Molecular therapies to enhance brain recovery after experimental stroke

分子疗法促进实验性中风后大脑恢复

• 批准号: 8004760
• 负责人: Jun Chen
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8004760
• 关键词: Acute; Adult; Age; Animals; Area; Blood Vessels; Brain; Brain Injuries; Caenorhabditis elegans; Caring; Cell Death Inhibition; Cell Proliferation; Cerebral Ischemia; Cerebrum; Clinical; Data; Dependovirus; Diet; Docosahexaenoic Acids; Emergency Medicine; Enzymes; Epidemiologic Studies; Exhibits; Fatty acid glycerol esters; Gene Expression; Generations; Genes; Goals; Infarction; Inflammation; Injury; Intake; Investigation; Ischemia; Ischemic Brain Injury; Ischemic Stroke; Lead; Long-Term Effects; Medical; Methods; Middle Cerebral Artery Occlusion; Military Personnel; Mission; Molecular; Mus; N-3 polyunsaturated fatty acid; Natural regeneration; Neurologic; Neurological outcome; Neurons; Omega-3 Fatty Acids; Patient Care; Performance; Phase; Population; Production; Proteins; Quality of life; Recovery; Resistance; Risk; Stroke; Stroke prevention; Supplementation; Survivors; Testing; Therapeutic; Transgenic Mice; Transgenic Organisms; United States; Veterans; Work; aged; angiogenesis; brain repair; brain tissue; disability; effective therapy; functional outcomes; improved; migration; neovascularization; nerve stem cell; neurogenesis; neurological recovery; neuron loss; neuronal replacement; novel; post stroke; prophylactic; protective effect; repaired; restoration; stroke rehabilitation; success; white matter injury; young adult

DESCRIPTION (provided by applicant): ABSTRACT Stroke is one of the major medical concerns for United States military veterans. Stroke is devastating as currently no therapy is available to prevent stroke-induced neurological deficit. Prophylactic or therapeutic supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFAs) has recently emerged as a highly promising neuroprotective strategy for stroke. Epidemiological studies have shown an inverse association between n-3 PUFAs intake and risk of ischemic stroke. Supplementation with n-3 PUFAs, especially DHA, effectively reduces the extent of brain damage and neurological deficits in the acute phase of ischemic injury in experimental animals. However, the long-term effect of n-3 PUFAs on brain damage and post- stroke neurological recovery is unknown. We have recently created transgenic (Tg) mice over-expressing the C elegans fat-1 gene encoding an enzyme that converts endogenous n-6 to n-3 PUFAs. Our preliminary studies with fat-1 Tg mice have suggested two-phase (acute and delayed) beneficial effects of n-3 PUFAs on ischemic stroke. The fat-1 Tg mice at either young (3-month-old) or old age (15-month-old) were remarkably resistant to focal ischemic injury compared to their age-matched wild-type (Wt) littermates, showing reduced infarct size and improved neurological functional performance up to 14 days after middle cerebral artery occlusion. We have found that angiogenesis and neurogenesis were robustly enhanced after ischemia in 3-month old fat-1 Tg mice compared to Wt littermates, suggesting that n-3 PUFAs promote post-stroke neurovascular regeneration. Strikingly, we found that post-stroke angiogenesis and neurogenesis were profoundly impaired in aged mice, but almost fully restored by transgenic expression of fat-1. This proposal attempts to further explore the long-term protective effect of n-3 PUFAs on focal cerebral ischemia. The goal is to develop n-3 PUFA supplementation as a novel, clinically feasible prophylactic and/or therapeutic strategy to promote long-term neurological recovery after stroke through stimulating the generation of functional blood vessels and new neurons. The central hypothesis to be tested in the current proposal is that prophylactic or therapeutic n-3 PUFA treatment improves long-term neurological outcomes after stroke by stimulating and enhancing post-ischemia brain repair, including augmented neurogenesis and angiogenesis. The following specific objectives are proposed: Aim 1. Test the hypothesis that n-3 PUFAs reduce long-term neurological deficits as well as brain tissue damage after focal cerebral ischemia in both young adult and aged mice. Two clinically applicable methods: 1) dietary delivery; and 2) augmented endogenous production of n-3 PUFAs via adeno-associated virus (AAV)-directed fat-1 gene expression, will be established to elevate brain levels of n-3 PUFAs. The effect of elevated n-3 PUFAs on ischemic brain injury induced by MCAO will be quantitatively evaluated. The endpoints of assessment include functional outcomes, infarct size, and white matter injury. Aim 2. Test the hypothesis that n-3 PUFA treatment enhances cerebral neurovascular regeneration, including augmented angiogenesis and neurogenesis after cerebral ischemia in both young adult and aged mice. The proposed studies will quantitatively determine the effect of n-3 PUFAs on post-stroke neovascularization and on neural stem cell proliferation, migration, differentiation and neuronal replacement following ischemic stroke. PUBLIC HEALTH RELEVANCE: NARRATIVE Stroke is one of the major medical concerns for United States military veterans. Stroke is devastating as currently no therapy is available to prevent stroke-induced neurological deficit. Prophylactic or therapeutic supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFAs) has recently emerged as a highly promising neuroprotective strategy for stroke. Supplementation with n-3 PUFAs, especially DHA, effectively reduces the extent of brain damage and neurological deficits in the acute phase of ischemic injury in experimental animals. However, the long-term effect of n-3 PUFAs on brain damage and post-stroke neurological recovery is unknown. Our preliminary studies have suggested two-phase (acute and delayed) beneficial effects of n-3 PUFAs on ischemic stroke. We have found evidence that n-3 PUFAs promote post-stroke neurovascular regeneration. Thus, the objective of the current proposal is to develop n-3 PUFA supplementation as a novel, clinically feasible prophylactic and/or therapeutic strategy to promote long-term neurological recovery after stroke. First, we will test the hypothesis that n-3 PUFAs reduce long-term neurological deficits as well as brain tissue damage after focal cerebral ischemia in both young adult and aged mice. Second, we will test the hypothesis that n-3 PUFA treatment enhances cerebral neurovascular regeneration.

描述（由申请人提供）： 摘要 中风是美国退伍军人面临的主要医疗问题之一。中风具有毁灭性，因为目前尚无治疗方法可以预防中风引起的神经功能缺损。预防性或治疗性补充 omega-3 多不饱和脂肪酸 (n-3 PUFA) 最近已成为一种非常有前景的中风神经保护策略。流行病学研究表明，n-3 PUFA 摄入量与缺血性中风风险呈负相关。补充n-3 PUFA，尤其是DHA，可以有效减轻实验动物缺血性损伤急性期的脑损伤和神经功能缺损程度。然而，n-3 PUFA 对脑损伤和中风后神经恢复的长期影响尚不清楚。我们最近创建了转基因 (Tg) 小鼠，其过度表达线虫 fat-1 基因，该基因编码将内源性 n-6 转化为 n-3 PUFA 的酶。我们对 fat-1 Tg 小鼠的初步研究表明，n-3 PUFA 对缺血性中风具有两阶段（急性和延迟）有益作用。与年龄匹配的野生型 (Wt) 同窝小鼠相比，年轻（3 个月大）或老年（15 个月大）的 fat-1 Tg 小鼠对局灶性缺血性损伤具有显着的抵抗力，显示梗塞减少大脑中动脉闭塞后长达 14 天的尺寸和神经功能表现得到改善。我们发现，与同窝 Wt 小鼠相比，3 个月大的 fat-1 Tg 小鼠在缺血后血管生成和神经发生显着增强，这表明 n-3 PUFA 促进中风后神经血管再生。引人注目的是，我们发现老年小鼠中风后的血管生成和神经发生严重受损，但通过 fat-1 的转基因表达几乎完全恢复。本提案试图进一步探讨n-3 PUFA对局灶性脑缺血的长期保护作用。目标是开发 n-3 PUFA 补充剂作为一种新型的、临床上可行的预防和/或治疗策略，通过刺激功能性血管和新神经元的生成来促进中风后的长期神经功能恢复。当前提案中要测试的中心假设是，预防性或治疗性 n-3 PUFA 治疗通过刺激和增强缺血后脑修复（包括增强神经发生和血管生成）来改善中风后的长期神经系统结果。提出以下具体目标： 目标 1. 检验 n-3 PUFA 减少年轻成年和老年小鼠局灶性脑缺血后长期神经功能缺损以及脑组织损伤的假设。临床上适用的两种方法：1）饮食给药； 2）通过腺相关病毒（AAV）指导的 fat-1 基因表达增强 n-3 PUFA 的内源性生产，以提高 n-3 PUFA 的大脑水平。将定量评估升高的 n-3 PUFA 对 MCAO 引起的缺血性脑损伤的影响。评估终点包括功能结果、梗塞面积和白质损伤。目标 2. 测试 n-3 PUFA 治疗增强脑神经血管再生的假设，包括增强年轻成年和老年小鼠脑缺血后的血管生成和神经发生。拟议的研究将定量确定 n-3 PUFA 对中风后新生血管形成以及缺血性中风后神经干细胞增殖、迁移、分化和神经元替代的影响。 公共卫生相关性： 叙述中风是美国退伍军人面临的主要医疗问题之一。中风具有毁灭性，因为目前尚无治疗方法可以预防中风引起的神经功能缺损。预防性或治疗性补充 omega-3 多不饱和脂肪酸 (n-3 PUFA) 最近已成为一种非常有前景的中风神经保护策略。补充n-3 PUFA，尤其是DHA，可以有效减轻实验动物缺血性损伤急性期的脑损伤程度和神经功能缺损。然而，n-3 PUFA 对脑损伤和中风后神经恢复的长期影响尚不清楚。我们的初步研究表明 n-3 PUFA 对缺血性中风有两阶段（急性和延迟）有益作用。我们发现 n-3 PUFA 促进中风后神经血管再生的证据。因此，当前提案的目标是开发 n-3 PUFA 补充剂作为一种新型的、临床上可行的预防和/或治疗策略，以促进中风后的长期神经功能恢复。首先，我们将检验以下假设：n-3 PUFA 可减少年轻成年和老年小鼠局灶性脑缺血后的长期神经功能缺损以及脑组织损伤。其次，我们将检验 n-3 PUFA 治疗增强脑神经血管再生的假设。