过氧化物酶体增殖物激活受体γ对哮喘小鼠气道平滑肌细胞增殖的影响

Effect of peroxisome proliferator-activated receptor-gamma on proliferation of airway smooth muscle cells in mice with asthma

摘要:

目的：探讨过氧化物酶体增殖物激活受体γ（PPARγ）激动剂罗格列酮对支气管哮喘小鼠肺组织细胞周期蛋白D1（CyclinD1）的表达及气道平滑肌细胞（ASMC）增殖的影响。方法：将30只清洁级BALA/c小鼠随机分为对照组、哮喘组和罗格列酮干预组，每组10只。卵清蛋白（OVA）致敏和激发建立哮喘小鼠模型，干预组在每次激发前1 h通过灌胃给予小鼠罗格列酮（5 mg/kg）进行干预，对照组小鼠以生理盐水代替OVA致敏和激发。显微镜下计数小鼠支气管肺泡灌洗液（BLAF）中的白细胞及嗜酸性粒细胞（EOS）；苏木精-伊红染色观察气道结构改变；免疫组化染色检测CyclinD1蛋白的表达水平；逆转录-聚合酶链反应（RT-PCR）法检测CyclinD1 mRNA表达变化；图像分析软件测定管腔基底膜周长（Pbm）、气管壁总面积（WAt）、气道平滑肌面积（WAm）和ASMC核数（N），结果：以Pbm标准化。结果与对照组相比，哮喘组小鼠BALF中白细胞总数及EOS百分比显著增加，CyclinD1 mRNA和蛋白表达亦显著增高，而干预组可降低上述改变，差异有统计学意义（P<0.05）。此外，与对照组相比，哮喘组小鼠WAt/Pbm、WAm/Pbm和N/Pbm显著增加，而罗格列酮干预可减少上述比值，差异有统计学意义（P<0.05）。结论：罗格列酮可通过抑制ASMC的增殖，延缓气道重塑的进程，从而预防和治疗慢性哮喘。

Abstract:

OBJECTIVE: To investigate the effects of peroxisome proliferator-activated receptor-gamma (PPARγ) agonist rosiglitazone on the expression of cyclin D1 in lung tissue, and the proliferation of airway smooth muscle cells (ASMCs) in mice with bronchial asthma. METHODS: Thirty clean BALB/c mice were randomly divided into control group (n=10), asthma group (n=10), and rosiglitazone treatment group (n=10). A mouse model of asthma was established by ovalbumin (OVA) sensitization and challenge. The treatment group received rosiglitazone (5 mg/kg) by gavage 1 hour before each challenge and the control group received saline instead of OVA sensitization and challenge. Leukocytes and eosinophils in bronchoalveolar lavage fluid (BALF) were counted under a microscope. Airway structural changes were observed by hematoxylin-eosin staining. Protein and mRNA expression levels of cyclin D1 were measured by immunohistochemical staining and RT-PCR. Perimeter of the basement membrane (Pbm), total bronchial wall area (WAt), airway smooth muscle area (WAm), and number of nuclei in ASMCs (N) were determined using image analysis software, and WAt/Pbm, WAm/Pbm, and N/Pbm were calculated. RESULTS: Compared with the control group, the asthma group showed significant increases in the total number of leukocytes and percentage of eosinophils in BALF, as well as in the mRNA and protein expression of cyclin D1, but changes in these indices were significantly reduced in the rosiglitazone treatment group (P<0.05). In addition, compared with the control group, the asthma group had significantly increased WAt/Pbm, WAm/Pbm, and N/Pbm, but rosiglitazone significantly decreased these ratios (P<0.05). CONCLISONS: Rosiglitazone may delay the process of airway remodeling by inhibiting the proliferation of ASMCs, so it can be used for preventing and treating chronic asthma.