CAJ | 학술논문

目的探讨石英粉尘诱导人正常支气管上皮细胞16HBE氧化应激与线粒体相关途径细胞凋亡的关系.方法实验分为对照组和37.5、75.0、150.0、300.0 μg/mL的石英粉尘悬液染尘组,采用呼吸性纯石英粉尘(粒径＜2 μm,平均粒径1μm),以37.5、75.0、150.0、300.0 μg/ml浓度染尘16HBE细胞24 h后,检测细胞存活率、乳酸脱氢酶(LDH)活力和超氧化物歧化酶(SOD)活力、细胞凋亡率、Bax和Bcl-2 mRNA基因相对表达水平.观察上述浓度染尘1.5、3、6、12h后细胞内活性氧(ROS)水平.结果随石英粉尘浓度升高,细胞存活率、SOD活力下降,LDH活力升高,均有剂量-效应关系.与对照组比较,染尘浓度≥75.0 μg/ml时,细胞存活率明显降低,差异有统计学意义(P＜0.05);染尘浓度≥150.0μg/ml时,LDH活力升高,差异有统计学意义(P＜0.05);各染尘组SOD活力均低于对照组,差异均有统计学意义(P＜0.05).细胞内ROS水平在1.5 h达到最高,而后逐渐降低,12h回复至基线水平.在染尘1.5、3和6h,ROS水平随染尘浓度的升高而升高,存在剂量-效应关系(P＜0.05).染尘组细胞凋亡率均高于对照组,呈剂量-效应关系(P＜0.05).随着染尘浓度的升高,Bcl-2 mRNA相对表达水平呈降低趋势,而Bax mRNA相对表达水平呈升高趋势.相关分析表明细胞凋亡率、Bax mRNA相对表达水平与细胞内ROS水平均呈正相关(r值分别为0.892,0.850,P＜0.05),Bcl-2 mRNA相对表达水平与细胞内ROS水平呈负相关(r值为-0.703,P＜0.05).结论石英粉尘可致16HBE细胞损伤、氧化应激和线粒体相关途径细胞凋亡,氧化应激可能是诱导线粒体相关途径凋亡的环节之一.
목적 탐토석영분진유도인정상지기관상피세포16HBE양화응격여선립체상관도경세포조망적관계.방법 실험분위대조조화37.5、75.0、150.0、300.0 μg/mL적석영분진현액염진조,채용호흡성순석영분진(립경＜2 μm,평균립경1μm),이37.5、75.0、150.0、300.0 μg/ml농도염진16HBE세포24 h후,검측세포존활솔、유산탈경매(LDH)활력화초양화물기화매(SOD)활력、세포조망솔、Bax화Bcl-2 mRNA기인상대표체수평.관찰상술농도염진1.5、3、6、12h후세포내활성양(ROS)수평.결과 수석영분진농도승고,세포존활솔、SOD활력하강,LDH활력승고,균유제량-효응관계.여대조조비교,염진농도≥75.0 μg/ml시,세포존활솔명현강저,차이유통계학의의(P＜0.05);염진농도≥150.0μg/ml시,LDH활력승고,차이유통계학의의(P＜0.05);각염진조SOD활력균저우대조조,차이균유통계학의의(P＜0.05).세포내ROS수평재1.5 h체도최고,이후축점강저,12h회복지기선수평.재염진1.5、3화6h,ROS수평수염진농도적승고이승고,존재제량-효응관계(P＜0.05).염진조세포조망솔균고우대조조,정제량-효응관계(P＜0.05).수착염진농도적승고,Bcl-2 mRNA상대표체수평정강저추세,이Bax mRNA상대표체수평정승고추세.상관분석표명세포조망솔、Bax mRNA상대표체수평여세포내ROS수평균정정상관(r치분별위0.892,0.850,P＜0.05),Bcl-2 mRNA상대표체수평여세포내ROS수평정부상관(r치위-0.703,P＜0.05).결론 석영분진가치16HBE세포손상、양화응격화선립체상관도경세포조망,양화응격가능시유도선립체상관도경조망적배절지일.
Objective To investigate oxidative stress and mitochondria-related cell apoptosis induced by silica dust in human normal bronchial epithelial 16HBE cells.Methods Cell viability,lactate dehydrogenase (LDH),superoxide dismutase (SOD),cell apoptotic rate,the expression level of Bax and Bcl-2 mRNA were measured after 16HBE cells were exposed to 37.5,75,150,300 μg/mL respirable silica dust (diameter＜2 μm,d50=1 μm) for 24 h in vitro.Reactive oxygen species (ROS) were tested after 16HBE cells were exposed to silica dust at above concentrations for 1.5,3,6,12 h,respectively.Results Dose-dependent decreases of cell viability and the activity of SOD were observed when silica concentrations increased.The activity of LDH increased when silica concentrations elevated.Compared with the control group,cell viability significantly reduced in 75,150,300 μg/mL silica-treated groups (P＜0.05).The activity of LDH significandy increased in 150,300 μg/mL silica-treated groups when compared with the control group (P＜0.05).The activity of SOD in all silica-treated groups were significantly lower in comparison with controls (P＜0.05).Intracellular ROS levels reached peak values at 1.5 h of silica exposure and gradually dropped to the base level at 12 h.The relationship between ROS levels and silica exposure were dose-response at 1.5 h,3 h and 6 h of exposure (P＜ 0.05).Similar dose-dependent increase were observed for apoptotic rate and silica exposure (P＜0.05).The expression levels of Bcl-2 mRNA decreased,and the expression levels of Bax mRNA increased when silica concentrations increased.The results showed that significantly positive correlations between ROS level and apoptotic rate (r=0.892,P＜0.05) or the expression level of Bax mRNA (r=0.850,P＜0.05).There was a negative correlation between ROS level and the expression level of Bcl-2 mRNA (r=-0.703,P＜0.05).Conelusion Silica dust could induce cytotoxicity,oxidative stress and mitochondria-related cell apoptosis in 16HBE cells.Oxidative stress may play role in the processes of mitochondria-related apoptosis.