Jia Lingling, Liu Kai, Fei Teng, Liu Qian, Zhao Xiwei, Hou Linyi, Zhang Wenkai
Department of Thoracic Surgery, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China.
Department of Intensive Care Unit, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China.
Exp Ther Med. 2021 Apr;21(4):400. doi: 10.3892/etm.2021.9831. Epub 2021 Feb 24.
Acute lung injury caused by sepsis remains one of the most difficult challenges faced by patients in intensive care units and is associated with a high mortality rate. The aim of the present study was to investigate whether programmed cell death (PD)-1/programmed cell death-ligand 1 (PD-L1) inhibitors reduce alveolar macrophage apoptosis, reduce inflammatory factor release and relieve inflammation. For this purpose, murine alveolar macrophages, MH-S, were cultured and divided into control, lipopolysaccharide (LPS) and LPS+BMS-1 (PD-1/PD-L1 inhibitors) groups. LPS (10 ng/ml) was added to the LPS and LPS+BMS-1 groups for 24 h and PD-1/PD-L1 inhibitor BMS-1 (1 µmol/l) was added to the LPS+BMS-1 group for 72 h. PD-1 mRNA expression was detected using reverse transcription-quantitative PCR and PD-1 protein expression was detected using western blotting in the control, LPS and LPS+BMS-1 groups of macrophages. MH-S apoptosis was detected using flow cytometry with Annexin V/PI staining. The levels of the inflammatory factors interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α and IL-10 were detected by ELISA. Murine alveolar macrophages expressed PD-1 at both the molecular and protein levels and PD-1 expression was increased in MH-S cells stimulated with LPS. Compared with the LPS group, the expression of PD-1 in the LPS+BMS-1 group was significantly decreased. Flow cytometry demonstrated that there was increased apoptosis of alveolar macrophages in the LPS group compared with the control group, whereas, alveolar macrophages notably decreased apoptosis in the LPS+BMS-1 group compared with the LPS group. There was no statistical difference between the control group and the LPS+BMS-1 group. IL-1β, IL-6, TNF-α and IL-10 were increased in the LPS group compared with the control group. The levels of IL-1β, IL-6 and TNF-α in the LPS+BMS-1 group were lower compared with those in the LPS group whereas IL-10 was further increased. , the PD-1/PD-L1 inhibitor, BMS-1, decreases alveolar macrophage apoptosis compared with the LPS group to maintain effective immune clearance and reduce inflammatory factor release. This decreased the inflammatory response and reduced acute lung injury caused by sepsis. Therefore, PD-1/PD-L1 inhibitors may be a potential therapeutic target for acute lung injury in patients with sepsis.
脓毒症引起的急性肺损伤仍然是重症监护病房患者面临的最艰巨挑战之一，且与高死亡率相关。本研究的目的是调查程序性细胞死亡（PD）-1/程序性细胞死亡配体1（PD-L1）抑制剂是否能减少肺泡巨噬细胞凋亡、减少炎症因子释放并减轻炎症。为此，培养小鼠肺泡巨噬细胞MH-S，并将其分为对照组、脂多糖（LPS）组和LPS+BMS-1（PD-1/PD-L1抑制剂）组。向LPS组和LPS+BMS-1组中加入LPS（10 ng/ml）作用24小时，并向LPS+BMS-1组中加入PD-1/PD-L1抑制剂BMS-1（1 µmol/l）作用72小时。在巨噬细胞的对照组、LPS组和LPS+BMS-1组中，使用逆转录定量PCR检测PD-1 mRNA表达，使用蛋白质印迹法检测PD-1蛋白表达。使用Annexin V/PI染色的流式细胞术检测MH-S凋亡。通过酶联免疫吸附测定法检测炎症因子白细胞介素（IL）-1β、IL-6、肿瘤坏死因子（TNF）-α和IL-10的水平。小鼠肺泡巨噬细胞在分子和蛋白水平均表达PD-1，且在用LPS刺激的MH-S细胞中PD-1表达增加。与LPS组相比，LPS+BMS-1组中PD-1的表达显著降低。流式细胞术表明，与对照组相比，LPS组中肺泡巨噬细胞凋亡增加，而与LPS组相比，LPS+BMS-1组中肺泡巨噬细胞凋亡显著减少。对照组和LPS+BMS-1组之间无统计学差异。与对照组相比，LPS组中IL-1β、IL-6、TNF-α和IL-10增加。与LPS组相比，LPS+BMS-1组中IL-1β、IL-6和TNF-α水平较低，而IL-10进一步增加。PD-1/PD-L1抑制剂BMS-1与LPS组相比可减少肺泡巨噬细胞凋亡，以维持有效的免疫清除并减少炎症因子释放。这减轻了炎症反应并减轻了脓毒症引起的急性肺损伤。因此，PD-1/PD-L1抑制剂可能是脓毒症患者急性肺损伤的潜在治疗靶点。
