Jennifer C. Sullivan, PhD, FAHA


Associate Professor

Dr. Jennifer Sullivan

 Phone: (706) 721-9796
 Fax: (706) 721-7299
 Emailjensullivan@augusta.edu
 Office: CB-2204
 Lab: CB-2210

 

 

 

Learn more about Dr. Sullivan's research


Education and Training

State University of New York at Geneseo, Geneseo, NY, BS in Biology, 1996

Albany Medical College, Albany, NY, MS and PhD in Cardiovascular Pharmacology, 2000

Medical College of Georgia, Augusta, GA, postdoctoral fellowship in Cardiovascular Biology and Physiology


Academic Appointments

2014-present    Associate Professor, Department of Physiology, Augusta University, Augusta, GA

2013-2014       Associate Professor, Department of Medicine, Georgia Regents University, Augusta, GA

2011-2013       Assistant Professor, Department of Medicine, Georgia Health Sciences University, Augusta, GA

2011-present    Associate member of the Department of Pharmacology and Associate member of the Vascular Biology Center

2008-2011       Assistant Professor, Vascular Biology Center, Medical College of Georgia, Augusta, GA

2006-2008       Instructor, Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA

2003-2006      Assistant Research Scientist, Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA


Research Interests

The overall goal of my laboratory is to better understand the molecular mechanisms that regulate blood pressure in males and females under both physiological and pathophysiological conditions, including hypertension. Traditionally, it has been assumed that blood pressure control and the basis of hypertension is the same in males and females; just the magnitude of the response differs. However, based on the vast number of differences that have been identified in cardiovascular physiology, pathophysiology, and pharmacology between the sexes, there is growing evidence to suggest that the pathways by which males and females develop cardiovascular and renal diseases may be distinct. Ongoing studies are focused on 3 pathways involved in blood pressure control and cardiovascular function: the renin angiotensin system (RAS), the nitric oxide (NO) pathway, and inflammation.


Current Projects

The primary research focus of my laboratory is to address gaps in our knowledge regarding the mechanisms controlling blood pressure under normal physiological conditions and in disease states in females.  Hypertension affects ~33% of adults in the U.S. and is the most common independent risk factor for cardiovascular disease.  While ~81% of hypertensive women are treated for their hypertension, fewer than ~50% achieve blood pressure controlled to recommended levels.  This likely relates to the fact that although women account for ~53% of the hypertensive population, the majority of basic science research is performed only in males and representation of women in clinical trials for cardiovascular disease is well below 50%.  The importance of increasing our understanding of physiology in females is underscored by recent NIH mandates to include a discussion of sex as a biological variable in all grant applications.

Technical Illustration of Dr. Sullivan's research.

 

Recent studies in my laboratory have examined sex differences in blood pressure control with respect to three major pathways known to regulate cardiovascular health: the nitric oxide (NO) pathway and oxidative stress, the renin-angiotensin system (RAS), and inflammation.  NO is a critical regulator of blood pressure and experimental and clinical data show that females have greater NO bioavailability than males. Despite well-documented sex differences in NO bioavailability, the mechanisms responsible for sex differences and the consequences of these sex differences on CV health were unknown.  We published the first characterization of NOS in the kidney of hypertensive males and females; female spontaneously hypertensive rats (SHR) have greater renal NO bioavailability than males. Additional studies then examined 1) the mechanism driving sex differences in NO and 2) the physiological implication(s) of sex differences in NO.  We found sex differences in renal medullary NOS are mediated by a sex hormone and BP dependent increase in NOS in females.  In contrast, greater levels of oxidative stress and decreases in tetrahydrobiopterin contribute to lower renal NO in males.  To further assess the contribution of NOS on blood pressure control, SHR were treated with the NOS inhibitor L-NAME.  Consistent with our biochemical data, female SHR are more dependent on NOS to maintain blood pressure.  Male SHR also exhibit impaired endothelium-dependent vasodilation and decreases in NO-dependent dilation compared to females.  Current studies are examining the molecular mechanisms by which females maintain greater NO, including the role of sex hormones, maturation, and NOS cofactors.

Inhibitors of the RAS are among the most widely used drugs to treat hypertension irrespective of sex, despite numerous sex differences in the RAS.  Our group has been critical in defining the molecular mechanisms driving sex differences in RAS activation.  Our laboratory was the first to report that greater levels of the vasodilatory peptide Ang (1-7) antagonizes Ang II-induced increases in blood pressure in females and Ang (1-7) contributes more to the BP lowering effects of angiotensin receptor blockers in females.  We further showed that greater Ang (1-7) levels occur via an ACE-dependent mechanism, in contrast to an expected role for ACE2. We have also begun to translate our findings to humans and recently reported that women have higher circulating Ang (1-7) levels than men.  Ongoing studies are examining the role of the angiotensin type 2 (AT2) receptor on blood pressure control and immune cell activation in males compared to females.

There is growing appreciation in the field of hypertension that immune cells, in particular T cells, are critical for the development and maintenance of hypertension.  Prior to 2012, all of the data supporting a role for immune cells had been collected using male experimental animals exclusively.  Our laboratory reported for the first time that blood pressure in female SHR is sensitive to lymphocyte inhibition.  We were also the first to report that male SHR have greater numbers of renal effector T cells, while females have more immuno-suppressive T regulatory cells (Tregs).  Furthermore, either preventing increases in BP or lowering BP in SHR decreased Tregs only in females and abolished the sex difference.  These data suggest a compensatory increase in Tregs in female SHR to limit increases in BP.  Additional studies examined the impact of angiotensin (Ang) II on T cells in kidneys of male and female Sprague-Dawley (SD) rats.  Although Ang II increased total renal T cells in both sexes, Tregs increased only in females.   Ongoing studies are testing the hypothesis that this increase in Tregs in females is critical to the ability of females to maintain a lower blood pressure relative to males.  We are also examining the contribution of T cells to high-fat diet-induced increases in blood pressure in females, the role of cell death in mediating T cell activation, and the mechanisms responsible for producing the sex difference in the renal T clel profile.


Awards and Accomplishments

2017      Augusta University Faculty Senate Outstanding Faculty Award from The Graduate School
2016      Augusta University Authentic Women Leaders Pilot Pipeline Program
2016      American Journal of Physiology - Regulatory, Comparative and Integrative Physiology Star Reviewer
2015      Chair, APS Sex and Gender-Related Research Interest Group
2014      Named the 2015 APS Renal Section Young Investigator 
2013      Promoted with tenure 
2013      Selected as Associate Editor for AJP:Renal Physiology 
2013      Selected as Cardiorenal Study Section Co-Chair; American Heart Association 
2013      Named Chair of the Augusta University Women’s Health Research Interest Group in the Div. of Clinical Translational Science 
2011      Recipient of GHSU Outstanding Young Basic Science Faculty Award 
2011      Recipient of GHSU Research Institute Emerging Scientist Award 
2010      Named Fellow of the American Heart Association and the Council for High Blood Pressure Research 
2007      Recipient of Consortium for Southeastern Hypertension Control Arthur Guyton New Investigator Award 
2007      Named the APS Water and Electrolyte Homeostasis Section New Investigator 
2008      Recipient of Kidney Council New Investigator Travel Award 
2006      Recipient of Merck New Investigator Award

*Representative Publications*

(Go to Pub Med)

Tipton AJ, Musall JB, Crislip GR, Sullivan JC.  Greater transforming growth factor-β in adult female SHR is dependent on blood pressure, but does not account for sex differences in renal T regulatory cells. Am J Physiol Renal Physiol, 2017, Epub ahead of print.  DOI:    10.1152/ajprenal.00175.2017

Gillis EE and Sullivan JC.  Sex Differences in Hypertension: Recent Advances. Hypertension, 68(6):1322-1327 2016.  DOI: 10.1161/HYPERTENSIONAHA.116. 06602

Taylor L and Sullivan JC.  Sex Differences in Obesity-Induced Hypertension and Vascular Dysfunction: A Protective Role for Estrogen in Adipose Tissue Inflammation?  Am J Physiol Regu, 2016, Epub ahead of print. DOI: 10.1152/ajpregu.00202.2016

Sasser JM, Brinson KN, Tipton AJ, Crislip GR and Sullivan JC.  Blood pressure, sex and female sex hormones influence renal inner medullary nitric oxide synthase activity and expression in Spontaneously Hypertensive Rats.  J Am Heart Association. 4(4); pii: e0017382015, 2015. DOI: 10.1161/JAHA.114.001738

Tipton AJ, Baban B, Sullivan JC.  Female SHR Have a Compensatory Increase in Renal Regulatory T Cells in Response to Elevations in Blood Pressure.  Hypertension, 64(3):557-64; 2014. DOI: 10.1161/HYPERTENSIONAHA.114.03512

Dr. Sullivan's FACULTY Profile Link to Dr. Sullivan on PubMed

LAB PERSONNEL

Mahmoud Abdelbary
Graduate Student

Ryan Crislip
Graduate Student

Ellen Gillis, PhD
Post-doctoral Fellow

Riyaz Mohamed, PhD
Post-doctoral Fellow

Jackie Musall
Research Manager

Delaney Rauch
Research Assistant

Lia Taylor
Graduate Student

Dr. Sullivan's Lab (2016)Pictured left to right: Ryan Crislip, Jackie Musall, Dr. Jennifer Sullivan, Dr. Ellen Gillis, Lia Taylor (2016)

 Dr. Sullivan's FACULTY Profile Dr. Sullivan's Lab Pictured left to right: Ryan Crislip, Dr. Jennifer Sullivan, A Tipton, M. Zimmerman

Dr. Sullivan with StudentsDr. Sullivan with students


Recent Lab Personnel Achievements

Ryan Crislip received the Augusta University Graduate School Excellence of Research in Physiology Award.

Dr. Ellen Gillis and Lia Taylor received Caroline tum Suden/Frances Hellebrandt Professional an Opportunity Awards for the 2017 Experimential Biology meeting.


Dr. Ellen Gillis received an Abstract Travel Award to attend the 2016 APS Conference.

Lia Taylor received a NIH Diversity Supplement to Dr. Sullivan's R01 award as well as a Minority Travel Fellowship Award to attend the 2016 APS Conference.
Ryan Crislip and Dr. Ellen Gillis received a Travel Award to attend the FASEB Summer Research Conference on Renal Hemodynamics and Cardiovascular Function in Health and Disease.

Lia Taylor was announced as a 2016-2017 Porter Physiology Fellowship awardee by The American Physiological Society, on behalf of the Porter Physiology Development and Minority Affairs Committee.

Lia Taylor was named as a finalist for the 2016 Water & Electrolyte Homeostasis Section Predoctoral Research Recognition Award.