Department of Pathophysiology, School of Basic Medicine, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, People's Republic of China.
Institute for Brain Research, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, People's Republic of China.
Mol Neurobiol. 2017 Nov;54(9):7251-7261. doi: 10.1007/s12035-016-0173-z. Epub 2016 Oct 29.
Sirtuin 2 (SIRT2) is a member of NAD-dependent protein deacetylases involved in a wide range of pathophysiological processes including myocardial injury, Parkinson's disease, and Huntington's disease. However, the direct implication of SIRT2 in ischemic stroke is still unclear. In the present study, we observed that SIRT2 protein was mainly expressed in the cytoplasm of neurons, but not in astrocyte and microglia. SIRT2 was upregulated in ischemic neurons in the oxygen-glucose deprivation cell model and in the transient middle cerebral artery occlusion (tMCAo) mouse model. Moreover, expression of SIRT2 was evaluated by immunohistochemistry in human brains consisting of ischemic penumbra of cerebral stroke, and their age-matched normal controls without diagnosed neurological disorders. The results revealed that SIRT2 was mainly expressed in the cytoplasm and neurites of neurons in the brains of normal subjects, while an elevated expression and nuclear translocation of SIRT2 were detected in the ischemic penumbra of cerebral stroke. Downregulation of SIRT2 using the SIRT2-specific inhibitor AGK2 or SIRT2 knockout had neuroprotective effects in tMCAo model, which could decrease the infract volume and neurological impairment scores. In summary, our findings revealed that SIRT2 was upregulated during neuronal ischemia and translocated into neuronal nuclei, while downregulation of SIRT2 could significantly protect neurons against cerebral ischemia.
Sirtuin 2(SIRT2)是 NAD 依赖性蛋白去乙酰化酶的成员,参与广泛的病理生理过程,包括心肌损伤、帕金森病和亨廷顿病。然而,SIRT2 对缺血性中风的直接影响仍不清楚。在本研究中,我们观察到 SIRT2 蛋白主要表达在神经元的细胞质中,而不是星形胶质细胞和小胶质细胞中。在氧葡萄糖剥夺细胞模型和短暂性大脑中动脉闭塞(tMCAo)小鼠模型中,SIRT2 蛋白在缺血神经元中上调。此外,通过免疫组织化学评估了人类大脑中包括中风缺血半影区及其年龄匹配的无诊断神经障碍的正常对照组中 SIRT2 的表达。结果表明,SIRT2 主要表达在正常受试者大脑中神经元的细胞质和突起中,而在中风缺血半影区则检测到 SIRT2 的高表达和核转位。使用 SIRT2 特异性抑制剂 AGK2 或 SIRT2 敲除下调 SIRT2 在 tMCAo 模型中具有神经保护作用,可减少梗死体积和神经损伤评分。总之,我们的研究结果表明,SIRT2 在神经元缺血期间上调并转位到神经元核内,而下调 SIRT2 可显著保护神经元免受脑缺血。