Adhesion GPCR Gpr126 (Adgrg6) Expression Profiling in Zebrafish, Mouse, and Human Kidney.

Adhesion G protein-coupled receptors (aGPCRs) comprise the second-largest class of GPCRs, the most common target for approved pharmacological therapies. aGPCRs play an important role in development and disease and have recently been associated with the kidney. Several aGPCRs are expressed in the kidney and some aGPCRs are either required for kidney development or their expression level is altered in diseased kidneys. Yet, general aGPCR function and their physiological role in the kidney are poorly understood. Here, we characterize in detail () expression based on RNAscope technology in zebrafish, mice, and humans during kidney development in adults. expression is enriched in the epithelial linage during nephrogenesis and persists in the adult kidney in parietal epithelial cells, collecting ducts, and urothelium. Single-cell RNAseq analysis shows that expression is detected in zebrafish in a distinct ionocyte sub-population. It is co-detected selectively with , , and , known to be involved in apical acid secretion, buffering blood or intracellular pH, and to maintain high cytoplasmic Ca concentration, respectively. Furthermore, -expressing cells were enriched in the expression of potassium transporter and , which regulate the expression of a calcium sensor receptor. Notably, the expression patterns of , , and in mouse kidneys are highly similar. Collectively, our approach permits a detailed insight into the spatio-temporal expression of and provides a basis to elucidate a possible role of Gpr126 in kidney physiology.