REGULATION OF CYP1A1 IN HUMAN EPITHELIAL CELLS

人类上皮细胞中 CYP1A1 的调节

• 批准号: 6055604
• 负责人: B LYNN ALLEN-HOFFMANN
• 金额: $ 20.72万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-30 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6055604
• 关键词: carbopolycyclic compound; cell adhesion; cell differentiation; cytochrome P450; drug receptors; enzyme induction /repression; epithelium; gene expression; human subject; keratinocyte; laboratory mouse; skin; tissue /cell culture

APPLICANT'S ABSTRACT: The focus of this proposal is to examine the tissue-specific regulation of a cytochrome P450 family member, CYP1A1, in normal human skin. CYP1A1 is a polycyclic and halogenated aromatic hydrocarbon-inducible monooxygenase. Since more than half of all cancers arise in epithelia having direct contact with the environment, an understanding of the endogenous regulation and expression of CYP1A1 in these tissues is important. Little is known about the tissue-specific regulation of CYPlA1 in normal human stratified squamous epithelia. However, PAHs and HAHs-dependent regulation of CYP1A1 is mediated by a basic helix-loop-helix transcription factor complex containing the aryl hydrocarbon receptor (AhR) and its dimerization partner, AhR nuclear translocator protein (Arnt). The role that AhR and Arnt play in tissue-specific CYP1A1 regulation in skin in not well understood. Furthermore, it is unknown if commitment to differentiation is necessary for CYP1A1 expression in skin or what role, if any, CYP1A1, AhR, and Arnt play in the terminal differentiation program of keratinocytes, the major cell type of stratified squamous epithelia. We have recently found that expression of the CYPlAl gene and enzyme activity is rapidly induced by cellular signaling events initiated by suspension of cultured human keratinocytes in the absence of xenobiotics or other differentiation-inducing conditions, such as high levels of calcium and serum. We suspect that similar cellular signaling events contribute to the induction of CYP1A1 in stratified squamous epithelia in vivo. This novel mechanism of CYP1A1 induction should enhance our understanding of mammalian cytochrome P450 gene regulation in stratified squamous epithelia and potentially aid in the identification of endogenous inducers and substrates for CYP1A1. The results we have generated thus far have led us to hypothesize that changes in cell adhesion are important regulators of CYP1A1 in normal human stratified epithelia. The specific aims are: 1) Characterize the endogenous expression of CYP1A1 in human keratinocytes, and in AhR+/+ and AhR-/- mouse keratinocytes at different stages of differentiation in vitro and in situ., 2) Investigate the molecular mechanism of CYP1A1 induction in keratinocytes following loss of cell-cell and cell-substratum contact, and 3) Identify specific cell-cell or cell-substratum interaction that, when disrupted, cause rapid induction of keratinocyte CYP1A1 and investigate the role of the AhR/Arnt signaling in adhesion-mediated CYP1A1 induction using AhR-/- mouse keratinocytes.

申请人摘要：本提案的重点是审查 细胞色素 P450 家族成员 CYP1A1 的组织特异性调节 正常人类皮肤。 CYP1A1 是一种多环卤代芳香族化合物 碳氢化合物诱导的单加氧酶。 因为超过一半的癌症 产生于与环境直接接触的上皮细胞中， 了解这些中 CYP1A1 的内源性调节和表达 组织很重要。 对于正常人体内 CYPlA1 的组织特异性调节知之甚少。 人类复层鳞状上皮。 然而，PAHs 和 HAHs 依赖 CYP1A1 的调节是由基本的螺旋-环-螺旋转录介导的 含有芳烃受体 (AhR) 的因子复合物及其 二聚化伴侣，AhR 核转位蛋白 (Arnt)。 角色 AhR 和 Arnt 在皮肤组织特异性 CYP1A1 调节中发挥作用 很好理解。 此外，尚不清楚是否承诺 分化对于皮肤中 CYP1A1 的表达是必要的，或者什么作用，如果 any、CYP1A1、AhR 和 Arnt 在终末分化程序中发挥作用 角质形成细胞，复层鳞状上皮的主要细胞类型。 我们 最近发现CYPlA1基因的表达和酶活性 被悬浮引发的细胞信号事件迅速诱导 在没有异生素或其他物质的情况下培养的人类角质形成细胞 分化诱导条件，例如高水平的钙和 血清。 我们怀疑类似的细胞信号传导事件有助于 体内复层鳞状上皮中 CYP1A1 的诱导。 这部小说 CYP1A1诱导机制应该增强我们对哺乳动物的理解 复层鳞状上皮细胞色素 P450 基因调控 可能有助于识别内源性诱导剂和底物 对于 CYP1A1。 迄今为止我们所取得的结果使我们能够 假设细胞粘附的变化是 CYP1A1 的重要调节因子 在正常人复层上皮细胞中。 具体目标是：1） 表征人角质形成细胞中 CYP1A1 的内源性表达，以及 在不同阶段的 AhR+/+ 和 AhR-/- 小鼠角质形成细胞中 体外和原位分化。，2）研究分子 细胞-细胞丢失后角质形成细胞中 CYP1A1 诱导的机制 和细胞-基质接触，以及 3) 识别特定的细胞-细胞或 细胞与基质的相互作用，当被破坏时，会导致快速诱导 角质形成细胞 CYP1A1 并研究 AhR/Arnt 信号在 使用 AhR-/- 小鼠角质形成细胞进行粘附介导的 CYP1A1 诱导。