mtDNA depleter mouse for decoding mitochondrial regulation of diverse organs

本申请响应PAR-19-369“动物模型和相关生物学的开发” 研究材料R21”，寻求申请开发适用于 多个NIH研究所的研究兴趣。它涉及的目标之一“新的和 显著改进的转基因动物模型，适用于影响多种疾病的疾病， 身体系统，例如，线粒体缺陷的动物模型。”线粒体功能受损 与许多以线粒体功能障碍为主要原因的原发性线粒体疾病相关 疾病。值得注意的是，线粒体DNA耗竭综合征（MDS）的特征是线粒体DNA的严重减少， 在受影响的组织和器官中的线粒体功能受损。次级线粒体 其中线粒体是次要参与的疾病包括心血管疾病、糖尿病、肥胖症、神经系统疾病、 疾病和癌症。此外，广泛报道了衰老过程中线粒体功能的普遍下降 并且已知是与年龄相关的人类疾病的潜在驱动力。尽管有巨大的重要性， 线粒体在各个器官中的最佳功能，线粒体在体内的作用绝大多数 哺乳动物的器官仍然未知。线粒体DNA聚合酶γ（POLG 1）是唯一的DNA聚合酶 参与线粒体DNA的合成。我们开发了一种可诱导的小鼠，在聚合酶结构域中表达 POLG 1，显性阴性（DN）突变（在位置1135处的天冬氨酸至丙氨酸（D至A）突变， 在整个动物中诱导线粒体DNA的消耗。我们的初步研究表明，受损的线粒体 在整个动物中的功能导致多系统功能障碍。这些包括皮肤皱纹的发展 以及肝、肾、心和脾的肥大。此外，线粒体DNA耗竭小鼠显示萎缩， 男性和女性生殖器官。基于这些观察，我们假设 线粒体DNA缺失小鼠的特征将有助于理解 线粒体在多器官系统的发育和功能中的作用。我们提出两个具体的 目的1：确定器官特异性肥大和萎缩 线粒体DNA缺失小鼠线粒体功能障碍的病理学研究 肥大和萎缩的器官特异性线粒体应激反应机制。 我们的长期目标是使这种小鼠模型能够广泛使用，这将加速线粒体 研究各种器官和疾病。该小鼠将在与人类基因组相关的各种研究领域中发挥作用。 国家糖尿病、消化和肾脏疾病研究所、国家老龄研究所、国家 心脏，肺和血液研究所，国家儿童和人类发展研究所，以及国家 神经疾病和中风研究所，国家癌症研究所，国家过敏研究所 传染病和妇女健康中心。

This application is responsive to PAR-19-369 “Development of Animal Models and Related Biological Materials for Research R21,” which seeks application to develop animal models that are applicable to the research interests of multiple NIH institutes. It addresses one of the objective “Characterization of new and significantly improved genetically modified animal models that are applicable to diseases that impact multiple body systems, e.g., animal models with mitochondrial defects.” Impaired mitochondrial function is associated with many primary mitochondrial diseases in which mitochondrial dysfunction is the primary cause of the disease. Notably, mtDNA depletion syndromes (MDS) are characterized by a severe reduction in mtDNA content leading to impaired mitochondrial function in affected tissues and organs. Secondary mitochondrial diseases in which mitochondria are secondarily involved include cardiovascular, diabetes, obesity, neurological disorders, and cancer. Moreover, a general decline in mitochondrial function is extensively reported during aging and is known to be a driving force underlying age-related human diseases. Despite the enormous importance of mitochondria in the optimal function of various organs, the in vivo role of mitochondria in the vast majority of mammalian organs remain unknown. Mitochondrial DNA polymerase γ (POLG1) is the only DNA polymerase involved in the synthesis of mtDNA. We developed an inducible mouse expressing, in the polymerase domain of POLG1, a dominant-negative (DN) mutation (an aspartic acid to alanine (D to A) mutation at position 1135, that induces depletion of mtDNA in the whole animal. Our preliminary studies suggest that impaired mitochondrial function in the whole animal results in multisystem dysfunction. These include the development of skin wrinkles and hypertrophy of the liver, kidney, heart and spleen. Furthermore, mtDNA depleter mice show atrophy of male and female reproductive organs. Based on these observations, we hypothesize that the characterization of mtDNA depleter mice will facilitate the understanding of the vital function of mitochondria in the development and function of multiple organ systems. We propose two specific aims to test this hypothesis: Aim 1: Determine the organ-specific hypertrophic and atrophic pathology associated with mitochondrial dysfunction in mtDNA depleter mouse Aim 2: Identify organ specific mitochondrial stress response mechanisms underlying hypertrophy and atrophy. Our long-term goal is to enable the widespread use of this mouse model, which will accelerate mitochondrial research across various organs and diseases. The mouse will be useful in diverse research areas relevant to the National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute on Aging, the National Heart, Lung and Blood Institute, the National Institute of Child and Human Development, and the National Institute of Neurological Disorders and Stroke, the National Cancer Institute, the National Institute of Allergy and Infectious Diseases and Center for Women’s health.