The Platelet Metabolome in Obesity

描述（由申请人提供）：本指导研究科学家发展提案的主要目标是在代谢组学和血栓形成研究领域创造一个密集的研究培训环境，这将导致在不久的将来进行独立调查。该项目将具有代谢失调和血栓形成专业知识的既定导师与具有健康和疾病中血小板分子表型经验的新兴年轻研究者联合起来。该申请得到了对候选人的强有力的机构承诺，强大的培训环境和指导计划以及支持每个具体目标的初步数据的支持。因此，该提案是对旨在增加代谢组学研究网络和能力的指导培训生倡议的回应。该提案的中心研究假设是，肥胖通过涉及线粒体融合蛋白-2（Mfn-2）的机制诱导血小板代谢组和转录组的协调变化。这些变化导致血小板高反应性，因此，增加了肥胖症患者血栓形成的风险。本研究假设将通过3个主题相关但不相互依赖的具体目标进行测试。具体 目的1将确定线粒体融合蛋白-2对血小板代谢组-转录组网络和相关功能活性的作用。通过特异性敲除血小板中的Mfn-2，这些研究将揭示Mfn-2在控制线粒体融合/分裂、代谢应激以及血小板的体外和体内功能中的作用。他们还将确定Mfn- 2是否改变了基础的 代谢组和转录组或血小板的活化代谢组足迹。具体目标2将建立在第一个目标的基础上，但仍然独立地测试血小板Mfn-2在肥胖小鼠模型中的作用。假设Mfn-2缺陷型血小板将更易感（即，无法补偿）到高脂肪环境。因此，Mfn-2缺陷型血小板将显示出与不能在代谢物和转录物水平上进行补偿一致的过度代谢应激和功能反应。第三个具体目标是将在小鼠中获得的功能和机制数据扩展到人类。具体地说，这些研究将确定Mfn-2表达（即，mRNA和蛋白质）和相关线粒体活性在从肥胖和正常体重人类受试者分离的血小板中不同。目标3还将确定肥胖是否诱导血小板代谢组和转录组的协调变化，预测血小板高反应性。对人类受试者的研究将产生新的临床相关信息，这些信息可能解释为什么血小板在肥胖个体中易于形成血栓。总之，这些临床前和临床研究将在促进研究职业发展的环境中探索代谢和血栓形成研究的新范式。

DESCRIPTION (provided by applicant): The primary goal of this Mentored Research Scientist Development Proposal is to create an intensive research training environment in the field of metabolomics and thrombosis research that will lead to independent investigation in the near future. This project unites established mentors that have expertise in metabolic dysregulation and thrombosis with an emerging young investigator who has experience in the molecular phenotyping of platelets in health and disease. The application is supported by strong institutional commitment to the candidate, a robust training environment and mentoring plan, and preliminary data that supports each of the specific aims. Thus, the proposal is responsive to the mentored trainee initiative that strives to increase the network and capacity of metabolomics research. The central research hypothesis of the proposal is that obesity induces coordinate changes in the platelet metabolome and transcriptome through mechanisms that involve mitofusin-2 (Mfn-2). These changes lead to platelet hyperreactivity and, as a result, increased risk for thrombosis in the setting of obesity. This research hypothesis will be tested with 3 specific aims that are thematically related but do not rely on one another for completion. Specific aim 1 will determine the role of mitofusin-2 on the platelet metabolome-transcriptome network and related functional activities. By specifically knocking down Mfn-2 in platelets, these studies will reveal the roles for Mfn-2 in controlling mitochondrial fusion/fission, metabolic stress, and the in vitro and in vivo function of platelets. They will also determine if Mfn- 2 alters the basal metabolome and transcriptome or the activated metabolome footprint of platelets. Specific aim 2 will build on the first aim but nonetheless independently test the role of platelet Mfn-2 in a mouse model of obesity. It is hypothesized that Mfn-2 deficient platelets will be more susceptible (i.e., fail to compensate) to a high fat environment. As a result, Mfn-2 deficient platelet will display exaggerated metabolic stress and functional responses that are consistent with an inability to compensate at the metabolite and transcript level. The third specific aim will extend the functional and mechanistic data obtained in mice to humans. Specifically, the studies will determine if Mfn-2 expression (i.e., mRNA and protein) and related mitochondrial activities differs in platelets isolated from obese and normal weight human subjects. Aim 3 will also determine if obesity induces coordinate changes in the platelet metabolome and transcriptome that predict platelet hyperreactivity. Studies in human subjects will result in new, clinically relevant information that may explain why platelets are prone to thrombose in obese individuals. Together, these preclinical and clinical studies will explore new paradigms in metabolism and thrombosis research in an environment that enhances research career development.