{"id":"587d077b-05c7-56bb-876c-6bdf54c0966d","stable_key":"b26c9d01-98fd-50d3-8f39-44db46961ee5:acetate-ffar2-on-pyy-cells","predicate":"is_expressed_in","statement":"GPR43 immunoreactivity was localised to enteroendocrine cells expressing peptide YY, whereas 5-hydroxytryptamine-immunoreactive enteroendocrine cells were not immunoreactive for GPR43, and mast cells of the lamina propria expressing 5-hydroxytryptamine were also GPR43-immunoreactive.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"4f446e0c-8b24-5934-8c40-112b815e44a6","mechanism_event_label":"The receptor sits on the gut cells that make PYY, and on mast cells, but not on the serotonin-making gut cells.","subject":{"id":"2339ae63-1f30-58c0-8b4f-1a46c8a87418","slug":"ffar2","display_name":"Human free fatty acid receptor 2 / FFAR2","entity_type_key":"protein"},"object":{"id":"ecbd32f4-d547-52ca-8f3f-3175bff73579","slug":"enteroendocrine-cell","display_name":"Enteroendocrine cell","entity_type_key":"cell_type"},"evidence_count":1,"mechanism_event":{"id":"4f446e0c-8b24-5934-8c40-112b815e44a6","stable_key":"b26c9d01-98fd-50d3-8f39-44db46961ee5:acetate-ffar2-on-pyy-cells-event","event_type":"observed_intervention","label":"The receptor sits on the gut cells that make PYY, and on mast cells, but not on the serotonin-making gut cells.","description":"GPR43 immunoreactivity was localised to enteroendocrine cells expressing peptide YY, whereas 5-hydroxytryptamine-immunoreactive enteroendocrine cells were not immunoreactive for GPR43, and mast cells of the lamina propria expressing 5-hydroxytryptamine were also GPR43-immunoreactive.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"3772cb27-881b-5077-8e5e-c370c9e87983","slug":"mucosal-mast-cell","display_name":"Mucosal mast cell of the lamina propria","entity_type_key":"cell_type"},"role":"co_expressing_cell","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"fd91b56b-3280-57b0-b2d0-61d5319616c0","slug":"pyy","display_name":"Peptide YY / PYY","entity_type_key":"peptide"},"role":"marker_peptide","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"fef9ecc3-7c04-553c-a207-d91e38a2665a","slug":"serotonin","display_name":"Serotonin","entity_type_key":"small_molecule"},"role":"distinguishing_marker","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"2339ae63-1f30-58c0-8b4f-1a46c8a87418","slug":"ffar2","display_name":"Human free fatty acid receptor 2 / FFAR2","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"ecbd32f4-d547-52ca-8f3f-3175bff73579","slug":"enteroendocrine-cell","display_name":"Enteroendocrine cell","entity_type_key":"cell_type"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/acetate-research/16453106.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"14165574bceda6c6197de30baae79895b87d2b95272ea42c231554d7a4c015d2\", \"start_char\": 0, \"end_char\": 1605, \"text_sha256\": \"14165574bceda6c6197de30baae79895b87d2b95272ea42c231554d7a4c015d2\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"RT-PCR, Western blotting and immunohistochemistry with a rat-specific GPR43 antiserum","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Receptor localisation across mucosal cell types","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"An anatomical result naming the cells that carry the receptor. Localisation is not function, and the antiserum was raised against a synthesised fragment.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Acetic acid research collection; topical membership is not evidence of a direct clinical effect, and the ingested acid is recorded separately from the circulating acetate anion.","comparator":null,"unit":null,"notes":"","entity":{"slug":"acetic-acid","display_name":"Acetic acid","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Rat","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The receptor sits on the gut cells that make PYY, and on mast cells, but not on the serotonin-making gut cells.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[acetate-p16453106] Short-chain fatty acid receptor, GPR43, is expressed by enteroendocrine cells and mucosal mast cells in rat intestine. (2006). https://pubmed.ncbi.nlm.nih.gov/16453106/ DOI: 10.1007/s00441-005-0140-x","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Distal ileum and colon","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"7b0a3e2d-eece-56f7-923b-50b17ce31d3c","evidence_kind":"source_excerpt","locator":"Lines 277-288","start_line":277,"end_line":288,"excerpt":"### acetate-ffar2-on-pyy-cells\nGPR43 immunoreactivity was localised to enteroendocrine cells expressing peptide YY, whereas 5-hydroxytryptamine-immunoreactive enteroendocrine cells were not immunoreactive for GPR43, and mast cells of the lamina propria expressing 5-hydroxytryptamine were also GPR43-immunoreactive.\nCondition category: normal\nnutrient_topic: Acetic acid research collection; topical membership is not evidence of a direct clinical effect, and the ingested acid is recorded separately from the circulating acetate anion.\nplain_language: The receptor sits on the gut cells that make PYY, and on mast cells, but not on the serotonin-making gut cells.\norganism: Rat\ntissue_or_cell_type: Distal ileum and colon\nexperimental_model: RT-PCR, Western blotting and immunohistochemistry with a rat-specific GPR43 antiserum\nlimitations: An anatomical result naming the cells that carry the receptor. Localisation is not function, and the antiserum was raised against a synthesised fragment.\nexposure: Receptor localisation across mucosal cell types\nevidence_span: {\"source_cache\": \"artifacts/acetate-research/16453106.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"14165574bceda6c6197de30baae79895b87d2b95272ea42c231554d7a4c015d2\", \"start_char\": 0, \"end_char\": 1605, \"text_sha256\": \"14165574bceda6c6197de30baae79895b87d2b95272ea42c231554d7a4c015d2\"}\n[acetate-p16453106] Short-chain fatty acid receptor, GPR43, is expressed by enteroendocrine cells and mucosal mast cells in rat intestine. (2006). https://pubmed.ncbi.nlm.nih.gov/16453106/ DOI: 10.1007/s00441-005-0140-x","model_system":"RT-PCR, Western blotting and immunohistochemistry with a rat-specific GPR43 antiserum","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [acetate-p16453106] Short-chain fatty acid receptor, GPR43, is expressed by enteroendocrine cells and mucosal mast cells in rat intestine. (2006). https://pubmed.ncbi.nlm.nih.gov/16453106/ DOI: 10.1007/s00441-005-0140-x","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"8356baaf-173c-5549-80cd-bbbb2007ffb5","stable_key":"import-b26c9d01-98fd-50d3-8f39-44db46961ee5","title":"Acetic acid: the ingested acid, the receptors acetate binds, the acetyl-CoA it becomes, and the acetyl groups that reach histones (2026-09-21)","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":"1441d249b16db25c0d488407e5cc881222acffc2f16af88cb3197d9d5697bccc","revision_id":"9bfeb605-f589-5e99-84b9-e56968a3bc1f","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[{"id":"041f86c9-6de8-53fb-a0a2-920d93264917","title":"Does FFAR2 sit on the hormone-secreting cells of the gut, or mainly on immune cells?","kind":"context_difference","status":"open","why":"Immunohistochemistry in rat ileum and colon localised GPR43 to peptide YY-expressing enteroendocrine cells and to mucosal mast cells. A reporter mouse line found the FFAR2 reporter strongly expressed in lamina propria leukocytes and only weakly in a subpopulation of enteroendocrine cells, while the FFAR3 reporter marked nearly all of them. The two disagree on where the receptor mainly is, which matters because the enteroendocrine location is what the gut hormone story rests on. They differ in species and in method, an antiserum against a synthesised fragment against a transgenic fluorescent reporter, and neither measures receptor protein in the other species. Recorded as a difference in what was measured, not resolved.","resolution":"Unresolved; needs review.","created_at":"2026-09-22 01:55:55","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/041f86c9-6de8-53fb-a0a2-920d93264917","sides":[{"conflict_id":"041f86c9-6de8-53fb-a0a2-920d93264917","ordinal":0,"label":"The receptor sits on the gut cells that make PYY, and on mast cells, but not on the serotonin-making gut cells.","revision_id":"9bfeb605-f589-5e99-84b9-e56968a3bc1f","start_line":277,"end_line":288,"quote":"### acetate-ffar2-on-pyy-cells\nGPR43 immunoreactivity was localised to enteroendocrine cells expressing peptide YY, whereas 5-hydroxytryptamine-immunoreactive enteroendocrine cells were not immunoreactive for GPR43, and mast cells of the lamina propria expressing 5-hydroxytryptamine were also GPR43-immunoreactive.\nCondition category: normal\nnutrient_topic: Acetic acid research collection; topical membership is not evidence of a direct clinical effect, and the ingested acid is recorded separately from the circulating acetate anion.\nplain_language: The receptor sits on the gut cells that make PYY, and on mast cells, but not on the serotonin-making gut cells.\norganism: Rat\ntissue_or_cell_type: Distal ileum and colon\nexperimental_model: RT-PCR, Western blotting and immunohistochemistry with a rat-specific GPR43 antiserum\nlimitations: An anatomical result naming the cells that carry the receptor. Localisation is not function, and the antiserum was raised against a synthesised fragment.\nexposure: Receptor localisation across mucosal cell types\nevidence_span: {\"source_cache\": \"artifacts/acetate-research/16453106.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"14165574bceda6c6197de30baae79895b87d2b95272ea42c231554d7a4c015d2\", \"start_char\": 0, \"end_char\": 1605, \"text_sha256\": \"14165574bceda6c6197de30baae79895b87d2b95272ea42c231554d7a4c015d2\"}\n[acetate-p16453106] Short-chain fatty acid receptor, GPR43, is expressed by enteroendocrine cells and mucosal mast cells in rat intestine. (2006). https://pubmed.ncbi.nlm.nih.gov/16453106/ DOI: 10.1007/s00441-005-0140-x","source_key":"import-b26c9d01-98fd-50d3-8f39-44db46961ee5","source_title":"Acetic acid: the ingested acid, the receptors acetate binds, the acetyl-CoA it becomes, and the acetyl groups that reach histones (2026-09-21)","claim_ids":["587d077b-05c7-56bb-876c-6bdf54c0966d"]},{"conflict_id":"041f86c9-6de8-53fb-a0a2-920d93264917","ordinal":1,"label":"FFAR2 turned out to sit mainly on immune cells rather than on the hormone cells, though its agonist still released the hormone.","revision_id":"9bfeb605-f589-5e99-84b9-e56968a3bc1f","start_line":303,"end_line":314,"quote":"### acetate-ffar2-mostly-leukocytes\nThe FFAR2 reporter was strongly expressed in a large population of leukocytes in the lamina propria, particularly of the small intestine, but surprisingly only weakly in a subpopulation of enteroendocrine cells; nevertheless synthetic ligands specific for either FFAR3 or FFAR2 each released GLP-1 from colonic crypt cultures.\nCondition category: normal\nnutrient_topic: Acetic acid research collection; topical membership is not evidence of a direct clinical effect, and the ingested acid is recorded separately from the circulating acetate anion.\nplain_language: FFAR2 turned out to sit mainly on immune cells rather than on the hormone cells, though its agonist still released the hormone.\norganism: Mouse\ntissue_or_cell_type: Whole gastrointestinal tract\nexperimental_model: Transgenic monomeric red fluorescent protein reporter mice with FACS purification and quantitative PCR\nlimitations: Reporter expression is not the same as receptor protein. The FFAR2 result here is weaker in enteroendocrine cells than the rat immunohistochemistry in this collection reports.\nexposure: Cell-type resolved expression of FFAR2 and FFAR3 reporters, with receptor-specific synthetic agonists on colonic crypt cultures\nevidence_span: {\"source_cache\": \"artifacts/acetate-research/23885020.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"b834455e11c2b8fa3c4c19c5d01375815e46c3b0f8e25eb184f0eaa6a51c749e\", \"start_char\": 0, \"end_char\": 2144, \"text_sha256\": \"b834455e11c2b8fa3c4c19c5d01375815e46c3b0f8e25eb184f0eaa6a51c749e\"}\n[acetate-p23885020] GPR41/FFAR3 and GPR43/FFAR2 as cosensors for short-chain fatty acids in enteroendocrine cells vs FFAR3 in enteric neurons and FFAR2 in enteric leukocytes. (2013). https://pubmed.ncbi.nlm.nih.gov/23885020/ DOI: 10.1210/en.2013-1142","source_key":"import-b26c9d01-98fd-50d3-8f39-44db46961ee5","source_title":"Acetic acid: the ingested acid, the receptors acetate binds, the acetyl-CoA it becomes, and the acetyl groups that reach histones (2026-09-21)","claim_ids":["4262481d-313d-5063-b163-dfbbd178e9c7"]}]}],"corrections":[],"research":null}