PATHOGENESIS OF LYME NEUROBORRELIOSIS IN THE RHESUS MONKEY: STUDIES EX VIVO

恒河猴莱姆病神经疏螺旋体病的发病机制：离体研究

• 批准号: 7716254
• 负责人: MARIO TOMAS PHILIPP
• 金额: $ 2.41万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-21 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7716254
• 关键词: Apoptosis; Astrocytes; Biological Response Modifiers; Borrelia burgdorferi; Brain; Brefeldin A; CXCL13 gene; Cells; Cessation of life; Cognitive deficits; Computer Retrieval of Information on Scientific Projects Database; Confocal Microscopy; Environment; Funding; Genes; Grant; IL8 gene; Immunofluorescence Immunologic; In Situ; Inflammatory; Institution; Interleukin-6; Life; Lyme Neuroborreliosis; Macaca mulatta; Microarray Analysis; Microglia; Modeling; Neuraxis; Neuroglia; Neurons; Oligodendroglia; Order Spirochaetales; PTGS2 gene; Pathogenesis; Protein Export Pathway; RNA; Research; Research Personnel; Resources; Slice; Source; Staining method; Stains; TdT-Mediated dUTP Nick End Labeling Assay; Testing; Tissue Extracts; Tissues; Transcript; United States National Institutes of Health; base; brain tissue; caspase-3; chemokine; cytokine; in vivo Model; nervous system disorder; neuron apoptosis

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. Lyme neuroborreliosis is a disease of the nervous system caused by the spirochete B. burgdorferi; it often leads to cognitive deficits that may be due to impaired neuronal function. The pathogenesis of LNB is unknown. We hypothesized that B. burgdorferi spirochetes induce cytokines, chemokines and immune mediators in the central nervous system. This inflammatory milieu results in neuroglial damage by apoptosis. To test our hypothesis we set up an ex vivo model consisting of fresh brain slices from the cortex of normal rhesus monkeys, and allowed live spirochetes to penetrate the tissue. Microarray analysis of RNA extracted from tissues stimulated with spirochetes or medium alone revealed that the transcripts of genes that regulate oligodendrocyte and neuronal apoptosis were perturbed. Importantly, we also observed apoptosis of oligodendrocytes and neurons in spirochete-stimulated tissues by the in situ-activated caspase-3 and TUNEL assays. We then stimulated brain explants with live B. bugdorferi in the presence of brefeldin A, which blocks protein export from cells, and detected immune mediators in glial cells in situ by immunofluorescence staining and confocal microscopy. Spirochete-stimulated brain tissue explants showed the cytokines IL-6 in astrocytes and IL-1b in microglia. The chemokine IL-8 was detected in astrocytes and microglia. The chemokine CXCL13 was detected in microglia. The immune mediator COX-2 was detected in astrocytes and microglia. We further extended our study into an in vivo model in which live spirochetes were injected stereotaxically into the rhesus monkey brain and observed IL-6 in astrocytes. These results provide evidence that B. bugdorferi is able to induce an inflammatory environment in the brain with concomitant oligodendrocyte and neuronal death. As per our hypothesis, this phenomenon could be the basis of Lyme neuroborreliosis pathogenesis.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 莱姆病是由螺旋体B引起的神经系统疾病。burgdorferi;它经常导致认知缺陷，这可能是由于受损的神经元功能。LNB的发病机制尚不清楚。我们假设B.伯氏螺旋体在中枢神经系统中诱导细胞因子、趋化因子和免疫介质。这种炎性环境通过细胞凋亡导致神经胶质细胞损伤。为了验证我们的假设，我们建立了一个离体模型，该模型由来自正常恒河猴皮层的新鲜脑切片组成，并允许活螺旋体穿透组织。微阵列分析从螺旋体或介质单独刺激的组织中提取的RNA显示，调节少突胶质细胞和神经元凋亡的基因的转录本受到干扰。重要的是，我们还观察了螺旋体刺激的组织中的少突胶质细胞和神经元凋亡的原位激活的caspase-3和TUNEL检测。然后我们用活性B刺激脑外植体。bugdorferi在存在布雷菲德菌素A的情况下，其阻断蛋白质从细胞输出，并通过免疫荧光染色和共聚焦显微镜原位检测神经胶质细胞中的免疫介质。螺旋体刺激的脑组织外植体显示星形胶质细胞中的细胞因子IL-6和小胶质细胞中的IL-1b。在星形胶质细胞和小胶质细胞中检测到趋化因子IL-8。在小胶质细胞中检测到趋化因子CXCL 13。免疫介质考克斯-2在星形胶质细胞和小胶质细胞中表达。我们进一步将我们的研究扩展到体内模型中，其中将活螺旋体立体定位注射到恒河猴脑中并观察星形胶质细胞中的IL-6。这些结果为B. Bugdorferi能够在脑中诱导炎性环境，伴随少突胶质细胞和神经元死亡。根据我们的假设，这种现象可能是莱姆病神经疏螺旋体病发病机制的基础。