中文摘要：

目的 探讨丙型肝炎病毒（HCV）核心（core）蛋白对诱导型一氧化氮合酶（iNOS）基因启动子转录的激活作用。方法 利用生物信息学技术确定iNOS基因的启动子区域（iNOSp），聚合酶链反应（PCR）扩增iNOSp的DNA，克隆至真核报告载体pCAT3-Basic中，构建pCAT3-iNOSp报告载体；以该质粒转染正常人肝细胞LO2，用酶联免疫吸附法（ELISA）检测氯霉素乙酰转移酶（CAT）的表达活性；并与HCV核心蛋白的真核表达载体pcDNA3．1（-）-core共转染LO2细胞，用ELISA法检测CAT的表达活性。结果 成功获得iNOS基因启动子的正确克隆，pCAT3-iNOSp和pcDNA3．1（-）core瞬时共转染LO2细胞时，报告基因表达载体中的SV40病毒的即刻早期启动子的转录活性明显提高，CAT表达活性是pCAT3-Basic空载体的11倍，是pCAT3-iNOSp的6倍，重复试验得到了相似的结果。结论 成功克隆的iNOS启动子有转录活性；HCV核心蛋白具有对iNOS基因启动子的反式激活作用。HCV核心蛋白在细胞内的表达对于iNOS基因反式激活在HCV感染相关的慢性肝脏疾病的发病过程中具有重要意义。

英文摘要：

Objective To investigate the transactivating effect of hepatitis C virus（HCV） core protein on inducible nitric oxide synthase （iNOS） gene promoter and the molecular biological mechanisms of HCV pathogenesis. Methods Polymerase chain reaction（PCR）technique was employed to amplify the sequence of iNOS promoter by using HepG2 genomic DNA as template,and the product was cloned into pGEM-T vector. The iNOSp gene was cut from T iNOSp by Kpn Ⅰ and Xho Ⅰ ,and then was cloned into pCAT3 Basic, the constructed vector was named as pCAT3-iNOSp, pCAT3 iN OSp was transfected into the LO2 cell line. LO2 cell was also cotransfected with pcDNA3. 1 （-）-core and pCAT3 iNOSp by FuGENE 6 transfection reagents. The LO2 cells transfected with pCAT3-Basic was used as negative control. The activity of CAT in LO2 cells was detected by an ELISA kit after 48 hours, which reflected the transactivating function of HCV core protein to iNOS gene promoter. Results The expressive vector pcDNA3.1（-）-core and report vector pCAT3-iNOSp had been construc ted and confirmed by restriction enzyme digestion and sequencing. The expression of CAT in LO2 cells transfected with pCAT3-iNOSp and pcDNA3. 1 （-）-core was 11 times as higher as that of pCAT3-basic, and 6 times as higher as that of pCAT3-iNOSp. Conclusion It is suggested that HCV core protein can transactivate iNOS gene promoter.