Alcohol Pathogenesis in CNS Microglial Cells

描述（由申请人提供）： 胎儿酒精综合征和相关疾病发生在美国大约1%的新生儿中，是智力迟钝的主要非遗传原因。我们知识中的一个主要空白是缺乏对酒精对神经元和神经胶质之间关系的影响的理解。为了解决这个问题，我们正在研究神经胶质细胞在酒精介导的神经毒性中的作用，特别关注小胶质细胞和小脑神经元之间的通信。我们在酒精暴露的新生大鼠模型中的初步研究显示，单剂量的酒精导致大约40%的小胶质细胞损失。在文化中，我们发现，中等水平的酒精抑制增殖，并产生显着的小胶质细胞死亡。此外，这些研究将过氧化物酶体增殖物激活受体γ（PPARgamma）信号通路确定为小胶质细胞中酒精的特异性靶点，并证明了PPARgamma的药理学激动剂可有效预防酒精诱导的小胶质细胞死亡。对小胶质细胞和小脑颗粒细胞共培养物的分析表明，小胶质细胞积极保护神经元免受酒精诱导的死亡，也防止酒精诱导的神经突丢失。这些研究结果表明，小胶质细胞在发育中的大脑可能提供保护神经元免受酒精毒性，并在酒精暴露过程中的小胶质细胞在体内的戏剧性损失可能有助于神经元对酒精的脆弱性。我们将调查的假设，酒精毒性的小胶质细胞在发育中的大脑可以通过激活PPARgamma，与保存小胶质细胞的神经保护活性。将采用初步研究中使用的补充体内（胎儿酒精暴露的新生大鼠模型）和体外（新生大鼠小胶质细胞和小脑颗粒细胞的纯化培养物）模型来检验这一假设。我们将评估PPARgamma激动剂在体内预防酒精毒性的能力，包括小胶质细胞、颗粒细胞和浦肯野细胞的损失。将确定由小胶质细胞分泌的神经保护因子。将确定PPARgamma激活对小胶质细胞产生保护因子的潜在影响。这些研究的结果将提供对小胶质细胞在产前酒精暴露期间的潜在神经保护作用以及PPARy信号转导通路在酒精毒性中的参与的首次理解。这些知识的应用可能为预防或治疗与产前酒精暴露相关的神经病理学提供新的治疗策略。

DESCRIPTION (provided by applicant): Fetal alcohol syndrome and related disorders occur in approximately 1% of births in the U.S. and are the leading non-genetic cause of mental retardation. A major gap in our knowledge is lack of understanding of the effect of alcohol on the relationship between neurons and glia. To address this gap, we are investigating the role of glia in alcohol-mediated neurotoxicity, with a specific focus on communication between microglial cells and cerebellar neurons. Our pilot studies in the neonatal rat model of alcohol exposure revealed a single dose of alcohol caused approximately 40% loss of microglia. In cultures, we found that moderate levels of alcohol inhibited proliferation and produced significant microglial death. In addition, these studies identified the peroxisome proliferator activated receptor gamma (PPARgamma) signaling pathway as a specific target of alcohol in microglia and demonstrated effective prevention of alcohol-induced microglial death with a pharmacologic agonist of PPARgamma. Analyses of co-cultures of microglia and cerebellar granule cells demonstrated that microglia actively protect neurons from alcohol-induced death and also prevent alcohol-induced neurite loss. These findings suggest that microglia in the developing brain may provide protection for neurons against alcohol toxicity, and that the dramatic loss of microglia in vivo during alcohol exposure may contribute to neuronal vulnerability to alcohol. We will investigate the hypothesis that alcohol toxicity in microglia in the developing brain can be blocked by activation of PPARgamma, with preservation of microglial neuroprotective activity. The complementary in vivo (neonatal rat model of fetal alcohol exposure) and in vitro (purified cultures of microglia and cerebellar granule cells from neonatal rat) models used in the pilot studies will be employed to test this hypothesis. We will evaluate the ability of PPARgamma agonists to prevent alcohol toxicity in vivo, including loss of microglia, granule cells and Purkinje cells. The neuroprotective factors secreted by microglia will be identified. The potential effect of PPARgamma activation on microglial production of protective factors will be determined. Results of these studies will provide the first understanding of the potential neuroprotective role of microglia during prenatal alcohol exposure and the involvement of the PPARy signal transduction pathway in alcohol toxicity. Application of this knowledge may provide new therapeutic strategies for prevention or treatment of the neuropathology associated with prenatal alcohol exposure.