MICROGLIA ACTIVATION IN RESPONSE TO BLOOD-BRAIN BARRIER DISRUPTION IN THE CNS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 血脑屏障(BBB)破坏是与血管通透性和血液蛋白渗入中枢神经系统相关的神经系统疾病的标志，如中风、多发性硬化症(MS)、阿尔茨海默病(AD)、脑胶质母细胞瘤和脊髓损伤。尽管血管异常和持续性血脑屏障破坏是MS脱髓鞘病变和AD和卒中神经退行性变区域的早期组织病理学改变之一，但血管通透性如何损害脑功能的分子基础仍很不清楚。我们以前的研究发现，血液因子在血脑屏障破坏后沉积在神经系统时，会抑制周围神经再生，并加剧中枢神经系统的炎性脱髓鞘。本研究中的具体假设是，血脑屏障破坏导致中枢神经系统血液泄漏导致小胶质细胞激活。我们的假说建立在以下观察基础上：1.使用双光子显微镜，小胶质细胞通过突起的延伸和脑内血管损伤部位的隔离非常迅速地做出反应；2.小胶质细胞在体外可以被激活，以响应血液因素，导致肌动蛋白细胞骨架的动态重排，膜褶皱，吞噬增加。基于这些观察，这项建议的实验重点是利用小鼠脑内的实时成像直接证明血脑屏障的破坏和血液渗漏对小胶质细胞的激活。由于血液因子对小胶质细胞激活的几种分子途径已被阐明，我们计划结合我们的体内成像方法，通过药物和遗传操作来测试这些途径的参与。通过这样做，我们希望我们的工作能够提供一个最先进的演示，说明血液因子和脑实质之间的分子联系，因为它与神经胶质细胞激活有关，神经胶质细胞激活是几种脑血管和神经退行性病变的标志。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Blood-brain barrier (BBB) disruption is a hallmark of nervous system diseases associated with vascular permeability and leakage of blood proteins into the CNS, such as stroke, multiple sclerosis (MS), Alzheimers Disease (AD), brain glioblastomas and spinal cord injury. Even though vascular abnormalities and persistent BBB disruption represent one of the early histopathological alterations of demyelinating lesions in MS and areas of neurodegeneration in AD and stroke, the molecular basis of how vascular permeability impairs brain function remains largely unknown. Our previous studies identified blood factors that when deposited in the nervous system after BBB disruption, they inhibit peripheral nerve regeneration and exacerbate inflammatory demyelination in the central nervous system in an animal model for MS. The specific hypothesis in this proposal is that BBB disruption that leads to leakage of blood in the CNS is responsible for microglia activation. Our hypothesis is based on the observations that: 1. Using two-photon microscopy, microglia respond very rapidly by process extension and isolation of the traumatized sites to blood vessel damage in the brain; 2. Microglia can get activated in vitro in response to blood factors, resulting in a dynamic rearrangement of the actin cytoskeleton, membrane ruffling, and increased phagocytosis. Based on these observations, the experimental focus of this proposal is on the direct demonstration of microglial activation by BBB disruption and blood leakage using live imaging in the mouse brain. Since several molecular pathways of microglial activation in response to blood factors have being elucidated, we plan to test the involvement of these pathways by pharmacologic and genetic manipulations in combination to our in vivo imaging approach. By doing so, we expect our work to provide a state-of-the-art demonstration of the molecular link between blood factors and brain parenchyma as it relates to glial cell activation, a hallmark of several cerebrovascular and neurodegenerative pathologies.