51ĀŅĀ×

Kevin Lee, Ph.D., associate professor in the 51ĀŅĀ× Heritage College of Osteopathic Medicine, recently received a $220,000 boost for his research looking at how adipose, or fat, tissue reacts to growth hormone.

The funding award comes from , a leading science and technology company. The funds will be paid out over three years as different conditions are met.  

ā€œGrowth hormone does a lot in the body, such as causing linear growth so that people get taller. However, it also causes people to lose fat mass,ā€ Lee said, noting this is why athletes may use growth hormone to increase lean muscle mass while reducing their amount of adipose tissue. 

The , with collaborators Vishwajeet Puri, Ph.D., and John Kopchick, Ph.D., of the Heritage College, and Jens Otto JĆørgensen, M.D., D.M.Sc., and Niels Jensen, M.D., Ph.D., from Aarhus University in Denmark, has discovered a molecular mechanism of how growth hormone causes lipolysis, which leads to a burning of the triglycerides in adipose tissue. 

ā€œGrowth hormone is secreted generally around while you sleep, generally from two to four in the morning,ā€ Lee said. ā€œYou get this pulsatile secretion of growth hormone, and what that leads to in both healthy and patients with diabetes is an increase in insulin resistance.ā€ 

Insulin resistance, meaning oneā€™s body does not respond to insulin effectively, can cause serious complications for people with diabetes. 

ā€œIn healthy subjects, this isnā€™t a problem because your pancreas can create more insulin, but patients with diabetes canā€™t make insulin because of a beta cell deficiency,ā€ Lee said. ā€œGrowth hormone replacement therapy in patients with growth hormone deficiency can also cause insulin resistance.ā€

His lab is also finding that not all fat cells are the same. 

ā€œThereā€™s all different kinds of fat cells, and what weā€™re finding is that thereā€™s a certain subpopulation that responds more to growth hormone than the other types of adipose cells,ā€ Lee said. ā€œNow that weā€™ve figured out the mechanism and the critical subpopulation of adipocytes that mediate these effects, weā€™re going to see if we can target growth hormone signaling in that one adipocyte subpopulation.ā€    

The grant will help fund the next step in Leeā€™s research, which is to study what changes happen to the whole bodyā€™s physiology and insulin resistance when targeting this subpopulation.

ā€œNow that weā€™ve figured out this mechanism, we want to see the physiological effects of growth hormone-mediated lipolysis and whether we can change those physiological effects of growth hormone-inducing lipolysis,ā€ Lee said. 

Lee hopes to apply the findings of how fat cells respond to growth hormone to a multitude of diseases. 

ā€œIndividual fat cells are really different and have all of these different properties, so weā€™re trying to figure out what these adipocyte subpopulations do in the context of the whole body and normal physiology,ā€ Lee said. ā€œWeā€™re trying to come up with targeted interventions to treat metabolic diseases by looking at these subpopulations.ā€ 

Lee was one of four diabetes researchers hired by the Heritage college in 2015 with funding from the Osteopathic Heritage Foundationā€™s Vision 2020: Leading the Transformation of Primary Care in Ohio award.