THE EFFECTS OF ERK PATHWAY INHIBITION ON DNA METHYLATION IN SLE

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。摘要：在药物诱导的狼疮和特发性狼疮中，包括CD11a、CD70和穿孔素在内的几个甲基化敏感基因均过表达。事实上，已经证明并证实这种过度表达是由于启动子序列的低甲基化所致。此外，用DNA甲基化抑制剂处理的T细胞在体外会产生自身反应，并在过继转移后在动物模型中产生自身免疫。DNA甲基化是由一系列酶即DNA甲基转移酶介导的。T细胞中DNA甲基转移酶的表达至少部分受通过MEK/ERK通路的信号调节。事实上，用MEK/ERK信号通路抑制剂治疗的T细胞过度表达甲基化敏感基因，类似于狼疮患者的T细胞。此外，用MEK/ERK途径抑制剂处理的T细胞在体内会产生自身反应并产生自身免疫。我们建议进一步研究和表征抑制MEK/ERK信号通路对T细胞DNA甲基化的影响。我们还建议使用转基因小鼠模型来研究T细胞MEK/ERK通路信号的减少和甲基化敏感基因的过度表达在自身免疫中的作用。此外，利用遗传关联方法，我们建议研究甲基化敏感基因CD70和穿孔素的遗传多态，这两个基因都被证明在狼疮患者的T细胞中过表达。之所以选择这两个基因，是因为在狼疮家族中，这两个基因所在的染色体区域已经建立并确认了遗传联系。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Abstract: In lupus, both drug-induced and idiopathic, several methylation sensitive genes are overexpressed including CD11a, CD70 and perforin. Indeed, it has been shown and confirmed that this overexpression is due to promoter sequence hypomethylation. Further, T cells treated with DNA methylation inhibitors become autoreactive in vitro, and upon adoptive transfer, produce autoimmunity in animal models. DNA methylation is mediated by a family of enzymes namely, the DNA methyltransferases. The expression of DNA methyltransferases in T cells is at least in part regulated by signaling through the MEK/ERK pathway. Indeed, T cells treated with MEK/ERK pathway signaling inhibitors overexpress methylation sensitive genes similar to T cells from lupus patients. Further, T cells treated with MEK/ERK pathway inhibitors become autoreactive and produce autoimmunity in vivo. We propose to further study and characterize the effect of inhibiting MEK/ERK pathway signaling on DNA methylation in T cells. We also propose to investigate the contribution of decreased T cell MEK/ERK pathway signaling and the overexpression of the methylation sensitive genes to autoimmunity using transgenic murine models. Furthermore, using genetic association approaches, we propose to study the genetic polymorphisms of the methylation sensitive genes CD70 and perforin, both shown to be overexpressed in T cells from lupus patients. These two genes are chosen because genetic linkage has been established and confirmed in lupus families on the chromosomal regions where the two genes reside.