Department of Respiratory and Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, PR China.
Department of Respiratory and Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, PR China; Department of Respiratory Medicine, The First Hospital of Changsha, Changsha, Hunan, 410008, PR China.
Biochem Biophys Res Commun. 2019 Oct 29;519(1):8-14. doi: 10.1016/j.bbrc.2019.08.054. Epub 2019 Aug 29.
To explore the effect of double-stranded RNA-dependent kinase (PKR) in acute lung injury (ALI) and resultant acute respiratory distress syndrome (ARDS). A mouse model of lipopolysaccharide (LPS)-induced ALI was used to evaluate the levels of phosphorylated (p)-PKR and NLRP3 in lung tissue, and the protective effects of a PKR inhibitor on lung injury. And in vitro, macrophages were incubated with LPS, with or without PKR inhibitor pre-treatment. It was observed that the levels of p-PKR protein and NLRP3 protein were significantly increased compared with those in control tissues after LPS administration. Meanwhile, treatment with PKR inhibitor decreased inflammation, injury score, wet/dry weight ratio, bronchoalveolar lavage fluid (BALF) protein levels, neutrophil count in BALF, myeloperoxidase activity and expression of high-mobility group box1(HMGB1) and interleukin(IL)-1β in the lungs of LPS-challenged mice. In vitro, we demonstrated that the levels of p-PKR and NLRP3, and cell mortality rate were increased in macrophages which were incubated with LPS compared with those without LPS administration, and PKR inhibitor significantly suppressed the level of NLRP3, caspase-1, HMGB1 and IL-1β. These results indicate that PKR plays a key role in ALI through NLRP3-pyrotosis pathway and pharmacological inhibition of PKR may have potential therapeutic effects in the treatment of patients with ALI and ARDS.
探讨双链 RNA 依赖性激酶（PKR）在急性肺损伤（ALI）和由此导致的急性呼吸窘迫综合征（ARDS）中的作用。使用脂多糖（LPS）诱导的 ALI 小鼠模型来评估肺组织中磷酸化（p）-PKR 和 NLRP3 的水平，以及 PKR 抑制剂对肺损伤的保护作用。并且在体外，用 LPS 孵育巨噬细胞，或用 PKR 抑制剂预处理。观察到 LPS 给药后 p-PKR 蛋白和 NLRP3 蛋白的水平与对照组织相比显著增加。同时，PKR 抑制剂治疗降低了 LPS challenged 小鼠肺中的炎症、损伤评分、湿/干重比、支气管肺泡灌洗液（BALF）蛋白水平、BALF 中性粒细胞计数、髓过氧化物酶活性以及高迁移率族蛋白 1（HMGB1）和白细胞介素（IL）-1β的表达。在体外，我们证明与未给予 LPS 的巨噬细胞相比，用 LPS 孵育的巨噬细胞中 p-PKR 和 NLRP3 的水平以及细胞死亡率增加，PKR 抑制剂显著抑制了 NLRP3、半胱天冬酶-1、HMGB1 和 IL-1β的水平。这些结果表明，PKR 通过 NLRP3-细胞焦亡途径在 ALI 中发挥关键作用，PKR 的药理学抑制可能对治疗 ALI 和 ARDS 患者具有潜在的治疗作用。
