Obesity and Metabolic Tissues
Group leaders are Drs. Rex Ahima, Harvey Grill, and Tom WaddenThis Scientific focus of the DERC is linked to the IDOM Obesity Unit.
Obesity and metabolism are important diabetes related issues which are the research focus of a significant group of Center investigators. The work in metabolism extends to the development and function of key metabolic, insulin-responsive tissues including adipose, liver, and muscle.
Highlights of Significant Findings
This area of research has been quite active among Penn DERC investigators. Dr. Ahima was first to demonstrate a role for another adipcyte-derived hormone, adiponectin, in the CNS. Dr. Bale, a new investigator funded by a DERC pilot and feasibility grant, demonstrated the importance of CRF in energy homeostasis, which represents a key link between feeding behavior and stress pathways.
Penn DERC investigators also made major patient-oriented contributions to obesity research. Dr. Wadden's group highlighted the similarities and differences in the mechanism and effectiveness of pharmacological and behavioral therapies for obesity. Drs. Iqbal and Samaha also completed a widely-cited study demonstrating the effectiveness as well as the limitations of low-cardohydrate diets in the treatment of obesity.
Dr. Lazar and colleagues discovered resistin as a novel adipocyte-secreted hormone, and demonstrated its biological role in knockout mice that were resistant to obesity-associated diabetes. Lazar's group also described a novel mechanism explaining why insulin sensitizing drugs differentially regulate PPAR g -gene targets in adipocytes. In addition, Dr. Kaestner used an elegant mouse genetic strategy to definitively describe the timing and requirement for Fox transcription factors in the development of the liver. Dr. Birnbaum definitively demonstrated the role o f AMPK in contraction-induced glucose transport in skeletal muscle.