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

鳞状细胞分化是一个多阶段的过程，发生在许多组织。环境的伤害可以对生长和分化的控制产生巨大的影响。目前正在研究控制生长停滞和分化之间的分子联系。几种不同的信号传导途径可以诱导鳞状细胞分化，包括干扰素g和佛波醇酯启动的那些。我们证明角质形成细胞在细胞周期的G1期的特定点生长停滞。这伴随着Rb磷酸化的抑制、cdk活性的降低和cdk抑制剂p27、p21和p16的诱导。尽管p21或p27的异位表达引起生长停滞，但细胞不分化，表明在终末分化中涉及额外的信号。癌细胞对终末分化具有抗性，并且未观察到生长调节基因的变化和鳞状细胞特异性基因的诱导。我们已经确定并克隆了几个基因，在鳞状细胞分化，包括转氨酶I型（TGase I）和膜蛋白CL-20/EMP-1的调节。为了研究这些基因的转录调控，我们克隆了TGase I和CL 20的上游调控区，并通过足迹法、缺失突变和迁移率变动分析确定了CREB/AP- 1样位点在其转录调控中起重要作用的DNA元件。还在体内分析了TGase I基因的2.9kb上游调控区，以控制氯霉素乙酰转移酶（CAT）报告基因的表达。这些研究表明，-2.9kb的启动子区包含了TGase I正确的组织特异性和分化特异性表达的所有信息。这些结果表明p38 MAPK信号通路在mRNA水平上控制考克斯-2的稳定性，而ERK信号通路在转录水平上调节考克斯-2。与NHEK相反，IFN-g或TGF α在几种鳞状细胞癌细胞系中诱导TGF α或考克斯-2表达不是非常有效，表明IFN-g和TGF α应答途径都发生了改变。IFN-g诱导TGF α和随后增加PGE 2产生重要信号，参与触发与皮肤中许多炎性疾病相关的过度增殖转化。- 气管，皮肤，生长调控，鳞状细胞分化，基因调控，转氨酶，视黄酸，干扰素