穿孔素和颗粒酶B在哮喘大鼠肺组织中的表达及重组人生长激素的干预作用

Expression of perforin and granzyme B in asthmatic rats and intervention of recombinant human growth hormone

目的探讨哮喘大鼠肺组织中穿孔素(PFP)、颗粒酶B(GzmB)的表达变化及重组人生长激素(rhGH)的干预作用。方法 30只雄性Sprague-Dawley大鼠随机分为正常对照组、哮喘模型组及rhGH干预组。通过苏木精-伊红染色观察卵蛋白激发作用及rhGH干预后哮喘大鼠气道的病理变化。TUNEL原位凋亡检测支气管上皮细胞凋亡,RT-PCR方法检测肺组织中PFP及GzmB mRNA的表达。结果哮喘组支气管上皮细胞凋亡指数明显增高,而rhGH干预组的凋亡指数则明显低于哮喘组(P<0.05);PFP和GzmB mRNA在对照组中呈低表达;在哮喘组的表达明显强于对照组(P<0.05);rhGH进行干预后,PFP和GzmB mRNA表达明显低于哮喘组(0.48±0.08 vs 0.63±0.08;0.44±0.13 vs 0.71±0.15;均P<0.05)。PFP和GzmB mRNA表达与支气管上皮细胞凋亡率呈正相关(r分别为0.800和0.806,P<0.05)。结论 PFP和GzmB参与了哮喘发病过程中的重要环节;rhGH可能通过降低PFP和GzmB的表达抑制支气管上皮细胞的凋亡从而抑制气道重塑。

Objective To study the expression of perforin and granzyme B（GzmB） in the lungs of asthmatic rats and the effect of recombinant human growth hormone（rhGH） on the expression. Methods Thirty Sprague-Dawley male rats were randomly divided into a normal control group and asthma groups with and without rhGH treatment.An asthma model was prepared by repeated sensitization with ovalbumin and aluminium hydroxide.The morphological changes of the airway were observed by hematoxylin and eosin staining.Terminal deoxyribonucleotide transferase-mediated dUTP-bintin（TUNLE） was used to detect the apoptosis of epithelial cells in the airway.RT-PCR was used to detect the mRNA transcripts of perforin and GzmB in the lung tissues. Results A significantly increased apoptosis rate of airway epithelial cells was noted in the untreated asthma group.The apoptosis rate was significantly ruduced in the rhGH-treated asthma group（P〈0.05）.Compared with the control group,perforin and GzmB expression in the lungs in the untreated asthma group increased significantly.The rhGH-treated asthma group demonstrated significantly decreased perforin（0.48±0.08 vs 0.63±0.08;P〈0.05） and GzmB（0.44±0.13 vs 0.71±0.15;P〈0.05） expression in the lungs compared with the untreated asthma group.Both PFP（r=0.800,P〈0.05） and GzmB（r=0.806,P〈0.01） were positively correlated with the apoptosis rate of airway epithelial cells. Conclusions Perforin and GzmB may play important roles in the pathogenesis of asthma.rhGH treatment can inhibit apoptosis of airway epithelial cells and airway remodeling,possibly through a reduction in perforin and GzmB expression.