{"id":"e7a1d3fc-af2b-5926-b250-e9a610f68549","stable_key":"fe6af7fc-7372-5c4f-9c2f-2bbf56695397:phosphorus-pit2-compensation","predicate":"increases_expression_of","statement":"Aortic medial PiT2 mRNA increased approximately twofold after smooth-muscle PiT1 deletion.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"d16646b3-45bd-52f4-8516-dba5f314b84d","mechanism_event_label":"The backup transporter increased when the first transporter was absent.","subject":{"id":"ea3a2d83-e67c-5617-8290-5ef4370d0048","slug":"mouse-slc20a1-smc-null","display_name":"Mouse vascular smooth-muscle Slc20a1 knockout","entity_type_key":"protein_state"},"object":{"id":"e75eb5e4-5317-5660-bc33-d1e5c9cadbe7","slug":"mouse-slc20a2","display_name":"Mouse phosphate transporter PiT-2 / Slc20a2","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"d16646b3-45bd-52f4-8516-dba5f314b84d","stable_key":"fe6af7fc-7372-5c4f-9c2f-2bbf56695397:phosphorus-pit2-compensation-event","event_type":"biochemical_relationship","label":"The backup transporter increased when the first transporter was absent.","description":"Aortic medial PiT2 mRNA increased approximately twofold after smooth-muscle PiT1 deletion.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ea3a2d83-e67c-5617-8290-5ef4370d0048","slug":"mouse-slc20a1-smc-null","display_name":"Mouse vascular smooth-muscle Slc20a1 knockout","entity_type_key":"protein_state"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e75eb5e4-5317-5660-bc33-d1e5c9cadbe7","slug":"mouse-slc20a2","display_name":"Mouse phosphate transporter PiT-2 / Slc20a2","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/phosphorus-research/23968976.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"6704ac0400a286d5137384f4339dd6dffb0061a41a121b6c72a0b23353cbc6f9\", \"start_char\": 0, \"end_char\": 1852, \"text_sha256\": \"6704ac0400a286d5137384f4339dd6dffb0061a41a121b6c72a0b23353cbc6f9\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Smooth-muscle-specific knockout and transporter compensation experiments","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Mouse CKD plus dietary phosphate loading; PiT2 knockdown or expression rescue","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Loss of one transporter can be masked by another. This refines a single-transporter model without proving every calcification pathway requires transport.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Phosphorus research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"phosphorus","display_name":"Phosphorus","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Mouse","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The backup transporter increased when the first transporter was absent.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[phosphorus-p23968976] Sodium-dependent phosphate cotransporters and phosphate-induced calcification of vascular smooth muscle cells: redundant roles for PiT-1 and PiT-2. (2013). https://pubmed.ncbi.nlm.nih.gov/23968976/ DOI: 10.1161/atvbaha.113.302249","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Vascular smooth muscle","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"e3148b94-4f76-5838-b2ee-99878287516b","evidence_kind":"source_excerpt","locator":"Lines 802-813","start_line":802,"end_line":813,"excerpt":"### phosphorus-pit2-compensation\nAortic medial PiT2 mRNA increased approximately twofold after smooth-muscle PiT1 deletion.\nCondition category: machinery_impairment\nnutrient_topic: Phosphorus research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The backup transporter increased when the first transporter was absent.\norganism: Mouse\ntissue_or_cell_type: Vascular smooth muscle\nexperimental_model: Smooth-muscle-specific knockout and transporter compensation experiments\nlimitations: Loss of one transporter can be masked by another. This refines a single-transporter model without proving every calcification pathway requires transport.\nexposure: Mouse CKD plus dietary phosphate loading; PiT2 knockdown or expression rescue\nevidence_span: {\"source_cache\": \"artifacts/phosphorus-research/23968976.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"6704ac0400a286d5137384f4339dd6dffb0061a41a121b6c72a0b23353cbc6f9\", \"start_char\": 0, \"end_char\": 1852, \"text_sha256\": \"6704ac0400a286d5137384f4339dd6dffb0061a41a121b6c72a0b23353cbc6f9\"}\n[phosphorus-p23968976] Sodium-dependent phosphate cotransporters and phosphate-induced calcification of vascular smooth muscle cells: redundant roles for PiT-1 and PiT-2. 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