Calcineurin and inflammatory signaling processes in aging and Alzheimer's Disease

描述（由申请人提供）：阿尔茨海默病（AD）是一种破坏性和不可逆转的神经系统疾病，它会逐渐改变人格和行为，并破坏认知功能。每年的治疗费用超过1000亿美元，阿尔茨海默病也是美国最昂贵的疾病之一。近年来，抗炎药已成为延缓AD症状发作的有希望的化合物。然而，我们对大脑中神经免疫/炎症（im/inf）信号传导机制的理解仍然不完整。钙调蛋白依赖蛋白磷酸酶，钙调磷酸酶，在淋巴细胞和其他细胞类型的im/inf信号级联反应中起关键作用，但在神经组织中的类似作用很少被考虑。在过去的一年里，我们发现神经胶质共培养中的钙调磷酸酶激活足以概括与衰老和AD一致的im/inf反应的几个组成部分，包括星形胶质细胞激活和诱导许多im/inf相关基因级联。我们还观察到AD模型小鼠淀粉样蛋白沉积物周围活化星形胶质细胞中钙调磷酸酶的显著选择性上调。因此，该项目的长期目标是验证钙调磷酸酶是激活与AD相关的im/inf信号传导过程的关键成分的假设。前两个目的是测试星形胶质细胞中钙调磷酸酶和/或钙调磷酸酶依赖的转录因子NFAT的激活是否对im/inf信号传导是必要的。在存在或不存在强效钙调磷酸酶和NFAT抑制剂的情况下，生物学上相关的炎症介质将被递送到星形胶质细胞特异性培养物中。im/inf标记物的诱导将通过Western blots， RT-PCR和细胞因子阵列进行评估。星形胶质细胞中钙调神经磷酸酶激活的潜在Ca2+来源也将被检查，以及钙调神经磷酸酶通过上调这些Ca2+来源来放大自身活性的可能性。目的三将使用细胞分离、免疫沉淀、Western blot、磷酸酶活性测定、免疫组织化学和原位杂交来定性和定量地评估AD脑标本和/或AD啮鼠模型中钙调磷酸酶信号的变化。这些研究的完成将大大增加我们对钙调磷酸酶在神经炎症和AD中的作用的认识，并可能导致这种疾病和其他神经炎症突出的退行性疾病的新治疗策略的发展。

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a devastating and irreversible neurological disease that progressively alters personality and behavior, and destroys cognitive function. With an annual price tag exceeding 100 billion dollars, AD is also one of the nation's most costly diseases. In recent years, anti-inflammatory agents have emerged as promising compounds for delaying the onset of AD symptoms. Yet, our understanding of the mechanisms underlying neuro-immune/inflammatory (im/inf) signaling in the brain remains incomplete. The Ca2+/calmodulin dependent protein phosphatase, calcineurin, plays a critical role in im/inf signaling cascades in lymphocytes and other cell types, but has received little consideration for a similar role in nervous tissue. In the past year, we found that calcineurin activation in neuron-glia co-cultures was sufficient for recapitulating several components of the im/inf response found consistently with aging and AD, including astrocyte activation and the induction of numerous im/inf-related gene cascades. We also observed a marked and selective upregulation of calcineurin in activated astrocytes surrounding amyloid deposits in AD model mice. The long-term goal of this project is to therefore test the hypothesis that calcineurin is a critical component for the activation of im/inf signaling processes associated with AD. The first two aims will test whether activation of calcineurin and/or the calcineurin-dependent transcription factor, NFAT is necessary for im/inf signaling in astrocytes. Biologically relevant inflammatory mediators will be delivered to astrocyte- specific cultures in the presence or absence of potent calcineurin and NFAT inhibitors. The induction of im/inf markers will be assessed with Western blots, RT-PCR, and cytokine arrays. Potential Ca2+ sources for calcineurin activation in astrocytes will also be examined, along with the possibility that calcineurin amplifies its own activity by up-regulating these Ca2+ sources. Aim three will use cell fractionation, immunoprecipitation, Western blot, phosphatase activity assays, immunohistochemistry, and in situ hybridization to qualitatively and quantitatively assess changes in calcineurin signaling in AD brain specimens and/or in a rodent model of AD. Completion of these studies will greatly increase our knowledge of the role of calcineurin in neuroinflammation and AD, and may lead to the development of novel treatment strategies for this disease and other degenerative conditions where neuroinflammation is prominent.