evaluation-respiratory-muscle-activation-using-respiratory-motor

Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury

During breathing, activation of respiratory muscles is coordinated by integrated input from the brain, brainstem, and spinal cord. When this coordination ...

University of Louisville

Reperfusion of the ischemic lung is associated with increased pulmonary vascular resistance and reduced alveolar perfusion in conjunction with an inflammatory response. To determine the contribution of platelet-endothelial interactions, we examined effects of pulmonary ischemia-reperfusion (IR) on platelet adhesion and diameter of arterioles and investigated the hypothesis that this process is P-selectin mediated. In anesthetized rabbits with open-chest and ventilated lungs, we examined subpleural arterioles by fluorescence microscopy. Ischemia was caused by reversibly occluding the right pulmonary artery for 2 h. Fluorescently labeled platelets were injected into the right atrium and the right lung was observed after 0.5, 1.0, and 2.0 h of reperfusion. Platelets rolling and adherence along arterioles occurred with a decrease in diameter that was significant during IR, but not after 3- to 5-min occlusion (control). Systemic pretreatment with Fucoidan (a ligand to P- and L-selectin) inhibited platelet rolling, adherence, and the decrease in diameter. Pretreatment of only exogenously labeled platelets with monoclonal antibody (MoAb) to P-selectin prevented platelet rolling and adherence, but not the decrease in diameter. These results indicate that in the intact lung, pulmonary IR causes platelet rolling and adhesion along arteriolar walls, and suggest that this process, which is mediated by P-selectin, contributes to vasoconstriction and hypoperfusion. Thus, it appears that platelet-endothelial interactions may contribute to the development of pulmonary IR injury.

Effects of pulmonary ischemia-reperfusion on platelet adhesion in subpleural arterioles in rabbits.

Reperfusion du poumon isch&eacute;mique est associ&eacute;e &agrave; une augmentation de r&eacute;sistance vasculaire pulmonaire et r&eacute;duite perfusion alv&eacute;olaire en conjonction avec une r&eacute;action inflammatoire. Pour d&eacute;terminer la contribution des interactions entre les plaquettes-endoth&eacute;liales, nous avons examin&eacute; les effets de l&#39;isch&eacute;mie-reperfusion pulmonaire (IR) sur l&#39;adh&eacute;sion des plaquettes et le diam&egrave;tre des art&eacute;rioles et &eacute;tudi&eacute; l&#39;hypoth&egrave;se que ce processus est P-s&eacute;lectine m&eacute;di&eacute;e par. Chez les lapins anesth&eacute;si&eacute;s avec poumons thorax ouvert et a&eacute;r&eacute;s, nous avons examin&eacute; sous-pleurales art&eacute;rioles par microscopie de fluorescence. L&#39;isch&eacute;mie est due &agrave; r&eacute;versiblement occlusion de l&#39;art&egrave;re pulmonaire droite pour 2 h. fluorescent &eacute;tiquet&eacute; plaquettes ont &eacute;t&eacute; inject&eacute;es dans l&#39;oreillette droite et le poumon droit est observ&eacute; apr&egrave;s 0,5, 1,0 et 2,0 h de reperfusion. Plaquettes de roulement et l&#39;adh&eacute;rence le long des art&eacute;rioles s&#39;est produite avec une diminution de diam&egrave;tre qui a &eacute;t&eacute; importante au cours de l&#39;IR, mais non apr&egrave;s occlusion de 3 &ndash; 5 min (contr&ocirc;le). Un pr&eacute;traitement syst&eacute;mique avec Fucoidan (un ligand &agrave; P - et L-s&eacute;lectine) inhibe les plaquettes de roulement, l&#39;adh&eacute;rence et la r&eacute;duction du diam&egrave;tre. Le pr&eacute;traitement des seuls plaquettes exog&egrave;ne marqu&eacute;es avec un anticorps monoclonal (MoAb) &agrave; la P-s&eacute;lectine a emp&ecirc;ch&eacute; plaquettes roulement et l&#39;adh&eacute;rence, mais pas la r&eacute;duction du diam&egrave;tre. Ces r&eacute;sultats indiquent que dans le poumon intact, IR pulmonaire provoque des plaquettes roulement et adh&eacute;rence le long des parois des art&eacute;rioles et sugg&egrave;rent que ce processus, qui est v&eacute;hicul&eacute; par la P-s&eacute;lectine, contribue &agrave; la vasoconstriction et l&#39;hypoperfusion. Il semble donc que les interactions plaquettes-endoth&eacute;liales peuvent contribuer au d&eacute;veloppement des l&eacute;sions pulmonaires plus l&#39;IR.

Effets de l&#39;isch&eacute;mie-reperfusion pulmonaire sur l&#39;adh&eacute;sion des plaquettes en art&eacute;rioles sous-pleurales chez le lapin.

Riperfusione ischemica polmonare &egrave; associato con aumento della resistenza vascolare polmonare e ridotta perfusione alveolare in congiunzione con una risposta infiammatoria. Per determinare il contributo delle interazioni piastrine-endoteliale, abbiamo esaminato gli effetti dell&#39;ischemia-reperfusion polmonare (IR) sull&#39;adesione delle piastrine e diametro delle arteriole e studiato l&#39;ipotesi che questo processo &egrave; mediato P-Selectina. Nei conigli anestetizzati con polmoni petto aperto e ventilati, abbiamo esaminato sottopleuriche &#39; arteriole da microscopia di fluorescenza. Ischemia &egrave; stato causato da reversibilmente occludendo l&#39;arteria polmonare destra per 2 h. fluorescente etichettato le piastrine sono state iniettate nell&#39;atrio destro e il polmone di destra &egrave; stato osservato dopo 0,5, 1,0 e 2,0 h di riperfusione. Piastrine di rotolamento e l&#39;aderenza lungo arteriole si &egrave; verificato con una diminuzione di diametro che fu significativo durante l&#39;IR, ma non dopo 3-5 min occlusione (controllo). Pretrattamento sistemica con Fucoidan (un ligando a P - e L-selectina) inibito piastrinica rolling, adesione e la diminuzione di diametro. Pretrattamento delle piastrine esogenicamente etichettate sola con anticorpi monoclonali (MoAb) P-Selectina impedito piastrinica rotolamento e aderenza, ma non la diminuzione di diametro. Questi risultati indicano che nel polmone intatto, IR polmonare provoca delle piastrine rotolamento e adesione lungo pareti arteriolare e suggeriscono che questo processo, che &egrave; mediato dal P-selectina, contribuisce alla vasocostrizione e hypoperfusion. Cos&igrave;, sembra che le interazioni piastrine-endoteliale possono contribuire allo sviluppo di lesioni polmonari di IR.

Effetti dell&#39;ischemia-reperfusion polmonare su adesione delle piastrine in arteriole sottopleuriche &#39; nei conigli.

We examined the hypothesis that oxidants generated nitroso derivatives, activated latent matrix metalloproteinase (MMP), and induced proteinase-activated receptor 1 (PAR-1), leading to disconnection between the endothelium and myocytes. Administration of cardiospecific tissue inhibitor of metalloproteinase-4 (TIMP-4/CIMP) ameliorated the oxidative-proteolytic stress and endothelial-myocyte uncoupling in chronic heart failure (CHF) in mice. Aortic-vena cava fistula (AVF) was created in 30 male mice (C57BL/6J) and studied at 0-, 2-, and 8-wk AVF. To reverse cardiac remodeling, as measured by MMP activation, purified CIMP was administered by an osmotic minipump subcutaneously after 8-wk AVF, and groups of mice (n = 6 mice/group) were examined after 12 and 16 wk. Levels of PAR-1 in the left ventricle (LV) were increased at 2 and 8 wk (compared with 0 wk of no CIMP treatment) but were normal at 12 and 16 wk after CIMP treatment, as measured by Western blot analysis. Similar results were obtained for LV levels of nitrotyrosine, MMP-2 and -9 activities, and TIMP-1 and -3. However, the levels of TIMP-4, endothelial cell density, and responses of cardiac rings to acetylcholine and bradykinin were attenuated at 2 and 8 wk and normalized after CIMP administration in AVF mice. CIMP induced nitric oxide in microvascular endocardial endothelial cells. The results suggest that nitro generation activated MMP and PAR-1, leading to endothelial-myocyte uncoupling. CIMP treatment normalized PAR-1 expression and ameliorated endothelial-myocyte uncoupling by decreasing oxidant-mediated proteolytic stress in CHF.

Protease-activated receptor and endothelial-myocyte uncoupling in chronic heart failure.

Nous avons examin&eacute; l&#39;hypoth&egrave;se que les oxydants produits d&eacute;riv&eacute;s nitros&eacute;s, activ&eacute; latente matrix m&eacute;talloprot&eacute;inases (MMP) et induite par les r&eacute;cepteurs activ&eacute;s par la prot&eacute;inase 1 (PAR-1), menant &agrave; la d&eacute;connexion entre l&#39;endoth&eacute;lium et les myocytes. Administration de cardiospecific tissu inhibiteur de m&eacute;talloprot&eacute;inase-4 (TIMP-4/CIMP) am&eacute;lior&eacute; le stress oxydatif prot&eacute;olytique et endoth&eacute;lium-myocyte d&eacute;telage de la remorque dans l&#39;insuffisance cardiaque chronique (ICC) chez la souris. Fistule aorte-vena cava (AVF) a &eacute;t&eacute; cr&eacute;&eacute;e chez les souris m&acirc;les 30 (C57BL/6J) et a &eacute;tudi&eacute; &agrave; 0, 2- et 8-wk AVF. Pour inverser un remodelage cardiaque, telle que mesur&eacute;e par l&#39;activation de la MMP, CIMP purifi&eacute;e &eacute;tait administr&eacute; par une Minipompe osmotique par voie sous-cutan&eacute;e apr&egrave;s 8 semaines AVF et des groupes de souris (n = 6 souris/groupe) ont &eacute;t&eacute; examin&eacute;s apr&egrave;s 12 &agrave; 16 par semaine : niveaux de PAR-1 dans le ventricule gauche (VG) passait &agrave; 2 et 8 sem (contre 0 SEM d&#39;aucun traitement de CIMP) mais &eacute;taient normaux &agrave; 12 et 16 semaines apr&egrave;s le traitement de CIMP, telle que mesur&eacute;e par analyse par Western blot. Des r&eacute;sultats similaires ont &eacute;t&eacute; obtenus pour LV nitrotyrosine, MMP-2 et -9 activit&eacute;s et TIMP-1 et -3. Cependant, les niveaux de TIMP-4, endothelial cell densit&eacute;, et les r&eacute;ponses des anneaux cardiaques &agrave; l&#39;ac&eacute;tylcholine et la bradykinine sont att&eacute;nu&eacute;s &agrave; 2 et 8 sem et normalis&eacute;e apr&egrave;s administration de CIMP chez les souris de l&#39;AVF. CIMP induite par l&#39;oxyde nitrique dans les cellules endoth&eacute;liales microvasculaires endocardiques. Les r&eacute;sultats sugg&egrave;rent que la g&eacute;n&eacute;ration de nitro activ&eacute; MMP et PAR-1, conduisant &agrave; l&#39;endoth&eacute;lium-myocyte d&eacute;telage de la remorque. CIMP traitement normalis&eacute; PAR-1 expression et am&eacute;liorables endoth&eacute;lium-myocyte d&eacute;telage de la remorque en diminuant le stress prot&eacute;olytique induite par l&#39;oxydant en CHF.

R&eacute;cepteur activ&eacute; par prot&eacute;ase et endoth&eacute;lium-myocyte d&eacute;telage de la remorque dans l&#39;insuffisance cardiaque chronique.

Abbiamo esaminato l&#39;ipotesi che ossidanti generati nitroso derivati, attivato latente matrix metalloproteinase (MMP) e indotta da recettore della proteinasi attivata (PAR-1), 1 conduce alla disconnessione tra endotelio e miociti. Somministrazione di cardiospecific tessuto inibitore della metalloproteinase-4 (TIMP-4/CIMP) migliorato lo stress ossidativo-proteolitico ed endoteliali del miocita disgiungere in insufficienza cardiaca cronica (CHF) nei topi. Fistola aortico-vena cava (AVF) &egrave; stato creato in 30 topi maschi (C57BL/6J) e studiato a 0, 2 e 8-wk AVF. Per invertire il rimodellamento cardiaco, come misurato mediante l&#39;attivazione di MMP, CIMP purificato &egrave; stato amministrato da una minipompa membrana osmotica per via sottocutanea dopo 8-wk AVF e i gruppi di topi (n = 6 topi/gruppo) sono stati esaminati dopo 12 e 16 settimana livelli di PAR-1 nel ventricolo sinistro (LV) sono state aumentate a 2 e 8 wk (confrontato con 0 wk di nessun trattamento CIMP) ma erano normali a 12 e 16 Sett dopo trattamento CIMP, misurata mediante analisi Western blot. Risultati simili sono stati ottenuti per i livelli di LV nitrotyrosine, MMP-2 e -9 attivit&agrave; e TIMP-1 e -3. Tuttavia, i livelli di TIMP-4, endothelial cell densit&agrave; e risposte degli anelli cardiaci a acetilcolina e bradichinina erano attenuati a 2 e 8 wk e normalizzato dopo somministrazione CIMP nei topi AVF. CIMP indotta da ossido nitrico nelle cellule endoteliali endocardica microvascolare. I risultati suggeriscono che la generazione nitro attivato MMP e PAR-1, portando a disgiungere endoteliali del miocita. Espressione di PAR-1 trattamento normalizzato CIMP e migliorato del miocita endoteliali disgiungere diminuendo lo stress proteolitico ossidante-mediata in CHF.

Recettori attivati da proteasi ed endoteliali-myocyte disgiungere in insufficienza cardiaca cronica.

Oxidative stress, induced by lung ischemia-reperfusion, leads to platelet and leukocyte activation and may contribute to decreased alveolar perfusion by platelet adhesion to the arteriolar wall. We investigated the hypothesis that ischemia-reperfusion injury increases inducible nitric oxide synthase (iNOS) activity and subsequent generation of reactive nitrogen species with P-selectin-dependent platelet-endothelial interactions and vasoconstriction during lung reperfusion. Subpleural arterioles, labeled platelets, and leukocytes were examined in anesthetized, open-chest rabbits by intravital fluorescence microscopy. Ischemia was caused by reversible occlusion of the right pulmonary artery for 1 or 2 h (1IR and 2IR groups). During 2 h of reperfusion, postischemic platelet rolling and adhesion were independent from leukocyte-arteriolar wall interactions and correlated with pulmonary arteriolar constriction in proportion to the length of ischemia. In rabbits treated with an iNOS inhibitor (1400W) before occlusion (2IR + 1400W group), platelet-arteriolar wall interactions and vasoconstriction were prevented. iNOS expression and activity in ischemic lung tissue were markedly greater than control and also were proportional to ischemia duration. NOS activity, immunochemically detected P-selectin, and nitrotyrosine expression in ischemic lung tissue from animals subjected to ischemia-reperfusion, as well as the plasma level of soluble P-selectin, were significantly higher than in nonischemic lungs and were inhibited by pretreatment with 1400W. These results show that platelet adhesion and arteriolar constriction during early reperfusion in the ventilated lung can result from increased iNOS activity and is highly correlated with reactive nitrogen species and P-selectin expression.

Inhibition of inducible nitric oxide synthase attenuates platelet adhesion in subpleural arterioles caused by lung ischemia-reperfusion in rabbits.

Le stress oxydatif, induit par le poumon isch&eacute;mie-reperfusion, conduit &agrave; l&#39;activation plaquettaire et leucocytaire et peuvent contribuer &agrave; une diminution de la perfusion alv&eacute;olaire par l&#39;adh&eacute;sion des plaquettes &agrave; la paroi art&eacute;riolaire. Nous avons examin&eacute; l&#39;hypoth&egrave;se que l&#39;isch&eacute;mie-reperfusion augmente inductible par l&#39;oxyde nitrique synthase (iNOS) activit&eacute; et une g&eacute;n&eacute;ration ult&eacute;rieure des esp&egrave;ces d&#39;azote r&eacute;actif avec les interactions entre les plaquettes-endoth&eacute;liales P-s&eacute;lectine-d&eacute;pendante et une vasoconstriction durant la reperfusion du poumon. Art&eacute;rioles sous-pleurales, &eacute;tiquet&eacute;es de plaquettes et leucocytes ont &eacute;t&eacute; examin&eacute;s chez des lapins anesth&eacute;si&eacute;s, &agrave; thorax ouvert par microscopie intravitale fluorescence. Isch&eacute;mie est due &agrave; l&#39;occlusion de l&#39;art&egrave;re pulmonaire droite pour 1 ou 2 h (groupes 1IR et 2IR) r&eacute;versible. Pendant 2 h de reperfusion, adh&eacute;rence et plaquettes post-isch&eacute;mique roulant &eacute;taient ind&eacute;pendants des interactions leucocyte-art&eacute;riolaire mur et en corr&eacute;lation avec une constriction art&eacute;riolaire pulmonaire au prorata de la dur&eacute;e d&#39;isch&eacute;mie. Chez les lapins trait&eacute;s avec un inhibiteur d&#39;iNOS (1400W) avant l&#39;occlusion (2IR + groupe 1400W), interactions mur plaquettaire-art&eacute;riolaire et la vasoconstriction ont &eacute;t&eacute; emp&ecirc;ch&eacute;s. expression d&#39;iNOS et l&#39;activit&eacute; dans les tissus isch&eacute;miques pulmonaires &eacute;taient nettement sup&eacute;rieurs de contr&ocirc;le et aussi &eacute;taient proportionnelles &agrave; la dur&eacute;e de l&#39;isch&eacute;mie. Activit&eacute; d&#39;amendements, immunochimie d&eacute;tect&eacute; la P-s&eacute;lectine et expression de nitrotyrosine dans le tissu pulmonaire isch&eacute;mique d&#39;animaux soumis &agrave; l&#39;isch&eacute;mie-reperfusion, ainsi que le taux plasmatique de la P-s&eacute;lectine soluble, &eacute;tait bien plus &eacute;lev&eacute;e dans les poumons nonischemic et sont inhib&eacute;es par un pr&eacute;traitement avec 1400W. Ces r&eacute;sultats montrent que l&#39;adh&eacute;sion des plaquettes et une constriction art&eacute;riolaire lors de la reperfusion pr&eacute;coce dans le poumon ventil&eacute; peut r&eacute;sulter de l&#39;activit&eacute; accrue iNOS et est fortement corr&eacute;l&eacute; avec les esp&egrave;ces r&eacute;actives de l&#39;azote et l&#39;expression P-s&eacute;lectine.

L&#39;inhibition du monoxyde d&#39;azote synthase inductible att&eacute;nue l&#39;adh&eacute;sion des plaquettes en art&eacute;rioles sous-pleurales caus&eacute;e par poumon isch&eacute;mie-reperfusion chez le lapin.

Lo stress ossidativo, indotto dal polmone ischemia-reperfusion, conduce alla attivazione delle piastrine e dei leucociti e pu&ograve; contribuire alla diminuzione della perfusione alveolare di adesione delle piastrine alla parete arteriolare. Abbiamo valutato l&#39;ipotesi che il danno da ischemia-riperfusione aumenta inducibile ossido nitrico sintasi (iNOS) attivit&agrave; e conseguente generazione di specie reattive dell&#39;azoto con interazioni piastrine-endoteliale P-Selectina-dipendente e vasocostrizione durante riperfusione polmonare. Sottopleuriche &#39; arteriole, classificati come le piastrine e leucociti sono stati esaminati nei conigli anestetizzati, torace aperto da microscopia di fluorescenza intravital. Ischemia &egrave; stato causato da occlusione reversibile dell&#39;arteria polmonare destra per 1 o 2 h (gruppi 1IR e 2IR). Durante 2 h di riperfusione, adesione e piastrine postischemic rolling erano indipendenti da interazioni leucocita-arteriolare parete e correlato con costrizione arteriolare polmonare in proporzione della lunghezza di ischemia. Nei conigli trattati con un inibitore di iNOS (1400W) prima di occlusione (2IR + gruppo 1400W), interazioni della parete arteriolare piastrinica e vasocostrizione sono stati evitati. espressione di iNOS e attivit&agrave; nel tessuto polmonare ischemico erano nettamente maggiore controllo e furono anche proporzionale alla durata di ischemia. Attivit&agrave; NOS, immunochemically P-Selectina e l&#39;espressione nitrotyrosine ha rilevato nel tessuto polmonare ischemico da animali sottoposti ad ischemia-reperfusion, come pure il livello del plasma di P-Selectina solubile, erano significativamente superiori nei polmoni nonischemic e furono inibita dal pretrattamento con 1400W. Questi risultati mostrano che adesione delle piastrine e costrizione arteriolare durante riperfusione precoce nel polmone ventilato pu&ograve; derivare da attivit&agrave; aumentata iNOS e altamente &egrave; correlata con l&#39;espressione di P-Selectina e specie reattive dell&#39;azoto.

Inibizione dell&#39;inducibile ossido nitrico sintasi attenua l&#39;adesione delle piastrine in arteriole sottopleuriche &#39; causata da polmone ischemia-reperfusion in conigli.

Accumulation of oxidized extracellular matrix between endothelium and muscle is an important risk factor in the endothelium-myocytes uncoupling in congestive heart failure. Although ventricular remodeling is accompanied by increased matrix metalloproteinase (MMP)-9 activity, it is unclear whether MMP-9 plays a role in endothelial apoptosis in chronic volume overload congestive heart failure. We tested the hypothesis that, in chronic volume overload, myocardial dysfunction involves endocardial endothelial (EE) apoptosis in response to MMP-9 activation, extracellular matrix accumulation, and endothelium-myocytes uncoupling. Arteriovenous fistula (AVF) was created in control (FVB/NJ) and MMP-9 knockout (MMP-9KO; FVB.Cg-MMP9(tm1Tvu)/J) mice. Sham surgery was used as control. Mice were grouped as follows: wild type, n = 3 (sham control); MMP-9KO, n = 3 (sham); AVF, n = 3; and MMP-9KO + AVF (n = 3). Heart function was analyzed by M-mode and Doppler echocardiography, and with a pressure-tipped Millar catheter placed in the left ventricle of anesthetized mice 8 wk after AVF. Apoptosis was detected by measuring caspase-3, transferase-mediated dUTP nick-end labeling (TUNEL), and CD-31 by immunolabeling. Protease-activated receptors-1, connexin-43, and a disintegrin and MMP-12 (ADAM-12) expression were measured by Western blot analyses. MMP-2 and MMP-9 expression were measured by quantitative RT-PCR. Compared with control, AVF caused an increase in left ventricle end diastolic pressure and decrease in -dP/dt. In contrast, in the MMP-9KO + AVF group, these variables were changed toward control levels. Increased EE apoptosis (caspase-3 activation and TUNEL/CD-31 colabeling) in AVF mice was prevented in the MMP-9KO + AVF group. Protease-activated receptor-1, connexin-43, and ADAM-12 were induced in AVF. MMP-9 gene ablation ameliorated the induction. The results suggest that impaired cardiac function in volume overload is associated with EE apoptosis, cardiac remodeling, and endothelium-myocytes uncoupling in response to MMP-9 activation.

Role of matrix metalloproteinase-9 in endothelial apoptosis in chronic heart failure in mice.

Accumulation d&#39;oxyd&eacute; matrice extracellulaire entre l&#39;endoth&eacute;lium et musculaire est un facteur de risque important dans le d&eacute;couplage de l&#39;endoth&eacute;lium-myocytes dans l&#39;insuffisance cardiaque congestive. Bien que le remodelage ventriculaire s&#39;accompagne d&#39;augmentation matrice m&eacute;talloprot&eacute;inases (MMP) -9 activit&eacute;, on ne sait pas si les MMP-9 joue un r&ocirc;le dans l&#39;apoptose endoth&eacute;liale dans chroniques volume surcharge cardiaque congestive. Nous avons test&eacute; l&#39;hypoth&egrave;se selon laquelle, dans le volume chronique de surcharge, Dysfonction myocardique implique endocardique apoptose endoth&eacute;liale de (EE) en r&eacute;ponse &agrave; l&#39;activation de la MMP-9, l&#39;accumulation de matrice extracellulaire et l&#39;endoth&eacute;lium-myocytes d&eacute;telage de la remorque. Fistule art&eacute;rio-veineuse (AVF) a &eacute;t&eacute; cr&eacute;&eacute; dans le contr&ocirc;le (FVB/NJ) et masquage de MMP-9 (MMP-9KO ; FVB.Cg-MMP9(tm1Tvu)/J) souris. Chirurgie de l&#39;imposture a &eacute;t&eacute; utilis&eacute;e comme t&eacute;moin. Souris ont &eacute;t&eacute; regroup&eacute;s comme suit : type sauvage, n = 3 (contr&ocirc;le de sham) ; MMP-9KO, n = 3 (sham) ; AVF, n = 3 ; et MMP-9KO + AVF (n = 3). Fonction cardiaque a &eacute;t&eacute; analys&eacute;e par le mode M et &eacute;chocardiographie de Doppler et avec un cath&eacute;ter Millar &agrave; pointe de pression plac&eacute;e dans le ventricule gauche de souris anesth&eacute;si&eacute;s 8 sem apr&egrave;s AVF. L&#39;apoptose a &eacute;t&eacute; d&eacute;tect&eacute;e en mesurant la caspase-3, transferase-mediated dUTP nick-end labeling (TUNEL) et CD-31 par immunomarquage. R&eacute;cepteurs-1 prot&eacute;ase activ&eacute;e, connexin-43 et un disintegrin et expression de MMP-12 (ADAM-12) ont &eacute;t&eacute; mesur&eacute;es par l&#39;analyse par transfert Western. Expression de MMP-9 et de MMP-2 ont &eacute;t&eacute; mesur&eacute;s par RT-PCR quantitative. Comparativement aux t&eacute;moins, AVF a provoqu&eacute; une augmentation de la pression t&eacute;l&eacute;diastolique ventriculaire gauche et diminution -dP/dt. En revanche, la MMP-9KO + groupe AVF, ces variables ont &eacute;t&eacute; modifi&eacute;es vers des niveaux de contr&ocirc;le. Augmentation apoptose EE (activation de la caspase-3 et TUNEL/CD-31 colabeling) chez les souris de l&#39;AVF n&#39;a pas pu dans la MMP-9KO + groupe AVF. R&eacute;cepteur-1 prot&eacute;ase activ&eacute;e, connexin-43 et ADAM-12 ont &eacute;t&eacute; induites chez AVF. Ablation de MMP-9 g&egrave;ne am&eacute;lior&eacute; l&#39;induction. Les r&eacute;sultats sugg&egrave;rent que la fonction cardiaque alt&eacute;r&eacute;e en surcharge volumique est li&eacute;e avec EE l&#39;apoptose cardiaque remodelage et endoth&eacute;lium-myocytes d&eacute;telage de la remorque en r&eacute;ponse &agrave; l&#39;activation de la MMP-9.

R&ocirc;le de la matrice m&eacute;talloprot&eacute;inase-9 en apoptose endoth&eacute;liale dans l&#39;insuffisance cardiaque chronique chez les souris.

Accumulo di matrice extracellulare ossidato tra endotelio e muscolare &egrave; un importante fattore di rischio nel disgiungere endotelio-miociti in insufficienza cardiaca congestizia. Sebbene rimodellamento ventricolare &egrave; accompagnato da aumento matrix metalloproteinase (MMP) -9 attivit&agrave;, non &egrave; chiaro se MMP-9 svolge un ruolo nell&#39;apoptosi endoteliale in sovraccarico cronico di volume un&#39;insufficienza cardiaca. Abbiamo testato l&#39;ipotesi che, nel volume cronico sovraccarico, disfunzione miocardica comporta di endocardica apoptosi endoteliale (EE) in risposta all&#39;attivazione di MMP-9, accumulo di matrice extracellulare ed endotelio-miociti disgiungere. Fistola arterovenosa (AVF) fu creato nel controllo (FVB/NJ) e knockout MMP-9 (MMP-9KO; FVB.Cg-MMP9(tm1Tvu)/J) topi. Sham chirurgia &egrave; stato utilizzato come controllo. Topi sono stati raggruppati come segue: wild type, n = 3 (sham control); MMP-9KO, n = 3 (sham); AVF, n = 3; e MMP-9KO + AVF (n = 3). Funzione cardiaca &egrave; stato analizzato da M-mode e Doppler ecocardiografia e con un catetere Millar punta pressione posizionato nel ventricolo sinistro di topi anestetizzati wk 8 dopo AVF. Apoptosis &egrave; stato rilevato misurando caspase-3, transferasi-mediated dUTP nick end labeling (TUNEL) e CD-31 di immunomarcatura. 1-Recettori attivati da proteasi, connessina-43 e un disintegrin e l&#39;espressione di MMP-12 (ADAM-12) sono stati misurati mediante analisi Western blot. MMP-2 e l&#39;espressione di MMP-9 sono stati misurati mediante RT-PCR quantitativa. Rispetto al controllo, AVF ha causato un aumento nella pressione diastolica ventricolo sinistro fine e diminuire in -dP/dt. Al contrario, la MMP-9KO + gruppo AVF, queste variabili sono state cambiate verso livelli di controllo. Aumentata apoptosi EE (attivazione di caspase-3 e 31-TUNEL/CD colabeling) nei topi AVF &egrave; stato evitato in MMP-9KO + gruppo AVF. 1-Recettori attivati da proteasi, connessina 43 e ADAM-12 sono stati indotti in AVF. Ablazione di MMP-9 gene migliorata l&#39;induzione. I risultati suggeriscono che la funzione cardiaca compromessa in sovraccarico di volume &egrave; associato con EE apoptosis cardiaco rimodellamento ed endotelio-miociti disgiungere in risposta all&#39;attivazione di MMP-9.

Ruolo di matrix metalloproteinase-9 nell&#39;apoptosi endoteliale nell&#39;insufficienza cardiaca cronica nei topi.

Hyperhomocysteinemia decreases vascular reactivity and is associated with cardiovascular morbidity and mortality. However, pathogenic mechanisms that increase oxidative stress by homocysteine (Hcy) are unsubstantiated. The aim of this study was to examine the molecular mechanism by which Hcy triggers oxidative stress and reduces bioavailability of nitric oxide (NO) in cardiac microvascular endothelial cells (MVEC). MVEC were cultured for 0-24 h with 0-100 microM Hcy. Differential expression of protease-activated receptors (PARs), thioredoxin, NADPH oxidase, endothelial NO synthase, inducible NO synthase, neuronal NO synthase, and dimethylarginine-dimethylaminohydrolase (DDAH) were measured by real-time quantitative RT-PCR. Reactive oxygen species were measured by using a fluorescent probe, 2',7'-dichlorofluorescein diacetate. Levels of asymmetric dimethylarginine (ADMA) were measured by ELISA and NO levels by the Griess method in the cultured MVEC. There were no alterations in the basal NO levels with 0-100 microM Hcy and 0-24 h of treatment. However, Hcy significantly induced inducible NO synthase and decreased endothelial NO synthase without altering neuronal NO synthase levels. There was significant accumulation of ADMA, in part because of reduced DDAH expression by Hcy in MVEC. Nitrotyrosine expression was increased significantly by Hcy. The results suggest that Hcy activates PAR-4, which induces production of reactive oxygen species by increasing NADPH oxidase and decreasing thioredoxin expression and reduces NO bioavailability in cultured MVEC by 1) increasing NO2-tyrosine formation and 2) accumulating ADMA by decreasing DDAH expression.

Mechanisms of homocysteine-induced oxidative stress.

Hyperhomocyst&eacute;in&eacute;mie diminue la r&eacute;activit&eacute; vasculaire et est associ&eacute;e &agrave; la mortalit&eacute; et la morbidit&eacute; cardiovasculaire. Cependant, les m&eacute;canismes pathog&egrave;nes qui augmentent le stress oxydatif de l&#39;homocyst&eacute;ine (Hcy) sont sans fondement. Le but de cette &eacute;tude &eacute;tait d&#39;examiner le m&eacute;canisme mol&eacute;culaire par lequel Hcy d&eacute;clenche le stress oxydatif et r&eacute;duit la biodisponibilit&eacute; de l&#39;oxyde nitrique (NO) dans les cellules endoth&eacute;liales microvasculaires cardiaques (MVEC). MVEC ont &eacute;t&eacute; cultiv&eacute;s pendant 0-24h avec 0-100 microM Hcy. Expression diff&eacute;rentielle des r&eacute;cepteurs activ&eacute;s par la prot&eacute;ase (PARs), thior&eacute;doxine, NADPH oxydase, endoth&eacute;lial aucun synthase inductible aucun synthase neuronale aucun synthase et dim&eacute;thylarginine-dim&eacute;thylaminohydrolase (DDAH) ont &eacute;t&eacute; mesur&eacute;es par RT-PCR quantitative en temps r&eacute;el. Les esp&egrave;ces r&eacute;actives de l&#39;oxyg&egrave;ne ont &eacute;t&eacute; mesur&eacute;es &agrave; l&#39;aide d&#39;une sonde fluorescente, 2&#39;, 7&#39;-dichlorofluoresc&eacute;ine diac&eacute;tate. Niveaux de dim&eacute;thylarginine asym&eacute;trique (ADMA) ont &eacute;t&eacute; mesur&eacute;s par ELISA et pas de niveaux par la m&eacute;thode de Griess dans la culture MVEC. Il n&#39;y a aucune alt&eacute;rations dans la basale aucun niveau avec 0-100 microM Hcy et 0-24 h de traitement. Cependant, Hcy induit significativement inductible NO synthase et une diminution non endoth&eacute;lial synthase sans alt&eacute;rer non neuronale niveaux synthase. Il y avait une accumulation importante de ADMA, en partie &agrave; cause de la r&eacute;duction de l&#39;expression DDAH par Hcy dans MVEC. Expression de nitrotyrosine a &eacute;t&eacute; significativement augment&eacute;e Hcy. Les r&eacute;sultats sugg&egrave;rent que Hcy l&#39;active PAR-4, ce qui induit la production d&#39;esp&egrave;ces r&eacute;actives de l&#39;oxyg&egrave;ne en augmentant la NADPH oxydase et diminue l&#39;expression de thioredoxin et ne r&eacute;duit aucun biodisponibilit&eacute; dans MVEC cultiv&eacute;e en 1) augmentant la formation de NO2-tyrosine et 2) accumulant ADMA en diminuant l&#39;expression DDAH.

M&eacute;canismes du stress oxydatif induit par l&#39;homocyst&eacute;ine.

Iperomocisteinemia diminuisce la reattivit&agrave; vascolare ed &egrave; associato con la mortalit&agrave; e morbilit&agrave; cardiovascolare. Tuttavia, i meccanismi patogenetici che aumentano lo stress ossidativo di omocisteina (Hcy) sono infondati. Lo scopo di questo studio era di esaminare il meccanismo molecolare con cui Hcy innesca lo stress ossidativo e riduce la biodisponibilit&agrave; di ossido nitrico (NO) in cellule endoteliali Microvascolari cardiache (MVEC). MVEC sono stati coltivati per 0-24 h con 0-100 microM Hcy. Espressione differenziale di recettori attivati da proteasi (PARs), la tioredossina, NADPH ossidasi, endoteliali NO sintasi, inducible NO sintasi neuronale NO sintasi e dimethylarginine-DDAH1 (DDAH) sono stati misurati mediante RT-PCR quantitativa in tempo reale. Specie reattive dell&#39;ossigeno sono state misurate utilizzando una sonda fluorescente, 2&#39;, 7&#39;-diclorofluoresceina Diacetato. Livelli di dimethylarginine asimmetrico (ADMA) sono stati misurati da ELISA e NO livelli dal metodo Griess nella MVEC colta. Non c&#39;erano alterazioni il basale NO livelli con 0-100 microM Hcy e 0-24 h di trattamento. Tuttavia, Hcy significativamente indotta inducible NO sintasi e diminuito endotelio NO sintasi senza alterare neuronale NO sintasi livelli. C&#39;era un accumulo significativo di ADMA, in parte a causa della ridotta espressione DDAH di Hcy in MVEC. Nitrotyrosine espressione era aumentato significativamente di Hcy. I risultati suggeriscono che l&#39;Hcy attiva PAR-4, che induce la produzione di specie reattive dell&#39;ossigeno aumentando la NADPH ossidasi e diminuendo l&#39;espressione tioredossina e non riduce biodisponibilit&agrave; nel colto MVEC 1) aumentando la formazione di NO2-tirosina e 2) accumulando ADMA diminuendo l&#39;espressione DDAH.

Meccanismi dello stress ossidativo indotto da omocisteina.

Accumulation of interstitial collagen (fibrosis) between the endothelium and myocytes is one of the hallmarks of cardiac failure in renovascular hypertension (RVH). Renal insufficiency increases plasma homocysteine (Hcy), and levels of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) are inversely related to plasma Hcy levels. We hypothesize that in RVH, accumulation of collagen between the endothelium and myocytes leads to endothelial-myocyte disconnection and uncoupling, in part, by hyperhomocysteinemia. Furthermore, we hypothesize that Hcy increases reactive oxygen species, generates nitrotyrosine, activates latent matrix metalloproteinase, and decreases the levels of endothelial nitric oxide in response to antagonizing PPAR-gamma. To create RVH in mice, the left renal artery was clipped with 0.4-mm silver wire for the 2 kidney, 1 clip (2K1C) method. Sham surgery was used as a control. To induce PPAR-gamma, 8 microg/mL ciglitazone (CZ) was administered to drinking water 2 days before surgery and continued for 4 weeks. Mice were grouped as 2K1C, sham, 2K1C+CZ, or sham+CZ (n = 6 in each group). Plasma Hcy increased 2-fold in the 2K1C-treated group (p < 0.05) as compared with the sham, and CZ had no effect on Hcy levels as compared to the 2K1C-treated group. Hcy binding in cardiac tissue homogenates decreased in the 2K1C-treated group but was substantially higher in the CZ-treated group. Cardiac reactive oxygen species levels were increased and endothelial nitric oxide were decreased in the 2K1C-treated group. Matrix metalloproteinase-2 and -9 activities were increased in the 2K1C-treated group compared with the control. Levels of cardiac inhibitor of metalloproteinase were decreased, whereas there was no change in tissue inhibitor of metalloproteinase-1 expression in the 2K1C-treated group vs. the sham-treated group. Collagen and nitrotyrosine levels were increased in the 2K1C-treated group, but mice treated with CZ showed lower levels comparatively. Cardiac transferase deoxyuridine nick-end labeling-positive cells were increased, and muscle cells were impaired in the 2K1C-treated mice vs. the sham-control mice. This was associated with decreased acetylcholine and bradykinin responses, which suggests endothelial-myocyte uncoupling in 2K1C-treated mice. Our results suggest that fibrosis between the endothelium and myocytes leads to an endothelial-myocyte disconnection and uncoupling by Hcy accumulation secondary to increased reactive oxygen species, nitrotyrosine, matrix metalloproteinase, and decreased endothelial nitric oxide in response to antagonizing PPAR-gamma.

Homocysteine-dependent cardiac remodeling and endothelial-myocyte coupling in a 2 kidney, 1 clip Goldblatt hypertension mouse model.

Accumulation de collag&egrave;ne interstitiel (fibrose) entre l&#39;endoth&eacute;lium et les myocytes est l&#39;une des principales caract&eacute;ristiques d&#39;une insuffisance cardiaque dans l&#39;hypertension r&eacute;novasculaire (HRV). Insuffisance r&eacute;nale augmente plasma homocyst&eacute;ine (Hcy), et des niveaux de peroxisome proliferator-activated receptor-gamma (PPAR-gamma) sont inversement proportionnels aux Hcy plasmatique. Nous &eacute;mettons l&#39;hypoth&egrave;se que dans HRV, accumulation de collag&egrave;ne entre l&#39;endoth&eacute;lium et les myocytes entra&icirc;ne endoth&eacute;lium-myocyte d&eacute;connexion et d&eacute;telage de la remorque, en partie, par l&#39;hyperhomocyst&eacute;in&eacute;mie. En outre, nous &eacute;mettons l&#39;hypoth&egrave;se que Hcy augmente les esp&egrave;ces r&eacute;actives de l&#39;oxyg&egrave;ne, g&eacute;n&egrave;re nitrotyrosine, active la m&eacute;talloprot&eacute;inase matricielle latente et diminue les taux de monoxyde d&#39;azote endoth&eacute;lial en r&eacute;ponse &agrave; contrarier les PPAR-gamma. Pour cr&eacute;er HRV chez la souris, l&#39;art&egrave;re r&eacute;nale gauche a &eacute;t&eacute; coup&eacute; avec fil d&#39;argent 0,4 mm pour les 2 reins, 1 m&eacute;thode de clip (2R1C). Chirurgie de l&#39;imposture a &eacute;t&eacute; utilis&eacute;e comme t&eacute;moin. Pour inciter les PPAR-gamma, 8 microg/mL ciglitazone (CZ) a &eacute;t&eacute; administr&eacute; &agrave; l&#39;eau potable 2 jours avant la chirurgie et a continu&eacute; pendant 4 semaines. Souris ont &eacute;t&eacute; regroup&eacute;s comme 2R1C, sham, 2R1C + CZ ou sham + CZ (n = 6 dans chaque groupe). Plasma Hcy a augment&eacute; deux fois dans le groupe 2R1C (p &lt; 0,05) que dans l&#39;imposture et CZ a eu aucun effet sur Hcy niveaux par rapport au groupe 2R1C. Fixation Hcy dans des homog&eacute;nats de tissu cardiaque a diminu&eacute; dans le groupe 2R1C, mais a &eacute;t&eacute; sensiblement plus &eacute;lev&eacute;e dans le groupe trait&eacute; CZ. Esp&egrave;ces r&eacute;actives de l&#39;oxyg&egrave;ne cardiaque sont augment&eacute;s et l&#39;oxyde nitrique endoth&eacute;liale ont diminu&eacute; chez le groupe 2R1C. Matrix metalloproteinase-2 et -9 activit&eacute;s ont augment&eacute; chez le groupe 2R1C compar&eacute; au t&eacute;moin. Des cardiaque inhibiteur de m&eacute;talloprot&eacute;inase ont diminu&eacute;, alors qu&#39;il n&#39;y n&#39;avait aucun changement dans l&#39;inhibiteur tissulaire de m&eacute;talloprot&eacute;inase-1 expression dans le groupe 2R1C vs le groupe impr&eacute;gn&eacute;es d&#39;imposture. Les niveaux de collag&egrave;ne et de nitrotyrosine ont augment&eacute; chez le groupe 2R1C, mais les souris trait&eacute;es avec CZ ont montr&eacute; des niveaux plus bas comparativement. Transf&eacute;rase cardiaque d&eacute;soxyuridine nick-end labeling-cellules positives ont &eacute;t&eacute; augment&eacute;s, et cellules musculaires ont &eacute;t&eacute; alt&eacute;r&eacute;s chez les souris 2R1C vs les souris sham-contr&ocirc;le. Ceci a &eacute;t&eacute; associ&eacute; aux r&eacute;ponses une diminution de l&#39;ac&eacute;tylcholine et de la bradykinine, qui sugg&egrave;re l&#39;endoth&eacute;lium-myocyte d&eacute;crochage chez les souris 2R1C. Nos r&eacute;sultats sugg&egrave;rent que la fibrose entre l&#39;endoth&eacute;lium et les myocytes entra&icirc;ne une d&eacute;connexion de l&#39;endoth&eacute;lium-myocyte et d&eacute;couplage par accumulation de Hcy secondaire d&#39;esp&egrave;ces r&eacute;actives de l&#39;oxyg&egrave;ne accru, nitrotyrosine, m&eacute;talloprot&eacute;inase matricielle et une diminution de l&#39;oxyde nitrique endoth&eacute;liale en r&eacute;ponse &agrave; efficament PPAR-gamma.

Homocyst&eacute;ine d&eacute;pendant de remodelage cardiaque et endoth&eacute;lium-myocyte de couplage dans un rein 2, mod&egrave;le de souris de 1 pince Goldblatt hypertension.

Accumulo di collagene interstiziali (fibrosi) tra l&#39;endotelio e miociti &egrave; uno dei marchi di insufficienza cardiaca nell&#39;ipertensione renovascolari (RVH). Insufficienza renale aumenta al plasma di omocisteina (Hcy), e livelli di peroxisome proliferator-activated receptor-gamma (PPAR-gamma) sono inversamente proporzionali ai livelli di Hcy al plasma. Ipotizziamo che in RVH, accumulo di collagene tra l&#39;endotelio e miociti conduce alla disconnessione del miocita endoteliale e disgiungere, in parte, da iperomocisteinemia. Inoltre, ipotizziamo che Hcy aumenta specie reattive dell&#39;ossigeno, genera nitrotyrosine, attiva latente matrix metalloproteinase e diminuisce i livelli di ossido nitrico endoteliale in risposta a inimicarsi PPAR-gamma. Per creare RVH nei topi, l&#39;arteria renale sinistra &egrave; stato ritagliato con 0,4 mm filo d&#39;argento per il rene 2, 1 Metodo clip (2K1C). Sham chirurgia &egrave; stato utilizzato come controllo. Per indurre il PPAR-gamma, 8 microg/mL ciglitazone (CZ) &egrave; stato somministrato a acqua potabile 2 giorni prima dell&#39;intervento e continuata per 4 settimane. Topi sono stati raggruppati come 2K1C, sham, 2K1C + CZ o ostentate + CZ (n = 6 in ciascun gruppo). Plasma Hcy 2 volte maggiore nel gruppo 2K1C-trattati (p &lt; 0.05) rispetto la farsa e CZ ha avuto alcun effetto sui livelli di Hcy rispetto al gruppo trattato 2K1C. Associazione di HCY nel tessuto cardiaco omogeneati &egrave; diminuito nel gruppo trattato 2K1C ma era sostanzialmente pi&ugrave; alta nel gruppo trattato CZ. Specie di ossigeno reattivo cardiaco sono stati aumentati livelli e ossido nitrico endoteliale sono diminuiti nel gruppo trattato 2K1C. Matrix metalloproteinase-2 e -9 attivit&agrave; erano aumentate nel gruppo 2K1C-trattato rispetto al controllo. Livelli di inibitore cardiaco del metalloproteinase erano diminuiti, considerando che non non c&#39;era nessun cambiamento nell&#39;inibitore di tessuto di espressione metalloproteinase-1 nel gruppo 2K1C-trattati vs il gruppo sham-trattati. Livelli di collagene e nitrotyrosine sono stati aumentati nel gruppo trattati con 2K1C, ma topi trattati con CZ hanno mostrato livelli inferiori comparativamente. Cellule cardiache trasferasi deossiuridina nick-end labeling-positive sono state aumentate, e cellule muscolari sono state alterate in topi trattati con 2K1C contro i topi di controllo sham. Questa &egrave; stata associata con risposte diminuzione dell&#39;acetilcolina e della bradichinina, che suggerisce endoteliali del miocita disgiungere nei topi trattati con 2K1C. I nostri risultati suggeriscono che la fibrosi tra l&#39;endotelio e miociti conduce ad una disconnessione del miocita endoteliale e lo sganciamento di Hcy accumulo secondario di specie ossigenate reattive aumentato, nitrotyrosine, matrix metalloproteinase e diminuito l&#39;ossido nitrico endoteliale in risposta a antagonizzando PPAR-gamma.

Rimodellamento cardiaco omocisteina-dipendente ed endoteliali-myocyte accoppiamento in un rene 2, modello 1 clip Goldblatt ipertensione del mouse.

Formation of homocysteine (Hcy) is the constitutive process of gene methylation. Hcy is primarily synthesized by de-methylation of methionine, in which s-adenosyl-methionine (SAM) is converted to s-adenosyl-homocysteine (SAH) by methyltransferase (MT). SAH is then hydrolyzed to Hcy and adenosine by SAH-hydrolase (SAHH). The accumulation of Hcy leads to increased cellular oxidative stress in which mitochondrial thioredoxin, and peroxiredoxin are decreased and NADH oxidase activity is increased. In this process, Ca2+-dependent mitochondrial nitric oxide synthase (mtNOS) and calpain are induced which lead to cytoskeletal de-arrangement and cellular remodeling. This process generates peroxinitrite and nitrotyrosine in contractile proteins which causes vascular dysfunction. Chronic exposure to Hcy instigates endothelial and vascular dysfunction and increases vascular resistance causing systemic hypertension. To compensate, the heart increases its load which creates adverse cardiac remodeling in which the elastin/collagen ratio is reduced, causing cardiac stiffness and diastolic heart failure in hyperhomocysteinemia.

Mitochondrial mechanism of oxidative stress and systemic hypertension in hyperhomocysteinemia.

La formation d&#39;homocyst&eacute;ine (Hcy) est le processus constitutif de la m&eacute;thylation des g&egrave;nes. Hcy est principalement synth&eacute;tis&eacute;e par de-methylation de m&eacute;thionine, dans laquelle s-ad&eacute;nosyl-m&eacute;thionine (SAM) est converti en s-ad&eacute;nosyl-homocyst&eacute;ine (SAH) par m&eacute;thyltransf&eacute;rase (MT). SAH est ensuite hydrolys&eacute; Hcy et ad&eacute;nosine par SAH-hydrolase (SAHH). L&#39;accumulation de l&#39;Hcy conduit &agrave; une augmentation stress oxydatif cellulaire dans lequel thior&eacute;doxine mitochondriale et peroxiredoxin sont r&eacute;duites et l&#39;activit&eacute; NADH oxydase est augment&eacute;e. Dans ce processus, Ca2 +-d&eacute;pendante mitochondrial nitric oxide synthase (mtNOS) et la calpa&iuml;ne sont induites qui conduisent &agrave; la de-arrangement du cytosquelette et remodelage cellulaire. Ce processus g&eacute;n&egrave;re peroxynitrite et nitrotyrosine dans des prot&eacute;ines contractiles qui provoque un dysfonctionnement vasculaire. Une exposition chronique &agrave; l&#39;Hcy incite le dysfonctionnement endoth&eacute;lial et vasculaire et augmente la r&eacute;sistance vasculaire provoquant hypertension syst&eacute;mique. Pour compenser, le coeur augmente sa charge qui cr&eacute;e des effets ind&eacute;sirables cardiaques remodelage chez qui le taux d&#39;&eacute;lastine/collag&egrave;ne est r&eacute;duit, entra&icirc;nant une raideur cardiaque et insuffisance cardiaque diastolique hyperhomocyst&eacute;in&eacute;mie.

M&eacute;canisme mitochondriale du stress oxydatif et hypertension syst&eacute;mique dans l&#39;hyperhomocyst&eacute;in&eacute;mie.

Formazione di omocisteina (Hcy) &egrave; il processo costitutivo di metilazione del gene. HCY &egrave; sintetizzata principalmente da de-methylation di metionina, in cui s-adenosil-metionina (SAM) viene convertita in s-adenosil-omocisteina (SAH) di metiltransferasi (MT). SAH &egrave; poi idrolizzato di Hcy e adenosina da SAH-idrolasi (selvini). L&#39;accumulo di Hcy conduce all&#39;aumento dello stress ossidativo cellulare in cui tioredossina mitocondriale e perossiredossina sono diminuiti e NADH ossidasi attivit&agrave; &egrave; aumentata. In questo processo, Ca2 +-dipendente mitocondriale ossido nitrico sintasi (mtNOS) e calpaina sono indotti che portano a de-arrangement citoscheletriche e rimodellamento cellulare. Questo processo genera peroxinitrite e nitrotyrosine in proteine contrattili che provoca disfunzioni vascolari. L&#39;esposizione cronica a Hcy istiga disfunzione endoteliale e vascolare e aumenta la resistenza vascolare, causando ipertensione sistemica. Per compensare, il cuore aumenta il carico che crea cardiaci avversi rimodellamento in cui &egrave; ridotto il rapporto collagene/elastina, provocando rigidit&agrave; cardiache e insufficienza cardiaca diastolica in iperomocisteinemia.

Mitocondriale meccanismo di stress ossidativo e ipertensione sistemica in iperomocisteinemia.

Homocysteine (Hcy) induces matrix metalloproteinase (MMP)-9 in microvascular endothelial cells (MVECs). We hypothesized that the ERK1/2 signaling pathway is involved in Hcy-mediated MMP-9 expression. In cultured MVECs, Hcy induced activation of ERK, which was blocked by PD-98059 and U0126 (MEK inhibitors). Pretreatment with BAPTA-AM, staurosporine (PKC inhibitor), or GÃ¶6976 (specific inhibitor for Ca(2+)-dependent PKC) abrogated ERK phosphorylation, suggesting the role of Ca(2+) and Ca(2+)-dependent PKC in Hcy-induced ERK activation. ERK phosphorylation was suppressed by pertussis toxin (PTX), suggesting the involvement of G protein-coupled receptors (GPCRs) in initiating signal transduction by Hcy and leading to ERK activation. Pretreatment of MVECs with genistein, BAPTA-AM, or thapsigargin abrogated Hcy-induced ERK activation, suggesting the involvement of the PTK pathway in Hcy-induced ERK activation, which was mediated by intracellular Ca(2+) pool depletion. ERK activation was attenuated by preincubation with N-acetylcysteine (NAC) and SOD, suggesting the role of oxidation in Hcy-induced ERK activation. Pretreatment with an ERK1/2 blocker (PD-98059), staurosporine, folate, or NAC modulated Hcy-induced MMP-9 activation as measured using zymography. Our results provide evidence that Hcy triggers the PTX-sensitive ERK1/2 signaling pathway, which is involved in the regulation of MMP-9 in MVECs.

Regulation of homocysteine-induced MMP-9 by ERK1/2 pathway.

Homocyst&eacute;ine (Hcy) induit la m&eacute;talloprot&eacute;inase matricielle (MMP) -9 dans les cellules endoth&eacute;liales microvasculaires (MVECs). Nous avons &eacute;mis l&#39;hypoth&egrave;se que le ERK1/2 signalisation voie est impliqu&eacute; dans l&#39;expression de MMP-9 induite par l&#39;Hcy. Dans la culture MVECs, Hcy induite par activation de ERK, qui a &eacute;t&eacute; bloqu&eacute; par PD-98059 et U0126 (inhibiteurs de MEK). Un pr&eacute;traitement avec BAPTA-AM, la staurosporine (inhibiteur de PKC) ou G&ouml;6976 (inhibiteur sp&eacute;cifique pour Ca(2+)-d&eacute;pendante PKC) a abrog&eacute; la phosphorylation de ERK, sugg&eacute;rant le r&ocirc;le de Ca(2+) et Ca(2+)-d&eacute;pendante PKC dans l&#39;activation induite par l&#39;Hcy ERK. La phosphorylation de ERK a &eacute;t&eacute; supprim&eacute;e par la toxine pertussique (PTX), ce qui sugg&egrave;re l&#39;implication des r&eacute;cepteurs coupl&eacute;s aux prot&eacute;ines G (RCPG) en initiant de transduction de signal par Hcy et conduisant &agrave; l&#39;activation de ERK. Le pr&eacute;traitement des MVECs avec la g&eacute;nist&eacute;ine, BAPTA-AM ou thapsigargine a abrog&eacute; l&#39;activation induite par l&#39;Hcy ERK, sugg&eacute;rant l&#39;implication de la voie de la PTK dans l&#39;activation induite par l&#39;Hcy ERK, qui a &eacute;t&eacute; v&eacute;hicul&eacute;e par l&#39;appauvrissement de pool intracellulaire Ca(2+). Activation de ERK a &eacute;t&eacute; att&eacute;nu&eacute;e par la pr&eacute;incubation avec la N-ac&eacute;tylcyst&eacute;ine (NAC) et de GAZONNI&Egrave;RES, sugg&eacute;rant le r&ocirc;le d&#39;oxydation dans l&#39;activation induite par l&#39;Hcy ERK. Un pr&eacute;traitement avec un bloqueur de ERK1/2 (PD-98059), la staurosporine, folate ou CNA modul&eacute; induite par l&#39;Hcy MMP-9 activation mesur&eacute;e &agrave; l&#39;aide de zymographie. Nos r&eacute;sultats d&eacute;montrent que l&#39;Hcy d&eacute;clenche la voie de signalisation sensibles PTX ERK1/2, qui est impliqu&eacute;e dans la r&eacute;gulation de MMP-9 en MVECs.

R&egrave;glement d&#39;induite par l&#39;homocyst&eacute;ine MMP-9 par voie de ERK1/2.

Omocisteina (Hcy) induce matrix metalloproteinase (MMP) -9 in cellule endoteliali Microvascolari (MVECs). Abbiamo ipotizzato che il ERK1/2 signaling pathway &egrave; coinvolto nell&#39;espressione di MMP-9 Hcy-mediata. In MVECs colta, Hcy indotta da attivazione di ERK, che &egrave; stato bloccato da PD-98059 e U0126 (inibitori di MEK). Pretrattamento con BAPTA-AM, staurosporine (inibitore PKC) o G&ouml;6976 (inibitore specifico per Ca(2+)-dipendente PKC) abrogata la fosforilazione di ERK, suggerendo il ruolo di Ca(2+) e Ca(2+)-dipendente PKC in attivazione di ERK Hcy-indotta. La fosforilazione di ERK fu soppressa dalla tossina pertosse (PTX), suggerendo il coinvolgimento dei recettori accoppiati a proteine G (GPCR) avvio di trasduzione del segnale di Hcy e che portano alla attivazione di ERK. Pretrattamento di MVECs con genisteina, BAPTA-AM o thapsigargin abrogata attivazione di ERK Hcy-indotta, suggerendo il coinvolgimento del percorso in attivazione di ERK Hcy-indotta, che fu mediata da deplezione di pool intracellulare Ca(2+) PTK. Attivazione di ERK &egrave; stato attenuato dalla preincubazione con N-acetilcisteina (NAC) e SOD, suggerendo il ruolo dell&#39;ossidazione nell&#39;attivazione di ERK Hcy-indotta. Pretrattamento con un blocco di ERK1/2 (PD-98059), staurosporine, folati o NAC modulata attivazione indotta da Hcy MMP-9 come misurato mediante Zimografia. I nostri risultati forniscono la prova che l&#39;Hcy innesca la via di segnalazione PTX-sensibile ERK1/2, che &egrave; coinvolto nella regolazione della MMP-9 nel MVECs.

Regolamento di omocisteina indotto MMP-9 da pathway ERK1/2.

An elevated level of homocysteine (Hcy) limits the growth and induces apoptosis. However, the mechanism of Hcy-induced programmed cell death in endothelial cells is largely unknown. We hypothesize that Hcy induces intracellular reactive oxygen species (ROS) production that leads to the loss of transmembrane mitochondrial potential (Deltapsi(m)) accompanied by the release of cytochrome-c from mitochondria. Cytochrome-c release contributes to caspase activation, such as caspase-9, caspase-6, and caspase-3, which results in the degradation of numerous nuclear proteins including poly (ADP-ribose) polymerase (PARP), which subsequently leads to the internucleosomal cleavage of DNA, resulting cell death. In this study, rat heart microvascular endothelial cells (MVEC) were treated with different doses of Hcy at different time intervals. Apoptosis was measured by DNA laddering and transferase-mediated dUTP nick-end labeling (TUNEL) assay. ROS production and MP were determined using fluorescent probes (2,7-dichlorofluorescein (DCFH-DA) and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-benzamidazolocarbocyanin iodide (JC-1), respectively, by confocal microscopy. Differential gene expression for apoptosis was analyzed by cDNA array. The results showed that Hcy-mediated ROS production preceded the loss of MP, the release of cytochrome-c, and the activation of caspase-9 and -3. Moreover the Hcy treatment resulted in a decrease in Bcl(2)/Bax ratio, evaluated by mRNA levels. Caspase-9 and -3 were activated, causing cleavage of PARP, a hallmark of apoptosis and internucleosomal DNA fragmentation. The cytotoxic effect of Hcy was blocked by using small interfering RNA (siRNA)-mediated suppression of caspase-9 in MVEC. Suppressing the activation of caspase-9 inhibited the activation of caspase -3 and enhanced the cell viability and MP. Our data suggested that Hcy-mediated ROS production promotes endothelial cell death in part by disturbing MP, which results in subsequent release of cytochrome-c and activation of caspase-9 and 3, leading to cell death.

Mitochondrial mechanism of microvascular endothelial cells apoptosis in hyperhomocysteinemia.

Un taux &eacute;lev&eacute; d&#39;homocyst&eacute;ine (Hcy) limite la croissance et induit l&#39;apoptose. Toutefois, le m&eacute;canisme de mort cellulaire programm&eacute;e induite par l&#39;Hcy dans les cellules endoth&eacute;liales est en grande partie inconnu. Nous &eacute;mettons l&#39;hypoth&egrave;se que l&#39;Hcy induit la production intracellulaire r&eacute;actives de l&#39;oxyg&egrave;ne (DRO) qui entra&icirc;ne la perte du potentiel transmembranaire de mitochondriale (Deltapsi(m)) accompagn&eacute;e de la lib&eacute;ration du cytochrome c des mitochondries. La lib&eacute;ration de cytochrome c contribue &agrave; l&#39;activation des caspases, comme caspase-9, caspase-6 et caspase-3, qui se traduit par la d&eacute;gradation de nombreuses prot&eacute;ines nucl&eacute;aires, y compris les poly (ADP-ribose) polym&eacute;rase (PARP), qui m&egrave;ne ensuite &agrave; l&#39;internucl&eacute;osomique clivage de l&#39;ADN, la mort des cellules qui en r&eacute;sulte. Dans cette &eacute;tude, les cellules endoth&eacute;liales microvasculaires rat cardiaques (MVEC) ont &eacute;t&eacute; trait&eacute;s avec diff&eacute;rentes doses de Hcy &agrave; diff&eacute;rents intervalles de temps. L&#39;apoptose a &eacute;t&eacute; mesur&eacute;e par ADN laddering et essai de transferase-mediated dUTP nick-fin &eacute;tiquetage (TUNEL). La production de ROS et les MP ont &eacute;t&eacute; d&eacute;termin&eacute;es &agrave; l&#39;aide de sondes fluorescentes (2,7-dichlorofluoresc&eacute;ine (DHFC-DA) et 5, 5&#39;, 6, 6&#39;-t&eacute;trachloro-1, 1&#39;, 3, 3&#39;-t&eacute;tra&eacute;thyle-benzamidazolocarbocyanin iodure (JC-1), respectivement, par microscopie confocale. Expression diff&eacute;rentielle des g&egrave;nes de l&#39;apoptose a &eacute;t&eacute; analys&eacute;e par un tableau de cDNA. Les r&eacute;sultats ont montr&eacute; que la production de ROS induite par l&#39;Hcy pr&eacute;c&eacute;d&eacute; la perte de la MP, la lib&eacute;ration du cytochrome c et l&#39;activation de la caspase-9 et -3. En outre le traitement Hcy entra&icirc;n&eacute; une diminution dans le ratio de 2/Bax Bcl, &eacute;valu&eacute; par l&#39;ARNm. Caspase-9 et -3 ont &eacute;t&eacute; activ&eacute;s, causant un clivage de PARP, une caract&eacute;ristique de l&#39;apoptose et de la fragmentation de l&#39;ADN internucl&eacute;osomique. L&#39;effet cytotoxique de l&#39;Hcy a &eacute;t&eacute; bloqu&eacute; &agrave; l&#39;aide de petits ARN interf&eacute;rents (siARN)-mediated suppression de caspase-9 en MVEC. Suppression de l&#39;activation de la caspase-9 inhibe l&#39;activation de la caspase -3 et am&eacute;lior&eacute; la viabilit&eacute; cellulaire et MP. Nos r&eacute;sultats sugg&egrave;rent que la production de ROS induite par l&#39;Hcy favorise la mort des cellules endoth&eacute;liales en partie par MP troublante, qui se traduit par la lib&eacute;ration subs&eacute;quente de cytochrome c et l&#39;activation de la caspase-9 et 3, conduisant &agrave; la mort cellulaire.

M&eacute;canisme mitochondriale de l&#39;apoptose des cellules endoth&eacute;liales microvasculaires dans hyperhomocyst&eacute;in&eacute;mie.

Un elevato livello di omocisteina (Hcy) limita la crescita e induce l&#39;apoptosi. Tuttavia, il meccanismo di morte cellulare programmata Hcy-indotta in cellule endoteliali &egrave; in gran parte sconosciuto. Ipotizziamo che Hcy induce la produzione di specie (ROS) intracellulare di ossigeno reattivo che porta alla perdita del potenziale mitocondriale transmembrana (Deltapsi(m)) accompagnato dal rilascio di citocromo c dai mitocondri. Rilascio di citocromo-c contribuisce all&#39;attivazione di caspase, come caspase-9, caspase-6 e caspase-3, che comporta la degradazione delle proteine nucleari numerosi compreso poli (ADP-ribosio) polimerasi (PARP), che successivamente conduce alla fenditura internucleosomal del DNA, conseguente morte cellulare. In questo studio, cellule endoteliali Microvascolari rat heart (MVEC) sono state trattate con diverse dosi di Hcy ad intervalli di tempo diversi. Apoptosis &egrave; stato misurato dal DNA i laddering e transferasi-mediated dUTP nick-end labeling (TUNEL) assay. Produzione di ROS e MP sono stati determinati mediante sonde fluorescenti (2,7-diclorofluoresceina (DCFH-DA) e 5, 5&#39;, 6, 6&#39;-tetracloro-1, 1&#39;, 3, 3&#39;-tetraetile-benzamidazolocarbocyanin ioduro (JC-1), rispettivamente, di microscopia confocale. Espressione genica differenziale per il apoptosis &egrave; stato analizzato da cDNA array. I risultati hanno mostrato che produzione di ROS Hcy-mediata ha preceduto la perdita di MP, il rilascio del citocromo-c e l&#39;attivazione di caspase-9 e -3. Inoltre il trattamento di Hcy ha provocato una diminuzione nella Bcl 2/Bax rapporto, valutato da livelli di mRNA. Caspase-9 e -3 sono stati attivati, causando la scissione di PARP, un segno distintivo di apoptosi e di frammentazione del DNA internucleosomal. L&#39;effetto citotossico di Hcy &egrave; stato bloccato tramite piccolo RNA interferente (siRNA)-mediata soppressione di caspase-9 in MVEC. Sopprimendo l&#39;attivazione di caspase-9 inibito l&#39;attivazione di caspase -3 e rafforzata la vitalit&agrave; cellulare e MP. I nostri dati suggerirono che ROS Hcy-mediata produzione promuove la morte delle cellule endoteliali in parte da inquietanti MP, che si traduce nell&#39;attivazione di caspase-9 e 3 e successivo rilascio del citocromo-c, che portano alla morte delle cellule.

Meccanismo mitocondriale dell&#39;apoptosi delle cellule endoteliali Microvascolari in iperomocisteinemia.

Chronic hyperhomocysteinemia (HHcy) is an important factor in development of arterial hypertension. HHcy is associated with activation of matrix metalloproteinases (MMPs); however, it is unclear whether HHcy-dependent extracellular matrix (ECM) accumulation plays a role in arterial hypertrophy and hypertension. We tested the hypothesis that in HHcy the mechanism of arterial hypertension involves arterial dysfunction in response to ECM accumulation between endothelial and arterial smooth muscle cells and subsequent endothelium-myocyte (E-M) uncoupling. To decrease plasma Hcy, dietary supplementation with 3-deazaadenosine (DZA), the S-adenosylhomocysteine hydrolase inhibitor, was administered to cystathionine beta-synthase (CBS) knockout (KO) mice. Mice were grouped as follows: wild type (WT; control), WT+DZA, CBSKO, and CBSKO+DZA (n = 4/group). Mean aortic blood pressure and heart rate were monitored in real time with a telemetric system before, during, and after DZA treatment (6 wk total). In vivo aorta function and morphology were analyzed by M-mode and Doppler echocardiography in anesthetized mice. Aorta MMP activity in unfixed cryostat sections was measured with DQ gelatin. Aorta MMP-2, MMP-9, and connexin 43 expression were measured by RT-PCR and Western blot analyses, respectively. HHcy caused increased aortic blood pressure and resistance, tachycardia, and increased wall thickness and ECM accumulation in aortic wall vs. control groups. There was a linear correlation between aortic wall thickness and plasma Hcy levels. MMP-2, MMP-9, and connexin 43 expression were increased in HHcy. In the CBSKO+DZA group, aortic blood pressure and levels of MMP and connexin 43 were close to those found in control groups. However, removal of DZA reversed the aortic lumen-to-wall thickness ratio in CBSKO mice, suggesting, in part, a role of vascular remodeling in the increase in blood pressure in HHcy. The results show that arterial hypertension in HHcy mice is, in part, associated with arterial remodeling and E-M uncoupling in response to MMP activation.

3-Deazaadenosine mitigates arterial remodeling and hypertension in hyperhomocysteinemic mice.

Hyperhomocyst&eacute;in&eacute;mie chronique (HHcy) est un facteur important dans le d&eacute;veloppement de l&#39;hypertension art&eacute;rielle. HHcy est associ&eacute;e &agrave; l&#39;activation de m&eacute;talloprot&eacute;inases matricielles (MMP) ; Toutefois, on ignore si les accumulation de matrice extracellulaire (ECM) HHcy-d&eacute;pendante joue un r&ocirc;le dans l&#39;hypertrophie art&eacute;rielle et l&#39;hypertension. Nous avons test&eacute; l&#39;hypoth&egrave;se selon laquelle, en HHcy le m&eacute;canisme de l&#39;hypertension art&eacute;rielle, implique la dysfonction art&eacute;rielle en r&eacute;ponse &agrave; l&#39;accumulation d&#39;ECM entre cellules endoth&eacute;liales et art&egrave;res musculaires lisses et de d&eacute;couplage endoth&eacute;lium-myocyte ult&eacute;rieur (E-M). Pour diminuer le plasma Hcy, dietary supplementation with 3-d&eacute;azaad&eacute;nosine (DZA), inhibiteur de la S-ad&eacute;nosylhomocyst&eacute;ine hydrolase, a &eacute;t&eacute; administr&eacute;e &agrave; des souris de cystathionine b&ecirc;ta-synthase (CBS) knockout (KO). Souris ont &eacute;t&eacute; regroup&eacute;s comme suit : type sauvage (WT; contr&ocirc;le), WT + DZA, CBSKO et CBSKO + DZA (n = 4/groupe). La pression aortique moyenne et la fr&eacute;quence cardiaque ont &eacute;t&eacute; suivis en temps r&eacute;el avec un syst&egrave;me t&eacute;l&eacute;m&eacute;trique, avant, pendant et apr&egrave;s le traitement DZA (total 6 SEM). Morphologie et le fonctionnement de l&#39;aorte in vivo ont &eacute;t&eacute; analys&eacute;s par &eacute;chocardiographie Doppler et en mode M chez les souris anesth&eacute;si&eacute;s. Activit&eacute; MMP aorte dans les sections non fix&eacute;es cryostat a &eacute;t&eacute; mesur&eacute;e avec g&eacute;latine DQ. Aorte MMP-2, MMP-9 et expression de la connexine 43 ont &eacute;t&eacute; mesur&eacute;s par RT-PCR et buvardage de Western, respectivement. HHcy provoqu&eacute; l&#39;augmentation de la pression sanguine aortique et de r&eacute;sistance, de tachycardie et a augment&eacute; l&#39;&eacute;paisseur des parois et l&#39;accumulation d&#39;ECM dans la paroi aortique vs groupes t&eacute;moins. Il y avait une corr&eacute;lation lin&eacute;aire entre l&#39;&eacute;paisseur de la paroi aortique et Hcy plasmatique. MMP-2, MMP-9 et expression de la connexine 43 ont augment&eacute; chez HHcy. Dans le groupe CBSKO + DZA, pression sanguine aortique et niveaux de MMP et connexin 43 &eacute;taient proches de ceux observ&eacute;s dans les groupes t&eacute;moins. Cependant, enl&egrave;vement de DZA invers&eacute; le rapport aortique lumen-mur &eacute;paisseur chez la souris CBSKO, sugg&eacute;rant, en partie, un r&ocirc;le de remodelage vasculaire dans l&#39;augmentation de la pression art&eacute;rielle chez HHcy. Les r&eacute;sultats montrent que l&#39;hypertension art&eacute;rielle dans HHcy souris est, en partie, l&#39;associ&eacute; de remodelage art&eacute;riel et E.-M. d&eacute;telage de la remorque en r&eacute;ponse &agrave; l&#39;activation de la MMP.

3-D&eacute;azaad&eacute;nosine att&eacute;nue remodelage art&eacute;riel et l&#39;hypertension chez les souris hyperhomocyst&eacute;in&eacute;miques.

Iperomocisteinemia cronica (HHcy) &egrave; un fattore importante nello sviluppo dell&#39;ipertensione arteriosa. HHcy &egrave; associato con l&#39;attivazione delle metalloproteinasi della matrice (MMP); Tuttavia, non &egrave; chiaro se accumulo di matrice extracellulare (ECM) HHcy-dipendente gioca un ruolo nella ipertrofia arteriosa e l&#39;ipertensione. Abbiamo testato l&#39;ipotesi che in HHcy il meccanismo dell&#39;ipertensione arteriosa comporta disfunzione arteriosa in risposta all&#39;accumulo di ECM tra cellule muscolari lisce endoteliali e arteriosa e disgiungere successivo endotelio-myocyte (E-M). Per diminuire il plasma Hcy, integrazione alimentare con 3-deazaadenosine (DZA), l&#39;inibitore di S-adenosilomocisteina idrolasi, &egrave; stata somministrata a topi knockout (KO) di cistationina beta-sintasi (CBS). Topi sono stati raggruppati come segue: wild type (WT control), WT + DZA, CBSKO e CBSKO + DZA (n = 4/gruppo). Media aortica pressione sanguigna e frequenza cardiaca sono stati monitorati in tempo reale con un sistema telemetrico prima, durante e dopo il trattamento DZA (totale 6 wk). Morfologia e funzione aorta in vivo sono stati analizzati con l&#39;ecocardiografia M-mode e Doppler nei topi anestetizzati. Attivit&agrave; MMP aorta in sezioni al criostato unfixed &egrave; stata misurata con gelatina DQ. Aorta MMP-2, MMP-9 e l&#39;espressione della connessina 43 sono stati misurati da RT-PCR e Western blot analisi, rispettivamente. HHcy ha causato l&#39;aumento della pressione arteriosa dell&#39;aorta e resistenza, tachicardia e aumentato spessore della parete ed ECM accumulo nella parete aortica contro gruppi di controllo. C&#39;era una correlazione lineare tra spessore della parete aortica e livelli plasmatici di Hcy. MMP-2, MMP-9 e l&#39;espressione della connessina 43 sono stati aumentati in HHcy. Nel gruppo CBSKO + DZA aortica pressione sanguigna e livelli di MMP e connessina 43 erano vicini a quelli trovati nei gruppi di controllo. Tuttavia, rimozione di DZA invertito il rapporto spessore lume a parete aortica nei topi CBSKO, suggerendo, in parte, un ruolo di rimodellamento vascolare nell&#39;aumento della pressione arteriosa in HHcy. I risultati mostrano che l&#39;ipertensione arteriosa in HHcy topi &egrave;, in parte, associato al rimodellamento arterioso ed E-M disgiungere in risposta all&#39;attivazione di MMP.

3-Deazaadenosine mitiga rimodellamento arterioso e ipertensione nei topi hyperhomocysteinemic.

Pulmonary ischemia-reperfusion (IR) injury may result from trauma, atherosclerosis, pulmonary embolism, pulmonary thrombosis and surgical procedures such as cardiopulmonary bypass and lung transplantation. IR injury induces oxidative stress characterized by formation of reactive oxygen (ROS) and reactive nitrogen species (RNS). Nitric oxide (NO) overproduction via inducible nitric oxide synthase (iNOS) is an important component in the pathogenesis of IR. Reaction of NO with ROS forms RNS as secondary reactive products, which cause platelet activation and upregulation of adhesion molecules. This mechanism of injury is particularly important during pulmonary IR with increased iNOS activity in the presence of oxidative stress. Platelet-endothelial interactions may play an important role in causing pulmonary arteriolar vasoconstriction and post-ischemic alveolar hypoperfusion. This review discusses the relationship between ROS, RNS, P-selectin, and platelet-arteriolar wall interactions and proposes a hypothesis for their role in microvascular responses during pulmonary IR.

Lung ischemia-reperfusion injury: implications of oxidative stress and platelet-arteriolar wall interactions.

Pulmonaire isch&eacute;mie-reperfusion (IR) peut r&eacute;sulter d&#39;un traumatisme, l&#39;ath&eacute;roscl&eacute;rose, embolie pulmonaire, thrombose pulmonaire et des interventions chirurgicales telles que la circulation extracorporelle et de la transplantation de poumon. Blessure IR induit un stress oxydatif caract&eacute;ris&eacute; par la formation de r&eacute;actives de l&#39;oxyg&egrave;ne (ROS) et les esp&egrave;ces r&eacute;actives de l&#39;azote (RNS). La surproduction de l&#39;oxyde nitrique (non) par l&#39;interm&eacute;diaire de monoxyde d&#39;azote synthase inductible (iNOS) est un &eacute;l&eacute;ment important dans la pathogen&egrave;se de l&#39;IR R&eacute;action de NO avec ROS forme RNS comme produits r&eacute;actifs secondaires, qui provoquent l&#39;activation plaquettaire et la stimulation de l&#39;expression des mol&eacute;cules d&#39;adh&eacute;sion. Ce m&eacute;canisme de blessure est particuli&egrave;rement important au cours de l&#39;IR pulmonaire avec activit&eacute; iNOS accrue en pr&eacute;sence de stress oxydatif. Interactions entre les plaquettes-endoth&eacute;liales peuvent jouer un r&ocirc;le important en provoquant une vasoconstriction art&eacute;riolaire pulmonaire et post-isch&eacute;mique hypoperfusion alv&eacute;olaire. Cette revue traite de la relation entre les interactions mur P-s&eacute;lectine et plaquettes-art&eacute;riolaire ROS, RNS et propose une hypoth&egrave;se pour leur r&ocirc;le dans les r&eacute;ponses microvasculaires durant IR pulmonaire

L&eacute;sion d&#39;isch&eacute;mie-reperfusion pulmonaire : cons&eacute;quences du stress oxydatif et les interactions mur plaquettaire-art&eacute;riolaire.

Trauma, aterosclerosi, l&#39;embolia polmonare, trombosi polmonare e interventi chirurgici come il bypass cardiopolmonare e trapianto polmonare pu&ograve; causare lesioni polmonari ischemia-reperfusion (IR). Lesioni IR induce stress ossidativo, caratterizzato dalla formazione di ossigeno reattivo (ROS) e specie reattive dell&#39;azoto (RNS). Sovrapproduzione di ossido nitrico (NO) via inducibile ossido nitrico sintasi (iNOS) &egrave; una componente importante nella patogenesi di IR. Reazione del NO con ROS forma RNS come prodotti reattivi secondari, che provocano l&#39;attivazione piastrinica e sovraregolazione di molecole di adesione. Questo meccanismo di lesione &egrave; particolarmente importante durante l&#39;IR polmonare con attivit&agrave; iNOS aumentato in presenza di stress ossidativo. Interazioni piastrine-endotelio possono giocare un ruolo importante nel causare vasocostrizione arteriolare polmonare e il hypoperfusion alveolare. Questa recensione viene illustrata la relazione tra interazioni P-Selectina e piastrinica arteriole parete ROS, RNS e propone un&#39;ipotesi per il loro ruolo nelle risposte microvascolare durante IR. polmonare

Danno da ischemia-riperfusione polmonare: implicazioni della parete piastrinica arteriole interazioni e stress ossidativo.

Lung ischemia-reperfusion (IR) injury causes alveolar, epithelial and endothelial cell dysfunction which often results in decreased alveolar perfusion, characteristic of an acute respiratory distress syndrome. Nitric oxide (NO) from endothelium-derived NO synthase (eNOS) helps maintain a low pulmonary vascular resistance. Paradoxically, during acute lung injury, overproduction of NO via inducible NO synthase (iNOS) and oxidative stress lead to reactive oxygen and nitrogen species (ROS and RNS) formation and vascular dysfunction. RNS potentiate vascular and cellular injury by oxidation, by decreasing NO bioavailability, and by regulating NOS isoforms. RNS potentiate their own production by uncoupling NO production through eNOS by oxidation and disruption of Akt-mediated phosphorylation of eNOS. This review focuses on effects of NO which cause vascular dysfunction in the unique environment of the lung and presents a hypothesis for interplay between eNOS and iNOS activation with implications for development of new strategies to treat vascular dysfunction associated with IR.

Differential effects of nitric oxide synthesis on pulmonary vascular function during lung ischemia-reperfusion injury.

L&eacute;sion d&#39;isch&eacute;mie-reperfusion (IR) pulmonaire provoque un dysfonctionnement cellulaire alv&eacute;olaire, &eacute;pith&eacute;liales et endoth&eacute;liales qui se traduit souvent par une baisse perfusion alv&eacute;olaire, caract&eacute;ristique d&#39;un syndrome de d&eacute;tresse respiratoire aigu&euml;. L&#39;oxyde nitrique (non) de d&eacute;riv&eacute; de l&#39;endoth&eacute;lium NO synthase (eNOS) permet de maintenir une faible r&eacute;sistance vasculaire pulmonaire. Paradoxalement, au cours de la l&eacute;sion pulmonaire aigu&euml;, surproduction d&#39;aucune via non inductible synthase (iNOS) et stress oxydatif conduisent &agrave; r&eacute;active d&#39;oxyg&egrave;ne et d&#39;azote (ROS et RNS) formation d&#39;esp&egrave;ces et de dysfonction vasculaire. RNS potentialiser les blessures vasculaires et cellulaires par oxydation, en ne diminuant aucun biodisponibilit&eacute; et en r&eacute;gulant NOS isoformes. RNS potentialiser leur production par ne d&eacute;couplage aucune production par eNOS par oxydation et perturbation de Akt induite par la phosphorylation d&#39;eNOS. Cet examen se concentre sur les effets des pas qui causent le dysfonctionnement vasculaire dans l&#39;environnement unique du poumon et pr&eacute;sente une hypoth&egrave;se pour l&#39;interaction entre l&#39;activation d&#39;eNOS et iNOS avec incidences sur le d&eacute;veloppement de nouvelles strat&eacute;gies pour traiter la dysfonction vasculaire associ&eacute;e &agrave; IR

Effets diff&eacute;rentiels de la synth&egrave;se du monoxyde d&#39;azote sur la fonction vasculaire pulmonaire au cours de l&#39;isch&eacute;mie-reperfusion de poumon.

Danno ischemia-reperfusion (IR) polmonare provoca la disfunzione delle cellule alveolari, epiteliali ed endoteliali che spesso provoca una riduzione della perfusione alveolare, caratteristico di una sindrome da distress respiratorio acuto. L&#39;ossido nitrico (NO) da endotelio-derivato NO sintasi (eNOS) aiuta a mantenere una bassa resistenza vascolare polmonare. Paradossalmente, durante il danno polmonare acuto, la sovrapproduzione di NO via inducible NO sintasi (iNOS) e stress ossidativo portare a reattiva dell&#39;ossigeno e dell&#39;azoto specie (ROS e RNS) formazione e disfunzione vascolare. RNS potenziare lesioni vascolari e cellulari da ossidazione, diminuendo non biodisponibilit&agrave; e regolando isoforme NOS. RNS potenziare la propria produzione di non disgiungere nessuna produzione attraverso eNOS di ossidazione e la rottura della fosforilazione di Akt-mediata di eNOS. Questa recensione si concentra sugli effetti del NO che causano disfunzione vascolare nell&#39;ambiente unico del polmone e presenta un&#39;ipotesi di interazione tra attivazione eNOS e iNOS con implicazioni per lo sviluppo di nuove strategie per trattare la disfunzione vascolare associata a IR.

Effetti differenziali della sintesi di ossido nitrico sulla funzione vascolare polmonare durante il danno polmonare ischemia-reperfusion.

Congestive heart failure remains a primary cause of cardiovascular-related events. Heart failure patients face two health care challenges. First, they are uncertain about their prognosis and second, they have an unpredictable clinical course with recurrent exacerbations of heart failure. The echocardiogram is an easily accessible bedside test without any associated procedural complications. Additionally, it provides a wealth of information about chamber size and function, valve integrity and the pericardial sac. In the present review, the most common echocardiographic predictors of impending cardiac events in congestive heart failure are described.

Echocardiography predicts adverse cardiac remodelling in heart failure.

Insuffisance cardiaque reste des principales causes des &eacute;v&eacute;nements cardiovasculaires. Patients atteints d&#39;insuffisance cardiaque face &agrave; deux d&eacute;fis de la sant&eacute;. Tout d&#39;abord, ils sont incertains de leur pronostic et la seconde, ils ont une &eacute;volution clinique impr&eacute;visible avec des pouss&eacute;es r&eacute;currentes de l&#39;insuffisance cardiaque. L&#39;&eacute;chocardiographie est un test de chevet facilement accessible sans aucune complication proc&eacute;durale associ&eacute;e. En outre, elle fournit une mine de renseignements sur la taille de la chambre et fonction, l&#39;int&eacute;grit&eacute; de la vanne et le p&eacute;ricarde. Dans cette revue, les pr&eacute;dicteurs &eacute;chocardiographiques plus courantes des &eacute;v&egrave;nements cardiaques imminents dans l&#39;insuffisance cardiaque congestive sont d&eacute;crites.

&Eacute;chocardiographie pr&eacute;dit un remodelage cardiaque ind&eacute;sirables dans l&#39;insuffisance cardiaque.

Insufficienza cardiaca congestizia resta una causa primaria di eventi cardiovascolari correlati. Pazienti con scompenso cardiaco affrontano due sfide sanitarie. In primo luogo, essi sono incerti circa la loro prognosi e la seconda, hanno un decorso clinico imprevedibile con ricorrenti esacerbazioni di insufficienza cardiaca. L&#39;ecocardiogramma &egrave; un test comodino facilmente accessibile senza complicazioni procedurali associate. Inoltre, esso fornisce una ricchezza delle informazioni sulla dimensione e funzione, l&#39;integrit&agrave; della valvola e il sacco pericardico. Nel presente riesame, vengono descritti i pi&ugrave; comuni predittori ecocardiografici di imminente eventi cardiaci nella insufficienza cardiaca congestizia.

L&#39;ecocardiografia predice avverso rimodellamento cardiaco nello scompenso cardiaco.

Complicanze polmonari associate a debolezza muscolare persistente delle vie respiratorie, paralisi e spasticit&agrave; sono tra i pi&ugrave; importanti problemi affrontati dai pazienti con lesioni del midollo spinale quando la mancanza di forza muscolare e la disorganizzazione del cavo di controllo reciproco muscoli respiratori per insufficienza di respirazione. Questa review descrive i meccanismi di controllo motore respiratorio e relativo cambiamento nei soggetti con lesioni del midollo spinale, metodi con cui &egrave; misurata la funzione respiratoria e trattamento riabilitativo utilizzato per ripristinare la funzione respiratoria in coloro che hanno sperimentato tale pregiudizio.

Controllo motore respiratorio interrotta da lesioni del midollo spinale: meccanismi di valutazione e restauro.

Pulmonary complications associated with persistent respiratory muscle weakness, paralysis, and spasticity are among the most important problems faced by patients with spinal cord injury when lack of muscle strength and disorganization of reciprocal respiratory muscle control lead to breathing insufficiency. This review describes the mechanisms of the respiratory motor control and its change in individuals with spinal cord injury, methods by which respiratory function is measured, and rehabilitative treatment used to restore respiratory function in those who have experienced such injury.

Respiratory Motor Control Disrupted by Spinal Cord Injury: Mechanisms, Evaluation, and Restoration.

Complications pulmonaires associ&eacute;es &agrave; une faiblesse persistante musculaire respiratoire, paralysie et spasticit&eacute; sont parmi les plus importants probl&egrave;mes auxquels font face les patients atteints de l&eacute;sion m&eacute;dullaire o&ugrave; manque de force musculaire et de la d&eacute;sorganisation du c&acirc;ble de commande des muscles respiratoires r&eacute;ciproque &agrave; l&#39;insuffisance de la respiration. Cette revue d&eacute;crit les m&eacute;canismes de la motricit&eacute; respiratoire et son changement chez les personnes atteintes de la moelle &eacute;pini&egrave;re, les m&eacute;thodes par lesquelles la fonction respiratoire est mesur&eacute;e et r&eacute;adaptation traitement utilis&eacute; pour restaurer la fonction respiratoire chez les personnes qui ont subi des blessures.

Motricit&eacute; respiratoire perturb&eacute;e par une blessure de la moelle &eacute;pini&egrave;re : m&eacute;canismes, d&#39;&eacute;valuation et de restauration.

Article	Year
Effects of pulmonary ischemia-reperfusion on platelet adhesion in subpleural arterioles in rabbits. Microvascular research\| PubMed ID: 14709400	2004
Protease-activated receptor and endothelial-myocyte uncoupling in chronic heart failure. American journal of physiology. Heart and circulatory physiology\| PubMed ID: 15681708	2005
Inhibition of inducible nitric oxide synthase attenuates platelet adhesion in subpleural arterioles caused by lung ischemia-reperfusion in rabbits. Journal of applied physiology (Bethesda, Md. : 1985)\| PubMed ID: 16037396	2005
Role of matrix metalloproteinase-9 in endothelial apoptosis in chronic heart failure in mice. Journal of applied physiology (Bethesda, Md. : 1985)\| PubMed ID: 16081621	2005
Mechanisms of homocysteine-induced oxidative stress. American journal of physiology. Heart and circulatory physiology\| PubMed ID: 16085680	2005
Homocysteine-dependent cardiac remodeling and endothelial-myocyte coupling in a 2 kidney, 1 clip Goldblatt hypertension mouse model. Canadian journal of physiology and pharmacology\| PubMed ID: 16091784	2005
Mitochondrial mechanism of oxidative stress and systemic hypertension in hyperhomocysteinemia. Journal of cellular biochemistry\| PubMed ID: 16149054	2005
Regulation of homocysteine-induced MMP-9 by ERK1/2 pathway. American journal of physiology. Cell physiology\| PubMed ID: 16251475	2006
Mitochondrial mechanism of microvascular endothelial cells apoptosis in hyperhomocysteinemia. Journal of cellular biochemistry\| PubMed ID: 16514665	2006
3-Deazaadenosine mitigates arterial remodeling and hypertension in hyperhomocysteinemic mice. American journal of physiology. Lung cellular and molecular physiology\| PubMed ID: 16815886	2006
Lung ischemia-reperfusion injury: implications of oxidative stress and platelet-arteriolar wall interactions. Archives of physiology and biochemistry\| PubMed ID: 17522980	2007
Differential effects of nitric oxide synthesis on pulmonary vascular function during lung ischemia-reperfusion injury. Archives of physiology and biochemistry\| PubMed ID: 19267281	2009
Echocardiography predicts adverse cardiac remodelling in heart failure. Experimental and clinical cardiology\| PubMed ID: 19641696	2004
Respiratory Motor Control Disrupted by Spinal Cord Injury: Mechanisms, Evaluation, and Restoration. Translational stroke research\| PubMed ID: 22408690	2011

Alexander V. Ovechkin

Biography

JoVE Journal Publications

Other Publications