{"id":"a1527ee9-590b-5fea-a2fc-ab5c5abeb27a","stable_key":"availability:thyroid-peroxide-defense:1","predicate":"can_reduce","statement":"Severe selenium deficiency can reduce thyroid defensive capacity contributed by GPXs and thioredoxin reductases.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"source_reported: Cell/biochemical mechanism and source-derived unverified synthesis.","direction":"negative","is_public":true,"mechanism_event_id":"908156f3-e33f-5f83-937f-283f4630d413","mechanism_event_label":"Severe selenium deficiency can reduce thyroid defensive capacity contributed by GPXs and thioredoxin reductases.","subject":{"id":"dc89d7e2-8f89-577b-838f-42bf5d8ec7c8","slug":"selenium","display_name":"Selenium","entity_type_key":"nutrient_element"},"object":{"id":"efae2f24-2736-563e-9726-ecd69ff4fb94","slug":"thyroid-redox-defense","display_name":"Thyroid peroxide defense","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"908156f3-e33f-5f83-937f-283f4630d413","stable_key":"availability:thyroid-peroxide-defense:1","event_type":"availability_dependent_change","label":"Severe selenium deficiency can reduce thyroid defensive capacity contributed by GPXs and thioredoxin reductases.","description":"Severe selenium deficiency reduces selenium-dependent thyroid redox capacity. Biochemical redox mechanism in severe deficiency; autoimmune disease is a separate, multifactorial outcome.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"dc89d7e2-8f89-577b-838f-42bf5d8ec7c8","slug":"selenium","display_name":"Selenium","entity_type_key":"nutrient_element"},"role":"condition_input","stoichiometry":null,"state_label":"Severe selenium deficiency reduces selenium-dependent thyroid redox capacity.","sequence_order":0,"notes":""},{"entity":{"id":"efae2f24-2736-563e-9726-ecd69ff4fb94","slug":"thyroid-redox-defense","display_name":"Thyroid peroxide defense","entity_type_key":"cellular_process"},"role":"affected_component","stoichiometry":null,"state_label":"Severe selenium deficiency reduces selenium-dependent thyroid redox capacity.","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"Severe selenium deficiency reduces selenium-dependent thyroid redox capacity.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_scope","value_text":"Biochemical redox mechanism in severe deficiency; autoimmune disease is a separate, multifactorial outcome.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This does not make deficiency a sufficient cause of Hashimoto thyroiditis or thyroid antibodies. No antibody or treatment benefit is inferred.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"0a90c219-e486-5495-ab1f-82f8e23bcfba","evidence_kind":"source_passage","locator":"lines 329-338","start_line":329,"end_line":338,"excerpt":"B. Oxidative defense in the thyroid\n\nThyroid-hormone synthesis requires locally generated H₂O₂:\n\nTSH signaling\n   → DUOX2/DUOXA2 generates H₂O₂ near the apical membrane\n   → TPO uses H₂O₂ to oxidize iodide and iodinate thyroglobulin\n   → antioxidant systems limit peroxide spillover and lipid/protein damage\n\nSelenoproteins such as GPXs and thioredoxin reductases contribute to thyroid redox control. Severe selenium deficiency can reduce this defensive capacity, but Hashimoto thyroiditis is multifactorial; selenium deficiency is not a sufficient one-step cause of anti-TPO or anti-thyroglobulin autoimmunity.","model_system":"Supplied reference; verify the primary study and experimental context.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"c788c19c-884c-5233-92b1-0bd063d87741","stable_key":"deficiency","title":"Selenium deficiency: a mechanism-first reference","document_type":"user_supplied_reference","citation_label":"Supplied selenium deficiency reference","file_path":"X:\\metabolic-ledger\\source_material\\selenium-deficiency-reference.md","sha256":"a3f14bc3fa24c595dda830664523090a7b5bfa76e9dcf517f42f62212ceb767e","revision_id":"f8f97804-c1fb-56df-9c06-c02e36e2a5b8","review_status":"unverified_draft","notes":"Preserved verbatim. Reported study types are source labels, not independent verification."}}],"relations":[],"conflicts":[],"corrections":[],"research":null}