摘要
目的研究不同碘摄入量对大鼠甲状腺功能、钠碘转运体(NIS)基因启动子区5′-CpG岛甲基化的影响,探讨碘是否通过调节NIS基因甲基化的途径来影响NIS的表达。方法将40只雌性SD大鼠分入5组(每组8只),分别给予低碘(LI组)、适碘(NI组)、5倍高碘(5HI组)、10倍高碘(10HI组)、20倍高碘(20HI组)饮食构建大鼠模型。3个月后处死动物,采用化学发光法测定大鼠血清游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、促甲状腺激素(TSH)水平,免疫组化检测NIS表达,并应用硫化测序PCR(BSP)检测每组大鼠甲状腺细胞NIS基因启动子区5′-CpG岛甲基化情况。结果①与适碘组比较,低碘组和各高碘组血清FT3浓度均降低,差异有统计学意义(P<0.05);与适碘组比较,低碘组和各高碘组血清FT4略增高,但差异无统计学意义(P>0.05);各组大鼠的血清TSH水平差异无统计学意义(P>0.05)。②LI组大鼠甲状腺组织中NIS表达水平高于NI组,差异有统计学意义(P<0.05),5HI组NIS表达水平低于NI组,差异无统计学意义(P>0.05),10HI组及20HI组NIS表达水平低于NI组(P<0.01);③比较各组CpG1甲基化比率及CpG2甲基化比率差异无统计学意义(P>0.05);进一步研究NIS启动子区域-420^-110核苷酸序列(CpG3),与适碘组比较,低碘组和各高碘组CpG3甲基化比率降低,但差异无统计学意义(P>0.05)。结论碘过量或碘缺乏均可致碘营养障碍,但不会影响大鼠甲状腺NIS基因启动子区5′-CpG岛甲基化状态,碘可能通过其他机制调节NIS的表达。
Objective To study the effects of different iodine intake on thyroid function and the methylation of 5′-CpG island in the promoter region of sodium iodine transporter(NIS) gene in rats, and to explore whether iodine affects the expression level of NIS through regulating the methylation of NIS gene. Methods Forty female SD rats were randomly divided into five groups(8 rats in each group). The rats in NI group(control) were fed with normal content of iodine, and the rats in LI group, 5 HI group,10 HI Group and 20 HI group were fed with different amounts of potassium iodide. These rats were sacrificed 3 months after the feeding and all serum samples were tested for free triiodothyronine(FT3),free thyroxine(FT4) and thyroid stimulating hormone(TSH) by using chemiluminescent detection technology. The expression of NIS protein in the rats’ thyroid tissues was determined by immunohistochemical staining. The status of 5′-CpG island promoter methylation of NIS gene in the rats’ thyroid tissues wasdetected by bisulfite sequencing PCR(BSP). Results ① Compared with the iodine-adapted group, the serum FT3 concentration of the low-iodine group and the high-iodine group decreased, and the difference was significant(P<0.05). Compared with the iodine-adapted group, the serum FT4 in the low-iodine group and the high-iodine group slightly increased, but the difference was not statistically significant(P>0.05). There was no significant difference in TSH level between groups(P>0.05).② The expression level of NIS in thyroid tissues of the LI group was higher than that of the NI group, with statistically significant difference(P<0.05), while that of the 5 HI group was lower than that of the NI group, with no statistically significant difference(P>0.05), while those of the 10 HI group and the 20 HI group were lower than that of the NI group(P<0.01);③ There was no significant difference in CpG1 methylation ratio and CpG2 methylation ratio between the groups(P>0.05). Further study on the sequence of-420 to-110 nucleotides in
作者
董小婉
陈婷婷
吴翌
金秀兰
汪靓婧
周换丽
王佑民
Dong Xiaowan;Chen Tingting;Wu Yi(Dept of Endocinology,The First Affiliated Hospital of Anhui Medical University,Hefei 230022;Dept of Endocinology 3 The Affiliated Hospital of Jiaxing University,Jiaxing 314000)
出处
《安徽医科大学学报》
CAS
北大核心
2020年第7期1052-1056,1063,共6页
Acta Universitatis Medicinalis Anhui
基金
公益性行业科研专项基金(编号:201402005)。
关键词
碘
甲状腺
钠碘转运体
甲基化
iodine
thyroid
sodium iodide symporter
methylation
