Maintenance of intestinal epithelial cell homeostasis by prohibitin

抑制素维持肠上皮细胞稳态

基本信息

批准号：
8633115
负责人：
ARIANNE L THEISS
金额：
$ 7.84万
依托单位：
BAYLOR RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-18 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8633115
关键词：
Address Adenoviruses Animal Model Apoptosis Apoptotic Architecture Atrophic Azoxymethane Biopsy Cell Cycle Progression Cell Death Cell Line Cell physiology Cells Characteristics Colitis Colon Crohn&apos s disease Data Electron Transport Epithelial Epithelial Cells Exhibits Functional disorder Funding Gastrointestinal Diseases Gene Silencing Generations Genes Genetic Transcription Grant Healed Homeostasis Inflammation Inflammatory Inflammatory Bowel Diseases Inflammatory Response Inflammatory disease of the intestine Injury Intestines Investigation Knockout Mice Maintenance Mediating Mitochondria Mitochondrial Proteins Modeling Molecular Mucous Membrane Mus Oxidative Stress PHB gene Pathogenesis Patients Phosphorylation Proteins Reactive Oxygen Species Recovery Regulation Reporting Respiratory Chain Role Severity of illness Small Interfering RNA Sodium Dextran Sulfate Source Stat3 protein Stress Sulfonic Acids Tamoxifen Testing Therapeutic Time Tissues Transgenic Mice Ulcerative Colitis Wild Type Mouse base colitis associated cancer combat cytokine genetic manipulation healing ileum in vivo Model intestinal epithelium intestinal homeostasis mitochondrial dysfunction mitochondrial membrane nanoparticle new therapeutic target novel prohibitin promoter public health relevance recombinase response restoration therapeutic target transcription factor villin

项目摘要

DESCRIPTION (provided by applicant): Disturbed intestinal epithelial cell homeostasis is a key feature of inflammatory bowel disease (IBD). Multiple studies have reported mitochondrial dysfunction in epithelial cells during IBD. Damaged mitochondria are a key source of increased intracellular reactive oxygen species (ROS) from respiratory chain dysfunction that can result in cell death. Expression of prohibitin (PHB), a mitochondrial protein, is decreased in mucosal biopsies from IBD patients and in animal models of colitis. Our previous studies have shown that restoration of colonic epithelial PHB expression using genetic manipulation (villin-PHB transgenic mice) or therapeutic delivery to the colon via nanoparticle or adenovirus protects mice from experimental colitis and reduces oxidative stress. Gene silencing of PHB in cultured intestinal epithelial cells increases mitochondrial membrane depolarization, intracellular ROS, mitophagy, and apoptosis, suggesting that PHB is involved in maintaining mitochondrial integrity and epithelial cell homeostasis. Furthermore, our recent data show that PHB interacts with STAT3 in colon mucosa and cultured intestinal epithelial cell lines and modulates its downstream apoptotic responses. In addition to its activities as a transcription factor, STAT3 has recently been shown to reside in the mitochondria of cells and promote optimal electron transport chain activity. Based on these data, the central hypothesis of this proposal is that PHB modulates mitochondrial STAT3 to maintain mitochondrial integrity and homeostasis in intestinal epithelial cells. To address this hypothesis, the following Aims will be tested: 1) to characterize PHB-mediated mitochondrial STAT3 modulation and its downstream effects on apoptosis and mitochondrial function and 2) to use an intestinal epithelial cell-specific PHB conditional knockout mouse as an in vivo model for examining the role of PHB in maintaining intestinal epithelium homeostasis and modulating mitochondrial STAT3 during basal conditions and colitis. The overall objective of this proposal integrated across the two Aims is to determine the role of PHB in maintaining epithelial homeostasis and mucosal integrity. Together, these studies will provide novel comprehensive data on the involvement of PHB and STAT3 in mitochondrial dysfunction characteristic of intestinal inflammation. We believe our findings will identify novel molecular mechanisms that act to preserve epithelial barrier integrity basally and in the context of tissue injury and will provide new therapeutic targets.

描述（由申请人提供）：肠道上皮细胞稳态受干扰是炎症性肠病（IBD）的关键特征。多项研究报道了IBD期间上皮细胞中线粒体功能障碍。线粒体受损是可能导致细胞死亡的呼吸链功能障碍的细胞内活性氧（ROS）增加的关键来源。 IBD患者和结肠炎动物模型中的粘膜活检中的线粒体蛋白（PHB）的表达降低。我们先前的研究表明，使用遗传操纵（villin-PHB转基因小鼠）或通过纳米颗粒或腺病毒可保护小鼠免受实验性结肠炎并减少氧化应激，对结肠上皮PHB表达恢复或治疗性递送。 PHB在培养的肠上皮细胞中的基因沉默会增加线粒体膜去极化，细胞内ROS，线粒体和凋亡，这表明PHB参与维持线粒体完整性和上皮细胞稳态。此外，我们最近的数据表明，在结肠粘膜和培养的肠上皮细胞系中，PHB与STAT3相互作用，并调节其下游凋亡反应。除了其作为转录因子的活性外，STAT3最近还显示出驻留在细胞的线粒体中并促进最佳电子传输链活性。基于这些数据，该建议的中心假设是PHB调节线粒体STAT3以维持肠上皮细胞中的线粒体完整性和稳态。为了解决这一假设，将测试以下目标：1）表征 PHB介导的线粒体STAT3调节及其对凋亡和线粒体功能的下游影响以及2）使用肠上皮细胞特异性的PHB有条件的敲除小鼠作为体内模型，以检查PHB在维持肠道上的肠道上表上皮稳态中的作用在基础条件和结肠炎中。这两个目标整合的该提案的总体目标是确定PHB在维持上皮稳态和粘膜完整性中的作用。总之，这些研究将提供有关PHB和STAT3参与线粒体功能障碍特征的新的综合数据。我们认为，我们的发现将确定新的分子机制，这些机制基本和在组织损伤的背景下，以维护上皮屏障完整性，并将提供新的治疗靶标。