摘要
【目的】探讨SIRT6通过调节内皮一氧化氮合酶(eNOS)抑制苯肾上腺素(PE)诱导的新生大鼠心肌细胞肥大的作用及机制。【方法】在PE诱导的心肌细胞肥大模型中采用si-RNA干扰或腺病毒过表达的方法改变心肌细胞中SIRT6表达水平,并通过实时定量RT-PCR(real time PCR)、Western Blotting等方法检测心肌肥大基因心钠素(ANF)、脑尿钠肽(BNP)的表达、心肌细胞表面积,以及eNOS的表达及NO的生成。【结果】与PE刺激组相比,腺病毒过表达SIRT6能显著抑制PE诱导的心肌细胞ANF、BNP mRNA水平及心肌细胞表面积的增加(P<0.05);与对照组相比,基因沉默SIRT6诱导心肌细胞ANF、BNP mRNA水平显著上调(P<0.05),说明SIRT6对心肌细胞肥大的抑制作用。SIRT6过表达能明显逆转PE引起的NO生成水平下降(P<0.05),并部分抑制PE诱导的eNOS蛋白水平下调;SIRT6 si RNA干扰明显降低eNOS蛋白表达及NO生成水平(P<0.05)。eNOS抑制剂Nω硝基左旋精氨酸甲酯(L-NAME)能阻断SIRT6对心肌细胞的保护作用(P<0.05),表明SIRT6对eNOS的表达和酶活性有明显的调控作用。【结论】SIRT6可能通过调节eNOS而发挥抗心肌肥大的作用。
[Objective] To investigate whether or not SIRT6 prevents phenylephrine-induced cardiomyocyte hypertrophy via eNOS.[Methods] SIRT6 was overexpressed by adenovirus infection,or was knocked down by RNA interference in primary culture of neonatal rat cardiomyocytes.The mRNA expressions of hypertrophic markers ANF and BNP,the cell surface area,the protein expression of eNOS and production of NO were investigated.[Results] SIRT6 overexpression inhibited the increase of ANF and BNP mRNA expressions,and the increase of cell surface area induced by PE （P ＜ 0.05）;SIRT6 silencing triggered the expressions of ANF and BNP as compared to the control （P ＜ 0.05）,indicating that SIRT6 prevented PE-induced cardiomyocyte hypertrophy.In addition,SIRT6 overexpression reversed PE-induced down-regulation of NO production and partially inhibited the decrease of eNOS （P ＜ 0.05）,while SIRT6 siRNA suppressed the expression of eNOS and NO production （P ＜ 0.05）,suggesting that SIRT6 regulated the expression and activity of eNOS.Furthermore,the eNOS inhibitor L-NAME blocked the protective effects of SIRT6 on cardiomyocytes hypertrophy （P ＜ 0.05）.[Conclusions] SIRT6 prevents cardiomyocyte hypertrophy through regulating eNOS.
出处
《中山大学学报（医学科学版）》
CAS
CSCD
北大核心
2015年第3期338-345,共8页
Journal of Sun Yat-Sen University:Medical Sciences
基金
国家自然科学基金面上项目(81473205,81273499)
广东省科技计划重点项目(2013B090700010)
国家自然基金青年科学基金项目(81400359)
