Protective role of OPN-High macrophages in NASH

OPN-High 巨噬细胞在 NASH 中的保护作用

基本信息

批准号：
10752928
负责人：
Natalia Nieto
金额：
$ 53.38万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-05 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10752928
关键词：
ARG2 gene Adipose tissue Adult Bioenergetics Body Fluids Cell physiology Cells Child Cholesterol Clinical Collagen Data Deposition Development Diet Embryo Equilibrium Event Extracellular Matrix Fatty Liver Fatty acid glycerol esters Fibrosis Fructose Gene Expression Profile Hepatic Hepatic Stellate Cell Hepatocyte Heterogeneity Human Human Milk Immune system Infant Infiltration Inflammatory Intervention Knock-in Knockout Mice Knowledge Kupffer Cells Laboratories Link Lipids Liver Liver Fibrosis Liver diseases Location Macrophage Messenger RNA Mitochondria Modeling Monounsaturated Fatty Acids Mus Myeloid Cells Nitric Oxide Obesity Pathogenesis Pathologic Pathway interactions Patients Phenotype Physiological Processes Plasma Preventive Production Proteins Regimen Regulator Genes Role Saturated Fatty Acids Signal Transduction Signaling Protein Testing Therapeutic Tissues Triglycerides Umbilical cord structure Up-Regulation cell behavior fatty acid oxidation feeding intercellular communication lipid metabolism lipidomics liver transplantation mRNA Expression monocyte nitrosative stress nonalcoholic steatohepatitis novel therapeutics osteopontin overexpression prevent promoter recruit single-cell RNA sequencing therapeutic evaluation transcriptome transcriptomics urea cycle

项目摘要

Non-alcoholic steatohepatitis (NASH) is emerging as a major worldwide cause of liver disease in children and adults. Recent studies demonstrate substantial heterogeneity in the phenotype of macrophages (MFs) infiltrating the liver during NASH. Recruited MFs exist as two subsets, with distinct activation states: (1) those closely resembling homeostatic Kupffer cells (KCs), or (2) lipid-associated MFs (LAMs). In 2020, a cluster of LAMs with high expression of osteopontin (OPN) was identified in livers with NASH. Notably, LAMs are differentially activated, compared to resident- and monocyte-derived KCs, and with a distinct ability to metabolize lipids. However, whether they also crosstalk with neighboring cells, to prevent steatosis and fibrosis in NASH, remains unknown. While recruitment of MFs into the liver, and subsequent activation, are considered proinflammatory and profibrotic events, currently a significant knowledge gap is a lack of understanding of whether OPNHigh MFs, are detrimental or protective in NASH. Preliminary data demonstrates that Spp1KI Mye are protected, whereas Spp1ΔMye have worse NASH activity scores than WT mice. Thus, our results suggest a paradigm shift, in that OPNHigh MFs may protect from NASH. Yet, the intercellular communication, and preventive and therapeutic potential of OPNHigh MFs, remain to be determined. Our overarching hypothesis is that OPNHigh MFs, by signaling to hepatocytes (HEPs) and hepatic stellate cells (HSCs), reduce liver steatosis and fibrosis, and protect from NASH. Aim 1 is to identify how OPNHigh MFs protect from steatosis. We hypothesize that OPNHigh MFs signal HEPs to upregulate arginase-2 (ARG2), which increases mitochondrial bioenergetics and fatty acid oxidation (FAO), reduces nitrosative stress, and protects from steatosis. To test this, first, we will identify the OPNHigh MF ‘secretome’ proteins that signal HEPs to upregulate ARG2; second, we will determine how the identified OPNHigh MF secretome proteins transactivate the ARG2 promoter, in HEPs; and third, we will elucidate how ARG2 increases mitochondrial bioenergetics and FAO, and reduces nitrosative stress, in HEPs. Aim 2 is to dissect how OPNHigh MFs protect from fibrosis. We hypothesize that OPNHigh MFs signal through secretome proteins to lower collagen-I, and/or modify the ‘matrisome’ landscape, to prevent fibrosis, and regulate cell behavior, in NASH. To prove this, first, we will identify the OPNHigh MF secretome proteins that signal HSCs to lower collagen-I deposition and/or increase its degradation; second, we will analyze whether OPNHigh MFs modify the matrisome landscape, and establish the OPNHigh MF-ECM correlation network; and third, we will perform liver scRNA-seq, and computationally identify how the OPNHigh MF-ECM network regulates cell behavior in NASH.

非酒精性脂肪性肝炎（NASH）正在成为儿童和成人肝病的主要原因。最近的研究表明，巨噬细胞表型（MFS）在NASH期间渗透肝脏的巨大异质性。招募的MF作为两个子集存在，具有不同的激活状态：（1）与稳态的kupffer细胞（KCS）或（2）脂质相关的MFS（LAMS）紧密相似的激活状态。在2020年，在NASH的肝脏中鉴定出具有高表达骨桥蛋白（OPN）的LAM簇。值得注意的是，与居民和单核细胞衍生的KC相比，LAM被差异化，并且具有与脂质代谢的独特能力。但是，它们是否也与邻近细胞串扰，以防止NASH中的脂肪变性和纤维化，仍然未知。虽然将MF招募到肝脏中以及随后的激活被认为是促炎性和纤维化事件，但目前存在重大的知识差距是缺乏对opnhigh MFS在NASH中是否有害还是受到保护。初步数据表明SPP1KI MYE受到保护，而SPP1ΔMYE的NASH活性得分比WT小鼠差。这是我们的结果表明范式转变，因为Opnhigh MFS可能会免受NASH的侵害。然而，Opnhigh MF的细胞间通信以及预防和治疗潜力仍有待确定。我们的总体假设是，通过向肝细胞（HEP）和肝星状星状细胞（HSC）发出信号，opnhigh MFS，减少肝脏脂肪变性和纤维化，并防止NASH。目的1是确定Opnhigh MFS如何保护脂肪变性。我们假设OpnHigh MFS信号HEP上调精氨酸酶-2（ARG2），从而增加了线粒体生物能和脂肪酸氧化（FAO）（FAO），可减少硝化应激，并保护脂肪症。首先，为了测试这一点，我们将确定信号提示更新ARG2的OpnHigh MF“分泌”蛋白；其次，我们将确定鉴定出的OpnHigh MF分泌蛋白如何在HEP中反式激活ARG2启动子；第三，我们将阐明ARG2如何增加线粒体生物能学和粮农组织，并减少HEP中的硝化应激。 AIM 2是剖析Opnhigh MFS如何免受纤维化的保护。我们假设OpnHigh MFS通过分粒子蛋白信号降低胶原蛋白，和/或修改“矩阵”景观，以防止NASH中的纤维化和调节细胞行为。首先，为了证明这一点，我们将确定opnhigh的MF分泌蛋白，该蛋白会信号HSC降低胶原蛋白沉积物和/或增加其降解；其次，我们将分析OpnHigh MFS是否修改了矩阵景观，并建立OpnHigh MF-ECM相关网络；第三，我们将执行肝脏SCRNA-SEQ，并在计算上确定OPNHIGH MF-ECM网络如何调节NASH中的细胞行为。