Regulation Of Differentiation In Lung And Epidermal Kera

肺和表皮角质层分化的调节

• 批准号: 6837504
• 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/6837504
• 关键词: biotransformation; bronchus; carcinogenesis; cell differentiation; cell growth regulation; cell proliferation; clinical research; developmental genetics; esophagus; functional /structural genomics; gene environment interaction; gene expression; gene targeting; genetic regulation; genetically modified animals; human tissue; keratinocyte; laboratory mouse; lung neoplasms; microarray technology; mucins; p53 gene /protein; peroxisome proliferator activated receptor; respiratory epithelium; retinoids; squamous cell carcinoma; trachea

I. The trachea and esophagus have a common origin evolving from the foregut endoderm during early embryonic development. These epithelia undergo a series of well-defined structural changes involving differentiation of progenitor cells into several cell types that ultimately result in the formation of the mature epithelium. In this study, we monitor the expression of p63 in the esophageal and tracheobronchial epithelium at several stages during development and determine the effect of the lack of p63 expression on the morphogenesis of these epithelia in p63-/- mice. At day E15.5, the esophageal and tracheobronchial epithelium contain 2-3 layers of cells; however, only the progenitor cells express p63. The progenitor cells differentiate first into ciliated cells (p63-/b-tubulin IV+) and at birth into basal cells (p63+/K14+/BS-I-B4+). In adult mouse and human, the lining of the esophagus matures into a (non)keratinizing, stratified epithelium while the tracheobronchial lining develops into a pseudostratified, columnar epithelium containing basal, ciliated and mucosecretory cells. In mature epithelia, the K14+/BS-I-B4+ basal cells are the most intensely stained for p63. Expression of p63 is dramatically repressed during squamous differentiation in vivo or in cultured cells. Generally, human squamous cell carcinomas stained strongly while human adenocarcinomas did not stain for p63. In contrast to the esophagus and trachea from wild type mice, the esophageal and tracheobronchial epithelium from newborn p63-/- mice consist largely of a columnar, ciliated epithelium that appear to lack basal cells. Our study indicates that p63 is critical for normal morphogenesis of the esophageal and tracheobronchial epithelium. In p63-/- mice, progenitor cells are able to differentiate into ciliated cells but do not appear to generate basal cells suggesting a role for p63 either in the regulation of the differentiation of progenitor cells into basal cells or in the survival of basal cells. II. Retinoids play an important role in the tracheobronchial epithelium. Retinoids can act via nuclear retinoid receptors or through other mechanisms. The synthetic retinoid 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (AHPN) can act both activate RARgamma and act by receptor-independent mechanisms. We have analyzed the effect of several retinoids on the expression of non-steroidal anti-inflammatory drug-activated gene (NAG-1) in normal human tracheobronchial epithelial (HTBE) cells and several lung carcinoma cell lines. The retinoid AHPN greatly enhances the expression of NAG-1 mRNA and protein in a time and dose-dependent manner in human lung adenocarcinoma H460 cells and several other carcinoma cell lines. This induction was specific for AHPN since retinoic acid, an RAR- and an RXR-pan-agonist were unable to induce NAG-1 suggesting that this induction is not mediated through activation of retinoid receptors. Although NAG-1 is a p53-responsive gene, AHPN-induced NAG-1 expression does not require p53. The induction of NAG-1 expression by AHPN is at least in part due to a 8-fold increase in the stability of NAG-1 mRNA. In contrast to carcinoma cells, NAG-1 expression is effectively induced by retinoic acid and the RAR-selective pan-agonist in normal HTBE cells and accompanies the inhibition of squamous differentiation and the initiation of normal differentiation. In vivo, NAG-1 expression was observed in the normal tracheobronchial epithelium while no expression was found in either squamous metaplastic tracheal epithelium or in sections of human lung tumors. Our results suggest that the induction of NAG-1 expression by retinoids in normal HTBE and lung carcinoma cells is regulated by distinct mechanisms and is associated with different biological processes. The linkage between AHPN treatment and NAG-1 expression revealed in this study provides a new mechanism for the anti-tumorigenic activity of AHPN.

I.气管和食管具有共同的起源，都是在早期胚胎发育过程中从前肠内胚层进化而来的。这些上皮经历一系列明确的结构变化，涉及祖细胞分化成多种细胞类型，最终导致成熟上皮的形成。在本研究中，我们监测了发育过程中多个阶段的食管和气管支气管上皮中 p63 的表达，并确定 p63 表达缺乏对 p63-/- 小鼠中这些上皮形态发生的影响。 E15.5天，食管和气管支气管上皮含有2-3层细胞；然而，只有祖细胞表达p63。祖细胞首先分化为纤毛细胞 (p63-/b-微管蛋白 IV+)，并在出生时分化为基底细胞 (p63+/K14+/BS-I-B4+)。在成年小鼠和人类中，食管内壁成熟为（非）角化的复层上皮，而气管支气管内壁发育为包含基底细胞、纤毛细胞和粘液分泌细胞的假复层柱状上皮。在成熟上皮细胞中，K14+/BS-I-B4+ 基底细胞的 p63 染色最为强烈。 p63 的表达在体内或培养细胞的鳞状分化过程中受到显着抑制。一般来说，人鳞状细胞癌对 p63 染色强烈，而人腺癌则不染色。与野生型小鼠的食管和气管相反，新生p63-/-小鼠的食管和气管支气管上皮主要由柱状纤毛上皮组成，似乎缺乏基底细胞。我们的研究表明 p63 对于食管和气管支气管上皮的正常形态发生至关重要。在p63-/-小鼠中，祖细胞能够分化为纤毛细胞，但似乎不产生基底细胞，这表明p63在调节祖细胞向基底细胞的分化或基底细胞的存活中发挥作用。 二.类维生素A在气管支气管上皮中发挥重要作用。类维生素A可以通过核类维生素A受体或通过其他机制发挥作用。合成的类视黄醇 6-[3-(1-金刚烷基)-4-羟基苯基]-2-萘甲酸 (AHPN) 既可以激活 RARgamma，又可以通过受体独立机制发挥作用。我们分析了几种视黄醇对正常人气管支气管上皮（HTBE）细胞和几种肺癌细胞系中非甾体抗炎药激活基因（NAG-1）表达的影响。类视黄醇 AHPN 以时间和剂量依赖性方式极大地增强人肺腺癌细胞 H460 细胞和其他几种癌细胞系中 NAG-1 mRNA 和蛋白质的表达。这种诱导对于 AHPN 是特异性的，因为视黄酸、RAR 和 RXR 泛激动剂不能诱导 NAG-1，表明这种诱导不是通过类视黄醇受体的激活介导的。尽管 NAG-1 是 p53 响应基因，但 AHPN 诱导的 NAG-1 表达不需要 p53。 AHPN 诱导 NAG-1 表达至少部分是由于 NAG-1 mRNA 的稳定性增加了 8 倍。与癌细胞相反，正常HTBE细胞中的NAG-1表达由视黄酸和RAR选择性全激动剂有效诱导，并伴随着鳞状细胞分化的抑制和正常分化的启动。在体内，在正常气管支气管上皮中观察到NAG-1表达，而在鳞状化生气管上皮或人肺肿瘤切片中未发现表达。我们的结果表明，正常 HTBE 和肺癌细胞中类视黄醇诱导 NAG-1 表达受到不同机制的调节，并与不同的生物过程相关。本研究揭示的 AHPN 治疗与 NAG-1 表达之间的联系为 AHPN 的抗肿瘤活性提供了新的机制。