Studying the Role of Thyroid Hormones in Regulating Cholesterol and Muscle Function
The American Thyroid Association (ATA), in its support of young scientists working in the field of thyroidology, awarded grants in 2013 to researchers studying a range of topics related to thyroid disease, thyroid cancer, and thyroid biology, including two young researchers whose studies will contribute to our understanding of the role thyroid hormones play in regulating cholesterol levels in the blood and the physiology of skeletal muscle. The ATA Research committee has recently reviewed their progress and approved funding for the second year grant.
Binding of thyroid hormones to the thyroid gland can cause a lowering of blood levels of total cholesterol and low density lipoprotein (LDL or “bad”) cholesterol. This has implications for the development of novel cholesterol-lowering therapies, particularly for individuals in whom statins are not safe or effective. Kevin Phillips, PhD and colleagues at Methodist Hospital, Houston, TX, have proposed a new mechanism to explain this cholesterol lowering effect of thyroid h ormones. The grant award to support Dr. Phillips’ research proposal entitled “The Contribution of Cyp7a1 to the Cholesterol Lowering Actions of TR Agonists” will fund studies to test the hypothesis that this mechanism is independent of functional LDL receptors and involves induction of the enzyme cholesterol 7a-hydroxylase (CYP7a). Bio
Joao Pedro Saar Werneck-de-Castro, PhD, University of Miami, Florida, received an ATA grant award for his research proposal entitled “What Is the Role of Type II Deiodinase (D2)-Mediated T3 Production in Skeletal Muscle.” His group has created a strain of mouse that is deficient in type II deiodinase (D2), an enzyme that converts the prohormone thyroxine (T4) to the bioactive thyroid hormone T3. They have proposed a dual source of D2 in skeletal muscle: muscle cells (myocytes), and fat cells (brown adipocytes) and aim to show that mouse skeletal muscle contains intermingled brown adipocytes that express high levels of D2. Bio
“These studies are very interesting because they expand our knowledge into the role of thyroid hormone in particular tissues and may lead to new and exciting treatment strategies based on thyroid hormone or related analogs,” says Ronald Cohen, MD, Associate Professor, Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Chicago, Illinois.