Diabetic complications can be reduced by normalization of blood glucose levels via intensive insulin therapy. This treatment, while effective, bears the risk of an increased incidence of recurrent hypoglycemia. It blunts the central counterregulatory response to low blood glucose (counterregulatory failure) and thereby magnifies the risk of severe hypoglycemia and brain injury. The overall goal of this proposal is to understand the changes in brain metabolism that underlie these phenomena and identify possible therapies in order to prevent them. We will determine the impact of a medium chain fatty acid enriched diet on brain metabolism in tightly controlled T1DM subjects with hypoglycemia unawareness and an animal model thereof. We will further test the hypothesis that chronic provision of medium chain fatty acids can improve cognitive performance under hypoglycemia in human subjects. Data gathered from our animal studies revealed a specific change of neuronal energy metabolism under hypoglycemia following exposure to antecedent recurrent hypoglycemia that make is more difficult for neurons to utilize fuels like glucose or lactate. We also found that after recurrent hypoglycemia, lactate uptake into the brain was facilitated, but because it could subsequently not be utilized by mitochondria as effectively as under control conditions, it may not be an ideal fuel. This let us to look for different alternate substrates that follow the same route of uptake as lactate, but enter metabolism via a different pathway. One group of fuels that fulfill these criteria are ketone bodies and medium chain fatty acids. Applying state of the art technologies like in vivo NMR spectroscopy to our animal model of recurrent hypoglycemia will allows us address the hypothesis that they are better suited to support metabolism. We will use this animal model to determine how diabetes confounds the adaptations induced by recurrent hypoglycemia alone and then go on to translate our findings to a clinical study of cognition and metabolism in intensively treated T1DM patients. Our work is the first step towards developing candidate molecules into novel therapies that would protect the brain from hypoglycemia induced brain injury. The projects proposed here are building on preliminary studies that I have performed during my NRSA fellowship training and since then. They will give me the ideal opportunity to continue my training in NMR spectroscopy and its application to neuroscience and diabetes related complications. Most of my training thus far has been in the use of basic science methods and animal models. Wanting to become a well trained physician scientist however I realized that I still needed more training in human investigation. To that end I enrolled in a Master of Health Sciences program to receive further training in translational methods. Funding under this career award will allow me to continue these activities and give me the protected time from clinical duties that I will need to accomplish my career goal of establishing myself as an independently funded physician-scientist, eventually with my own laboratory and workgroup.

Public Health Relevance

Understanding the changes of brain energy substrate transport and metabolism in intensively treated type 1 diabetic patients will provide the basis for the identification of novel therapeutic approaches that could protect the brain from hypoglycemia induced injury. This in turn could then sustain normal brain metabolism under hypoglycemia and would also allow for tighter glucose control with better protection from long-term diabetic related complications. Project Narrative Understanding the changes of brain energy substrate transport and metabolism in intensively treated type 1 diabetic patients will provide the basis for the identification of novel therapeutic approaches that could protect the brain from hypoglycemia induced injury. This in turn could then sustain normal brain metabolism under hypoglycemia and would also allow for tighter glucose control with better protection from long-term diabetic related complicaitons.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08DK082618-05
Application #
8720524
Study Section
Digestive Diseases and Nutrition C Subcommittee (DDK)
Program Officer
Hyde, James F
Project Start
2010-09-15
Project End
2015-04-30
Budget Start
2014-09-01
Budget End
2015-04-30
Support Year
5
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Yale University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
New Haven
State
CT
Country
United States
Zip Code
06510
Goldberg, Emily L; Asher, Jennifer L; Molony, Ryan D et al. (2017) ?-Hydroxybutyrate Deactivates Neutrophil NLRP3 Inflammasome to Relieve Gout Flares. Cell Rep 18:2077-2087
Tricò, Domenico; Prinsen, Hetty; Giannini, Cosimo et al. (2017) Elevated ?-Hydroxybutyrate and Branched-Chain Amino Acid Levels Predict Deterioration of Glycemic Control in Adolescents. J Clin Endocrinol Metab 102:2473-2481
de Graaf, Robin A; Prinsen, Hetty; Giannini, Cosimo et al. (2015) Quantification of (1)H NMR Spectra from Human Plasma. Metabolomics 11:1702-1707
Gurr, Werner; Shaw, Margaret; Herzog, Raimund I et al. (2013) Vaccination with single chain antigen receptors for islet-derived peptides presented on I-A(g7) delays diabetes in NOD mice by inducing anergy in self-reactiveT-cells. PLoS One 8:e69464
Herzog, Raimund I; Jiang, Lihong; Herman, Peter et al. (2013) Lactate preserves neuronal metabolism and function following antecedent recurrent hypoglycemia. J Clin Invest 123:1988-98
Herzog, Raimund I; Sherwin, Robert S (2012) Diabetes. Can tight glycemic control in diabetes benefit cognition? Nat Rev Neurol 8:124-6
Herzog, Raimund I; Sherwin, Robert S; Rothman, Douglas L (2011) Insulin-induced hypoglycemia and its effect on the brain: unraveling metabolism by in vivo nuclear magnetic resonance. Diabetes 60:1856-8
Jiang, Lihong; Herzog, Raimund I; Mason, Graeme F et al. (2009) Recurrent antecedent hypoglycemia alters neuronal oxidative metabolism in vivo. Diabetes 58:1266-74