高碘通过内质网应激和P38MAPK信号通路诱导甲状腺上皮细胞损伤的研究

Research of high iodine induced damage to thyroid epithelial cells through endoplasmic reticulum stress and P38MAPK signaling pathway

目的探讨内质网应激和p38丝裂原活化蛋白激酶(P38MAPK)信号通路在高碘诱导甲状腺上皮细胞损伤中的作用。方法将甲状腺上皮细胞Nthy-ori 3-1随机分为对照组(正常培养)、模型组(40 mmol·L^(-1)碘化钾)、4-苯基丁酸(4-PBA)组[40 mmol·L^(-1)碘化钾和2 mmol·L^(-1)4-PBA]、SB203580组(40 mmol·L^(-1)碘化钾和10μmol·L^(-1)SB203580)。用蛋白质印迹法检测细胞葡萄糖调节蛋白78(GRP78)、p-P38/P38的表达水平;用MTT和克隆形成实验检测增殖水平;用流式细胞术检测细胞凋亡水平;用酶联免疫吸附试验法检测白细胞介素-6(IL-6)水平。结果对照组、模型组、4-PBA组和SB203580组GRP78蛋白表达水平分别为0.15±0.03、0.61±0.07、0.27±0.03和0.37±0.04;p-P38/P38比值分别为0.12±0.03、0.53±0.04、0.35±0.04和0.25±0.03;细胞存活率分别为(100.00±0.00)%、(53.71±6.16)%、(80.24±8.17)%和(71.29±7.36)%;克隆形成数分别为(271.36±25.18)、(96.09±10.79)、(183.24±15.36)和(141.24±16.18)个;凋亡率分别为(1.04±0.21)%、(9.27±1.67)%、(3.18±1.52)%和(3.82±1.09)%;IL-6水平分别为(0.71±0.08)、(9.17±0.87)、(3.26±0.29)和(4.71±0.41)nmol·L^(-1)。上述指标,模型组和对照组比较,在统计学上差异均有统计学意义(均P<0.05);4-PBA组、SB203580组和模型组比较,在统计学上差异均有统计学意义(均P<0.05)。结论高碘可抑制Nthy-ori 3-1细胞增殖,诱导细胞凋亡和炎症因子分泌,其机制可能与高碘激活内质网应激和P38MAPK信号通路有关。

Objective To investigate the role of endoplasmic reticulum stress and p38 mitogen-activated protein kinase P38MAPK signaling pathway in thyroid epithelial cell injury induced by high iodine.Methods The thyroid epithelial cells Nthy-ori 3-1 were randomly divided into control group(normal culture),model group(40 mmol·L^(-1)potassium iodide),4-phenylbutyric acid(4-PBA)group(40 mmol·L^(-1)potassium iodide and 2 mmol·L^(-1)4-PBA)and SB203580 group(40 mmol·L^(-1)potassium iodide and 10μmol·L^(-1)SB203580).Western blot was used to detect the expression of glucose regulated protein 78(GRP78)and p-P38/P38 of Nthy-ori 3-1 cells.MTT and colony formation experiments were used to detect the proliferation level.Flow cytometry was used to detect the apoptosis level.Enzymelinked immunosorbent assay(ELISA)was used to detect the level of interleukin-6(IL-6).Results The expression levels of GRP78 protein in control group,model group,4-PBA group and SB203580 group were0.15±0.03,0.61±0.07,0.27±0.03 and 0.37±0.04;the ratios of p-P38/P38 were 0.12±0.03,0.53±0.04,0.35±0.04 and 0.25±0.03;cell survival rates were(100.00±0.00)%,(53.71±6.16)%,(80.24±8.17)%and(71.29±7.36)%;the number of clones formed was 271.36±25.18,96.09±10.79,183.24±15.36 and141.24±16.18;the apoptosis rates were(1.04±0.21)%,(9.27±1.67)%,(3.18±1.52)%and(3.82±1.09)%;IL-6 secretion levels were(0.71±0.08),(9.17±0.87),(3.26±0.29)and(4.71±0.41)nmol·L^(-1),respectively.For the above indicators,there was significant difference between the model group and the control group(all P<0.05);there was significant difference between the 4-PBA group,SB203580 group and the model group(all P<0.05).Conclusion High iodine can inhibit the proliferation of Nthy-ori 3-1 cells and induce apoptosis and secretion of inflammatory factors,which may be related to the activation of endoplasmic reticulum stress and P38MAPK signaling pathway by high iodine.