高碘和/或高氟致人甲状腺细胞凋亡与内质网应激的关系

Relationship between high iodide and/or high fluoride inducedapoptosis of human thyroid cells and endoplasmic reticulum stress

目的研究内质网应激在高碘和/或高氟致人甲状腺细胞(Nthy-ori 3-1)凋亡中的作用,探索高碘和/或高氟致甲状腺细胞凋亡的机制。方法用碘化钾(KI)1、10、50mmol/L,氟化钠(NaF)1mmol/L及高碘高氟联合(50mmol/L KI+1mmol/L NaF)作用于人甲状腺细胞(Nthy-ori 3-1)24h,利用噻唑蓝(MTT)法、比色法检测细胞活性和乳酸脱氢酶(LDH)漏出率,利用流式细胞术检测细胞凋亡率,利用逆转录PCR法、Western blot法检测葡萄糖调节蛋白78(GRP78)、肌醇需要酶(IRE1)和C/EBP同源蛋白(CHOP)的mRNA和蛋白及切割的X盒结合蛋白(sXBP-1)mRNA表达情况。结果 50mmol/L KI组、1mmol/L NaF组及50 mmol/L KI+1 mmol/L NaF组细胞活性[(73.54±8.37)%、(84.54±7.55)%、(72.62±7.15)%]低于对照组细胞活性[(100.00±0.00)%](P<0.05),LDH漏出率[(38.00±2.04)%、(36.43±0.82)%、(38.73±1.36)%]高于对照组[(32.86±2.32)%](P<0.05),凋亡率[(15.53±1.26)%、(12.42±2.05)%、(16.42±1.35)%]也高于对照组[(7.87±1.40)%](P<0.05)。高氟和高碘高氟联合可诱导GRP78、IRE1和CHOP的mRNA和蛋白及sXBP-1mRNA表达上升(P<0.05)。结论高碘和/或高氟可通过诱导细胞凋亡对甲状腺细胞造成毒性作用,高碘诱导的凋亡可能与IRE1途径无关,但高氟、高碘高氟联合诱导的甲状腺细胞凋亡可能与IRE1途径有关。高碘高氟共存作用于甲状腺时存在拮抗效应。

Objective To study the role of endoplasmic reticulum stress in high iodide and/or high fluoride induced-apoptosis of Nthy-ori 3-1cells and explore the mechanism of apoptosis of thyroid cells. Methods Human thyroid cells（Nthy-ori 3-1）were exposed to different concentrations of potassium iodide（KI,1,10,50mmol/L）,sodium fluoride（NaF,1 mmol/L）and the combination of high iodide and high fluoride（50mmol/L KI＋ 1mmol/L NaF）for 24 hours,the cell activity,lactate dehydrogenase（LDH）leakage rate were measured by using MTT method and colorimetry,cell apoptosis rate was detected using flow cytometry and the mRNA and protein expression of glucose regulated protein 78（GRP78）,inositol requiring enzyme（IRE1）,C/EBP homologous protein（CHOP）,as well as spliced X-box-binding protein-1（sXBP-1）mRNA were determined by reverse transcription PCR and Western blot. Results Cells exposed to 50 mmol/L KI（73.54±8.37）%,1mmol/L NaF（84.54 ±7.55）% and 50mmol/L KI＋1mmol/L NaF（72.62±7.15）%had lower cell activity compared to that in control group（100.00±0.00）%（P〈0.05）,while,LDH leakage rates of cells（38.00±2.04）%,（36.43±0.82）%,（38.73±1.36）% were higher than that in control group（32.86±2.32）%（P〈0.05）.Meanwhile,cell apoptosis rates [（15.53±1.26）%,（12.42±2.05）%,（16.42±1.35）%]were also higher compared to control group（7.87±1.40）%（P〈0.05）.High fluoride and the combination of KI and NaF could induce higher expression of GRP78,IRE1 and CHOP mRNA and protein as well as sXBP-1mRNA（P〈0.05）. Conclusions High iodine and/or high fluoride are toxic to thyroid cells by inducing cell apoptosis,which may be related to IRE1 pathway or IRE1 pathway.Antagonistic effect can be noticed when high iodine and high fluoride coexist