| 摘要: |
| 目的 探讨慢性哮喘病理生理过程中肺组织组蛋白去乙酰化酶(HDAC)活性变化趋势及其对气道平滑肌细胞表型及生物学性状的影响。方法 构建慢性哮喘小鼠模型,检测肺组织HDAC活性。以HDAC抑制剂曲古霉素A(TSA)刺激体外培养的大鼠气管平滑肌及人原代支气管平滑肌细胞,采用蛋白质印迹、MTT、Transwell及三维凝胶收缩等方法检测抑制HDAC活性对气道平滑肌细胞表型转变的影响及其相应的细胞增殖、迁移、收缩能力的变化。结果 慢性哮喘组小鼠肺组织HDAC活性为(0.371±0.054) μmol/(L·μg),较正常对照组的(0.603±0.034) μmol/(L·μg)显著降低,差异有统计学意义(P<0.01)。TSA(0.5 μmol/L)作用后12～24 h,体外培养的大鼠气管平滑肌环及人支气管平滑肌细胞的α-sm-actin、SM22-α表达明显增加,作用后24 h及48 h支气管平滑肌细胞数目分别为(1.719±0.044)×104及(1.808±0.009)×104个,明显低于空白对照组的(1.911±0.048)×104及(2.537±0.01)×104个(P<0.05)。血小板源性生长因子(PDGF)诱导的支气管平滑肌细胞迁移数也在TSA作用后显著降低(88±7.632 vs 52±7.5,P<0.05)。此外,TSA作用24 h后的三维凝胶收缩率\[(9.885±7.084)%\]较空白对照组\[(44.844±3.808)%\]及PDGF组\[(41.315±7.943)%\]明显降低(P<0.05)。结论 慢性哮喘小鼠肺部HDAC的活性下降,可能与气道平滑肌细胞向“收缩型”转变有关,但HDAC活性下降并不增加细胞的收缩能力。 |
| 关键词: 哮喘 平滑肌细胞 组蛋白脱乙酰基酶类 曲古霉素A |
| DOI：10.3724/SP.J.1008.2010.0937 |
| 投稿时间：2010-04-06修订日期：2010-07-08 |
| 基金项目:第二军医大学重点培育学科基金. |
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| Pulmonary histone deacetylase is involved in phenotype transformation of airway smooth muscle cells in chronic asthmatic mice |
| LI Qiang1*,胥武剑XU Wu-jian1, NING Yun-ye1, HONG Wei-jun1, SHAO Yan1, CAI Zai-long2 |
| (1. Department of Respiratory Diseases, Changhai Hospital, Second Military Medical University, Shanghai 200433, China;1. Department of Respiratory Diseases, Changhai Hospital, Second Military Medical University, Shanghai 200433, China;2. Central Laboratory, Changhai Hospital, Second Military Medical University, Shanghai 200433, China) |
| Abstract: |
| Objective To investigate the changes of histone deacetylase (HDAC) activity during chronic asthma and its effects on the phenotype and biological activities of airway smooth muscle cells. Methods Chronic asthma model was established with mice using repeated sensitization and challenge with OVA, and the lung was homogenated for total HDAC activity assay. Rat airway smooth muscle cells and human bronchial smooth muscle cells were stimulated with trichostatin A (TSA), an HDAC inhibitor. The effect of HDAC inhibition on phenotype switching was detected by Western Blotting analysis, and its effects on proliferation, migration and contraction of smooth muscle cells were examined by MTT, Transwell and gel contraction, respectively. Results The total HDAC activity was significantly decreased in chronic asthmatic mice compared with saline-treated controls (\[0.371±0.054\] vs \[0.603±0.034\] μmol/(L·μg), P<0.01). Incubation of the rat trachea ring and human bronchial smooth muscle cells with TSA (0.5 μmol/L) for 12-24 h increased the expression of α-sm-actin and SM22-α. TSA significantly decreased cell number after 24 h treatment (\[1.719±0.044)×104 vs (\[1.911±0.048\]×104, P<0.05) and 48 h \[1.808±0.009\]×104 vs \[2.537±0.01\]×104, P<0.05) compared with DMSO controls. TSA treatment for 24 h also significantly decreased the migrated cells compared with the PDGF-treated cells(52±7.5 vs 88±7.632, P<0.05). Furthermore, the gel contraction rate was significantly lower in the TSA-treated cells than in the DMSO or PDGF-treated cells(\[9.885±7.084\]% vs \[44.844±3.808\]% and \[41.315±7.943\]%, P<0.05). Conclusion HDAC activity is decreased in the lung of chronic asthmatic mice, which may be related to switching of the airway smooth muscle cells to a “contractic” phenotype, but with no increase of their contraction capability. |
| Key words: asthma smooth muscle myocytes histone deacetylases trichostatin A |
