Role of folliculin (FLCN) in lung cell survival

滤泡素 (FLCN) 在肺细胞存活中的作用

• 批准号: 8320578
• 负责人: VERA P KRYMSKAYA
• 金额: $ 51.55万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2016-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8320578
• 关键词: 5' -AMP-activated protein kinase; AMP-activated protein kinase kinase; Actins; Adaptor Signaling Protein; Affect; Airway Resistance; Alveolar; Alveolar Cell; Anoikis; Apoptosis; Binding; Biochemical; Birt-Hogg-Dube Syndrome; Bronchoalveolar Lavage; Cell Communication; Cell Death; Cell Polarity; Cell Survival; Cells; Cellular Morphology; Complex; Cyst; Cystic kidney; Cytoskeleton; DNA Sequence Rearrangement; Data; Disease; Distal; Down-Regulation; Energy Metabolism; Epithelial Cells; Epithelium; Etiology; Folliculin; Goals; Human; In Vitro; Induced Mutation; Kidney Neoplasms; Link; Lung; Lung diseases; Maintenance; Metabolism; Molecular; Molecular Target; Mus; Null Lymphocytes; Phosphorylation; Pneumothorax; Preclinical Testing; Production; Proteins; Publishing; Pulmonary Surfactants; Respiratory physiology; Role; Signal Pathway; Signal Transduction; Small Interfering RNA; Testing; Transgenic Mice; Transgenic Organisms; Tuberous sclerosis protein complex; Tumor-Suppressor Gene Inactivation; alveolar destruction; base; cell type; glucose transport; glucose uptake; in vivo; insight; mTOR protein; novel; novel therapeutic intervention; pulmonary function; recombinase; small hairpin RNA

DESCRIPTION (provided by applicant): Cystic airspace enlargement and spontaneous pneumothorax are major pathological manifestations Birt-Hogg- Dube (BHD) syndrome. Although the etiology of this disease is not known, lung cysts in BHD are linked to autosomal dominant mutational inactivation of tumor suppressor gene folliculin (FLCN). FLCN, a 64-kDa ubiquitously expressed protein with high homology throughout species that lacks apparent functional domain, through adaptor proteins FNIP1/2, binds the 5'-AMP-activated protein kinase (AMPK). Little, however, is known about a role of folliculin (FLCN) in lung cell survival. Our in vitro and in vivo studies demonstrate that FLCN is required for lung cell survival by acting within 5'-AMP-activated protein kinase (AMPK) - tuberous sclerosis complex 2 (TSC2) - mammalian target of rapamycin complex 2 (mTORC2) signaling pathway. To fill a gap in the current understanding of airspace enlargement, we have restricted the scope of this proposal to one testable, central hypothesis that FLCN is required for lung cell survival. To test our hypothesis, in Aim 1, we will determine whether FLCN is required for lung epithelial cell survival in vivo using new transgenic FLCNf/f:SP-C- Cre mice generated in PI's lab. Targeted conditional inducible deletion of FLCN in SP-C-expressing lung epithelial cells will allow us to identify the specific lung epithelial cell type affected by FLCN loss that promotes alveolar space enlargement. In Aim 2 we will examine whether FLCN is required for maintenance of epithelial cell morphology and metabolism. In Aim 3, we will determine FLCN role in regulating activities of Akt and AMPK kinases, and whether pharmacological activation of AMPK will rescue lung epithelial cell survival with targeted inducible deletion of FLCN in FLCNf/f:SP-C-Cre mice. These studies will identify the role of FLCN in lung cell survival, provide insights into the cellular an molecular mechanism of lung epithelial cell-cell contacts, actin cytoskeleton, and metabolism regulated by FLCN. These studies will also establish a mechanistic link between loss of FLCN and cystic airspace enlargement by using our unique novel FLCNf/f:SP- C-Cre transgenic mice and identify potential molecular target(s) for novel therapeutic approaches to treat BHD. PUBLIC HEALTH RELEVANCE: These studies will identify the role of FLCN in lung cell survival, and will provide insights into the cellular and molecular mechanism of lung epithelial cell interactions, actin cytoskeleton, and metabolism regulated by FLCN. Although our immediate specific aims focus on FLCN loss as it relates to BHD syndrome, our long term goals are to provide insights into mechanisms of lung cell survival and cystic airspace enlargement in other pulmonary diseases and to identify potential molecular target(s) for novel therapeutic approaches.

描述（申请人提供）：囊性空腔扩大和自发性气胸是 Birt-Hogg-Dube (BHD) 综合征的主要病理表现。尽管这种疾病的病因尚不清楚，但 BHD 中的肺囊肿与肿瘤抑制基因滤泡素 (FLCN) 的常染色体显性突变失活有关。 FLCN 是一种在整个物种中具有高同源性的 64 kDa 普遍表达蛋白，缺乏明显的功能域，通过接头蛋白 FNIP1/2 结合 5'-AMP 激活蛋白激酶 (AMPK)。然而，人们对卵泡素（FLCN）在肺细胞存活中的作用知之甚少。我们的体外和体内研究表明，FLCN 通过在肺细胞内发挥作用而成为肺细胞存活所必需的。 5'-AMP 激活蛋白激酶 (AMPK) - 结节性硬化症复合物 2 (TSC2) - 哺乳动物雷帕霉素靶标复合物 2 (mTORC2) 信号通路。为了填补目前对空域扩大理解的空白，我们将这一提议的范围限制在一个可测试的中心假设上，即肺细胞存活需要 FLCN。为了检验我们的假设，在目标 1 中，我们将使用 PI 实验室生成的新型转基因 FLCNf/f:SP-C-Cre 小鼠来确定 FLCN 是否是肺上皮细胞体内存活所必需的。在表达 SP-C 的肺上皮细胞中定向条件诱导删除 FLCN 将使我们能够识别受 FLCN 丢失影响的特定肺上皮细胞类型，从而促进肺泡腔扩大。在目标 2 中，我们将检查 FLCN 是否是维持上皮细胞形态和代谢所必需的。在目标 3 中，我们将确定 FLCN 在调节 Akt 和 AMPK 激酶活性中的作用，以及 AMPK 的药理学激活是否会通过在 FLCNf/f:SP-C-Cre 小鼠中定向诱导删除 FLCN 来挽救肺上皮细胞的存活。这些研究将确定 FLCN 在肺细胞存活中的作用，深入了解 FLCN 调节的肺上皮细胞-细胞接触、肌动蛋白细胞骨架和代谢的细胞分子机制。这些研究还将通过使用我们独特的新型 FLCNf/f:SP-C-Cre 转基因小鼠建立 FLCN 丧失和囊性空腔扩大之间的机制联系，并确定治疗 BHD 的新治疗方法的潜在分子靶点。 公共卫生相关性：这些研究将确定 FLCN 在肺细胞存活中的作用，并将深入了解 FLCN 调节的肺上皮细胞相互作用、肌动蛋白细胞骨架和代谢的细胞和分子机制。虽然我们当前的具体目标集中在与 BHD 综合征相关的 FLCN 损失上，但我们的长期目标是深入了解其他肺部疾病中肺细胞存活和囊性空腔扩大的机制，并确定新治疗方法的潜在分子靶点。