Cell cycle control of adipogenesis

脂肪生成的细胞周期控制

• 批准号: 10476647
• 负责人: Mary N Teruel
• 金额: $ 21.12万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-16 至 2022-09-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10476647
• 关键词: 3-Dimensional; Adipocytes; Adipose tissue; Adolescent; Biological Assay; Body Weight decreased; Brown Fat; CDK2 gene; CDK4 gene; Cell Cycle; Cell Cycle Progression; Cell Cycle Regulation; Cell Density; Cell Differentiation process; Cell division; Cell model; Cells; Child; Clonal Expansion; Cyclins; Data; Ensure; Extracellular Matrix; Fatty acid glycerol esters; Functional disorder; G1 Phase; Genetic; Goals; Health; Human; Hypertrophy; Image Analysis; In Vitro; Knock-out; Knockout Mice; Link; Maintenance; Metabolic; Metabolic Diseases; Methods; Mitotic; Molecular; Mus; Muscle; Natural regeneration; Neurons; Obesity; Obesity Epidemic; Outcome; Pancreas; Pathway interactions; Phase; Process; Proliferating; Publications; Publishing; RHOA gene; Reporter; Research; Risk; Role; SKP2 gene; Signal Pathway; Signal Transduction; Skeletal Muscle; Testing; Therapeutic; Time; Tissue Differentiation; Tissues; Wild Type Mouse; Work; adipocyte differentiation; adult obesity; cellular imaging; experimental study; imaging approach; in vivo; inhibitor/antagonist; interest; knockout gene; lipid biosynthesis; live cell imaging; mouse model; progenitor; programs; regenerative tissue; stem cells; synergism

Recent evidence shows that creating new fat cells (adipogenesis) can counteract the harmful metabolic effects of obesity, which have been shown to originate primarily from abnormal enlargement (hypertrophy) and resulting dysfunction of existing fat cells. Thus, how to increase adipogenesis over hypertrophy is of great interest. Previous work showed that preadipocytes in vivo and in vitro must complete one or more cell cycles, a process referred to as clonal expansion, before they can differentiate into adipocytes. One of the most striking genetic examples of increased adipogenesis was demonstrated by manipulating this clonal expansion period by knocking out the cell cycle inhibitors p21 and p27. Knockout of either p21 or p27 in mice results in a 2-fold increase in adipogenesis and fat mass, but knockout of both results in a dramatic 6-fold increase. Previous work suggests that p21 and p27 are regulated by very different mechanisms and are active at different times during adipogenesis. In recent published work, we identified the molecular mechanisms that could explain the increased adipogenesis observed in the p21- knockout mouse. However, how p27 regulates adipogenesis and tissue mass and how p21 and p27 synergize are poorly understood. We hypothesize that the synergistic expression of p21 and p27 during adipogenesis is the primary mechanism that controls the number of cell divisions before differentiation, and thus controls the number the adipocytes produced per preadipocyte. We will test this hypothesis by using live-cell imaging approaches. We will first use methods to inducibly express and rapidly degrade p27 to determine when and how p27 regulates cell cycle progression during adipogenesis. We will then use live cell reporters for CDK4/6 and CDK2 activity to understand when and how p27 and p21 synergize to regulate CDK4/6 and CDK2 activity and control the number of adipocytes produced. Finally, we will use live-cell reporters and p27 knockout cell and mouse models to understand how p27 is regulated by upstream cell density and extracellular matrix stiffness signals to open and close a proliferative window during adipogenesis. The outcome of this work will be a framework how the clonal expansion period can be controlled to significantly increase adipogenesis over hypertrophy while also ensuring that the progenitor pool is maintained. Our results will likely have broad applicability not only to the maintenance of adipose tissue, but also more generally for the maintenance and regeneration of neuronal, muscle, and other terminally differentiated tissues.

最近的证据表明，创造新的脂肪细胞（脂肪形成）可以抵消 肥胖的有害代谢影响已被证明主要源于异常 增大（肥大）和现有脂肪细胞的功能障碍。那么，如何提高 脂肪生成超过肥大是非常令人感兴趣的。先前的研究表明， 体内和体外必须完成一个或多个细胞周期，一个称为克隆扩增的过程， 才能分化成脂肪细胞其中一个最引人注目的遗传学例子， 增加的脂肪形成通过操纵该克隆扩增期来证明， 敲除细胞周期抑制剂p21和p27。敲除小鼠中的p21或p27结果 在脂肪生成和脂肪量增加2倍，但敲除这两者的结果是戏剧性的6倍， 增加以前的研究表明，p21和p27是由非常不同的机制调节的， 在脂肪形成过程中的不同时间是活跃的。在最近发表的工作中，我们确定了 可以解释在p21中观察到的脂肪形成增加的分子机制， 敲除小鼠。然而，p27如何调节脂肪形成和组织质量以及p21和p27如何调节脂肪形成和组织质量， 对协同作用了解很少。我们推测p21和p27的协同表达可能与p21和p27的表达有关。 脂肪形成期间是控制细胞分裂次数的主要机制， 前体脂肪细胞的分化，并因此控制每个前体脂肪细胞产生的脂肪细胞的数量。我们将 通过使用活细胞成像方法来验证这一假设。我们将首先使用方法来诱导 表达并快速降解p27，以确定p27何时以及如何调节细胞周期进程 在脂肪形成过程中。然后，我们将使用CDK 4/6和CDK 2活性的活细胞报告基因， 了解p27和p21何时以及如何协同调节CDK 4/6和CDK 2活性， 控制产生的脂肪细胞的数量。最后，我们将使用活细胞报告基因和p27 敲除细胞和小鼠模型，以了解p27如何受上游细胞密度的调节， 细胞外基质硬度发出信号以在脂肪形成期间打开和关闭增殖窗口。 这项工作的结果将是一个框架，如何克隆扩展期可以控制 显着增加脂肪生成而不是肥大，同时也确保祖细胞 池保持。我们的研究结果可能具有广泛的适用性，不仅适用于维护 脂肪组织，而且更普遍地用于神经元，肌肉， 和其他终末分化的组织。