Bilirubin Catabolism induces Plasminogen-Activator Inhibitor 1 (PAI-1) worsening Metabolic Dysfunction

胆红素分解代谢诱导纤溶酶原激活剂抑制剂 1 (PAI-1) 恶化代谢功能障碍

• 批准号: 10750132
• 负责人: Zachary A Kipp
• 金额: $ 3.37万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10750132
• 关键词: Adipose tissue; Affect; Antioxidants; Arterial Fatty Streak; Bilirubin; Binding; Blood Pressure; Blood Vessels; Body Weight; Calories; Cardiovascular Diseases; Cardiovascular system; Catabolism; Cause of Death; Cessation of life; Cholesterol; Circulation; Coagulation Process; Data; Development; Diet; Environment; Enzymes; Excretory function; Fat-Restricted Diet; Fatty acid glycerol esters; Fellowship; Fibrosis; Financial Hardship; Foundations; Future; Generations; Genetic Polymorphism; Gilbert Disease; Glucuronic Acids; Goals; Healthcare Systems; Heart; Heart Diseases; Heart failure; Heme; Hepatic; High Fat Diet; Hormonal; Human; Intestines; Knock-out; Knockout Mice; Lead; Link; Liver; Measures; Mediator; Messenger RNA; Metabolic; Metabolic Diseases; Metabolic dysfunction; Mus; Nuclear Receptors; Obese Mice; Obesity; PPAR alpha; Pathway interactions; Patients; Physiological; Plasma; Plasminogen Activator Inhibitor 1; Portal System; Prevention; Production; Proteins; RNA Interference; Research; Research Proposals; Research Technics; Risk; Risk Factors; Role; Scientist; Serum; Structure; Technology; Testing; Therapeutic; Thinness; Training; Translating; Travel; UGT1A1 gene; United States; Water; Woman; Work; absorption; bile duct; cardioprotection; cardiovascular disorder prevention; cardiovascular disorder risk; career; comorbidity; diet-induced obesity; feeding; glucose tolerance; gut microbiota; improved; men; mouse development; new therapeutic target; novel marker; novel therapeutics; obese patients; prevent; promoter; therapeutic target; tool; transcriptome; transcriptome sequencing

Summary: Urobilin is formed in the intestine as a biproduct of conjugated bilirubin catabolism. Currently, the physiological function of urobilin is unknown. Human association studies have indicated a positive correlation to obesity and cardiovascular diseases (CVD). Since obesity is a major risk factor for the development of CVD, we hypothesized that urobilin levels might change with the altered metabolic state and induce adiposity. To determine the role of urobilin in lean mice, we treated C57/bl6 mice on a normal-chow diet with urobilin for 4 weeks. We found that urobilin had no effect on body weight but significantly increased adiposity in the inguinal white adipose tissue (iWAT) depot compared to the vehicle-treated mice. To determine how urobilin changes the transcriptome profile in the iWAT, we preformed RNA-sequencing which showed that urobilin increases the expression of Serpine1 mRNA. Serpine1 is translated into the protein plasminogen activator inhibitor-1 (PAI-1). PAI-1 is secreted into circulation, promoting a prothrombotic environment, and is thought to increase the risk of CVD. The goal of this research proposal is to determine whether urobilin induces CVD via PAI-1 and if this mechanism is a link between CVD and obesity. We will investigate if lowering plasma urobilin is a possible therapeutic for the treatment and prevention of CVD. To study this, in Aim 1, we will use PAI-1 knockout (KO) mice and littermate controls treated with urobilin or vehicle while on a high-fat or calorie-match low-fat diets. We expect the PAI-1KO mice will be protected from urobilin induced CVD. In Aim 2, we will use diet-induced obese (DIO) mice treated with a liver- specific GalNac-Ugt1a1-RNAi or GalNac-scramble control to suppress hepatic Ugt1a1, which is responsible for initiating the conjugation of bilirubin that leads to elevated urobilin production. We show preliminary data that the RNAi technology suppresses Ugt1a1 94.7% and that this leads to a significant (p<0.01) decrease in plasma urobilin and an increase in plasma unconjugated bilirubin. We expect that the suppression of Ugt1a1 will protect the mice from the development of CVD by lowering urobilin levels, increasing unconjugated bilirubin, preventing adiposity and high PAI-1 plasma levels. This is the first proposed mechanism of urobilin in promoting the development of CVD, which we will extensively study to better understand how to reverse its deleterious effects. This fellowship will provided critical training in research techniques, scientific training and professional development to give me the tools to become a successful independent scientist.

概括： 尿液蛋白在肠中形成，是共轭胆红素分解代谢的两种双脂蛋白。目前，生理学 尿胶蛋白的功能未知。人类协会的研究表明与肥胖和 心血管疾病（CVD）。由于肥胖是CVD发展的主要危险因素，我们假设 该尿液素水平可能随着代谢状态的改变而变化，并诱导肥胖。确定 在瘦小小鼠中，我们在尿液中用尿液蛋白治疗了4周。我们发现 尿液素对体重没有影响，但腹股沟白色脂肪组织的肥胖显着增加 （IWAT）与车辆处理的小鼠相比。确定尿bilin如何改变转录组轮廓 在IWAT中，我们预先形成了RNA测序，这表明尿液素会增加Serpine1的表达 mRNA。 Serpine1转化为蛋白质纤溶酶原激活剂抑制剂1（PAI-1）。 Pai-1分泌到 循环，促进促血栓性环境，被认为会增加CVD的风险。目标的目标 研究提案是确定尿Bilin是否通过PAI-1诱导CVD，并且这种机制是否是联系 CVD和肥胖。我们将调查降低血浆尿布蛋白是否是治疗的可能治疗方法 预防CVD。为此，在AIM 1中，我们将使用PAI-1基因敲除（KO）小鼠和同窝式对照。 在高脂或卡路里匹配的低脂饮食上，使用尿胶蛋白或车辆。我们预计Pai-1ko小鼠将会 免受尿布蛋白诱导的CVD的保护。在AIM 2中，我们将使用用肝脏治疗的饮食诱导的肥胖（DIO）小鼠 特定的galnac-ugt1a1-rnai或galnac-scramble控制以抑制肝UGT1A1，这是负责的 启动胆红素的结合，从而导致尿胶蛋白产生升高。我们显示了初步数据 RNAi技术抑制了UGT1A1 94.7％，这导致血浆显着降低（P <0.01） 尿液蛋白和血浆未结合的胆红素的增加。我们希望抑制UGT1A1将保护 通过降低尿液素水平，增加未结合的胆红素，从CVD发育中的小鼠，阻止 肥胖和高PAI-1血浆水平。这是尿胶蛋白在促进的第一个提出的机制 CVD的开发，我们将广泛研究，以更好地了解如何扭转其有害影响。 该奖学金将为研究技术，科学培训和专业人士提供重要培训 开发为我提供了成为成功的独立科学家的工具。