Helena (Elena) Parfenova, Ph.D.

Helena (Elena) Parfenova, Ph.D.

Department of Physiology

The University of Tennessee Health Science Center
894 Union Avenue
Memphis, TN 38163
Phone: (901) 448-8319
Fax: (901) 448-7126
Lab: 305 Nash Research Building
Email: Helena (Elena) Parfenova



  • Ph.D. Institution:¬†Institute of Cytology, St Petersburg, Russia


Research Interests

We investigate the roles of heme oxygenase (HO) and carbon monoxide (CO), the HO-derived endogenous gaseous mediator, in regulating blood flow to the brain and in promoting survival of brain endothelial cells during cerebral vascular insult caused by seizures and oxidative stress. Seizures cause sustained cerebral vascular injury, reduction of endothelial vasodilator function, and loss of cerebral blood flow regulation. Glutamate, an excitatory neurotransmitter, and TNFa, a pro-inflammatory cytokine, are major injurious factors involved in the pathogenesis of seizure-induced cerebral vascular injury and endothelial apoptosis. Activation of endogenous HO/CO system or pharmacological delivery of CO to the brain reduces or prevents cerebral vascular endothelial injury and restores cerebral vascular endothelial function.

Cerebral Vascular Endothelial Cells HO-2 Immunostaining (Green) F-Actin (Red)

We investigate the HO/CO system as a critical component of anti-apoptotic mechanisms involved in protecting the brain from cerebral vascular injury caused by seizures and oxidative stress. The projects involve in vivo and in vitro studies in newborn pigs using the closed cranial window techniques for detection of cerebral blood flow responses, isolated cerebral resistance arterioles, and primary cultures of cerebral vascular endothelial, smooth muscle, and glial cells. My ultimate goal is to translate the knowledge gained from the animal models to pediatric practice to correct the deteriorating neurological outcome of neonatal cerebrovascular insults

Research Support

  • Home Oxygenase and Cerebral Vascular Injury. NIHLBI/NIH. 6/1/4-5/31/14 P.I.
  • Cerebrovascular Stress and Circulating Endothelial Cells. NINDS/NIHLBI. 2/1/10-1/31/15 P.I.
  • Control of neonatal circulation. NHLBI/NIH. 4/1/1984-3/31/2017 (Co-I, CW Leffler, P.I.)
  • Hydrogen Sulfide in Newborn Cerebral Circulation. NIHLBI/NIH. 8/1/1990-7/31/2015 (Co-I, CW Leffler, P.I.)

Representative Publications

  • Harsono M, Pourcyrous M, Jolly EJ, de Jongh Curry A, Fedinec AL, Liu J, Basuroy S, Zhuang D, Leffler CW, Parfenova H. Selective head cooling during neonatal seizures prevents postictal cerebral vascular dysfunction without reducing epileptiform activity. Am J Physiol Heart Circ Physiol. 2016 Nov 1;311(5):H1202-H1213. doi: 10.1152/ajpheart.00227.2016. Epub 2016 Sep 2. PubMed PMID: 27591217; PubMed Central PMCID: PMC5130497.
  • Pourcyrous M, Basuroy S, Tcheranova D, Arheart KL, Elabiad MT, Leffler CW, Parfenova H. Brain-derived circulating endothelial cells in peripheral blood of newborn infants with seizures: a potential biomarker for cerebrovascular injury. Physiol Rep. 2015 Mar;3(3). pii: e12345. doi: 10.14814/phy2.12345. PubMed PMID: 25804265; PubMed Central PMCID: PMC4393173.
  • Liu J, Fedinec AL, Leffler CW, Parfenova H. Enteral supplements of a carbon monoxide donor CORM-A1 protect against cerebrovascular dysfunction caused by neonatal seizures. J Cereb Blood Flow Metab. 2015 Feb;35(2):193-9. doi: 10.1038/jcbfm.2014.196. Epub 2014 Nov 5. PubMed PMID: 25370858; PubMed Central PMCID: PMC4426744.
  • Nnorom CC, Davis C, Fedinec AL, Howell K, Jaggar JH, Parfenova H, Pourcyrous M, Leffler CW. Contributions of KATP and KCa channels to cerebral arteriolar dilation to hypercapnia in neonatal brain. Physiol Rep. 2014 Aug 28;2(8). pii: e12127. doi: 10.14814/phy2.12127. Print 2014 Aug 1. PubMed PMID: 25168876; PubMed Central PMCID: PMC4246596.
  • Basuroy S, Leffler CW, Parfenova H. CORM-A1 prevents blood-brain barrier dysfunction caused by ionotropic glutamate receptor-mediated endothelial oxidative stress and apoptosis. Am J Physiol Cell Physiol. 2013 Jun 1;304(11):C1105-15. doi: 10.1152/ajpcell.00023.2013. Epub 2013 Apr 10. PubMed PMID: 23576575; PubMed Central PMCID: PMC3677176.
  • Parfenova H, Tcheranova D, Basuroy S, Fedinec AL, Liu J, Leffler CW. Functional role of astrocyte glutamate receptors and carbon monoxide in cerebral vasodilation response to glutamate. Am J Physiol Heart Circ Physiol. 2012 Jun 1;302(11):H2257-66. doi: 10.1152/ajpheart.01011.2011. Epub 2012 Mar 30. PubMed PMID: 22467311; PubMed Central PMCID: PMC3378289.

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