Novel anti-inflammatory mesothelial signaling to the spleen

向脾脏发出新型抗炎间皮信号

基本信息

批准号：
10092954
负责人：
Paul Michael O'Connor
金额：
$ 23.1万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-01 至 2023-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10092954
关键词：
Anti-Cholinergics Anti-Inflammatory Agents Biological Blood Breeding Cell Communication Cells Collagen Communication Complex Cytoplasm Data Development Disease Distal Elements Endotoxins Fibrosis Flow Cytometry Functional disorder Genes Goals Homologous Gene Hospitalization Hour Immune Immune response Incidence Infection Inflammation Inflammatory Inflammatory Response Institution Knock-out Laboratories Life Liver LoxP-flanked allele Lung Mediating Mesothelial Cell Mesothelium Mus Nerve Plexus Neurons Nicotinic Receptors Operative Surgical Procedures Organ Organelles Pathogenesis Pathway interactions Patients Peritoneum Phenotype Physiological Positioning Attribute Rattus Reflex action Reporting Reticuloendothelial System Sepsis Shock Signal Pathway Signal Transduction Site Source Spleen Stimulus Surgical incisions System TNF gene Testing Tissues WT1 gene alpha-bungarotoxin receptor cell type cholinergic cost cytokine ileum mortality nerve supply novel novel therapeutic intervention promoter relating to nervous system response splenic capsule systemic inflammatory response

项目摘要

Project Summary/Abstract Sepsis is a complex lethal condition defined as “life- threatening organ dysfunction caused by a dysregulated host response to infection”. In the U.S, sepsis is related to ~1 million hospitalizations annually, and the incidence of sepsis continues to rise. The mortality rate from in patients with sepsis remains unacceptably high. Novel data from our laboratory recently demonstrated that simply moving the spleen to midline and then returning it to its original position causes development of splenic capsular fibrosis and a pro-inflammatory shift in the immune cell phenotype of the spleen. While similar findings have been reported in mice, it remains unclear how these maneuvers promote a pro-inflammatory phenotype. Our novel data indicate that specialized mesothelial cells that form connections to the splenic capsule may transmit tonic anti-inflammatory signals to spleen via cholinergic signaling through alpha 7 nicotinic receptors. In addition to markers of cholinergic signaling, these mesothelial cells strongly express neuronal markers and display neuronal-like organelles within their cytoplasm. As the connections themselves are made of collagen lined with mesothelial cells, splenic capsular fibrosis following disruption of these connections may represent a physiological response to try to re-establish mesothelial cell to cell signaling. The primary goal of this proposal is to determine whether cholinergic signaling through specialized mesothelial cells does indeed transmit tonic anti-inflammatory signals to the splenic capsule and whether disruption of this signaling has a functional response, exacerbating the systemic inflammatory response to endotoxin. As such, Aim 1 will test whether `Surgical disruption of mesothelial signaling to the splenic capsule results in a prolonged anti-inflammatory profile and exacerbated inflammatory response to endotoxin'. We will access the spleen in rats via a flank incision and clear the spleen of mesothelial connections without interfering with the spleen. Baseline immune profiles (flow cytometry/cytokine analysis) and the physiological response to experimental inflammatory shock (endotoxin) in anesthetized disrupted and sham surgical rats will be determined 24 hours, 21 days and 3 months following surgical disruption of mesothelial connections to the spleen Aim 2 will test whether `Non-neuronal cholinergic signaling between mesothelial cells mediates a tonic anti-inflammatory response in the spleen'. Global deletion of α7nAChR in mice results in a pro-inflammatory splenic phenotype however, the cell type(s) mediating this effect remain unclear. We will use Wilms tumor 1 homolog gene promoter Cre and Chrna7tm1 floxed mice to `knockout' α7nAChR specifically in mesothelial cells. We predict that loss of the α7nAChR specifically in mesothelial cells will promote a pro-inflammatory phenotype in the spleen. If our hypothesis is correct, neuronal like signaling between distal sites through mesothelial cells would represent a previously unrecognized pathway of biological communication and would likely have a major impact not only on our understanding of the factors that regulate systemic immune responses in sepsis, but also idiopathic fibrosis of other organs involving the mesothelium.

项目概要/摘要败血症是一种复杂的致命性疾病，定义为“由失调引起的危及生命的器官功能障碍” 宿主对感染的反应”。在美国，败血症每年与约 100 万人住院有关，而且发病率也很高。脓毒症患者的死亡率仍然高得令人无法接受。我们实验室最近证明，只需将脾脏移至中线，然后将其返回到原来的位置原始位置导致脾被膜纤维化的发展和免疫细胞的促炎性转变虽然在小鼠中也有类似的发现，但目前尚不清楚这些结果是如何发生的。我们的新数据表明，特殊的间皮细胞会促进促炎表型。与脾被膜形成连接的细胞可能通过以下途径向脾脏传递补强抗炎信号：通过 α7 烟碱受体的胆碱能信号传导除了胆碱能信号传导的标记物之外，这些。间皮细胞强烈表达神经元标记，并在其细胞质内展示神经元样细胞器。由于连接本身是由衬有间皮细胞的胶原蛋白构成的，因此脾被膜纤维化这些连接中断后可能代表尝试重新建立的生理反应该提案的主要目标是确定间皮细胞间信号传导是否存在。通过专门的间皮细胞确实将强效抗炎信号传递到脾被膜以及该信号传导的破坏是否会产生功能性反应，从而加剧全身炎症因此，目标 1 将测试“脾脏间皮信号传导是否受到手术破坏”。胶囊导致延长的抗炎作用并加剧对内毒素的炎症反应。我们将通过侧腹切口进入大鼠的脾脏，并清除脾脏的间皮连接，而无需干扰脾脏的基线免疫特征（流式细胞术/细胞因子分析）和生理学。麻醉中断大鼠和假手术大鼠对实验性炎症休克（内毒素）的反应手术中断间皮连接后 24 小时、21 天和 3 个月确定脾脏目标 2 将测试“间皮细胞之间的非神经元胆碱能信号传导是否介导强直” 小鼠脾脏中 α7nAChR 的整体缺失导致促炎反应。然而，介导这种效应的细胞类型仍不清楚，我们将使用肾母细胞瘤 1。同源基因启动子 Cre 和 Chrna7tm1 使小鼠在间皮细胞中“敲除”α7nAChR。我们预测间皮细胞中 α7nAChR 的缺失将促进促炎表型如果我们的假设是正确的，远端部位之间的神经样信号传导将通过间皮细胞进行。将代表一种以前未被认识的生物通讯途径，并且可能具有重大意义不仅影响我们对脓毒症全身免疫反应调节因素的理解，而且涉及间皮的其他器官的特发性纤维化。