厚朴麻黄汤对哮喘小鼠气道炎症及TRPA1,TRPV1 mRNA与蛋白表达的影响

目的:探讨厚朴麻黄汤对哮喘小鼠气道炎症的效应及对瞬时受体电位通道蛋白A1(TRPA1),TRPV1 mRNA与蛋白表达的影响。方法:将60只雌性Balb/c小鼠随机分为6组,分别为空白组、模型组、厚朴麻黄汤低、中、高(7,14,28 g·kg^-1)剂量组和地塞米松组(0.0024 g·kg^-1),每组10只。复制卵蛋白(OVA)致敏及激发小鼠哮喘模型。检测各组小鼠气道反应性,以不同浓度氯化乙酰胆碱(ACh)雾化吸入激发后增强呼气间歇(Penh)值表示,观察各组小鼠肺组织病理学改变,外周血嗜酸性粒细胞数(EOS),支气管肺泡灌洗液(BALF)中EOS百分比的变化。酶联免疫吸附测定(ELISA)检测白细胞介素(IL)-4,IL-13,前列腺素D2(PGD2),P物质(SP),实时荧光定量聚合酶链式反应(Real-time PCR)及蛋白免疫印迹法(Western blot)检测肺组织TRPA1,TRPV1 mRNA与蛋白表达。结果:与正常组比较,给予质量浓度为12.5,25,50 g·L-1ACh雾化吸入后,模型组小鼠Penh明显上升(P<0.05,P<0.01);肺病理显示支气管及管壁周围有大量炎症细胞浸润,支气管黏膜水肿、增厚,黏液分泌增多;外周血中EOS数量及BALF中EOS百分比明显升高(P<0.01)。BALF中IL-4,IL-13,PGD2和SP水平以及肺组织中TRPA1,TRPV1 mRNA和蛋白表达明显升高(P<0.05,P<0.01)。与模型组比较,各给药组Penh明显降低(P<0.05,P<0.01),肺组织病理损伤改善,外周血中EOS数量及BALF中EOS百分比显著降低(P<0.01);BALF中IL-4,IL-13,PGD2和SP水平以及肺组织中TRPA1,TRPV1 mRNA与蛋白表达明显降低(P<0.05,P<0.01)。结论:厚朴麻黄汤可以改善哮喘小鼠气道炎症、降低气道反应性,其机制除降低Th2相关的细胞因子水平外,可能也与调控TRPA1,TRPV1mRNA与蛋白表达及降低相关神经因子水平有关。

Effect of Houpu Mahuangtang on Airway Inflammation and Expression of TRPA1, TRPV1 mRNA and Protein in Asthmatic Mice

Objective: To investigate the effect of Houpu Mahuangtang on airway inflammation and expressions of gene and proteins of Transient receptor potential ankyrin 1, vanilloid 1 (TRPA1, TRPV1) in asthmatic mice. Method: Sixty female Balb/c mice were randomly divided into six groups:control group, model group, low, medium and high-dose Houpu Mahuangtang groups (7,14,28 g·kg^-1) and dexamethasone group (0.002 4 g·kg^-1), with 10 mice in each group. A mouse model of asthma was replicated by sensitizing and challenging with ovalbumin. The changes of enhanced pause (Penh) following acetylcholine chloride (ACh) inhalation were detected. The pathological changes of the lung tissues were observed. The number of eosinophils (EOS) in peripheral blood and the percentage of EOS in bronchoalveolar lavage fluid (BALF) were detected. Interleukin (IL)-4, IL-13, prostaglandin D₂ (PGD₂) and substance P (SP) were detected by enzyme-linked immuno sorbent assay (ELISA). The expressions of TRPA1 and TRPV1 gene and protein in lung tissues were detected by Quantitative Real-time polymerase chain reaction (Real-time PCR) and Western blot. Result: Compared with control group, mice of model group showed significantly increased in Penh following ACh inhalation (P<0.05,P<0.01), EOS in blood and the percentage of EOS in BALF (P<0.01). Histopathological changes in lungs showed inflammatory cell infiltration and bronchial mucosa damage. The levels of IL-4, IL-13, PGD₂ and SP in BALF and the expressions of TRPA1,TRPV1 mRNA and protein in lung tissues significantly increased (P<0.05,P<0.01). Compared with model group, treatment groups had significant effects in decreasing Penh, relieving lung injury, reducing EOS count in blood and the percentage of EOS in BALF (P<0.05,P<0.01), reducing IL-4, IL-13, PGD₂ and SP levels in BALF (P<0.05,P<0.01), as well as down-regulating TRPA1 and TRPV1 mRNA and protein expressions in lung tissues (P<0.05,P<0.01). Conclusion: Houpu Mahuangtang could reduce airway inflammation, airway responsiveness. In addition to the reduction of levels of Th2 related cytokines, the mechanism of Houpu Mahuangtang might be related to the regulation of TRPA1, TRPV1 mRNA and protein expressions, and the decrease of associated neurofactor levels.