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Eliwan H.O.,National Maternity Hospital | Eliwan H.O.,University College Dublin | Eliwan H.O.,National Children Research Center | Eliwan H.O.,Royal College of Surgeons in Ireland | And 19 more authors.
Clinical and Experimental Immunology | Year: 2015

Infection and inflammation can be antecedents of neonatal encephalopathy (NE) and increase the risk of neurological sequelae. Activated protein C (APC) has anti-coagulant and anti-inflammatory effects and provides neuroprotection in brain and spinal cord injury. We examined neutrophil and monocyte responses to lipopolysaccharide (LPS) in infants with NE compared with healthy adult and neonatal controls, and also studied the effect of APC. Whole blood was incubated with LPS and APC and Toll-like receptor (TLR)-4 (LPS recognition), CD11b expression (activation) and intracellular reactive oxygen intermediate (ROI; function) release from neutrophils and monocytes was examined by flow cytometry serially from days 1 to 7. We found a significant increase in neutrophil ROI in infants with NE on day 3 following LPS compared to neonatal controls and this augmented response was reduced significantly by APC. Neutrophil and monocyte CD11b expression was increased significantly on day 1 in infants with NE compared to neonatal controls. LPS-induced neutrophil TLR-4 expression was increased significantly in infants with NE on days 3 and 7 and was reduced by APC. LPS-induced monocyte TLR-4 was increased significantly in infants with NE on day 7. Neutrophil and monocyte activation and production of ROIs may mediate tissue damage in infants with NE. APC modified LPS responses in infants with NE. APC may reduce the inflammatory responses in NE and may ameliorate multi-organ dysfunction. Further study of the immunomodulatory effects of protein C may be warranted using mutant forms with decreased bleeding potential. © 2014 British Society for Immunology.


Higgins G.,National Children Research Center | Buchanan P.,National Children Research Center | Perriere M.,National Children Research Center | Al-Alawi M.,Royal College of Surgeons in Ireland | And 7 more authors.
American Journal of Respiratory Cell and Molecular Biology | Year: 2014

In cystic fibrosis (CF), the airway surface liquid (ASL) height is reduced as a result of impaired ion transport, which favors bacterial colonization and inflammation of the airway and leads to progressive lung destruction. Lipoxin (LX)A4, which promotes resolution of inflammation, is inadequately produced in the airways of patients with CF. We previously demonstrated that LXA4 stimulates an ASL height increase and epithelial repair. Here we report the molecular mechanisms involved in these processes.Wefound thatLXA4 (1 nM) induced an apical ATP release from non-CF (NuLi-1) and CF (CuFi-1) airway epithelial cell lines and CF primary cultures. The ATP release induced by LXA4 was completely inhibited by antagonists of the ALX/FPR2 receptor and Pannexin-1 channels. LXA4 induced an increase in intracellular cAMP and calcium, which were abolished by the selective inhibition of the P2RY11 purinoreceptor. Pannexin-1 and ATP hydrolysis inhibition and P2RY11 purinoreceptor knockdown all abolished the increase of ASL height induced by LXA4. Inhibition of the A2b adenosine receptor did not affect the ASL height increase induced by LXA4, whereas the PKA inhibitor partially inhibited this response. The stimulation of NuLi-1 and CuFi-1 cell proliferation, migration, and wound repair by LXA4 was inhibited by the antagonists of Pannexin-1 channel and P2RY11 purinoreceptor. Taken together, our results provide evidence for a novel role of LXA4 in stimulating apical ATP secretion via Pannexin-1 channels and P2RY11 purinoreceptors activation leading to an ASL height increase and epithelial repair. Copyright © 2014 by the American Thoracic Society.


Higgins G.,National Children Research Center | Higgins G.,Royal College of Surgeons in Ireland | Torre C.F.,National Children Research Center | Tyrrell J.,Royal College of Surgeons in Ireland | And 6 more authors.
American Journal of Physiology - Lung Cellular and Molecular Physiology | Year: 2016

The specialized proresolution lipid mediator lipoxin A4 (LXA4) is abnormally produced in cystic fibrosis (CF) airways. LXA4 increases the CF airway surface liquid height and stimulates airway epithelial repair and tight junction formation. We report here a protective effect of LXA4 (1 nM) against tight junction disruption caused by Pseudomonas aeruginosa bacterial challenge together with a delaying action against bacterial invasion in CF airway epithelial cells from patients with CF and immortalized cell lines. Bacterial invasion and tight junction integrity were measured by gentamicin exclusion assays and confocal fluorescence microscopy in non-CF (NuLi-1) and CF (CuFi-1) bronchial epithelial cell lines and in primary CF cultures, grown under an air/liquid interface, exposed to either a clinical or laboratory strains of P. aeruginosa. LXA4 delayed P. aeruginosa invasion and transepithelial migration in CF and normal bronchial epithelial cell cultures. These protective effects of LXA4 were inhibited by the ALX/FPR2 lipoxin receptor antagonist BOC-2. LXA4 prevented the reduction in mRNA biosynthesis and protein abundance of the tight junction protein ZO-1 and reduced tight junction disruption induced by P. aeruginsosa inoculation. In conclusion, LXA4 plays a protective role in bronchial epithelium by stimulating tight junction repair and by delaying and reducing the invasion of CF bronchial epithelial cells by P. aeruginsosa. © 2016 the American Physiological Society.


PubMed | transnational University of Limburg, Wrocław University, National Children Research Center, Royal College of Surgeons in Ireland and 2 more.
Type: | Journal: Scientific reports | Year: 2016

Bacteriophage therapy is currently resurging as a potential complement/alternative to antibiotic treatment. However, preclinical evaluation lacks streamlined approaches. We here focus on preclinical approaches which have been implemented to assess bacteriophage efficacy against Pseudomonas biofilms and infections. Laser interferometry and profilometry were applied to measure biofilm matrix permeability and surface geometry changes, respectively. These biophysical approaches were combined with an advanced Airway Surface Liquid infection model, which mimics in vitro the normal and CF lung environments, and an in vivo Galleria larvae model. These assays have been implemented to analyze KTN4 (279,593bp dsDNA genome), a type-IV pili dependent, giant phage resembling phiKZ. Upon contact, KTN4 immediately disrupts the P. aeruginosa PAO1 biofilm and reduces pyocyanin and siderophore production. The gentamicin exclusion assay on NuLi-1 and CuFi-1 cell lines revealed the decrease of extracellular bacterial load between 4 and 7 logs and successfully prevents wild-type Pseudomonas internalization into CF epithelial cells. These properties and the significant rescue of Galleria larvae indicate that giant KTN4 phage is a suitable candidate for in vivo phage therapy evaluation for lung infection applications.


PubMed | National Children Research Center and Royal College of Surgeons in Ireland
Type: Journal Article | Journal: Physiological reports | Year: 2014

In cystic fibrosis (CF), the airway surface liquid (ASL) is depleted. We previously demonstrated that lipoxin A4 (LXA4) can modulate ASL height (ASLh) through actions on Cl(-) transport. Here, we report novel effects of lipoxin on the epithelial Na(+) channel ENaC in this response. ASL dynamics and ion transport were studied using live-cell confocal microscopy and short-circuit current measurements in CF (CuFi-1) and non-CF (NuLi-1) cell cultures. Low physiological concentrations of LXA4 in the picomolar range produced an increase in ASLh which was dependent on inhibition of an amiloride-sensitive Na(+) current and stimulation of a bumetanide-sensitive Cl(-) current. These ion transport and ASLh responses to LXA4 were blocked by Boc-2 an inhibitor of the specific LXA4 receptor ALX/FPR2. LXA4 affected the subcellular localization of its receptor and enhanced the localization of ALX/FPR2 at the apical membrane of CF cells. Our results provide evidence for a novel effect of low physiological concentrations of LXA4 to inhibit airway epithelial Na(+) absorption that results in an ASL height increase in CF airway epithelia.


PubMed | National Children Research Center and Royal College of Surgeons in Ireland
Type: Journal Article | Journal: American journal of physiology. Lung cellular and molecular physiology | Year: 2016

The specialized proresolution lipid mediator lipoxin A4 (LXA4) is abnormally produced in cystic fibrosis (CF) airways. LXA4 increases the CF airway surface liquid height and stimulates airway epithelial repair and tight junction formation. We report here a protective effect of LXA4 (1 nM) against tight junction disruption caused by Pseudomonas aeruginosa bacterial challenge together with a delaying action against bacterial invasion in CF airway epithelial cells from patients with CF and immortalized cell lines. Bacterial invasion and tight junction integrity were measured by gentamicin exclusion assays and confocal fluorescence microscopy in non-CF (NuLi-1) and CF (CuFi-1) bronchial epithelial cell lines and in primary CF cultures, grown under an air/liquid interface, exposed to either a clinical or laboratory strains of P. aeruginosa LXA4 delayed P. aeruginosa invasion and transepithelial migration in CF and normal bronchial epithelial cell cultures. These protective effects of LXA4 were inhibited by the ALX/FPR2 lipoxin receptor antagonist BOC-2. LXA4 prevented the reduction in mRNA biosynthesis and protein abundance of the tight junction protein ZO-1 and reduced tight junction disruption induced by P. aeruginsosa inoculation. In conclusion, LXA4 plays a protective role in bronchial epithelium by stimulating tight junction repair and by delaying and reducing the invasion of CF bronchial epithelial cells by P. aeruginsosa.

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