PDF(Pubmed)
Abstract：
Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. Epithelial-mesenchymal transition (EMT) is an essential player in these alterations. Scutellarin is isolated from Erigeron breviscapus. Its vascular relaxative, myocardial protective, and anti-inflammatory effects have been well established. This study was designed to detect the biological roles of scutellarin in asthma and its related mechanisms. The asthma-like conditions were induced by ovalbumin challenges. The airway resistance and dynamic compliance were recorded as the results of AHR. Bronchoalveolar lavage fluid (BALF) was collected and processed for differential cell counting. Hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson staining were conducted to examine histopathological changes. The levels of asthma-related cytokines were measured by enzyme-linked immunosorbent assay. For in vitro analysis, the 16HBE cells were stimulated with 10 ng/mL transforming growth beta-1 (TGF-β1). Cell migration was estimated by Transwell assays and wound healing assays. E-cadherin, N-cadherin, and α-smooth muscle actin (α-SMA) were analyzed by western blotting, real-time quantitative polymerase chain reaction, immunofluorescence staining, and immunohistochemistry staining. The underlying mechanisms of the mitogen-activated protein kinase (MAPK) and Smad pathways were investigated by western blotting. In an ovalbumin-induced asthmatic mouse model, scutellarin suppressed inflammation and inflammatory cell infiltration into the lungs and attenuated AHR and airway remodeling. Additionally, scutellarin inhibited airway EMT (upregulated E-cadherin level and downregulated N-cadherin and α-SMA) in ovalbumin-challenged asthmatic mice. For in vitro analysis, scutellarin prevented the TGF-β1-induced migration and EMT in 16HBE cells. Mechanistically, scutellarin inhibits the phosphorylation of Smad2, Smad3, ERK, JNK, and p38 in vitro and in vivo. In conclusion, scutellarin can inactivate the Smad/MAPK pathways to suppress the TGF-β1-stimulated epithelial fibrosis and EMT and relieve airway inflammation and remodeling in asthma. This study provides a potential therapeutic strategy for asthma.
摘要：
哮喘是一种以气道高反应性（AHR）为特征的慢性炎症性疾病，炎症,和重塑。上皮-间质转化（EMT）是这些改变的重要参与者。灯盏花素是从灯盏细辛中分离出来的。它的血管松弛剂，心肌保护，和抗炎作用已经确立。本研究旨在探讨灯盏乙素在哮喘中的生物学作用及其相关机制。哮喘样病症是由卵清蛋白激发引起的。记录气道阻力和动态顺应性作为AHR的结果。收集支气管肺泡灌洗液（BALF）并进行处理以进行差异细胞计数。苏木精和伊红染色，高碘酸希夫染色，进行Masson染色以检查组织病理学变化。采用酶联免疫吸附试验检测哮喘相关细胞因子水平。对于体外分析，用10ng/mL转化生长β-1（TGF-β1）刺激16HBE细胞。通过Transwell测定和伤口愈合测定估计细胞迁移。E-cadherin,N-钙黏着蛋白,和α-平滑肌肌动蛋白（α-SMA）通过蛋白质印迹分析，实时定量聚合酶链反应，免疫荧光染色，和免疫组织化学染色。通过蛋白质印迹研究了丝裂原活化蛋白激酶（MAPK）和Smad途径的潜在机制。在卵清蛋白诱导的哮喘小鼠模型中，灯盏乙素抑制炎症和炎症细胞浸润到肺部，并减轻AHR和气道重塑。此外,灯盏乙素抑制卵清蛋白攻击的哮喘小鼠的气道EMT（上调的E-cadherin水平和下调的N-cadherin和α-SMA）。对于体外分析，灯盏乙素可防止TGF-β1诱导的16HBE细胞迁移和EMT。机械上,灯盏乙素抑制Smad2，Smad3，ERK，JNK,和p38的体外和体内。总之,灯盏乙素可使Smad/MAPK通路失活,抑制TGF-β1刺激的上皮纤维化和EMT,缓解哮喘气道炎症和重塑。本研究为哮喘提供了一种潜在的治疗策略。
