Cellular Mechanisms of Matrix Regulation in Liver Repair

肝脏修复中基质调节的细胞机制

• 批准号: 7072336
• 负责人: THOMAS F TRACY
• 金额: $ 25.71万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7072336
• 关键词: Kupffer' s cell; RNase protection assay; SDS polyacrylamide gel electrophoresis; cell growth regulation; collagenase; cytokine; enzyme activity; extracellular matrix; fibrosis; gene expression; growth factor receptors; hepatocyte growth factor; immunocytochemistry; injury; laboratory rat; laser capture microdissection; liver regeneration; macrophage; messenger RNA; metalloendopeptidases; northern blottings; polymerase chain reaction; postmortem; tissue /cell culture; tissue inhibitor of metalloproteinases

DESCRIPTION (provided by applicant)At critical points in chronic liver injury the potential for liver repair is lost. Timely surgical and medical treatment however, initiates liver repair interrupting the cycle of inflammation and hepatic fibrosis. The subsequent cellular regulation of matrix protein degradation and resolution of injury dependent fibrosis is unknown. The long-term goals of our studies are to define the molecular mechanisms required for ordered matrix resorption and liver repair without scar. Specific aims have been designed to test the hypothesis that repair, resolution of scar, and the restoration of hepatic architecture depend on coordinated regulatory mechanisms of matrix degradation through matrix metalloproteinase (MMP) and tissue inhibitor of MMP (TIMP) gene expression, cellular localization and most importantly, biologic activity. Further, we propose that Kupffer cells (KC), the resident macrophage population, have a central role in the inflammatory and fibrogenic regulation of liver repair after chronic injury. Specific Aim 1 addresses the molecular and cellular mechanisms of reversible hepatic fibrosis and those of delayed matrix resorption. A unique rat model of reversible biliary obstruction will simulate early, intermediate, and late, near end stage cholestatic liver injury. This model allows biliary decompression to initiate liver repair. [The effect of injury duration on key matrix (collagen I and III, laminin), MMP (1,2,8,9) and TIMP (1,2) mRNA and protein expression will be measured in whole liver and in [individual] cells using new methods of laser capture microdissection. [These data will demonstrate the mechanism and physiology of matrix resorption through measurement of MMP activity by in-gel and in-situ zymography]. Specific Aim 2 tests the hypothesis that KC are in vivo regulators of matrix metabolism. Through strategies of KC depletion/ inactivation by gadolinium or Dexa-Man10-HSA targeted dexamethasone during repair, matrix resorption, regulatory cytokine profiles and MMP-TIMP activity will be localized in cells and measured. In Specific Aim 3 we will establish the effect of progressive injury on the in vitro capacity of isolated hepatic macrophages (MPh) to express specific MMP and fibrogenic/ antifibrogenic cytokine (TGFbeta, IL1, 6, 10) profiles during repair. KC inactivation and MMP stimulation/ suppression strategies will isolate the net collagenolytic activity of MPh. [In addition to the broad clinical implications for the treatment of cholestatic or other chronic liver diseases in infants, children, and adults, these studies may be the first to identify key molecular mechanisms for successful repair after progressive liver injury. They have the unique potential to yield targets for therapy to promote liver repair or rescue patients approaching end stage liver disease

描述（由申请人提供） 在慢性肝损伤的关键时刻，肝脏修复的潜力丧失。然而，及时的手术和药物治疗可以启动肝脏修复，中断炎症和肝纤维化的循环。基质蛋白降解和损伤依赖性纤维化消退的后续细胞调节尚不清楚。我们研究的长期目标是确定有序基质吸收和无疤痕肝脏修复所需的分子机制。我们设计了具体的目标来检验以下假设：修复、疤痕消退和肝结构恢复取决于通过基质金属蛋白酶 (MMP) 和 MMP 组织抑制剂 (TIMP) 基因表达、细胞定位和最重要的是，生物活性。此外，我们提出库普弗细胞（KC），常驻巨噬细胞群，在慢性损伤后肝脏修复的炎症和纤维形成调节中发挥核心作用。具体目标 1 解决可逆性肝纤维化和延迟基质吸收的分子和细胞机制。独特的可逆性胆道梗阻大鼠模型将模拟早期、中期、晚期、近终末期胆汁淤积性肝损伤。该模型允许胆道减压以启动肝脏修复。 [将在整个肝脏和[个体]中测量损伤持续时间对关键基质（胶原蛋白 I 和 III、层粘连蛋白）、MMP (1,2,8,9) 和 TIMP (1,2) mRNA 和蛋白质表达的影响使用激光捕获显微切割新方法的细胞。 [这些数据将通过凝胶内和原位酶谱法测量 MMP 活性来证明基质吸收的机制和生理学]。具体目标 2 检验 KC 是体内基质代谢调节剂的假设。通过在修复过程中使用钆或 Dexa-Man10-HSA 靶向地塞米松进行 KC 消耗/失活策略，基质吸收、调节性细胞因子谱和 MMP-TIMP 活性将定位在细胞中并进行测量。在具体目标 3 中，我们将确定进行性损伤对修复过程中分离的肝巨噬细胞 (MPh) 表达特定 MMP 和纤维形成/抗纤维形成细胞因子（TGFbeta、IL1、6、10）特征的体外能力的影响。 KC 失活和 MMP 刺激/抑制策略将隔离 MPh 的净胶原蛋白溶解活性。 [除了对治疗婴儿、儿童和成人胆汁淤积或其他慢性肝病具有广泛的临床意义外，这些研究可能是第一个确定进行性肝损伤后成功修复的关键分子机制的研究。它们具有独特的潜力，可以产生促进肝脏修复或挽救接近终末期肝病患者的治疗目标

项目成果

Repair after cholestatic liver injury correlates with neutrophil infiltration and matrix metalloproteinase 8 activity.

胆汁淤积性肝损伤后的修复与中性粒细胞浸润和基质金属蛋白酶 8 活性相关。

• 发表时间: 2005-08
• 作者: Harty, Mark W;Huddleston, Hannah M;Papa, Elaine F;Puthawala, Tauquir;Tracy, Aaron P;Ramm, Grant A;Gehring, Stephan;Gregory, Stephen H;Tracy Jr, Thomas F
• 通讯作者: Tracy Jr, Thomas F

Hepatic macrophages promote the neutrophil-dependent resolution of fibrosis in repairing cholestatic rat livers.

肝巨噬细胞在修复胆汁淤积的大鼠肝脏中促进中性粒细胞依赖性纤维化消退。

• 发表时间: 2008-05
• 影响因子: 3.8
• 作者: Harty, Mark W;Papa, Elaine F;Huddleston, Hannah M;Young, Ezekiel;Nazareth, Samantha;Riley, Charles A;Ramm, Grant A;Gregory, Stephen H;Tracy Jr, Thomas F
• 通讯作者: Tracy Jr, Thomas F

Dexamethasone alters the hepatic inflammatory cellular profile without changes in matrix degradation during liver repair following biliary decompression.

地塞米松改变肝脏炎症细胞特征，但在胆道减压后的肝脏修复过程中不改变基质降解。

• 发表时间: 2009-10
• 作者: Muratore, Christopher S;Harty, Mark W;Papa, Elaine F;Tracy Jr, Thomas F
• 通讯作者: Tracy Jr, Thomas F

Neutrophil depletion blocks early collagen degradation in repairing cholestatic rat livers.

中性粒细胞耗竭可阻止修复胆汁淤积的大鼠肝脏中的早期胶原蛋白降解。

• 发表时间: 2010-03
• 作者: Harty, Mark W;Muratore, Christopher S;Papa, Elaine F;Gart, Michael S;Ramm, Grant A;Gregory, Stephen H;Tracy Jr, Thomas F
• 通讯作者: Tracy Jr, Thomas F