Binge alcohol-induced neurodegeneration and omega-3 DHA Protection

描述（由申请人提供）：长期酗酒会导致脑损伤，但机制仍不确定。从成年大鼠体内和大鼠脑切片培养的研究中，我们知道慢性酗酒（乙醇）暴露和戒断（“酒精”水平，70-120 mM）引起海马/皮质神经变性，其（a）不是典型的兴奋毒性;（B）引起脑水肿（利尿剂可预防水肿和神经损伤）;（c）涉及氧化应激（d）需要磷脂酶A2（PLA 2）活化，其动员（JO-6）花生四烯酸（AA），一种自由基源（PLA 2抑制剂减少神经损伤）。值得注意的是，ω-3脂肪酸二十二碳六烯酸（DHA）抑制AA释放并提供神经保护。与此同时，H.Y. Kim，NIAAA内部调查员和DHA/酒精研究先驱，指出了酒精诱导的凋亡神经损伤的相关“基于脂质”的机制，涉及含DHA的磷脂酰丝氨酸（PS）的耗尽和促生存信号的减少，这也被DHA补充剂所阻止。在Kim博士的合作下，U 01应用程序探索了这两种神经退行性机制之间的功能联系，以及如何实现DHA保护。我们建议研究三个目标，在这里提出的问题，使用成年年龄（而不是通常的青少年）大鼠器官型海马/内嗅皮层切片文化长期暴露于酗酒/戒断;技术包括基因枪转染，反义寡核苷酸和HPLC/MS分析。目标一：酒精诱导的膜PS、DHA含量和下游促存活激酶（Akt，raf-1）活性的降低是否是随后神经变性/凋亡的原因？目标二：酒精诱导的水肿、PLA 2激活、AA动员和氧化应激是否导致神经退行性变与酒精诱导的膜氨基磷脂和存活激酶活性变化相关？目标3：补充DHA的神经保护作用是否需要DHA掺入/增强膜PS，增加促生存信号传导，降低PLA 2活性和减少AA释放/氧化应激？目标1和3中的脂质分析是在Kim博士的NIAAA实验室完成的;所有其他研究都在Loyola大学进行。相关性（参见说明）：这项U 01合作研究慢性酗酒的潜在神经炎症，基于脂质的脑毒性和DHA神经保护机制，有望产生营养和其他见解，这些见解在减少酒精滥用和戒断中的神经变性和脑功能障碍方面具有治疗价值。

DESCRIPTION (provided by applicant): Prolonged alcohol abuse causes brain damage, but the mechanisms remain uncertain. From studies with adult rats in vivo and rat brain slice cultures, we know that chronic binge alcohol (ethanol) exposure and withdrawal ("alcoholic" levels, 70-120 mM) cause hippocampal/cortical neurodegeneration that (a) is not typically excitotoxic; (b) entails brain edema (diuretics prevent the edema and neurodamage); (c) involves oxidative stress (antioxidants neuroprotect); and (d) requires phospholipase A2 (PLA2) activation, which mobilizes (JO-6 arachidonic acid (AA), a free radical source (PLA2 inhibitors reduce neurodamage). Notably, u)-3 fatty acid docosahexaenoic acid (DHA) suppresses AA release and provides neuroprotection. Meanwhile, research by H.Y. Kim, NIAAA intramural investigator and DHA/alcohol research pioneer, indicates a related "lipid-based" mechanism of alcohol-induced apoptotic neurodamage involving depletion of DHA-containing phosphatidylserine (PS) and reduced pro-survival signaling that are also prevented by DHA supplementation. With Dr. Kim's collaboration, this U01 application explores functional connections between these two neurodegenerative mechanisms, and how DHA protection is realized. We propose to research three aims, posed here as questions, using adult-age (as opposed to usual adolescent) rat organotypic hippocampal/ entorhinal cortical slice cultures chronically exposed to binge alcohol/ withdrawal; techniques include biolistic transfection, antisense oligos and HPLC/MS analysis. Aim I: Are alcohol-induced reductions of membrane PS, DHA content and downstream pro-survival kinase (Akt, raf-1) activities causative events in subsequent neurodegeneration/apoptosis? Aim 2: Are alcohol-induced edema, PLA2 activation, AA mobilization and oxidative stress leading to neurodegeneration coupled to alcohol-induced changes in membrane aminophospholipids and survival kinase activities? and Aim 3: Does DHA-supplemented neuroprotection during binge alcohol entail DHA incorporation into/ potentiation of membrane PS, increased pro-survival signaling, reduced PLA2 activity and diminished AA release/oxidative stress? The lipid analyses in Aims 1 & 3 are accomplished in Dr. Kim's NIAAA laboratory; all other research is at Loyola University. RELEVANCE (See instructions): This U01 collaborative study of chronic binge alcohol's potential neuroinflammatory, lipid-based mechanisms of brain toxicity and DHA neuroprotection holds the promise of yielding nutritional and other insights that can be therapeutically valuable in reducing neurodegeneration and brain dysfunction in alcohol abuse and withdrawal.