A new DMD model with a humanized glycome

具有人源化糖组的新 DMD 模型

基本信息

批准号：
8449165
负责人：
PAUL Taylor MARTIN
金额：
$ 49.57万
依托单位：
RESEARCH INST NATIONWIDE CHILDREN'S HOSP
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-01 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8449165
关键词：
12 year old Address Age-Months Animal Model Animals Antibodies Autoimmune Responses Back Biological Response Modifier Therapy Birth Cardiac Cardiac Death Cell surface Child Childhood Complex Diet Disease Disease model Duchenne muscular dystrophy Dystrophin Employee Strikes Ensure Flushing Genes Glycoproteins Goals Grant Heart Heart failure Human Immune Immune response Immunosuppressive Agents Inflammation Inflammatory Lead Life Limb-Girdle Muscular Dystrophies Link Longevity Mammals Modeling Modification Morbidity - disease rate Mus Muscle Muscle Cells Muscle function Muscular Dystrophies Mutation Myocardium Myopathy N-glycolylneuraminic acid Neuromuscular Diseases Patients Pharmaceutical Preparations Phenotype Play Polysaccharides Pongidae Prevalence Proteins Relative (related person)Respiratory Diaphragm Rodent Role Sarcoglycans Severity of illness Sialic Acids Skeletal Muscle Testing Therapeutic Tissues Transgenes Translating Translational Research disease phenotype feeding gain of function glycosylation human disease loss of function mdx mouse mortality mouse genome mouse model muscle strength muscular dystrophy mouse model research study respiratory sialomucin sialomucins sugar therapy development

项目摘要

DESCRIPTION (provided by applicant): In this grant, we propose to define the role of an important human-specific change in glycosylation, the loss of N-glycolylneuraminic acid (Neu5Gc), in Duchenne muscular dystrophy (DMD) and in Limb Girdle Muscular Dystrophy 2D. Neu5Gc is a form of sialic acid that is absent in all humans due to an inactivating mutation in the human CMAH gene. By contrast, Neu5Gc is an abundant form of sialic acid in heart and skeletal muscles in almost all other mammals besides humans, including the great apes. To assess the role of human CMAH in DMD, we have created Cmah-/-mdx mice, in effect humanizing this aspect of mouse glycosylation. The mdx mouse has been studied for several decades as a model for DMD, a relatively common and ultimately fatal X- linked neuromuscular disorder. Despite mimicking loss of dystrophin, the gene defective in DMD, in almost all muscle cells, mdx mice do not show the mouse equivalent of a pediatric presentation of disease. Children with DMD show loss of ambulation, usually by 12 years of age, followed by respiratory and/or cardiac failure and death usually in the third decade of life. mdx mice, by contrast, show little change in these same features until near the end of their normal lifespan, which is typically reduced by only 1-2 months relative to wild type animals. Cmah-/-mdx mice, by contrast to mdx animals, show an 88% deficit in diaphragm muscle strength and a 66% deficit in cardiac trabecular muscle strength, compared to wild type, by 8 months of age, with half of animals dying by 11 months. Such mice also show significantly impaired ambulation relative to mdx. The early and robust presentation of these phenotypes, which are the primary drivers of DMD morbidity and mortality, in a small animal model that carries a genetically appropriate human-like change in the mouse genome will be a great asset to translational research to identify therapies for DMD and other human diseases. In Aim 1 of this proposal, we will investigate both the loss of function aspects to Neu5Gc deficiency as well as gain of function immune aspects as they relate to disease severity in Cmah-/-mdx mice. In Aim 2, we will devise therapies to offset the increased disease severity resulting from deletion of Cmah that could be translated into therapies for muscular dystrophy patients. In Aim 3, we will study the role of Cmah in a second mouse model of muscular dystrophy, the Sgca-/- model of Limb Girdle Muscular Dystrophy 2D. These experiments will investigate the cause of increased disease severity resulting from Cmah deficiency, assess the generality of Cmah deficiency in altering disease, and develop therapies to offset the loss of human CMAH that could ameliorate muscular dystrophy in DMD and LGMD2D patients.

描述（由申请人提供）：在这笔赠款中，我们建议定义人类特异性变化在糖基化中的作用，N-糖苷基因神经氨酸的丧失（NEU5GC）在Duchenne肌肉营养不良（DMD）和肢体腰肌肌肉肌肉不足2D中的作用。 neu5gc是一种唾液酸的一种形式，由于人类CMAH基因的灭活突变，所有人类都没有。相比之下，除了人类（包括大猿）以外的几乎所有其他哺乳动物中，Neu5GC是心脏和骨骼肌中的一种丰富形式。为了评估人CMAH在DMD中的作用，我们创建了CMAH - / - MDX小鼠，实际上使小鼠糖基化的这一方面人性化。 MDX小鼠已经被研究了数十年，作为DMD的模型，DMD是一种相对常见且最终致命的X神经肌肉疾病。尽管模仿了肌营养不良蛋白的丧失，但在几乎所有肌肉细胞中，DMD中的基因有缺陷，但MDX小鼠并未显示小鼠等同于疾病的儿科表现。 DMD的儿童通常在12岁之前出现流动损失，其次是呼吸道和/或心脏衰竭以及死亡，通常在生命的第三个十年中。相比之下，MDX小鼠在正常寿命结束时几乎没有变化，而相对于野生型动物，通常仅减少1-2个月。与MDX动物相比，CMAH - / - MDX小鼠在隔膜肌肉强度和心脏小梁肌肉强度的赤字不足88％，与野生型相比，到8个月大，一半的动物死于11个月。相对于MDX，此类小鼠还显示出显着损害的行动。这些表型的早期和可靠的表现是DMD发病率和死亡率的主要驱动因素，它在小型动物模型中携带了小鼠基因组中具有遗传适当的人类样变化的小动物模型，将是转化研究的巨大资产，以鉴定DMD和其他人类疾病的疗法。在本提案的目标1中，我们将研究既损失NEU5GC缺乏症的功能方面，又要研究与CMAH疾病严重程度相关的功能免疫方面的增益 - / - MDX小鼠。在AIM 2中，我们将设计疗法，以抵消删除CMAH导致的疾病严重程度的增加，该疾病的严重程度可转化为肌营养不良患者的疗法。在AIM 3中，我们将研究CMAH在第二个小鼠肌肉营养不良的小鼠模型中的作用，即肢体束缚肌营养不良2D的SGCA - / - 模型。这些实验将调查导致CMAH缺乏症导致疾病严重程度增加的原因，评估CMAH缺乏症在改变疾病时的普遍性，并开发疗法以抵消人CMAH的丧失，从而可以改善DMD和LGMD2D患者的肌肉营养不良。