老年小鼠心脏左室重塑和存活相关蛋白的表达变化

【目的】 探讨老年小鼠心脏左室重塑以及左室心肌蛋白激酶B(Akt)、磷酸化Akt、B细胞淋巴瘤-2蛋白(Bcl-2)和存活素(Survivin)的蛋白表达变化。【方法】 8只成年(5 ~ 5.5 月龄)雄性 C57bl/6小鼠作为对照组,8只老年(21.5 ~ 24 月龄)雄性 C57bl/6小鼠作为老年组(n = 8),计算心脏质量指数和左室质量指数,并利用Western-blot方法检测小鼠左室心肌β-肌动蛋白(β-actin)、Akt、磷酸化Akt (Ser473)、Bcl-2和Survivin的蛋白表达。【结果】 与成年对照组小鼠相比,老年组小鼠心脏质量指数、左室质量指数、左室心肌β-actin表达显著增加(P = 0.003, P = 0.001,P < 0.001),左室心肌Akt、磷酸化Akt (Ser473)、Survivin表达显著下降(P < 0.001, P = 0.028, P = 0.002),而Bcl-2表达却显著增加(P < 0.001)。【结论】这些研究结果表明,小鼠老年化过程中心脏发生左室重塑,同时左室心肌Akt、磷酸化Akt (Ser473)和Survivin表达下降,而Bcl-2表达增加,这些改变可能与老年心脏耐受缺血损伤能力下降有关。

Left Ventricular Remodeling and Associated Alterations in Expression of Surviving Proteins in Aged Mice

【Objective】 This study was designed to explore cardiac remodeling and associated changes in protein expression of Akt, phospho-Akt (Ser473), Bcl-2, and survivin in the aged mice. 【Methods】 Eight adult (5-5.5 months) male C57bl/6 mice (adult group) and eight senescent (21.5-24 months old) male C57bl/6 mice (aged group) were studied (n = 8). Heart mass index and left ventricular mass index were calculated. Western blot analysis was used to quantify the protein expression of β-actin, Akt, phospho-Akt (Ser473), Bcl-2, and survivin in the left ventricles of adult and aged mice. 【Results】 Heart mass index, left ventricular mass index, and left ventricular β-actin content of the aged mice increased significantly compared with adult mice (P = 0.003, P = 0.001,P < 0.001). The expression of Akt, phospho-Akt (Ser473), and survivin in the left ventricles of aged mice decreased significantly compared with adult mice(P < 0.001,P = 0.028,P = 0.002). On the contrary, the level of myocardial Bcl-2 increased significantly in aged mice(P < 0.001). 【Conclusion】 These findings indicate that left ventricular remodeling occurs during mouse ageing. The expression of Akt, phospho-Akt, survivin, and Bcl-2, molecules that play a role in cardiac remodeling and cell surviving and death after ischemia or various stresses, is also changed with ageing. These changes may contribute to the decreased tolerance to ischemia in the aged hearts.