Protective role of OPN-High macrophages in NASH

OPN-High 巨噬细胞在 NASH 中的保护作用

• 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
• 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

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脏疾病的主要全球原因。最近的研究表明，在NASH期间浸润肝脏的巨噬细胞（MFs）的表型存在实质性异质性。募集的MF分为两个子集，具有不同的激活状态：（1）与稳态枯否细胞（KC）非常相似的那些，或（2）脂质相关MF（LAM）。2020年，在NASH肝脏中发现了一组骨桥蛋白（OPN）高表达的LAM。值得注意的是，与居民和单核细胞来源的KC相比，LAM被差异活化，并且具有独特的代谢脂质的能力。然而，它们是否也与邻近细胞相互作用，以防止NASH中的脂肪变性和纤维化，仍然是未知的。虽然将MF募集到肝脏中以及随后的活化被认为是促炎性和促纤维化事件，但目前的重大知识缺口是缺乏对OPNHigh MF在NASH中是有害的还是保护性的理解。初步数据表明，Spp 1 KI Mye受到保护，而Spp 1 ΔMye的NASH活性评分比WT小鼠更差。因此，我们的研究结果表明了一种范式转变，即OPN高MFs可以保护NASH。然而，OPNHigh MFs的细胞间通讯以及预防和治疗潜力仍有待确定。我们的总体假设是，OPN高MFs通过向肝细胞（HEP）和肝星状细胞（HSC）发出信号，减少肝脏脂肪变性和纤维化，并防止NASH。目的1是确定OPN高MFs如何防止脂肪变性。我们假设，OPN高MFs信号HEP上调脂肪酶-2（ARG 2），增加线粒体生物能量学和脂肪酸氧化（FAO），减少亚硝化应激，并防止脂肪变性。为了测试这一点，首先，我们将确定信号HEP上调ARG 2的OPNHigh MF“分泌组”蛋白;其次，我们将确定所确定的OPNHigh MF分泌组蛋白如何在HEP中反式激活ARG 2启动子;第三，我们将阐明ARG 2如何在HEP中增加线粒体生物能学和FAO，并减少亚硝化应激。目的2是剖析OPN高MFs如何保护纤维化。我们假设，在NASH中，OPN高MFs通过分泌组蛋白发出信号以降低胶原-I和/或修改“基质体”景观，从而防止纤维化并调节细胞行为。为了证明这一点，首先，我们将鉴定向HSC发出信号以降低胶原-I沉积和/或增加其降解的OPNHigh MF分泌组蛋白;其次，我们将分析OPNHigh MF是否改变基质体景观，并建立OPNHigh MF-ECM相关网络;第三，我们将进行肝脏scRNA-seq，并通过计算确定OPNHigh MF-ECM网络如何调节NASH中的细胞行为。