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Prognostic and Pathogenic Role of Angiopoietin-1 and -2 in Pneumonia

Birgitt Gutbier, Anne-Kathrin Neuhauß, Katrin Reppe, Carolin Ehrler, Ansgar Santel, Jörg Kaufmann, Markus Scholz, Norbert Weissmann, Lars Morawietz, Timothy J Mitchell, Stefano Aliberti, Stefan Hippenstiel, etc.

Am J Respir Crit Care Med. 2018 Jul 15;198(2):220-231.

PMID: 29447449

Abstract:

Rationale:
During pneumonia, pathogen-host interaction evokes inflammation and lung barrier dysfunction. Tie2 activation by angiopoietin-1 reduces, whereas Tie2 blockade by angiopoietin-2 increases, inflammation and permeability during sepsis. The role of angiopoietin-1/-2 in pneumonia remains unidentified.
Objectives:
To investigate the prognostic and pathogenic impact of angiopoietins in regulating pulmonary vascular barrier function and inflammation in bacterial pneumonia.
Methods:
Serum angiopoietin levels were quantified in pneumonia patients of two independent cohorts (n = 148, n = 395). Human postmortem lung tissue, pneumolysin- or angiopoietin-2-stimulated endothelial cells, isolated perfused and ventilated mouse lungs, and mice with pneumococcal pneumonia were investigated.
Measurements and main results:
In patients with pneumonia, decreased serum angiopoietin-1 and increased angiopoietin-2 levels were observed as compared with healthy subjects. Higher angiopoietin-2 serum levels were found in patients with community-acquired pneumonia who died within 28 days of diagnosis compared with survivors. Receiver operating characteristic analysis revealed improved prognostic accuracy of CURB-65 for 28-day survival, intensive care treatment, and length of hospital stay if combined with angiopoietin-2 serum levels. In vitro, pneumolysin enhanced endothelial angiopoietin-2 release, angiopoietin-2 increased endothelial permeability, and angiopoietin-1 reduced pneumolysin-evoked endothelial permeability. Ventilated and perfused lungs of mice with angiopoietin-2 knockdown showed reduced permeability on pneumolysin stimulation. Increased pulmonary angiopoietin-2 and reduced angiopoietin-1 mRNA expression were observed in Streptococcus pneumoniae-infected mice. Finally, angiopoietin-1 therapy reduced inflammation and permeability in murine pneumonia.
Conclusions:
These data suggest a central role of angiopoietin-1/-2 in pneumonia-evoked inflammation and permeability. Increased angiopoietin-2 serum levels predicted mortality and length of hospital stay, and angiopoietin-1 may provide a therapeutic target for severe pneumonia.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
IAR4248741 Angiopoietin-1 human Angiopoietin-1 human Price
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