Adipsin in NASH

NASH 中的脂肪素

基本信息

批准号：
10530839
负责人：
Utpal Pajvani
金额：
$ 58.27万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10530839
关键词：
Activation Analysis Adipocytes Adipose tissue Alternative Complement Pathway Animals Binding C3AR1 gene CRISPR/Cas technology Cells Coculture Techniques Complement Complement 3a Complement 3b Complement Activation Complement Factor D Complication Conditioned Culture Media Cross-Sectional Studies Data Data Set Development Diet Disease Disease Progression Fibrosis Goals Hepatic Stellate Cell Hepatocyte Human In Vitro Knock-in Mouse Knock-out Knockout Mice Lead Lipids Liver Liver Fibrosis LoxP-flanked allele Mediating Mediator of activation protein Metabolic Molecular Morbidity - disease rate Mus Obesity Obesity Epidemic PPARgamma2 Pathogenesis Pathogenicity Pathology Pathway interactions Patients Pharmacotherapy Phenocopy Phenotype Play Population Prevalence Prevention strategy Protein Isoforms Proteins Proteolysis Recombinants Reproducibility Role Signal Transduction Small Interfering RNA Testing Therapeutic Viral Vector Wild Type Mouse base chronic liver disease comorbidity cytokine dietary disease heterogeneity experimental study feeding in vitro activity in vivo inhibitor knock-down knockout animal liver biopsy liver inflammation liver transplantation mortality mouse model non-alcoholic fatty liver disease nonalcoholic steatohepatitis novel obese patients overexpression pandemic disease receptor small hairpin RNA tool transcriptome sequencing transcriptomics translational potential treatment strategy

项目摘要

Project Abstract The obesity pandemic brings with it multiple attendant metabolic comorbidities, including Non-Alcoholic Fatty Liver Disease (NAFLD). NAFLD is now the leading cause for chronic liver disease, with prevalence approaching 30% in certain populations, but may in fact be considered a “pre-disease” state for Non-Alcoholic Steatohepatitis (NASH) and associated liver fibrosis. NASH has no approved pharmacotherapy, and is thus the fastest-growing reason for liver transplantation. As the prevalence of obesity-related NASH continues to rise, and available livers for transplantation remain limiting, this unmet need grows more urgent. Intercellular crosstalk between lipid-laden hepatocytes and non-parenchymal cells (NPCs), including hepatic stellate cells (HSC), determine obesity-induced liver pathology. To determine signals that mediate hepatocyte- NPC crosstalk, we performed transcriptomic analysis in hepatocytes isolated from mice fed a NASH-provoking diet. When compared to normal chow-fed mice, we found significantly increased expression of Cfd (Complement factor d), which encodes Adipsin, a secreted protein thought uniquely produced in adipocytes that mediates complement factor C3 cleavage. We first confirmed these data in three other dietary NASH mouse models, as well as in liver biopsies from patients with NASH, all of which revealed increased liver (but not adipose) Adipsin in NASH. These robust correlations prompted us to test potential of Adipsin to mediate NASH phenotypes. First, as Adipsin cleaves complement factor C3 to two bioactive species – C3a, which binds C3aR1 on target cells, and C3b that drives alternative complement pathway activation – we analyzed C3 knockout mice fed NASH diet, which showed lower fibrosis than controls. Next, we transduced NASH diet-fed wildtype mice with a viral vector encoding shRNA to Cfd, which phenocopied lower fibrosis seen in C3 knockout animals, in both prevention and treatment strategies. Consistently, application of recombinant C3a increased HSC activity in vitro. These results suggest that aberrant liver Adipsin plays a pathogenic role in NASH, which we will test in Aim 1 of this application, including studies to test whether Adipsin-derived C3a acts directly on HSC C3aR1 to drive liver fibrosis. In Aim 2, we study mechanistic determinants of aberrant liver Adipsin in NASH. Preliminary data revealed a striking induction of the master adipogenic factor PPARγ2 in mouse and human NASH. These data prompt the hypothesis that a PPARγ2-mediated adipogenic reprogramming of hepatocytes in NASH is necessary and sufficient to drive Cfd expression in the obese liver. Achieving the goals of this application will identify mechanistic determinants of aberrant Adipsin expression and resultant liver pathology, and potentially lead to development of Adipsin or C3aR1 inhibitors for NASH-induced fibrosis.

项目摘要肥胖症流行带来了多种伴随的代谢合并症，包括非酒精性脂肪肝病 (NAFLD) 现在是慢性肝病的主要原因，其患病率已接近尾声。在某些人群中为 30%，但实际上可能被视为非酒精性脂肪性肝炎的“病前”状态（NASH）和相关的肝纤维化尚未获得批准的药物治疗，因此是增长最快的。随着肥胖相关NASH的患病率持续上升，可用的肝脏越来越多。由于移植仍然受到限制，这种未满足的需求变得更加紧迫。富含脂质的肝细胞和非实质细胞 (NPC)（包括肝细胞）之间的细胞间串扰星状细胞（HSC），确定肥胖引起的肝脏病理学。 NPC 串扰，我们对从喂食引起 NASH 的小鼠中分离出的肝细胞进行了转录组分析与正常饮食喂养的小鼠相比，我们发现 Cfd（补体）的表达显着增加。因子 d），编码 Adipsin，一种被认为在脂肪细胞中独特产生的分泌蛋白，介导我们首先在其他三种饮食 NASH 小鼠模型中证实了这些数据的补充，如以及 NASH 患者的肝活检，所有这些都显示肝脏（但不是脂肪）Adipsin 增加这些强有力的相关性促使我们测试 Adipsin 介导 NASH 表型的潜力。由于 Adipsin 将补体因子 C3 裂解为两种生物活性物质 - C3a，它与靶细胞上的 C3aR1 结合，和驱动替代补体途径激活的 C3b——我们分析了喂食 NASH 饮食的 C3 敲除小鼠，接下来，我们用病毒载体转导 NASH 饮食喂养的野生型小鼠。将 shRNA 编码为 Cfd，其表型复制了 C3 敲除动物中观察到的较低纤维化，无论是在预防还是一致地，重组 C3a 的应用增加了体外 HSC 活性。表明异常的肝脏 Adipsin 在 NASH 中发挥致病作用，我们将在本申请的目标 1 中对其进行测试，包括测试 Adipsin 衍生的 C3a 是否直接作用于 HSC C3aR1 以驱动肝纤维化的研究。 2、我们研究 NASH 中异常肝脏 Adipsin 的机制决定因素初步数据揭示了惊人的结果。在小鼠和人类 NASH 中诱导主要脂肪形成因子 PPARγ2。假设 NASH 中 PPARγ2 介导的肝细胞脂肪生成重编程是必要的足以驱动肥胖肝脏中的 Cfd 表达实现该应用的目标将确定机制。 Adipsin 表达异常和由此产生的肝脏病理学的决定因素，并可能导致发育 Adipsin 或 C3aR1 抑制剂治疗 NASH 诱导的纤维化。