MAPK signaling in injury, proliferation and fibrosis

MAPK 信号传导在损伤、增殖和纤维化中的作用

• 批准号: 6901791
• 负责人: Brooke Taylor Mossman
• 金额: $ 24.09万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-04 至 2006-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6901791
• 关键词: AP1 protein; JUN kinase; asbestos; biological signal transduction; cell cycle; cell proliferation; enzyme activity; genetically modified animals; histochemistry /cytochemistry; laboratory mouse; lung injury; mitogen activated protein kinase; pneumoconiosis; pulmonary fibrosis /granuloma; respiratory epithelium; transfection

Asbestos activates mitogen-activated protein kinase (MAPK) cascades in alveolar type II epithelial (C10) cells in vitro and in vivo. In C10 cells, these signaling events precede early increases in mRNA levels of fos/jun family members and more protracted increases in mRNA levels of fra-1 and Fra-1/Jun (AP-1) complexes. We hypothesize that activation of ERK and JNK pathways by asbestos leads to changes in expression of AP-1 family members and subunit composition that then govern cell cycle changes, injury and subsequent proliferation of pulmonary epithelial cells. In Specific Aim #1, we will determine in C10 alveolar type II epithelial cells using transfection techniques whether activation of ERK and JNK cascades by asbestos are linked causally to increased expression of the fos/jun members, c-fos, c-jun and fra-1, composition of AP-1 complexes, transactivation of AP-1 dependent gene expression, and subsequent outcomes (cell cycle alterations, injury and compensatory proliferation). In Specific Aim #2, we will assess using transgenic mice over-expressing dominant negative (dn)MEK1 or dnJNK1 with lung epithelial cell promoters (CC10 and SPC), whether ERK and JNK pathways are causally related to proliferation of distal bronchiolar and alveolar type II epithelial cells and the development of fibrosis in a murine model of asbestosis. In Specific Aim #3, we will determine using laser capture microdissection and real time PCR (TaqMan) whether c-fos, c-jun and fra-1 expression is increased in distal bronchiolar and alveolar type II epithelial cells of mice exposed to asbestos, and whether patterns are modified in transgenic mice expressing epithelial cell-specific dnMEK1, dnJNK1 or backcrosses of these mice to block both pathways. The goals of this Project are related to the theme of the Program Project, the role of MAPK cascades in epithelial cell injury and proliferation, and will ascertain whether modification of these cell signaling events modifies these outcomes in vitro and in an inhalation model of asbestosis. Our hypothesis are novel in that they will provide a mechanistic framework for MAPK pathways and AP-1 subunit composition in the causation of epithelial cell injury and compensatory hyperplasia.

石棉在体外和体内激活肺泡II型上皮（C10）细胞中有丝分裂原激活的蛋白激酶（MAPK）级联反应。在C10细胞中，这些信号事件在FOS/JUN家族成员的mRNA水平的早期升高和FRA-1和FRA-1/JUN（AP-1）复合物的mRNA水平的持久增加。我们假设石棉对ERK和JNK途径的激活会导致AP-1家族成员表达和亚基组成的变化，然后控制细胞周期的变化，损伤和随后的肺上皮细胞增殖。在特定目的＃1中，我们将使用转染技术在C10肺泡II型上皮细胞中确定ERK和JNK CASCADE的激活是否与FOS/JUN成员的表达增加有关增殖）。 In Specific Aim #2, we will assess using transgenic mice over-expressing dominant negative (dn)MEK1 or dnJNK1 with lung epithelial cell promoters (CC10 and SPC), whether ERK and JNK pathways are causally related to proliferation of distal bronchiolar and alveolar type II epithelial cells and the development of fibrosis in a murine model of asbestosis. 在特定目的＃3中，我们将确定使用激光捕获显微解剖和实时P​​CR（Taqman）（taqman）在细支气管和暴露于石棉的小鼠的II型上皮细胞中是否会增加c-fos，c-jun和fra-1表达是否会增加阻止这两个路径。该项目的目标与计划项目的主题，MAPK级联反应在上皮细胞损伤和增殖中的作用有关，并将确定这些细胞信号事件的修饰是否会在体外和在石棉下吸入模型中修饰这些结果。我们的假设是新颖的，因为它们将在上皮细胞损伤和补偿性增生的因果关系中为MAPK途径和AP-1亚基组成提供机械框架。