Transforming growth factor-β/connective tissue growth factor axis in the kidney

Transforming growth factor-β1 (TGFβ1) is recognized as both a fibrogenic and inflammatory cytokine and plays a critical role in the kidney pathophysiology. The dysregulation of TGFβ1 has been linked with the development of diabetic nephropathy. Connective tissue growth factor (CTGF) is a fibrogenic cytokine and is recognized as a downstream mediator of TGFβ1 in kidney fibrosis. TGFβ1 is involved in immunomodulation and fibrosis in the kidney. However, CTGF plays a more specific role in the fibrogenic pathways in the kidney proximal tubule cells. Moreover, CTGF facilitates TGFβ1 signaling and promotes renal fibrosis. This suggests CTGF could be a potential target for kidney fibrosis. Long-term inhibition and targeting TGFβ1 directly is problematic, therefore, a more fruitful direction targeting diabetic nephropathy may involve the development of therapeutic strategies specifically targeting CTGF.