Effect Of Leptin On The Transdifferentiation And TGF-β1Expression Of Human Renal Tubular Epithelial Cell Line

Objective:To investigate the effect of leptin on the trans-differentiation and TGF-β1 expression of human renal tubular epithelial cell line (HK-2) in vitro, and to analyze the role of leptin in renal interstitial fibrosis.Method:Cultured HK-2 cells were divided into control group and leptin-treated groups (10,50, 100ng/ml for 48h, respectively; 100ng/ml for 24,48h,72h, respectively;). The cell morphological changes were traced with inverted microscope;The expression of a-smooth muscle actin (a-SMA) and E-cadherin at both transcriptional and protein levels were detected by real-time quantitative reverse transcription polymerase chain reaction(RT-PCR) and Western blot; The expression of TGF-β1 mRNA were detected by RT-PCR, while TGF-β1 secreted into the culture supernatant was assessed by enzyme-linked immunosorbent assay (ELISA).Results:(1) Leptin stimulated the oval-to-fusiform transdifferentiation in morphology of HK-2 cells. (2) Compared to control group, the expression of a-SMA was up-regulated while the expression of E-cadherin was down-regulated. There was a obvious correlation between a-SMA and TGF-β1 mRNA expression. (3) These above-mentioned effects could be inhibited by anti-TGF-β1 antibody. Conclusion:Leptin can promote transdifferentiation of human renal tubular epithelial cells and play an important role in renal interstitial fibrosis. Leptin induced epithelial mesenchymal transition may be partially related to increased TGF-β1 secretion.