Objectives: To explore the mechanism of Pingchuanning Formula (PCN) for inhibiting airway inflammation in rats with asthmatic cold syndrome.
Methods: A total of 105 SD rats were randomized equally into 7 groups, including a control group, an asthmatic cold syndrome model group, 3 PCN treatment groups at high, medium and low doses, a Guilong Kechuanning (GLCKN) treatment group, and a dexamethasone (DEX) treatment group. In all but the control rats, asthma cold syndrome models were established and daily gavage of saline, PCN, GLCKN or DEX was administered 29 days after the start of modeling. The changes in general condition, lung function and lung histopathology of the rats were observed, and inflammatory factors in the alveolar lavage fluid (BALF), oxidative stress, lung tissue ultrastructure, cytokine levels, and expressions of the genes related to the HMGB1/Beclin-1 axis and autophagy were analyzed.
Results: The rat models had obvious manifestations of asthmatic cold syndrome with significantly decreased body mass, food intake, and water intake, reduced FEV0.3, FVC, and FEV0.3/FVC, obvious inflammatory cell infiltration in the lung tissue, and increased alveolar inflammation score and counts of neutrophils, eosinophils, lymphocytes, macrophages, and leukocytes in the BALF. The rat models also had significantly increased MDA level and decreased SOD level and exhibited obvious ultrastructural changes in the lung tissues, where the expressions of HMGB1, Beclin-1, ATG5, TNF-α, IL-6,IL-1β, and IL-13 and the LC3II/I ratio were increased, while the levels of Bcl-2 and IFN-γ were decreased. PCN treatment significantly improved these pathological changes in the rat models, and its therapeutic effect was better than that of GLKCN and similar to that of DEX.
Conclusions: PCN can effectively alleviate airway inflammation in rat models of asthmatic cold syndrome possibly by modulating the HMGB1/Beclin-1 signaling axis to suppress cell autophagy, thereby attenuating airway inflammatory damages.
目的: 基于高迁移率族蛋白 B1（HMGB1）/自噬相关基因Beclin-1（Beclin-1）轴探讨平喘宁方（PCN）调控细胞自噬减轻寒哮证大鼠气道炎症的作用。方法: 105只SPF级SD大鼠，随机分为对照组（CON）、模型组（MOD）、平喘宁高、中、低剂量组（PCN-H、PCN-M、PCN-L）、桂龙咳喘宁组（GLCKN）和地塞米松组（DEX），15只/组。除CON组外，其余大鼠构建寒哮证模型，并从第29天开始灌胃PCN、DEX及GLCKN。观察各组大鼠体质量、摄食量、摄水量，肺功能、肺组织氧化应激水平、肺泡灌洗液（BALF）炎性因子、肺组织病理、肺组织超微结构，细胞因子水平以及HMGB1/Beclin-1信号轴和细胞自噬相关基因和蛋白的表达。结果: 与CON组比较，MOD组大鼠表现出呼吸急促、喘息、流涕、腹部收缩明显、反应迟钝、反应缓慢，进食量减少，明显的皮毛枯槁或脱落等表现；体质量、摄食量、摄水量明显下降（P<0.05）；第0.3秒用力呼气量（FEV0.3）、用力肺活量（FVC）、FEV0.3/FVC明显降低（P<0.05）；肺组织表现出明显的炎性浸润，肺泡炎症评分明显上升（P<0.05）；BALF中性粒细胞、嗜酸性粒细胞、淋巴细胞、巨噬细胞、白细胞数量明显上升（P<0.05）；肺组织MDA明显上升，SOD明显下降（P<0.05）；透射电镜（TEM）观察发现MOD组有自噬小泡数量较多，线粒体排列有紊乱及水肿现象，嗜锇性板层小体排空比较明显；肺组织HMGB1、Beclin-1、ATG5蛋白及mRNA表达明显上升，Bcl-2蛋白表达及mRNA明显降低，LC3II/I比值明显上升（P<0.05）；大鼠肺组织细胞因子IFN-γ明显降低，TNF-α、IL-6IL-1β、IL-13明显上升（P<0.05）。与MOD组比较，PCN能明显改善各项指标的病理改变，且作用效果优于GLKCN组，不亚于DEX组（P<0.05）。结论: PCN能有效改善寒哮证模型大鼠气道炎症，其机制可能与调控HMGB1/Beclin-1信号轴，抑制细胞自噬从而缓解炎症损伤有关。.
Keywords: Pingchuanning Formula; airway inflammation; asthmatic cold syndrome; bronchial asthma; cell autophagy; lung function.