Enteric glia mediate neuron death in colitis through purinergic pathways that require connexin-43 and nitric oxide.
Enteric glia mediate neuron death in colitis through purinergic pathways that require connexin-43 and nitric oxide.
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DOI：
10.1016/j.jcmgh.2015.08.007
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发表时间：
2016-01-01
影响因子：
7.2
通讯作者：
Gulbransen BD
中科院分区：
文献类型：
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作者：
Brown IA;McClain JL;Watson RE;Patel BA;Gulbransen BD
肠神经胶质细胞作为肠内环境稳定的调节者的概念正慢慢地被接受为神经胃肠病学的中心概念。然而，神经胶质细胞如何导致肠道疾病仍然知之甚少。炎症期间产生的嘌呤通过激活神经元P2 X7嘌呤受体（P2 X7 R）驱动肠神经元死亡;通过神经元泛连接蛋白-1通道触发三磷酸腺苷（ATP）释放，随后在周围肠胶质细胞中募集细胞内钙（[Ca 2 +]i）。我们测试了炎症过程中肠神经胶质细胞的激活导致神经元死亡的假设。我们研究了神经炎症在体内使用的2，4-二硝基苯磺酸模型的结肠炎和原位使用的人和小鼠肠道的整装制剂。使用具有胶质连接蛋白-43（Cx43）[GFAP：：CreERT 2 +/−/Cx43 f/f]的靶向缺失的转基因小鼠来特异性地破坏胶质信号传导途径。使用诱导型一氧化氮（NO）合酶（iNOS−/−）缺陷的小鼠来研究NO的产生。用免疫组化法检测蛋白表达和氧化应激，用原位Ca 2+和NO成像监测胶质细胞[Ca 2 +]i和[NO]i。肠神经胶质细胞的嘌呤能激活通过Cx43依赖性机制驱动[Ca 2 +]i反应和肠神经元死亡。神经毒性Cx43活性，驱动NO生产胶质iNOS，需要神经元死亡。神经胶质细胞Cx43开放释放ATP和Cx43依赖的ATP释放被NO增强。我们的研究结果表明，在神经炎症的背景下，神经胶质细胞的激活杀死肠神经元。炎症介质，包括ATP和NO激活神经毒性途径，汇聚在神经胶质细胞Cx43半通道。胶质细胞对炎症介质的反应可能有助于动力障碍的发展。
The concept of enteric glia as regulators of intestinal homeostasis is slowly gaining acceptance as a central concept in neurogastroenterology. Yet how glia contribute to intestinal disease is still poorly understood. Purines generated during inflammation drive enteric neuron death by activating neuronal P2X7 purine receptors (P2X7R); triggering adenosine triphosphate (ATP) release via neuronal pannexin-1 channels that subsequently recruits intracellular calcium ([Ca2+]i) in surrounding enteric glia. We tested the hypothesis that the activation of enteric glia contributes to neuron death during inflammation. We studied neuroinflammation in vivo using the 2,4-dinitrobenzene sulfonic acid model of colitis and in situ using whole-mount preparations of human and mouse intestine. Transgenic mice with a targeted deletion of glial connexin-43 (Cx43) [GFAP::CreERT2+/−/Cx43f/f] were used to specifically disrupt glial signaling pathways. Mice deficient in inducible nitric oxide (NO) synthase (iNOS−/−) were used to study NO production. Protein expression and oxidative stress were measured using immunohistochemistry and in situ Ca2+ and NO imaging were used to monitor glial [Ca2+]i and [NO]i. Purinergic activation of enteric glia drove [Ca2+]i responses and enteric neuron death through a Cx43-dependent mechanism. Neurotoxic Cx43 activity, driven by NO production from glial iNOS, was required for neuron death. Glial Cx43 opening liberated ATP and Cx43-dependent ATP release was potentiated by NO. Our results show that the activation of glial cells in the context of neuroinflammation kills enteric neurons. Mediators of inflammation that include ATP and NO activate neurotoxic pathways that converge on glial Cx43 hemichannels. The glial response to inflammatory mediators might contribute to the development of motility disorders.