Rutgers, The State University of New Jersey
Department of Animal Sciences
Office 166 - Foran Hall
The effect of environmental stresses, both naturally occurring and anthropogenic, on the physiological functions of organisms is the general focus of my research. I have a keen interest in the actions of environmental estrogens and other endocrine disrupting compounds on physiological functions including energy balance, thermoregulation and reproduction that are controlled by the hypothalamus. In recent years, membrane-initiated steroid signaling has emerged as an important component in the estrogenic modulation of hypothalamic functions and offer novel mechanisms of toxicity for environmental contaminants. My goal is for a greater understanding of the interaction between novel steroid (estrogen) signaling pathways, neuroendocrine function and environmental estrogens and the impacts these compounds have on human and ecosystem health. My long-term research goal is to improve our understanding of the rapid responses to E2 and environmental estrogens in hypothalamic neurons that control homeostatic functions using mammalian and non-mammalian model species. I am particularly interested in the long-term consequences of low-dose exposure to these compounds in terrestrial and aquatic species and how these exposures may affect normal physiological and behavioral functions.
Currently, my research will have 3 main aims:
1. Determining the consequences of environmental estrogen, bisphenol A, etc., on homeostatic functions including energy intake, energy expenditure, fat accumulation, thermoregulation, etc., in two transgenic strains of mice that have modifications to ERa, ERaKO and the newly developed ERa KI/KO, and their wild-type littermates.
2. Comparing the gene expression profiles of relevant hypothalamic nuclei (arcuate nucleus, ventromedial hypothalamus, etc.) from the same transgenic strains exposed to env. Estrogens using gene microarray technology coupled with quantitative real-time PCR. The combination of the whole animal studies and gene expression tools will provide potential neuronal targets (channels, scaffolding proteins, signaling molecules, etc.) for electrophysiological studies.
3. Determining the effects of environmental estrogens on the neuronal activity of hypothalamic neurons via whole-cell patch clamp using transgenic GFP-tagged mouse models (POMC and NPY). It is unknown at this time if environmental estrogens impinge on the activity of cation channels (K+ and Ca2+) in hypothalamic neurons through both nuclear-initiated and membrane-initiated mechanisms as reported for E2.
I am also interested in other hypothalamic functions and the associated neurons that are also controlled by E2 and thereby affected by environmental estrogens. The results of these studies have the potential for further expansion as future studies could take advantage of the basic experimental design ~ genomic expression to functional effects to behavioral outcomes. Finally, my future research goals will also entail incorporating these same techniques and hypothesis to non-mammalian model species such as transgenic zebrafish and medaka models that are not only models for biomedical investigations but also used as models to investigate the effects of environmental contaminants on reproduction, development and neurobiological functions..
|Physiology, University of California at Davis||
|Biology, San Francisco State University||
|Marine Science/Biology, Long Island University, Southhampton College||
Grants-in-Aid of Research
2011 - Present
National Institute of Diabetes, Digestive and Kidney Diseases Pathway to Independence Award, R00 DK083457, Rutgers University
Society for Neuroscience
American Society for Neuroendocrinology
American Physiological Society
Animal Reproduction, Research Advances in Endocrinology
Hamdoun, A.M., Cherr, G.N., Roepke, T.A. and Epel, D. 2004. Activation of Multidrug Efflux Transporter Activity at Fertilization in Sea Urchin Embryos (Strongylocentrotus purpuratus). Dev. Biol. 276(2): 452-462. PubMed
Roepke, T.A., Snyder, M.J. and Cherr, G.N. 2005. Estradiol and Endocrine Disrupting Compounds Adversely Affect the Normal Development of the Sea Urchin Embryo at Environmentally Relevant Concentrations. Aquat. Toxicol. 71(2): 155-173. PubMed
Julian, D., Statile, J., Roepke, T.A. and Arp, A.J. 2005. Sodium nitroprusside potentiates H2S-induced contractions in body wall muscle from a marine worm. Biol. Bull. 209(1): 6-10. PubMed
Roepke, T.A., Chang, E.S. and Cherr, G.N. 2006. Maternal exposure to estradiol and endocrine disrupting compounds alters the sensitivity of sea urchin embryos and the expression of an orphan steroid receptor. J. Exp. Zool. 305A: 830-841. PubMed
Roepke, T.A., Hamdoun, A.M. and Cherr, G.N. 2006. Increased in multidrug transport
activity is associated with oocyte maturation in sea stars. Dev. Growth Differ. 48: 559-573. PubMed
Roepke, T.A., Malyala, A., Bosch, M.A., Kelly, M.J. and Rønnekleiv, O.K. 2007. Estrogen regulates gene important for K+ channel signaling in the arcuate nucleus. Endocrinology 148:4937-4951. PubMed
*Xu, C., Roepke, T.A., Zhang, C., Rønnekleiv, O.K. and Kelly, M.J. 2008. GnRH I activates the M-current in GnRH neurons: an autoregulatory negative feedback mechanism? Endocrinology 149: 2459-2466. *Co-first author. PubMed
Zhang, C., Roepke, T.A., Rønnekleiv, O.K. and Kelly, M.J. 2008. Ionic mechanisms of kisspeptin depolarizes GnRH neurons through activation of TRPC-like cationic channels. J Neurosci. 28(17):4423-34. PubMed
Roepke, T.A., Xue, C., Bosch, M.A., Scanlan, T.S., Kelly, M.J and Rønnekleiv, O.K. 2008. Genes associated with membrane-initiated signaling of estrogen and energy homeostasis. Endocrinology 149(12):6113-6214 PubMed
Roepke, T.A. 2009. Oestrogen modulates hypothalamic control of energy homeostasis through multiple mechanisms. J Neuroendocrinol. 21(2):141-50. Young Investigators Perspective PubMed
Roepke, T.A., Qiu, J., Bosch, M.A., Rønnekleiv, O.K and Kelly, M.J. 2009. Cross-talk between nuclear-initiated and membrane-initiated oestrogen signalling in the hypothalamus. J Neuroendocrinol. 21:263-270. PubMed
Roepke, T.A., Bosch, M.A*., Rick, E.A., Lee, B., Wagner, E.J., Seidlova-Wuttke, D., Wuttke, W., Scanlan, T.S., Ronnekleiv, O.K. and Kelly, M.J. 2010. Contribution of a membrane estrogen receptor to the estrogenic regulation of body temperature and energy homeostasis. Endocrinology 151:4926-4937 *Co-first author. PubMed
Roepke, T.A., Rønnekleiv, O.K and Kelly, M.J. 2011. Physiological consequences of membrane-initiated estrogen signaling in the brain. Frontiers Biosci. 16:1560-1573. PubMed
Roepke, T.A., Qiu, J., Smith, A.W, Rønnekleiv, O.K., Kelly, M.J. 2011. Fasting and 17β-estradiol modulates of the M-current in NPY neurons. J. Neurosci. 31(33):11825-11835. PubMed
Roepke TA, Smith AW, Rønnekleiv OK, and Kelly MJ. 2012. Serotonin 5-HT2C receptor-mediated inhibition of the M-current in hypothalamic POMC neurons. Am J Physiol Endocrinol Metab. 302(11):E1399-406. PubMed
Ropero AB, Alonso-Magdalena P, Soriano S, Juan-Picó P, Roepke TA, Kelly MJ, and Nadal Á. 2012. Insulinotropic effect of the non-steroidal compound STX in pancreatic beta-cells. PLoS One. 7(4):e34650. PubMed