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Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats
BACKGROUND: Alveolar macrophages (AM) are known to play an important role in the regulation of inflammatory reactions in the lung, e.g. during the development of chronic lung diseases. Exposure of rats to NO(2 )has recently been shown to induce a shift in the activation type of AM that is characteri...
Autores principales: | , , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2006
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1368986/ https://www.ncbi.nlm.nih.gov/pubmed/16398938 http://dx.doi.org/10.1186/1465-9921-7-4 |
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author | Garn, Holger Siese, Anette Stumpf, Sabine Wensing, Anka Renz, Harald Gemsa, Diethard |
author_facet | Garn, Holger Siese, Anette Stumpf, Sabine Wensing, Anka Renz, Harald Gemsa, Diethard |
author_sort | Garn, Holger |
collection | PubMed |
description | BACKGROUND: Alveolar macrophages (AM) are known to play an important role in the regulation of inflammatory reactions in the lung, e.g. during the development of chronic lung diseases. Exposure of rats to NO(2 )has recently been shown to induce a shift in the activation type of AM that is characterized by reduced TNF-α and increased IL-10 production. So far it is unclear, whether a functional shift in the already present AM population or the occurrence of a new, phenotypically different AM population is responsible for these observations. METHODS: AM from rat and mice were analyzed by flow cytometry for surface marker expression and in vivo staining with PKH26 was applied to characterize newly recruited macrophages. Following magnetic bead separation, AM subpopulations were further analyzed for cytokine, inducible NO synthase (iNOS) and matrix metalloproteinase (MMP) mRNA expression using quantitative RT-PCR. Following in vitro stimulation, cytokines were quantitated in the culture supernatants by ELISA. RESULTS: In untreated rats the majority of AM showed a low expression of the surface antigen ED7 (CD11b) and a high ED9 (CD172) expression (ED7(-)/ED9(high)). In contrast, NO(2 )exposure induced the occurrence of a subpopulation characterized by the marker combination ED7(+)/ED9(low). Comparable changes were observed in mice and by in vivo labeling of resident AM using the dye PKH26 we could demonstrate that CD11b positive cells mainly comprise newly recruited AM. Subsequent functional analyses of separated AM subpopulations of the rat revealed that ED7(+ )cells showed an increased expression and production of the antiinflammatory cytokine IL-10 whereas TNF-α production was lower compared to ED7(- )AM. However, iNOS and IL-12 expression were also increased in the ED7(+ )subpopulation. In addition, these cells showed a significantly higher mRNA expression for the matrix metalloproteinases MMP-7, -8, -9, and -12. CONCLUSION: NO(2 )exposure induces the infiltration of an AM subpopulation that, on the one hand may exert antiinflammatory functions by the production of high amounts of IL-10 but on the other hand may contribute to the pathology of NO(2)-induced lung damage by selective expression of certain matrix metalloproteinases. |
format | Text |
id | pubmed-1368986 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2006 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-13689862006-02-16 Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats Garn, Holger Siese, Anette Stumpf, Sabine Wensing, Anka Renz, Harald Gemsa, Diethard Respir Res Research BACKGROUND: Alveolar macrophages (AM) are known to play an important role in the regulation of inflammatory reactions in the lung, e.g. during the development of chronic lung diseases. Exposure of rats to NO(2 )has recently been shown to induce a shift in the activation type of AM that is characterized by reduced TNF-α and increased IL-10 production. So far it is unclear, whether a functional shift in the already present AM population or the occurrence of a new, phenotypically different AM population is responsible for these observations. METHODS: AM from rat and mice were analyzed by flow cytometry for surface marker expression and in vivo staining with PKH26 was applied to characterize newly recruited macrophages. Following magnetic bead separation, AM subpopulations were further analyzed for cytokine, inducible NO synthase (iNOS) and matrix metalloproteinase (MMP) mRNA expression using quantitative RT-PCR. Following in vitro stimulation, cytokines were quantitated in the culture supernatants by ELISA. RESULTS: In untreated rats the majority of AM showed a low expression of the surface antigen ED7 (CD11b) and a high ED9 (CD172) expression (ED7(-)/ED9(high)). In contrast, NO(2 )exposure induced the occurrence of a subpopulation characterized by the marker combination ED7(+)/ED9(low). Comparable changes were observed in mice and by in vivo labeling of resident AM using the dye PKH26 we could demonstrate that CD11b positive cells mainly comprise newly recruited AM. Subsequent functional analyses of separated AM subpopulations of the rat revealed that ED7(+ )cells showed an increased expression and production of the antiinflammatory cytokine IL-10 whereas TNF-α production was lower compared to ED7(- )AM. However, iNOS and IL-12 expression were also increased in the ED7(+ )subpopulation. In addition, these cells showed a significantly higher mRNA expression for the matrix metalloproteinases MMP-7, -8, -9, and -12. CONCLUSION: NO(2 )exposure induces the infiltration of an AM subpopulation that, on the one hand may exert antiinflammatory functions by the production of high amounts of IL-10 but on the other hand may contribute to the pathology of NO(2)-induced lung damage by selective expression of certain matrix metalloproteinases. BioMed Central 2006 2006-01-06 /pmc/articles/PMC1368986/ /pubmed/16398938 http://dx.doi.org/10.1186/1465-9921-7-4 Text en Copyright © 2006 Garn et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Garn, Holger Siese, Anette Stumpf, Sabine Wensing, Anka Renz, Harald Gemsa, Diethard Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats |
title | Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats |
title_full | Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats |
title_fullStr | Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats |
title_full_unstemmed | Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats |
title_short | Phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of NO(2)-exposed rats |
title_sort | phenotypical and functional characterization of alveolar macrophage subpopulations in the lungs of no(2)-exposed rats |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1368986/ https://www.ncbi.nlm.nih.gov/pubmed/16398938 http://dx.doi.org/10.1186/1465-9921-7-4 |
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