{"gene":"DHH","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":2000,"finding":"DHH (expressed by Sertoli cells) is required for formation of adult-type Leydig cells and normal peritubular cell and seminiferous tubule development; its receptor Patched (Ptc) is localized to both Leydig cells and peritubular cells, placing DHH as a paracrine signaling molecule in testicular development.","method":"Genetic knockout (Dhh-null mice), histological and immunolocalization analysis","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO mouse model with defined cellular phenotypes, receptor localization by IHC, replicated across multiple subsequent studies","pmids":["11090455"],"is_preprint":false},{"year":2010,"finding":"A missense mutation in Dhh in rats results in loss of DHH signaling, markedly reduced fetal Leydig cell numbers, absence of adult-type Leydig cells, and testosterone deficiency, confirming DHH is essential for Leydig cell development.","method":"Fine linkage mapping, sequence analysis, immunohistochemistry with Leydig cell-specific markers, testosterone measurement","journal":"Reproduction (Cambridge, England)","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function missense mutation in an independent species (rat) recapitulates Dhh-null mouse phenotype, multiple orthogonal methods","pmids":["21062903"],"is_preprint":false},{"year":2018,"finding":"In vitro cleavage assays showed that the DHH p.(Glu212Lys) mutation retains ~50% auto-processing activity (partial abolishment of DHh auto-cleavage), while p.(Asn337Lysfs*24) completely abolishes auto-proteolysis, demonstrating that DHH undergoes intein-mediated auto-processing required for its function.","method":"In vitro cleavage assay of mutant DHH proteins compared to wild-type and Drosophila Hh","journal":"Human mutation","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — direct in vitro biochemical assay establishing auto-processing mechanism, single lab","pmids":["30298535"],"is_preprint":false},{"year":2020,"finding":"Several pathogenic DHH variants associated with 46,XY gonadal dysgenesis are unable to perform self-cleavage (auto-processing), and this correlates (imperfectly) with altered subcellular localization of the resulting DHH proteins.","method":"In vitro self-cleavage assays, subcellular localization experiments, structural modeling and molecular dynamics simulations","journal":"Human genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct biochemical assay plus localization experiments with multiple variants, single lab, two orthogonal methods","pmids":["32504121"],"is_preprint":false},{"year":2017,"finding":"Molecular dynamics simulations showed that the DHH p.Trp173Cys mutation increases conformational flexibility of DHH and potentially alters its interaction with BOC (brother of CDO), a positive regulator of Hedgehog signalling, implicating DHH–BOC interaction in normal DHH signaling.","method":"Whole-exome sequencing for variant identification; molecular dynamics simulations for structural/interaction analysis","journal":"Clinical endocrinology","confidence":"Low","confidence_rationale":"Tier 4 / Weak — interaction inference based solely on computational simulation, no direct binding experiment","pmids":["28708305"],"is_preprint":false},{"year":2018,"finding":"DHH and IHH produced by granulosa cells act together to regulate theca cell specification and androgen production in the ovary; single Dhh knockout mice retain fertility but show decreased androgen production, while combined Dhh/Ihh double knockout results in complete loss of theca cells and infertility.","method":"Conditional single and double knockout mice, hormonal profiling, ovarian transcriptome analysis","journal":"Endocrinology","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean genetic KO with defined cellular phenotype (theca cell loss), multiple orthogonal readouts, double-KO epistasis","pmids":["29788357"],"is_preprint":false},{"year":2023,"finding":"DHH is the key Hedgehog ligand that acts as an adipogenic brake in skeletal muscle fibro/adipogenic progenitors (FAPs), preventing their adipogenic differentiation; sustained DHH/Hh activation forces FAPs toward a fibrogenic fate causing fibrosis.","method":"Conditional mutagenesis (in vivo), pharmacological Hh modulators (in vivo and in vitro), fate-tracing","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional genetic KO plus pharmacological rescue, multiple orthogonal methods in vivo and in vitro, single publication but rigorous design","pmids":["37355632"],"is_preprint":false},{"year":2015,"finding":"Loss of GPR37 in Sertoli cells leads to altered expression of DHH mitogenic cascade components (increased Dhh, Gli2, and Ptch1), and Ptch1 is co-localized with and co-immunoprecipitates with GPR37 in primary Sertoli cells, indicating GPR37 modulates DHH signaling in Sertoli cells.","method":"Gpr37-null mouse analysis, qRT-PCR for pathway components, co-immunoprecipitation of Ptch1 and GPR37 in primary Sertoli cells","journal":"FASEB journal","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — co-IP binding experiment plus KO phenotype, single lab, two methods","pmids":["25609427"],"is_preprint":false},{"year":2020,"finding":"In antler chondrocytes, DHH signals through Ptch1/Smo to activate Gli transcription factors, which in turn regulate Foxa1/2/3 expression; this DHH→Smo→Gli→Foxa axis induces chondrocyte proliferation and hypertrophic differentiation (Col X and Runx2 upregulation).","method":"Recombinant DHH treatment, siRNA knockdown of Ptch1/Smo/Gli/Foxa, pharmacological inhibition (cyclopamine, GANT58), cell cycle analysis","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple loss-of-function and pathway inhibitor experiments with defined phenotypic readouts, single lab","pmids":["31960430"],"is_preprint":false},{"year":2022,"finding":"The DHH signaling pathway (via Smoothened and Gli1) regulates reconstruction of seminiferous tubule-like structure in vitro, promoting Sertoli cell polarity, peritubular myoid cell organization, laminin secretion/basal membrane formation, and proliferation of Leydig, peritubular myoid, germ, and Sertoli cells.","method":"In vitro tubule reconstruction assay with cyclopamine (Smo inhibitor) and SAG (Smo agonist), Gli1 expression measurement","journal":"Reproductive biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological gain- and loss-of-function with multiple defined cellular readouts, single lab","pmids":["35987158"],"is_preprint":false},{"year":2020,"finding":"Dhh-expressing Schwann cell precursors (SCPs) contribute to skin and cochlear melanocytes (but not vestibular melanocytes), as demonstrated by lineage tracing using a Dhh-Cre driver with a fluorescent Rosa26 reporter in a pure FVB/N background.","method":"Lineage tracing (Dhh-Cre x Rosa26-YFP reporter mice), histological analysis","journal":"Pigment cell & melanoma research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct genetic lineage tracing with defined cellular outcome, single lab","pmids":["33089656"],"is_preprint":false},{"year":2023,"finding":"PKNOX1 acts as a transcription factor for DHH, binding the DHH promoter region and upregulating DHH expression to activate the Hedgehog signaling pathway in stomach adenocarcinoma cells.","method":"Dual-luciferase reporter assay, qPCR, western blotting, siRNA knockdown","journal":"International journal of immunopathology and pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct luciferase reporter assay for transcriptional regulation plus knockdown, single lab, single paper","pmids":["37864517"],"is_preprint":false},{"year":2020,"finding":"GATA4 and GATA6 positively regulate Dhh transcription in rat adrenocortical autografts; reporter assays using the upstream rDhh promoter region containing a GATA binding motif showed significant upregulation upon GATA4 and/or GATA6 co-transfection.","method":"Reporter gene assay with rDhh upstream promoter region, PCR and RNAscope expression analysis in autograft tissue","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct promoter-reporter assay establishing transcriptional regulation, single lab","pmids":["31949236"],"is_preprint":false},{"year":2025,"finding":"DHH regulates stem Leydig cell (SLC) differentiation (not survival) via a Ptch2/Gli1/Sf1 signaling axis: Ptch2 acts as the functional receptor for DHH in SLCs, Gli1 is the primary transcriptional effector that transactivates Sf1, and Sf1 is indispensable for SLC differentiation.","method":"CRISPR/Cas9 knockout of dhh, ptch1, ptch2, gli1, sf1; SLC transplantation rescue; luciferase transactivation assays; DHH agonist treatment; 11-ketotestosterone rescue (in Nile tilapia model)","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple CRISPR KOs plus rescue transplantation plus luciferase assays in a single study, preprint not yet peer-reviewed","pmids":["bio_10.1101_2025.06.13.659479"],"is_preprint":true},{"year":2025,"finding":"DHH and PDGF rapidly activate energy metabolism in fetal Leydig cell progenitors without altering gene expression, while DHH signaling through GLI1/GLI2 upregulates Ad4BP/SF-1 (NR5A1) gene expression (shown by reporter assay) and activates cholesterogenic gene expression via Srebf2 upregulation.","method":"Transcriptome analysis, CUT&RUN-seq, metabolic activity assays, reporter gene assays","journal":"Endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (transcriptomics, CUT&RUN, reporter assay, metabolic assay) in single study, single lab","pmids":["40878802"],"is_preprint":false}],"current_model":"DHH is a secreted Hedgehog ligand produced by Sertoli cells (and other cell types) that signals through Patched receptors (primarily Ptch1 on Leydig and peritubular cells, Ptch2 on stem Leydig cell progenitors) to activate Smoothened and downstream GLI transcription factors, driving fetal and adult Leydig cell differentiation via a DHH→Ptch2→Gli1→Sf1 axis, regulating peritubular cell and seminiferous tubule organization, controlling theca cell specification and androgen production in the ovary, acting as an adipogenic brake in muscle fibro/adipogenic progenitors, and requiring intein-mediated auto-processing of its precursor for proper signaling; loss-of-function mutations cause 46,XY gonadal dysgenesis and minifascicular neuropathy in humans."},"narrative":{"mechanistic_narrative":"DHH is a secreted Hedgehog ligand that acts as a paracrine driver of gonadal somatic cell differentiation. In the testis, DHH produced by Sertoli cells signals through the Patched receptor, localized on Leydig and peritubular cells, to direct formation of adult-type Leydig cells and normal peritubular cell and seminiferous tubule development [PMID:11090455]; loss-of-function in Dhh-null mice and a loss-of-function missense mutation in rats both eliminate adult-type Leydig cells and cause testosterone deficiency, with markedly reduced fetal Leydig cell numbers [PMID:11090455, PMID:21062903]. Downstream, DHH engages a receptor-to-transcription-factor cascade in which Ptch2 acts as the functional receptor on stem Leydig cells, Gli1 is the primary transcriptional effector that transactivates Sf1, and Sf1 drives differentiation [PMID:bio_10.1101_2025.06.13.659479]; DHH signaling through GLI1/GLI2 likewise upregulates the steroidogenic factor Ad4BP/SF-1 (NR5A1) and cholesterogenic gene expression via Srebf2 in fetal Leydig progenitors [PMID:40878802]. The same Smoothened/Gli1 pathway organizes seminiferous tubule architecture, promoting Sertoli cell polarity, peritubular myoid cell organization, and basal membrane formation [PMID:35987158]. Beyond the testis, DHH (with IHH) from granulosa cells controls ovarian theca cell specification and androgen production [PMID:29788357], and DHH acts as an adipogenic brake in skeletal muscle fibro/adipogenic progenitors, restraining their adipogenic differentiation [PMID:37355632]. DHH function requires intein-mediated auto-processing of its precursor: pathogenic variants associated with 46,XY gonadal dysgenesis impair self-cleavage and alter subcellular localization of the protein [PMID:30298535, PMID:32504121]. DHH transcription is driven by upstream regulators including GATA4/GATA6 [PMID:31949236] and PKNOX1 [PMID:37864517].","teleology":[{"year":2000,"claim":"Established DHH as a Sertoli-cell-derived paracrine signal required for testicular somatic cell development, answering where the ligand acts and on which cells.","evidence":"Dhh-null mouse knockout with histology and Patched immunolocalization","pmids":["11090455"],"confidence":"High","gaps":["Did not define the downstream transcriptional effectors","Did not resolve which Patched paralog mediates which cellular response"]},{"year":2010,"claim":"Confirmed the requirement for DHH signaling in Leydig cell development in an independent species, showing the phenotype is conserved and ligand-dependent.","evidence":"Loss-of-function missense Dhh mutation in rat with marker IHC and testosterone measurement","pmids":["21062903"],"confidence":"High","gaps":["Did not establish the molecular consequence of the missense mutation on the protein","Fetal vs adult Leydig lineage relationship not dissected"]},{"year":2018,"claim":"Defined a molecular mechanism of dysfunction for disease variants by showing DHH requires intein-mediated auto-proteolysis for function.","evidence":"In vitro cleavage assays comparing mutant DHH to wild-type and Drosophila Hh","pmids":["30298535"],"confidence":"Medium","gaps":["Single lab biochemistry","Did not link cleavage defect to downstream signaling output in cells"]},{"year":2018,"claim":"Extended DHH function to the ovary, showing redundancy with IHH in theca cell specification and androgen production.","evidence":"Conditional single and double Dhh/Ihh knockout mice with hormonal profiling and ovarian transcriptomics","pmids":["29788357"],"confidence":"High","gaps":["Did not separate the unique contribution of DHH from IHH at the receptor level","Effector transcription factors in theca cells not mapped"]},{"year":2020,"claim":"Linked auto-processing failure of disease variants to mislocalization, connecting biochemical defect to subcellular fate in 46,XY gonadal dysgenesis.","evidence":"In vitro self-cleavage assays, subcellular localization, and molecular dynamics across multiple variants","pmids":["32504121"],"confidence":"Medium","gaps":["Correlation between cleavage and localization was imperfect","Did not measure signaling activity of mislocalized variants"]},{"year":2020,"claim":"Identified upstream transcriptional regulators (GATA4/GATA6) and a lineage role for Dhh-expressing Schwann cell precursors, broadening control and output of DHH-expressing cells.","evidence":"rDhh promoter-reporter assays with GATA co-transfection; Dhh-Cre lineage tracing of melanocyte origins","pmids":["31949236","33089656"],"confidence":"Medium","gaps":["GATA regulation shown in adrenocortical autograft context only","Lineage tracing reflects Dhh-expressing cells, not DHH signaling function"]},{"year":2022,"claim":"Demonstrated that the Smoothened/Gli1 arm of DHH signaling organizes seminiferous tubule architecture, extending the role from cell differentiation to tissue morphogenesis.","evidence":"In vitro tubule reconstruction with cyclopamine and SAG, Gli1 readout","pmids":["35987158"],"confidence":"Medium","gaps":["Pharmacological perturbation only","Cell-type-specific ligand source within the assay not resolved"]},{"year":2023,"claim":"Established DHH as the Hedgehog ligand restraining adipogenesis in muscle FAPs, identifying a non-gonadal homeostatic function.","evidence":"Conditional mutagenesis, pharmacological Hh modulators, and fate-tracing in vivo and in vitro","pmids":["37355632"],"confidence":"High","gaps":["Receptor and effector identity in FAPs not specified","Cellular source of DHH in muscle not pinpointed"]},{"year":2025,"claim":"Resolved the receptor-to-transcription-factor axis for Leydig cell differentiation, defining Ptch2 as the functional receptor and a Gli1→Sf1 cascade, and linking GLI to steroidogenic and cholesterogenic gene programs.","evidence":"CRISPR knockouts (dhh, ptch1, ptch2, gli1, sf1), transplantation rescue and luciferase assays (tilapia, preprint); transcriptomics, CUT&RUN-seq, metabolic and reporter assays in fetal Leydig progenitors","pmids":["bio_10.1101_2025.06.13.659479","40878802"],"confidence":"Medium","gaps":["Ptch2-specific axis demonstrated in a fish model","Direct GLI binding at Sf1/NR5A1 regulatory regions in mammals not fully established"]},{"year":null,"claim":"How DHH ligand processing, secretion, and receptor selectivity (Ptch1 vs Ptch2, BOC co-receptor engagement) are coordinated to produce cell-type-specific outputs remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No direct binding data for DHH–BOC interaction","Determinants of Ptch1 vs Ptch2 selectivity across tissues unknown","Structural basis of auto-processing-dependent signaling competence not solved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[0,13,14]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[2,3]}],"localization":[{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,8,13]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[0,5,6]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[0,5,9]}],"complexes":[],"partners":["PTCH1","PTCH2","GPR37","BOC"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O43323","full_name":"Desert hedgehog protein","aliases":["HHG-3"],"length_aa":396,"mass_kda":43.6,"function":"The C-terminal part of the desert hedgehog protein precursor displays an autoproteolysis and a cholesterol transferase activity (By similarity). Both activities result in the cleavage of the full-length protein into two parts (N-product and C-product) followed by the covalent attachment of a cholesterol moiety to the C-terminal of the newly generated N-product (DHH-N) (By similarity). Both activities occur in the endoplasmic reticulum (By similarity). Once cleaved, the C-product is degraded in the endoplasmic reticulum (By similarity). Functions in cell-cell mediated juxtacrine signaling (PubMed:24342078). Promotes endothelium integrity (PubMed:33063110). Binds to PTCH1 receptor, which functions in association with smoothened (SMO), to activate the transcription of target genes in endothelial cells (PubMed:33063110). In Schwann cells, controls the development of the peripheral nerve sheath and the transition of mesenchymal cells to form the epithelium-like structure of the perineurial tube (By similarity) The dually lipidated desert hedgehog protein N-product is essential for a variety of patterning events during development (By similarity). Binds to the patched (PTCH1) receptor, which functions in association with smoothened (SMO), to activate the transcription of target genes (PubMed:11472839, PubMed:33063110). Required for normal testis development and spermatogenesis, namely for the formation of adult-type Leydig cells and normal development of peritubular cells and seminiferous tubules (By similarity). Activates primary cilia signaling on neighboring valve interstitial cells through a paracrine mechanism (By similarity). May induce motor neurons in lateral neural tube and may have a polarizing activity (PubMed:11472839). Prevents the desert hedgehog protein precursor binding to PTCH1 (PubMed:33063110)","subcellular_location":"Endoplasmic reticulum membrane; Golgi apparatus membrane; Secreted; Cell membrane","url":"https://www.uniprot.org/uniprotkb/O43323/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DHH","classification":"Not Classified","n_dependent_lines":6,"n_total_lines":1208,"dependency_fraction":0.004966887417218543},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/DHH","total_profiled":1310},"omim":[{"mim_id":"619811","title":"UHRF1-BINDING PROTEIN 1-LIKE; UHRF1BP1L","url":"https://www.omim.org/entry/619811"},{"mim_id":"617481","title":"NEURODEVELOPMENTAL DISORDER WITH MICROCEPHALY, HYPOTONIA, AND VARIABLE BRAIN ANOMALIES; NMIHBA","url":"https://www.omim.org/entry/617481"},{"mim_id":"617413","title":"PRUNE EXOPOLYPHOSPHATASE 1; PRUNE1","url":"https://www.omim.org/entry/617413"},{"mim_id":"617362","title":"DEAH-BOX HELICASE 37; DHX37","url":"https://www.omim.org/entry/617362"},{"mim_id":"609396","title":"PH DOMAIN AND LEUCINE-RICH REPEAT PROTEIN PHOSPHATASE 1; PHLPP1","url":"https://www.omim.org/entry/609396"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in single","driving_tissues":[{"tissue":"testis","ntpm":9.8}],"url":"https://www.proteinatlas.org/search/DHH"},"hgnc":{"alias_symbol":["HHG-3","MGC35145"],"prev_symbol":[]},"alphafold":{"accession":"O43323","domains":[{"cath_id":"3.30.1380.10","chopping":"46-192","consensus_level":"high","plddt":93.284,"start":46,"end":192},{"cath_id":"2.170.16.10","chopping":"195-365","consensus_level":"high","plddt":88.4853,"start":195,"end":365}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O43323","model_url":"https://alphafold.ebi.ac.uk/files/AF-O43323-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O43323-F1-predicted_aligned_error_v6.png","plddt_mean":84.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DHH","jax_strain_url":"https://www.jax.org/strain/search?query=DHH"},"sequence":{"accession":"O43323","fasta_url":"https://rest.uniprot.org/uniprotkb/O43323.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O43323/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O43323"}},"corpus_meta":[{"pmid":"11090455","id":"PMC_11090455","title":"Desert hedgehog (Dhh) gene is required in the mouse testis for formation of adult-type Leydig cells and normal development of peritubular cells and seminiferous tubules.","date":"2000","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/11090455","citation_count":281,"is_preprint":false},{"pmid":"15356051","id":"PMC_15356051","title":"Mutations in the desert hedgehog (DHH) gene in patients with 46,XY complete pure gonadal dysgenesis.","date":"2004","source":"The Journal of clinical endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/15356051","citation_count":109,"is_preprint":false},{"pmid":"22147708","id":"PMC_22147708","title":"Structural and functional insights into the DNA replication factor Cdc45 reveal an evolutionary relationship to the DHH family of phosphoesterases.","date":"2011","source":"The Journal of biological 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communications","url":"https://pubmed.ncbi.nlm.nih.gov/37355632","citation_count":41,"is_preprint":false},{"pmid":"21768284","id":"PMC_21768284","title":"Two DHH subfamily 1 proteins contribute to pneumococcal virulence and confer protection against pneumococcal disease.","date":"2011","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/21768284","citation_count":40,"is_preprint":false},{"pmid":"25549322","id":"PMC_25549322","title":"Evolutionary genomics and adaptive evolution of the Hedgehog gene family (Shh, Ihh and Dhh) in vertebrates.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25549322","citation_count":32,"is_preprint":false},{"pmid":"24878921","id":"PMC_24878921","title":"Unique subunit packing in mycobacterial nanoRNase leads to alternate substrate recognitions in DHH phosphodiesterases.","date":"2014","source":"Nucleic acids 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involved in 46,XY disorders of sex development differentially impact protein self-cleavage and structural conformation.","date":"2020","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/32504121","citation_count":4,"is_preprint":false},{"pmid":"21366396","id":"PMC_21366396","title":"Mutation analysis of the SRY, NR5A1, and DHH genes in six Chinese 46,XY women.","date":"2011","source":"The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians","url":"https://pubmed.ncbi.nlm.nih.gov/21366396","citation_count":4,"is_preprint":false},{"pmid":"30266964","id":"PMC_30266964","title":"Involvement of DHH and GLI1 in adrenocortical autograft regeneration in rats.","date":"2018","source":"Scientific 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\"method\": \"Genetic knockout (Dhh-null mice), histological and immunolocalization analysis\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO mouse model with defined cellular phenotypes, receptor localization by IHC, replicated across multiple subsequent studies\",\n      \"pmids\": [\"11090455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"A missense mutation in Dhh in rats results in loss of DHH signaling, markedly reduced fetal Leydig cell numbers, absence of adult-type Leydig cells, and testosterone deficiency, confirming DHH is essential for Leydig cell development.\",\n      \"method\": \"Fine linkage mapping, sequence analysis, immunohistochemistry with Leydig cell-specific markers, testosterone measurement\",\n      \"journal\": \"Reproduction (Cambridge, England)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function missense mutation in an independent species (rat) recapitulates Dhh-null mouse phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"21062903\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In vitro cleavage assays showed that the DHH p.(Glu212Lys) mutation retains ~50% auto-processing activity (partial abolishment of DHh auto-cleavage), while p.(Asn337Lysfs*24) completely abolishes auto-proteolysis, demonstrating that DHH undergoes intein-mediated auto-processing required for its function.\",\n      \"method\": \"In vitro cleavage assay of mutant DHH proteins compared to wild-type and Drosophila Hh\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — direct in vitro biochemical assay establishing auto-processing mechanism, single lab\",\n      \"pmids\": [\"30298535\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Several pathogenic DHH variants associated with 46,XY gonadal dysgenesis are unable to perform self-cleavage (auto-processing), and this correlates (imperfectly) with altered subcellular localization of the resulting DHH proteins.\",\n      \"method\": \"In vitro self-cleavage assays, subcellular localization experiments, structural modeling and molecular dynamics simulations\",\n      \"journal\": \"Human genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct biochemical assay plus localization experiments with multiple variants, single lab, two orthogonal methods\",\n      \"pmids\": [\"32504121\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Molecular dynamics simulations showed that the DHH p.Trp173Cys mutation increases conformational flexibility of DHH and potentially alters its interaction with BOC (brother of CDO), a positive regulator of Hedgehog signalling, implicating DHH–BOC interaction in normal DHH signaling.\",\n      \"method\": \"Whole-exome sequencing for variant identification; molecular dynamics simulations for structural/interaction analysis\",\n      \"journal\": \"Clinical endocrinology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — interaction inference based solely on computational simulation, no direct binding experiment\",\n      \"pmids\": [\"28708305\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"DHH and IHH produced by granulosa cells act together to regulate theca cell specification and androgen production in the ovary; single Dhh knockout mice retain fertility but show decreased androgen production, while combined Dhh/Ihh double knockout results in complete loss of theca cells and infertility.\",\n      \"method\": \"Conditional single and double knockout mice, hormonal profiling, ovarian transcriptome analysis\",\n      \"journal\": \"Endocrinology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean genetic KO with defined cellular phenotype (theca cell loss), multiple orthogonal readouts, double-KO epistasis\",\n      \"pmids\": [\"29788357\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"DHH is the key Hedgehog ligand that acts as an adipogenic brake in skeletal muscle fibro/adipogenic progenitors (FAPs), preventing their adipogenic differentiation; sustained DHH/Hh activation forces FAPs toward a fibrogenic fate causing fibrosis.\",\n      \"method\": \"Conditional mutagenesis (in vivo), pharmacological Hh modulators (in vivo and in vitro), fate-tracing\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional genetic KO plus pharmacological rescue, multiple orthogonal methods in vivo and in vitro, single publication but rigorous design\",\n      \"pmids\": [\"37355632\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Loss of GPR37 in Sertoli cells leads to altered expression of DHH mitogenic cascade components (increased Dhh, Gli2, and Ptch1), and Ptch1 is co-localized with and co-immunoprecipitates with GPR37 in primary Sertoli cells, indicating GPR37 modulates DHH signaling in Sertoli cells.\",\n      \"method\": \"Gpr37-null mouse analysis, qRT-PCR for pathway components, co-immunoprecipitation of Ptch1 and GPR37 in primary Sertoli cells\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — co-IP binding experiment plus KO phenotype, single lab, two methods\",\n      \"pmids\": [\"25609427\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"In antler chondrocytes, DHH signals through Ptch1/Smo to activate Gli transcription factors, which in turn regulate Foxa1/2/3 expression; this DHH→Smo→Gli→Foxa axis induces chondrocyte proliferation and hypertrophic differentiation (Col X and Runx2 upregulation).\",\n      \"method\": \"Recombinant DHH treatment, siRNA knockdown of Ptch1/Smo/Gli/Foxa, pharmacological inhibition (cyclopamine, GANT58), cell cycle analysis\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple loss-of-function and pathway inhibitor experiments with defined phenotypic readouts, single lab\",\n      \"pmids\": [\"31960430\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The DHH signaling pathway (via Smoothened and Gli1) regulates reconstruction of seminiferous tubule-like structure in vitro, promoting Sertoli cell polarity, peritubular myoid cell organization, laminin secretion/basal membrane formation, and proliferation of Leydig, peritubular myoid, germ, and Sertoli cells.\",\n      \"method\": \"In vitro tubule reconstruction assay with cyclopamine (Smo inhibitor) and SAG (Smo agonist), Gli1 expression measurement\",\n      \"journal\": \"Reproductive biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological gain- and loss-of-function with multiple defined cellular readouts, single lab\",\n      \"pmids\": [\"35987158\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Dhh-expressing Schwann cell precursors (SCPs) contribute to skin and cochlear melanocytes (but not vestibular melanocytes), as demonstrated by lineage tracing using a Dhh-Cre driver with a fluorescent Rosa26 reporter in a pure FVB/N background.\",\n      \"method\": \"Lineage tracing (Dhh-Cre x Rosa26-YFP reporter mice), histological analysis\",\n      \"journal\": \"Pigment cell & melanoma research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct genetic lineage tracing with defined cellular outcome, single lab\",\n      \"pmids\": [\"33089656\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PKNOX1 acts as a transcription factor for DHH, binding the DHH promoter region and upregulating DHH expression to activate the Hedgehog signaling pathway in stomach adenocarcinoma cells.\",\n      \"method\": \"Dual-luciferase reporter assay, qPCR, western blotting, siRNA knockdown\",\n      \"journal\": \"International journal of immunopathology and pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct luciferase reporter assay for transcriptional regulation plus knockdown, single lab, single paper\",\n      \"pmids\": [\"37864517\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"GATA4 and GATA6 positively regulate Dhh transcription in rat adrenocortical autografts; reporter assays using the upstream rDhh promoter region containing a GATA binding motif showed significant upregulation upon GATA4 and/or GATA6 co-transfection.\",\n      \"method\": \"Reporter gene assay with rDhh upstream promoter region, PCR and RNAscope expression analysis in autograft tissue\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct promoter-reporter assay establishing transcriptional regulation, single lab\",\n      \"pmids\": [\"31949236\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DHH regulates stem Leydig cell (SLC) differentiation (not survival) via a Ptch2/Gli1/Sf1 signaling axis: Ptch2 acts as the functional receptor for DHH in SLCs, Gli1 is the primary transcriptional effector that transactivates Sf1, and Sf1 is indispensable for SLC differentiation.\",\n      \"method\": \"CRISPR/Cas9 knockout of dhh, ptch1, ptch2, gli1, sf1; SLC transplantation rescue; luciferase transactivation assays; DHH agonist treatment; 11-ketotestosterone rescue (in Nile tilapia model)\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple CRISPR KOs plus rescue transplantation plus luciferase assays in a single study, preprint not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.06.13.659479\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DHH and PDGF rapidly activate energy metabolism in fetal Leydig cell progenitors without altering gene expression, while DHH signaling through GLI1/GLI2 upregulates Ad4BP/SF-1 (NR5A1) gene expression (shown by reporter assay) and activates cholesterogenic gene expression via Srebf2 upregulation.\",\n      \"method\": \"Transcriptome analysis, CUT&RUN-seq, metabolic activity assays, reporter gene assays\",\n      \"journal\": \"Endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (transcriptomics, CUT&RUN, reporter assay, metabolic assay) in single study, single lab\",\n      \"pmids\": [\"40878802\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DHH is a secreted Hedgehog ligand produced by Sertoli cells (and other cell types) that signals through Patched receptors (primarily Ptch1 on Leydig and peritubular cells, Ptch2 on stem Leydig cell progenitors) to activate Smoothened and downstream GLI transcription factors, driving fetal and adult Leydig cell differentiation via a DHH→Ptch2→Gli1→Sf1 axis, regulating peritubular cell and seminiferous tubule organization, controlling theca cell specification and androgen production in the ovary, acting as an adipogenic brake in muscle fibro/adipogenic progenitors, and requiring intein-mediated auto-processing of its precursor for proper signaling; loss-of-function mutations cause 46,XY gonadal dysgenesis and minifascicular neuropathy in humans.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DHH is a secreted Hedgehog ligand that acts as a paracrine driver of gonadal somatic cell differentiation. In the testis, DHH produced by Sertoli cells signals through the Patched receptor, localized on Leydig and peritubular cells, to direct formation of adult-type Leydig cells and normal peritubular cell and seminiferous tubule development [#0]; loss-of-function in Dhh-null mice and a loss-of-function missense mutation in rats both eliminate adult-type Leydig cells and cause testosterone deficiency, with markedly reduced fetal Leydig cell numbers [#0, #1]. Downstream, DHH engages a receptor-to-transcription-factor cascade in which Ptch2 acts as the functional receptor on stem Leydig cells, Gli1 is the primary transcriptional effector that transactivates Sf1, and Sf1 drives differentiation [#13]; DHH signaling through GLI1/GLI2 likewise upregulates the steroidogenic factor Ad4BP/SF-1 (NR5A1) and cholesterogenic gene expression via Srebf2 in fetal Leydig progenitors [#14]. The same Smoothened/Gli1 pathway organizes seminiferous tubule architecture, promoting Sertoli cell polarity, peritubular myoid cell organization, and basal membrane formation [#9]. Beyond the testis, DHH (with IHH) from granulosa cells controls ovarian theca cell specification and androgen production [#5], and DHH acts as an adipogenic brake in skeletal muscle fibro/adipogenic progenitors, restraining their adipogenic differentiation [#6]. DHH function requires intein-mediated auto-processing of its precursor: pathogenic variants associated with 46,XY gonadal dysgenesis impair self-cleavage and alter subcellular localization of the protein [#2, #3]. DHH transcription is driven by upstream regulators including GATA4/GATA6 [#12] and PKNOX1 [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Established DHH as a Sertoli-cell-derived paracrine signal required for testicular somatic cell development, answering where the ligand acts and on which cells.\",\n      \"evidence\": \"Dhh-null mouse knockout with histology and Patched immunolocalization\",\n      \"pmids\": [\"11090455\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the downstream transcriptional effectors\", \"Did not resolve which Patched paralog mediates which cellular response\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Confirmed the requirement for DHH signaling in Leydig cell development in an independent species, showing the phenotype is conserved and ligand-dependent.\",\n      \"evidence\": \"Loss-of-function missense Dhh mutation in rat with marker IHC and testosterone measurement\",\n      \"pmids\": [\"21062903\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish the molecular consequence of the missense mutation on the protein\", \"Fetal vs adult Leydig lineage relationship not dissected\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Defined a molecular mechanism of dysfunction for disease variants by showing DHH requires intein-mediated auto-proteolysis for function.\",\n      \"evidence\": \"In vitro cleavage assays comparing mutant DHH to wild-type and Drosophila Hh\",\n      \"pmids\": [\"30298535\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab biochemistry\", \"Did not link cleavage defect to downstream signaling output in cells\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Extended DHH function to the ovary, showing redundancy with IHH in theca cell specification and androgen production.\",\n      \"evidence\": \"Conditional single and double Dhh/Ihh knockout mice with hormonal profiling and ovarian transcriptomics\",\n      \"pmids\": [\"29788357\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not separate the unique contribution of DHH from IHH at the receptor level\", \"Effector transcription factors in theca cells not mapped\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Linked auto-processing failure of disease variants to mislocalization, connecting biochemical defect to subcellular fate in 46,XY gonadal dysgenesis.\",\n      \"evidence\": \"In vitro self-cleavage assays, subcellular localization, and molecular dynamics across multiple variants\",\n      \"pmids\": [\"32504121\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Correlation between cleavage and localization was imperfect\", \"Did not measure signaling activity of mislocalized variants\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified upstream transcriptional regulators (GATA4/GATA6) and a lineage role for Dhh-expressing Schwann cell precursors, broadening control and output of DHH-expressing cells.\",\n      \"evidence\": \"rDhh promoter-reporter assays with GATA co-transfection; Dhh-Cre lineage tracing of melanocyte origins\",\n      \"pmids\": [\"31949236\", \"33089656\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"GATA regulation shown in adrenocortical autograft context only\", \"Lineage tracing reflects Dhh-expressing cells, not DHH signaling function\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Demonstrated that the Smoothened/Gli1 arm of DHH signaling organizes seminiferous tubule architecture, extending the role from cell differentiation to tissue morphogenesis.\",\n      \"evidence\": \"In vitro tubule reconstruction with cyclopamine and SAG, Gli1 readout\",\n      \"pmids\": [\"35987158\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Pharmacological perturbation only\", \"Cell-type-specific ligand source within the assay not resolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established DHH as the Hedgehog ligand restraining adipogenesis in muscle FAPs, identifying a non-gonadal homeostatic function.\",\n      \"evidence\": \"Conditional mutagenesis, pharmacological Hh modulators, and fate-tracing in vivo and in vitro\",\n      \"pmids\": [\"37355632\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor and effector identity in FAPs not specified\", \"Cellular source of DHH in muscle not pinpointed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Resolved the receptor-to-transcription-factor axis for Leydig cell differentiation, defining Ptch2 as the functional receptor and a Gli1\\u2192Sf1 cascade, and linking GLI to steroidogenic and cholesterogenic gene programs.\",\n      \"evidence\": \"CRISPR knockouts (dhh, ptch1, ptch2, gli1, sf1), transplantation rescue and luciferase assays (tilapia, preprint); transcriptomics, CUT&RUN-seq, metabolic and reporter assays in fetal Leydig progenitors\",\n      \"pmids\": [\"bio_10.1101_2025.06.13.659479\", \"40878802\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ptch2-specific axis demonstrated in a fish model\", \"Direct GLI binding at Sf1/NR5A1 regulatory regions in mammals not fully established\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How DHH ligand processing, secretion, and receptor selectivity (Ptch1 vs Ptch2, BOC co-receptor engagement) are coordinated to produce cell-type-specific outputs remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct binding data for DHH\\u2013BOC interaction\", \"Determinants of Ptch1 vs Ptch2 selectivity across tissues unknown\", \"Structural basis of auto-processing-dependent signaling competence not solved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [0, 13, 14]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [2, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 8, 13]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [0, 5, 6]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [0, 5, 9]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"PTCH1\", \"PTCH2\", \"GPR37\", \"BOC\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}