{"id":"6f223f35-5248-5bee-a374-068b3a3f7c21","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-mouse-pxr-dependence","predicate":"supports_k2_induction_of","statement":"Vitamin K2 induced bone-marker expression in wild-type mouse calvarial cells but not Pxr-deficient cells.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"fab389ed-2696-5bdc-a23c-0e893384cf8d","mechanism_event_label":"The transcriptional response depended on the receptor in this model.","subject":{"id":"10e4b201-804c-52c7-985a-1a7047f0cdc5","slug":"mouse-nr1i2","display_name":"Mouse pregnane X receptor / Pxr / Nr1i2","entity_type_key":"protein"},"object":{"id":"2dafa1d0-d06f-5bc9-a05a-f773b391f233","slug":"osteoblast-marker-expression","display_name":"Osteoblast marker gene expression","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"fab389ed-2696-5bdc-a23c-0e893384cf8d","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-mouse-pxr-dependence-event","event_type":"biochemical_relationship","label":"The transcriptional response depended on the receptor in this model.","description":"Vitamin K2 induced bone-marker expression in wild-type mouse calvarial cells but not Pxr-deficient cells.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"10e4b201-804c-52c7-985a-1a7047f0cdc5","slug":"mouse-nr1i2","display_name":"Mouse pregnane X receptor / Pxr / Nr1i2","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"2dafa1d0-d06f-5bc9-a05a-f773b391f233","slug":"osteoblast-marker-expression","display_name":"Osteoblast marker gene expression","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/k2-research/12920130.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\", \"start_char\": 0, \"end_char\": 1589, \"text_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Ligand binding, gene expression and receptor-null mouse cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Vitamin K2 exposure and receptor deficiency","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The measured outcome was expression of bone markers, not actual mineral deposition; loss of the mouse receptor need not predict human supplement response.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Human osteosarcoma cells and mouse calvarial cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The transcriptional response depended on the receptor in this model.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[k2-p12920130] Vitamin K2 regulation of bone homeostasis is mediated by the steroid and xenobiotic receptor SXR. (2003). https://pubmed.ncbi.nlm.nih.gov/12920130/ DOI: 10.1074/jbc.m303136200","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"SXR/PXR transcription","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"c9c3325e-9401-5abf-bb96-ab2caf088256","evidence_kind":"source_excerpt","locator":"Lines 708-719","start_line":708,"end_line":719,"excerpt":"### k2-mouse-pxr-dependence\nVitamin K2 induced bone-marker expression in wild-type mouse calvarial cells but not Pxr-deficient cells.\nCondition category: normal\nnutrient_topic: Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The transcriptional response depended on the receptor in this model.\norganism: Human osteosarcoma cells and mouse calvarial cells\ntissue_or_cell_type: SXR/PXR transcription\nexperimental_model: Ligand binding, gene expression and receptor-null mouse cells\nlimitations: The measured outcome was expression of bone markers, not actual mineral deposition; loss of the mouse receptor need not predict human supplement response.\nexposure: Vitamin K2 exposure and receptor deficiency\nevidence_span: {\"source_cache\": \"artifacts/k2-research/12920130.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\", \"start_char\": 0, \"end_char\": 1589, \"text_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\"}\n[k2-p12920130] Vitamin K2 regulation of bone homeostasis is mediated by the steroid and xenobiotic receptor SXR. (2003). https://pubmed.ncbi.nlm.nih.gov/12920130/ DOI: 10.1074/jbc.m303136200","model_system":"Ligand binding, gene expression and receptor-null mouse cells","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [k2-p12920130] Vitamin K2 regulation of bone homeostasis is mediated by the steroid and xenobiotic receptor SXR. (2003). https://pubmed.ncbi.nlm.nih.gov/12920130/ DOI: 10.1074/jbc.m303136200","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dfeae572-af3d-5042-a10e-e67596f9ab28","stable_key":"import-4fef8d72-f107-5eb5-b2fb-483ca85465e0","title":"Vitamin K2: menaquinone forms, carboxylation, recycling and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. 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