The synaptic proteins Neurexins and Neuroligins are widely expressed in the vascular system and contribute to its functions

Unlike other neuronal counterparts, primarysynaptic proteins are not known to be involved invascular physiology.Here, we demonstrate that Neurexins and Neuroligins, whichconstitute large and complex families of fundamental players in synaptic activity,are produced and processed by endothelial and vascular smooth muscle cells throughout the vasculature. Moreover, they are dynamically regulated during vessel remodeling and form endogenous complexes in large vessels as well as in the brain. We then used the chicken chorioallantoic membrane as a system to pursue functional studies and demonstrate that a monoclonal recombinant antibody against beta Neurexin inhibits angiogenesis while exogenous Neuroligin has a role in promoting it. Finally, as an insight into the mechanism of action of betaNeurexin, we show that the anti beta NRXN antibody influences vessel tone in isolated chicken arteries. Ourdiscovery strongly supportsthe idea that even the mostcomplex and plasticeventstaking place inthe nervous system, i.e. synaptic activity, share molecular cues with the vascular system

Pulmonary atelectasis during low stretch ventilation: "open lung" versus "lung rest" strategy

OBJECTIVE: Limiting tidal volume (VT) may minimize ventilator-induced lung injury (VILI). However, atelectasis induced by low VT ventilation may cause ultrastructural evidence of cell disruption. Apoptosis seems to be involved as protective mechanisms from VILI through the involvement of mitogen-activated protein kinases (MAPKs). We examined the hypothesis that atelectasis may influence the response to protective ventilation through MAPKs. DESIGN: Prospective randomized study. SETTING: University animal laboratory. SUBJECTS: Adult male 129/Sv mice. INTERVENTIONS: Isolated, nonperfused lungs were randomized to VILI: VT of 20 mL/kg and positive end-expiratory pressure (PEEP) zero; low stretch/lung rest: VT of 6 mL/kg and 8-10 cm H2O of PEEP; low stretch/open lung: VT of 6 mL/kg, two recruitment maneuvers and 14-16 cm H2O of PEEP. Ventilator settings were adjusted using the stress index. MEASUREMENT AND MAIN RESULT: Both low stretch strategies equally blunted the VILI-induced derangement of respiratory mechanics (static volume-pressure curve), lung histology (hematoxylin and eosin), and inflammatory mediators (interleukin-6, macrophage inflammatory protein-2 [enzyme-linked immunosorbent assay], and inhibitor of nuclear factor-kB[Western blot]). VILI caused nuclear swelling and membrane disruption of pulmonary cells (electron microscopy). Few pulmonary cells with chromatin condensation and fragmentation were seen during both low stretch strategies. However, although cell thickness during low stretch/open lung was uniform, low stretch/lung rest demonstrated thickening of epithelial cells and plasma membrane bleb formation. Compared with the low stretch/open lung, low stretch/lung rest caused a significant decrease in apoptotic cells (terminal deoxynucleotidyl transferase mediated deoxyuridine-triphosphatase nick end-labeling) and tissue expression of caspase-3 (Western blot). Both low stretch strategies attenuated the activation of MAPKs. Such reduction was larger during low stretch/open lung than during low stretch/lung rest (p < 0.001). CONCLUSION: Low stretch strategies provide similar attenuation of VILI. However, low stretch/lung rest strategy is associated to less apoptosis and more ultrastructural evidence of cell damage possibly through MAPKs-mediated pathway. Comment in The role of positive end-expiratory pressure in modulating the apoptosis response during atelectasis-induced lung injury. [Crit Care Med. 2009

Pulmonary atelectasis during low stretch ventilation: "open lung" versus "lung rest" strategy

OBJECTIVE: Limiting tidal volume (VT) may minimize ventilator-induced lung injury (VILI). However, atelectasis induced by low VT ventilation may cause ultrastructural evidence of cell disruption. Apoptosis seems to be involved as protective mechanisms from VILI through the involvement of mitogen-activated protein kinases (MAPKs). We examined the hypothesis that atelectasis may influence the response to protective ventilation through MAPKs. DESIGN: Prospective randomized study. SETTING: University animal laboratory. SUBJECTS: Adult male 129/Sv mice. INTERVENTIONS: Isolated, nonperfused lungs were randomized to VILI: VT of 20 mL/kg and positive end-expiratory pressure (PEEP) zero; low stretch/lung rest: VT of 6 mL/kg and 8-10 cm H2O of PEEP; low stretch/open lung: VT of 6 mL/kg, two recruitment maneuvers and 14-16 cm H2O of PEEP. Ventilator settings were adjusted using the stress index. MEASUREMENT AND MAIN RESULT: Both low stretch strategies equally blunted the VILI-induced derangement of respiratory mechanics (static volume-pressure curve), lung histology (hematoxylin and eosin), and inflammatory mediators (interleukin-6, macrophage inflammatory protein-2 [enzyme-linked immunosorbent assay], and inhibitor of nuclear factor-kB[Western blot]). VILI caused nuclear swelling and membrane disruption of pulmonary cells (electron microscopy). Few pulmonary cells with chromatin condensation and fragmentation were seen during both low stretch strategies. However, although cell thickness during low stretch/open lung was uniform, low stretch/lung rest demonstrated thickening of epithelial cells and plasma membrane bleb formation. Compared with the low stretch/open lung, low stretch/lung rest caused a significant decrease in apoptotic cells (terminal deoxynucleotidyl transferase mediated deoxyuridine-triphosphatase nick end-labeling) and tissue expression of caspase-3 (Western blot). Both low stretch strategies attenuated the activation of MAPKs. Such reduction was larger during low stretch/open lung than during low stretch/lung rest (p < 0.001). CONCLUSION: Low stretch strategies provide similar attenuation of VILI. However, low stretch/lung rest strategy is associated to less apoptosis and more ultrastructural evidence of cell damage possibly through MAPKs-mediated pathway. Comment in The role of positive end-expiratory pressure in modulating the apoptosis response during atelectasis-induced lung injury. [Crit Care Med. 2009

Pulmonary atelectasis during low stretch ventilation: "open lung" versus "lung rest" strategy

OBJECTIVE: Limiting tidal volume (VT) may minimize ventilator-induced lung injury (VILI). However, atelectasis induced by low VT ventilation may cause ultrastructural evidence of cell disruption. Apoptosis seems to be involved as protective mechanisms from VILI through the involvement of mitogen-activated protein kinases (MAPKs). We examined the hypothesis that atelectasis may influence the response to protective ventilation through MAPKs. DESIGN: Prospective randomized study. SETTING: University animal laboratory. SUBJECTS: Adult male 129/Sv mice. INTERVENTIONS: Isolated, nonperfused lungs were randomized to VILI: VT of 20 mL/kg and positive end-expiratory pressure (PEEP) zero; low stretch/lung rest: VT of 6 mL/kg and 8-10 cm H2O of PEEP; low stretch/open lung: VT of 6 mL/kg, two recruitment maneuvers and 14-16 cm H2O of PEEP. Ventilator settings were adjusted using the stress index. MEASUREMENT AND MAIN RESULT: Both low stretch strategies equally blunted the VILI-induced derangement of respiratory mechanics (static volume-pressure curve), lung histology (hematoxylin and eosin), and inflammatory mediators (interleukin-6, macrophage inflammatory protein-2 [enzyme-linked immunosorbent assay], and inhibitor of nuclear factor-kB[Western blot]). VILI caused nuclear swelling and membrane disruption of pulmonary cells (electron microscopy). Few pulmonary cells with chromatin condensation and fragmentation were seen during both low stretch strategies. However, although cell thickness during low stretch/open lung was uniform, low stretch/lung rest demonstrated thickening of epithelial cells and plasma membrane bleb formation. Compared with the low stretch/open lung, low stretch/lung rest caused a significant decrease in apoptotic cells (terminal deoxynucleotidyl transferase mediated deoxyuridine-triphosphatase nick end-labeling) and tissue expression of caspase-3 (Western blot). Both low stretch strategies attenuated the activation of MAPKs. Such reduction was larger during low stretch/open lung than during low stretch/lung rest (p < 0.001). CONCLUSION: Low stretch strategies provide similar attenuation of VILI. However, low stretch/lung rest strategy is associated to less apoptosis and more ultrastructural evidence of cell damage possibly through MAPKs-mediated pathway. Comment in The role of positive end-expiratory pressure in modulating the apoptosis response during atelectasis-induced lung injury. [Crit Care Med. 2009