The PI3K/Akt/mTOR pathway regulates the replicative senescence of human VSMCs

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• 作者：Pan Tan ; Yan-Jiao Wang ; Shuang Li ; Yi Wang ; Je-Yu He…
• 关键词：Vascular smooth muscle cells ; Replicative senescence ; PI3K/Akt/mTOR ; Vascular aging
• 刊名：Molecular and Cellular Biochemistry
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：422
• 期：1-2
• 页码：1-10
• 全文大小：2,720 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Biochemistry
  Medical Biochemistry
  Oncology
  Cardiology
  
• 出版者：Springer Netherlands
• ISSN：1573-4919
• 卷排序：422

文摘

Replicative senescence of vascular smooth muscle cells (VSMCs) contributes to aging as well as age-related cardiovascular diseases. Rapamycin can delay the onset of aging-related diseases via inhibition of the mammalian target of rapamycin (mTOR), but its role in vascular aging remains elusive. This study investigated the involvement of mTOR signaling in replicative senescence of VSMCs. Replicative senescence was induced by the extended passages of human VSMCs. Aging-related cell morphology was observed. The aging-related proteins and enzyme activity, and oxidative stress were measured. Significant increase in SA-β-gal activity and protein expression, p53 and p16 protein expression, proliferation index (PI), malondialdehyde (MDA) concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, and significant decrease in telomerase activity was observed in aging VSMCs compared to young cells. Significant activation of PI3K/Akt/mTOR signaling was observed in aging cells but not young cells. Pretreatment of VSMCs with PI3K inhibitor blocked while PI3K activator increased the changes of the above replicative senescence-related parameters in VSMCs. Rapamycin and silencing of mTOR expression inhibited replicative senescence in VSMCs through decreasing the level of p-mTOR Ser2448, p-mTOR Thr2446, and S6K1 phosphorylation. This study for the first time demonstrated that the PI3K/Akt/mTOR/S6K1 signal pathway plays an important role in regulating replicative senescence of human VSMCs.