FACTORS MODULATING GAMMA GLOBIN GENE EXPRESSION

调节伽马珠蛋白基因表达的因素

• 批准号: 6650007
• 负责人: John Michael Cunningham
• 金额: $ 12.63万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6650007
• 关键词: SCID mouse; binding proteins; clinical research; erythropoiesis; gene expression; genetic promoter element; genetically modified animals; globin; hemoglobin F; hemoprotein biosynthesis; human subject; laboratory mouse; regulatory gene; sickle cell anemia

The clinical amelioration in sickle cell disease seen with persistent fetal hemoglobin expression should be explored for this disease. Gene transfer of a transcription factor capable of reversing the gamma to beta globin switch in adult erythroid cells represents one approach to the treatment of this devastating disorder. n advantage of this strategy over the transfer of cis-sequences encoding the globin genes is the concomitant reduction of beta/S expression that would be anticipated. The long-term goal of this project is to identify a factor(s) which may be utilized in this approach to gene therapy. Over the current funding period we have identified three factors which may fulfill this criteria. Firstly, we have identified a fetal and erythroid component of the stage selector protein complex. This complex has been implicated in the recruitment of the locus control region to the gamma promoter during fetal erythropoiesis. This complex has studies proposed in our first specific aim seek to define the role of this factor, c106, in the formation of the SSP complex and determine its role in fetal erythroid cells. We will evaluate the ability of the factor to activate fetal hemoglobin expression in a novel model of primitive and definitive erythropoiesis, mice transgenic for the human beta globin locus and human erythroid progenitors. Ultimately, if these studies demonstrate that c106 is capable of reactivating fetal hemoglobin expression, its ability to modulate gamma-globin gene expression in a NOD/SCID model of sickle erythropoiesis and non-human primates will be determined in collaboration with Projects 4 and 5. In addition, we have also developed a novel screening strategy to identify further fetal globin regulatory genes utilizing novel chemical probes. With this strategy, as outlined in the work proposed in specific aim 2, we have identified two factors, the HLH protein Id2 and a novel CCAAT box binding protein homologue Hap5h. Interestingly, enforced expression of Id2 in fetal erythroid cells results in a 9 fold induction of gamma globin gene expression. We propose to characterize these factors further, to determine their role in the gamma to beta switch, as well as their potential therapeutic role. Finally, in specific aim 3 we describe the use of further novel chemical probes with diverse structures that allow us to identify further fetal regulatory factors. In summary, these studies will enhance our understanding of the molecular regulation of gamma globin gene expression and may provide new therapeutic strategies for the treatment of sickle cell disease.

对于这种疾病，应探索持续的胎儿血红蛋白表达的镰状细胞疾病的临床改善。在成年红细胞细胞中能够逆转γ到β球蛋白转换的转录因子的基因转移是治疗这种毁灭性疾病的一种方法。 n该策略比编码球蛋白基因的顺式序列的转移的优势是预期的β/s表达的同时还原。该项目的长期目标是确定在这种基因治疗方法中可以使用的因素。在当前的资金期间，我们确定了可能满足此标准的三个因素。首先，我们已经确定了阶段选择器蛋白复合物的胎儿和红细胞成分。该复合物与在胎儿红细胞生成期间募集了基因座控制区域为伽马启动子。这一综合体提出了我们在第一个特定目的中提出的研究，旨在定义该因素C106在形成SSP复合物中的作用，并确定其在胎儿红细胞细胞中的作用。我们将评估该因子激活胎儿血红蛋白表达的能力，这是人类β球蛋白基因座和人类红细胞祖细胞的新型原始和确定性红细胞生成模型，小鼠转基因。 Ultimately, if these studies demonstrate that c106 is capable of reactivating fetal hemoglobin expression, its ability to modulate gamma-globin gene expression in a NOD/SCID model of sickle erythropoiesis and non-human primates will be determined in collaboration with Projects 4 and 5. In addition, we have also developed a novel screening strategy to identify further fetal globin regulatory genes utilizing novel chemical probes.正如特定目标2中提出的工作所概述的那样，我们已经确定了两个因素，即HLH蛋白ID2和一种新型的CCAAT盒结合蛋白同源物HAP5H。有趣的是，在胎儿红细胞细胞中ID2的强化表达导致γ球蛋白基因表达的9倍诱导。我们建议进一步表征这些因素，以确定它们在伽马转到β转换中的作用，以及它们的潜在治疗作用。最后，在特定目标3中，我们描述了具有多种结构的进一步新型化学探针的使用，使我们能够识别进一步的胎儿调节因素。总而言之，这些研究将增强我们对Gamma Globin基因表达的分子调节的理解，并可能为治疗镰状细胞疾病提供新的治疗策略。