Adipsin in NASH

NASH 中的脂肪素

• 批准号: 10636848
• 负责人: Utpal Pajvani
• 金额: $ 58.85万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 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/10636848
• 关键词: 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; Genetic Transcription; Goals; Hepatic Stellate Cell; Hepatocyte; Human; In Vitro; Knock-in Mouse; Knock-out; Knockout Mice; Lipids; Liver; Liver Fibrosis; LoxP-flanked allele; Mediating; Mediator; Metabolic; Molecular; Morbidity - disease rate; Mus; Obesity; Obesity Epidemic; PPAR gamma; PPARgamma2; Pathogenesis; Pathogenicity; Pathology; Pathway interactions; Patients; Pharmacotherapy; Phenocopy; Phenotype; Play; Population; Prevalence; Prevention strategy; Protein Isoforms; Protein Secretion; Proteolysis; Recombinants; Reproducibility; Role; Signal Transduction; Small Interfering RNA; Testing; Therapeutic; Viral Vector; Wild Type Mouse; 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

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 肥胖大流行带来了多种服务的代谢合并症，包括非酒精脂肪 肝病（NAFLD）。 NAFLD现在是慢性肝病的主要原因 在某些人群中，有30％，但实际上可能被认为是非酒精性脂肪性肝炎的“疾病前”状态 （NASH）和相关的肝纤维化。纳什没有批准的药物疗法，因此增长最快 肝移植的原因。随着与肥胖相关的纳什的患病率继续上升，可用的生活 为了移植保持限制，这种未满足的需求变得更加紧迫。 含脂质的肝细胞和非副作用细胞（NPC）之间的细胞间串扰，包括肝 星状细胞（HSC），确定肥胖性诱导的肝脏病理。确定介导肝细胞的信号 NPC串扰，我们在喂养NASH的小鼠中分离出的肝细胞中进行了转录组分析 饮食。与正常食小鼠相比，我们发现CFD的表达显着增加（补充 因子D），编码adipsin，这是一种在脂肪细胞中独特产生的分泌的蛋白质思想 补体因子C3裂解。我们首先在其他三个饮食纳什小鼠模型中证实了这些数据， 以及NASH患者的肝活检中，所有这些都显示肝脏（但不是脂肪）脂肪蛋白增加 在纳什。这些强大的相关性促使我们测试脂肪素的潜力介导NASH表型。第一的， 由于脂肪蛋白裂解与两个生物活性物种的补体C3 -C3A，它在靶细胞上结合C3AR1， 和C3B驱动替代完成途径激活的C3B - 我们分析了喂Nash饮食的C3基因敲除小鼠， 纤维化比对照较低。接下来，我们用病毒载体翻译了纳什饮食喂养的野生型小鼠 编码shRNA到cfd，在预防和 治疗策略。一致地，重组C3A的应用在体外增加了HSC活性。这些结果 表明异常肝adipsin在NASH中起致病作用，我们将在本应用的AIM 1中进行测试， 包括测试脂肪蛋白衍生的C3A是否直接在HSC C3AR1上起作用以驱动肝纤维化的研究。目标 2，我们研究NASH异常肝脂肪素的机理决定。初步数据揭示了罢工 在小鼠和人NASH中诱导主脂肪因子PPARγ2。这些数据促使 假设纳什（Nash 足以在肥胖肝脏中驱动CFD表达。实现此应用程序的目标将确定机制 异常脂肪素表达和导致的肝脏病理学的决定因素，并有可能导致发育 用于NASH诱导的纤维化的脂肪素或C3AR1抑制剂的抑制剂。