TGF-β in Renal Injury and Disease

SummaryChronic progressive kidney diseases typically are characterized by loss of differentiated epithelial cells and activation of mesenchymal cell populations leading to renal fibrosis in response to a broad range of diverse renal injuries. Recent evidence has indicated that epithelial microinjury leads to unbalanced epithelial-mesenchymal communication to initiate the fibrotic response. Transforming growth factors β constitute a large family of cytokines that control key cellular responses in development and tissue repair. Activation of autocrine and paracrine transforming growth factor-β signaling cascades in the context of epithelial microinjuries initiate a variety of cell type–dependent signaling and activity profiles, including epithelial apoptosis and epithelial-to-mesenchymal transition, that trigger fibrogenic foci and initiate progressive fibrogenesis in chronic renal injury.