Metabolic Syndrome and Robustness Tradeoffs

Metabolic Syndrome and Robustness Tradeoffs Hiroaki Kitano 1 2 3 , Kanae Oda 4 , Tomomi Kimura 2 4 , Yukiko Matsuoka 5 , Marie Csete 6 , John Doyle 7 and Masaaki Muramatsu 4 1 Sony Computer Science Laboratories, Inc., Tokyo, Japan 2 Systems Biology Institute, Tokyo, Japan 3 Keio University, Tokyo, Japan 4 Medicala Research Institute, Tokyo Medical and Dental University, Tokyo, Japan 5 ERATO-SORST Kitano Symbiotic Systems Project, Japan Science and Technology Agency, Tokyo, Japan 6 Anesthesiology Department, Emory University, Atlanta, Georgia 7 Control and Dynamical Systems, California Institute of Technology, Pasadena, California Address correspondence and reprint requests to Hiroaki Kitano, Sony Computer Science Laboratories, Inc. 3-14-13, Higashi-Gotanda, Shinagawa, Tokyo 141-0022 Japan. E-mail: kitano{at}csl.sony.co.jp Abstract The metabolic syndrome is a highly complex breakdown of normal physiology characterized by obesity, insulin resistance, hyperlipidemia, and hypertension. Type 2 diabetes is a major manifestation of this syndrome, although increased risk for cardiovascular disease (CVD) often precedes the onset of frank clinical diabetes. Prevention and cure for this disease constellation is of major importance to world health. Because the metabolic syndrome affects multiple interacting organ systems (i.e., it is a systemic disease), a systems-level analysis of disease evolution is essential for both complete elucidation of its pathophysiology and improved approaches to therapy. The goal of this review is to provide a perspective on systems-level approaches to metabolic syndrome, with particular emphasis on type 2 diabetes. We consider that metabolic syndromes take over inherent dynamics of our body that ensure robustness against unstable food supply and pathogenic infections, and lead to chronic inflammation that ultimately results in CVD. This exemplifies how trade-offs between robustness against common perturbations (unstable food and infections) and fragility against unusual perturbations (high–energy content foods and low–energy utilization lifestyle) is exploited to form chronic diseases. Possible therapeutic approaches that target fragility of emergent robustness of the disease state have been discussed. A detailed molecular interaction map for adipocyte, hepatocyte, skeletal muscle cell, and pancreatic β-cell cross-talk in the metabolic syndrome can be viewed at http://www.systems-biology.org/001/003.html . CVD, cardiovascular disease FFA,