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Electrostatic field may regulate proliferation and immune responses of macrophages induced by polyethylene wear particles. J Taiwan Inst Chem Eng 2017. [DOI: 10.1016/j.jtice.2017.04.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Deering-Rice CE, Stockmann C, Romero EG, Lu Z, Shapiro D, Stone BL, Fassl B, Nkoy F, Uchida DA, Ward RM, Veranth JM, Reilly CA. Characterization of Transient Receptor Potential Vanilloid-1 (TRPV1) Variant Activation by Coal Fly Ash Particles and Associations with Altered Transient Receptor Potential Ankyrin-1 (TRPA1) Expression and Asthma. J Biol Chem 2016; 291:24866-24879. [PMID: 27758864 DOI: 10.1074/jbc.m116.746156] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/29/2016] [Indexed: 01/22/2023] Open
Abstract
Transient receptor potential (TRP) channels are activated by environmental particulate materials. We hypothesized that polymorphic variants of transient receptor potential vanilloid-1 (TRPV1) would be uniquely responsive to insoluble coal fly ash compared with the prototypical soluble agonist capsaicin. Furthermore, these changes would manifest as differences in lung cell responses to these agonists and perhaps correlate with changes in asthma symptom control. The TRPV1-I315M and -T469I variants were more responsive to capsaicin and coal fly ash. The I585V variant was less responsive to coal fly ash particles due to reduced translation of protein and an apparent role for Ile-585 in activation by particles. In HEK-293 cells, I585V had an inhibitory effect on wild-type TRPV1 expression, activation, and internalization/agonist-induced desensitization. In normal human bronchial epithelial cells, IL-8 secretion in response to coal fly ash treatment was reduced for cells heterozygous for TRPV1-I585V. Finally, both the I315M and I585V variants were associated with worse asthma symptom control with the effects of I315M manifesting in mild asthma and those of the I585V variant manifesting in severe, steroid-insensitive individuals. This effect may be due in part to increased transient receptor potential ankyrin-1 (TRPA1) expression by lung epithelial cells expressing the TRPV1-I585V variant. These findings suggest that specific molecular interactions control TRPV1 activation by particles, differential activation, and desensitization of TRPV1 by particles and/or other agonists, and cellular changes in the expression of TRPA1 as a result of I585V expression could contribute to variations in asthma symptom control.
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Affiliation(s)
- Cassandra E Deering-Rice
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
| | - Chris Stockmann
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
| | - Erin G Romero
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
| | - Zhenyu Lu
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
| | - Darien Shapiro
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
| | - Bryan L Stone
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84108
| | - Bernhard Fassl
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84108
| | - Flory Nkoy
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84108
| | - Derek A Uchida
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84108
| | - Robert M Ward
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84108
| | - John M Veranth
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
| | - Christopher A Reilly
- From the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112 and
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Deering-Rice CE, Shapiro D, Romero EG, Stockmann C, Bevans TS, Phan QM, Stone BL, Fassl B, Nkoy F, Uchida DA, Ward RM, Veranth JM, Reilly CA. Activation of Transient Receptor Potential Ankyrin-1 by Insoluble Particulate Material and Association with Asthma. Am J Respir Cell Mol Biol 2016; 53:893-901. [PMID: 26039217 DOI: 10.1165/rcmb.2015-0086oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Inhaled irritants activate transient receptor potential ankyrin-1 (TRPA1), resulting in cough, bronchoconstriction, and inflammation/edema. TRPA1 is also implicated in the pathogenesis of asthma. Our hypothesis was that particulate materials activate TRPA1 via a mechanism distinct from chemical agonists and that, in a cohort of children with asthma living in a location prone to high levels of air pollution, expression of uniquely sensitive forms of TRPA1 may correlate with reduced asthma control. Variant forms of TRPA1 were constructed by mutating residues in known functional elements and corresponding to single-nucleotide polymorphisms in functional domains. TRPA1 activity was studied in transfected HEK-293 cells using allyl-isothiocynate, a model soluble electrophilic agonist; 3,5-ditert butylphenol, a soluble nonelectrophilic agonist and a component of diesel exhaust particles; and insoluble coal fly ash (CFA) particles. The N-terminal variants R3C and R58T exhibited greater, but not additive, activity with all three agonists. The ankyrin repeat domain-4 single nucleotide polymorphisms E179K and K186N exhibited decreased response to CFA. The predicted N-linked glycosylation site residues N747A and N753A exhibited decreased responses to CFA, which were not attributable to differences in cellular localization. The pore-loop residue R919Q was comparable to wild-type, whereas N954T was inactive to soluble agonists but not CFA. These data identify roles for ankyrin domain-4, cell surface N-linked glycans, and selected pore-loop domain residues in the activation of TRPA1 by insoluble particles. Furthermore, the R3C and R58T polymorphisms correlated with reduced asthma control for some children, which suggest that TRPA1 activity may modulate asthma, particularly among individuals living in locations prone to high levels of air pollution.
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Affiliation(s)
| | - Darien Shapiro
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
| | - Erin G Romero
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
| | - Chris Stockmann
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and.,2 Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Tatjana S Bevans
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
| | - Quang M Phan
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
| | - Bryan L Stone
- 2 Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Bernhard Fassl
- 2 Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Flory Nkoy
- 2 Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Derek A Uchida
- 2 Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Robert M Ward
- 2 Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - John M Veranth
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
| | - Christopher A Reilly
- 1 Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
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Interaction of SiO2 nanoparticles with neuronal cells: Ionic mechanisms involved in the perturbation of calcium homeostasis. Int J Biochem Cell Biol 2015. [DOI: 10.1016/j.biocel.2015.07.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Thach CT, Finkelstein JN. Cationic nanoparticles disrupt cellular signaling in a cholesterol dependent manner. Toxicol In Vitro 2013; 27:1277-86. [PMID: 23274767 DOI: 10.1016/j.tiv.2012.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/17/2012] [Accepted: 12/18/2012] [Indexed: 01/08/2023]
Abstract
In this study, we investigate the interaction of charged polystyrene particles with respiratory epithelial cells. Experiments were designed to reveal the effect of cellular interaction with particles of varying size and charge and how such interactions could alter cytokine induced cellular processes. A549 cells, containing a stably transfected Interleukin-8 (IL-8) Luciferase promoter construct, were cultured in the presence of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) and polystyrene particles for 4.5h. Several endpoints were measured: IL-8 gene expression, IL-6 protein, IL-8 protein, and NF-кB translocation. At 4.5h, cellular viability was maintained for the particle exposed cells. Interestingly, we found that only the cationic nanoparticles have the ability to disrupt the TNF-α stimulated cellular signaling by reducing the IL-8 promoter activity, IL-6 and IL-8 protein. Cationic nanoparticles reduce these processes through interfering with NF-κB translocation. However, the activity of the cationic nanoparticles on the IL-8 promoter and NF-κB translocation is lost when cholesterol is depleted from A549 cells before particle exposure, which suggests that cationic nanoparticles rely on membrane cholesterol integrity to disrupt cellular signaling.
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Affiliation(s)
- Chia T Thach
- University of Rochester, NY 14642, United States
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Deering-Rice CE, Johansen ME, Roberts JK, Thomas KC, Romero EG, Lee J, Yost GS, Veranth JM, Reilly CA. Transient receptor potential vanilloid-1 (TRPV1) is a mediator of lung toxicity for coal fly ash particulate material. Mol Pharmacol 2011; 81:411-9. [PMID: 22155782 DOI: 10.1124/mol.111.076067] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Environmental particulate matter (PM) pollutants adversely affect human health, but the molecular basis is poorly understood. The ion channel transient receptor potential vanilloid-1 (TRPV1) has been implicated as a sensor for environmental PM and a mediator of adverse events in the respiratory tract. The objectives of this study were to determine whether TRPV1 can distinguish chemically and physically unique PM that represents important sources of air pollution; to elucidate the molecular basis of TRPV1 activation by PM; and to ascertain the contributions of TRPV1 to human lung cell and mouse lung tissue responses exposed to an insoluble PM agonist, coal fly ash (CFA1). The major findings of this study are that TRPV1 is activated by some, but not all of the prototype PM materials evaluated, with rank-ordered responses of CFA1 > diesel exhaust PM > crystalline silica; TRP melastatin-8 is also robustly activated by CFA1, whereas other TRP channels expressed by airway sensory neurons and lung epithelial cells that may also be activated by CFA1, including TRPs ankyrin 1 (A1), canonical 4α (C4α), M2, V2, V3, and V4, were either slightly (TRPA1) or not activated by CFA1; activation of TRPV1 by CFA1 occurs via cell surface interactions between the solid components of CFA1 and specific amino acid residues of TRPV1 that are localized in the putative pore-loop region; and activation of TRPV1 by CFA1 is not exclusive in mouse lungs but represents a pathway by which CFA1 affects the expression of selected genes in lung epithelial cells and airway tissue.
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Miyata R, van Eeden SF. The innate and adaptive immune response induced by alveolar macrophages exposed to ambient particulate matter. Toxicol Appl Pharmacol 2011; 257:209-26. [PMID: 21951342 DOI: 10.1016/j.taap.2011.09.007] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 08/09/2011] [Accepted: 09/08/2011] [Indexed: 12/16/2022]
Abstract
Emerging epidemiological evidence suggests that exposure to particulate matter (PM) air pollution increases the risk of cardiovascular events but the exact mechanism by which PM has adverse effects is still unclear. Alveolar macrophages (AM) play a major role in clearing and processing inhaled PM. This comprehensive review of research findings on immunological interactions between AM and PM provides potential pathophysiological pathways that interconnect PM exposure with adverse cardiovascular effects. Coarse particles (10 μm or less, PM(10)) induce innate immune responses via endotoxin-toll-like receptor (TLR) 4 pathway while fine (2.5 μm or less, PM(2.5)) and ultrafine particles (0.1 μm or less, UFP) induce via reactive oxygen species generation by transition metals and/or polyaromatic hydrocarbons. The innate immune responses are characterized by activation of transcription factors [nuclear factor (NF)-κB and activator protein-1] and the downstream proinflammatory cytokine [interleukin (IL)-1β, IL-6, and tumor necrosis factor-α] production. In addition to the conventional opsonin-dependent phagocytosis by AM, PM can also be endocytosed by an opsonin-independent pathway via scavenger receptors. Activation of scavenger receptors negatively regulates the TLR4-NF-κB pathway. Internalized particles are subsequently subjected to adaptive immunity involving major histocompatibility complex class II (MHC II) expression, recruitment of costimulatory molecules, and the modulation of the T helper (Th) responses. AM show atypical antigen presenting cell maturation in which phagocytic activity decreases while both MHC II and costimulatory molecules remain unaltered. PM drives AM towards a Th1 profile but secondary responses in a Th1- or Th-2 up-regulated milieu drive the response in favor of a Th2 profile.
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Affiliation(s)
- Ryohei Miyata
- The James Hogg iCAPTURE Centre, University of British Columbia, St. Paul's Hospital, 1081 Burrard Street, Vancouver, BC, Canada
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Deering-Rice CE, Romero EG, Shapiro D, Hughen RW, Light AR, Yost GS, Veranth JM, Reilly CA. Electrophilic components of diesel exhaust particles (DEP) activate transient receptor potential ankyrin-1 (TRPA1): a probable mechanism of acute pulmonary toxicity for DEP. Chem Res Toxicol 2011; 24:950-9. [PMID: 21591660 DOI: 10.1021/tx200123z] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Inhalation of environmental particulate matter (PM) is correlated with adverse health effects in humans, but gene products that couple detection with cellular responses, and the specific properties of PM that target different pathways, have not been fully elucidated. TRPA1 and V1 are two cation channels expressed by sensory neurons and non-neuronal cells of the respiratory tract that have been implicated as possible mediators of PM toxicity. The goals of this research were to determine if environmental PM preferentially activated TRPA1 and to elucidate the criteria responsible for selectivity. Quantification of TRPA1 activation by 4 model PM revealed that diesel exhaust PM (DEP) and coal fly ash PM (CFA1) were TRPA1 agonists at concentrations >0.077 mg/mL. DEP was more potent, and approximately 97% of the activity of DEP was recovered by serial extraction of the solid DEP with ethanol and hexane/n-butyl chloride. Modification of the electrophile/agonist binding sites on TRPA1 (C621, C641, C665, and K710) to non-nucleophilic residues reduced TRPA1 activation by DEP and abolished activation by DEP extracts as well as multiple individual electrophilic chemical components of DEP. However, responses to CFA1 and DEP solids were not affected by these mutations. Activity-guided fractionation of DEP and high resolution mass spectroscopy identified several new DEP-derived TRPA1 agonists, and activation of mouse dorsal root ganglion neurons demonstrated that TRPA1 is a primary target for DEP in a heterogeneous population of primary sensory nerves. It is concluded that TRPA1 is a specific target for electrophilic chemical components of DEP and proposed that activation of TRPA1 in the respiratory tract is likely to be an important mechanism for DEP pneumotoxicity.
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Affiliation(s)
- Cassandra E Deering-Rice
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, Utah 84112, United States
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Block ML, Calderón-Garcidueñas L. Air pollution: mechanisms of neuroinflammation and CNS disease. Trends Neurosci 2009; 32:506-16. [PMID: 19716187 PMCID: PMC2743793 DOI: 10.1016/j.tins.2009.05.009] [Citation(s) in RCA: 924] [Impact Index Per Article: 61.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 05/28/2009] [Accepted: 05/29/2009] [Indexed: 12/21/2022]
Abstract
Air pollution has been implicated as a chronic source of neuroinflammation and reactive oxygen species (ROS) that produce neuropathology and central nervous system (CNS) disease. Stroke incidence and Alzheimer's and Parkinson's disease pathology are linked to air pollution. Recent reports reveal that air pollution components reach the brain; systemic effects that impact lung and cardiovascular disease also impinge upon CNS health. While mechanisms driving air pollution-induced CNS pathology are poorly understood, new evidence suggests that microglial activation and changes in the blood-brain barrier are key components. Here we summarize recent findings detailing the mechanisms through which air pollution reaches the brain and activates the resident innate immune response to become a chronic source of pro-inflammatory factors and ROS, culminating in CNS disease.
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Affiliation(s)
- Michelle L Block
- Department of Anatomy and Neurobiology, Virginia Commonwealth University Medical Campus, Richmond, VA 23298, USA.
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Watterson TL, Hamilton B, Martin R, Coulombe RA. Urban particulate matter causes ER stress and the unfolded protein response in human lung cells. Toxicol Sci 2009; 112:111-22. [PMID: 19675143 DOI: 10.1093/toxsci/kfp186] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Because of its presumed adverse health effects, particulate air pollution (PM) has received growing attention, but the cellular mechanisms by which PM exerts toxicity are not well elucidated. PM has been associated with early mortality from illnesses that share endoplasmic reticulum (ER) stress as a mechanism of pathogenesis. In this study, we examined whether PM would induce the unfolded protein response (UPR) which is a cellular response to ER stress. Coarse (PM(10)) and fine (PM(2.5)) PM was collected from a single location in Northern Utah's Cache Valley during atmospheric inversions occurring in January 2002 and January 2003. Extracts of PM samples were added (12.5 and 25 microg/ml) to cultured human bronchial epithelial (BEAS-2B) cells for 24 h. At these concentrations neither PM nor LPS exhibited demonstrable cytotoxicity by the neutral red assay. However, PM elicited significant increases of unfolded protein response (UPR)-related post-translational modifications, such as S6 ribosomal protein, heat-shock protein (Hsp)27, and protein kinase related protein phosphorylation and cleavage of activating transcription factor (ATF)-6. PM exposure also resulted in significant increases in the UPR-associated proteins ATF-4, Hsp70, Hsp90, and binding immunoglobulin protein. PM also interfered with the export of Hsp70 from the cells in a concentration-dependent manner and resulted in release of C-reactive protein. Calpain was upregulated and activated in PM-treated cultures, though these events were not proapoptotic. This study demonstrates that PM is capable of inducing ER stress and the UPR in vitro and may be a mechanism by which PM exerts toxicity.
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Affiliation(s)
- Todd L Watterson
- Graduate Program in Toxicology, and Department of Veterinary Sciences, Utah State University, Logan, Utah 84322-4620
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Singh S, Taneja B, Salvi SS, Agrawal A. Physical properties of intact proteins may predict allergenicity or lack thereof. PLoS One 2009; 4:e6273. [PMID: 19609445 PMCID: PMC2707619 DOI: 10.1371/journal.pone.0006273] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 05/27/2009] [Indexed: 01/15/2023] Open
Abstract
Background Predicting the allergenicity of proteins is challenging. We considered the possibility that the properties of the intact protein that may alter the likelihood of being taken up by antigen presenting cells, may be useful adjuncts in predicting allergens and non-allergens in silico. It has been shown that negatively charged acidic proteins are preferentially processed by dendritic cells. Methodology Datasets (aeroallergen, food-allergen and non-allergen) for in-silico study were obtained from public databases. Isoelectric point (pI), net charge, and electrostatic potential (EP) were calculated from the protein sequence (for pI and net charge) or predicted structure (for EP). Result Allergens and non allergens differed significantly in pI, net charge, and EP (p<0.0001). Cluster analysis based on these parameters resulted in well defined clusters. Non-allergens were characterized by neutral to basic pI (mean±SE, 7.6±0.16) and positive charge. In contrast allergens were acidic (5.7±0.15) and negatively charged. Surface electrostatic potentials calculated from predicted structures were mostly negative for allergens and mostly positive for non-allergens. The classification accuracy for non-allergens was superior to that for allergens. Thus neutral to basic pI, positive charge, and positive electrostatic potentials characterize non-allergens, and seem rare in allergens (p<0.0001). It may be possible to predict reduced likelihood of allergenicity in such proteins, but this needs to be prospectively validated.
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Affiliation(s)
- Suchita Singh
- Institute of Genomics & Integrative Biology, Delhi, India
| | - Bhupesh Taneja
- Institute of Genomics & Integrative Biology, Delhi, India
| | | | - Anurag Agrawal
- Institute of Genomics & Integrative Biology, Delhi, India
- * E-mail:
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Veronesi B, Tajuba J, Saleh N, Veronesi B, Tajuba J, Saleh N, Ward W, Hester S, Carter J, Lowry GV. Functionally charged polystyrene particles activate immortalized mouse microglia (BV2): cellular and genomic response. Nanotoxicology 2009. [DOI: 10.1080/17435390802296347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Repine JE, Reiss OK, Elkins N, Chughtai AR, Smith DM. Effects of fine carbonaceous particles containing high and low unpaired electron spin densities on lungs of female mice. Transl Res 2008; 152:185-93. [PMID: 18940721 DOI: 10.1016/j.trsl.2008.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 08/11/2008] [Accepted: 08/19/2008] [Indexed: 10/21/2022]
Abstract
The negative impacts on human health that accompany inhalation of atmospheric particles are documented in numerous epidemiologic studies, but the effect of specific chemical properties of the particles is generally unknown. We developed and employed technology for generating inhalable aerosols of carbonaceous air pollution particles that have specific physical and chemical properties. We find that inhaling particles with greater unpaired electron spin (free radical) densities stimulates greater lung inflammatory and oxidative stress responses. Cultured alveolar macrophages take up more particles of greater free radical content, develop mitochondrial abnormalities, and release more leukotriene B(4) (LTB(4)) than alveolar macrophages exposed to lesser free-radical-containing particles in vitro. Mice exposed to high free radical particles in vivo also develop mitochondrial abnormalities in alveolar macrophages and increased oxidative stress, which is reflected by increases in lung nitrotyrosine staining and lung lavage nitrogen oxide levels compared with those of lesser free radical density. These results provide insight for the unexplained geographic differences and have implications for fossil fuel combustion conditions and the impact of fine particles on health and disease.
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Affiliation(s)
- John E Repine
- Webb-Waring Institute for Cancer, Aging, and Antioxidant Research, University of Colorado Denver Health Sciences Center, Denver, CO 80262, USA.
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Ghelfi E, Rhoden CR, Wellenius GA, Lawrence J, Gonzalez-Flecha B. Cardiac Oxidative Stress and Electrophysiological Changes in Rats Exposed to Concentrated Ambient Particles are Mediated by TRP-Dependent Pulmonary Reflexes. Toxicol Sci 2008; 102:328-36. [DOI: 10.1093/toxsci/kfn005] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Veranth JM, Kaser EG, Veranth MM, Koch M, Yost GS. Cytokine responses of human lung cells (BEAS-2B) treated with micron-sized and nanoparticles of metal oxides compared to soil dusts. Part Fibre Toxicol 2007. [PMID: 17326846 DOI: 10.1186/1743‐8977‐4‐2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of Al2O3, CeO2, Fe2O3, NiO, SiO2, and TiO2, with soil-derived particles from fugitive dust sources, and with the positive controls LPS, TNF-alpha, and VOSO4. RESULTS The nano-sized particles were not consistently more potent than an equal mass of micron-sized particles of the same nominal composition for the induction of IL-6 and IL-8 secretion in the in vitro models used in this study. The manufactured pure oxides were much less potent than natural PM2.5 particles derived from soil dust, and the cells were highly responsive to the positive controls. The nano-sized particles in the media caused artifacts in the measurement of IL-6 by ELISA due to adsorption of the cytokine on the high-surface-area particles. The potency for inducing IL-6 secretion by BEAS-2B cells did not correlate with the generation of reactive oxygen species in cell-free media. CONCLUSION Direct comparisons of manufactured metal oxide nanoparticles and previously studied types of particles and surrogate proinflammatory agonists showed that the metal oxide particles have low potency to induce IL-6 secretion in BEAS-2B cells. Particle artifacts from non-biological effects need to be considered in experiments of this type, and the limitations inherent in cell culture studies must be considered when interpreting in vitro results. This study suggests that manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles.
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Affiliation(s)
- John M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA.
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Veranth JM, Kaser EG, Veranth MM, Koch M, Yost GS. Cytokine responses of human lung cells (BEAS-2B) treated with micron-sized and nanoparticles of metal oxides compared to soil dusts. Part Fibre Toxicol 2007; 4:2. [PMID: 17326846 PMCID: PMC1821039 DOI: 10.1186/1743-8977-4-2] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 02/27/2007] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of Al2O3, CeO2, Fe2O3, NiO, SiO2, and TiO2, with soil-derived particles from fugitive dust sources, and with the positive controls LPS, TNF-alpha, and VOSO4. RESULTS The nano-sized particles were not consistently more potent than an equal mass of micron-sized particles of the same nominal composition for the induction of IL-6 and IL-8 secretion in the in vitro models used in this study. The manufactured pure oxides were much less potent than natural PM2.5 particles derived from soil dust, and the cells were highly responsive to the positive controls. The nano-sized particles in the media caused artifacts in the measurement of IL-6 by ELISA due to adsorption of the cytokine on the high-surface-area particles. The potency for inducing IL-6 secretion by BEAS-2B cells did not correlate with the generation of reactive oxygen species in cell-free media. CONCLUSION Direct comparisons of manufactured metal oxide nanoparticles and previously studied types of particles and surrogate proinflammatory agonists showed that the metal oxide particles have low potency to induce IL-6 secretion in BEAS-2B cells. Particle artifacts from non-biological effects need to be considered in experiments of this type, and the limitations inherent in cell culture studies must be considered when interpreting in vitro results. This study suggests that manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles.
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Affiliation(s)
- John M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Erin G Kaser
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Martha M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Michael Koch
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Garold S Yost
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
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Huang JK, Cheng HH, Huang CJ, Kuo CC, Chen WC, Liu SI, Hsu SS, Chang HT, Lu YC, Tseng LL, Chiang AJ, Chou CT, Jan CR. Effect of capsazepine on cytosolic Ca2+ levels and proliferation of human prostate cancer cells. Toxicol In Vitro 2006; 20:567-74. [PMID: 16271848 DOI: 10.1016/j.tiv.2005.09.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 09/02/2005] [Accepted: 09/26/2005] [Indexed: 11/18/2022]
Abstract
Capsazepine has been widely used as a selective antagonist of vanilloid type 1 receptors; however, its other in vitro effect on most cell types is unknown. In human PC3 prostate cancer cells, the effect of capsazepine on intracellular Ca(2+) concentrations ([Ca(2+)](i)) and cytotoxicity was investigated by using fura-2 and tetrazolium, respectively. Capsazepine caused a rapid rise in [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 75 microM. Capsazepine-induced [Ca(2+)](i) rise was reduced by 60% by removal of extracellular Ca(2+), suggesting that the capsazepine-induced [Ca(2+)](i) rise was contributed by extracellular Ca(2+) influx and intracellular Ca(2+). Consistently, the capsazepine (200 microM)-induced [Ca(2+)](i) rise was decreased by La(3+) by half. In Ca(2+)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2+)-ATPase, caused a monophasic [Ca(2+)](i) rise, after which the effect of capsazepine on [Ca(2+)](i) was inhibited by 80%. Conversely, pretreatment with capsazepine partly reduced thapsigargin-induced [Ca(2+)](i) rise. U73122, an inhibitor of phospholipase C, abolished histamine (an inositol 1,4,5-trisphosphate-dependent Ca(2+) mobilizer)-induced, but not capsazepine-induced, [Ca(2+)](i) rise. These findings suggest that in human PC3 prostate cancer cells, capsazepine increases [Ca(2+)](i) by evoking Ca(2+) influx and releasing Ca(2+) from the endoplasmic reticulum via a phospholiase C-independent manner. Overnight incubation with capsazepine (200 microM) killed 37% of cells, which could not be prevented by chelating intracellular Ca(2+) with BAPTA.
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Affiliation(s)
- Jong-Khing Huang
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
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19
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Veranth JM, Moss TA, Chow JC, Labban R, Nichols WK, Walton JC, Watson JG, Yost GS. Correlation of in vitro cytokine responses with the chemical composition of soil-derived particulate matter. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:341-9. [PMID: 16507455 PMCID: PMC1392226 DOI: 10.1289/ehp.8360] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We treated human lung epithelial cells, type BEAS-2B, with 10-80 microg/cm2 of dust from soils and road surfaces in the western United States that contained particulate matter (PM) < 2.5 microm aerodynamic diameter. Cell viability and cytokine secretion responses were measured at 24 hr. Each dust sample is a complex mixture containing particles from different minerals mixed with biogenic and anthropogenic materials. We determined the particle chemical composition using methods based on the U.S. Environmental Protection Agency Speciation Trends Network (STN) and the National Park Service Interagency Monitoring of Protected Visual Environments (IMPROVE) network. The functionally defined carbon fractions reported by the ambient monitoring networks have not been widely used for toxicology studies. The soil-derived PM2.5 from different sites showed a wide range of potency for inducing the release of the proinflammatory cytokines interleukin-6 (IL-6) and IL-8 in vitro. Univariate regression and multivariate redundancy analysis were used to test for correlation of viability and cytokine release with the concentrations of 40 elements, 7 ions, and 8 carbon fractions. The particles showed positive correlation between IL-6 release and the elemental and pyrolyzable carbon fractions, and the strongest correlation involving crustal elements was between IL-6 release and the aluminum:silicon ratio. The observed correlations between low-volatility organic components of soil- and road-derived dusts and the cytokine release by BEAS-2B cells are relevant for investigation of mechanisms linking specific air pollution particle types with the initiating events leading to airway inflammation in sensitive populations.
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Affiliation(s)
- John M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112-5820, USA.
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20
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Block ML, Hong JS. Microglia and inflammation-mediated neurodegeneration: multiple triggers with a common mechanism. Prog Neurobiol 2005; 76:77-98. [PMID: 16081203 DOI: 10.1016/j.pneurobio.2005.06.004] [Citation(s) in RCA: 1137] [Impact Index Per Article: 59.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 06/21/2005] [Accepted: 06/28/2005] [Indexed: 12/21/2022]
Abstract
Inflammation, a common denominator among the diverse list of neurodegenerative diseases, has recently been implicated as a critical mechanism responsible for the progressive nature of neurodegeneration. Microglia are the resident innate immune cells in the central nervous system and produce a barrage of factors (IL-1, TNFalpha, NO, PGE2, superoxide) that are toxic to neurons. Evidence supports that the unregulated activation of microglia in response to environmental toxins, endogenous proteins, and neuronal death results in the production of toxic factors that propagate neuronal injury. In the following review, we discuss the common thread of microglial activation across numerous neurodegenerative diseases, define current perceptions of how microglia are damaging neurons, and explain how the microglial response to neuronal damage results in a self-propelling cycle of neuron death.
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Affiliation(s)
- Michelle L Block
- Neuropharmacology Section, MD F1-01, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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21
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Reilly CA, Johansen ME, Lanza DL, Lee J, Lim JO, Yost GS. Calcium-dependent and independent mechanisms of capsaicin receptor (TRPV1)-mediated cytokine production and cell death in human bronchial epithelial cells. J Biochem Mol Toxicol 2005; 19:266-75. [PMID: 16173059 PMCID: PMC2291358 DOI: 10.1002/jbt.20084] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Activation of the capsaicin receptor (VR1 or TRPV1) in bronchial epithelial cells by capsaicinoids and other vanilloids promotes pro-inflammatory cytokine production and cell death. The purpose of this study was to investigate the role of TRPV1-mediated calcium flux from extracellular sources as an initiator of these responses and to define additional cellular pathways that control cell death. TRPV1 antagonists and reduction of calcium concentrations in treatment solutions attenuated calcium flux, induction of interleukin-6 and 8 gene expression, and IL-6 secretion by cells treated with capsaicin or resiniferatoxin. Most TRPV1 antagonists also attenuated cell death, but the relative potency and extent of protection did not directly correlate with inhibition of total calcium flux. Treatment solutions with reduced calcium content or chelators had no effect on cytotoxicity. Inhibitors of arachidonic acid metabolism and cyclo-oxygenases also prevented cell death indicating that TRPV1 agonists disrupted basal arachidonic acid metabolism and altered cyclo-oxygenase function via a TRPV1-dependent mechanism in order to produce toxicity. These data confirm previous results demonstrating calcium flux through TRPV1 acts as a trigger for cytokine production by vanilloids, and provides new mechanistic insights on mechanisms of cell death produced by TRPV1 agonists in respiratory epithelial cells.
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Affiliation(s)
- Christopher A. Reilly
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
| | - Mark E. Johansen
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
| | - Diane L. Lanza
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
| | - Jeewoo Lee
- College of Pharmacy, Seoul National University, Shinlim-Dong, Kwanak-Ku, Seoul 151-742, Korea
| | - Ju-Ok Lim
- College of Pharmacy, Seoul National University, Shinlim-Dong, Kwanak-Ku, Seoul 151-742, Korea
| | - Garold S. Yost
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
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22
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Teng HP, Huang CJ, Yeh JH, Hsu SS, Lo YK, Cheng JS, Cheng HH, Chen JS, Jiann BP, Chang HT, Huang JK, Jan CR. Capsazepine elevates intracellular Ca2+ in human osteosarcoma cells, questioning its selectivity as a vanilloid receptor antagonist. Life Sci 2004; 75:2515-26. [PMID: 15363657 DOI: 10.1016/j.lfs.2004.04.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Accepted: 04/21/2004] [Indexed: 11/30/2022]
Abstract
Capsazepine is thought to be a selective antagonist of vanilloid type 1 receptors; however, its other in vitro effect on different cell types is unclear. In human MG63 osteosarcoma cells, the effect of capsazepine on intracellular Ca(2+) concentrations ([Ca(2+)](i)) and cytotoxicity was explored by using fura-2 and tetrazolium, respectively. Capsazepine caused a rapid rise in [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 100 microM. Capsazepine-induced [Ca(2+)](i) rise was partly reduced by removal of extracellular Ca(2+), suggesting that the capsazepine-induced [Ca(2+)](i) rise was composed of extracellular Ca(2+) influx and intracellular Ca(2+). In Ca(2+)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2+)-ATPase, caused a monophasic [Ca(2+)](i) rise, after which the increasing effect of capsazepine on [Ca(2+)](i) was inhibited by 75%. Conversely, pretreatment with capsazepine to deplete intracellular Ca(2+) stores totally prevented thapsigargin from releasing more Ca(2+). U73122, an inhibitor of phospholipase C, abolished histamine (an inositol 1,4,5-trisphosphate-dependent Ca(2+) mobilizer)-induced, but not capsazepine-induced, [Ca(2+)](i) rise. Overnight treatment with 1-100 microM capsazepine inhibited cell proliferation in a concentration-dependent manner. These findings suggest that in human MG63 osteosarcoma cells, capsazepine increases [Ca(2+)](i) by stimulating extracellular Ca(2+) influx and also by causing intracellular Ca(2+) release from the endoplasmic reticulum via a phospholiase C-independent manner. Capsazepine may be mildly cytotoxic.
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Affiliation(s)
- Hsiu-Peng Teng
- Department of Orthopaedic Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
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23
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Block ML, Wu X, Pei Z, Li G, Wang T, Qin L, Wilson B, Yang J, Hong JS, Veronesi B. Nanometer size diesel exhaust particles are selectively toxic to dopaminergic neurons: the role of microglia, phagocytosis, and NADPH oxidase. FASEB J 2004; 18:1618-20. [PMID: 15319363 DOI: 10.1096/fj.04-1945fje] [Citation(s) in RCA: 264] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The contributing role of environmental factors to the development of Parkinson's disease has become increasingly evident. We report that mesencephalic neuron-glia cultures treated with diesel exhaust particles (DEP; 0.22 microM) (5-50 microg/ml) resulted in a dose-dependent decrease in dopaminergic (DA) neurons, as determined by DA-uptake assay and tyrosine-hydroxylase immunocytochemistry (ICC). The selective toxicity of DEP for DA neurons was demonstrated by the lack of DEP effect on both GABA uptake and Neu-N immunoreactive cell number. The critical role of microglia was demonstrated by the failure of neuron-enriched cultures to exhibit DEP-induced DA neurotoxicity, where DEP-induced DA neuron death was reinstated with the addition of microglia to neuron-enriched cultures. OX-42 ICC staining of DEP treated neuron-glia cultures revealed changes in microglia morphology indicative of activation. Intracellular reactive oxygen species and superoxide were produced from enriched-microglia cultures in response to DEP. Neuron-glia cultures from NADPH oxidase deficient (PHOX-/-) mice were insensitive to DEP neurotoxicity when compared with control mice (PHOX+/+). Cytochalasin D inhibited DEP-induced superoxide production in enriched-microglia cultures, implying that DEP must be phagocytized by microglia to produce superoxide. Together, these in vitro data indicate that DEP selectively damages DA neurons through the phagocytic activation of microglial NADPH oxidase and consequent oxidative insult.
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Affiliation(s)
- M L Block
- Neuropharmacology Section, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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Agopyan N, Head J, Yu S, Simon SA. TRPV1 receptors mediate particulate matter-induced apoptosis. Am J Physiol Lung Cell Mol Physiol 2003; 286:L563-72. [PMID: 14633515 DOI: 10.1152/ajplung.00299.2003] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Exposure to airborne particulate matter (PM) is a world-wide health problem mainly because it produces adverse cardiovascular and respiratory effects that frequently result in morbidity. Despite many years of epidemiological and basic research, the mechanisms underlying PM toxicity remain largely unknown. To understand some of these mechanisms, we measured PM-induced apoptosis and necrosis in normal human airway epithelial cells and sensory neurons from both wild-type mice and mice lacking TRPV1 receptors using Alexa Fluor 488-conjugated annexin V and propidium iodide labeling, respectively. Exposure of environmental PMs containing residual oil fly ash and ash from Mount St. Helens was found to induce apoptosis, but not necrosis, as a consequence of sustained calcium influx through TRPV1 receptors. Apoptosis was completely prevented by inhibiting TRPV1 receptors with capsazepine or by removing extracellular calcium or in sensory neurons from TRPV1(-/-) mice. Binding of either one of the PMs to the cell membrane induced a capsazepine-sensitive increase in cAMP. PM-induced apoptosis was augmented upon the inhibition of PKA. PKA inhibition on its own also induced apoptosis, thereby suggesting that this pathway may be endogenously protective against apoptosis. In summary, it was found that inhibiting TRPV1 receptors prevents PM-induced apoptosis, thereby providing a potential mechanism to reduce their toxicity.
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Affiliation(s)
- N Agopyan
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA.
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