过表达PGRN抑制LPS诱导的肺泡上皮细胞损伤

目的:探讨颗粒体蛋白前体(progranulin,PGRN)对脂多糖(lipopolysaccharide,LPS)诱导的人肺泡上皮A549细胞和HPAEpi C细胞增殖、凋亡及炎症的影响。方法:实验分为4组:对照(control)组为正常培养的细胞;LPS组用LPS(10 mg/L)处理;PGRN+LPS组在转染pc DNA3.1-PGRN质粒后加入LPS处理;pc DNA3.1+LPS组在转染pc DNA3.1-EGFP质粒后加入LPS处理。MTT试剂盒检测细胞活力;Brd U掺入实验检测细胞增殖;流式细胞术检测细胞凋亡率;RT-q PCR和Western blot分别检测PGRN的mRNA和蛋白表达;Western blot检测caspase-3、Bcl-2、Bax、IL-1β、IL-6、TNF-α、p65和p-IκB-α的蛋白水平。结果:与对照组相比,LPS组的细胞增殖率下降(P0.05),凋亡率上升(P0.05),caspase-3和Bax的蛋白表达上调(P0.05),Bcl-2的蛋白表达下调(P0.05),IL-1β、IL-6和TNF-α的蛋白表达上调(P0.05),p65和p-IκB-α的蛋白水平增加(P0.05),与LPS组相比,PGRN+LPS组的细胞增殖率上升(P0.05),凋亡率下降(P0.05),caspase-3和Bax的蛋白表达下调(P0.05),Bcl-2的蛋白表达上调(P0.05),IL-1β、IL-6和TNF-α的蛋白表达下调(P0.05),p65和p-IκB-α的蛋白水平降低(P0.05)。结论:PGRN过表达可以减轻LPS诱导的A549细胞和HPAEpi C细胞增殖、凋亡异常及炎症因子产生等损伤,这可能与PGRN参与调控NF-κB信号通路有关。

PGRN over-expression inhibits LPS-induced alveolar epithelial cell injury

AIM: To investigate the effects of progranulin (PGRN) on the proliferation, apoptosis and inflammatory responses in lipopolysaccharide (LPS)-induced human alveolar epithelial A549 cells and HPAEpiC cells.METHODS: The cells were divided into 4 groups:control group (the normal cultured cells), LPS groupthe cells were treated with LPS (10 mg/L)], PGRN+LPS group (the cells were transfected with pcDNA3.1-PGRN plasmids and then treated with LPS), and pcDNA3.1+LPS group (the cells were transfected with pcDNA3.1-EGFP plasmids and then treated with LPS). The cell viability was measured by MTT assay, cell proliferation was measured by BrdU incorporation assay, and cell apoptosis was analyzed by flow cytometry. The expression of PGRN at mRNA and protein levels was detected by RT-qPCR and Western blot. The protein levels of caspase-3, Bcl-2, Bax, IL-1β, IL-6, TNF-α, p65 and p-IκB-α were determined by Western blot.RESULTS: Compared with control group, the cell proliferation rate was decreased (P<0.05), and the apoptotic rate was increased (P<0.05) in LPS group. The protein levels of caspase-3 and Bax were significantly up-regulated (P<0.05), and the expression of Bcl-2 was down-regulated (P<0.05). The protein levels of IL-1β, IL-6 and TNF-α were significantly up-regulated (P<0.05), and the protein levels of p65 and p-IκB-α were enhanced (P<0.05). Compared with LPS group, the cell proliferation rate was increased (P<0.05), and the apoptotic rate was decreased (P<0.05) in PGRN+LPS group. The protein levels of caspase-3 and Bax were significantly down-regulated (P<0.05), and the expression of Bcl-2 was up-regulated (P<0.05). The protein levels of IL-1β, IL-6 and TNF-α were significantly down-regulated (P<0.05), and the protein levels of p65 and p-IκB-α were decreased (P<0.05).CONCLUSION: PGRN over-expression may alleviate LPS-induced abnormal proliferation, apoptosis and inflammatory cytokine production in the A549 cells and HPAEpiC cells, which may be associated with the regulation of NF-κB signaling pathway.