RESUMO
The aim of this study is to ascertain whether the simultaneous measurement of hemoglobin O2 saturation (StO2 ) and dimension of venous leg ulcers (VLU) by near infrared spectroscopy (NIRS) imaging can predict the healing course with protocols employing a conventional treatment alone or in combination with hyperbaric oxygen therapy (HBOT). NIRS 2D images of wound region were obtained in 81 patients with hard-to-heal VLU that had been assigned, in a randomized controlled clinical trial, to the following protocols: 30 HBOT sessions, adjunctive to the conventional therapy, either twice daily over 3 weeks (group A) or once daily over 6 weeks (group B), and conventional therapy without HBOT (group C). Seventy-three patients completed the study with a total of 511 NIRS images being analyzed. At the end of treatment, wound area was significantly smaller in all three groups. However, at the 3-week mark the wound area reduction tended to be less evident in group A than in the other groups. This trend continued up to the 6-week end-point when a significantly greater area reduction was found with group B (65.5%) and group C (56.8%) compared to group A (29.7%) (P < .01). Furthermore, a higher incidence of complete healing was noted with group B (20%) than with group A (4.5%) and group C (3.8%). When using a final wound reduction in excess of 40% to distinguish healing from nonhealing ulcers, it was found that only the former present NIRS StO2 values abating over the study period both at center and edge of lesions. In conclusion, NIRS analysis of StO2 and wound area can predict the healing course of VLU. Adjunctive HBOT significantly facilitates VLU healing compared to the conventional treatment alone. This positive action, however, becomes manifest only with a longer and less intensive treatment schedule.
Assuntos
Bandagens Compressivas , Hemoglobinas/metabolismo , Oxigenoterapia Hiperbárica/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Úlcera Varicosa/terapia , Cicatrização/fisiologia , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Consumo de Oxigênio , Resultado do Tratamento , Úlcera Varicosa/sangueRESUMO
Antenatal cardiac intervention affords new prospects for hypoplastic left heart syndrome. Its success, however, may come not only from absence of impediments to blood flow but also from a sufficiently developed cardiac wall. Here, we examined the feasibility to perfuse selectively the fetal coronary circulation for treatment with growth promoting agents. Pregnant sheep (94-114 days gestation, term 145 days) were used. An aortic stop-flow procedure was developed for intracoronary access in the nonexposed fetus and human mesenchymal stem cells and their exosomes served as test agents. We found that aortic stop-flow ensures preferential distribution of fluorescent microspheres to the heart. However, intracoronary administration of stem cells or exosomes was detrimental, with fetal demise occurring around surgery or at variable intervals afterwards. Coincidentally, stop-flow caused by itself a marked rise of intraluminal pressure within the occluded aorta along with histological signs of coronary obstruction. We conclude that it is feasible to perfuse selectively the coronary circulation of the preterm fetus, but treatments are not compatible with survival of the animals. The cause for failure is found in the absence of hemodynamic compensation to stop-flow via a left-to-right shunt. This unexpected event is attributed to a largely membranous foramen ovale, characteristic of sheep, that collapses under pressure.
Assuntos
Circulação Coronária/fisiologia , Forame Oval/fisiologia , Ovinos/fisiologia , Animais , Aorta/fisiologia , Feminino , Feto/fisiologia , Coração/fisiologia , Hemodinâmica/fisiologia , Humanos , Síndrome do Coração Esquerdo Hipoplásico/fisiopatologia , Recém-Nascido , Perfusão/métodos , GravidezRESUMO
The fetal ductus arteriosus (DA) closes postnatally first functionally and then structurally. Normal rise in blood oxygenation is regarded as a prime trigger, but closure may occur more slowly without this stimulus. Here, our aim was to assess the role of angiotensin II (Ang II) in functional closure of DA since its action may not be conditioned by oxygen. Experiments were performed with wild-type fetal and neonatal mice, using whole-body freezing technique to assess DA caliber in vivo. Transcripts for Ang II type 1 (AT1R) and type 2 (AT2R) receptors were also examined. We found that the AT1R antagonist olmesartan had no effect in the fetus, but delayed ductus closure in the neonate. However, this response was short-lived and disappeared upon concomitant treatment with the AT2R antagonist PD123319. Coincidentally, olmesartan promoted the Agtr2 transcript. We conclude that AT1R-based Ang II has no role in the functional closure of DA. Conversely, the compound may modulate this process through AT2R-mediated vasodilatation.
Assuntos
Angiotensina II/metabolismo , Canal Arterial/fisiologia , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor Tipo 2 de Angiotensina/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 2 de Angiotensina II/farmacologia , Animais , Animais Recém-Nascidos , Feminino , Imidazóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Olmesartana Medoxomila , Piridinas/farmacologia , Receptor Tipo 1 de Angiotensina/efeitos dos fármacos , Receptor Tipo 2 de Angiotensina/efeitos dos fármacos , Tetrazóis/farmacologia , Vasodilatação/efeitos dos fármacosRESUMO
We have previously reported that bradykinin relaxes the fetal ductus arteriosus via endothelium-derived hyperpolarizing factor (EDHF) when other naturally occurring relaxants (prostaglandin E2, nitric oxide, and carbon monoxide) are suppressed, but the identity of the agent could not be ascertained. Here, we have examined in the mouse whether hydrogen sulfide (H2S) is a relaxant of the ductus and, if so, whether it may also function as an EDHF. We found in the vessel transcripts for the H2S synthetic enzymes, cystathionine-γ-lyase (CSE) and cystathionine-ß-synthase (CBS), and the presence of these enzymes was confirmed by immunofluorescence microscopy. CSE and CBS were distributed across the vessel wall with the former prevailing in the intimal layer. Both enzymes occurred within the endoplasmic reticulum of endothelial and muscle cells, whereas only CSE was located also in the plasma membrane. The isolated ductus contracted to inhibitors of CSE (d,l-propargylglycine, PPG) and CBS (amino-oxyacetic acid), and PPG contraction was attenuated by removal of the endothelium. EDHF-mediated bradykinin relaxation was curtailed by both PPG and amino-oxyacetic acid, whereas the relaxation to sodium nitroprusside was not affected by either treatment. The H2S donor sodium hydrogen sulfide (NaHS) was also a potent, concentration-dependent relaxant. We conclude that the ductus is endowed with a H2S system exerting a tonic relaxation. In addition, H2S, possibly via an overriding CSE source, qualifies as an EDHF. These findings introduce a novel vasoregulatory mechanism into the ductus, with implications for antenatal patency of the vessel and its transitional adjustments at birth.
Assuntos
Canal Arterial/metabolismo , Fatores Relaxantes Dependentes do Endotélio/metabolismo , Sulfeto de Hidrogênio/metabolismo , Vasodilatação , Alcinos/farmacologia , Ácido Amino-Oxiacético/farmacologia , Animais , Bradicinina/farmacologia , Membrana Celular/metabolismo , Cistationina beta-Sintase/antagonistas & inibidores , Cistationina beta-Sintase/genética , Cistationina beta-Sintase/metabolismo , Cistationina gama-Liase/antagonistas & inibidores , Cistationina gama-Liase/genética , Cistationina gama-Liase/metabolismo , Canal Arterial/enzimologia , Canal Arterial/fisiologia , Retículo Endoplasmático/metabolismo , Células Endoteliais/metabolismo , Glicina/análogos & derivados , Glicina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/metabolismo , Nitroprussiato/farmacologia , RNA Mensageiro/biossíntese , Transcrição Gênica , Túnica Íntima/citologia , Túnica Íntima/enzimologia , Túnica Íntima/metabolismoRESUMO
We have previously shown that a cytochrome P450 (CYP450) hemoprotein from the 3A subfamily CYP3A13 for the mouse, serves as the sensor in the contraction of the ductus arteriosus in response to increased oxygen tension. In addition, we have identified endothelin-1 (ET-1) as the effector for this response. Here, we examined whether Cyp3a13 gene transfer confers oxygen sensitivity to cultured muscle cells from mouse aorta. Coincidentally, we determined whether the same hemoprotein is normally present in the vessel. Cyp3a13-transfected aortic cells responded to oxygen, whereas no significant response was seen in native cells or in cells transfected with an empty vector. Furthermore, this oxygen effect was curtailed by the ET-1/ETA receptor antagonist BQ-123. We also found that CYP3A13 occurs naturally in aortic tissue and its isolated muscle cells in culture. We conclude that CYP3A13 is involved in oxygen sensing, and its action in the transfected muscle cells of the aorta, as in the native cells of the ductus, takes place through a linkage to ET-1. However, the response of aortic muscle to oxygen, conceivably entailing the presence of CYP3A13 at some special site, is not seen in the native situation, and may instead unfold upon transfection of the parent gene.
Assuntos
Aorta Torácica/metabolismo , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Células Musculares/metabolismo , Oxigênio/farmacologia , Animais , Aorta Torácica/citologia , Aorta Torácica/efeitos dos fármacos , Cálcio/metabolismo , Células Cultivadas , Endotelina-1/genética , Endotelina-1/metabolismo , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Hemeproteínas/genética , Hemeproteínas/metabolismo , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/efeitos dos fármacos , Células Musculares/enzimologia , Oxigênio/metabolismo , Peptídeos Cíclicos/farmacologia , Receptores de Endotelina/genética , Receptores de Endotelina/metabolismo , Transfecção/métodosRESUMO
Closure of the ductus arteriosus at birth is known to be related to the physiological rise in blood oxygen tension. Two main schemes have been proposed to explain the peculiar contraction of the ductus to oxygen, and their function is based on distinct sensor-effector complexes. Specifically, these schemes comprise a cytochrome P450 monooxygenase-endothelin complex or, alternatively, a mitochondrial redox mechanism-voltage gated potassium channel complex. However, it is not clear how these systems may relate to the closure process. Here, it is proposed that they operate jointly within a single functional entity, with their combined activation being required for a full-fledged contraction of the vessel to oxygen. This arrangement is thought to ensure a smooth transition from the powerful relaxant mechanism that is evident through the early postnatal period. Validation of this concept would not only settle a central question in the operation of the ductus but may also afford a broader perspective in any future translational research.
Assuntos
Canal Arterial , Sistema Enzimático do Citocromo P-450/metabolismo , Canal Arterial/metabolismo , Mitocôndrias , Oxigênio/metabolismoRESUMO
The fetal ductus arteriosus (DA) contracts to oxygen, and this feature, maturing through gestation, is considered important for its closure at birth. We have previously obtained evidence of the involvement of cytochrome P-450, possibly of the 3A subfamily (CYP3A), in oxygen sensing and have also identified endothelin (ET)-1 as the attendant effector for the contraction. Here, we examined comparatively wild-type (WT) and CYP3A-null (Cyp3a(-/-)) mice for direct validation of this concept. We found that the CYP3A subfamily is represented only by CYP3A13 in the WT DA. CYP3A13 was also detected in the DA by immunofluorescence microscopy, being primarily colocalized with the endoplasmic reticulum in both endothelial and muscle cells. However, a distinct signal was also evident in the plasma membrane. Isolated DAs from term WT animals developed a sustained contraction to oxygen with transient contractions superimposed. Conversely, no tonic response occurred in Cyp3a(-/-) DAs, whereas the phasic response persisted unabated. Oxygen did not contract the preterm WT DA but caused a full-fledged contraction after retinoic acid (RA) treatment. RA also promoted an oxygen contraction in the Cyp3a(-/-) DA. However, responses of RA-treated WT and Cyp3a(-/-) mice differed in that only the former abated with ET-1 suppression. This implies the existence of an alternative target for RA responsible for the oxygen-induced contraction in the absence of CYP3A13. In vivo, the DA was constricted in WT and Cyp3a(-/-) newborns, although with a tendency to be less narrowed in the mutant. We conclude that oxygen acts primarily through the complex CYP3A13 (sensor)/ET-1 (effector) and, in an accessory way, directly onto ET-1. However, even in the absence of CYP3A13, the DA may close postnatally thanks to the contribution of ET-1 and the likely involvement of compensating mechanism(s) identifiable with an alternative oxygen-sensing system and/or the withdrawal of relaxing influence(s) operating prenatally.
Assuntos
Citocromo P-450 CYP3A/fisiologia , Canal Arterial/fisiologia , Endotelina-1/fisiologia , Proteínas de Membrana/fisiologia , Oxigênio/fisiologia , Vasoconstrição/fisiologia , Animais , Animais Recém-Nascidos , Citocromo P-450 CYP3A/metabolismo , Canal Arterial/metabolismo , Endotelina-1/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Contração Miocárdica/fisiologia , Oxigênio/metabolismo , Tretinoína/metabolismo , Tretinoína/fisiologiaRESUMO
Oxygen promotes closure of the ductus arteriosus at birth. We have previously presented a scheme for oxygen action with a cytochrome P450 (CYP450) hemoprotein and endothelin-1 (ET-1) being, respectively, sensor and effector, and a hypothetical monooxygenase product serving as a coupling link. We have also found in the vessel arachidonic acid (AA) 12(S)-lipoxygenase (12-lipoxygenase) undergoing upregulation at birth. Here, we examined the feasibility of a sensor-to-effector messenger originating from AA monooxygenase and 12-lipoxygenase pathways. The epoxygenase inhibitor, N-methylsulfonyl-6-(2-)hexanamide, suppressed the tonic contraction of ductus to oxygen. A similar effect was obtained with 12-lipoxygenase inhibitors baicalein and PD 146176. By contrast, none of the inhibitors modified the endothelin-1 contraction. Furthermore, an AA ω-hydroxylation product, 20-hydroxyeicosatetraenoic acid (20-HETE), reportedly responsible for oxygen contraction in the systemic microvasculature, had no such effect on the ductus. We conclude that AA epoxygenase and 12-lipoxygenase jointly produce a hitherto uncharacterized compound acting as oxygen messenger in the ductus.
Assuntos
Araquidonato 12-Lipoxigenase/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Canal Arterial/efeitos dos fármacos , Oxigênio/farmacologia , Vasoconstrição/efeitos dos fármacos , Amidas/farmacologia , Animais , Citocromo P-450 CYP2J2 , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/genética , Relação Dose-Resposta a Droga , Canal Arterial/enzimologia , Canal Arterial/fisiologia , Endotelina-1/farmacologia , Inibidores Enzimáticos/farmacologia , Feto/fisiologia , Flavanonas/farmacologia , Fluorenos/farmacologia , Ácidos Hidroxieicosatetraenoicos/farmacologia , Inibidores de Lipoxigenase/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Endoperóxidos Sintéticos de Prostaglandinas/farmacologia , Transdução de Sinais/fisiologia , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacologia , Vasoconstrição/fisiologia , Vasoconstritores/farmacologia , Vasodilatadores/farmacologiaAssuntos
Canal Arterial/fisiologia , GTP Fosfo-Hidrolases/fisiologia , Proteínas Associadas aos Microtúbulos/fisiologia , Dinâmica Mitocondrial/fisiologia , Proteínas Mitocondriais/fisiologia , Músculo Liso Vascular/fisiologia , Oxigênio/fisiologia , Vasoconstrição/fisiologia , Animais , Feminino , Humanos , MasculinoRESUMO
The possibility of intervening in utero on certain cardiac malformations with the intent to prevent secondary major alterations in structure and function is becoming a reality. Central to progress in this area is the development of instrumentation specifically designed for minimally invasive cardiac surgery in the fetus. The present review introduces a novel set of devices for interventional cardiology, based on current knowledge and prior experience, and highlights their prospective application. In meeting this objective, particular importance is assigned to the synergic contribution of diverse disciplines, both medical and nonmedical.
Assuntos
Procedimentos Cirúrgicos Cardíacos/instrumentação , Difusão de Inovações , Feto/cirurgia , Cardiopatias Congênitas/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Cateterismo Cardíaco/instrumentação , Procedimentos Cirúrgicos Cardíacos/métodos , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos/métodosRESUMO
We have previously shown (Ref. 2) that endothelium-derived hyperpolarizing factor (EDHF) becomes functional in the fetal ductus arteriosus on removal of nitric oxide and carbon monoxide. From this, it was proposed that EDHF originates from a cytochrome P-450 (CYP450)-catalyzed reaction being inhibited by the two agents. Here, we have examined in the mouse ductus whether EDHF can be identified as an arachidonic acid product of a CYP450 epoxygenase and allied pathways. We did not detect transcripts of the mouse CYP2C subfamily in vessel, while CYP2J subfamily transcripts were expressed with CYP2J6 and CYP2J9. These CYP2J hemoproteins were also detected in the ductus by immunofluorescence microscopy, being colocalized with the endoplasmic reticulum in both endothelial and muscle cells. Distinct CYP450 transcripts were also detected and were responsible for omega-hydroxylation (CYP4A31) and 12R-hydroxylation (CYP4B1). Mass spectrometric analysis showed formation of epoxyeicosatrienoic acids (EETs) in the intact ductus, with 11,12- and 14,15-EETs being more prominent than 5,6- and 8,9-EETs. However, their yield did not increase with nitric oxide/carbon monoxide suppression, nor did it abate with endothelium removal. No evidence was obtained for formation of 12R-hydroxyeicosatrienoic acid and omega-hydroxylation products. 2S-hydroxyeicosatetraenoic acid was instead detected, and, contrary to data implicating this compound as an alternative EDHF, its suppression with baicalein did not modify the EDHF-mediated relaxation to bradykinin. We conclude that none of the more common CYP450-linked arachidonic acid metabolites appears to qualify as EDHF in mouse ductus. We speculate that some novel eicosanoid or a totally unrelated compound requiring CYP450 for its synthesis accounts for EDHF in this vessel.
Assuntos
Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/metabolismo , Ácido Araquidônico/metabolismo , Fatores Biológicos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Canal Arterial/enzimologia , Vasodilatação , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Bradicinina/metabolismo , Citocromo P-450 CYP2J2 , Citocromo P-450 CYP4A/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Células Endoteliais/enzimologia , Medicina Baseada em Evidências , Regulação Enzimológica da Expressão Gênica , Hidroxilação , Camundongos , Camundongos Endogâmicos C57BL , Oxigenases de Função Mista/metabolismo , Músculo Liso Vascular/enzimologiaRESUMO
BACKGROUND: In the Western world, a major cause of blindness is age-related macular degeneration (AMD). Recent research in angiogenesis has furthered the understanding of choroidal neovascularization, which occurs in the "wet" form of AMD. In contrast, very little is known about the mechanisms of the predominant, "dry" form of AMD, which is characterized by retinal atrophy and choroidal involution. The aim of this study is to elucidate the possible implication of the scavenger receptor CD36 in retinal degeneration and choroidal involution, the cardinal features of the dry form of AMD. METHODS AND FINDINGS: We here show that deficiency of CD36, which participates in outer segment (OS) phagocytosis by the retinal pigment epithelium (RPE) in vitro, leads to significant progressive age-related photoreceptor degeneration evaluated histologically at different ages in two rodent models of CD36 invalidation in vivo (Spontaneous hypertensive rats (SHR) and CD36-/- mice). Furthermore, these animals developed significant age related choroidal involution reflected in a 100%-300% increase in the avascular area of the choriocapillaries measured on vascular corrosion casts of aged animals. We also show that proangiogenic COX2 expression in RPE is stimulated by CD36 activating antibody and that CD36-deficient RPE cells from SHR rats fail to induce COX2 and subsequent vascular endothelial growth factor (VEGF) expression upon OS or antibody stimulation in vitro. CD36-/- mice express reduced levels of COX2 and VEGF in vivo, and COX2-/- mice develop progressive choroidal degeneration similar to what is seen in CD36 deficiency. CONCLUSIONS: CD36 deficiency leads to choroidal involution via COX2 down-regulation in the RPE. These results show a novel molecular mechanism of choroidal degeneration, a key feature of dry AMD. These findings unveil a pathogenic process, to our knowledge previously undescribed, with important implications for the development of new therapies.
Assuntos
Antígenos CD36/genética , Doenças da Coroide/enzimologia , Ciclo-Oxigenase 2/metabolismo , Regulação para Baixo/genética , Animais , Antígenos CD36/fisiologia , Células Cultivadas , Doenças da Coroide/genética , Ciclo-Oxigenase 2/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Degeneração Retiniana/enzimologia , Degeneração Retiniana/genéticaRESUMO
Prostaglandin E2 (PGE2) plays a key role in the ductus arteriosus, prenatally by maintaining patency and postnatally by promoting tissue remodeling for closure. Here, by using near-term mouse fetuses with (wild-type, WT) and without microsomal PGE synthase-1 (mPGES1-/-), we have examined the importance of this enzyme for PGE2 formation and function. mPGES1-/- ductus, unlike WT ductus, contracted little, or not all, to indomethacin in vitro. Coincidentally, as evident from responses to NG-nitro-L-arginine methyl ester and zinc photoporphyrin, the mutant showed no significant enhancement of nitric oxide (NO)- and carbon monoxide (CO)-based relaxation. mPGES1 suppression differs, therefore, from cyclooxygenase (COX) suppression, whether genetically or pharmacologically induced, where NO is markedly up-regulated. In vivo, the ductus was patent, albeit occasionally with a narrowed lumen, in all mPGES1-/- fetuses. Conversely, postnatal closure progressed regularly in mPGES1-/- animals thanks to residual PGE2 originating via mPGES2. We conclude that mPGES1 is critical for PGE2 formation in the ductus but its loss does not entail compensatory up-regulation of other relaxing mechanisms. Accordingly, an mPGES1 inhibitor stands out as a prospective better tool, compared with the currently used COX inhibitors, for the management of premature infants with persistent ductus.
Assuntos
Dinoprostona/metabolismo , Permeabilidade do Canal Arterial/enzimologia , Canal Arterial/enzimologia , Oxirredutases Intramoleculares/metabolismo , Grau de Desobstrução Vascular , Animais , Monóxido de Carbono/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Canal Arterial/fisiopatologia , Permeabilidade do Canal Arterial/fisiopatologia , Inibidores Enzimáticos/farmacologia , Idade Gestacional , Heme Oxigenase (Desciclizante)/antagonistas & inibidores , Heme Oxigenase (Desciclizante)/metabolismo , Indometacina/farmacologia , Oxirredutases Intramoleculares/deficiência , Oxirredutases Intramoleculares/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Prostaglandina-E Sintases , Protoporfirinas/farmacologia , RNA Mensageiro/metabolismoRESUMO
The initial clinical manifestation of ischemic heart disease (IHD) i.e. unheralded myocardial infarction (MI) versus chronic angina pectoris (AP) is statistically associated with adverse or mild disease progression respectively in the long-term follow-up. Here, we subjected AP and MI patients to blood proteomic analysis by Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS) in order to investigate putative new prognostic biomarkers of IHD manifestation. We found several differentially expressed peaks but four of them (4176, 4475, 14,158m/z and 8922m/z for AP and MI, respectively) were most reliable. Two of them were identified; 14,158m/z peak was the double-charged form of Apolipoprotein A-I and its vasoprotective action accords with prominence in AP. The 4176m/z peak was related to FAM83C protein, while neither the 4475m/z peak nor the MI-linked 8922m/z peak could be identified. We conclude that SELDI-TOF-MS analysis may yield a panel of molecular signals able to retrospectively classify patients according to their clinical and molecular features, exploitable for predicting the natural course of IHD.
Assuntos
Angina Estável/diagnóstico , Angina Estável/metabolismo , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/metabolismo , Proteômica , Angina Estável/sangue , Biomarcadores/sangue , Proteínas Sanguíneas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , PrognósticoRESUMO
Ductus arteriosus (DA) closure is initiated by oxygen rise postnatally and progresses in two, functional-to-permanent, stages. Here, using GeneChip Arrays in rats (normoxic and hyperoxic fetus, normoxic newborn), we examined whether oxygen alone duplicates the birth process in affecting DA genes. In addition, by comparing DA with aorta (Ao), we identified features in postnatal gene profile marking transitional adjustments in a closing (DA) vs. a persistent (Ao) vessel. We found changes in neonatal DA denoting enhanced formation and action of the constrictor endothelin-1 (ET-1). Likewise, ANG II type 1 receptor was upregulated, and the compound was a constrictor. Conversely, relaxant PGE2 became less effective. Among agents for functional closure, only ET-1 was affected similarly by oxygen and birth. Coincidentally, neonatal DA showed enhanced contractile drive with upregulation of Rho-Rho kinase and calcium signaling along with downregulation of contractile proteins. The latter effect was shared by oxygen. Changes denoting active remodeling were also seen in neonatal but not hyperoxic fetal DA. Ao, unlike DA, exhibited postnatal variations in noradrenergic, purinergic, and PGI2 systems with opposing effects on vasomotion. Contraction and remodeling processes were also less affected by birth, whereas lipid and glucose metabolism were upregulated. We conclude that several agents, including ANG II as novel effector, promote functional closure of DA, but only ET-1 is causally coupled with oxygen. Oxygen has no role in processes for permanent closure. Functional closure is associated with downregulation of contractile apparatus, and this may render neonatal DA less amenable to tone manipulation. Conceivably, activation of metabolism in neonatal Ao is a distinguishing feature for transitional adaptations in the permanent vasculature.
Assuntos
Aorta/metabolismo , Canal Arterial/metabolismo , Regulação da Expressão Gênica , Hiperóxia/metabolismo , Oxigênio/farmacologia , Parto/metabolismo , Vasoconstrição , Algoritmos , Angiotensina II/farmacologia , Animais , Animais Recém-Nascidos , Aorta/embriologia , Proteínas Contráteis/genética , Proteínas Contráteis/metabolismo , Relação Dose-Resposta a Droga , Canal Arterial/efeitos dos fármacos , Canal Arterial/embriologia , Feminino , Feto/irrigação sanguínea , Feto/efeitos dos fármacos , Feto/metabolismo , Fator de Transcrição GATA2/genética , Fator de Transcrição GATA2/metabolismo , Hiperóxia/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Parto/genética , Gravidez , RNA Mensageiro/metabolismo , Ratos , Ratos Long-Evans , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 1 de Angiotensina/metabolismo , Reprodutibilidade dos Testes , Vasoconstritores/farmacologiaRESUMO
There is increasing evidence that cytochrome P450 (CYP) enzymes are involved not only in the metabolism of xenobiotics, but also in vascular homeostasis. Among the CYP-derived vasoactive agents, special importance is assigned to endogenous products from arachidonic acid (AA). Specifically, the vasodilator epoxyeicosatrienoic acids (EETs), being linked to the CYP 2B, 2C, and 2J subfamilies, and the vasoconstrictor 20-hydroxyeicosatetraenoic acid (20-HETE) connected instead to the CYP 4A subfamily and, to a lesser degree, to isoforms of the CYP 1A and 2E subfamilies. Here, we have examined the occurrence of functional CYP isoforms in the coronary arteries of cattle by RT-PCR with sequence verification, Western immunoblotting, and analysis of distinct catalytic activities with fluorescent substrate probes. Liver tissue was examined comparatively. Coronary tissue expressed mRNA transcripts and immunoreactive proteins belonging to the CYP 1A, 2C, 2E, and 2J subfamilies. Appropriate catalytic activity was ascertained with all these CYP species except 2J. A broader spectrum of CYP enzymes (CYP 1A, 2B, 2C, 2D, 2E, 2J, 3A, 4A subfamilies) was found in liver tissue with catalytic activities exceeding many fold those of coronary tissue. We conclude that bovine coronary arteries are endowed with a full-fledged CYP system with potential for AA-linked vasoregulation through dilator rather than constrictor agents. The same tissue and, to a much larger degree, liver tissue possess the capability of metabolizing xenobiotics via the CYP pathway.
Assuntos
Vasos Coronários/enzimologia , Sistema Enzimático do Citocromo P-450/genética , Fígado/enzimologia , Sequência de Aminoácidos , Animais , Bovinos , Sistema Enzimático do Citocromo P-450/metabolismo , Primers do DNA , Isoenzimas/genética , Isoenzimas/metabolismo , Microssomos Hepáticos/enzimologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , OvinosRESUMO
Leon Wolfe was a brilliant scientist who was gifted with curiosity and drive. This personal account touches on salient events in a rewarding collaboration and lifelong friendship, starting from the original identification of prostaglandin as a natural neurohumoral agent and progressing with the unpredictable developments of this research beyond the brain. Design and serendipity are the leitmotifs in an exciting story unfolding over the years.
Assuntos
Prostaglandinas/fisiologia , Animais , Neurotransmissores/fisiologiaRESUMO
Prenatal patency of the ductus arteriosus is maintained mainly by prostaglandin (PG) E(2). Accordingly, the vessel is endowed in its muscular component with a complete, cyclooxygenase (COX) and PGE synthase (PGES), system for the synthesis of the compound. COX1 is better expressed than COX2, particularly in the premature, but COX2 is more extensively coupled with microsomal PGES (mPGES). No evidence was obtained of either COX being coupled with cytosolic PGES (cPGES). Functionally, these data translate into a differential constrictor response of the ductus to dual, COX1/COX2, vs. COX2-specific inhibitors (indomethacin vs. L-745,337), with the latter being less effective specifically prior to term. This difference, however, subsides upon treatment with endotoxin and the attendant upregulation of COX2 and mPGES. Furthermore, when studied separately, COX1 and COX2 prove to be unevenly responsive to indomethacin, and an immediate and fast developing contraction of the vessel occurs only when COX2 is inhibited. Deletion of either COX gene results into upregulation of NO synthase, and a similar compensatory reaction is expected when enzymes are suppressed pharmacologically. We conclude that PGE(2) and NO can function synergistically in keeping the ductus patent. This arrangement provides a possible explanation for failures of indomethacin or ibuprofen treatment in the management of the prematurely born infant with persistent ductus. Coincidentally, it opens the way to new therapeutic possibilities being based on interference with the NO effector or a more selective disruption, possibly having mPGES as a target, of the PGE(2) synthetic cascade.
Assuntos
Canal Arterial/enzimologia , Prostaglandina-Endoperóxido Sintases/fisiologia , Grau de Desobstrução Vascular , Animais , Ciclo-Oxigenase 1 , Ciclo-Oxigenase 2 , Humanos , Isoenzimas/fisiologia , Proteínas de MembranaRESUMO
Prostaglandin E2 (PGE2) is recognized as a key intermediate in the sequence of events leading to fever. Normally undetectable or barely detectable in brain, it rises selectively on exposure to an infectious noxa and the attendant generation of pyrogenic cytokines outside and, in the case of interleukin (IL)-6, inside the brain. The mechanism by which pyrogens in the circulation promote the appearance of PGE2 within the confines of brain is not clear, and it is not known how PGE2 activation is selective with IL-6 being induced in brain. We have found that the cerebral microvasculature is not suitable as a source of PGE2 in response to blood-borne pyrogens. In addition, we show that IL-6 differs from other pyrogens in being able to stimulate specifically PGE2 synthesis. Nevertheless, brain-derived IL-6 does not appear to be necessary for PGE2 activation and the attendant fever. We conclude that signal-transducing mechanisms operating across the blood-brain barrier are most critical for the development of the febrile response to a systemic noxa.