Construction of an aging model of renal tubular epithelial cells / 中华老年医学杂志

ABSTRACT

Objective:To compare aging models for renal tubular epithelial cells induced by different drugs.Methods:Different concentrations of D-galactose(D-gal), hydrogen peroxide(H 2O 2)and cisplatin(CDDP)were administered to the human proximal tubular epithelial cell line(HK2). Cell activity and the half maximal inhibitory concentration(IC50)were measured by the CCK-8 assay; cell senescence was assessed by senescence-related β-galactosidase staining(SA-β-gal); senescence-related gene expression was detected by Western blotting; cell cycle distribution and apoptosis were determined by flow cytometry.Pathological changes in renal tubules and interstitial tissues were examined in D-gal-induced and naturally aging mice using HE staining, and p16 expression was detected using immunohistochemistry. Results:CCK-8 assay results showed that HK2 cell activity was inhibited treatment with each of the three compounds.The 48-hour IC50 values were(365.8±9.7)mmol/L for D-gal, (385.4±20.8)μmol/L for H 2O 2 and(8.4±1.6)μmol/L for CDDP.Light microscopic observation revealed slowed growth of HK2 cells in the three groups.The rate of SA-β-gal-positive cells increased, compared with the control group( P<0.05). Treatment resulted in an increase in G0/G1 phase cells by(22.9±1.0)% in the 400 mmol/L D-gal group and by(13.0±4.4)% in the 400 μmol/L H 2O 2 group, while G2/M phase cells increased by(14.4±1.9)%( t=48.07, 6.40, 16.53, P<0.05)in the 8 μmol/L CDDP group, compared with the control group.Also, compared with the control group, HK2 cell apoptosis increased by(50.3±1.0)% in the 400 μmol/L H 2O 2 group and by(41.9±2.0)% in the 8 μmol/L CDDP group, which was significantly higher than(7.7±0.4)% in the 400 mmol/L D-gal group( t=77.47, 33.73, 28.35, all P<0.05). Western blotting results indicated that the expression of CCND1 was down-regulated after any of the three drugs reached a certain concentration.The expression of p16 in the D-gal group was up-regulated( F=92.88, P<0.05), but there was no statistical difference in the expression of p16 after H 2O 2 or CDDP treatment.Mice of the D-gal model showed a decline in renal tubular cells, thickened basement membrane, widened interstitial spaces and increased expression of p16 in renal tubules similar to those observed in naturally aging mice. Conclusions:For HK2 cell senescence models induced by three different drugs, the renal tubular epithelial cell senescence model induced by D-gal is relatively close to the natural senescence model.