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Wyatt TA, Bailey KL, Simet SM, Warren KJ, Sweeter JM, DeVasure JM, Pavlik JA, Sisson JH. Alcohol potentiates RSV-mediated injury to ciliated airway epithelium. Alcohol 2019; 80:17-24. [PMID: 31235345 PMCID: PMC7100607 DOI: 10.1016/j.alcohol.2018.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/18/2018] [Accepted: 07/23/2018] [Indexed: 02/07/2023]
Abstract
Alcohol impairs resolution of respiratory viral infections. Numerous immune response pathways are altered in response to alcohol misuse, including alcohol-induced ciliary dysfunction in the lung. We hypothesized that mucociliary clearance-mediated innate immunity to respiratory syncytial virus (RSV) would be compromised by alcohol exposure. Cilia were assayed using Sisson-Ammons Video Analysis by quantitating the average number of motile points in multiple whole field measurements of mouse tracheal epithelial cells grown on an air-liquid interface. Pretreatment with ethanol alone (100 mM for 24 hours) had no effect on the number of motile cilia. A single dose (TCID50 1 × 105) of RSV resulted in a significant (p < 0.05) decrease in motile cilia after 2 days. Ethanol pretreatment significantly (p < 0.05) potentiated RSV-induced cilia loss by 2 days. Combined RSV and ethanol treatment led to a sustained activation-induced auto-downregulation of PKC epsilon (PKCε). Ethanol-induced enhancement of ciliated cell detachment was confirmed by dynein ELISA and LDH activity from the supernates. RSV-induced cilia loss was evident until 7 days, when RSV-only infected cells demonstrated no significant cilia loss vs. control cells. However, cells pretreated with ethanol showed significant cilia loss until 10 days post-RSV infection. To address the functional significance of ethanol-enhanced cilia detachment, mice fed alcohol ad libitum (20% for 12 weeks) were infected once with RSV, and clearance was measured by plaque-forming assay from lung homogenates for up to 7 days. After 3 days, RSV plaque formation was no longer detected from the lungs of control mice, while significant (p < 0.01) RSV plaque-forming units were detected at 7 days in alcohol-fed mice. Alcohol-fed mice demonstrated enhanced cilia loss and delayed cilia recovery from tracheal measurements in wild-type C57BL/6 mice, but not PKCε KO mice. These data suggest that alcohol worsens RSV-mediated injury to ciliated epithelium in a PKCε-dependent manner.
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Affiliation(s)
- Todd A Wyatt
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States; Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, 68105, United States; University of Nebraska Medical Center, Department of Environmental, Agricultural, & Occupational Health, Omaha, NE, 68198-5910, United States.
| | - Kristina L Bailey
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States; Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, 68105, United States
| | - Samantha M Simet
- University of Nebraska Medical Center, Department of Genetics, Cell Biology & Anatomy, Omaha, NE, 68198-6395, United States
| | - Kristi J Warren
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States
| | - Jenea M Sweeter
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States
| | - Jane M DeVasure
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States
| | - Jaqueline A Pavlik
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States
| | - Joseph H Sisson
- University of Nebraska Medical Center, Pulmonary, Critical Care, Sleep & Allergy, 985910 Nebraska Medical Center, Omaha, NE, 68198-5910, United States
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Simet SM, Sisson JH. Alcohol's Effects on Lung Health and Immunity. Alcohol Res 2015; 37:199-208. [PMID: 26695745 PMCID: PMC4590617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
It has long been known that people with alcohol use disorder (AUD) not only may develop physical dependence but also may experience devastating long-term health problems. The most common and identifiable alcohol-associated health problems include liver cirrhosis, pancreatitis, cardiomyopathies, neuropathies, and dementia. However, the lung also is adversely affected by alcohol abuse, a fact often overlooked by clinicians and the public. Individuals with AUD are more likely to develop pneumonia, tuberculosis (TB), respiratory syncytial virus (RSV) infection, and acute respiratory distress syndrome (ARDS). Increased susceptibility to these and other pulmonary infections is caused by impaired immune responses in people with AUD. The key immune cells involved in combating pulmonary conditions such as pneumonia, TB, RSV infection, and ARDS are neutrophils, lymphocytes, alveolar macrophages, and the cells responsible for innate immune responses. Researchers are only now beginning to understand how alcohol affects these cells and how these effects contribute to the pathophysiology of pulmonary diseases in people with AUD.
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Bailey KL, Bonasera SJ, Wilderdyke M, Hanisch BW, Pavlik JA, DeVasure J, Robinson JE, Sisson JH, Wyatt TA. Aging causes a slowing in ciliary beat frequency, mediated by PKCε. Am J Physiol Lung Cell Mol Physiol 2014; 306:L584-9. [PMID: 24487393 DOI: 10.1152/ajplung.00175.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The elderly are at much higher risk for developing pneumonia than younger individuals. Pneumonia is a leading cause of death and is the third most common reason for hospitalization in the elderly. One reason that elderly people may be more susceptible to pneumonia is a breakdown in the lung's first line of defense, mucociliary clearance. Cilia beat in a coordinated manner to propel out invading microorganisms and particles. Ciliary beat frequency (CBF) is known to slow with aging, however, little is known about the mechanism(s) involved. We compared the CBF in BALB/c and C57BL/6 mice aged 2, 12, and 24 mo and found that CBF diminishes with age. Cilia in the mice at age 12 and 24 mo retained their ability to be stimulated by the β2 agonist procaterol. To help determine the mechanism of ciliary slowing, we measured protein kinase C alpha and epsilon (PKCα and PKCε) activity. There were no activity differences in PKCα between the mice aged 2, 12, or 24 mo. However, we demonstrated a significantly higher PKCε activity in the mice at 12 and 24 mo than the in the mice 2 mo of age. The increase in activity is likely due to a nearly threefold increase in PKCε protein in the lung during aging. To strengthen the connection between activation of PKCε and ciliary slowing, we treated tracheas of mice at 2 mo with the PKCε agonist 8-[2-(2-pentylcyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA). We noted a similar decrease in baseline CBF, and the cilia remained sensitive to stimulation with β2 agonists. The mechanisms for the slowing of baseline CBF have not been previously determined. In this mouse model of aging we were able to show that decreases in CBF are related to an increase in PKCε activity.
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Affiliation(s)
- K L Bailey
- Pulmonary, Critical Care, Sleep & Allergy Division, Dept. of Internal Medicine, Univ. of Nebraska Medical Center, Omaha, NE 68198-5910.
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Bailey KL, LeVan TD, Yanov DA, Pavlik JA, DeVasure JM, Sisson JH, Wyatt TA. Non-typeable Haemophilus influenzae decreases cilia beating via protein kinase Cε. Respir Res 2012; 13:49. [PMID: 22712879 PMCID: PMC3487807 DOI: 10.1186/1465-9921-13-49] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 05/24/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Haemophilus influenzae infection of the nasal epithelium has long been associated with observations of decreased nasal ciliary beat frequency (CBF) and injury to the ciliated epithelium. Previously, we have reported that several agents that slow CBF also have the effect of activating protein kinase C epsilon (PKCε) activity in bronchial epithelial cells. The subsequent auto-downregulation of PKCε or the direct inhibition of PKCε leads to the specific detachment of the ciliated cells. METHODS Primary cultures of ciliated bovine bronchial epithelial cells were exposed to filtered conditioned media supernatants from non-typeable H. influenzae (NTHi) cultures. CBF and motile points were measured and PKCε activity assayed. RESULTS NTHi supernatant exposure significantly and rapidly decreased CBF in a dose-dependent manner within 10 minutes of exposure. After 3 hours of exposure, the number of motile ciliated cells significantly decreased. Direct measurement of PKCε activity revealed a dose-dependent activation of PKCε in response to NTHi supernatant exposure. Both CBF and PKCε activity changes were only observed in fresh NTHi culture supernatant and not observed in exposures to heat-inactivated or frozen supernatants. CONCLUSIONS Our results suggest that CBF slowing observed in response to NTHi is consistent with the stimulated activation of PKCε. Ciliated cell detachment is associated with PKCε autodownregulation.
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Affiliation(s)
- Kristina L Bailey
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
| | - Tricia D LeVan
- VA Nebraska-Western Iowa Health Care System Research Service, Department of Veterans Affairs Medical Center, 4101 Woolworth Avenue, Omaha, NE, 68105, USA
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
- Department of Epidemiology, College of Public Health, University of Nebraska Medical Center, Omaha, NE, 68198-5910, USA
| | - Daniel A Yanov
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
| | - Jaqueline A Pavlik
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
| | - Jane M DeVasure
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
| | - Joseph H Sisson
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
| | - Todd A Wyatt
- VA Nebraska-Western Iowa Health Care System Research Service, Department of Veterans Affairs Medical Center, 4101 Woolworth Avenue, Omaha, NE, 68105, USA
- Department of Environmental, Agricultural, and Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE, 68198-5910, USA
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, 985300 Nebraska Medical Center, Omaha, NE, 68198-5300, USA
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Co-exposure to cigarette smoke and alcohol decreases airway epithelial cell cilia beating in a protein kinase Cε-dependent manner. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:431-40. [PMID: 22677421 DOI: 10.1016/j.ajpath.2012.04.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 04/12/2012] [Accepted: 04/24/2012] [Indexed: 11/22/2022]
Abstract
Alcohol use disorders are associated with increased lung infections and exacerbations of chronic lung diseases. Whereas the effects of cigarette smoke are well recognized, the interplay of smoke and alcohol in modulating lung diseases is not clear. Because innate lung defense is mechanically maintained by airway cilia action and protein kinase C (PKC)-activating agents slow ciliary beat frequency (CBF), we hypothesized that the combination of smoke and alcohol would decrease CBF in a PKC-dependent manner. Primary ciliated bronchial epithelial cells were exposed to 5% cigarette smoke extract plus100 mmol/L ethanol for up to 24 hours and assayed for CBF and PKCε. Smoke and alcohol co-exposure activated PKCε by 1 hour and decreased both CBF and total number of beating cilia by 6 hours. A specific activator of PKCε, DCP-LA, slowed CBF after maximal PKCε activation. Interestingly, activation of PKCε by smoke and alcohol was only observed in ciliated cells, not basal bronchial epithelium. In precision-cut mouse lung slices treated with smoke and alcohol, PKCε activation preceded CBF slowing. Correspondingly, increased PKCε activity and cilia slowing were only observed in mice co-exposed to smoke and alcohol, regardless of the sequence of the combination exposure. No decreases in CBF were observed in PKCε knockout mice co-exposed to smoke and alcohol. These data identify PKCε as a key regulator of cilia slowing in response to combined smoke and alcohol-induced lung injury.
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Simet SM, Sisson JH, Pavlik JA, Devasure JM, Boyer C, Liu X, Kawasaki S, Sharp JG, Rennard SI, Wyatt TA. Long-term cigarette smoke exposure in a mouse model of ciliated epithelial cell function. Am J Respir Cell Mol Biol 2009; 43:635-40. [PMID: 20042711 DOI: 10.1165/rcmb.2009-0297oc] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Exposure to cigarette smoke is associated with airway epithelial mucus cell hyperplasia and a decrease in cilia and ciliated cells. Few models have addressed the long-term effects of chronic cigarette smoke exposure on ciliated epithelial cells. Our previous in vitro studies showed that cigarette smoke decreases ciliary beat frequency (CBF) via the activation of protein kinase C (PKC). We hypothesized that chronic cigarette smoke exposure in an in vivo model would decrease airway epithelial cell ciliary beating in a PKC-dependent manner. We exposed C57BL/6 mice to whole-body cigarette smoke 2 hours/day, 5 days/week for up to 1 year. Tracheal epithelial cell CBF and the number of motile cells were measured after necropsy in cut tracheal rings, using high-speed digital video microscopy. Tracheal epithelial PKC was assayed according to direct kinase activity. At 6 weeks and 3 months of smoke exposure, the baseline CBF was slightly elevated (~1 Hz) versus control mice, with no change in β-agonist-stimulated CBF between control mice and cigarette smoke-exposed mice. By 6 months of smoke exposure, the baseline CBF was significantly decreased (2-3 Hz) versus control mice, and a β-agonist failed to stimulate increased CBF. The loss of β-agonist-increased CBF continued at 9 months and 12 months of smoke exposure, and the baseline CBF was significantly decreased to less than one third of the control rate. In addition to CBF, ciliated cell numbers significantly decreased in response to smoke over time, with a significant loss of tracheal ciliated cells occurring between 6 and 12 months. In parallel with the slowing of CBF, significant PKC activation from cytosol to the membrane of tracheal epithelial cells was detected in mice exposed to smoke for 6-12 months.
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Affiliation(s)
- Samantha M Simet
- Pulmonary, Critical Care, Sleep, and Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 Nebraska Medical Center, Omaha, NE 68198-5910, USA
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Wyatt TA, Slager RE, Heires AJ, Devasure JM, Vonessen SG, Poole JA, Romberger DJ. Sequential activation of protein kinase C isoforms by organic dust is mediated by tumor necrosis factor. Am J Respir Cell Mol Biol 2009; 42:706-15. [PMID: 19635931 DOI: 10.1165/rcmb.2009-0065oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Dust samples collected from Nebraska swine confinement facilities (hog dust extract [HDE]) are known to elicit proinflammatory cytokine release from human bronchial epithelial (HBE) cells in vitro. This response involves the activation of two protein kinase C (PKC) isoforms: PKCalpha and PKCepsilon. Experiments were designed to investigate the relationship between the two isoenzymes and the degree to which each is responsible for cytokine release in HBE. Experiments also examined the contribution of TNF-alpha to IL-6 and IL-8 release. PKCalpha and PKCepsilon activities were inhibited using isoform-specific pharmacologic inhibitors and genetically modified dominant-negative (DN) expressing cell lines. Release of the proinflammatory cytokines IL-6, IL-8, and TNF-alpha was measured and PKC isoform activities assessed. We found that HDE stimulates PKCalpha activity by 1 hour, and within 6 hours the activity returns to baseline. PKCalpha-specific inhibitor or PKCalphaDN cells abolish this HDE-mediated effect. Both IL-6 and IL-8 release are likewise diminished under these conditions compared with normal HBE, and treatment with TNF-alpha-neutralizing antibody does not further inhibit cytokine release. In contrast, PKCepsilon activity was enhanced by 6 hours after HDE treatment. TNF-alpha blockade abrogated this effect. HDE-stimulated IL-6, but not IL-8 release in PKCepsilonDN cells. The concentration of TNF-alpha released by HDE-stimulated HBE is sufficient to have a potent cytokine-eliciting effect. A time course of TNF-alpha release suggests that TNF-alpha is produced after PKCalpha activation, but before PKCepsilon. These results suggest a temporal ordering of events responsible for the release of cytokines, which initiate and exacerbate inflammatory events in the airways of people exposed to agricultural dust.
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Affiliation(s)
- Todd A Wyatt
- Department of Internal Medicine, Pulmonary, Critical Care, Sleep & Allergy Section, University of Nebraska Medical Center, 985300 Nebraska Medical Center, Omaha, NE 68198-5300, USA.
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Carter CA, Hamm JT. Multiplexed quantitative high content screening reveals that cigarette smoke condensate induces changes in cell structure and function through alterations in cell signaling pathways in human bronchial cells. Toxicology 2009; 261:89-102. [PMID: 19394402 DOI: 10.1016/j.tox.2009.04.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 04/06/2009] [Accepted: 04/15/2009] [Indexed: 12/27/2022]
Abstract
Human bronchial cells are one of the first cell types exposed to environmental toxins. Toxins often activate nuclear factor-kappaB (NF-kappaB) and protein kinase C (PKC). We evaluated the hypothesis that cigarette smoke condensate (CSC), the particulate fraction of cigarette smoke, activates PKC-alpha and NF-kappaB, and concomitantly disrupts the F-actin cytoskeleton, induces apoptosis and alters cell function in BEAS-2B human bronchial epithelial cells. Compared to controls, exposure of BEAS-2B cells to doses of 30mug/ml CSC significantly activated PKC-alpha, while CSC doses above 20mug/ml CSC significantly activated NF-kappaB. As NF-kappaB was activated, cell number decreased. CSC treatment of BEAS-2B cells induced a decrease in cell size and an increase in cell surface extensions including filopodia and lamellipodia. CSC treatment of BEAS-2B cells induced F-actin rearrangement such that stress fibers were no longer prominent at the cell periphery and throughout the cells, but relocalized to perinuclear regions. Concurrently, CSC induced an increase in the focal adhesion protein vinculin at the cell periphery. CSC doses above 30mug/ml induced a significant increase in apoptosis in BEAS-2B cells evidenced by an increase in activated caspase 3, an increase in mitochondrial mass and a decrease in mitochondrial membrane potential. As caspase 3 increased, cell number decreased. CSC doses above 30mug/ml also induced significant concurrent changes in cell function including decreased cell spreading and motility. CSC initiates a signaling cascade in human bronchial epithelial cells involving PKC-alpha, NF-kappaB and caspase 3, and consequently decreases cell spreading and motility. These CSC-induced alterations in cell structure likely prevent cells from performing their normal function thereby contributing to smoke-induced diseases.
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Affiliation(s)
- Charleata A Carter
- A.W. Spears Research Center, 420 N. English Street, Lorillard Tobacco Company, Greensboro, NC 27405, USA.
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Slager RE, Devasure JM, Pavlik JA, Sisson JH, Wyatt TA. RACK1, a PKC targeting protein, is exclusively localized to basal airway epithelial cells. J Histochem Cytochem 2007; 56:7-14. [PMID: 17875659 PMCID: PMC2323118 DOI: 10.1369/jhc.7a7249.2007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The novel isoform of protein kinase C (PKC), PKCepsilon, is an important regulator of ciliated cell function in airway epithelial cells, including cilia motility and detachment of ciliated cells after environmental insult. However, the mechanism of PKCepsilon signaling in the airways and the potential role of the PKCepsilon-interacting protein, receptor for activated C kinase 1 (RACK1), has not been widely explored. We used immunohistochemistry and Western blot analysis to show that RACK1 is localized exclusively to basal, non-ciliated (and non-goblet) bovine and human bronchial epithelial cells. Our immunohistochemistry experiments used the basal body marker pericentrin, a marker for cilia, beta-tubulin, and an airway goblet cell marker, MUC5AC, to confirm that RACK1 was excluded from differentiated airway cell subtypes and is only expressed in the basal cells. These results suggest that PKCepsilon signaling in the basal airway cell may involve RACK1; however, PKCepsilon regulation in ciliated cells uses RACK1-independent pathways.
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Affiliation(s)
- Rebecca E Slager
- Department of Internal Medicine, Pulmonary and Critical Care Medicine Section, University of Nebraska Medical Center, 985300 Nebraska Medical Center, Omaha, NE 68198-5300, USA
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Wyatt TA, Slager RE, Devasure J, Auvermann BW, Mulhern ML, Von Essen S, Mathisen T, Floreani AA, Romberger DJ. Feedlot dust stimulation of interleukin-6 and -8 requires protein kinase Cepsilon in human bronchial epithelial cells. Am J Physiol Lung Cell Mol Physiol 2007; 293:L1163-70. [PMID: 17720876 DOI: 10.1152/ajplung.00103.2007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Individuals exposed to dusts from concentrated animal feeding operations report increased numbers of respiratory tract symptoms, and bronchoalveolar lavage samples from such individuals demonstrate elevated lung inflammatory mediators, including interleukin (IL)-8 and IL-6. We previously found that exposure of bronchial epithelial cells to hog barn dusts resulted in a protein kinase C (PKC)-dependent increase in IL-6 and IL-8 release. We hypothesized that cattle feedlot dusts would also generate bronchial epithelial interleukin release in vitro. To test this, we used interleukin ELISAs and direct PKC isoform assays. We found that a dust extract from cattle feedlots [feedlot dust extract (FLDE)] augments PKC activity of human bronchial epithelial cells in vitro. A 5-10% dilution of FLDE stimulated a significant release of IL-6 and IL-8 at 6-24 h in a PKC-dependent manner vs. control medium-treated cells. An increase in PKCalpha activity was observed with 1 h of FLDE treatment, and PKCepsilon activity was elevated at 6 h of FLDE exposure. The PKCalpha inhibitor, Gö-6976, did not inhibit FLDE-stimulated IL-8 and IL-6 release. However, the PKCepsilon inhibitor, Ro 31-8220, effectively inhibited FLDE-stimulated IL-8 and IL-6 release. Inhibition of FLDE-stimulated IL-6 and IL-8 was confirmed in a dominant-negative PKCepsilon-expressing BEAS-2B cell line but not observed in a PKCalpha dominant negative BEAS-2B cell line. These data support the hypothesis that FLDE exposure stimulates bronchial epithelial IL-8 and IL-6 release via a PKCepsilon-dependent pathway.
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Affiliation(s)
- Todd A Wyatt
- Pulmonary and Critical Care Medicine Section, Department of Internal Medicine, Omaha, NE, USA
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