Inhibitory effect of erythropoietin on high glucose-induced transition of human kidney proximal tubular epithelial cells and its possible mechanism / 医学研究生学报

ABSTRACT

Objective The core mechanism of renal insterstitial fibrosis (RIF) is epithelial-mesenchymal transition.This study aimed to investigate the effect of erythropoietin on high glucose-induced epithelial-mesenchymal transition ( EMT) of normal hu-man kidney proximal tubular epithelial cells (HK-2) and its possible mechanism. Mothods HK-2 cells cultured in vitro were ran-domly divided into a blank control group , a high glucose induction group , a mannitol induction group , an EPO induction group , an EPO (5, 10, and 20U/mL) inhibition group, and an Rho kinase inhibitor group.After 24 hours of intervention, the mRNA levels of RhoA and ROCK were determined by RT-PCR, those of E-cadherin and α-smooth muscle actin (α-SMA) proteins detected by immu-nofluorescence staining , and the expression of FN proteins in the supernatant measured by ELISA . Results Compared with the blank control group , the expressions of RhoA and ROCK 1 mRNA were significantly increased in the high glucose induction group (0.945 ±0.132 vs 1.400 ±0.022, 1.007 ±0.002 vs 1.913 ±0.011, P<0.05), but markedly decreased in the 5, 10, and 20U/mL EPO inhibition groups (1.400 ±0.022 vs 1.278 ±0.006, 1.400 ±0.022 vs 0.770 ±0.005, 1.400 ±0.022 vs 0.334 ±0.009, P<0.006) in comparison with the high glucose induction group , and the effects were related to the concentration of EPO .Compared with the blank control, the expression of E-cadherin protein was increased in the high glucose induction group (0.644 ±0.006 vs 0.107 ± 0.004, P<0.05), but remarkably decreased in the 5, 10, and 20 U/mL EPO inhibition groups (0.236 ±0.006, 0.433 ±0.010, 0.521 ±0.010) in comparison with the high glucose induction group (P<0.05), and the effects were also related to the concentration of EPO.Pearson correlation analysis showed a positive correlation between the mRNA expressions of RhoA and ROCK 1 in the high glu-cose induction and EPO inhibition groups . Conclusion EPO can inhibit high glucose-induced epithelial-mesenchymal transition of normal human kidney HK-2 cells and thus delay renal fibrosis , which mignt be related to the RhoA/ROCK signaling pathway .