Biliary Epithelial Cell-derived SDF-1a in Hepatic Fibrogenesis and Inflammation

胆管上皮细胞衍生的 SDF-1a 在肝纤维形成和炎症中的作用

• 批准号: 8585054
• 负责人: Yedidya Saiman
• 金额: $ 3.25万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-17 至 2014-06-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8585054
• 关键词: Animals; Bile Acids; Biliary; Bone Marrow; CXCL12 gene; CXCR4 Receptors; CXCR4 gene; Cells; Cellular biology; Cessation of life; Characteristics; Chemotaxis; Chronic; Cirrhosis; Coculture Techniques; Collagen; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Etiology; Fibrosis; Gene Delivery; Goals; Hematopoietic stem cells; Hepatic; Hepatic Fibrogenesis; Hepatic Stellate Cell; Hepatitis C virus; Histopathologic Grade; Hydroxyproline; Hypoxia; In Vitro; Infiltration; Inflammation; Inflammatory; Inflammatory Infiltrate; Injury; Ligation; Link; Liver; Liver Failure; Liver Fibrosis; Liver diseases; Lymphocyte; Measures; Mediating; Messenger RNA; Modeling; Molecular; Mus; Neoplasm Metastasis; Organ Donor; Pathogenesis; Pathway interactions; Patients; Plasma; Plasma Proteins; Plasmids; Process; Proteins; Reactive Oxygen Species; Role; Site; Staging; Staining method; Stains; Stromal Cell-Derived Factor 1; Stromal Cells; System; Testing; Tissues; Up-Regulation; Western Blotting; angiogenesis; base; bile duct; chemokine; fibrogenesis; inflammatory marker; inhibitor/antagonist; injured; liver injury; liver transplantation; migration; mouse model; neutralizing antibody; platelet-derived growth factor BB; public health relevance; regenerative; small molecule; stellate cell

DESCRIPTION (provided by applicant): Regardless of the etiology, fibrosis is the final common pathway for chronic liver injury and failure. Fibrosis with subsequent complications of cirrhosis results in the death of patients with end stage liver disease if liver transplantation is not performed. As a result of the liver's unique regenerative capacity, progression to severe complications is a slow process often spanning decades. Slowing the progression of fibrosis will therefore have significant long-term benefit and mandates a greater understanding of the molecular and cellular basis of hepatic fibrosis. Stromal cell derived factor-11 (SDF-11/CXCL12), is a chemokine that promotes retention of hematopoietic stem cells in the bone marrow, cancer metastasis, angiogenesis and migration of lymphocytes to sites of injury through interactions with its receptor, CXCR4. Hepatic stellate cell (HSC) activation is central feature of fibrosis in all forms of chronic liver injury and we have established that HSCs express functional CXCR4 receptor and its engagement by SDF-11 induces cellular activation, collagen I expression, and proliferation, providing a direct link between SDF-11 and liver disease pathogenesis. The hepatic expression of SDF-11 is predominantly localized to biliary epithelial cells (BECs). During liver injury, BECs undergo marked proliferation associated with elevated hepatic and plasma protein levels of SDF-11. Importantly, plasma levels of SDF-11 correlate with increased liver fibrosis in patients with chronic HCV, indicating an important relationship to fibrosis. Interestingly, nearly all lymphocyte infiltration into the injured liver is localized to the SDF-11-expressing periportal region, indicating an additional role for SDF-11 in lymphocyte migration to the liver. Therefore I propose that BEC-derived SDF-11 promotes fibrosis by activation of hepatic stellate cells and mediates hepatic inflammation via recruitment of inflammatory cells. The aims of this proposal are: 1) To determine the importance of the SDF-11/CXCR4 axis in promoting hepatic fibrosis and inflammation in mechanistically distinct mouse models of liver injury (BDL and CCl4) by blocking the SDF-11/CXCR4 (SDF-11 neutralizing antibody or CXCR4 small molecule inhibitor). Fibrosis will be assessed using Sirius Red staining for collagen/morphometric analysis, hydroxyproline quantitation, and qRT-PCR for fibrogenic markers and inflammation will be assessed by histologic grading and characteristics of inflammatory infiltrate will be analyzed using FACS for cell-specific markers. 2) To evaluate the factors leading to increased SDF-11 expression by BECs by measuring mRNA and protein levels of SDF-11 in culture stimulated BECs and to determine whether BEC produced SDF-11 is sufficient to promote HSC biology in in vitro co-culture models. PUBLIC HEALTH RELEVANCE: Fibrosis with subsequent complications of cirrhosis results in the death of patients with end stage liver disease if liver transplantation is not performed. Given the shortage of donor organs there is an urgent need to develop effective anti-fibrotic treatments. The results from this proposal will help us understand the molecular basis of the fibrotic liver and reveal the feasibility modulating of the SDF-11/CXCR4 axis as an anti-fibrotic strategy.

描述(申请人提供)：无论病因如何，纤维化是慢性肝损伤和衰竭的最终共同途径。如果不进行肝移植，纤维化和随后的肝硬变并发症会导致终末期肝病患者的死亡。由于肝脏独特的再生能力，进展到严重并发症是一个缓慢的过程，通常需要数十年的时间。因此，减缓纤维化的进展将具有重大的长期益处，并要求对肝纤维化的分子和细胞基础有更多的了解。基质细胞衍生因子-11(SDF-11/CXCL12)是一种趋化因子，通过与其受体CXCR4相互作用，促进造血干细胞在骨髓中的滞留、肿瘤转移、血管生成和淋巴细胞向损伤部位的迁移。肝星状细胞(HSC)的活化是各种形式慢性肝损伤纤维化的主要特征，我们已经证实HSC表达功能性的CXCR4受体，SDF-11参与其诱导细胞激活、I型胶原表达和增殖，提供了SDF-11与肝病发病机制之间的直接联系。SDF-11在肝脏中的表达主要定位于胆管上皮细胞。在肝损伤期间，BEC经历了与肝脏和血浆SDF-11蛋白水平升高相关的显著增殖。重要的是，血浆SDF-11水平与慢性丙型肝炎患者肝纤维化的增加相关，表明与纤维化有重要关系。有趣的是，几乎所有渗入受损肝脏的淋巴细胞都定位于表达SDF-11的门脉周围区域，这表明SDF-11在淋巴细胞迁移到肝脏中发挥了额外的作用。因此，我认为BEC来源的SDF-11通过激活肝星状细胞来促进纤维化，并通过募集炎症细胞来介导肝脏炎症。本研究的目的是：1)通过阻断SDF-11/CXCR4(SDF-11中和抗体或CXCR4小分子抑制物)，确定SDF-11/CXCR4轴在通过阻断SDF-11/CXCR4(SDF-11中和抗体或CXCR4小分子抑制物)在不同机制的小鼠肝损伤模型(BDL和CCl4)促进肝纤维化和炎症中的重要性。纤维化将使用天狼星红染色进行胶原/形态计量分析、羟脯氨酸定量和qRT-PCR进行纤维化标志物的评估，炎症将通过组织学分级进行评估，炎症浸润物的特征将使用流式细胞仪进行细胞特异性标志物的分析。2)通过检测体外培养刺激的BECs中SDF-11的mRNA和蛋白水平，探讨导致BECs SDF-11表达增加的因素，并在体外共培养模型中确定BEC产生SDF-11是否足以促进HSC的生物学行为。 公共卫生相关性：如果不进行肝移植，纤维化和随后的肝硬变并发症会导致终末期肝病患者的死亡。鉴于供体器官的短缺，迫切需要开发有效的抗纤维化治疗方法。这项研究的结果将有助于我们理解肝纤维化的分子基础，并揭示SDF-11/CXCR4轴作为一种抗纤维化策略的可行性。