Molecular regulation of the brown-like ("beige") cells of white fat depots

白色脂肪库棕色（“米色”）细胞的分子调控

• 批准号: 8662256
• 负责人: Jun Wu
• 金额: $ 15.53万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8662256
• 关键词: Adipocytes; Adipose tissue; Adult; Advisory Committees; Biological Assay; Brown Fat; Cardiovascular Diseases; Cell Lineage; Cell Separation; Cell physiology; Cell surface; Cells; Chemical Burns; Chiroptera; Commit; Communities; Complement; Computational Biology; Cyclic AMP; Data; Development; Development Plans; Diabetes Mellitus; Disease; Dyslipidemias; Embryo; Energy Metabolism; Expenditure; Faculty; Fatty acid glycerol esters; Five-Year Plans; Future; Gene Expression; Gene Expression Profile; Genes; Genetic; Goals; Health; Heating; Homeostasis; Human; Hypertension; Immunodeficient Mouse; Immunohistochemistry; In Vitro; Institution; Intake; Journals; Laboratories; Leukocytes; Mammals; Medical; Mentors; Metabolic; Metabolic syndrome; Metabolism; Mitochondria; Molecular; Molecular and Cellular Biology; Morphology; Mus; Obesity; Pathway interactions; Pharmacologic Substance; Physiological; Physiology; Play; Population; Positioning Attribute; Positron-Emission Tomography; Postdoctoral Fellow; Prevention; Publishing; Regulation; Research; Research Personnel; Research Project Grants; Resources; Respiration; Rodent; Role; Scientist; Surface; System; Techniques; Testing; Therapeutic; Therapeutic Intervention; Thermogenesis; Time; Tissues; Training; Transgenic Mice; Transplantation; Triglycerides; Work; adipocyte biology; career; career development; clinical application; design; energy balance; experience; immortalized cell; in vitro testing; in vivo; insight; interest; loss of function; medical schools; molecular phenotype; mouse model; novel strategies; obesity treatment; peer; progenitor; programs; response; transcription factor

DESCRIPTION (provided by applicant): This proposal describes a five-year plan for training Jun Wu to achieve her goal to become an independent investigator in metabolic research. The training and career development plan includes a compelling research project with potential clinical applications, training in laboratory techniques and didactic scientific and career development seminars and courses. The applicant has more than a decade of experiences working in molecular and cellular biology, mouse genetics and physiology. Her previous important findings have been published in many high-impact journals, and have been then cited more than 2,000 times in the subsequent works of her peers. Dr. Bruce Spiegelman, a well-recognized leader in the field of diabetes and obesity will mentor the applicant's scientific and career development. Dr. Spiegelman has trained numerous postdoctoral fellows who now have faculty positions in academic institutions. In addition, an advisory committee of highly- regarded experts in the field of molecular metabolism, adipocyte biology in particular, will provide the applicant scientific and career advices. The overall goal of the project is to study molecular phenotype of the newly isolated beige fat cells and delineate mechanisms responsible for beige cell commitment and regulation. Obesity is associated with diabetes, hypertension, dyslipidemia and cardiovascular disease. Obesity is essentially a disorder of energy balance, in which intake exceeds expenditure. There are two major types of adipose tissues in mammals, white and brown. White adipose tissue (WAT) stores excess energy in the form of triglycerides, whereas brown adipose tissue (BAT) can counteract obesity by safely burning off chemical energy through adaptive thermogenesis. In addition to "classical" brown adipose depots, UCP1 positive, brown fat-like cells have also been observed interspersed in WAT in response to cold exposure. Myf5-expressing embryonic progenitors give rise to the classic depots of BAT, but the brown-like cells in WAT (so-called beige cells) do not arise from this cell lineage. The cellular and developmental origin of beige cells remains unknown at present. Recent studies that revealed adult humans have functional "BAT" have raised the question regarding the molecular identity of these metabolically active cells. This proposal attempts to clarify the basic mechanisms regarding the control of beige cell development and activation, which will enable molecular definition of human "brown" fat and may suggest new approaches for the prevention and treatment of obesity and associated medical conditions. We clonally derived multiple lines of immortalized preadipocytes from inguinal WAT, interscapular BAT and epididymal WAT depots. Preliminary analysis shown that a subset of inguinal lines have a gene expression pattern similar to the brown lines and comparable Ucp1 expression in response to cAMP stimulations. These data strongly support our hypothesis that there is a distinct pool of progenitors in the inguinal depot that gives rise to the beige cells. Aim #1 is to compare physiological functions of beige fat cells, adaptive thermogenesis potential in particular, to thos of the bona fide brown fat cells. Mitochondrial content and respiration rate will be tested in cultured beige cells with brown cells as controls. Thermogenic gene expression will be assayed in transplanted fat pads derived by beige cells in immunodeficient mice. A role for beige fat cells in raising energy expenditure and protecting mice against obesity will be tested. Aim #2 is to determine molecular mechanisms by which beige fat is committed and regulated. A list of beige cell enriched "beige fat gene signature" will be identified through computational biology approach and validated in multiple in vitro and in vivo systems. Transcription factors as beige cell regulators will be identified through three complementary approaches and their functions will be tested in vitro via retroviral gain/loss of function in our immortalized cells and in vivo in transgenic mouse models. Aim #3 is to apply insights gained from this study to design novel strategies of prevention and treatment of obesity. To define molecular identify of human "BAT", the expression levels of "beige fat gene signature" and "brown fat gene signature" will be investigated in PET positive human "brown" fat tissues. We will test and validate beige fat specific surface markers identified in aim 2 and design beige cell sorting strategies to purify beige cell populations from rodent and human adipose tissues. The Spiegelman laboratory and Harvard Medical School Longwood research community provide an ideal setting for training future independent investigators. This project will also bring together leading laboratories of the advisory committee that complement each other's expertise. These outstanding resources will maximize the potential for the applicant to successfully transition to an independent investigator.

描述(申请人提供)：本提案描述了一个五年计划，旨在培养吴军，以实现她成为代谢研究独立研究员的目标。培训和职业发展计划包括一个具有潜在临床应用的引人注目的研究项目、实验室技术培训以及教学科学和职业发展研讨会和课程。应聘者在分子和细胞生物学、小鼠遗传学和生理学方面有十多年的工作经验。她之前的重要发现已经发表在许多有影响力的期刊上，随后在她的同行的后续作品中被引用了2000多次。布鲁斯·斯皮格曼博士是糖尿病和肥胖症领域公认的领导者，他将指导申请人的科学和职业发展。斯皮格尔曼博士培养了许多博士后研究员，他们现在在学术机构担任教职。此外，一个由分子代谢领域，特别是脂肪细胞生物学领域的知名专家组成的咨询委员会将为申请者提供科学和职业建议。该项目的总体目标是研究新分离的米色脂肪细胞的分子表型，并描述负责米色细胞承诺和调节的机制。肥胖与糖尿病、高血压、血脂异常和心血管疾病有关。肥胖本质上是一种能量平衡的紊乱，即摄入超过支出。哺乳动物有两种主要的脂肪组织，白色和棕色。白色脂肪组织(Wat)以甘油三酯的形式储存多余的能量，而棕色脂肪组织(BAT)可以通过适应性产热安全地燃烧化学能量来对抗肥胖。除了“经典的”棕色脂肪储存库外，还观察到UCP1阳性的棕色脂肪样细胞散布在Wat中，以回应寒冷的暴露。表达Myf5的胚胎前体细胞产生了经典的蝙蝠细胞库，但Wat中的棕色样细胞(所谓的米色细胞)并不是从这个细胞谱系产生的。目前，米色细胞的细胞和发育起源尚不清楚。最近的研究表明，成年人类具有功能性的“蝙蝠”，这就提出了关于这些代谢活性细胞的分子身份的问题。这项建议试图阐明控制米色细胞发育和激活的基本机制，这将使人们能够从分子上定义人类的“棕色”脂肪，并可能为预防和治疗肥胖症及相关的医疗条件提供新的方法。我们从腹股沟Wat、肩胛间BAT和附睾水储存库克隆了多株永生化前脂肪细胞。初步分析表明，腹股沟系的一部分具有与棕色系相似的基因表达模式，并且对cAMP刺激有类似的Ucp1表达。这些数据有力地支持了我们的假设，即在腹股沟仓库中存在一个独特的祖细胞池，从而产生了米色细胞。目的1是比较米色脂肪细胞的生理功能，特别是适应性产热潜力，与真正的棕色脂肪细胞的生理功能。线粒体含量和呼吸频率将在培养的米色细胞中进行测试，并以棕色细胞为对照。将在免疫缺陷小鼠的米色细胞来源的移植脂肪垫中检测产热基因的表达。米色脂肪细胞的作用 在增加能量消耗和保护小鼠免受肥胖方面，将进行测试。目的#2是确定米色脂肪被控制和调节的分子机制。将通过计算生物学方法确定一系列富含米色细胞的“米色脂肪基因签名”，并在多个体外和体内系统中进行验证。转录因子将通过三种互补的方法被确定为米色细胞调节因子，它们的功能将在体外通过我们的永生化细胞中的逆转录病毒获得/丧失来测试，并在体内通过转基因小鼠模型进行测试。目标3是应用从这项研究中获得的见解来设计预防和治疗肥胖症的新策略。为了明确人类“蝙蝠”的分子识别，我们将研究“米色脂肪基因标志”和“棕色脂肪基因标志”在PET阳性的人类“棕色”脂肪组织中的表达水平。我们将测试和验证AIM 2中确定的米色脂肪特定表面标记，并设计米色细胞分选策略，以从啮齿动物和人类脂肪组织中纯化米色细胞群。斯皮格曼实验室和哈佛医学院朗伍德研究社区为培训未来的独立调查人员提供了理想的环境。该项目还将汇聚世界领先的实验室 相互补充专业知识的咨询委员会。这些突出的资源将最大限度地扩大申请人成功过渡到独立调查员的潜力。