Mechanisms of Circadian Rhythmicity in CLOCK-Deficient Mice

时钟缺陷小鼠的昼夜节律机制

• 批准号: 8506154
• 负责人: DAVID Raymond WEAVER
• 金额: $ 36.39万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8506154
• 关键词: Affect; Age; Aging; Alleles; Animals; Aortic Valve Stenosis; Behavioral; Brain; Breeding; Bypass; Calcified; Cartilage; Cells; Circadian Rhythms; Complex; Complication; Couples; Defect; Deposition; Development; Disease; Event; Feedback; Fertility; Fertilization in Vitro; Gene Expression; Generations; Genes; Genetic; Genetic Models; Health; Heart; Heart Valves; Heterotopic Ossification; Hormonal; Human; Infertility; Knock-out; Label; Lead; Lesion; Logic; Male Infertility; Mediating; Medical; Methods; Molecular; Molecular Analysis; Motion; Mus; Operative Surgical Procedures; Osteogenesis; Other Genetics; Pain; Pathologic Processes; Pathology; Periodicity; Phenotype; Population; Prevention; Process; Production; Regulation; Reporting; Reproductive Behavior; Reproductive Endocrinology; Role; Serotyping; Sex Behavior; Site; Skeletal system; Somatic Cell; Spermatogenesis; Sterility; Tamoxifen; Tendon structure; Testing; Testis; Therapeutic; Time; Tissues; Transcription Coactivator; Trauma; age related; aortic valve; arthropathies; bone; calcification; cell type; circadian pacemaker; economic impact; improved; in vivo; male; mineralization; mouse model; prevent; promoter; public health relevance; recombinase; repaired; soft tissue; sperm cell; transcription factor

DESCRIPTION (provided by applicant): The proposed studies will use a mouse model to investigate causes for two conditions, infertility and arthropathy. Infertility affects ~ 10% of couples, with about half of this related to male infertility. Abnormal formation of bone-like substances in tissues that are normally not calcified (arthropathy) interferes with tissue function limits motion, and is often painful. Forms of ectopic calcification range from heterotopic ossification (occurs with aging, following trauma, and in genetic and idiopathic forms), to age-related aortic stenosis, and aortic valve calcification (which is a prominent complication limiting surgical repair of the heart and cardiac valves). Understanding the process of ectopic calcification thus has significant potential therapeutic benefit. Mice with disruption of two genes involved in circadian rhythm generation, CLOCK and NPAS2, not only lose their circadian rhythms, but they are also infertile and developed a severe, age-related and progressive ectopic calcification. CLOCK and NPAS2 normally partner with BMAL1 in regulating circadian rhythms; BMAL1- deficient mice are also have reduced fertility and progressive arthropathy. These pathological phenotypes do not occur in animals lacking circadian rhythms due to other genetic lesions, indicating that it is disruption of the CLOCK/NPAS2:BMAL1 transcriptional complexes, likely unrelated to circadian clock function, that allows these pathologies to develop. Studies of animals with gene disruption throughout the body are complicated by the multiple potential sites of action of these genes, ranging from potential effects on reproductive endocrinology and behavior to defects in spermatogenesis (for infertility), and multiple potential cell types of the musculo-skeletal system (for arthropathy). We will thus use advanced genetics approaches to produce tissue-specific genetic lesions, to identify and isolate the cell types involved in fertiliy regulation and in arthropathy prevention, allowing assessment of the molecular events that lead to the pathological conditions. Our overall hypothesis is that local dysregulation of gene expression in animals lacking CLOCK and NPAS2 (or BMAL1) allows these pathological conditions (calcification in specialized but poorly defined cell types at the junction of cartilage and tendon to bone, and infertility). Our overall objective is to define the cell types involved using an unbiased, genetic approach in vivo, and then use these same approaches to label the cell types involved and to isolate them for molecular analysis at times when the genes are critically important for preventing these phenotypes. Identification of the cellular and molecular events occurring in this very reproducible, genetic model in mice should contribute to understanding and ultimately regulating fertility, and for understanding and ultimately preventing pathological ectopic calcification in humans.

描述（由申请人提供）：拟议的研究将使用小鼠模型来研究两种疾病的原因：不育症和关节病。不育会影响约10％的夫妻，其中约有一半与男性不育症有关。通常未钙化（关节病）的组织中骨状物质的异常形成会干扰组织功能的运动限制运动，并且通常很痛苦。异位钙化的形式范围从异位骨化（发生衰老，创伤后以及遗传和特发性形式）到与年龄相关的主动脉瓣狭窄以及主动脉瓣钙化（这是一个显着的并发症限制 心脏和心脏瓣膜的手术修复）。因此，了解异位钙化的过程具有显着的潜在治疗益处。有两个基因的小鼠 参与昼夜节律的产生，时钟和NPAS2，不仅失去了昼夜节律，而且还不育并且发展了严重的，与年龄相关的和进行性的异位钙化。时钟和NPAS2通常与BMAL1合作，以调节昼夜节律； BMAL1-缺乏小鼠的生育能力和进行性关节炎也降低。这些病理表型不会发生在由于其他遗传病变引起的昼夜节律的动物中，这表明这是时钟/NPAS2：BMAL1转录复合物的破坏，可能与昼夜节律钟功能无关，从而允许这些病理学发展。这些基因的多个潜在作用部位对动物的研究变得复杂，从对生殖内分泌学和行为的潜在影响到精子发生的缺陷（对于不育症）以及多种潜在细胞类型，以及肌肉骨骼骨骼的多种潜在细胞类型系统（用于关节病）。因此，我们将使用先进的遗传学方法来产生组织特异性的遗传病变，以识别和分离肥料调节和预防促进性疾病的细胞类型，从而评估导致病理状况的分子事件。我们的总体假设是，缺乏时钟和NPAS2（或BMAL1）的动物中基因表达的局部失调允许这些病理条件（在软骨结合处的专用但定义较差的细胞类型中的钙化 肌腱到骨，不育）。我们的总体目的是在体内使用公正的遗传方法定义涉及的细胞类型，然后使用这些相同的方法标记涉及的细胞类型，并在基因对预防这些表型至关重要的情况下分离它们进行分子分析。在这种非常可重复的小鼠中发生的细胞和分子事件的鉴定应有助于理解和最终调节生育能力，并理解并最终预防人类的病理异位钙化。