{"id":"3f3f4e1b-698b-5fe7-a584-275a56e559ba","stable_key":"ea2f0904-ab2c-5d1e-a3d4-3f7ecdd70cd6:caf-clock-cell","predicate":"lengthens","statement":"Caffeine lengthened the circadian reporter period dose-dependently in U2OS cells.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"cfca7a13-76f1-52de-92e5-467f7691067f","mechanism_event_label":"The effect also reached a cellular clock model.","subject":{"id":"ef028472-7c33-583d-b52e-40676004d370","slug":"caffeine","display_name":"Caffeine","entity_type_key":"small_molecule"},"object":{"id":"0c8cf6c3-3325-5b22-abe2-0b736f302dbb","slug":"u2os-circadian-period","display_name":"Circadian reporter period in human U2OS cells","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"cfca7a13-76f1-52de-92e5-467f7691067f","stable_key":"ea2f0904-ab2c-5d1e-a3d4-3f7ecdd70cd6:caf-clock-cell-event","event_type":"observed_relationship","label":"The effect also reached a cellular clock model.","description":"Caffeine lengthened the circadian reporter period dose-dependently in U2OS cells.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ef028472-7c33-583d-b52e-40676004d370","slug":"caffeine","display_name":"Caffeine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"0c8cf6c3-3325-5b22-abe2-0b736f302dbb","slug":"u2os-circadian-period","display_name":"Circadian reporter period in human U2OS cells","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human osteosarcoma cells with clock-gene luciferase reporters.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Cell period is not identical to human sleep duration.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Caffeine collection; salts, coffee, species and coexposure contexts retain their identities.","comparator":null,"unit":null,"notes":"","entity":{"slug":"caffeine","display_name":"Caffeine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The effect also reached a cellular clock model.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Effects of caffeine on the human circadian clock in vivo and in vitro. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26378246/ · DOI 10.1126/scitranslmed.aac5125","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"59579454-cb96-56de-816b-412d18a1fa69","evidence_kind":"source_excerpt","locator":"Lines 84-90","start_line":84,"end_line":90,"excerpt":"## caf-clock-cell\nThe effect also reached a cellular clock model.\nCaffeine lengthened the circadian reporter period dose-dependently in U2OS cells.\nModel: Human osteosarcoma cells with clock-gene luciferase reporters.\nLimitations: Cell period is not identical to human sleep duration.\nEvidence access: Primary abstract\nEffects of caffeine on the human circadian clock in vivo and in vitro. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26378246/ · DOI 10.1126/scitranslmed.aac5125","model_system":"Human osteosarcoma cells with clock-gene luciferase reporters.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access stated with the claim.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"40a654db-878c-5471-bc6c-88f4f52599c0","stable_key":"import-ea2f0904-ab2c-5d1e-a3d4-3f7ecdd70cd6","title":"Caffeine: receptors, metabolism, nutrient interactions, adaptation and discovery questions (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"780d73d4abd45a0284d2cc0c646dbe8432ae347362891a4b98a19a61341a7325","revision_id":"f36ffb0a-d6df-522f-b783-5e30214b9e26","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}