Role of Interferon-Gamma / Interleukin-12 Axis in Metabolic Liver Disease

干扰素-γ/白介素-12 轴在代谢性肝病中的作用

• 批准号: 10735419
• 负责人: JASON K KIM
• 金额: $ 49万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10735419
• 关键词: 3D ultrasound; Acute; Adipose tissue; Adult; Affect; Attenuated; Biological Assay; Cells; Chronic; Coculture Techniques; Complex; Data; Dendritic Cells; Dependovirus; Deposition; Development; Diabetes Mellitus; Diet; Encapsulated; FGF21 gene; FOXO1A gene; Fatty Liver; Fibrosis; Glucans; Glucose Clamp; Goals; Hepatic; Hepatic Stellate Cell; Hepatocyte; High Fat Diet; Histologic; Histology; Human; Hyperinsulinism; IFNGR1 gene; IRS2 gene; Immune; Immunofluorescence Immunologic; Immunologics; Impairment; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Insulin Resistance; Interferon Activation; Interferon Suppression; Interferon Type II; Interferons; Interleukin-10; Interleukin-12; Interleukin-12 therapy; Knockout Mice; Kupffer Cells; Ligands; Link; Lipids; Liver; Liver Fibrosis; Liver diseases; Macrophage; Mediating; Mediator; Metabolic; Molecular; Molecular Profiling; Mus; Muscle; Myeloid Cells; Natural Immunity; Natural Killer Cells; Obesity; Pathogenesis; Pathway interactions; Play; Proteins; Research; Role; Serum; Signal Transduction; Skeletal Muscle; Small Interfering RNA; System; T-Lymphocyte; Testing; Th1 Cells; Time; Weight; adaptive immunity; cell type; cytokine; diet-induced obesity; experimental study; fibroblast growth factor 21; fibrogenesis; gain of function; glucose metabolism; improved; in vivo; insulin receptor substrate 1 protein; insulin signaling; intrahepatic; islet amyloid polypeptide; liver inflammation; loss of function; new therapeutic target; non-alcoholic fatty liver; nonalcoholic steatohepatitis; novel; obese person; obesogenic; p38 Mitogen Activated Protein Kinase; particle; single-cell RNA sequencing; therapeutic target

Metabolic liver disease, encompassing nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) with insulin resistance as the pathophysiological hallmark, is an emerging issue affecting one in four adults in the U.S. Obesity is characterized by inflammation in the liver, and surrounding macrophages and cytokines may play a major role in metabolic liver disease. Our long-term goal is to understand the molecular mechanism by which obesity causes metabolic liver disease by delineating the role of macrophages and cytokines as a molecular link between insulin resistance, NAFL, and NASH. Interferon-γ (IFNγ), a key regulator of innate and adaptive immunity by priming macrophages, is elevated in obese humans. Our preliminary data indicate that mice with conditional loss of IFNγ signaling in myeloid cells (Lyz-IFNgR2 KO) develop fatty liver after a high-fat diet but are protected from insulin resistance and inflammation in the liver. Moreover, interleukin-12 (IL-12) plays a major role in bridging innate and adaptive immunity by inducing differentiation of Th1 cells, and IL-12 levels are elevated in obese humans and NASH liver. We made a novel observation that IL-12 treatment in vivo causes hepatic insulin resistance by impairing IRS-1 activity in the liver. We also found that IL-12 modulates IRS-2/FoxO1/FGF21 expression in hepatocytes, that may lead to the activation of hepatic stellate cells (HSCs) and fibrogenesis during NAFL progression to NASH. Based on these observations, we hypothesize that obesity-mediated activation of IFNγ signaling in macrophages, through the release of IL-12, causes metabolic liver disease. In Aim 1, we will determine the role of the IFNg-IL12 axis in obesity-mediated insulin resistance in the liver. Metabolic, molecular, and cell-based experiments will be performed in newly created mice with Kupffer cell-selective loss of IFNγ signaling (Clec4f-IFNgR2 KO). We will also apply chronic and liver-targeted IL-12 treatment using AAV8 and mice lacking IL-12 genetically or via liver-selective IL-12 targeting siRNA using GeRPs to test a hypothesis that IL-12 activation of p38 mitogen-activated protein kinase impairs insulin signaling activity and causes insulin resistance in the liver. Aim 2 will delineate the role of the IFNg-IL12 axis in regulating intercellular crosstalk between macrophages, hepatocytes, and HSCs during NAFL progression to NASH. We will examine the effects of the obesogenic Gubra Amylin NASH diet on liver steatosis and fibrosis in Clec4f-IFNgR2 KO, Lyz-IFNgR2 KO, and mice with gain/loss-of-function of IL-12 using 3D-ultrasound and histology. Kupffer cells, hepatocytes, and HSCs will be isolated from the liver for molecular and cell-based experiments to test a hypothesis that IL-12 modulates hepatocyte IRS-2/FoxO1/FGF21 pathway, leading to HSC activation and fibrogenesis. Taken together, these aims will introduce a novel paradigm in which IFNγ signaling and IL-12 act as key mediators of intercellular crosstalk between macrophages, hepatocytes, and HSCs in hepatic insulin resistance and during NAFL progression to NASH in obesity. Our findings will identify IFNγ signaling and IL-12 as potential therapeutic targets to treat metabolic liver disease in humans.

代谢性肝病，包括非酒精性脂肪肝（NAFL）和非酒精性脂肪性肝炎（NASH），具有胰岛素抵抗为病理生理标志，是一个新兴问题，影响了美国肥胖症中四分之一的成年人的新兴问题，表征了肝脏，周围乳腺癌的炎症，可能会在liver症中发挥作用，并在live症中发挥了作用。我们的长期目标是了解分子机制，通过将巨噬细胞和细胞因子的作用描述为胰岛素抵抗，NAFL和NASH之间的分子联系，从而通过将肥胖引起代谢性肝病。干扰素-γ（IFNγ）是肥胖人的启动巨噬细胞的关键调节剂和适应性免疫的关键调节剂。我们的初步数据表明，在高脂肪饮食后，髓样细胞（LYZ-IFNGR2 KO）中有条件丧失IFNγ信号传导的小鼠会出现脂肪肝，但受到胰岛素抵抗和肝脏炎症的保护。此外，白介素12（IL-12）通过诱导TH1细胞的分化来弥合先天和适应性免疫，在肥胖人类和纳什肝脏中升高IL-12水平。我们进行了一个新的观察结果，即IL-12治疗在体内的治疗通过损害肝脏中的IRS-1活性来引起肝胰岛素抵抗。我们还发现，IL-12在肝细胞中调节IRS-2/FOXO1/FGF21的表达，这可能导致肝星状细胞（HSC）的激活和NaFL进展为NASH期间的纤维发生。基于这些观察结果，我们假设肥胖症介导的巨噬细胞中IFNγ信号传导的激活，通过释放IL-12引起代谢性肝病。在AIM 1中，我们将确定IFNG-IL12轴在肝脏中肥胖介导的胰岛素抵抗中的作用。代谢，分子和基于细胞的实验将在新创建的小鼠中进行IFNγ信号传导的新小鼠（CLEC4F-IFNGR2 KO）。我们还将使用缺乏IL-12的AAV8和肝选择性IL-12进行慢性和肝脏靶向IL-12处理，使用GERPS使用GERPS靶向siRNA来检验IL-12的假设，即IL-12激活p38有丝裂原激活的蛋白激活蛋白激活的蛋白激酶损害了胰岛素信号活性活性和引起胰岛素胰岛素的耐胰岛素耐药性。 AIM 2将描述IFNG-IL12轴在NAFL进展过程中巨噬细胞，肝细胞和HSC之间控制巨噬细胞之间的细胞间串扰中的作用。我们将使用3D-ultrasound and Holistology和组织学研究IL-12的CLEC4F-IFNGR2 KO，LYZ-IFNGR2 KO和小鼠的CLEC4F-IFNGR2 KO，LYZ-IFNGR2 KO和小鼠对肝脏脂肪变性和纤维化的影响。 Kupffer细胞，肝细胞和HSC将从肝脏中分离出分子和基于细胞的实验，以测试IL-12调节肝类-2/FOXO-2/FOXO1/FGF21途径的假说，导致HSC激活和纤维发生。综上所述，这些目标将引入一种新的范式，其中IFNγ信号传导和IL-12充当巨噬细胞，肝细胞和肝胰岛素抵抗中HSC之间的细胞间串扰的关键介体，以及在肥胖症中NAFL向NASH进展的过程中。我们的发现将确定IFNγ信号传导和IL-12是治疗人类代谢肝病的潜在治疗靶点。