{"gene":"TSKU","run_date":"2026-06-10T10:51:56","timeline":{"discoveries":[{"year":2019,"finding":"TSK (Tsukushi) is a hepatokine secreted by the liver. Genetic deletion (TSK-null mice) or overexpression of TSK did not affect thermogenic gene expression in brown adipose tissue, sympathetic innervation markers, body weight, body temperature, or glucose homeostasis, indicating that TSK is not a significant regulator of BAT thermogenesis under the conditions tested.","method":"TSK-null and TSK-overexpressing mouse models; thermogenic gene expression assays; body weight and glucose tolerance measurements","journal":"Molecular metabolism","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO and OE mouse models with multiple physiological readouts in a single lab; rigorous negative result challenging a prior claim","pmids":["31767170"],"is_preprint":false},{"year":2017,"finding":"TSK (Tsukushi), a secreted small leucine-rich repeat proteoglycan (SLRP), is required for normal bone elongation and bone mass. TSK-deficient (TSK−/−) mice showed decreased weight, short stature, and reduced longitudinal bone growth at 3 weeks. In vitro siRNA knockdown of TSK in a chondrogenic cell line caused down-regulation of early chondrogenic marker genes and up-regulation of mid-to-late chondrogenic markers, placing TSK as a modulator of growth plate chondrocyte differentiation.","method":"TSK-knockout mouse phenotyping (skeletal measurements, bone mass); siRNA knockdown in chondrogenic cell line with marker gene expression analysis","journal":"Regenerative therapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO mouse with defined skeletal phenotype plus in vitro siRNA with gene expression readout; single lab, two complementary methods","pmids":["30271858"],"is_preprint":false},{"year":2021,"finding":"Hepatic TSK expression and plasma TSK concentrations are induced by feeding and are regulated by melanocortin-4 receptor (MC4R) signaling. TSK inactivation in MC4R-knockout mice restores energy balance, ameliorates hyperphagia, enhances thermogenic gene expression in brown fat, reduces obesity-associated inflammation in liver and adipose tissue, and protects against diet-induced nonalcoholic steatohepatitis. TSK ablation also augments feeding-induced c-Fos expression in the paraventricular nucleus of the hypothalamus, indicating cross talk between TSK and the central melanocortin circuit.","method":"TSK/MC4R double-knockout mice; thermogenic gene expression; c-Fos immunostaining in hypothalamic paraventricular nucleus; liver histology and inflammation markers; body weight and metabolic phenotyping","journal":"Diabetes","confidence":"High","confidence_rationale":"Tier 2 / Strong — double-KO epistasis experiment with multiple orthogonal physiological and molecular readouts establishing pathway position of TSK downstream of MC4R","pmids":["34183373"],"is_preprint":false},{"year":2022,"finding":"TSK (Tsukushi) secreted by the liver is required for maintaining skeletal muscle mass, contractile (slow-twitch) myofiber gene expression, grip strength, and exercise endurance. TSK-null mice show selective impairment of myofibrillar genes characteristic of slow-twitch fibers and abnormal neuromuscular junction formation. TSK-null mice also exhibit diminished muscle regeneration after cardiotoxin injury. AAV-mediated TSK overexpression in adult mice failed to rescue these myofiber defects, suggesting developmental-stage-restricted action.","method":"TSK-knockout mouse phenotyping (grip strength, treadmill exercise); skeletal muscle transcriptomics; neuromuscular junction morphology; cardiotoxin-induced injury regeneration assay; AAV-mediated TSK overexpression","journal":"JCI insight","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse with multiple orthogonal readouts (functional, transcriptomic, morphological, regeneration) plus OE rescue experiment; single lab but highly rigorous","pmids":["35025761"],"is_preprint":false},{"year":2025,"finding":"HIF1α inhibitor (KC7F2) up-regulates TSKU expression in hepatocytes in vitro and in a CDAHFD-induced NASH mouse model, and the resulting increased TSKU leads to hepatocellular lipid accumulation; siRNA knockdown of TSKU in hepatocytes reverses the KC7F2-induced lipid accumulation, placing TSKU downstream of HIF1α in hepatic lipid metabolism.","method":"CDAHFD NASH mouse model with KC7F2 treatment; in vitro hepatocyte culture with KC7F2; siRNA knockdown of TSKU; lipid accumulation assays","journal":"Archives of biochemistry and biophysics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo mouse model plus in vitro siRNA rescue establishing epistatic relationship; single lab, two complementary methods","pmids":["39832609"],"is_preprint":false},{"year":2024,"finding":"A novel PXR-inducible enhancer of TSKU was identified in human hepatocytes by CAGE-based transcription initiation profiling and validated by CRISPR/Cas9 knockout. Additionally, siRNA-mediated knockdown of TSKU unexpectedly reduced the expression of vitamin D-metabolizing enzymes in hepatocytes, revealing a functional role for TSKU in regulating this metabolic pathway.","method":"CAGE transcription initiation profiling; CRISPR/Cas9 enhancer knockout; siRNA knockdown of TSKU with measurement of vitamin D-metabolizing enzyme expression","journal":"bioRxiv (preprint)","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — CRISPR enhancer validation and siRNA functional assay are rigorous methods but preprint, single lab, and partial mechanistic follow-up","pmids":["bio_10.1101_2024.07.24.604883"],"is_preprint":true}],"current_model":"Tsukushi (TSKU) is a secreted small leucine-rich repeat proteoglycan (SLRP) produced primarily by the liver whose expression is induced by feeding and regulated by MC4R signaling; it acts as a hormonal cue that inhibits brown adipose tissue thermogenesis, maintains slow-twitch skeletal muscle fiber gene programs and neuromuscular junction integrity, supports muscle regeneration, modulates bone elongation by directing growth plate chondrocyte differentiation, and influences hepatic lipid metabolism downstream of HIF1α, with evidence also that it regulates expression of vitamin D-metabolizing enzymes in hepatocytes."},"narrative":{"mechanistic_narrative":"TSKU (Tsukushi) is a secreted, liver-derived small leucine-rich repeat proteoglycan (SLRP) that functions as a hepatokine coupling nutritional and hormonal signals to peripheral metabolism, musculoskeletal development, and tissue homeostasis [PMID:30271858, PMID:34183373, PMID:35025761]. Hepatic TSKU expression and circulating TSKU are induced by feeding under control of melanocortin-4 receptor (MC4R) signaling, and TSKU acts downstream of this central circuit: its ablation in MC4R-deficient mice restores energy balance, relieves hyperphagia, augments brown-fat thermogenic gene expression, and protects against diet-induced steatohepatitis, while increasing feeding-induced c-Fos activation in the hypothalamic paraventricular nucleus [PMID:34183373]. In the musculoskeletal system, TSKU is required for normal longitudinal bone growth, where it directs growth-plate chondrocyte differentiation by sustaining early and restraining mid-to-late chondrogenic gene programs [PMID:30271858], and for maintaining skeletal muscle mass, slow-twitch myofiber gene expression, neuromuscular junction integrity, and post-injury regeneration, with its action restricted to a developmental window since adult re-expression fails to rescue myofiber defects [PMID:35025761]. In hepatocytes, TSKU lies downstream of HIF1α in the control of cellular lipid accumulation and additionally regulates expression of vitamin D-metabolizing enzymes [PMID:39832609, PMID:bio_10.1101_2024.07.24.604883]. The molecular partners and biochemical mechanism by which secreted TSKU transduces these effects have not been characterized in the available corpus.","teleology":[{"year":2017,"claim":"Established TSKU as a determinant of skeletal growth by showing it modulates the timing of chondrocyte differentiation in the growth plate, answering whether a secreted SLRP shapes endochondral bone elongation.","evidence":"TSK-knockout mouse skeletal phenotyping plus siRNA knockdown in a chondrogenic cell line with chondrogenic marker analysis","pmids":["30271858"],"confidence":"Medium","gaps":["No molecular receptor or binding partner for TSKU in chondrocytes identified","Mechanism linking secreted TSKU to the chondrogenic transcriptional switch unknown"]},{"year":2019,"claim":"Tested whether TSKU regulates brown adipose tissue thermogenesis directly and found that, in isolation, neither loss nor overexpression altered thermogenic gene programs or systemic metabolism, narrowing the conditions under which TSKU acts on energy balance.","evidence":"TSK-null and TSK-overexpressing mice with thermogenic gene expression, body weight, and glucose tolerance readouts","pmids":["31767170"],"confidence":"Medium","gaps":["Negative result under baseline conditions does not exclude context-dependent action","Did not test TSKU in a sensitized metabolic background"]},{"year":2021,"claim":"Positioned TSKU as a feeding-induced hepatokine acting downstream of MC4R signaling, reconciling the earlier negative thermogenesis result by showing TSKU's metabolic effects emerge within the central melanocortin context.","evidence":"TSK/MC4R double-knockout epistasis mice with thermogenic gene expression, hypothalamic c-Fos immunostaining, liver/adipose inflammation, and metabolic phenotyping","pmids":["34183373"],"confidence":"High","gaps":["Receptor or target tissue mediating TSKU's peripheral and central effects not identified","Mechanism of feeding-induced hepatic TSKU transcription not defined"]},{"year":2022,"claim":"Defined a developmental-stage-restricted role for liver-derived TSKU in establishing slow-twitch myofiber identity, neuromuscular junction integrity, and regenerative capacity, showing adult re-expression cannot rescue.","evidence":"TSK-knockout mouse grip strength and endurance testing, muscle transcriptomics, NMJ morphology, cardiotoxin regeneration assay, and AAV overexpression rescue","pmids":["35025761"],"confidence":"High","gaps":["Molecular signal linking circulating TSKU to muscle fiber-type and NMJ programs unknown","Basis for the developmental window of action unresolved"]},{"year":2024,"claim":"Identified a PXR-inducible enhancer controlling hepatic TSKU transcription and revealed an unexpected role for TSKU in supporting expression of vitamin D-metabolizing enzymes, linking xenobiotic/nuclear-receptor regulation to TSKU output.","evidence":"CAGE transcription initiation profiling, CRISPR/Cas9 enhancer knockout, and siRNA knockdown of TSKU with vitamin D enzyme readout (preprint)","pmids":["bio_10.1101_2024.07.24.604883"],"confidence":"Medium","gaps":["Preprint, single lab, awaits peer review","Mechanism by which TSKU regulates vitamin D enzyme expression not defined"]},{"year":2025,"claim":"Placed TSKU downstream of HIF1α in hepatocyte lipid handling, showing HIF1α inhibition raises TSKU and drives lipid accumulation reversible by TSKU knockdown.","evidence":"CDAHFD NASH mouse model with KC7F2 HIF1α inhibitor, in vitro hepatocyte culture, and siRNA knockdown rescue of lipid accumulation","pmids":["39832609"],"confidence":"Medium","gaps":["Direct molecular effector by which TSKU promotes hepatocellular lipid accumulation unknown","Whether the HIF1α–TSKU axis intersects the MC4R feeding axis not tested"]},{"year":null,"claim":"The cell-surface receptor(s) and direct binding partners through which secreted TSKU transduces its diverse effects on adipose, muscle, bone, and hepatocyte biology remain unidentified.","evidence":"No direct receptor-binding or biochemical interaction study present in the timeline","pmids":[],"confidence":"Low","gaps":["No TSKU receptor identified","No structural or biochemical characterization of TSKU interactions","Unclear whether one shared mechanism underlies effects across tissues"]}],"mechanism_profile":{"molecular_activity":[],"localization":[{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[0,1,2,3]}],"pathway":[{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[2,4]}],"complexes":[],"partners":[],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8WUA8","full_name":"Tsukushi","aliases":["E2-induced gene 4 protein","Leucine-rich repeat-containing protein 54"],"length_aa":353,"mass_kda":37.8,"function":"Contributes to various developmental events and other processes such as wound healing and cholesterol homeostasis through its interactions with multiple signaling pathways. Wnt signaling inhibitor which competes with WNT2B for binding to Wnt receptor FZD4 and represses WNT2B-dependent development of the peripheral eye. Plays a role in regulating the hair cycle by controlling TGFB1 signaling. Required for the development of the anterior commissure in the brain by inhibiting neurite outgrowth. Essential for terminal differentiation of hippocampal neural stem cells. Plays a role in regulating bone elongation and bone mass by modulating growth plate chondrocyte function and overall body size. Required for development of the inner ear through its involvement in stereocilia formation in inner hair cells. Facilitates wound healing by inhibiting secretion of TGFB1 from macrophages which prevents myofibroblast differentiation, maintaining inflammatory cell quiescence. Plays a role in cholesterol homeostasis by reducing circulating high-density lipoprotein cholesterol, lowering cholesterol efflux capacity and decreasing cholesterol-to-bile acid conversion in the liver. In one study, shown to negatively regulate sympathetic innervation in brown fat, leading to reduced energy expenditure. In another study, shown not to affect brown fat thermogenic capacity, body weight gain or glucose homeostasis","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/Q8WUA8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TSKU","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TSKU","total_profiled":1310},"omim":[{"mim_id":"608015","title":"TSUKUSHIN; TSKU","url":"https://www.omim.org/entry/608015"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Nuclear bodies","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"liver","ntpm":222.0}],"url":"https://www.proteinatlas.org/search/TSKU"},"hgnc":{"alias_symbol":["E2IG4","TSK"],"prev_symbol":["LRRC54"]},"alphafold":{"accession":"Q8WUA8","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WUA8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WUA8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WUA8-F1-predicted_aligned_error_v6.png","plddt_mean":86.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TSKU","jax_strain_url":"https://www.jax.org/strain/search?query=TSKU"},"sequence":{"accession":"Q8WUA8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8WUA8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8WUA8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WUA8"}},"corpus_meta":[{"pmid":"219222","id":"PMC_219222","title":"Control of herpes simplex virus type 1 mRNA synthesis in cells infected with wild-type virus or the temperature-sensitive mutant tsK.","date":"1979","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/219222","citation_count":473,"is_preprint":false},{"pmid":"8421704","id":"PMC_8421704","title":"Developmental regulation of a murine T-cell-specific tyrosine kinase gene, Tsk.","date":"1993","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/8421704","citation_count":156,"is_preprint":false},{"pmid":"8810341","id":"PMC_8810341","title":"Identification of Itk/Tsk Src homology 3 domain ligands.","date":"1996","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8810341","citation_count":150,"is_preprint":false},{"pmid":"228063","id":"PMC_228063","title":"Abnormal properties of an immediate early polypeptide in cells infected with the herpes simplex virus type 1 mutant tsK.","date":"1979","source":"Journal of 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investigative dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/11168809","citation_count":99,"is_preprint":false},{"pmid":"2416757","id":"PMC_2416757","title":"Increased collagen biosynthesis and increased expression of type I and type III procollagen genes in tight skin (TSK) mouse fibroblasts.","date":"1986","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/2416757","citation_count":85,"is_preprint":false},{"pmid":"7561053","id":"PMC_7561053","title":"Activation and interaction with protein kinase C of a cytoplasmic tyrosine kinase, Itk/Tsk/Emt, on Fc epsilon RI cross-linking on mast cells.","date":"1995","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/7561053","citation_count":83,"is_preprint":false},{"pmid":"10506192","id":"PMC_10506192","title":"Itk/Emt/Tsk activation in response to CD3 cross-linking in Jurkat T cells requires ZAP-70 and Lat and is independent of membrane recruitment.","date":"1999","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10506192","citation_count":76,"is_preprint":false},{"pmid":"8609388","id":"PMC_8609388","title":"The EMT/ITK/TSK (EMT) tyrosine kinase is activated during TCR signaling: LCK is required for optimal activation of EMT.","date":"1996","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/8609388","citation_count":73,"is_preprint":false},{"pmid":"3110419","id":"PMC_3110419","title":"Inhibition of fibrosis in TSK mice by blocking mast cell degranulation.","date":"1987","source":"The Journal of rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/3110419","citation_count":69,"is_preprint":false},{"pmid":"7271067","id":"PMC_7271067","title":"Hereditary emphysema in the tight-skin (Tsk/+) mouse.","date":"1981","source":"The American review of respiratory disease","url":"https://pubmed.ncbi.nlm.nih.gov/7271067","citation_count":68,"is_preprint":false},{"pmid":"7359004","id":"PMC_7359004","title":"The ultrastructure of collagen in the dermis of tight-skin (Tsk) mutant mice.","date":"1980","source":"The Journal of investigative dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/7359004","citation_count":56,"is_preprint":false},{"pmid":"10586033","id":"PMC_10586033","title":"Regulated association between the tyrosine kinase Emt/Itk/Tsk and phospholipase-C gamma 1 in human T lymphocytes.","date":"1999","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/10586033","citation_count":45,"is_preprint":false},{"pmid":"11705455","id":"PMC_11705455","title":"Reduction in dermal fibrosis in the tight-skin (Tsk) mouse after local application of halofuginone.","date":"2001","source":"Biochemical 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EMT/ITK/TSK.","date":"1996","source":"International immunology","url":"https://pubmed.ncbi.nlm.nih.gov/8943565","citation_count":35,"is_preprint":false},{"pmid":"7902327","id":"PMC_7902327","title":"The tight skin (Tsk) mutation in the mouse, a model for human fibrotic diseases, is tightly linked to the beta 2-microglobulin (B2m) gene on chromosome 2.","date":"1993","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/7902327","citation_count":32,"is_preprint":false},{"pmid":"2813452","id":"PMC_2813452","title":"Adoptive transfer of tsk skin fibrosis to +/+ recipients by tsk bone marrow and spleen cells.","date":"1989","source":"Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/2813452","citation_count":32,"is_preprint":false},{"pmid":"12482197","id":"PMC_12482197","title":"Effect of halofuginone on the development of tight skin (TSK) syndrome.","date":"2002","source":"Autoimmunity","url":"https://pubmed.ncbi.nlm.nih.gov/12482197","citation_count":30,"is_preprint":false},{"pmid":"15336923","id":"PMC_15336923","title":"Viscoelastic properties of skin in Mov-13 and Tsk mice.","date":"2004","source":"Journal of biomechanics","url":"https://pubmed.ncbi.nlm.nih.gov/15336923","citation_count":29,"is_preprint":false},{"pmid":"9820515","id":"PMC_9820515","title":"Phosphatidylinositol 3-kinase is required for CD28 but not CD3 regulation of the TEC family tyrosine kinase EMT/ITK/TSK: functional and physical interaction of EMT with phosphatidylinositol 3-kinase.","date":"1998","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/9820515","citation_count":28,"is_preprint":false},{"pmid":"22071972","id":"PMC_22071972","title":"Effect of topical interferon-γ gene therapy using gemini nanoparticles on pathophysiological markers of cutaneous scleroderma in Tsk/+ mice.","date":"2011","source":"Gene therapy","url":"https://pubmed.ncbi.nlm.nih.gov/22071972","citation_count":26,"is_preprint":false},{"pmid":"16583319","id":"PMC_16583319","title":"Extracellular matrix containing mutated fibrillin-1 (Fbn1) down regulates Col1a1, Col1a2, Col3a1, Col5a1, and Col5a2 mRNA levels in Tsk/+ and Tsk/Tsk embryonic fibroblasts.","date":"2006","source":"Amino acids","url":"https://pubmed.ncbi.nlm.nih.gov/16583319","citation_count":21,"is_preprint":false},{"pmid":"15610515","id":"PMC_15610515","title":"Fibulin-2 and fibulin-5 alterations in tsk mice associated with disorganized hypodermal elastic fibers and skin tethering.","date":"2004","source":"The Journal of investigative dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/15610515","citation_count":21,"is_preprint":false},{"pmid":"9494076","id":"PMC_9494076","title":"Efficient CD28 signalling leads to increases in the kinase activities of the TEC family tyrosine kinase EMT/ITK/TSK and the SRC family tyrosine kinase LCK.","date":"1998","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/9494076","citation_count":20,"is_preprint":false},{"pmid":"1382866","id":"PMC_1382866","title":"Self-reactive repertoire of tight skin (TSK/+) mouse: immunochemical and molecular characterization of anti-cellular autoantibodies.","date":"1992","source":"Cellular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/1382866","citation_count":20,"is_preprint":false},{"pmid":"9405934","id":"PMC_9405934","title":"Structure of the mutant fibrillin-1 gene in the tight skin (TSK) mouse.","date":"1997","source":"DNA research : an international journal for rapid publication of reports on genes and genomes","url":"https://pubmed.ncbi.nlm.nih.gov/9405934","citation_count":19,"is_preprint":false},{"pmid":"31767170","id":"PMC_31767170","title":"The Hepatokine TSK does not affect brown fat thermogenic capacity, body weight gain, and glucose homeostasis.","date":"2019","source":"Molecular metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/31767170","citation_count":19,"is_preprint":false},{"pmid":"17705049","id":"PMC_17705049","title":"Marfan-like skeletal phenotype in the tight skin (Tsk) mouse.","date":"2007","source":"Calcified tissue international","url":"https://pubmed.ncbi.nlm.nih.gov/17705049","citation_count":19,"is_preprint":false},{"pmid":"11123012","id":"PMC_11123012","title":"Genetic and immunologic features associated with scleroderma-like syndrome of TSK mice.","date":"1999","source":"Current rheumatology reports","url":"https://pubmed.ncbi.nlm.nih.gov/11123012","citation_count":16,"is_preprint":false},{"pmid":"4086168","id":"PMC_4086168","title":"Use of high-performance size-exclusion chromatography to measure protein molecular weight and hydrodynamic radius. An investigation of the properties of the TSK 3000 SW column.","date":"1985","source":"International journal of peptide and protein research","url":"https://pubmed.ncbi.nlm.nih.gov/4086168","citation_count":16,"is_preprint":false},{"pmid":"33860453","id":"PMC_33860453","title":"Tsukushi and TSKU genotype in obesity and related metabolic disorders.","date":"2021","source":"Journal of endocrinological investigation","url":"https://pubmed.ncbi.nlm.nih.gov/33860453","citation_count":15,"is_preprint":false},{"pmid":"1699570","id":"PMC_1699570","title":"Amino acid side chain interaction with chelate-liganded crosslinked dextran, agarose and TSK gel. A mini review of recent work.","date":"1990","source":"Journal of molecular recognition : JMR","url":"https://pubmed.ncbi.nlm.nih.gov/1699570","citation_count":15,"is_preprint":false},{"pmid":"3680408","id":"PMC_3680408","title":"Improved Stokes radius measurement of the glucocorticoid receptor using TSK G4000SW and TSK G3000SW high-performance size-exclusion columns. Analytical and preparative applications.","date":"1987","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/3680408","citation_count":13,"is_preprint":false},{"pmid":"34183373","id":"PMC_34183373","title":"Deletion of the Feeding-Induced Hepatokine TSK Ameliorates the Melanocortin Obesity Syndrome.","date":"2021","source":"Diabetes","url":"https://pubmed.ncbi.nlm.nih.gov/34183373","citation_count":12,"is_preprint":false},{"pmid":"36012288","id":"PMC_36012288","title":"The Role of the TSK/TONSL-H3.1 Pathway in Maintaining Genome Stability in Multicellular Eukaryotes.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36012288","citation_count":12,"is_preprint":false},{"pmid":"30271858","id":"PMC_30271858","title":"The role of Tsukushi (TSK), a small leucine-rich repeat proteoglycan, in bone growth.","date":"2017","source":"Regenerative therapy","url":"https://pubmed.ncbi.nlm.nih.gov/30271858","citation_count":11,"is_preprint":false},{"pmid":"7959775","id":"PMC_7959775","title":"Tight-skin (Tsk) maps on mouse chromosome 2 within the region of linkage homology with human chromosome 15.","date":"1994","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/7959775","citation_count":11,"is_preprint":false},{"pmid":"22759510","id":"PMC_22759510","title":"Gene regulatory network from microarray data of colon cancer patients using TSK-type recurrent neural fuzzy network.","date":"2012","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/22759510","citation_count":10,"is_preprint":false},{"pmid":"1617705","id":"PMC_1617705","title":"Granulated metrial gland cells in the pregnant uterus of mice expressing the collagen mutation tight-skin (Tsk/+).","date":"1992","source":"Cell and tissue research","url":"https://pubmed.ncbi.nlm.nih.gov/1617705","citation_count":10,"is_preprint":false},{"pmid":"23266630","id":"PMC_23266630","title":"MicroRNA-mRNA interaction network using TSK-type recurrent neural fuzzy network.","date":"2012","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/23266630","citation_count":8,"is_preprint":false},{"pmid":"35025761","id":"PMC_35025761","title":"The hepatokine TSK maintains myofiber integrity and exercise endurance and contributes to muscle regeneration.","date":"2022","source":"JCI insight","url":"https://pubmed.ncbi.nlm.nih.gov/35025761","citation_count":6,"is_preprint":false},{"pmid":"35438149","id":"PMC_35438149","title":"Structured Sparse Regularized TSK Fuzzy System for predicting therapeutic peptides.","date":"2022","source":"Briefings in bioinformatics","url":"https://pubmed.ncbi.nlm.nih.gov/35438149","citation_count":6,"is_preprint":false},{"pmid":"7047547","id":"PMC_7047547","title":"Rapid method for purification of plasmid DNA and DNA fragments from DNA linkers using high-performance liquid chromatography on TSK-PW gel.","date":"1982","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/7047547","citation_count":6,"is_preprint":false},{"pmid":"8864822","id":"PMC_8864822","title":"Silicone does not potentiate development of the scleroderma-like syndrome in tight skin (TSK/+) mice.","date":"1996","source":"Journal of autoimmunity","url":"https://pubmed.ncbi.nlm.nih.gov/8864822","citation_count":5,"is_preprint":false},{"pmid":"4030961","id":"PMC_4030961","title":"Application of a new ion exchanger TSK-GEL DEAE-5PW, to the purification of Cu,Zn-superoxide dismutase of bovine erythrocytes.","date":"1985","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/4030961","citation_count":5,"is_preprint":false},{"pmid":"2254388","id":"PMC_2254388","title":"High-performance size-exclusion chromatography of porcine colonic mucins. Comparison of Bio-Gel TSK 40XL and Sepharose 4B columns.","date":"1990","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/2254388","citation_count":5,"is_preprint":false},{"pmid":"2843556","id":"PMC_2843556","title":"Use of a small TSK GSW high-performance liquid chromatographic column for large-zone chromatographic studies of monomer-oligomer equilibria of membrane protein.","date":"1988","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/2843556","citation_count":5,"is_preprint":false},{"pmid":"38347040","id":"PMC_38347040","title":"Aqueous humor TGFβ and fibrillin-1 in Tsk mice reveal clues to POAG pathogenesis.","date":"2024","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/38347040","citation_count":4,"is_preprint":false},{"pmid":"11855838","id":"PMC_11855838","title":"Synthesis, 3-D structure, and pharmacology of a reticulated chimeric peptide derived from maurotoxin and Tsk scorpion toxins.","date":"2002","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/11855838","citation_count":4,"is_preprint":false},{"pmid":"8565570","id":"PMC_8565570","title":"Development of scleroderma-like syndrome in Tsk/+ mice is not enhanced by silicone administration.","date":"1996","source":"Current topics in microbiology and immunology","url":"https://pubmed.ncbi.nlm.nih.gov/8565570","citation_count":4,"is_preprint":false},{"pmid":"2613776","id":"PMC_2613776","title":"TSK-Toyopearl gels for the preparative separation of sterol carrier protein2 from rat liver.","date":"1989","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/2613776","citation_count":4,"is_preprint":false},{"pmid":"3155887","id":"PMC_3155887","title":"Isolation of Fab and Fc fragments from a plasmin-treated human immunoglobulin by high-speed gel filtration on TSK G3000SW and G3000SWG.","date":"1985","source":"Vox sanguinis","url":"https://pubmed.ncbi.nlm.nih.gov/3155887","citation_count":2,"is_preprint":false},{"pmid":"6490770","id":"PMC_6490770","title":"Use of TSK-SW columns for the high-performance liquid chromatographic analysis of proteins, isolated from sympathetic nerves and fractionated by fractogel TSK-HW chromatography. Purification of L-DOPA decarboxylase.","date":"1984","source":"Journal of chromatography","url":"https://pubmed.ncbi.nlm.nih.gov/6490770","citation_count":2,"is_preprint":false},{"pmid":"9129989","id":"PMC_9129989","title":"Monoclonal antibody to heparan sulfate from autoimmune tight skin (TSK) mice binds to the endothelial cell surface.","date":"1997","source":"Immunological investigations","url":"https://pubmed.ncbi.nlm.nih.gov/9129989","citation_count":2,"is_preprint":false},{"pmid":"29568311","id":"PMC_29568311","title":"Enhanced Ant Colony Optimization with Dynamic Mutation and Ad Hoc Initialization for Improving the Design of TSK-Type Fuzzy System.","date":"2018","source":"Computational intelligence and neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/29568311","citation_count":1,"is_preprint":false},{"pmid":"39832609","id":"PMC_39832609","title":"Hypoxia-inducible factor-1α inhibitor promotes non-alcoholic steatohepatitis development and increases hepatocellular lipid accumulation via TSKU upregulation.","date":"2025","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/39832609","citation_count":0,"is_preprint":false},{"pmid":"39713323","id":"PMC_39713323","title":"H3.1K27M-induced misregulation of the TSK/TONSL-H3.1 pathway causes genomic instability.","date":"2024","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/39713323","citation_count":0,"is_preprint":false},{"pmid":"41008788","id":"PMC_41008788","title":"Cancer Growth and Invasion Are Increased in the Tight Skin (TSK) Mouse.","date":"2025","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/41008788","citation_count":0,"is_preprint":false},{"pmid":"15344603","id":"PMC_15344603","title":"Transcription activity in fibroblasts from the adult tight skin (TSK) mouse.","date":"2004","source":"Clinical and experimental rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/15344603","citation_count":0,"is_preprint":false},{"pmid":"21709856","id":"PMC_21709856","title":"Multi Groups Cooperation based Symbiotic Evolution for TSK-type Neuro-Fuzzy Systems Design.","date":"2010","source":"Expert systems with applications","url":"https://pubmed.ncbi.nlm.nih.gov/21709856","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.01.25332781","title":"Relationship Between Kinesiophobia and Fear of Falling in Patients Suffering from Stroke Leading to Physical Disability in Selected Rehabilitation Center of Bangladesh","date":"2025-08-05","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.01.25332781","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.07.24.604883","title":"Drug-induced cis-regulatory elements in human hepatocytes affect molecular phenotypes associated with adverse reactions","date":"2024-07-24","source":"bioRxiv","url":"https://doi.org/10.1101/2024.07.24.604883","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.05.14.25327357","title":"Psychological Readiness, Injury-Related Fear, and Persistent Knee Symptoms After Anterior Cruciate Ligament Reconstruction in Riyadh, Saudi Arabia: A Cross-Sectional Study","date":"2025-05-16","source":"bioRxiv","url":"https://doi.org/10.1101/2025.05.14.25327357","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.08.28.610095","title":"Sex specific knee joint soft tissue mineralization with Fibrillin-1 mutation in male Tight Skin mice","date":"2024-08-28","source":"bioRxiv","url":"https://doi.org/10.1101/2024.08.28.610095","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.06.19.24309180","title":"Multiple Physiological and Behavioural Parameters Identification for Dietary Monitoring Using Wearable Sensors: A Study Protocol","date":"2024-06-20","source":"bioRxiv","url":"https://doi.org/10.1101/2024.06.19.24309180","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":32497,"output_tokens":2272,"usd":0.065785,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8882,"output_tokens":2562,"usd":0.05423,"stage2_stop_reason":"end_turn"},"total_usd":0.120015,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"Looking at the corpus, I need to identify papers about the canonical TSKU gene (also known as TSK, Tsukushi, LRRC54, E2IG4) — a secreted small leucine-rich repeat proteoglycan/hepatokine. I need to distinguish this from:\n- HSV-1 tsK mutant (papers 1, 4, 18) → virus, not the gene\n- Itk/Tsk tyrosine kinase (papers 2, 3, 5, 9, 10, 11, 15, 19, 24, 28) → this is ITK (a different gene; \"Tsk\" here is an alias for ITK, not TSKU)\n- Tight skin (Tsk) mouse with fibrillin-1 mutation (papers 6, 7, 8, 12-14, 16, 17, 20-23, 25-33, 41, 43, 48, 52, 54, 62, 63, 68) → fibrillin-1/Tsk mouse model, not TSKU protein\n- TSK chromatography columns (papers 34-37, 42, 44, 46-51, 53, 55-57, 59, 64) → chromatography equipment\n- Tampa Scale for Kinesiophobia (papers 65, 67) → clinical scale\n- Scorpion toxin Tsk (paper 53) → different protein\n- TSK/TONSL in Arabidopsis (paper 39, 61) → plant TONSOKU, not human TSKU\n- Fuzzy logic TSK systems (papers 42, 44, 46, 59, 64) → mathematical models\n\nPapers genuinely about TSKU (Tsukushi hepatokine/SLRP): 31, 35, 38, 40, 45, 60, 66\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2019,\n      \"finding\": \"TSK (Tsukushi) is a hepatokine secreted by the liver. Genetic deletion (TSK-null mice) or overexpression of TSK did not affect thermogenic gene expression in brown adipose tissue, sympathetic innervation markers, body weight, body temperature, or glucose homeostasis, indicating that TSK is not a significant regulator of BAT thermogenesis under the conditions tested.\",\n      \"method\": \"TSK-null and TSK-overexpressing mouse models; thermogenic gene expression assays; body weight and glucose tolerance measurements\",\n      \"journal\": \"Molecular metabolism\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO and OE mouse models with multiple physiological readouts in a single lab; rigorous negative result challenging a prior claim\",\n      \"pmids\": [\"31767170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"TSK (Tsukushi), a secreted small leucine-rich repeat proteoglycan (SLRP), is required for normal bone elongation and bone mass. TSK-deficient (TSK−/−) mice showed decreased weight, short stature, and reduced longitudinal bone growth at 3 weeks. In vitro siRNA knockdown of TSK in a chondrogenic cell line caused down-regulation of early chondrogenic marker genes and up-regulation of mid-to-late chondrogenic markers, placing TSK as a modulator of growth plate chondrocyte differentiation.\",\n      \"method\": \"TSK-knockout mouse phenotyping (skeletal measurements, bone mass); siRNA knockdown in chondrogenic cell line with marker gene expression analysis\",\n      \"journal\": \"Regenerative therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO mouse with defined skeletal phenotype plus in vitro siRNA with gene expression readout; single lab, two complementary methods\",\n      \"pmids\": [\"30271858\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Hepatic TSK expression and plasma TSK concentrations are induced by feeding and are regulated by melanocortin-4 receptor (MC4R) signaling. TSK inactivation in MC4R-knockout mice restores energy balance, ameliorates hyperphagia, enhances thermogenic gene expression in brown fat, reduces obesity-associated inflammation in liver and adipose tissue, and protects against diet-induced nonalcoholic steatohepatitis. TSK ablation also augments feeding-induced c-Fos expression in the paraventricular nucleus of the hypothalamus, indicating cross talk between TSK and the central melanocortin circuit.\",\n      \"method\": \"TSK/MC4R double-knockout mice; thermogenic gene expression; c-Fos immunostaining in hypothalamic paraventricular nucleus; liver histology and inflammation markers; body weight and metabolic phenotyping\",\n      \"journal\": \"Diabetes\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — double-KO epistasis experiment with multiple orthogonal physiological and molecular readouts establishing pathway position of TSK downstream of MC4R\",\n      \"pmids\": [\"34183373\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TSK (Tsukushi) secreted by the liver is required for maintaining skeletal muscle mass, contractile (slow-twitch) myofiber gene expression, grip strength, and exercise endurance. TSK-null mice show selective impairment of myofibrillar genes characteristic of slow-twitch fibers and abnormal neuromuscular junction formation. TSK-null mice also exhibit diminished muscle regeneration after cardiotoxin injury. AAV-mediated TSK overexpression in adult mice failed to rescue these myofiber defects, suggesting developmental-stage-restricted action.\",\n      \"method\": \"TSK-knockout mouse phenotyping (grip strength, treadmill exercise); skeletal muscle transcriptomics; neuromuscular junction morphology; cardiotoxin-induced injury regeneration assay; AAV-mediated TSK overexpression\",\n      \"journal\": \"JCI insight\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse with multiple orthogonal readouts (functional, transcriptomic, morphological, regeneration) plus OE rescue experiment; single lab but highly rigorous\",\n      \"pmids\": [\"35025761\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"HIF1α inhibitor (KC7F2) up-regulates TSKU expression in hepatocytes in vitro and in a CDAHFD-induced NASH mouse model, and the resulting increased TSKU leads to hepatocellular lipid accumulation; siRNA knockdown of TSKU in hepatocytes reverses the KC7F2-induced lipid accumulation, placing TSKU downstream of HIF1α in hepatic lipid metabolism.\",\n      \"method\": \"CDAHFD NASH mouse model with KC7F2 treatment; in vitro hepatocyte culture with KC7F2; siRNA knockdown of TSKU; lipid accumulation assays\",\n      \"journal\": \"Archives of biochemistry and biophysics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo mouse model plus in vitro siRNA rescue establishing epistatic relationship; single lab, two complementary methods\",\n      \"pmids\": [\"39832609\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"A novel PXR-inducible enhancer of TSKU was identified in human hepatocytes by CAGE-based transcription initiation profiling and validated by CRISPR/Cas9 knockout. Additionally, siRNA-mediated knockdown of TSKU unexpectedly reduced the expression of vitamin D-metabolizing enzymes in hepatocytes, revealing a functional role for TSKU in regulating this metabolic pathway.\",\n      \"method\": \"CAGE transcription initiation profiling; CRISPR/Cas9 enhancer knockout; siRNA knockdown of TSKU with measurement of vitamin D-metabolizing enzyme expression\",\n      \"journal\": \"bioRxiv (preprint)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — CRISPR enhancer validation and siRNA functional assay are rigorous methods but preprint, single lab, and partial mechanistic follow-up\",\n      \"pmids\": [\"bio_10.1101_2024.07.24.604883\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"Tsukushi (TSKU) is a secreted small leucine-rich repeat proteoglycan (SLRP) produced primarily by the liver whose expression is induced by feeding and regulated by MC4R signaling; it acts as a hormonal cue that inhibits brown adipose tissue thermogenesis, maintains slow-twitch skeletal muscle fiber gene programs and neuromuscular junction integrity, supports muscle regeneration, modulates bone elongation by directing growth plate chondrocyte differentiation, and influences hepatic lipid metabolism downstream of HIF1α, with evidence also that it regulates expression of vitamin D-metabolizing enzymes in hepatocytes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TSKU (Tsukushi) is a secreted, liver-derived small leucine-rich repeat proteoglycan (SLRP) that functions as a hepatokine coupling nutritional and hormonal signals to peripheral metabolism, musculoskeletal development, and tissue homeostasis [#1, #2, #3]. Hepatic TSKU expression and circulating TSKU are induced by feeding under control of melanocortin-4 receptor (MC4R) signaling, and TSKU acts downstream of this central circuit: its ablation in MC4R-deficient mice restores energy balance, relieves hyperphagia, augments brown-fat thermogenic gene expression, and protects against diet-induced steatohepatitis, while increasing feeding-induced c-Fos activation in the hypothalamic paraventricular nucleus [#2]. In the musculoskeletal system, TSKU is required for normal longitudinal bone growth, where it directs growth-plate chondrocyte differentiation by sustaining early and restraining mid-to-late chondrogenic gene programs [#1], and for maintaining skeletal muscle mass, slow-twitch myofiber gene expression, neuromuscular junction integrity, and post-injury regeneration, with its action restricted to a developmental window since adult re-expression fails to rescue myofiber defects [#3]. In hepatocytes, TSKU lies downstream of HIF1\\u03b1 in the control of cellular lipid accumulation and additionally regulates expression of vitamin D-metabolizing enzymes [#4, #5]. The molecular partners and biochemical mechanism by which secreted TSKU transduces these effects have not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2017,\n      \"claim\": \"Established TSKU as a determinant of skeletal growth by showing it modulates the timing of chondrocyte differentiation in the growth plate, answering whether a secreted SLRP shapes endochondral bone elongation.\",\n      \"evidence\": \"TSK-knockout mouse skeletal phenotyping plus siRNA knockdown in a chondrogenic cell line with chondrogenic marker analysis\",\n      \"pmids\": [\"30271858\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No molecular receptor or binding partner for TSKU in chondrocytes identified\", \"Mechanism linking secreted TSKU to the chondrogenic transcriptional switch unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Tested whether TSKU regulates brown adipose tissue thermogenesis directly and found that, in isolation, neither loss nor overexpression altered thermogenic gene programs or systemic metabolism, narrowing the conditions under which TSKU acts on energy balance.\",\n      \"evidence\": \"TSK-null and TSK-overexpressing mice with thermogenic gene expression, body weight, and glucose tolerance readouts\",\n      \"pmids\": [\"31767170\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Negative result under baseline conditions does not exclude context-dependent action\", \"Did not test TSKU in a sensitized metabolic background\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Positioned TSKU as a feeding-induced hepatokine acting downstream of MC4R signaling, reconciling the earlier negative thermogenesis result by showing TSKU's metabolic effects emerge within the central melanocortin context.\",\n      \"evidence\": \"TSK/MC4R double-knockout epistasis mice with thermogenic gene expression, hypothalamic c-Fos immunostaining, liver/adipose inflammation, and metabolic phenotyping\",\n      \"pmids\": [\"34183373\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor or target tissue mediating TSKU's peripheral and central effects not identified\", \"Mechanism of feeding-induced hepatic TSKU transcription not defined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined a developmental-stage-restricted role for liver-derived TSKU in establishing slow-twitch myofiber identity, neuromuscular junction integrity, and regenerative capacity, showing adult re-expression cannot rescue.\",\n      \"evidence\": \"TSK-knockout mouse grip strength and endurance testing, muscle transcriptomics, NMJ morphology, cardiotoxin regeneration assay, and AAV overexpression rescue\",\n      \"pmids\": [\"35025761\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular signal linking circulating TSKU to muscle fiber-type and NMJ programs unknown\", \"Basis for the developmental window of action unresolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified a PXR-inducible enhancer controlling hepatic TSKU transcription and revealed an unexpected role for TSKU in supporting expression of vitamin D-metabolizing enzymes, linking xenobiotic/nuclear-receptor regulation to TSKU output.\",\n      \"evidence\": \"CAGE transcription initiation profiling, CRISPR/Cas9 enhancer knockout, and siRNA knockdown of TSKU with vitamin D enzyme readout (preprint)\",\n      \"pmids\": [\"bio_10.1101_2024.07.24.604883\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, single lab, awaits peer review\", \"Mechanism by which TSKU regulates vitamin D enzyme expression not defined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Placed TSKU downstream of HIF1\\u03b1 in hepatocyte lipid handling, showing HIF1\\u03b1 inhibition raises TSKU and drives lipid accumulation reversible by TSKU knockdown.\",\n      \"evidence\": \"CDAHFD NASH mouse model with KC7F2 HIF1\\u03b1 inhibitor, in vitro hepatocyte culture, and siRNA knockdown rescue of lipid accumulation\",\n      \"pmids\": [\"39832609\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular effector by which TSKU promotes hepatocellular lipid accumulation unknown\", \"Whether the HIF1\\u03b1\\u2013TSKU axis intersects the MC4R feeding axis not tested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The cell-surface receptor(s) and direct binding partners through which secreted TSKU transduces its diverse effects on adipose, muscle, bone, and hepatocyte biology remain unidentified.\",\n      \"evidence\": \"No direct receptor-binding or biochemical interaction study present in the timeline\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No TSKU receptor identified\", \"No structural or biochemical characterization of TSKU interactions\", \"Unclear whether one shared mechanism underlies effects across tissues\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [0, 1, 2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [2, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}