Role of C/EBPbeta in mechanical regulation of MSC potential

描述（由申请人提供）：候选人是一名临床内分泌学家，致力于基础科学研究，在过去2.5年中，在Janet Rubin博士的指导下工作，最初是T32研究员，目前是由美国著名的BIRCWH奖资助的初级教师。在Rubin博士的实验室里，Styner博士获得了大量的间充质干细胞（MSC）分化调节机制研究方面的专业知识。Rubin实验室先前的工作表明，MSC脂肪形成的机械抑制涉及PPAR 3表达的减少;候选人自己的工作导致了这样一种假设，即C/EBP 2，一种在脂肪形成早期表达的转录因子，可能通过调节PPAR 3关键地参与脂肪形成的机械抑制。该假设将在SA 1中进行测试，其中将使用底物拉伸来体外递送机械输入并在小鼠体内使用基于轮的跑步运动来分析C/EBP 2在MSC分化中的作用。C/EBP 2和潜在的调节剂将在机械/运动输入期间使用分子技术改变。在SA 2中，候选人提出机械运动诱导的C/EBP 2下调将保护MSC内质网（ER）应激。初步数据显示，受到机械应变的MSC抵抗ER应激的促凋亡作用，防止脂肪形成并保持MSC潜力。实验将表征C/EBP 2在体外和体内ER应激中的作用以及通过限制C/EBP 2表达来保护的能力。运动通过C/EBP 2调节脂肪形成和ER应激的作用将代表运动有益作用的新机制。候选人的短期职业目标包括：1）建立在她在分子生物学方面的技术技能基础上，并获得显微镜和动物研究的新技能，包括使用体内运动模型，2）提高她的策略和数据分析技能，以及运行实验室的技能3）扩大她在ER压力领域的知识和4）发展她的写作和写作技巧。候选人的长期职业目标是成为一名独立的调查员，在运动对脂肪和骨骼生物学的影响方面具有专业知识， 了解运动影响的基本机制（MSC分化和ER应激）。候选人的主要导师Janet Rubin博士是一位医生科学家，有培训年轻研究人员的记录，在骨骼生物学机械效应领域享有国际声誉。共同导师Cam Patterson博士在培训研究人员方面有着出色的记录，并将为Styner博士提供ER压力领域的内容领域专业知识。研究环境将提供一个富有成效的，支持性的和合议的背景，以追求拟议的研究，并发展一个独立的职业生涯，候选人打算把运动对细胞的影响的知识，以治疗慢性疾病，如骨质疏松症，虚弱和肥胖。

DESCRIPTION (provided by applicant): The candidate is a clinical endocrinologist dedicated to basic science research working under the mentorship of Dr. Janet Rubin for the past 2.5 years, initially as a T32 fellow and currently as junior faculty funded by UNC's prestigious BIRCWH award. In Dr. Rubin's laboratory, Dr. Styner acquired substantial expertise in the study of mechanisms by which mesenchymal stem cell (MSC) differentiation is regulated. Prior work in the Rubin lab revealed that mechanical repression of MSC adipogenesis involves decreased expression of PPAR3; the candidate's own work led to the hypothesis that C/EBP2, a transcription factor expressed early in adipogenesis, might be critically involved in mechanical repression of adipogenesis through regulation of PPAR3. This hypothesis will be tested in SA1, where C/EBP2's role in MSC differentiation will be analyzed using substrate stretch to deliver mechanical input in vitro and using wheel based running exercise in mice in vivo. C/EBP2 and potential regulators will be varied using molecular techniques during the mechanical/exercise input. In SA2 the candidate proposes that mechanical-exercise induced downregulation of C/EBP2 will protect against MSC endoplasmic reticulum (ER) stress. Preliminary data show that MSCs subject to mechanical strain are resistant to the pro-apoptotic effects of ER stress, preventing adipogenesis and preserving MSC potential. Experiments will characterize C/EBP2's role in ER stress in vitro and in vivo and the ability exercise to protect through limiting C/EBP2 expression. An effect of exercise to regulate both adipogenesis and ER stress via C/EBP2 would represent novel mechanisms for salutary effects of exercise. The candidate's short-term career goals include 1) building on her technical skills in molecular biology and acquiring new skills in microscopy and the conduct of animal research including the use of in-vivo exercise models, 2) increasing her strategy and data analysis skills, as well as skills in running a laboratory 3) expanding her knowledge in the field of ER stress and 4) developing her skills in writing and grantsmanship. The candidate's long-term-career goal is to become an independent investigator with expertise in the effects of exercise on fat and skeletal biology with an emphasis on understanding basic mechanisms affected by exercise (MSC differentiation and ER stress). The candidate's primary mentor, Dr. Janet Rubin, is a physician scientist with a record of training young investigators and with an international reputation in the field of mechanical effect in skeletal biology. The co-mentor, Dr. Cam Patterson, has an excellent record of training investigators and will provide Dr. Styner with content area expertise in the field of ER stress. The research environment will provide a productive, supportive and collegial background to pursue the proposed research and to develop an independent career where the candidate intends to bring knowledge of exercise effects on cells to the treatment of chronic diseases such as osteoporosis, frailty and obesity.