孟鲁司特和卡介苗多糖核酸对哮喘大鼠血单个核细胞中STAT5b mRNA和IL-4 mRNA表达的影响

Effects of montelukast and BCG-PSN on the expression of STAT5b mRNA and IL-4 mRNA in blood mononuclearcells of rats with asthma

摘要:

目的：研究孟鲁司特和卡介苗多糖核酸对哮喘大鼠血单个核细胞中信号转导子和转录激活子5b(STAT5b) mRNA和白细胞介素4（IL-4）mRNA的转录表达的影响。方法：52只体重为140~200 g清洁级Sprague-Dawley雄性大鼠，随机分为4组：哮喘组、孟鲁司特组、卡介苗多糖核酸组和正常对照组。用卵白蛋白制备大鼠哮喘模型。计数血中嗜酸性粒细胞(EOS)；应用双抗体夹心酶联免疫吸附试验测定血浆中IL-4和γ-干扰素（IFN-γ）浓度；采用SYBR GREEN I荧光实时定量PCR法测定STAT5b mRNA和IL-4 mRNA的相对表达量。结果：①哮喘组血单个核细胞中STAT5b mRNA和IL-4 mRNA的表达量高于其他各组（P<0.01）；在孟鲁司特组和卡介苗多糖核酸组中两者的表达量相近（P>0.05）。哮喘组除了IFN-γ水平低外，其余无论是STAT5b mRNA，IL-4 mRNA，EOS绝对值等都是4组中最高的（P<0.01）；除哮喘组外，其余组的各项指标相近（P>0.05）。②STAT5b mRNA表达量与IL-4 mRNA表达量、IL-4浓度、EOS绝对值呈正相关(P<0.01)，与IFN-γ浓度呈负相关（P<0.01）。结论：哮喘大鼠血单个核细胞中STAT5b mRNA和IL-4 mRNA的表达增强且呈正相关；孟鲁司特和卡介苗多糖核酸可以下调STAT5b mRNA和IL-4 mRNA的表达，可能为其抑制哮喘气道炎症形成的重要机制之一。［中国当代儿科杂志，2009，11（2）：133-137］

Abstract:

OBJECTIVE: To study the expression of signal transducer and activator of transcription 5b (STAT5b) mRNA and interleukin-4 (IL-4) mRNA in blood mononuclearcells in a rat model of asthma and the effect of montelukast (MK) and BCG-polysaccharide and nucleic acid injection (BCG-PSN) on STAT5b mRNA and IL-4 mRNA expression. METHODS: Fifty-two male Sprague-Dawley rats (weight:140-200 g) were randomly divided into four groups: asthma, MK-treated and BCG-PSN-treated and control groups. Rat model of asthma was prepared by ovalbumin (OVA) sensitization. The rats were sacrificed 24 hrs after the last sensitization. Blood eosinophils (EOS) were counted. Plasma contens of IL-4 and interferon-γ (IFN-γ) were measured using ELISA. Expression of STAT5b mRNA and IL-4 mRNA in blood mononuclearcells was detected with SYBR GREEN I fluorescent quantitation PCR method. RESULTS: Blood contents of STAT5b mRNA and IL-4 mRNA in the untreated asthma group were significantly higher than those in the other three groups (P<0.01). Blood EOS count and plasma IL-4 contents in the untreated asthma group significantly increased, while plasma IFN-γ contents significantly decreased compared with the other three groups (P<0.01). There were no significant differences in the parameters measured among the MK-treated, the BCG-PSN-treated and the control groups. STAT5b mRNA expression was positively correlated to IL-4 mRNA expression, IL-4 content and EOS count (r=0.730, 0.650, 0.664, respectively; P<0.01), but negatively correlated to IFN-γ content (r=-0.798; P<0.01). CONCLUSIONS: STAT5b mRNA and IL-4 mRNA were strongly expressed in blood mononuclearcells in rats with asthma, and there was a positive correlation between them. MK and BCG-PSN had inhibitory effects on the expression of STAT5b mRNA and IL-4 mRNA, which might be contributed to suppression of airway inflammation in asthma.［Chin J Contemp Pediatr, 2009, 11 (2):133-137］