The aim of this study was to investigate the role and mechanism of perilipin 2 (PLIN2) in Pseudomonas aeruginosa pulmonary infection in vivo and in vitro. Twenty-eight-week-old male Balb/c mice were randomly divided into the control and PAO1 (P. aeruginosa standard strain) groups, which were administered phosphate-buffered saline (PBS) or PAO1 intratracheal instillation, respectively. RAW264.7 cells and BEAS-2B cells were stimulated with PBS or PAO1. The mRNA levels of PLIN2 and cytosolic phospholipase A2 (cPLA2) were detected by PCR. The protein expression of PLIN2 was detected by WB. BEAS-2B cells were transfected with shRNA against PLIN2, and cell proliferation was measured by CCK8. After 72 h, the expression of the PLIN2 gene in the PAO1 group was significantly higher than that in the control group. Compared with those in the control group, the protein levels of PLIN2, cyclooxygenase-2 (COX-2), and nuclear transcription factor-κB (NF-κB) in the PAO1 group were upregulated, while the expression of PLIN5 protein was downregulated. Furthermore, lung injury in the PAO1 group was more severe than that in the control group, and the lipid droplet (LD) level in lung tissue of PAO1 mice increased. After stimulation with P. aeruginosa, PLIN2 and cPLA2 genes in RAW264.7 and BEAS-2B cells were upregulated. CCK8 assay showed that proliferation decreased significantly in cells transfected with shRNA against PLIN2. In mice infected with P. aeruginosa, LDs accumulated in the lung tissue through an increase in PLIN2, which may result in increased COX-2-mediated anti-inflammatory cytokine release. This study provides a new understanding of the mechanism of lung infection and a new target for the treatment of clinical pulmonary injury.

本研究的目的是研究perilipin 2（PLIN2）在体内和体外铜绿假单胞菌肺部感染中的作用和机制。28周龄雄性Balb/c小鼠随机分为对照组和PAO1（铜绿假单胞菌标准株）组，分别给予磷酸盐缓冲盐水（PBS）或PAO1气管内滴注。RAW264.7 细胞和 BEAS-2B 细胞用 PBS 或 PAO1 刺激。PLIN2和胞质磷脂酶 A2 ( cPLA2)的 mRNA 水平) 通过 PCR 检测。WB检测PLIN2蛋白表达。用针对 PLIN2 的 shRNA 转染 BEAS-2B 细胞，并通过 CCK8 测量细胞增殖。72 h后，PAO1组PLIN2基因的表达量明显高于对照组。与对照组相比，PAO1组PLIN2、环氧合酶-2（COX-2）和核转录因子-κB（NF-κB）蛋白水平上调，而PLIN5蛋白表达下调。此外，PAO1组的肺损伤比对照组更严重，PAO1小鼠肺组织中的脂滴（LD）水平升高。用铜绿假单胞菌、PLIN2和cPLA2刺激后RAW264.7 和 BEAS-2B 细胞中的基因被上调。CCK8 测定表明，在用针对 PLIN2 的 shRNA 转染的细胞中，增殖显着降低。在感染铜绿假单胞菌的小鼠中，LDs 通过增加 PLIN2 在肺组织中积累，这可能导致 COX-2 介导的抗炎细胞因子释放增加。该研究为肺部感染的机制提供了新的认识，为临床肺损伤的治疗提供了新的靶点。