RETINOIC ACID RECEPTORS AND HEMATOPOIESIS

描述：(改编自研究者摘要)维甲酸(RA) 和RA受体(RAR)参与调节生长和 多种不同细胞类型的分化。探索这一角色 关于RA在造血中的作用，研究人员使用了逆转录病毒 携带显性负RAR的载体干扰正常 不同造血细胞的内源性RAR活性。他们有 在正常小鼠骨髓培养中观察到抑制 内源性RA受体在不同浓度下的活性 造血生长因子导致建立 中性粒细胞在特定阶段冷冻的造血细胞系 差异化。调查人员希望进一步扩展这些研究 RA受体在造血中的作用定义如下。特定的 目的1：确定培养的淋巴造血系EML细胞能否 在受辐射的小鼠中发挥造血干细胞的作用。通过感染 含有显性基因逆转录病毒载体的正常小鼠骨髓 阴性的RA受体结构，研究人员已经重复性地 衍生干细胞因子依赖的细胞系 自我更新的淋巴造血祖细胞的特性 (指定为EML)。调查人员将正式评估这根杆子 通过评估这些培养的EML细胞的能力来检测其细胞活性 在受辐射的同基因小鼠体内作为造血干细胞。 特定目的2：利用显性阴性RA受体逆转录病毒 构建造血生长因子依赖的造血细胞的载体 干细胞系。进一步探讨RA受体在调节血管紧张素转换酶活性中的作用 造血干细胞谱系的定位和分化 和祖细胞，研究人员将培养感染的骨髓 与显性阴性RA受体逆转录病毒构建 特异性造血生长因子包括IL-1、IL-3、IL-4、IL-6、 Flk2/Flt3配体和TPO试图建立其他生长因子 不同造血期冻存依赖细胞系 差异化。具体目标3：利用显性否定RA 受体逆转录病毒载体建立生长因子依赖性 人骨髓淋巴造血祖细胞系。特定的 目的4：确定RA受体拮抗剂在自身体内的作用 培养的小鼠和人类干细胞的更新和增殖。这个 研究人员将使用显示RA受体的合成维甲酸 试图优化体外条件下的拮抗剂活性 促进造血干细胞的自我更新和增殖 阻碍了它们的分化。

DESCRIPTION: (Adapted from investigator's abstract) Retinoic acid (RA) and RA receptors (RARs) are involved in regulating the growth and differentiation of multiple different cell types. To explore the role of RA in hematopoiesis, the investigators have utilized retroviral vectors harboring a dominant negative RAR to interfere with normal endogenous RAR activity in different hematopoietic cells. They have observed in cultures of normal mouse bone marrow that inhibiting endogenous RA receptor activity in the presence of different hematopoietic growth factors results in the establishment of hematopoietic cell lines frozen at specific stages of neutrophil differentiation. The investigators wish to further extend these studies defining the role of RA receptors in hematopoiesis as follows. Specific Aim 1: Determine whether the cultured lymphohematopoietic EML cells can function as hematopoietic stem cells in irradiated mice. By infecting normal mouse bone marrow with a retroviral vector harboring a dominant negative RA receptor construct, the investigators have reproducibly derived stem cell factor-dependent cell lines that display characteristics of self-renewing lympho-hematopoietic progenitors (designated EML). The investigators will formally evaluate the stem cell activity of these cultured EML cells by assessing their ability to act as hematopoietic stem cells in vivo in irradiated syngeneic mice. Specific Aim 2: Utilize the dominant negative RA receptor retroviral vector to establish hematopoietic growth factor dependent hematopoietic stem cell lines. To further explore the RA receptors in regulating the commitment and differentiation of lineages of hematopoietic stem cells and progenitors, the investigators will culture bone marrow infected with the dominant negative RA receptor retroviral construct with specific hematopoietic growth factors including IL-1, IL-3 IL-4, IL-6, flk2/flt3 ligand and TPO in an attempt to establish other growth factor dependent cell lines frozen at different stages of hematopoietic differentiation. Specific Aim 3: Utilize the dominant negative RA receptor retroviral vector to establish growth factor dependent lymphohematopoietic progenitor lines from human bone marrow. Specific Aim 4: Determine the effect of RA receptor antagonists in the self renewal and proliferation of cultured mouse and human stem cells. The investigators will use synthetic retinoids exhibiting RA receptor antagonist activity in attempts to optimize in vitro conditions that enhance self-renewal and proliferation of hematopoietic stem cells while blocking their differentiation.