地塞米松干预对哮喘大鼠气道形态、肺组织Galectin-8及ERK1/2表达的影响

The Effect of Dexamethasone Intervention on Airway Morphology,Galectin-8 in Lung Tissue and Expression of ERK1/2 in Asthmatic Rats

为探讨地塞米松对哮喘大鼠气道形态、肺组织半乳糖凝集素-8(Galectin-8)、细胞外信号调节激酶1/2(ERK1/2)表达情况的干预作用,本研究选取SPF级健康雄性SD大鼠30只,随机分为对照组、哮喘组和地塞米松组,每组10只,哮喘组和地塞米松组大鼠采用卵清白蛋白致敏与激发,建立大鼠哮喘模型。其中,地塞米松组在每次激发前给予地塞米松干预,对照组用生理盐水腹腔注射和雾化吸入。采用图像分析技术测定各组气道壁形态指标,免疫组化、RT-PCR检测Galectin-8、p-ERK1/2、Galectin-8 mRNA和ERK1/2 mRNA的表达。在气道壁厚度、平滑肌厚度、Galectin-8、ERK1/2表达上,哮喘组较对照组均显著增加(p<0.05);地塞米松组较哮喘组均明显降低(p<0.05),但仍高于对照组(p<0.05)。相关性分析显示:哮喘组大鼠气道壁厚度、平滑肌厚度与Galectin-8、Galectin-8 mRNA、p-ERK1/2及ERK1/2 mRNA呈正相关。研究说明,Galectin-8和ERK1/2可能参与了大鼠哮喘气道重塑过程,而地塞米松干预可抑制气道壁厚度和平滑肌厚度,并显著降低Galectin-8和ERK1/2表达。

In order to investigate the intervention effect of dexamethason on the morphology of airways, galactose lectin-8 （Galectin-8） in lung tissue and the expression of extracellular signal regulated kinase 1/2 （ERK1/2） in asthmatic rats, 30 healthy male SD rats of SPF level were selected and randomly divided into control group, asthma group and dexamethasone group, with 10 rats in each group. Asthma group and dexamethasone group were sensitized and induced by egg albumin to establish asthmatic rat models. Dexamethasone group was given dexamethasone intervention before each stimulation, while the control group was treated with normal saline by intraperitoneal injection and aerosol inhalation. Image analysis was used to measure the morphological indicators of airway walls of each group, and immunohistochemistry technique and RT-PCR were applied to detect the expression of Galectin-8, p-ERK1/2, Galectin-8 mRNA and ERK1/2 mRNA. The results showed that the thickness of airway walls, the thickness of smooth muscles and the expression of Galectin-8 as well as ERK1/2 in asthma group were significantly increased compared with the control group （/9〈0.05）; these data of dexamethasone group were significantly decreased compared with those of asthma group （p〈0.05）, but were still higher than those of the control group （p 〈0.05）. Correlation analysis indicated that the thickness of airway walls and smooth muscles in asthma rats were in positive correlation with Galectin-8, Galectin-8 mRNA, p-ERK1/2 and ERK1/2 mRNA. In conclusion, this study implied that Galectin-8 and ERK1/2 might be involved in the remodeling process of asthmatic airway in rats, while the intervention of dexamethasone could inhibit the thickness of airway walls and smooth muscles, which could significantly decrease the expression of Galectin-8 and ERK1/2.