Teams of basic scientists at Rutgers University and UMDNJ-Robert Wood Johnson Medical School have been interested in hormones regulating bone metabolism and how these interact in obesity and diabetes. This is an interdisciplinary effort involving Dr. Nicola Partridge's research group at UMDNJ-Robert Wood Johnson Medical School and Dr. Sue Shapses' group in the Department of Nutritional Sciences at Rutgers University. These two teams are addressing the role hormones play in bone loss. In particular, they are interested in a hormone called parathyroid hormone, or PTH, which is an important regulator of serum calcium. This hormone not only has a normal physiological role (to control serum calcium) but has recently been shown to be the most effective agent to treat osteoporosis (Forteo; teriparatide). These research groups (Partridge and Shapses) are also addressing how immune factors may be influenced by PTH to affect bone.
Dr. Partridge's group is studying how parathyroid hormone does this. They have identified that parathyroid hormone turns on many genes in bone. A number of these genes are proteins which are involved in immune responses, suggesting that the hormone causes a temporary immune-like response in bone. Other proteins which are increased are growth factors which may stimulate more bone to be made in osteoporosis. Through this research, new oral agents to treat osteoporosis may be developed, in place of PTH, which must be given by injection.
Dr. Shapses is focusing on how different hormones are influencing obesity and bone. Her group has shown that parathyroid hormone and estrogen are important regulators of calcium absorption during weight loss. She also suspects that restricting calories may increase vitamin D demands, thereby lowering calcium absorption. Shapses is also studying the effect of gastric bypass surgery, which may have dramatic effects on bones, in addition to the extreme weight loss. Her current research is focused on bone quality in obesity and the role of dietary protein and vitamin D in regulating bone during weight loss.