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Ganesan N, Ronsmans S, Hoet P. Differential immunological effects of silica nanoparticles on peripheral blood mononuclear cells of silicosis patients and controls. Front Immunol 2022; 13:1025028. [PMID: 36311760 PMCID: PMC9606771 DOI: 10.3389/fimmu.2022.1025028] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/21/2022] [Indexed: 11/29/2022] Open
Abstract
Silicosis is a fibrotic disease caused by the inhalation of respirable silica particles, which are typically engulfed by alveolar macrophages and subsequently induce the release of inflammatory cytokines. Various animal experimental and human studies have focused on modeling silicosis, to assess the interactions of macrophages and other cell types with silica particles. There is still, however, limited knowledge on the differential response upon silica-exposure between silicosis patients and controls. We focused on studying the responsiveness of peripheral blood mononuclear cells (PBMCs) to silica nanoparticles (SiNPs) - Ludox and NM-200 - of silicosis patients and controls. The proliferative capacity of T- CD3+ and B- CD19+ cells, were evaluated via Carboxyfluorescein succinimidyl ester (CFSE) assay. The activation status of lymphocyte subsets and response to silica were also evaluated by comparing the extent of micro-granuloma or aggregate formation with the cytokine secretion profiles between both groups of individuals. The proliferative capacity of CD19+ cells was elevated in silicotic patients as opposed to controls. Subsets of regulatory T cells (CD4+ CD25+ and CD8+ CD25+) and immunoglobulins IgM and IgG were also significantly increased in patients. The number and the size of aggregates formed were higher with SiNPs stimulation in patients compared to controls. Multivariable analysis also elucidated the role of key cytokines like interleukin-1β (IL-1β), IL-6 and interferon-gamma (IFN-γ), which were upregulated in SiNP-stimulated PBMCs of patients compared to controls. Our ex vivo model thus has potential to provide insights into the immunological effects of silica particles in lymphocytes of silicosis patients and controls.
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Affiliation(s)
- Nirosha Ganesan
- Laboratory of Toxicology, Unit of Environment & Health, Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven, Leuven, Belgium
| | - Steven Ronsmans
- Laboratory of Toxicology, Unit of Environment & Health, Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium
- Clinic for Occupational and Environmental Medicine, Department of Respiratory Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Peter Hoet
- Laboratory of Toxicology, Unit of Environment & Health, Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven, Leuven, Belgium
- *Correspondence: Peter Hoet,
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Rajasinghe LD, Bates MA, Benninghoff AD, Wierenga KA, Harkema JR, Pestka JJ. Silica Induction of Diverse Inflammatory Proteome in Lungs of Lupus-Prone Mice Quelled by Dietary Docosahexaenoic Acid Supplementation. Front Immunol 2022; 12:781446. [PMID: 35126352 PMCID: PMC8813772 DOI: 10.3389/fimmu.2021.781446] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/06/2021] [Indexed: 11/18/2022] Open
Abstract
Repeated short-term intranasal instillation of lupus-prone mice with crystalline silica (cSiO2) induces inflammatory gene expression and ectopic lymphoid neogenesis in the lung, leading to early onset of systemic autoimmunity and rapid progression to glomerulonephritis. These responses are suppressed by dietary supplementation with the ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA). Here, we tested the hypothesis that dietary DHA supplementation suppresses cSiO2-induced inflammatory proteins in bronchoalveolar alveolar lavage fluid (BALF) and plasma of lupus-prone mice. Archived tissue fluid samples were used from a prior investigation in which 6 wk-old lupus-prone female NZBWF1 mice were fed isocaloric diets containing 0 or 10 g/kg DHA for 2 wks and then intranasally instilled with 1 mg cSiO2 or vehicle once weekly for 4 wks. Cohorts were terminated at 1, 5, 9 or 13 wk post-instillation (PI). BALF and plasma from each cohort were analyzed by high density multiplex array profiling of 200 inflammatory proteins. cSiO2 time-dependently induced increases in the BALF protein signatures that were highly reflective of unresolved lung inflammation, although responses in the plasma were much less robust. Induced proteins in BALF included chemokines (e.g., MIP-2, MCP-5), enzymes (e.g., MMP-10, granzyme B), adhesion molecules (e.g., sE-selectin, sVCAM-1), co-stimulatory molecules (e.g., sCD40L, sCD48), TNF superfamily proteins (e.g., sTNFRI, sBAFF-R), growth factors (e.g., IGF-1, IGFBP-3), and signal transduction proteins (e.g., MFG-E8, FcgRIIB), many of which were blocked or delayed by DHA supplementation. The BALF inflammatory proteome correlated positively with prior measurements of gene expression, pulmonary ectopic lymphoid tissue neogenesis, and induction of autoantibodies in the lungs of the control and treatment groups. Ingenuity Pathway Analysis (IPA) revealed that IL-1β, TNF-α, and IL-6 were among the top upstream regulators of the cSiO2-induced protein response. Furthermore, DHA's effects were associated with downregulation of cSiO2-induced pathways involving i) inhibition of ARE-mediated mRNA decay, ii) bacterial and viral pattern recognition receptor activation, or iii) TREM1, STAT3, NF-κB, and VEGF signaling and with upregulation of PPAR, LXR/RXR and PPARα/RXRα signaling. Altogether, these preclinical findings further support the contention that dietary DHA supplementation could be applicable as an intervention against inflammation-driven autoimmune triggering by cSiO2 or potentially other environmental agents.
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Affiliation(s)
- Lichchavi D. Rajasinghe
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, United States
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
| | - Melissa A. Bates
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, United States
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
| | - Abby D. Benninghoff
- Department of Animal, Dairy and Veterinary Sciences, School of Veterinary Medicine, Utah State University, Logan, UT, United States
| | - Kathryn A. Wierenga
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Jack R. Harkema
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, United States
| | - James J. Pestka
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, United States
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
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Endothelial Dysfunction through Oxidatively Generated Epigenetic Mark in Respiratory Viral Infections. Cells 2021; 10:cells10113067. [PMID: 34831290 PMCID: PMC8623825 DOI: 10.3390/cells10113067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/30/2021] [Accepted: 11/03/2021] [Indexed: 12/16/2022] Open
Abstract
The bronchial vascular endothelial network plays important roles in pulmonary pathology during respiratory viral infections, including respiratory syncytial virus (RSV), influenza A(H1N1) and importantly SARS-Cov-2. All of these infections can be severe and even lethal in patients with underlying risk factors.A major obstacle in disease prevention is the lack of appropriate efficacious vaccine(s) due to continuous changes in the encoding capacity of the viral genome, exuberant responsiveness of the host immune system and lack of effective antiviral drugs. Current management of these severe respiratory viral infections is limited to supportive clinical care. The primary cause of morbidity and mortality is respiratory failure, partially due to endothelial pulmonary complications, including edema. The latter is induced by the loss of alveolar epithelium integrity and by pathological changes in the endothelial vascular network that regulates blood flow, blood fluidity, exchange of fluids, electrolytes, various macromolecules and responses to signals triggered by oxygenation, and controls trafficking of leukocyte immune cells. This overview outlines the latest understanding of the implications of pulmonary vascular endothelium involvement in respiratory distress syndrome secondary to viral infections. In addition, the roles of infection-induced cytokines, growth factors, and epigenetic reprogramming in endothelial permeability, as well as emerging treatment options to decrease disease burden, are discussed.
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Salum KCR, Castro MCS, Nani ÂSF, Kohlrausch FB. Is individual genetic susceptibility a link between silica exposure and development or severity of silicosis? A systematic review. Inhal Toxicol 2020; 32:375-387. [PMID: 33006295 DOI: 10.1080/08958378.2020.1825569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Silicosis is a lung disease of fibrotic nature resulting from the inhalation and deposition of dust containing crystalline silica. Subjects exposed to the same environmental factors may show distinct radiological manifestations, and since silicosis is known as a multifactorial disease, it is plausible that individual genetic susceptibility may play a role in the pathology. This review of the literature aims to provide an assessment of the present data on the genetic association studies in silicosis and describe the genes that potentially might influence silicosis susceptibility in silica-exposed individuals. METHODS We accessed the database of PubMed for articles published in English about interindividual genetic susceptibility to silicosis using terms related to the subject matter. RESULTS Following the evaluation process, 28 studies were included in this systematic review, including 23 original studies and 5 meta-analyses. CONCLUSIONS Regardless of the advances in the knowledge of the importance of gene variations in silicosis, more studies need to be performed, in particular, special polygenic and genome-wide investigations.
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Affiliation(s)
- Kaio Cezar Rodrigues Salum
- Programa de Pós-Graduação em Ciências e Biotecnologia, Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Marcos Cesar Santos Castro
- Programa de Pós-Graduação em Ciências e Biotecnologia, Universidade Federal Fluminense (UFF), Niterói, Brazil.,Hospital Universitário Antônio Pedro, Universidade Federal Fluminense (UFF), Niterói, Brazil.,Hospital Universitário Pedro Ernesto, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, Brazil
| | | | - Fabiana Barzotto Kohlrausch
- Programa de Pós-Graduação em Ciências e Biotecnologia, Universidade Federal Fluminense (UFF), Niterói, Brazil
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Skuland T, Låg M, Gutleb AC, Brinchmann BC, Serchi T, Øvrevik J, Holme JA, Refsnes M. Pro-inflammatory effects of crystalline- and nano-sized non-crystalline silica particles in a 3D alveolar model. Part Fibre Toxicol 2020; 17:13. [PMID: 32316988 PMCID: PMC7175518 DOI: 10.1186/s12989-020-00345-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/07/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Silica nanoparticles (SiNPs) are among the most widely manufactured and used nanoparticles. Concerns about potential health effects of SiNPs have therefore risen. Using a 3D tri-culture model of the alveolar lung barrier we examined effects of exposure to SiNPs (Si10) and crystalline silica (quartz; Min-U-Sil) in the apical compartment consisting of human alveolar epithelial A549 cells and THP-1-derived macrophages, as well as in the basolateral compartment with Ea.hy926 endothelial cells. Inflammation-related responses were measured by ELISA and gene expression. RESULTS Exposure to both Si10 and Min-U-Sil induced gene expression and release of CXCL8, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α) and interleukin-1β (IL-1β) in a concentration-dependent manner. Cytokine/chemokine expression and protein levels were highest in the apical compartment. Si10 and Min-U-Sil also induced expression of adhesion molecules ICAM-1 and E-selectin in the apical compartment. In the basolateral endothelial compartment we observed marked, but postponed effects on expression of all these genes, but only at the highest particle concentrations. Geneexpressions of heme oxygenase-1 (HO-1) and the metalloproteases (MMP-1 and MMP-9) were less affected. The IL-1 receptor antagonist (IL-1RA), markedly reduced effects of Si10 and Min-U-Sil exposures on gene expression of cytokines and adhesion molecules, as well as cytokine-release in both compartments. CONCLUSIONS Si10 and Min-U-Sil induced gene expression and release of pro-inflammatory cytokines/adhesion molecules at both the epithelial/macrophage and endothelial side of a 3D tri-culture. Responses in the basolateral endothelial cells were only induced at high concentrations, and seemed to be mediated by IL-1α/β released from the apical epithelial cells and macrophages.
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Affiliation(s)
- Tonje Skuland
- Section of Air Pollution and Noise, Department of Environment and Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403, Oslo, Norway.
| | - Marit Låg
- Section of Air Pollution and Noise, Department of Environment and Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403, Oslo, Norway
| | - Arno C Gutleb
- Environmental Research and Innovation (ERIN), Luxembourg Institute of Science and Technology (LIST), Belvaux, Grand Duchy of Luxembourg, Luxembourg
| | - Bendik C Brinchmann
- Section of Air Pollution and Noise, Department of Environment and Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403, Oslo, Norway
- Department of Occupational Medicine and Epidemiology, National Institute of Occupational Health, Oslo, Norway
| | - Tommaso Serchi
- Environmental Research and Innovation (ERIN), Luxembourg Institute of Science and Technology (LIST), Belvaux, Grand Duchy of Luxembourg, Luxembourg
| | - Johan Øvrevik
- Section of Air Pollution and Noise, Department of Environment and Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403, Oslo, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Jørn A Holme
- Section of Air Pollution and Noise, Department of Environment and Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403, Oslo, Norway
| | - Magne Refsnes
- Section of Air Pollution and Noise, Department of Environment and Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403, Oslo, Norway
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Ferreira L, Peng HH, Cox DP, Chambers DW, Bhula A, Young JD, Ojcius DM, Ramos-Junior ES, Morandini AC. Investigation of foreign materials in gingival lesions: a clinicopathologic, energy-dispersive microanalysis of the lesions and in vitro confirmation of pro-inflammatory effects of the foreign materials. Oral Surg Oral Med Oral Pathol Oral Radiol 2019; 128:250-267. [PMID: 31300373 DOI: 10.1016/j.oooo.2019.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/26/2019] [Accepted: 04/13/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This study aimed to evaluate the clinical and histopathologic features of gingival lesions containing foreign material (GLFMs). In parallel, the composition of the foreign material and its effects in primary human gingival fibroblasts (HGFs) were investigated. STUDY DESIGN Eighty-six GLFMs were retrieved from an oral pathology biopsy service. Clinical and microscopic data were analyzed, and the composition of the particles was identified by using energy-dispersive X-ray spectroscopy (EDX). Furthermore, HGFs were stimulated with silica (SiO2) microparticles to investigate the production of collagen type 1 (COL-1), matrix metalloproteinase 2 (MMP2), and inflammatory cytokines. RESULTS GLFMs were most commonly found in women (60.5%) and most frequently described as white plaques. Histopathologic examination identified verrucous hyperplasia in 59% and epithelial dysplasia in 28% of the cases. EDX microanalysis revealed that Si (94%) was the most frequently detected foreign element. SiO2 microparticles induced higher COL-1 expression; higher levels of proinflammatory cytokines, such as interleukin-6 (IL-6), IL-8, and transforming growth factor-β, and increased MMP-2 activity in HGFs. CONCLUSIONS There was a strong association between the presence of foreign material in the gingiva and white verrucous clinical lesions. In addition, the most common element in the foreign material was Si, and our in vitro findings demonstrate the importance of silica-mediated effects on gingival fibroblasts.
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Affiliation(s)
- Leticia Ferreira
- Department of Diagnostic Sciences, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA.
| | - Hsin-Hsin Peng
- Center for Molecular and Clinical Immunology, Chang Gung University, Taiwan; Laboratory Animal Center, Chang Gung Memorial Hospital, Taiwan
| | - Darren P Cox
- Department of Diagnostic Sciences, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA
| | - David W Chambers
- Department of Orthodontics, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA
| | - Avni Bhula
- International Dental Studies Program, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA; Department of Oral and Maxillofacial Radiology, University of California, Los Angeles, CA, USA
| | - John D Young
- Center for Molecular and Clinical Immunology, Chang Gung University, Taiwan; Laboratory of Cellular Physiology and Immunology, The Rockefeller University, New York, NY, USA
| | - David M Ojcius
- Department of Biomedical Sciences, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA
| | - Erivan S Ramos-Junior
- Department of Biomedical Sciences, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA
| | - Ana Carolina Morandini
- Department of Biomedical Sciences, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA
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Hyphae fragments from A. fumigatus sensitize lung cells to silica particles (Min-U-Sil): Increased release of IL-1β. Toxicol In Vitro 2018; 55:1-10. [PMID: 30414920 DOI: 10.1016/j.tiv.2018.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/30/2018] [Accepted: 11/05/2018] [Indexed: 12/16/2022]
Abstract
Exposure to particulate matter (PM), such as mineral particles and biological particles/components may be linked to aggravation of respiratory diseases, including asthma. Here we report that exposure to Aspergillus fumigatus hyphae fragments (AFH) and lipopolysaccharide (LPS) induced both mRNA synthesis and release of pro-inflammatory interleukin-1 beta (IL-1β) in both human THP-1 monocytes (THP-1 Mo) and phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 monocytes (THP-1 macrophages; THP-1 Ma); while Min-U-Sil alone enhanced the release of IL-1β only in THP-1 Ma. Co-exposure to LPS or AFH with Min-U-Sil caused a synergistic release of IL-1β when compared to single exposures. In contrast, Min-U-Sil did not markedly change LPS- and AFH-induced release of tumor necrosis factor alpha (TNF-α). The combined exposures did not increase the LPS- and AFH-induced expression of IL-1β mRNA. Notably, the AFH- and LPS-induced IL-1β responses with and without co-exposure to Min-U-Sil in THP-1 Mo were found to be caspase-dependent as shown by inhibition with zYVAD-fmk. Furthermore, co-exposure with AFH and Min-U-Sil resulted in similar synergistic releases of IL-1β in primary human airway macrophages (AM; sputum), peripheral blood monocyte-derived macrophages (MDM) and in the human bronchial epithelial cell line (BEAS-2B). In conclusion, AFH induce both the synthesis and release of IL-1β. However, Min-U-Sil further enhanced the cleavage of the induced pro-IL-1β.
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Li J, Yao W, Zhang L, Bao L, Chen H, Wang D, Yue Z, Li Y, Zhang M, Hao C. Genome-wide DNA methylation analysis in lung fibroblasts co-cultured with silica-exposed alveolar macrophages. Respir Res 2017; 18:91. [PMID: 28499430 PMCID: PMC5429546 DOI: 10.1186/s12931-017-0576-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/08/2017] [Indexed: 01/14/2023] Open
Abstract
Background Exposure to crystalline silica is considered to increase the risk of lung fibrosis. The primary effector cell, the myofibroblast, plays an important role in the deposition of extracellular matrix (ECM). DNA methylation change is considered to have a potential effect on myofibroblast differentiation. Therefore, the present study was designed to investigate the genome-wide DNA methylation profiles of lung fibroblasts co-cultured with alveolar macrophages exposed to crystalline silica in vitro. Methods AM/fibroblast co-culture system was established. CCK8 was used to assess the toxicity of AMs. mRNA and protein expression of collagen I, α-SMA, MAPK9 and TGF-β1 of fibroblasts after AMs exposed to 100 μg /ml SiO2 for 0–, 24–, or 48 h were determined by means of quantitative real-time PCR, immunoblotting and immunohistochemistry. Genomic DNA of fibroblasts was isolated using MeDIP-Seq to sequence. R software, GO, KEGG and Cytoscape were used to analyze the data. Results SiO2 exposure increased the expression of collagen I and α-SMA in fibroblasts in co-culture system. Analysis of fibroblast methylome identified extensive methylation changes involved in several signaling pathways, such as the MAPK signaling pathway and metabolic pathways. Several candidates, including Tgfb1 and Mapk9, are hubs who can connect the gene clusters. MAPK9 mRNA expression was significantly higher in fibroblast exposed to SiO2 in co-culture system for 48 h. MAPK9 protein expression was increased at both 24-h and 48-h treatment groups. TGF-β1 mRNA expression of fibroblast has a time-dependent manner, but we didn’t observe the TGF-β1 protein expression. Conclusion Tgfb1 and Mapk9 are helpful to explore the mechanism of myofibroblast differentiation. The genome-wide DNA methylation profiles of fibroblasts in this experimental silicosis model will be useful for future studies on epigenetic gene regulation during myofibroblast differentiation. Electronic supplementary material The online version of this article (doi:10.1186/s12931-017-0576-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan Li
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Wu Yao
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Lin Zhang
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Lei Bao
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Huiting Chen
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Di Wang
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Zhongzheng Yue
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Yiping Li
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Miao Zhang
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China
| | - Changfu Hao
- College of Public Health, Zhengzhou University, No.100, Kexue Road, Zhengzhou city, Henan province, China.
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Herseth JI, Volden V, Bolling AK. Particulate matter-mediated release of long pentraxin 3 (PTX3) and vascular endothelial growth factor (VEGF) in vitro: Limited importance of endotoxin and organic content. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2017; 80:105-119. [PMID: 28071984 DOI: 10.1080/15287394.2016.1257399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
Exposure to particulate matter (PM) is associated with adverse health effects, but it is still relatively unknown which role PM sources and physicochemical properties play in the observed effects. It was postulated that PM in vitro induces release of long pentraxin 3 (PTX3) and vascular endothelial growth factor (VEGF) and that endotoxin and organic compounds present in the PM regulate this release. A contact coculture of THP-1 human leukemia monocytes and A549 human adenocarcinoma alveolar pneumocytes was exposed to PM from Traffic, Wood, Diesel, and Quartz (10-40 µg/cm2) for 12-64 h to determine release of PTX3 and VEGF. The role of endotoxin and the organic fraction in the mediator release was assessed using polymyxin B sulfate and organic extracts, respectively. Finally, antagonists were used to investigate whether the early proinflammatory cytokines interleukin (IL)-1 and tumor necrosis factor (TNF)-α affected the PTX3 and VEGF release. All PM samples induced a time-dependent release of both PTX3 and VEGF. Traffic mediated the greatest release of PTX3, whereas Wood and Diesel were more potent inducers of VEGF. The endotoxin content did not markedly affect release of either mediator, while the organic fraction exerted no significant effect on VEGF release and limited influence on PTX3 release. In addition, the IL-1 and TNF-α agonists affected PTX3 release more strongly than VEGF release. In conclusion, the current data show a limited impact of endotoxin and organic compounds on PTX3 and VEGF release. Further, the observed differences in response patterns may point toward differential regulation of PM-mediated release of PTX3 and VEGF.
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Affiliation(s)
- J I Herseth
- a Faculty of Health Sciences , Oslo and Akershus University College of Applied Sciences , Oslo , Norway
| | - V Volden
- a Faculty of Health Sciences , Oslo and Akershus University College of Applied Sciences , Oslo , Norway
| | - A K Bolling
- b Department of Air Pollution and Noise , Norwegian Institute of Public Health , Oslo , Norway
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Affiliation(s)
- Bernardo S. Franklin
- Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn 53127, Germany; , ,
| | - Matthew S. Mangan
- Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn 53127, Germany; , ,
- German Center for Neurodegenerative Diseases, Bonn 53175, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn 53127, Germany; , ,
- German Center for Neurodegenerative Diseases, Bonn 53175, Germany
- Department of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim 7491, Norway
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Liu X, Sun J. Potential proinflammatory effects of hydroxyapatite nanoparticles on endothelial cells in a monocyte-endothelial cell coculture model. Int J Nanomedicine 2014; 9:1261-73. [PMID: 24648726 PMCID: PMC3956627 DOI: 10.2147/ijn.s56298] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Currently, synthetic hydroxyapatite nanoparticles (HANPs) are used in nanomedicine fields. The delivery of nanomedicine to the bloodstream exposes the cardiovascular system to a potential threat. However, the possible adverse cardiovascular effects of HANPs remain unclear. Current observations using coculture models of endothelial cells and monocytes with HANPs to mimic the complex physiological functionality of the vascular system demonstrate that monocytes could play an important role in the mechanisms of endothelium dysfunction induced by the exposure to HANPs. Our transmission electron microscopy analysis revealed that both monocytes and endothelial cells could take up HANPs. Moreover, our findings demonstrated that at a subcytotoxic dose, HANPs alone did not cause direct endothelial cell injury, but they did induce an indirect activation of endothelial cells, resulting in increased interleukin-6 production and elevated adhesion molecule expression after coculture with monocytes. The potential proinflammatory effect of HANPs is largely mediated by the release of soluble factors from the activated monocytes, leading to an inflammatory response of the endothelium, which is possibly dependent on p38/c-Jun N-terminal kinase, and nuclear factor-kappa B signaling activation. The use of in vitro monocyte–endothelial cell coculture models for the biocompatibility assessment of HANPs could reveal their potential proinflammatory effects on endothelial cells, suggesting that exposure to HANPs possibly increases the risk of cardiovascular disease.
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Affiliation(s)
- Xin Liu
- Shanghai Biomaterials Research and Testing Center, Shanghai Key Laboratory of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jiao Sun
- Shanghai Biomaterials Research and Testing Center, Shanghai Key Laboratory of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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Bølling AK, Totlandsdal AI, Sallsten G, Braun A, Westerholm R, Bergvall C, Boman J, Dahlman HJ, Sehlstedt M, Cassee F, Sandstrom T, Schwarze PE, Herseth JI. Wood smoke particles from different combustion phases induce similar pro-inflammatory effects in a co-culture of monocyte and pneumocyte cell lines. Part Fibre Toxicol 2012; 9:45. [PMID: 23176191 PMCID: PMC3544657 DOI: 10.1186/1743-8977-9-45] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 11/02/2012] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Exposure to particulate matter (PM) has been linked to several adverse cardiopulmonary effects, probably via biological mechanisms involving inflammation. The pro-inflammatory potential of PM depends on the particles' physical and chemical characteristics, which again depend on the emitting source. Wood combustion is a major source of ambient air pollution in Northern countries during the winter season. The overall aim of this study was therefore to investigate cellular responses to wood smoke particles (WSPs) collected from different phases of the combustion cycle, and from combustion at different temperatures. RESULTS WSPs from different phases of the combustion cycle induced very similar effects on pro-inflammatory mediator release, cytotoxicity and cell number, whereas WSPs from medium-temperature combustion were more cytotoxic than WSPs from high-temperature incomplete combustion. Furthermore, comparisons of effects induced by native WSPs with the corresponding organic extracts and washed particles revealed that the organic fraction was the most important determinant for the WSP-induced effects. However, the responses induced by the organic fraction could generally not be linked to the content of the measured polycyclic aromatic hydrocarbons (PAHs), suggesting that also other organic compounds were involved. CONCLUSION The toxicity of WSPs seems to a large extent to be determined by stove type and combustion conditions, rather than the phase of the combustion cycle. Notably, this toxicity seems to strongly depend on the organic fraction, and it is probably associated with organic components other than the commonly measured unsubstituted PAHs.
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Affiliation(s)
| | | | - Gerd Sallsten
- Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital and Academy, University of Gothenburg, Gothenburg, Sweden
| | - Artur Braun
- Laboratory for High Performance Ceramics, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Roger Westerholm
- Department of Analytical Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, 106 91, Sweden
| | - Christoffer Bergvall
- Department of Analytical Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, 106 91, Sweden
| | - Johan Boman
- Department of Chemistry, University of Gothenburg, Gothenburg, Sweden
| | - Hans Jørgen Dahlman
- Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo, Norway
| | - Maria Sehlstedt
- Department of Respiratory Medicine and Allergy, University of Umeå, Umeå, Sweden
| | - Flemming Cassee
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | - Thomas Sandstrom
- Department of Respiratory Medicine and Allergy, University of Umeå, Umeå, Sweden
| | - Per E Schwarze
- Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo, Norway
| | - Jan Inge Herseth
- Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, Oslo, Norway
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Bølling AK, Totlandsdal AI, Sallsten G, Braun A, Westerholm R, Bergvall C, Boman J, Dahlman HJ, Sehlstedt M, Cassee F, Sandstrom T, Schwarze PE, Herseth JI. Wood smoke particles from different combustion phases induce similar pro-inflammatory effects in a co-culture of monocyte and pneumocyte cell lines. Part Fibre Toxicol 2012. [PMID: 23176191 DOI: 10.1186/1743-8977-9-45/figures/4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
BACKGROUND Exposure to particulate matter (PM) has been linked to several adverse cardiopulmonary effects, probably via biological mechanisms involving inflammation. The pro-inflammatory potential of PM depends on the particles' physical and chemical characteristics, which again depend on the emitting source. Wood combustion is a major source of ambient air pollution in Northern countries during the winter season. The overall aim of this study was therefore to investigate cellular responses to wood smoke particles (WSPs) collected from different phases of the combustion cycle, and from combustion at different temperatures. RESULTS WSPs from different phases of the combustion cycle induced very similar effects on pro-inflammatory mediator release, cytotoxicity and cell number, whereas WSPs from medium-temperature combustion were more cytotoxic than WSPs from high-temperature incomplete combustion. Furthermore, comparisons of effects induced by native WSPs with the corresponding organic extracts and washed particles revealed that the organic fraction was the most important determinant for the WSP-induced effects. However, the responses induced by the organic fraction could generally not be linked to the content of the measured polycyclic aromatic hydrocarbons (PAHs), suggesting that also other organic compounds were involved. CONCLUSION The toxicity of WSPs seems to a large extent to be determined by stove type and combustion conditions, rather than the phase of the combustion cycle. Notably, this toxicity seems to strongly depend on the organic fraction, and it is probably associated with organic components other than the commonly measured unsubstituted PAHs.
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Li M, Gunter ME, Fukagawa NK. Differential activation of the inflammasome in THP-1 cells exposed to chrysotile asbestos and Libby "six-mix" amphiboles and subsequent activation of BEAS-2B cells. Cytokine 2012; 60:718-30. [PMID: 23017228 DOI: 10.1016/j.cyto.2012.08.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 07/28/2012] [Accepted: 08/27/2012] [Indexed: 11/29/2022]
Abstract
Inflammatory responses of THP-1 cells (macrophage cell line) exposed to chrysotile asbestos (Chry) and Libby six-mix (LIB) and the subsequent impact on bronchial epithelial cells were determined. Direct treatment of THP-1 cells with Chry caused cell death, activation of caspase-1 and release of IL-1β, while the addition of caspase-1 inhibitor, Z-YVAD-FMK, reduced IL-1β, suggesting that Chry activated the caspase-1 mediated Nod-like receptor protein 3 (NLRP3) inflammasome; by comparison, LIB had less effects on all of these parameters. Expression of antioxidant enzymes, protein oxidation and nitration, and lipid peroxides in THP-1 cells treated with the two particles suggest that LIB generated more reactive oxygen species (ROS) than the same dose of Chry. Differences in fiber length and surface area suggest a possible role for particulate size in the differential activation of the inflammasome. BEAS-2B cells, representing the bronchial epithelium, treated with supernatants of medium from Chry- or LIB-treated THP-1 cells (conditioned medium) activated the MAPK cascade, increased phosphorylation of ERK and Cot (MAP3K8), increased AP-1 binding activity and induced IL-6 release. To verify that IL-1β from THP-1 cells was responsible for activation of BEAS-2B, conditioned medium with added IL-1Ra, an IL-1β antagonist, was applied to BEAS-2B. Results show that IL-1Ra attenuated effects of conditioned medium, supporting a role of IL-1β, as a secondary mediator, in the transduction of inflammatory signaling from the macrophage to epithelial cells. The effects of LIB-conditioned medium appeared to be less dependent on IL-1β. In conclusion, Chry and LIB induce differential inflammatory responses in THP-1 cells that subsequently lead to differential effects in epithelial cells.
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Affiliation(s)
- Muyao Li
- Department of Medicine, University of Vermont College of Medicine, Burlington, VT 05405, USA
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Fang SC, Mehta AJ, Alexeeff SE, Gryparis A, Coull B, Vokonas P, Christiani DC, Schwartz J. Residential black carbon exposure and circulating markers of systemic inflammation in elderly males: the normative aging study. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:674-80. [PMID: 22336131 PMCID: PMC3346771 DOI: 10.1289/ehp.1103982] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 02/15/2012] [Indexed: 05/19/2023]
Abstract
BACKGROUND Traffic-related particles (TRPs) are associated with adverse cardiovascular events. The exact mechanisms are unclear, but systemic inflammatory responses likely play a role. OBJECTIVES We conducted a repeated measures study among male participants of the Normative Aging Study in the greater Boston, Massachusetts, area to determine whether individual-level residential black carbon (BC), a marker of TRPs, is associated with systemic inflammation and whether coronary heart disease (CHD), diabetes, and obesity modify associations. METHODS We quantified markers of inflammation in 1,163 serum samples from 580 men. Exposure to BC up to 4 weeks prior was predicted from a validated spatiotemporal land-use regression model. Linear mixed effects models estimated the effects of BC on each marker while adjusting for potential confounders. RESULTS Associations between BC and blood markers were not observed in main effects models or when stratified by obesity status. However, BC was positively associated with markers of inflammation in men with CHD (particularly vascular endothelial growth factor) and in men with diabetes (particularly interleukin-1β and tumor necrosis factor-α). Significant exposure time windows varied by marker, although in general the strongest associations were observed with moving averages of 2-7 days after a lag of several days. CONCLUSIONS In an elderly male population, estimated BC exposures were positively associated with markers of systemic inflammation but only in men with CHD or diabetes.
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Affiliation(s)
- Shona C Fang
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
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Napierska D, Thomassen LCJ, Lison D, Martens JA, Hoet PH. The nanosilica hazard: another variable entity. Part Fibre Toxicol 2010; 7:39. [PMID: 21126379 PMCID: PMC3014868 DOI: 10.1186/1743-8977-7-39] [Citation(s) in RCA: 472] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 12/03/2010] [Indexed: 11/10/2022] Open
Abstract
Silica nanoparticles (SNPs) are produced on an industrial scale and are an addition to a growing number of commercial products. SNPs also have great potential for a variety of diagnostic and therapeutic applications in medicine. Contrary to the well-studied crystalline micron-sized silica, relatively little information exists on the toxicity of its amorphous and nano-size forms. Because nanoparticles possess novel properties, kinetics and unusual bioactivity, their potential biological effects may differ greatly from those of micron-size bulk materials. In this review, we summarize the physico-chemical properties of the different nano-sized silica materials that can affect their interaction with biological systems, with a specific emphasis on inhalation exposure. We discuss recent in vitro and in vivo investigations into the toxicity of nanosilica, both crystalline and amorphous. Most of the in vitro studies of SNPs report results of cellular uptake, size- and dose-dependent cytotoxicity, increased reactive oxygen species levels and pro-inflammatory stimulation. Evidence from a limited number of in vivo studies demonstrates largely reversible lung inflammation, granuloma formation and focal emphysema, with no progressive lung fibrosis. Clearly, more research with standardized materials is needed to enable comparison of experimental data for the different forms of nanosilicas and to establish which physico-chemical properties are responsible for the observed toxicity of SNPs.
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Affiliation(s)
- Dorota Napierska
- Unit of Lung Toxicology, Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium
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Herseth JI, Refsnes M, Låg M, Schwarze PE. Role of IL-1β and COX2 in silica-induced IL-6 release and loss of pneumocytes in co-cultures. Toxicol In Vitro 2009; 23:1342-53. [DOI: 10.1016/j.tiv.2009.06.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 06/18/2009] [Accepted: 06/30/2009] [Indexed: 01/02/2023]
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Hsieh CH, Sun CK, Lu TH, Chen YC, Lin CJ, Wu CJ, Rau CS, Jeng SF. Simvastatin induces heme oxygenase-1 expression but fails to reduce inflammation in the capsule surrounding a silicone shell implant in rats. J Surg Res 2009; 168:272-80. [PMID: 20018301 DOI: 10.1016/j.jss.2009.07.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 06/14/2009] [Accepted: 07/30/2009] [Indexed: 02/03/2023]
Abstract
BACKGROUND Statins are lipid-lowering agents that are widely used in medical practice. Some studies have demonstrated that statins reduce proinflammatory signaling and have antioxidant and anti-inflammatory effects. The inducible heme oxygenase-1 (HO-1) catalyzes the stepwise degradation of heme to produce equimolar quantities of biliverdin, iron, and carbon monoxide; it has also been suggested to promote the important cholesterol-independent cytoprotective action of statins against oxidative insults. However, overexpression of HO-1 may have dual effects under oxidative stress, and the overaccumulation of ferric iron from heme may result in detrimental rather than cytoprotective effects. This study was designed to investigate the effect of a specific statin, simvastatin, and the role of HO-1 on the inflammatory status of the capsule surrounding a silicone shell implant in rats. METHODS Sprague-Dawley rats were randomly assigned to different groups according to the indicated implantation time (1 , 2 wk, 1 , 2 , and 3 mo postimplant) and the presence or absence of additional treatment (2 mg/kg oral simvastatin daily and/or 2 mg/kg HO inhibitor zinc protoporphyrin (ZnPP) by intraperitoneal injection daily). The formed de novo capsular tissue around the silicone implant was dissected away at the indicated time of sacrifice for experiments regarding the HO-1 expression and the inflammatory status. RESULTS We found a biphasic pattern of inflammation of the capsule with increased production of TNF-α, IL-1β, and COX-2, and activation of NF-κB at 1 wk and again at 1 mo postimplantation. Numerous CD68+monocytes or macrophages were diffusely distributed in the capsule in the early stage but not in the late stage postimplantation. In addition, the implantation procedure induced HO-1 expression, which was significantly up-regulated in the first 2 wk but decreased after 1 mo. Although daily feeding of the rats with simvastatin at 2 mg/kg induced HO-1 expression in the capsule throughout the experimental period, simvastatin treatment failed to reduce the production of TNF-α, IL-1β, and COX-2, or limit NF-κB activation in the early or late stages after implantation. Additionally, simvastatin treatment did not decrease the amount of CD68+cells distributed in the capsule at 1 wk postimplantation. HO-1 up-regulation by simvastatin treatment or down-regulation by additional injection of ZnPP did not demonstrate significant correlation with the inflammatory status of the capsule. CONCLUSION Simvastatin failed to reduce inflammation of the capsule surrounding a silicone shell implant. Although simvastatin induced HO-1 expression throughout the experimental time, up-regulated HO-1 expression could not be attributed to the inflammatory status of the capsule.
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Affiliation(s)
- Ching-Hua Hsieh
- Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan
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Herseth JI, Volden V, Schwarze PE, Låg M, Refsnes M. IL-1beta differently involved in IL-8 and FGF-2 release in crystalline silica-treated lung cell co-cultures. Part Fibre Toxicol 2008; 5:16. [PMID: 19014534 PMCID: PMC2588635 DOI: 10.1186/1743-8977-5-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 11/13/2008] [Indexed: 12/16/2022] Open
Abstract
Background Inhalation of crystalline silica particles is in humans associated with inflammation and development of fibrosis. The aim of the present study was to investigate the effect of crystalline silica on the release of the fibrosis- and angiogenesis-related mediator FGF-2 and the pro-inflammatory mediator IL-8, and how IL-1β and TNF-α were involved in this release from various mono- and co-cultures of monocytes, pneumocytes and endothelial cells. Results Silica exposure induced an increase of IL-8 release from monocytes and from pneumocytes alone, and the FGF-2 level in the medium increased upon silica exposure of pneumocytes. Both the responses were enhanced in non-contact co-cultures with endothelial cells. The FGF-2 release seemed to increase with the silica-induced decrease in the number of pneumocytes. The release of IL-8 and FGF-2 was partially suppressed in cultures with pneumocytes in contact with monocytes compared to non-contact cultures. Treatment with anti-TNF-α and the IL-1 receptor antagonist revealed that release of IL-1β, and not TNF-α, from monocytes dominated the regulation of IL-8 release in co-cultures. For release of FGF-2, IL-1ra was without effect. However, exogenous IL-1β reduced the FGF-2 levels, strongly elevated the FGF-2-binding protein PTX3, and prevented the reduction in the number of pneumocytes induced by silica. Conclusion IL-1β seems to be differently involved in the silica-induced release of IL-8 and FGF-2 in different lung cell cultures. Whereas the silica-induced IL-8 release is regulated via an IL-1-receptor-mediated mechanism, IL-1β is suggested only indirectly to affect the silica-induced FGF-2 release by counteracting pneumocyte loss. Furthermore, the enhanced IL-8 and FGF-2 responses in co-cultures involving endothelial cells show the importance of the interaction between different cell types and may suggest that both these mediators are important in angiogenic or fibrogenic processes.
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Affiliation(s)
- Jan I Herseth
- Department for Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo, Norway.
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