THE EFFECTS OF ERK PATHWAY INHIBITION ON DNA METHYLATION IN SLE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 在药物诱导和特发性狼疮中，几种甲基化敏感基因过表达，包括CD 11 a，CD 70和穿孔素。事实上，已经显示并证实这种过表达是由于启动子序列低甲基化。此外，用DNA甲基化抑制剂处理的T细胞在体外变成自身反应性的，并且在过继转移后，在动物模型中产生自身免疫。DNA甲基化由一个酶家族介导，即DNA甲基转移酶。T细胞中DNA甲基转移酶的表达至少部分地由通过MEK/ERK途径的信号传导调节。事实上，用MEK/ERK途径信号传导抑制剂处理的T细胞过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通路抑制剂处理的T细胞变得自身反应性并在体内产生自身免疫。 我们建议进一步研究和表征抑制MEK/ERK通路信号传导对T细胞中DNA甲基化的影响。我们还建议使用转基因小鼠模型研究T细胞MEK/ERK通路信号转导减少和甲基化敏感基因过表达对自身免疫的贡献。此外，使用遗传关联方法，我们建议研究甲基化敏感基因CD 70和穿孔素的遗传多态性，这两个基因在狼疮患者的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上已经建立并证实了遗传连锁。

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. 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.