Mesenchymal stem cells protect against hypoxia-reoxygenation injury of rat renal tubular epithelial cells via paracrine HGF in vitro

Objective To preliminarily explore the effect of paracrine hepatocyte growth factor （HGF） from mesenchymal stem cells （MSCs） on the repair of hypoxia-reoxygenation injury in renal tubular epithelial cells of rats and the relevant mechanism. Method The bone marrow MSCs of rats were harvested and cultured, and transfected with HGF-siRNA plasmid. The corresponding genes of rat MSCs were silenced to build a hypoxia-reoxygenation model of the renal tubular epithelial cells （NRK-52E） in rats. On the basis of the foregoing, the experiment was divided into four groups to establish co-culture system： （1） the control group, simple culture of NRK cells not treated with hypoxia-reoxygenation; （2） hypoxia-reoxygenation group, simple culture of NRK cells treated with hypoxia-reoxygenatiom （3） the wild MSCs group, coculture of hypoxia-reoxygenation-treated NRK cells （upper chamber） ＋ wild type MSCs （lower chamber） ; （4） MSCs transfection group, eoeulture of hypoxia-reoxygenation-NRK cells （ upper chamber） ＋ HGF siRNA-MSCs （ lower chamber）. The proliferation of NRK cells was assayed by MTT method. The mRNA and protein relative expression of HGF, HMGB1, IL-1β and TNFα was detected by real-time PCR, and by Western blottingrespectively. Result The effect of HGF siRNA transfection was satisfactory and transfection efficiency was above 70%. The HGF mRNA relative expression in MSCs transfection group was decreased significantly. The proliferation of NRK cells was detectable in each group along with the extension of incubation time. The proliferation of NRK cells in wild MSCs group was highest, followed by MSCs transfection group, and lowest in hypoxia-reoxygenation group （P〈0. 01） at 32 h after culture. The relative expression of HMGB1, IL-1β and TNFa mRNA and protein was highest, follwed by hypoxia-reoxygenation group, and lowest in MSCs transfection group, and there was significant difference between two groups among the three groups （P〈0. 05）. Conclusion MSCs can promote the repair of hypoxia-reoxygenation injury on renal tubular epithelial cells in rats by the paracrine of HGF. Key words: Rat;  Mesenchymal stem cell;  Hepatocyte growth factor;  Renal tubular;  Epithelial cell;  Hypoxia injury