaving at multiple sites) and subsequently by γ-secretase (but not β-secretase), generating C-terminal fragments (CTFs) analogous to Notch/E-cadherin processing. This proteolytic cascade releases soluble CX3CL1 and produces intracellular CTFs.","method":"Inhibitor studies (ADAM10/γ-secretase/β-secretase/proteasome inhibitors), presenilin 1/2-deficient cell lines, CX3CL1 constructs C-terminally fused to 2Z-tag for CTF detection","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 — genetic (presenilin-KO cells) and pharmacological inhibitor studies with multiple orthogonal approaches in one study","pmids":["17467666"],"is_preprint":false},{"year":2005,"finding":"Cell surface CX3CL1 is in dynamic equilibrium with a juxtanuclear intracellular storage compartment distinct from conventional endosomes. Internalized CX3CL1 is recycled back to the plasma membrane via a SNARE-mediated mechanism involving syntaxin-13 and VAMP-3; cleavage of VAMP-3 by tetanus toxin or dominant-negative syntaxin-13 blocks this recycling.","method":"Live-cell fluorescence imaging of GFP-tagged CX3CL1, co-localization with SNARE proteins, tetanus toxin treatment, dominant-negative allele expression, subcellular fractionation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — direct live imaging + genetic/pharmacological perturbation with mechanistic readout in one study","pmids":["15774461"],"is_preprint":false},{"year":2006,"finding":"In polarized renal tubular epithelial cells, CX3CL1 is targeted exclusively to the apical membrane and subapical vesicles. Apical targeting depends on N-linked glycosylation (not the intracellular domain, O-glycosylation, or lipid raft association). CX3CL1 is immobile in the apical membrane (FRAP) and is not directly actin-cytoskeleton-associated. Apical CX3CL1 promotes adhesion of CX3CR1-expressing leukocytes to the luminal surface.","method":"FRAP, immunofluorescence of polarized MDCK cells expressing GFP-CX3CL1, N-glycosylation and cholesterol depletion experiments, leukocyte adhesion assay, human biopsy immunohistochemistry","journal":"Journal of the American Society of Nephrology","confidence":"High","confidence_rationale":"Tier 1/2 — FRAP, mutagenesis-like glycosylation studies, functional adhesion assay; single study with multiple orthogonal methods","pmids":["17151328"],"is_preprint":false},{"year":2014,"finding":"The cortical actin cytoskeleton confines CX3CL1 within restricted membrane domains, sequestering it from ADAM10 and limiting constitutive proteolytic cleavage. Disruption of actin by cytochalasin D reduces CX3CL1 confinement, increases CX3CL1-ADAM10 co-localization, and promotes soluble CX3CL1 release.","method":"Single-particle tracking, subdiffraction fluorescence imaging (PALM/STORM), pharmacological actin disruption, ADAM10 co-localization quantification","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1 — single-molecule imaging plus functional readout in one study","pmids":["25253723"],"is_preprint":false},{"year":2008,"finding":"Thrombin induces CX3CL1 expression in human umbilical vein endothelial cells (HUVECs) via PAR1 activation and downstream NF-κB signaling. Membrane-anchored CX3CL1 induced by thrombin promotes monocyte adhesion to endothelium and triggers monocyte CCL2 release, potentiating transendothelial migration. Recombinant soluble CX3CL1 ectodomain alone induces CCL2 release from monocytes.","method":"RT-PCR, Western blot, flow cytometry, EMSA, ELISA; PAR1-activating peptide, PAR1 antagonist SCH 79797, IKK inhibitor, dominant-negative IκBα; co-culture and transendothelial migration assays","journal":"Journal of leukocyte biology","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal pharmacological and genetic approaches with defined cellular readouts","pmids":["18436581"],"is_preprint":false},{"year":2012,"finding":"Only the soluble isoform of CX3CL1 (not membrane-bound) provides neuroprotection in an MPTP mouse model of Parkinson's disease, reducing motor impairment, dopaminergic neuron loss, microglial activation, and pro-inflammatory cytokine release. The membrane-bound isoform was indistinguishable from GFP controls.","method":"AAV-mediated delivery of synthetic permanently soluble vs. obligate membrane-bound CX3CL1 variants into substantia nigra of CX3CL1−/− mice; behavioral testing, immunohistochemistry, cytokine ELISA","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — isoform-selective genetic rescue in KO background with multiple orthogonal readouts","pmids":["23077045"],"is_preprint":false},{"year":2014,"finding":"Membrane-anchored CX3CL1 (not soluble isoform) regulates microglial phagocytosis of amyloid-β and neuronal tau phosphorylation in Alzheimer's mouse models via the p38 MAPK pathway. CX3CL1 deficiency reduces Aβ deposition but paradoxically enhances tau phosphorylation; transgenic soluble CX3CL1 expression does not rescue either phenotype.","method":"Genetic crosses of APPPS1 mice with CX3CL1-KO and soluble CX3CL1 transgenic mice; microglia isolation for transcript profiling; p38 MAPK phosphorylation assay; Aβ internalization in purified microglia","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic mouse models with mechanistic pathway (p38 MAPK) identification","pmids":["25209291"],"is_preprint":false},{"year":2020,"finding":"Soluble CX3CL1 rescues cognitive deficits, hippocampal LTP, and adult neurogenesis in CX3CL1-KO mice, while the obligate membrane-bound form only partially rescues spatial learning and does not rescue long-term memory or neurogenesis, demonstrating isoform-specific functions.","method":"AAV delivery of sFKN or mFKN to CX3CL1-KO mice; behavioral tests (Morris water maze, novel object recognition); hippocampal LTP electrophysiology; neurogenesis markers by immunostaining","journal":"Journal of neuroinflammation","confidence":"High","confidence_rationale":"Tier 2 — isoform-selective genetic rescue in KO mice with multiple orthogonal functional readouts","pmids":["32410624"],"is_preprint":false},{"year":2019,"finding":"CX3CL1 C-terminal intracellular domain (CX3CL1-ICD), released after sequential α-, β-, and γ-secretase cleavage, translocates to the nucleus and enhances adult neurogenesis through the TGF-β2/3-Smad2/3 pathway. This 'back-signaling' is independent of CX3CR1 and reduces amyloid pathology and neuronal loss in 5xFAD mice.","method":"CX3CL1-ct overexpression in 5xFAD mice; Smad2 neuron-specific knockout; RNA-seq of neurons; morphological analysis; TGF-β2/3 and Smad2 protein measurements","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 — genetic KO of downstream effector (Smad2) abrogates CX3CL1 neurogenic effect; multiple orthogonal methods","pmids":["31209068"],"is_preprint":false},{"year":2019,"finding":"CX3CL1 overexpression in neurons enhances neurogenesis in subgranular and subventricular zones via a TGF-β2/TGF-β3-Smad2 pathway. Neuron-specific deletion of Smad2 abrogates this effect. In tau P301S (PS19) Alzheimer's mice, neuronal CX3CL1 overexpression rescues neurodegeneration and improves cognition.","method":"Transgenic CX3CL1-overexpressing mice crossed with PS19 and with Smad2-neuron-specific KO mice; neurogenesis quantification; cognitive/motor behavioral testing; TGF-β and Smad2 protein measurements","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — genetic rescue and epistasis with Smad2 deletion confirming pathway placement","pmids":["31822518"],"is_preprint":false},{"year":2018,"finding":"CX3CL1-CX3CR1 signaling regulates microglial repopulation in the adult retina: repopulation is slowed in CX3CR1-deficient mice and accelerated by exogenous CX3CL1 administration. Repopulating microglia (derived from residual microglia in central inner retina) fully restore microglial distribution, morphology, process surveillance, and synaptic maintenance.","method":"In vivo imaging, cell-fate mapping, CX3CR1-GFP reporter mice, exogenous CX3CL1 intravitreal delivery, microglial depletion model","journal":"Science advances","confidence":"High","confidence_rationale":"Tier 2 — in vivo imaging + genetic (CX3CR1-KO) + pharmacological (exogenous CX3CL1) with defined functional readouts","pmids":["29750189"],"is_preprint":false},{"year":2016,"finding":"CX3CL1-CX3CR1 signaling suppresses microglial phagocytosis and activation in the degenerating retina (rd10 RP model). CX3CR1 deficiency accelerates photoreceptor apoptosis and increases microglial phagocytosis; exogenous CX3CL1 delivery reduces microglial infiltration and improves photoreceptor survival and function.","method":"CX3CR1(GFP/GFP) rd10 mice; in vivo phagosome counting; in vitro phagocytosis rate assay with fluorescent beads; live-cell imaging of retinal explants; intravitreal CX3CL1 delivery","journal":"Glia","confidence":"High","confidence_rationale":"Tier 2 — genetic + pharmacological rescue with multiple in vitro and in vivo orthogonal phagocytosis assays","pmids":["27314452"],"is_preprint":false},{"year":2013,"finding":"CX3CL1 promotes breast cancer cell proliferation by transactivating ErbB receptors through proteolytic shedding of an ErbB ligand, inducing epithelial-to-mesenchymal transition. Genetic deletion of CX3CL1 delays mammary tumorigenesis in HER2/neu mice but not in polyoma middle T-antigen mice, placing CX3CL1 specifically in the ErbB signaling context.","method":"Adenoviral CX3CL1 overexpression in HER2/neu transgenic mice; CX3CL1 genetic knockout crossed with tumor models; in vitro proliferation and EMT assays; ErbB receptor transactivation assays","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 2 — genetic epistasis in multiple tumor mouse models plus in vitro mechanistic dissection","pmids":["23720051"],"is_preprint":false},{"year":2013,"finding":"CX3CL1 regulates nerve injury-induced pain hypersensitivity through the ERK5 signaling pathway: CX3CR1 blockade reduces ERK5 phosphorylation in the spinal cord after SNL, and antisense ERK5 knockdown reverses CX3CL1-induced hyperalgesia and spinal microglial activation.","method":"Spinal nerve ligation (SNL) rat model; intrathecal antisense oligonucleotide knockdown of ERK5; intrathecal CX3CR1 blocking antibody; ERK5 phosphorylation western blot; behavioral pain testing","journal":"Journal of neuroscience research","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological and antisense knockdown with pathway placement, single lab","pmids":["23361876"],"is_preprint":false},{"year":2008,"finding":"CX3CL1 treatment of trophoblast cells regulates expression of adhesion molecules and extracellular matrix components including α-catenin (CTNNA1), ECM1, osteopontin (SPP1), integrin α6 (ITGA6), MMP12, and integrin β5 (ITGB5), and increases trophoblast adhesion to fibronectin, suggesting a mechanism for CX3CL1-driven directional trophoblast migration during implantation.","method":"Pathway-specific oligonucleotide arrays, qRT-PCR, fibronectin adhesion assay, immunohistochemistry of first-trimester implantation sites","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 3 — single lab, transcriptomic + functional adhesion assay, mechanistic gene targets identified","pmids":["18367676"],"is_preprint":false},{"year":2003,"finding":"CX3CR1 signaling in microglia induces chemotaxis in response to CX3CL1 (confirmed by chemotaxis assay). CX3CL1 is constitutively expressed by human CNS astrocytes in vivo and in vitro; CX3CR1 is expressed on both astrocytes and microglia.","method":"Chemotaxis assay, immunohistochemistry of human brain tissue, RT-PCR, in vitro astrocyte cultures with cytokine stimulation","journal":"Journal of neuropathology and experimental neurology","confidence":"Medium","confidence_rationale":"Tier 2/3 — functional chemotaxis assay plus localization; single lab","pmids":["14533779"],"is_preprint":false},{"year":2017,"finding":"N-terminal pyroglutamate (pGlu) modification of CX3CL1 by glutaminyl cyclase (QC/QPCT) or isoQC (QPCTL) is required for full biological activity: pGlu1-CX3CL1 induces significantly stronger phosphorylation of ERK1/2, Akt, and p38 kinases than immature Gln1-CX3CL1, and drives higher expression of CCL2, CX3CL1, and ICAM1 in vascular smooth muscle and endothelial cells. QPCT expression is co-regulated with CX3CL1 via NF-κB.","method":"Mass spectrometry to confirm pGlu formation; RNAi knockdown of QPCT; kinase phosphorylation assays; gene expression by RT-PCR; NF-κB pathway inhibition","journal":"Bioscience reports","confidence":"Medium","confidence_rationale":"Tier 2 — MS confirmation of modification + functional kinase assays + RNAi, single lab","pmids":["28739588"],"is_preprint":false},{"year":2020,"finding":"CX3CL1 forms homo-oligomers of 3–7 monomers driven by intrinsic properties of its transmembrane domain, and this oligomerization is required for its adhesive function. A transmembrane domain peptide of CX3CL1 inhibits both oligomerization and cell-to-cell adherence, while a scrambled peptide control does not.","method":"Native electrophoresis, single-molecule fluorescence kinetics, FRAP in cellular and acellular lipid environments, molecular modeling, transmembrane peptide inhibition assay","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 1 — reconstitution in lipid bilayers + single-molecule assays + functional inhibition by TM peptide; multiple orthogonal methods in one study","pmids":["32494000"],"is_preprint":false},{"year":2012,"finding":"ERK pathway and metalloprotease sheddases (ADAM17 and MMP) are required for CX3CL1 release from pancreatic stellate cells. Ethanol synergistically increases CX3CL1 secretion by activating ERK and ADAM17; specific inhibitors of ERK, MMP, and ADAM suppress CX3CL1 release. ERK is associated with CX3CL1 transcription.","method":"RT-PCR, western blot, ELISA in PSCs; kinase and protease inhibitors; in vivo CP rat model (WBN/Kob)","journal":"Laboratory investigation","confidence":"Medium","confidence_rationale":"Tier 2 — multiple inhibitor approaches with orthogonal transcriptional and secretion readouts; single lab","pmids":["23147224"],"is_preprint":false},{"year":2012,"finding":"Exogenous fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic loss and death by acting on CX3CR1-expressing microglia. Fractalkine normalizes elevated microglial motility caused by Tat/morphine co-exposure and fails to protect neurons co-cultured with CX3CR1-null microglia, demonstrating that protection requires microglial CX3CR1.","method":"Wild-type neurons co-cultured with Cx3cr1-KO or wild-type mixed glia; time-lapse microscopy; exogenous CX3CL1 addition; anti-CX3CR1 blocking antibody; ELISA for TNF-α and CX3CL1","journal":"Molecular neurodegeneration","confidence":"High","confidence_rationale":"Tier 2 — CX3CR1-KO glia as genetic control + pharmacological blockade + live-cell imaging with defined readout; single lab multiple methods","pmids":["22093090"],"is_preprint":false},{"year":2014,"finding":"HIV-1 Tat protein suppresses CX3CR1 expression in microglia via NF-κB activation followed by YY1-mediated transcriptional repression, disrupting CX3CL1-CX3CR1 signaling (calcium mobilization, MAPK activation, and microglial migration in response to CX3CL1).","method":"Primary microglia and BV2 cells exposed to Tat; RT-PCR and western blot for CX3CR1; NF-κB pathway inhibition; YY1 binding site identification; calcium mobilization assay; MAPK phosphorylation; microglial migration assay","journal":"Current HIV research","confidence":"Medium","confidence_rationale":"Tier 2 — mechanistic pathway identified through pharmacological and transcriptional analysis; single lab","pmids":["24862326"],"is_preprint":false},{"year":2019,"finding":"CX3CL1-CX3CR1 interaction mediates macrophage-mesothelial crosstalk in peritoneal fibrosis: mesothelial CX3CL1 engages macrophage CX3CR1, promoting TGF-β production in a positive feedback loop where macrophage IL-1β upregulates mesothelial CX3CL1 and TGF-β; TGF-β in turn upregulates CX3CR1 in monocytic cells. CX3CR1 deficiency reduces peritoneal fibrosis in vivo.","method":"Murine PD model; CX3CR1-KO mice; human PD patient biopsies; in vitro macrophage-mesothelial cell co-culture; TGF-β and CX3CL1 protein measurements","journal":"Kidney international","confidence":"Medium","confidence_rationale":"Tier 2 — genetic KO mice + in vitro co-culture + human validation; single lab","pmids":["30948201"],"is_preprint":false},{"year":2021,"finding":"CX3CL1 promotes M1 macrophage polarization and osteoclast differentiation through the NF-κB signaling pathway in ankylosing spondylitis. NF-κB inhibition (BAY-117082) or anti-CX3CL1 mAb blocks M1 polarization, inflammation, and osteoclastogenesis in vitro and alleviates disease in AS model mice.","method":"In vitro macrophage polarization and osteoclast differentiation assays; NF-κB inhibitor; anti-CX3CL1 mAb; AS model mice; western blot and ELISA for inflammatory markers","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological and antibody blockade with defined cellular and in vivo readouts; single lab","pmids":["37626378"],"is_preprint":false},{"year":2018,"finding":"CX3CL1 enhances prostate cancer spinal metastasis by activating the Src/FAK signaling pathway, dependent on EGFR Tyr992 phosphorylation. CX3CR1 overexpression promotes tumor cell proliferation, migration, invasion, and spinal metastasis in vivo; Src/FAK inhibitors block CX3CL1-induced migration.","method":"CX3CR1 overexpression and knockdown in prostate cancer cells; kinase inhibitor assays; phosphorylation western blot; in vivo spinal metastasis mouse model","journal":"International journal of oncology","confidence":"Medium","confidence_rationale":"Tier 2 — kinase pathway identification with inhibitor validation and in vivo model; single lab","pmids":["30066854"],"is_preprint":false},{"year":2012,"finding":"Shear stress reduces TNFα-induced endothelial CX3CL1 expression and CX3CL1-dependent monocyte adhesion. Under low shear stress, transmembrane CX3CL1 mediates monocyte arrest on endothelium (blocked by neutralizing anti-CX3CL1 antibody); physiological shear stress abrogates this response.","method":"Endothelial cells (arterial, venous, microvascular) under controlled flow; TNFα stimulation; anti-CX3CL1 neutralizing antibody; monocyte THP-1 adhesion assay; CX3CL1 expression by western blot and immunofluorescence","journal":"Mediators of inflammation","confidence":"Medium","confidence_rationale":"Tier 2 — neutralizing antibody demonstrates CX3CL1-specific contribution to adhesion; defined flow conditions; single lab","pmids":["28522896"],"is_preprint":false},{"year":2003,"finding":"CX3CL1 is required for in vivo NK cell activity: antibody blockade of CX3CL1 or CX3CR1 reduces NK-mediated tumor cell clearance by 4–5-fold in mice without affecting in vitro NK cytolytic activity. CX3CR1 blockade inhibits NK cell adhesion to activated endothelium, indicating that CX3CL1 regulates NK cell extravasation/trafficking.","method":"In vivo NK clearance assay using radiolabeled YAC-1 cells; anti-CX3CL1 and anti-CX3CR1 blocking antibodies; in vitro NK cytotoxicity assay; NK adhesion assay to endothelial monolayers","journal":"Cellular immunology","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo blocking antibody study with in vitro adhesion mechanistic follow-up; single lab","pmids":["14698146"],"is_preprint":false},{"year":2020,"finding":"ADAM17-regulated shedding of CX3CL1 from bone marrow endothelial cells promotes hepatocellular carcinoma spinal metastasis. CX3CL1 activates Src/PTK2 signaling in HCC cells, subsequently activating PIK3CA/AKT1 and RHOA/ROCK2 pathways to drive invasion and migration. ADAM17 is activated by MAPK in BMECs, and neutralization of CX3CL1 inhibits BMEC-induced cancer cell invasion.","method":"Western blot for Src/FAK/PI3K/RHOA pathways; CX3CL1 neutralization; ADAM17 inhibition; in vivo mouse spinal metastasis model; CX3CR1 overexpression in HCC cells","journal":"International journal of oncology","confidence":"Medium","confidence_rationale":"Tier 2 — multiple pathway validations + in vivo model; single lab","pmids":["32319605"],"is_preprint":false},{"year":2020,"finding":"CX3CL1 directly induces platelet migration via CX3CR1/Syk/PI3K pathway components; hypoxia enhances platelet migration by upregulating CX3CL1 in HCC cells. Migrating platelets promote HCC cell apoptosis in vitro; CX3CL1 knockdown in HCC cells reduces platelet infiltration in an orthotopic HCC model.","method":"In vitro platelet migration assay; CX3CL1 knockdown in HCC cells; orthotopic HCC mouse model; mitochondrial membrane potential assay; apoptosis flow cytometry; pathway inhibition","journal":"Molecular oncology","confidence":"Medium","confidence_rationale":"Tier 2 — in vitro mechanistic pathway + in vivo knockdown model; single lab","pmids":["32799418"],"is_preprint":false},{"year":2019,"finding":"In retinitis pigmentosa, soluble CX3CL1 gene therapy (AAV8-sCX3CL1) significantly prolongs cone photoreceptor survival and improves visual function across three RP mouse strains. The mechanism does not require normal microglial numbers (pharmacological depletion of ~99% of microglia does not abrogate the effect), and RNA-seq reveals marked transcriptional changes in residual microglia.","method":"Subretinal AAV8-sCX3CL1 injection in three RP mouse strains; ERG functional testing; cone survival quantification; microglia pharmacological depletion; RNA-seq of microglia","journal":"Proceedings of the National Academy of Sciences","confidence":"High","confidence_rationale":"Tier 2 — multiple mouse strains, functional rescue, microglia depletion epistasis, RNA-seq; strong evidence","pmids":["31036641"],"is_preprint":false},{"year":2024,"finding":"Platelet-derived TLR4/NF-κB signaling upregulates ADAM10 in HCC tumor cells; ADAM10 then sheds CX3CL1, which acts on CX3CR1 to induce EMT and activate RhoA signaling, promoting lung metastasis. Knockdown of tumor cell TLR4 or ADAM10 inhibition prevents platelet-augmented tumor invasion.","method":"TLR4/ADAM10 knockdown in HCC cells; NF-κB pathway analysis; CX3CL1 shedding assay; RhoA signaling western blot; in vivo lung metastasis mouse model with platelet co-injection","journal":"Cancer letters","confidence":"Medium","confidence_rationale":"Tier 2 — genetic knockdown + pathway analysis + in vivo model; single lab","pmids":["38280480"],"is_preprint":false},{"year":2022,"finding":"CX3CL1 inhibits NLRP3 inflammasome-induced microglial pyroptosis and suppresses NF-κB signaling, thereby reducing IL-1β and IL-18 expression in ischemic stroke models (MCAO in vivo and OGD/R in vitro). Exogenous rCX3CL1 reduces GSDMD-dependent pyroptosis and decreases infarct volume.","method":"MCAO mouse model; OGD/R BV2 cells; intracerebroventricular CX3CL1 injection; NLRP3 and GSDMD western blot; NF-κB activation assay; ELISA for cytokines; immunostaining","journal":"Life sciences","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo + in vitro parallel experiments with NLRP3/GSDMD pathway readouts; single lab","pmids":["35461837"],"is_preprint":false},{"year":2024,"finding":"In hepatocytes, YTHDF2 (an m6A reader) stabilizes Cx3cl1 mRNA in an m6A-dependent manner downstream of OXA-activated cGAS-STING signaling, promoting CX3CL1 production that recruits CD8+ T cells to suppress liver tumor growth. Liver-specific Ythdf2 knockout reduces CX3CL1, CD8+ T cell infiltration, and anti-tumor immunity.","method":"Liver-specific Ythdf2 KO tumor-bearing mice; m6A-seq; RNA stability assay; CX3CL1 ELISA; CD8+ T cell flow cytometry; cGAS-STING pathway analysis","journal":"Molecular cancer","confidence":"Medium","confidence_rationale":"Tier 2 — genetic KO with mechanistic m6A pathway identification; single lab","pmids":["39237909"],"is_preprint":false},{"year":2024,"finding":"In gastric cancer, lactate acts via GPR81 to upregulate CX3CL1 expression, which recruits regulatory T cells (Tregs) into the tumor microenvironment to suppress CD8+ T cell function. GPR81 deficiency reduces CX3CL1 and Treg infiltration, inhibiting tumor progression.","method":"In vitro lactate/GPR81 signaling assays; GPR81 knockdown; CX3CL1 ELISA; Treg and CD8+ T cell flow cytometry; humanized mouse model","journal":"Oncoimmunology","confidence":"Medium","confidence_rationale":"Tier 2 — mechanistic pathway from lactate to CX3CL1 to Tregs with in vivo validation; single lab","pmids":["38419759"],"is_preprint":false}],"current_model":"CX3CL1 (fractalkine) is a transmembrane chemokine expressed primarily by neurons and endothelial cells that exists in two functional forms: a membrane-anchored form that promotes firm leukocyte adhesion (functioning as an adhesion molecule via homo-oligomerization driven by its transmembrane domain) and a soluble form generated by ADAM10/ADAM17-mediated ectodomain shedding (regulated by cytoskeletal actin confinement) and further processed by γ-secretase; the soluble form acts as a chemoattractant for CX3CR1-expressing microglia, monocytes, NK cells, and T cells. Within the CNS, soluble CX3CL1 is the dominant neuroprotective isoform that suppresses microglial activation (inhibiting phagocytosis and NLRP3 inflammasome/pyroptosis via NF-κB), promotes adult neurogenesis and LTP through CX3CR1-dependent pathways and independently via an intracellular domain (CX3CL1-ICD) that is released by sequential secretase cleavage and translocates to the nucleus to activate TGF-β2/3-Smad2/3 signaling; in cancer, CX3CL1 signals through CX3CR1-coupled Src/FAK, PI3K/AKT, and RhoA pathways to drive tumor cell migration and metastasis, and regulates immune cell trafficking in the tumor microenvironment."},"narrative":{"teleology":[{"year":2003,"claim":"Establishing that CX3CL1 is a functional chemoattractant for microglia and mediates NK cell trafficking in vivo resolved the question of which immune cell types respond to fractalkine signaling in physiological contexts.","evidence":"Microglial chemotaxis assay plus human brain immunohistochemistry; in vivo NK clearance assay with anti-CX3CL1/CX3CR1 blocking antibodies in mice","pmids":["14533779","14698146"],"confidence":"Medium","gaps":["Downstream signaling cascades in responding microglia and NK cells not defined","Relative contributions of soluble versus membrane-bound forms to NK trafficking unclear"]},{"year":2004,"claim":"Demonstrating that CX3CL1 exists as both a membrane-anchored adhesion molecule and a proteolytically released chemoattractant, with expression regulated by inflammatory cytokines, established the dual-function paradigm central to all subsequent mechanistic work.","evidence":"Cell stimulation, protein expression, and leukocyte adhesion assays in endothelial cells","pmids":["15067194"],"confidence":"High","gaps":["Identity of the sheddase(s) not yet determined","Relative functional importance of soluble versus membrane forms unknown"]},{"year":2005,"claim":"Revealing that surface CX3CL1 undergoes SNARE-dependent recycling through a juxtanuclear compartment answered how cells maintain a dynamic surface pool available for both adhesion and shedding.","evidence":"Live-cell GFP-CX3CL1 imaging, VAMP-3/syntaxin-13 perturbation by tetanus toxin and dominant-negative alleles","pmids":["15774461"],"confidence":"High","gaps":["Signals that regulate the recycling rate are undefined","Whether recycling compartment identity differs across cell types is untested"]},{"year":2007,"claim":"Identifying ADAM10 as the α-secretase and γ-secretase (presenilin-dependent) as the subsequent intramembrane protease defined the sequential cleavage cascade generating both soluble CX3CL1 and intracellular C-terminal fragments.","evidence":"Pharmacological inhibitor panel and presenilin 1/2-deficient cell lines with CTF detection","pmids":["17467666"],"confidence":"High","gaps":["Biological function of the intracellular CTF was unknown","Relative contributions of ADAM10 versus ADAM17 in different tissues not resolved"]},{"year":2008,"claim":"Showing that thrombin/PAR1 induces endothelial CX3CL1 via NF-κB and that membrane-bound CX3CL1 triggers monocyte CCL2 release linked the coagulation cascade to CX3CL1-dependent vascular inflammation.","evidence":"PAR1 agonist/antagonist, IKK inhibitor, dominant-negative IκBα, co-culture and transendothelial migration assays in HUVECs","pmids":["18436581"],"confidence":"High","gaps":["In vivo relevance in thrombotic disease models not tested","Whether soluble versus membrane CX3CL1 differentially triggers CCL2 undefined"]},{"year":2012,"claim":"Isoform-selective genetic rescue in CX3CL1-knockout mice proved that soluble CX3CL1 is the neuroprotective isoform in Parkinson's disease models, while membrane-bound CX3CL1 is dispensable for dopaminergic neuron survival.","evidence":"AAV delivery of obligate soluble vs. membrane-bound CX3CL1 into CX3CL1−/− mice; MPTP model with behavioral, histological, and cytokine readouts","pmids":["23077045"],"confidence":"High","gaps":["CX3CR1-downstream signaling mediating neuroprotection not identified","Whether isoform specificity holds in other neurodegenerative contexts was unknown"]},{"year":2013,"claim":"In cancer biology, demonstrating that CX3CL1 promotes breast cancer growth through ErbB receptor transactivation and that its genetic deletion delays HER2/neu tumorigenesis placed CX3CL1 as a tumor-promoting factor in ErbB-dependent contexts.","evidence":"CX3CL1-KO crossed with HER2/neu and PyMT tumor mouse models; ErbB transactivation and EMT assays","pmids":["23720051"],"confidence":"High","gaps":["Molecular identity of the ErbB ligand shed downstream of CX3CL1 not identified","Whether CX3CL1 acts on tumor cells directly or through stroma was not fully resolved"]},{"year":2014,"claim":"Two discoveries clarified how membrane topology controls CX3CL1 shedding and how each isoform has distinct CNS functions: cortical actin confines CX3CL1 away from ADAM10 to limit constitutive cleavage, and the membrane-bound (not soluble) form regulates microglial phagocytosis of Aβ via p38 MAPK.","evidence":"Single-particle tracking/PALM-STORM with actin disruption; genetic crosses of APPPS1 mice with CX3CL1-KO and soluble CX3CL1 transgenics","pmids":["25253723","25209291"],"confidence":"High","gaps":["Structural basis for actin-CX3CL1 confinement unknown","How membrane CX3CL1 selectively activates p38 in microglia not resolved"]},{"year":2017,"claim":"Showing that N-terminal pyroglutamate modification by glutaminyl cyclase is required for full CX3CL1 signaling potency revealed a post-translational maturation step controlling chemokine bioactivity.","evidence":"Mass spectrometry confirming pGlu modification; QPCT RNAi; ERK1/2, Akt, p38 phosphorylation assays in SMCs and ECs","pmids":["28739588"],"confidence":"Medium","gaps":["In vivo relevance of pGlu modification not tested","Whether pGlu differentially affects soluble vs. membrane CX3CL1 is unknown"]},{"year":2019,"claim":"The discovery that the γ-secretase-released intracellular domain (CX3CL1-ICD) translocates to the nucleus and activates TGF-β2/3–Smad2/3 signaling to drive neurogenesis independently of CX3CR1 established a 'back-signaling' mechanism analogous to Notch, fundamentally expanding CX3CL1's functional repertoire.","evidence":"CX3CL1-ct overexpression in 5xFAD mice; neuron-specific Smad2 knockout abrogating neurogenic effect; RNA-seq; PS19 tau model rescue with Smad2 epistasis","pmids":["31209068","31822518"],"confidence":"High","gaps":["Nuclear targets of CX3CL1-ICD beyond TGF-β2/3 not identified","Whether ICD signaling occurs in non-neuronal tissues unknown","Structural basis for ICD nuclear import not defined"]},{"year":2019,"claim":"Soluble CX3CL1 gene therapy preserves cone photoreceptors across multiple retinitis pigmentosa models even after near-complete microglial depletion, demonstrating that CX3CL1's retinal neuroprotection involves transcriptional reprogramming of residual microglia rather than requiring normal microglial numbers.","evidence":"AAV8-sCX3CL1 in three RP mouse strains; ERG; pharmacological microglia depletion; RNA-seq of residual microglia","pmids":["31036641"],"confidence":"High","gaps":["Identity of the protective transcriptional program in reprogrammed microglia not fully resolved","Whether other glial cells contribute to the rescue is untested"]},{"year":2020,"claim":"Demonstrating that membrane CX3CL1 forms homo-oligomers of 3–7 monomers via its transmembrane domain and that oligomerization is required for adhesive function provided the structural basis for the membrane-anchored adhesion phenotype.","evidence":"Native gel electrophoresis, single-molecule fluorescence, FRAP in lipid bilayers, TM domain peptide inhibition","pmids":["32494000"],"confidence":"High","gaps":["Atomic-resolution structure of the oligomer not available","Whether oligomerization modulates shedding efficiency is untested"]},{"year":2020,"claim":"In metastatic cancer, shed CX3CL1 was shown to activate Src/FAK, PI3K/AKT, and RhoA/ROCK2 signaling through CX3CR1 on tumor cells, with ADAM17-mediated shedding from bone marrow endothelium driving spinal metastasis of prostate and hepatocellular carcinoma.","evidence":"CX3CR1 overexpression/knockdown; kinase inhibitor panels; CX3CL1 neutralization; in vivo spinal metastasis models","pmids":["30066854","32319605"],"confidence":"Medium","gaps":["Whether these pathways are independent or form a linear cascade is unclear","Clinical relevance in human metastatic samples not validated"]},{"year":2022,"claim":"Establishing that CX3CL1 inhibits NLRP3 inflammasome assembly and GSDMD-dependent microglial pyroptosis via NF-κB suppression in ischemic stroke identified a specific anti-inflammatory mechanism beyond general microglial suppression.","evidence":"MCAO mouse model; OGD/R BV2 cells; intracerebroventricular CX3CL1; NLRP3/GSDMD western blot; NF-κB activation assay","pmids":["35461837"],"confidence":"Medium","gaps":["Direct molecular target of CX3CL1 upstream of NF-κB suppression not identified","Whether soluble or membrane form mediates this effect in vivo not distinguished"]},{"year":2024,"claim":"Recent work placed CX3CL1 at the intersection of tumor metabolism and immune evasion: lactate/GPR81 signaling upregulates CX3CL1 to recruit Tregs in gastric cancer, and YTHDF2-dependent m6A stabilization of CX3CL1 mRNA recruits CD8+ T cells to suppress liver tumors, revealing context-dependent pro- and anti-tumor immune roles.","evidence":"GPR81 knockdown with Treg flow cytometry in humanized mice; liver-specific Ythdf2 KO with m6A-seq, RNA stability, and CD8+ T cell analysis","pmids":["38419759","39237909"],"confidence":"Medium","gaps":["How the same chemokine recruits immunosuppressive Tregs in one context and cytotoxic CD8+ T cells in another is not mechanistically resolved","Post-transcriptional regulation of CX3CL1 in non-hepatic cancers not examined"]},{"year":null,"claim":"Key unresolved questions include the atomic structure of CX3CL1 transmembrane oligomers, the full nuclear interactome of CX3CL1-ICD, why soluble and membrane-bound isoforms activate distinct downstream pathways through the same receptor CX3CR1, and how CX3CL1 exerts opposing immune effects (immunosuppressive vs. immunostimulatory) in different tumor microenvironments.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of full-length or oligomeric CX3CL1","Nuclear binding partners of CX3CL1-ICD beyond Smad2/3 pathway undefined","Mechanism distinguishing CX3CR1-dependent vs. CX3CR1-independent signaling outputs incompletely characterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098631","term_label":"cell adhesion mediator activity","supporting_discovery_ids":[0,3,18,25,26]},{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[0,5,6,16,20,24]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[9,10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,2,3,4,18]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[2,3]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[0,1,6,8,29]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[9]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0,5,6,11,12,16,20,26,33]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5,9,10,14,17,24,27,31]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[0,3,18,25]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[31]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[9,10]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[13,24,27,30,33]}],"complexes":[],"partners":["CX3CR1","ADAM10","ADAM17","VAMP3","STX13","SMAD2","PSEN1"],"other_free_text":[]},"mechanistic_narrative":"CX3CL1 (fractalkine) is a transmembrane chemokine that functions as both a membrane-anchored adhesion molecule and, after ADAM10/ADAM17-mediated ectodomain shedding followed by γ-secretase cleavage, a soluble chemoattractant for CX3CR1-expressing monocytes, NK cells, T cells, and microglia [PMID:15067194, PMID:17467666, PMID:25253723]. Membrane-bound CX3CL1 mediates firm leukocyte adhesion through transmembrane domain-driven homo-oligomerization and regulates microglial phagocytosis via p38 MAPK, whereas soluble CX3CL1 is the dominant neuroprotective isoform that suppresses microglial activation, rescues hippocampal LTP and adult neurogenesis, and inhibits NLRP3 inflammasome-driven pyroptosis through NF-κB suppression [PMID:32494000, PMID:25209291, PMID:32410624, PMID:35461837]. Sequential secretase processing also releases an intracellular domain (CX3CL1-ICD) that translocates to the nucleus and activates TGF-β2/3–Smad2/3 signaling to promote neurogenesis independently of CX3CR1 [PMID:31209068, PMID:31822518]. In cancer, shed CX3CL1 signals through CX3CR1-coupled Src/FAK, PI3K/AKT, and RhoA pathways to drive tumor cell migration, metastasis, and immune cell trafficking in the tumor microenvironment [PMID:30066854, PMID:32319605, PMID:38280480]."},"prefetch_data":{"uniprot":{"accession":"P78423","full_name":"Fractalkine","aliases":["C-X3-C motif chemokine 1","CX3C membrane-anchored chemokine","Neurotactin","Small-inducible cytokine D1"],"length_aa":397,"mass_kda":42.2,"function":"Chemokine that acts as a ligand for both CX3CR1 and integrins ITGAV:ITGB3 and ITGA4:ITGB1 (PubMed:12055230, PubMed:21829356, PubMed:23125415, PubMed:9782118, PubMed:9931005). The CX3CR1-CX3CL1 signaling exerts distinct functions in different tissue compartments, such as immune response, inflammation, cell adhesion and chemotaxis (PubMed:12055230, PubMed:9024663, PubMed:9177350, PubMed:9782118). Regulates leukocyte adhesion and migration processes at the endothelium (PubMed:9024663, PubMed:9177350). Can activate integrins in both a CX3CR1-dependent and CX3CR1-independent manner (PubMed:23125415, PubMed:24789099). In the presence of CX3CR1, activates integrins by binding to the classical ligand-binding site (site 1) in integrins (PubMed:23125415, PubMed:24789099). In the absence of CX3CR1, binds to a second site (site 2) in integrins which is distinct from site 1 and enhances the binding of other integrin ligands to site 1 (PubMed:23125415, PubMed:24789099) The soluble form is chemotactic for T-cells and monocytes, but not for neutrophils The membrane-bound form promotes adhesion of those leukocytes to endothelial cells (Microbial infection) Mediates the cytoadherence of erythrocytes infected with parasite P.falciparum (strain 3D7) with endothelial cells by interacting with P.falciparum CBP1 and CBP2 expressed at the surface of erythrocytes (PubMed:27653778). The adhesion prevents the elimination of infected erythrocytes by the spleen (Probable)","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/P78423/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CX3CL1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CX3CL1","total_profiled":1310},"omim":[{"mim_id":"621526","title":"GLUTAMINYL-PEPTIDE CYCLOTRANSFERASE-LIKE PROTEIN; QPCTL","url":"https://www.omim.org/entry/621526"},{"mim_id":"607884","title":"CKLF-LIKE MARVEL TRANSMEMBRANE DOMAIN-CONTAINING 1; CMTM1","url":"https://www.omim.org/entry/607884"},{"mim_id":"607065","title":"GLUTAMINYL-PEPTIDE CYCLOTRANSFERASE; QPCT","url":"https://www.omim.org/entry/607065"},{"mim_id":"605402","title":"CD274 MOLECULE; CD274","url":"https://www.omim.org/entry/605402"},{"mim_id":"605398","title":"CHEMOKINE, CXC MOTIF, LIGAND 16; CXCL16","url":"https://www.omim.org/entry/605398"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Plasma membrane","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/CX3CL1"},"hgnc":{"alias_symbol":["NTN","C3Xkine","ABCD-3","CXC3C","CXC3"],"prev_symbol":["SCYD1"]},"alphafold":{"accession":"P78423","domains":[{"cath_id":"2.40.50.40","chopping":"48-97","consensus_level":"high","plddt":93.1456,"start":48,"end":97}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P78423","model_url":"https://alphafold.ebi.ac.uk/files/AF-P78423-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P78423-F1-predicted_aligned_error_v6.png","plddt_mean":55.94},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CX3CL1","jax_strain_url":"https://www.jax.org/strain/search?query=CX3CL1"},"sequence":{"accession":"P78423","fasta_url":"https://rest.uniprot.org/uniprotkb/P78423.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P78423/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P78423"}},"corpus_meta":[{"pmid":"29361745","id":"PMC_29361745","title":"Microglia and Aging: The Role of the TREM2-DAP12 and CX3CL1-CX3CR1 Axes.","date":"2018","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/29361745","citation_count":216,"is_preprint":false},{"pmid":"33065974","id":"PMC_33065974","title":"The Impact of the CX3CL1/CX3CR1 Axis in Neurological Disorders.","date":"2020","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/33065974","citation_count":202,"is_preprint":false},{"pmid":"25152714","id":"PMC_25152714","title":"Modulating neurotoxicity through CX3CL1/CX3CR1 signaling.","date":"2014","source":"Frontiers in cellular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/25152714","citation_count":186,"is_preprint":false},{"pmid":"15993821","id":"PMC_15993821","title":"Induction of CX3CL1 expression in astrocytes and CX3CR1 in microglia in the spinal cord of a rat model of neuropathic pain.","date":"2005","source":"The journal of pain","url":"https://pubmed.ncbi.nlm.nih.gov/15993821","citation_count":170,"is_preprint":false},{"pmid":"27314452","id":"PMC_27314452","title":"Microglial phagocytosis and activation underlying photoreceptor degeneration is regulated by CX3CL1-CX3CR1 signaling in a mouse model of retinitis pigmentosa.","date":"2016","source":"Glia","url":"https://pubmed.ncbi.nlm.nih.gov/27314452","citation_count":168,"is_preprint":false},{"pmid":"34492237","id":"PMC_34492237","title":"CX3CL1/CX3CR1 signaling targets for the treatment of neurodegenerative diseases.","date":"2021","source":"Pharmacology & therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/34492237","citation_count":141,"is_preprint":false},{"pmid":"15067194","id":"PMC_15067194","title":"Regulation of CX3CL1/fractalkine expression in endothelial cells.","date":"2004","source":"Journal of atherosclerosis and thrombosis","url":"https://pubmed.ncbi.nlm.nih.gov/15067194","citation_count":128,"is_preprint":false},{"pmid":"23077045","id":"PMC_23077045","title":"The soluble isoform of CX3CL1 is necessary for neuroprotection in a mouse model of Parkinson's disease.","date":"2012","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/23077045","citation_count":116,"is_preprint":false},{"pmid":"11890528","id":"PMC_11890528","title":"Genomic variability in Potato potyvirus Y (PVY): evidence that PVY(N)W and PVY(NTN) variants are single to multiple recombinants between PVY(O) and PVY(N) isolates.","date":"2002","source":"Archives of virology","url":"https://pubmed.ncbi.nlm.nih.gov/11890528","citation_count":115,"is_preprint":false},{"pmid":"23974513","id":"PMC_23974513","title":"Chemokines and atherosclerosis: focus on the CX3CL1/CX3CR1 pathway.","date":"2013","source":"Acta pharmacologica Sinica","url":"https://pubmed.ncbi.nlm.nih.gov/23974513","citation_count":109,"is_preprint":false},{"pmid":"29750189","id":"PMC_29750189","title":"Repopulating retinal microglia restore endogenous organization and function under CX3CL1-CX3CR1 regulation.","date":"2018","source":"Science advances","url":"https://pubmed.ncbi.nlm.nih.gov/29750189","citation_count":107,"is_preprint":false},{"pmid":"25209291","id":"PMC_25209291","title":"Opposing effects of membrane-anchored CX3CL1 on amyloid and tau pathologies via the p38 MAPK pathway.","date":"2014","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/25209291","citation_count":101,"is_preprint":false},{"pmid":"28125278","id":"PMC_28125278","title":"Roles for the CX3CL1/CX3CR1 and CCL2/CCR2 Chemokine Systems in Hypoxic Pulmonary Hypertension.","date":"2017","source":"American journal of respiratory cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/28125278","citation_count":97,"is_preprint":false},{"pmid":"21126357","id":"PMC_21126357","title":"CCL2/CCR2 and CX3CL1/CX3CR1 chemokine axes and their possible involvement in age-related macular degeneration.","date":"2010","source":"Journal of neuroinflammation","url":"https://pubmed.ncbi.nlm.nih.gov/21126357","citation_count":95,"is_preprint":false},{"pmid":"32466280","id":"PMC_32466280","title":"Fractalkine/CX3CL1 in Neoplastic Processes.","date":"2020","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32466280","citation_count":90,"is_preprint":false},{"pmid":"33391453","id":"PMC_33391453","title":"Regulation and biological functions of the CX3CL1-CX3CR1 axis and its relevance in solid cancer: A mini-review.","date":"2021","source":"Journal of Cancer","url":"https://pubmed.ncbi.nlm.nih.gov/33391453","citation_count":84,"is_preprint":false},{"pmid":"32819407","id":"PMC_32819407","title":"MicroRNA-195 prevents hippocampal microglial/macrophage polarization towards the M1 phenotype induced by chronic brain hypoperfusion through regulating CX3CL1/CX3CR1 signaling.","date":"2020","source":"Journal of neuroinflammation","url":"https://pubmed.ncbi.nlm.nih.gov/32819407","citation_count":82,"is_preprint":false},{"pmid":"17467666","id":"PMC_17467666","title":"Sequential processing of the transmembrane chemokines CX3CL1 and CXCL16 by alpha- and gamma-secretases.","date":"2007","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/17467666","citation_count":82,"is_preprint":false},{"pmid":"20630606","id":"PMC_20630606","title":"Role of CX3CR1/CX3CL1 axis in primary and secondary involvement of the nervous system by cancer.","date":"2010","source":"Journal of neuroimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/20630606","citation_count":79,"is_preprint":false},{"pmid":"23720051","id":"PMC_23720051","title":"CX3CL1 promotes breast cancer via transactivation of the EGF pathway.","date":"2013","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/23720051","citation_count":77,"is_preprint":false},{"pmid":"30948201","id":"PMC_30948201","title":"CX3CL1-CX3CR1 interaction mediates macrophage-mesothelial cross talk and promotes peritoneal fibrosis.","date":"2019","source":"Kidney international","url":"https://pubmed.ncbi.nlm.nih.gov/30948201","citation_count":75,"is_preprint":false},{"pmid":"12476352","id":"PMC_12476352","title":"Fractalkine (CX3CL1) and brain inflammation: Implications for HIV-1-associated dementia.","date":"2002","source":"Journal of neurovirology","url":"https://pubmed.ncbi.nlm.nih.gov/12476352","citation_count":75,"is_preprint":false},{"pmid":"35914622","id":"PMC_35914622","title":"CX3CL1/CX3CR1 interaction protects against lipotoxicity-induced nonalcoholic steatohepatitis by regulating macrophage migration and M1/M2 status.","date":"2022","source":"Metabolism: clinical and experimental","url":"https://pubmed.ncbi.nlm.nih.gov/35914622","citation_count":72,"is_preprint":false},{"pmid":"14533779","id":"PMC_14533779","title":"CX3CL1 and CX3CR1 expression in human brain tissue: noninflammatory control versus multiple sclerosis.","date":"2003","source":"Journal of neuropathology and experimental neurology","url":"https://pubmed.ncbi.nlm.nih.gov/14533779","citation_count":70,"is_preprint":false},{"pmid":"15608300","id":"PMC_15608300","title":"Up regulated expression of fractalkine/CX3CL1 and CX3CR1 in patients with systemic sclerosis.","date":"2005","source":"Annals of the rheumatic diseases","url":"https://pubmed.ncbi.nlm.nih.gov/15608300","citation_count":69,"is_preprint":false},{"pmid":"22464888","id":"PMC_22464888","title":"Altered expression of CX3CL1 in patients with epilepsy and in a rat model.","date":"2012","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/22464888","citation_count":65,"is_preprint":false},{"pmid":"20511186","id":"PMC_20511186","title":"CX3CR1/CX3CL1 axis negatively controls glioma cell invasion and is modulated by transforming growth factor-β1.","date":"2010","source":"Neuro-oncology","url":"https://pubmed.ncbi.nlm.nih.gov/20511186","citation_count":65,"is_preprint":false},{"pmid":"22647647","id":"PMC_22647647","title":"Gabapentin reduces CX3CL1 signaling and blocks spinal microglial activation in monoarthritic rats.","date":"2012","source":"Molecular brain","url":"https://pubmed.ncbi.nlm.nih.gov/22647647","citation_count":64,"is_preprint":false},{"pmid":"18367676","id":"PMC_18367676","title":"CX3CL1 and CCL14 regulate extracellular matrix and adhesion molecules in the trophoblast: potential roles in human embryo implantation.","date":"2008","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/18367676","citation_count":63,"is_preprint":false},{"pmid":"34163473","id":"PMC_34163473","title":"Fractalkine (CX3CL1) and Its Receptor CX3CR1: A Promising Therapeutic Target in Chronic Kidney Disease?","date":"2021","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/34163473","citation_count":62,"is_preprint":false},{"pmid":"32060841","id":"PMC_32060841","title":"CX3CL1 Signaling in the Tumor Microenvironment.","date":"2020","source":"Advances in experimental medicine and biology","url":"https://pubmed.ncbi.nlm.nih.gov/32060841","citation_count":61,"is_preprint":false},{"pmid":"30066854","id":"PMC_30066854","title":"CX3CL1/fractalkine enhances prostate cancer spinal metastasis by activating the Src/FAK pathway.","date":"2018","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/30066854","citation_count":58,"is_preprint":false},{"pmid":"27484962","id":"PMC_27484962","title":"Fractalkine/CX3CL1 in rheumatoid arthritis.","date":"2016","source":"Modern rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/27484962","citation_count":55,"is_preprint":false},{"pmid":"32445958","id":"PMC_32445958","title":"Fractalkine (CX3CL1) signaling and neuroinflammation in Parkinson's disease: Potential clinical and therapeutic implications.","date":"2020","source":"Pharmacological research","url":"https://pubmed.ncbi.nlm.nih.gov/32445958","citation_count":54,"is_preprint":false},{"pmid":"35461837","id":"PMC_35461837","title":"CX3CL1 inhibits NLRP3 inflammasome-induced microglial pyroptosis and improves neuronal function in mice with experimentally-induced ischemic stroke.","date":"2022","source":"Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35461837","citation_count":54,"is_preprint":false},{"pmid":"23361876","id":"PMC_23361876","title":"CX3CL1/CX3CR1 regulates nerve injury-induced pain hypersensitivity through the ERK5 signaling pathway.","date":"2013","source":"Journal of neuroscience research","url":"https://pubmed.ncbi.nlm.nih.gov/23361876","citation_count":53,"is_preprint":false},{"pmid":"30843484","id":"PMC_30843484","title":"Crosstalk between the CX3CL1/CX3CR1 Axis and Inflammatory Signaling Pathways in Tissue Injury.","date":"2019","source":"Current protein & peptide science","url":"https://pubmed.ncbi.nlm.nih.gov/30843484","citation_count":50,"is_preprint":false},{"pmid":"32410624","id":"PMC_32410624","title":"Two forms of CX3CL1 display differential activity and rescue cognitive deficits in CX3CL1 knockout mice.","date":"2020","source":"Journal of neuroinflammation","url":"https://pubmed.ncbi.nlm.nih.gov/32410624","citation_count":48,"is_preprint":false},{"pmid":"29543714","id":"PMC_29543714","title":"Plant Cell Wall Dynamics in Compatible and Incompatible Potato Response to Infection Caused by Potato Virus Y (PVYNTN).","date":"2018","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/29543714","citation_count":48,"is_preprint":false},{"pmid":"37626378","id":"PMC_37626378","title":"CX3CL1 promotes M1 macrophage polarization and osteoclast differentiation through NF-κB signaling pathway in ankylosing spondylitis in vitro.","date":"2023","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/37626378","citation_count":46,"is_preprint":false},{"pmid":"31036641","id":"PMC_31036641","title":"Soluble CX3CL1 gene therapy improves cone survival and function in mouse models of retinitis pigmentosa.","date":"2019","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/31036641","citation_count":46,"is_preprint":false},{"pmid":"29259682","id":"PMC_29259682","title":"Therapeutic intervention of inflammatory/immune diseases by inhibition of the fractalkine (CX3CL1)-CX3CR1 pathway.","date":"2016","source":"Inflammation and regeneration","url":"https://pubmed.ncbi.nlm.nih.gov/29259682","citation_count":46,"is_preprint":false},{"pmid":"38419759","id":"PMC_38419759","title":"Lactate/GPR81 recruits regulatory T cells by modulating CX3CL1 to promote immune resistance in a highly glycolytic gastric cancer.","date":"2024","source":"Oncoimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/38419759","citation_count":44,"is_preprint":false},{"pmid":"32179066","id":"PMC_32179066","title":"Pivotal Involvement of the CX3CL1-CX3CR1 Axis for the Recruitment of M2 Tumor-Associated Macrophages in Skin Carcinogenesis.","date":"2020","source":"The Journal of investigative dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/32179066","citation_count":44,"is_preprint":false},{"pmid":"29446734","id":"PMC_29446734","title":"CX3CL1/CX3CR1 Axis, as the Therapeutic Potential in Renal Diseases: Friend or Foe?","date":"2017","source":"Current gene therapy","url":"https://pubmed.ncbi.nlm.nih.gov/29446734","citation_count":43,"is_preprint":false},{"pmid":"34009468","id":"PMC_34009468","title":"Regulation and function of CX3CR1 and its ligand CX3CL1 in kidney disease.","date":"2021","source":"Cell and tissue research","url":"https://pubmed.ncbi.nlm.nih.gov/34009468","citation_count":41,"is_preprint":false},{"pmid":"31744815","id":"PMC_31744815","title":"Tenophages: a novel macrophage-like tendon cell population expressing CX3CL1 and CX3CR1.","date":"2019","source":"Disease models & mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/31744815","citation_count":41,"is_preprint":false},{"pmid":"23956503","id":"PMC_23956503","title":"Fractalkine (CX3CL1) and its receptor CX3CR1 may contribute to increased angiogenesis in diabetic placenta.","date":"2013","source":"Mediators of inflammation","url":"https://pubmed.ncbi.nlm.nih.gov/23956503","citation_count":41,"is_preprint":false},{"pmid":"31822518","id":"PMC_31822518","title":"Activated CX3CL1/Smad2 Signals Prevent Neuronal Loss and Alzheimer's Tau Pathology-Mediated Cognitive Dysfunction.","date":"2019","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/31822518","citation_count":40,"is_preprint":false},{"pmid":"38731899","id":"PMC_38731899","title":"CX3CL1 (Fractalkine)-CX3CR1 Axis in Inflammation-Induced Angiogenesis and Tumorigenesis.","date":"2024","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/38731899","citation_count":39,"is_preprint":false},{"pmid":"29729150","id":"PMC_29729150","title":"CD200-, CX3CL1-, and TREM2-mediated neuron-microglia interactions and their involvements in Alzheimer's disease.","date":"2018","source":"Reviews in the neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/29729150","citation_count":38,"is_preprint":false},{"pmid":"24324211","id":"PMC_24324211","title":"CX3CL1 and CX3CR1 expression in tertiary lymphoid structures in salivary gland infiltrates: fractalkine contribution to lymphoid neogenesis in Sjogren's syndrome.","date":"2013","source":"Rheumatology (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/24324211","citation_count":37,"is_preprint":false},{"pmid":"15774461","id":"PMC_15774461","title":"Recycling of the membrane-anchored chemokine, CX3CL1.","date":"2005","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15774461","citation_count":37,"is_preprint":false},{"pmid":"31765724","id":"PMC_31765724","title":"Involvement of CX3CL1/CX3CR1 in depression and cognitive impairment induced by chronic unpredictable stress and relevant underlying mechanism.","date":"2019","source":"Behavioural brain research","url":"https://pubmed.ncbi.nlm.nih.gov/31765724","citation_count":36,"is_preprint":false},{"pmid":"32717023","id":"PMC_32717023","title":"Human CD16+ monocytes promote a pro-atherosclerotic endothelial cell phenotype via CX3CR1-CX3CL1 interaction.","date":"2021","source":"Cardiovascular research","url":"https://pubmed.ncbi.nlm.nih.gov/32717023","citation_count":35,"is_preprint":false},{"pmid":"31209068","id":"PMC_31209068","title":"The intracellular domain of CX3CL1 regulates adult neurogenesis and Alzheimer's amyloid pathology.","date":"2019","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/31209068","citation_count":34,"is_preprint":false},{"pmid":"32319605","id":"PMC_32319605","title":"ADAM17-regulated CX3CL1 expression produced by bone marrow endothelial cells promotes spinal metastasis from hepatocellular carcinoma.","date":"2020","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/32319605","citation_count":34,"is_preprint":false},{"pmid":"10946353","id":"PMC_10946353","title":"Mutational analysis of RET/GDNF/NTN genes in children with total colonic aganglionosis with small bowel involvement.","date":"2000","source":"American journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10946353","citation_count":34,"is_preprint":false},{"pmid":"18436581","id":"PMC_18436581","title":"Thrombin-induced expression of endothelial CX3CL1 potentiates monocyte CCL2 production and transendothelial migration.","date":"2008","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/18436581","citation_count":33,"is_preprint":false},{"pmid":"33858422","id":"PMC_33858422","title":"Orthopedic surgery-induced cognitive dysfunction is mediated by CX3CL1/R1 signaling.","date":"2021","source":"Journal of neuroinflammation","url":"https://pubmed.ncbi.nlm.nih.gov/33858422","citation_count":33,"is_preprint":false},{"pmid":"22093090","id":"PMC_22093090","title":"Fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic losses and death.","date":"2011","source":"Molecular neurodegeneration","url":"https://pubmed.ncbi.nlm.nih.gov/22093090","citation_count":33,"is_preprint":false},{"pmid":"33765141","id":"PMC_33765141","title":"CX3CL1-CX3CR1 Signaling Deficiency Exacerbates Obesity-induced Inflammation and Insulin Resistance in Male Mice.","date":"2021","source":"Endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/33765141","citation_count":32,"is_preprint":false},{"pmid":"25503251","id":"PMC_25503251","title":"CX3CL1/CX3CR1 and CCL2/CCR2 chemokine/chemokine receptor complex in patients with AMD.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25503251","citation_count":31,"is_preprint":false},{"pmid":"23117657","id":"PMC_23117657","title":"Arterial and venous endothelia display differential functional fractalkine (CX3CL1) expression by angiotensin-II.","date":"2012","source":"Arteriosclerosis, thrombosis, and vascular biology","url":"https://pubmed.ncbi.nlm.nih.gov/23117657","citation_count":31,"is_preprint":false},{"pmid":"24862326","id":"PMC_24862326","title":"HIV-1 Tat disrupts CX3CL1-CX3CR1 axis in microglia via the NF-κBYY1 pathway.","date":"2014","source":"Current HIV research","url":"https://pubmed.ncbi.nlm.nih.gov/24862326","citation_count":31,"is_preprint":false},{"pmid":"17151328","id":"PMC_17151328","title":"Expression and targeting of CX3CL1 (fractalkine) in renal tubular epithelial cells.","date":"2006","source":"Journal of the American Society of Nephrology : JASN","url":"https://pubmed.ncbi.nlm.nih.gov/17151328","citation_count":30,"is_preprint":false},{"pmid":"14698146","id":"PMC_14698146","title":"The chemokine CX3CL1 regulates NK cell activity in vivo.","date":"2003","source":"Cellular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/14698146","citation_count":30,"is_preprint":false},{"pmid":"32346064","id":"PMC_32346064","title":"Entry and exit of chemotherapeutically-promoted cellular dormancy in glioblastoma cells is differentially affected by the chemokines CXCL12, CXCL16, and CX3CL1.","date":"2020","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/32346064","citation_count":30,"is_preprint":false},{"pmid":"20004358","id":"PMC_20004358","title":"Relevance of the CX3CL1/fractalkine-CX3CR1 pathway in vasculitis and vasculopathy.","date":"2010","source":"Translational research : the journal of laboratory and clinical medicine","url":"https://pubmed.ncbi.nlm.nih.gov/20004358","citation_count":29,"is_preprint":false},{"pmid":"28470428","id":"PMC_28470428","title":"Genome-wide DNA methylation analysis of articular chondrocytes identifies TRAF1, CTGF, and CX3CL1 genes as hypomethylated in osteoarthritis.","date":"2017","source":"Clinical rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/28470428","citation_count":29,"is_preprint":false},{"pmid":"39237909","id":"PMC_39237909","title":"YTHDF2 in peritumoral hepatocytes mediates chemotherapy-induced antitumor immune responses through CX3CL1-mediated CD8+ T cell recruitment.","date":"2024","source":"Molecular cancer","url":"https://pubmed.ncbi.nlm.nih.gov/39237909","citation_count":28,"is_preprint":false},{"pmid":"35770395","id":"PMC_35770395","title":"Structure and Function of Ligand CX3CL1 and its Receptor CX3CR1 in Cancer.","date":"2022","source":"Current medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/35770395","citation_count":28,"is_preprint":false},{"pmid":"37875838","id":"PMC_37875838","title":"Targeted inhibition of CX3CL1 limits podocytes ferroptosis to ameliorate cisplatin-induced acute kidney injury.","date":"2023","source":"Molecular medicine (Cambridge, Mass.)","url":"https://pubmed.ncbi.nlm.nih.gov/37875838","citation_count":27,"is_preprint":false},{"pmid":"23470165","id":"PMC_23470165","title":"Interaction between CX3CL1 and CX3CR1 regulates vasculitis induced by immune complex deposition.","date":"2013","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/23470165","citation_count":27,"is_preprint":false},{"pmid":"18267286","id":"PMC_18267286","title":"Issues regarding gene therapy products for Parkinson's disease: the development of CERE-120 (AAV-NTN) as one reference point.","date":"2007","source":"Parkinsonism & related disorders","url":"https://pubmed.ncbi.nlm.nih.gov/18267286","citation_count":27,"is_preprint":false},{"pmid":"31780870","id":"PMC_31780870","title":"Role of CX3CL1/CX3CR1 Signaling Axis Activity in Osteoporosis.","date":"2019","source":"Mediators of inflammation","url":"https://pubmed.ncbi.nlm.nih.gov/31780870","citation_count":26,"is_preprint":false},{"pmid":"28522896","id":"PMC_28522896","title":"Shear Stress Counteracts Endothelial CX3CL1 Induction and Monocytic Cell Adhesion.","date":"2017","source":"Mediators of inflammation","url":"https://pubmed.ncbi.nlm.nih.gov/28522896","citation_count":26,"is_preprint":false},{"pmid":"12727021","id":"PMC_12727021","title":"Human keratinocytes express fractalkine/CX3CL1.","date":"2003","source":"Journal of dermatological science","url":"https://pubmed.ncbi.nlm.nih.gov/12727021","citation_count":26,"is_preprint":false},{"pmid":"18538418","id":"PMC_18538418","title":"Glial cross-talk by transmembrane chemokines CX3CL1 and CXCL16.","date":"2008","source":"Journal of neuroimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/18538418","citation_count":26,"is_preprint":false},{"pmid":"25845619","id":"PMC_25845619","title":"Chemokine CX3CL1 and its receptor CX3CR1 are associated with human atherosclerotic lesion volnerability.","date":"2015","source":"Thrombosis research","url":"https://pubmed.ncbi.nlm.nih.gov/25845619","citation_count":26,"is_preprint":false},{"pmid":"23147224","id":"PMC_23147224","title":"ERK pathway and sheddases play an essential role in ethanol-induced CX3CL1 release in pancreatic stellate cells.","date":"2012","source":"Laboratory investigation; a journal of technical methods and pathology","url":"https://pubmed.ncbi.nlm.nih.gov/23147224","citation_count":26,"is_preprint":false},{"pmid":"28739588","id":"PMC_28739588","title":"N-terminal pyroglutamate formation in CX3CL1 is essential for its full biologic activity.","date":"2017","source":"Bioscience reports","url":"https://pubmed.ncbi.nlm.nih.gov/28739588","citation_count":26,"is_preprint":false},{"pmid":"32799418","id":"PMC_32799418","title":"Platelets are recruited to hepatocellular carcinoma tissues in a CX3CL1-CX3CR1 dependent manner and induce tumour cell apoptosis.","date":"2020","source":"Molecular oncology","url":"https://pubmed.ncbi.nlm.nih.gov/32799418","citation_count":26,"is_preprint":false},{"pmid":"27156946","id":"PMC_27156946","title":"Expression of Chemokine XCL2 and CX3CL1 in Lung Cancer.","date":"2016","source":"Medical science monitor : international medical journal of experimental and clinical research","url":"https://pubmed.ncbi.nlm.nih.gov/27156946","citation_count":25,"is_preprint":false},{"pmid":"33641164","id":"PMC_33641164","title":"Potential biomarkers reflecting inflammation in patients with severe periodontitis: Fractalkine (CX3CL1) and its receptor (CX3CR1).","date":"2021","source":"Journal of periodontal research","url":"https://pubmed.ncbi.nlm.nih.gov/33641164","citation_count":24,"is_preprint":false},{"pmid":"22692452","id":"PMC_22692452","title":"CX3CL1 expression in the conjunctiva is involved in immune cell trafficking during toxic ocular surface inflammation.","date":"2012","source":"Mucosal immunology","url":"https://pubmed.ncbi.nlm.nih.gov/22692452","citation_count":23,"is_preprint":false},{"pmid":"26745855","id":"PMC_26745855","title":"The role of CX3CL1 in fetal-maternal interaction during human gestation.","date":"2016","source":"Cell adhesion & migration","url":"https://pubmed.ncbi.nlm.nih.gov/26745855","citation_count":23,"is_preprint":false},{"pmid":"31030249","id":"PMC_31030249","title":"GABAAR α2-activated neuroimmune signal controls binge drinking and impulsivity through regulation of the CCL2/CX3CL1 balance.","date":"2019","source":"Psychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/31030249","citation_count":23,"is_preprint":false},{"pmid":"30606080","id":"PMC_30606080","title":"Regulation of CX3CL1 Expression in Human First-Trimester Decidual Cells: Implications for Preeclampsia.","date":"2019","source":"Reproductive sciences (Thousand Oaks, Calif.)","url":"https://pubmed.ncbi.nlm.nih.gov/30606080","citation_count":22,"is_preprint":false},{"pmid":"14605272","id":"PMC_14605272","title":"Expression of CX3CL1/fractalkine by mesangial cells in vitro and in acute anti-Thy1 glomerulonephritis in rats.","date":"2003","source":"Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association","url":"https://pubmed.ncbi.nlm.nih.gov/14605272","citation_count":22,"is_preprint":false},{"pmid":"24764683","id":"PMC_24764683","title":"Preliminary study correlating CX3CL1/CX3CR1 expression with gastric carcinoma and gastric carcinoma perineural invasion.","date":"2014","source":"World journal of gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/24764683","citation_count":21,"is_preprint":false},{"pmid":"30717334","id":"PMC_30717334","title":"Placental CX3CL1 is Deregulated by Angiotensin II and Contributes to a Pro-Inflammatory Trophoblast-Monocyte Interaction.","date":"2019","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/30717334","citation_count":21,"is_preprint":false},{"pmid":"25253723","id":"PMC_25253723","title":"Cytoskeletal confinement of CX3CL1 limits its susceptibility to proteolytic cleavage by ADAM10.","date":"2014","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/25253723","citation_count":21,"is_preprint":false},{"pmid":"32494000","id":"PMC_32494000","title":"CX3CL1 homo-oligomerization drives cell-to-cell adherence.","date":"2020","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/32494000","citation_count":20,"is_preprint":false},{"pmid":"38280480","id":"PMC_38280480","title":"Direct interaction of platelet with tumor cell aggravates hepatocellular carcinoma metastasis by activating TLR4/ADAM10/CX3CL1 axis.","date":"2024","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/38280480","citation_count":20,"is_preprint":false},{"pmid":"37175729","id":"PMC_37175729","title":"The Cytokine CX3CL1 and ADAMs/MMPs in Concerted Cross-Talk Influencing Neurodegenerative Diseases.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/37175729","citation_count":20,"is_preprint":false},{"pmid":"30575978","id":"PMC_30575978","title":"Pharmacokinetics, Pharmacodynamics, and Safety of E6011, a Novel Humanized Antifractalkine (CX3CL1) Monoclonal Antibody: A Randomized, Double-Blind, Placebo-Controlled Single-Ascending-Dose Study.","date":"2018","source":"Journal of clinical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/30575978","citation_count":20,"is_preprint":false},{"pmid":"23229614","id":"PMC_23229614","title":"The transmembrane chemokines CXCL16 and CX3CL1 and their receptors are expressed in human meningiomas.","date":"2012","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/23229614","citation_count":20,"is_preprint":false},{"pmid":"28848146","id":"PMC_28848146","title":"Naringin Protects Against High Glucose-Induced Human Endothelial Cell Injury Via Antioxidation and CX3CL1 Downregulation.","date":"2017","source":"Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/28848146","citation_count":20,"is_preprint":false},{"pmid":"15843029","id":"PMC_15843029","title":"Pro-sequence and Ca2+-binding: implications for folding and maturation of Ntn-hydrolase penicillin amidase from E. coli.","date":"2005","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/15843029","citation_count":19,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":52813,"output_tokens":9367,"usd":0.149472},"stage2":{"model":"claude-opus-4-6","input_tokens":13292,"output_tokens":4316,"usd":0.26154},"total_usd":0.411012,"stage1_batch_id":"msgbatch_011kfMfE81o6CTcyhVUqumuW","stage2_batch_id":"msgbatch_01DTputS6WNkH745x1nVSoBo","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"CX3CL1 is synthesized in endothelial cells as a transmembrane protein; the N-terminal chemokine domain is proteolytically cleaved and secreted as a soluble chemoattractant, while the membrane-bound form acts as an adhesion molecule for CX3CR1-expressing leukocytes (monocytes and lymphocytes). Expression is induced by TNF-α, IL-1, LPS, and IFN-γ, and inhibited by soluble IL-6Rα, 15-deoxy-Δ(12,14)-PGJ2, and hypoxia.\",\n      \"method\": \"Cell stimulation assays, protein expression analysis, functional adhesion assays in endothelial cells\",\n      \"journal\": \"Journal of atherosclerosis and thrombosis\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods, replicated across labs\",\n      \"pmids\": [\"15067194\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"CX3CL1 transmembrane chemokine is sequentially processed by α-secretase activity (ADAM10, cleaving at multiple sites) and subsequently by γ-secretase (but not β-secretase), generating C-terminal fragments (CTFs) analogous to Notch/E-cadherin processing. This proteolytic cascade releases soluble CX3CL1 and produces intracellular CTFs.\",\n      \"method\": \"Inhibitor studies (ADAM10/γ-secretase/β-secretase/proteasome inhibitors), presenilin 1/2-deficient cell lines, CX3CL1 constructs C-terminally fused to 2Z-tag for CTF detection\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — genetic (presenilin-KO cells) and pharmacological inhibitor studies with multiple orthogonal approaches in one study\",\n      \"pmids\": [\"17467666\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Cell surface CX3CL1 is in dynamic equilibrium with a juxtanuclear intracellular storage compartment distinct from conventional endosomes. Internalized CX3CL1 is recycled back to the plasma membrane via a SNARE-mediated mechanism involving syntaxin-13 and VAMP-3; cleavage of VAMP-3 by tetanus toxin or dominant-negative syntaxin-13 blocks this recycling.\",\n      \"method\": \"Live-cell fluorescence imaging of GFP-tagged CX3CL1, co-localization with SNARE proteins, tetanus toxin treatment, dominant-negative allele expression, subcellular fractionation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — direct live imaging + genetic/pharmacological perturbation with mechanistic readout in one study\",\n      \"pmids\": [\"15774461\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"In polarized renal tubular epithelial cells, CX3CL1 is targeted exclusively to the apical membrane and subapical vesicles. Apical targeting depends on N-linked glycosylation (not the intracellular domain, O-glycosylation, or lipid raft association). CX3CL1 is immobile in the apical membrane (FRAP) and is not directly actin-cytoskeleton-associated. Apical CX3CL1 promotes adhesion of CX3CR1-expressing leukocytes to the luminal surface.\",\n      \"method\": \"FRAP, immunofluorescence of polarized MDCK cells expressing GFP-CX3CL1, N-glycosylation and cholesterol depletion experiments, leukocyte adhesion assay, human biopsy immunohistochemistry\",\n      \"journal\": \"Journal of the American Society of Nephrology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — FRAP, mutagenesis-like glycosylation studies, functional adhesion assay; single study with multiple orthogonal methods\",\n      \"pmids\": [\"17151328\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"The cortical actin cytoskeleton confines CX3CL1 within restricted membrane domains, sequestering it from ADAM10 and limiting constitutive proteolytic cleavage. Disruption of actin by cytochalasin D reduces CX3CL1 confinement, increases CX3CL1-ADAM10 co-localization, and promotes soluble CX3CL1 release.\",\n      \"method\": \"Single-particle tracking, subdiffraction fluorescence imaging (PALM/STORM), pharmacological actin disruption, ADAM10 co-localization quantification\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — single-molecule imaging plus functional readout in one study\",\n      \"pmids\": [\"25253723\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Thrombin induces CX3CL1 expression in human umbilical vein endothelial cells (HUVECs) via PAR1 activation and downstream NF-κB signaling. Membrane-anchored CX3CL1 induced by thrombin promotes monocyte adhesion to endothelium and triggers monocyte CCL2 release, potentiating transendothelial migration. Recombinant soluble CX3CL1 ectodomain alone induces CCL2 release from monocytes.\",\n      \"method\": \"RT-PCR, Western blot, flow cytometry, EMSA, ELISA; PAR1-activating peptide, PAR1 antagonist SCH 79797, IKK inhibitor, dominant-negative IκBα; co-culture and transendothelial migration assays\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal pharmacological and genetic approaches with defined cellular readouts\",\n      \"pmids\": [\"18436581\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Only the soluble isoform of CX3CL1 (not membrane-bound) provides neuroprotection in an MPTP mouse model of Parkinson's disease, reducing motor impairment, dopaminergic neuron loss, microglial activation, and pro-inflammatory cytokine release. The membrane-bound isoform was indistinguishable from GFP controls.\",\n      \"method\": \"AAV-mediated delivery of synthetic permanently soluble vs. obligate membrane-bound CX3CL1 variants into substantia nigra of CX3CL1−/− mice; behavioral testing, immunohistochemistry, cytokine ELISA\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — isoform-selective genetic rescue in KO background with multiple orthogonal readouts\",\n      \"pmids\": [\"23077045\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Membrane-anchored CX3CL1 (not soluble isoform) regulates microglial phagocytosis of amyloid-β and neuronal tau phosphorylation in Alzheimer's mouse models via the p38 MAPK pathway. CX3CL1 deficiency reduces Aβ deposition but paradoxically enhances tau phosphorylation; transgenic soluble CX3CL1 expression does not rescue either phenotype.\",\n      \"method\": \"Genetic crosses of APPPS1 mice with CX3CL1-KO and soluble CX3CL1 transgenic mice; microglia isolation for transcript profiling; p38 MAPK phosphorylation assay; Aβ internalization in purified microglia\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic mouse models with mechanistic pathway (p38 MAPK) identification\",\n      \"pmids\": [\"25209291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Soluble CX3CL1 rescues cognitive deficits, hippocampal LTP, and adult neurogenesis in CX3CL1-KO mice, while the obligate membrane-bound form only partially rescues spatial learning and does not rescue long-term memory or neurogenesis, demonstrating isoform-specific functions.\",\n      \"method\": \"AAV delivery of sFKN or mFKN to CX3CL1-KO mice; behavioral tests (Morris water maze, novel object recognition); hippocampal LTP electrophysiology; neurogenesis markers by immunostaining\",\n      \"journal\": \"Journal of neuroinflammation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — isoform-selective genetic rescue in KO mice with multiple orthogonal functional readouts\",\n      \"pmids\": [\"32410624\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CX3CL1 C-terminal intracellular domain (CX3CL1-ICD), released after sequential α-, β-, and γ-secretase cleavage, translocates to the nucleus and enhances adult neurogenesis through the TGF-β2/3-Smad2/3 pathway. This 'back-signaling' is independent of CX3CR1 and reduces amyloid pathology and neuronal loss in 5xFAD mice.\",\n      \"method\": \"CX3CL1-ct overexpression in 5xFAD mice; Smad2 neuron-specific knockout; RNA-seq of neurons; morphological analysis; TGF-β2/3 and Smad2 protein measurements\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO of downstream effector (Smad2) abrogates CX3CL1 neurogenic effect; multiple orthogonal methods\",\n      \"pmids\": [\"31209068\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CX3CL1 overexpression in neurons enhances neurogenesis in subgranular and subventricular zones via a TGF-β2/TGF-β3-Smad2 pathway. Neuron-specific deletion of Smad2 abrogates this effect. In tau P301S (PS19) Alzheimer's mice, neuronal CX3CL1 overexpression rescues neurodegeneration and improves cognition.\",\n      \"method\": \"Transgenic CX3CL1-overexpressing mice crossed with PS19 and with Smad2-neuron-specific KO mice; neurogenesis quantification; cognitive/motor behavioral testing; TGF-β and Smad2 protein measurements\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic rescue and epistasis with Smad2 deletion confirming pathway placement\",\n      \"pmids\": [\"31822518\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CX3CL1-CX3CR1 signaling regulates microglial repopulation in the adult retina: repopulation is slowed in CX3CR1-deficient mice and accelerated by exogenous CX3CL1 administration. Repopulating microglia (derived from residual microglia in central inner retina) fully restore microglial distribution, morphology, process surveillance, and synaptic maintenance.\",\n      \"method\": \"In vivo imaging, cell-fate mapping, CX3CR1-GFP reporter mice, exogenous CX3CL1 intravitreal delivery, microglial depletion model\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — in vivo imaging + genetic (CX3CR1-KO) + pharmacological (exogenous CX3CL1) with defined functional readouts\",\n      \"pmids\": [\"29750189\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CX3CL1-CX3CR1 signaling suppresses microglial phagocytosis and activation in the degenerating retina (rd10 RP model). CX3CR1 deficiency accelerates photoreceptor apoptosis and increases microglial phagocytosis; exogenous CX3CL1 delivery reduces microglial infiltration and improves photoreceptor survival and function.\",\n      \"method\": \"CX3CR1(GFP/GFP) rd10 mice; in vivo phagosome counting; in vitro phagocytosis rate assay with fluorescent beads; live-cell imaging of retinal explants; intravitreal CX3CL1 delivery\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic + pharmacological rescue with multiple in vitro and in vivo orthogonal phagocytosis assays\",\n      \"pmids\": [\"27314452\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"CX3CL1 promotes breast cancer cell proliferation by transactivating ErbB receptors through proteolytic shedding of an ErbB ligand, inducing epithelial-to-mesenchymal transition. Genetic deletion of CX3CL1 delays mammary tumorigenesis in HER2/neu mice but not in polyoma middle T-antigen mice, placing CX3CL1 specifically in the ErbB signaling context.\",\n      \"method\": \"Adenoviral CX3CL1 overexpression in HER2/neu transgenic mice; CX3CL1 genetic knockout crossed with tumor models; in vitro proliferation and EMT assays; ErbB receptor transactivation assays\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic epistasis in multiple tumor mouse models plus in vitro mechanistic dissection\",\n      \"pmids\": [\"23720051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"CX3CL1 regulates nerve injury-induced pain hypersensitivity through the ERK5 signaling pathway: CX3CR1 blockade reduces ERK5 phosphorylation in the spinal cord after SNL, and antisense ERK5 knockdown reverses CX3CL1-induced hyperalgesia and spinal microglial activation.\",\n      \"method\": \"Spinal nerve ligation (SNL) rat model; intrathecal antisense oligonucleotide knockdown of ERK5; intrathecal CX3CR1 blocking antibody; ERK5 phosphorylation western blot; behavioral pain testing\",\n      \"journal\": \"Journal of neuroscience research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological and antisense knockdown with pathway placement, single lab\",\n      \"pmids\": [\"23361876\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"CX3CL1 treatment of trophoblast cells regulates expression of adhesion molecules and extracellular matrix components including α-catenin (CTNNA1), ECM1, osteopontin (SPP1), integrin α6 (ITGA6), MMP12, and integrin β5 (ITGB5), and increases trophoblast adhesion to fibronectin, suggesting a mechanism for CX3CL1-driven directional trophoblast migration during implantation.\",\n      \"method\": \"Pathway-specific oligonucleotide arrays, qRT-PCR, fibronectin adhesion assay, immunohistochemistry of first-trimester implantation sites\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, transcriptomic + functional adhesion assay, mechanistic gene targets identified\",\n      \"pmids\": [\"18367676\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"CX3CR1 signaling in microglia induces chemotaxis in response to CX3CL1 (confirmed by chemotaxis assay). CX3CL1 is constitutively expressed by human CNS astrocytes in vivo and in vitro; CX3CR1 is expressed on both astrocytes and microglia.\",\n      \"method\": \"Chemotaxis assay, immunohistochemistry of human brain tissue, RT-PCR, in vitro astrocyte cultures with cytokine stimulation\",\n      \"journal\": \"Journal of neuropathology and experimental neurology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — functional chemotaxis assay plus localization; single lab\",\n      \"pmids\": [\"14533779\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"N-terminal pyroglutamate (pGlu) modification of CX3CL1 by glutaminyl cyclase (QC/QPCT) or isoQC (QPCTL) is required for full biological activity: pGlu1-CX3CL1 induces significantly stronger phosphorylation of ERK1/2, Akt, and p38 kinases than immature Gln1-CX3CL1, and drives higher expression of CCL2, CX3CL1, and ICAM1 in vascular smooth muscle and endothelial cells. QPCT expression is co-regulated with CX3CL1 via NF-κB.\",\n      \"method\": \"Mass spectrometry to confirm pGlu formation; RNAi knockdown of QPCT; kinase phosphorylation assays; gene expression by RT-PCR; NF-κB pathway inhibition\",\n      \"journal\": \"Bioscience reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — MS confirmation of modification + functional kinase assays + RNAi, single lab\",\n      \"pmids\": [\"28739588\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CX3CL1 forms homo-oligomers of 3–7 monomers driven by intrinsic properties of its transmembrane domain, and this oligomerization is required for its adhesive function. A transmembrane domain peptide of CX3CL1 inhibits both oligomerization and cell-to-cell adherence, while a scrambled peptide control does not.\",\n      \"method\": \"Native electrophoresis, single-molecule fluorescence kinetics, FRAP in cellular and acellular lipid environments, molecular modeling, transmembrane peptide inhibition assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstitution in lipid bilayers + single-molecule assays + functional inhibition by TM peptide; multiple orthogonal methods in one study\",\n      \"pmids\": [\"32494000\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"ERK pathway and metalloprotease sheddases (ADAM17 and MMP) are required for CX3CL1 release from pancreatic stellate cells. Ethanol synergistically increases CX3CL1 secretion by activating ERK and ADAM17; specific inhibitors of ERK, MMP, and ADAM suppress CX3CL1 release. ERK is associated with CX3CL1 transcription.\",\n      \"method\": \"RT-PCR, western blot, ELISA in PSCs; kinase and protease inhibitors; in vivo CP rat model (WBN/Kob)\",\n      \"journal\": \"Laboratory investigation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple inhibitor approaches with orthogonal transcriptional and secretion readouts; single lab\",\n      \"pmids\": [\"23147224\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Exogenous fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic loss and death by acting on CX3CR1-expressing microglia. Fractalkine normalizes elevated microglial motility caused by Tat/morphine co-exposure and fails to protect neurons co-cultured with CX3CR1-null microglia, demonstrating that protection requires microglial CX3CR1.\",\n      \"method\": \"Wild-type neurons co-cultured with Cx3cr1-KO or wild-type mixed glia; time-lapse microscopy; exogenous CX3CL1 addition; anti-CX3CR1 blocking antibody; ELISA for TNF-α and CX3CL1\",\n      \"journal\": \"Molecular neurodegeneration\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — CX3CR1-KO glia as genetic control + pharmacological blockade + live-cell imaging with defined readout; single lab multiple methods\",\n      \"pmids\": [\"22093090\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"HIV-1 Tat protein suppresses CX3CR1 expression in microglia via NF-κB activation followed by YY1-mediated transcriptional repression, disrupting CX3CL1-CX3CR1 signaling (calcium mobilization, MAPK activation, and microglial migration in response to CX3CL1).\",\n      \"method\": \"Primary microglia and BV2 cells exposed to Tat; RT-PCR and western blot for CX3CR1; NF-κB pathway inhibition; YY1 binding site identification; calcium mobilization assay; MAPK phosphorylation; microglial migration assay\",\n      \"journal\": \"Current HIV research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — mechanistic pathway identified through pharmacological and transcriptional analysis; single lab\",\n      \"pmids\": [\"24862326\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CX3CL1-CX3CR1 interaction mediates macrophage-mesothelial crosstalk in peritoneal fibrosis: mesothelial CX3CL1 engages macrophage CX3CR1, promoting TGF-β production in a positive feedback loop where macrophage IL-1β upregulates mesothelial CX3CL1 and TGF-β; TGF-β in turn upregulates CX3CR1 in monocytic cells. CX3CR1 deficiency reduces peritoneal fibrosis in vivo.\",\n      \"method\": \"Murine PD model; CX3CR1-KO mice; human PD patient biopsies; in vitro macrophage-mesothelial cell co-culture; TGF-β and CX3CL1 protein measurements\",\n      \"journal\": \"Kidney international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO mice + in vitro co-culture + human validation; single lab\",\n      \"pmids\": [\"30948201\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CX3CL1 promotes M1 macrophage polarization and osteoclast differentiation through the NF-κB signaling pathway in ankylosing spondylitis. NF-κB inhibition (BAY-117082) or anti-CX3CL1 mAb blocks M1 polarization, inflammation, and osteoclastogenesis in vitro and alleviates disease in AS model mice.\",\n      \"method\": \"In vitro macrophage polarization and osteoclast differentiation assays; NF-κB inhibitor; anti-CX3CL1 mAb; AS model mice; western blot and ELISA for inflammatory markers\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological and antibody blockade with defined cellular and in vivo readouts; single lab\",\n      \"pmids\": [\"37626378\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CX3CL1 enhances prostate cancer spinal metastasis by activating the Src/FAK signaling pathway, dependent on EGFR Tyr992 phosphorylation. CX3CR1 overexpression promotes tumor cell proliferation, migration, invasion, and spinal metastasis in vivo; Src/FAK inhibitors block CX3CL1-induced migration.\",\n      \"method\": \"CX3CR1 overexpression and knockdown in prostate cancer cells; kinase inhibitor assays; phosphorylation western blot; in vivo spinal metastasis mouse model\",\n      \"journal\": \"International journal of oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — kinase pathway identification with inhibitor validation and in vivo model; single lab\",\n      \"pmids\": [\"30066854\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Shear stress reduces TNFα-induced endothelial CX3CL1 expression and CX3CL1-dependent monocyte adhesion. Under low shear stress, transmembrane CX3CL1 mediates monocyte arrest on endothelium (blocked by neutralizing anti-CX3CL1 antibody); physiological shear stress abrogates this response.\",\n      \"method\": \"Endothelial cells (arterial, venous, microvascular) under controlled flow; TNFα stimulation; anti-CX3CL1 neutralizing antibody; monocyte THP-1 adhesion assay; CX3CL1 expression by western blot and immunofluorescence\",\n      \"journal\": \"Mediators of inflammation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — neutralizing antibody demonstrates CX3CL1-specific contribution to adhesion; defined flow conditions; single lab\",\n      \"pmids\": [\"28522896\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"CX3CL1 is required for in vivo NK cell activity: antibody blockade of CX3CL1 or CX3CR1 reduces NK-mediated tumor cell clearance by 4–5-fold in mice without affecting in vitro NK cytolytic activity. CX3CR1 blockade inhibits NK cell adhesion to activated endothelium, indicating that CX3CL1 regulates NK cell extravasation/trafficking.\",\n      \"method\": \"In vivo NK clearance assay using radiolabeled YAC-1 cells; anti-CX3CL1 and anti-CX3CR1 blocking antibodies; in vitro NK cytotoxicity assay; NK adhesion assay to endothelial monolayers\",\n      \"journal\": \"Cellular immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo blocking antibody study with in vitro adhesion mechanistic follow-up; single lab\",\n      \"pmids\": [\"14698146\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"ADAM17-regulated shedding of CX3CL1 from bone marrow endothelial cells promotes hepatocellular carcinoma spinal metastasis. CX3CL1 activates Src/PTK2 signaling in HCC cells, subsequently activating PIK3CA/AKT1 and RHOA/ROCK2 pathways to drive invasion and migration. ADAM17 is activated by MAPK in BMECs, and neutralization of CX3CL1 inhibits BMEC-induced cancer cell invasion.\",\n      \"method\": \"Western blot for Src/FAK/PI3K/RHOA pathways; CX3CL1 neutralization; ADAM17 inhibition; in vivo mouse spinal metastasis model; CX3CR1 overexpression in HCC cells\",\n      \"journal\": \"International journal of oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple pathway validations + in vivo model; single lab\",\n      \"pmids\": [\"32319605\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CX3CL1 directly induces platelet migration via CX3CR1/Syk/PI3K pathway components; hypoxia enhances platelet migration by upregulating CX3CL1 in HCC cells. Migrating platelets promote HCC cell apoptosis in vitro; CX3CL1 knockdown in HCC cells reduces platelet infiltration in an orthotopic HCC model.\",\n      \"method\": \"In vitro platelet migration assay; CX3CL1 knockdown in HCC cells; orthotopic HCC mouse model; mitochondrial membrane potential assay; apoptosis flow cytometry; pathway inhibition\",\n      \"journal\": \"Molecular oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro mechanistic pathway + in vivo knockdown model; single lab\",\n      \"pmids\": [\"32799418\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In retinitis pigmentosa, soluble CX3CL1 gene therapy (AAV8-sCX3CL1) significantly prolongs cone photoreceptor survival and improves visual function across three RP mouse strains. The mechanism does not require normal microglial numbers (pharmacological depletion of ~99% of microglia does not abrogate the effect), and RNA-seq reveals marked transcriptional changes in residual microglia.\",\n      \"method\": \"Subretinal AAV8-sCX3CL1 injection in three RP mouse strains; ERG functional testing; cone survival quantification; microglia pharmacological depletion; RNA-seq of microglia\",\n      \"journal\": \"Proceedings of the National Academy of Sciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple mouse strains, functional rescue, microglia depletion epistasis, RNA-seq; strong evidence\",\n      \"pmids\": [\"31036641\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Platelet-derived TLR4/NF-κB signaling upregulates ADAM10 in HCC tumor cells; ADAM10 then sheds CX3CL1, which acts on CX3CR1 to induce EMT and activate RhoA signaling, promoting lung metastasis. Knockdown of tumor cell TLR4 or ADAM10 inhibition prevents platelet-augmented tumor invasion.\",\n      \"method\": \"TLR4/ADAM10 knockdown in HCC cells; NF-κB pathway analysis; CX3CL1 shedding assay; RhoA signaling western blot; in vivo lung metastasis mouse model with platelet co-injection\",\n      \"journal\": \"Cancer letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic knockdown + pathway analysis + in vivo model; single lab\",\n      \"pmids\": [\"38280480\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CX3CL1 inhibits NLRP3 inflammasome-induced microglial pyroptosis and suppresses NF-κB signaling, thereby reducing IL-1β and IL-18 expression in ischemic stroke models (MCAO in vivo and OGD/R in vitro). Exogenous rCX3CL1 reduces GSDMD-dependent pyroptosis and decreases infarct volume.\",\n      \"method\": \"MCAO mouse model; OGD/R BV2 cells; intracerebroventricular CX3CL1 injection; NLRP3 and GSDMD western blot; NF-κB activation assay; ELISA for cytokines; immunostaining\",\n      \"journal\": \"Life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo + in vitro parallel experiments with NLRP3/GSDMD pathway readouts; single lab\",\n      \"pmids\": [\"35461837\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In hepatocytes, YTHDF2 (an m6A reader) stabilizes Cx3cl1 mRNA in an m6A-dependent manner downstream of OXA-activated cGAS-STING signaling, promoting CX3CL1 production that recruits CD8+ T cells to suppress liver tumor growth. Liver-specific Ythdf2 knockout reduces CX3CL1, CD8+ T cell infiltration, and anti-tumor immunity.\",\n      \"method\": \"Liver-specific Ythdf2 KO tumor-bearing mice; m6A-seq; RNA stability assay; CX3CL1 ELISA; CD8+ T cell flow cytometry; cGAS-STING pathway analysis\",\n      \"journal\": \"Molecular cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO with mechanistic m6A pathway identification; single lab\",\n      \"pmids\": [\"39237909\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In gastric cancer, lactate acts via GPR81 to upregulate CX3CL1 expression, which recruits regulatory T cells (Tregs) into the tumor microenvironment to suppress CD8+ T cell function. GPR81 deficiency reduces CX3CL1 and Treg infiltration, inhibiting tumor progression.\",\n      \"method\": \"In vitro lactate/GPR81 signaling assays; GPR81 knockdown; CX3CL1 ELISA; Treg and CD8+ T cell flow cytometry; humanized mouse model\",\n      \"journal\": \"Oncoimmunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — mechanistic pathway from lactate to CX3CL1 to Tregs with in vivo validation; single lab\",\n      \"pmids\": [\"38419759\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CX3CL1 (fractalkine) is a transmembrane chemokine expressed primarily by neurons and endothelial cells that exists in two functional forms: a membrane-anchored form that promotes firm leukocyte adhesion (functioning as an adhesion molecule via homo-oligomerization driven by its transmembrane domain) and a soluble form generated by ADAM10/ADAM17-mediated ectodomain shedding (regulated by cytoskeletal actin confinement) and further processed by γ-secretase; the soluble form acts as a chemoattractant for CX3CR1-expressing microglia, monocytes, NK cells, and T cells. Within the CNS, soluble CX3CL1 is the dominant neuroprotective isoform that suppresses microglial activation (inhibiting phagocytosis and NLRP3 inflammasome/pyroptosis via NF-κB), promotes adult neurogenesis and LTP through CX3CR1-dependent pathways and independently via an intracellular domain (CX3CL1-ICD) that is released by sequential secretase cleavage and translocates to the nucleus to activate TGF-β2/3-Smad2/3 signaling; in cancer, CX3CL1 signals through CX3CR1-coupled Src/FAK, PI3K/AKT, and RhoA pathways to drive tumor cell migration and metastasis, and regulates immune cell trafficking in the tumor microenvironment.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CX3CL1 (fractalkine) is a transmembrane chemokine that functions as both a membrane-anchored adhesion molecule and, after ADAM10/ADAM17-mediated ectodomain shedding followed by γ-secretase cleavage, a soluble chemoattractant for CX3CR1-expressing monocytes, NK cells, T cells, and microglia [PMID:15067194, PMID:17467666, PMID:25253723]. Membrane-bound CX3CL1 mediates firm leukocyte adhesion through transmembrane domain-driven homo-oligomerization and regulates microglial phagocytosis via p38 MAPK, whereas soluble CX3CL1 is the dominant neuroprotective isoform that suppresses microglial activation, rescues hippocampal LTP and adult neurogenesis, and inhibits NLRP3 inflammasome-driven pyroptosis through NF-κB suppression [PMID:32494000, PMID:25209291, PMID:32410624, PMID:35461837]. Sequential secretase processing also releases an intracellular domain (CX3CL1-ICD) that translocates to the nucleus and activates TGF-β2/3–Smad2/3 signaling to promote neurogenesis independently of CX3CR1 [PMID:31209068, PMID:31822518]. In cancer, shed CX3CL1 signals through CX3CR1-coupled Src/FAK, PI3K/AKT, and RhoA pathways to drive tumor cell migration, metastasis, and immune cell trafficking in the tumor microenvironment [PMID:30066854, PMID:32319605, PMID:38280480].\",\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Establishing that CX3CL1 is a functional chemoattractant for microglia and mediates NK cell trafficking in vivo resolved the question of which immune cell types respond to fractalkine signaling in physiological contexts.\",\n      \"evidence\": \"Microglial chemotaxis assay plus human brain immunohistochemistry; in vivo NK clearance assay with anti-CX3CL1/CX3CR1 blocking antibodies in mice\",\n      \"pmids\": [\"14533779\", \"14698146\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Downstream signaling cascades in responding microglia and NK cells not defined\", \"Relative contributions of soluble versus membrane-bound forms to NK trafficking unclear\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Demonstrating that CX3CL1 exists as both a membrane-anchored adhesion molecule and a proteolytically released chemoattractant, with expression regulated by inflammatory cytokines, established the dual-function paradigm central to all subsequent mechanistic work.\",\n      \"evidence\": \"Cell stimulation, protein expression, and leukocyte adhesion assays in endothelial cells\",\n      \"pmids\": [\"15067194\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the sheddase(s) not yet determined\", \"Relative functional importance of soluble versus membrane forms unknown\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Revealing that surface CX3CL1 undergoes SNARE-dependent recycling through a juxtanuclear compartment answered how cells maintain a dynamic surface pool available for both adhesion and shedding.\",\n      \"evidence\": \"Live-cell GFP-CX3CL1 imaging, VAMP-3/syntaxin-13 perturbation by tetanus toxin and dominant-negative alleles\",\n      \"pmids\": [\"15774461\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Signals that regulate the recycling rate are undefined\", \"Whether recycling compartment identity differs across cell types is untested\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Identifying ADAM10 as the α-secretase and γ-secretase (presenilin-dependent) as the subsequent intramembrane protease defined the sequential cleavage cascade generating both soluble CX3CL1 and intracellular C-terminal fragments.\",\n      \"evidence\": \"Pharmacological inhibitor panel and presenilin 1/2-deficient cell lines with CTF detection\",\n      \"pmids\": [\"17467666\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Biological function of the intracellular CTF was unknown\", \"Relative contributions of ADAM10 versus ADAM17 in different tissues not resolved\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Showing that thrombin/PAR1 induces endothelial CX3CL1 via NF-κB and that membrane-bound CX3CL1 triggers monocyte CCL2 release linked the coagulation cascade to CX3CL1-dependent vascular inflammation.\",\n      \"evidence\": \"PAR1 agonist/antagonist, IKK inhibitor, dominant-negative IκBα, co-culture and transendothelial migration assays in HUVECs\",\n      \"pmids\": [\"18436581\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo relevance in thrombotic disease models not tested\", \"Whether soluble versus membrane CX3CL1 differentially triggers CCL2 undefined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Isoform-selective genetic rescue in CX3CL1-knockout mice proved that soluble CX3CL1 is the neuroprotective isoform in Parkinson's disease models, while membrane-bound CX3CL1 is dispensable for dopaminergic neuron survival.\",\n      \"evidence\": \"AAV delivery of obligate soluble vs. membrane-bound CX3CL1 into CX3CL1−/− mice; MPTP model with behavioral, histological, and cytokine readouts\",\n      \"pmids\": [\"23077045\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"CX3CR1-downstream signaling mediating neuroprotection not identified\", \"Whether isoform specificity holds in other neurodegenerative contexts was unknown\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"In cancer biology, demonstrating that CX3CL1 promotes breast cancer growth through ErbB receptor transactivation and that its genetic deletion delays HER2/neu tumorigenesis placed CX3CL1 as a tumor-promoting factor in ErbB-dependent contexts.\",\n      \"evidence\": \"CX3CL1-KO crossed with HER2/neu and PyMT tumor mouse models; ErbB transactivation and EMT assays\",\n      \"pmids\": [\"23720051\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular identity of the ErbB ligand shed downstream of CX3CL1 not identified\", \"Whether CX3CL1 acts on tumor cells directly or through stroma was not fully resolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Two discoveries clarified how membrane topology controls CX3CL1 shedding and how each isoform has distinct CNS functions: cortical actin confines CX3CL1 away from ADAM10 to limit constitutive cleavage, and the membrane-bound (not soluble) form regulates microglial phagocytosis of Aβ via p38 MAPK.\",\n      \"evidence\": \"Single-particle tracking/PALM-STORM with actin disruption; genetic crosses of APPPS1 mice with CX3CL1-KO and soluble CX3CL1 transgenics\",\n      \"pmids\": [\"25253723\", \"25209291\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis for actin-CX3CL1 confinement unknown\", \"How membrane CX3CL1 selectively activates p38 in microglia not resolved\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Showing that N-terminal pyroglutamate modification by glutaminyl cyclase is required for full CX3CL1 signaling potency revealed a post-translational maturation step controlling chemokine bioactivity.\",\n      \"evidence\": \"Mass spectrometry confirming pGlu modification; QPCT RNAi; ERK1/2, Akt, p38 phosphorylation assays in SMCs and ECs\",\n      \"pmids\": [\"28739588\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo relevance of pGlu modification not tested\", \"Whether pGlu differentially affects soluble vs. membrane CX3CL1 is unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"The discovery that the γ-secretase-released intracellular domain (CX3CL1-ICD) translocates to the nucleus and activates TGF-β2/3–Smad2/3 signaling to drive neurogenesis independently of CX3CR1 established a 'back-signaling' mechanism analogous to Notch, fundamentally expanding CX3CL1's functional repertoire.\",\n      \"evidence\": \"CX3CL1-ct overexpression in 5xFAD mice; neuron-specific Smad2 knockout abrogating neurogenic effect; RNA-seq; PS19 tau model rescue with Smad2 epistasis\",\n      \"pmids\": [\"31209068\", \"31822518\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Nuclear targets of CX3CL1-ICD beyond TGF-β2/3 not identified\", \"Whether ICD signaling occurs in non-neuronal tissues unknown\", \"Structural basis for ICD nuclear import not defined\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Soluble CX3CL1 gene therapy preserves cone photoreceptors across multiple retinitis pigmentosa models even after near-complete microglial depletion, demonstrating that CX3CL1's retinal neuroprotection involves transcriptional reprogramming of residual microglia rather than requiring normal microglial numbers.\",\n      \"evidence\": \"AAV8-sCX3CL1 in three RP mouse strains; ERG; pharmacological microglia depletion; RNA-seq of residual microglia\",\n      \"pmids\": [\"31036641\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the protective transcriptional program in reprogrammed microglia not fully resolved\", \"Whether other glial cells contribute to the rescue is untested\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Demonstrating that membrane CX3CL1 forms homo-oligomers of 3–7 monomers via its transmembrane domain and that oligomerization is required for adhesive function provided the structural basis for the membrane-anchored adhesion phenotype.\",\n      \"evidence\": \"Native gel electrophoresis, single-molecule fluorescence, FRAP in lipid bilayers, TM domain peptide inhibition\",\n      \"pmids\": [\"32494000\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic-resolution structure of the oligomer not available\", \"Whether oligomerization modulates shedding efficiency is untested\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"In metastatic cancer, shed CX3CL1 was shown to activate Src/FAK, PI3K/AKT, and RhoA/ROCK2 signaling through CX3CR1 on tumor cells, with ADAM17-mediated shedding from bone marrow endothelium driving spinal metastasis of prostate and hepatocellular carcinoma.\",\n      \"evidence\": \"CX3CR1 overexpression/knockdown; kinase inhibitor panels; CX3CL1 neutralization; in vivo spinal metastasis models\",\n      \"pmids\": [\"30066854\", \"32319605\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether these pathways are independent or form a linear cascade is unclear\", \"Clinical relevance in human metastatic samples not validated\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Establishing that CX3CL1 inhibits NLRP3 inflammasome assembly and GSDMD-dependent microglial pyroptosis via NF-κB suppression in ischemic stroke identified a specific anti-inflammatory mechanism beyond general microglial suppression.\",\n      \"evidence\": \"MCAO mouse model; OGD/R BV2 cells; intracerebroventricular CX3CL1; NLRP3/GSDMD western blot; NF-κB activation assay\",\n      \"pmids\": [\"35461837\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular target of CX3CL1 upstream of NF-κB suppression not identified\", \"Whether soluble or membrane form mediates this effect in vivo not distinguished\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Recent work placed CX3CL1 at the intersection of tumor metabolism and immune evasion: lactate/GPR81 signaling upregulates CX3CL1 to recruit Tregs in gastric cancer, and YTHDF2-dependent m6A stabilization of CX3CL1 mRNA recruits CD8+ T cells to suppress liver tumors, revealing context-dependent pro- and anti-tumor immune roles.\",\n      \"evidence\": \"GPR81 knockdown with Treg flow cytometry in humanized mice; liver-specific Ythdf2 KO with m6A-seq, RNA stability, and CD8+ T cell analysis\",\n      \"pmids\": [\"38419759\", \"39237909\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How the same chemokine recruits immunosuppressive Tregs in one context and cytotoxic CD8+ T cells in another is not mechanistically resolved\", \"Post-transcriptional regulation of CX3CL1 in non-hepatic cancers not examined\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the atomic structure of CX3CL1 transmembrane oligomers, the full nuclear interactome of CX3CL1-ICD, why soluble and membrane-bound isoforms activate distinct downstream pathways through the same receptor CX3CR1, and how CX3CL1 exerts opposing immune effects (immunosuppressive vs. immunostimulatory) in different tumor microenvironments.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of full-length or oligomeric CX3CL1\", \"Nuclear binding partners of CX3CL1-ICD beyond Smad2/3 pathway undefined\", \"Mechanism distinguishing CX3CR1-dependent vs. CX3CR1-independent signaling outputs incompletely characterized\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [0, 3, 18, 25, 26]},\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [0, 5, 6, 16, 20, 24]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [9, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 2, 3, 4, 18]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [0, 1, 6, 8, 29]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 5, 6, 11, 12, 16, 20, 26, 33]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5, 9, 10, 14, 17, 24, 27, 31]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [0, 3, 18, 25]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [31]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [9, 10]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [13, 24, 27, 30, 33]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"CX3CR1\",\n      \"ADAM10\",\n      \"ADAM17\",\n      \"VAMP3\",\n      \"STX13\",\n      \"SMAD2\",\n      \"PSEN1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}