Role of enteric glia in acute and chronic inflammation

肠神经胶质细胞（EGC）沿着整个肠道分布，并定位于维持肠道内稳态的所有相关位置。EGC与巨噬细胞、上皮细胞和神经细胞紧密相连。同时，我们知道EGC在肠道炎症中起关键作用，如在遭受严重空回肠炎的EGC消融转基因小鼠中所示。在术后肠梗阻（POI）（一种急性肠道炎症和运动障碍）模型中，我们最近证明了MyD 88或IL-1受体1（IL 1 R1）缺陷的小鼠免受POI的影响。我们发现人和小鼠EGC表达IL-1 R1，培养的EGC对IL-1刺激产生白细胞介素-6和MCP-1。POI期间EGC活化通过三种原型活化标志物GFAP、Nestin和S100 B的表达增加来证实。此外，我们证明了EGC在化学诱导（DSS）慢性结肠炎小鼠模型中的激活。这些数据指向EGC的促炎功能，并且毫无疑问地证明EGC参与肠道炎症。然而，它们在肠道疾病状态中的意义和详细功能尚不清楚。在本项目中，我们集中在三个主要问题：（1）EGC特异性IL-1信号传导的意义将在条件敲除小鼠（GFAPcre+/-/Myd 88 fl/fl）中进行分析，这些小鼠在EGC中缺乏MyD 88和IL-1 R1信号传导。在POI模型中，将在术后时间过程中进行基因表达和流式细胞术以及收缩性和运动性测量。在这些小鼠的DSS-结肠炎模型中，我们将关注来自这些小鼠的粘膜探针的肠屏障功能。我们将测量一氧化氮中间体和其他参与屏障稳态的蛋白质。此外，屏障完整性将通过协同工作中的Ussing室实验确定。(2)已知神经递质调节肠道炎症。在这里，我们专注于嘌呤能，胆碱能，但也交感神经/肾上腺素能的影响EGC功能在IL-1触发的炎症。在体外培养的EGC在选择性神经递质受体（ant）激动和IL-1刺激和选择性手术去神经的小鼠疾病模型的研究将进行（3）最后，我们将研究EGC和驻留巨噬细胞的相互作用。后者在肠道炎症的触发阶段发挥关键作用，特别是在POI中。在两种细胞类型的共培养物中，将分析EGC特异性S100 B免疫激活剂的释放及其对巨噬细胞的影响。GFAPcre+/-/Myd 88 fl/fl的体内实验将有助于评估该途径在POI中的意义。因此，我们期望对EGC的免疫功能有新的认识，这可能有助于治疗或预防急性或慢性炎症性肠道疾病。

Enteric glial cells (EGC) are distributed along the complete intestine and are localized in all positions relevant to maintain enteral homeostasis. EGC stay in close proximity to resident macrophages, epithelial cells and nerves. Meanwhile we know that EGC crucially participate in intestinal inflammation as shown within EGC-ablated transgenic mice that suffer from a severe jejuno-ileitis. This points toward an immunoregulatory function of EGC.IIn a model of postoperative ileus (POI), an acute intestinal inflammation and dysmotility, we recently demonstrated that mice deficient for MyD88 or IL-1 receptor type 1(IL1R1), were protected from POI. We found that IL1R1 was expressed by human and mouse EGC and cultured EGC released Interleukin-6 and MCP-1 in response to IL-1 stimulation. EGC activation during POI was confirmed by increased expression of three prototypical activation markers, GFAP, Nestin and S100B. Furthermore, we demonstrated an EGC activation in a mouse model of chemically induced (DSS) chronic colitis. These data point toward a proinflammatory function of EGC and undoubtedly demonstrate involvement of EGC in intestinal inflammation. However, their significance and detailed function in intestinal disease states is unknown. In this project we focus on three major question:(1) The significance of an EGC specific IL-1 signalling will be analysed within conditional knockout mice (GFAPcre+/-/Myd88fl/fl), deficient for MyD88 and IL-1R1 signalling within EGC. In a POI model, gene expression and flow cytometry as well as contractility and motility measurements will be performed in a postoperative time course. In a DSS-colitis model in these mice we will focus on intestinal barrier function of mucosa probes from these mice. We will measure nitric oxide intermediates and other proteins involved in barrier homeostasis. Additionally, barrier integrity will be determined by Ussing chamber experiments in a collaborative work. (2) Neurotransmitters are known to modulate intestinal inflammation. Herein we focus on purinergic, cholinergic but also sympathetic/adrenergic effects on EGC function during IL-1-triggered inflammation. In vitro cultures of EGC under selective neurotransmitter receptor (ant)agonism and IL-1 stimulation and selective surgical denervation studies in the murine disease models will be performed (3) Finally, we will investigate the interaction of EGC and resident macrophages. The latter play a key role in the trigger phase of intestinal inflammation, particularly in POI. In cocultures of both cell types, release of the EGC-specific S100B immune activator and its effects on macrophages will be analysed. In vivo experiments in GFAPcre+/-/Myd88fl/fl will help to evaluate the significance of this pathway in POI. Subsumed we expect new insights about the immunological function of EGC that could be helpful in the treatment or prevention of acute or chronic inflammatory intestinal diseases.