Olfactory receptor Olfr544 responding to azelaic acid regulates glucagon secretion in α-cells of mouse pancreatic islets

Olfactory receptors (ORs) are extensively expressed in olfactory as well as non-olfactory tissues. Although many OR transcripts are expressed in non-olfactory tissues, only a few studies demonstrate the functional role of ORs. Here, we verified that mouse pancreatic α-cells express potential OR-mediated downstream effectors. Moreover, high levels of mRNA for the olfactory receptors Olfr543, Olfr544, Olfr545, and Olfr1349 were expressed in α-cells as assessed using RNA-sequencing, microarray, and quantitative real-time RT-PCR analyses. Treatment with dicarboxylic acids (azelaic acid and sebacic acid) increased intracellular Ca²⁺ mobilization in pancreatic α-cells. The azelaic acid-induced Ca²⁺ response as well as glucagon secretion was concentration- and time-dependent manner. Olfr544 was expressed in α-cells, and the EC₅₀ value of azelaic acid to Olfr544 was 19.97 μM, whereas Olfr545 did not respond to azelaic acid. Our findings demonstrate that Olfr544 responds to azelaic acid to regulate glucagon secretion through Ca²⁺ mobilization in α-cells of the mouse pancreatic islets, suggesting that Olfr544 may be an important therapeutic target for metabolic diseases.