权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Mechanisms and modulation of neuro-immune interactions: Cross-talk between mast cells and enteric neurons

神经免疫相互作用的机制和调节：肥大细胞和肠神经元之间的串扰

基本信息

批准号：
299037655
负责人：
Professor Dr. Martin Diener
金额：
--
依托单位：
Institut für Veterinär-Physiologie und -Biochemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/299037655?language=en
关键词：
Mechanisms modulation neuro immune interactions

项目摘要

The enteric nervous system (ENS) is able to regulate nearly all functions of the gastrointestinal tract independent from the brain or the spinal cord. There is a strong interaction of this part of the autonomous nervous system with other cells in the gastrointestinal wall such as e.g. mast cells, which are located in high densitiy within the lamina propria and the submucosa in close vicinitiy to nerve cells. A degranulation of mast cells induces the release of mediators like histamine, proteases, eicosanoids and others stimulating secretomotor submucosal neurons. The consequence is the induction of epithelial anion secretion, clinically leading to secretory diarrhea. From previous experiments performed at isolated submucosal neurons it is known that these neurons express several types of histamine receptors. Activation of these receptors leads to depolarization of the membrane and an increase in the cytosolic Ca2+ concentration. Coculture experiments with mast cells show that histamine receptors are centrally involved in the response of the ENS to mast cell degranulation.The aim of the project is to elucidate the mechanisms and the potential modulation of this neuro-immune-interaction. It shall be clarified by which signaling mechanisms histamine H1 and H2, receptors, i.e. the functionally predominant histamine receptor subtypes of rat submucosal neurons, excite neurons in this part of the enteric nervous system. Whole-cell patch-clamp recordings shall elucidate the ionic mechanisms and the signal transduction pathways underlying the membrane depolarization evoked by histamine observed during microelectrode impalements. As mast cells are assumed not only to be involved in food allergy, but are also thought to play a significant role e.g. for inflammatory bowel disease, the cross-talk of mast cells with submucosal neurons will be studied in coculture experiments with RBL-2H3 cells (a permanent mast cell-equivalent cell line) as well as in submucosa-lamina propria-preparations (to study neuronal interaction with mucosal mast cells) after pretreatment with proinflammatory cytokins. Changes in the cytosolic Ca2+ concentration within the neurons induced by mast cell degranulation serves as functional read-out for these experiments. At preparations from animals which have been sensitized against ovalbumin it will be tested whether changes in ion transport or paracellular permeability induced ex vivo by antigen exposure in Ussing chambers is altered, when the animals have been pretreaded with TNBS (trinitrobenzenesulfonic acid), i.e. whether a colitis aggravates allergic responses in the gut. Furthermore, it shall be investigated whether the cross-talk between mast cells and enteric neurons is modulated by cholinergic receptors as suggested by data from the literature.

肠神经系统（ENS）能够独立于脑或脊髓调节胃肠道的几乎所有功能。自主神经系统的这一部分与胃肠壁中的其他细胞（例如肥大细胞）存在强烈的相互作用，肥大细胞以高密度位于固有层和粘膜下层内，靠近神经细胞。肥大细胞的脱颗粒诱导介质如组胺、蛋白酶、类花生酸和刺激分泌运动粘膜下神经元的其他介质的释放。其结果是诱导上皮阴离子分泌，临床上导致分泌性腹泻。从先前在分离的粘膜下神经元上进行的实验可知，这些神经元表达几种类型的组胺受体。这些受体的激活导致膜的去极化和胞质Ca 2+浓度的增加。与肥大细胞共培养的实验表明，组胺受体参与了ENS对肥大细胞脱颗粒的反应，本项目旨在阐明这种神经免疫相互作用的机制和潜在的调节作用。应阐明组胺H1和H2受体（即大鼠粘膜下神经元的功能性主要组胺受体亚型）通过何种信号传导机制激发肠神经系统这一部分的神经元。全细胞膜片钳记录应阐明微电极穿刺过程中观察到的组胺引起的膜去极化的离子机制和信号转导途径。由于肥大细胞被认为不仅参与食物过敏，而且还被认为在例如炎症性肠病中起重要作用，将在与RBL-2 H3细胞的共培养实验中研究肥大细胞与粘膜下神经元的串扰（一种永久性肥大细胞等效细胞系）以及粘膜下固有层制剂（研究神经元与粘膜肥大细胞的相互作用）。肥大细胞脱颗粒诱导的神经元内胞质Ca 2+浓度的变化作为这些实验的功能读数。在对卵清蛋白致敏的动物制备的制剂中，将测试当动物用TNBS（三硝基苯磺酸）预处理时，在Ussing室中由抗原暴露离体诱导的离子转运或细胞旁通透性的变化是否改变，即结肠炎是否引起肠道中的过敏反应。此外，应研究肥大细胞和肠神经元之间的串扰是否如文献数据所示受胆碱能受体调节。