Maureen J. Charron, Ph.D.

Research

Our studies are focused on two members of the glucose transporter gene family, GLUT4 and GLUT8. GLUT4 is insulin and exercise responsive and is the major glucose transporter expressed in cardiac and skeletal muscle and adipose tissue. By using techniques such as recombinant DNA methods, immunofluorescence microscopy, chimeric gene transfections, and transgenic and knockout mouse models, we study the role of GLUT4 in normal glucose homeostasis and in disease states (e.g. diabetes mellitus and obesity) and its target in trafficking within these cells. GLUT8 is a newly identified member of the glucose transporter gene family which is expressed in many tissues in addition to GLUT4-expressing tissues (e.g. heart, adipose, muscle). GLUT8 is upregulated in several tissues in response to GLUT4 ablation and may represent a novel anti-diabetic target. We are also studying the potential role of GLUT8 in tumor cell growth and metabolism which may lead to novel chemotherapeutic modalities. In contrast to our studies on insulin action and glucose uptake we are also studying the glucagon receptor. Glucagon is a peptide hormone that functions to elevate serum glucose levels (in opposition to insulin). We have cloned the glucagon receptor gene and studied its regulation by hormones and nutrients.