Brain lipid metabolism/alpha-synuclein gene-abated mice

虽然α -突触核蛋白在神经元突触中高度表达，但其功能作用尚不清楚。阐明α -突触核蛋白的生理功能是很重要的，因为这种蛋白与家族性帕金森病（PD）的致病因素有关，主要是因为它与路易体（PD的病理标志物）有关。在转染突变型α -synuclein或野生型α -synuclein的细胞系中，野生型α -synuclein而非突变型α -synuclein与脂滴相关，这表明天然蛋白可能参与脂转运或代谢。在对α -突触核蛋白基因减少的小鼠进行的一系列平行研究中，与对照小鼠相比，全脑和分离突触体中许多不同磷脂的稳态质量都大幅下降。此外，在许多不同种类的磷脂中，二十二碳六烯酸的数量显著减少，这表明二十二碳六烯酸的摄取和运输减少。这些数据提示神经元脂质代谢下调。由于脂肪酸结合蛋白可以改变磷脂代谢，改变磷脂酰基链组成，我提出以下假设：α - synuclein直接影响神经元中脂肪酸的摄取和靶向，本质上是作为神经元脂肪酸结合蛋白起作用。然而，α -突触核蛋白在神经元脂质摄取、运输和代谢中起作用的假设需要通过全动物和细胞培养研究的结合进一步阐明。通过α -突触核蛋白基因减弱的小鼠，来源于这些小鼠的神经元培养物，以及稳定转染表达突变型和野生型α -突触核蛋白的H293细胞，研究α -突触核蛋白在脑脂质代谢中的潜在作用。这些目标是：1。采用稳态示踪动力学分析确定α -synuclein对对照和α -synuclein基因减弱小鼠脑内[3H]-棕榈酸、[3H]-花生四烯酸和[3H]-二十二碳六烯酸摄取及随后代谢的影响。2. 使用来自对照和基因减弱小鼠的细胞以及稳定转染的细胞系，确定α -突触核蛋白对细胞脂肪酸摄取、代谢和运输的影响。

Although alpha-synuclein is highly expressed in neuronal synapses, the functional role of this protein remains unclear. Elucidating the physiological function of alpha-synuclein is important as this protein is implicated as a causative factor in familial Parkinson disease (PD), primarily because of its association with Lewy bodies, a pathological marker of PD. In cell lines transfected with either mutant alpha- synuclein or wildtype alpha-synuclein, wildtype but not mutant alpha- synuclein associate with lipid droplets, suggesting that the native protein may be involved in lipid trafficking or metabolism. In a parallel set of studies using alpha-synuclein gene-abated mice, there was a large decrease in the steady-state mass of a number of different phospholipids in both whole brain and isolated synaptosomes compared to control mice. Further, there was a significant decrease in the amount of docosahexaenoic acid in a number of different phospholipid classes, suggesting a decrease in uptake and trafficking of docosahexaenoic acid. These data suggest a down-regulation of neuronal lipid metabolism. Because fatty acid binding proteins can alter phospholipid metabolism and alter phospholipid acyl chain composition, I submit the following hypothesis: alpha-Synuclein directly affects fatty acid uptake and targeting in neurons, essentially functioning as a neuronal fatty acid binding protein. However, this hypothesis that alpha-synuclein has a role in neuronal lipid uptake, trafficking, and metabolism needs to be further elucidated using a combination of whole animal and cell culture studies. The following specific aims are designed to address the potential role of alpha-synuclein in brain lipid metabolism using alpha- synuclein gene abated mice, neuronal cultures derived from these mice, and stably transfected H293 cells expressing mutant and wildtype alpha-synuclein. These aims are: 1. Determine the effect of alpha-synuclein on the uptake and subsequent metabolism of [3H]-palmitic, [3H]-arachidonic, and [3H]- docosahexaenoic acid in brains of control and alpha-synuclein gene- abated mice in vivo using steady-state tracer kinetic analysis. 2. Using cells derived from control and gene-abated mice as well as stably transfected cell lines, determine the effect of alpha-synuclein on cellular fatty acid uptake, metabolism, and trafficking.