孟鲁司特对气道重塑及白细胞介素类与转移生长因子β_2 mRNA表达的影响

The effect of montelukast on airway remodeling and the expression of interleukins and transforming growth factor-β2 mRNA

目的 探讨白细胞介素4(IL-4)、IL-5、IL-13、转移生长因子β:(TGF-β2)与气道重塑的关系及白三烯受体拮抗剂孟鲁司特(MK)对支气管哮喘(简称哮喘)炎症、气道重塑的影响。方法20只BALB/c雌性小鼠,按随机数字表法分为重塑组、MK治疗组,每组10只,两组均以卵白蛋白(OVA)致敏,仅MK治疗组给予MK(15 mg/kg)灌胃;检测支气管肺泡灌洗液(BAIF)中的细胞计数,用光镜、电镜观察病理、形态学改变;用原位杂交、逆转录-聚合酶链反应(RT-PCR)检测肺组织中IL-13、TGF-β2、IL-4、IL-5 mRNA的表达。结果 重塑组BALF中细胞总数、嗜酸粒细胞数分别为(5.4±1.1)×105/ml、2.32±0.20,MK治疗组分别为(3.9±1.6)×105/ml、1.64±0.32,两组比较差异有显著性(P均<0.01);病理和电镜结果显示,重塑组小鼠具有明显的气道炎症,细胞呈团状聚集,以淋巴细胞、嗜酸粒细胞为主,上皮细胞增生呈指状突起、平滑肌肌层增厚、结缔组织增生,黏液分泌旺盛并伴小气道栓塞,气道周围有大量胶原纤维沉积,杯状细胞分泌黏液增加,MK治疗组小鼠则炎症明显改善,无明显气道痉挛、黏液产生减少,上皮增生、平滑肌层增厚不明显,气道周围胶原纤维及黏液颗粒均减少。原位杂交结果显示,重塑组小鼠肺组织中IL-13 mRNA、TGF-β2 mRNA表达分别为24±7、17±5。

bjective To study the relation between Interleukin-4(IL-4),IL-5,IL-13, transforming grouth factor-β2 (TGF-β2) and airway remodeling and to investigate the effects of Montelukast (MK) on airway inflammation and airway remodeling of asthma. Methods Twenty female BALB/c mice were randomly divided into a remodeling group and a treatment group (MK group) , with 10 BALB/c mice in each group . The mice were sensitized by ovalbumin ( OVA) , and only the MK group was treated with MK (15 mg/kg) . The number of total cells and eosinophils in bronchoalveolar lavage fluid(BALF) were counted. Light and electronic microscope were used to detect the pathologic histology and morphologic change. In situ hybridization and reverse transcription-polymerase chain reaction ( RT-PCR) were used to measure IL-4, L-5, IL-13, and TGF-β2 mRNAs in the lung. Results The numbers of total cells and eosinophils in BALF of the remodeling group were (5. 4±1. 1)×105/ml and 2. 32±0. 20, while those of the treatment group were (3. 9±1. 6)×105/ml and 1. 64±0. 32, respectively, the difference being significant (P<0. 01). Histological and electronic microscopic examination showed extensive airway inflammation, notably accumulation of significant numbers of eosinophils and lymphocytes in the remodeling group. Other features including prominent proliferation of airway epithelial cells protruded like fingers, increased thickness of smooth muscle, hyperplasia of connective tissue, goblet cell hyperplasia and a marked increase in airway mucus secretion with mucus plugging and extensive collagen deposition around the airways were also noted in the remodeling group. In the treatment group, the inflammation was significantly decreased, with decreased production of mucus, decreased collagen and granule of mucus around airway, less proliferation of airway epithelium, smooth muscle hypertrophy and airway spasm. In situ hybridization showed that the expression of IL-13 mRNA and TGF-β2 mRNA in the lung of the remodeling group were 24±7 and 17±5 respectively, while those of the treatment group were 17±4 and 10±3. RT-PCR results showed that the absorbance of IL-4 mRNA and IL-5 mRNA in the lung of the remodeling group were 0.91 and 0.96, while those of the treatment group were 0. 22 and 0. 35 ; the differences between the groups were all significant (all P <0. 01). Conclusion MK could effectively inhibit airway remodeling, which suggests a possible role of cysteinyl leukotrienes in the pathogenesis of chronic allergic inflammation with fibrosis.