Olcese Laboratory James M. Olcese, Ph.D. Florida State University College of Medicine Dept. of Biomedical Sciences 1115 West Call Street Tallahassee, FL 32306-4300 USA Office: (850) 645-1479, rm 2300-E Lab: (850) 645-2921, rm 2310-P Dr. Olcese's Faculty Profile
Research Interests
The expression of circadian rhythmicity in the brain is manifest in many diverse neurobiological functions, from electrical activity and metabolic states to temperature rhythms and neurosecretory profiles. A better understanding of the temporal interaction and coordination of circadian systems would serve to promote many disciplines, e.g. psychiatry (sleep-wake disturbances, seasonal affective disorders, age-related dysfunctions, etc.), reproductive biology (developmental dysfunctions, disruptions in hormonal rhythms, fertility disorders, etc.), and oncology (chronopharmacology, neuroimmunology) to name just a few examples. As an example of “peripheral” oscillator systems we study GnRH neurons and the major neuroendocrine target cells of the GnRH peptide, namely the pituitary gonadotropes, for mRNA and protein expression of the cognate “circadian clock genes”. Using quantitative PCR we have been able to demonstrate regulatory pathways through which expression of Per-1 can be modulated in these cells. By means of chromatin immunoprecipitation, RNA interference and reporter assays, we identified the GnRH receptor to be a molecular target for the bHLH transcription factor/clock genes, Clock and Bmal1. Currently we are determining the kinetics and cellular mechanisms of clock gene expression in vivo in the transgenic rodent neuroendocrine axis during the course of the estrus cycle by means of real-time bioluminometry and double-labelling confocal microscopy. This work should provide important new insights into hypothalamic-pituitary function generally and the role of circadian timekeeping mechanisms in normal as well as abnormal physiological states, especially in the context of reproductive biology. A second line of research in our lab is the understanding of how the brain hormone melatonin acts on central and peripheral tissues. Melatonin has been shown to participate in many divergent biological processes in all vertebrate animals, and even in some invertebrates. This hormone is recognized to regulate seasonal rhythmicity in various vertebrates, it affects the phasing of mammalian circadian rhythms and it modulates retinal functions in many animals. Melatonin has long been studied in the context of reproductive physiology, and more recently, as an output marker of the hypothalamic circadian clock. The current view is that melatonin’s primary endogenous role is as a neurochemical signal of subjective night, since its synthesis and release from the pineal gland occurs almost entirely during the dark phase of the 24-hour day/night cycle. Our laboratory was the first to identify melatonin receptors in the myometrium of pregnant and nonpregnant women, and to show differential signaling as a function of reproductive status. More recently, we discovered marked increases in myometrial melatonin receptor expression at the time of labor, consistent with a pro-contractile role of melatonin. We have also shown that melatonin synergizes with oxytocin to promote myometrial smooth muscle cell contractions and gap junction dye spread in vitro. Remarkably, melatonin at physiological concentrations and exposure durations also has significant effects on the expression of the oxytocin receptor gene, effects that appear to mirror the action of oxytocin itself on the myometrium. In view of these data, we seek to better understand how myometrial melatonin receptors are regulated during term and preterm labor, and how these receptors interact with and influence oxytocin receptors and other components of the contractile-activating system in this excitable tissue. Further characterization of novel regulatory networks in the human uterus involving melatonin and OT can be expected to motivate the fields of reproductive biology and obstetrics. For example, such data will be important in the development of new strategies for supporting or promoting parturition in pregnant women whose uterine contractility is inadequate for normal labor. In this context, we have recently secured a patent to develop new melatonin-based uterotonic compounds. This research can also contribute to the search for novel tocolytic agents that help to maintain pregnancy in the face of pre-term labor, a major cause of neonatal mortality in Western societies. Since the discovery of its reported free-radical scavenging properties, melatonin has garnered increasing attention as a potential prophylactic in the context of neurodegenerative disease. Involvement of melatonin in the pathogenesis of AD is suggested from studies showing that AD patients have decreased blood and CSF levels of melatonin. Indeed, lower CSF levels of melatonin have been strongly correlated with progression of AD neuropathology. In addition to these findings, several epidemiologic studies have suggested that melatonin treatment provides cognitive benefit to MCI and AD patients. Recently, we published the first comprehensive investigation of melatonin’s therapeutic potential in an animal model for AD. These studies evaluated the “protective” effects of long-term melatonin administration to transgenic AD mice on their cognitive performance, brain Aβ levels/deposition, cytokine levels, and expression of antioxidant enzymes — all in the same animals. We found that long-term melatonin administration protects the brain of Alzheimer’s mice against cognitive impairment while concomitantly reducing brain amyloid load, lowering brain cytokine levels and diminishing brain oxidative stress. Collectively, our findings provide support for long-term melatonin therapy as a part of the strategy for directly abating the progression of Alzheimer disease.
Current Projects
Clock genes in the neuroendocrine axis We have shown that mammalian GnRH neurons as well as pituitary gonadotrope cells, which are critically important for induction and maintenance of fertility, express all of the known “clock genes” (Period, Clock, Bmal1, Cryptochrome, etc.), an interacting group of genes first recognized in the context of circadian “clock” function (e.g. sleep-wake rhythms). Additionally we have reported that Period1 expression is under cyclic AMP regulation in the GnRH neuron and under PKC/MAPK regulation in the gonadotrope. Recently we identified the GnRH receptor (found in both GnRH neurons and gonadotropes) to be a molecular target for these clock genes. Our current studies seek to define by RNA interference and microarray analyses all of the molecular targets for the clock genes in these important neuroendocrine cells. Melatonin and the regulation of labor Our working hypothesis is that an increase in MTR expression during labor permits MEL to synergistically potentiate other uterotonic factors. By extension we envision that premature myometrial expression of MTR may contribute to preterm increases in contractility and subsequently to premature labor, in at least some women. Our specific aims are to establish the degree of melatonin’s uterotonic activity in primary human myometrial smooth muscle (MSM) cells and to evaluate further the expression of MTR in preterm labor. Furthermore, we are continuing to characterize melatonin signaling pathways in human MSM cells. Melatonin and Alzheimer dementia Our investigations have identified multiple mechanisms through which melatonin may be protecting AD transgenic mice from cognitive impairment. In an effort to better understand the specific mechanisms of melatonin action against AD, we are collaborating with several groups to address several important questions that have arisen from our preliminary data. For example: What is the role of the immune system in melatonin’s cognitive benefits? What ameliorative effects might melatonin have on mitochondrial function and dysfunction? Are melatonin’s mechanisms of action dependent or independent of melatonin receptor action? We are addressing these issues by comprehensively exploring explicit mechanisms of melatonin action in vitro with cell lines expressing the sweAPP protein and by using transgenic AD model systems.
Current Laboratory Members
James Sharkey, B.S. Florida Atlantic University, 2004 (graduate student) Holly Sikes, B.S. Florida State University, 2003 (graduate student) Gina O’Neal-Moffitt, B.S. Florida State University, 2007 (graduate student) Anushi Patel (undergraduate student)
Selected References
Olcese J, Domagalski R, Weaver DR, Reuss S, Middendorf R, Urbanski HF, Bednorz A. 2003. Expression and regulation of mPeriod1 in immortalized GnRH neurons. NeuroReport 14: 613-618.   Resuehr D, Olcese J. 2005. Caloric restriction and melatonin substitution: Effects on murine circadian parameters. Brain Research 1048: 146-152.   Olcese J, Sikes HE, Resuehr D. 2006. Induction of mPer1 mRNA expression in immortalized gonadotropes by gonadotropin-releasing hormone (GnRH): Involvement of protein kinase C and MAP kinase signaling. Chronobiology International 23: 143-150.   Resuehr D, Wildemann U, Sikes HE, Olcese J. 2007 E-box regulation of gonadotropin-releasing hormone (GnRH) receptor expression in immortalized gonadotrope cells. Molecular & Cellular Endocrinology 278: 36-43.   Sharkey J, Olcese J. 2007 Transcriptional inhibition of oxytocin receptor expression in human myometrial cells by melatonin involves protein kinase C signaling. Journal of Clinical Endocrinology & Metabolism 92: 4015-19.   Sharkey J, Puttaramu R, Word RA, Olcese J. 2009 Melatonin synergizes with oxytocin to enhance contractility of human myometrial smooth muscle cells. J. Clin. Endocrinol. Metabol. 94: 421-427.   Sikes-Resuehr HE, Resuehr D, Olcese J. 2009 Induction of mPer1 expression by GnRH in pituitary gonadotrope cells involves EGR-1. Molec. Cell. Endocrinol. (in press)   Olcese JM, Cao C, Mori T, Mamcarz MB, Maxwell A, Runfeldt MJ, Wang L,Zhang C, Lin X , Zhang G, Arendash GW. 2009 Protection against cognitive deficits and markers of neurodegeneration by long-term oral administration of melatonin in a transgenic model of Alzheimer disease. J. Pineal Res. (in press)