斯钙素-1改善哮喘小鼠气道炎症和气道重塑的机制

The mechanism of stanniocalcin-1 alleviates airway inflammation and remodeling in asthma mice

目的探讨斯钙素-1(STC-1)减轻哮喘小鼠气道炎症及气道重塑的机制。方法采用腹腔注射鸡卵清蛋白(OVA)与氢氧化铝凝胶[Al(OH)3]的混合物致敏、OVA雾化激发成功诱导构建哮喘小鼠模型。随机将40只雌性C57BL/6J小鼠分为正常对照组、哮喘组、哮喘+低剂量重组人斯钙素-1(rhSTC-1,1.25μg/L)组、哮喘+高剂量rhSTC-1(5.0μg/L)组和哮喘+地塞米松(5 mg/kg)组。收集右肺支气管肺泡灌洗液(BALF)检测炎性细胞分类及计数,左肺进行HE染色和Masson染色观察肺组织病理改变、气道重塑变化,右肺行Western blot、免疫组化检测STC-1、核转录因子-κB p65(NF-κB p65)、磷酸化NF-κB p65(p-p65)、α-平滑肌肌动蛋白(α-SMA)表达,qPCR检测STC-1、NF-κB p65、α-SMA mRNA表达。结果与正常对照组比较,哮喘组BALF中的白细胞(WBC)总数、嗜酸性粒细胞数(EOS)以及中性粒细胞数(NEU)均升高,肺组织STC-1、NF-κB p65、p-p65、α-SMA蛋白表达升高,STC-1、NF-κB p65、α-SMA mRNA表达升高,差异均有统计学意义(P均<0.05)。与哮喘组比较,哮喘+低、高剂量rhSTC-1组和哮喘+地塞米松组BALF白细胞总数、嗜酸性粒细胞数、中性粒细胞数降低,肺组织NF-κB p65、p-p65、α-SMA蛋白表达降低,NF-κB p65、α-SMA mRNA表达降低,差异均有统计学意义(P均<0.05)。结论rhSTC-1可减少哮喘小鼠气道炎症、胶原纤维沉积。STC-1作为一种应激性保护蛋白,起到抗炎作用,STC-1可能通过抑制NF-κB活化减轻气道炎症和气道重塑。

Objective To explore the effect of stanniocalcin-1(STC-1)on airway inflammation and airway remodeling in asthmatic mice and the related mechanisms.Methods A mouse model of asthma was induced by sensitization and ovalbumin(OVA)atomization stimulation by intraperitoneal injection of OVA/aluminium hydroxide gel.40 C57 BL/6 J female mice were randomly divided into 5 groups:normal control group,asthma group,asthma+low-dose recombinant human stanniocalcin-1(rhSTC-1,1.25μg/L)group,asthma+high-dose rhSTC-1(5μg/L)group and asthma+dexamethasone(5 mg/kg)group.The right lung bronchoalveolar lavage fluid(BALF)was collected to detect the count and classification of inflammatory cells.The left lung HE staining and Masson staining were used to observe lung tissue pathological changes and airway remodeling changes.Western blot and immunohistochemistry were used to detect STC-1,nuclear transcription factor-κB p65(NF-κB p65),phosphorylation nuclear transcription factor-κB p65(p-p65)andα-smooth muscle actin(α-SMA)protein expression;real-time fluorescent quantitative PCR was used to detect STC-1,NF-κB p65,α-SMA mRNA expression.Results Compared with the normal control group,the total number of white blood cells,the number of eosinophils and neutrophils in BALF in the asthma group increased;in the lung tissue the protein expression of STC-1,NF-κB p65,p-p65,andα-SMA increased,and the mRNA expression of STC-1,NF-κB p65,α-SMA increased(all P<0.05).Compared with the asthma group,in the asthma+low-dose rhSTC-1 group,asthma+high-dose rhSTC-1 group and asthma+dexamethasone group,the total number of white blood cells,eosinophils,and neutrophils decreased;the expression of NF-κB p65,p-p65,α-SMA protein and NF-kB p65,α-SMA mRNA in lung tissue decreased,the difference are statistically significant(P<0.05).Conclusions rhSTC-1 could reduce airway inflammation and collagen fiber deposition in asthmatic mice.STC-1 as a stress protective protein might play a role in reducing airway inflammation and airway remodeling by inhibiting NF-κB activation.