Mir M, Asensio V J, Tolosa L, Gou-Fabregas M, Soler R M, Lladó J, Olmos G
Grup de Neurobiologia Cel.lular, Institut Universitari d'Investigacions en Ciències de la Salut/Departament de Biologia, Universitat de les Illes Balears, Cra. de Valldemossa, km 7.5, E-07122 Palma de Mallorca, Illes Balears, Spain.
Neuroscience. 2009 Sep 15;162(4):959-71. doi: 10.1016/j.neuroscience.2009.05.049. Epub 2009 May 27.
The accumulation of reactive microglia in the degenerating areas of amyotrophic lateral sclerosis (ALS) tissue is a key cellular event creating a chronic inflammatory environment that results in motoneuron death. We have developed a new culture system that consists in rat spinal cord embryonic explants in which motoneurons migrate outside the explant, growing as a monolayer in the presence of glial cells. The proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) have been proposed to be involved in ALS-linked microglial activation. In our explants, the combined exposure to these cytokines resulted in an increased expression of the pro-oxidative enzymes inducible nitric oxide synthase (iNOS), the catalytic subunit of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, gp91(phox) and cyclooxygenase-2 (COX-2), as compared to each cytokine alone. This effect was related to their cooperation in the activation of the transcription factor nuclear factor kappa B (NF-kappaB). TNF-alpha and IFN-gamma also cooperated to promote protein oxidation and nitration, thus increasing the percentage of motoneurons immunoreactive for nitrotyrosine. Apoptotic motoneuron death, measured through annexin V-Cy3 and active caspase-3 immunoreactivities, was also found cooperatively induced by TNF-alpha and IFN-gamma. Interestingly, these cytokines did not affect the viability of purified spinal cord motoneurons in the absence of glial cells. It is proposed that the proinflammatory cytokines TNF-alpha and IFN-gamma have cooperative/complementary roles in inflammation-induced motoneuron death.
在肌萎缩侧索硬化症（ALS）组织的退化区域中，反应性小胶质细胞的积累是一个关键的细胞事件，会形成导致运动神经元死亡的慢性炎症环境。我们开发了一种新的培养系统，该系统由大鼠脊髓胚胎外植体组成，其中运动神经元迁移到外植体之外，在神经胶质细胞存在的情况下呈单层生长。促炎细胞因子肿瘤坏死因子α（TNF-α）和干扰素γ（IFN-γ）被认为与ALS相关的小胶质细胞激活有关。在我们的外植体中，与单独使用每种细胞因子相比，联合暴露于这些细胞因子会导致促氧化酶诱导型一氧化氮合酶（iNOS）、烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶的催化亚基gp91(phox)和环氧合酶-2（COX-2）的表达增加。这种效应与它们在激活转录因子核因子κB（NF-κB）方面的协同作用有关。TNF-α和IFN-γ还协同促进蛋白质氧化和硝化，从而增加对硝基酪氨酸免疫反应的运动神经元的百分比。通过膜联蛋白V-Cy3和活性半胱天冬酶-3免疫反应性测量的凋亡运动神经元死亡，也被发现是由TNF-α和IFN-γ协同诱导的。有趣的是，在没有神经胶质细胞的情况下，这些细胞因子不会影响纯化的脊髓运动神经元的活力。有人提出，促炎细胞因子TNF-α和IFN-γ在炎症诱导的运动神经元死亡中具有协同/互补作用。
