孟鲁司特钠和细菌溶解产物对支气管哮喘豚鼠气道重塑及TGF-β1、Smad7表达的影响

目的 探讨白三烯受体拮抗剂孟鲁司特钠（MK）和（或）细菌溶解产物（OM-85BV）干预下，对支气管哮喘豚鼠气道重塑及转化生长因子-β1（TGF-β1）、Smad7水平变化的影响及其相关性。方法 将40只Hartley雄性豚鼠随机分成正常对照组、哮喘组、MK组、OM-85BV组和MK+OM-85BV组，每组8只。经腹腔内注射10%卵清蛋白（OVA）致敏并雾化吸入1% OVA激发以制备哮喘气道重塑模型，正常对照组以生理盐水替代；在雾化吸入激发阶段，MK组、OM-85BV组和MK+OM-85BV组给予相应的药物混悬液灌胃，正常对照组和哮喘组给予等量的生理盐水灌胃。激发阶段结束后24 h内，取豚鼠支气管肺泡灌洗液（BALF），用ELISA法测定BALF中TGF-β1、Smad7含量；并处死豚鼠，取肺组织病理切片观察气道重塑程度，采用图像分析技术测定肺内支气管基底膜周径（Pbm）、总管壁面积（Wat）及平滑肌面积（Wam）。采用Pearson直线相关对两变量间进行相关分析。结果 哮喘组、MK组、OM-85BV组和MK+OM-85BV组肺组织病理切片显示支气管平滑肌、肺泡壁均较正常对照组明显增厚，标准化的支气管总管壁面积（Wat/Pbm）及平滑肌面积（Wam/Pbm）均较正常对照组增大，TGF-β1水平均高于正常对照组，Smad7水平均低于正常对照组（均P < 0.05）；MK组、OM-85BV组和MK+OM-85BV组肺组织病理切片显示病理损害程度较哮喘组有所改善，Wat/Pbm、Wam/Pbm均较哮喘组降低，TGF-β1水平均低于哮喘组，Smad7水平均高于哮喘组，且MK+OM-85BV组较MK组、OM-85BV组改善得更多（均P < 0.05）。TGF-β1与Smad7表达水平呈负相关；TGF-β1表达水平与Wat/Pbm及Wam/Pbm分别呈正相关；Smad7表达水平与Wat/Pbm及Wam/Pbm分别呈负相关（均P < 0.01）。结论 MK和（或）OM-85BV干预哮喘豚鼠后能减轻气道重塑，其中MK联合OM-85BV干预效果最好；其机制可能是降低TGF-β1和提高Smad7含量，从而改善TGF-β1和Smad7表达水平的失衡，最终减轻气道重塑。

Effects of montelukast sodium and bacterial lysates on airway remodeling and expression of transforming growth factor-β1 and Smad7 in guinea pigs with bronchial asthma

Objective To study the effect of montelukast sodium (MK), a leukotriene receptor antagonist, and bacterial lysates (OM-85BV), used alone or in combination, on airway remodeling and the expression of transforming growth factor-β1 (TGF-β1) and Smad7 in guinea pigs with bronchial asthma and their correlation.Methods A total of 40 male Hartley guinea pigs were randomly divided into normal control group, asthma group, MK group, OM-85BV group, and MK+OM-85BV group, with 8 guinea pigs in each group. Intraperitoneal injection of 10% ovalbumin (OVA) for sensitization and aerosol inhalation of 1% OVA for challenge were performed to establish a model of airway remodeling of asthma in all of the groups apart from the normal control group, which were treated with normal saline. In the stage of challenge by aerosol inhalation, the guinea pigs in the MK, OM-85BV, and MK+OM-85BV groups were given corresponding suspension by gavage, and those in the normal control and asthma groups were given an equal volume of normal saline by gavage. Bronchoalveolar lavage fluid (BALF) of the guinea pigs was collected within 24 hours after challenge, and ELISA was used to measure the levels of TGF-β1 and Smad7 in BALF. The guinea pigs were sacrificed and the pathological section of lung tissue was prepared to observe the degree of airway remodeling. An image analysis technique was used to measure perimeter of the basement membrane (Pbm), total bronchial wall area (Wat), and airway bronchial smooth muscle area (Wam). Pearson linear regression was used to investigate the correlation between two variables.Results According to the lung pathological section, compared with the normal control group, the asthma, MK, OM-85BV, and MK+OM-85BV groups had significant thickening of bronchial smooth muscle and alveolar wall, significantly higher Wat/Pbm and Wam/Pbm, a significantly higher level of TGF-β1, and a significantly lower level of Smad7 (P < 0.05). Compared with the asthma group, the MK, OM-85BV, and MK+OM-85BV groups had a significant improvement in pathological injury, significantly lower Wat/Pbm and Wam/Pbm, a significantly lower level of TGF-β1, and a significantly higher level of Smad7 (P < 0.05). The MK+OM-85BV group had significantly greater improvements than the MK group and the OM-85BV group (P < 0.05). The expression of TGF-β1 was negatively correlated with that of Smad7 and positively correlated with Wat/Pbm and Wam/Pbm, and the expression of Smad7 was negatively correlated with Wat/Pbm and Wam/Pbm (P < 0.01).Conclusions MK and OM-85BV, used alone or in combination, can reduce airway remodeling in guinea pigs with asthma, and MK combined with OM-85BV has the best effect, possibly by reducing TGF-β1 expression, increasing Smad7 expression, and improving the TGF-β1/Smad7 imbalance.