Grantee Research Project Results
Final Report: Atherothrombotic Effects of Particulate Matter
EPA Grant Number: EM833367Title: Atherothrombotic Effects of Particulate Matter
Investigators: Bhatnagar, Aruni , Conklin, Daniel
Institution: University of Louisville
EPA Project Officer: Chung, Serena
Project Period: August 1, 2007 through July 31, 2010
Project Amount: $1,500,000
RFA: Targeted Research Grant (2007) Recipients Lists
Research Category: Targeted Research , Particulate Matter
Objective:
To understand the atherothrombotic effects of concentrated ambient fine particulate matter (CAPs, PM2.5) exposure in mice.
Summary/Accomplishments (Outputs/Outcomes):
With EPA support we completed construction of a ~1,600 ft2 inhalation facility, which contains a barrier-style entry way, a pass-through autoclave, an animal housing room (capacity ~4,000 mice), a surgical procedures room, and a ~400 ft2 inhalation room. The inhalation facility operates as a barrier facility with card-code access only. The procedures room has been prepared for performing survival surgery including surgical implantation of telemetric devices for recording blood pressure and electrocardiogram in conscious mice during exposures as well as in home cages after exposures. The telemetry system has 2 data matrices, 8 receivers, 8 blood pressure transmitters, and 8 ECG transmitters as well as all necessary software for data collection and analysis (DSI, St. Paul, MN). It has equipment for performing acrolein and chlorine gas inhalation exposures, as well as, a custom-designed versatile aerosol concentration and enrichment system (VACES) modeled after a system currently used by Dr. Lung-Chi Chen (New York University). For filtering and concentrating ambient particles we have a fine PM (PM2.5) line using a cyclone impactor and an ultrafine PM (UFP) line that uses a custom-designed UFP cut-plate (Dr. C. Sioutas, USC) made for our collaborator, Dr. Q-W. Zhang (School of Public Health, Univ. of Louisville). In addition to these two devoted lines to PM, we have 2 HEPA-filtered ambient air lines for air control exposures.
Because our basic premise states that environmental aldehydes contribute to the cardiovascular toxicity of air, water, and food pollutants – and especially as a component of fine and ultrafine PM, we performed dose- and time-dependent acrolein inhalation exposures in mice. We assessed dyslipidemia, endothelial dysfunction, thrombosis and atherosclerosis in these mice.
Similarly, we have collaborated on several different projects that bear upon cardiovascular effects of environmental pollutant exposure. One study was a collaborative effort with Dr. Judy Zelikoff, NYU, to evaluate the effects of prenatal mainstream cigarette smoke exposure on adult lipid profile in mice and the potential synergistic effects of post-natal high fat diet feeding. We also collaborated with Dr. Matthew Campen, formerly of Lovelace Respiratory Research Institute, in a NCER-funded study of atherosclerotic effects of diesel emissions and the specific role of particles. We evaluated both lipids and atherosclerosis in these mice and results of this study are published. With our collaborator, Dr. Russell Prough, Dept. Biochemistry and Mol. Biol. at Univ. of Louisville, we have developed a genetic signature for C57BL/6 mice and the Nrf2-null mice by comparing the effects of the oxidant butylated hydroxyanisole (BHA) exposure with the effects stimulated by acrolein exposure. Additionally we initiated a collaborative human study with C. Arden Pope, Ph.D. (Brigham Young University) to evaluate the effects of PM2.5 Inversions on circulating endothelial progenitor cells (EPCs) and plateletmonocytes by flow cytometry.
We also performed multiple acute PM2.5 exposures in mice and plasma total; high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol along with several other plasmatic components were measured. We also assessed vascular function following PM exposure; the aortic vascular reactivity and biochemical responses to insulin ex vivo were measured. Additionally, the level of circulating EPCs also was measured in these studies.
Conclusions:
With the EPA’s support we now have a fully functional inhalation exposure facility.
Collectively, data from the acrolein inhalation exposure studies indicate that acrolein induces prothrombotic and proatherosclerotic changes in a dose dependent manner and these data are published or being readied for publication (see Sithu et al., 2010).
The collaboration with Dr. Zelikoff, NYU, revealed long-lasting, epigenetic changes in the smoke exposed mice following an acute high fat diet challenge in adult life. These data support the hypothesis that fetal exposures and fetal programming are important contributors to increased cardiovascular disease risk in adults (see Ng et al., EHP 2009).
Results from the study with Dr. Campen support the contention that particles contribute to some, but not all, of the detrimental cardiovascular effects of diesel exposure in mice (see Campen et al., TAPP 2010).
The study with Dr. Prough served as a test-case for the utility of our basic approach, which posited that specific chemical exposure produces a specific biological signature in the cardiovascular system that is discernable from other chemical stimuli because it provokes a select set of adaptive genes that are regulated by specific transcription factors. A small subset of data comparing the effects of BHA and the effects of acrolein exposure on hepatic cytochromes P450 (CYP) gene mRNAs indicates that while there are gene effects that are shared in common between the two exposures, the patterns are also distinct indicating that other transcription factors in addition to Nrf2 regulate CYP gene expression.
In our collaboration with Dr. Pope we sought to examine whether exposure to fine PM2.5 affects the circulating levels of endothelial progenitors cell (EPC) populations, systemic inflammation and coagulation in humans and mice. In humans exposed to episodic increases in PM2.5 along the Wasatch Mountain Front in Utah, statistically significant associations between PM2.5 exposure and the plasma levels of platelet-monocyte aggregates, HDL, and non-albumin protein were observed. Episodic increases in PM2.5 did not change plasma levels of C-reactive protein, IL-1b, IL-6, fibrinogen or serum amyloid A. In addition, Sca-1+/Flk-1+ cells were measured in the peripheral blood of mice exposed to concentrated particles from ambient air in Louisville, Kentucky. In both studies, PM exposure was negatively correlated with circulating EPC levels these observations indicate that episodic exposure to PM2.5 induces reversible vascular injury, reflected in part by depletion of circulating EPC levels, and increases in platelet activation and the plasma level of HDL. These changes were also accompanied by an increase in non-albumin protein and may be related to mechanisms by which exposure to particulate air pollution increases the risk of cardiovascular disease and adverse cardiovascular events (see O'Toole et al., 2010).
Our PM2.5 inhalation exposure studies indicate the following:
PM exposure, independent of diet, significantly increased total and HDL cholesterol but not LDL cholesterol. No other measured factor, including body weight, organ/body weight ratios (heart, liver, lung, spleen), triglycerides, non-esterified fatty acids, albumin, total protein, ALT, AST, creatine kinase, creatinine, and HbA1c, was affected by PM independent of diet. However, HFD-fed mice had significantly higher plasma albumin and total protein levels and lower organ/body weight ratios (heart, liver, lung, spleen) than matched HFD-fed HEPA-exposed controls, indicating that HFD made these mice more susceptible to PM-induced toxicity. An intermittent exposure was performed and these mice had no changes in any lipids, including cholesterol indicating that extended PM exposure not intermittent exposure is likely necessary for PM-induced dyslipidemia. Although PM induced an increase in HDL cholesterol, we do not assume this is necessarily an indication that this is an atheroprotective HDL phenotype. On the contrary, accumulation of nascent HDL will occur as a product of decreased reverse cholesterol clearance, and thus, HDL function will be measured in future PM exposures to ascertain the functional significance of this change.
Journal Articles on this Report : 16 Displayed | Download in RIS Format
| Other project views: | All 25 publications | 18 publications in selected types | All 16 journal articles |
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Barski OA, Tipparaju SM, Bhatnagar A. The aldo-keto reductase superfamily and its role in drug metabolism and detoxification. Drug Metabolism Reviews 2008;40(4):553-624. |
EM833367 (Final) |
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Bhatnagar A. Could dirty air cause diabetes? Circulation 2009; 119(4):492-494. |
EM833367 (Final) |
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Brook RD, Rajagopalan S, Pope III CA, Brook JR, Bhatnagar A, Diez-Roux AV, Holguin F, Hong Y, Luepker RV, Mittleman MA, Peters A, Siscovick D, Smith SC, Whitsel L, Kaufman JD. Particulate matter air pollution and cardiovascular disease: an update to the scientific statement from the American Heart Association. Circulation 2010;121(21):2331-2378. |
EM833367 (Final) R834797 (2016) R834797C001 (Final) |
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Cai J, Bhatnagar A, Pierce Jr WM. Protein modification by acrolein: formation and stability of cysteine adducts. Chemical Research in Toxicology 2009;22(4):708-716. |
EM833367 (Final) |
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Campen MJ, Lund AK, Knuckles TL, Conklin DJ, Bishop B, Young D, Sielkop SK, Seagrave JC, Reed MD, McDonald JD. Inhaled diesel emissions alter atherosclerotic plaque composition in ApoE-/- mice. Toxicology and Applied Pharmacology 2010;242(3):310-317. |
EM833367 (2009) EM833367 (Final) |
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Conklin DJ, Haberzettl P, Prough RA, Bhatnagar A. Glutathione S-transferase P protects against endothelial dysfunction induced by exposure to tobacco smoke. American Journal of Physiology Heart and Circulatory Physiology 2009;296(5):H1586-H1597. |
EM833367 (2008) EM833367 (2009) EM833367 (Final) |
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Conklin DJ, Haberzettl P, Lesgards J-F, Prough RA, Srivastava S, Bhatnagar A. Increased sensitivity of glutathione-S-transferase P-null mice to cyclophosphamide-induced urinary bladder toxicity. Journal of Pharmacology and Experimental Therapeutics 2009;331(2):456-469. |
EM833367 (Final) |
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Conklin DJ, Barski OA, Lesgards JF, Juvan P, Rezen T, Rozman D, Prough RA, Vladykovskaya E, Liu S, Srivastava S, Bhatnagar A. Acrolein consumption induces systemic dyslipidemia and lipoprotein modification. Toxicology and Applied Pharmacology 2010;243(1):1-12. |
EM833367 (2008) EM833367 (Final) |
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Haberzettl P, Vladykovskaya E, Srivastava S, Bhatnagar A. Role of endoplasmic reticulum stress in acrolein-induced endothelial activation. Toxicology and Applied Pharmacology 2009;234(1):14-24. |
EM833367 (2008) EM833367 (2009) EM833367 (Final) |
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Hill BG, Bhatnagar A. Beyond reactive oxygen species: aldehydes as arbitrators of alarm and adaptation. Circulation Research 2009;105(11):1044-1046. |
EM833367 (Final) |
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Joshi-Barve S, Amancherla K, Patil M, Bhatnagar A, Mathews S, Gobejishvili L, Cave M, McClain C, Barve S. Acrolein, a ubiquitous pollutant and lipid hydroperoxide product, inhibits antiviral activity of interferon-alpha: relevance to hepatitis C. Free Radical Biology and Medicine 2009;47(1):47-54. |
EM833367 (Final) |
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Ng SP, Conklin DJ, Bhatnagar A, Bolanowski DD, Lyon J, Zelikoff JT. Prenatal exposure to cigarette smoke induces diet- and sex-dependent dyslipidemia and weight gain in adult murine offspring. Environmental Health Perspectives 2009;117(7):1042-1048. |
EM833367 (2009) EM833367 (Final) |
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O'Toole TE, Zheng YT, Hellmann J, Conklin DJ, Barski O, Bhatnagar A. Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages. Toxicology and Applied Pharmacology 2009;236(2):194-201. |
EM833367 (2008) EM833367 (2009) EM833367 (Final) |
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O’Toole TE, Conklin DJ, Bhatnagar A. Environmental risk factors for heart disease. Reviews on Environmental Health 2008;23(3):167-202. |
EM833367 (2009) EM833367 (Final) R834514 (2011) R834514 (Final) |
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O’Toole TE, Hellman J, Wheat L, Haberzettl P, Lee J, Conklin DJ, Bhatnagar A, Pope III CA. Episodic exposure to fine particulate air pollution decreases circulating levels of endothelial progenitor cells. Circulation Research 2010;107(2):200-203. |
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Sithu SD, Srivastava S, Siddiqui MA, Vladykovskaya E, Riggs DW, Conklin DJ, Haberzettl P, O’Toole TE, Bhatnagar A, D’Souza SE. Exposure to acrolein by inhalation causes platelet activation. Toxicology and Applied Pharmacology 2010;248(2):100-110. |
EM833367 (Final) |
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Supplemental Keywords:
acrolein, aldehydes, antioxidant response, endothelial progenitor cells (EPCs), endothelial dysfunction, fine PM (PM2.5), insulin resistance, metals, thrombosis, ultrafine PM (UFP)Relevant Websites:
N/AProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.