Role of sensory nerves in perivascular inflammation and vasomotor dysfunction with inflammatory bowel disease

项目摘要和摘要 炎症性肠病(IBD)是一种以免疫异常为特征的慢性疾病 反应和肠道及肠外炎症。IBD与心血管疾病并存， 与流向肠道的血流量减少有关，对肠系膜起关键作用，但研究较少 (MAs)调节肠道血流的动脉。血管周围感觉神经(PSN)持续支配 MA外膜和血管周围脂肪组织(PVAT)，调节血管运动功能，促进血流 通过扩张mA和抑制交感血管收缩。对于IBD，这些PSN功能严重 受损，通常是抗收缩的PVAT通过一种未知的机制变得促进收缩， 进一步损害MA扩张。感觉神经肽、降钙素基因相关肽及其物质 P(SP)在这些IBD相关的血管功能障碍中可能也很重要，因为它们与疾病的严重程度有关 并可通过激活局部免疫介导血管周围神经免疫和神经脂肪信号转导 细胞。以前的工作表明，巨噬细胞在MA外膜和PVAT中积聚 IBD和巨噬细胞耗竭恢复了PSNS扩张MA和抑制交感神经收缩的能力。 这表明血管周围巨噬细胞可以调节IBD的动脉功能，可能是通过一种 外膜和PVAT涉及感觉神经递质的机制。目前尚不清楚的是 巨噬细胞参与PSN、PVAT和血流功能障碍，以及这些变化何时发生在IBD 发展。该项目将检验PSN神经递质在外膜和外膜释放的总体假设 MAS的PVAT促进巨噬细胞活化、聚集和炎性介质释放，导致 血管运动缺陷和血流受损在IBD发病机制的早期。为了调查这些关系， 免疫驱动、肝螺杆菌诱导的IL10/-小鼠IBD模型将用于3项研究 目标。AIM 1将使用共聚焦成像、流式细胞术和体内血流量在时间点的测量 在整个IBD发展过程中，以确定巨噬细胞浸润何时导致PSN和PVAT功能障碍 与结肠炎的发展相比，它会损害血液流动。目标2将使用感觉去神经和 缺乏PVAT的转基因小鼠结合分离的动脉准备来确定是否存在 三七总皂甙和/或PVAT的活性可促进IBD患者MA周围巨噬细胞的浸润。AIM 3将使用高级 影像，初级外膜和PVAT巨噬细胞，以及生化分析，以测试感觉 神经肽可以激活MA外膜和PVAT的巨噬细胞，从而释放炎症介质。 该项目将独一无二地确定PSNS及其信号通路在神经免疫脂肪中的作用 调节血管舒缩功能的相互作用，它将决定这些通路在 IBD的发病机制。研究结果将为制定选择性治疗策略提供新的见解 治疗血管功能障碍和肠道血流受损，以改善IBD患者的生活质量。

Project Summary and Abstract Inflammatory Bowel Disease (IBD) is an increasingly prevalent chronic disease marked by aberrant immune responses and intestinal and extra-intestinal inflammation. IBD is comorbid with cardiovascular disease and associated with decreased blood flow to the intestines, with a critical but poorly-studied role for the mesenteric (MAs) arteries that regulate intestinal perfusion. Perivascular sensory nerves (PSNs) continuously innervate the MA adventitia and perivascular adipose tissue (PVAT), regulating vasomotor function and facilitating blood flow by dilating MAs and inhibiting sympathetic vasoconstriction. With IBD, these PSN functions are severely impaired, and the PVAT that is normally anticontractile becomes procontractile through an unknown mechanism, further impairing MA dilation. The sensory neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP) may also be important in these IBD-related vascular dysfunctions, as they are linked to disease severity and can mediate perivascular neuro-immune and neuro-adipose signaling through activation of local immune cells. Previous work demonstrates that macrophages accumulate in both the MA adventitia and PVAT during IBD, and macrophage depletion restores the ability of PSNs to dilate MAs and inhibit sympathetic constriction. This suggests that perivascular macrophages can modulate arterial function with IBD, likely through a mechanism involving sensory neurotransmitters in the adventitia and PVAT. What remains unclear is how macrophages participate in PSN, PVAT, and blood flow dysfunction and when these changes occur in IBD development. This project will test the overall hypothesis that PSN neurotransmitter released in adventitia and PVAT of MAs promotes macrophage activation, accumulation, and inflammatory mediator release, leading to vasomotor defects and impaired blood flow early in IBD pathogenesis. To investigate these relationships, the immune-driven, Helicobacter hepaticus-induced IL10-/- mouse model of IBD will be used to address 3 research Aims. Aim 1 will use confocal imaging, flow cytometry, and in vivo blood flow measurements at timepoints throughout IBD development to determine when macrophage infiltration causes PSN and PVAT dysfunction and impairs blood flow compared to the development of colon inflammation. Aim 2 will use sensory denervation and transgenic mice lacking PVAT in conjunction with isolated artery preparations to determine whether the presence and activity of PSNs and/or PVAT drive macrophage infiltration around MAs with IBD. Aim 3 will use advanced imaging, primary adventitial and PVAT macrophages, and biochemical assays to test whether sensory neuropeptides can activate macrophages from the MA adventitia and PVAT to release inflammatory mediators. This project will uniquely define the role of PSNs and their signaling pathways in neuro-immune-adipose interactions mediating vasomotor function, and it will determine how these pathways are affected during the pathogenesis of IBD. Results will provide new insight towards developing selective therapeutic strategies for treating vascular dysfunction and impaired intestinal blood flow to improve quality of life for IBD patients.