Regulation of hepatic substrate flux by leptin via POMC neurons and hepatocytes

描述（由申请人提供）：该K 01申请的基础是研究激素瘦素如何在大脑和肝脏中起作用，以积极调节肝脏葡萄糖和脂质流量，从而减轻高血糖症和胰岛素抵抗。为此，我将在获奖期间利用稳定同位素示踪技术结合质谱和核磁共振分析肝脏葡萄糖和脂质通量来发展专业知识。这些都是强大的方法，允许在体内研究动物和代谢途径的功能影响的测量。这将在Joel Elmquist博士和Shawn Burgess实验室的共同指导下完成。目前正在研究的瘦素作用的靶点是ARH中的POMC神经元和直接瘦素作用于肝细胞以调节肝脏葡萄糖和脂质代谢。还将进行更传统的蛋白质表达和基因表达分析，以补充与功能相关的体内研究结果，并确定可能更直接靶向药物治疗的特定分子途径。未来的工作可以使用代谢组学和微阵列（或更先进的）方法来识别未知或未被充分认识的代谢物和基因，这些代谢物和基因在不同的基因型之间存在差异。目前的重点是了解功能的影响，生理扰动通量。这种关注并没有低估或减少与分子信号传导或识别新的调控成分或靶点相关的发现的重要性。相反，这种强调认识到优先发展执行这些实验的专业知识，分析/解释数据，以及将这些技能转移到其他问题和/或其他环境的能力。此外，与分子信号和/或新信号差异相关的发现可能是我成为独立学术科学家的目标的基础。与本申请相关的最后一个注意事项是，所有拟议的转基因小鼠，试剂和必要的设备都在手中，可供我继续使用。我们不建议在此期间开发新的研究工具，因此可以专注于培训和完成拟议的目标。

DESCRIPTION (provided by applicant): The basis for this K01 application is to study how the hormone leptin acts in both the brain and liver to positively regulate hepatic glucose and lipid flux and thus mitigate hyperglycemia and insulin resistance. To do so, I will develop expertise during the award period using stable isotope tracer techniques combined with mass spectrometry and nuclear magnetic resonance analyses of hepatic glucose and lipid fluxes. These are powerful methods that allow study of animals in vivo and measurements of functional effects on metabolic pathways. This will be done under the co-mentorship of Drs. Joel Elmquist and Shawn Burgess laboratory. Current targets of leptin action under study are POMC neurons in the ARH and direct leptin action on hepatocytes to regulate hepatic glucose and lipid metabolism. More traditional analyses of protein expression and gene expression will also be performed to complement in vivo findings related to function and identify specific molecular pathways that may be more directly targeted by pharmacotherapy. Future work could use metabolomic and microarray (or more advanced) approaches to identify unknown or under-appreciated metabolites and genes that vary between various genotypes. The current focus is to understand functional implications of physiological perturbations on flux. This focus does not undervalue or diminish the importance of findings related to molecular signaling or identification of novel regulatory components or targets. Instead, this emphasis recognizes the priority to develop expertise performing these experiments, analyzing/interpreting the data, and the ability to transfer these skills to other questions and/or other environments. Moreover, findings related to differences in molecular signaling and/or novel signaling may be the foundation for my goal to become an independent academic scientist. A final note related to this application is that ALL proposed genetically modified mice, reagents, and necessary equipment are in-hand and available to me for continued use. We are NOT proposing to develop novel research tools during this award period and can thus focus on training and completing the proposed aims.