Investigation of the role of VEGFA in harnessing cholangiocyte-driven liver regeneration

VEGFA 在利用胆管细胞驱动的肝再生中的作用的研究

基本信息

批准号：
10631156
负责人：
VALERIE B GOUON-EVANS
金额：
$ 57.76万
依托单位：
BOSTON MEDICAL CENTER
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/10631156
关键词：
Ablation Acute Affect Albumins Apoptosis Bile fluid Biliary Bilirubin Cause of Death Cell Lineage Cells Chemical Models Chemicals Chronic Cirrhosis Clinical Complex Data Disease model Disease regression Documentation Dominant-Negative Mutation Endothelial Cells Epithelial Cell Proliferation Epithelial Cells Face Fibrosis Fishes Generations Goals Hepatocyte Human Inflammation Injury Investigation KDR gene Knock-out Knockout Mice Liver Liver Regeneration Liver diseases Maps Mediating Mediator Messenger RNA Metabolic Mission Mitogens Modeling Molecular Mechanisms of Action Mus Natural regeneration Nucleosides Organ Donor PI3K/AKT Pathway interactions Persons Phase Procedures Process Proliferating Public Health Rattus Reaction Recovery Reporting Research Rodent Role Testing Therapeutic Therapeutic Uses Transgenic Organisms Transplantation United States National Institutes of Health VEGFA gene Zebrafish acute liver injury cell dedifferentiation cell type cholangiocyte clinically significant end stage liver disease exhaust genetic approach in vivo injured lipid nanoparticle liver cell proliferation liver function liver injury liver repair liver transplantation mortality mouse model novel novel therapeutic intervention overexpression p38 Mitogen Activated Protein Kinase prevent regenerative repaired senescence stem cells therapeutic target virtual

项目摘要

PROJECT SUMMARY / ABSTRACT Liver disease affects hundreds of millions of people worldwide. Liver transplantation remains the only treatment for end stage liver disease (ESLD); however, transplantation faces a major burden due to a shortage of liver donors. The liver is known for a remarkable regenerative ability through hepatocyte-driven regeneration, the proliferation of the main functional liver cell type, the hepatocyte. However, in ESLD, hepatocyte proliferation becomes exhausted. An alternative strategy to treat ESLD would be to promote liver regeneration through biliary epithelial cell (BEC)-driven regeneration as a novel mechanism that could be exploited as a therapeutic target. BEC-driven liver regeneration is a process by which BECs proliferate, transition to a liver progenitor cell (LPC) stage, a process defined as ductular reaction (DR), and differentiate into functional hepatocytes and restore liver function. BEC-driven regeneration has been experimentally demonstrated in mouse models in which hepatocyte proliferation was compromised and in our zebrafish models after near complete ablation of hepatocytes. Observation of DR in virtually all chronic and acute human liver diseases and of budding hepatocytes from BECs in human cirrhotic livers suggests that BEC-driven repair occurs in human, yet differentiation into hepatocytes is insufficient to alleviate the liver disease. Our goal is therefore to identify and test a druggable pathway that triggers BEC-to-hepatocyte conversion for the efficient therapeutic use of BECs to treat liver diseases. We propose that VEGFA promotes BEC-to-hepatocyte conversion and rescues liver function in complementary mouse and zebrafish liver injury models. Our preliminary data demonstrate that delivery of VEGFA in injured mouse livers via the non-integrative and safe nucleoside-modified mRNA complexed with lipid nanoparticles (mRNA-LNP) induces robust BEC-to-hepatocyte conversion and reversion of steatosis and fibrosis. Moreover, blocking VEGFR2, the main receptor for VEGFA, or downstream mediators PI3K/AKT abrogates BEC-driven liver regeneration in zebrafish, suggesting the key contribution of the VEGFR2/PI3K/AKT axis. Previous studies showed that VEGFA promotes liver repair in rodents by stimulating VEGFR2 on endothelial cells (ECs) that induce the secretion of hepatocyte mitogens and thus drives hepatocyte-driven repair. However, it has not been reported that VEGFA directly affects BECs for BEC-driven repair, which is suggested by our preliminary data showing VEGFR2 induction in a subset of BECs in injured mouse livers, an observation also reported by others in injured rats. Therefore, our findings combined with studies from others lead us to test 2 hypotheses using the complementary mouse and zebrafish liver injury models: (Aim 1) VEGFA delivery in vivo triggers BEC-to- hepatocyte conversion to replenish the lost cell mass and restore liver functions, and that (Aim 2) VEGFA acts directly on BECs and/or indirectly on ECs that express VEGFR2. This study may have key clinical significance by establishing a treatment to prevent progression of the liver disease, by exploiting the alternative intrinsic regenerative ability of the liver via BEC-driven liver regeneration using clinically safe mRNA-LNPs.

项目概要/摘要肝病影响着全世界数亿人。肝移植仍然是唯一的治疗方法用于终末期肝病（ESLD）；然而，由于肝脏短缺，移植面临着巨大的负担捐助者。众所周知，肝脏通过肝细胞驱动的再生具有显着的再生能力，主要功能性肝细胞类型——肝细胞的增殖。然而，在 ESLD 中，肝细胞增殖变得筋疲力尽。治疗 ESLD 的另一种策略是通过胆道促进肝再生上皮细胞（BEC）驱动的再生作为一种新机制，可用作治疗靶点。 BEC 驱动的肝再生是 BEC 增殖并转变为肝祖细胞 (LPC) 的过程阶段，这一过程被定义为导管反应（DR），并分化为功能性肝细胞并恢复肝脏功能。 BEC 驱动的再生已在小鼠模型中得到实验证明，其中肝细胞在我们的斑马鱼模型中，肝细胞几乎完全消融后，增殖受到损害。观察几乎所有慢性和急性人类肝脏疾病中的 DR 以及来自 BEC 的出芽肝细胞人类肝硬化肝脏中的 BEC 驱动的修复发生在人类中，但分化为肝细胞的过程是不足以缓解肝脏疾病。因此，我们的目标是确定并测试一种可成药的途径触发 BEC 向肝细胞的转化，从而有效利用 BEC 治疗肝脏疾病。我们提出 VEGFA 促进 BEC 向肝细胞的转化并以互补的方式挽救肝功能小鼠和斑马鱼肝损伤模型。我们的初步数据表明，将 VEGFA 递送至受伤的通过与脂质纳米颗粒复合的非整合且安全的核苷修饰 mRNA 来研究小鼠肝脏 (mRNA-LNP) 诱导 BEC 向肝细胞的强劲转化以及脂肪变性和纤维化的逆转。而且，阻断 VEGFR2（VEGFA 的主要受体）或下游介质 PI3K/AKT 消除 BEC 驱动斑马鱼的肝脏再生，表明 VEGFR2/PI3K/AKT 轴的关键贡献。之前的研究研究表明，VEGFA 通过刺激内皮细胞 (EC) 上的 VEGFR2 来促进啮齿类动物的肝脏修复，诱导肝细胞有丝分裂原的分泌，从而驱动肝细胞驱动的修复。然而，它并没有被据报道，VEGFA 直接影响 BEC 进行 BEC 驱动的修复，我们的初步数据表明了这一点显示受损小鼠肝脏的 BEC 子集中 VEGFR2 诱导，其他人也报道了这一观察结果在受伤的老鼠身上。因此，我们的发现与其他人的研究相结合，使我们使用以下方法检验了 2 个假设：互补小鼠和斑马鱼肝损伤模型：（目标 1）体内 VEGFA 递送触发 BEC-to- 肝细胞转化以补充丢失的细胞量并恢复肝功能，并且（目标 2）VEGFA 发挥作用直接作用于 BEC 和/或间接作用于表达 VEGFR2 的 EC。这项研究可能具有重要的临床意义通过建立一种治疗方法来预防肝病的进展，通过利用替代内在的使用临床安全的 mRNA-LNP 通过 BEC 驱动的肝脏再生来增强肝脏的再生能力。