Clemmer Biosketch

OMB No. 0925-0001 and 0925-0002 (Rev. 10/2021 Approved Through 01/31/2026)

BIOGRAPHICAL SKETCH

NAME: John Steeneck Clemmer

eRA COMMONS USER NAME (credential, e.g., agency login): johnclemmer

POSITION TITLE: Assistant Professor

EDUCATION/TRAINING 

Personal Statement

My long-term research interests include integrative physiological modeling, mechanisms of hypertension, chronic kidney disease, and heart failure and their treatments, and the roles of race/ethnicity, salt intake, and obesity and their impact on cardiovascular disease. My previous academic training and research experience as a biological engineer have given me a unique background in biological concepts, physics, and mathematics. During my predoctoral training, I investigated traumatic hemorrhage and endocrine function in obesity. I had the opportunity to master several laboratory techniques including the assessment of microvascular function in isolated arterioles and in vivo preparations, measuring the impact of endocrine function on vascular permeability. While my current research is in a different field than my previous training, my knowledge of study design, research techniques, and integrative physiology allows me to assess experimental and clinical literature, extract important physiological concepts and relationships, and translate them into quantitative physiological relationships to support a large mathematical model of integrative physiology. This model was originally developed by Dr. Arthur Guyton and Dr. Tom Coleman. In 1972, this model was comprised of 354 mathematical equations describing cardiovascular and renal physiology. This model has been developed over the past 50 years at UMMC, and I have the privilege and honor to stand on shoulders of giants to continue that legacy.

Positions, Scientific Appointments, and Honors

Positions and Employment

05/2006 – 08/2006      Health Center Technician, Mississippi State University, Starkville, MS

05/2007 – 04/2008      Chemistry Laboratory Technician, Mississippi State University, Starkville, MS      

08/2015 – 04/2016      Adjunct Instructor, William Carey University, Hattiesburg, MS

06/2015 – 06/2017      Postdoctoral Fellow, University of Mississippi Medical Center, Department of Physiology and Biophysics, Jackson, MS

06/2017 – 05/2022       Instructor, University of Mississippi Medical Center, Department of Physiology and Biophysics, Jackson, MS

05/2022 – Present       Assistant Professor, University of Mississippi Medical Center, Department of Physiology and Biophysics, Jackson, MS

Professional Memberships

2011 – Present           American Heart Association

2011 – Present           American Physiological Society

2013 – 2016              Society for Experimental Biology and Medicine

2011 – 2015              Microcirculatory Society

2008 – 2010               Biomedical Engineering Society

2004 – 2010               Institute of Biological Engineering

Academic and Professional Honors

2005 – 2006                Dean's List, Mississippi State University, Starkville, MS

2006 – 2007                President's Scholar, Mississippi State University, Starkville, MS

2010 – 2014                T32 Training Grant (Joey P. Granger, PhD), UMC, Jackson, MS

2010 – 2015                Dean’s Scholarship, UMC, Jackson, MS

2012                           Benjamin Zweifach Student Travel Award, Microcirculatory Society

2014                           Caroline tum Suden/Hellebrandt Professional Award, American Physiological Society

2014                           Young Investigator Award, Society for Experimental Biology and Medicine

2014 – 2015                American Heart Association Predoctoral Fellowship Grant, AHA-14PRE20380069

2015                           Selected for Featured Topic Oral Presentation: Recent Advances in Obesity Research, American Physiological Society

2015                           Regions Outstanding Graduate Research Award, UMC

2015                           International Academy of Cardiovascular Sciences Travel Award

2017 – 2019                American Heart Association Postdoctoral Fellowship Grant, AHA-17POST33661071

2019                           Hypertension Scientific Sessions Poster Competition Award

2023                           Arthur C. Guyton Award for Excellence in Integrative Physiology and Medicine, American Physiological Society

Contributions to Science

Early Career: My early career was spent at Mississippi State University as a biological engineering graduate student working under Dr. Lakeisha Williams and Dr. Jun Liao. I worked on several research projects that assessed the biomechanics of soft tissue for the purposes of 3D modeling and physics-based simulations. I also completed a Master’s degree in Dr. William’s laboratory. My thesis was titled “A mechanistic study of tendon under interrupted tension and high rate compression”. This work gave me experience in animal research, mechanical testing, microscopy techniques (SEM, TEM, and LSCM), finite element analysis, and modeling.

1. Clemmer J, Liao J, Davis D, Horstemeyer M, Williams L. A Mechanistic Study for Strain Rate Sensitivity of Rabbit Patellar Tendon. Journal of Biomechanics. 43: 2785-91, 2010. PMCID: PMC5032624
2. Clemmer J, Prabhu R, Chen J, Colebeck E, Priddy L, McCollum M, Brazile B, Whittington W, Wardlaw J, Rhee H, Horstemeyer M, Williams L, Liao J. Experimental observation of high strain rate responses of porcine brain, liver, and tendon. J Mech Med Biol. 16 (3),

Graduate career:  As a PhD student, I participated in projects related to the impact of obesity and insulin resistance on outcomes after trauma in the obese Zucker rat model. I become proficient at several microcirculatory techniques including isolating arterioles and in vivo arteriolar experiments and assessing lung and kidney function after trauma or hemorrhage. I also developed an obese rat model of hemorrhage to examine the role of insulin resistance and obesity on the acute hyperglycemic responses after hemorrhage. I then studied the consequences of this acute hyperglycemia in the context of vascular oxidation and permeability in the lung. While working toward my doctorate, I gained broad experience in western blotting, ELISA, multi-photon microscopy, and measuring renal hemodynamics in conscious animals. 

1. Clemmer J, Xiang L, Lu S, Mittwede P, Hester R. Hyperglycemia-mediated oxidative stress increases pulmonary vascular permeability. Microcirculation. 23(3):221-9,2016. PMCID: PMC4818684
2. Clemmer J, Xiang L, Lu S, Mittwede P, Hester R. β₂-adrenergic regulation of stress hyperglycemia following hemorrhage in the obese Zucker rat. Physiol Rep. 2014 Dec;2(12):e12215. PMCID: PMC4332203
3. Xiang L, Lu S, Mittwede P,Clemmer J, Husband G, Hester R. β2 adrenoreceptor blockade improves early post-trauma hyperglycemia and pulmonary injury in obese rats. Am J Physiol Heart Circ Physiol. 2014 Aug 15;307:H621-H627. PMCID: PMC4137123
4. Xiang L, Clemmer J, Lu S, Mittwede P. Impaired blood pressure compensation following hemorrhage in conscious obese Zucker rats.  Life Sci. 2013 Aug 14:93(0):214-219. PMCID: PMC4059392

Postdoctoral career: During my postdoctoral training, I relied heavily on my engineering and physiology background while also learning new approaches and techniques. My research involved mathematical modeling to understand integrative physiology and interactions with changes in salt intake and antihypertensive therapy. I used the model to simulate water and electrolyte homeostasis and multiple types of hypertension that may or may not cause salt sensitivity of blood pressure. Also, in my postdoctoral career, I started to use the model to stimulate devices that are currently in clinical trials for the treatment of hypertension (baroreflex activation therapy) and investigate the physiological mechanisms of how these devices work in different patients, which is currently unclear. Lastly, my interest in hypertension disparities in African Americans has led to work investigating both sex and racial differences in the response to antihypertensive drugs.

1. Clemmer J, Pruett WA, Coleman T, Hall J, Hester R. Mechanisms of blood pressure salt sensitivity: new insights from mathematical modeling. Am J Physiol Regul Integr Comp Physiol. 2017, Apr 1;312(4):R451-R466. PMCID: PMC5407080
2. Clemmer J, Pruett WA, Hester R. Simulating a virtual population’s sensitivity to salt and uninephrectomy. Interface Focus. 2018 Feb 6;8(1):20160134. PMCID: PMC5740217
3. Clemmer JS, Pruett WA, Hester RL, Iliescu R, Lohmeier TE. Role of the heart in blood pressure lowering during chronic baroreflex activation: Insight from an in silico analysis. Am J Physiol Heart Circ Physiol. 2018, Nov 1; 315: H1368–H1382. PMCID: PMC6297821
4. Clemmer JS, Faulkner JL, Mullen AJ, Butler KR, Hester RL. Sex-specific Responses to Mineralocorticoid Receptor Antagonism in African American Males and Females. Biol Sex Diff. 2019, May 9; 10(1):24. PMCID: PMC6507140
5. Clemmer JS, Pruett WA, Lirette, ST. Racial and sex differences in the response to antihypertensive monotherapy. Front Cardiovasc Med. 17 (7):608037, 2020.

Faculty career: My current research uses the model to predict clinical trial outcomes, by using models of hypertension, chronic kidney disease, and/or heart failure with preserved ejection fraction. Mathematical modeling allows the ability to investigate treatment of these diseases independently or integrated together as they are commonly seen in the clinic. My lab also uses these models to create thousands of virtual patients to recreate clinical and physiological variability. With these virtual populations, we are able to validate against available clinical trial data, and predict outcomes and propose mechanisms of pathophysiology and its treatment using newer pharmacological-based treatments (e.g. SGLT2 inhibitors or ARNI) or device-based therapies not yet approved by the FDA (e.g. baroreflex activation). Continuing our interests in large clinical datasets and health disparities, we have recently demonstrated that black HFpEF patients have increased risk of end stage renal disease (ESRD) but those taking SGLT2 inhibitors (newly approved for HFpEF) have a decreased risk of ESRD and death.

1. Moore KH, Clemmer JS. Questioning the renoprotective role of L-type calcium channel blockers in chronic kidney disease using physiological modeling. Am J Physiol Renal Physiol. 321(4):F548-F557, 2021
2. Clemmer JS, Pruett WA, Hester RL. In silico trial of baroreflex activation therapy for the treatment of hypertension. PLOS ONE. 16(11):e0259917, 2021.
3. Clemmer JS, Pruett WA. Modeling the physiological role of the heart and kidney in heart failure with preserved ejection fraction during baroreflex activation therapy. Am J Physiol Heart Circ Physiol. 323(3):H597:H607, 2022.
4. Clemmer JS, Ward TJ, Lirette ST. Retrospective analysis of SGLT2 inhibitors in heart failure with preserved ejection fraction. ESC Heart Failure. 10(3):2010-2018, 2023.

 Complete list of published work in MyBibliography:

https://www.ncbi.nlm.nih.gov/myncbi/john.clemmer.1/bibliography/public/