Journal of Nephrology & Therapeutics

Cellular and Molecular Basis of Epithelial-Mesenchymal Transition in Renal Fibrosis

Abstract

Yoshiyuki Morishita and Eiji Kusano

Regardless of the underlying etiology, tubulointerstitial fibrosis is a common mechanism in the progression of chronic kidney disease (CKD) to end-stage renal disease. Epithelial-mesenchymal transition (EMT) of renal tubular cells plays an important role in tubulointerstitial fibrosis. Transforming growth factor-?1/Sma and Mad protein (TGF-?1/Smad) is thought to be a main signaling pathway for EMT of renal tubular cells. Progressive renal disease is also characterized histologically by an interstitial infiltrate of mononuclear cells. The chemokines secreted from renal tubular cells can trigger integrin-dependent adhesion of circulating mononuclear cells that leads to infiltration at tubulointerstitial space. The direct interaction of integrin lymphocyte function-associated antigen 1(LFA-1: ?L?2 integrin) on mononuclear cells and its ligand, intracellular adhesion molecule-1(ICAM-1) on renal tubular epithelial cells, contributes to a part of the EMT of renal tubular cells.