Interferon-γ-dependent cytotoxic activation of human astrocytes and astrocytoma cells
Interferon-γ-dependent cytotoxic activation of human astrocytes and astrocytoma cells
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DOI：
10.1016/j.neurobiolaging.2008.02.019
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发表时间：
2009-12-01
影响因子：
4.2
通讯作者：
McGeer, Patrick L.
中科院分区：
文献类型：
--
作者：
Hashioka, Sadayuki;Klegeris, Andis;McGeer, Patrick L.
星形胶质细胞和小胶质细胞在广泛的炎症性神经退行性疾病中被激活。在这些疾病中，激活的小胶质细胞被广泛认为是炎症诱导的神经元变性的主要来源。为了研究人星形胶质细胞的神经毒性潜力，我们将它们和人星形胶质细胞U-373 MG细胞暴露在各种炎性刺激剂中。用干扰素-γ(150U/ml)刺激星形胶质细胞和U-373 MG细胞，其上清液显著降低SH-SY5Y细胞的存活率。内毒素(0 5mU g/m l)、肿瘤坏死因子-α(10 ng/m l)和白介素1β(10 ng/m l)等强效炎症刺激剂单独或联合应用均不能增强干扰素-γ效应。其诱导的细胞毒作用可被JAK抑制剂I逆转。这一结果表明，神经毒性作用是通过干扰素-γ受体(IFNGR)-JAK-STAT细胞内途径进行的。为了确定IFNGR在培养的星形胶质细胞和U-373 MG细胞上都有表达，我们对总RNA提取液进行了RT-PCR以确定特定的IFNGR产物。我们用IFNGR抗体通过免疫细胞化学方法显示了这些培养细胞上的蛋白质产物。最后，使用人类尸检材料，我们显示在阿尔茨海默病、帕金森氏病、肌萎缩侧索硬化症和多发性硬化症受影响区域的激活星形胶质细胞上IFNGR急剧上调。这些发现表明，激活的星形胶质细胞在干扰素-伽马的刺激下可能会变得具有神经毒性，因此可能会加剧一系列神经退行性疾病的病理。(C)2008 Elsevier Inc.保留所有权利。
Astrocytes and microglia become activated in a broad spectrum of inflammatory neurodegenerative diseases. Activated microglia are widely believed to be the principal source of inflammation-induced neuronal degeneration in these disorders. To investigate the neurotoxic potential of human astrocytes, we exposed them and human astrocytic U-373 MG cells to a variety of inflammatory stimulants. We then assessed the effects of their supernatants on human SH-SY5 cells When astrocytes and U-373 MG cells were stimulated with interferon (IFN)-gamma (150 U/ml), their supernatants significantly reduced SH-SY5Y cell viability. Other powerful inflammatory stimulants such as lipopolysaccharide (0 5 mu g/ml), tumor necrosis factor-alpha (10 ng/ml) and interleukin-1 beta (10 ng/ml), alone or in combination, were without effect These combinations were also unable to enhance the IFN-gamma effect. The induced cytotoxicities were reversed by JAK inhibitor I, a potent and specific inhibitor of JAKs. This result indicates that the neurotoxic effect was proceeding through the IFN-gamma receptor (IFNGR)-JAK-STAT intracellular pathway. To establish that the IFNGR is expressed on both cultured astrocytes and U-373 MG cells, we performed RT-PCR on total RNA extracts to identify a specific IFNGR product. We showed the protein product on these cultured cells by immunocytochemistry using an antibody to IFNGR. Finally, using human postmortem material, we showed sharp upregulation of the IFNGR on activated astrocytes in affected areas in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. These findings suggest that activated astrocytes may become neurotoxic when stimulated by IFN-gamma and may therefore exacerbate the pathology in a spectrum of neurodegenerative diseases (C) 2008 Elsevier Inc. All rights reserved.