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1.
Pharm Dev Technol ; 25(4): 408-415, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31847658

RESUMEN

Introduction: Glioblastoma (GB) is the most common malignant brain tumor and is characterized by high invasiveness, poor prognosis, and limited therapeutic options. Silencing gene expression, through the use of small interfering RNA (siRNA), has been proposed as an alternative to conventional cancer therapy. Here, we evaluated the potential of CD73 as a new therapeutic target, since it is overexpressed in solid tumors and has emerged as a promising target to control GB progression.Methods: A cationic nanoemulsion (NE) as an intravenous siRNA-CD73 delivery system was developed and its effect on C6 glioma cell viability was determined.Results: The nanostructured system was effective in complexing oligonucleotides for delivery to target cells. In addition, we observed that the NE-siRNA-CD73 complex was effective in reducing CD73 protein levels and AMPase activity, which were related to decreased C6 glioma cell viability.Conclusions: These findings indicate the potential of siRNA-CD73-loaded cationic NE as a therapeutic alternative for glioma treatment.


Asunto(s)
5'-Nucleotidasa/genética , Glioma/terapia , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/uso terapéutico , Animales , Astrocitos/citología , Astrocitos/metabolismo , Cationes/química , Línea Celular Tumoral , Células Cultivadas , Portadores de Fármacos/química , Emulsiones/química , Glioma/genética , ARN Interferente Pequeño/genética , Tratamiento con ARN de Interferencia , Ratas
2.
J Cell Sci ; 129(18): 3437-48, 2016 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-27528403

RESUMEN

During brain development, cells proliferate, migrate and differentiate in highly accurate patterns. In this context, published results indicate that bradykinin functions in neural fate determination, favoring neurogenesis and migration. However, mechanisms underlying bradykinin function are yet to be explored. Our findings indicate a previously unidentified role for bradykinin action in inducing neuron-generating division in vitro and in vivo, given that bradykinin lengthened the G1-phase of the neural progenitor cells (NPC) cycle and increased TIS21 (also known as PC3 and BTG2) expression in hippocampus from newborn mice. This role, triggered by activation of the kinin-B2 receptor, was conditioned by ERK1/2 activation. Moreover, immunohistochemistry analysis of hippocampal dentate gyrus showed that the percentage of Ki67(+) cells markedly increased in bradykinin-treated mice, and ERK1/2 inhibition affected this neurogenic response. The progress of neurogenesis depended on sustained ERK phosphorylation and resulted in ERK1/2 translocation to the nucleus in NPCs and PC12 cells, changing expression of genes such as Hes1 and Ngn2 (also known as Neurog2). In agreement with the function of ERK in integrating signaling pathways, effects of bradykinin in stimulating neurogenesis were reversed following removal of protein kinase C (PKC)-mediated sustained phosphorylation.


Asunto(s)
Bradiquinina/farmacología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/enzimología , Neuronas/metabolismo , Animales , Calcio/metabolismo , Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Linaje de la Célula/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , AMP Cíclico/metabolismo , Activación Enzimática/efectos de los fármacos , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Péptidos y Proteínas de Señalización Intercelular/farmacología , Ratones Endogámicos C57BL , Células-Madre Neurales/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Neuronas/citología , Neuronas/efectos de los fármacos , Células PC12 , Fenotipo , Fosforilación/efectos de los fármacos , Ratas , Transducción de Señal/efectos de los fármacos
3.
Biochim Biophys Acta ; 1770(9): 1352-9, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17643826

RESUMEN

Gliomas are the most malignant of the primary brain tumors. Nucleotides represent an important class of extracellular molecules that are crucial for the normal function of the nervous system. ATP and adenosine can stimulate cell proliferation in different glioma cell lines; the events induced by extracellular adenine nucleotides are controlled by the action of ecto-nucleotidases, which hydrolyze ATP into adenosine in the extracellular space. Recent studies have shown that quercetin has an anti-proliferative effect on the U138MG glioma cell line. Since evidence suggests that purinergic signaling is involved in the growth and progression of glioma and, taking into consideration the anti-proliferative effect elicited by quercetin in this tumor type, the aim of the present study was to better investigate the extracellular metabolism of AMP and evaluate the effect of quercetin on this system in the human U138MG glioma cell line. The adenine products secreted by glioma cells were first characterized; extracellular AMP was efficiently metabolized by the glioma culture, demonstrating a very active ecto-5'-NT/CD73. Quercetin was able to inhibit the ecto-5'-NT/CD73 activity and modulate its expression. In addition, the cell treatment with APCP (alpha,beta-methyleneadenosine-5'-diphosphate), an ecto-5'-NT/CD73 inhibitor, led to a significant reduction in glioma cell proliferation. We suggest that the inhibition of ecto-5'-NT/CD73 may result in a decrease in extracellular adenosine production with a consequent reduction in tumor progression.


Asunto(s)
5'-Nucleotidasa/antagonistas & inhibidores , Glioma/tratamiento farmacológico , Quercetina/farmacología , Nucleótidos de Adenina/metabolismo , Adenosina Difosfato/análogos & derivados , Adenosina Difosfato/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Glioma/metabolismo , Humanos , Quercetina/uso terapéutico , ARN Mensajero/metabolismo
4.
Eur J Pharmacol ; 586(1-3): 24-34, 2008 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-18371953

RESUMEN

Gliomas are the most common and devastating tumors of the central nervous system. Several studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) are promising anticancer agents. Biodegradable nanoparticulate systems have received considerable attention as potential drug delivery vehicles. The aim of this study was to evaluate the effects of indomethacin-loaded nanocapsules and indomethacin ethyl ester-loaded nanocapsules on glioma cell lines. In addition, the effect of these formulations on normal neural tissue was also evaluated. In order to investigate this, glioma cell lines (U138-MG and C6) and hippocampal organotypic cultures were used. The main finding of the present study is that indomethacin-loaded nanocapsules formulation was more potent than a solution of indomethacin in decreasing the viability and cell proliferation of glioma lines. Indomethacin and indomethacin ethyl ester associated together in the same nanocapsule formulation caused a synergic effect decreasing glioma cell proliferation. In addition, when the glioma cells were exposed to 25 microM of indomethacin-loaded nanocapsules or indomethacin ethyl ester-loaded nanocapsules, a necrotic cell death was observed. Interestingly, 5 microM of indomethacin-loaded nanocapsules was able to cause an antiproliferative effect without promoting necrosis in glioma cells. Another important finding was that the cytotoxic effect induced by 25 microM or 50 microM of indomethacin-loaded nanocapsules or indomethacin ethyl ester-loaded nanocapsules, in glioma cells was not observed in the organotypic cultures, indicating selective cytotoxicity of those formulations for tumoral cells. Further investigations using in vivo glioma model should be helpful to confirm the distinct effects of indomethacin-loaded nanocapsules and indomethacin ethyl ester-loaded nanocapsules, in normal versus tumoral cells.


Asunto(s)
Antiinflamatorios no Esteroideos/toxicidad , Antineoplásicos , Neoplasias Encefálicas/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa 2/toxicidad , Glioma/tratamiento farmacológico , Indometacina/análogos & derivados , Indometacina/toxicidad , Animales , Neoplasias Encefálicas/patología , Recuento de Células , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fenómenos Químicos , Química Física , Colorantes , Composición de Medicamentos , Glioma/patología , Hipocampo/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Masculino , Nanocápsulas , Técnicas de Cultivo de Órganos , Propidio , Ratas , Ratas Wistar , Suspensiones
5.
Int J Pharm ; 359(1-2): 288-93, 2008 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-18495390

RESUMEN

The encapsulation of lipophilic drugs in polymeric nanoparticles can form simultaneously both polymeric nanoparticles and drug nanocrystals. The objective was to detect the presence of nanocrystals in the nanoparticle suspensions using a simple methodology, and to determine if the nanocrystals are formed during preparation or by drug leakage from the particles during storage. Indomethacin was chosen as drug model. Unloaded and drug-loaded (1mg/mL) nanocapsules showed diameters close to 280nm and polydispersity lower than 0.20, remaining constant after 120 days. Comparing indomethacin loaded (3mg/mL) and unloaded formulations, variations in the scattered light depolarization degree indicated the simultaneous presence of nanocrystals and nanocapsules in the suspensions. A relation between the scattered light intensities and the drug precipitation was established. As a function of time, when the decrease in the Rayleigh ratios occurred, the drug contents decreased due to precipitation. On the other hand, when the Rayleigh ratios slightly increase, the drug contents are constant. The nanocrystals formed in the oversaturated formulations, agglomerate and precipitate during storage. When the drug is adsorbed on the nanocapsules, but the system is not oversaturated, no nanocrystal was formed and the formulation is physico-chemically stable at least for 150 days of storage.


Asunto(s)
Indometacina/química , Nanocápsulas , Polímeros/química , Adsorción , Precipitación Química , Cristalización , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Luz , Tamaño de la Partícula , Dispersión de Radiación , Factores de Tiempo
6.
Eur J Pharmacol ; 569(1-2): 8-15, 2007 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-17568578

RESUMEN

Gliomas are the most common and devastating primary tumors of the central nervous system. Ecto-NTPDases and ecto-5'-nucleotidase/CD73 can control extracellular ATP/adenosine levels, which have been described as proliferation factors. Here, we investigate the influence of indomethacin on the enzyme cascade that catalyses the interconversion of purine nucleotides in U138-MG and C6 glioma cell lines. Exposure of glioma cells to 100 microM indomethacin for 48 h caused increases of 52% (P < 0.05) and 62% (P < 0.05) in the AMP hydrolysis rate in C6 and U138-MG cell lines, respectively. Indomethacin treatments also increased ATP hydrolysis. Significant increase in ecto-5'-nucleotidase/CD73 mRNA and protein levels were observed after treatment with indomethacin. Pretreatment of glioma cells with a specific antagonist of the adenosine A(3) receptor, MRS1220 (1 microM; 9-Chloro-2-(2-furanyl)-5-((phenylacetyl)amino)-[1,2,4]triazolo[1,5-c]quinazoline), significantly reduced the inhibition of cell proliferation induced by indomethacin. In addition, a significant increase in mRNA levels of the adenosine A(3) receptor was observed after treatment with indomethacin. In conclusion, our data indicate that adenosine A(3) receptors and the enzyme, ecto-5'-nucleotidase/CD73, are involved in the anti-proliferative effect of indomethacin in glioma cells.


Asunto(s)
5'-Nucleotidasa/genética , Indometacina/farmacología , 5'-Nucleotidasa/metabolismo , Actinas/metabolismo , Adenosina Difosfato/análogos & derivados , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Antiinflamatorios no Esteroideos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Dimetilsulfóxido/farmacología , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Citometría de Flujo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Glioma/enzimología , Glioma/genética , Glioma/patología , Humanos , Agonistas del Receptor Purinérgico P1 , Antagonistas de Receptores Purinérgicos P1 , Quinazolinas/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Teofilina/análogos & derivados , Teofilina/farmacología , Factores de Tiempo , Triazoles/farmacología , Xantinas/farmacología
7.
Eur J Pharmacol ; 532(3): 214-22, 2006 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-16487511

RESUMEN

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used drugs for the treatment of inflammatory disease and have a chemopreventive effect in a variety of tumors. Several studies have demonstrated unequivocally that certain NSAIDs cause antiproliferative effects independent of cyclooxygenase (COX) activity. In this study, we investigated the effect of chemically unrelated NSAIDs in the proliferation of glioma cell lines and the possible mechanisms involved in indomethacin-mediated inhibition of proliferation in glioma cells lines. The glioma cell lines were treated with NSAIDs and proliferation was measured by cell counting. Indomethacin, acetaminophen, sulindac sulfide and NS-398 (N-[2-cyclohexyloxy)-4-nitrophenyl]methane-sulfonamide) induced a time- and concentration-dependent inhibition of C6 rat glioma cell proliferation. The inhibition of COX by chemically unrelated NSAIDs leads to inhibition of rat and human glioma cell proliferation. The tetrazolium reduction assay (MTT) indicated a reduction in cell viability induced by indomethacin. None of the NSAIDs tested induced caspase-3/7 activation, assayed with a fluorigenic substrate. The indomethacin-induced inhibition of C6 cells proliferation was abrogated by the use of the c-Src inhibitor, PP2 and the MEK inhibitor, PD 098059, suggesting COX-independent mechanisms. Indomethacin decreased the percentage of cells in the S phase, with relative increases in the G0/G1 and/or the G2/M phase. NSAIDs may be clinically important for pharmacological intervention in gliomas.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Proliferación Celular/efectos de los fármacos , Inhibidores de la Ciclooxigenasa/farmacología , Indometacina/farmacología , Nitrobencenos/farmacología , Sulfonamidas/farmacología , Acetaminofén/farmacología , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Flavonoides/farmacología , Glioma , Humanos , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Ratas , Factores de Tiempo , Familia-src Quinasas/antagonistas & inhibidores , Familia-src Quinasas/metabolismo
8.
Blood Coagul Fibrinolysis ; 17(6): 437-44, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16905946

RESUMEN

Despite the extensive research on the pharmacology of L-arginine, there are only few data on its antithrombotic properties. We studied the effect of oral L-arginine administration in a model of arterial thrombosis in rabbits divided into three groups: group 1, group without intervention; group 2, control group, treated with normal diet and submitted to the thrombosis-triggering protocol; group 3, treated for 2 weeks with L-arginine (2.25%) prior the protocol. L-Arginine did not alter platelet aggregation nor coagulation parameters but reduced vascular activities of both ADPase (49.1 +/- 8.5 versus 28.9 +/- 8.3 versus 18.8 +/- 10.3 nmoles inorganic phosphate/min per mg protein; mean +/- SD; group 1 versus group 2 versus group 3, respectively; ANOVA F = 19.21; P < 0.0001) and ATPase (97.8 +/- 15.8 versus 52.1 +/- 11.6 versus 31.9 +/- 16.3 nmoles inorganic phosphate/min per mg protein; mean +/- SD; group 1 versus group 2 versus group 3, respectively; ANOVA, F = 34.65; P < 0.0001). L-Arginine did not reduce the thrombi area (17.1 mm, 9.02 and 48.07, versus 27.04 mm, 25.4 and 70.39, median, percentile 25 and 75 respectively, P = 0.079; group 2 versus group 3, respectively). In conclusion, oral L-arginine administration did not inhibit thrombosis, and, conversely, it significantly reduced the arterial wall ADPase and ATPase activities. This effect may limit its antithrombotic properties.


Asunto(s)
Adenosina Trifosfatasas/efectos de los fármacos , Apirasa/efectos de los fármacos , Arginina/farmacología , Agregación Plaquetaria/efectos de los fármacos , Trombosis/prevención & control , Adenosina Trifosfatasas/metabolismo , Administración Oral , Análisis de Varianza , Animales , Aorta Torácica/efectos de los fármacos , Aorta Torácica/enzimología , Apirasa/metabolismo , Arginina/administración & dosificación , Coagulación Sanguínea/efectos de los fármacos , Distribución de Chi-Cuadrado , Arteria Femoral/efectos de los fármacos , Arteria Femoral/enzimología , Masculino , Modelos Animales , Conejos , Estadísticas no Paramétricas , Trombosis/etiología , Trombosis/patología
9.
Physiol Behav ; 85(2): 213-9, 2005 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-15882881

RESUMEN

It has been reported that animals submitted to repeated restraint stress present various adaptation responses which are dependent on the sex. These adaptations include changes in nociception and adenine nucleotide hydrolysis. In this study, we report the effect of chronic administration of a gonadal steroid (17beta-estradiol) on ATP, ADP and AMP hydrolysis in spinal cord synaptosomes of adult ovariectomized (OVX) Wistar rats submitted to repeated restraint stress over 40 days. We also measured nociceptive threshold in these animals using the tail-flick test. The results show that tail-flick latencies were decreased in both stressed groups, OVX and OVX rats receiving estradiol replacement therapy, indicating reduced nociceptive threshold after exposure to repeated stress. Repeated restraint stress caused no effect on ATPase or ADPase activities. On the other hand, AMP hydrolysis in spinal cord synaptosomes from repeatedly stressed rats was decreased in OVX rats compared to non-stressed OVX ones, indicating reduced extracellular adenosine production; this effect was reversed by hormonal replacement. These observations suggest that nociceptive sensitivity to noxious stimuli is affected by repeated stress and that modulation of neurotransmission by adenine nucleotides in spinal cord may be altered by the interaction of sexual hormones and psychological factors, such as exposure to stress.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Estradiol/administración & dosificación , Nociceptores/fisiopatología , Médula Espinal/citología , Estrés Fisiológico/enzimología , Sinaptosomas/efectos de los fármacos , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Análisis de Varianza , Animales , Femenino , Hidrólisis/efectos de los fármacos , Ovariectomía/métodos , Dimensión del Dolor/métodos , Ratas , Ratas Wistar , Tiempo de Reacción/efectos de los fármacos , Restricción Física/métodos , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismo , Sinaptosomas/enzimología
10.
Eur J Med Chem ; 95: 552-62, 2015 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-25863023

RESUMEN

We described the first synthesis of fatty acid 3,4-dihydropyrimidinones (DHPM-fatty acids) using the Biginelli multicomponent reaction. Antiproliferative activity on two glioma cell lines (C6 rat and U-138-MG human) was also reported. The novel DHPM-fatty acids reduced glioma cell viability relative to temozolomide. Hybrid oxo-monastrol-palmitic acid was the most potent, reducing U-138-MG human cell viability by ca. 50% at 10 µM. In addition, the DHPM-fatty acids showed a large safety range to neural cells, represented by the organotypic hippocampal culture. These results suggest that the increased lipophilicity of DHPM-fatty acids offer a promising approach to overcoming resistance to chemotherapy and may play an important role in the development of new antitumor drugs.


Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Ácidos Grasos/síntesis química , Ácidos Grasos/farmacología , Glioma/patología , Uridina/análogos & derivados , Animales , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Técnicas de Química Sintética , Diseño de Fármacos , Ácidos Grasos/química , Humanos , Masculino , Ratas , Ratas Wistar , Uridina/química
11.
Cancer Lett ; 198(2): 211-8, 2003 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-12957360

RESUMEN

In order to characterize the enzymes involved in the purine nucleotide catabolism as indicators of invasiveness and aggressiveness of malignant gliomas, the degradation of extracellular nucleotides by five different glioma cell lines was investigated and compared with primary astrocytes. Rapid hydrolysis of extracellular ATP and ADP by astrocytes was observed, whereas all glioma cell lines examined presented low rates of ATP hydrolysis. In contrast, ecto-5'-nucleotidase activity was increased in glioma cell lines when compared to astrocytes. Considering that ATP is recognized as a mitogenic factor that induces proliferation in human glioma cells, the substantial decrease in ATP and ADP hydrolysis observed in gliomas leads us to suggest that alterations in the ecto-nucleotidases pathway may represent an important mechanism associated with malignant transformation of glioma cell lines.


Asunto(s)
Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Astrocitos/metabolismo , 5'-Nucleotidasa/metabolismo , Animales , Células Cultivadas , Espacio Extracelular/metabolismo , Glioma , Humanos , Cinética , L-Lactato Deshidrogenasa , Ratas , Células Tumorales Cultivadas
12.
Neurochem Int ; 44(6): 423-31, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-14687607

RESUMEN

Glutamate uptake into synaptic vesicles is driven by a proton electrochemical gradient generated by a vacuolar H(+)-ATPase and stimulated by physiological concentrations of chloride. This uptake plays an important role in glutamatergic transmission. We show here that vesicular glutamate uptake is selectively inhibited by guanine derivatives, in a time- and concentration-dependent manner. Guanosine, GMP, GDP, guanosine-5'-O-2-thiodiphosphate, GTP, or 5'-guanylylimidodiphosphate (GppNHp) inhibited glutamate uptake in 1.5 and 3 min incubations, however, when incubating for 10 min, only GTP or GppNHp displayed such inhibition. By increasing ATP concentrations, the inhibitory effect of GTP was no longer observed, but GppNHp still inhibited glutamate uptake. In the absence of ATP, vesicular ATPase can hydrolyze GTP in order to drive glutamate uptake. However, 5mM GppNHp inhibited ATP hydrolysis by synaptic vesicle preparations. GTP or GppNHp decreased the proton electrochemical gradient, whereas the other guanine derivatives did not. Glutamate saturation curves were assayed in order to evaluate the specificity of inhibition of the vesicular glutamate carrier by the guanine derivatives. The maximum velocity of the initial rate of glutamate uptake was decreased by all guanine derivatives. These results indicate that, although GppNHp can inhibit ATPase activity, guanine derivatives are more likely to be acting through interaction with vesicular glutamate carrier.


Asunto(s)
Encéfalo/efectos de los fármacos , Ácido Glutámico/metabolismo , Nucleótidos de Guanina/farmacología , Vesículas Sinápticas/metabolismo , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Encéfalo/enzimología , Encéfalo/metabolismo , Hidrólisis , Masculino , Ratas , Ratas Wistar
13.
Neurochem Int ; 43(7): 621-8, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12892649

RESUMEN

Primary astrocyte cultures from hippocampus, cortex and cerebellum presented different extracellular pattern of adenine nucleotide hydrolysis. The ATP/ADP hydrolysis ratio was 8:1 for hippocampal and cortical astrocytes and 5:1 for cerebellar astrocytes. The AMP hydrolysis in cerebellar astrocytes was seven-fold higher than in cortical or hippocampal cells. No accumulation of extracellular adenosine in all structures studied was observed. Dipyridamol increased significantly inosine levels in the extracellular medium of hippocampal and cortical, but not in cerebellar astrocytes medium. A higher expression of ecto-5'-nucleotidase was identified by RT-PCR in cerebellum. The differences observed may indicate functional heterogeneity of nucleotides in the brain.


Asunto(s)
Nucleótidos de Adenina/metabolismo , Astrocitos/metabolismo , Encéfalo/metabolismo , 5'-Nucleotidasa/metabolismo , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Animales Recién Nacidos , Encéfalo/citología , Cerebelo/metabolismo , Corteza Cerebral/metabolismo , Dipiridamol/farmacología , Espacio Extracelular/metabolismo , Hipocampo/metabolismo , Proteínas de Transporte de Nucleósidos/antagonistas & inhibidores , Especificidad de Órganos , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
14.
Eur J Pharmacol ; 437(3): 151-4, 2002 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-11890903

RESUMEN

Male Wistar rats were bilaterally implanted with indwelling cannulae in the caudal region of the posterior cingulate cortex. After recovery, animals were trained in a step-down inhibitory avoidance task (3.0-s, 0.4-mA foot shock) and received, immediately after training, a 0.5-microl infusion of the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA; 1, 50 or 100 nM) or of the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 1, 25 or 50 nM). Animals were tested twice, 1.5 h and, again, 24 h after training, in order to examine the effects of these agents on short- and long-term memory, respectively. Only 50-nM DPCPX was effective in altering memory, promoting a facilitation. These results suggest that adenosine A1 receptors in the posterior cingulate cortex inhibit memory consolidation in a way that their blockade facilitates memory for inhibitory avoidance in rats.


Asunto(s)
Adenosina/análogos & derivados , Giro del Cíngulo/efectos de los fármacos , Memoria/efectos de los fármacos , Antagonistas de Receptores Purinérgicos P1 , Xantinas/farmacología , Adenosina/farmacología , Animales , Reacción de Prevención/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Giro del Cíngulo/metabolismo , Masculino , Ratas , Receptores Purinérgicos P1/fisiología , Retención en Psicología/efectos de los fármacos
15.
Thromb Res ; 114(4): 275-81, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15381391

RESUMEN

The low prevalence of coronary heart disease in premenopausal women and its increase after menopause are well established. Many studies have suggested that steroid hormones can inhibit platelet aggregation, reducing the cardiovascular risk. In addition, a number of studies have shown an effect of estrogen on vascular function. The process of haemostasis and thrombus formation can be also affected by adenine nucleotides and adenosine. Consequently, the regulation of enzymes that hydrolyze these nucleotides in the bloodstream is essential in the modulation of the processes of platelet aggregation, vasodilatation and coronary flow. Thus, in this study, we examined the effect of ovariectomy (OVX), estradiol replacement therapy and the in vitro administration of 17beta-estradiol, dehydroisoandrosterone 3-sulfate (DHEAS) and pregnenolone (PREG) on the activity of the enzymes that degrade adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in the blood serum of female rats. OVX significantly increased the hydrolysis of ATP, ADP and AMP, whilst phosphodiesterase activity was unchanged. Estradiol replacement therapy significantly decreased the hydrolysis of the adenine nucleotides and of the substrate marker of phosphodiesterase. In vitro, the addition of steroid hormones did not have any effect on the nucleotide hydrolysis by rat serum. These results suggest the presence of a strong relation between these enzymes and the hormonal system. In addition, the alterations observed are important, because these enzymes control the nucleotides/nucleosides ratio in the circulation and thus the events related to haemostasis.


Asunto(s)
Nucleótidos de Adenina/metabolismo , Terapia de Reemplazo de Hormonas , Ovariectomía , 5'-Nucleotidasa/metabolismo , Nucleótidos de Adenina/sangre , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Apirasa/metabolismo , Sulfato de Deshidroepiandrosterona/farmacología , Estradiol/farmacología , Femenino , Hormonas Esteroides Gonadales/farmacología , Hidrólisis , Pregnanolona/farmacología , Ratas , Ratas Wistar
16.
Clin Chim Acta ; 349(1-2): 53-60, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15469855

RESUMEN

BACKGROUND AND METHODS: The in vitro effect of the nonsteroidal anti-inflammatory drug, acetylsalicylic acid (ASA), on the extracellular adenine nucleotide hydrolysis by intact rat blood platelets was studied. RESULTS: Our results demonstrate that aspirin, at final concentrations of 2.0 and 3.0 mM, inhibits ATP extracellular hydrolysis in vitro by approximately 17% and 21%, respectively. Aspirin, at a final concentration of 3.0 mM, also inhibited in vitro extracellular ADP hydrolysis by approximately 41%. The same concentrations of this drug, however, did not alter AMP hydrolysis by intact rat blood platelets under similar assay conditions. The kinetic analysis demonstrated that the inhibition of ADP and ATP hydrolysis by aspirin in rat platelets is of the uncompetitive type. CONCLUSION: In this study, we demonstrated an inhibitory effect of ASA upon E-NTPDase 3 activity of platelets from adult rats and discussed the significance of our findings.


Asunto(s)
Apirasa/antagonistas & inhibidores , Apirasa/sangre , Aspirina/farmacología , Plaquetas/enzimología , Inhibidores de la Ciclooxigenasa/farmacología , 5'-Nucleotidasa/antagonistas & inhibidores , Nucleótidos de Adenina/metabolismo , Adenosina Difosfato/sangre , Adenosina Monofosfato/sangre , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/sangre , Animales , Plaquetas/efectos de los fármacos , Técnicas In Vitro , Masculino , Ratas , Colorantes de Rosanilina
17.
J Biomed Nanotechnol ; 9(12): 2086-104, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24266263

RESUMEN

Resveratrol, a natural polyphenolic compound, has attracted considerable interest for its anti-inflammatory and neuroprotective properties. However, the biological effects of resveratrol appear strongly limited because it is photosensitive, easily oxidized, and has unfavorable pharmacokinetics. The present study aimed to elucidate the effect of resveratrol on Abeta-triggered neuroinflammation by comparing the effects of free resveratrol (RSV) treatment with those of treatment with resveratrol-loaded lipid-core nanocapsules (RSV-LNC). Organotypic hippocampal cultures were stimulated by Abeta1-42 with or without different concentrations of RSV or RSV-LNC. We found that Abeta triggered a harmful neuroinflammation process in organotypic hippocampal cultures. Pre- and co-treatments with RSV-LNC were able to protect cultures against ROS formation and cell death induced by Abeta, possibly through sustained blocking of TNF-alpha, IL-1beta, and IL-6 release. Furthermore, RSV-LNC was able to increase IL-10 release even in the presence of Abeta and prevent or decrease both glial and JNK activation. On the other hand, both pre- and co-treatment with RSV exhibited a lower ability to prevent or decrease neuroinflammation, ROS formation, and cell death, and failed to increase IL-10 release. Our findings suggest that modulation of neuroinflammation through a combination of resveratrol and a lipid-core nanocapsule-based delivery system might represent a promising approach for preventing or delaying the neurodegenerative process triggered by Abeta. The results open new vistas to the interplay between inflammation and amyloid pathology.


Asunto(s)
Antiinflamatorios/farmacología , Inflamación/prevención & control , Lípidos/farmacología , Nanocápsulas/química , Neuronas/efectos de los fármacos , Estilbenos/farmacología , Péptidos beta-Amiloides , Animales , Antiinflamatorios/administración & dosificación , Células Cultivadas , Sinergismo Farmacológico , Encefalitis/inducido químicamente , Encefalitis/patología , Encefalitis/prevención & control , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/patología , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/patología , Lípidos/administración & dosificación , Lípidos/química , Masculino , Neuronas/patología , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Resveratrol , Estilbenos/administración & dosificación
18.
Mol Neurobiol ; 47(3): 1066-80, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23315270

RESUMEN

Alzheimer's disease (AD), a neurodegenerative disorder exhibiting a gradual decline in cognitive function, is characterized by the presence of neuritic plaques composed of neurofibrillary tangles and amyloid-ß (Aß) peptide. Available drugs for AD therapy have small effect sizes and do not alter disease progression. Several studies have been shown that resveratrol is associated with anti-amyloidogenic properties, but therapeutic application of its beneficial effects is limited. Here we compared the neuroprotective effects of free resveratrol treatment with those of resveratrol-loaded lipid-core nanocapsule treatment against intracerebroventricular injection of Aß1-42 in rats. Animals received a single intracerebroventricular injection of Aß1-42 (2 nmol), and 1 day after Aß infusion, they were administered either free resveratrol (RSV) or resveratrol-loaded lipid-core nanocapsules (5 mg/kg, each 12 h, intraperitoneally), for 14 days. Aß1-42-infused animals showed a significant impairment on learning memory ability, which was paralleled by a significant decrease in hippocampal synaptophysin levels. Furthermore, animals exhibited activated astrocytes and microglial cells, as well as disturbance in c-Jun N-terminal kinase (JNK) and glycogen synthase kinase-3ß (GSK-3ß) activation, beyond destabilization of ß-catenin levels. Our results clearly show that by using lipid-core nanocapsules, resveratrol was able to rescue the deleterious effects of Aß1-42 while treatment with RSV presented only partial beneficial effects. These findings might be explained by the robust increase of resveratrol concentration in the brain tissue achieved by lipid-core nanocapsules. Our data not only confirm the potential of resveratrol in treating AD but also offer an effective way to improve the efficiency of resveratrol through the use of nanodrug delivery systems.


Asunto(s)
Péptidos beta-Amiloides/administración & dosificación , Lípidos/química , Nanocápsulas/química , Fármacos Neuroprotectores/farmacología , Estilbenos/farmacología , Péptidos beta-Amiloides/toxicidad , Animales , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Astrocitos/patología , Citoprotección/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/efectos de los fármacos , Hipocampo/enzimología , Hipocampo/patología , Inyecciones Intraventriculares , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , Trastornos de la Memoria/tratamiento farmacológico , Microglía/efectos de los fármacos , Microglía/metabolismo , Microglía/patología , Fármacos Neuroprotectores/uso terapéutico , Estabilidad Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Resveratrol , Transducción de Señal/efectos de los fármacos , Estilbenos/efectos adversos , Estilbenos/uso terapéutico , Sinapsis/efectos de los fármacos , Sinapsis/patología , Distribución Tisular/efectos de los fármacos , beta Catenina/metabolismo
19.
Eur J Med Chem ; 48: 255-64, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22209415

RESUMEN

Gliomas are the most common and devastating tumors of the central nervous system (CNS). Many pieces of evidence point out the relevance of natural compounds for cancer therapy and prevention, including chalcones. In the present study, eight synthetic quinoxaline-derived chalcones, structurally based on the selective PI3Kγ inhibitor AS605240, were evaluated for anti-proliferative activity and viability inhibition using glioma cell lines from human and rat origin (U-138 MG and C6, respectively), at different time-periods of incubation and concentrations. The results revealed that four chalcones (compounds 1, 6, 7 and 8), which present methoxy groups at A-ring, displayed higher efficacies and potencies, being able to inhibit either cell proliferation or viability, in a time- and concentration-dependent manner, with an efficacy that was greater than that seen for the positive control compound AS605240. Flow cytometry analysis demonstrated that incubation of C6 cells with compound 6 led to G1 phase arrest, likely indicating an interference with apoptosis. Furthermore, compound 6 was able to visibly inhibit AKT activation, allied to the stimulation of ERK MAP-kinase. The chalcones tested herein, especially those displaying a methoxy substituent, might well represent promising molecules for the adjuvant treatment of glioma progression.


Asunto(s)
Antineoplásicos/síntesis química , Neoplasias Encefálicas/tratamiento farmacológico , Chalconas/síntesis química , Chalconas/farmacología , Glioma/tratamiento farmacológico , Quinoxalinas/síntesis química , Quinoxalinas/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Neoplasias Encefálicas/patología , Puntos de Control del Ciclo Celular/fisiología , Procesos de Crecimiento Celular/efectos de los fármacos , Línea Celular Tumoral , Chalconas/química , Glioma/patología , Humanos , Concentración 50 Inhibidora , Espectroscopía de Resonancia Magnética , Estructura Molecular , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Quinoxalinas/química , Ratas , Espectrofotometría Infrarroja , Relación Estructura-Actividad
20.
J Biomed Nanotechnol ; 6(6): 694-703, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21361135

RESUMEN

Several studies have reported that orally ingested trans-resveratrol is extensively metabolized in the enterocyte before it enters the blood and target organs. Additionally, trans-resveratrol is photosensitive, easily oxidized and presents unfavorable pharmacokinetics. Therefore, it is of great interest to stabilize trans-resveratrol in order to preserve its biological activities and to improve its bioavailability in the brain. Here, trans-resveratrol was loaded into lipid-core nanocapsules and analyzed for particle size, polydispersity and zeta potential. The nanocapsule distribution in brain tissue was evaluated by intraperitoneal (i.p.) and gavage routes in healthy rats. The lipid-core nanocapsules had a mean diameter of 241 nm, a polydispersity index of 0.2, and a zeta potential of -15 mV. No physical changes were observed after 1, 2 and 3 months of storage at 25 degrees C. Lipid-core nanocapsules showed high entrapment of trans-resveratrol and displayed a higher trans-resveratrol concentration in the brain, the liver and the kidney after daily i.p. or gavage administration than that observed for the free trans-resveratrol. Because trans-resveratrol is a potent cyclooxygenase-1 inhibitor, gastrointestinal damage was evaluated. The animals that were administered with trans-resveratrol-loaded lipid-core nanocapsules showed significantly less damage when compared to those administered with free trans-resveratrol. In summary, lipid-core nanocapsules exhibited great trans-resveratrol encapsulation efficiency. trans-Resveratrol-loaded lipid-core nanocapsules increased the concentration of trans-resveratrol in the brain tissue. Gastrointestinal safety was improved when compared with free trans-resveratrol. Thus, trans-resveratrol-loaded lipid-core nanocapsules may be used as an alternative potential therapeutic for several diseases including Alzheimer's disease.


Asunto(s)
Antioxidantes/farmacocinética , Lípidos , Nanocápsulas , Estilbenos/farmacocinética , Animales , Antioxidantes/farmacología , Estabilidad de Medicamentos , Tracto Gastrointestinal/efectos de los fármacos , Concentración de Iones de Hidrógeno , Lípidos/química , Masculino , Nanocápsulas/química , Ratas , Ratas Wistar , Resveratrol , Estilbenos/farmacología
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