Expression Profile of G Protein‐Coupled Receptor 37L1 in mouse

Abstract

The orphan G protein‐coupled receptor GPR37L1, also known as ETBR‐LP2, has strong homology with the endothelin‐B receptor (ETBR). However, GPR37L1 does not interact with endothelins. GPR37L1 is implicated to participate in brain development and the regulation of arterial blood pressure. GPR37L1 has been shown to be expressed in several regions in the brain, however its expression profile and the function in peripheral organs is poorly understood. We studied the expression profile of GPR37L1 in the brain, heart, kidney, liver, lung, spleen, stomach, pancreas, skeletal muscle, testis, and ovaries by RT‐PCR and immunoblot analyses and further used immunohistochemical analyses on tissue sections to identify the location of GPR37L1 expression within the tissue. Immunoblot analyses revealed the predicted 50 kDa and 40 kDa isoforms in most organs, and a ~35 kDa isoform mainly in the stomach and to a lesser extent in the brain, and a diffuse band of 45 kDa isoform mainly in the testis. The expression of GPR37L1 was highest in the brain, heart, stomach, pancreas, and skeletal muscle while GPR37L1 protein expression was lower in the kidney, liver, lung, spleen, testis, and ovary. The brain and pancreas expressed predominantly a 50 kDa isoform, while heart and skeletal muscle expressed mainly a 40 kDa isoform of GPR37L1. The kidney, liver, lung and ovary expressed almost equivalent levels of 50 kDa and 40 kDa isoforms of GPR37L1. The spleen expressed mainly a 40 kDa isoform of GPR37L1. RT‐PCR analyses confirmed the relative levels of GPR37L1 expression in the organs analyzed. Immunohistochemical analyses revealed the expression of GPR37L1, in the granule cell layer of the cerebellum, apical membrane of proximal tubule cells in the kidney, and airway epithelial cells in the lung. Further, RT‐PCR of proximal tubule and collecting duct cells obtained by laser capture micro‐dissection of mouse kidney sections, confirmed that the GPR37L1 is expressed in renal the proximal tubule but not in the collecting duct. These data show that GPR37L1 is expressed in the specific cell types within the organs and may play a key role in the physiology of the respective organs.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.