Translational Studies of Lipidomics-Associated Signaling Pathways in VCP Disease

VCP 疾病中脂质组学相关信号通路的转化研究

• 批准号: 8912058
• 负责人: VIRGINIA Eunice KIMONIS
• 金额: $ 15.45万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8912058
• 关键词: Affect; Anabolism; Animals; Apoptosis; Apoptotic; Autophagocytosis; Autophagosome; Binding; Biological Models; Brain Pathology; Cell Survival; Cells; Ceramides; Chromosomes; Clinical; Development; Diet; Disease; Exhibits; Family; Fibroblasts; Frontotemporal Dementia; Genes; Health; Homozygote; Human; In Vitro; Inclusion Bodies; Intervention; Knock-in Mouse; Knowledge; Label; Laboratories; Lead; Limb structure; Link; Lipids; Liver; Measures; Metabolic; Metabolism; Mitochondria; Molecular; Motor Activity; Mus; Muscle; Muscle Fibers; Muscle Weakness; Mutant Strains Mice; Mutation; Myoblasts; Myopathy; Neurodegenerative Disorders; Nutritional; Online Mendelian Inheritance In Man; Osteitis Deformans; Palmitic Acids; Parkinson Disease; Pathogenesis; Pathology; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Primary Lateral Sclerosis; Process; Production; Publishing; Recruitment Activity; Reporting; Research; Respiratory Insufficiency; Signal Pathway; Signal Transduction; Skeletal Muscle; Sphingolipids; Spinal Cord; Supplementation; System; Testing; Therapeutic; Therapeutic Agents; Tissues; Toxic effect; Translating; Ubiquitin; Vacuole; bone; cohort; cytotoxic; effective therapy; feeding; improved; in vivo Model; innovation; interest; mitochondrial dysfunction; mouse model; novel; novel therapeutics; offspring; pregnant; protein TDP-43; screening; translational approach; translational study; valosin-containing protein

DESCRIPTION (provided by applicant): Inclusion Body Myopathy associated with Paget's disease of the bone, and Frontotemporal Dementia (IBMPFD, OMIM 167320), was first reported by Kimonis et al. in 2000 and was subsequently attributed to being caused by mutations in the gene encoding Valosin-Containing Protein (VCP) in 2004. The disease is associated with progressive limb girdle muscle weakness and early demise from respiratory insufficiency. Muscle pathology is significant for vacuoles, TDP-43 and ubiquitin-positive inclusions. There is great interest in understanding the cellular and molecular pathophysiological mechanism(s) underlying VCP disease in view of the overlap with other common neurodegenerative diseases. Our laboratory has generated the first knock-in mouse model with the most common VCP R155H mutation, which has many features of human VCP-associated myopathy including progressive muscle, bone, spinal cord and brain pathology. The VCPR155H/R155H homozygous mice exhibit rapid progressive weakness and accelerated pathology including disrupted autophagosome formation and mitochondrial dysfunction and typically die by 21 days. However, feeding pregnant VCPR155H/+ heterozygous dams with a lipid- enriched diet (LED) resulted in the reversal of the lethal phenotype in homozygous offspring. The LED fed mice showed improvement of motor activity, muscle pathology, and autophagy/mitophagy signaling cascades. A targeted lipidomic analysis of skeletal muscle and liver revealed elevations in tissue levels of non-esterified palmitic acid and ceramide (d18:1/16:0), the latter of which has been implicated in binding and recruiting LC3-II labeled autophagosomes to damaged mitochondria for lysosomal degradation, also termed 'lethal mitophagy'. Preliminary in vitro studies demonstrated that ceramide treatments increased expression levels of the autophagy markers p62/SQSTM1 and LC3-II in myoblasts. We hypothesize that decreasing the levels of the ceramide intermediates in the homozygote mice fed the LED ameliorates the pathophysiologic manifestations of VCP disease. In Aim 1, we will utilize the VCP mouse model and in vitro cell systems as an innovative translational approach to explore the intermediate steps in ceramide metabolism that are altered in VCP disease. In Aim 2, we will investigate mechanisms underlying LED supplementation rescue of the sphingolipid- induced lethal autophagy, mitophagy, mitochondrial dysfunction and apoptosis signaling pathways. In Aim 3, we will evaluate the effects of reducing ceramide on disease pathology by pharmacologic drugs. We hope that these studies will lead to potential new therapeutic strategies in VCP and related diseases.

描述（由申请人提供）：Kimonis等人于2000年首次报告了与骨佩吉特病和额颞痴呆（IBMPFD，OMIM 167320）相关的包涵体肌病，随后于2004年将其归因于编码含瓦洛辛蛋白（VCP）的基因突变。这种疾病与进行性肢带肌无力和呼吸功能不全的早期死亡有关。肌肉病理学对于空泡、TDP-43和泛素阳性包涵体是显著的。鉴于VCP与其他常见神经退行性疾病的重叠，人们对了解VCP疾病的细胞和分子病理生理机制非常感兴趣。我们的实验室已经产生了第一个具有最常见的VCP R155 H突变的基因敲入小鼠模型，该模型具有人类VCP相关肌病的许多特征，包括进行性肌肉，骨骼，脊髓和脑病理学。VCPR 155 H/R155 H纯合子小鼠表现出快速进行性虚弱和加速的病理学，包括自噬体形成破坏和线粒体功能障碍，通常在21天内死亡。然而，用富含脂质的饮食（LED）喂养怀孕的VCPR 155 H/+杂合子母鼠导致纯合子后代中致死表型的逆转。LED喂养的小鼠显示出运动活动、肌肉病理学和自噬/线粒体自噬信号级联的改善。骨骼肌和肝脏的靶向脂质组学分析显示，非酯化棕榈酸和神经酰胺（d18：1/16：0）的组织水平升高，后者涉及将LC 3-II标记的自噬体结合并募集至受损线粒体进行溶酶体降解，也称为“致死性线粒体自噬”。初步体外研究表明，神经酰胺处理增加了成肌细胞中自噬标志物p62/SQSTM 1和LC 3-II的表达水平。我们推测，降低喂食LED的纯合子小鼠中神经酰胺中间体的水平可改善VCP疾病的病理生理学表现。在目标1中，我们将利用VCP小鼠模型和体外细胞系统作为一种创新的翻译方法来探索VCP疾病中神经酰胺代谢的中间步骤。在目标2中，我们将研究LED补充剂拯救鞘脂诱导的致死性自噬、线粒体自噬、线粒体功能障碍和凋亡信号通路的潜在机制。在目标3中，我们将评估药理学药物减少神经酰胺对疾病病理学的影响。我们希望这些研究将导致潜在的新的治疗策略VCP和相关疾病。