1
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Phillips BW, Schlage WK, Titz B, Kogel U, Sciuscio D, Martin F, Leroy P, Vuillaume G, Krishnan S, Lee T, Veljkovic E, Elamin A, Merg C, Ivanov NV, Peitsch MC, Hoeng J, Vanscheeuwijck P. A 90-day OECD TG 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects of the aerosol from the carbon heated tobacco product version 1.2 (CHTP1.2) compared with cigarette smoke. I. Inhalation exposure, clinical pathology and histopathology. Food Chem Toxicol 2018; 116:388-413. [PMID: 29654848 DOI: 10.1016/j.fct.2018.04.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/28/2018] [Accepted: 04/07/2018] [Indexed: 01/25/2023]
Abstract
Within the framework of a systems toxicology approach, the inhalation toxicity of aerosol from a novel tobacco-heating potentially modified risk tobacco product (MRTP), the carbon-heated tobacco product (CHTP) 1.2, was characterized and compared with that of mainstream smoke (CS) from the 3R4F reference cigarette in a 90-day nose-only rat inhalation study in general accordance with OECD TG 413. CHTP1.2 is a heat-not-burn product using a carbon heat source to produce an aerosol that contains nicotine and tobacco flavor. At equal or twice the nicotine concentration in the test atmospheres, inhalation of CHTP1.2 aerosol led to a significantly lower exposure to harmful constituents and induced less respiratory tract irritation, systemic, and pathological effects compared with CS. Nasal epithelial changes were less pronounced in the CHTP1.2- than in the CS-exposed groups and reverted in the nicotine concentration-matched group after a recovery period. Lung inflammation was minimal in the CHTP1.2-treated groups compared with the moderate extent seen in the 3R4F groups. Many other toxicological endpoints evaluated did not show CHTP1.2 aerosol exposure-related effects, and no effects not seen for 3R4F were observed. These observations were consistent with findings from previous studies in which rats were exposed to MRTP aerosols containing similar nicotine concentrations.
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Affiliation(s)
- Blaine W Phillips
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Walter K Schlage
- Biology Consultant, Max-Baermann-Str. 21, 51429, Bergisch Gladbach, Germany
| | - Bjoern Titz
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Ulrike Kogel
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Davide Sciuscio
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Florian Martin
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Patrice Leroy
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Gregory Vuillaume
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Subash Krishnan
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Tom Lee
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Emilija Veljkovic
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Ashraf Elamin
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Celine Merg
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Nikolai V Ivanov
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Manuel C Peitsch
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Julia Hoeng
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Patrick Vanscheeuwijck
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland.
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2
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Sparfel L. Effets immunotoxiques des polluants environnementaux : exemple des hydrocarbures aromatiques polycycliques. ARCH MAL PROF ENVIRO 2016. [DOI: 10.1016/j.admp.2016.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Abstract
Until recently, the published literature on inhalation studies with laboratory animals and cigarette smoke consisted entirely of negative findings, as far as neoplastic disease is concerned. This paper brings readers up to date, with analyses of recent studies that do indeed appear to report success after so many years of failure. The paper consists of a brief analysis of the literature up until a couple of years ago, giving brief, representative examples of inhalation studies with the five main species of laboratory animals that have been used: rat, mouse, hamster, dog, and nonhuman primate. A brief examination of the various technologies used to expose laboratory animals is given, along with an analysis of the histopathology and related toxicology data (specifically, biomarkers of exposure) that have been reported. The paper concludes by briefly mentioning the most recent studies, where positive results have been reported.
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Abstract
The aim of future research in this area is to provide the mechanistic understanding and the tools for effective prevention, early diagnosis, and therapy of lung cancer. With the established causal link between cigarette smoking and the risk of developing lung cancer, the most effective prevention is certainly not to smoke. A much better mechanistic understanding of lung cancer and its variability will support the development and evaluation of potentially reduced risk products for those who maintain smoking as well as for the development of early diagnostic tools and targeted therapies. Because of the complexity of lung cancer and the long duration for its development, nonclinical and clinical research efforts need to complement each other. Recent promising advances in this research area are the understanding of the interaction between genotoxic and epigenetic effects of smoking, the development of laboratory animal models for lung tumorigenesis by smoke inhalation, the unraveling of molecular pathways and signatures in clinical lung cancer research useful for developing diagnostic tools and therapeutic approaches, and the first successful therapy for lung cancer—although less suitable for smokers. The above—in combination with emerging data sets from explorative non-clinical and clinical studies as well as improved modeling approaches—are setting the stage for accelerated progress towards developing successful early diagnostic tools and therapies as well as for the assessment of new consumer products with potentially reduced risk.
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Oviedo A, Lebrun S, Kogel U, Ho J, Tan WT, Titz B, Leroy P, Vuillaume G, Bera M, Martin F, Rodrigo G, Esposito M, Dempsey R, Ivanov NV, Hoeng J, Peitsch MC, Vanscheeuwijck P. Evaluation of the Tobacco Heating System 2.2. Part 6: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects of a mentholated version compared with mentholated and non-mentholated cigarette smoke. Regul Toxicol Pharmacol 2016; 81 Suppl 2:S93-S122. [DOI: 10.1016/j.yrtph.2016.11.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/28/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
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6
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Wong ET, Kogel U, Veljkovic E, Martin F, Xiang Y, Boue S, Vuillaume G, Leroy P, Guedj E, Rodrigo G, Ivanov NV, Hoeng J, Peitsch MC, Vanscheeuwijck P. Evaluation of the Tobacco Heating System 2.2. Part 4: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects compared with cigarette smoke. Regul Toxicol Pharmacol 2016; 81 Suppl 2:S59-S81. [DOI: 10.1016/j.yrtph.2016.10.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/04/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
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7
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Phillips B, Esposito M, Verbeeck J, Boué S, Iskandar A, Vuillaume G, Leroy P, Krishnan S, Kogel U, Utan A, Schlage WK, Bera M, Veljkovic E, Hoeng J, Peitsch MC, Vanscheeuwijck P. Toxicity of aerosols of nicotine and pyruvic acid (separate and combined) in Sprague-Dawley rats in a 28-day OECD 412 inhalation study and assessment of systems toxicology. Inhal Toxicol 2015; 27:405-31. [PMID: 26295358 DOI: 10.3109/08958378.2015.1046000] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxicity of nebulized nicotine (Nic) and nicotine/pyruvic acid mixtures (Nic/Pyr) was characterized in a 28-day Organization for Economic Co-operation and Development 412 inhalation study with additional transcriptomic and lipidomic analyses. Sprague-Dawley rats were nose-only exposed, 6 h/day, 5 days/week to filtered air, saline, nicotine (50 µg/l), sodium pyruvate (NaPyr, 33.9 µg/l) or equimolar Nic/Pyr mixtures (18, 25 and 50 µg nicotine/l). Saline and NaPyr caused no health effects, but rats exposed to nicotine-containing aerosols had decreased body weight gains and concentration-dependent increases in liver weight. Blood neutrophil counts were increased and lymphocyte counts decreased in rats exposed to nicotine; activities of alkaline phosphatase and alanine aminotransferase were increased, and levels of cholesterol and glucose decreased. The only histopathologic finding in non-respiratory tract organs was increased liver vacuolation and glycogen content. Respiratory tract findings upon nicotine exposure (but also some phosphate-buffered saline aerosol effects) were observed only in the larynx and were limited to adaptive changes. Gene expression changes in the lung and liver were very weak. Nic and Nic/Pyr caused few significant changes (including Cyp1a1 gene upregulation). Changes were predominantly related to energy metabolism and fatty acid metabolism but did not indicate an obvious toxicity-related response. Nicotine exposure lowered plasma lipids, including cholesteryl ester (CE) and free cholesterol and, in the liver, phospholipids and sphingolipids. Nic, NaPyr and Nic/Pyr decreased hepatic triacylglycerol and CE. In the lung, Nic and Nic/Pyr increased CE levels. These data suggest that only minor biologic effects related to inhalation of Nic or Nic/Pyr aerosols were observed in this 28-day study.
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Affiliation(s)
- Blaine Phillips
- a Philip Morris International Research Laboratories Pte Ltd , Science Park II , Singapore and
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A 7-month cigarette smoke inhalation study in C57BL/6 mice demonstrates reduced lung inflammation and emphysema following smoking cessation or aerosol exposure from a prototypic modified risk tobacco product. Food Chem Toxicol 2015; 80:328-345. [PMID: 25843363 DOI: 10.1016/j.fct.2015.03.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 03/04/2015] [Accepted: 03/10/2015] [Indexed: 01/13/2023]
Abstract
Modified risk tobacco products (MRTP) are designed to reduce smoking-related health risks. A murine model of chronic obstructive pulmonary disease (COPD) was applied to investigate classical toxicology end points plus systems toxicology (transcriptomics and proteomics). C57BL/6 mice were exposed to conventional cigarette smoke (3R4F), fresh air (sham), or a prototypic MRTP (pMRTP) aerosol for up to 7 months, including a cessation group and a switching-to-pMRTP group (2 months of 3R4F exposure followed by fresh air or pMRTP for up to 5 months respectively). 3R4F smoke induced the typical adaptive changes in the airways, as well as inflammation in the lung, associated with emphysematous changes (impaired pulmonary function and alveolar damage). At nicotine-matched exposure concentrations of pMRTP aerosol, no signs of lung inflammation and emphysema were observed. Both the cessation and switching groups showed a similar reversal of inflammatory responses and no progression of initial emphysematous changes. A significant impact on biological processes, including COPD-related inflammation, apoptosis, and proliferation, was identified in 3R4F-exposed, but not in pMRTP-exposed lungs. Smoking cessation or switching reduced these perturbations to near sham-exposed levels. In conclusion, the mouse model indicated retarded disease progression upon cessation or switching to pMRTP which alone had no adverse effects.
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9
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Fujimoto H, Tsuji H, Okubo C, Fukuda I, Nishino T, Lee KM, Renne R, Yoshimura H. Biological responses in rats exposed to mainstream smoke from a heated cigarette compared to a conventional reference cigarette. Inhal Toxicol 2015; 27:224-36. [PMID: 25969858 DOI: 10.3109/08958378.2015.1027799] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The heated cigarette (HC) generates mainstream smoke by vaporizing the components of the tobacco rod using a carbon heat source at the cigarette tip. Mainstream smoke of HC contains markedly less chemical constituents compared to combusted cigarettes. Mainstream smoke from HC was generated under Health Canada Intense regimen and its biological effects were compared to those of Reference (3R4F) cigarettes, using nose-only 5-week and 13-week inhalation studies. In the 13-week study, SD rats were necropsied following exposure to mainstream smoke from each cigarette at 200, 600 or 1000 µg wet total particulate matter/L for 1 h/day, 7 days/week or following a 13-week recovery period. Histopathological changes in the respiratory tract were significantly lesser in HC groups; e.g. respiratory epithelial hyperplasia in the nasal cavity and accumulation of pigmented macrophages in alveoli. After a 13-week recovery, the lesions were completely or partially regressed, except for accumulation of pigmented macrophages in alveoli, in both HC and 3R4F groups. In the 5-week study, SD rats were necropsied following exposure to mainstream smoke of either cigarette at 600 or 1000 µg/L for 1 h, two times/day (with 30 min interval), 7 days/week or following a 4-week recovery period. Bronchoalveolar lavage fluid (BALF) analysis of neutrophil percentages and enzyme levels like γ-GT, ALP and LDH indicated that pulmonary inflammation was significantly less in HC groups compared to 3R4F groups. In conclusion, HC demonstrated significantly lower biological effects compared to 3R4F, based on the BALF parameters and histopathology.
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Affiliation(s)
- Hitoshi Fujimoto
- Product and Science Division, R&D Group, Japan Tobacco Inc. , Kanagawa , Japan
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10
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Toxicological assessment of kretek cigarettes part 5: Mechanistic investigations, inhalation toxicity. Regul Toxicol Pharmacol 2014; 70 Suppl 1:S54-65. [DOI: 10.1016/j.yrtph.2014.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/29/2014] [Indexed: 01/18/2023]
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11
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Toxicological assessment of kretek cigarettes. Regul Toxicol Pharmacol 2014; 70 Suppl 1:S2-14. [DOI: 10.1016/j.yrtph.2014.11.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/27/2014] [Accepted: 11/29/2014] [Indexed: 11/23/2022]
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12
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Toxicological assessment of kretek cigarettes Part 3: kretek and American-blended cigarettes, inhalation toxicity. Regul Toxicol Pharmacol 2014; 70 Suppl 1:S26-40. [PMID: 25455226 DOI: 10.1016/j.yrtph.2014.09.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 09/29/2014] [Indexed: 11/20/2022]
Abstract
A typical Indonesian kretek cigarette brand and an experimental kretek reference cigarette were compared to the reference cigarette 2R4F in two 90-day inhalation studies. Male and female rats were exposed nose-only to mainstream smoke for 6 hours daily, for 90 consecutive days. Biological endpoints were assessed according to OECD guideline 413, with special emphasis on respiratory tract histopathology and on lung inflammation (broncho-alveolar lavage fluid levels of neutrophils, macrophages and lymphocytes). Histopathological alterations included: in the nose, hyperplasia and squamous metaplasia of the respiratory epithelium and squamous metaplasia and atrophy of the olfactory epithelium; in the larynx, epithelial squamous metaplasia and hyperplasia; in the lungs, accumulation of macrophages in alveoli and goblet cell hyperplasia in bronchial epithelium. The findings were qualitatively consistent with observations from previous similar studies on conventional cigarettes. Compared to 2R4F cigarette, however, kretek smoke exposure was associated with a pronounced attenuation of pulmonary inflammation and less severe histopathological changes in the respiratory tract. Neutrophilic inflammation was also significantly lower (>70%). These results are consistent with the observations made on smoke chemistry and in vitro toxicology. They do not support any increased toxicity of the smoke of kretek cigarettes compared to conventional American-blended cigarettes.
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Kogel U, Schlage WK, Martin F, Xiang Y, Ansari S, Leroy P, Vanscheeuwijck P, Gebel S, Buettner A, Wyss C, Esposito M, Hoeng J, Peitsch MC. A 28-day rat inhalation study with an integrated molecular toxicology endpoint demonstrates reduced exposure effects for a prototypic modified risk tobacco product compared with conventional cigarettes. Food Chem Toxicol 2014; 68:204-17. [PMID: 24632068 DOI: 10.1016/j.fct.2014.02.034] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/21/2014] [Accepted: 02/24/2014] [Indexed: 11/26/2022]
Abstract
Towards a systems toxicology-based risk assessment, we investigated molecular perturbations accompanying histopathological changes in a 28-day rat inhalation study combining transcriptomics with classical histopathology. We demonstrated reduced biological activity of a prototypic modified risk tobacco product (pMRTP) compared with the reference research cigarette 3R4F. Rats were exposed to filtered air or to three concentrations of mainstream smoke (MS) from 3R4F, or to a high concentration of MS from a pMRTP. Histopathology revealed concentration-dependent changes in response to 3R4F that were irritative stress-related in nasal and bronchial epithelium, and inflammation-related in the lung parenchyma. For pMRTP, significant changes were seen in the nasal epithelium only. Transcriptomics data were obtained from nasal and bronchial epithelium and lung parenchyma. Concentration-dependent gene expression changes were observed following 3R4F exposure, with much smaller changes for pMRTP. A computational-modeling approach based on causal models of tissue-specific biological networks identified cell stress, inflammation, proliferation, and senescence as the most perturbed molecular mechanisms. These perturbations correlated with histopathological observations. Only weak perturbations were observed for pMRTP. In conclusion, a correlative evaluation of classical histopathology together with gene expression-based computational network models may facilitate a systems toxicology-based risk assessment, as shown for a pMRTP.
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Affiliation(s)
- Ulrike Kogel
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstrasse 3, 51149 Cologne, Germany; Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Walter K Schlage
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstrasse 3, 51149 Cologne, Germany; Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Florian Martin
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Yang Xiang
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Sam Ansari
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstrasse 3, 51149 Cologne, Germany; Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Patrice Leroy
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Patrick Vanscheeuwijck
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstrasse 3, 51149 Cologne, Germany; Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland; Philip Morris International R&D, Philip Morris Research Laboratories bvba, Grauwmeer 14, Researchpark Haasrode, 3001 Leuven, Belgium.
| | - Stephan Gebel
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstrasse 3, 51149 Cologne, Germany.
| | - Ansgar Buettner
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstrasse 3, 51149 Cologne, Germany.
| | - Christoph Wyss
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Marco Esposito
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Julia Hoeng
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Manuel C Peitsch
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
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14
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Stinn W, Buettner A, Weiler H, Friedrichs B, Luetjen S, van Overveld F, Meurrens K, Janssens K, Gebel S, Stabbert R, Haussmann HJ. Lung inflammatory effects, tumorigenesis, and emphysema development in a long-term inhalation study with cigarette mainstream smoke in mice. Toxicol Sci 2013; 131:596-611. [PMID: 23104432 PMCID: PMC3551427 DOI: 10.1093/toxsci/kfs312] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 10/17/2012] [Indexed: 12/14/2022] Open
Abstract
Cigarette smoking is the leading cause of lung cancer and chronic obstructive pulmonary disease, yet there is little mechanistic information available in the literature. To improve this, laboratory models for cigarette mainstream smoke (MS) inhalation-induced chronic disease development are needed. The current study investigated the effects of exposing male A/J mice to MS (6h/day, 5 days/week at 150 and 300 mg total particulate matter per cubic meter) for 2.5, 5, 10, and 18 months in selected combinations with postinhalation periods of 0, 4, 8, and 13 months. Histopathological examination of step-serial sections of the lungs revealed nodular hyperplasia of the alveolar epithelium and bronchioloalveolar adenoma and adenocarcinoma. At 18 months, lung tumors were found to be enhanced concentration dependently (up to threefold beyond sham exposure), irrespective of whether MS inhalation had been performed for the complete study duration or was interrupted after 5 or 10 months and followed by postinhalation periods. Morphometric analysis revealed an increase in the extent of emphysematous changes after 5 months of MS inhalation, which did not significantly change over the following 13 months of study duration, irrespective of whether MS exposure was continued or not. These changes were found to be accompanied by a complex pattern of transient and sustained pulmonary inflammatory changes that may contribute to the observed pathogeneses. Data from this study suggest that the A/J mouse model holds considerable promise as a relevant model for investigating smoking-related emphysema and adenocarcinoma development.
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Affiliation(s)
- Walter Stinn
- *Philip Morris Research Laboratories GmbH, 51149 Cologne, Germany
| | - Ansgar Buettner
- *Philip Morris Research Laboratories GmbH, 51149 Cologne, Germany
| | - Horst Weiler
- *Philip Morris Research Laboratories GmbH, 51149 Cologne, Germany
| | | | - Sonja Luetjen
- *Philip Morris Research Laboratories GmbH, 51149 Cologne, Germany
| | | | - Kris Meurrens
- †Philip Morris Research Laboratories bvba, 3001 Leuven, Belgium
| | - Kris Janssens
- *Philip Morris Research Laboratories GmbH, 51149 Cologne, Germany
| | - Stephan Gebel
- *Philip Morris Research Laboratories GmbH, 51149 Cologne, Germany
| | - Regina Stabbert
- ‡Philip Morris International R&D, Neuchâtel, Switzerland; and
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Lin JCJ, Roy JP, Verreault J, Talbot S, Côté F, Couture R, Morin A. An ex vivo approach to the differential parenchymal responses induced by cigarette whole smoke and its vapor phase. Toxicology 2012; 293:125-131. [PMID: 22266391 DOI: 10.1016/j.tox.2012.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 01/01/2012] [Accepted: 01/06/2012] [Indexed: 10/14/2022]
Abstract
Using a rat lung slice model, this study compared the stress responses induced by cigarette whole smoke (WS) to that induced by the vapor phase (VP) of the smoke. Following a 3-day exposure, lung slices exposed to 4, 10 and 20% WS retained 85, 42 and 16% relative survival respectively in comparison to the air-exposed ones. Consistently, histological observations revealed concentration-related alveolar damages in the lung slices. Expression of 5 stress-response genes was examined following a single 30 min exposure to 4% WS or VP. WS exposure resulted in 4, 11 and 50-fold induction of IL-1β, kinin type I receptor (B₁R) and CYP1A1 genes, respectively, while CYP1B1 and TNF-α genes expression was found only two times higher in comparison to VP group. Since cigarette WS consists of particulate and vapor phases, these results highlight the preferential or synergistic role of the particulate phase in the induction of IL-1β, B₁R and CYP1A1 genes and that VP did not have comparable effects on expression of these genes. However, both phases fairly contributed to the induction of CYP1B1 and TNF-α genes. VP was the fraction responsible for the toxic effect since WS did not produce further toxicity. The 4% whole smoke deposited about 7.1 μg/cm² of total particulate matter (TPM) to the exposure chamber which may account for observed differential stress responses in the lung slices.
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Affiliation(s)
| | | | | | - Sébastien Talbot
- Department of Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - France Côté
- Imperial Tobacco Canada Ltd, Montréal, QC, H4C 3P6, Canada
| | - Réjean Couture
- Department of Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - André Morin
- Imperial Tobacco Canada Ltd, Montréal, QC, H4C 3P6, Canada
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16
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Dorman DC, Mokashi V, Wagner DJ, Olabisi AO, Wong BA, Moss OR, Centeno JA, Guandalini G, Jackson DA, Dennis WE, Lewis JA, Thomas RS, Chapman GD. Biological responses in rats exposed to cigarette smoke and Middle East sand (dust). Inhal Toxicol 2012; 24:109-24. [DOI: 10.3109/08958378.2011.647413] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- David C. Dorman
- College of Veterinary Medicine, North Carolina State University,
Raleigh, NC, USA
| | - Vishwesh Mokashi
- Environmental Health Effects Laboratory, Naval Medical Research Unit,
Dayton, OH, USA
| | - Dean J. Wagner
- Environmental Health Effects Laboratory, Naval Medical Research Unit,
Dayton, OH, USA
| | - Ayodele O. Olabisi
- Environmental Health Effects Laboratory, Naval Medical Research Unit,
Dayton, OH, USA
| | - Brian A. Wong
- The Hamner Institutes for Health Sciences,
Research Triangle Park, NC, USA
| | - Owen R. Moss
- The Hamner Institutes for Health Sciences,
Research Triangle Park, NC, USA
| | - Jose A. Centeno
- The Joint Pathology Center, Division of Biophysical Toxicology,
Joint Base Andrews Naval Air Facility Washington, MD, USA
| | - Gustavo Guandalini
- The Joint Pathology Center, Division of Biophysical Toxicology,
Joint Base Andrews Naval Air Facility Washington, MD, USA
| | - David A. Jackson
- United States Army Center for Environmental Health Research,
Fort Detrick, MD, USA
| | - William E. Dennis
- United States Army Center for Environmental Health Research,
Fort Detrick, MD, USA
| | - John A. Lewis
- United States Army Center for Environmental Health Research,
Fort Detrick, MD, USA
| | - Russell S. Thomas
- The Hamner Institutes for Health Sciences,
Research Triangle Park, NC, USA
| | - Gail D. Chapman
- Military Infectious Disease Research Program, U.S. Army Medical Research & Material Command, Fort Detrick, MD, USA
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Stinn W, Arts JHE, Buettner A, Duistermaat E, Janssens K, Kuper CF, Haussmann HJ. Murine lung tumor response after exposure to cigarette mainstream smoke or its particulate and gas/vapor phase fractions. Toxicology 2010; 275:10-20. [PMID: 20594951 DOI: 10.1016/j.tox.2010.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 05/17/2010] [Accepted: 05/17/2010] [Indexed: 11/18/2022]
Abstract
Knowledge on mechanisms of smoking-induced tumorigenesis and on active smoke constituents may improve the development and evaluation of chemopreventive and therapeutic interventions, early diagnostic markers, and new and potentially reduced-risk tobacco products. A suitable laboratory animal disease model of mainstream cigarette smoke inhalation is needed for this purpose. In order to develop such a model, A/J and Swiss SWR/J mouse strains, with a genetic susceptibility to developing lung adenocarcinoma, were whole-body exposed to diluted cigarette mainstream smoke at 0, 120, and 240 mg total particulate matter per m(3) for 6h per day, 5 days per week. Mainstream smoke is the smoke actively inhaled by the smoker. For etiological reasons, parallel exposures to whole smoke fractions (enriched for particulate or gas/vapor phase) were performed at the higher concentration level. After 5 months of smoke inhalation and an additional 4-month post-inhalation period, both mouse strains responded similarly: no increase in lung tumor multiplicity was seen at the end of the inhalation period; however, there was a concentration-dependent tumorigenic response at the end of the post-inhalation period (up to 2-fold beyond control) in mice exposed to the whole smoke or the particulate phase. Tumors were characterized mainly as pulmonary adenomas. At the end of the inhalation period, epithelial hyperplasia, atrophy, and metaplasia were found in the nasal passages and larynx, and cellular and molecular markers of inflammation were found in the bronchoalveolar lavage fluid. These inflammatory effects were mostly resolved by the end of the post-inhalation period. In summary, these mouse strains responded to mainstream smoke inhalation with enhanced pulmonary adenoma formation. The major tumorigenic potency resided in the particulate phase, which is contrary to the findings published for environmental tobacco smoke surrogate inhalation in these mouse models.
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Affiliation(s)
- Walter Stinn
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstr. 3, 51149 Cologne, Germany.
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18
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Weber K, Germann PG, Iwata H, Hardisty J, Kaufmann W, Rosenbruch M. Lesions in the Larynx of Wistar RccHan: WIST Rats. J Toxicol Pathol 2009; 22:229-46. [PMID: 22271998 PMCID: PMC3234598 DOI: 10.1293/tox.22.229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Accepted: 07/14/2009] [Indexed: 11/25/2022] Open
Abstract
Specific regions in the rat larynx exhibit cellular changes in response to
inhaled xenobiotics. These regions include the base of the epiglottis, ventral
pouch, and medial surfaces of the vocal processes of the arytenoid
cartilages. 1 , 2 In order to collect information on the usefulness of
trimming techniques, the influence of different vehicles, the impact of
different application routes in toxicity studies, and differences between
induced vs. spontaneous lesions, the data obtained from a large number of
inhalation and non-inhalation studies performed in Wistar RCCHanTM:
Wist rats at Harlan Laboratories Ltd Switzerland, all evaluated or reviewed by
the same pathologist, were compiled for a detailed review. The value of
different trimming techniques was deemed to be greatest for transverse and
sagittolongitudinal section techniques, as compared to horizontolongitudinally
section techniques. The comparison of lesions encountered in control rats of
inhalation studies treated with different vehicles did not reveal differences in
the type, distribution pattern, incidence and/or severity of spontaneous
lesions. The types of lesions were also independent of different application
routes in non-inhalation studies compared to inhalation studies. The pattern of
spontaneous lesions in the rodent larynx was determined by degenerative and
inflammatory lesions starting most often in the submucosal glands by desiccated
secretion followed by mineralization and local inflammation or were induced by
impacted foreign bodies. Squamous metaplasia was recorded in the respiratory
epithelium overlaying the ventral gland as a spontaneous lesion in male Wistar
rats from inhalation studies with a maxim of 20.0% in an inhalation oncogenicity
study. Induced metaplastic changes recorded in the larynx were reversible. Other
induced lesions in inhalation studies consisted of submucosal edema, necrosis,
inflammation and/or granuloma. Induced lesions in non-inhalation studies were
found to be exclusively related to reflux laryngitis or food impaction. It is
concluded, that in rodents induced lesions of the larynx differ in type,
distribution pattern, severity and incidence from spontaneous lesions.
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Affiliation(s)
- Klaus Weber
- Harlan Laboratories Ltd., Zelgliweg 1, 4452 Itingen,
Switzerland
| | | | - Hijiri Iwata
- Harlan Laboratories Ltd., Zelgliweg 1, 4452 Itingen,
Switzerland
| | - Jerry Hardisty
- EPL Experimental Pathology Laboratories Inc., Research Triangle
Park, North Carolina 27709, USA
| | - Wolfgang Kaufmann
- Experimental Toxicology and Ecology, BASF SE, GV/TD–Z 470,
D-67056 Ludwigshafen, Germany
| | - Martin Rosenbruch
- Bayer Schering Pharma AG, GDD-GED-GTOX-Pathology & Clinical
Pathology, P.O. Box 101709, D-42096 Wuppertal, Germany
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19
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Fuchs P, Demir E, Reuber K, Stromps P, Wolter T, Pallua N. Intra-alveolar IL-6 levels following burn and inhalation injury. Burns 2009; 35:840-4. [DOI: 10.1016/j.burns.2008.05.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 05/28/2008] [Indexed: 10/20/2022]
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20
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Gaworski CL, Schramke H, Diekmann J, Meisgen TJ, Tewes FJ, Veltel DJ, Vanscheeuwijck PM, Rajendran N, Muzzio M, Haussmann HJ. Effect of filtration by activated charcoal on the toxicological activity of cigarette mainstream smoke from experimental cigarettes. Inhal Toxicol 2009; 21:688-704. [PMID: 19555222 DOI: 10.1080/08958370802406290] [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] [Indexed: 10/20/2022]
Abstract
Activated charcoal (AC) filtration reportedly decreases the yields of smoke vapor phase constituents including some identified as human carcinogens and respiratory irritants. Non-clinical studies including chemical smoke analysis, in vitro cytotoxicity and mutagenicity (bacterial and mammalian cells), and in vivo subchronic rat inhalation studies were carried out using machine smoking at ISO conditions with lit-end research cigarettes containing AC filters. The objective was to assess whether AC filter technology would alter the established toxicity profile of mainstream smoke by increasing or decreasing any known toxicological properties, or elicit new ones. The reduced yield of vapor phase irritants from AC filter cigarettes correlated with markedly decreased in vitro cytotoxicity and in vivo morphology of the nose and lower respiratory tract. Increased yields of particulate phase constituents (e.g. polycyclic aromatic hydrocarbons) in AC filtered smoke were noted in comparison to controls in some studies. The in vitro bacterial mutagenicity of AC filtered smoke particulate preparations was occasionally increased over control levels. Laryngeal epithelial thickness was increased in some rats inhaling AC filtered smoke in comparison to controls, an effect perhaps related to higher inspiratory flow. When tested under more intense Massachusetts Department of Public Health smoking conditions, AC filter associated reductions in vapor phase constituent yields were smaller than those seen with ISO conditions, but the effect on in vitro cytotoxicity remained.
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21
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Smoke chemistry, in vitro and in vivo toxicology evaluations of the electrically heated cigarette smoking system series K. Regul Toxicol Pharmacol 2008; 52:122-39. [DOI: 10.1016/j.yrtph.2008.05.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 05/19/2008] [Accepted: 05/22/2008] [Indexed: 11/24/2022]
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22
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Patskan GJ, Podraza KF, Meurrens K, Coggins CRE, Friedrichs B, Gerstenberg B, Gomm W, Schnell P, Stabbert R, Veltel D, Weber S, Terpstra P. Toxicological comparisons of three styles of a commercial U.S. cigarette (Marlboro with the 1R4F reference cigarette. Inhal Toxicol 2008; 20:695-721. [PMID: 18464057 DOI: 10.1080/08958370801935174] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Toxicological comparisons were made of three commercial cigarettes, namely Marlboro full flavor, Marlboro Lights, and Marlboro Ultra Lights, with the 1R4F reference cigarette. The main comparison was a 90-d inhalation study with mainstream smoke at 150 mg total particulate matter per cubic meter, in Sprague-Dawley rats using 6 h/d and 7 d/w exposures. The principal endpoint was histopathology of the respiratory tract, along with examinations of free lung cell counts after broncho-alveolar lavage. Additional studies on mainstream smoke included Salmonella mutagenicity, cytotoxicity of particulate and gas/vapor phases, and analytical chemistry. The exposures produced effectively the same responses in each of the four groups, and the histopathology results in the commercial cigarette groups were also effectively the same. The 1R4F was also tested at 75 and 200 mg/m(3), and most of the histopathology results obtained here showed dose-response relationships. The free lung cell responses were similar in the 1R4F/commercial cigarette comparison, and there were dose-related changes in the 1R4F groups, most notably for neutrophils. Most of the changes produced in the 90-d of exposure were resolved in a 42-d post-inhalation period. Responses in the in vitro and analytical assays for the four cigarettes were in general similar, when data were expressed either per mg TPM or per mg tar yield. There were judged to be no toxicologically meaningful differences between the profiles evaluated at similar smoke concentrations for the three commercial cigarettes and for the 1R4F using these assays.
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23
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Moennikes O, Vanscheeuwijck PM, Friedrichs B, Anskeit E, Patskan GJ. Reduced toxicological activity of cigarette smoke by the addition of ammonia magnesium phosphate to the paper of an electrically heated cigarette: subchronic inhalation toxicology. Inhal Toxicol 2008; 20:647-63. [PMID: 18464053 PMCID: PMC2442902 DOI: 10.1080/08958370701813273] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 11/17/2007] [Indexed: 11/09/2022]
Abstract
Cigarette smoke is a complex chemical mixture that causes a variety of diseases, such as lung cancer. With the electrically heated cigarette smoking system (EHCSS), temperatures are applied to the tobacco below those found in conventional cigarettes, resulting in less combustion, reduced yields of some smoke constituents, and decreased activity in some standard toxicological tests. The first generation of electrically heated cigarettes (EHC) also resulted in increased formaldehyde yields; therefore, a second generation of EHC was developed with ammonium magnesium phosphate (AMP) in the cigarette paper in part to address this increase. The toxicological activity of mainstream smoke from these two generations of EHC and of a conventional reference cigarette was investigated in two studies in rats: a standard 90-day inhalation toxicity study and a 35-day inhalation study focusing on lung inflammation. Many of the typical smoke exposure-related changes were found to be less pronounced after exposure to smoke from the second-generation EHC with AMP than to smoke from the first-generation EHC or the conventional reference cigarette, when compared on a particulate matter or nicotine basis. Differences between the EHC without AMP and the conventional reference cigarette were not as prominent. Overall, AMP incorporated in the EHC cigarette paper reduced the inhalation toxicity of the EHCSS more than expected based on the observed reduction in aldehyde yields.
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Affiliation(s)
- O Moennikes
- Philip Morris Products S.A., PMI Research and Development, Neuchâtel, Switzerland.
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24
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Yin W, Ghebrehiwet B, Weksler B, Peerschke EIB. Regulated complement deposition on the surface of human endothelial cells: effect of tobacco smoke and shear stress. Thromb Res 2007; 122:221-8. [PMID: 18166221 DOI: 10.1016/j.thromres.2007.11.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 11/20/2007] [Accepted: 11/27/2007] [Indexed: 12/23/2022]
Abstract
Cigarette smoke and hemodynamic stress both contribute to vascular inflammation and associated atherosclerosis. We recently demonstrated direct activation of complement components C4 and C3 on human endothelial cells (EC). The present study was designed to explore complement activation on bone marrow microvascular endothelial cells (BMEC) and human umbilical vein endothelial cells (HUVEC) in response to endothelial cell injury by tobacco smoke extract, shear stress, or other known inflammatory and atherogenic mediators, lipopolysaccharide (LPS) and INF-gamma. Following treatment, confluent EC monolayers were exposed to plasma (60 min, 37 degrees C), and cell surface deposition of stable complement derivatives C4d, iC3b and SC5b-9 was measured in situ using an ELISA approach. Consistent with previous results, moderate levels of C4d, iC3b and SC5b-9 deposition were observed on native EC monolayers exposed to human plasma. Tobacco smoke and shear stress enhanced EC C4d deposition. In contrast, LPS and INF-gamma failed to affect EC mediated complement activation, despite evidence of EC activation illustrated by ICAM-1 expression. The combination of tobacco smoke and shear stress nearly doubled EC C4d expression. No increases in iC3b or SC5b-9 were noted, suggesting inhibition of classical and alternative pathway C3 convertase assembly or activity. Indeed, concomitantly increased surface expression of complement regulatory proteins CD35 (CR1) and CD55 was observed following EC exposure to tobacco smoke and shear stress. These results suggest that a balance between complement activation and regulation exists at the EC surface, and may impact vascular injury leading to thrombosis, arteriosclerosis, and atherogenesis.
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Affiliation(s)
- Wei Yin
- Department of Pathology and Laboratory of Medicine, Weill Medical College of Cornell University, New York, New York, USA
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25
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Kitamura M, Kasai A. Cigarette smoke as a trigger for the dioxin receptor-mediated signaling pathway. Cancer Lett 2007; 252:184-94. [PMID: 17189671 DOI: 10.1016/j.canlet.2006.11.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 11/14/2006] [Accepted: 11/16/2006] [Indexed: 11/17/2022]
Abstract
Dioxins and dioxin-like chemicals cause a wide range of pathologies including carcinogenesis, immune dysfunction, and developmental/reproductive abnormalities. Most of these toxic effects are mediated by aryl hydrocarbon receptor (AhR; also called the dioxin receptor), a ligand-activated transcription factor. Constitutive activation of AhR via genetic manipulation causes development of cancers, inflammation and immune abnormality in mice even without exposure to xenobiotic ligands. Recent investigation disclosed that cigarette smoke contains high levels of agonists for AhR and strongly activates the dioxin signaling pathway. In this review, we describe and discuss possible roles of AhR activation in cigarette smoke-related pathologies, especially focusing on carcinogenesis, inflammation, atherosclerosis, immune dysfunction and teratogenesis.
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Affiliation(s)
- Masanori Kitamura
- Department of Molecular Signaling, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan.
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Gebel S, Gerstmayer B, Kuhl P, Borlak J, Meurrens K, Müller T. The kinetics of transcriptomic changes induced by cigarette smoke in rat lungs reveals a specific program of defense, inflammation, and circadian clock gene expression. Toxicol Sci 2006; 93:422-31. [PMID: 16870687 DOI: 10.1093/toxsci/kfl071] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gene expression profiling in animal models exposed to cigarette mainstream smoke (CS) shapes up as a promising tool for investigating the molecular mechanisms involved in the onset and development of CS-related disease and may aid in the identification of disease candidate genes. Here we report on differential gene expression in lungs of rats exposed for 2, 7, and 13 weeks to 300 and 600 microg total particulate matter/l CS with sacrifice 2, 6, or 20 h after the last exposure. Regarding antioxidant and xenobiotic-metabolizing (phase I/II) enzymes, a stereotypic, mostly transient, expression pattern of differentially expressed genes was observed after each exposure period. The expression patterns were generally dose dependent for antioxidant and phase II genes and not dose dependent for phase I genes at the CS concentrations tested. However, with increasing length of exposure, there was a distinct, mostly sustained and dose-sensitive, expression of genes implicated in innate and adaptive immune responses, clearly pointing to an emerging inflammatory response. Notably, this inflammatory response included the expression of lung disease-related genes not yet linked to CS exposure, such as galectin-3, arginase 1, and chitinase, as well as genes encoding proteolytic enzymes. Finally, our experiments also revealed a CS exposure-dependent shift in the cyclical expression of genes involved in controlling the circadian rhythm. Altogether, these results provide further insight into the molecular mechanisms of CS-dependent disease onset and development and thus may also be useful for defining CS-specific molecular biomarkers of disease.
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Affiliation(s)
- Stephan Gebel
- Philip Morris Research Laboratories GmbH, D-51149 Köln, Germany
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