Molecular Mechanisms of Liver Fibrosis

肝纤维化的分子机制

• 批准号: 10612941
• 负责人: VIJAY H. SHAH
• 金额: $ 35.78万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10612941
• 关键词: Alcohol consumption; Alcohols; Attenuated; Beta Cell; Binding; Binding Proteins; Biological Assay; Cellular biology; Cirrhosis; Clustered Regularly Interspaced Short Palindromic Repeats; Data; Deposition; Development; EZH2 gene; Endosomes; Enhancers; Epigenetic Process; Etiology; Fibrosis; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Goals; Growth Factor; Hepatic Stellate Cell; Hi-C; Histones; Human; Image; In Vitro; Instruction; Insulin; Investigation; Knock-out; Liver; Liver Fibrosis; Lobule; Magnetic Resonance Elastography; Mediating; Modeling; Modification; Molecular; Morbidity - disease rate; Mus; PDGF receptor tyrosine kinase; Peptides; Platelet-Derived Growth Factor; Platelet-Derived Growth Factor alpha Receptor; Play; Population; Portal vein structure; Process; Production; Proliferating; Proteins; Receptor Signaling; Role; Signal Transduction; Signaling Protein; Techniques; Testing; Transferase; Transforming Growth Factor beta; Vesicle; cell motility; chromatin modification; epigenetic regulation; fibrogenesis; gene network; histone methylation; histone methyltransferase; in vivo; innovation; knock-down; liver injury; migration; mortality; mouse model; novel; parent grant; promoter; protein transport; recruit; single-cell RNA sequencing; therapeutic target; trafficking; transcriptome sequencing; Alcohol consumption; Alcohols; Attenuated; Beta Cell; Binding; Binding Proteins; Biological Assay; Cellular biology; Cirrhosis; Clustered Regularly Interspaced Short Palindromic Repeats; Data; Deposition; Development; EZH2 gene; Endosomes; Enhancers; Epigenetic Process; Etiology; Fibrosis; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Goals; Growth Factor; Hepatic Stellate Cell; Hi-C; Histones; Human; Image; In Vitro; Instruction; Insulin; Investigation; Knock-out; Liver; Liver Fibrosis; Lobule; Magnetic Resonance Elastography; Mediating; Modeling; Modification; Molecular; Morbidity - disease rate; Mus; PDGF receptor tyrosine kinase; Peptides; Platelet-Derived Growth Factor; Platelet-Derived Growth Factor alpha Receptor; Play; Population; Portal vein structure; Process; Production; Proliferating; Proteins; Receptor Signaling; Role; Signal Transduction; Signaling Protein; Techniques; Testing; Transferase; Transforming Growth Factor beta; Vesicle; cell motility; chromatin modification; epigenetic regulation; fibrogenesis; gene network; histone methylation; histone methyltransferase; in vivo; innovation; knock-down; liver injury; migration; mortality; mouse model; novel; parent grant; promoter; protein transport; recruit; single-cell RNA sequencing; therapeutic target; trafficking; transcriptome sequencing

Hepatic stellate cell (HSC) activation encompasses aphenotype that includes enhanced migration, proliferation, and matrix deposition. Migration is critical for coordinately situating HSC for matrix deposition and development of cirrhosis. Our Long-Term Objectives are to understand the molecular underpinnings of HSC biology that lead to cirrhosis with the goal of identifying therapeutic targets. Recently,we identified a critical role of synectin in the process of HSC migration and fibrosis. Synectin is a cytosolic protein that mediates signal transduction, vesicle trafficking, and ultimately gene expression. Synectin is chosen for this proposal as a significant protein warranting detailed investigation because, as we demonstrate, it is upregulated in human cirrhosis and is required for murine fibrogenesis. Mechanistically, we implicate synectin inHSC migration through both short term receptor signaling as well as longer term epigenetic regulation of gene expression networks. Our preliminary data show that depletion of HSC synectin reduces migration signaling downstream of the receptor tyrosine kinase, platelet derived growth factor receptor alpha (PDGFRα); attenuates transcription of a set of HSC activation genes including one that encodes the multifunctional signaling protein, IGFBP3 (insulin growth factor binding protein-3); and abrogates murine fibrosis in vivo. These important observations have led us to propose the central hypothesis that synectin increases HSC migration and fibrosis by promoting PDGFRα signaling and by regulating a network of genes that include IGFBP3. This hypothesis leads to the following Specific Aims: 1) Synectin promotes HSC migration by regulating PDGFRα targeting and signal activation. Aim 1a will determine how synectin recruits and binds specific vesicle trafficking proteins that maintain PDGFRα protein levels, target the protein to endosomes and activate migration signaling. Aim 1b will uncover how disruption of synectin function leads to autophagic degradation of PDGFRα and attenuated HSC migration. 2) Synectin epigenetically controls IGFBP3 gene expression to promote HSC migration. Aim 2a will identify how synectin regulates a specific histone methyl transferase, EZH2 and how this governs IGFBP3 gene expressionthrough histone methylation. Aim 2b will determine how IGFBP3 production stimulates HSC migration. 3) Synectin regulates fibrosis in vivo. Aim 3a will use a novel fibrosis regression model in mice with HSC selective modifications to synectin and PDGFRα to further ascertain the proposed role of these proteins in vivo. Aim 3b will use a synectin neutralizing peptide that selectively targets HSC in coordination with magnetic resonance elastography (MRE) imaging, and mice with genetic deletion of IGFBP3 to elucidate how synectin promotes fibrosis in vivo. In total, this proposal will utilize conceptually and technically innovative approaches and concepts to test a novel hypothesis pertaining to synectin as a “master regulator” of HSC signals that lead to migration and fibrosis. RELEVANCE (See instructions): Liver injury from alcohol and other etiologies can culminate in cirrhosis with significant associated morbidity and mortality.

肝星状细胞（HSC）激活包括包括增强的迁移的厌氧型 增殖和基质沉积。迁移对于协同位置HSC的矩阵沉积至关重要 和肝硬化的发展。我们的长期目标是了解 导致肝硬化的HSC生物学，目的是鉴定治疗靶标。最近，我们确定了 同步在HSC迁移和纤维化过程中的关键作用。合成素是一种胞质蛋白 介导信号翻译，囊泡运输和最终基因表达。为此选择合蛋白 提案是一项重要的蛋白质警告详细调查，因为正如我们所证明的那样， 在人肝硬化中上调，是鼠纤维发生所必需的。从机械上讲，我们暗示同步 INHSC通过短期受体信号传导以及长期表观遗传调节的迁移 基因表达网络。我们的初步数据表明，HSC同步的部署减少了迁移 受体酪氨酸激酶下游的信号传导，血小板衍生的生长因子受体α （PDGFRα）;减弱了一组HSC激活基因的转录，其中包括编码的HSC激活基因 多功能信号蛋白IGFBP3（胰岛素生长因子结合蛋白-3）；并废除鼠 体内纤维化。这些重要的观察结果使我们提出了同步的中心假设 通过促进PDGFRα信号传导和调节基因网络来增加HSC迁移和纤维化 其中包括IGFBP3。该假设导致以下特定目的：1）促素促进HSC 通过控制PDGFRα靶向和信号激活来迁移。 AIM 1A将确定同步素的新生 并结合维持PDGFRα蛋白水平的特定囊泡运输蛋白，将蛋白靶向 内体并激活迁移信号。 AIM 1B将发现同步函数的破坏导致 PDGFRα的自噬降解并减弱HSC迁移。 2）合成素表观遗传控制 IGFBP3基因表达以促进HSC迁移。 AIM 2A将确定如何同步特定 组蛋白甲基转移，EZH2及其如何控制IGFBP3基因表达。 甲基化。 AIM 2B将确定IGFBP3生产如何刺激HSC迁移。 3）合成蛋白调节 体内纤维化。 AIM 3A将使用HSC选择性修饰的小鼠中使用新型的纤维化回归模型 合成蛋白和PDGFRα进一步确定这些蛋白在体内提出的作用。 AIM 3B将使用 在与磁共振协调方面有选择地靶向HSC的同步肽 弹性图（MRE）成像和具有IGFBP3遗传缺失的小鼠，以阐明同步如何促进 体内纤维化。总的来说，该提案将在概念和技术上创新的方法以及 测试与同步为HSC信号的“主调节器”有关的新假设的概念 迁移和纤维化。 相关性（请参阅说明）： 酒精和其他病因造成的肝损伤可以达到肝硬化，并具有显着相关的发病率 和死亡率。