外周血单个核细胞诱导为肝细胞样细胞及初步探讨对乙酰氨基酚作用下的细胞损伤反应

Induction of peripheral blood mononuclear cells to hepatocyte-Iike cells and preliminary study of cell response to injury under the effect of acetaminophen

目的建立外周血单个核细胞诱导肝细胞样细胞的方法,初步探讨其在对乙酰氨基酚(APAP)作用下的细胞损伤反应。方法流式细胞术和免疫荧光法检测外周血分离的单个核细胞表面标志CD45;针对诱导的肝细胞样细胞,倒置显微镜观察细胞形态,实时荧光定量PCR(RT-PCR)检测肝细胞特异性基因细胞色素P450(CYP)1A2、CYP3A4、CYP2C9、白蛋白(ALB)、甲胎蛋白(AFP)、肝细胞核因子(HNF)4α mRNA的表达水平;免疫荧光法检测肝细胞标志物AFP、HNF4α、ALB在细胞中蛋白的表达水平,生化分析仪检测肝细胞特有的AFP、ALB、尿素的分泌功能,荧光素酶化学发光法检测肝细胞关键药物代谢酶CYP3A4酶活性;肝损伤药物APAP作用肝细胞样细胞后,比色测定法检测肝细胞损伤指标丙氨酸转氨酶(ALT)。采用t检验与秩和检验比较数据间的统计学差异。结果外周血分离的单个核细胞表面标志CD45表达阳性率约98%,诱导第15天细胞形态出现肝细胞样变化;与分离的单个核细胞相比,CYP1A2、CYP3A4、CYP2C9、ALB、AFP、HNF4α mRNA明显升高,AFP、ALB,HNF4α蛋白表达水平均升高,AFP、ALB,尿素的分泌功能增强;与原代肝细胞相比CYP1A2、CYP2C9、AFP、HNF4α mRNA,CYP3A4 mRNA无降低,ALB mRNA较低,AFP、ALB、HNF4α蛋白在细胞中的表达水平无降低,AFP、ALB,尿素的分泌功能无降低。此外肝细胞样细胞产生了与原代肝细胞相似的CYP3A4酶活性;APAP孵育较不含APAP孵育的肝细胞样细胞会释放更多的ALT;在APAP作用下肝细胞样细胞相比分离的单个核细胞ALT释放增加。结论外周血单个核细胞能诱导为具有肝细胞部分特性的肝细胞样细胞,通过诱导具有了肝细胞关键药物代谢酶CYP3A4活性,肝损伤药物APAP作用下,肝细胞样细胞初步体现了肝细胞损伤时ALT分泌的特征。

Objective To establish a method for the induction of peripheral blood mononuclear cells to hepatocyte-likc cells,and preliminarily investigate cell response to injury under the effect of acetaminophen(APAP).Methods The surface marker CD45 of peripheral blood mononuclear cells wase detected cells by using flow cytometry and immunofluorescence methods.The cellular morphology of induced hepatocyte-like cells was observed under an inverted microscope.Real-time fluorescent quantitative PCR(RT-PCR)was used to detect the expression level of hepatocyte-specific genes,such as cytochrome(CY)PI A2,CYP3A4,CYP2C9,albumin(ALB),alpha-fetoprotein(AFP),and hepatocyte nuclear factor(HNF)4a mRNA.Immunofluorescence method was used to detect intracellular hepatocyte markers AFP,HNF4a,and ALB expression at the protein level.Biochemical analyzer was used to detect hepatocyte-specific secretory functions of AFP,ALB,and urea.Luciferase chemiluminescence method was used to detect the activity of key drug metabolizing enzyme CYP3A4.Colorimetric assay was used to detect the effect of the drug acetaminophen on hepatocyte-like cells,and alanine aminotransferase(ALT)was used as an indicator of liver cell injury.The statistical differences between the data were compared with t-test and rank-sum test.Results The positive expression rate of CD45 cell surface markers isolated from peripheral blood mononuclear cells was about 98%,and hepatocyte-like cell morphology changes appeared on 15th day of induction.Compared with isolated mononuclear cells,CYP1A2,CYP3A4,CYP2C9,ALB,AFP and HNF4a mRNA was markedly elevated.The expression level of AFP,ALB and HNF4a protein were equally increased,and the secretory function of AFP,ALB and urea were enhanced.Compared with primary hepatocytes,CYP1A2,CYP2C9,AFP,HNF4a mRNA,and CYP3A4 mRNA did not decrease.The expression levels of AFP,ALB.and HNF4a proteins in the cells did not decrease,and the secretory function of AFP,ALB,and urea did not decrease.In addition,the CYP3A4 enzyme activity produced by hepatocyte-likc cells was similar to that of primary hepatocytes.Compared with hepatocyte-like cells incubated without APAP,hepatocyte-like cells incubated with APAP had higher ALT level.Under the effect of APAP,the ALT level of hepatocyte-like cells was higher than isolated mononuclear cells.Conclusion Peripheral blood mononuclear cells can be induced into hepatocyte-like cells with partial characteristics of hepatocytes,including the activity of CYP3A4,a key enzyme of hepatocyte drug metabolism.Additionally,preliminarily ALT secretory features reflect the hepatocytes injury under the effect of acetaminophen.