Transcriptomic profiling of alpha, beta, and delta cell populations provides new insights into the role of ghrelin in the pancreas

Intra-islet crosstalk between islet cells is critical in orchestrating the body’s response to changes in blood glucose levels, but is incompletely understood. In this study, we used transgenic mouse lines that allowed the purification and transcriptomic characterisation of alpha, beta, and delta cells, yielding an RNA-sequencing database that can be searched for regulatory proteins which are differentially expressed between cell types. As an illustrative example, we examined the expression of g-protein coupled receptors, and found that the ghrelin receptor, Ghsr, was highly expressed in delta cells compared to alpha and beta cells. GHSR excitation elicited increases in cytosolic calcium levels in primary delta cells. In the perfused pancreas, the application of ghrelin stimulated somatostatin secretion, correlating with a decrease in insulin and glucagon release, which was sensitive to somatostatin receptor antagonism. These results show that ghrelin acts specifically on delta cells within pancreatic islets to affect blood glucose regulation. Overall design: Examination of transcriptomic profiles obtained from pancreatic alpha, beta and delta cells

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Adriaenssens AE, Svendsen B, Lam BY, Yeo GS, Holst JJ, Reimann F, Gribble FM