Expression of short-chain fatty acid receptor GPR41 in the human colon

摘要

Short-chain fatty acids (SCFAs), including acetate, propionate and butyrate, are the most common-ly found anions found in the monogastric mammalian large intestine, and are known to have a va-riety of physiological and pathophysiological effects on the gastrointestinal tract. We investigatedthe protein and mRNA expression levels of GPR4 1 , a possible G protein coupled receptor forSCFA, using Western blot analysis and reverse transcriptase-polymerase chain reaction. We foundthat GPR41 protein and mRNA are expressed in human colonic mucosa. Immunohistochemistryfor GPR41 showed that mucosal GPR41 protein is localized in cytoplasm of enterocytes and en-teroendocrine cells. Moreover, GPR41-immunoreactive endocrine cells contained peptide YY butnot serotonin or GPR43. The cellular population of GPR41 (0.01 ± 0.01 cells/crypt) was muchsmaller than that of GPR43 (0.33 0.01 cells/crypt) in the human colon. However, the potencyorder of SCFA-induced phasic contraction of colonic smooth muscle that we previously reportedis consistent with GPR41 (propionate ≥butyrate > acetate) but not GPR43 (propionate = butyrate =acetate). Therefore, the present study suggests that GPR41 expressed in human colonic mucosamay function as a sensor for luminal SCFAs.