Targeting alpha-synuclein after cerebral ischemia as a function of sex and age

α-突触核蛋白(α-Syn)是中枢神经系统中含量最丰富的蛋白质之一，被认为是 帕金森氏症中观察到的神经变性。我们发现卒中(短暂性局灶性脑缺血) 上调成年啮齿动物和人类神经元中α-syn蛋白的表达和核转位。我们 进一步表明，α-Syn的敲除或敲除显著减少了脑梗塞，促进了更好的 局灶性脑缺血啮齿动物的神经功能恢复。基于这些令人兴奋的新线索，在这个 我们希望通过遵循以下标准来测试靶向α-Syn在卒中后脑内的治疗潜力 由中风治疗学术行业圆桌会议(STAIR)联盟设定。目标1是评估 α-Syn siRNA的治疗机会窗、性别、年龄、给药途径和毒性 啮齿类动物局灶性脑缺血后的治疗。 我们进一步观察到一种名为miR-7a的microRNA有效地靶向α-syn。重要的是，miR-7a显示出 与α-Syn呈负相关(MIR-7a水平下调，而α-Syn水平上调 笔划)。因此，我们将测试在卒中后脑内补充miR-7a以抑制α-syn和 从而减少对大脑的损伤。测试靶向蛋白质的替代方法提供了更好的机会 未来的临床翻译。因此，miR-7a模拟疗法将作为α-Syn siRNA的替代方法。 心理治疗。目的2是评估治疗机会的窗口，性别，年龄，给药途径， 模拟局灶性脑缺血后miR-7a的毒性和远期效应。 α-Syn介导的卒中后继发性脑损伤的机制尚不清楚 明白了。我们证明了在卒中后的急性期，α-Syn蛋白在脑内过量形成 随着时间的推移，齐聚并形成聚集体。我们进一步表明，α-SYN通过多个途径促进脑损伤 包括线粒体分裂在内的病理机制。在慢性神经退行性变中，α-syn被认为是 一种激活GSK-3β和随后Tau过度磷酸化的必要支架分子 这会导致Drp1的激活，从而促进线粒体的分裂。在初步研究中，我们观察到 GSK-3β、Tau和DRP1的磷酸化增加。在目标3中，我们将测试α-SYN是否促进缺血后 涉及GSK-3、β和Tau的线粒体分裂和脑损伤。 这些研究的长期目标是评估靶向α-syn是否是治疗两者的中风的可行选择 有男有女，年龄也不同。

Alpha-synuclein (α-Syn) is one of the most abundant proteins in the CNS that is known to be a major player in the neurodegeneration observed in Parkinson’s disease. We show that stroke (transient focal ischemia) upregulates α-Syn protein expression and nuclear translocation in neurons of adult rodents and humans. We further show that knockdown or knockout of α-Syn significantly decreases the infarction and promotes better neurological recovery in rodents subjected to focal ischemia. Based on these exciting new leads, in this proposal we wish to test the therapeutic potential of targeting α-Syn in post-stroke brain by following the criteria set by the Stroke Treatment Academic Industry Roundtable (STAIR) consortium. Aim 1 is to evaluate the window of therapeutic opportunity, effect of sex, age, route of administration and toxicity of α-Syn siRNA therapy following focal ischemia in rodents. We further observed that a microRNA called miR-7a potently targets α-Syn. Importantly miR-7a showed an inverse relation to α-Syn (miR-7a levels were down-regulated while α-Syn levels were upregulated after stroke). Hence, we will test the efficacy of replenishing miR-7a in the post-stroke brain to repress α-Syn and thus decrease brain damage. Testing alternate approaches to target a protein gives better opportunities for future clinical translation. Hence, miR-7a mimic therapy will serve as an alternate approach to α-Syn siRNA therapy. Aim 2 is to evaluate the window of therapeutic opportunity, effect of sex, age, route of administration, toxicity and long-term effects of miR-7a mimic after focal ischemia. The mechanisms that contribute to α-Syn-mediated secondary brain damage after stroke are not well understood. We demonstrate that α-Syn protein formed in excess in brain during the acute phase after stroke oligomerizes and forms aggregates with time. We further show that α-Syn promotes brain damage by multiple pathologic mechanisms including mitochondrial fission. In chronic neurodegeneration, α-Syn is known to act as an essential scaffolding molecule for the activation of GSK-3β and the subsequent Tau hyperphosphorylation that leads to activation of Drp1 which promotes mitochondrial fission. In preliminary studies we observed increased phosphorylation of GSK-3β, Tau and Drp1. In Aim 3, we will test if α-Syn promotes post-ischemic mitochondrial fission and brain damage by involving GSK-3β and Tau. The long-term goal of these studies is to evaluate if targeting α-Syn is a viable option for stroke therapy in both males and females and at different ages.