CHOP在妊娠期肝内胆汁淤积症新生鼠心肌细胞表达水平变化

Changes of CHOP Expression in Neonatal Rat Cardiomyocytes with Intrahepatic Cholestasis of Pregnant Rats

目的探讨CHOP在孕鼠妊娠期肝内胆汁淤积症(ICP)胎鼠心肌细胞表达水平变化及意义。方法健康清洁级孕龄14 d的SD大鼠随机分成ICP组和对照组,ICP组利用17α-乙炔基雌二醇诱导建立ICP大鼠模型,光镜观察妊娠第21天新生鼠心脏的病理改变,TUNEL检测心肌细胞凋亡、免疫荧光染色及Western Blot技术检测心肌细胞CHOP水平。结果ICP组新生鼠心肌细胞萎缩,体积缩小,空泡样变性,核固缩;ICP组心肌细胞凋亡指数[(20.8±6.1)%]较对照组[(5.0±1.8)%]明显增高,差异有统计学意义(P<0.01)。ICP组新生鼠心肌细胞CHOP表达免疫荧光染色(IOD值108.96±21.82)较对照组(62.12±11.09)明显增加,Western Blot(IOD值1.17±0.04)较对照组(0.81±0.00)明显增加,差异均有统计学意义(P<0.01)。相关性分析结果显示,新生鼠心肌细胞凋亡率与心肌细胞CHOP表达量呈正相关(r=0.780,P<0.01),新生鼠心肌细胞凋亡率(r=0.835,P<0.01)和CHOP表达量(r=0.650,P<0.05)与孕鼠死胎率均呈正相关,且新生鼠心肌细胞凋亡率(r=0.740,P<0.01)和CHOP表达量(r=0.801,P<0.01)、孕鼠死胎率(r=0.736,P<0.01)与孕鼠总胆汁酸呈正相关。结论CHOP在孕鼠ICP新生鼠心肌细胞中表达明显增加,孕鼠ICP时胎鼠心肌细胞凋亡可能由CHOP介导。

Objective To investigate the changes and significance of CHOP expression in neonatal rat Cardiomyocytes with intrahepatic cholestasis of pregnant(ICP).Methods Healthy and clean SD rats at gestational age of 14 days were randomly divided into ICP group and the control group.ICP rats were induced by 17α-ethinyl estradiol followed by observation of the pathological changes of neonatal rat heart on day 21 of gestation under optical microscopy,TUNEL assay for detection of myocardial cell apoptosis,immunofluorescence staining and western blot to detect myocardial cell CHOP.Results The myocardial cells of neonatal rats in ICP group were atrophied,reduced in volume,vacuolated,and nucleated.The apoptosis index of myocardial cells in ICP group[(20.8±6.1)%]was significantly higher than that in control group[(5.0±1.8)%],and the differences were statistically significant(P<0.01).Immunofluorescence staining(IOD value 108.96±21.82)and western blot(IOD value 1.17±0.04)of CHOP in neonatal rat myocardial cells in ICP group were significantly higher than that in control group(62.12±11.09),and the differences were statistically significant(P<0.01).Correlation analysis showed that the apoptosis rate of neonatal myocardial cells was positively correlated with the expression level of CHOP(r=0.780,P<0.01),and the apoptosis rate of neonatal myocardial cells(r=0.835,P<0.01)and the expression level of CHOP(r=0.650,P<0.05)were positively correlated with the stillbirth rate of pregnant mice.The apoptosis rate of neonatal myocardial cells(r=0.740,P<0.01),the expression level of CHOP(r=0.801,P<0.01)and the stillbirth rate of pregnant mice(r=0.736,P<0.01)were positively correlated with total bile-acids in pregnant mice.Conclusion CHOP expression significantly increases in neonatal myocardial cells of pregnant rats with ICP,and apoptosis of neonatal myocardial cells during ICP may be mediated by CHOP.