肺炎支原体脂质相关膜蛋白刺激 THP-1细胞表达血红素氧合酶-1

The lipid-associated membrane proteins derived from Mycoplasma pneumoniae strains induced the expression of HO-1 in THP-1 cells

目的：研究肺炎支原体（ Mycoplasma pneumonia， Mp）脂质相关膜蛋白（ lipid-associated membrane proteins ， LAMPs）对人单核细胞系THP-1表达血红素氧合酶-1（heme oxygenase 1，HO-1）的影响。方法体外培养THP-1细胞，根据实验目的加入不同浓度LAMPs作用不同时间，并设阳性和阴性对照。收集各处理组细胞，LDH漏出实验检测LAMPs对THP-1细胞的毒性，实时荧光反转录PCR检测 HO-1 mRNA 表达， Western blot 检测 HO-1蛋白表达，比色法检测 HO-1酶活性。结果LAMPs浓度为10μg／ml时，LDH漏出率明显增高。 LAMPs刺激THP-1细胞9 h后HO-1 mRNA表达水平最高；HO-1蛋白表达水平与LAMPs刺激呈剂量依赖性和时间依赖性，其中5．0μg／ml LAMPs刺激表达的HO-1蛋白水平最高；LAMPs刺激12 h 后的HO-1蛋白浓度最高。 LAMPs刺激THP-1细胞后，随着HO-1表达水平的增高，其酶活性亦显著增强。结论 Mp LAMPs可诱导THP-1细胞表达HO-1，并可上调其酶活性。

Objective To investigate the effects of lipid-associated membrane proteins （ LAMPs） derived from Mycoplasma pneumoniae （ M.pneumoniae） strains on the expression of heme oxygenase 1 （ HO-1） in a human monocyte cell line （THP-1）.Methods THP-1 cells were in vitro cultured with different concentrations of LAMPs for different times.The cytotoxicity of LAMPs to THP-1 cells was analyzed by using lactate dehydrogenase （ LDH） releasing test.The expression of HO-1 at protein and mRNA levels were de-tected by Western blot and real-time RT-PCR, respectively.The enzymatic activity of HO-1 protein was ex-amined by colorimetric assay.THP-1 cells stimulated with PBS and LPS were set up as the negative and pos-itive controls, respectively.Results A significantly enhanced LDH releasing rate was observed in THP-1 cells treated with 10 μg/ml of LAMPs.The expression of HO-1 at protein and mRNA levels in THP-1 cells were induced by LAMPs in a dose-dependent and time-dependent manner.The highest level of HO-1 protein was detected in THP-1 cells treated with 5.0 μg/ml of LAMPs.The transcriptional levels of HO-1 induced by LAMPs were significantly elevated at 3 h, peaked at 9 h and were decreased at 12 h.The expression of HO-1 protein in THP-1 cells was enhanced after 8 h of treatment with LAMPs and a significant decrease was observed at 20 h after reaching peaks at 12 h and 16 h.The activity of HO-1 protein was significantly en-hanced along with the increased expression of HO-1 protein.Conclusion The LAMPs derived from M.pneumoniae strains induced the expression of HO-1 at mRNA and protein levels.Moreover, the enzyme activity of HO-1 protein was enhanced in LAMPs treated THP-1 cells.