【摘要】 目的观察miR-34a/SIRT1及下游信号分子在大鼠白内障晶状体中表达水平的变化情况。方法选取18只SD大鼠晶状体,分为3组,每组6只,分别是2个月龄透明晶状体(青年组)、18个月龄透明晶状体(老年组)及同月龄的自然发生的白内障晶状体(白内障组)。采用实时荧光定量PCR检测各组miR-34a/SIRT1表达情况;采用Western blot检测SIRT1蛋白、P53及乙酰化P53蛋白表达情况。结果荧光定量PCR结果显示:miR-34a在白内障大鼠晶状体中表达水平明显上调(t=12.60,P=0.0002),同时伴随着SIRT1 mRNA表达水平下调(t=3.299,P=0.03);与青年组大鼠透明晶状体相比,老龄组大鼠透明晶状体中miR-34a表达水平明显下调(t=9.609,P=0.0007),相应的SIRT1 mRNA表达水平则上调(t=7.242,P=0.0019)。Western blot检测结果显示:SIRT1蛋白在白内障大鼠晶状体中表达降低(t=8.924,P=0.0009),相应的P53乙酰化明显的增加(t=9.280,P=0.0008);而老年组大鼠透明晶状体中SIRT1蛋白较2个月龄大鼠晶状体呈明显增加(t=3.419,P=0.0345),相应的P53乙酰化明显的降低(t=4.768,P=0.0089)。结论 miR-34a表达水平上调与大鼠白内障发生相关,可能通过调控SIRT1蛋白表达下降,促进P53乙酰化,从而引起大鼠白内障发生。更多还原

【Abstract】 Objective To detect the changes in the expression levels of miR-34 a/SIRT1 and P53 in cataract lens in rats.Methods Thirty-six lenses from SD rats were divided into three groups:clear lenses of young and old rats and cataractous lenses.Expression of miR-34 a/SIRT1 mRNA in the clear lenses of young and old rats and cataractous lenses was detected by real-time RT-PCR,and SIRT1 and P53 expression was detected by Western blot.Results Real-time PCR analysis showed that miR-34 a expression was significantly up-regulated,accompanied by down-regulation of SIRT1 mRNA expression in rat cataractous lenses(t = 12.60,P = 0.0002; t = 3.299,P = 0.03,respectively).miR-34 a expression was significantly lower(t = 9.609,P = 0.0007) and SIRT1 mRNA expression was significantly higher(t = 7.242,P = 0.0019) in clear lenses of old rats than in clear lenses of old lenses.Western blot analysis showed that SIRT1 protein expression was significantly down-regulated,accompanied by up-regulated expression of acetylated P53 protein in rat cataractous lenses(t = 8.924,P = 0.0009; t = 9.280,P = 0.0008,respectively).SIRT1 protein expression was significantly higher(t = 3.419,P = 0.0345) and acetylated P53 protein expression was significantly lower(t = 4.768,P = 0.0089) in clear lenses of old rats than in clear lenses of old lenses.Conclusion High expression of miR-34 a is related to cataract in rats,possibly by decreasing SIRT1 protein expression and promoting the acetylation of P53.更多还原