在不同热量饮食下大鼠肾脏组织SIRT3的变化及意义

摘要

目的 研究SIRT3在不同热量饮食下大鼠肾脏的表达变化规律.方法 取12月龄自由饮食、热量限制、高热量饮食、健康雄性Fisher344大鼠肾组织进行衰老相关β-半乳糖苷酶(SA-β-gal)活性染色,Western印迹法(Western blot assay)和免疫组织化学法检测肾脏组织中SIRT3的表达变化与定位,并用Western blot检测p16INK4AK4A在肾脏组织中的表达变化.结果 大鼠肾脏组织SA-β-gal活性随饮食中热最的增长逐渐增强(P＜0.05);p16INK4A表达随饮食中热量增加逐渐增强(P＜0.05).Western blot亦显示SIRT3蛋白表达随饮食中热量的增加逐渐减弱(P＜0.05).免疫组化结果显示,SIRT3蛋白主要表达于大鼠肾小管中,其在肾小球也有微量表达,且跟Western blot结果一致,随饮食中热量增长表达增加(P＜0.05).结论 热量限制能延缓大鼠肾脏衰老,SIRT3可能与高热量引起的肾脏衰老有密切关系.%To study the expression of SIRT3 in kidneys of rats on diets with different calories. Methods Renal tissue was taken from 344 healthy male Fisher rats at the age of 12 months that had free access to high calorie (HC) diets with their calorie restricted. Expressions of SIRT3 and pl6INK4A were detected by immunohistochemistry and Western blot, respectively, with aging-associated β-galactosidase (SA-β-gal) staining. Results The activity of β-galactosidase and the expression of pl6INK4A in renal tissue of rats increased with the increased calorie of diets(P<0.05). Western blot showed that the expression of SIRT3 protein in renal tissue of rats decreased with the increased calorie of diets. Immunohistochemistry showed that the SIRT3 protein was mainly expressed in renal tubules and weakly expressed in glomeruli, which increased with the increased calorie of diets (P<0.05) and was consistent with that detected by Western blot. Conclusion Calorie restriction can delay the aging of rat kidneys. Expression of SIRT3 may be closely related with the aging of rat kidneys caused by HC.