The basis for this K99/R00 application is to study the molecular mechanism by which the sympathetic nervous system regulates liver glucose flux and metabolism. 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 flux. These are powerful methods that allow study of animals in vivo and measurements of functional effects on metabolic pathways. This proposal will provide the award recipient with mentored scientific and professional development, including improvement in communication and management skills, and expansion of scientific network. The recipient will acquire research skills and expertise in metabolism to pursue the long-term independent research goal of identifying molecular targets of sympathetic nervous system in liver and other peripheral metabolic tissues. The extensive metabolic resources, rich collaborative environment, and career development at UT Southwestern Medical Center will support the recipient?s development plan. The recipient will be under the co-mentorship of Drs. Joel Elmquist and Shawn Burgess laboratory, experts in autonomic control of metabolism and metabolic flux respectively. 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 RNA Sequencing approaches to identify unknown or under-appreciated metabolites and genes that vary between various genotypes. The current focus is to understand functional implications of liver adrenergic receptor alpha 1b (Aim 1), Gq signaling (Aim 2) and the gap junction protein Connexin 32 (Aim 3) on metabolic 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. The findings obtained from this proposal will serve as independent line of research to launch the recipient independent career. In sum, this proposal will address an important missing piece in integrative biology and will uniquely prepare the recipient for an independent research career in diabetes.
Glucose produced by the liver is a critical energy source for the brain. As such, the brain has several ways of influencing hepatic glucose production, including activation of the sympathetic nervous system, which can be impaired in metabolic diseases such as type 2 diabetes. However, the mechanisms by which the brain communicates with the liver are poorly understood. The purpose of this project is to identify the mechanisms by which the sympathetic nervous system controls liver glucose homeostasis. These studies will may provide novel targets for the development of anti-diabetic therapies.