In vivo imaging of astrocytes to investigate their functional and structural interactions with the blood brain barrier, immune cells and the demyelinating axon in the animal model of Multiple Sclerosis.

星形胶质细胞的体内成像，以研究其在多发性硬化症动物模型中与血脑屏障、免疫细胞和脱髓鞘轴突的功能和结构相互作用。

• 批准号: 279791496
• 负责人: Privatdozent Dr. Volker Siffrin
• 金额: --
• 依托单位: Experimental and Clinical Research Center (ECRC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/279791496?language=en
• 关键词: vivo; imaging; astrocytes; investigate; their

Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system (CNS) that causes prolonged and severe disability in young adults in North America and Europe. Early damage of neuroaxonal structures has been recognized as a major aspect of MS pathology and correlates best with later disability. However, it is not clear why the extent of accumulation of disability over time varies between individual patients. Recent reports suggest that differences in disability accumulation might derive from genetic variations in safeguarding CNS glutamate homeostasis. We have recently demonstrated a direct effect of CD4+ T cells on neuronal damage formation. One important mechanism of immune cell mediated neuronal damage in our study was (glutamate-mediated) excitotoxicity. Glutamate homeostasis is a major task of astrocytes, which have the capacity to remove excitotoxic substances from the extracellular space and are responsible for local confinement of transmitter release. Up to date astrocytes range among the most neglected players in MS pathogenesis with an alleged bystander role as scar forming cells. We aim to better understand the involvement of astrocytes in the pathophysiology in neuroinflammatory conditions. We will investigate the role of astrocytes in established EAE lesions in respect to neuronal and myelin damage. We are primarily interested in the metabolic and detoxification role of astrocytes for the axono-glial unit in the inflamed CNS. We will use different transgenic models to analyze Ca2+ dynamics in neurons/axons and/or astrocytes. Furthermore we will interfere with astrocyte biology using different pharmacological and transgenic approaches to analyze the effect on axonal integrity. We will analyze FACS-sorted astrocytes from different days after EAE induction by conventional molecular biology methods. We will critically evaluate the results from the animal model on the background of the results from genetic MS susceptibility and disease progression studies. In addition, we will confirm this data in an own patient cohort. Furthermore, we plan to characterize in vivo the role of astrocytes in the developing EAE lesion with focus on the blood brain barrier (BBB) and their interaction with immune cells. We will use our two-photon microscopy imaging method to investigate the interaction of astrocytes with immune cells at the blood brain barrier of EAE lesions. Here, the focus will be on the developing lesion, i.e. before onset and in the onset of clinical signs to investigate the early involvement of astrocytes in the pathophysiology of these lesions. These experiments will highlight the overall role of astrocytes for lesion evolution, damage, protection and/or repair in the inflamed CNS. These findings might open up new therapeutic targets to stop neurodegeneration and progressing disability in MS patients.

多发性硬化症（MS）是最常见的中枢神经系统（CNS）慢性炎症性疾病，在北美和欧洲的年轻人中导致长期和严重的残疾。神经轴突结构的早期损伤已被认为是MS病理学的一个主要方面，并且与后来的残疾最相关。然而，尚不清楚为什么残疾的累积程度随着时间的推移而因患者而异。最近的报告表明，残疾积累的差异可能来自遗传变异，在维护中枢神经系统谷氨酸稳态。我们最近已经证明了CD 4 + T细胞对神经元损伤形成的直接作用。在我们的研究中，免疫细胞介导的神经元损伤的一个重要机制是（谷氨酸介导的）兴奋性毒性。谷氨酸稳态是星形胶质细胞的主要任务，星形胶质细胞具有从细胞外空间清除兴奋性毒性物质的能力，并负责局部限制递质释放。到目前为止，星形胶质细胞在MS发病机制中最被忽视的参与者之一，据称是瘢痕形成细胞的旁观者。我们的目的是更好地了解星形胶质细胞在神经炎症条件下的病理生理学的参与。我们将研究星形胶质细胞在已建立的EAE病变中神经元和髓鞘损伤的作用。我们主要感兴趣的是星形胶质细胞的代谢和解毒作用的轴神经胶质细胞单位在发炎的中枢神经系统。我们将使用不同的转基因模型来分析神经元/轴突和/或星形胶质细胞中的Ca 2+动力学。此外，我们将使用不同的药理学和转基因方法干扰星形胶质细胞生物学，以分析对轴突完整性的影响。我们将通过常规分子生物学方法分析EAE诱导后不同天数的FACS分选星形胶质细胞。我们将在遗传性MS易感性和疾病进展研究结果的背景下，对动物模型的结果进行批判性评价。此外，我们将在自己的患者队列中确认该数据。此外，我们计划在体内表征星形胶质细胞在EAE病变发展中的作用，重点是血脑屏障（BBB）及其与免疫细胞的相互作用。我们将使用我们的双光子显微镜成像方法来研究星形胶质细胞与免疫细胞在EAE病变的血脑屏障上的相互作用。在这里，重点将放在发展中的病变，即发病前和临床体征的发病，以研究星形胶质细胞在这些病变的病理生理学的早期参与。这些实验将突出星形胶质细胞在炎症CNS中的损伤演变、损伤、保护和/或修复的整体作用。这些发现可能开辟新的治疗靶点，以阻止MS患者的神经退行性变和进展性残疾。