柠檬酸对纳米细菌致人肾小管上皮细胞损伤的保护作用

目的:体外观察柠檬酸对纳米细菌(NB)致人肾小管上皮细胞损伤的影响,并探讨其可能机制。方法:取对数生长期人肾小管上皮细胞并随机分为五组:对照组、损伤组、干预组A、干预组B及干预组C。检测各组细胞中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和一氧化氮(NO)水平,实时荧光定量PCR检测ICAM-1mRNA相对表达量,Western blot检测ICAM-1、NF-κB p65、p-IκBα蛋白的表达。结果:与对照组比较,损伤组MDA含量、NO水平显著增加,SOD活性显著下降,柠檬酸干预后,MDA含量、NO水平降低,SOD活性升高,而且上述改变随柠檬酸浓度增加而明显,差异有统计学意义(P<0.05)。RT-PCR法检测结果显示对照组、损伤组、干预组A、干预组B和干预组C ICAM-1mRNA相对表达量分别为1、36.56±2.65、17.36±1.51、6.76±0.95和2.77±0.46;Western blot法检测结果显示各组细胞ICAM-1蛋白相对表达量分别为0.35±0.05、0.93±0.03、0.86±0.04、0.81±0.04和0.70±0.03;NF-κB p65蛋白相对表达量分别为0.41±0.03、0.99±0.02、0.91±0.03、0.82±0.03和0.55±0.05;p-IκBα蛋白表达量分别为0.21±0.04、0.61±0.05、0.52±0.03、0.44±0.03和0.32±0.02。结论:NB作用于体外培养的人肾小管上皮细胞后可通过激活NF-κB通路来刺激细胞表达ICAM-1,而柠檬酸可显著抑制此过程,且具有剂量依赖性。

Protective effects of citric acid on human renal tubular epithelial cell injury induced by nanobacteria

Objective:To observe the effect of citric acid on the injury of human renal tubular epithelial cells induced by nanobacteria in vitro and to explore its possible mechanism.Method:Human renal tubular epithelial cells were randomly divided into five groups:control group,injury group,intervention group A,intervention group B and intervention group C.The levels of malondialdehyde(MDA),superoxide dismutase(SOD)and nitric oxide(NO)in the cells were detected.The relative expression of ICAM-1 mRNA was detected by real-time quantitative PCR.The expression of ICAM-1,NF-κB p65 and p-IκBαprotein was detected by western blot.Result:Compared with the control group,the MDA content,NO level increased and SOD activity decreased in the injury group.After citric acid intervention,MDA content,NO level decreased,and SOD activity increased,and these changes increased significantly with increasing concentration of citric acid.The results of RT-PCR showed that the relative expression of ICAM-1 mRNA in the control group,injury group,intervention group A,intervention group B and intervention group C were respectively 1,36.56±2.65,17.36±1.51,6.76±0.95 and 2.77±0.46.Western blot results showed that the relative expression of ICAM-1 protein in each group were 0.35±0.05,0.93±0.03,0.86±0.04,0.81±0.04 and 0.70±0.03.The relative expression of NF-κB p65 protein was 0.41±0.03,0.99±0.02,0.91±0.03,0.82±0.03 and 0.55±0.05 respectively.The expression of p-IκBαprotein was0.21±0.04,0.61±0.05,0.52±0.03,0.44±0.03 and 0.32±0.02.Conclusion:Nanobacteria can stimulate the expression of ICAM-1 by activating NF-κB pathway in human renal tubular epithelial cells cultured in vitro,while citric acid can significantly inhibit this process and is dose-dependent.