The Influence Of Atorvastatin On Contrast Media Induced Apoptosis Of HKC Cells Under The Serum-free And Hypoxia Condition

[Objective] To study the influence of atorvastatin (ATO) on the apoptosis of renaltubular epithelial cell (HKC) induced by contrast media (CM) underthe serum-free and hypoxia condition, as well as the possiblemechanism of oxidative stress in the process.[Methods] As the research object, human renal tubular epithelial cells（HKC）were cultured and exposed to different concentrations100,120,150,200mgI/mL of iohexol under the serum-free and hypoxia conditionsfor12h. HKC were incubated with iohexol (120mgI/mL) for2,6,9,12h, respectively. In the separate experiments, cells were incubatedwith different concentrations of ATO (10-11,10-10,10-9,10-8,10-7,10-6,10-5mol/L), and then they were cultured with iohexol (120mgI/mL) for12h under the serum-free and hypoxia. Cells were incubated with ATO(10-7mol/L) for6,12,24,36,48h, respectively, and then cells werecultured with iohexol (120mgI/mL) for12h under the serum-free andhypoxia. HKC cells were cultured in different concentrations of ATO(10-10,10-9,10-8,10-7mol/L) for24h, and after that cells were exposedto iohexol (120mgI/mL) for12h under the serum-free and hypoxia.Cell proliferation was detected by cell counting kit-8(CCK-8). Cellapoptosis was detected by TUNEL. The malondialdehyde (MDA)content and the superoxide dismutase (SOD) activity were detected bychemical method. The expression of gp91phox, p22phox, bax and bcl-2were detected by Western blotting.[Results] CCK-8showed that, compared with normal group (6.06±0.18)%, theproliferation of cells were inhibited in different degrees and the survivalinhibition rates of cell survival had increased in other groups and theinfluence on the group of hypoxia+CM was the most significant [(57.86±0.28)%, P<0.05], while ATO could improve the situation,which changed over statin concentrations. TUNEL test displayed that, theapoptosis of the group of hypoxia+CM was the seriousist one [(88.33±0.03)%, P<0.05)] compared with the normal group [(0.06±0.01)%],while ATO could improve the situation of cell apoptosis. The test ofMDA and the activity of SOD showed that, CM could increase thecontent of MDA but decrease the activity of SOD, while ATO couldproduce the opposite effect (P<0.05). Western blot test showed that, CMmade the expression of gp91phox, p22phox and bax up-regulated(P<0.05), while the expression of bcl-2down-regulated. However, ATOcould not only down-regulated the expression of gp91phox, p22phox andbax expression, but also up-regulated the expression of bcl-2(P<0.05).[Conclusion] Under the condition of serum-free and hypoxia, iohexol induced thedecrease of proliferation capacity, as well as the apoptosis of HKC ina concentration-and time-dependent manner, while ATO can inhibitapoptosis of cells induced by iohexol, which was related with timeand concentration. Meanwhile, iohexol might enhance the level ofoxidative stress through the pathway of NADPH oxidase pathway,which might induce the apoptosis of HKC, while ATO could protectHKC through attenuating the damage of oxidative stress to them.