Abstract:
Objective: To investigate the effect of plasminogen activator urokinase receptor (PLAUR) gene on neutrophil activation and apoptosis in neutrophil-like cell model. Methods: Human acute myeloid leukemia cell line HL60 was cultured in vitro and induced to differentiate into neutrophil-like cells by all-trans retinoic acid (ATRA). Lentiviral vectors interfering with human PLAUR gene was constructed and transfected into neutrophil-like cells (siRNA group). The phosphate buffer saline (PBS) group (untransfected neutrophil-like cells) and normal blank control group (NC group) (neutrophil-like cells transfected with blank plasmid) were used as controls (n=3). After starvation culture and addition of interleukin-17 afterwards in these 3 groups, the expression of CD11b on the cell membrane was detected by flow cytometry, and the levels of myeloperoxide (MPO) and extracellular neutrophil traps (NETs) in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA) to investigate the activation of neutrophil-like cells. The apoptosis was detected by flow cytometry with annexin V/propidium iodide (PI) double staining and the expressions of apoptosis-related proteins caspase-3, bax and bcl-2 were detected by Western blotting. Results: The expression of CD11b in siRNA group (32.37±8.17) was lower than that in PBS group (46.27±1.54) and NC group (53.07±8.14) (P<0.05) by flow cytometry. The levels of MPO and NETs (33.37±1.11, 57.69±3.03) in the supernatant of siRNA group were significantly lower than those in PBS group (41.64±2.20, 77.60±4.33) and NC group (40.84±5.11, 76.15±2.10) (P<0.05). Flow cytometry with annexin V/PI showed that the expression of apoptosis in siRNA group (20.42%±2.45%) was significantly higher than that in PBS group (11.91%±2.23%) and NC group (11.13%±2.56%) (P<0.05). The relative expression of caspase-3 protein and bax protein (0.84±0.05, 0.83±0.04) in siRNA group was significantly higher than that in PBS group (0.68±0.02, 0.63±0.08) and NC group (0.71±0.01, 0.66±0.10) (P<0.05), and the relative expression of anti-apoptosis protein bcl-2 decreased in siRNA group (0.38±0.02) than in PBS group (0.73±0.05) and NC group (0.69±0.06) (P<0.05). Conclusion: PLAUR promotes the activation of neutrophil-like cells and inhibits the apoptosis.
目的: 在类中性粒细胞模型中,探讨尿激酶型纤溶酶原激活物受体(PLAUR)基因对中性粒细胞活化及凋亡的影响。 方法: 采用体外培养的人急性髓系粒细胞白血病细胞株HL60作为研究对象,全反式维甲酸(ATRA)诱导HL60细胞分化为类中性粒细胞。构建干扰人PLAUR基因的慢病毒载体,转染入类中性粒细胞(siRNA组),并设置磷酸盐缓冲液(PBS)组(未转染)和空白对照(NC组,转染空白质粒)作为对照(n=3)。饥饿培养、加入白细胞介素-17干预后,流式细胞术检测细胞膜CD11b表达,以及酶联免疫吸附法检测细胞培养液上清中髓过氧化物(MPO)、中性粒细胞胞外诱捕网(NETs)水平,了解类中性粒细胞活化情况。Annexin V/PI染色流式细胞术检测细胞凋亡,并用Western蛋白印迹法检测凋亡相关蛋白caspase-3、bax、bcl-2表达。 结果: 流式细胞术检测siRNA组HL60细胞细胞膜CD11b表达(32.37±8.17)较另两组下降(PBS组46.27±1.54,NC组53.07±8.14)(P<0.05)。siRNA组细胞培养液上清中MPO和NETs水平(33.37±1.11、57.69±3.03)也均较PBS组(41.64±2.20、77.60±4.33)和NC组(40.84±5.11、76.15±2.10)下降,差异均有统计学意义(均P<0.05)。流式细胞术检测siRNA组凋亡率(20.42%±2.45%)较PBS组(11.91%±2.23%)和NC组(11.13%±2.56%)升高(P<0.05)。siRNA组caspase-3和bax蛋白表达(0.84±0.05、0.83±0.04)较PBS组(0.68±0.02、0.63±0.08)和NC组(0.71±0.01、0.66±0.10)高,差异有统计学意义(P<0.05);抗凋亡蛋白bcl-2表达量减少(siRNA组:0.38±0.02,PBS组:0.73±0.05,NC组:0.69±0.06)(P<0.05)。 结论: PLAUR可促进类中性粒细胞活化,抑制其凋亡。.