Transcription factor 21 deletion from podocyte precursors as a model for congenital nephrotic syndrome

. Parietal epithelial cells in mutant kidneys underwent secondary changes that have been shown to promote glomerular injury in other models of kidney disease. Additionally, we observed tubulointerstitial changes coincident with the massive proteinuria produced by this genetic model - namely, an expansion of fibroblasts accompanied by the appearance of a new injury cell state in the loop of Henle. These changes preceded the onset of severe, irreversible injury, presenting pathways that could be intervened upon early in disease to prevent progression of renal fibrosis.