Timothy E. O'Toole, Ph.D.

Associate Professor of Medicine
Core Director, Flow Cytometry


502-852-5886 E-mail

Education and Training

Ph.D.: University of Michigan, Biological Chemistry
Postdoctoral Fellowship: Scripps Research Institute


Research Interests

The goal of studies in Dr. O'Toole's lab is to develop a mechanistic understanding whereby environmental exposure adversely impact cardiovascular function. Prior work from this lab characterized the cardiovascular and immune responses of exposure to fine air-borne particulate matter (PM2.5). In humans, exposure to PM2.5 resulted in endothelial damage, deficits of circulating angiogenic cells (CACs), changes in immune cell populations, changes in plasma cytokines, and increased thrombogenicity. In animal models, exposure to concentrated ambient particles induced quantitative and qualitative defects in CACs and platelet activation. Some of these outcomes in mice were mitigated when means were taken to limit oxidative stress. Current efforts seek to identify additional, adverse outcomes in response PM2.5 exposure, the molecular basis of these outcomes, and effective strategies to limit these outcomes. A study characterizing the efficacy and feasibility of carnosine (a naturally occurring β-alanyl-L-histidine dipeptide) supplementation in mitigating adverse outcomes in humans is currently ongoing. In addition to particulate air pollution, Dr. O'Toole's laboratory is also examining the cardiovascular consequences of exposure to volatile organic compounds. Mice exposed to benzene develop insulin resistance while mice exposed to either acrolein or benzene also have CAC deficits. Mechanistic studies to better understand these outcomes of VOC exposure are underway.


Featured Publications

Find all papers and citations via ResearchGate

  • Riggs DW, Zafar N, Krishnasamy S, Yeager R, Rai SN, Bhatnagar A, O'Toole TE. Exposure to airborne fine particulate matter is associated with impaired endothelial function and biomarkers of oxidative stress and inflammation. Environ Res. 2020 Jan;180:108890. doi: 10.1016/j.envres.2019.108890. Epub 2019 Nov 5. PubMed PMID: 31718786; PubMed Central PMCID: PMC6899204.
  • Abplanalp W, Haberzettl P, Bhatnagar A, Conklin DJ, O'Toole TE. Carnosine Supplementation Mitigates the Deleterious Effects of Particulate Matter Exposure in Mice. J Am Heart Assoc. 2019 Jul 2;8(13):e013041. doi: 10.1161/JAHA.119.013041. Epub 2019 Jun 25. PubMed PMID: 31234700; PubMed Central PMCID: PMC6662354.
  • Abplanalp WT, Wickramasinghe NS, Sithu SD, Conklin DJ, Xie Z, Bhatnagar A, Srivastava S, O'Toole TE. Benzene Exposure Induces Insulin Resistance in Mice. Toxicol Sci. 2019 Feb 1;167(2):426-437. doi: 10.1093/toxsci/kfy252. PubMed PMID: 30346588; PubMed Central PMCID: PMC6358255.
  • Malovichko MV, Zeller I, Krivokhizhina TV, Xie Z, Lorkiewicz P, Agarwal A, Wickramasinghe N, Sithu SD, Shah J, O'Toole T, Rai SN, Bhatnagar A, Conklin DJ, Srivastava S. Systemic Toxicity of Smokeless Tobacco Products in Mice. Nicotine Tob Res. 2019 Jan 1;21(1):101-110. doi: 10.1093/ntr/ntx230. PubMed PMID: 30085294; PubMed Central PMCID: PMC6329408.
  • Yeager R, Riggs DW, DeJarnett N, Tollerud DJ, Wilson J, Conklin DJ, O'Toole TE, McCracken J, Lorkiewicz P, Xie Z, Zafar N, Krishnasamy SS, Srivastava S, Finch J, Keith RJ, DeFilippis A, Rai SN, Liu G, Bhatnagar A. Association Between Residential Greenness and Cardiovascular Disease Risk. J Am Heart Assoc. 2018 Dec 18;7(24):e009117. doi: 10.1161/JAHA.118.009117. PubMed PMID: 30561265; PubMed Central PMCID: PMC6405613.
  • Zafar N, Krishnasamy SS, Shah J, Rai SN, Riggs DW, Bhatnagar A, O'Toole TE. Circulating angiogenic stem cells in type 2 diabetes are associated with glycemic control and endothelial dysfunction. PLoS One. 2018 Oct 15;13(10):e0205851. doi: 10.1371/journal.pone.0205851. eCollection 2018. PubMed PMID: 30321232; PubMed Central PMCID: PMC6188890.
  • Keith RJ, Fetterman JL, Riggs DW, O'Toole T, Nystoriak JL, Holbrook M, Lorkiewicz P, Bhatnagar A, DeFilippis AP, Hamburg NM. Protocol to assess the impact of tobacco-induced volatile organic compounds on cardiovascular risk in a cross- sectional cohort: Cardiovascular Injury due to Tobacco Use study. BMJ Open. 2018 Mar 30;8(3):e019850. doi: 10.1136/bmjopen-2017-019850. PubMed PMID: 29602846; PubMed Central PMCID: PMC5884372.
  • Haberzettl P, Conklin DJ, Abplanalp WT, Bhatnagar A, O'Toole TE. Inhalation of Fine Particulate Matter Impairs Endothelial Progenitor Cell Function Via Pulmonary Oxidative Stress. Arterioscler Thromb Vasc Biol. 2018 Jan;38(1):131-142. doi: 10.1161/ATVBAHA.117.309971. Epub 2017 Nov 30. PubMed PMID: 29191925; PubMed Central PMCID: PMC5746456.