Han Yanhong, Ge Chuang, Ye Junmei, Li Ruiyan, Zhang Yubin
State Key Laboratory of Natural Medicines, Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China.
State Key Laboratory of Natural Medicines, Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China.
Pulm Pharmacol Ther. 2023 Dec;83:102259. doi: 10.1016/j.pupt.2023.102259. Epub 2023 Sep 17.
Acute pneumonia induced by Pseudomonas aeruginosa is characterized by massive infiltration of inflammatory cell and the production of reactive oxygen species (ROS), which lead to severe and transient pulmonary inflammation and acute lung injury. However, P.aeruginosa infection is resistant to multiple antibiotics and causes high mortality in clinic, the search for alternative prophylactic and therapeutic strategies is imperative.
This study was aimed to investigate the anti-inflammatory and antioxidant effects of DMB, a novel derivative of berberine, and explore the role of AIM2 inflammasome in P. aeruginosa-induced acute pneumonia.
Acute pneumonia mice were established by tracheal injection of P. aeruginosa suspension. Pathological changes of lung tissue were observed by its appearance and H&E staining. The lung coefficient ratio was measured to evaluate pulmonary edema. Inflammatory factors were detected by qRT-PCR, western blotting and immunohistochemistry. ROS and other indicators of oxidative damage were analyzed by flow cytometry and specific kit. Proteins related to AIM2 inflammasome were detected by western blotting.
Compared with the P. aeruginosa-induced group, DMB ameliorated pulmonary edema, hyperemia, and pathological damage based on its appearance and H&E staining in DMB groups. First, DMB attenuated the inflammatory response induced by P.aeruginosa. Compared with the P. aeruginosa-induced group, the lung coefficient ratio was decreased by 31.5%, the MPO activity of lung tissue was decreased by 44.0%, the mRNA expression levels of TNF-α, IL-1β and IL-6 were decreased by 64.8%, 51.2% and 64.0% respectively, and those protein expression levels were decreased by 40.1%, 42.8% and 47.8% respectively, and the number of white blood cells, neutrophils and monocytes were decreased by 53.5%, 29.4% and 13.7% in high dose (200 mg/kg) DMB group. Second, DMB alleviates oxidative stress in the lung tissue during P. aeruginosa-induced acute pneumonia. Compared with the P. aeruginosa-induced group, the level of GSH was increased by 42.5% and MDA was decreased by 49.5% in high dose DMB group. Moreover, the western blotting results showed that DMB markedly suppressed the expression of AIM2, ASC, Cleaved caspase1 and decreased the secretion of IL-1β. Additionally, these results were also confirmed by in vitro experiments using MH-S and BEAS-2B cell lines.
Taken together, these results indicated that DMB ameliorates P. aeruginosa-induced acute pneumonia through anti-inflammatory, antioxidant effects, and inhibition of AIM2 inflammasome activation.
铜绿假单胞菌引起的急性肺炎的特征是炎症细胞大量浸润和活性氧（ROS）的产生，这会导致严重且短暂的肺部炎症和急性肺损伤。然而，铜绿假单胞菌感染对多种抗生素耐药，在临床上导致高死亡率，因此寻找替代的预防和治疗策略势在必行。
本研究旨在探讨小檗碱新型衍生物DMB的抗炎和抗氧化作用，并探讨AIM2炎性小体在铜绿假单胞菌诱导的急性肺炎中的作用。
通过气管注射铜绿假单胞菌悬液建立急性肺炎小鼠模型。通过观察肺组织外观和苏木精-伊红（H&E）染色观察肺组织的病理变化。测量肺系数比值以评估肺水肿。通过实时定量聚合酶链反应（qRT-PCR）、蛋白质免疫印迹法和免疫组织化学检测炎症因子。通过流式细胞术和特定试剂盒分析ROS和其他氧化损伤指标。通过蛋白质免疫印迹法检测与AIM2炎性小体相关的蛋白质。
与铜绿假单胞菌诱导组相比，基于DMB组的外观和H&E染色，DMB改善了肺水肿、充血和病理损伤。首先，DMB减轻了铜绿假单胞菌诱导的炎症反应。与铜绿假单胞菌诱导组相比，高剂量（200mg/kg）DMB组的肺系数比值降低了31.5%，肺组织髓过氧化物酶（MPO）活性降低了44.0%，肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的mRNA表达水平分别降低了64.8%、51.2%和64.0%，这些蛋白质表达水平分别降低了40.1%、42.
