mtDNA depleter mouse for decoding mitochondrial regulation of diverse organs

本申请响应PAR-19-369《动物模型及相关生物学的发展》 研究材料R21，寻求应用程序来开发适用于 美国国立卫生研究院多个研究所的研究兴趣。它阐述了目标之一，即对新的和 显著改进的转基因动物模型，适用于影响多个 身体系统，例如，有线粒体缺陷的动物模型。线粒体功能受损是 与许多以线粒体功能障碍为主要原因的原发线粒体疾病有关 这种疾病的危害。值得注意的是，mtdna耗竭综合征(Mds)的特征是mtdna严重减少。 导致受影响组织和器官线粒体功能受损的内容。次级线粒体 线粒体继发参与的疾病包括心血管疾病、糖尿病、肥胖、神经疾病 疾病和癌症。此外，据广泛报道，线粒体功能在衰老过程中普遍下降。 并被认为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， 线粒体在各个器官的最佳功能，在体内线粒体的作用占绝大多数 哺乳动物的器官仍然未知。线粒体dna聚合酶γ(Polg1)是世界上唯一的 参与线粒体DNA的合成。我们开发了一种可诱导的小鼠，在聚合酶区域表达 POLG1，显性-阴性(DN)突变(1135位天冬氨酸到丙氨酸(D到A)的突变)， 导致整个动物线粒体DNA的耗尽。我们的初步研究表明受损的线粒体 整个动物的功能会导致多系统功能障碍。其中包括皮肤皱纹的形成。 肝、肾、心、脾肥大。此外，线粒体DNA耗竭的小鼠表现出 雄性和雌性生殖器官。基于这些观察结果，我们假设 线粒体DNA耗竭小鼠的特性将有助于理解线粒体DNA耗竭小鼠的重要功能 线粒体在多器官系统的发育和功能中的作用我们提出了两个具体的 旨在验证这一假说：目的1：确定特定器官的肥大和萎缩 线粒体DNA耗竭小鼠线粒体功能障碍的病理学研究目的2：鉴定 肥大和萎缩背后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得到广泛应用，这种模型将加速线粒体 对各种器官和疾病进行研究。该鼠标将在与 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、肺和血液研究所、国家儿童与人类发展研究所和国家 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.