赖氨大黄酸对D-半乳糖致衰老模型小鼠的肾脏保护作用及其作用机制

Protective effect of rhein lysinate on kidney of aging model mice induced by D-galactose and its mechanism

目的:研究赖氨大黄酸(RHL)对D-半乳糖衰老模型小鼠的抗衰老和肾脏保护作用,阐明其作用机制,为RHL预防衰老的研究提供依据。方法:通过腹腔注射D-半乳糖建立小鼠衰老模型,将小鼠随机分为对照组、衰老模型组和低、高剂量RHL组。除对照组外,其余各组小鼠每天腹部皮下注射D-半乳糖100mg·kg-1,持续8周,对照组小鼠每天皮下注射等量生理盐水,低和高剂量RHL组小鼠分别每天1次灌胃25和50mg·kg-1的RHL。观察各组小鼠一般状况,计算肾脏指数;检测血清和肾脏组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化酶(GSH-Px)活性;HE染色行肾脏组织病理学检查;Western blotting法检测肾脏衰老相关蛋白表达水平。结果:与对照组比较,衰老模型组小鼠肾脏指数降低(P<0.05),血清和肾脏组织中SOD和GSH-Px活性降低(P<0.05),MDA含量升高(P<0.05);与模型组比较,RHL组小鼠肾脏指数升高(P<0.05),血清和肾脏组织中SOD和GSH-Px活性升高(P<0.05),MDA含量下降(P<0.05)。肾脏病理组织学检查,与衰老模型组小鼠比较,低和高剂量RHL组小鼠肾脏组织中肾小管上皮细胞水肿减轻,且存在剂量依赖性。Western blotting法检测,与对照组比较,衰老模型组小鼠肾脏组织中沉默信息调节因子1(SIRT1)蛋白表达水平降低(P<0.05),P16和P21蛋白表达水平升高(P<0.05);与衰老模型组比较,低和高剂量RHL组小鼠肾脏组织中SIRT1蛋白表达水平升高(P<0.05),P16和P21蛋白表达水平降低(P<0.05)。结论:RHL通过抑制氧化应激、肾小管上皮细胞水肿和调控衰老相关基因的表达来发挥对衰老小鼠肾脏的保护作用。

Objective To investigate the protective effect of rhein lysinate（RHL）on the kidney of aging mice induced by D-galactose（D-gal）and to clarfy its mechanism,and to provide the basis for research on prevention of RHL on aging.Methods The models of aging mice were established by intraperitoneally injecting with D-gal.The mice were randomly divided into control,aging model,low and high doses of RHL groups.In addition to the control group,the mice in the other groups were injected subcutaneously with D-gal daily for 8weeks,while the mice in control group were injected subcutaneously with the same amount of saline daily,and the mice in low and high doses of RHL groups were given 25 and 50mg·kg^-1 RHL daily by gavage.The contents of malonaldehyde（MDA）and the activities of superoxide dismutase（SOD）and glutathione peroxidase（GSH-Px）in serum and kidney tissue were detected by microplate reader according to the instruction of respective kits.The pathological changes of kidney tissue were observed by hematoxylin and eosin（HE）staining;the expression levels of age-related proteins were detected by Western blotting method.Results Compared with control group,the kidney index of the mice in aging model group was decreased（P〈0.05）;the activities of SOD and GSH-Px in serum and kidney tissue were decreased（P〈0.05）,while the content of MDA was increased（P〈0.05）.Compared with aging model group,the kidney indexes of the mice in 25 and 50mg·kg^-1 RHL groups were increased（P〈0.05）;the activities of SOD and GSH-Px in serum and kidney tissue of the mice were increased（P〈0.05）and the contents of MDA were decreased（P〈0.05）.Compared with aging model group,the edema of renal tubular epithelial cells in kidney tissue was decreased in a dose-dependent manner in 25 and 50mg·kg^-1 RHL groups.Compared with aging model group,the expression levels of SIRT1 in kidney tissue of the mice in 25 and 50 mg·kg^-1 RHL groups were increased（P〈0.05）,while the expression levels of p16 and p21were decreased（P〈0.05）.Conclusion RHL can inhibit the oxidative stress and the edema of renal tubular epithelial cells and regulate the expressions of agerelated genes to protect the kidney of aging mice.