Role of C/EBPbeta in mechanical regulation of MSC potential

应聘者描述(由申请人提供)：应聘者是一名临床内分泌学家，在珍妮特·鲁宾博士的指导下工作了两年半，最初是T32研究员，目前是由北卡罗来纳大学著名的BIRCWH奖资助的初级教员。在鲁宾博士的实验室里，斯泰纳博士在间充质干细胞(MSC)分化调控机制的研究中获得了丰富的专业知识。Rubin实验室之前的工作表明，机械抑制MSC脂肪生成涉及PPAR3的表达减少；候选人自己的工作导致了一种假说，即C/EBP2，一种在脂肪形成早期表达的转录因子，可能通过调节PPAR3而关键地参与了对脂肪生成的机械抑制。这一假说将在SA1中得到验证，其中C/EBP2的S在MSC分化中的作用将通过在体外使用底物拉伸来传递机械输入以及在体内使用基于轮子的跑步运动来分析。在机械/运动输入过程中，将使用分子技术改变C/EBP2和潜在的调节因子。在SA2中，候选人提出机械运动诱导的C/EBP2下调将保护MSC内质网(ER)应激。初步数据显示，受机械应变的MSCs能够抵抗内质网应激的促凋亡作用，阻止脂肪形成并保留MSC潜能。实验将表征C/EBP2‘S在体内外内质网应激中的作用以及通过限制C/EBP2的表达来发挥保护作用的能力。运动通过C/EBP2调节脂肪生成和内质网应激的作用将代表运动有益效果的新机制。应聘者的短期职业目标包括1)在分子生物学技术技能的基础上，获得显微镜和进行动物研究的新技能，包括使用体内运动模型；2)增加她的策略和数据分析技能，以及管理实验室的技能；3)扩大她在内质网应激领域的知识；4)发展她的写作技能和能力。候选人的长期职业目标是成为一名独立的调查员，拥有运动对脂肪和骨骼生物学影响的专业知识，重点是 了解运动影响的基本机制(MSC分化和内质网应激)。候选人的主要导师珍妮特·鲁宾博士是一位内科科学家，有培训年轻研究人员的记录，在骨骼生物学的机械效应领域享有国际声誉。共同导师Cam Patterson博士在培训调查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、支持性的和合作的背景，以进行拟议的研究并发展独立的职业生涯，候选人打算将运动对细胞的影响的知识应用于治疗骨质疏松症、虚弱和肥胖等慢性疾病。

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.