widmaier@bu.edu

Cell Signaling and Gene Regulation Endocrinology and Reproductive Biology Neuroendocrinology

Professor of Biology
Ph.D., University of California, San Francisco, 1984

Molecular and endocrine control of body weight; endocrinology and metabolism; neuroendocrinology; reproduction

We are interested in the molecular and behavioral mechanisms that result in obesity or weight gain in mammals. To study this, we use several models of either adaptive weight gain or maladaptive weight gain. For example, pregnant mammals gain adiposity and weight as an adaptive response to the metabolic demands of pregnancy and subsequent lactation. Hibernating mammals also gain weight and adipose mass as an adaptive response, in this case to meet the challenges of long-term fasting during hibernation.   We are examining the endocrine, neural, and molecular mechanisms that promote such adaptive weight gain, in order to determine how mammals control their body mass and adiposity. Understanding the mechanisms of adaptive weight gain may provide clues to the causative factors of maladaptive weight gain (obesity).   We are examining several models of maladaptive weight gain. In one, mice are fed diets composed of various combinations and amounts of fats (saturated or unsaturated) and carbohydrates.

We have found that mice fed high-fat diets gain weight without increasing energy consumption. The weight gain is associated with changes in hypothalamic expression of genes that mediate the actions of the satiety hormone leptin.   We are also examining the effects of high fat diets on mice that are deficient in leptin (ob/ob mice), with or without leptin-replacement. It is hoped that using an approach that compares and contrasts the molecular mechanisms that result in adaptive vs. maladaptive fattening in mammals, it may be possible to better understand the etiology of obesity.

Townsend KL, Kunz TH and Widmaier EP. 2008 Changes in body mass, plasma leptin, and mRNA levels of leptin receptor isoforms during the premigration/prehibernation period in Myotis lucifugus. J Comp Physiol B, in press.

Bruder ED, JL Lee, EP Widmaier, and H Raff. 2007 Microarray and real-time PCR analysis of adrenal gland gene expression in the 7-day-old rat: effects of hypoxia from birth. Physiological Genomics 29:193-200

Schulz LC, Townsend K, Kunz TH and Widmaier EP. 2007. Inhibition of trophoblast invasiveness in vitro by immunoneutralization of leptin in the bat, Myotis lucifugus (Chiroptera). Gen Comp Endo 150:59-65.

Reeder DM, Kosteczko NS, Kunz TH and Widmaier EP. 2006.   The hormonal and behavioral response to group formation, seasonal changes and restraint stress in the highly social malayan flying fox (Pteropus vampyrus ) and the less social little golden-mantled flying fox (P. pumilus ) (Chiroptera: Pteropodidae).   Horm Behav, in press. (epub ahead of print)

Schulz LC and Widmaier EP. 2006.  Leptin receptors.   In: Henson MC and Castracane VD, eds., Leptin.   Endocrinology Update Series, Springer Publishing Co. (CHAPTER)

Reeder DM, Raff H, Kunz TH, and Widmaier EP.   2006. Characterization of pituitary-adrenocortical activity in the Malayan flying fox (Pteropus vampyrus). J Comp Physiol B, 176:512-519.

Lee JJ and Widmaier EP. 2005.  Gene array analysis of the effects of chronic adrenocorticotropic hormone in vivo on immature rat adrenal glands.   J Ster Biochem Mol Biol , 96:31-44.

Schulz LC and Widmaier EP. 2004. The effect of leptin on mouse trophoblast cell invasion.   Biol Reprod , 71(6):1963-7

Jeong H-K, Sakihara S, Widmaier EP, and Majzoub JA   2004. Impaired leptin expression and abnormal response to fasting in corticotropin-releasing hormone-deficient mice.   Endocrinology   145:3174-3181.

Lee J, Eisenberg PI, Papadopoulos V, Wang J, and Widmaier EP.   2004. Developmental changes in adrenal steroidogenesis and in expression of proteins associated with steroidogenesis in the postnatal rat.   Endocrinology   145:2165-2173.

Zhao J, Townsend K, Schulz LC, Kunz TH, Li C, and Widmaier EP.   2004   Leptin receptor expression increases in placenta, but not hypothalamus, during gestation in Mus musculus and Myotis lucifugus .   Placenta 25:712-722

Raff H, Lee JJ, Oaks M, Widmaier EP , and Engeland W.  2004.   Basal and ACTH-stimulated corticosterone in the neonatal rat exposed to hypoxia from birth: modulation by chemical sympathectomy.   Endocrinology 145:79-86.

Reeder DM, Kosteczko NS, Kunz TH, and Widmaier EP. 2004.   Changes in baseline and stress-induced glucocorticoid levels during the active period in free-ranging male and female little brown myotis, Myotis lucifugus (Chiroptera:Vespertilionidae).   Gen Comp Endo 136:260-269.

Reeder D, Kunz TH, and Widmaier EP.   2004. Pituitary-adrenocortical activity in captive male Pteropus hypomelanus in established breeding groups.   J Expt Zool Part A Comp Exp Biol   301:682-690.

Zhao J, Kunz TH, Tumba N, Schulz L, Li C, Reeves M, and Widmaier EP. 2003. Comparative analysis of placental leptin expression in mammals. Am J Physiol Regul Integr Comp Physiol 285:R438-R446

Raff H, Hong JJ, Oaks MK, and Widmaier EP.   2003. Adrenocortical responses to ACTH in the neonatal rat: the effect of hypoxia from birth on corticosterone, StAR, and PBR.   Am J Physiol Regul Integr Comp Physiol 284:R78-R85.

Kronfeld-Schor, N, Zhao, J, Widmaier, EP, Silvia, B A, Mathews, P, Zimmerman, S, and Kunz, T H.   2001. Placental contribution to hyperleptinemia in pregnant bats.   Endocrine 14:225-233 .

Kronfeld-Schor, N, Zhao, J, Silvia, B A, Bicer, E, Mathews, P, Urban, R, Zimmerman, S, Kunz, TH, and Widmaier, EP.   2000. Steroid-dependent up-regulation of adipose leptin secretion in vitro during pregnancy in mice .   Biol Reprod 63:274-280.

Kronfeld-Schor, N, Richardson, C., Silvia, BA, Kunz, TH, and Widmaier, EP.   2000. Dissociation of leptin secretion and adiposity during prehibernatory fattening in little brown bats.   Am J Physiol 279:R1277-R1281.

Jeong, K-H, Jacobson, L, Pacak, K, Widmaier, EP , Goldstein, DS and Majzoub, JA. 2000.   Impaired basal and restraint-induced epinephrine secretion in corticotropin-releasing hormone-deficient mice. Endocrinology 141:1142-1150.

GenBank submissions:

1. Widmaier EP, Reeves M, Sorenson M, Kunz TH, and Li C.   2001. Myotis lucifugu s leptin.   Accession number:   AY055474

2. Zhao J, Li C, Sorenson M, Kunz TH, and Widmaier EP.   2001.   M. lucifugus leptin receptor.   Accession #AY057101

3. Hong JJ and Widmaier EP. 2002. Rattus norvegicus adrenocorticotropic hormone receptor MC-2 mRNA.   Accession # AF547168

4. Schulz L, Townsend K, and Widmaier EP.   2004. Myotis lucifugus leptin receptor long form. Accession # AY728075

5. Schulz L, Townsend K, and Widmaier EP.   2004.   Myotis lucifugus leptin receptor isoform -a mRNA. Accession # AY736326

Text Books:

Widmaier EP , Raff H, and Strang K.   Vander's Human Physiology: The Mechanisms of Body Function, 9 th through 11 th editions, McGraw-Hill Higher Education, NY. Publication date for 11 th edition 2007.

Brooker R, Widmaier EP , Graham LK, and Stiling P.   Biology.   1 st edition. McGraw-Hill Higher Education, publication date 2007

Trade Books:

Widmaier, EP :   Why Geese Don't Get Obese (and we do): How Evolution's Strategies for Survival Affect Our Everyday Lives .   Publisher: W H Freeman and Co., NY. 1998.  

Widmaier, EP: The Stuff of Life: Profiles of the Molecules That Make us Tick.   Publisher: Henry Holt and Co., NY. 2002

Questions and comments are always welcome.
Copyright © 1996, The Trustees of Boston University
This document was last modified on January 10, 2008.