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Expression of SAA1, SAA2 and SAA4 genes in human primary monocytes and monocyte-derived macrophages
- Source :
- PLoS ONE, Vol 14, Iss 5, p e0217005 (2019), PLoS ONE, PLoS ONE, Public Library of Science, 2019, 14 (5), pp.e0217005. ⟨10.1371/journal.pone.0217005⟩
- Publication Year :
- 2019
- Publisher :
- Public Library of Science (PLoS), 2019.
-
Abstract
- International audience; Circulating serum amyloid A (SAA) is increased in various inflammatory conditions. The human SAA protein family comprises the acute phase SAA1/SAA2, known to activate a large set of innate and adaptive immune cells, and the constitutive SAA4. The liver synthesis of SAA1/SAA2 is well-established but there is still an open debate on extrahepatic SAA expression especially in macrophages. We aimed to investigate the ability of human primary monocytes and monocyte-derived macrophages to express SAA1, SAA2 and SAA4 at both the transcriptional and protein levels, as previous studies almost exclusively dealt with monocytic cell lines. Monocytes and derived macrophages from healthy donors were stimulated under various conditions. In parallel with SAA, pro-inflammatory IL1A, IL1B and IL6 cytokine expression was assessed. While LPS alone was non-effective, a combined LPS/dexamethasone treatment induced SAA1 and to a lesser extent SAA2 transcription in human monocytes and macrophages. In contrast, as expected, pro-inflammatory cytokine expression was strongly induced following stimulation with LPS, an effect which was dampened in the presence of dexamethasone. Furthermore, in monocytes polarized towards a pro-inflammatory M1 phenotype, SAA expression in response to LPS/dexamethasone was potentiated; a result mainly seen for SAA1. However, a major discrepancy was observed between SAA mRNA and intracellular protein levels under the experimental conditions used. Our results demonstrate that human monocytes and macrophages can express SAA genes, mainly SAA1 in response to an inflammatory environment. While SAA is considered as a member of a large cytokine network, its expression in the monocytes-macrophages in response to LPS-dexamethasone is strikingly different from that observed for classic pro-inflammatory cytokines. As monocytes-macrophages are major players in chronic inflammatory diseases, it may be hypothesized that SAA production from macrophages may contribute to the local inflammatory microenvironment, especially when macrophages are compactly organized in granulomas as in sarcoidosis.
- Subjects :
- Lipopolysaccharides
Physiology
Interleukin-1beta
Gene Expression
Pathology and Laboratory Medicine
[SDV.IMM.II]Life Sciences [q-bio]/Immunology/Innate immunity
Monocytes
Dexamethasone
White Blood Cells
Animal Cells
Immune Physiology
Interleukin-1alpha
Medicine and Health Sciences
Enzyme-Linked Immunoassays
Immune Response
Innate Immune System
Healthy Volunteers
Precipitation Techniques
Liver
Cytokines
Medicine
Cellular Types
Research Article
Immune Cells
Science
Immunology
Research and Analysis Methods
Signs and Symptoms
Diagnostic Medicine
[SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN]
Genetics
Immunoprecipitation
Humans
Immunoassays
Secretion
Inflammation
Serum Amyloid A Protein
Blood Cells
Interleukin-6
Macrophages
Biology and Life Sciences
Cell Biology
Molecular Development
Gene Expression Regulation
Immune System
Immunologic Techniques
Physiological Processes
Developmental Biology
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 14
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.pmid.dedup....e5d6a74a60e47d84bf674da62c642735
- Full Text :
- https://doi.org/10.1371/journal.pone.0217005⟩