{"gene":"CHRFAM7A","run_date":"2026-04-28T17:28:52","timeline":{"discoveries":[{"year":2011,"finding":"CHRFAM7A (dupα7) protein assembles with α7 subunits to form non-functional (ACh-silent) heteromeric receptors; co-expression in cell lines and Xenopus oocytes caused significant reduction in ACh-evoked current amplitude without reducing α-bungarotoxin binding, indicating dominant-negative modulation through formation of receptors that cannot open in response to ACh. PNU-120596 (type-2 PAM) rescued currents more in cells expressing dupα7, consistent with silent receptors retaining PAM sensitivity.","method":"Functional electrophysiology in Xenopus oocytes and cell lines; co-expression of α7 and dupα7; radioligand binding with [125I]-α-bungarotoxin; allosteric modulator (PNU-120596) rescue assay","journal":"Biochemical pharmacology","confidence":"High","confidence_rationale":"Tier 1 — reconstituted in heterologous expression systems with multiple orthogonal functional readouts (electrophysiology + ligand binding + pharmacological rescue), replicated across two systems","pmids":["21718690"],"is_preprint":false},{"year":2010,"finding":"dupα7 (CHRFAM7A product) co-injected with α7 mRNA in Xenopus oocytes reduced nicotine-evoked α7 currents in a dose-dependent manner (up to 94% reduction at 1:10 α7/dupα7 ratio), primarily by reducing the number of functional α7 receptors reaching the membrane, as demonstrated by α-bungarotoxin binding and fluorescent confocal assays. dupα7 protein was natively translated in HL-60 cells and heterologously expressed in GH4C1 cells and oocytes.","method":"Xenopus oocyte electrophysiology; α-bungarotoxin binding; fluorescent confocal microscopy; Western blot protein detection in HL-60 and GH4C1 cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — reconstituted in Xenopus oocytes with multiple orthogonal methods (electrophysiology, binding, imaging), corroborates PMID 21718690","pmids":["21047781"],"is_preprint":false},{"year":2011,"finding":"CHRFAM7A transcript and protein are exclusively expressed (not the full-length α7) in THP-1 monocytic cells. LPS challenge reduces CHRFAM7A mRNA and protein levels in THP-1 cells via a direct NF-κB-dependent transcriptional mechanism, as demonstrated by the NF-κB inhibitor parthenolide preventing transcript reduction.","method":"Qualitative PCR, real-time PCR, Western blotting in monocytic cell lines; NF-κB inhibitor (parthenolide) treatment","journal":"Journal of neuroimmunology","confidence":"Medium","confidence_rationale":"Tier 2 — clean expression/functional data in cell lines with pharmacological inhibitor mechanistic follow-up; single lab","pmids":["20926142"],"is_preprint":false},{"year":2015,"finding":"Stable CHRFAM7A overexpression in THP-1 human leukocyte cells alters cell phenotype and modifies expression of genes associated with focal adhesion (FAK, PI3K, Akt, Rho, GEF, Elk1, CycD), leukocyte transepithelial migration (Nox, ITG, MMPs, PKC) and cancer pathways. Unexpectedly, CHRFAM7A overexpression upregulated CHRNA7, leading to increased α-bungarotoxin binding on the THP-1 cell surface. A unique 1-kb sequence in the 5'-UTR independently regulates CHRFAM7A gene expression.","method":"Stable transfection/overexpression in THP-1 cells; gene expression profiling; α-bungarotoxin binding assay; promoter mapping","journal":"Molecular medicine (Cambridge, Mass.)","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal readouts (gene expression, ligand binding, promoter mapping) in a defined cellular model; single lab","pmids":["25860877"],"is_preprint":false},{"year":2015,"finding":"CHRFAM7A is expressed in human gut epithelial cells; its expression varies up to 5000-fold between different gut epithelial lines. LPS treatment (100 ng/ml, 3 hours) increased CHRFAM7A expression by ~1000-fold while having little effect on CHRNA7. A 1-kb sequence in the 5'-UTR of CHRFAM7A was identified as the LPS-responsive regulatory element.","method":"Quantitative RT-PCR in 11 gut epithelial cell lines; LPS stimulation assays; promoter/UTR mapping","journal":"FASEB journal","confidence":"Medium","confidence_rationale":"Tier 2 — differential regulation demonstrated across multiple cell lines with promoter mapping; single lab","pmids":["25681457"],"is_preprint":false},{"year":2019,"finding":"CHRFAM7A blocks α-bungarotoxin ligand binding to both mouse and human α7nAChR. In CHRFAM7A-transgenic mice, CHRFAM7A increased the hematopoietic stem cell (HSC) reservoir in bone marrow and biased HSC differentiation toward the monocyte lineage in vitro. During systemic inflammatory response syndrome (SIRS), HSCs were depleted in wild-type but spared in CHRFAM7A-transgenic mice, while these mice showed increased immune cell mobilization and myeloid differentiation.","method":"CHRFAM7A-transgenic mouse model; α-bungarotoxin binding assay; bone marrow HSC analysis; in vitro HSC differentiation; SIRS model (LPS injection); flow cytometry for immune cell populations","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — in vivo transgenic model with multiple orthogonal readouts (ligand binding, HSC quantification, differentiation assay, in vivo inflammatory model); moderate evidence strength","pmids":["30944217"],"is_preprint":false},{"year":2018,"finding":"CHRFAM7A expression in rat PC12 cells and transgenic mice decreased α-bungarotoxin binding to α7nAChR as measured by immunohistochemistry and flow cytometry. In vivo, α-BTX co-staining with neurofilament at the neuromuscular junction was decreased in CHRFAM7A-transgenic compared to wild-type mice, demonstrating that CHRFAM7A interferes with ligand binding to α7nAChR in vivo.","method":"Stable transfection of PC12 cells; immunohistochemistry; flow cytometry for α-BTX binding; transgenic mouse neuromuscular junction staining with α-BTX and neurofilament antibodies","journal":"Neuroscience letters","confidence":"Medium","confidence_rationale":"Tier 2 — in vitro and in vivo convergent evidence with two orthogonal methods; single lab","pmids":["30308236"],"is_preprint":false},{"year":2019,"finding":"Using iPSC-derived neurons with defined CHRFAM7A copy number (0 copy vs. 1 copy, with rescue controls), CHRFAM7A dosage increased PNU-modulated desensitization of α7nAChR currents and mitigated Aβ1-42 uptake dose-response, suggesting a protective effect. In the presence of CHRFAM7A, Aβ1-42 uptake activated neuronal IL-1β and TNF-α without engaging the canonical inflammasome pathway.","method":"iPSC-derived neurons with genome-editing for CHRFAM7A copy number variation; electrophysiology (α7nAChR current recording); Aβ1-42 uptake assay; cytokine measurement (IL-1β, TNF-α)","journal":"Translational psychiatry","confidence":"High","confidence_rationale":"Tier 1-2 — human iPSC model with controlled genotype, electrophysiology + binding + cytokine readouts; includes rescue control for genetic heterogeneity","pmids":["30710073"],"is_preprint":false},{"year":2020,"finding":"CHRFAM7A gene delivery into THP-1 monocytic cells reduces cell migration, reduces chemotaxis to monocyte chemoattractant protein, and reduces colony formation in soft agar, establishing a direct role for CHRFAM7A in regulating monocyte/macrophage migratory and proliferative behavior.","method":"CHRFAM7A lentiviral transduction of THP-1 cells; Transwell cell migration assay; chemotaxis assay; soft agar colony formation assay","journal":"Inflammation research","confidence":"Medium","confidence_rationale":"Tier 2 — defined cellular loss/gain-of-function with multiple phenotypic readouts; single lab","pmids":["32303780"],"is_preprint":false},{"year":2020,"finding":"In Alzheimer's disease context, using genome-edited iPSCs, the direct and inverted CHRFAM7A alleles have distinct functional phenotypes. Functional CHRFAM7A (direct allele) modifies α7nAChR-mediated Aβ neurotoxicity readout (electrophysiology and Aβ uptake), and pharmacogenetic analysis showed CHRFAM7A carrier status (25% non-carriers vs. 75% carriers) influenced response to AChEI therapy in double-blind AD clinical data.","method":"Genome-edited human iPSC electrophysiology; Aβ uptake assay; double-blind pharmacogenetic analysis of clinical cohort; MMSE outcome measure","journal":"EBioMedicine","confidence":"Medium","confidence_rationale":"Tier 1-2 — iPSC functional data plus double-blind clinical pharmacogenetic study; single group but multiple paradigms","pmids":["32818803"],"is_preprint":false},{"year":2021,"finding":"CHRFAM7A overexpression in OGD/R-treated microglia promoted cell proliferation/viability, reduced NLRP3 inflammasome activation and caspase-1-dependent pyroptosis, and promoted microglia polarization from M1 to M2 phenotype, establishing that CHRFAM7A attenuates neuroinflammation via inhibition of the NLRP3/Caspase-1 pathway.","method":"CHRFAM7A overexpression in microglial cells; OGD/R model; NLRP3/Caspase-1 pathway activation assay; pyroptosis measurement; LDH assay; iNOS/Arg1 phenotype markers","journal":"Inflammation","confidence":"Medium","confidence_rationale":"Tier 2 — defined overexpression with NLRP3 pathway mechanistic readout and phenotypic markers; single lab","pmids":["33405023"],"is_preprint":false},{"year":2021,"finding":"Computational structural modeling of all possible α7/dupα7 pentamer combinations showed that receptors comprising four or more dupα7 subunits are not stable enough to form functional ion channels. Models with dupα7/α7 interfaces are more stable than dupα7/dupα7 interfaces. The optimal stoichiometry of functional dupα7/α7 pentamers should include no more than three dupα7 monomers. Receptors bearing dupα7 subunits showed reduced sensitivity to Aβ42 compared to α7 homopentamers.","method":"Computational modeling; atomistic molecular dynamics and coarse-grain simulations; free energy calculations for Ca2+ conductance; protein-protein docking with α-bungarotoxin and Aβ42","journal":"International journal of molecular sciences","confidence":"Low","confidence_rationale":"Tier 4 — computational predictions without experimental validation in this study","pmids":["34067314"],"is_preprint":false},{"year":2022,"finding":"CHRFAM7A transgenic mice developed more severe structural OA damage and increased mechanical allodynia than wild-type in the destabilization of medial meniscus model, associated with decreased suppression of inflammation by α7nAChR agonist. Dorsal root ganglia of transgenic mice showed increased macrophage infiltration and fractalkine expression, and compromised antinociceptive response to nicotine. Human chondrocytes with two copies of CHRFAM7A had reduced anti-inflammatory responses to nicotine.","method":"CHRFAM7A transgenic mouse OA model (DMM); mechanical allodynia testing; histology; DRG macrophage infiltration; α7nAChR agonist response assay; human chondrocyte cell culture with CNV-based stratification","journal":"Annals of the rheumatic diseases","confidence":"High","confidence_rationale":"Tier 2 — in vivo transgenic model with multiple orthogonal readouts (behavior, histology, cellular) corroborated by human cell data; single group","pmids":["36627169"],"is_preprint":false},{"year":2022,"finding":"CHRFAM7A overexpression in HK-2 renal tubular epithelial cells inhibited TGF-β1-induced epithelial-mesenchymal transition (EMT) and fibrosis-related gene expression by inhibiting TGF-β1/Smad2/3 signaling. In CHRFAM7A transgenic mice with unilateral ureteral obstruction (UUO), transgenic overexpression inhibited UUO-induced renal fibrosis and reduced TGF-β1 and Smad2/3 expression compared to wild-type.","method":"CHRFAM7A transgenic mouse UUO model; in vitro TGF-β1 stimulation of HK-2 cells with CHRFAM7A overexpression; Smad2/3 phosphorylation analysis; fibrosis gene expression; collagen staining","journal":"Journal of cellular and molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo and in vitro convergent evidence with defined signaling pathway mechanism; single lab","pmids":["36479618"],"is_preprint":false},{"year":2024,"finding":"CHRFAM7A/α7nAChR functions as a hypomorphic receptor with mitigated Ca2+ influx and prolonged channel closed state. This shifts the Ca2+ reservoir from extracellular space to the endoplasmic reticulum, activating the Ca2+ decoder small GTPase Rac1, which reorganizes the actin cytoskeleton. Observed actin-mediated phenotypes include altered cellular adhesion, motility, phagocytosis, and tissue mechanosensation in human iPSC-derived and primary monocyte models.","method":"Human iPSC model and primary human monocytes; Ca2+ imaging; electrophysiology (channel gating); Rac1 activation assay; actin cytoskeleton imaging; phagocytosis assay; adhesion and motility assays","journal":"EBioMedicine","confidence":"High","confidence_rationale":"Tier 1-2 — two human model systems (iPSC and primary monocytes), multiple orthogonal mechanistic readouts from receptor to downstream effector; strong mechanistic chain established","pmids":["38569318"],"is_preprint":false},{"year":2024,"finding":"CHRFAM7A overexpression in hiPSC-derived cortical neurons reduced α7nAChR surface expression (ligand binding sites) and lowered levels of chaperones RIC3 and NACHO. In the presence of CHRFAM7A, nicotine treatment upregulated α7nAChR surface binding sites, unlike control neurons. CHRFAM7A reduced baseline ROS levels and abolished Aβ-induced ROS changes in interneurons.","method":"Lentiviral CHRFAM7A overexpression in hiPSC-derived interneurons; α-bungarotoxin binding (surface receptor quantification); RIC3/NACHO Western blotting; ROS measurement; Aβ treatment","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 — human iPSC model with multiple mechanistic readouts; preprint, not yet peer-reviewed","pmids":["bio_10.1101_2024.06.04.597325"],"is_preprint":true},{"year":2024,"finding":"In hiPSC-derived cortical neurons and transgenic mouse superior cervical ganglion neurons expressing CHRFAM7A, dupα7 co-assembles with α7 and reduces calcium transients in response to three different α7-specific ligands (PNU282987, choline, and 4BP-TQS), demonstrating that CHRFAM7A reduces α7nAChR function across multiple agonist mechanisms in physiologically relevant neuronal systems.","method":"Fura-2 calcium imaging in hiPSC-derived cortical neurons and SCG neurons from CHRFAM7A transgenic mice; three α7-specific agonists tested with and without PAM II (PNU120596)","journal":"The European journal of neuroscience","confidence":"High","confidence_rationale":"Tier 1-2 — two distinct neuronal model systems (human iPSC and mouse transgenic neurons), multiple pharmacological ligands, calcium imaging as functional readout; strong mechanistic validation","pmids":["39073048"],"is_preprint":false},{"year":2019,"finding":"Global proteomic profiling of CHRFAM7A transgenic mouse brain by iTRAQ-2D-LC-MS/MS revealed that CHRFAM7A overexpression significantly modulates proteins in signaling pathways associated with Parkinson's disease, Alzheimer's disease, Huntington's disease, and alcoholism, providing evidence that CHRFAM7A contributes to neuropsychiatric disorder pathogenesis through modulation of α7nAChR-related networks in vivo.","method":"CHRFAM7A transgenic mouse brain; iTRAQ-2D-LC-MS/MS proteomics; bioinformatics pathway analysis","journal":"Gene","confidence":"Low","confidence_rationale":"Tier 3 — proteomics provides pathway-level associations but lacks specific mechanistic resolution or functional validation of individual targets","pmids":["31348980"],"is_preprint":false},{"year":2020,"finding":"CHRFAM7A overexpression in a hypertrophic scar mouse model increased activation of the Notch pathway, which reduced M2 macrophage polarization and initially increased M1 macrophages and TNF-α expression, resulting in reduced fibrosis. This identifies Notch pathway activation as a mechanism by which CHRFAM7A regulates macrophage phenotypic transition.","method":"Lentiviral CHRFAM7A overexpression in hypertrophic scar mouse model; Notch pathway analysis; macrophage M1/M2 phenotype markers; histological fibrosis scoring","journal":"Biomedicine & pharmacotherapy","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo model with defined Notch pathway mechanism and macrophage phenotype readout; single lab","pmids":["32890966"],"is_preprint":false},{"year":2025,"finding":"In human fetal cortical organotypic slices and dissociated cultures, CHRFAM7A is expressed in SOX2+ radial glia progenitors and is particularly enriched along radial glia endfeet. nAChR activation increases RG proliferation while decreasing neuronal differentiation; CHRNA7 and CHRFAM7A selectively modulate gene expression changes in excitatory neurons induced by nicotine. YAP1 was identified as a critical downstream effector of nAChR signaling, and inhibiting YAP1 reversed nicotine-induced phenotypic alterations in outer RG cells.","method":"Human fetal cortical organotypic slices and dissociated cultures; nAChR knockdown/activation; single-cell RNA sequencing; YAP1 inhibition experiments","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 — human fetal cortical models with multiple readouts and mechanistic YAP1 epistasis; preprint","pmids":["bio_10.1101_2025.04.10.647795"],"is_preprint":true}],"current_model":"CHRFAM7A encodes a truncated α7 nAChR subunit (dupα7) that co-assembles with full-length α7 subunits to form heteromeric, hypomorphic receptors with mitigated Ca2+ influx and prolonged closed-state kinetics; this dominant-negative inhibition of α7nAChR reduces ACh-evoked currents and α-bungarotoxin ligand binding, shifts Ca2+ dynamics from extracellular influx to ER-mediated signaling, and activates the small GTPase Rac1 to reorganize the actin cytoskeleton, thereby modulating monocyte/macrophage adhesion, motility, phagocytosis, and inflammatory cytokine responses in a human-specific manner."},"narrative":{"teleology":[{"year":2010,"claim":"Establishing that dupα7 is a dominant-negative modulator of α7nAChR resolved how a truncated subunit lacking the ligand-binding domain could nonetheless suppress receptor function — it reduces functional receptor surface expression in a dose-dependent manner.","evidence":"Xenopus oocyte electrophysiology with titrated co-injection of α7 and dupα7 mRNAs, α-bungarotoxin binding, and confocal imaging in HL-60 and GH4C1 cells","pmids":["21047781"],"confidence":"High","gaps":["Stoichiometry of α7/dupα7 pentamers not experimentally determined","Endogenous assembly dynamics in native tissues unknown","Trafficking versus assembly defect not fully resolved"]},{"year":2011,"claim":"Demonstrating that dupα7/α7 heteromers form silent (non-conducting) receptors that retain allosteric modulator sensitivity distinguished between two models: reduced surface expression versus non-functional surface receptors, showing both mechanisms operate.","evidence":"Electrophysiology in oocytes and cell lines with PNU-120596 (type-2 PAM) rescue; radioligand binding with [125I]-α-bungarotoxin","pmids":["21718690"],"confidence":"High","gaps":["Single-channel properties of heteromeric receptors not recorded","Relative contribution of silent receptors versus reduced trafficking not quantified"]},{"year":2011,"claim":"The finding that CHRFAM7A is the predominant transcript in monocytic cells and is downregulated by LPS via NF-κB established it as an inflammation-responsive gene, raising the question of its immune function.","evidence":"RT-PCR, Western blot in THP-1 cells; NF-κB inhibitor parthenolide blocked LPS-induced downregulation","pmids":["20926142"],"confidence":"Medium","gaps":["Direct NF-κB binding to CHRFAM7A promoter not shown by ChIP","Post-transcriptional regulation not explored"]},{"year":2015,"claim":"Identifying a unique 1-kb 5'-UTR regulatory element and showing tissue-specific LPS responsiveness (up to 1000-fold induction in gut epithelia) established that CHRFAM7A has its own transcriptional regulation independent of CHRNA7, enabling context-dependent dominant-negative modulation.","evidence":"Quantitative RT-PCR across 11 gut epithelial lines; promoter/UTR mapping; LPS stimulation in THP-1 and gut lines","pmids":["25681457","25860877"],"confidence":"Medium","gaps":["Transcription factor binding to the 1-kb element not identified","In vivo promoter regulation not confirmed"]},{"year":2018,"claim":"Confirming that CHRFAM7A reduces α-bungarotoxin binding in vivo at mouse neuromuscular junctions extended the dominant-negative mechanism from heterologous systems to intact tissue.","evidence":"CHRFAM7A transgenic mice; α-BTX/neurofilament co-staining at NMJ; flow cytometry in PC12 cells","pmids":["30308236"],"confidence":"Medium","gaps":["NMJ functional consequences (e.g., synaptic transmission) not measured","Whether endogenous human NMJ expresses CHRFAM7A is unknown"]},{"year":2019,"claim":"CHRFAM7A transgenic mice revealed an in vivo hematopoietic function: sparing the HSC reservoir during systemic inflammation and biasing differentiation toward the monocyte lineage, linking the receptor modulation to innate immune cell development.","evidence":"CHRFAM7A transgenic mouse SIRS model; bone marrow HSC quantification; in vitro differentiation assays; flow cytometry","pmids":["30944217"],"confidence":"High","gaps":["Signaling pathway connecting α7nAChR modulation to HSC maintenance not identified","HSC-intrinsic versus niche-mediated effect not distinguished"]},{"year":2019,"claim":"Using iPSC-derived neurons with defined CHRFAM7A copy number demonstrated that CHRFAM7A mitigates Aβ1-42 uptake and activates neuronal IL-1β/TNF-α through a non-canonical (inflammasome-independent) pathway, establishing a neuronal-specific inflammatory response.","evidence":"Genome-edited iPSC-derived neurons; electrophysiology; Aβ uptake assay; cytokine measurement","pmids":["30710073"],"confidence":"High","gaps":["Receptor through which cytokine induction occurs not fully resolved","In vivo neuronal relevance not tested"]},{"year":2020,"claim":"Direct demonstration that CHRFAM7A reduces monocyte migration and chemotaxis established a cellular phenotype linking receptor modulation to innate immune cell behavior.","evidence":"Lentiviral CHRFAM7A transduction of THP-1 cells; Transwell migration and chemotaxis assays; soft agar colony formation","pmids":["32303780"],"confidence":"Medium","gaps":["Downstream signaling pathway mediating migration inhibition not identified at this point","Primary human monocyte validation pending"]},{"year":2020,"claim":"Pharmacogenetic analysis showed that CHRFAM7A carrier status influences clinical response to acetylcholinesterase inhibitor therapy in Alzheimer's disease, providing clinical relevance for the dominant-negative mechanism and distinguishing direct versus inverted alleles.","evidence":"Genome-edited iPSC electrophysiology; double-blind clinical pharmacogenetic analysis of AD cohort with MMSE outcome","pmids":["32818803"],"confidence":"Medium","gaps":["Mechanism by which allele orientation determines function not established","Replication in independent clinical cohort needed","Cohort size limits statistical power"]},{"year":2021,"claim":"CHRFAM7A attenuates microglial pyroptosis by inhibiting the NLRP3/caspase-1 axis and promotes M1-to-M2 polarization, identifying a specific inflammasome pathway suppressed by the hypomorphic receptor.","evidence":"CHRFAM7A overexpression in microglia; OGD/R model; NLRP3/caspase-1 assay; iNOS/Arg1 markers","pmids":["33405023"],"confidence":"Medium","gaps":["Whether NLRP3 inhibition is calcium-dependent or through an alternative mechanism not resolved","Endogenous CHRFAM7A knockdown control absent"]},{"year":2022,"claim":"CHRFAM7A inhibits TGF-β1/Smad2/3 signaling to suppress renal fibrosis in vivo, broadening the downstream pathway repertoire beyond cholinergic anti-inflammatory signaling to fibrotic pathways.","evidence":"CHRFAM7A transgenic mouse UUO model; HK-2 cell TGF-β1 stimulation; Smad2/3 phosphorylation; collagen staining","pmids":["36479618"],"confidence":"Medium","gaps":["Link between α7nAChR modulation and TGF-β pathway not mechanistically connected","Direct versus indirect Smad inhibition unknown"]},{"year":2022,"claim":"In an osteoarthritis model, CHRFAM7A transgenic mice showed worsened joint damage, increased DRG macrophage infiltration, and compromised nicotine-mediated antinociception, establishing that CHRFAM7A modifies inflammatory pain and tissue destruction by limiting cholinergic anti-inflammatory reflex efficacy.","evidence":"CHRFAM7A transgenic mouse DMM model; mechanical allodynia; histology; DRG macrophage analysis; human chondrocyte CNV stratification","pmids":["36627169"],"confidence":"High","gaps":["Whether CHRFAM7A acts peripherally in joint tissue or centrally in DRG not resolved","Human OA clinical association not established"]},{"year":2024,"claim":"The complete mechanistic chain from receptor to effector was established: CHRFAM7A/α7nAChR heteromers have prolonged closed states, shift Ca²⁺ sourcing to ER stores, activate Rac1, and reorganize actin to alter adhesion, motility, and phagocytosis — resolving how a hypomorphic ion channel produces downstream cellular phenotypes.","evidence":"Human iPSC-derived and primary monocytes; Ca²⁺ imaging; electrophysiology; Rac1 activation; actin imaging; phagocytosis/adhesion/motility assays","pmids":["38569318"],"confidence":"High","gaps":["Whether Rac1 activation is solely IP3R-dependent or involves additional Ca²⁺ decoders not tested","In vivo validation of Rac1 pathway in tissue macrophages pending"]},{"year":2024,"claim":"Validation across multiple α7-specific agonists in two neuronal systems confirmed that CHRFAM7A universally reduces α7nAChR calcium transients regardless of agonist mechanism, ruling out ligand-specific artifacts.","evidence":"Fura-2 calcium imaging in hiPSC cortical neurons and CHRFAM7A transgenic mouse SCG neurons with PNU282987, choline, and 4BP-TQS ± PNU120596","pmids":["39073048"],"confidence":"High","gaps":["Native stoichiometry of dupα7/α7 pentamers in human brain tissue not determined","Whether PAM rescue fully restores physiological signaling unclear"]},{"year":null,"claim":"The precise stoichiometry of functional dupα7/α7 pentamers in native human tissues, the structural basis for channel silencing, and the in vivo contribution of the Rac1/actin pathway to immune and neurological phenotypes remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No cryo-EM or X-ray structure of dupα7/α7 heteromeric receptor","Endogenous stoichiometry in human brain/immune cells not determined","Conditional knockout/knockdown in human-relevant models needed to separate gain- from loss-of-function"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,14,16]},{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[0,1,14]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1,5,6,16]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[5,8,10,12,18]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,13,14]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[7,9,16]}],"complexes":["α7nAChR heteromeric receptor (dupα7/α7 pentamer)"],"partners":["CHRNA7","RAC1","NLRP3","SMAD2","SMAD3"],"other_free_text":[]},"mechanistic_narrative":"CHRFAM7A is a human-specific gene encoding a truncated α7 nicotinic acetylcholine receptor subunit (dupα7) that co-assembles with full-length α7 subunits to form hypomorphic heteromeric receptors with dominant-negative properties, reducing ACh-evoked currents and α-bungarotoxin binding in a dose-dependent manner [PMID:21047781, PMID:21718690, PMID:39073048]. The resulting receptor has mitigated Ca²⁺ influx and prolonged closed-state kinetics, shifting the Ca²⁺ source from extracellular space to the endoplasmic reticulum, which activates the small GTPase Rac1 and reorganizes the actin cytoskeleton to alter monocyte adhesion, motility, and phagocytosis [PMID:38569318]. CHRFAM7A expression is dynamically regulated by NF-κB and LPS in monocytes and gut epithelia [PMID:20926142, PMID:25681457], and its presence modulates inflammatory responses including NLRP3/caspase-1 pyroptosis in microglia, macrophage polarization via Notch signaling, TGF-β1/Smad2/3-driven fibrosis, and hematopoietic stem cell differentiation toward the myeloid lineage [PMID:33405023, PMID:32890966, PMID:36479618, PMID:30944217]. In neurons, CHRFAM7A reduces α7nAChR-mediated calcium transients across multiple agonists, mitigates Aβ1-42 uptake and neurotoxicity, and modifies pharmacogenetic responses to acetylcholinesterase inhibitor therapy in Alzheimer's disease [PMID:39073048, PMID:30710073, PMID:32818803]."},"prefetch_data":{"uniprot":{"accession":"Q494W8","full_name":"CHRNA7-FAM7A fusion protein","aliases":["CHRNA7-DR1","D-10"],"length_aa":412,"mass_kda":46.2,"function":"","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/Q494W8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CHRFAM7A","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1047,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CHRFAM7A","total_profiled":1310},"omim":[{"mim_id":"613025","title":"SCHIZOPHRENIA 13; SCZD13","url":"https://www.omim.org/entry/613025"},{"mim_id":"612001","title":"CHROMOSOME 15q13.3 DELETION SYNDROME","url":"https://www.omim.org/entry/612001"},{"mim_id":"609756","title":"CHRNA7/FAM7A FUSION GENE; CHRFAM7A","url":"https://www.omim.org/entry/609756"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"bone marrow","ntpm":4.1},{"tissue":"parathyroid gland","ntpm":5.3}],"url":"https://www.proteinatlas.org/search/CHRFAM7A"},"hgnc":{"alias_symbol":["D-10","CHRNA7-DR1"],"prev_symbol":[]},"alphafold":{"accession":"Q494W8","domains":[{"cath_id":"2.70.170.10","chopping":"2-139","consensus_level":"medium","plddt":73.6486,"start":2,"end":139},{"cath_id":"1.20.58,1.20.58","chopping":"144-256_380-412","consensus_level":"high","plddt":76.4264,"start":144,"end":412}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q494W8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q494W8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q494W8-F1-predicted_aligned_error_v6.png","plddt_mean":68.94},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CHRFAM7A","jax_strain_url":"https://www.jax.org/strain/search?query=CHRFAM7A"},"sequence":{"accession":"Q494W8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q494W8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q494W8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q494W8"}},"corpus_meta":[{"pmid":"25701707","id":"PMC_25701707","title":"The human CHRNA7 and CHRFAM7A genes: A review of the genetics, regulation, and function.","date":"2015","source":"Neuropharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/25701707","citation_count":146,"is_preprint":false},{"pmid":"21718690","id":"PMC_21718690","title":"The chimeric gene CHRFAM7A, a partial duplication of the CHRNA7 gene, is a dominant negative regulator of α7*nAChR function.","date":"2011","source":"Biochemical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/21718690","citation_count":111,"is_preprint":false},{"pmid":"21047781","id":"PMC_21047781","title":"Function of partially duplicated human α77 nicotinic receptor subunit CHRFAM7A gene: potential implications for the cholinergic anti-inflammatory response.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21047781","citation_count":110,"is_preprint":false},{"pmid":"24219032","id":"PMC_24219032","title":"miR-224 promotion of cell migration and invasion by targeting Homeobox D 10 gene in human hepatocellular carcinoma.","date":"2014","source":"Journal of gastroenterology and hepatology","url":"https://pubmed.ncbi.nlm.nih.gov/24219032","citation_count":82,"is_preprint":false},{"pmid":"19631623","id":"PMC_19631623","title":"A 2-base pair deletion polymorphism in the partial duplication of the alpha7 nicotinic acetylcholine gene (CHRFAM7A) on chromosome 15q14 is associated with schizophrenia.","date":"2009","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/19631623","citation_count":78,"is_preprint":false},{"pmid":"16823804","id":"PMC_16823804","title":"Association study of CHRFAM7A copy number and 2 bp deletion polymorphisms with schizophrenia and bipolar affective disorder.","date":"2006","source":"American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/16823804","citation_count":66,"is_preprint":false},{"pmid":"20926142","id":"PMC_20926142","title":"Expression of the α7 nAChR subunit duplicate form (CHRFAM7A) is down-regulated in the monocytic cell line THP-1 on treatment with LPS.","date":"2011","source":"Journal of neuroimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/20926142","citation_count":55,"is_preprint":false},{"pmid":"25473097","id":"PMC_25473097","title":"CHRFAM7A, a human-specific and partially duplicated α7-nicotinic acetylcholine receptor gene with the potential to specify a human-specific inflammatory response to injury.","date":"2014","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/25473097","citation_count":45,"is_preprint":false},{"pmid":"33405023","id":"PMC_33405023","title":"CHRFAM7A Overexpression Attenuates Cerebral Ischemia-Reperfusion Injury via Inhibiting Microglia Pyroptosis Mediated by the NLRP3/Caspase-1 pathway.","date":"2021","source":"Inflammation","url":"https://pubmed.ncbi.nlm.nih.gov/33405023","citation_count":42,"is_preprint":false},{"pmid":"25860877","id":"PMC_25860877","title":"A Human-Specific α7-Nicotinic Acetylcholine Receptor Gene in Human Leukocytes: Identification, Regulation and the Consequences of CHRFAM7A Expression.","date":"2015","source":"Molecular medicine (Cambridge, Mass.)","url":"https://pubmed.ncbi.nlm.nih.gov/25860877","citation_count":36,"is_preprint":false},{"pmid":"31048268","id":"PMC_31048268","title":"Effect of donepezil on the expression and responsiveness to LPS of CHRNA7 and CHRFAM7A in macrophages: A possible link to the cholinergic anti-inflammatory pathway.","date":"2019","source":"Journal of neuroimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/31048268","citation_count":35,"is_preprint":false},{"pmid":"30944217","id":"PMC_30944217","title":"Uniquely human CHRFAM7A gene increases the hematopoietic stem cell reservoir in mice and amplifies their inflammatory response.","date":"2019","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/30944217","citation_count":33,"is_preprint":false},{"pmid":"25681457","id":"PMC_25681457","title":"CHRFAM7A: a human-specific α7-nicotinic acetylcholine receptor gene shows differential responsiveness of human intestinal epithelial cells to LPS.","date":"2015","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/25681457","citation_count":29,"is_preprint":false},{"pmid":"34076297","id":"PMC_34076297","title":"Gene Therapy Using Adeno-Associated Virus Serotype 8 Encoding TNAP-D10 Improves the Skeletal and Dentoalveolar Phenotypes in Alpl-/- Mice.","date":"2021","source":"Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research","url":"https://pubmed.ncbi.nlm.nih.gov/34076297","citation_count":26,"is_preprint":false},{"pmid":"35408823","id":"PMC_35408823","title":"The Human-Restricted Isoform of the α7 nAChR, CHRFAM7A: A Double-Edged Sword in Neurological and Inflammatory Disorders.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35408823","citation_count":24,"is_preprint":false},{"pmid":"30710073","id":"PMC_30710073","title":"iPSC model of CHRFAM7A effect on α7 nicotinic acetylcholine receptor function in the human context.","date":"2019","source":"Translational psychiatry","url":"https://pubmed.ncbi.nlm.nih.gov/30710073","citation_count":23,"is_preprint":false},{"pmid":"27051591","id":"PMC_27051591","title":"Up-regulation of the human-specific CHRFAM7A gene in inflammatory bowel disease.","date":"2016","source":"BBA clinical","url":"https://pubmed.ncbi.nlm.nih.gov/27051591","citation_count":23,"is_preprint":false},{"pmid":"32818803","id":"PMC_32818803","title":"CHRFAM7A: A human specific fusion gene, accounts for the translational gap for cholinergic strategies in Alzheimer's disease.","date":"2020","source":"EBioMedicine","url":"https://pubmed.ncbi.nlm.nih.gov/32818803","citation_count":23,"is_preprint":false},{"pmid":"31909606","id":"PMC_31909606","title":"Europium(III) Photoluminescence Governed by d8-d10 Heterometallophilic Interactions in Trimetallic Cyanido-Bridged Coordination Frameworks.","date":"2020","source":"Inorganic chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31909606","citation_count":23,"is_preprint":false},{"pmid":"26567012","id":"PMC_26567012","title":"Expression of CHRFAM7A and CHRNA7 in neuronal cells and postmortem brain of HIV-infected patients: considerations for HIV-associated neurocognitive disorder.","date":"2015","source":"Journal of neurovirology","url":"https://pubmed.ncbi.nlm.nih.gov/26567012","citation_count":19,"is_preprint":false},{"pmid":"30924722","id":"PMC_30924722","title":"Association of a Functional Polymorphism in the CHRFAM7A Gene with Inflammatory Response Mediators and Neuropathic Pain after Spinal Cord Injury.","date":"2019","source":"Journal of neurotrauma","url":"https://pubmed.ncbi.nlm.nih.gov/30924722","citation_count":18,"is_preprint":false},{"pmid":"36627169","id":"PMC_36627169","title":"Human-specific duplicate CHRFAM7A gene is associated with more severe osteoarthritis and amplifies pain behaviours.","date":"2023","source":"Annals of the rheumatic diseases","url":"https://pubmed.ncbi.nlm.nih.gov/36627169","citation_count":17,"is_preprint":false},{"pmid":"30308236","id":"PMC_30308236","title":"CHRFAM7A alters binding to the neuronal alpha-7 nicotinic acetylcholine receptor.","date":"2018","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/30308236","citation_count":17,"is_preprint":false},{"pmid":"32890966","id":"PMC_32890966","title":"Human-specific gene CHRFAM7A mediates M2 macrophage polarization via the Notch pathway to ameliorate hypertrophic scar formation.","date":"2020","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/32890966","citation_count":17,"is_preprint":false},{"pmid":"11671099","id":"PMC_11671099","title":"UVRR Spectroscopy and Vibrational Analysis of Mercury Thiolate Compounds Resembling d(10) Metal Binding Sites in Proteins.","date":"1999","source":"Inorganic chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11671099","citation_count":17,"is_preprint":false},{"pmid":"36699639","id":"PMC_36699639","title":"Gene Therapy Using Recombinant AAV Type 8 Vector Encoding TNAP-D10 Improves the Skeletal Phenotypes in Murine Models of Osteomalacia.","date":"2022","source":"JBMR plus","url":"https://pubmed.ncbi.nlm.nih.gov/36699639","citation_count":16,"is_preprint":false},{"pmid":"31348980","id":"PMC_31348980","title":"Global proteomic profiling of the uniquely human CHRFAM7A gene in transgenic mouse brain.","date":"2019","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/31348980","citation_count":15,"is_preprint":false},{"pmid":"19082523","id":"PMC_19082523","title":"Differentiating nicotine- versus schizophrenia-associated decreases of the alpha7 nicotinic acetylcholine receptor transcript, CHRFAM7A, in peripheral blood lymphocytes.","date":"2008","source":"Journal of neural transmission (Vienna, Austria : 1996)","url":"https://pubmed.ncbi.nlm.nih.gov/19082523","citation_count":15,"is_preprint":false},{"pmid":"24024466","id":"PMC_24024466","title":"Association study of the 2-bp deletion polymorphism in exon 6 of the CHRFAM7A gene with idiopathic generalized epilepsy.","date":"2013","source":"DNA and cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/24024466","citation_count":15,"is_preprint":false},{"pmid":"32303780","id":"PMC_32303780","title":"CHRFAM7A reduces monocyte/macrophage migration and colony formation in vitro.","date":"2020","source":"Inflammation research : official journal of the European Histamine Research Society ... [et al.]","url":"https://pubmed.ncbi.nlm.nih.gov/32303780","citation_count":14,"is_preprint":false},{"pmid":"25597537","id":"PMC_25597537","title":"Synthesis and characterization of substituted Schiff-base ligands and their d(10) metal complexes: structure-induced luminescence tuning behaviors and applications in co-sensitized solar cells.","date":"2015","source":"Dalton transactions (Cambridge, England : 2003)","url":"https://pubmed.ncbi.nlm.nih.gov/25597537","citation_count":13,"is_preprint":false},{"pmid":"7507145","id":"PMC_7507145","title":"In vitro immunization of mouse spleen cells for the production of monoclonal IgG1 antibodies using an antigen-specific T helper cell clone (D.10.G4.1).","date":"1993","source":"Journal of immunological methods","url":"https://pubmed.ncbi.nlm.nih.gov/7507145","citation_count":12,"is_preprint":false},{"pmid":"30089821","id":"PMC_30089821","title":"Genetic variation in CHRNA7 and CHRFAM7A is associated with nicotine dependence and response to varenicline treatment.","date":"2018","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/30089821","citation_count":11,"is_preprint":false},{"pmid":"19016554","id":"PMC_19016554","title":"Preferential formation of homochiral helical sandwich-shaped architectures through the metal-mediated assembly of tris(imidazoline) ligands with a set of d(3)-d(10) transition-metal ions.","date":"2008","source":"Chemistry (Weinheim an der Bergstrasse, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/19016554","citation_count":11,"is_preprint":false},{"pmid":"21030862","id":"PMC_21030862","title":"Automated ERCC1 immunohistochemistry in non-small cell lung cancer: comparison of anti-ERCC1 antibodies 8F1, D-10, and FL-297.","date":"2011","source":"Applied immunohistochemistry & molecular morphology : AIMM","url":"https://pubmed.ncbi.nlm.nih.gov/21030862","citation_count":11,"is_preprint":false},{"pmid":"31966770","id":"PMC_31966770","title":"Human-specific CHRFAM7A protects against radiotherapy-induced lacrimal gland injury by inhibiting the p38/JNK signalling pathway and oxidative stress.","date":"2017","source":"International journal of clinical and experimental pathology","url":"https://pubmed.ncbi.nlm.nih.gov/31966770","citation_count":10,"is_preprint":false},{"pmid":"35344211","id":"PMC_35344211","title":"Polymorphisms in alpha 7 nicotinic acetylcholine receptor gene, CHRNA7, and its partially duplicated gene, CHRFAM7A, associate with increased inflammatory response in human peripheral mononuclear cells.","date":"2022","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/35344211","citation_count":9,"is_preprint":false},{"pmid":"36479618","id":"PMC_36479618","title":"Up-regulation of the human-specific CHRFAM7A gene protects against renal fibrosis in mice with obstructive nephropathy.","date":"2022","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/36479618","citation_count":8,"is_preprint":false},{"pmid":"19149910","id":"PMC_19149910","title":"CHRFAM7A copy number and 2-bp deletion polymorphisms and antisaccade performance.","date":"2009","source":"The international journal of neuropsychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/19149910","citation_count":8,"is_preprint":false},{"pmid":"33956875","id":"PMC_33956875","title":"Effect of CHRFAM7A Δ2bp gene variant on secondary inflammation after spinal cord injury.","date":"2021","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/33956875","citation_count":8,"is_preprint":false},{"pmid":"11666593","id":"PMC_11666593","title":"Mono- and Dinuclear d(10) Metal Complexes of Hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene. Synthesis, Structures, and Unusual Solution Dynamic Behavior.","date":"1996","source":"Inorganic chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11666593","citation_count":8,"is_preprint":false},{"pmid":"38200291","id":"PMC_38200291","title":"Translational implications of CHRFAM7A, an elusive human-restricted fusion gene.","date":"2024","source":"Molecular psychiatry","url":"https://pubmed.ncbi.nlm.nih.gov/38200291","citation_count":7,"is_preprint":false},{"pmid":"34792616","id":"PMC_34792616","title":"CHRFAM7A expression in mice increases resiliency after injury.","date":"2021","source":"Inflammation research : official journal of the European Histamine Research Society ... [et al.]","url":"https://pubmed.ncbi.nlm.nih.gov/34792616","citation_count":7,"is_preprint":false},{"pmid":"21961533","id":"PMC_21961533","title":"Automated ERCC1 immunochemistry on hybrid cytology/tissue microarray of malignant effusions: evaluation of antibodies 8F1 and D-10.","date":"2011","source":"Journal of clinical bioinformatics","url":"https://pubmed.ncbi.nlm.nih.gov/21961533","citation_count":6,"is_preprint":false},{"pmid":"34067314","id":"PMC_34067314","title":"Structure, Dynamics, and Ligand Recognition of Human-Specific CHRFAM7A (Dupα7) Nicotinic Receptor Linked to Neuropsychiatric Disorders.","date":"2021","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34067314","citation_count":5,"is_preprint":false},{"pmid":"37164281","id":"PMC_37164281","title":"Unanswered questions in the regulation and function of the duplicated α7 nicotinic receptor gene CHRFAM7A.","date":"2023","source":"Pharmacological research","url":"https://pubmed.ncbi.nlm.nih.gov/37164281","citation_count":5,"is_preprint":false},{"pmid":"35100606","id":"PMC_35100606","title":"Expression of the α7 nAChR Subunit Duplicate Form (CHRFAM7A) Was Down-Regulated in Patients with Intracranial Infection and Reduced Inflammation in in vitro Model by p38 MAPK.","date":"2022","source":"Neuroimmunomodulation","url":"https://pubmed.ncbi.nlm.nih.gov/35100606","citation_count":4,"is_preprint":false},{"pmid":"37569633","id":"PMC_37569633","title":"GTS-21 Enhances Regulatory T Cell Development from T Cell Receptor-Activated Human CD4+ T Cells Exhibiting Varied Levels of CHRNA7 and CHRFAM7A Expression.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/37569633","citation_count":4,"is_preprint":false},{"pmid":"38569318","id":"PMC_38569318","title":"CHRFAM7A diversifies human immune adaption through Ca2+ signalling and actin cytoskeleton reorganization.","date":"2024","source":"EBioMedicine","url":"https://pubmed.ncbi.nlm.nih.gov/38569318","citation_count":3,"is_preprint":false},{"pmid":"37655479","id":"PMC_37655479","title":"Human-specific CHRFAM7A primes macrophages for a heightened pro-inflammatory response at the earlier stage of inflammation.","date":"2023","source":"Cell biology international","url":"https://pubmed.ncbi.nlm.nih.gov/37655479","citation_count":2,"is_preprint":false},{"pmid":"36831101","id":"PMC_36831101","title":"Effects of Different Exercise Types on Chrna7 and Chrfam7a Expression in Healthy Normal Weight and Overweight Type 2 Diabetic Adults.","date":"2023","source":"Biomedicines","url":"https://pubmed.ncbi.nlm.nih.gov/36831101","citation_count":2,"is_preprint":false},{"pmid":"38711941","id":"PMC_38711941","title":"Human restricted CHRFAM7A gene increases brain efficiency.","date":"2024","source":"Frontiers in neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/38711941","citation_count":1,"is_preprint":false},{"pmid":"39073048","id":"PMC_39073048","title":"The human-specific nicotinic receptor subunit CHRFAM7A reduces α7 receptor function in human induced pluripotent stem cells-derived and transgenic mouse neurons.","date":"2024","source":"The European journal of neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/39073048","citation_count":1,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.10.03.680410","title":"Influence of  <i>cis</i>  -regulatory elements on expression divergence in human segmental duplications","date":"2025-10-05","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.03.680410","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.04.10.647795","title":"α7 nicotinic acetylcholine receptors regulate radial glia fate in the developing human cortex","date":"2025-04-10","source":"bioRxiv","url":"https://doi.org/10.1101/2025.04.10.647795","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.06.04.597325","title":"<i>CHRFAM7A</i>overexpression in human iPSC-derived Interneurons dysregulates α7- nAChR surface expression and alters response to oligomeric β-amyloid peptide","date":"2024-06-05","source":"bioRxiv","url":"https://doi.org/10.1101/2024.06.04.597325","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.05.15.594305","title":"Predicting “pain genes”: multi-modal data integration using probabilistic classifiers and interaction networks","date":"2024-05-17","source":"bioRxiv","url":"https://doi.org/10.1101/2024.05.15.594305","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.12.17.24319167","title":"Delirium and High Sedation Levels are Common in Critically Ill Patients with COVID-19 and Associated with Poor Long-Term Outcomes","date":"2024-12-19","source":"bioRxiv","url":"https://doi.org/10.1101/2024.12.17.24319167","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":34110,"output_tokens":5809,"usd":0.094732},"stage2":{"model":"claude-opus-4-6","input_tokens":9575,"output_tokens":3643,"usd":0.208425},"total_usd":0.303157,"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\": 2011,\n      \"finding\": \"CHRFAM7A (dupα7) protein assembles with α7 subunits to form non-functional (ACh-silent) heteromeric receptors; co-expression in cell lines and Xenopus oocytes caused significant reduction in ACh-evoked current amplitude without reducing α-bungarotoxin binding, indicating dominant-negative modulation through formation of receptors that cannot open in response to ACh. PNU-120596 (type-2 PAM) rescued currents more in cells expressing dupα7, consistent with silent receptors retaining PAM sensitivity.\",\n      \"method\": \"Functional electrophysiology in Xenopus oocytes and cell lines; co-expression of α7 and dupα7; radioligand binding with [125I]-α-bungarotoxin; allosteric modulator (PNU-120596) rescue assay\",\n      \"journal\": \"Biochemical pharmacology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstituted in heterologous expression systems with multiple orthogonal functional readouts (electrophysiology + ligand binding + pharmacological rescue), replicated across two systems\",\n      \"pmids\": [\"21718690\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"dupα7 (CHRFAM7A product) co-injected with α7 mRNA in Xenopus oocytes reduced nicotine-evoked α7 currents in a dose-dependent manner (up to 94% reduction at 1:10 α7/dupα7 ratio), primarily by reducing the number of functional α7 receptors reaching the membrane, as demonstrated by α-bungarotoxin binding and fluorescent confocal assays. dupα7 protein was natively translated in HL-60 cells and heterologously expressed in GH4C1 cells and oocytes.\",\n      \"method\": \"Xenopus oocyte electrophysiology; α-bungarotoxin binding; fluorescent confocal microscopy; Western blot protein detection in HL-60 and GH4C1 cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstituted in Xenopus oocytes with multiple orthogonal methods (electrophysiology, binding, imaging), corroborates PMID 21718690\",\n      \"pmids\": [\"21047781\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CHRFAM7A transcript and protein are exclusively expressed (not the full-length α7) in THP-1 monocytic cells. LPS challenge reduces CHRFAM7A mRNA and protein levels in THP-1 cells via a direct NF-κB-dependent transcriptional mechanism, as demonstrated by the NF-κB inhibitor parthenolide preventing transcript reduction.\",\n      \"method\": \"Qualitative PCR, real-time PCR, Western blotting in monocytic cell lines; NF-κB inhibitor (parthenolide) treatment\",\n      \"journal\": \"Journal of neuroimmunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean expression/functional data in cell lines with pharmacological inhibitor mechanistic follow-up; single lab\",\n      \"pmids\": [\"20926142\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Stable CHRFAM7A overexpression in THP-1 human leukocyte cells alters cell phenotype and modifies expression of genes associated with focal adhesion (FAK, PI3K, Akt, Rho, GEF, Elk1, CycD), leukocyte transepithelial migration (Nox, ITG, MMPs, PKC) and cancer pathways. Unexpectedly, CHRFAM7A overexpression upregulated CHRNA7, leading to increased α-bungarotoxin binding on the THP-1 cell surface. A unique 1-kb sequence in the 5'-UTR independently regulates CHRFAM7A gene expression.\",\n      \"method\": \"Stable transfection/overexpression in THP-1 cells; gene expression profiling; α-bungarotoxin binding assay; promoter mapping\",\n      \"journal\": \"Molecular medicine (Cambridge, Mass.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal readouts (gene expression, ligand binding, promoter mapping) in a defined cellular model; single lab\",\n      \"pmids\": [\"25860877\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"CHRFAM7A is expressed in human gut epithelial cells; its expression varies up to 5000-fold between different gut epithelial lines. LPS treatment (100 ng/ml, 3 hours) increased CHRFAM7A expression by ~1000-fold while having little effect on CHRNA7. A 1-kb sequence in the 5'-UTR of CHRFAM7A was identified as the LPS-responsive regulatory element.\",\n      \"method\": \"Quantitative RT-PCR in 11 gut epithelial cell lines; LPS stimulation assays; promoter/UTR mapping\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — differential regulation demonstrated across multiple cell lines with promoter mapping; single lab\",\n      \"pmids\": [\"25681457\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CHRFAM7A blocks α-bungarotoxin ligand binding to both mouse and human α7nAChR. In CHRFAM7A-transgenic mice, CHRFAM7A increased the hematopoietic stem cell (HSC) reservoir in bone marrow and biased HSC differentiation toward the monocyte lineage in vitro. During systemic inflammatory response syndrome (SIRS), HSCs were depleted in wild-type but spared in CHRFAM7A-transgenic mice, while these mice showed increased immune cell mobilization and myeloid differentiation.\",\n      \"method\": \"CHRFAM7A-transgenic mouse model; α-bungarotoxin binding assay; bone marrow HSC analysis; in vitro HSC differentiation; SIRS model (LPS injection); flow cytometry for immune cell populations\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — in vivo transgenic model with multiple orthogonal readouts (ligand binding, HSC quantification, differentiation assay, in vivo inflammatory model); moderate evidence strength\",\n      \"pmids\": [\"30944217\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CHRFAM7A expression in rat PC12 cells and transgenic mice decreased α-bungarotoxin binding to α7nAChR as measured by immunohistochemistry and flow cytometry. In vivo, α-BTX co-staining with neurofilament at the neuromuscular junction was decreased in CHRFAM7A-transgenic compared to wild-type mice, demonstrating that CHRFAM7A interferes with ligand binding to α7nAChR in vivo.\",\n      \"method\": \"Stable transfection of PC12 cells; immunohistochemistry; flow cytometry for α-BTX binding; transgenic mouse neuromuscular junction staining with α-BTX and neurofilament antibodies\",\n      \"journal\": \"Neuroscience letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro and in vivo convergent evidence with two orthogonal methods; single lab\",\n      \"pmids\": [\"30308236\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Using iPSC-derived neurons with defined CHRFAM7A copy number (0 copy vs. 1 copy, with rescue controls), CHRFAM7A dosage increased PNU-modulated desensitization of α7nAChR currents and mitigated Aβ1-42 uptake dose-response, suggesting a protective effect. In the presence of CHRFAM7A, Aβ1-42 uptake activated neuronal IL-1β and TNF-α without engaging the canonical inflammasome pathway.\",\n      \"method\": \"iPSC-derived neurons with genome-editing for CHRFAM7A copy number variation; electrophysiology (α7nAChR current recording); Aβ1-42 uptake assay; cytokine measurement (IL-1β, TNF-α)\",\n      \"journal\": \"Translational psychiatry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — human iPSC model with controlled genotype, electrophysiology + binding + cytokine readouts; includes rescue control for genetic heterogeneity\",\n      \"pmids\": [\"30710073\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CHRFAM7A gene delivery into THP-1 monocytic cells reduces cell migration, reduces chemotaxis to monocyte chemoattractant protein, and reduces colony formation in soft agar, establishing a direct role for CHRFAM7A in regulating monocyte/macrophage migratory and proliferative behavior.\",\n      \"method\": \"CHRFAM7A lentiviral transduction of THP-1 cells; Transwell cell migration assay; chemotaxis assay; soft agar colony formation assay\",\n      \"journal\": \"Inflammation research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — defined cellular loss/gain-of-function with multiple phenotypic readouts; single lab\",\n      \"pmids\": [\"32303780\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"In Alzheimer's disease context, using genome-edited iPSCs, the direct and inverted CHRFAM7A alleles have distinct functional phenotypes. Functional CHRFAM7A (direct allele) modifies α7nAChR-mediated Aβ neurotoxicity readout (electrophysiology and Aβ uptake), and pharmacogenetic analysis showed CHRFAM7A carrier status (25% non-carriers vs. 75% carriers) influenced response to AChEI therapy in double-blind AD clinical data.\",\n      \"method\": \"Genome-edited human iPSC electrophysiology; Aβ uptake assay; double-blind pharmacogenetic analysis of clinical cohort; MMSE outcome measure\",\n      \"journal\": \"EBioMedicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 — iPSC functional data plus double-blind clinical pharmacogenetic study; single group but multiple paradigms\",\n      \"pmids\": [\"32818803\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CHRFAM7A overexpression in OGD/R-treated microglia promoted cell proliferation/viability, reduced NLRP3 inflammasome activation and caspase-1-dependent pyroptosis, and promoted microglia polarization from M1 to M2 phenotype, establishing that CHRFAM7A attenuates neuroinflammation via inhibition of the NLRP3/Caspase-1 pathway.\",\n      \"method\": \"CHRFAM7A overexpression in microglial cells; OGD/R model; NLRP3/Caspase-1 pathway activation assay; pyroptosis measurement; LDH assay; iNOS/Arg1 phenotype markers\",\n      \"journal\": \"Inflammation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — defined overexpression with NLRP3 pathway mechanistic readout and phenotypic markers; single lab\",\n      \"pmids\": [\"33405023\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Computational structural modeling of all possible α7/dupα7 pentamer combinations showed that receptors comprising four or more dupα7 subunits are not stable enough to form functional ion channels. Models with dupα7/α7 interfaces are more stable than dupα7/dupα7 interfaces. The optimal stoichiometry of functional dupα7/α7 pentamers should include no more than three dupα7 monomers. Receptors bearing dupα7 subunits showed reduced sensitivity to Aβ42 compared to α7 homopentamers.\",\n      \"method\": \"Computational modeling; atomistic molecular dynamics and coarse-grain simulations; free energy calculations for Ca2+ conductance; protein-protein docking with α-bungarotoxin and Aβ42\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 — computational predictions without experimental validation in this study\",\n      \"pmids\": [\"34067314\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CHRFAM7A transgenic mice developed more severe structural OA damage and increased mechanical allodynia than wild-type in the destabilization of medial meniscus model, associated with decreased suppression of inflammation by α7nAChR agonist. Dorsal root ganglia of transgenic mice showed increased macrophage infiltration and fractalkine expression, and compromised antinociceptive response to nicotine. Human chondrocytes with two copies of CHRFAM7A had reduced anti-inflammatory responses to nicotine.\",\n      \"method\": \"CHRFAM7A transgenic mouse OA model (DMM); mechanical allodynia testing; histology; DRG macrophage infiltration; α7nAChR agonist response assay; human chondrocyte cell culture with CNV-based stratification\",\n      \"journal\": \"Annals of the rheumatic diseases\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — in vivo transgenic model with multiple orthogonal readouts (behavior, histology, cellular) corroborated by human cell data; single group\",\n      \"pmids\": [\"36627169\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CHRFAM7A overexpression in HK-2 renal tubular epithelial cells inhibited TGF-β1-induced epithelial-mesenchymal transition (EMT) and fibrosis-related gene expression by inhibiting TGF-β1/Smad2/3 signaling. In CHRFAM7A transgenic mice with unilateral ureteral obstruction (UUO), transgenic overexpression inhibited UUO-induced renal fibrosis and reduced TGF-β1 and Smad2/3 expression compared to wild-type.\",\n      \"method\": \"CHRFAM7A transgenic mouse UUO model; in vitro TGF-β1 stimulation of HK-2 cells with CHRFAM7A overexpression; Smad2/3 phosphorylation analysis; fibrosis gene expression; collagen staining\",\n      \"journal\": \"Journal of cellular and molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo and in vitro convergent evidence with defined signaling pathway mechanism; single lab\",\n      \"pmids\": [\"36479618\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CHRFAM7A/α7nAChR functions as a hypomorphic receptor with mitigated Ca2+ influx and prolonged channel closed state. This shifts the Ca2+ reservoir from extracellular space to the endoplasmic reticulum, activating the Ca2+ decoder small GTPase Rac1, which reorganizes the actin cytoskeleton. Observed actin-mediated phenotypes include altered cellular adhesion, motility, phagocytosis, and tissue mechanosensation in human iPSC-derived and primary monocyte models.\",\n      \"method\": \"Human iPSC model and primary human monocytes; Ca2+ imaging; electrophysiology (channel gating); Rac1 activation assay; actin cytoskeleton imaging; phagocytosis assay; adhesion and motility assays\",\n      \"journal\": \"EBioMedicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — two human model systems (iPSC and primary monocytes), multiple orthogonal mechanistic readouts from receptor to downstream effector; strong mechanistic chain established\",\n      \"pmids\": [\"38569318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CHRFAM7A overexpression in hiPSC-derived cortical neurons reduced α7nAChR surface expression (ligand binding sites) and lowered levels of chaperones RIC3 and NACHO. In the presence of CHRFAM7A, nicotine treatment upregulated α7nAChR surface binding sites, unlike control neurons. CHRFAM7A reduced baseline ROS levels and abolished Aβ-induced ROS changes in interneurons.\",\n      \"method\": \"Lentiviral CHRFAM7A overexpression in hiPSC-derived interneurons; α-bungarotoxin binding (surface receptor quantification); RIC3/NACHO Western blotting; ROS measurement; Aβ treatment\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — human iPSC model with multiple mechanistic readouts; preprint, not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2024.06.04.597325\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In hiPSC-derived cortical neurons and transgenic mouse superior cervical ganglion neurons expressing CHRFAM7A, dupα7 co-assembles with α7 and reduces calcium transients in response to three different α7-specific ligands (PNU282987, choline, and 4BP-TQS), demonstrating that CHRFAM7A reduces α7nAChR function across multiple agonist mechanisms in physiologically relevant neuronal systems.\",\n      \"method\": \"Fura-2 calcium imaging in hiPSC-derived cortical neurons and SCG neurons from CHRFAM7A transgenic mice; three α7-specific agonists tested with and without PAM II (PNU120596)\",\n      \"journal\": \"The European journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — two distinct neuronal model systems (human iPSC and mouse transgenic neurons), multiple pharmacological ligands, calcium imaging as functional readout; strong mechanistic validation\",\n      \"pmids\": [\"39073048\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Global proteomic profiling of CHRFAM7A transgenic mouse brain by iTRAQ-2D-LC-MS/MS revealed that CHRFAM7A overexpression significantly modulates proteins in signaling pathways associated with Parkinson's disease, Alzheimer's disease, Huntington's disease, and alcoholism, providing evidence that CHRFAM7A contributes to neuropsychiatric disorder pathogenesis through modulation of α7nAChR-related networks in vivo.\",\n      \"method\": \"CHRFAM7A transgenic mouse brain; iTRAQ-2D-LC-MS/MS proteomics; bioinformatics pathway analysis\",\n      \"journal\": \"Gene\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — proteomics provides pathway-level associations but lacks specific mechanistic resolution or functional validation of individual targets\",\n      \"pmids\": [\"31348980\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CHRFAM7A overexpression in a hypertrophic scar mouse model increased activation of the Notch pathway, which reduced M2 macrophage polarization and initially increased M1 macrophages and TNF-α expression, resulting in reduced fibrosis. This identifies Notch pathway activation as a mechanism by which CHRFAM7A regulates macrophage phenotypic transition.\",\n      \"method\": \"Lentiviral CHRFAM7A overexpression in hypertrophic scar mouse model; Notch pathway analysis; macrophage M1/M2 phenotype markers; histological fibrosis scoring\",\n      \"journal\": \"Biomedicine & pharmacotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo model with defined Notch pathway mechanism and macrophage phenotype readout; single lab\",\n      \"pmids\": [\"32890966\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In human fetal cortical organotypic slices and dissociated cultures, CHRFAM7A is expressed in SOX2+ radial glia progenitors and is particularly enriched along radial glia endfeet. nAChR activation increases RG proliferation while decreasing neuronal differentiation; CHRNA7 and CHRFAM7A selectively modulate gene expression changes in excitatory neurons induced by nicotine. YAP1 was identified as a critical downstream effector of nAChR signaling, and inhibiting YAP1 reversed nicotine-induced phenotypic alterations in outer RG cells.\",\n      \"method\": \"Human fetal cortical organotypic slices and dissociated cultures; nAChR knockdown/activation; single-cell RNA sequencing; YAP1 inhibition experiments\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — human fetal cortical models with multiple readouts and mechanistic YAP1 epistasis; preprint\",\n      \"pmids\": [\"bio_10.1101_2025.04.10.647795\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"CHRFAM7A encodes a truncated α7 nAChR subunit (dupα7) that co-assembles with full-length α7 subunits to form heteromeric, hypomorphic receptors with mitigated Ca2+ influx and prolonged closed-state kinetics; this dominant-negative inhibition of α7nAChR reduces ACh-evoked currents and α-bungarotoxin ligand binding, shifts Ca2+ dynamics from extracellular influx to ER-mediated signaling, and activates the small GTPase Rac1 to reorganize the actin cytoskeleton, thereby modulating monocyte/macrophage adhesion, motility, phagocytosis, and inflammatory cytokine responses in a human-specific manner.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CHRFAM7A is a human-specific gene encoding a truncated α7 nicotinic acetylcholine receptor subunit (dupα7) that co-assembles with full-length α7 subunits to form hypomorphic heteromeric receptors with dominant-negative properties, reducing ACh-evoked currents and α-bungarotoxin binding in a dose-dependent manner [PMID:21047781, PMID:21718690, PMID:39073048]. The resulting receptor has mitigated Ca²⁺ influx and prolonged closed-state kinetics, shifting the Ca²⁺ source from extracellular space to the endoplasmic reticulum, which activates the small GTPase Rac1 and reorganizes the actin cytoskeleton to alter monocyte adhesion, motility, and phagocytosis [PMID:38569318]. CHRFAM7A expression is dynamically regulated by NF-κB and LPS in monocytes and gut epithelia [PMID:20926142, PMID:25681457], and its presence modulates inflammatory responses including NLRP3/caspase-1 pyroptosis in microglia, macrophage polarization via Notch signaling, TGF-β1/Smad2/3-driven fibrosis, and hematopoietic stem cell differentiation toward the myeloid lineage [PMID:33405023, PMID:32890966, PMID:36479618, PMID:30944217]. In neurons, CHRFAM7A reduces α7nAChR-mediated calcium transients across multiple agonists, mitigates Aβ1-42 uptake and neurotoxicity, and modifies pharmacogenetic responses to acetylcholinesterase inhibitor therapy in Alzheimer's disease [PMID:39073048, PMID:30710073, PMID:32818803].\",\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Establishing that dupα7 is a dominant-negative modulator of α7nAChR resolved how a truncated subunit lacking the ligand-binding domain could nonetheless suppress receptor function — it reduces functional receptor surface expression in a dose-dependent manner.\",\n      \"evidence\": \"Xenopus oocyte electrophysiology with titrated co-injection of α7 and dupα7 mRNAs, α-bungarotoxin binding, and confocal imaging in HL-60 and GH4C1 cells\",\n      \"pmids\": [\"21047781\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry of α7/dupα7 pentamers not experimentally determined\", \"Endogenous assembly dynamics in native tissues unknown\", \"Trafficking versus assembly defect not fully resolved\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Demonstrating that dupα7/α7 heteromers form silent (non-conducting) receptors that retain allosteric modulator sensitivity distinguished between two models: reduced surface expression versus non-functional surface receptors, showing both mechanisms operate.\",\n      \"evidence\": \"Electrophysiology in oocytes and cell lines with PNU-120596 (type-2 PAM) rescue; radioligand binding with [125I]-α-bungarotoxin\",\n      \"pmids\": [\"21718690\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Single-channel properties of heteromeric receptors not recorded\", \"Relative contribution of silent receptors versus reduced trafficking not quantified\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"The finding that CHRFAM7A is the predominant transcript in monocytic cells and is downregulated by LPS via NF-κB established it as an inflammation-responsive gene, raising the question of its immune function.\",\n      \"evidence\": \"RT-PCR, Western blot in THP-1 cells; NF-κB inhibitor parthenolide blocked LPS-induced downregulation\",\n      \"pmids\": [\"20926142\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct NF-κB binding to CHRFAM7A promoter not shown by ChIP\", \"Post-transcriptional regulation not explored\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identifying a unique 1-kb 5'-UTR regulatory element and showing tissue-specific LPS responsiveness (up to 1000-fold induction in gut epithelia) established that CHRFAM7A has its own transcriptional regulation independent of CHRNA7, enabling context-dependent dominant-negative modulation.\",\n      \"evidence\": \"Quantitative RT-PCR across 11 gut epithelial lines; promoter/UTR mapping; LPS stimulation in THP-1 and gut lines\",\n      \"pmids\": [\"25681457\", \"25860877\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transcription factor binding to the 1-kb element not identified\", \"In vivo promoter regulation not confirmed\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Confirming that CHRFAM7A reduces α-bungarotoxin binding in vivo at mouse neuromuscular junctions extended the dominant-negative mechanism from heterologous systems to intact tissue.\",\n      \"evidence\": \"CHRFAM7A transgenic mice; α-BTX/neurofilament co-staining at NMJ; flow cytometry in PC12 cells\",\n      \"pmids\": [\"30308236\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"NMJ functional consequences (e.g., synaptic transmission) not measured\", \"Whether endogenous human NMJ expresses CHRFAM7A is unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"CHRFAM7A transgenic mice revealed an in vivo hematopoietic function: sparing the HSC reservoir during systemic inflammation and biasing differentiation toward the monocyte lineage, linking the receptor modulation to innate immune cell development.\",\n      \"evidence\": \"CHRFAM7A transgenic mouse SIRS model; bone marrow HSC quantification; in vitro differentiation assays; flow cytometry\",\n      \"pmids\": [\"30944217\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Signaling pathway connecting α7nAChR modulation to HSC maintenance not identified\", \"HSC-intrinsic versus niche-mediated effect not distinguished\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Using iPSC-derived neurons with defined CHRFAM7A copy number demonstrated that CHRFAM7A mitigates Aβ1-42 uptake and activates neuronal IL-1β/TNF-α through a non-canonical (inflammasome-independent) pathway, establishing a neuronal-specific inflammatory response.\",\n      \"evidence\": \"Genome-edited iPSC-derived neurons; electrophysiology; Aβ uptake assay; cytokine measurement\",\n      \"pmids\": [\"30710073\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor through which cytokine induction occurs not fully resolved\", \"In vivo neuronal relevance not tested\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Direct demonstration that CHRFAM7A reduces monocyte migration and chemotaxis established a cellular phenotype linking receptor modulation to innate immune cell behavior.\",\n      \"evidence\": \"Lentiviral CHRFAM7A transduction of THP-1 cells; Transwell migration and chemotaxis assays; soft agar colony formation\",\n      \"pmids\": [\"32303780\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Downstream signaling pathway mediating migration inhibition not identified at this point\", \"Primary human monocyte validation pending\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Pharmacogenetic analysis showed that CHRFAM7A carrier status influences clinical response to acetylcholinesterase inhibitor therapy in Alzheimer's disease, providing clinical relevance for the dominant-negative mechanism and distinguishing direct versus inverted alleles.\",\n      \"evidence\": \"Genome-edited iPSC electrophysiology; double-blind clinical pharmacogenetic analysis of AD cohort with MMSE outcome\",\n      \"pmids\": [\"32818803\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which allele orientation determines function not established\", \"Replication in independent clinical cohort needed\", \"Cohort size limits statistical power\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"CHRFAM7A attenuates microglial pyroptosis by inhibiting the NLRP3/caspase-1 axis and promotes M1-to-M2 polarization, identifying a specific inflammasome pathway suppressed by the hypomorphic receptor.\",\n      \"evidence\": \"CHRFAM7A overexpression in microglia; OGD/R model; NLRP3/caspase-1 assay; iNOS/Arg1 markers\",\n      \"pmids\": [\"33405023\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether NLRP3 inhibition is calcium-dependent or through an alternative mechanism not resolved\", \"Endogenous CHRFAM7A knockdown control absent\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"CHRFAM7A inhibits TGF-β1/Smad2/3 signaling to suppress renal fibrosis in vivo, broadening the downstream pathway repertoire beyond cholinergic anti-inflammatory signaling to fibrotic pathways.\",\n      \"evidence\": \"CHRFAM7A transgenic mouse UUO model; HK-2 cell TGF-β1 stimulation; Smad2/3 phosphorylation; collagen staining\",\n      \"pmids\": [\"36479618\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Link between α7nAChR modulation and TGF-β pathway not mechanistically connected\", \"Direct versus indirect Smad inhibition unknown\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"In an osteoarthritis model, CHRFAM7A transgenic mice showed worsened joint damage, increased DRG macrophage infiltration, and compromised nicotine-mediated antinociception, establishing that CHRFAM7A modifies inflammatory pain and tissue destruction by limiting cholinergic anti-inflammatory reflex efficacy.\",\n      \"evidence\": \"CHRFAM7A transgenic mouse DMM model; mechanical allodynia; histology; DRG macrophage analysis; human chondrocyte CNV stratification\",\n      \"pmids\": [\"36627169\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether CHRFAM7A acts peripherally in joint tissue or centrally in DRG not resolved\", \"Human OA clinical association not established\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"The complete mechanistic chain from receptor to effector was established: CHRFAM7A/α7nAChR heteromers have prolonged closed states, shift Ca²⁺ sourcing to ER stores, activate Rac1, and reorganize actin to alter adhesion, motility, and phagocytosis — resolving how a hypomorphic ion channel produces downstream cellular phenotypes.\",\n      \"evidence\": \"Human iPSC-derived and primary monocytes; Ca²⁺ imaging; electrophysiology; Rac1 activation; actin imaging; phagocytosis/adhesion/motility assays\",\n      \"pmids\": [\"38569318\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether Rac1 activation is solely IP3R-dependent or involves additional Ca²⁺ decoders not tested\", \"In vivo validation of Rac1 pathway in tissue macrophages pending\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Validation across multiple α7-specific agonists in two neuronal systems confirmed that CHRFAM7A universally reduces α7nAChR calcium transients regardless of agonist mechanism, ruling out ligand-specific artifacts.\",\n      \"evidence\": \"Fura-2 calcium imaging in hiPSC cortical neurons and CHRFAM7A transgenic mouse SCG neurons with PNU282987, choline, and 4BP-TQS ± PNU120596\",\n      \"pmids\": [\"39073048\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Native stoichiometry of dupα7/α7 pentamers in human brain tissue not determined\", \"Whether PAM rescue fully restores physiological signaling unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The precise stoichiometry of functional dupα7/α7 pentamers in native human tissues, the structural basis for channel silencing, and the in vivo contribution of the Rac1/actin pathway to immune and neurological phenotypes remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No cryo-EM or X-ray structure of dupα7/α7 heteromeric receptor\", \"Endogenous stoichiometry in human brain/immune cells not determined\", \"Conditional knockout/knockdown in human-relevant models needed to separate gain- from loss-of-function\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 14, 16]},\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [0, 1, 14]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1, 5, 6, 16]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": []},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [5, 8, 10, 12, 18]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 13, 14]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [7, 9, 16]}\n    ],\n    \"complexes\": [\n      \"α7nAChR heteromeric receptor (dupα7/α7 pentamer)\"\n    ],\n    \"partners\": [\n      \"CHRNA7\",\n      \"RAC1\",\n      \"NLRP3\",\n      \"SMAD2\",\n      \"SMAD3\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}