Paracrine Signaling by Kupffer Cells in Hepatic Insulin Resistance

肝胰岛素抵抗中库普弗细胞的旁分泌信号传导

基本信息

批准号：
8888443
负责人：
MICHAEL P CZECH
金额：
$ 57.56万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-03-09 至 2019-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8888443
关键词：
Address Affect Animal Model Attenuated CD14 Antigen CD14 gene CD36 gene Cell Lineage Cell Transplantation Cells Ceramides Cytokine Signaling Data Diabetes Mellitus Dissociation Educational process of instructing Encapsulated Endotoxins Experimental Models Fatty Acids Fatty Liver Fatty acid glycerol esters Functional disorder Gene Expression Gene Silencing Gene Targeting Genes Glucans Glucose Intolerance Goals Hepatic Hepatocyte Human Immune Immunologic Receptors Inflammation Inflammatory Insulin Insulin Resistance Interleukin-1 Knowledge Kupffer Cells Lead Left Lipids Liver Liver diseases MAPK8 gene Mediating Mediator of activation protein Metabolic Metabolic Diseases Metabolism Methods Molecular Mus Myeloid Cells Non-Insulin-Dependent Diabetes Mellitus Obese Mice Obesity Organ Paracrine Communication Pathology Pathway interactions Peptides Population Proteins Proteomics Research Rodent Role Signal Transduction Small Interfering RNA TLR4 gene TNF gene Technology Testing Tissues Transgenic Mice Triglycerides cytokine deep sequencing design glucose metabolism glucose output glucose tolerance in vivo insight insulin sensitivity insulin signaling insulin tolerance liver inflammation macrophage mouse model new technology novel nutrition p65 paracrine public health relevance receptor release factor response scavenger receptor sensor uptake

项目摘要

DESCRIPTION (provided by applicant): The overall long term goal of this project is to understand the mechanisms that generate fatty liver and hepatic insulin resistance in obesity, and the molecular relationships between these two phenomena. We seek to unravel the paradox whereby hepatic steatosis is tightly correlated with insulin resistance in humans, whereas these pathways can be clearly dissociated in experimental models. We hypothesize that this paradox may be solved by investigating Kupffer cells as mediators of insulin resistance in neighboring hepatocytes through their release of inflammatory cytokines in response to innate immune receptors and lipid sensors CD36 and Msr1 scavenger receptor. New evidence that these lipid sensors activate inflammasome and NFkB pathways in Kupffer cells provides a plausible mechanism whereby over-nutrition in obesity can lead to activation of liver inflammation. In order to attack this problem, we developed a unique glucan encapsulated siRNA (GeRP) delivery method to silence genes selectively in macrophages and Kupffer cells that reside specifically in liver, while leaving hepatocytes and macrophages in other tissues unaffected. With this method we can selectively probe Kupffer cell contributions to hepatocyte function in vivo in various mouse models of obesity. Using this approach we shall selectively silence Kupffer cell NFkB p65, Nlrp3, TLR4 co-receptor CD14, CD36 and Msr1 and other targets, alone and in combinations, to disrupt release of inflammatory factors in vivo. Metabolic profiling will be performed on these mice (glucose tolerance, insulin tolerance, systemic insulin sensitivity, hepatic glucose output and other metabolic parameters) to assess systemic effects of silencing Kupffer cell inflammation. We will then test the hypothesis that Kupffer cell factors that modulate whole body metabolism do so by paracrine signaling to neighboring hepatocytes. We also seek to discover novel Kupffer cell factors that disrupt hepatic insulin sensitivity using deep sequencing, proteomics and lipidomics approaches. Finally, we shall identify which intracellular pathways within hepatocytes cause impaired hepatocyte insulin signaling in response to Kupffer cell factors. Candidates such as DAG, ceramides, JNK as well as novel signaling components found in unbiased screens will be evaluated following GeRP-mediated silencing of inflammatory pathways in Kupffer cells in vivo.

描述（由申请人提供）：该项目的总体长期目标是了解肥胖中产生脂肪肝和肝脏胰岛素抵抗的机制，以及这两种现象之间的分子关系，我们试图揭开肝脏脂肪变性的悖论。与人类胰岛素抵抗密切相关，而这些途径在实验模型中可以清楚地分离出来，我们努力通过研究库普弗细胞通过释放炎症作为邻近肝细胞胰岛素抵抗的介质来解决这一悖论。细胞因子对先天免疫受体和脂质传感器 CD36 和 Msr1 清道夫受体的反应提供了一个合理的机制，即这些脂质传感器激活 Kupffer 细胞中的炎症小体和 NFkB 通路，从而提供了肥胖中营养过剩可能导致肝脏炎症激活的合理机制。为了解决这个问题，我们开发了一种独特的葡聚糖封装的 siRNA (GeRP) 递送方法，可以选择性地沉默特定于肝脏中的巨噬细胞和库普弗细胞中的基因，同时保留通过这种方法，我们可以在各种肥胖小鼠模型中选择性地探究库普弗细胞对体内肝细胞功能的贡献，我们将选择性地沉默库普弗细胞 NFkB p65、Nlrp3、TLR4 辅助受体 CD14、 CD36 和 Msr1 以及其他靶标（单独或组合）将在这些小鼠身上进行代谢分析，以破坏体内炎症因子的释放。（葡萄糖耐量、胰岛素耐量、全身胰岛素敏感性、肝葡萄糖输出和其他代谢参数）来评估抑制库普弗细胞炎症的系统效应，然后我们将检验这样的假设：库普弗细胞因子通过旁分泌信号传导来调节全身代谢。我们还寻求利用深度测序、蛋白质组学和脂质组学方法发现破坏肝脏胰岛素敏感性的新库普弗细胞因子。最后，我们将确定肝细胞内的哪些细胞内途径导致肝细胞受损。在 GeRP 介导的体内 Kupffer 细胞炎症通路沉默后，将评估对 Kupffer 细胞因子（如 DAG、神经酰胺、JNK 以及在无偏筛选中发现的新型信号传导成分）的胰岛素信号传导。