{"gene":"SERPINA12","run_date":"2026-06-10T07:46:30","timeline":{"discoveries":[{"year":2013,"finding":"Vaspin inhibits human kallikrein 7 (hK7) by classical serpin mechanism with high specificity in vitro. The crystal structure of vaspin was solved, vaspin-hK7 complexes were detected in human plasma, and co-expression was found in murine pancreatic β-cells. hK7 was shown to cleave human insulin in the A- and B-chain. Improved glucose tolerance in C57BL/6NTac and db/db mice treated with recombinant vaspin was fully dependent on vaspin serpin activity (inactive mutants had no effect), and was not related to changes in insulin sensitivity by euglycemic-hyperinsulinemic clamp. Vaspin treatment of isolated pancreatic islets increased insulin concentration in media upon glucose stimulation without influencing insulin secretion, suggesting vaspin may inhibit insulin degradation by hK7 in circulation.","method":"Crystal structure determination; in vitro protease inhibition assay; active-site mutagenesis (inactive mutants); co-immunoprecipitation of vaspin-hK7 complexes from plasma; euglycemic-hyperinsulinemic clamp; isolated islet assay","journal":"Cellular and molecular life sciences : CMLS","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure plus in vitro reconstitution of serpin mechanism, active-site mutagenesis confirming catalytic dependence, co-IP from human plasma, and in vivo functional validation with clamp studies in single rigorous study","pmids":["23370777"],"is_preprint":false},{"year":2020,"finding":"Loss-of-function homozygous nonsense variants in SERPINA12 cause autosomal recessive palmoplantar keratoderma. Reduced SERPINA12 expression in patients' skin biopsies and SERPINA12 knockdown in 3D skin equivalents produced epidermal acanthosis and hyperkeratosis. Mechanistically, decreased SERPINA12 expression led to reduced inhibition of kallikrein 7 (KLK7) activity, resulting in decreased levels of desmoglein-1 and corneodesmosin—two known KLK7 substrates required for normal epidermal differentiation.","method":"Whole-exome sequencing; 3D skin equivalent knockdown model; immunohistochemistry; KLK7 activity assay; protein quantification of KLK7 substrates (desmoglein-1, corneodesmosin)","journal":"The Journal of investigative dermatology","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function genetics confirmed in patients, replicated in 3D knockdown model, mechanistic link to KLK7 substrate cleavage established with multiple orthogonal methods","pmids":["32247861"],"is_preprint":false},{"year":2012,"finding":"Vaspin binds to cell-surface GRP78 (78-kDa glucose-regulated protein), which is recruited from ER to the plasma membrane under ER stress. Vaspin forms a complex with GRP78 and MTJ-1 (DnaJ homolog subfamily C member 1) on the plasma membrane, confirmed by tandem affinity purification, cell-surface biotin labeling, and co-immunoprecipitation in liver tissues and H-4-II-E-C3 cells. Addition of recombinant vaspin increased phosphorylation of Akt and AMPK in a dose-dependent manner; anti-GRP78 antibodies completely abrogated vaspin-induced pAkt and pAMPK upregulation.","method":"Tandem affinity tag purification (HepG2 cells); cell-surface biotin labeling; co-immunoprecipitation; western blotting; antibody blockade of GRP78","journal":"Diabetes","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — reciprocal co-IP, tandem affinity purification, cell-surface labeling, and antibody-blockade rescue in single study with multiple orthogonal methods","pmids":["22837305"],"is_preprint":false},{"year":2023,"finding":"In HCC, SERPINA12 expression is driven by TCF7L2 (a β-catenin effector) binding to the SERPINA12 promoter. Endogenous SERPINA12 promotes HCC stem cell self-renewal, therapy resistance, and metastasis by binding to GRP78, resulting in hyperactivation of the AKT/GSK3β/β-catenin signaling cascade forming a positive feed-forward loop. rAAV8-shSERPINA12 in vivo sensitized HCC cells to sorafenib.","method":"Transcriptome profiling; promoter binding assay (TCF7L2 to SERPINA12 promoter); co-immunoprecipitation (SERPINA12-GRP78 binding); loss-of-function (shRNA knockdown) with functional readouts; in vivo AAV-mediated knockdown","journal":"Hepatology (Baltimore, Md.)","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP for GRP78 binding, promoter-binding assay, multiple loss-of-function readouts, and in vivo validation; single lab but multiple orthogonal methods","pmids":["36630996"],"is_preprint":false},{"year":2021,"finding":"During internalization into proximal tubular cells (PTCs), vaspin forms a complex with HSPA1L (heat shock protein family A member 1-like) and GRP78. Both vaspin partners bind to clathrin heavy chain and are involved in endocytosis. Vaspin-/- obese mice showed enlarged and leaky lysosomes in PTCs with increased apoptosis. Overexpression of HSPA1L dissolved organelle stresses including autophagy impairment, placing vaspin/HSPA1L-mediated endocytosis upstream of organellar homeostasis in PTCs.","method":"Co-immunoprecipitation (vaspin-HSPA1L-GRP78 complex, clathrin interaction); vaspin-/- knockout mouse model with histological analysis; HSPA1L overexpression rescue experiment","journal":"Communications biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — co-IP complex identification, knockout mouse phenotype, and overexpression rescue with multiple orthogonal methods in a single rigorous study","pmids":["33742129"],"is_preprint":false},{"year":2011,"finding":"Vaspin is expressed in the hypothalamus and detected in cerebrospinal fluid of healthy individuals. Both peripheral (intraperitoneal) and central (intracerebroventricular) vaspin administration decreased food intake in obese db/db and lean C57BL/6 mice. In db/db mice, central vaspin treatment produced sustained blood glucose-lowering effects for at least 6 days after injection, suggesting vaspin inhibits a protease that degrades an anti-orexigenic factor.","method":"Western blotting (hypothalamus protein); ELISA (CSF vaspin); intracerebroventricular injection; intraperitoneal injection; food intake and blood glucose measurement in db/db and C57BL/6 mice","journal":"Diabetologia","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization (hypothalamus/CSF) tied to functional consequence (food intake reduction) with in vivo experiments; proposed protease target not yet identified","pmids":["21465327"],"is_preprint":false},{"year":2011,"finding":"Vaspin protects vascular endothelial cells from free fatty acid (linoleic acid)-induced apoptosis through upregulation of the PI3K/Akt signaling pathway. Vaspin significantly increased Akt phosphorylation, prevented linoleic acid-induced impairment of Akt phosphorylation in insulin-stimulated endothelial cells, and the anti-apoptotic effect was abolished by the PI3K inhibitor Wortmannin.","method":"Cell culture (endothelial cells); western blotting for Akt phosphorylation; PI3K inhibitor (Wortmannin) blockade; apoptosis assay","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological inhibitor establishes pathway position, western blot for signaling, single lab with two orthogonal methods","pmids":["21893030"],"is_preprint":false},{"year":2012,"finding":"Vaspin increases nitric oxide (NO) bioavailability in vascular endothelial cells by activating the STAT3 signaling pathway, stimulating eNOS phosphorylation (Ser1177) via STAT3, and increasing DDAH II (dimethylarginine dimethylaminohydrolase II) expression through STAT3-mediated stimulation of the DDAH II promoter, leading to reduced ADMA levels. Vaspin-induced NO increase was confirmed in isolated rat aorta.","method":"NO secretion assay (endothelial cells and isolated aorta); western blotting (STAT3, eNOS phosphorylation, DDAH II); DDAH II promoter-luciferase assay; vasorelaxation assay (isolated aorta)","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — promoter activity assay plus phosphorylation western blots and ex vivo vasorelaxation; single lab, multiple orthogonal methods","pmids":["23284999"],"is_preprint":false},{"year":2014,"finding":"Vaspin inhibits cytokine-induced NF-κB activation and expression of adhesion molecules (ICAM-1, VCAM-1, E-selectin, MCP-1) in human aortic endothelial cells by activating AMPK. Vaspin increased phosphorylation of AMPK and its downstream target acetyl-CoA carboxylase. These effects were abolished by AMPKα1-specific siRNA knockdown. In a monocyte adhesion assay, vaspin reduced TNFα-induced monocyte adhesion in an AMPK-dependent manner.","method":"Western blotting (AMPK, ACC phosphorylation); siRNA knockdown of AMPKα1; NF-κB activation assay; adhesion molecule expression; monocyte-endothelial adhesion assay","journal":"Cardiovascular diabetology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA-based pathway epistasis plus downstream functional readout; single lab, two orthogonal methods","pmids":["24517399"],"is_preprint":false},{"year":2017,"finding":"Vaspin suppresses IL-1β-induced expression and secretion of pro-inflammatory cytokines (IL-6, MCP1, TNFα) in 3T3-L1 adipocytes by inhibiting the NF-κB signaling cascade (IKKα/β, IκB, NF-κB). Endogenous vaspin expression (stable transfection) also positively affected insulin signaling by increasing insulin-stimulated AKT phosphorylation.","method":"Stable transfection of 3T3-L1 cells with vaspin; exogenous vaspin treatment; western blotting (IKKα/β, IκB, NF-κB, AKT phosphorylation); cytokine secretion ELISA","journal":"Molecular and cellular endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — stable expression plus exogenous treatment with signaling western blots and secretion assay; single lab, two orthogonal approaches","pmids":["28756250"],"is_preprint":false},{"year":2016,"finding":"Central administration of vaspin to the third cerebral ventricle in HFD-fed rats inhibited hepatic glucose production and improved hepatic insulin sensitivity via DVC N-methyl-D-aspartate (NMDA) receptor signaling to the hepatic branch of the vagus nerve. Selective hepatic branch vagotomy or DVC MK-801 (NMDA receptor inhibitor) infusion blocked the central vaspin effect on glucose production and hepatic insulin signaling.","method":"Intracerebroventricular infusion; pancreatic euglycemic clamp; hepatic branch vagotomy; DVC MK-801 infusion; western blotting (hepatic insulin signaling: IR, IRS-1, Akt, FOXO1 phosphorylation); hepatic gluconeogenic gene expression","journal":"International journal of obesity (2005)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological and surgical epistasis establishing neural pathway; single lab, multiple complementary methods","pmids":["26975443"],"is_preprint":false},{"year":2013,"finding":"Vaspin inhibits RANKL-induced osteoclastogenesis in RAW264.7 cells and bone marrow cells, and inhibits RANKL-induced expression of NFATc1, matrix metalloproteinase-9, and cathepsin K.","method":"RANKL-induced osteoclast differentiation assay (RAW264.7 cells and bone marrow cells); western blotting/PCR for NFATc1, MMP-9, cathepsin K","journal":"Connective tissue research","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab with two cell types (RAW264.7 and BMCs) providing replication; mechanism tied to NFATc1 but no upstream pathway inhibitor used","pmids":["23323745"],"is_preprint":false},{"year":2012,"finding":"Vaspin inhibits apoptosis in human osteoblasts (hOBs) induced by serum deprivation via activation of the MAPK/ERK signaling pathway, upregulating Bcl-2 and downregulating Bax. The ERK inhibitor PD98059 blocked vaspin-induced ERK phosphorylation. Vaspin did not stimulate phosphorylation of p38, JNK, or Akt.","method":"Serum deprivation apoptosis model; ELISA and TUNEL apoptosis assays; western blotting (ERK, p38, JNK, Akt, Bcl-2, Bax); ERK inhibitor PD98059 blockade","journal":"Amino acids","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological inhibitor establishes pathway specificity, negative controls for p38/JNK/Akt, single lab","pmids":["23135225"],"is_preprint":false},{"year":2019,"finding":"Vaspin is secreted from human subcutaneous adipose tissue and skeletal muscle, is more highly expressed in obese older individuals, and activates the PI3K/AKT axis independent of insulin receptor activation, promotes GLUT4 expression and translocation, and sensitizes older obese human skeletal muscle to insulin-mediated glucose uptake.","method":"Human tissue expression profiling; recombinant vaspin treatment of human skeletal muscle cells; western blotting (PI3K/AKT); GLUT4 translocation assay; glucose uptake assay","journal":"The Journal of endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct functional assay in primary human muscle cells with GLUT4 translocation and glucose uptake; single lab, multiple orthogonal methods","pmids":["30721136"],"is_preprint":false},{"year":2016,"finding":"Vaspin attenuates high-glucose-induced vascular smooth muscle cell (VSMC) proliferation and chemokinesis by inhibiting ROS generation, NADPH oxidase activity, and the MAPK, PI3K/Akt, and NF-κB signaling pathways, including abolishing phosphorylation of p47phox, Akt, p38, JNK1/2, insulin receptor, IRS-1, IRS-2, and suppressing NF-κB activity and IκBα phosphorylation.","method":"EdU cell proliferation assay; scratch migration assay; H2DCFDA ROS assay; NADPH oxidase activity assay; luciferase reporter (NF-κB); western blotting (multiple signaling proteins)","journal":"Atherosclerosis","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple complementary assays and signaling readouts; single lab","pmids":["23497782"],"is_preprint":false},{"year":2020,"finding":"Vaspin expression in porcine ovarian follicle cells is regulated by gonadotropins, insulin, IGF-1, and steroids (progesterone, testosterone, estradiol) through JAK/STAT, ERK1/2, PI3K, and AMPK kinase pathways as well as NF-κB. Vaspin stimulates basal steroidogenesis (progesterone and estradiol) via GRP78 receptor and PKA; the stimulatory effect was reversed by PKA inhibitor KT5720 and GRP78 siRNA knockdown.","method":"Real-time PCR and western blot (vaspin, GRP78); PKA inhibitor (KT5720); siRNA knockdown of GRP78; steroid hormone secretion ELISA","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown of receptor and pharmacological inhibitor establish pathway; single lab, multiple orthogonal methods","pmids":["32149334"],"is_preprint":false},{"year":2021,"finding":"Vaspin enhances human granulosa cell steroidogenesis, proliferation, and viability through GRP78 receptor in a concentration-dependent manner, confirmed by GRP78 siRNA knockdown which abrogated vaspin effects.","method":"Recombinant vaspin treatment of human granulosa cells; siRNA knockdown of GRP78; steroidogenesis assay; proliferation and viability assays; western blot; RT-qPCR","journal":"The Journal of endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA receptor knockdown establishes GRP78 dependence; single lab, multiple functional readouts","pmids":["33608490"],"is_preprint":false},{"year":2020,"finding":"Vaspin promotes osteoblastic differentiation and ALP activity in rat primary osteoblasts via activation of the Smad2/3-Runx2 signaling pathway, upregulating Runx2, Osterix, and Collagen alpha1; in vivo, vaspin administration to HFD rats antagonized bone loss.","method":"Primary rat osteoblast differentiation assay; ALP activity assay; western blotting (Smad2/3, p-Smad2/3, Runx2); real-time PCR; micro-CT and three-point bending tests (in vivo)","journal":"Nutrition & metabolism","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro mechanistic pathway (Smad2/3-Runx2) supported by in vivo bone parameter readouts; single lab","pmids":["31993071"],"is_preprint":false},{"year":2022,"finding":"Vaspin reduces hepatocyte steatosis and fibrosis via the GRP78 receptor by activating AMPK, increasing fatty acid oxidation and secretion, decreasing lipogenesis and fatty acid uptake, and reducing α-SMA and TGF-β1 expression in co-cultured hepatocyte/stellate cell model.","method":"HepG2/LX-2 co-culture model; Nile Red lipid assay; flow cytometry; RT-qPCR (lipid metabolism genes); western blot (α-SMA, TGF-β1, AMPK); GRP78 receptor blockade","journal":"Journal of physiology and biochemistry","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single publication, GRP78 involvement inferred from receptor blocking rather than siRNA; mechanistic follow-up is partial","pmids":["35001345"],"is_preprint":false},{"year":2009,"finding":"Vaspin (SERPINA12) was identified from visceral white adipose tissue (WAT) of OLETF rats using PCR-based cDNA subtraction. Administration of recombinant vaspin into high-fat high-sucrose chow-induced obese ICR mice improved glucose tolerance and insulin sensitivity.","method":"cDNA subtraction cloning; recombinant protein administration to obese mice; glucose tolerance test; insulin sensitivity assay","journal":"Expert opinion on investigational drugs","confidence":"Low","confidence_rationale":"Tier 3 / Weak — foundational identification paper with in vivo phenotype but no molecular pathway established; single lab, single publication","pmids":["18321232"],"is_preprint":false},{"year":2016,"finding":"Vaspin is specifically expressed in keratinocytes (KCs) in skin, closely associated with epidermal differentiation. Downregulation of vaspin in KCs in psoriasis resulted in decreased differentiation-associated gene expression and upregulation of inflammation-associated psoriasis signature genes. Vaspin decreased secretion of TNF-α, IL-1β, IL-6, IL-8, and MCP-1 by co-cultured immune cells; application of vaspin inhibited myeloid cell infiltration in a psoriasis-like mouse model.","method":"Immunohistochemistry; RT-PCR; siRNA knockdown of vaspin in KCs; co-culture of KCs with immune cells; in vivo mouse psoriasis model with vaspin application","journal":"The American journal of pathology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct vaspin knockdown in KCs with functional immune co-culture readout and in vivo model; single lab, multiple methods","pmids":["26783881"],"is_preprint":false},{"year":2017,"finding":"Vaspin in brown adipose tissue (BAT) is specifically induced at mRNA and protein levels by cold exposure and obesogenic (high-fat or high-sugar) diets in mice. Cold-induced BAT vaspin expression is accompanied by acute reduction in DNA methylation within the vaspin promoter in BAT, providing an epigenetic regulatory mechanism.","method":"mRNA and protein expression analysis in adipose tissue depots; adipogenesis and adrenergic stimulation experiments in brown adipocytes; vaspin promoter DNA methylation analysis","journal":"Molecular metabolism","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct DNA methylation measurement linked to gene expression change with functional stimuli; single lab, two orthogonal methods","pmids":["28580279"],"is_preprint":false},{"year":2019,"finding":"Vaspin promotes porcine granulosa cell proliferation, cell cycle progression into S and G2/M phases, and decreases apoptosis. GRP78 siRNA silencing and pharmacological inhibitors of MAP3/1 (ERK1/2), STAT3, and AKT blocked vaspin-induced proliferation and enhanced caspase-3/7 activities, establishing GRP78 as the receptor and these kinases as downstream mediators.","method":"alamarBlue proliferation assay; flow cytometry (cell cycle); Caspase-Glo 3/7 assay; siRNA silencing of GRP78; pharmacological kinase inhibitors; western blotting (cyclin D, E, A; BAX, BCL2, caspases, p53)","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA receptor knockdown plus multiple pharmacological inhibitors establishing pathway; single lab, multiple orthogonal methods","pmids":["31752432"],"is_preprint":false},{"year":2020,"finding":"Vaspin enhances porcine luteal cell angiogenesis, proliferation, and decreases apoptosis via GRP78 receptor and MAP3/1 kinase pathways; GRP78 siRNA and MAP3/1 inhibitor (PD98059) reversed all vaspin effects.","method":"Luteal cell culture; alamarBlue proliferation; Caspase-Glo 3/7; angiogenic factor ELISA and PCR; GRP78 siRNA; PD98059 inhibition; western blotting","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown plus pharmacological inhibitor with multiple functional readouts; single lab","pmids":["32957618"],"is_preprint":false},{"year":2020,"finding":"Vaspin affects luteal cell steroidogenesis (stimulates progesterone synthesis), increases luteotropic PGE2:luteolytic PGF2α ratio, and activates PKA and MAP3/1 kinases via GRP78 receptor, as shown by GRP78 siRNA knockdown and MAP3/1 inhibitor reversal of vaspin effects.","method":"Luteal cell culture; GRP78 siRNA knockdown; MAP3/1 inhibitor (PD98059); PKA phosphorylation western blot; steroid hormone ELISA","journal":"The Journal of endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA receptor knockdown and pharmacological inhibitor establish pathway dependence; single lab","pmids":["33108345"],"is_preprint":false},{"year":2020,"finding":"SerpinA12 (vaspin) secreted by hepatic stellate cells (HSCs) is protective against ethanol-induced steatosis in hepatocytes in vitro. In NRP-1 knockdown HSCs, SerpinA12 secretion was increased, and recombinant SerpinA12 was protective against ethanol-induced lipid droplet formation in hepatocytes. SerpinA12 was decreased in serum and liver tissue from patients with alcoholic hepatitis.","method":"HSC conditioned medium experiments; adipokine/inflammatory protein array; recombinant protein treatment of hepatocytes in vitro; lipid droplet assay; immunocompetent HCC mouse model","journal":"Journal of hepatology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — conditioned medium and recombinant protein rescue establish vaspin as HSC-secreted hepatoprotective factor; single lab, two orthogonal approaches","pmids":["32087348"],"is_preprint":false},{"year":2009,"finding":"Vaspin protein is expressed in human and rat placenta with tissue-specific localization: in rat, in trophoblast of the fetal labyrinth; in human, in cytotrophoblast and syncytiotrophoblast in first trimester and syncytiotrophoblast in third trimester. Food restriction increases placental vaspin mRNA and protein levels in rats, indicating nutritional regulation of vaspin expression.","method":"Immunohistochemistry (human and rat placenta); RT-PCR; food restriction experiment in rats","journal":"Histology and histopathology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — localization by IHC and expression regulation, no functional consequence established; single lab","pmids":["19554505"],"is_preprint":false},{"year":2009,"finding":"Vaspin (TNF-α-stimulated human umbilical vein endothelial cells): vaspin (10–100 ng/mL, 24 h) had no effect on basal endothelial cell morphology and did not inhibit TNF-α-induced activation of JNK, p38, or NF-κB (with only slight Akt inhibition), and did not decrease TNF-α-induced expression of VCAM-1, ICAM-1, E-selectin, COX-2, MCP-1, tissue factor, or PAI-1.","method":"Western blotting (JNK, p38, NF-κB, Akt); mRNA expression; protein expression in HUVECs with TNF-α stimulation","journal":"The Journal of veterinary medical science","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — rigorous negative result with multiple signaling targets tested; single lab, single publication; reported as negative","pmids":["19801900"],"is_preprint":false}],"current_model":"SERPINA12/vaspin is a serine protease inhibitor (serpin) adipokine that acts primarily by inhibiting kallikrein 7 (hK7) via classical serpin mechanism—confirmed by crystal structure, in vitro reconstitution, and active-site mutagenesis—thereby protecting insulin from hK7-mediated cleavage and regulating epidermal differentiation; it signals through cell-surface GRP78/MTJ-1 receptor complexes to activate PI3K/AKT and AMPK, suppress NF-κB-driven inflammation, and modulate steroidogenesis, osteogenesis, and energy metabolism across multiple tissues including adipose, liver, vascular endothelium, skin, and reproductive organs."},"narrative":{"mechanistic_narrative":"SERPINA12 (vaspin) is an adipokine of the serpin superfamily that functions both as a specific protease inhibitor and as a receptor-engaging signaling ligand, coordinating glucose metabolism, epithelial differentiation, vascular protection, and tissue homeostasis [PMID:23370777, PMID:22837305, PMID:18321232]. Its defining biochemical activity is high-specificity inhibition of kallikrein 7 (KLK7/hK7) by the classical serpin mechanism, established by crystal structure, in vitro reconstitution with active-site mutagenesis, and detection of vaspin-hK7 complexes in human plasma; this protective inhibition shields insulin from hK7-mediated A/B-chain cleavage and improves glucose tolerance in vivo in a manner strictly dependent on serpin activity [PMID:23370777]. The same protease-inhibitory function operates in skin, where loss-of-function nonsense variants in SERPINA12 cause autosomal recessive palmoplantar keratoderma: reduced KLK7 inhibition lowers the KLK7 substrates desmoglein-1 and corneodesmosin and drives epidermal acanthosis and hyperkeratosis [PMID:32247861]. Independently of its serpin activity, vaspin signals through a cell-surface receptor complex of GRP78 and MTJ-1 (DnaJC1) recruited to the plasma membrane, activating Akt and AMPK; antibody blockade of GRP78 abolishes this signaling [PMID:22837305]. Through GRP78 engagement and downstream PI3K/AKT, AMPK, ERK, STAT3, and PKA cascades, vaspin promotes insulin-independent GLUT4 translocation and muscle glucose uptake [PMID:30721136], suppresses NF-κB-driven inflammatory and adhesion programs in endothelium and adipocytes [PMID:24517399, PMID:28756250], enhances endothelial NO bioavailability and protects vascular cells from apoptosis [PMID:21893030, PMID:23284999], drives osteoblast differentiation and survival [PMID:23135225, PMID:31993071], and supports ovarian and luteal steroidogenesis, proliferation, and survival [PMID:32149334, PMID:33608490, PMID:31752432, PMID:33108345]. In liver, GRP78-dependent AMPK activation reduces hepatocyte steatosis [PMID:35001345], and a TCF7L2/β-catenin-driven SERPINA12-GRP78-AKT/GSK3β feed-forward loop sustains hepatocellular carcinoma stemness and therapy resistance [PMID:36630996]. Vaspin is also internalized into renal proximal tubular cells in a complex with HSPA1L and GRP78 via clathrin-mediated endocytosis, maintaining lysosomal and autophagic homeostasis [PMID:33742129].","teleology":[{"year":2009,"claim":"Establishing that an adipose-derived factor could improve metabolic phenotype defined vaspin as a candidate insulin-sensitizing adipokine and motivated mechanistic dissection.","evidence":"cDNA subtraction cloning from OLETF rat visceral WAT and recombinant protein administration to obese mice","pmids":["18321232"],"confidence":"Low","gaps":["No molecular receptor or pathway identified","Single lab foundational report without mechanistic resolution"]},{"year":2012,"claim":"Identifying the cell-surface GRP78/MTJ-1 complex answered how a secreted serpin transmits an intracellular signal, defining vaspin's receptor-based signaling arm.","evidence":"Tandem affinity purification, cell-surface biotin labeling, reciprocal co-IP in liver and hepatoma cells, and GRP78 antibody blockade of Akt/AMPK activation","pmids":["22837305"],"confidence":"High","gaps":["Stoichiometry and structural basis of vaspin-GRP78 binding unresolved","Whether GRP78 transduces signal directly or via co-receptors not established"]},{"year":2013,"claim":"Solving the crystal structure and reconstituting KLK7 inhibition defined vaspin's primary enzymatic target and showed its metabolic effect operates by protecting insulin from proteolytic degradation rather than altering insulin sensitivity.","evidence":"Crystal structure, in vitro protease inhibition with active-site mutants, plasma co-IP of vaspin-hK7 complexes, euglycemic-hyperinsulinemic clamp, and isolated islet assays","pmids":["23370777"],"confidence":"High","gaps":["Full repertoire of physiological vaspin protease targets beyond hK7 not mapped","Relationship between serpin activity and GRP78 signaling arm not reconciled"]},{"year":2016,"claim":"Linking vaspin to keratinocyte differentiation extended its serpin/KLK7 axis to epithelial biology and connected its loss to inflammatory skin pathology.","evidence":"Immunohistochemistry, siRNA knockdown in keratinocytes, immune cell co-culture, and a psoriasis-like mouse model","pmids":["26783881"],"confidence":"Medium","gaps":["Whether skin effects are KLK7-dependent not directly tested in this work"]},{"year":2020,"claim":"Human loss-of-function genetics established SERPINA12 as a Mendelian disease gene and confirmed in vivo that its physiological role is KLK7 inhibition controlling epidermal differentiation.","evidence":"Whole-exome sequencing of patients, 3D skin equivalent knockdown, KLK7 activity assays, and quantification of KLK7 substrates desmoglein-1 and corneodesmosin","pmids":["32247861"],"confidence":"High","gaps":["Genotype-phenotype variability and extracutaneous consequences of human deficiency not detailed"]},{"year":2021,"claim":"Defining vaspin internalization via an HSPA1L/GRP78/clathrin complex positioned receptor-mediated endocytosis upstream of organellar homeostasis in renal tubular cells.","evidence":"Co-IP of vaspin-HSPA1L-GRP78-clathrin complexes, vaspin-/- knockout mouse histology, and HSPA1L overexpression rescue","pmids":["33742129"],"confidence":"High","gaps":["Whether endocytosis terminates or propagates GRP78 signaling unclear","Generality of this trafficking route to other tissues unknown"]},{"year":2023,"claim":"Showing a TCF7L2/β-catenin-driven SERPINA12-GRP78-AKT feed-forward loop in HCC reframed vaspin as a context-dependent tumor-promoting factor rather than a purely protective adipokine.","evidence":"Transcriptome profiling, TCF7L2 promoter-binding assay, SERPINA12-GRP78 co-IP, shRNA loss-of-function, and in vivo AAV knockdown sensitizing tumors to sorafenib","pmids":["36630996"],"confidence":"High","gaps":["Reconciliation with hepatoprotective roles of vaspin in steatosis not addressed","Whether serpin activity contributes to the oncogenic loop untested"]},{"year":null,"claim":"How vaspin's serpin protease-inhibitory activity and its GRP78-receptor signaling arm are integrated—and which physiological outputs depend on which mode—remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No single study dissects serpin-dependent versus GRP78-dependent outputs in the same system","The protease degrading the anti-orexigenic factor inferred from CNS studies is unidentified","Structural basis and exact binding site for the vaspin-GRP78 interaction undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[2,3,13]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma 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journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32580404","citation_count":21,"is_preprint":false},{"pmid":"25210758","id":"PMC_25210758","title":"Relationship of plasma level of chemerin and vaspin to early atherosclerotic changes and cardiac autonomic neuropathy in adolescent type 1 diabetic patients.","date":"2015","source":"Journal of pediatric endocrinology & metabolism : JPEM","url":"https://pubmed.ncbi.nlm.nih.gov/25210758","citation_count":21,"is_preprint":false},{"pmid":"19801900","id":"PMC_19801900","title":"Vaspin can not inhibit TNF-alpha-induced inflammation of human umbilical vein endothelial cells.","date":"2009","source":"The Journal of veterinary medical science","url":"https://pubmed.ncbi.nlm.nih.gov/19801900","citation_count":20,"is_preprint":false},{"pmid":"23135683","id":"PMC_23135683","title":"Vaspin gene in rat adipose tissue: relation to obesity-induced insulin resistance.","date":"2012","source":"Molecular and cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23135683","citation_count":20,"is_preprint":false},{"pmid":"33608490","id":"PMC_33608490","title":"Vaspin, a novel adipokine in woman granulosa cells physiology and PCOS pathogenesis?","date":"2021","source":"The Journal of endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/33608490","citation_count":19,"is_preprint":false},{"pmid":"32964986","id":"PMC_32964986","title":"VASPIN reduces inflammation and endoplasmic reticulum stress of renal tubular epithelial cells by inhibiting HMGB1 and relieves renal ischemia-reperfusion injury.","date":"2020","source":"European review for medical and pharmacological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32964986","citation_count":19,"is_preprint":false},{"pmid":"32957618","id":"PMC_32957618","title":"Novel Insights on the Corpus Luteum Function: Role of Vaspin on Porcine Luteal Cell Angiogenesis, Proliferation and Apoptosis by Activation of GRP78 Receptor and MAP3/1 Kinase Pathways.","date":"2020","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32957618","citation_count":19,"is_preprint":false},{"pmid":"23160181","id":"PMC_23160181","title":"Novel common and rare genetic determinants of paraoxonase activity: FTO, SERPINA12, and ITGAL.","date":"2012","source":"Journal of lipid research","url":"https://pubmed.ncbi.nlm.nih.gov/23160181","citation_count":18,"is_preprint":false},{"pmid":"33108345","id":"PMC_33108345","title":"The role of vaspin in porcine corpus luteum.","date":"2020","source":"The Journal of endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/33108345","citation_count":18,"is_preprint":false},{"pmid":"25419381","id":"PMC_25419381","title":"Expression of vaspin in the joint and the levels in the serum and synovial fluid of patients with osteoarthritis.","date":"2014","source":"International journal of clinical and experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/25419381","citation_count":18,"is_preprint":false},{"pmid":"28479386","id":"PMC_28479386","title":"Obesity risk prediction among women of Upper Egypt: The impact of serum vaspin and vaspin rs2236242 gene polymorphism.","date":"2017","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/28479386","citation_count":18,"is_preprint":false},{"pmid":"33742129","id":"PMC_33742129","title":"A Vaspin-HSPA1L complex protects proximal tubular cells from organelle stress in diabetic kidney disease.","date":"2021","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/33742129","citation_count":18,"is_preprint":false},{"pmid":"24530312","id":"PMC_24530312","title":"Association between vaspin rs2236242 gene polymorphism and polycystic ovary syndrome risk.","date":"2014","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/24530312","citation_count":17,"is_preprint":false},{"pmid":"25608237","id":"PMC_25608237","title":"Plasma levels and placental expression of vaspin in pregnant women with diabetes mellitus.","date":"2015","source":"Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas","url":"https://pubmed.ncbi.nlm.nih.gov/25608237","citation_count":17,"is_preprint":false},{"pmid":"29734265","id":"PMC_29734265","title":"Vaspin Prevents Tumor Necrosis Factor-α-Induced Apoptosis in Cardiomyocytes by Promoting Autophagy.","date":"2018","source":"Journal of cardiovascular pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/29734265","citation_count":17,"is_preprint":false},{"pmid":"26221476","id":"PMC_26221476","title":"Resveratrol attenuates visfatin and vaspin genes expression in adipose tissue of rats with type 2 diabetes.","date":"2015","source":"Iranian journal of basic medical sciences","url":"https://pubmed.ncbi.nlm.nih.gov/26221476","citation_count":17,"is_preprint":false},{"pmid":"27966294","id":"PMC_27966294","title":"The association of vaspin rs2236242 and leptin rs7799039 polymorphism with metabolic syndrome in Egyptian women.","date":"2016","source":"Turkish journal of medical sciences","url":"https://pubmed.ncbi.nlm.nih.gov/27966294","citation_count":17,"is_preprint":false},{"pmid":"20497691","id":"PMC_20497691","title":"Calorie control increased vaspin levels of serum and periepididymal adipose tissue in diet-induced obese rats in association with serum free fatty acid and tumor necrosis factor alpha.","date":"2010","source":"Chinese medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/20497691","citation_count":16,"is_preprint":false},{"pmid":"35001345","id":"PMC_35001345","title":"Vaspin attenuates steatosis-induced fibrosis via GRP78 receptor by targeting AMPK signaling pathway.","date":"2022","source":"Journal of physiology and biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/35001345","citation_count":15,"is_preprint":false},{"pmid":"33302416","id":"PMC_33302416","title":"Expression and Impact of Vaspin on In Vitro Oocyte Maturation through MAP3/1 and PRKAA1 Signalling Pathways.","date":"2020","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/33302416","citation_count":15,"is_preprint":false},{"pmid":"26436376","id":"PMC_26436376","title":"Changes and clinical significance of serum vaspin levels in patients with type 2 diabetes.","date":"2015","source":"Genetics and molecular research : GMR","url":"https://pubmed.ncbi.nlm.nih.gov/26436376","citation_count":15,"is_preprint":false},{"pmid":"35377336","id":"PMC_35377336","title":"New insights into cell apoptosis and proliferation: the potential role of vaspin.","date":"2022","source":"Journal of physiology and pharmacology : an official journal of the Polish Physiological Society","url":"https://pubmed.ncbi.nlm.nih.gov/35377336","citation_count":14,"is_preprint":false},{"pmid":"25277770","id":"PMC_25277770","title":"Serum vaspin levels and vaspin mRNA expression in subcutaneous adipose tissue in women with gestational diabetes mellitus.","date":"2014","source":"European journal of obstetrics, gynecology, and reproductive biology","url":"https://pubmed.ncbi.nlm.nih.gov/25277770","citation_count":14,"is_preprint":false},{"pmid":"26434866","id":"PMC_26434866","title":"Medullary Thyroid Carcinoma--Circulating Status of Vaspin and Retinol Binding Protein-4 in Iranian Patients.","date":"2015","source":"Asian Pacific journal of cancer prevention : APJCP","url":"https://pubmed.ncbi.nlm.nih.gov/26434866","citation_count":14,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":53853,"output_tokens":7939,"usd":0.140322,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":17731,"output_tokens":3367,"usd":0.086415,"stage2_stop_reason":"end_turn"},"total_usd":0.226737,"stage1_batch_id":"msgbatch_013LWZZT6MWaqB9qyTSeQBmU","stage2_batch_id":"msgbatch_0194ZzQaTGNpruoNJBbEMbt3","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2013,\n      \"finding\": \"Vaspin inhibits human kallikrein 7 (hK7) by classical serpin mechanism with high specificity in vitro. The crystal structure of vaspin was solved, vaspin-hK7 complexes were detected in human plasma, and co-expression was found in murine pancreatic β-cells. hK7 was shown to cleave human insulin in the A- and B-chain. Improved glucose tolerance in C57BL/6NTac and db/db mice treated with recombinant vaspin was fully dependent on vaspin serpin activity (inactive mutants had no effect), and was not related to changes in insulin sensitivity by euglycemic-hyperinsulinemic clamp. Vaspin treatment of isolated pancreatic islets increased insulin concentration in media upon glucose stimulation without influencing insulin secretion, suggesting vaspin may inhibit insulin degradation by hK7 in circulation.\",\n      \"method\": \"Crystal structure determination; in vitro protease inhibition assay; active-site mutagenesis (inactive mutants); co-immunoprecipitation of vaspin-hK7 complexes from plasma; euglycemic-hyperinsulinemic clamp; isolated islet assay\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure plus in vitro reconstitution of serpin mechanism, active-site mutagenesis confirming catalytic dependence, co-IP from human plasma, and in vivo functional validation with clamp studies in single rigorous study\",\n      \"pmids\": [\"23370777\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Loss-of-function homozygous nonsense variants in SERPINA12 cause autosomal recessive palmoplantar keratoderma. Reduced SERPINA12 expression in patients' skin biopsies and SERPINA12 knockdown in 3D skin equivalents produced epidermal acanthosis and hyperkeratosis. Mechanistically, decreased SERPINA12 expression led to reduced inhibition of kallikrein 7 (KLK7) activity, resulting in decreased levels of desmoglein-1 and corneodesmosin—two known KLK7 substrates required for normal epidermal differentiation.\",\n      \"method\": \"Whole-exome sequencing; 3D skin equivalent knockdown model; immunohistochemistry; KLK7 activity assay; protein quantification of KLK7 substrates (desmoglein-1, corneodesmosin)\",\n      \"journal\": \"The Journal of investigative dermatology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function genetics confirmed in patients, replicated in 3D knockdown model, mechanistic link to KLK7 substrate cleavage established with multiple orthogonal methods\",\n      \"pmids\": [\"32247861\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Vaspin binds to cell-surface GRP78 (78-kDa glucose-regulated protein), which is recruited from ER to the plasma membrane under ER stress. Vaspin forms a complex with GRP78 and MTJ-1 (DnaJ homolog subfamily C member 1) on the plasma membrane, confirmed by tandem affinity purification, cell-surface biotin labeling, and co-immunoprecipitation in liver tissues and H-4-II-E-C3 cells. Addition of recombinant vaspin increased phosphorylation of Akt and AMPK in a dose-dependent manner; anti-GRP78 antibodies completely abrogated vaspin-induced pAkt and pAMPK upregulation.\",\n      \"method\": \"Tandem affinity tag purification (HepG2 cells); cell-surface biotin labeling; co-immunoprecipitation; western blotting; antibody blockade of GRP78\",\n      \"journal\": \"Diabetes\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — reciprocal co-IP, tandem affinity purification, cell-surface labeling, and antibody-blockade rescue in single study with multiple orthogonal methods\",\n      \"pmids\": [\"22837305\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In HCC, SERPINA12 expression is driven by TCF7L2 (a β-catenin effector) binding to the SERPINA12 promoter. Endogenous SERPINA12 promotes HCC stem cell self-renewal, therapy resistance, and metastasis by binding to GRP78, resulting in hyperactivation of the AKT/GSK3β/β-catenin signaling cascade forming a positive feed-forward loop. rAAV8-shSERPINA12 in vivo sensitized HCC cells to sorafenib.\",\n      \"method\": \"Transcriptome profiling; promoter binding assay (TCF7L2 to SERPINA12 promoter); co-immunoprecipitation (SERPINA12-GRP78 binding); loss-of-function (shRNA knockdown) with functional readouts; in vivo AAV-mediated knockdown\",\n      \"journal\": \"Hepatology (Baltimore, Md.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP for GRP78 binding, promoter-binding assay, multiple loss-of-function readouts, and in vivo validation; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"36630996\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"During internalization into proximal tubular cells (PTCs), vaspin forms a complex with HSPA1L (heat shock protein family A member 1-like) and GRP78. Both vaspin partners bind to clathrin heavy chain and are involved in endocytosis. Vaspin-/- obese mice showed enlarged and leaky lysosomes in PTCs with increased apoptosis. Overexpression of HSPA1L dissolved organelle stresses including autophagy impairment, placing vaspin/HSPA1L-mediated endocytosis upstream of organellar homeostasis in PTCs.\",\n      \"method\": \"Co-immunoprecipitation (vaspin-HSPA1L-GRP78 complex, clathrin interaction); vaspin-/- knockout mouse model with histological analysis; HSPA1L overexpression rescue experiment\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — co-IP complex identification, knockout mouse phenotype, and overexpression rescue with multiple orthogonal methods in a single rigorous study\",\n      \"pmids\": [\"33742129\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Vaspin is expressed in the hypothalamus and detected in cerebrospinal fluid of healthy individuals. Both peripheral (intraperitoneal) and central (intracerebroventricular) vaspin administration decreased food intake in obese db/db and lean C57BL/6 mice. In db/db mice, central vaspin treatment produced sustained blood glucose-lowering effects for at least 6 days after injection, suggesting vaspin inhibits a protease that degrades an anti-orexigenic factor.\",\n      \"method\": \"Western blotting (hypothalamus protein); ELISA (CSF vaspin); intracerebroventricular injection; intraperitoneal injection; food intake and blood glucose measurement in db/db and C57BL/6 mice\",\n      \"journal\": \"Diabetologia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization (hypothalamus/CSF) tied to functional consequence (food intake reduction) with in vivo experiments; proposed protease target not yet identified\",\n      \"pmids\": [\"21465327\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Vaspin protects vascular endothelial cells from free fatty acid (linoleic acid)-induced apoptosis through upregulation of the PI3K/Akt signaling pathway. Vaspin significantly increased Akt phosphorylation, prevented linoleic acid-induced impairment of Akt phosphorylation in insulin-stimulated endothelial cells, and the anti-apoptotic effect was abolished by the PI3K inhibitor Wortmannin.\",\n      \"method\": \"Cell culture (endothelial cells); western blotting for Akt phosphorylation; PI3K inhibitor (Wortmannin) blockade; apoptosis assay\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological inhibitor establishes pathway position, western blot for signaling, single lab with two orthogonal methods\",\n      \"pmids\": [\"21893030\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Vaspin increases nitric oxide (NO) bioavailability in vascular endothelial cells by activating the STAT3 signaling pathway, stimulating eNOS phosphorylation (Ser1177) via STAT3, and increasing DDAH II (dimethylarginine dimethylaminohydrolase II) expression through STAT3-mediated stimulation of the DDAH II promoter, leading to reduced ADMA levels. Vaspin-induced NO increase was confirmed in isolated rat aorta.\",\n      \"method\": \"NO secretion assay (endothelial cells and isolated aorta); western blotting (STAT3, eNOS phosphorylation, DDAH II); DDAH II promoter-luciferase assay; vasorelaxation assay (isolated aorta)\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — promoter activity assay plus phosphorylation western blots and ex vivo vasorelaxation; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"23284999\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Vaspin inhibits cytokine-induced NF-κB activation and expression of adhesion molecules (ICAM-1, VCAM-1, E-selectin, MCP-1) in human aortic endothelial cells by activating AMPK. Vaspin increased phosphorylation of AMPK and its downstream target acetyl-CoA carboxylase. These effects were abolished by AMPKα1-specific siRNA knockdown. In a monocyte adhesion assay, vaspin reduced TNFα-induced monocyte adhesion in an AMPK-dependent manner.\",\n      \"method\": \"Western blotting (AMPK, ACC phosphorylation); siRNA knockdown of AMPKα1; NF-κB activation assay; adhesion molecule expression; monocyte-endothelial adhesion assay\",\n      \"journal\": \"Cardiovascular diabetology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA-based pathway epistasis plus downstream functional readout; single lab, two orthogonal methods\",\n      \"pmids\": [\"24517399\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Vaspin suppresses IL-1β-induced expression and secretion of pro-inflammatory cytokines (IL-6, MCP1, TNFα) in 3T3-L1 adipocytes by inhibiting the NF-κB signaling cascade (IKKα/β, IκB, NF-κB). Endogenous vaspin expression (stable transfection) also positively affected insulin signaling by increasing insulin-stimulated AKT phosphorylation.\",\n      \"method\": \"Stable transfection of 3T3-L1 cells with vaspin; exogenous vaspin treatment; western blotting (IKKα/β, IκB, NF-κB, AKT phosphorylation); cytokine secretion ELISA\",\n      \"journal\": \"Molecular and cellular endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — stable expression plus exogenous treatment with signaling western blots and secretion assay; single lab, two orthogonal approaches\",\n      \"pmids\": [\"28756250\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Central administration of vaspin to the third cerebral ventricle in HFD-fed rats inhibited hepatic glucose production and improved hepatic insulin sensitivity via DVC N-methyl-D-aspartate (NMDA) receptor signaling to the hepatic branch of the vagus nerve. Selective hepatic branch vagotomy or DVC MK-801 (NMDA receptor inhibitor) infusion blocked the central vaspin effect on glucose production and hepatic insulin signaling.\",\n      \"method\": \"Intracerebroventricular infusion; pancreatic euglycemic clamp; hepatic branch vagotomy; DVC MK-801 infusion; western blotting (hepatic insulin signaling: IR, IRS-1, Akt, FOXO1 phosphorylation); hepatic gluconeogenic gene expression\",\n      \"journal\": \"International journal of obesity (2005)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological and surgical epistasis establishing neural pathway; single lab, multiple complementary methods\",\n      \"pmids\": [\"26975443\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Vaspin inhibits RANKL-induced osteoclastogenesis in RAW264.7 cells and bone marrow cells, and inhibits RANKL-induced expression of NFATc1, matrix metalloproteinase-9, and cathepsin K.\",\n      \"method\": \"RANKL-induced osteoclast differentiation assay (RAW264.7 cells and bone marrow cells); western blotting/PCR for NFATc1, MMP-9, cathepsin K\",\n      \"journal\": \"Connective tissue research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab with two cell types (RAW264.7 and BMCs) providing replication; mechanism tied to NFATc1 but no upstream pathway inhibitor used\",\n      \"pmids\": [\"23323745\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Vaspin inhibits apoptosis in human osteoblasts (hOBs) induced by serum deprivation via activation of the MAPK/ERK signaling pathway, upregulating Bcl-2 and downregulating Bax. The ERK inhibitor PD98059 blocked vaspin-induced ERK phosphorylation. Vaspin did not stimulate phosphorylation of p38, JNK, or Akt.\",\n      \"method\": \"Serum deprivation apoptosis model; ELISA and TUNEL apoptosis assays; western blotting (ERK, p38, JNK, Akt, Bcl-2, Bax); ERK inhibitor PD98059 blockade\",\n      \"journal\": \"Amino acids\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological inhibitor establishes pathway specificity, negative controls for p38/JNK/Akt, single lab\",\n      \"pmids\": [\"23135225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Vaspin is secreted from human subcutaneous adipose tissue and skeletal muscle, is more highly expressed in obese older individuals, and activates the PI3K/AKT axis independent of insulin receptor activation, promotes GLUT4 expression and translocation, and sensitizes older obese human skeletal muscle to insulin-mediated glucose uptake.\",\n      \"method\": \"Human tissue expression profiling; recombinant vaspin treatment of human skeletal muscle cells; western blotting (PI3K/AKT); GLUT4 translocation assay; glucose uptake assay\",\n      \"journal\": \"The Journal of endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct functional assay in primary human muscle cells with GLUT4 translocation and glucose uptake; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"30721136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Vaspin attenuates high-glucose-induced vascular smooth muscle cell (VSMC) proliferation and chemokinesis by inhibiting ROS generation, NADPH oxidase activity, and the MAPK, PI3K/Akt, and NF-κB signaling pathways, including abolishing phosphorylation of p47phox, Akt, p38, JNK1/2, insulin receptor, IRS-1, IRS-2, and suppressing NF-κB activity and IκBα phosphorylation.\",\n      \"method\": \"EdU cell proliferation assay; scratch migration assay; H2DCFDA ROS assay; NADPH oxidase activity assay; luciferase reporter (NF-κB); western blotting (multiple signaling proteins)\",\n      \"journal\": \"Atherosclerosis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple complementary assays and signaling readouts; single lab\",\n      \"pmids\": [\"23497782\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Vaspin expression in porcine ovarian follicle cells is regulated by gonadotropins, insulin, IGF-1, and steroids (progesterone, testosterone, estradiol) through JAK/STAT, ERK1/2, PI3K, and AMPK kinase pathways as well as NF-κB. Vaspin stimulates basal steroidogenesis (progesterone and estradiol) via GRP78 receptor and PKA; the stimulatory effect was reversed by PKA inhibitor KT5720 and GRP78 siRNA knockdown.\",\n      \"method\": \"Real-time PCR and western blot (vaspin, GRP78); PKA inhibitor (KT5720); siRNA knockdown of GRP78; steroid hormone secretion ELISA\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown of receptor and pharmacological inhibitor establish pathway; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"32149334\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Vaspin enhances human granulosa cell steroidogenesis, proliferation, and viability through GRP78 receptor in a concentration-dependent manner, confirmed by GRP78 siRNA knockdown which abrogated vaspin effects.\",\n      \"method\": \"Recombinant vaspin treatment of human granulosa cells; siRNA knockdown of GRP78; steroidogenesis assay; proliferation and viability assays; western blot; RT-qPCR\",\n      \"journal\": \"The Journal of endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA receptor knockdown establishes GRP78 dependence; single lab, multiple functional readouts\",\n      \"pmids\": [\"33608490\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Vaspin promotes osteoblastic differentiation and ALP activity in rat primary osteoblasts via activation of the Smad2/3-Runx2 signaling pathway, upregulating Runx2, Osterix, and Collagen alpha1; in vivo, vaspin administration to HFD rats antagonized bone loss.\",\n      \"method\": \"Primary rat osteoblast differentiation assay; ALP activity assay; western blotting (Smad2/3, p-Smad2/3, Runx2); real-time PCR; micro-CT and three-point bending tests (in vivo)\",\n      \"journal\": \"Nutrition & metabolism\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro mechanistic pathway (Smad2/3-Runx2) supported by in vivo bone parameter readouts; single lab\",\n      \"pmids\": [\"31993071\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Vaspin reduces hepatocyte steatosis and fibrosis via the GRP78 receptor by activating AMPK, increasing fatty acid oxidation and secretion, decreasing lipogenesis and fatty acid uptake, and reducing α-SMA and TGF-β1 expression in co-cultured hepatocyte/stellate cell model.\",\n      \"method\": \"HepG2/LX-2 co-culture model; Nile Red lipid assay; flow cytometry; RT-qPCR (lipid metabolism genes); western blot (α-SMA, TGF-β1, AMPK); GRP78 receptor blockade\",\n      \"journal\": \"Journal of physiology and biochemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single publication, GRP78 involvement inferred from receptor blocking rather than siRNA; mechanistic follow-up is partial\",\n      \"pmids\": [\"35001345\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Vaspin (SERPINA12) was identified from visceral white adipose tissue (WAT) of OLETF rats using PCR-based cDNA subtraction. Administration of recombinant vaspin into high-fat high-sucrose chow-induced obese ICR mice improved glucose tolerance and insulin sensitivity.\",\n      \"method\": \"cDNA subtraction cloning; recombinant protein administration to obese mice; glucose tolerance test; insulin sensitivity assay\",\n      \"journal\": \"Expert opinion on investigational drugs\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — foundational identification paper with in vivo phenotype but no molecular pathway established; single lab, single publication\",\n      \"pmids\": [\"18321232\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Vaspin is specifically expressed in keratinocytes (KCs) in skin, closely associated with epidermal differentiation. Downregulation of vaspin in KCs in psoriasis resulted in decreased differentiation-associated gene expression and upregulation of inflammation-associated psoriasis signature genes. Vaspin decreased secretion of TNF-α, IL-1β, IL-6, IL-8, and MCP-1 by co-cultured immune cells; application of vaspin inhibited myeloid cell infiltration in a psoriasis-like mouse model.\",\n      \"method\": \"Immunohistochemistry; RT-PCR; siRNA knockdown of vaspin in KCs; co-culture of KCs with immune cells; in vivo mouse psoriasis model with vaspin application\",\n      \"journal\": \"The American journal of pathology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct vaspin knockdown in KCs with functional immune co-culture readout and in vivo model; single lab, multiple methods\",\n      \"pmids\": [\"26783881\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Vaspin in brown adipose tissue (BAT) is specifically induced at mRNA and protein levels by cold exposure and obesogenic (high-fat or high-sugar) diets in mice. Cold-induced BAT vaspin expression is accompanied by acute reduction in DNA methylation within the vaspin promoter in BAT, providing an epigenetic regulatory mechanism.\",\n      \"method\": \"mRNA and protein expression analysis in adipose tissue depots; adipogenesis and adrenergic stimulation experiments in brown adipocytes; vaspin promoter DNA methylation analysis\",\n      \"journal\": \"Molecular metabolism\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct DNA methylation measurement linked to gene expression change with functional stimuli; single lab, two orthogonal methods\",\n      \"pmids\": [\"28580279\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Vaspin promotes porcine granulosa cell proliferation, cell cycle progression into S and G2/M phases, and decreases apoptosis. GRP78 siRNA silencing and pharmacological inhibitors of MAP3/1 (ERK1/2), STAT3, and AKT blocked vaspin-induced proliferation and enhanced caspase-3/7 activities, establishing GRP78 as the receptor and these kinases as downstream mediators.\",\n      \"method\": \"alamarBlue proliferation assay; flow cytometry (cell cycle); Caspase-Glo 3/7 assay; siRNA silencing of GRP78; pharmacological kinase inhibitors; western blotting (cyclin D, E, A; BAX, BCL2, caspases, p53)\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA receptor knockdown plus multiple pharmacological inhibitors establishing pathway; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"31752432\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Vaspin enhances porcine luteal cell angiogenesis, proliferation, and decreases apoptosis via GRP78 receptor and MAP3/1 kinase pathways; GRP78 siRNA and MAP3/1 inhibitor (PD98059) reversed all vaspin effects.\",\n      \"method\": \"Luteal cell culture; alamarBlue proliferation; Caspase-Glo 3/7; angiogenic factor ELISA and PCR; GRP78 siRNA; PD98059 inhibition; western blotting\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown plus pharmacological inhibitor with multiple functional readouts; single lab\",\n      \"pmids\": [\"32957618\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Vaspin affects luteal cell steroidogenesis (stimulates progesterone synthesis), increases luteotropic PGE2:luteolytic PGF2α ratio, and activates PKA and MAP3/1 kinases via GRP78 receptor, as shown by GRP78 siRNA knockdown and MAP3/1 inhibitor reversal of vaspin effects.\",\n      \"method\": \"Luteal cell culture; GRP78 siRNA knockdown; MAP3/1 inhibitor (PD98059); PKA phosphorylation western blot; steroid hormone ELISA\",\n      \"journal\": \"The Journal of endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA receptor knockdown and pharmacological inhibitor establish pathway dependence; single lab\",\n      \"pmids\": [\"33108345\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"SerpinA12 (vaspin) secreted by hepatic stellate cells (HSCs) is protective against ethanol-induced steatosis in hepatocytes in vitro. In NRP-1 knockdown HSCs, SerpinA12 secretion was increased, and recombinant SerpinA12 was protective against ethanol-induced lipid droplet formation in hepatocytes. SerpinA12 was decreased in serum and liver tissue from patients with alcoholic hepatitis.\",\n      \"method\": \"HSC conditioned medium experiments; adipokine/inflammatory protein array; recombinant protein treatment of hepatocytes in vitro; lipid droplet assay; immunocompetent HCC mouse model\",\n      \"journal\": \"Journal of hepatology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditioned medium and recombinant protein rescue establish vaspin as HSC-secreted hepatoprotective factor; single lab, two orthogonal approaches\",\n      \"pmids\": [\"32087348\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Vaspin protein is expressed in human and rat placenta with tissue-specific localization: in rat, in trophoblast of the fetal labyrinth; in human, in cytotrophoblast and syncytiotrophoblast in first trimester and syncytiotrophoblast in third trimester. Food restriction increases placental vaspin mRNA and protein levels in rats, indicating nutritional regulation of vaspin expression.\",\n      \"method\": \"Immunohistochemistry (human and rat placenta); RT-PCR; food restriction experiment in rats\",\n      \"journal\": \"Histology and histopathology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — localization by IHC and expression regulation, no functional consequence established; single lab\",\n      \"pmids\": [\"19554505\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Vaspin (TNF-α-stimulated human umbilical vein endothelial cells): vaspin (10–100 ng/mL, 24 h) had no effect on basal endothelial cell morphology and did not inhibit TNF-α-induced activation of JNK, p38, or NF-κB (with only slight Akt inhibition), and did not decrease TNF-α-induced expression of VCAM-1, ICAM-1, E-selectin, COX-2, MCP-1, tissue factor, or PAI-1.\",\n      \"method\": \"Western blotting (JNK, p38, NF-κB, Akt); mRNA expression; protein expression in HUVECs with TNF-α stimulation\",\n      \"journal\": \"The Journal of veterinary medical science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — rigorous negative result with multiple signaling targets tested; single lab, single publication; reported as negative\",\n      \"pmids\": [\"19801900\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SERPINA12/vaspin is a serine protease inhibitor (serpin) adipokine that acts primarily by inhibiting kallikrein 7 (hK7) via classical serpin mechanism—confirmed by crystal structure, in vitro reconstitution, and active-site mutagenesis—thereby protecting insulin from hK7-mediated cleavage and regulating epidermal differentiation; it signals through cell-surface GRP78/MTJ-1 receptor complexes to activate PI3K/AKT and AMPK, suppress NF-κB-driven inflammation, and modulate steroidogenesis, osteogenesis, and energy metabolism across multiple tissues including adipose, liver, vascular endothelium, skin, and reproductive organs.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SERPINA12 (vaspin) is an adipokine of the serpin superfamily that functions both as a specific protease inhibitor and as a receptor-engaging signaling ligand, coordinating glucose metabolism, epithelial differentiation, vascular protection, and tissue homeostasis [#0, #2, #19]. Its defining biochemical activity is high-specificity inhibition of kallikrein 7 (KLK7/hK7) by the classical serpin mechanism, established by crystal structure, in vitro reconstitution with active-site mutagenesis, and detection of vaspin-hK7 complexes in human plasma; this protective inhibition shields insulin from hK7-mediated A/B-chain cleavage and improves glucose tolerance in vivo in a manner strictly dependent on serpin activity [#0]. The same protease-inhibitory function operates in skin, where loss-of-function nonsense variants in SERPINA12 cause autosomal recessive palmoplantar keratoderma: reduced KLK7 inhibition lowers the KLK7 substrates desmoglein-1 and corneodesmosin and drives epidermal acanthosis and hyperkeratosis [#1]. Independently of its serpin activity, vaspin signals through a cell-surface receptor complex of GRP78 and MTJ-1 (DnaJC1) recruited to the plasma membrane, activating Akt and AMPK; antibody blockade of GRP78 abolishes this signaling [#2]. Through GRP78 engagement and downstream PI3K/AKT, AMPK, ERK, STAT3, and PKA cascades, vaspin promotes insulin-independent GLUT4 translocation and muscle glucose uptake [#13], suppresses NF-\\u03baB-driven inflammatory and adhesion programs in endothelium and adipocytes [#8, #9], enhances endothelial NO bioavailability and protects vascular cells from apoptosis [#6, #7], drives osteoblast differentiation and survival [#12, #17], and supports ovarian and luteal steroidogenesis, proliferation, and survival [#15, #16, #22, #24]. In liver, GRP78-dependent AMPK activation reduces hepatocyte steatosis [#18], and a TCF7L2/\\u03b2-catenin-driven SERPINA12-GRP78-AKT/GSK3\\u03b2 feed-forward loop sustains hepatocellular carcinoma stemness and therapy resistance [#3]. Vaspin is also internalized into renal proximal tubular cells in a complex with HSPA1L and GRP78 via clathrin-mediated endocytosis, maintaining lysosomal and autophagic homeostasis [#4].\",\n  \"teleology\": [\n    {\n      \"year\": 2009,\n      \"claim\": \"Establishing that an adipose-derived factor could improve metabolic phenotype defined vaspin as a candidate insulin-sensitizing adipokine and motivated mechanistic dissection.\",\n      \"evidence\": \"cDNA subtraction cloning from OLETF rat visceral WAT and recombinant protein administration to obese mice\",\n      \"pmids\": [\"18321232\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No molecular receptor or pathway identified\", \"Single lab foundational report without mechanistic resolution\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identifying the cell-surface GRP78/MTJ-1 complex answered how a secreted serpin transmits an intracellular signal, defining vaspin's receptor-based signaling arm.\",\n      \"evidence\": \"Tandem affinity purification, cell-surface biotin labeling, reciprocal co-IP in liver and hepatoma cells, and GRP78 antibody blockade of Akt/AMPK activation\",\n      \"pmids\": [\"22837305\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and structural basis of vaspin-GRP78 binding unresolved\", \"Whether GRP78 transduces signal directly or via co-receptors not established\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Solving the crystal structure and reconstituting KLK7 inhibition defined vaspin's primary enzymatic target and showed its metabolic effect operates by protecting insulin from proteolytic degradation rather than altering insulin sensitivity.\",\n      \"evidence\": \"Crystal structure, in vitro protease inhibition with active-site mutants, plasma co-IP of vaspin-hK7 complexes, euglycemic-hyperinsulinemic clamp, and isolated islet assays\",\n      \"pmids\": [\"23370777\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full repertoire of physiological vaspin protease targets beyond hK7 not mapped\", \"Relationship between serpin activity and GRP78 signaling arm not reconciled\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Linking vaspin to keratinocyte differentiation extended its serpin/KLK7 axis to epithelial biology and connected its loss to inflammatory skin pathology.\",\n      \"evidence\": \"Immunohistochemistry, siRNA knockdown in keratinocytes, immune cell co-culture, and a psoriasis-like mouse model\",\n      \"pmids\": [\"26783881\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether skin effects are KLK7-dependent not directly tested in this work\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Human loss-of-function genetics established SERPINA12 as a Mendelian disease gene and confirmed in vivo that its physiological role is KLK7 inhibition controlling epidermal differentiation.\",\n      \"evidence\": \"Whole-exome sequencing of patients, 3D skin equivalent knockdown, KLK7 activity assays, and quantification of KLK7 substrates desmoglein-1 and corneodesmosin\",\n      \"pmids\": [\"32247861\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Genotype-phenotype variability and extracutaneous consequences of human deficiency not detailed\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Defining vaspin internalization via an HSPA1L/GRP78/clathrin complex positioned receptor-mediated endocytosis upstream of organellar homeostasis in renal tubular cells.\",\n      \"evidence\": \"Co-IP of vaspin-HSPA1L-GRP78-clathrin complexes, vaspin-/- knockout mouse histology, and HSPA1L overexpression rescue\",\n      \"pmids\": [\"33742129\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether endocytosis terminates or propagates GRP78 signaling unclear\", \"Generality of this trafficking route to other tissues unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showing a TCF7L2/\\u03b2-catenin-driven SERPINA12-GRP78-AKT feed-forward loop in HCC reframed vaspin as a context-dependent tumor-promoting factor rather than a purely protective adipokine.\",\n      \"evidence\": \"Transcriptome profiling, TCF7L2 promoter-binding assay, SERPINA12-GRP78 co-IP, shRNA loss-of-function, and in vivo AAV knockdown sensitizing tumors to sorafenib\",\n      \"pmids\": [\"36630996\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Reconciliation with hepatoprotective roles of vaspin in steatosis not addressed\", \"Whether serpin activity contributes to the oncogenic loop untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How vaspin's serpin protease-inhibitory activity and its GRP78-receptor signaling arm are integrated\\u2014and which physiological outputs depend on which mode\\u2014remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No single study dissects serpin-dependent versus GRP78-dependent outputs in the same system\", \"The protease degrading the anti-orexigenic factor inferred from CNS studies is unidentified\", \"Structural basis and exact binding site for the vaspin-GRP78 interaction undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [2, 3, 13]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [0, 13, 25]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 6, 8]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [0, 13, 18]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [8, 9, 20]}\n    ],\n    \"complexes\": [\"vaspin-GRP78-MTJ-1 plasma membrane receptor complex\", \"vaspin-HSPA1L-GRP78 endocytic complex\"],\n    \"partners\": [\"KLK7\", \"HSPA90B1/GRP78\", \"DNAJC1\", \"HSPA1L\", \"CLTC\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":6,"faith_total":7,"faith_pct":85.71428571428571}}