吸烟大鼠支气管肺组织中Gq的表达及其影响

目的探讨Gq在COPD大鼠模型支气管肺组织中的表达变化及其在COPD大鼠模型气道炎症中的作用.方法将Wistar大鼠44只随机分为4组:①非吸烟对照组;②吸烟1个月组;③吸烟2个月组;④干预(地塞米松 吸烟2个月)组.观察肺组织病理学变化和支气管肺泡灌洗液(BALF)中白细胞记数和分类.支气管肺组织Gq表达检测采用免疫组织化学和Western blot 分析.结果吸烟大鼠的支气管粘膜和肺实质均有大量炎细胞浸润,BALF中白细胞总数和中性粒细胞数均显著高于对照组,吸烟2个月大鼠出现明显肺气肿改变.Gq在对照组大鼠支气管肺组织有弱表达,在模型组和干预组均有过度表达,Gq阳性细胞主要为气道上皮细胞、炎细胞和毛细血管内皮细胞.模型组大鼠Gq阳性细胞百分比和BALF中白细胞总数、中性粒细胞数呈显著正相关.Western blot 分析显示模型组和干预组Gq表达水平显著高于对照组,而药物干预后Gq表达水平显著下降,却仍高于对照组.结论 Gq的强表达可能在吸烟大鼠的气道炎症中发挥作用,干预其过度表达可能是治疗气道炎症的有效方法,糖皮质激素有可能通过抑制Gq的过度表达而减轻气道炎症的作用.

Expression of Gq in bronchopulmonary tissues in rats after inhalation of cigarette smoke

Objective To study the expression of Gq protein in bronchopulmonary tissues of rats of chronic obstructive pulmonary disease (COPD) model and the roles of inflammation in airway of COPD rats. Methods A total of 44 Wistar rats were divided randomly into 4 groups: nonsmoking control group, 1 month smoking group, 2 month smoking group, and intervention group (dexamethasone smoking for 2 months). The pathological changes of lung tissues and the total and differential count of white blood cells in bronchoalveolar lavage fluid (BALF) in all groups were observed. The expression of Gq in bronchopulmonary tissues was detected by immunohistochemical method and Western blot analysis. Results More significant increases in total number of leukocytes and neutrophils in BALF were found in the model group than those in the control group. Gq was mainly expressed in airway epithelial cells, inflammatory cells, and pulmonary capillary endothelia. Weak expression of Gq was found in bronchopulmonary tissues in the control group, but overexpression of Gq in the model group. The ratios of Gq positive cells in bronchopulmonary tissues were significantly correlated with the number of white blood cells and neutrophils in BALF. The levels of expression of Gq were significantly higher in the model groups and intervention group than those in the control group. More significant decrease in Gq expression was found in the intervention group as compared with that in 3 month smoking group. Conclusion Gq may be involved in the process of airway inflammation in COPD. Inhibition of the Gq overexpression might be a new approach to the treatment of COPD. Corticosteroid might have some effects on the inhibition of the airway inflammation.