Homocysteine upregulates interleukin-17A expression via NSun2-mediated RNA methylation in T lymphocytes
Homocysteine upregulates interleukin-17A expression via NSun2-mediated RNA methylation in T lymphocytes
复制标题
同型半胱氨酸通过 NSun2 介导的 RNA 甲基化上调 T 淋巴细胞中白细胞介素 17A 的表达
DOI：
10.1016/j.bbrc.2017.09.069
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发表时间：
2017
影响因子：
3.1
通讯作者：
Wang WG
中科院分区：
文献类型：
--
作者：
Wang Nan;Wang Xian;Feng Juan;Tang Hao;Wang Wengong;Wang X;Feng J;Wang WG
白细胞介素- 17a （IL-17A）已被证实参与多种自身免疫性疾病的发生过程。血浆同型半胱氨酸（Hcy）升高，又称高同型半胱氨酸血症（HHcy），与多种慢性炎症性疾病有关。虽然已经研究了hhcy诱导的T淋巴细胞IL-17A表达上调，但IL-17A的调节方式尚不清楚。western blotting检测结果显示，Hcy （100 μM）上调了大鼠T淋巴细胞NOP2/Sun结构域家族成员2 （NSun2）的表达。在NSun2 - / -大鼠体内，hhcy诱导的IL-17A上调在野生型大鼠血浆中明显降低。通过体外甲基化实验和高效液相色谱-质谱（HPLC-MS）分析，我们发现tRNA甲基转移酶NSun2以m5C模式甲基化IL-17A mRNA。亚硫酸氢盐测序结果表明，NSun2在体外和体内的胞嘧啶c466位点甲基化IL-17A mRNA。此外，我们分析了pgl3衍生的携带IL-17A mRNA片段的报告基因的活性，发现NSun2的甲基化促进了IL-17A的翻译。综上所述，NSun2通过甲基化IL-17A mRNA并促进其在T淋巴细胞中的翻译，介导hhcy诱导的IL-17A表达上调。
Interleukin-17A (IL-17A) has been proven to participate in the process of various autoimmune diseases. The elevation of plasma homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), is related to various chronic inflammatory diseases. Though HHcy-induced upregulation of IL-17A expression in T lymphocytes has been examined, the way in which IL-17A is regulated remains unclear. In this study, western blotting assays showed that Hcy (100 μM) upregulated NOP2/Sun domain family, member 2 (NSun2) expression in rat T lymphocytes. HHcy-induced upregulation of IL-17A observed in plasma of wild-type rats was markedly decreased in NSun2−/−ratsin vivo. Mechanistically, by usingin vitromethylation assays and high-performance liquid chromatography-mass spectrum (HPLC-MS) analysis, we showed that the tRNA methyltransferase NSun2 methylated the IL-17A mRNA in an m5C pattern. The results from bisulfite sequencing indicated that NSun2 methylated IL-17A mRNA at cytosine C466in vitroandin vivo. Furthermore, we analyzed the activity of pGL3-derived reporters bearing IL-17A mRNA fragments and found that methylation by NSun2 promoted the translation of IL-17A. In conclusion, NSun2 mediates HHcy-induced upregulation of IL-17A expression by methylating IL-17A mRNA and promoting its translation in T lymphocytes.