DNA甲基转移酶抑制剂在人源地贫鼠模型中诱导γ-珠蛋白基因的作用及机制研究

广西是地中海贫血（地贫）的高发区，重型β-地贫临床缺乏有效的治疗手段。我们前期工作证实药物刺激γ-珠蛋白基因表达，增加HbF合成有助于改善β-地贫患者症状，疗效与数量性状位点相关。DNA甲基转移酶抑制剂-地西他滨在地贫和镰状细胞贫血治疗中表现出γ-珠蛋白基因激活效应，但作用机制未明。本课题拟选取中国南方较常见地贫类型-HbE/β-地贫作为研究对象，采用定量PCR、高效液相法等方法，以羟基脲为对照，在人源HbE/β-地贫鼠模型中观察地西他滨对γ-珠蛋白基因激活，HbF合成等影响。进一步运用DNA甲基化、染色质免疫共沉淀等方法，分析其作用与γ-珠蛋白基因相关的数量性状位点分布、表观遗传修饰的相关性，探讨其作用机制。本课题拟在人源地贫鼠模型中评价地西他滨作用，探讨其机制，为将来地贫的临床治疗提供实验依据。

β-thalassemia is one of the most common hereditary hemolytic diseases in Guangxi.Our works have proved that induced gamma-globin gene expression and increased fetal hemoglobin(HbF)levels by drug can ameliorate the disease severity of β-thalassemia,and the effect was related with quantitative trait loci(QTLs). DNA methyltransferase inhibitors-decitabine can produce individual gamma-globin gene and HbF increases in the treatments of thalassemia and sickle cell disease, but its mechanisms may still be difficult to identify. In this study in humanized hemogolbin E/β-thalassemia mouse model, as with hydroxyurea, the effect of decitabine on production of fetal globin and HbF expression will be praised through real time RT-PCR, high-performance liquid chromatography. Furthermore, through DNA methylation test and chromatin immunoprecipitation, association studies of the influence of decitabine with HbF QTLs and epigenetic modification may help to explain the mechanisms of decitabine on gamma-globin gene. In humanized thalassemia mouse model, the objective of this study is to evaluate the effect of decitabine on gamma-globin gene and identify its mechanisms, and provide more experiment data for the thalassemic clinical treatments.