肝细胞凋亡可通过 TIMP1 途径调节肝纤维化。

Hepatic apoptosis can modulate liver fibrosis through TIMP1 pathway.

机构信息

Departments of Surgery, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL, 61605, USA.

出版信息

Apoptosis. 2013 May;18(5):566-77. doi: 10.1007/s10495-013-0827-5.

Abstract

Apoptotic injury participates in hepatic fibrosis, but the molecular mechanisms are not well understood. The present study aimed to investigate the role of inducible TIMP1 in the pathogenesis of hepatic apoptosis-fibrosis. Apoptosis was induced with GCDC, LPS, and alcohol in precision-cut liver slices or bile duct ligation (BDL) in rats, as reflected by caspase-3 activity, TUNEL assay, and apoptosis-related gene profiles. The hepatic fibrosis was detected with Picrosirius staining, hydroxyproline determination, and expression profiling of fibrosis-related genes. Levels of TIMP1 were upregulated by the hepatic apoptosis, but downregulated by caspase inhibitor. The inducible TIMP1 was apoptosis-dependent. Once TIMP1 was inhibited with treatment of TIMP1-siRNA, the fibrotic response was reduced as demonstrated by hydroxyproline assay. In addition, the expression of fibrosis-related genes aSMA, CTGF, and TGFb2r were down-regulated subsequent to the treatment of TIMP1-siRNA. TIMP1 could mediate the expression of fibrosis-related genes. TIMP1 was transcriptionally regulated by nuclear factor c-Jun as demonstrated by EMSA and ChIP assay. The treatment of c-Jun siRNA could significantly decrease the expression of TIMP1 induced by alcohol, GCDC, or LPS treatment. Hepatic apoptosis induces the expression of TIMP1. Inducible TIMP1 can modulate the expression of fibrosis-related genes in liver. TIMP1 pathway is a potential target for therapeutic intervention of fibrotic liver diseases.

摘要

细胞凋亡损伤参与肝纤维化，但其中的分子机制尚不清楚。本研究旨在探讨诱导型 TIMP1 在肝细胞凋亡-纤维化发病机制中的作用。采用 GCDC、LPS 和酒精诱导原代肝切片或胆管结扎（BDL）大鼠细胞凋亡，通过 caspase-3 活性、TUNEL 检测和凋亡相关基因谱反映细胞凋亡；采用天狼星红染色、羟脯氨酸测定和纤维化相关基因表达谱检测肝纤维化。肝细胞凋亡可上调 TIMP1 水平，但 caspase 抑制剂可下调 TIMP1。诱导型 TIMP1 是凋亡依赖性的。用 TIMP1-siRNA 处理抑制可诱导型 TIMP1 后，羟脯氨酸测定显示纤维化反应降低。此外，TIMP1-siRNA 处理后，纤维化相关基因 aSMA、CTGF 和 TGFb2r 的表达下调。TIMP1 可介导纤维化相关基因的表达。EMSA 和 ChIP 检测显示 TIMP1 的转录受核因子 c-Jun 调控。c-Jun siRNA 处理可显著降低酒精、GCDC 或 LPS 处理诱导的 TIMP1 表达。肝细胞凋亡诱导 TIMP1 表达。诱导型 TIMP1 可调节肝纤维化相关基因的表达。TIMP1 途径是治疗纤维化性肝病的潜在靶点。