Effect Of Aldose Reductase Inhibitor On Epithelial-mesenchymal Transition Induced By High Concentration Of Glucose

Objective:To evaluate the effects of aldose reductase inhibitor (ARI) Epalrestat and Eucommia Lignans on epithelial to mesenchymal transition and extracellular matrix(ECM) accumulation in human renal proximal tubular cells(HK-2) induced by high concentration glucose, and to obtain evidence for the application of ARI and Lignan in DN.Methods: HK-2 cells were treated with high glucose or a combination high glucose and epalrestat / Eucommia Lignans. Morphological changes were assessed by phase contrast microscopy. The expression of mRNA levels ofα-SMA, E-cadherin, ColⅠ, FN were evaluated by real-time PCR respectively. The expression of protein levels ofα-SMA, E-cadherin, ColⅠ, FN were analysed by Western Blot.Results: 1. The control cells displayed typical cobblestone morphology of epithelial cells. High glucose treatment of confluent HK-2 cells resulted in distinct morphological changes. High glucose treated cells showed evidence of gross elongation with filopodia formation but inhibited partly in the presence of lumol/L, 10umol/L epalrestat or 0.1mg/L, 1mg/L, 1mg/L Eucommia Lignans.2. Real-time PCR staining showed that high glucose up-regulated the expression of mRNA levels of a-SMA, E-cadherin, FN, Col I in a time and dose-depentent manner.α-SMA mRNA expression increase is most significant at 50mmol/L and 48h, whereas FN,Col I at 20mmol/L and 48h.3.1.10μmol/L epalrestat decreaseα-SMA mRNA:2.01±0.28 and 0.93±0.37, Difference of compared to control group (2.38±0.26) has statistically significant (P=0.036 and P<0.001); Different concentrations of Eucommia Lignans could reduce the mRNA levels ofα-SMA(L:2.19±0.33; M:1.93±0.98; H: 1.57±0.94), but have no statistically significant.4. epalrestat and Eucommia Lignans all could up-regulate E-cadherin mRNA:epalrestat, 2.01±0.28 and 0.93±0.37; Eucommia Lignans,1.77±0.37,2.63±0.41 and 3.61±1.05, Difference of compared to control group (0.94±0.42) has statistically significant(epalrestat, P=0.007 and P=0.033; Eucommia Lignans, P=0.026, P< 0.001 and P=0.004).50mmol/L mannitol up-regulate the expression of mRNA levels of a-SMA(2.88±1.30, P =0.016), E-cadherin(2.00±1.29), FN(1.62±0.33, P=0.019), ColⅠ(2.10±1.11, P=0.036).Conclusions:High glucose might induced EMT and produce ECM components. Epalrestat/lignan might block high glucose-induced EMT, prevent tubulointestitial fibrosis in diabetic nephropathy ulteriorly.