Dr. Karas received his undergraduate degree in Earth and Planetary Sciences from Johns Hopkins University in 1978, his Ph.D. in Biology from Harvard University in 1984, and his M.D. degree from Tufts University in 1986. He then completed his residency in Internal Medicine at Brigham and Women's Hospital followed by a clinical cardiology fellowship at Duke University and a research fellowship at the University of Texas, Southwestern Medical Center in Dallas. Dr. Karas, the Elisa Kent Mendelsohn Professor of Molecular Cardiology and Medicine at Tufts University School of Medicine, is the Chief Scientific Officer of Tufts Medical Center, Executive Director of the Molecular Cardiology Research Institute and Director of the MCRC. In addition, he is Vice Chairman for Scientific Affairs for the Department of Medicine, Director of Preventive Cardiology and Co-Director of the Women's Heart Center at Tufts Medical Center.
Dr. Karas' major research interest is the effect of estrogen on the cardiovascular system. More specifically, Dr. Karas' research focuses on the molecular pathways that mediate estrogen's direct effects on vascular cells. Recent studies from the MCRC have shown that estrogen receptors in vascular cells can be activated in several novel ways, and several of these signaling pathways are actively being studied in the lab. Current studies are directed at understanding the role of rapid estrogen receptor signaling, and how this shares cross-talk with traditional genomic signaling pathways. Estrogens effects on microRNA expression are also being studied. Ongoing, as well, are attempts to clone novel estrogen receptor-interacting proteins that regulate receptor activation. In addition to these cell-based, molecular studies, Dr. Karas also uses whole animal, mouse models of cardiovascular diseases to study the effects of estrogen on the vascular system in vivo. In conjunction with the MCRI's mouse physiology core and mouse transgenic core laboratories, studies of estrogens effects on the response to vascular injury, on myocardial infarction, and on cardiac electrophysiology are all ongoing. These studies take advantage of the availability of several different genetically altered mouse models to define the molecular pathways that mediate estrogens effects. Finally, Dr. Karas also maintains an active interest in clinically-based studies focused on the regulation of vasomotor tone and on the effects of lipid lowering interventions and adverse events related to lipid-altering interventions.
Administrative Assistant: David Ostrosky
Mendelsohn ME, Karas RH. Rapid progress for non-nuclear estrogen receptor signaling. Journal of Clinical Investigation 2010; 120(7):2277-2279. PubMed Abstract
Alsheikh-Ali AA, Karas RH. Balancing the intended and unintended effects of statins. British Medical Journal 2010; 340:c2240. PubMed Abstract
Advisory Panel for NAMS. Position Statement: Estrogen and progestogen use in postmenopausal women: 2010 position statement of The North American Menopause Society. Journal of North American Menopause Society 2010; 17:242-255.
Alsheikh-AA, Trikalinos T, Kent DM, Karas RH. Statins, low-density lipoprotein cholesterol and risk of cancer. Journal of the American College of Cardiology 2008;52(14):1141-1147. PubMed Abstract Abstract
Michael S, Surks HK, Wang Y, Zhu Y, Blanton R, Jamnongit M, Aronovitz M, Baur W, Ohtani K, Wilkerson MK, Bonev AD, Nelson MT, Karas RH, Mendelsohn ME. High blood pressure arising from a defect in vascular function. Proceedings of the National Academy of Sciences, USA 2008;105(18):6702-6707. PubMed Abstract
Mendelsohn ME, Karas RH. HRT and the Young at Heart. New England Journal of Medicine 2007;356(25):2639-2641.
Mendelsohn ME, Karas RH. Molecular and cellular basis of cardiovascular gender differences. Science 2005;308(5728):1583-1587. PubMed Abstract
Lu Q, Pallas DC, Surks HK, Baur WE, Mendelsohn ME, Karas RH. Striatin assembles a membrane signaling complex necessary for rapid, nongenomic activation of endothelial no synthase by estrogen receptor α. Proceedings of the National Academy of Sciences, 2004;USA 101(49):17126-17131. PubMed Abstract
Shearman AM, Cupples LA, Demissie S, Peter I, Schmid CH, Karas RH, Mendelsohn ME, Housman DE, Levy D. Association between estrogen receptor α gene variation and cardiovascular disease. (SCOR) The Journal of the American Medical Association 2003;290(17):2263-2270. PubMed Abstract
Thompson PD, Clarkson P, Karas RH. Statin-associated myopathy. The Journal of the American Medical Association 2003;289(13):1681-1690. PubMed Abstract
Zhu Y, Bian Z, Lu P, Karas RH, Bao L, Cox D, Hodgin J, Shaul PW,Thoren P, Smithies O, Gustafsson JA, Mendelsohn ME. Abnormal Vascular Function and Hypertension in Mice Deficient in Estrogen Receptor b. Science 2002;295:505-508. PubMed Abstract
Karas RH, Schulten H, Pare G, Aronovitz M, Ohlsson C, Gustafsson J, Mendelsohn ME. Effects of estrogen on the vascular injury response in estrogen receptor ∝,β (double) knockout mice. Circulation Research 2001;89:534-539. PubMed Abstract
Karas RH, Eickels MV, Lydon JP, Roddy S, Kwoun M, Aronovitz M, Baur WE, Conneely O, O’Malley BW, Mendelsohn ME. A Complex role for the progesterone receptor in the response to vascular injury. (SCOR) Journal of Clinical Investigation 2001;108(4):611-618. PubMed Abstract
Karas RH, Hodgin J, Kwoun M, Krege JH, Aronovitz M, Mackey W, Gustafsson JA, Korach KE, Smithies O, Mendelsohn ME. Estrogen inhibits the vascular injury response in estrogen receptor b-deficient female mice, Proc Nat'l Acad of Sci, 1999; 96:15133-15136. PubMed Abstract
Mendelsohn ME, Karas RH. Mechanisms of Disease: The protective effects of estrogen on the cardiovascular system. N Engl J Med, 1999; 340:1801-1811. PubMed Abstract
Karas RH, Gauer EA, Bieber HE, Baur WE, Mendelsohn ME. Growth factor activation of the estrogen receptor in vascular cells occurs via a mitogen-activated protein kinase-independent pathway. Journal of Clinical Investigation 1998;101(12):2851-2861. PubMed Abstract
Col NF, Eckman MH, Karas RH, Pauker SG, Goldberg RJ, Ross EM, Orr RK, Wong JB. Patient-specific decisions about hormone replacement therapy in postmenopausal women. JAMA 1997; 277:1140-1147. PubMed Abstract
Iafrati MD, Karas RH, Aronovitz M, Kim S, Sullivan TR Jr, Lubahn DB, O'Donnell TF Jr, Korach KS, Mendelsohn ME. Estrogen inhibits the vascular injury response in estrogen receptor alpha-deficient mice. Nature Med 1997; 3:545-548. PubMed Abstract
Karas RH, Patterson BL, Mendelsohn ME. Human vascular smooth muscle cells contain functional estrogen receptor. Circulation 1994; 89:1943-1950. PubMed Abstract