Cholangiocyte-Derived Endothelin Signaling Mediates Biliary Injury and Liver Fibrosis

胆管细胞衍生的内皮素信号传导介导胆道损伤和肝纤维化

• 批准号: 10341130
• 负责人: Lindsey Kennedy
• 金额: --
• 依托单位: RLR VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10341130
• 关键词: Angiogenic Factor; Angiopoietin-2; Architecture; Automobile Driving; Biliary; Biology; Blood; Blood Vessels; Blood capillaries; Cell Proliferation; Cell Separation; Cellular biology; Cholangiocarcinoma; Cholestasis; Chronic; Cirrhosis; Collagen; Complex; Corrosion Casting; Coupled; Data; Deposition; Development; Disease Progression; Down-Regulation; Duct (organ) structure; Endothelin; Endothelin-1; Endothelin-2; Endothelin-3; Epithelial Cells; FDA approved; Feedback; Goals; Growth; HIF1A gene; Hepatic; Hepatic Stellate Cell; Human; Incidence; Inflammation; Injections; Injury; Ink; Knock-out; Lead; Ligation; Liver; Liver Cirrhosis; Liver Fibrosis; Liver diseases; Malignant neoplasm of liver; Mediating; Mentors; Mentorship; MicroRNAs; Modeling; Morbidity - disease rate; Multi-Drug Resistance; Mus; Nutrient; Patients; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Portal Hypertension; Portal Pressure; Proliferating; Pulmonary Hypertension; Research; Research Proposals; Risk; Role; Safety; Signal Transduction; Techniques; Therapeutic; Tissues; Training; Transforming Growth Factors; VEGFA gene; Vascular Endothelial Cell; Vasoconstrictor Agents; Veterans; Work; ambrisentan; angiogenesis; antagonist; autocrine; base; bile duct; bile stricture; blood vessel development; career; cell growth; cholangiocyte; hypoxia inducible factor 1; in vivo; liver inflammation; liver injury; liver transplantation; mortality; mortality risk; mouse model; novel; novel therapeutics; paracrine; primary sclerosing cholangitis; restoration; senescence; symposium; therapeutically effective; vascular bed

The main goal of this application is to clarify the signaling mechanisms mediating biliary senescence and angiogenesis during primary sclerosing cholangitis (PSC). It is known that (i) endothelin (ET)-1 signaling is enhanced in the bile duct ligation (BDL) model of obstructive cholestasis, (ii) it is primarily upregulated in cholangiocytes and (iii) enhances liver fibrosis via hepatic stellate cell (HSC) activation. Outside of the liver, ET-1 is a potent vasoconstrictor and enhances transforming growth factor-β1 (TGF-β1, pro-angiogenic factor) expression in vascular endothelial cells (VECs). Overall, it is unknown how ET signaling (including ET-2 and ET- 3) mediate biliary senescence and VEC proliferation/angiogenesis during PSC. Additionally, changes in the vascular bed and VEC proliferation during PSC is unknown. We found that ET-1, ET-2, ET-3 and ET-A and ET-B are increased, particularly in cholangiocytes and VECs, in human PSC and the multidrug resistance-2 knockout (Mdr2-/-) mouse model of PSC. Furthermore, we have novel preliminary data showing increased VEC proliferation and angiogenesis in both human PSC and in Mdr2-/- mice. Changes in angiogenesis versus vasopenia during cholestasis is controversial, but considering PSC patients with portal hypertension have an increased morbidity and mortality, there is likely some underlying VEC-mediated changes occurring. Therefore, our novel findings are the first to indicate liver VEC proliferation and angiogenesis during PSC. Additionally, these findings are the first to delve into ET signaling in cholangiocytes and VECs during PSC. We provide data indicating a feedback loop, whereby ET signaling promotes TGF-β1 expression, which can in turn increase miR- 125b/HIF-1α expression, which is known to increase ET expression. These are the first data demonstrating a positive feedback loop between ET/TGF-β1/miR-125b/HIF-1α that can perpetuate biliary senescence and liver fibrosis in autocrine and paracrine manners. Furthermore, we found that inhibition of ET-A or ET-B in Mdr2-/- mice using currently FDA-approved drugs (for the treatment of pulmonary hypertension) reduces biliary senescence and liver fibrosis when compared to controls. Our overall hypothesis is that cholangiocytes and liver VEC communicate with one another via endothelin ET/TGF-β1 signaling that increases biliary senescence and VEC angiogenesis through autocrine and paracrine mechanisms. Our findings may lead to the identification of new, effective therapeutics for the treatment of PSC. This application proposal is the first step to developing independence for the PI, Dr. Lindsey Kennedy. This proposal elegantly marries the background work of her mentors on cholangiocyte biology, microRNA signaling and angiogenesis with new techniques and concepts that further delve into vascular biology during cholestasis. Following successful completion of this application, Dr. Kennedy will have a better understanding of angiogenesis/vasopenia, VEC biology and vascular interactions with the bile ducts, and this can develop into independent studies. The KEY ELEMENTS of this research proposal are the (i) strong mentoring team developed, who will provide top-tier training for the applicant, (ii) introduction of new techniques (ink injection, corrosion casting, VEC isolation, human primary cell isolation) and concepts (vascular biology in cholestasis), (iii) comprehensive mentoring and career plan, including one-on-one training, conference attendance, presentation opportunities and development of grantsmanship, and (iv) opportunity for the applicant to develop her own independent, successful research lab.

该应用的主要目的是阐明介导胆道感应的信号传导机制 原发性硬化性胆管炎（PSC）期间的血管生成。众所周知，（i）内皮素（ET）-1 阻塞性胆汁淤积的胆管连接（BDL）模型增强了信号传导，（ii）它主要更新 在胆管细胞和（iii）中，通过肝星状细胞（HSC）激活增强了肝纤维化。在肝脏外， ET-1是一种潜在的血管收缩剂，增强了转化生长因子-β1（TGF-β1，促血管生成因子） 血管内皮细胞（VEC）中的表达。总体而言，未知ET信号传导（包括ET-2和ET-）是未知的 3）PSC期间的培养基胆汁感受和VEC增殖/血管生成。此外，变化 PSC期间的血管床和VEC增殖尚不清楚。我们发现ET-1，ET-2，ET-3和ET-A以及 ET-B增加，特别是在胆管细胞和VEC中 PSC的敲除（MDR2 - / - ）鼠标模型。此外，我们有新的初步数据显示VEC增加 人PSC和MDR2 - / - 小鼠的增殖和血管生成。血管生成与 胆汁淤积过程中的血管替症是有争议的，但是考虑到门静脉高压患者的PSC患者具有 发病率和死亡率提高，可能发生了一些基本的VEC介导的变化。所以， 我们的新发现是第一个指示PSC期间肝脏VEC增殖和血管生成的结果。此外， 这些发现是在PSC期间首次探究胆管细胞和VEC中的ET信号传导的发现。我们提供数据 指示反馈循环，通过ET信号促进TGF-β1表达，这又可以增加mir- 125B/HIF-1α表达，已知会增加ET表达。这些是证明一个的第一个数据 ET/TGF-β1/mir-125b/hif-1α之间的正反馈回路，该反馈可以使胆汁感受和肝脏永存 纤维化自分泌和旁分泌礼节。此外，我们发现MDR2中对ET-A或ET-B的抑制作用 - / - 使用当前FDA批准的药物（用于治疗肺动脉高压）的小鼠减少了胆道 与对照组相比，感应和肝纤维化。我们的总体假设是胆管细胞和 肝脏VEC通过内皮素ET/TGF-β1信号相互通信，从而增加胆道 通过自分泌和旁分泌机制的感应和VEC血管生成。我们的发现可能会带来 鉴定用于治疗PSC的新有效疗法。该申请建议是第一个 为PI发展独立的步骤Lindsey Kennedy博士。该提议优雅地嫁给了 她的导师对胆管细胞生物学，microRNA信号传导和血管生成的背景工作 在胆汁淤积期间进一步研究血管生物学的技术和概念。成功 完成此应用的完成，肯尼迪博士将更好地了解血管生成/血管减少症，VEC 生物学和血管相互作用与胆管的相互作用，这可以发展成独立的研究。钥匙 该研究建议的要素是（i）强大的心理团队，他们将提供顶级 申请人的培训，（ii）引入新技术（墨水注入，腐蚀铸件，VEC隔离， 人类主要细胞隔离）和概念​​（胆汁淤积的血管生物学），（iii）全面的心理和 职业计划，包括一对一培训，会议出勤，演示机会和发展 授予技巧，以及（iv）申请人开发自己独立，成功研究的机会 实验室。