Biomedical Seminars

Nina Hengen, M.D., Ph.D.

Abstract:

Major depression is twice as prevalent in women as in men. Additionally, in females, clinical depression is more common during periods of decreasing estrogen levels, such as menopausal and postpartum periods. Serotonin transporter (SERT) plays a significant role in regulating serotonergic neurotransmission and in the pathogenesis of depression. Most drugs currently used in the treatment of depression block SERT. Estrogen has been shown to affect SERT expression and function. These estrogen effects have been mostly studied in whole animal or in vivo models and conflicting results have been reported. However, due to their complexity, in vivo models are not suitable for studying the intracellular events involved in estrogen regulation of different molecular targets within the serotonin neurons. Our studies using serotonergic RN46A cells as an in vitro cell model have shown that SERT-mediated serotonin (5-HT) uptake capacity is influenced both by the presence of estrogen and by estrogen withdrawal. In addition, estrogen rapidly regulates 5-HT uptake capacity through non-genomic pathway(s) involving rapid changes in intracellular Ca2+ levels. The results of studies like this could expand our knowledge of intracellular events involved in estrogen regulation of serotonergic neurotransmission, which could ultimately lead to new, gender-specific approaches in the treatment of depression.

Professional Summary:

Dr. Nina Hengen (formerly Nina Koldzic-Zivanovic) received her M.D. from Belgrade University School of Medicine in Belgrade, Serbia in 1991. She worked for four years as a physician in her native Serbia before starting her doctoral studies at The University of Texas Medical Branch (UTMB) in Galveston, TX, in the Pharmacology and Toxicology program. While in her doctorate program, Dr. Hengen received the Dean’s Award for Academic Excellence.

After receiving her Ph.D. in 2004, Dr. Hengen completed three years of postdoctoral training at UTMB and the University of Texas Health Science Center at San Antonio, TX. While at UTMB, Dr. Hengen gained teaching experience at the Graduate School of Biomedical Sciences and School of Medicine. Since June 2007 she has been an Assistant Professor at the University of Charleston School of Pharmacy, Charleston, WV where she has been teaching Pharmacology, Pharmacokinetics, Pathophysiology, and Integrated Pharmaceutical Care and Sciences Modules. At the end of her first year with the University of Charleston School of Pharmacy, she received the Teacher of the Year Award.

Dr. Hengen’s research interests include examining interactions between steroid hormones and the serotonin system in the brain. Her research has resulted in five publications in peer-reviewed journals, as well as several presentations at national meetings. Her latest project “Estrogen regulation of serotonin transporter and serotonin autoreceptors in vitro” was funded by a West Virginia IDeA Network of Biomedical Research Excellence (WV-INBRE) Pilot Grant in May 2008

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