Research Summaries in General Endocrinology and Metabolism
Francesco S. Celi, MD: Peripheral Conversion of Thyroid Hormone and the Modulation of Thyroid Hormone Action
Dr. Celi studies deiodinase-regulated peripheral metabolism of thyroid hormone and its effect on modulating the hormone’s tissue-specific actions. Dr. Celi’s studies include in vitro cell culture systems, and clinical studies. The clinical protocol aims to analyze the interaction between the peripheral metabolism of thyroid hormone and glucose, energy, and lipid homeostasis.
Giovanni Cizza, MD, PhD: Role of Neuroendocrine Factors in the Pathogenesis of Certain Obesity Syndromes in Humans
Dr. Cizza studies the appetite stimulating neuropeptide named orexin as a cause of weight gain in subjects with narcolepsy (a sleep disorder characterized by a central orexin deficiency and by a reduction in the normal circadian rhythmicity of circulating leptin, a satiety signal). Other clinical studies include the potential role of another neuropeptide (corticotrophin-releasing hormone or CRH) on the regulation of appetite control by using a novel CRH antagonist.
Marvin C. Gershengorn, MD: Factor Promoting Differentiation of Human Endocrine Pancreas into Mature, Hormone Producing Cells
One aspect of research in our laboratory involves the study of the factors responsible for and the genes expressed during the differentiation of human endocrine pancreas into mature, hormone (insulin, glucagon, somatostatin and pancreatic polypeptide)-producing cells of the pancreatic islets of Langerhans. The goal is to delineate a milieu in vitro in which human progenitor cells can be made to proliferate and then differentiate into islets by determining which growth and differentiation factors are necessary for development of these cells.
Stephen J. Marx, MD: Pathophysiology of Endocrine Tumors
Dr. Marx’s interests are in the genetics of hyperparathyroidism. His group has played a major role in discovery of the main gene for four of six known hyperparathyroid syndromes. His clinical interests relate to expressions and management of these syndromes. His laboratory interests cover the mechanism of action of the MEN1 gene. His group participates in a large NIH campus collaboration on MEN1. Their approaches include protein-partnering methods for menin, biology of menin tumorigenesis particularly through junD, mouse models of MEN1, and proteomic dissection of tumorigenesis.
William F. Simonds, MD: Biology of G Protein Beta5*RGS Complexes, and the HRPT2 Tumor Suppressor
Dr. Simonds' laboratory conducts both basic scientific and clinical investigation. One research focus involves signal transduction by complexes of G protein beta5 with regulator of G protein signaling (RGS) proteins that are expressed in cells of neuroendocrine origin. The other major area of research focuses on the recently identified gene HRPT2 that encodes the novel tumor suppressor protein parafibromin, implicated in both the hereditary hyperparathyroidism-jaw tumor syndrome and sporadic parathyroid cancer.
Monica C. Skarulis, MD: Studies of Thyroid Function and Growth in Health and Disease/ Endocrine and Metabolic Consequences of Weight Loss
Dr. Skarulis has a long standing interest in the diagnosis and therapy of thyroid cancer. In these studies, the significance and limitations of methods for follow-up and new therapeutic approaches are evaluated. An additional area of interest in the section is obesity. Interdisciplinary studies are underway to elucidate the endocrine, metabolic and inflammatory changes associated with extreme weight loss and especially the long term adaptations of energy expenditure and body composition of morbidly obese patients undergoing bariatric surgery.
Lee S. Weinstein, MD: Genetics of Parathyroid Hormone Resistance States
Dr. Weinstein’s interests are focused on the genetics of hormone resistance states, with particular focus on pseudohypoparathyroidism. His group has shown that different forms of pseudohypoparathyroidism are caused by genetic or epigenetic (imprinting) defects in GNAS, a complex imprinted gene encoding the G protein Gsa. His laboratory work focuses on various genetically modified mouse models examining the imprinting mechanisms of GNAS and the role of Gsa in hormone action, metabolism, and development.
