血管紧张素Ⅱ对肝星状细胞基因表达的影响

The effects of angiotensinⅡon gene expression of hepatic stellate cells

目的观察血管紧张素Ⅱ对培养肝星状细胞(HSC)株LX2细胞基因表达的影响。方法以1×10^(-5)mol/L的血管紧张素Ⅱ与LX2细胞孵育48 h,对照组不加血管紧张素Ⅱ。收集实验组和对照组细胞,分别提取mRNA及总蛋白质,进行抑制性消减杂交和蛋白质双向电泳及质谱分析。结果抑制性消减杂交产物经两轮聚合酶链反应(PCR)扩增,结果显示为200～1000 bp大小不等的插入片段,挑选36个克隆测序,应用生物信息学技术分析,发现13个克隆与未知基因序列高度同源,其中GenBank号为BC097361、BC057380的基因为具有开放读码框架的完整基因。其余23个克隆均与已知基因的部分序列高度同源(98%～100%),主要相关基因包括β肌动蛋白、亮氨酰tRNA合成酶、基础免疫球蛋白2、丙酮酸激酶,过氧化物酶1、人类白细胞抗原-B关联转录物3等。在血管紧张素Ⅱ孵育的和阴性对照HSC的双向电泳图谱中分别探测到1110、1008个点,两个图谱有504个点匹配。其中108个点和对照相比明显上调(容积比＞1．5),153个点和对照相比明显下调(容积比＜0．67),选取其中相对容积上调的10对点进行质谱分析,其中8个点在数据库中检索得到相应结果,分别为抑素、电子转移黄索蛋白亚单位、超氧化物歧化酶2、三磷酸核苷酶等。结论血管紧张素Ⅱ处理后的HSC mRNA表达上调具有增殖加速、凋亡抑制和促进分化等生物学作用,部分上调蛋白质为细胞内信号传导蛋白质、代谢调控蛋白质、细胞凋亡抑制蛋白质以及纤维化相关调控蛋白质。

Objective Our previous investigation demonstrated that angiotensin Ⅱ could induce proliferation and differentiation of hepatic stellate cells, and also could up-regulate its extracellular matrix synthesis. The objective of this study was to determine the effects of 10^-5 mol/L angiotensin Ⅱ on gene expression of hepatic stellate cells. Methods After incubation with 10^-5 mol/L angiotensin Ⅱ for 48 hours, the cultured hepatic stellate cells were collected. The mRNA and total protein were obtained from cell lysate and then suppression subtractive hybridization （SSH）, 2D-gel electrophoresis and MALDI-TOF mass spectrometry were used to identify these cDNAs and proteins. Results A total of 36 clones from the subtracted cDNA library were sequenced and compared to sequences in the GenBank using BLAST. Of the 36 differentially expressed gene fragments from the subtracted library, 13 differentially expressed gene fragments showed significant homology to other known proteins, such as ribosomal protein, 15 -actin FE-3, leucyl-tRNA synthetase, CD147, pyruvate kinase, peroxiredoxin 1, and BAT3, while 2 other gene fragments encoding protein BC097361 and BC057380 and their functions were not disclosed. About 1110 and 1008 protein spots were detected by employing the ImageMaster 2D Platinum 4.9 proteome image analysis system in angiotensin-treated hepatic stellate cells and control cells separately. Among these spots 108 proteins were up- regulated while the other 153 proteins were down-regulated. Several up-regulated proteins were chosen to be excised and in-gel digest MALDI-TOF-MS and Database analysis showed that among the high expression proteins, there were prohibitin, RBL- NDP kinase 1.8 × 10^4 subunit, electron transfer flavoprotein alpha-subunit, guanine nucleotide binding protein, alpha 15, and heat shock 7.0 × 10^4 protein 5. Conclusion Our results suggest that the up-regulation of hepatic stellate cell mRNA influences proliferation, differentiation and apoptosis of those cells. The proteins of signal transduction, metabolizing regulation, apoptosis suppression, and fibrogenesis regulation of hepatic stelllate cells were up-regulated.