Galectin-3对哮喘豚鼠肺组织嗜酸粒细胞凋亡及Bax蛋白表达的影响

Influence of Galectin-3 on Eosinophil Apoptosis and Expression of Bax Protein in Lung Tissues of Asthmatic Guinea Pig

目的研究Galectin-3对哮喘豚鼠肺组织嗜酸粒细胞凋亡及Bax蛋白表达的影响。方法将36只豚鼠随机分为0.9%氯化钠注射液组(生理盐水组)、哮喘组及Galectin-3组,每组12只。哮喘组及Galectin-3组豚鼠用卵白蛋白(OVA)致敏和激发制作哮喘模型,Galectin-3组豚鼠于致敏第15～21天激发前1h腹腔注射Galectin-3(0.5mg/kg),1次/d,连续7d。测定3组豚鼠支气管肺泡灌洗液(BALF)中白介素5(IL-5)含量,计数BALF中嗜酸粒细胞数目,观察肺组织病理变化,应用缺口末端标记技术(TUNEL)法检测肺组织嗜酸粒细胞的凋亡,采用免疫组化法检测肺组织Bax蛋白的表达。结果Galectin-3组豚鼠BALF中IL-5含量〔(21.3±7.8)ng/L〕显著低于哮喘组〔(48.6±8.9)ng/L〕,差异有统计学意义(P<0.01);嗜酸粒细胞计数〔(24.2±7.8)×106/L〕显著低于哮喘组的〔(140.9±27.1)×106/L〕,差异有统计学意义(P<0.01);肺组织炎症反应明显轻于哮喘组;肺组织嗜酸粒细胞凋亡指数〔(14.7±4.6)%〕显著高于哮喘组〔(3.5±0.4)%〕,差异有统计学意义(P<0.01);肺组织Bax蛋白表达量平均积分吸光度值(2854.2±532.1)显著高于哮喘组(673.4±195.6),差异亦有统计学意义(P<0.01)。结论Galectin-3能减少哮喘豚鼠BALF中嗜酸粒细胞数量,减轻肺组织炎症反应,与其降低哮喘豚鼠BALF中IL-5含量、上调肺组织Bax蛋白表达、促进肺组织嗜酸粒细胞凋亡有关。

Objective To study the influence of Galectin-3 on eosinophil apoptosis and Bax protein expression in lung tissue of asthmatic guinea pig.Methods Thirty-six guinea pigs were randomly divided into groups saline （receiving 0.9% sodium chloride injection）,asthma,and Galectin-3,12 in each.Asthma models were established by sensitization and stimulation with ovalbumin （OVA） in groups asthma and Galectin-3.Galectin-3 group were given intraperitoneal injection of Galectin-3 （0.5 mg/kg,once/d,continuously for 7 d） before stimulation on days 15～21 of sensitization.Interleukin 5 （IL-5） content in guinea pig bronchoalveolar lavage fluid （BALF） was determined,eosinophil number in BALF was counted,and expression of Bax protein in lung detected by immunohistochemistry.Results IL-5 content in BALF was lower in Galectin-3 group （21.3±7.8 ng/L） than in asthma group （48.6±8.9 ng/L）,the difference was significant （P〈0.01）,and the eosinophil count was lower〔（24.2±7.8）×106/L,（140.9±27.1）×106/L,respectively）,the difference was significant （P〈0.01）.Lung tissue inflammation was lighter and lung tissue eosinophil apoptosis index higher in Galectin-3 group 〔（14.7±4.6）%〕 than in asthma group 〔（3.5±0.4）%〕,the difference was significant （P〈0.01）.Lung tissue Bax protein expression of Galectin-3 group was higher than that of asthma group,the difference was significant （P〈0.01）.Conclusion Galectin-3 can reduce the number of eosinophils in BALF and inflammation in lung tissue in asthma guinea pigs,related to its reducing IL-5 content,up-regulating Bax protein expression and promoting eosinophil apoptosis.