Iodine excess did not affect the global DNA methylation status and DNA methyltransferase expression in T and B lymphocytes from NOD.H-2h4 and Kunming mice
Iodine excess did not affect the global DNA methylation status and DNA methyltransferase expression in T and B lymphocytes from NOD.H-2h4 and Kunming mice
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碘过量不影响NOD.H-2h4和昆明小鼠T淋巴细胞和B淋巴细胞的整体DNA甲基化状态和DNA甲基转移酶表达。
DOI：
10.1016/j.intimp.2017.12.018
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发表时间：
2018-02-01
影响因子：
5.6
通讯作者：
Teng, Weiping
中科院分区：
文献类型：
--
作者：
Guo, Qingling;Wu, Dan;Teng, Weiping
淋巴细胞中DNA甲基化失调与各种自身免疫性疾病有关。过量的碘摄入导致淋巴细胞功能障碍，并导致人类和动物的自身免疫性甲状腺炎（AIT）发作。然而，过量碘是否改变淋巴细胞中的DNA甲基化状态尚不清楚。将20只NOD.H-2（h4）小鼠和20只昆明种小鼠随机分为高碘组和对照组。我们通过苏木精和伊红（H&E）染色对甲状腺淋巴浸润进行评分，并通过间接酶联免疫吸附试验测定血清甲状腺球蛋白抗体（TgAb）水平。流式细胞仪分离CD 3（+）T细胞和CD 19（+）B细胞。通过吸光光度法检查总体DNA甲基化水平。亚硫酸氢盐测序PCR检测长散布核苷酸元件1（LINE-1）重复序列的甲基化。采用实时荧光定量PCR和Western blot方法分别检测细胞DNA甲基转移酶（DNMT）1、DNMT 3a和DNMT 3b mRNA和蛋白的表达。高碘组NOD.H-2（h4）小鼠出现明显的甲状腺炎，而其他三组小鼠未出现甲状腺炎。高碘处理NOD.H-2（h4）小鼠和昆明小鼠T和B淋巴细胞LINE-1重复序列的甲基化水平和甲基化状态与正常碘对照组相比均无差异。各实验组T、B淋巴细胞DNMT mRNA和蛋白表达水平无明显变化。总之，我们首次发现过量碘不影响NOD、H-2（h4）和昆明小鼠T和B淋巴细胞的整体甲基化状态或DNMT表达。
Dysregulated DNA methylation in lymphocytes has been linked to various autoimmune disorders. Excessive iodine intake leads to lymphocyte dysfunction and contributes to autoimmune thyroiditis (AIT) flares in humans and animals. However, whether excessive iodine modifies the DNA methylation status in lymphocytes is unknown. Twenty NOD.H-2(h4) mice and 20 Kunming mice were randomly divided into high iodine and control groups. We scored lymphatic infiltration in the thyroid by hematoxylin and eosin (H&E) staining and assayed serum thyroglobulin antibody (TgAb) levels by an indirect enzyme-linked immunosorbent assay. CD3(+) T cells and CD19(+) B cells were separated by flow cytometry. Global DNA methylation levels were examined by absorptiometry. Methylation of long interspersed nucleotide element-1 (LINE-1) repeats was detected with bisulfite sequencing PCR. Expression of DNA methyltransferase (DNMT) 1, DNMT3a and DNMT3b mRNA and protein were determined by real-time PCR and Western blot, respectively. We observed evident thyroiditis in the high-iodine-treated NOD.H-2(h4) mice, while mice in the other three groups did not develop thyroiditis. No differences were found in the global methylation levels and methylation status of LINE-1 repeats in T and B lymphocytes from high-iodine-treated NOD.H-2(h4) mice and Kunming mice compared with those from normal-iodine-supplemented controls. We did not find obvious changes in DNMT mRNA and protein expression levels in T and B lymphocytes among the studied groups. In conclusion, we showed for the first time that excess iodine did not affect the global methylation status or DNMT expression in T and B lymphocytes in NOD.H-2(h4) and Kunming mice.