IV, therapeutic study.

Taken together, formation of sVE-cadherin is associated and contributes to inflammation-induced breakdown of endothelial barrier functions by inhibition of VE-cadherin binding. The underlying mechanism of VE-cadherin cleavage involves ADAM10 and appears to be of clinical relevance since sVE-cadherin was augmented in patients with severe sepsis.

Key points• A specific therapy to treat capillary leakage in systemic inflammation and sepsis is not available at present.• Recent studies demonstrated that reduced cAMP levels in endothelial cells contribute to inflammation-induced breakdown of the endothelial barrier.• The present study demonstrates that systemically applied phosphodiesterase-4 inhibitors to increase endothelial cAMP are effective to prevent and to treat capillary leakage followed by improved microcirculation in a rodent model of systemic inflammation.• These data suggest a highly clinically relevant and applicable approach to stabilize capillary leakage in sepsis and systemic inflammation.Abstract In sepsis and systemic inflammation, increased microvascular permeability and consecutive breakdown of microcirculatory flow significantly contribute to organ failure and death. Evidence points to a critical role of cAMP levels in endothelial cells to maintain capillary endothelial barrier properties in acute inflammation. However, approaches to verify this observation in systemic models are rare. Therefore we tested here whether systemic application of the phosphodiesterase-4-inhibitors (PD-4-Is) rolipram or roflumilast to increase endothelial cAMP was effective to attenuate capillary leakage and breakdown of microcirculatory flow in severe lipopolysaccharide (LPS)-induced systemic inflammation in rats. Measurements of cAMP in mesenteric microvessels demonstrated significant LPS-induced loss of cAMP levels which was blocked by application of rolipram. Increased endothelial cAMP by application of either PD-4-I rolipram or roflumilast led to stabilization of endothelial barrier properties as revealed by measurements of extravasated FITC-albumin in postcapillary mesenteric venules. Accordingly, microcirculatory flow in mesenteric venules was significantly increased following PD-4-I treatment and blood gas analyses indicated improved metabolism. Furthermore application of PD-4-I after manifestation of LPS-induced systemic inflammation and capillary leakage therapeutically stabilized endothelial barrier properties as revealed by significantly reduced volume resuscitation for haemodynamic stabilization. Accordingly microcirculation was significantly improved following treatment with PD-4-Is. Our results demonstrate that inflammation-derived loss of endothelial cAMP contributes to capillary leakage which was blocked by systemic PD-4-I treatment. Therefore these data suggest a highly clinically relevant and applicable approach to stabilize capillary leakage in sepsis and systemic inflammation.