慢性乙型肝炎病毒感染对人肝细胞色素酶P4502C9的影响

Effects of chronic hepatitis B virus infection on human hepatic cytochrome P450 2C9

目的探讨慢性HBV感染对人肝细胞色素酶P450 2C9（CYP2C9）的影响。方法收集慢性HBV感染者和健康对照者的肝组织和血液标本各10份，聚合酶链反应-限制性片段长度多态性（PCR—RFLP）检测CYP2C9基因型，高效液相色谱（HPLC）检测肝组织样本中CYP2C9酶活性。RT—PCR和Western印迹法测定肝组织样本中CYP2C9 mRNA和蛋白表达的差异，数据行t检验。结果20份样本均为野生型CYP2C9（＊1＊1），未检测到突变型基因。反映酶活力的指标最大反应速度（Vmax）在慢性HBV感染组为（40．4±10．4）pmol·mg^-1·min^-1，健康对照组为（52．6±13．4）pmol·mg^-1·min^-1（t=2．269，P=0．0367）；而酶特征性常数米氏常数（Km）分别为（263．5±66．4）μmol／L和（284．6±85．9）μmol／L（t=0．614，P=0．5471）。慢性HBV感染组和健康对照组CYP2C9 mRNA相对表达量分别为0．39±0．28和0．65±0．13（t=2．628，P=0．0171）；蛋白相对表达量分别为0．26±0．13和0．60±0．19（t=4．688，P=0．0002）。结论慢性HBV感染在mRNA和蛋白水平降低肝脏CYP2C9酶的表达，导致酶活性下降。

Objective To investigate the effects of chronic hepatitis B virus （HBV） infection on human hepatic cytochrome P450 2C9 （CYP2C9）. Methods Liver tissue samples and blood samples were obtained from 10 patients with chronic HBV infection and 10 healthy controls. CYP2C9 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method. The activity of CYP2C9 was detected utilizing high performance liquid chromatography （HPLC）. The expressions of CYP2C9 mRNA and protein were determined by reverse transcriptase-polymerase chain reaction （RT-PCR） and Western-blotting. The data were analyzed by t test. Results All the liver samples showed CYP2C9 wild-type （ ＊ 1＊ 1）, while CYP2C9 （ ＊ 2） and CYP2C9 （ ＊ 3） were not detected. The maximum velocity （Vmax） of CYP2C9 in patients with chronic HBV infection was （40.4±10.4） pmol·mg^-1·min^-1 and that of healthy controls was （52.6±13.4） pmol·mg^-1·min^-1（t=2. 269, P=0.036 7）. The enzyme specific Km values of chronic HBV infection and healthy controls were （263.5 ±66.4） μmol/L and （284. 6 ±85. 9） μmol/L, respectively （t=0. 614, P= 0. 547 1）. The expression of CYP2C9 mRNA in patients with chronic HBV infection （0.39±0.28） was significantly lower than that of healthy controls （0.65±0.13） （t=2. 628, P = 0. 017 1）. Accordingly, the protein expression in patients with chronic HBV infection （0.26±0. 13） was lower than that of healthy controls （0. 60±0. 19） （t=4.688, P=0.000 2）. Conclusion The expressions of CYP2C9 mRNA and protein are decreased in chronic HBV infection which may down-regulate the enzyme activity.