Altered renin synthesis and secretion in the kidneys of heterozygous mice with a null mutation in the TGF-β₂ gene

Transforming growth factors β (TGF-βs) are peptides involved in autocrine and paracrine control of cell growth and differentiation. In the kidneys, TGF-β₂ has been shown to localize specifically in renin-producing cells in various conditions stimulating the renin response. To test in vivo the functional role of TGF-β₂, the renin response was investigated in mice heterozygous for a null mutation of the TGF-β₂ gene, which had a two-fold reduction in the amount of TGF-β₂ mRNA. Although the increase in plasma renin concentration triggered by dehydration was not different from wild-type mice, renal renin mRNA and protein levels were higher in mutant mice under hydrated or dehydrated conditions. These data suggest that TGF-β₂ exerts an inhibitory effect on renin synthesis and release from the juxtaglomerular apparatuses. Copyright