Activation of ectopic olfactory receptor 544 induces GLP-1 secretion, alters gut microbiome, and improves colonal permeability.

To study the anti-inflammatory effects of Olfr544 activation by AzA in gut, we performed RNA-seq analysis in LPS-stimulated colonic tissue explants isolated from WT and Olfr544-dificient mice. In pathway analysis, activation of Olfr544 altered gene expressions in several biological pathways including inflammatory response and immune response as well as apoptotic process and cell death. However, the numbers of significantly up- and downregulated genes in these biological pathways were dramatically reduced in colonic explants from Olfr544 KO mice (e.g. the number of significantly up and downregulated genes in inflammatory response are 13 and 33 in WT but 4 and 8 in KO colonic tissues). These suggest that AzA affects several biological pathways in ex vivo colonic tissues such as immune response and inflammatory response by Olfr544-dependent manner.