REPRESSION OF HBS IN SICKLE CELL ANEMIA

镰状细胞性贫血中 HBS 的抑制

• 批准号: 6337234
• 负责人: Patricia E Berg
• 金额: $ 7.38万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6337234
• 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(改编自申请者摘要)：这些研究的目标 是为了检测我们已经克隆的三个基因的分子性质，bp1， BP2和HMG-1(Y)，来自我们实验室和其他实验室的数据表明 B-珠蛋白基因的抑制因子。本提案中提供的数据表明 BP1在造血中的潜在重要性：BP1的表达是 仅限于出生后的造血细胞，测序显示 该bp1含有一个同源异型盒基因，将其置于一类基因的中心 发展。BP2被无处不在地表达，暗示着更普遍的作用 在珠蛋白调节方面。研究人员还克隆了一个编码cDNA的 HMG-1(Y)，一种已知的蛋白质，我们证明了它与沉默蛋白1结合并弯曲 DNA，使其成为参与镇压 B-珠蛋白基因。他们将确定BP1、BP2和HMG-1(Y)在其中的角色(S) 正常的红系发育并确定其改善红系发育的潜力 镰状细胞性贫血(SCA)的并发症。减少废气排放的好处 抑制物表达珠蛋白可能是间接的，因为抑制 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， 有利于在引入正常g后形成Hb F或Hb A -珠蛋白基因或b-珠蛋白基因。BP1和/或BP2可以直接 同时激活g-珠蛋白基因表达：两种转录因子 结合在g-珠蛋白基因的上游，与 大鼠胚胎基因的重新激活和BP1结合活性的增加 病人。这些基因抑制b-珠蛋白的能力将被测量。 在培养的细胞和在液体培养中生长的红系祖细胞中 系统。BP1、BP2和HMG-1(Y)在红系中的表达降低 来自脐带血的祖细胞来确定这是否会导致 从胎儿到成人的血红蛋白合成。要进一步研究这些函数 在BP1和BP2中，将产生高表达BP1和BP2的转基因小鼠 在他们的红系细胞中。拟议的研究将坚定地确立 克隆的BP1、BP2和HMG-1(Y)cDNA在抑制b-珠蛋白中的作用 基因，并将确定这些基因是否可能在治疗糖尿病方面有用 镰状细胞性贫血。