REGULATION OF DIFFERENTIATION IN LUNG AND EPIDERMAL KERATINOCYTES

肺和表皮角质形成细胞分化的调节

• 批准号: 6289934
• 负责人: Anton M Jetten
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6289934
• 关键词: DNA binding protein; biological signal transduction; cell cycle proteins; cell differentiation; cell growth regulation; cyclin dependent kinase; cyclins; enzyme activity; enzyme inhibitors; genetic transcription; guanine nucleotide binding protein; human tissue; interferon gamma; keratin; molecular cloning; oncoprotein p21; phosphorylation; protein glutamine gamma glutamyltransferase; regulatory gene; relaxin; retinoblastoma protein; retinoids; skin; tissue /cell culture

Squamous differentiation is a multi-stage process that occurs in many tissues. Environmental insults can have a dramatic impact on the control of growth and differentiation. The molecular link between control of growth arrest and differentiation is being studied. Several different signaling pathways can induce squamous differentiation including those initiated by interferon g and phorbol esters. We demonstrated that keratinocytes become growth arrested at specific point in G1 of the cell cycle. This is accompanied by inhibition of Rb phosphorylation, decrease in cdk activity and induction of the cdk- inhibitors p27, p21 and p16. Although ectopic expression of p21 or p27 causes growth arrest, cells do not differentiate suggesting that additional signals are involved in terminal differentiation. Carcinoma cells are resistant to terminal differentiation and changes in growth- regulatory genes and induction of squamous-specific genes were not observed. We have identified and cloned several genes that are regulated during squamous differentiation, including transglutaminase type I (TGase I) and a membrane protein CL-20/EMP-1. To study the transcriptional regulation of these genes, we cloned the upstream regulatory region of TGase I and CL20, and determined by footprinting, deletion mutation and mobility shift assays DNA elements that CREB/AP- 1-like sites are important in their transcriptional control. The 2.9kb upstream regulatory region of the TGase I gene to control the expression of a chloramphenicol acetyltransferase (CAT) reporter gene was also analyzed in vivo. These studies showed that the -2.9kb promoter region contains all the information for the proper issue- and differentiation-specific expression of TGase I. These results suggest that the p38 MAPK signaling pathway controls COX-2 at the level of mRNA stability while the ERK signaling pathway regulates COX-2 at the level of transcription. In contrast to NHEK, IFN-g or TGFa are not very effective in inducing TGFa or COX-2 expression in several squamous carcinoma cell lines indicating alterations in both IFN-g and TGFa response pathways. The induction of TGFa by IFN-g and the subsequent increase in PGE2 generate important signals involved in triggering the hyperproliferative transformation associated with many inflammatory diseases in the skin. - trachea, skin, growth control, squamous differentiation, gene regulation, transglutaminase, retinoic acid, interferon

鳞状分化是在许多组织中发生的多阶段过程。环境侮辱会对生长和分化的控制产生巨大影响。正在研究控制生长停滞和分化之间的分子联系。几种不同的信号通路可以诱导鳞状分化，包括干扰素G和佛波酯引发的信号分化。我们证明了角质形成细胞在细胞周期的G1的特定点上变为生长。这伴随着RB磷酸化的抑制作用，CDK活性的降低以及CDK-抑制剂P27，P21和P16的诱导。尽管p21或p27的异位表达会导致生长停滞，但细胞并未区分表明其他信号参与末端分化。癌细胞对末端分化和生长调节基因的变化具有抵抗力，也没有观察到鳞状特异性基因的诱导。我们已经确定并克隆了在鳞状分化过程中受调节的几个基因，包括跨谷氨酰胺酶I型（TGASE I）和膜蛋白CL-20/EMP-1。为了研究这些基因的转录调控，我们克隆了TGase I和Cl20的上游调节区域，并通过足迹，缺失突变和迁移率转移测定的DNA元素确定，即CREB/AP-1样位点在其转录控制中很重要。在体内还分析了TGase I基因的2.9kb上游调节区域，以控制氯霉素乙酰基转移酶（CAT）报告基因的表达。这些研究表明，-2.9kb启动子区域包含TGase I的适当发行和分化特异性表达的所有信息。这些结果表明，p38 MAPK信号传导途径在mRNA稳定性水平上控制COX-2，而ERK信号通路在转录水平下调节COX-2。与NHEK相反，IFN-G或TGFA在几种鳞状癌细胞系中诱导TGFA或COX-2表达并不是很有效，表明IFN-G和TGFA响应途径的改变。 IFN-G对TGFA的诱导和随后的PGE2诱导会产生与皮肤中许多炎症性疾病相关的高增殖性转化涉及的重要信号。 - 气管，皮肤，生长控制，鳞状分化，基因调节，转谷氨酰胺酶，视黄酸，干扰素