中文摘要：

目的研究肝再生增强因子（ALR）保护急性肝损伤的作用及其机制。方法HL-7702细胞分为正常对照组、CCl4急性肝损伤组、ALR＋CCl4干预组、3-甲基腺嘌呤（3-MA）＋CCl4干预组以及ALR＋3-MA＋CCl4干预组，CCl4处理前8h对ALR＋CCl4和ALR＋3-MA＋CCl4干预组转染ALR质粒，对除正常对照组外其余四组给予CCl4处理，30min后对3-MA＋CCl4和ALR＋3-MA＋CCl4干预组给予3-MA处理，CCl4处理24h后收集细胞。收集HL-7702细胞和培养上清液，检测丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）水平；Westernblot检测细胞中ALR、细胞周期蛋白D、细胞周期蛋白E、增殖细胞核抗原（PCNA）、自噬相关基因7（Atg7）和自噬基因LC3、p62、Beclin-1水平；实时定量PCR检测ALRmRNA水平。多组样本均数的两两比较采用One-wayANOVA分析。结果ALR＋CCl4干预组与急性肝损伤组相比，ALR蛋白以及mRNA表达水平显著升高（P值均〈0．05）；CCl4急性肝损伤组与正常对照组相比，ALR蛋白以及mRNA表达水平同样显著升高（P值均〈0．05）。ALR＋CCl4干预组与CCl4急性肝损伤组相比，细胞上清液中ALT（0．73±0．17与1．43±0．38，P值均〈0．05）、AST（19．85±1．83与56．73±6．25，P值均〈0．05）水平显著降低（单位均为IU／L）；肝细胞中再生相关细胞周期蛋白D、细胞周期蛋白E、PCNA表达水平以及自噬相关LC3、Atg7、Beclin-1表达水平显著增高，P62表达水平显著降低，提示ALR可以保护急性肝损伤，促进肝细胞的再生，增强肝细胞的自噬水平。ALR＋3-MA＋CCl4干预组再生相关蛋白的表达水平相较于ALR＋CCl4干预组明显降低，与3-MA＋CCl4干预组相比无明显差异，提示抑制自噬后，肝细胞再生水平明显下降，ALR促进肝再生的作用也明显减弱。结论ALR可以促进肝脏实质细胞再生，这种再生是通过调节自噬完成的。

英文摘要：

Objective To investigate the protective effect of augmenter of liver regeneration （ALR） against acute liver injury and related mechanisms. Methods HL-7702 cells were divided into normal control group, carbon tetrachloride （CCl4）-induced acute liver injury group, ALR＋CCl4 intervention group, 3-methyladenine （3-MA）＋CCl4 intervention group, and ALR＋3-MA＋CCl4 intervention group. The ALR＋CCl4 and ALR＋3-MA＋CCl4 intervention groups were transfected with ALR plasmids at 8 hours before CCl4 treatment. All groups except the normal control group were treated with CCl4, and 30 minutes later, the 3-MA＋CCl4 and ALR＋3-MA＋CCl4 intervention groups were treated with 3-MA. The cells were collected at 24 hours after CCl4 treatment. The HL-7702 cells and supematant were collected to measure the levels of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） （IU/L）. Western blot was used to measure the levels ofALR, cyclin D, cyclin E, proliferating cell nuclear antigen （PCNA）, autophagy-related gene 7 （Atg7）, and autophagy genes LC3, p62, and Beclin-1. Quantitative real-time PCR was used to measure the mRNA expression ofALR. A one- way analysis of variance was used for comparison of means between any two groups. Results The ALR＋CCl4 intervention group had significant increases in the protein and mRNA expression of ALR compared with the acute liver injury group （both P 〈 0.05）. The CCl4-induced acute liver injury group had significant increases in the protein and mRNA expression of ALR compared with the normal control group （both P 〈 0.05）. Compared with the CCl4-induced acute liver injury group, the ALR＋CCl4 intervention group had significant reductions in ALT （0.73±0.17 IU/L vs 1.43±0.38 IU/L, P 〈 0.05） and AST （19.85±1.83 IU/L vs 56.73±6.25 IU/L, P 〈 0.05） in supematant, significantly increased expression of cyclin D, cyclin E, PCNA, LC3, Atg7, and Beclin-1 in hepatocytes, and significantly reduced expression of p62, which suggested th