Renin expressing cells in the kidney normally appear as mural cells of developing preglomerular vessels and finally impose as granulated juxtaglomerular cells in adult kidneys. The differentiation of renin expressing cells from the metanephric mesenchyme in general, and the potential role of special precursor stages in special, is not well understood. It was the aim of this study therefore to search for renin cell precursors in the kidney. As an experimental model we used kidneys of aldosterone synthase deficient mice which display a prominent compensatory overproduction of renin cells that are arranged in multilayered perivascular cell clusters. We found that the perivascular cell clusters contained two apparently distinct cell types. One staining positive for renin and another one staining positive for type I procollagen (PC1). It appeared as if PC1 and renin expression were inversely related at the cellular level. The proportion of renin positive to PC1 positive cells in the clusters was inversely linked to the rate of salt intake as was overall renin expression. Our findings suggest that the cells in the perivascular cell clusters can reversibly switch between procollagen 1 and renin expression, and that PC1 expressing cells might be precursors of renin cells. Few of those PC1 positive cells were found also in adult wildtype kidneys in the juxtaglomerular lacis cell area, in which renin expression can be induced on demand.
Type of Publication:
Journal article published