The intermediate filament protein nestin is expressed in the developing kidney and heart and might be regulated by the Wilms’ tumor suppressor Wt1

Nestin is an intermediate filament protein originally described in neural stem cells and a variety of progenitor cells. More recently, nestin was detected in rat kidney podocytes. We show here that nestin is expressed in a developmentally regulated pattern in the kidney. Nestin was detected by immunohistochemistry in the condensing mesenchyme surrounding the ureter, in developing glomeruli, in podocytes of the adult kidney, and in a podocyte cell line. Nestin shared a strikingly overlap in expression with the Wilms’ tumor suppressor Wt1. Nestin was significantly up-regulated in a cell line with inducible Wt1 expression upon induction of Wt1. Co-transfection experiments in human embryonic kidney cells (HEK293) revealed stimulation of a nestin intron 2 enhancer element up to 6-fold by the Wt1(-KTS) splice variant. Nestin expression was significantly reduced in an inducible mouse model of glomerular disease. This model is based on podocyte-specific over-expression of Pax2 and associated with a loss of Wt1 expression [33]. Furthermore, also in the developing heart, nestin was found in an overlapping pattern with Wt1 in the epicardium and the forming coronary vessels. Strikingly, in the hearts of Wt1 knockout mice, nestin was barely detectable when compared to the hearts of wild-type embryos. Our results show that nestin is expressed at different stages of kidney and cardiac development and suggest that its expression in these organs might be regulated by the Wilms’ tumor suppressor Wt1.