Recombinant human hepassocin stimulates proliferation of hepatocytes in vivo and improves survival in rats with fulminant hepatic failure
Recombinant human hepassocin stimulates proliferation of hepatocytes in vivo and improves survival in rats with fulminant hepatic failure
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DOI：
10.1136/gut.2008.171124
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发表时间：
2010-06-01
期刊：
影响因子：
24.5
通讯作者：
Yang, Xiao-Ming
中科院分区：
文献类型：
--
作者：
Li, Chang-Yan;Cao, Chuan-Zeng;Yang, Xiao-Ming
背景人肝蛋白酶（humanhepassocin，HPS）是一个在肝再生过程中表达显著上调的肝脏特异性基因，最初是通过消减和差异cDNA克隆技术发现的。以前的研究表明，HPS在体外对离体肝细胞具有促有丝分裂活性。然而，其在体内的功能仍然在很大程度上未知。方法采用[H-3]胸苷掺入法和增殖细胞核抗原（PCNA）免疫组织化学染色法，观察重组人HPS对原代肝细胞增殖的影响。进行RNA干扰以敲低HPS的内源性表达。MTS法检测L02细胞增殖情况;采用蛋白质印迹法检测细胞外信号调节激酶1/2（extracellular signal-regulated kinase 1/2）的磷酸化水平。肝损伤评估（组织学，血清丙氨酸氨基转移酶（ALT）和天冬氨酸氨基转移酶（AST）水平）和细胞凋亡，通过TUNEL（末端脱氧核苷酸转移酶介导的dUTP缺口末端标记）测定，结果纯化的重组人HPS在原代肝细胞和正常肝细胞系上显示出特异的促有丝分裂活性，并在丝裂原活化蛋白激酶（MAPK）-依赖性方式并刺激70%部分肝切除大鼠肝细胞增殖。在D-半乳糖和四氯化碳（CCl 4）处理后，向大鼠给予HPS可防止肝损伤（最小肝坏死，ALT和AST水平降低，致死率降低），减少细胞凋亡并增强增殖。结论HPS是一种肝生长因子，具有促进肝细胞增殖、保护肝细胞的作用。这些数据表明HPS在治疗暴发性肝功能衰竭中的潜在利益。
Background Human hepassocin (HPS) was originally detected by subtractive and differential cDNA cloning as a liver-specific gene that was markedly upregulated during liver regeneration. Previous studies suggested that HPS showed mitogenic activity on isolated hepatocytes in vitro. However, its in vivo functions remained largely unknown. Therefore, the function of recombinant human HPS during liver regeneration and chemically induced liver injury was investigated.Methods The proliferation of primary hepatocytes was examined by [H-3] thymidine incorporation and immunohistological staining of proliferating cell nuclear antigen (PCNA). RNA interference was performed to knock down the endogenous expression of HPS. The proliferation of L02 cells was examined by MTS assay. The phosphorylation of ERK1/2 (extracellular signal-regulated kinase 1/2) was investigated by western blotting analysis. Assessment of liver injury (histology, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels) and of apoptosis, by TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay, was performed.Results Purified recombinant human HPS showed specific mitogenic activity on primary hepatocytes and normal liver cell lines in a mitogen-activated protein kinase (MAPK)-dependent manner and stimulated the proliferation of hepatocytes in rats with 70% partial hepatectomy. Administration of HPS to rats after D-galactose and carbon tetrachloride (CCl4) treatment protected against liver injury (minimal liver necrosis, depressed ALT and AST levels, and decreased lethality), reduced apoptosis and enhanced proliferation. Knockdown of endogenous HPS in vivo enhanced the liver injury induced by D-galactose by increasing the apoptosis and elevating ALT and AST levels.Conclusions HPS is a hepatic growth factor which can accelerate hepatocyte proliferation in vivo and protect against liver injury. These data point to the potential interest of HPS in the treatment of fulminant hepatic failure.