内毒素引起的乳鼠心肌细胞血红素加氧酶-1基因的表达

刘俊昌　张敏　郑新程　吴立玲　时安云　伍贻经　李玉明　

摘　要：为了探讨在内毒素作用下的乳鼠心肌细胞(neonatalratcardiomyocytes,NRCMs)血红素加氧酶-1(hemeoxygenase-1,HO-1)基因的表达及其在细胞损伤中的作用,分别用10、30及50μg/ml的脂多糖(lipopolysaccharide,LPS),10μg/mlLPS+10μmol/ml锌原卟啉Ⅸ(Zn-protoporphyrin-Ⅸ,ZnPPⅨ)和单纯10μmol/mlZnPPⅨ与培养的NRCMs共同孵育6h,以及10μg/mlLPS与NRCMs共同孵育9h和18h。分别观察细胞HO-1mRNA表达、MDA含量、LDH释放量与台盼蓝摄取率的变化。结果显示,同样与细胞孵育6h,LPS10μg/ml时HO-1mRNA表达比对照组增加81.2%,30μg/ml时表达量增加126.3%,50μg/ml时表达量增加92.8%;LPS为10μg/ml时,孵育9h后HO-1mRNA的表达量比对照组增加93.6%,孵育18h后表达量增加105.8%。LPS30、50μg/ml,10μg/mlLPS+10μmol/mlZnPPⅨ与细胞孵育6h及LPS10μg/ml孵育18h后,细胞MDA含量、LDH释放量与台盼蓝摄取率明显增加(P<0.01);单纯10μg/mlLPS与单纯10μmol/mlZnPPⅨ孵育6h后,上述指标均无明显升高。结果表明,LPS可诱导NRCMsHO-1mRNA的表达,且在较低LPS剂量范围内具有时间依赖性和浓度依赖性;NRCMsHO-1mRNA的表达可减低LPS引起的细胞损伤,这可能是细胞产生的一种自身保护性反应。
关键词：内毒素; 血红素加氧酶; 基因表达
分类号：R363; R631.1-332　文献标识码：A

Expression of heme oxygenase-1 in neonatal rat cardiocytes induced by lipopolysaccharide

LI Yu-Ming（Laboratory of Hypothermic Physiology, Chengde Medical College, Chengde 067000）　
LIU Jun-Chang（Department of Pathophysiology, Beijing Medical University, Beijing 100083）　
ZHANG Min（Department of Pathophysiology, Beijing Medical University, Beijing 100083）　
ZHENG Xin-Cheng（Department of Pathophysiology, Beijing Medical University, Beijing 100083）　
WU Li-Ling（Department of Pathophysiology, Beijing Medical University, Beijing 100083）　
SHI An-Yun（Department of Pathophysiology, Beijing Medical University, Beijing 100083）　
WU Yi-Jing（Department of Pathophysiology, Beijing Medical University, Beijing 100083）　

Abstract：To study the alterations of heme oxygenase-1 mRNA in neonatal rat cardiomyocytes (NRCMs) induced by lipopolysaccharide (LPS) and the role of heme oxygenase-1 (HO-1) in the LPS induced disorders of myocardium function, 10 (L, 6 h), 30 (M, 6 h), 50 μg/ml (H, 6 h) LPS and 10 μg/ml LPS +10 μmol/ml Zn-protoporphyrin-Ⅸ (ZnPPⅨ; L+I, 6 h) and 10 μmol/ml ZnPPⅨ alone (I, 6 h) were added to the medium for a 6-hour culture of NRCMs, and 10 μg/ml LPS for 9 h (L, 9 h) and 18 h (L, 18 h) cultures. LDH release and MDA contents of the cells were measured. When NRCMs were collected, Trypan blue stain method was used to examine the mortality (the rate of Trypan blue uptake) of NRCMs. HO-1 mRNA expression was examined by Northern blot. The results showed that HO-1 mRNA expression of NRCMs increased gradually along with the increase of LPS concentration below the level of 30 μg/ml. When the final concentrations of LPS were 10 and 30 μg/ml, the HO-1 mRNA expression of NRCMs increased by 81.2% and 126.3% respectively compared with control. When the final concentration of LPS was 50 μg/ml, the HO-1 mRNA expression decreased to the level of 10 μg/ml group.　 When the 　final 　　concentration 　was 10 μg/ml,　 the HO-1 mRNA　 expression 　increased 　gradually along with the culture time.　 After a 9- or 18-hour culture, the HO-1 mRNA expression of NRCMs increased by 93.6% and 105.8% respectively compared with control.Only when NRCMs had been cultured with 30, 50 μg/ml LPS and 10 μg/ml LPS +10 μmol/ml ZnPPⅨ for 6 h and 10 μg/ml LPS for 18 h, the rate of Trypan blue stain uptake, MDA contents and LDH release significantly increased. With 10 μg/ml LPS alone and 10 μmol/ml ZnPPⅨ alone for 6 h, the above parameters were not significantly increased (P>0.05). The results demonstrate that LPS induces HO-1 mRNA expression of NRCMs dose- and time-dependently to some extent. The inducible HO can protect NRCMs from injury and thus play an important role in pathogenesis of myocardium under LPS.
Keywords：gene expression; lipopolysaccharide; heme oxygenase

基金项目：This work was supported by the National Natural Science Foundation of China (No. 39670308)
作者单位：刘俊昌（北京医科大学病理生理学教研室, 北京 100083）　
　　　　　张敏（北京医科大学病理生理学教研室, 北京 100083）　
　　　　　郑新程（北京医科大学病理生理学教研室, 北京 100083）　
　　　　　吴立玲（北京医科大学病理生理学教研室, 北京 100083）　
　　　　　时安云（北京医科大学病理生理学教研室, 北京 100083）　
　　　　　伍贻经（北京医科大学病理生理学教研室, 北京 100083）　
　　　　　李玉明（承德医学院低温生理研究室, 承德 067000）　

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收稿日期：2000年7月6日

修稿日期：2000年10月14日