NEUROPROTECTIVE MECHANISMS OF STATINS IN NEURONS

我们的重点是他汀类药物发挥神经保护作用的胆固醇非依赖性和依赖性机制。 到经历氧化应激的细胞。他汀类药物可以降低胆固醇水平，但它们也含有胆固醇- 独立的行动机制。他汀类药物的神经保护作用可能涉及多个途径。 已经发现他汀类药物改变了与细胞凋亡、细胞生长、信号和信号有关的基因的表达 贩卖小鼠大脑皮层。一项新的发现是辛伐他汀增加了基因表达和 体内和体外的Bcl2蛋白表达水平。BCL-2和抗凋亡成员在BCL-2家族中的作用 在神经细胞存活中的作用。辛伐他汀还显著增加ET-1的表达水平，其产物 是ET-1蛋白的前体。ET-1参与了Bcl2的转录激活。初步数据 研究表明，当实验中降低Bcl-2蛋白水平时， 辛伐他汀对AP的挑战被淘汰。我们假设：辛伐他汀既有胆固醇- 具有神经保护作用的独立和依赖的作用机制。神经保护 Bcl2家族成员对细胞凋亡的调控是其机制之一。 ET-1/Calcineurin/NFAT依赖的信号通路对Bcl2的转录调控及其抑制作用 Rac1香叶化。这些假说将主要在小鼠的初级皮质和 海马神经元。目的1.检测神经元中Bcl2和Bax基因的表达及蛋白水平 用辛伐他汀预处理，并用A(Jor NMDA)挑战。确定辛伐他汀是否导致血压升高 BCL-2抑制AP或NMDA诱导的线粒体凋亡诱导因子转位 神经元中的核。检测是否抑制了Bcl-2基因的表达或使其失活 降低辛伐他汀对AP或NMDA处理的神经母细胞瘤细胞的神经保护作用。目标2. 确定ET-1是否增加AP或AP刺激的神经元中Bcl2基因的表达和蛋白水平 NMDA。评价ET-1/Calcineurin是否诱导NFAT进入细胞核，与Bcl2上的NFAT结合 启动子区，增加神经元中Bcl2基因的表达。确定是否抑制ET-1 表达降低辛伐他汀对Bcl2基因表达和蛋白水平的刺激作用 AP或NMDA对人神经母细胞瘤细胞的神经保护作用。目标3.确定是否 环糊精直接降低胆固醇水平可增加Bcl-2和ET-1基因和蛋白的表达 神经元和神经保护的水平。检测Bcl-2和ET-1基因表达和蛋白水平 当非他汀类药物抑制法尼化和香叶化时，神经保护作用增强 神经元中的抑制物。确定辛伐他汀是否刺激了Bc l-2和ET-1基因的表达 神经元中的异戊二烯类化合物可以抑制蛋白质水平和神经保护。

Our focus is on cholesterol-independent and dependent mechanisms whereby statins afford neuroprotection to cells undergoing oxidative stress. Statins reduce cholesterol levels but also they have cholesterol- independent mechanisms of action. Neuroprotective effects of statins could involve multiple pathways.We have discovered that statins altered expression of genes involved in apoptosis, cell growth, signaling and trafficking in the murine cerebral cortex. A novel finding was that simvastatin increased gene expressionand protein levels of Bcl-2 in vivo and in vitro. Bcl-2 and anti-apoptotic members of the Bcl-2 family play apivotal role in neuronal cell survival. Simvastatin also significantly increased ET-1 expression levels whose product is the precursor for the ET-1 protein. ET-1 is involved in transcriptional activation of Bcl-2. Preliminary data revealed that when Bcl-2 protein levels were experimentally reduced the neuroprotective effects of simvastatin to an Ap challenge were eliminated. We hypothesizethat: Simvastatin has both cholesterol- independent and-dependent mechanisms of action that are neuroprotective. Neuroprotective mechanisms are due to regulation of apoptosis by Bcl-2 family members, including the transcriptional regulation of Bcl-2 by ET-1/calcineurin/NFAT-dependent pathways and inhibition of Rac1 geranylgeranylation. These hypotheses will be testing primarily in mouse primary cortical and hippocampal neurons. Aim 1. Determine Bcl-2 and Bax gene expression and protein levels in neurons pretreated with simvastatin and challenged by A(Jor NMDA. Determine if simvastatin-induced increasein Bcl-2 inhibits translocation of apoptosis -inducing factor induced by Ap or NMDA from the mitochondria to the nucleus in neurons. Examine whether suppression of Bcl-2 gene expression or inactivation of the protein diminishes neuroprotective effects of simvastatin in neuroblastoma cells treated with Ap or NMDA. Aim 2. Determine if ET-1 increases Bcl-2 gene expression and protein levels in neurons challenged with Ap or NMDA. Evaluate if ET-1/calcineurin induces NFAT to the nucleus, binding to the NFAT sites on the Bcl-2 promoter region and increases Bcl-2 gene expression in neurons. Determine if suppression of ET-1 expression reduces simvastatin-induced stimulation of Bcl-2 gene expression and protein levels and neuroprotection when challenged by Ap or NMDA in human neuroblastoma cells. Aim 3. Determine if lowering cholesterol levels directly by cyclodextrin increases Bcl-2 and ET-1 gene expression andprotein levels in neurons and if neuroprotective. Evaluate if Bcl-2 and ET-1 gene expression and protein levels and neuroprotection are increased when farnesylation and geranylgeranylation are inhibited by non-statin inhibitors in neurons. Determine if simvastatin-induced stimulation of Bcl-2 and ET-1 gene expression and protein levels and neuroprotection can be inhibited by isoprenoids in neurons.