Whole Mount Immunofluorescent Staining of the Neonatal Mouse Retina to Investigate Angiogenesis <em>In vivo</em>

Angiogenesis  is the complex process of new blood vessel formation defined by the sprouting  of new blood vessels from a pre-existing vessel network. ...

Newcastle University 

Pulmonary arterial hypertension (PAH) is a severe disease characterized by an increase of pulmonary vascular resistance, which is accompanied by functional and structural changes in pulmonary arteries. Microparticles (MPs) have been described as biological vector of endothelial dysfunction in other pathologies.

Circulating microparticles from pulmonary hypertensive rats induce endothelial dysfunction.

Hypertension art&eacute;rielle pulmonaire (HTAP) est une maladie grave caract&eacute;ris&eacute;e par une augmentation de la r&eacute;sistance vasculaire pulmonaire, qui s&#39;accompagne de changements fonctionnels et structurels dans les art&egrave;res pulmonaires. MICROPARTICULES (MPs) ont &eacute;t&eacute; d&eacute;crits comme vecteur biologique de la dysfonction endoth&eacute;liale dans d&#39;autres pathologies.

Microparticules circulantes des rats hypertendus pulmonaires induisent la dysfonction endoth&eacute;liale.

Ipertensione arteriosa polmonare (PAH) &egrave; una malattia grave, caratterizzata da un aumento della resistenza vascolare polmonare, che &egrave; accompagnata da cambiamenti strutturali e funzionali nelle arterie polmonari. Microparticelle (MPs) sono stati descritti come vettore biologico della disfunzione endoteliale in altre patologie.

Microparticelle circolanti da ratti ipertesi polmonare inducono disfunzione endoteliale.

Bone marrow-derived endothelial progenitor cells (EPCs) are critical for neovascularization. We hypothesized that microparticles (MPs), small fragments generated from the plasma membrane, can activate angiogenic programming of EPCs.

PPARalpha is essential for microparticle-induced differentiation of mouse bone marrow-derived endothelial progenitor cells and angiogenesis.

Les cellules de moelle osseuse endoth&eacute;liales prog&eacute;nitrices (EPCs) sont critiques pour la n&eacute;ovascularisation. Nous avons suppos&eacute; que les microparticules (MPs), petits fragments produits de la membrane plasmique, peuvent activer angiog&eacute;nique programmation du CPE.

PPAR-alpha est essentielle pour la diff&eacute;renciation induite sur les microparticules de cellules prog&eacute;nitrices endoth&eacute;liales d&eacute;riv&eacute;es de la moelle osseuse de souris et de l&#39;angiogen&egrave;se.

Cellule derivate dal midollo osseo progenitrici endoteliali (EPC) sono critiche per la neovascolarizzazione. Abbiamo ipotizzato che le microparticelle (MPs), piccoli frammenti generati dalla membrana del plasma, possono attivare angiogenic programmazione dell&#39;EPC.

PPARalpha &egrave; essenziale per la differenziazione delle cellule progenitrici endoteliali derivate dal midollo osseo di topo e l&#39;angiogenesi indotta da microparticelle.

Microv&eacute;sicules : intercellulaires vecteurs de messages biologiques.

Microvesicles: vettori intercellulare dei messaggi biologici.

Microvesicles: intercellular vectors of biological messages.

Cells communicate with other cells not only via direct cell-cell contact and the production of signaling molecules but also through release of microparticles (MPs). MPs are small vesicles released from stimulated and/or apoptotic cells. They harbor membrane proteins that are characteristic of the original parent cell and intracellular components involved in cell signaling. MPs are considered to be both biomarkers and effectors of cell signaling that maintain and/or initiate cell dysfunction. Thus, MPs can evoke endothelial dysfunction by decreasing nitric oxide (NO) production and promoting vascular inflammation which favor the prothrombotic state in atherosclerosis. Novel pharmacological approaches targeting MP production or properties could be used to treat cardiovascular pathologies. Paradoxically, another useful approach might be to employ engineered MPs with modified compositions as therapeutic agents to correct cardiovascular pathologies. This review is focused on the mechanisms of MP formation and their effects on target cells under physiological or pathophysiological conditions.

Microparticles: targets and tools in cardiovascular disease.

Les cellules communiquent avec d&#39;autres cellules, non seulement par contact direct de cellule-cellule et la production de mol&eacute;cules de signalisation mais aussi par la lib&eacute;ration de microparticules (MPs). D&eacute;put&eacute;s sont de petites v&eacute;sicules sortis de stimul&eacute; et/ou les cellules apoptotiques. Ils abritent des prot&eacute;ines membranaires qui sont caract&eacute;ristiques de la cellule-m&egrave;re originale et composants intracellulaires impliqu&eacute;s dans la signalisation cellulaire. MPs sont consid&eacute;r&eacute;s comme les biomarqueurs et les effecteurs de cellule signalisation qui maintiennent ou initier la dysfonction des cellules. Ainsi, les MPs peuvent &eacute;voquer la dysfonction endoth&eacute;liale en diminuant la production d&#39;oxyde nitrique (non) et en favorisant l&#39;inflammation vasculaire qui favorisent l&#39;&eacute;tat prothrombotique dans l&#39;ath&eacute;roscl&eacute;rose. Roman pharmacologique approche ciblant MP production ou propri&eacute;t&eacute;s pourraient &ecirc;tre utilis&eacute;es pour traiter des pathologies cardiovasculaires. Paradoxalement, une autre approche utile serait d&#39;employer des MPs machin&eacute;s avec des compositions modifi&eacute;es comme agents th&eacute;rapeutiques pour corriger des pathologies cardiovasculaires. Cet examen se concentre sur les m&eacute;canismes de formation de MP et de leurs effets sur les cellules cibles dans des conditions physiologiques ou physiopathologiques.

Microparticules : objectifs et outils dans les maladies cardiovasculaires.

Le cellule comunicano con altre cellule non solo tramite contatto diretto cellula-cellula e la produzione di molecole di segnalazione, ma anche attraverso il rilascio di microparticelle (MPs). MPs sono piccole vescicole rilasciate da stimolato e/o cellule apoptotic. Essi porto di proteine di membrana che sono caratteristici della cellula genitore originale e componenti intracellulari coinvolti nella segnalazione delle cellule. MPs sono considerati sia i biomarcatori ed effettori della segnalazione che mantenere e/o avviare la disfunzione delle cellule delle cellule. Cos&igrave;, MPs pu&ograve; evocare la disfunzione endoteliale diminuendo la produzione di ossido nitrico (NO) e promuovendo l&#39;infiammazione vascolare che favoriscono lo stato protrombotico in aterosclerosi. Romanzo farmacologico si avvicina targeting produzione MP o propriet&agrave; potrebbe essere utilizzato per il trattamento di patologie cardiovascolari. Paradossalmente, potrebbe essere un altro approccio utile impiegare ingegnerizzati MPs con composizioni modificati come agenti terapeutici per correggere patologie cardiovascolari. Questa recensione &egrave; focalizzata sui meccanismi di formazione di MP e i loro effetti sulle cellule bersaglio in condizioni fisiologiche o fisiopatologica.

Microparticelle: obiettivi e strumenti nella malattia cardiovascolare.

Oxidative stress results in deleterious cell function in pathologies associated with inflammation. Here, we investigated the generation of superoxide anion as well as the anti-oxidant defense systems related to the isoforms of superoxide dismutases (SOD) in cystic fibrosis (CF) cells. Pro-apoptotic agents induced apoptosis in CF but not in control cells that was reduced by treatment with SOD mimetic. These effects were associated with increased superoxide anion production, sensitive to the inhibition of IÎºB-Î± phosphorylation, in pancreatic but not tracheal CF cells, and reduced upon inhibition of either mitochondrial complex I or NADPH oxidase. CF cells exhibited reduced expression, but not activity, of both Mn-SOD and Cu/Zn-SOD when compared to control cells. Although, expression of EC-SOD was similar in normal and CF cells, its activity was reduced in CF cells. We provide evidence that high levels of oxidative stress are associated with increased apoptosis in CFTR-mutated cells, the sources being different depending on the cell type. These observations underscore a reduced anti-oxidant defense mechanism, at least in part, via diminished EC-SOD activity and regulation of Cu/Zn-SOD and Mn-SOD expressions. These data point to new therapeutic possibilities in targeting anti-oxidant pathways to reduce oxidative stress and apoptosis in CF cells.

Increased oxidative stress induces apoptosis in human cystic fibrosis cells.

Le stress oxydatif entra&icirc;ne la fonction des cellules d&eacute;l&eacute;t&egrave;res dans les pathologies associ&eacute;es &agrave; l&#39;inflammation. Ici, nous avons &eacute;tudi&eacute; la g&eacute;n&eacute;ration de l&#39;anion superoxyde ainsi que les syst&egrave;mes de d&eacute;fense antioxydants associ&eacute;s &agrave; isoformes de superoxyde dismutases (SOD) dans les cellules de la fibrose kystique (FK). Agents de Pro-apoptotic induit l&#39;apoptose dans les FC, mais pas dans les cellules de contr&ocirc;le qui a &eacute;t&eacute; r&eacute;duite par un traitement avec SOD mim&eacute;tique. Ces effets ont &eacute;t&eacute; associ&eacute;s &agrave; la production d&#39;anions superoxyde accrue, sensible &agrave; l&#39;inhibition de la phosphorylation de I&kappa;B-&alpha;, dans les cellules du pancr&eacute;as mais pas trach&eacute;ales CF et r&eacute;duits par l&#39;inhibition de chaque complexe mitochondrique I ou NADPH oxydase. CF cellules ont montr&eacute; une expression r&eacute;duite, mais pas l&#39;activit&eacute;, de Mn-SOD et de Cu/Zn-SOD comparativement aux cellules contr&ocirc;les. Bien que, l&#39;expression de SOD-EC &eacute;tait similaire dans les normales et les cellules de CF, son activit&eacute; a &eacute;t&eacute; r&eacute;duite dans les cellules de CF. Nous d&eacute;montrons que des niveaux &eacute;lev&eacute;s de stress oxydatif sont associ&eacute;s &agrave; une augmentation apoptose dans les cellules CFTR mut&eacute;, les sources &eacute;tant diff&eacute;rentes selon le type de cellule. Ces observations soulignent un m&eacute;canisme de d&eacute;fense antioxydant r&eacute;duit, au moins en partie, via diminu&eacute;e activit&eacute; SOD-EC et le r&egrave;glement des expressions Cu/Zn-SOD et de la Mn-SOD. Ces donn&eacute;es pointent vers nouvelles possibilit&eacute;s th&eacute;rapeutiques dans le ciblage des voies anti-oxydantes pour r&eacute;duire le stress oxydatif et l&#39;apoptose dans les cellules de CF.

Une augmentation du stress oxydatif induit l&#39;apoptose dans les cellules humaines de fibrose kystique.

Lo stress ossidativo risultati nella funzione cella deleteri in patologie associate con infiammazione. Qui, abbiamo studiato la generazione di anione superossido, nonch&eacute; i sistemi di difesa antiossidanti correlati per le isoforme della dismutasi (SOD) di superossido in cellule di fibrosi cistica (CF). Agenti pro-apoptotico indussero apoptosi in CF, ma non in cellule di controllo che &egrave; stata ridotta dal trattamento con SOD mimetico. Questi effetti sono stati associati con la produzione di anione superossido aumentata, sensibile per l&#39;inibizione della fosforilazione di I&kappa;B-&alpha;, nelle cellule del pancreas ma non tracheale CF e ridotto all&#39;inibizione di uno complesso mitocondriale I o NADPH ossidasi. Le cellule CF esposto espressione ridotta, ma non l&#39;attivit&agrave;, di Mn-SOD e di Cu/Zn-SOD rispetto alle cellule di controllo. Anche se, espressione di CE-SOD era simile in cellule CF e normale, l&#39;attivit&agrave; &egrave; stata ridotta in cellule CF. Forniamo evidenze che alti livelli di stress ossidativo sono associati con aumentato apoptosis in cellule CFTR mutati, le fonti differenti a seconda del tipo di cella. Queste osservazioni sottolineatura un meccanismo di difesa anti-ossidante ridotto, almeno in parte, via diminuita attivit&agrave; CE-SOD e regolamento delle espressioni Cu/Zn-SOD e Mn-SOD. Questi dati indicano nuove possibilit&agrave; terapeutiche nel targeting percorsi anti-ossidante per ridurre lo stress ossidativo e apoptosi in cellule CF.

Aumento dello stress ossidativo induce apoptosi nelle cellule umane la fibrosi cistica.

We aimed to characterize circulating microparticles in association with arterial stiffness, inflammation and endothelial dysfunction in aldosterone-salt-induced hypertension in rats and to investigate the preventive effects of red wine polyphenols. Uninephrectomized male Sprague-Dawley rats were treated with aldosterone-salt (1 Âµg.h(-1)), with or without administration of either red wine polyphenols, Provinolsâ„¢ (20 mg.kg(-1).day(-1)), or spironolactone (30 mg.kg(-1).day(-1)) for 4 weeks. Microparticles, arterial stiffness, nitric oxide (NO) spin trapping, and mesenteric arterial function were measured. Aldosterone-salt rats showed increased microparticle levels, including those originating from platelets, endothelium and erythrocytes. Hypertension resulted in enhanced aortic stiffness accompanied by increased circulating and aortic NO levels and an upregulation of aortic inducible NO-synthase, NFÎºB, superoxide anions and nitrotyrosine. Flow-induced dilatation was reduced in mesenteric arteries. These effects were prevented by spironolactone. Provinolsâ„¢ did not reduce arterial stiffness or systolic hypertension but had effects similar to those of spironolactone on endothelial function assessed by flow-mediated vasodilatation, microparticle generation, aortic NO levels and oxidative stress and apoptosis in the vessel wall. Neither the contractile response nor endothelium-dependent relaxation in mesenteric arteries differed between groups. The in vivo effects of Provinolsâ„¢ were not mediated by mineralocorticoid receptors or changes in shear stress. In conclusion, vascular remodelling and endothelial dysfunction in aldosterone-salt-mediated hypertension are associated with increased circulating microparticles. Polyphenols prevent the enhanced release of microparticles, macrovascular inflammation and oxidative stress, and microvascular endothelial dysfunction independently of blood pressure, shear stress and mineralocorticoid receptor activation in a model of hyperaldosteronism.

Increased microparticle production and impaired microvascular endothelial function in aldosterone-salt-treated rats: protective effects of polyphenols.

L&#39;&eacute;tude visait &agrave; caract&eacute;riser les microparticules circulantes en liaison avec la dysfonction endoth&eacute;liale induite par l&#39;aldost&eacute;rone-sel de l&#39;hypertension chez le rat, l&#39;inflammation et la rigidit&eacute; art&eacute;rielle et &agrave; &eacute;tudier les effets pr&eacute;ventifs de polyph&eacute;nols de vin rouge. Unin&eacute;phrectomis&eacute;s m&acirc;les Sprague-Dawley ont &eacute;t&eacute; trait&eacute;s avec l&#39;aldost&eacute;rone-sel (1 &micro;g.h(-1)), avec ou sans administration de soit polyph&eacute;nols de vins rouges, Provinols &trade; (20 mg.kg(-1).day(-1)) ou spironolactone (30 mg.kg(-1).day(-1)) pendant 4 semaines. On a mesur&eacute; les microparticules, rigidit&eacute; art&eacute;rielle, pi&eacute;geage de spin de l&#39;oxyde nitrique (non) et la fonction art&eacute;rielle m&eacute;sent&eacute;rique. Aldost&eacute;rone-sel des rats ont montr&eacute; des niveaux de microparticules accrue, y compris ceux issus de l&#39;endoth&eacute;lium, les plaquettes et les &eacute;rythrocytes. L&#39;hypertension a entra&icirc;n&eacute; meilleure rigidit&eacute; aortique aortique et accompagn&eacute;e d&#39;une augmentation de la circulation pas de niveaux et une stimulation de l&#39;expression de la NO synthase inductible aortique, NF&kappa;B, anions superoxydes et nitrotyrosine. Dilatation induite par le flux a &eacute;t&eacute; r&eacute;duite dans les art&egrave;res m&eacute;sent&eacute;riques. Ces effets ont &eacute;t&eacute; emp&ecirc;ch&eacute;s par la spironolactone. Provinols &trade; n&#39;a pas r&eacute;duit la rigidit&eacute; art&eacute;rielle ou l&#39;hypertension systolique mais ont eu des effets similaires &agrave; ceux de la spironolactone sur la fonction endoth&eacute;liale &eacute;valu&eacute;s par vasodilatation induite par l&#39;&eacute;coulement, g&eacute;n&eacute;ration de microparticules, aortique et aucun stress oxydatif et l&#39;apoptose dans la paroi des vaisseaux. La r&eacute;ponse contractile ni une relaxation endoth&eacute;lium-d&eacute;pendante dans les art&egrave;res m&eacute;sent&eacute;riques diff&egrave;re entre les groupes. Les effets in vivo de Provinols &trade; ne &eacute;taient pas m&eacute;di&eacute;es par les r&eacute;cepteurs min&eacute;ralocortico&iuml;des ou des changements dans la contrainte de cisaillement. En conclusion, remodelage vasculaire et la dysfonction endoth&eacute;liale dans l&#39;hypertension induite par l&#39;aldost&eacute;rone-sel sont associ&eacute;s avec des microparticules circulantes accrues. Polyph&eacute;nols emp&ecirc;chent la lib&eacute;ration accrue de microparticules, macrovasculaires inflammation et du stress oxydatif et la dysfonction endoth&eacute;liale microvasculaire ind&eacute;pendamment de la pression art&eacute;rielle, de cisaillement et min&eacute;ralocortico&iuml;des l&#39;activation du r&eacute;cepteur dans un mod&egrave;le d&#39;hyperaldost&eacute;ronisme.

Augmentation de la production au moyen de microparticules et une alt&eacute;ration de la fonction endoth&eacute;liale microvasculaire chez les rats trait&eacute;s aldost&eacute;rone-sel : les effets protecteurs de polyph&eacute;nols.

Abbiamo mirato a caratterizzare le microparticelle circolanti in associazione con rigidit&agrave; arteriosa, infiammazione e disfunzione endoteliale in aldosterone-sale ipertensione indotta nei ratti e di indagare gli effetti preventivi di polifenoli vino rosso. Uninephrectomized ratti Sprague-Dawley maschi sono stati trattati con l&#39;aldosterone-sale (1 &micro;g.h(-1)), con o senza somministrazione di entrambi polifenoli vino rosso, Provinols &trade; (20 mg.kg(-1).day(-1)), o Spironolattone (30 mg.kg(-1).day(-1)) per 4 settimane. Sono state misurate le microparticelle, rigidit&agrave; arteriosa, ossido nitrico (NO) spin trapping e funzione arteriosa mesenterica. Aldosterone-sale ratti ha mostrato maggiore microparticelle livelli, compresi quelli provenienti da piastrine, endotelio e gli eritrociti. L&#39;ipertensione ha portato maggiore rigidit&agrave; aortica aortica e accompagnata da aumento di circolazione NO livelli e un upregulation di NO-sintasi inducibile aortica, NF&kappa;B, anioni superossido e nitrotyrosine. Dilatazione flusso-indotta &egrave; stato ridotto nelle arterie mesenteriche. Questi effetti sono stati evitati dal Spironolattone. Provinols &trade; non ha fatto ridurre la rigidit&agrave; arteriosa o ipertensione sistolica ma ha avuto effetti simili a quelli dello spironolattone sulla funzione endoteliale, valutato da vasodilatazione flusso-mediata, generazione di microparticelle, aortica senza livelli e lo stress ossidativo e apoptosi nella parete del vaso. Risposta contrattile n&eacute; rilassamento endotelio-dipendente nelle arterie mesenteriche differiva tra i gruppi. Gli effetti in vivo di Provinols &trade; sono non stati mediati dai recettori dei mineralcorticoidi o cambiamenti nella sollecitazione di taglio. In conclusione, rimodellamento vascolare e disfunzione endoteliale nell&#39;ipertensione aldosterone-sale-mediata sono associati con aumentate microparticelle circolanti. Polifenoli impediscono il rilascio maggiore di microparticelle, macrovascular infiammazione e stress ossidativo e microvascolare disfunzione endoteliale indipendentemente dall&#39;attivazione del recettore, pressione sanguigna, shear stress e mineralcorticoidi in un modello di iperaldosteronismo.

Aumento della produzione di microparticelle e alterata funzione endoteliale microvascolare nei ratti trattati aldosterone-sale: effetto protettivo dei polifenoli.

Obstructive sleep apnea (OSA) is characterized by repetitive apnea-hypopnea cycles during sleep associated with oxygen desaturation and sleep disruption. We evaluated the role of circulating microparticles (MPs) from patients with OSA in the regulation of vascular function. MPs from whole blood from patients with OSA or control subjects were injected i.v. into mice. Injection of MPs from patients with OSA induced ex vivo vascular hyperreactivity in aortas with functional endothelium but, in contrast, hyporeactivity in vessels without functional endothelium. Vascular hyperreactivity was blunted in the presence of a nitric oxide synthase inhibitor alone or combined with the cyclooxygenase inhibitor indomethacin. MPs from patients with OSA reduced endothelial nitric oxide synthase activity and nitric oxide production, increased aortic cyclooxygenase-1 and cyclooxygenase-2 expression, and increased thromboxane A(2) and prostacyclin production. Blockade of thromboxane A(2) receptor did not affect the serotonin response in arteries from OSA MP-treated mice. A superoxide dismutase mimetic reduced the vascular hyperreactivity induced by MPs from patients with OSA but had no effect on contraction in vessels from control and non-OSA MP-treated mice. These data provide evidence that circulating MPs from patients with OSA induce ex vivo vascular hyperreactivity with the obligatory role of the endothelium and subtle interactions between the nitric oxide and cyclooxygenase pathways and metabolites. These results highlight the participation of MPs in vascular dysfunction associated with OSA.

Circulating microparticles from patients with obstructive sleep apnea enhance vascular contraction: mandatory role of the endothelium.

Syndrome d&#39;apn&eacute;e obstructive du sommeil (SAOS) est caract&eacute;ris&eacute; par des cycles r&eacute;p&eacute;titifs d&#39;apn&eacute;e-hypopn&eacute;e pendant le sommeil associ&eacute;e de perturbation d&eacute;saturation et sommeil d&#39;oxyg&egrave;ne. Nous avons &eacute;valu&eacute; le r&ocirc;le des microparticules (MPs) en circulation de patients atteints de OSA dans la r&eacute;gulation de la fonction vasculaire. D&eacute;put&eacute;s du sang de patients atteints de OSA ou contr&ocirc;le de sujets ont &eacute;t&eacute; inject&eacute;es i.v. &agrave; souris. Injection de d&eacute;put&eacute;s provenant de patients avec OSA induite par ex vivo hyperr&eacute;activit&eacute; vasculaire dans les aortes avec l&#39;endoth&eacute;lium fonctionnel mais au contraire, hypor&eacute;activit&eacute; dans les vaisseaux sans endoth&eacute;lium fonctionnel. Hyperr&eacute;activit&eacute; vasculaire a &eacute;t&eacute; affaiblie en pr&eacute;sence d&#39;un inhibiteur de l&#39;oxyde nitrique synthase seul ou combin&eacute; avec l&#39;inhibiteur de la cyclo-oxyg&eacute;nase indom&eacute;tacine. D&eacute;put&eacute;s provenant de patients avec OSA r&eacute;duit endothelial nitric oxide synthase activit&eacute; et oxyde nitrique production, augmentation de l&#39;expression cyclo-oxyg&eacute;nase-1 et la cyclo-oxyg&eacute;nase-2 aortique et accru thromboxane a (2) et production de prostacycline. Blocage des r&eacute;cepteurs de thromboxane a (2) n&#39;a pas affect&eacute; la r&eacute;ponse de s&eacute;rotonine dans les art&egrave;res des souris trait&eacute;es OSA MP. Une superoxyde dismutase mim&eacute;tique r&eacute;duit l&#39;hyperr&eacute;activit&eacute; vasculaire induite par les d&eacute;put&eacute;s provenant de patients avec OSA mais n&#39;avait aucun effet sur la contraction dans les vaisseaux du contr&ocirc;le et des souris non trait&eacute;es OSA MP. Ces donn&eacute;es d&eacute;montrent que MPs circulants de patients avec OSA induisent ex vivo hyperr&eacute;activit&eacute; vasculaire avec le r&ocirc;le obligatoire de l&#39;endoth&eacute;lium et subtiles interactions entre le monoxyde d&#39;azote et de voies de la cyclo-oxyg&eacute;nase et de m&eacute;tabolites. Ces r&eacute;sultats mettent en &eacute;vidence la participation de d&eacute;put&eacute;s dans la dysfonction vasculaire associ&eacute;e aux OSA.

Microparticules circulantes de patients atteints d&#39;apn&eacute;e obstructive du sommeil am&eacute;liorent la contraction vasculaire : r&ocirc;le obligatoire de l&#39;endoth&eacute;lium.

Apnea ostruttiva nel sonno (OSA) &egrave; caratterizzato da cicli ripetitivi apnea-hypopnea durante il sonno associati con ossigeno desaturazione e sonno perturbazione. Abbiamo valutato il ruolo di microparticelle (MPs) in circolazione da pazienti con OSA nella regolazione della funzione vascolare. MPs da sangue intero da pazienti con OSA o controllo soggetti sono state iniettate i.v. in topi. Iniezione di MPs da pazienti con OSA indotta ex vivo iperreattivit&agrave; vascolare in aortas con endotelio funzionale ma, in contrasto, iporeattivit&agrave; nei vasi senza funzionale dell&#39;endotelio. Iperreattivit&agrave; vascolare &egrave; stato attenuato in presenza di un ossido nitrico sintasi inibitore da solo o in combinazione con l&#39;indometacina inibitore della cicloossigenasi. MPs da pazienti con OSA ridotta produzione di attivit&agrave; e ossido nitrico sintasi endoteliale di ossido nitrico, espressione dell&#39;aorta maggiore di cyclooxygenase-1 e cyclooxygenase-2 e aumentato trombossano a (2) e la produzione di prostaciclina. Blocco del recettore di trombossano a (2) non ha influito la risposta di serotonina nelle arterie da topi trattati OSA MP. Un superossido dismutasi mimetico ridotto l&#39;iperreattivit&agrave; vascolari indotte da MPs da pazienti con OSA, ma ha avuto alcun effetto sulla contrazione in vasi da controllo e topi non OSA MP-trattati. Questi dati forniscono prove che inducono la MPs circolanti da pazienti con OSA ex vivo iperreattivit&agrave; vascolare con il ruolo obbligatorio l&#39;endotelio e sottili interazioni tra ossido nitrico e percorsi di cyclooxygenase e metaboliti. Questi risultati evidenziano la partecipazione di MPs in disfunzione vascolare associata OSA.

Microparticelle circolanti nei pazienti con apnea ostruttiva del sonno migliorano la contrazione vascolare: ruolo obbligatorio dell&#39;endotelio.

Remote ischemic conditioning (RCond) induced by short periods of ischemia and reperfusion of an organ or tissue before myocardial reperfusion is an attractive strategy of cardioprotection in the context of acute myocardial infarction. Nonetheless, its mechanism remains unknown. A humoral factor appears to be involved, although its identity is currently unknown. We hypothesized that the circulating microparticles (MPs) are the link between the remote tissue and the heart. MPs from rats and healthy humans undergoing RCond were characterized. In rats, RCond was induced by 10 min of limb ischemia. In humans, RCond was induced by three cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff. In the second part of the study, rats underwent 40 min myocardial ischemia followed by 2 h reperfusion. Infarct size was measured and compared among three groups of rats: 1) myocardial infarction alone (MI) (n = 6); 2) MI + RCond started 20 min after coronary ligation (n = 6); and 3) MI + injection of RCond-derived rat MPs (MI + MPs) (n = 5). MPs from endothelial cells (CD54(+) and CD146(+) for rats and humans, respectively) and procoagulant MPs (Annexin V(+)) markedly increased after RCond, both in rats and humans. RCond reduced infarct size (24.4 Â± 5.9% in MI + RCond vs. 54.6 Â± 4.7% in MI alone; P < 0.01). Infarct size did not decrease in MI + MPs compared with MI alone (50.2 Â± 6.4% vs. 54.6 Â± 4.7%, not significantly different). RCond increased endothelium-derived and procoagulant MPs in both rats and humans. However, MP release did not appear to be a biological vector of RCond in our model.

Microparticle release in remote ischemic conditioning mechanism.

Climatisation isch&eacute;mique distante (RCond) induit par courtes p&eacute;riodes d&#39;isch&eacute;mie-reperfusion d&#39;un organe ou un tissu avant reperfusion myocardique est une strat&eacute;gie s&eacute;duisante de cardioprotection dans le contexte d&#39;infarctus aigu du myocarde. N&eacute;anmoins, son m&eacute;canisme demeure inconnu. Un facteur humoral semble &ecirc;tre impliqu&eacute;e, m&ecirc;me si son identit&eacute; est actuellement inconnue. Nous avons &eacute;mis l&#39;hypoth&egrave;se que les microparticules circulantes (MPs) sont le lien entre le tissu distant et le c&oelig;ur. D&eacute;put&eacute;s de rats et des humains en bonne sant&eacute; en cours de RCond ont &eacute;t&eacute; caract&eacute;ris&eacute;es. Chez les rats, RCond a &eacute;t&eacute; induite par 10 min d&#39;isch&eacute;mie des membres. Chez l&#39;homme, RCond a &eacute;t&eacute; induite par trois cycles de 5 min l&#39;inflation et la d&eacute;flation de 5 min d&#39;un brassard de tensiom&egrave;tre. Dans la deuxi&egrave;me partie de l&#39;&eacute;tude, les rats ont subi une isch&eacute;mie myocardique 40 min, suivie d&#39;une reperfusion 2 h. Taille de l&#39;infarctus a &eacute;t&eacute; mesur&eacute;e et compar&eacute;e entre les trois groupes de rats: 1) seul myocarde du infarctus (MI) (n = 6) ; 2) MI + RCond commenc&eacute; 20 min apr&egrave;s ligature coronaire (n = 6) ; et 3) MI + injection de d&eacute;riv&eacute;s RCond rat MPs (MI + MPs) (n = 5). D&eacute;put&eacute;s des cellules endoth&eacute;liales (CD54(+) et CD146(+) pour les rats et les humains, respectivement) et procoagulant MPs (annexine V(+)) nettement augment&eacute; apr&egrave;s RCond, tant chez les rats et les humains. RCond r&eacute;duit la taille de l&#39;infarctus (24,4 &plusmn; 5,9 % dans MI + RCond contre 54,6 &plusmn; 4,7 % &agrave; MI seul ; P &lt; 0,01). Taille de l&#39;infarctus n&#39;a pas diminu&eacute; en MI + MPs par rapport &agrave; MI seul (50,2 &plusmn; 6,4 % contre 54,6 &plusmn; 4,7 %, diff&eacute;rence non significative). RCond augment&eacute; d&eacute;riv&eacute; de l&#39;endoth&eacute;lium et procoagulant MPs chez les rats et les humains. Toutefois, le communiqu&eacute; de MP ne semble pas &ecirc;tre un vecteur biologique de RCond dans notre mod&egrave;le.

Communiqu&eacute; de microparticules en m&eacute;canisme de conditionnement isch&eacute;mique distant.

Condizionamento ischemico remoto (RCond) indotta da brevi periodi di ischemia e riperfusione di un organo o tessuto prima di riperfusione miocardica &egrave; un&#39;interessante strategia di cardioprotezione nel contesto dell&#39;infarto miocardico acuto. Comunque, il suo meccanismo rimane sconosciuto. Un fattore umorale sembra essere coinvolto, anche se la sua identit&agrave; &egrave; attualmente sconosciuto. Abbiamo ipotizzato che le microparticelle circolanti (MPs) sono il collegamento tra il tessuto remoto e il cuore. MPs da ratti e gli esseri umani sani sottoposti a RCond sono stati caratterizzati. Nei ratti, RCond &egrave; stata indotta da 10 min di ischemia dell&#39;arto. Negli esseri umani, RCond &egrave; stata indotta da tre cicli di 5 min l&#39;inflazione e deflazione 5 min di un polsino di pressione sanguigna. Nella seconda parte dello studio, ratti ha subito 40 min di ischemia miocardica seguita da riperfusione h 2. Formato di infarto &egrave; stato misurato e confrontato tra i tre gruppi di ratti: 1) solo un infarto del miocardio (MI) (n = 6); 2) MI + RCond iniziato 20 min dopo legatura coronarica (n = 6); e 3) MI + iniezione di derivati RCond ratto MPs (MI + MPs) (n = 5). MPs da cellule endoteliali (CD54(+) e CD146(+) per ratti e gli esseri umani, rispettivamente) e procoagulante MPs (Annexin V(+)) notevolmente aumentato dopo RCond, sia nei ratti e gli esseri umani. RCond ridotto di infarct (24,4 &plusmn; 5,9% in MI + RCond vs 54,6 &plusmn; 4,7% a MI da solo; P &lt; 0,01). Formato di infarto non ha fatto diminuire in MI + MPs rispetto MI da solo (50,2 &plusmn; 6,4% vs 54,6 &plusmn; 4,7%, non significativamente differenti). RCond aumentato endotelio-derivato e procoagulante MPs in ratti e gli esseri umani. Tuttavia, rilascio MP non sembra essere un vettore biologico di RCond nel nostro modello.

Simon Tual-Chalot

Institute of Genetic Medicine

Newcastle University

Whole Mount Immunofluorescent Staining of the Neonatal Mouse Retina to Investigate Angiogenesis In vivo

Simon Tual-Chalot

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Institute of Genetic Medicine

Newcastle University

Whole Mount Immunofluorescent Staining of the Neonatal Mouse Retina to Investigate Angiogenesis In vivo

Institute of Genetic Medicine