KERATINOCYTES--MODULATION BY RETINOIC ACID

角质细胞——视黄酸的调节

• 批准号: 3457306
• 负责人: Noreen J Hickok
• 金额: $ 11.45万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-05-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3457306
• 关键词: DNA footprinting; acne; aging; basal cell carcinoma; binding proteins; chloramphenicol; complementary DNA; congenital ichthyosis; cycloheximide; decarboxylase inhibitor; estrogen receptors; fibronectins; gel mobility shift assay; gene induction /repression; growth inhibitors; keratinocyte; light adverse effect; messenger RNA; nutrition related tag; ornithine decarboxylase; plasmids; protein glutamine gamma glutamyltransferase; psoriasis; retinoate; skin disorder; skin disorder chemotherapy; thymidine kinase; transcription factor; vitamin therapy

Retinoids are a class of compounds which are potent therapeutic agents for a number of dermatological diseases. In order to improve treatment of these diseases, it is necessary to elucidate the mechanism whereby retinoids, such as all-trans-retinoic acid (RA), exert their anti- proliferative effects. The long term goal of these studies is, therefore, to determine how RA inhibits keratinocyte growth. An important action of RA is keratinocytes is to inhibit ornithine decarboxylase (OD), an enzyme whose products, the polyamines, are necessary for cell growth. It is therefore proposed to determine if inhibition of ODC gene expression is a direct consequence of retinoid action and how this repression is exerted. These experiments re designed to test the hypothesis that RA suppresses ODC gene transcription through a RA receptor (RAR)-mediated mechanism. This will be examined by (1) determining the effects of RA and/or cycloheximide on the relative transcription rates of the human ODC gene using run-on transcription; (2) determining which RAR is expressed in keratinocytes and discriminating between the actions of the cellular RA binding protein and the alpha-, beta-, and gamma-RARs through the use of chimeric RAR/estrogen receptors that will be transfected into keratinocytes; (3) identifying cis- acting DNA elements that interact with trans-acting factors to cause RA- mediated changes in ODC gene transcription, using in vitro footprinting, gel retardation assays, and transfectin of isolated elements ligated to the thymidine kinase-beta-globin gene; and (4) isolation of cDNAs encoding non- RAR trans-acting factors which are implicated in RA action. Elucidation of the mechanisms whereby RA suppresses ODC gene expression will yield important information on how retinoids exert their anti-proliferative effects.

类维生素A是一类化合物，是有效的治疗剂 一些皮肤病。 为了提高治疗效果 对于这些疾病，有必要阐明其发病机制 类视黄醇，例如全反式视黄酸（RA），发挥其抗- 增殖效应。 因此，这些研究的长期目标是： 确定 RA 如何抑制角质细胞生长。 的一项重要行动 RA是角质形成细胞中抑制鸟氨酸脱羧酶（OD）的一种酶 其产物多胺是细胞生长所必需的。 这是 因此建议确定 ODC 基因表达的抑制是否是一种 类维生素A作用的直接后果以及这种抑制是如何发挥的。 这些实验重新设计是为了检验 RA 抑制 ODC 的假设 通过 RA 受体 (RAR) 介导的机制进行基因转录。 这 将通过 (1) 确定 RA 和/或放线菌酮的影响进行检查 使用连载法研究人类 ODC 基因的相对转录率 转录； (2)确定哪种RAR在角质形成细胞中表达，以及 区分细胞 RA 结合蛋白和 通过使用嵌合 RAR/雌激素产生 α-、β- 和 γ-RAR 将转染至角质形成细胞的受体； (3) 识别顺式 与反式作用因子相互作用导致 RA- 的作用 DNA 元件 使用体外足迹法介导 ODC 基因转录的变化， 凝胶阻滞测定，以及连接到的分离元件的转染 胸苷激酶-β-珠蛋白基因； (4) 分离编码非 RAR 反式作用因子与 RA 作用有关。 阐明 RA 抑制 ODC 基因表达的机制将产生 关于类维生素A如何发挥其抗增殖作用的重要信息 影响。