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1.
Biomaterials ; 289: 121782, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36099713

RESUMEN

Bioprosthetic heart valves (BHV) fabricated from heterograft tissue, such as glutaraldehyde pretreated bovine pericardium (BP), are the most frequently used heart valve replacements. BHV durability is limited by structural valve degeneration (SVD), mechanistically associated with calcification, advanced glycation end products (AGE), and serum protein infiltration. We investigated the hypothesis that anti-AGE agents, Aminoguanidine, Pyridoxamine [PYR], and N-Acetylcysteine could mitigate AGE-serum protein SVD mechanisms in vitro and in vivo, and that these agents could mitigate calcification or demonstrate anti-calcification interactions with BP pretreatment with ethanol. In vitro, each of these agents significantly inhibited AGE-serum protein infiltration in BP. However, in 28-day rat subdermal BP implants only orally administered PYR demonstrated significant inhibition of AGE and serum protein uptake. Furthermore, BP PYR preincubation of BP mitigated AGE-serum protein SVD mechanisms in vitro, and demonstrated mitigation of both AGE-serum protein uptake and reduced calcification in vivo in 28-day rat subdermal BP explants. Inhibition of BP calcification as well as inhibition of AGE-serum protein infiltration was observed in 28-day rat subdermal BP explants pretreated with ethanol followed by PYR preincubation. In conclusion, AGE-serum protein and calcification SVD pathophysiology are significantly mitigated by both PYR oral therapy and PYR and ethanol pretreatment of BP.


Asunto(s)
Bioprótesis , Calcinosis , Prótesis Valvulares Cardíacas , Acetilcisteína , Animales , Proteínas Sanguíneas , Bovinos , Etanol/farmacología , Glutaral , Productos Finales de Glicación Avanzada , Piridoxamina , Ratas
2.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35131859

RESUMEN

Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde-fixed heterograft tissue, such as bovine pericardium (BP), are widely used for treating heart valve disease, a group of disorders that affects millions. Structural valve degeneration (SVD) of BHV due to both calcification and the accumulation of advanced glycation end products (AGE) with associated serum proteins limits durability. We hypothesized that BP modified with poly-2-methyl-2-oxazoline (POZ) to inhibit protein entry would demonstrate reduced accumulation of AGE and serum proteins, mitigating SVD. In vitro studies of POZ-modified BP demonstrated reduced accumulation of serum albumin and AGE. BP-POZ in vitro maintained collagen microarchitecture per two-photon microscopy despite AGE incubation, and in cell culture studies was associated with no change in tumor necrosis factor-α after exposure to AGE and activated macrophages. Comparing POZ and polyethylene glycol (PEG)-modified BP in vitro, BP-POZ was minimally affected by oxidative conditions, whereas BP-PEG was susceptible to oxidative deterioration. In juvenile rat subdermal implants, BP-POZ demonstrated reduced AGE formation and serum albumin infiltration, while calcification was not inhibited. However, BP-POZ rat subdermal implants with ethanol pretreatment demonstrated inhibition of both AGE accumulation and calcification. Ex vivo laminar flow studies with human blood demonstrated BP-POZ enhanced thromboresistance with reduced white blood cell accumulation. We conclude that SVD associated with AGE and serum protein accumulation can be mitigated through POZ functionalization that both enhances biocompatibility and facilitates ethanol pretreatment inhibition of BP calcification.


Asunto(s)
Enfermedades de las Válvulas Cardíacas/tratamiento farmacológico , Enfermedades de las Válvulas Cardíacas/terapia , Oxazoles/farmacología , Pericardio/efectos de los fármacos , Animales , Materiales Biocompatibles , Calcificación Fisiológica/efectos de los fármacos , Calcinosis/tratamiento farmacológico , Calcinosis/metabolismo , Calcinosis/terapia , Línea Celular , Colágeno/metabolismo , Etanol/farmacología , Productos Finales de Glicación Avanzada/metabolismo , Enfermedades de las Válvulas Cardíacas/metabolismo , Prótesis Valvulares Cardíacas , Xenoinjertos/efectos de los fármacos , Humanos , Masculino , Oxidación-Reducción/efectos de los fármacos , Pericardio/metabolismo , Ratas , Ratas Sprague-Dawley , Células THP-1
3.
Acta Biomater ; 123: 275-285, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33444798

RESUMEN

Glutaraldehyde cross-linked heterograft tissues, bovine pericardium (BP) or porcine aortic valves, are the leaflet materials in bioprosthetic heart valves (BHV) used in cardiac surgery for heart valve disease. BHV fail due to structural valve degeneration (SVD), often with calcification. Advanced glycation end products (AGE) are post-translational, non-enzymatic reaction products from sugars reducing proteins. AGE are present in SVD-BHV clinical explants and are not detectable in un-implanted BHV. Prior studies modeled BP-AGE formation in vitro with glyoxal, a glucose breakdown product, and serum albumin. However, glucose is the most abundant AGE precursor. Thus, the present studies investigated the hypothesis that BHV susceptibility to glucose related AGE, together with serum proteins, results in deterioration of collagen structure and mechanical properties. In vitro experiments studied AGE formation in BP and porcine collagen sponges (CS) comparing 14C-glucose and 14C-glyoxal with and without bovine serum albumin (BSA). Glucose incorporation occurred at a significantly lower level than glyoxal (p<0.02). BSA co-incubations demonstrated reduced glyoxal and glucose uptake by both BP and CS. BSA incubation caused a significant increase in BP mass, enhanced by glyoxal co-incubation. Two-photon microscopy of BP showed BSA induced disruption of collagen structure that was more severe with glucose or glyoxal co-incubation. Uniaxial testing of CS demonstrated that glucose or glyoxal together with BSA compared to controls, caused accelerated deterioration of viscoelastic relaxation, and increased stiffness over a 28-day time course. In conclusion, glucose, glyoxal and BSA uniquely contribute to AGE-mediated disruption of heterograft collagen structure and deterioration of mechanical properties.


Asunto(s)
Prótesis Valvulares Cardíacas , Animales , Bovinos , Colágeno , Glucosa/farmacología , Productos Finales de Glicación Avanzada , Glioxal , Xenoinjertos , Albúmina Sérica , Albúmina Sérica Bovina , Porcinos
4.
J Biol Chem ; 293(20): 7703-7716, 2018 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-29622677

RESUMEN

Hereditary multiple exostoses (HME) is a pediatric disorder caused by heparan sulfate (HS) deficiency and is characterized by growth plate-associated osteochondromas. Previously, we found that osteochondroma formation in mouse models is preceded by ectopic bone morphogenetic protein (BMP) signaling in the perichondrium, but the mechanistic relationships between BMP signaling and HS deficiency remain unclear. Therefore, we used an HS antagonist (surfen) to investigate the effects of this HS interference on BMP signaling, ligand availability, cell-surface BMP receptor (BMPR) dynamics, and BMPR interactions in Ad-293 and C3H/10T1/2 cells. As observed previously, the HS interference rapidly increased phosphorylated SMAD family member 1/5/8 levels. FACS analysis and immunoblots revealed that the cells possessed appreciable levels of endogenous cell-surface BMP2/4 that were unaffected by the HS antagonist, suggesting that BMP2/4 proteins remained surface-bound but became engaged in BMPR interactions and SMAD signaling. Indeed, surface mobility of SNAP-tagged BMPRII, measured by fluorescence recovery after photobleaching (FRAP), was modulated during the drug treatment. This suggested that the receptors had transitioned to lipid rafts acting as signaling centers, confirmed for BMPRII via ultracentrifugation to separate membrane subdomains. In situ proximity ligation assays disclosed that the HS interference rapidly stimulates BMPRI-BMPRII interactions, measured by oligonucleotide-driven amplification signals. Our in vitro studies reveal that cell-associated HS controls BMP ligand availability and BMPR dynamics, interactions, and signaling, and largely restrains these processes. We propose that HS deficiency in HME may lead to extensive local BMP signaling and altered BMPR dynamics, triggering excessive cellular responses and osteochondroma formation.


Asunto(s)
Proteína Morfogenética Ósea 2/metabolismo , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/metabolismo , Condrogénesis/efectos de los fármacos , Exostosis Múltiple Hereditaria/patología , Regulación de la Expresión Génica/efectos de los fármacos , Heparitina Sulfato/antagonistas & inhibidores , Urea/análogos & derivados , Animales , Proteína Morfogenética Ósea 2/genética , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , Células Cultivadas , Exostosis Múltiple Hereditaria/genética , Exostosis Múltiple Hereditaria/metabolismo , Humanos , Ratones , Ratones Endogámicos C3H , Fosforilación , Transducción de Señal , Urea/farmacología
5.
Nat Neurosci ; 13(5): 584-91, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20418874

RESUMEN

Reactive astrocytosis develops in many neurologic diseases, including epilepsy. Astrocytotic contributions to pathophysiology are poorly understood. Studies examining this are confounded by comorbidities accompanying reactive astrocytosis. We found that high-titer transduction of astrocytes with enhanced green fluorescent protein (eGFP) via adeno-associated virus induced reactive astrocytosis without altering the intrinsic properties or anatomy of neighboring neurons. We examined the consequences of selective astrocytosis induction on synaptic transmission in mouse CA1 pyramidal neurons. Neurons near eGFP-labeled reactive astrocytes had reduced inhibitory, but not excitatory, synaptic currents. This inhibitory postsynaptic current (IPSC) erosion resulted from a failure of the astrocytic glutamate-glutamine cycle. Reactive astrocytes downregulated expression of glutamine synthetase. Blockade of this enzyme normally induces rapid synaptic GABA depletion. In astrocytotic regions, residual inhibition lost sensitivity to glutamine synthetase blockade, whereas exogenous glutamine administration enhanced IPSCs. Astrocytosis-mediated deficits in inhibition triggered glutamine-reversible hyperexcitability in hippocampal circuits. Thus, reactive astrocytosis could generate local synaptic perturbations, leading to broader functional deficits associated with neurologic disease.


Asunto(s)
Astrocitos/fisiología , Gliosis/fisiopatología , Inhibición Neural/fisiología , Neuronas/fisiología , Análisis de Varianza , Animales , Animales Recién Nacidos , Antígenos/metabolismo , Bromodesoxiuridina/metabolismo , Proteínas de Unión al Calcio/metabolismo , Estimulación Eléctrica/métodos , Antagonistas del GABA/farmacología , Glutamato-Amoníaco Ligasa/metabolismo , Proteínas Fluorescentes Verdes/genética , Hipocampo/citología , Técnicas In Vitro , Ratones , Proteínas de Microfilamentos , Proteínas del Tejido Nervioso/metabolismo , Inhibición Neural/efectos de los fármacos , Neuronas/efectos de los fármacos , Técnicas de Placa-Clamp/métodos , Ácidos Fosfínicos/farmacología , Proteoglicanos/metabolismo , Piridazinas/farmacología , Piridinas/farmacología , Potenciales Sinápticos/efectos de los fármacos , Potenciales Sinápticos/fisiología , Transducción Genética/métodos
6.
Proc Natl Acad Sci U S A ; 106(35): 15037-42, 2009 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-19706442

RESUMEN

Gliotransmission, the release of molecules from astrocytes, regulates neuronal excitability and synaptic transmission in situ. Whether this process affects neuronal network activity in vivo is not known. Using a combination of astrocyte-specific molecular genetics, with in vivo electrophysiology and pharmacology, we determined that gliotransmission modulates cortical slow oscillations, a rhythm characterizing nonrapid eye movement sleep. Inhibition of gliotransmission by the expression of a dominant negative SNARE domain in astrocytes affected cortical slow oscillations, reducing the duration of neuronal depolarizations and causing prolonged hyperpolarizations. These network effects result from the astrocytic modulation of intracortical synaptic transmission at two sites: a hypofunction of postsynaptic NMDA receptors, and by reducing extracellular adenosine, a loss of tonic A1 receptor-mediated inhibition. These results demonstrate that rhythmic brain activity is generated by the coordinated action of the neuronal and glial networks.


Asunto(s)
Corteza Cerebral/metabolismo , Transmisión Sináptica , Animales , Astrocitos/metabolismo , Electroencefalografía , Expresión Génica , Ratones , Ratones Endogámicos C57BL , Receptores de N-Metil-D-Aspartato/metabolismo , Proteínas SNARE/genética , Proteínas SNARE/metabolismo , Sueño
7.
J Comp Neurol ; 515(3): 295-312, 2009 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-19425080

RESUMEN

Regenerative failure of spinal axons is commonly ascribed to signaling of F-actin depolymerization and growth cone collapse by molecules such as the myelin-associated growth inhibitors. cAMP is thought to promote regeneration at least in part by neutralizing this effect, either by direct action in the growth cone or indirectly by transcriptional mechanisms. In vivo evidence for this is based mainly on partial lesion studies in which it is sometimes difficult to distinguish regeneration of injured axons from collateral sprouting by uninjured axons. Moreover, previous observations on fixed lamprey central nervous system (CNS) suggested that regeneration may not involve growth cones. To distinguish actively growing axons from static or retracting ones, fluorescently labeled large reticulospinal axons were imaged in the living, transected lamprey cord with and without application of cAMP analogs and then studied by 2-photon microscopy. Axon tip movements over 2-48-hour intervals indicated: 1) regeneration was intermittent; 2) cAMP decreased initial axon retraction and increased subsequent regeneration up to 11-fold; 3) the increase in regeneration was due to an increase in velocity of axon growth, but not in the time spent in forward movement; 4) tips of actively regenerating axons were more sharply contoured than static tips but no filopodia or lamellipodia were observed, even in db-cAMP; and 5) during active growth, axon tips contained vesicle-like inclusions and were highly immunoreactive for neurofilaments. Staining for F-actin and microtubules was variable and F-actin was not concentrated at the leading edge. Thus, cAMP accelerates regeneration of lamprey spinal axons without inducing formation of growth cones.


Asunto(s)
Axones/fisiología , AMP Cíclico/metabolismo , Conos de Crecimiento/fisiología , Regeneración Nerviosa/fisiología , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animales , Axones/efectos de los fármacos , Axones/ultraestructura , Células Cultivadas , AMP Cíclico/farmacología , Conos de Crecimiento/efectos de los fármacos , Conos de Crecimiento/ultraestructura , Lampreas , Microtúbulos/metabolismo , Regeneración Nerviosa/efectos de los fármacos , Seudópodos/metabolismo , Médula Espinal/citología , Médula Espinal/patología
8.
J Cardiovasc Pharmacol ; 51(4): 365-71, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18427279

RESUMEN

We determined time course of stabilization of echolucent carotid plaques by statin therapy in patients with acute coronary syndrome (ACS). Treatment with 4 mg/d pitavastatin (n = 33) or placebo (n = 32) was initiated within 3 days after onset of ACS in 65 patients with echolucent carotid plaque. Vulnerable carotid plaques were assessed by measuring plaque echolucency using carotid ultrasound with integrated backscatter (IBS) analysis before and 1 month after treatment in all patients. The calibrated IBS value (intima-media IBS value minus adventia IBS) of vulnerable carotid plaques favorably changed at 1 month after treatment in both groups, but the echolucency at 1 month improved more in the pitavastatin than in the placebo group (pitavastatin group: -18.7 +/- 3.3 dB at pretreatment versus -12.7 +/- 2.3 dB at 1 month *P < 0.001; placebo: -19.0 +/- 3.5 dB versus -16.9 +/- 3.2 dB, P < 0.05, *P < 0.01 versus the value at 1 month in placebo group). Levels of CRP, VEGF, and TNFalpha at 1 month were significantly lower in pitavastatin than placebo group. In conclusion, pitavastatin improved carotid plaque echolucency within 1 month of therapy in patients with ACS, in association with decrease in the inflammatory biomarkers related to vulnerable plaques.


Asunto(s)
Síndrome Coronario Agudo/tratamiento farmacológico , Estenosis Carotídea/tratamiento farmacológico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Quinolinas/uso terapéutico , Síndrome Coronario Agudo/diagnóstico por imagen , Proteína C-Reactiva/metabolismo , Estenosis Carotídea/diagnóstico por imagen , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Triglicéridos/sangre , Factor de Necrosis Tumoral alfa/metabolismo , Ultrasonografía , Factor A de Crecimiento Endotelial Vascular/metabolismo
9.
J Am Coll Cardiol ; 50(14): 1305-9, 2007 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-17903627

RESUMEN

OBJECTIVES: This study examined whether sirolimus-eluting stent (SES) implantation may affect endothelial vasomotor dysfunction in resistance and epicardial infarct-related coronary arteries in acute myocardial infarction (AMI). BACKGROUND: Myocardial ischemia-reperfusion causes endothelial injury entirely in the vasculature of the infarct-related coronary artery. Sirolimus-eluting stent implantation inhibits re-endothelialization at the site of stenting. METHODS: This study included 29 patients with a first AMI due to occlusion of the left anterior descending coronary artery (LAD) and successful reperfusion therapy using a SES (n = 13) or bare-metal stent (BMS) (n = 16). The diameter of the epicardial segment distal to the site of SES deployment and coronary blood flow in the LAD in response to an intracoronary infusion of acetylcholine were measured at 2 weeks after AMI. Levels of vascular endothelial growth factor (VEGF) were measured by enzyme-linked immunoadsorbent assay in plasma obtained from the aortic root (AO) and the anterior interventricular vein (AIV) in all patients. RESULTS: The epicardial coronary artery was more severely constricted in response to acetylcholine in the SES than in the BMS group. The increase in coronary blood flow in response to acetylcholine was lower in the SES than in the BMS group. Vascular endothelial growth factor levels in the AIV were significantly lower than in the AO in the SES group but not in the BMS group. CONCLUSIONS: During the course of AMI, SES implantation adversely affects endothelium-dependent vasomotor function in resistance and epicardial coronary arteries after the ischemia-reperfusion in association with a reduction in myocardial VEGF secretion.


Asunto(s)
Implantación de Prótesis Vascular , Estenosis Coronaria/terapia , Endotelio Vascular/efectos de los fármacos , Inmunosupresores/efectos adversos , Infarto del Miocardio/terapia , Sirolimus/efectos adversos , Stents , Anciano , Estenosis Coronaria/sangre , Estenosis Coronaria/complicaciones , Estenosis Coronaria/fisiopatología , Endotelio Vascular/fisiopatología , Femenino , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/sangre , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/etiología , Infarto del Miocardio/fisiopatología , Factores de Riesgo , Sirolimus/administración & dosificación , Sirolimus/sangre , Factor A de Crecimiento Endotelial Vascular/sangre , Sistema Vasomotor/efectos de los fármacos , Sistema Vasomotor/fisiopatología
10.
Am J Physiol Heart Circ Physiol ; 293(6): H3490-7, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17906114

RESUMEN

Statin treatment improves insulin resistance in skeletal muscle. Thus this study assessed whether statin may affect the myocardial expression levels of AdipoR1 and AdipoR2, receptors of adiponectin that enhance insulin sensitivity, and whether statin may improve insulin resistance in cardiomyocytes. Myocardial infarction (MI) was created by the ligation of the left coronary artery in male mice. Expression levels of mRNA and protein levels of AdipoR1 but not of AdipoR2 were significantly decreased in the remote area as well as in the healed infarcted area in the left ventricles 4 wk after MI. Oral administration of pravastatin (50 mg.kg(-1).day(-1) for 4 wk after MI) reversed the decrease in myocardial expression levels of AdipoR1 independently of changes in serum lipid profiles and insulin levels. With the use of cultured cardiomyocytes, incubation with tumor necrosis factor (TNF)-alpha, a mediator of postinfarction myocardial dysfunction, inhibited AdipoR1 mRNA and protein expression levels. Coincubation of the cells with pravastatin reversed the inhibitory effects of TNF-alpha on AdipoR1 expression. In parallel, pravastatin reversed the TNF-alpha-induced decrease in globular adiponectin-induced 2-deoxy-d-[(3)H]glucose uptake in insulin-treated cultured cells. Moreover, this effect of pravastatin was inhibited by the suppression of AdipoR1 expression by small-interfering RNA specific for AdipoR1. Incubation with H(2)O(2) reduced AdipoR1 expression in cultured cardiomyocytes that were attenuated by N-acetyl-l-cysteine or pravastatin. Pravastatin suppressed TNF-alpha-induced intracellular oxidants in cultured cardiomyocytes. In conclusion, pravastatin reversed the reduction of AdipoR1 expression in postinfarction mouse myocardium and in TNF-alpha-treated cardiomyocytes partly through an antioxidative mechanism in association with improved glucose uptake.


Asunto(s)
Antioxidantes/farmacología , Glucosa/metabolismo , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Infarto del Miocardio/tratamiento farmacológico , Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Pravastatina/farmacología , Receptores de Adiponectina/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Acetilcisteína/farmacología , Adiponectina/metabolismo , Administración Oral , Animales , Animales Recién Nacidos , Antioxidantes/administración & dosificación , Glucemia/metabolismo , Células Cultivadas , Vasos Coronarios/cirugía , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ácidos Grasos/metabolismo , Peróxido de Hidrógeno/metabolismo , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Insulina/sangre , Resistencia a la Insulina , Ligadura , Lípidos/sangre , Masculino , Ratones , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Miocardio/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Oxidación-Reducción , Pravastatina/administración & dosificación , Interferencia de ARN , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Adiponectina/genética , Proteínas Recombinantes/metabolismo , Factores de Tiempo
12.
Int J Cardiol ; 119(2): 156-62, 2007 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-17067705

RESUMEN

BACKGROUND: Angiogenic growth factors, produced in the myocardium and coronary vascular bed, increase myocardial blood flow. This study examined whether plasma levels of vascular endothelial growth factor (VEGF) in coronary circulation may be related to coronary blood flow responses. METHODS: Blood flow responses in the left anterior descending coronary artery to an intracoronary infusion of acetylcholine (ACh) were measured by an intracoronary flow wire technique in 46 consecutive control subjects with normal coronary angiograms and left ventriculograms. Circulating VEGF levels were measured by ELISA in plasma obtained from the aortic root (AO) and anterior interventricular vein (AIV). RESULTS: The transcardiac gradient of VEGF, calculated by the difference in VEGF concentrations between the AIV and AO, showed a positive correlation with the coronary blood flow increase in response to ACh independently of traditional coronary risk factors. In patients with cardiac syndrome X (n=17), defined as a positive exercise stress test with a normal coronary angiograms and left ventriculogram, the transcardiac VEGF gradient was significantly lower than in the risk factors-matched control subjects (n=21). CONCLUSIONS: The transcardiac gradient of plasma VEGF was independently and positively correlated with the coronary blood flow increase in response to ACh. A reduced transcardiac VEGF gradient was present in cardiac syndrome X, a condition with a blunted coronary blood flow response.


Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Circulación Coronaria/fisiología , Angina Microvascular/fisiopatología , Factor A de Crecimiento Endotelial Vascular/sangre , Distribución de Chi-Cuadrado , Angiografía Coronaria , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Modelos Lineales , Masculino , Angina Microvascular/diagnóstico por imagen , Persona de Mediana Edad
13.
J Exp Med ; 203(12): 2749-61, 2006 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-17116735

RESUMEN

The tumor microenvironment is composed of an intricate mixture of tumor and host-derived cells that engage in a continuous interplay. T cells are particularly important in this context as they may recognize tumor-associated antigens and induce tumor regression. However, the precise identity of cells targeted by tumor-infiltrating T lymphocytes (TILs) as well as the kinetics and anatomy of TIL-target cell interactions within tumors are incompletely understood. Furthermore, the spatiotemporal conditions of TIL locomotion through the tumor stroma, as a prerequisite for establishing contact with target cells, have not been analyzed. These shortcomings limit the rational design of immunotherapeutic strategies that aim to overcome tumor-immune evasion. We have used two-photon microscopy to determine, in a dynamic manner, the requirements leading to tumor regression by TILs. Key observations were that TILs migrated randomly throughout the tumor microenvironment and that, in the absence of cognate antigen, they were incapable of sustaining active migration. Furthermore, TILs in regressing tumors formed long-lasting (>or=30 min), cognate antigen-dependent contacts with tumor cells. Finally, TILs physically interacted with macrophages, suggesting tumor antigen cross-presentation by these cells. Our results demonstrate that recognition of cognate antigen within tumors is a critical determinant of optimal TIL migration and target cell interactions, and argue against TIL guidance by long-range chemokine gradients.


Asunto(s)
Comunicación Celular/inmunología , Movimiento Celular/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Neoplasias Experimentales/inmunología , Linfocitos T/inmunología , Animales , Línea Celular Tumoral , Citotoxicidad Inmunológica , Linfocitos Infiltrantes de Tumor/patología , Macrófagos/inmunología , Macrófagos/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neoplasias Experimentales/patología , Linfocitos T/patología , Timoma/inmunología , Timoma/patología
14.
J Am Coll Cardiol ; 48(1): 43-50, 2006 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-16814647

RESUMEN

OBJECTIVES: This study examined whether atorvastatin increases plasma levels of soluble Fms-like tyrosine kinase 1 (sFlt-1) and reciprocally decreases vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) levels in patients with acute myocardial infarction (AMI). BACKGROUND: Statins exert cardioprotective actions partly through anti-inflammatory actions. By capturing VEGF and PlGF in plasma, sFlt-1 acts as a natural inhibitor of VEGF and PlGF, which have proinflammatory properties. METHODS: Left ventriculography and enzyme-linked immunosorbent assay of plasma levels of sFlt-1, VEGF, and PlGF were repeated after AMI in 50 consecutive patients with a first AMI. Patients were randomized to treatment with atorvastatin (10 mg/day; n=25) or placebo (n=25) within 3 days after AMI, and therapy was continued for 6 months. RESULTS: The sFlt-1 levels were low in the acute phase, followed by an increase at 2 weeks after AMI, whereas free VEGF and PlGF levels were high in the acute phase, followed by a decrease at 2 weeks. Atorvastatin increased sFlt-1 levels and reciprocally decreased VEGF and PlGF levels at 6 months compared with placebo. The increase in sFlt-1 levels and the decrease in VEGF and PlGF levels were correlated with improvement of left ventricular ejection fraction during the follow-up period. CONCLUSIONS: There was a reciprocal relationship between changes in sFlt-1 levels and changes in VEGF and PlGF levels after AMI; and atorvastatin increased sFlt-1 levels while decreasing VEGF and PlGF levels. These changes were associated with late improvement of post-MI ventricular function, and may represent an additional benefit of statin therapy.


Asunto(s)
Sustancias de Crecimiento/sangre , Ácidos Heptanoicos/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Mediadores de Inflamación/sangre , Infarto del Miocardio/tratamiento farmacológico , Proteínas Gestacionales/sangre , Pirroles/uso terapéutico , Factor A de Crecimiento Endotelial Vascular/sangre , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , Función Ventricular Izquierda , Atorvastatina , Método Doble Ciego , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/fisiopatología , Factor de Crecimiento Placentario , Volumen Sistólico
15.
Novartis Found Symp ; 276: 208-17; discussion 217-21, 233-7, 275-81, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16805432

RESUMEN

Glutamatergic and purinergic signalling play key roles in synaptic transmission and modulation in the CNS. Here, we review recent evidence showing that glial cells, and in particular astrocytes, are active players in ATP and glutamate signalling in the brain. ATP and glutamate coordinately activate astrocytes, through the mobilization of their internal Ca2+, which in turn triggers the release from astrocytes of several neuroactive molecules including ATP and glutamate themselves. These 'gliotransmitters' signal either to astrocytes, where they generate Ca2+ waves, or to neurons, where they modulate synaptic transmission and neuronal excitability. By using microfabricated lanes of adhesive substrate, we provide further evidence for a diffusible factor-mediated propagation of Ca2+ waves and, through flash photolysis experiments in hippocampal slices, we show that glutamate and ATP cooperate in the generation of the astrocytic Ca2+ signal. Once astrocytes are activated they provide both excitatory and inhibitory effects on neighbouring neurons. Through the Ca2+-dependent release of glutamate, which acts on extrasynaptic neuronal NMDA receptors, astrocytes excite neurons while, in contrast, ATP released from astrocytes, after the delayed conversion to adenosine, causes neuronal suppression.


Asunto(s)
Adenosina Trifosfato/metabolismo , Astrocitos/fisiología , Comunicación Celular , Ácido Glutámico/metabolismo , Neuronas/fisiología , Potenciales de Acción/fisiología , Animales , Astrocitos/citología , Calcio/metabolismo , Señalización del Calcio/fisiología , Proteína Ácida Fibrilar de la Glía/metabolismo , Neuronas/citología , Receptores de N-Metil-D-Aspartato/metabolismo
16.
Am J Physiol Heart Circ Physiol ; 290(6): H2409-16, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16415076

RESUMEN

Adiponectin, an adipocyte-derived protein, has cardioprotective actions. We elucidated the role of the adiponectin receptors AdipoR1 and AdipoR2 in the effects of adiponectin on endothelin-1 (ET-1)-induced hypertrophy in cultured cardiomyocytes, and we examined the expression of adiponectin receptors in normal and infarcted mouse hearts. Recombinant full-length adiponectin suppressed the ET-1-induced increase in cell surface area and [(3)H]leucine incorporation into cultured cardiomyocytes compared with cells treated with ET-1 alone. Transfection of small interfering RNA (siRNA) specific for AdipoR1 or AdipoR2 reversed the suppressive effects of adiponectin on ET-1-induced cellular hypertrophy in cultured cardiomyocytes. Adiponectin induced phosphorylation of AMP-activated protein kinase (AMPK) and inhibited ET-1-induced ERK1/2 phosphorylation, which were also reversible by transfection of siRNA for AdipoR1 or AdipoR2 in cultured cardiomyocytes. Transfection of siRNA for alpha(2)-catalytic subunits of AMPK reduced the inhibitory effects of adiponectin on ET-1-induced cellular hypertrophy and ERK1/2 phosphorylation. Effects of globular adiponectin were similar to those of full-length adiponectin, and siRNA for AdipoR1 reversed the actions of globular adiponectin. Compared with normal left ventricle, expression levels of AdipoR1 mRNA and protein were decreased in the remote, as well as the infarcted, area after myocardial infarction in mouse hearts. In conclusion, AdipoR1 and AdipoR2 mediate the suppressive effects of full-length and globular adiponectin on ET-1-induced hypertrophy in cultured cardiomyocytes, and AMPK is involved in signal transduction through these receptors. AdipoR1 and AdipoR2 might play a role in the pathogenesis of ET-1-related cardiomyocyte hypertrophy after myocardial infarction.


Asunto(s)
Cardiomegalia/inducido químicamente , Endotelinas/farmacología , Infarto del Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Receptores de Superficie Celular/fisiología , Adiponectina/fisiología , Angiotensina II/farmacología , Animales , Cardiomegalia/fisiopatología , Células Cultivadas , Endotelina-1/farmacología , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Infarto del Miocardio/patología , Miocitos Cardíacos/ultraestructura , Neurotransmisores/fisiología , Norepinefrina/farmacología , ARN Mensajero/biosíntesis , ARN Interferente Pequeño/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de Adiponectina , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/genética , Transfección , Factor de Necrosis Tumoral alfa/farmacología
17.
Science ; 310(5745): 113-6, 2005 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-16210541

RESUMEN

To investigate the role of astrocytes in regulating synaptic transmission, we generated inducible transgenic mice that express a dominant-negative SNARE domain selectively in astrocytes to block the release of transmitters from these glial cells. By releasing adenosine triphosphate, which accumulates as adenosine, astrocytes tonically suppressed synaptic transmission, thereby enhancing the dynamic range for long-term potentiation and mediated activity-dependent, heterosynaptic depression. These results indicate that astrocytes are intricately linked in the regulation of synaptic strength and plasticity and provide a pathway for synaptic cross-talk.


Asunto(s)
Adenosina/metabolismo , Astrocitos/fisiología , Sinapsis/fisiología , Transmisión Sináptica , Antagonistas del Receptor de Adenosina A1 , Adenosina Trifosfatasas/antagonistas & inhibidores , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Animales , Astrocitos/efectos de los fármacos , Células Cultivadas , Potenciales Postsinápticos Excitadores , Hipocampo/efectos de los fármacos , Hipocampo/fisiología , Técnicas In Vitro , Potenciación a Largo Plazo/efectos de los fármacos , Ratones , Ratones Transgénicos , Plasticidad Neuronal/efectos de los fármacos , Antagonistas de Receptores Purinérgicos P1 , Antagonistas del Receptor Purinérgico P2 , Receptor de Adenosina A1/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores Purinérgicos P1/metabolismo , Receptores Purinérgicos P2/metabolismo , Transmisión Sináptica/efectos de los fármacos , Xantinas/farmacología
18.
J Am Coll Cardiol ; 45(9): 1461-6, 2005 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-15862419

RESUMEN

OBJECTIVES: This study was aimed to determine the relationship between pulse pressure (PP) and coronary vasomotor dysfunction, a predictor of coronary events. BACKGROUND: Pulse pressure is a strong risk factor for coronary artery disease (CAD). However, the mechanisms by which an increase in PP affects the pathogenesis of CAD are unclear. METHODS: Ambulatory blood pressure (BP) monitoring for 24 h was performed in 103 consecutive patients with normal coronary angiograms (51 hypertensive and 52 normotensive; age 42 to 70 years). The relationship between changes in coronary arterial diameter and blood flow during an intracoronary infusion of acetylcholine (ACh) (5, 10, 50 microg/min), and BP parameters, and other traditional risk factors was evaluated using univariate and multivariate linear regression analyses. RESULTS: With multivariate analyses, the 24-h PP showed an inverse correlation with the epicardial coronary dilator response to ACh independently of other covariates including age, smoking, and 24-h systolic BP in normotensive as well as hypertensive patients. Furthermore, multivariate analysis showed that the 24-h PP was inversely and independently correlated with the increase in coronary blood flow in response to ACh. The dilator response of epicardial coronary arteries to nitrate was not significantly correlated with 24-h PP. CONCLUSIONS: Increased 24-h PP is independently associated with endothelial vasomotor dysfunction in conduit and resistance coronary arteries irrespective of the presence of hypertension. Increased ambulatory PP may have an intimate relation to coronary endothelial vasomotor dysfunction.


Asunto(s)
Presión Sanguínea , Enfermedad de la Arteria Coronaria/fisiopatología , Vasos Coronarios/fisiopatología , Hipertensión/fisiopatología , Acetilcolina , Velocidad del Flujo Sanguíneo , Monitoreo Ambulatorio de la Presión Arterial , Estudios de Casos y Controles , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/efectos de los fármacos , Femenino , Humanos , Flujometría por Láser-Doppler , Masculino , Persona de Mediana Edad , Flujo Pulsátil , Factores de Riesgo , Ultrasonografía
19.
J Cardiol ; 43(4): 179-83, 2004 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-15125382

RESUMEN

A 78-year-old woman with arteriosclerosis obliterans was admitted with complaints of progressive ischemic change and resting pain of the left leg. She had severe ischemic limb in stage IV of the Fontaine classification. Angiography showed total occlusion of the three main arteries with poor collateral flow at the left crus. Autologous transplantation of bone-marrow mononuclear cell to her left leg was performed to achieve therapeutic angiogenesis. One month later, follow-up angiography showed excellent angiogenesis of collateral vessels at the left crus. Her pain was relieved and leg amputation was not necessary. Recently, the TACT study in Japan showed the efficacy of angiogenesis by autologous bone-marrow transplantation for peripheral artery disease. This case illustrates the efficacy of this therapy.


Asunto(s)
Arteriosclerosis Obliterante/complicaciones , Arteriosclerosis Obliterante/terapia , Trasplante de Médula Ósea , Isquemia/etiología , Isquemia/terapia , Extremidad Inferior/irrigación sanguínea , Neovascularización Fisiológica/fisiología , Anciano , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Trasplante Autólogo , Resultado del Tratamiento
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