Li Tangjia, Zhang Chu, Wei Yuke, Zhong Haijing, Shan Luchen, Yu Pei, Wang Yuqiang, Xu Lipeng
Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-Cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China.
Curr Pharm Des. 2022;28(30):2508-2517. doi: 10.2174/1381612828666220729094806.
Acute lung injury (ALI) is a serious respiratory disease with a high mortality rate, and there is an urgent need for a more effective treatment strategy. Andrographolide derivative AL-1 has been identified to possess anti-inflammatory activity. However, whether it could reduce LPS-induced lung injury in mice through inhibiting NLRP3 inflammasome activation and protecting lung permeability has not yet been elucidated. In the present research, we investigated the protective effect of AL-1 on ALI mice and demonstrated the potential mechanisms.
Male Balb/c mice were anesthetized with isoflurane, and ALI mice were induced by intratracheal instillation of LPS. The mice were euthanized after LPS administration for 12 h, then bronchoalveolar lavage fluid (BALF) and lung tissues were collected. The levels of inflammatory factors were measured by ELISA assay, and HE staining and lung injury scoring were used to evaluate the pathological changes in the pulmonary tissues. Immunohistochemistry and immunofluorescence examination were conducted to detect the expression levels of related proteins. Western blot was performed to measure the levels of NLRP3 inflammasome and tight junction proteins.
The study indicated that AL-1 effectively alleviated lung injury by reduction of proinflammatory cytokine levels, MPO activity, lung W/D ratio, and total protein levels. Furthermore, AL-1 improved pathological changes in lung tissue and significantly reduced the infiltration of inflammatory cells. Administration with AL-1 markedly inhibited the expression of NLRP3, ASC, Caspase-1, IL-1β, gasdermin D (GSDMD), and VCAM-1 but increased the expression of ZO-1, Occludin, JAM-A, and Claudin-1.
Taken together, these results demonstrated that AL-1 ameliorated pulmonary damage by inhibiting the activation of the NLRP3 inflammasome pathway and restoring TJ protein expression.
急性肺损伤（ALI）是一种死亡率很高的严重呼吸系统疾病，迫切需要更有效的治疗策略。穿心莲内酯衍生物AL-1已被证实具有抗炎活性。然而，其是否能通过抑制NLRP3炎性小体激活和保护肺通透性来减轻脂多糖（LPS）诱导的小鼠肺损伤尚未阐明。在本研究中，我们研究了AL-1对ALI小鼠的保护作用并阐明了潜在机制。
雄性Balb/c小鼠用异氟烷麻醉，通过气管内滴注LPS诱导ALI小鼠。LPS给药12小时后对小鼠实施安乐死，然后收集支气管肺泡灌洗液（BALF）和肺组织。通过酶联免疫吸附测定（ELISA）检测炎症因子水平，并用苏木精-伊红（HE）染色和肺损伤评分评估肺组织的病理变化。进行免疫组织化学和免疫荧光检查以检测相关蛋白的表达水平。采用蛋白质免疫印迹法检测NLRP3炎性小体和紧密连接蛋白的水平。
研究表明，AL-1通过降低促炎细胞因子水平、髓过氧化物酶（MPO）活性、肺湿干重比和总蛋白水平有效减轻肺损伤。此外，AL-1改善了肺组织的病理变化并显著减少了炎症细胞浸润。给予AL-1显著抑制了NLRP3、凋亡相关斑点样蛋白（ASC）、半胱天冬酶-1（Caspase-1）、白细胞介素-1β（IL-1β）、gasdermin D（GSDMD）和血管细胞黏附分子-1（VCAM-1）的表达，但增加了紧密连接蛋白1（ZO-1）、闭合蛋白（Occludin）、连接黏附分子A（JAM-A）和紧密连接蛋白1（Claudin-1）的表达。
综上所述，这些结果表明AL-1通过抑制NLRP3炎性小体途径的激活和恢复紧密连接蛋白表达来改善肺损伤。
