间歇低氧程度与频率对人脐静脉内皮细胞白介素6及白介素8影响的体外实验

目的 探讨不同程度和频率间歇低氧(intermittent hypoxia,IH)对血管内皮细胞炎性反应的影响及规律.方法 将人脐静脉内皮细胞可传代细胞株ECV304植于培养舱,以模拟睡眠呼吸暂停模式低氧/复氧模式,将舱内气体由计算机程控为不同程度与频率IH环境.细胞株分为1个持续正常氧的对照组和8个实验组.不同IH程度分3组,频率固定为12次/h,即IH程度组1～3的低氧时O_2体积分数分别为10%、1.5%及0.5%.不同IH频率分5组,固定低氧时O_2体积分数为0.5%,频率组1～5的IH频率分别为40次/h、20次/h、12次/h、9次/h和6次/h.细胞暴露后以酶联免疫吸附法(enzyme linked immuno sorbent assay,ELISA)测定培养液中白细胞介素6(IL-6)及白细胞介素8(IL-8)质量浓度.结果 IL-6和IL-8水平在3个不同程度IH组均高于正常O_2组(F值分别为1961.100和103.855,P值均<0.001),随IH程度加重IL-6及IL-8水平呈逐步升高趋势,不同程度IH组间两两比较,差异均有统计学意义(P值均<0.05).重度IH暴露,不同频率IH各组ECV304细胞的IL-6和IL-8水平不同(F值分别为544.396和149.328,P值均<0.001).随着IH频率降低IL-6及IL-8水平在20次/h组轻度升高(P<0.05),至12次/h达最高(P<0.05),9次/h略减低(P<0.05),6次/h进一步减低(P<0.05).结论 IH可造成血管内皮细胞的炎性损伤,且IL-6及IL-8分泌水平具低氧程度依赖性.重度低氧暴露下,IL-6和IL-8分泌水平有随频率下降而增加,而后减低的趋势.

Effect of different intermittent hypoxia patterns on interleukin-6 and interlenldn-8 levels of human umbilical vein endothelial cells

Objective To investigate the effect of different patterns of intermittent hypoxia on the levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) of vascular endothehal cell.Methods The human umbilical vein endothelial cells of the line ECV304 were used to set up the cells model.The experiment cell strains contained one control group and eight experimental groups, 1 constance normoxia group (control group), 3 different intermittent hypoxia (IH) degree groups (10% O_2 group, 1.5% O_2 group, 0.5% O_2 group with 12 times/h), 4 different IH frequency groups (40 times/h, 20 times/h, 12 times/h, 9 times/h and 6 times/h with 0.5% O_2).The specimen were put into a program-controlled gas delivery system with different level and frequency of IH respectively.Then enzyme linked immunosorbent assay (ELISA) was used to examine the levels of IL-6 and IL-8.Results Higher level of IL-6 and IL-8 were found in 3 different IH degree groups than in control group (F were 1961.100 and 103.855 respectively, P all <0.001).The level of IL-6 and IL-8 was gradually increased with the decreasing of IH degree.The difference of IL-6 and IL-8 levels between each two different groups in IH degree was significant (P all < 0.05).The level of IL-6 and IL-8 groups was significantly different in severe IH exposure (F were 544.396 and 149.328 respectively, P all <0.001 in both groups).There was a trend as the IH frequency decreased, the level of IL-6 and IL-8 was tenderly increased in 20/hour group (P <0.05), highest in 12/hour group (P <0.05), decreased in 9/hour group (P < 0.05), and decreased further in 6/hour group (P < 0.05) in severe IH expose.There was statistical significance between each two different frequency IH groups (P < 0.05).Conclusions Intermittent hypoxia caused significant inflammatory reaction in vascular endothelial cells.The secreted level of IL-6 and IL-8 depended on the degree of hypoxis.There was a trend as the level of IH frequency decreased, the level of IL-6 and IL-8 gradually increased at first, and then decreased in the same way.