Change search
ReferencesLink to record
Permanent link

Direct link
Pseudomonas aeruginosa N-3-oxo-dodecanoyl-homoserine Lactone Elicits Changes in Cell Volume, Morphology, and AQP9 Characteristics in Macrophages
Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
2016 (English)In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 6, no 32Article in journal (Refereed) PublishedText
Abstract [en]

Quorum sensing (QS) communication allows Pseudomonas aeruginosa to collectively control its population density and the production of biofilms and virulence factors. QS signal molecules, like N-3-oxo-dodecanoyl-L-homoserine lactone (30-C-12-HSL), can also affect the behavior of host cells, e.g., by modulating the chemotaxis, migration, and phagocytosis of human leukocytes. Moreover, host water homeostasis and water channels aquaporins (AQP) are critical for cell morphology and functions as AQP interact indirectly with the cell cytoskeleton and signaling cascades. Here, we investigated how P aeruginosa 30-C-12-HSL affects cell morphology, area, volume and AQP9 expression and distribution in human primary macrophages, using quantitative PCR, immunoblotting, two- and three-dimensional live imaging, confocal and nanoscale imaging. Thus, 30-C-12-HSL enhanced cell volume and area and induced cell shape and protrusion fluctuations in macrophages, processes tentatively driven by fluxes of water across cell membrane through AQP9, the predominant AQP in macrophages. Moreover, 30-C-12-HSL upregulated the expression of AQP9 at both the protein and mRNA levels. This was accompanied with enhanced whole cell AQP9 fluorescent intensity and redistribution of AQP9 to the leading and trailing regions, in parallel with increased cell area in the macrophages. Finally, nanoscopy imaging provided details on AQP9 dynamics and architecture within the lamellipodial area of 30-C-12-HSL-stimulated cells. We suggest that these novel events in the interaction between P aeruginosa and macrophage may have an impact on the effectiveness of innate immune cells to fight bacteria, and thereby resolve the early stages of infections and inflammations.

Place, publisher, year, edition, pages
FRONTIERS MEDIA SA , 2016. Vol. 6, no 32
Keyword [en]
host-bacteria interactions; quorum sensing; N-acylhomoserinelactone; innate immunity; macrophage; water homeostasis; aquaporin
National Category
Clinical Medicine
URN: urn:nbn:se:liu:diva-127262DOI: 10.3389/fcimb.2016.00032ISI: 000372710500001PubMedID: 27047801OAI: diva2:921630

Funding Agencies|Swedish Research Council [2010-3045]; European Science foundation (TraPPs Euromembrane project); Magnus Bergvall Foundation; Faculty of Medicine and Health Sciences, Linkoping University

Available from: 2016-04-20 Created: 2016-04-19 Last updated: 2016-05-10
In thesis
1. Aquaporins in Infection and Inflammation
Open this publication in new window or tab >>Aquaporins in Infection and Inflammation
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The ability of eukaryotic cells to change their shape and to migrate directionally is highly dependent on active volume regulation in cells building up tissues as well as in individual cells. Transmembrane fluxes of water via specialized water channels, called aquaporins (AQPs), facilitate the changes of volume and shape, which additionally require a complex interplay between the plasma membrane and the cytoskeleton. AQPs have been shown to be involved in the development of inflammatory processes and diseases. The aims of the studies underlying this thesis were to further elucidate the expression and function of AQPs in both bacterial and viral infections as well as in the inflammatory disease, microscopic colitis. For this, molecular techniques qPCR, immunoblotting and live, holographic, confocal and super-resolution imaging were used.

When cells of the innate immune system encounter pathogens they need to respond and prepare for migration and phagocytosis and do so through volume regulatory processes. The Gramnegative bacterium Pseudomonas aeruginosa utilizes a small molecule-based communication system, called quorum sensing (QS) to control the production of its virulence factors and biofilms. We found that P. aeruginosa with a complete QS system elicits a stronger phagocytic response in human blood-derived macrophages compared to its lasI-/rhlI- mutant lacking the production of the QS molecules N-butyryl-L-homoserine lactone (C4-HSL) and N-3-oxododecanoyl-L-homoserine lactone (3O-C12-HSL). Infection with P. aeruginosa further increases the expression of AQP9 and induces re-localisation of AQP9 to the front and trailing ends of macrophages. Moreover, the 3O-C12-HSL alone elevates the expression of AQP9, redistribute the water channel to the front and rear ends and increases the cell area and volume of macrophages. Both infection with the wild type P. aeruginosa and the treatment with 3OC12-HSL change the nano-structural architecture of the AQP9 distribution in macrophages.

Viruses use the intracellular machinery of the invaded cells to produce and assemble new viral bodies. Intracellular AQPs are localised in a membranes of cellular organelles to regulate their function and morphology. C3H10T1/2 fibroblasts transiently expressing green fluorescent protein (GFP)-AQP6 show a reduced expression of AQP6 after Hazara virus infection and an increased cell area. Overexpressing AQP6 in C3H10T1/2 cells reduces the infectivity of Hazara virus indicating that AQP6 expression has a protective role in virus infections.

Ion and water channels in the epithelial cell lining tightly regulate the water homeostasis. In microscopic colitis (MC), patients suffer from severe watery diarrhoeas. For the first time, we have shown that the expression of AQP1, 8 and 11 and the sodium/hydrogen exchanger NHE1 are reduced in colonic biopsies from MC patients compared to healthy control individuals. Following treatment with the glucocorticoid budesonide the patients experienced a rapid recovery and we observed a restored or increased expression of the AQPs and NHE1 during treatment, suggesting a role for AQPs in the diarrhoeal mechanisms in MC.

Taken together, this thesis provides new evidence on the importance of water homeostasis regulation through AQPs during infections and inflammation and opens up a door for further investigations of roles for AQPs in inflammatory processes.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2016. 58 p.
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1520
National Category
Public Health, Global Health, Social Medicine and Epidemiology Clinical Laboratory Medicine Cell and Molecular Biology
urn:nbn:se:liu:diva-127500 (URN)10.3384/diss.diva-127500 (DOI)978-91-7685-792-2 (Print) (ISBN)
Public defence
2016-06-02, Hasselqvistsalen, Campus US, Linköping, 09:00 (Swedish)
Available from: 2016-04-28 Created: 2016-04-28 Last updated: 2016-04-28Bibliographically approved

Open Access in DiVA

fulltext(2924 kB)18 downloads
File information
File name FULLTEXT01.pdfFile size 2924 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Holm, AngelikaMagnusson, Karl-EricVikström, Elena
By organisation
Division of Microbiology and Molecular MedicineFaculty of Medicine and Health Sciences
In the same journal
Frontiers in Cellular and Infection Microbiology
Clinical Medicine

Search outside of DiVA

GoogleGoogle Scholar
Total: 18 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 199 hits
ReferencesLink to record
Permanent link

Direct link