REPRESSION OF HBS IN SICKLE CELL ANEMIA

镰状细胞性贫血中 HBS 的抑制

• 批准号: 6127712
• 负责人: Patricia E Berg
• 金额: $ 7.2万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6127712
• 关键词: cell line; chloramphenicol acetyltransferase; developmental genetics; disease /disorder model; embryogenesis; erythroid stem cell; erythropoiesis; gene induction /repression; genetically modified animals; hemoglobin Ss; homeobox genes; human tissue; in situ hybridization; laboratory mouse; model design /development; molecular cloning; reporter genes; sickle cell anemia; transfection; transfection /expression vector

DESCRIPTION (Adapted from Applicant's Abstract): The goal of these studies is to examine the molecular properties of three genes we have cloned, BP1, BP2, and HMG-1(Y), which data from our laboratory and others suggest are repressors of the b-globin gene. Data presented in this proposal points to the potential importance of BP1 in hematopoiesis: the expression of BP1 is restricted to hematopoietic cells after birth, and sequencing has revealed that BP1 contains a homeobox gene, placing it in a class of genes central to development. BP2 is ubiquitously expressed, suggesting a more general role in globin regulation. The investigators have also cloned a CDNA encodng HMG-1(Y), a known protein which we demonstrate binds to and bends Silencer 1 DNA, making it a strong candidate for involvement in repression of the b-globin gene. They will define the role(s) of BP1, BP2 and HMG-1(Y) in normal erythroid development and determine their potential to ameliorate the complications seen in sickle cell anemia (SCA). Benefits of reduction of bs globin expression by repressors may be indirect, since repression of b-globin may lead to reciprocal activation of g -globin. In addition repression of the endogenous bs globin gene would reduce the amount of HbS, favoring the formation of Hb F or Hb A after introduction of a normal g -globin gene or b-globin gene, respectively. BP1 and/or BP2 may directly activate g -globin gene expression, as well: both transcription factors bind upstream of g -globin genes, and there is a direct correlation of reactivation of fetal genes and increased binding activity of BP1 in patients. The ability of these genes to repress b-globin will be measured in cultured cells and in erythroid progenitors grown in a liquid culture system. Expression of BP1, BP2 and HMG-1(Y) will be decreased in erythroid progenitors from cord blood to determine whether this will cause a switch from fetal to adult hemoglobin synthesis. To further examine the functions of BP1 and BP2, transgenic mice will be created overexpressing BP1 and BP2 in their erythroid cells. The proposed studies will firmly establish the role of cloned BP1, BP2 and HMG-1(Y) CDNAS in the repression of the b-globin gene and will determine whether these genes may be useful in the therapy of sickle cell anemia.

描述（改编自申请人的摘要）：这些研究的目标 是检查我们克隆的三个基因的分子特性，BP1， BP2 和 HMG-1(Y)，我们实验室和其他实验室的数据表明 b-珠蛋白基因的抑制子。 该提案中提供的数据表明 BP1 在造血中的潜在重要性：BP1 的表达为 出生后仅限于造血细胞，测序显示 BP1包含一个同源盒基因，将其置于一类核心基因中 发展。 BP2 普遍表达，表明其具有更普遍的作用 在珠蛋白调节中。 研究人员还克隆了一个 cDNA 编码 HMG-1(Y)，一种已知的蛋白质，我们证明它可以结合并弯曲 Silencer 1 DNA，使其成为参与镇压的有力候选者 b-珠蛋白基因。 他们将定义 BP1、BP2 和 HMG-1(Y) 的角色 正常红细胞发育并确定其改善红细胞的潜力 镰状细胞性贫血（SCA）中出现的并发症。 减少 bs 的好处 阻遏物的珠蛋白表达可能是间接的，因为阻遏物 b-珠蛋白可能导致g-珠蛋白的相互激活。 此外 抑制内源性 bs 珠蛋白基因会减少 HbS 的量， 引入正常 g 后有利于 Hb F 或 Hb A 的形成 分别为-珠蛋白基因或b-珠蛋白基因。 BP1和/或BP2可以直接 还激活 g 球蛋白基因表达：两种转录因子 结合 g 球蛋白基因的上游，并且存在直接相关性 胎儿基因的重新激活和 BP1 结合活性的增加 患者。 将测量这些基因抑制 b-珠​​蛋白的能力 在培养细胞和液体培养物中生长的红系祖细胞中 系统。 红细胞中BP1、BP2和HMG-1(Y)的表达降低 来自脐带血的祖细胞以确定这是否会导致转变 从胎儿到成人血红蛋白的合成。 进一步检查功能 BP1和BP2的转基因小鼠将被创建为过度表达BP1和BP2 在他们的红细胞中。 拟议的研究将牢固地确立 克隆的 BP1、BP2 和 HMG-1(Y) CDNAS 在抑制 b 珠蛋白中的作用 基因，并将确定这些基因是否可用于治疗 镰状细胞性贫血。