在这项研究中,我们试图验证甲羟戊酸途径影响淀粉样β前体蛋白(AβPP)加工并调节簇蛋白水平的假设。通过绿色荧光(FL)和蛋白质印迹(WB)监测AβPP的表达。WB显示AβPP-wt细胞中存在可溶性淀粉样蛋白前体α(sAβPPα),AβPP-sw细胞中表达Aβ。神经生长因子(NGF)分化的大鼠神经元嗜铬细胞瘤PC-12细胞用他汀类药物单独或与非甾醇类异戊二烯一起处理/处理。与甲羟戊酸共治疗,dolichol,泛醇,法尼醇,香叶基香叶醇,或水溶性胆固醇显示他汀类药物依赖性神经毒性是由于甲羟戊酸途径的活性减弱而不是胆固醇水平降低。阿托伐他汀(50μM)或辛伐他汀(50μM)以及胆固醇螯合剂甲基-β-环糊精(0.2mM)降低了细胞活力(p<0.05)和簇蛋白水平。有趣的是,与甲羟戊酸共同治疗,dolichol,泛醇,法尼醇,香叶基香叶醇,或水溶性胆固醇刺激(p<0.05)的簇集蛋白表达。非甾醇类异戊二烯的影响,但不是水溶性胆固醇(Chol-PEG),在模拟转染的细胞中最显著。香叶基香叶醇(GGOH)克服了阿托伐他汀(ATR)依赖性细胞毒性。这种效果似乎不依赖于簇蛋白,因为它的水平在GGOH之后变得更低。这些发现的新颖之处在于,它们表明甲羟戊酸(MEV)途径而不是胆固醇本身在簇蛋白表达水平中起着重要作用。在模拟转染中,而不是在AβPP过表达的细胞中,GGOH/法尼醇(FOH)具有保护作用。因此,GGOH/FOH的戊烯化可能在神经元细胞存活中起重要作用。
In this
study we attempted to verify the hypothesis that the mevalonate pathway affects amyloid beta precursor protein (AβPP) processing and regulates clusterin protein levels. AβPP expression was monitored by green fluorescence (FL) and Western blot (WB). WB showed soluble amyloid protein precursor alpha (sAβPPα) presence in AβPP-wt cells and Aβ expression in AβPP-sw cells. Nerve growth factor (NGF)-differentiated rat neuronal pheochromocytoma PC-12 cells were untreated/treated with statins alone or together with non-sterol
isoprenoids. Co-treatment with mevalonate, dolichol, ubiquinol, farnesol, geranylgeraniol, or water-soluble cholesterol demonstrated statin-dependent neurotoxicity resulted from the attenuated activity of mevalonate pathway rather than lower cholesterol level. Atorvastatin (50 μM) or simvastatin (50 μM) as well as cholesterol chelator methyl-β-cyclodextrin (0.2 mM) diminished cell viability (p < 0.05) and clusterin levels. Interestingly, co-treatment with mevalonate, dolichol, ubiquinol, farnesol, geranylgeraniol, or water-soluble cholesterol stimulated (p < 0.05) clusterin expression. Effects of non-sterol
isoprenoids, but not water soluble cholesterol (Chol-PEG), were the most significant in mock-transfected cells. Geranylgeraniol (GGOH) overcame atorvastatin (ATR)-dependent cytotoxicity. This effect does not seem to be dependent on clusterin, as its level became lower after GGOH. The novelty of these findings is that they show that the mevalonate (MEV) pathway rather than cholesterol itself plays an important role in clusterin expression levels. In mock-transfected, rather than in AβPP-overexpressing cells, GGOH/farnesol (FOH) exerted a protective effect. Thus, protein prenylation with GGOH/FOH might play substantial role in neuronal cell survival.