{"id":"711c9133-4018-58b3-ae7d-2a9d56437428","stable_key":"4df6a932-097e-563a-91fe-5dceec471ffd:chloride-calu3-pendrin-null","predicate":"knockdown_no_detected_effect_on","statement":"Pendrin knockdown did not change measured Calu-3 bicarbonate secretion.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"ca734f72-22a6-506b-968e-fae4e57001da","mechanism_event_label":"One airway model relied mainly on CFTR, despite detectable pendrin.","subject":{"id":"57fef31d-e7e6-5b6f-aee1-77fb94592ce7","slug":"slc26a4","display_name":"Human pendrin / SLC26A4","entity_type_key":"protein"},"object":{"id":"49a2f02e-e7c8-51eb-9f0d-0858ddfa8d9a","slug":"airway-bicarbonate-secretion","display_name":"Airway epithelial bicarbonate secretion","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"ca734f72-22a6-506b-968e-fae4e57001da","stable_key":"4df6a932-097e-563a-91fe-5dceec471ffd:chloride-calu3-pendrin-null-event","event_type":"biochemical_relationship","label":"One airway model relied mainly on CFTR, despite detectable pendrin.","description":"Pendrin knockdown did not change measured Calu-3 bicarbonate secretion.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"53064670-c3d1-59e8-aeaa-a8d673d00f3a","slug":"cftr","display_name":"Human cystic fibrosis transmembrane conductance regulator / CFTR","entity_type_key":"protein"},"role":"major_route","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"57fef31d-e7e6-5b6f-aee1-77fb94592ce7","slug":"slc26a4","display_name":"Human pendrin / SLC26A4","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"49a2f02e-e7c8-51eb-9f0d-0858ddfa8d9a","slug":"airway-bicarbonate-secretion","display_name":"Airway epithelial bicarbonate secretion","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/chloride-research/29536650.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"9da6a23e90b30ab4d0c2b537af65076e93cc3370470f64a9dafdeaaff525f157\", \"start_char\": 0, \"end_char\": 1519, \"text_sha256\": \"9da6a23e90b30ab4d0c2b537af65076e93cc3370470f64a9dafdeaaff525f157\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Knockdown and epithelial secretion assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Pendrin shRNA, CFTR deficiency, culture conditions","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Authors explicitly limit extrapolation to other airway epithelia.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Chloride research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"chloride","display_name":"Chloride","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Human Calu-3 cell line","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"One airway model relied mainly on CFTR, despite detectable pendrin.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[chloride-p29536650] Most bicarbonate secretion by Calu-3 cells is mediated by CFTR and independent of pendrin. (2018). https://pubmed.ncbi.nlm.nih.gov/29536650/ DOI: 10.14814/phy2.13641","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Airway gland-like epithelial model","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"e45123e0-bf86-5ca9-b22d-bb73834d3feb","evidence_kind":"source_excerpt","locator":"Lines 1043-1054","start_line":1043,"end_line":1054,"excerpt":"### chloride-calu3-pendrin-null\nPendrin knockdown did not change measured Calu-3 bicarbonate secretion.\nCondition category: normal\nnutrient_topic: Chloride research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: One airway model relied mainly on CFTR, despite detectable pendrin.\norganism: Human Calu-3 cell line\ntissue_or_cell_type: Airway gland-like epithelial model\nexperimental_model: Knockdown and epithelial secretion assays\nlimitations: Authors explicitly limit extrapolation to other airway epithelia.\nexposure: Pendrin shRNA, CFTR deficiency, culture conditions\nevidence_span: {\"source_cache\": \"artifacts/chloride-research/29536650.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"9da6a23e90b30ab4d0c2b537af65076e93cc3370470f64a9dafdeaaff525f157\", \"start_char\": 0, \"end_char\": 1519, \"text_sha256\": \"9da6a23e90b30ab4d0c2b537af65076e93cc3370470f64a9dafdeaaff525f157\"}\n[chloride-p29536650] Most bicarbonate secretion by Calu-3 cells is mediated by CFTR and independent of pendrin. (2018). https://pubmed.ncbi.nlm.nih.gov/29536650/ DOI: 10.14814/phy2.13641","model_system":"Knockdown and epithelial secretion assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [chloride-p29536650] Most bicarbonate secretion by Calu-3 cells is mediated by CFTR and independent of pendrin. (2018). https://pubmed.ncbi.nlm.nih.gov/29536650/ DOI: 10.14814/phy2.13641","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"1c2070d5-9f15-5945-b325-d0b49a32c04b","stable_key":"import-4df6a932-097e-563a-91fe-5dceec471ffd","title":"Chloride: transport, acid-base balance, nutrient interactions and loss states (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"e32e796f293a3287c6b8f4394881db94cc741ba96e3166e44da2dd14f208f645","revision_id":"8d5fd8ef-db54-5198-a368-23329a02d81b","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}