Recombinant human activated protein C improves endotoxemia-induced endothelial dysfunction: a blood-free model in isolated mouse arteries.
Recombinant human activated protein C (rhAPC) is one of the treatment panels for improving vascular dysfunction in septic patients. In a previous study, we reported that rhAPC treatment in rat endotoxemia improved vascular reactivity, although the mechanisms involved are still under debate. In the present study, we hypothesized that rhAPC may improve arterial dysfunction through its nonanticoagulant properties. Ten hours after injection of LPS in mice (50 mg/kg ip), aortic rings and mesenteric arteries were isolated and incubated with or without rhAPC for 12 h. Aortic rings were mounted in a myograph, after which arterial contractility and endothelium-dependent relaxation were measured in the presence or absence of nitric oxide synthase or cyclooxygenase inhibitors. Flow (shear stress)-mediated dilation with or without the above inhibitors was also measured in mesenteric resistance arteries. Protein expression was assessed by Western blotting. Lipopolysaccharide (LPS) reduced aortic contractility to KCl and phenylephrine as well as dilation to acetylcholine. LPS also reduced flow-mediated dilation in mesenteric arteries. In rhAPC-treated aorta and mesenteric arteries, contractility and endothelial responsiveness to vasodilator drug and shear stress were improved. rhAPC treatment also improved LPS-induced endothelial dysfunction; this effect was associated with an increase in the phosphorylated form of endothelial nitric oxide synthase and protein kinase B as well as cyclooxygenase vasodilatory pathways, thus suggesting that these pathways, together with the decrease in nuclear factor-kappaB activation and inducible nitric oxide synthase expression in the vascular wall, are implicated in the endothelial effect of rhAPC. In conclusion, ex vivo application of rhAPC improves arterial contractility and endothelial dysfunction resulting from endotoxemia in mice. This finding provides important insights into the mechanism underlying rhAPC-induced improvements on arterial dysfunction during septic shock.
Sennoun
Nacira
N
Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 771, Centre National de la Recherche Scientifique (CNRS) UMR 6214, Université d'Angers, Angers, France.
Baron-Menguy
Celine
C
Burban
Mélanie
M
Lecompte
Thomas
T
Andriantsitohaina
Ramaroson
R
Henrion
Daniel
D
Mercat
Alain
A
Asfar
Pierre
P
Levy
Bruno
B
Meziani
Ferhat
F
D000109:Acetylcholine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects; D001158:Arteries / Q000187:drug effects*; D015153:Blotting, Western; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects*; D019446:Endotoxemia / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008070:Lipopolysaccharides; D008297:Male; D008638:Mesenteric Arteries / Q000502:physiology; D051379:Mice; D016328:NF-kappa B / Q000096:biosynthesis / Q000235:genetics; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000235:genetics; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000378:metabolism; D011486:Protein C / Q000494:pharmacology* / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use; D014655:Vascular Resistance / Q000502:physiology; D014665:Vasodilator Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology
D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D011486:Protein C; D011994:Recombinant Proteins; D014665:Vasodilator Agents; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester