The renin cell precursor: distribution and fate

Abstract

Renin‐synthesizing cells are crucial in the regulation of blood pressure and fluid and electrolyte homeostasis. These cells have been considered for a long time as terminally differentiated because they synthesize a hormone (renin), they are few in numbers, and they are restricted to a juxtaglomerular localization in the adult mammalian kidney. However, by generating knock‐in mice expressing cre recombinase in renin‐expressing cells and crossing them with reporter mice we showed that renin‐expressing cells are precursors for a variety of cells that differentiate into non‐renin‐expressing cells within and outside the kidney. These differentiated cells that descend from renin‐expressing cells consist of a subset of vascular smooth‐muscle, epithelial, and mesangial cells within the kidney. Extrarrenal descendents are found in the adrenal gland, testes, sympathetic ganglia, cartilage, bone marrow. When homeostasis is threatened, specific subpopulations of apparently differentiated cells that descended from renin cells de‐differentiate and re‐express renin in an attempt to reestablish homeostasis, and re‐differentiate when the crisis passes.