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

描述（由申请人提供）：本K01申请的基础是研究瘦素激素如何在脑和肝脏中积极调节肝脏葡萄糖和脂质通量，从而减轻高血糖和胰岛素抵抗。为此，我将在奖励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。这些都是强有力的方法，可以在动物体内进行研究，并测量代谢途径的功能影响。这项工作将在dr。Joel Elmquist和Shawn Burgess实验室。目前正在研究的瘦素作用靶点是ARH中的POMC神经元和瘦素直接作用于肝细胞调节肝脏糖脂代谢。更传统的蛋白质表达和基因表达分析也将进行，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不同基因型之间的基因。目前的重点是了解生理扰动对通量的功能影响。这种关注并不低估或减少与分子信号或新调控成分或靶点鉴定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，分析/解释数据的专业知识，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/或新信号的差异相关的发现可能是我成为一名独立学术科学家的目标的基础。与此申请相关的最后一个说明是，所有建议的转基因小鼠，试剂和必要的设备都在我手中，可供我继续使用。在此奖励期间，我们不建议开发新的研究工具，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.