Shc相关磷酸化酪氨酸适配蛋白在大鼠血管衰老中的调控作用

Regulatory effects of Shc-related phosphotyrosine adaptor proteins on vascular aging in rats

摘要:

目的 探讨Shc相关磷酸化酪氨酸适配蛋白p66shc在血管衰老表达的变化，对阐明血管衰老对动脉粥样硬化的诊治具有重要意义。方法 将Wistar大鼠分为4、10、16、24月龄组，测定各组血浆丙二醛（MDA）、超氧化物歧化酶（SOD）水平，同时采用恒速注入流体方法测定大鼠颈动脉血管的顺应性，并利用蛋白免疫印迹法分析各组p66shc、半胱氨酸天门冬氨酸蛋白酶-3水平。结果 随增龄，大鼠主动脉管壁增厚，纤维化程度增高，MDA浓度明显升高（与4月龄和10月龄相比，均P＜0.01），SOD浓度明显降低（与4月龄相比，均P＜0.01；与10月龄相比，均P＜0.05），颈动脉血管的顺应性增高、弹性速率和弹性面积的差异有统计学意义（与4月龄相比，均P＜0.01；与10月龄相比，均P＜0.05），p66shc、Caspase-3蛋白表达呈时间依赖性上调。结论 血管衰老性重塑的分子机制之一可能与上调p66shc、Caspase-3蛋白的表达有关，进一步阐明其调控机制可为延缓血管衰老、防治动脉硬化提供理论依据。

Abstract:

Objective p66shc (66-kilodalton isoform of Shc gene products) gene, encoding a phosphotyrosine signal adapter protein, is confirmed to extend life span by 30%. Our aim was to determine the expression of Shc-related phosphotyrosine adaptor proteins in rat vascular aging in order to elucidate the value of vascular aging in the diagnosis and treatment of atherosclerosis. Methods A total of 60 Wistar rats were divided into 4 groups according to age, that is 4, 10, 16 and 24 months old rats respectively. Aorta plasma levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were detected, and the compliance of rat carotid segment was measured by constant liquid injection. Western blotting was used to detect the expression of p66shc and caspase-3 in the healthy rats of different ages. Results With aging, aorta wall was thickened with more severe fibrosis. MDA content in the rats of 16 and 24 months old was evidently ascended when compared with 4 and 10 months old (P＜0.01), but that of SOD was markedly declined (P＜0.01 compared with that of 4 month old rats; P＜0.05 compared with that of 10 month old rats). The carotid flexibility was increased, especially flexibility area was significantly different (P＜0.01 compared with that of 4 month old rats; P＜0.05 compared with that of 10 month old rats). The expression of p66shc and Caspase-3 at protein level was increased in a time-dependent manner. Conclusion The molecular mechanism of vascular aging might be associated with up-regulaton of p66shc and Caspase-3 with aging. Its underlying mechanism may provide theoretical basis for slowing down of vascular aging, and prevention and treatment of atherosclerosis.