RANTES在哮喘大鼠肺组织中的表达及维生素D的干预作用

Expression of RANTES in the lung tissue of asthmatic rats,and the intervention effect of vitamin D on RANTES expression

目的探讨维生素D对哮喘大鼠肺组织中调节正常T细胞表达和分泌的趋化因子(RANTES)表达的影响及维生素D参与控制哮喘气道炎症及与激素协同作用的作用机制。方法 40只雌性Wistar大鼠随机分为正常对照组、哮喘组、维生素D干预组、布地奈德干预组、布地奈德联合维生素D干预组,每组8只。采用苏木精-伊红染色观察肺组织病理改变;免疫组化方法测定肺组织RANTES蛋白的表达;ELISA检测肺泡灌洗液(BALF)中RANTES的含量;实时定量PCR测定RANTES mRNA的表达。结果哮喘组大鼠气道炎症反应最明显,出现炎症细胞浸润、气道狭窄变形及平滑肌的断裂,各个干预组较哮喘组有不同程度的缓解,其中布地奈德干预组的缓解程度优于维生素干预D组;联合干预组的病理改变最轻,与正常对照组相近。哮喘组大鼠肺组织及BALF中RANTES蛋白的表达明显高于正常对照组(P<0.05),各干预组的表达较哮喘组有不同程度下降,除维生素D干预组与哮喘组BALF中RANTES蛋白的表达差异无统计学意义外,其余各干预组与哮喘组之间的差异均有统计学意义(P<0.05),且联合干预组肺组织及BALF中RANTES蛋白表达量均低于单独使用布地奈德及维生素D组(P<0.05);哮喘组RANTES mRNA的表达较正常对照组显著升高(P<0.05),各干预组较哮喘组有不同程度的下降(P<0.05),但各干预组间差异无统计学意义,且联合干预组RANTES mRNA表达的下降幅度最大,与正常对照组比较差异无统计学意义。结论哮喘大鼠BALF、肺组织中的RANTES蛋白及其mRNA的表达水平明显增高;维生素D干预可以降低其表达水平,提示维生素D可以通过调节RANTES的表达来减轻气道炎症反应;且维生素D可以协同布地奈德进一步降低RANTES蛋白及mRNA的表达水平。

Objective To investigate the effect of vitamin D on the expression of chemokine regulated on activation,normal T cells expressed and secreted（RANTES） in the lung tissue of asthmatic rats,and the role of vitamin D in the control of asthmatic airway inflammation and the synergistic action of hormones.Methods Forty female Wistar rats were randomly and equally divided into normal control,asthma,vitamin D intervention,budesonide intervention,and budesonide＋vitamin D intervention groups.Hematoxylin and eosin staining was used to observe pathological changes in the lung tissue.Immunohistochemistry was used to measure the protein expression of RANTES in lung tissue.Enzyme-linked immunosorbent assay was used to measure the level of RANTES in bronchoalveolar lavage fluid（BALF）.Real-time quantitative PCR was used to measure the mRNA expression of RANTES.Results The asthma group showed the most significant pathological changes in the lung tissue,including inflammatory cell infiltration,bronchial stenosis and distortion and smooth muscle rupture,while the intervention groups showed fewer pathological changes.Of the intervention groups,the budesonide intervention group showed fewer pathological changes than the vitamin D intervention group,and the budesonide＋vitamin D intervention group showed the mildest pathological changes,which were similar to those observed in the normal control group.Protein expression of RANTES in the lung tissue and BALF was significantly higher in the asthma group than in the normal control group（P0.05）,while it was lower in the intervention groups than in the asthma group,exhibiting significant differences between each intervention group and the asthma group（P0.05）（except the difference in protein expression of RANTES in BALF between the vitamin D intervention and asthma groups）.The budesonide＋vitamin D intervention group showed less protein expression of RANTES in the lung tissue and BALF than both the budesonide intervention and vitamin D intervention groups（P0.05）.The mRNA expression of RANTES was significantly higher in the asthma group than in the normal control group（P0.05）,while it was significantly lower in three intervention groups than in the asthma group（P0.05）,however no significant difference was found between the intervention groups in this regard.The budesonide＋vitamin D intervention group showed the lowest level of RANTES mRNA,with no significant difference from the normal control group.Conclusions The mRNA and protein expression of RANTES in BALF and lung tissue increases significantly in asthmatic rats.Vitamin D intervention can decrease the expression of RANTES,suggesting that vitamin D can reduce airway inflammation by regulating the expression of RANTES.Vitamin D can be used together with budesonide to further decrease the mRNA and protein expression of RANTES.