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) 正在成为全球儿童和成人肝病的主要原因。最近的研究表明 NASH 期间浸润肝脏的巨噬细胞 (MF) 表型存在显着异质性。招募的 MF 作为两个子集存在，具有不同的激活状态：(1) 与稳态库普弗细胞 (KC) 非常相似的 MF，或 (2) 脂质相关 MF (LAM)。 2020 年，在 NASH 患者的肝脏中发现了一组高表达骨桥蛋白 (OPN) 的 LAM。值得注意的是，与常驻细胞和单核细胞来源的 KC 相比，LAM 的激活存在差异，并且具有独特的脂质代谢能力。然而，它们是否也与邻近细胞相互作用以预防 NASH 中的脂肪变性和纤维化仍不清楚。虽然 MF 募集到肝脏以及随后的激活被认为是促炎和促纤维化事件，但目前的一个重大知识差距是缺乏对 OPNHigh MF 在 NASH 中是否有害或具有保护作用的了解。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。因此，我们的结果表明范式转变，OPNHigh MF 可以预防 NASH。然而，OPNHigh MF 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 OPNHigh MF 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，并预防 NASH。目标 1 是确定 OPNHigh MF 如何预防脂肪变性。我们假设 OPNHigh MF 向 HEP 发出上调精氨酸酶 2 (ARG2) 的信号，从而增加线粒体生物能和脂肪酸氧化 (FAO)、减少亚硝化应激并防止脂肪变性。为了测试这一点，首先，我们将鉴定 OPNHigh MF“分泌组”蛋白，该蛋白向 HEP 发出上调 ARG2 的信号；其次，我们将确定已鉴定的 OPNHigh MF 分泌蛋白如何反式激活 HEP 中的 ARG2 启动子；第三，我们将阐明 ARG2 如何在 HEP 中增加线粒体生物能和 FFA，并减少亚硝化应激。目标 2 是剖析 OPNHigh MF 如何防止纤维化。我们假设 OPNHigh MF 通过分泌蛋白发出信号来降低 I 型胶原蛋白，和/或修改 NASH 中的“基质体”景观，以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 OPNHigh MF 分泌蛋白，该蛋白向 HSC 发出信号以降低 I 型胶原沉积和/或增加其降解；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。