RESUMEN
Sleep disturbances and persistent pain conditions are public health challenges worldwide. Although it is well-known that sleep deficit increases pain sensitivity, the underlying mechanisms remain elusive. We have recently demonstrated the involvement of nucleus accumbens (NAc) and anterior cingulate cortex (ACC) in the pronociceptive effect of sleep restriction. In this study, we found that sleep restriction increases c-Fos expression in NAc and ACC, suggesting hyperactivation of these regions during prolonged wakefulness in male Wistar rats. Blocking adenosine A2A receptors in the NAc or GABAA receptors in the ventral tegmental area (VTA), dorsal raphe nucleus (DRN), or locus coeruleus (LC) effectively mitigated the pronociceptive effect of sleep restriction. In contrast, the blockade of GABAA receptors in each of these nuclei only transiently reduced carrageenan-induced hyperalgesia. Pharmacological activation of dopamine D2, serotonin 5-HT1A and noradrenaline alpha-2 receptors within the ACC also prevented the pronociceptive effect of sleep restriction. While pharmacological inhibition of these same monoaminergic receptors in the ACC restored the pronociceptive effect which had been prevented by the GABAergic disinhibition of the of the VTA, DRN or LC. Overall, these findings suggest that the pronociceptive effect of sleep restriction relies on increased adenosinergic activity on NAc, heightened GABAergic activity in VTA, DRN, and LC, and reduced inhibitory monoaminergic activity on ACC. These findings advance our understanding of the interplay between sleep and pain, shedding light on potential NAc-brainstem-ACC mechanisms that could mediate increased pain sensitivity under conditions of sleep impairment.
Asunto(s)
Núcleo Accumbens , Ratas Wistar , Privación de Sueño , Área Tegmental Ventral , Animales , Masculino , Privación de Sueño/metabolismo , Privación de Sueño/fisiopatología , Ratas , Área Tegmental Ventral/metabolismo , Área Tegmental Ventral/efectos de los fármacos , Núcleo Accumbens/metabolismo , Núcleo Accumbens/efectos de los fármacos , Receptor de Adenosina A2A/metabolismo , Hiperalgesia/metabolismo , Núcleo Dorsal del Rafe/metabolismo , Núcleo Dorsal del Rafe/efectos de los fármacos , Giro del Cíngulo/metabolismo , Giro del Cíngulo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-fos/metabolismo , Tronco Encefálico/metabolismo , Tronco Encefálico/efectos de los fármacos , Locus Coeruleus/metabolismo , Locus Coeruleus/efectos de los fármacos , Carragenina , Receptores de GABA-A/metabolismo , Receptores de Dopamina D2/metabolismo , Antagonistas del Receptor de Adenosina A2/farmacologíaRESUMEN
Caffeine has been extensively studied in the context of CNS pathologies as many researchers have shown that consuming it reduces pro-inflammatory biomarkers, potentially delaying the progression of neurodegenerative pathologies. Several lines of evidence suggest that adenosine receptors, especially A1 and A2A receptors, are the main targets of its neuroprotective action. We found that caffeine pretreatment 15 min before LPS administration reduced the expression of Il1b in the hippocampus and striatum. The harmful modulation of caffeine-induced inflammatory response involved the downregulation of the expression of A2A receptors, especially in the hippocampus. Caffeine treatment alone promoted the downregulation of the adenosinergic receptor Adora2A; however, this promotion effect was reversed by LPS. Although administering caffeine increased the expression of the enzymes DNA methyltransferases 1 and 3A and decreased the expression of the demethylase enzyme Tet1, this effect was reversed by LPS in the hippocampus of mice that were administered Caffeine + LPS, relative to the basal condition; no significant differences were observed in the methylation status of the promoter regions of adenosine receptors. Finally, the bioinformatics analysis of the expanded network demonstrated the following results: the Adora2B gene connects the extended networks of the adenosine receptors Adora1 and Adora2A; the Mapk3 and Esr1 genes connect the extended Adora1 network; the Mapk4 and Arrb2 genes connect the extended Adora2A network with the extended network of the proinflammatory cytokine Il1ß. These results indicated that the anti-inflammatory effects of acute caffeine administration in the hippocampus may be mediated by a complex network of interdependencies between the Adora2B and Adora2A genes.
Asunto(s)
Cafeína , Regulación hacia Abajo , Hipocampo , Lipopolisacáridos , Enfermedades Neuroinflamatorias , Fármacos Neuroprotectores , Receptor de Adenosina A2A , Animales , Lipopolisacáridos/farmacología , Receptor de Adenosina A2A/metabolismo , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Cafeína/farmacología , Masculino , Regulación hacia Abajo/efectos de los fármacos , Ratones , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Enfermedades Neuroinflamatorias/inducido químicamente , Fármacos Neuroprotectores/farmacología , Ratones Endogámicos C57BL , Interleucina-1beta/metabolismo , Inflamación/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/inducido químicamenteRESUMEN
Sustained hypoxia (SH) in mice induces changes in the respiratory pattern and increase in the parasympathetic tone to the heart. Among adenosine G-protein-coupled receptors (GPCRs), the A2A receptors are especially important in mediating adenosine actions during hypoxia due to their expression in neurons involved with the generation and modulation of the autonomic and respiratory functions. Herein, we performed an in vivo evaluation of the baseline cardiovascular and respiratory parameters and their changes in response to SH in knockout mice for A2A receptors (A2A KO). SH produced similar and significant reductions in mean arterial pressure and heart rate in both wild-type (WT) and A2A KO mice when compared to their respective normoxic controls. Mice from WT and A2A KO groups submitted to normoxia or SH presented similar cardiovascular responses to peripheral chemoreflex activation (KCN). Under normoxic conditions A2A KO mice presented a respiratory frequency (fR ) significantly higher in relation to the WT group, which was reduced in response to SH. These data show that the lack of adenosine A2A receptors in mice does not affect the cardiovascular parameters and the autonomic responses to chemoreflex activation in control (normoxia) and SH mice. We conclude that the A2A receptors play a major role in the control of respiratory frequency and in the tachypnoeic response to SH in mice. NEW FINDINGS: What is the central question of this study? Are cardiovascular and respiratory parameters and their changes in response to sustained hypoxia (SH) altered in adenosine A2A receptor knockout mice? What is the main finding and its importance? Cardiovascular parameters and their changes in response to SH were not altered in A2A KO mice. The respiratory frequency in A2A KO was higher than in WT mice. In response to SH the respiratory frequency increased in WT, while it was reduced in A2A KO mice. A2A receptors play a major role in the modulation of respiratory frequency and in the tachypnoeic response to SH in mice.
Asunto(s)
Adenosina , Sistema Cardiovascular , Animales , Ratones , Hipoxia , Ratones Noqueados , Receptor de Adenosina A2A/metabolismoRESUMEN
The retinotectal topography of rats develops within the first three postnatal weeks during the critical period. Previous studies have shown that monocular enucleation results in plasticity of the intact retinotectal pathway in a time-dependent manner. Glial fibrillary acidic protein (GFAP), an astrocyte marker, is up-regulated after central nervous system injury. Adenosine is a neuromodulator involved in the development and plasticity of the visual system acting through the inhibitory A1 and excitatory A2a receptor activities. Herein, we examined whether adenosine receptors and astrocytes are crucial for monocular enucleation (ME)-induced plasticity. We also investigate whether A2a blockade alters retinotectal plasticity in an astrocyte-dependent manner. Lister Hooded rats were submitted to monocular enucleation at postnatal day 10 (PND10) or PND21 and, after different survival times, were processed for immunohistochemistry or western blotting assays. Another group underwent subpial implantation of ELVAX containing vehicle (DMSO) or SCH58261 (1 µM - an A2a receptor antagonist), simultaneously with ME at PND10. After a 72 h survival, GFAP content and the retinotectal plasticity were evaluated. Our data show that monocular enucleation leads to an upregulation in GFAP expression in the contralateral superior colliculus. At PND10, a slight increase in GFAP labeling was observed at 72 h post-enucleation, while at PND21 GFAP increase was detected in the deafferented superior colliculus after 1 to 3 weeks of survival. The content of adenosine receptors also varies in the contralateral target after ME. A transient increase in A1 receptors is observed in the early periods of plasticity, while A2a receptors are upregulated later. Interestingly, the local blockade of A2a receptors abolished the increase in GFAP and the retinotectal reorganization induced by monocular enucleation during the critical period. Taken together these results suggest a correlation between astrocytes and A2a adenosine receptors in the subcortical visual plasticity.
Asunto(s)
Astrocitos , Colículos Superiores , Animales , Ratas , Astrocitos/metabolismo , Enucleación del Ojo , Colículos Superiores/metabolismo , Receptores Purinérgicos P1/metabolismo , Inmunohistoquímica , Receptor de Adenosina A2A/metabolismoRESUMEN
Guanosine has been considered a promising candidate for antidepressant responses, but if this nucleoside could modulate adenosine A1 (A1R) and A2A (A2AR) receptors to exert antidepressant-like actions remains to be elucidated. This study investigated the role of A1R and A2AR in the antidepressant-like response of guanosine in the mouse tail suspension test and molecular interactions between guanosine and A1R and A2AR by docking analysis. The acute (60 min) administration of guanosine (0.05 mg/kg, p.o.) significantly decreased the immobility time in the tail suspension test, without affecting the locomotor performance in the open-field test, suggesting an antidepressant-like effect. This behavioral response was paralleled with increased A1R and reduced A2AR immunocontent in the hippocampus, but not in the prefrontal cortex, of mice. Guanosine-mediated antidepressant-like effect was not altered by the pretreatment with caffeine (3 mg/kg, i.p., a non-selective adenosine A1R/A2AR antagonist), 8-cyclopentyl-1,3-dipropylxanthine (DPCPX - 2 mg/kg, i.p., a selective adenosine A1R antagonist), or 4-(2-[7-amino-2-{2-furyl}{1,2,4}triazolo-{2,3-a}{1,3,5}triazin-5-yl-amino]ethyl)-phenol (ZM241385 - 1 mg/kg, i.p., a selective adenosine A2AR antagonist). However, the antidepressant-like response of guanosine was completely abolished by adenosine (0.5 mg/kg, i.p., a non-selective adenosine A1R/A2AR agonist), N-6-cyclohexyladenosine (CHA - 0.05 mg/kg, i.p., a selective adenosine A1 receptor agonist), and N-6-[2-(3,5-dimethoxyphenyl)-2-(methylphenyl)ethyl]adenosine (DPMA - 0.1 mg/kg, i.p., a selective adenosine A2A receptor agonist). Finally, docking analysis also indicated that guanosine might interact with A1R and A2AR at the adenosine binding site. Overall, this study reinforces the antidepressant-like of guanosine and unveils a previously unexplored modulation of the modulation of A1R and A2AR in its antidepressant-like effect.
Asunto(s)
Adenosina , Guanosina , Ratones , Animales , Guanosina/farmacología , Cafeína , Antidepresivos/farmacología , Agonistas del Receptor de Adenosina A2 , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismoRESUMEN
In this work, we evaluated the conformational effect promoted by the isosteric exchange of sulfur by selenium in the heteroaromatic ring of new N-acylhydrazone (NAH) derivatives (3-8, 13, 14), analogues of the cardioactive compounds LASSBio-294 (1) and LASSBio-785 (2). NMR spectra analysis demonstrated a chemical shift variation of the iminic Csp2 of NAH S/Se-isosters, suggesting a stronger intramolecular chalcogen interaction for Se-derivatives. To investigate the pharmacological profile of these compounds at the adenosine A2A receptor (A2AR), we performed a previously validated functional binding assay. As expected for bioisosteres, the isosteric-S/Se replacement affected neither the affinity nor the intrinsic efficacy of our NAH derivatives (1-8). However, the N-methylated compounds (2, 6-8) presented a weak partial agonist profile at A2AR, contrary to the non-methylated counterparts (1, 3-5), which appeared as weak inverse agonists. Additionally, retroisosterism between aromatic rings of NAH on S/Se-isosters mimicked the effect of the N-methylation on intrinsic efficacy at A2AR, while meta-substitution in the phenyl ring of the acyl moiety did not. This study showed that the conformational effect of NAH-N-methylation and aromatic rings retroisosterism changed the intrinsic efficacy on A2AR, indicating the S/Se-chalcogen effect to drive the conformational behavior of this series of NAH.
Asunto(s)
Hidrazonas/química , Receptor de Adenosina A2A/metabolismo , Selenio/química , Azufre/química , Tiofenos/química , Agonistas del Receptor de Adenosina A2/química , Agonistas del Receptor de Adenosina A2/farmacología , Animales , Humanos , Hidrazonas/farmacología , Masculino , Modelos Moleculares , Ratas Wistar , Selenio/farmacología , Azufre/farmacología , Tiofenos/farmacologíaRESUMEN
Early life stressors, such as social isolation (SI), can disrupt brain development contributing to behavioral and neurochemical alterations in adulthood. Purinergic receptors and ectonucleotidases are key regulators of brain development in embryonic and postnatal periods, and they are involved in several psychiatric disorders, including schizophrenia. The extracellular ATP drives purinergic signaling by activating P2X and P2Y receptors and it is hydrolyzed by ectonucleotidases in adenosine, which activates P1 receptors. The purpose of this study was to investigate if SI, a rodent model used to replicate abnormal behavior relevant to schizophrenia, impacts purinergic signaling. Male Wistar rats were reared from weaning in group-housed or SI conditions for 8 weeks. SI rats exhibited impairment in prepulse inhibition and social interaction. SI presented increased ADP levels in cerebrospinal fluid and ADP hydrolysis in the hippocampus and striatum synaptosomes. Purinergic receptor expressions were upregulated in the prefrontal cortex and downregulated in the hippocampus and striatum. A2A receptors were differentially expressed in SI prefrontal cortex and the striatum, suggesting distinct roles in these brain structures. SI also presented decreased ADP, adenosine, and guanosine levels in the cerebrospinal fluid in response to D-amphetamine. Like patients with schizophrenia, uric acid levels were prominently increased in SI rats after D-amphetamine challenge. We suggest that the SI-induced deficits in prepulse inhibition might be related to the SI-induced changes in purinergic signaling. We provide new evidence that purinergic signaling is markedly affected in a rat model relevant to schizophrenia, pointing out the importance of purinergic system in psychiatry conditions.
Asunto(s)
Receptores Purinérgicos , Transducción de Señal , Aislamiento Social , Adenosina Difosfato/líquido cefalorraquídeo , Animales , Conducta Animal , Estimulantes del Sistema Nervioso Central/farmacología , Dextroanfetamina/farmacología , Masculino , Nucleotidasas/metabolismo , Ratas , Ratas Wistar , Receptor de Adenosina A2A/metabolismo , Receptores Purinérgicos P2X/metabolismo , Receptores Purinérgicos P2Y/metabolismo , Reflejo de Sobresalto , Psicología del Esquizofrénico , Conducta Social , Aislamiento Social/psicología , DesteteRESUMEN
Novel coronavirus disease 2019 (COVID-19) causes pulmonary and cardiovascular disorders and has become a worldwide emergency. Myocardial injury can be caused by direct or indirect damage, particularly mediated by a cytokine storm, a disordered immune response that can cause myocarditis, abnormal coagulation, arrhythmia, acute coronary syndrome, and myocardial infarction. The present review focuses on the mechanisms of this viral infection, cardiac biomarkers, consequences, and the possible therapeutic role of purinergic and adenosinergic signalling systems. In particular, we focus on the interaction of the extracellular nucleotide adenosine triphosphate (ATP) with its receptors P2X1, P2X4, P2X7, P2Y1, and P2Y2 and of adenosine (Ado) with A2A and A3 receptors, as well as their roles in host immune responses. We suggest that receptors of purinergic signalling could be ideal candidates for pharmacological targeting to protect against myocardial injury caused by a cytokine storm in COVID-19, in order to reduce systemic inflammatory damage to cells and tissues, preventing the progression of the disease by modulating the immune response and improving patient quality of life.
Asunto(s)
Adenosina Trifosfato/metabolismo , COVID-19/inmunología , Enfermedades Cardiovasculares/virología , Receptores Purinérgicos/metabolismo , SARS-CoV-2 , Agonistas del Receptor de Adenosina A2/farmacología , COVID-19/metabolismo , Enfermedades Cardiovasculares/inmunología , Enfermedades Cardiovasculares/fisiopatología , Citocinas/metabolismo , Humanos , Isquemia Miocárdica/inmunología , Isquemia Miocárdica/fisiopatología , Isquemia Miocárdica/virología , Pandemias , Antagonistas Purinérgicos/farmacología , Receptor de Adenosina A2A/metabolismo , Receptor de Adenosina A3/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Tratamiento Farmacológico de COVID-19RESUMEN
Adenosine and nitric oxide act on the fine-tuning regulation of neural cardiovascular control in the nucleus tractus solitarius (NTS). Although the interaction between adenosine and NO is well known in the periphery, the mechanisms by which adenosine interferes in the dynamics of nitrergic neurotransmission, related to neural control of circulation, are not completely understood and might be relevant for individuals predisposed to hypertension. In this study we evaluate the interaction between adenosinergic and nitrergic systems in cell culture from the dorsomedial medulla oblongata of Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). Using quantification of nitrite levels, RT-PCR analysis and RNA interference we demonstrate that adenosine A1 (A1R) and A2a receptor (A2aR) agonists induce a concentration-dependent decrease and increase of nitrite and nNOS mRNA levels in cultured cells from WKY and SHR, respectively. These effects in nitrite levels are attenuated by the administration of A1R and A2aR selective antagonists, CPT and ZM 241385. Furthermore, knockdown of A1R and A2aR show an increase and decrease of nNOS mRNA levels, respectively. Pretreatment with the nonselective inhibitor of NOS, L-NAME, abolishes nitrite-increased levels triggered by CGS 21680 in WKY and SHR cells. Finally, it is shown that the cAMP-PKA pathway is involved in A1R and A2aR-mediated decrease and increase in nitrite levels in SHR and WKY cells. Our results highlight the influence of adenosine on nitric oxide levels in cultured cells from dorsal medulla oblongata of neonate WKY and SHR rats. In part, the modulatory profile is different in the SHR strain.
Asunto(s)
Adenosina/metabolismo , Hipertensión/metabolismo , Bulbo Raquídeo/metabolismo , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismo , Animales , Células Cultivadas , Femenino , Masculino , Agonistas del Receptor Purinérgico P1/farmacología , Antagonistas de Receptores Purinérgicos P1/farmacología , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKYRESUMEN
Estrogenic steroids and adenosine A2A receptors promote the wound healing and angiogenesis processes. However, so far, it is unclear whether estrogen may regulate the expression and pro-angiogenic activity of A2A receptors. Using in vivo analyses, we showed that female wild type (WT) mice have a more rapid wound healing process than female or male A2A-deficient mice (A2AKO) mice. We also found that pulmonary endothelial cells (mPEC) isolated from female WT mice showed higher expression of A2A receptor than mPEC from male WT mice. mPEC from female WT mice were more sensitive to A2A-mediated pro-angiogenic response, suggesting an ER and A2A crosstalk, which was confirmed using cells isolated from A2AKO. In those female cells, 17ß-estradiol potentiated A2A-mediated cell proliferation, an effect that was inhibited by selective antagonists of estrogen receptors (ER), ERα, and ERß. Therefore, estrogen regulates the expression and/or pro-angiogenic activity of A2A adenosine receptors, likely involving activation of ERα and ERß receptors. Sexual dimorphism in wound healing observed in the A2AKO mice process reinforces the functional crosstalk between ER and A2A receptors.
Asunto(s)
Estradiol/farmacología , Receptor alfa de Estrógeno/genética , Receptor beta de Estrógeno/genética , Neovascularización Fisiológica/efectos de los fármacos , Receptor de Adenosina A2A/genética , Heridas Penetrantes/genética , Adenosina/análogos & derivados , Adenosina/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Receptor alfa de Estrógeno/antagonistas & inhibidores , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/antagonistas & inhibidores , Receptor beta de Estrógeno/metabolismo , Femenino , Regulación de la Expresión Génica , Pulmón/citología , Pulmón/metabolismo , Masculino , Ratones , Ratones Noqueados , Neovascularización Fisiológica/genética , Fenetilaminas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Receptor Cross-Talk , Receptor de Adenosina A2A/metabolismo , Factores Sexuales , Transducción de Señal , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/genética , Heridas Penetrantes/tratamiento farmacológico , Heridas Penetrantes/metabolismo , Heridas Penetrantes/patologíaRESUMEN
We aim to investigate the role of A2A receptor in peritonitis-related sepsis by injection of a fecal solution (FS) as a model of polymicrobial infection. C57/black J6 wild-type (WT) and A2A-deficient mice (A2AKO) were exposed to sepsis induced by intraperitoneal injection of a FS (FS-induced peritonitis) or instead was injected with saline buffer (Sham). Survival rate and sepsis score were measured up to 48 h. The presence of bacteria in tissue homogenates was analyzed. Telemetry and speckle laser Doppler were used for systemic blood pressure and peripheral blood perfusion analysis, respectively. Histological analysis and identification of active caspase 3 were performed in selected organs, including the liver. The survival rate of A2AKO mice exposed to FS-induced peritonitis was significantly higher, and the sepsis score was lower than their respective WT counterpart. Injection of FS increases (50 to 150 folds) the number of colonies forming units in the liver, kidney, blood, and lung in WT mice, while these effects were significantly attenuated in A2AKO mice exposed to FS-induced peritonitis. A significant reduction in both systolic and diastolic blood pressure, as well as in the peripheral perfusion was observed in WT and A2AKO mice exposed to FS-induced peritonitis. Although, these last effects were significantly attenuated in A2AKO mice. Histological analysis showed a large perivascular infiltration of polymorphonuclear in the liver of WT and A2AKO mice exposed to FS-induced peritonitis, but again, this effect was attenuated in A2AKO mice. Finally, high expression of active caspase 3 was found only in the liver of WT mice exposed to FS-induced peritonitis. The absence of the A2A receptor increases the survival rate in mice exposed to polymicrobial sepsis. This outcome was associated with both hemodynamic compensation and enhanced anti-bacterial response.
Asunto(s)
Peritonitis/metabolismo , Receptor de Adenosina A2A/metabolismo , Sepsis/metabolismo , Animales , Presión Sanguínea/fisiología , Modelos Animales de Enfermedad , Ratones , Ratones Noqueados , Peritonitis/genética , Peritonitis/microbiología , Peritonitis/mortalidad , Receptor de Adenosina A2A/genética , Sepsis/genética , Sepsis/mortalidad , Tasa de SupervivenciaRESUMEN
Parkinson's disease (PD) signs and symptoms regularly include tremor. Interestingly, the nucleoside guanosine (GUO) has already proven to be effective in reducing reserpine-induced tremulous jaw movements (TJMs) in rodent models, thus becoming a promising antiparkinsonian drug. Here, we aimed at revealing the mechanism behind GUO antiparkinsonian efficacy by assessing the role of adenosine A1 and A2A receptors (A1R and A2AR) on GUO-mediated anti-tremor effects in the reserpinized mouse model of PD. Reserpinized mice showed elevated reactive oxygen species (ROS) production and cellular membrane damage in striatal slices assessed ex vivo and GUO treatment reversed ROS production. Interestingly, while the simultaneous administration of sub-effective doses of GUO (5 mg/kg) and SCH58261 (0.01 mg/kg), an A2AR antagonist, precluded reserpine-induced TJMs, these were ineffective on reverting ROS production in ex vivo experiments. Importantly, GUO was able to reduce TJM and ROS production in reserpinized mouse lacking the A2AR, thus suggesting an A2AR-independent mechanism of GUO-mediated effects. Conversely, the administration of DPCPX (0.75 mg/kg), an A1R antagonist, completely abolished both GUO-mediated anti-tremor effects and blockade of ROS production. Overall, these results indicated that GUO anti-tremor and antioxidant effects in reserpinized mice were A1R dependent but A2AR independent, thus suggesting a differential participation of adenosine receptors in GUO-mediated effects.
Asunto(s)
Guanosina/uso terapéutico , Enfermedad de Parkinson Secundaria/metabolismo , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismo , Temblor/metabolismo , Antagonistas del Receptor de Adenosina A1/farmacología , Antagonistas del Receptor de Adenosina A2 , Animales , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Guanosina/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Ratones , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/tratamiento farmacológico , Especies Reactivas de Oxígeno/metabolismo , Temblor/inducido químicamente , Temblor/tratamiento farmacológico , Xantinas/farmacologíaRESUMEN
Bipolar Disorder is a disorder characterized by alternating episodes of depression, mania or hypomania, or even mixed episodes. The treatment consists on the use of mood stabilizers, which imply serious adverse effects. Therefore, it is necessary to identify new therapeutic targets to prevent or avoid new episodes. Evidence shows that individuals in manic episodes present a purinergic system dysfunction. In this scenario, inosine is a purine nucleoside known to act as an agonist of A1 and A2A adenosine receptors. Thus, we aimed to elucidate the preventive effect of inosine on locomotor activity, changes in purine levels, and adenosine receptors density in a ketamine-induced model of mania in rats. Inosine pretreatment (25 mg/kg, oral route) prevented the hyperlocomotion induced by ketamine (25 mg/kg, intraperitoneal route) in the open-field test; however, there was no difference in hippocampal density of A1 and A2A receptors, where ketamine, as well as inosine, were not able to promote changes in immunocontent of the adenosine receptors. Likewise, no effects of inosine pretreatments or ketamine treatment were observed for purine and metabolic residue levels evaluated. In this sense, we suggest further investigation of signaling pathways involving purinergic receptors, using pharmacological strategies to better elucidate the action mechanisms of inosine on bipolar disorder. Despite the limitations, inosine administration could be a promising candidate for bipolar disorder treatment, especially by attenuating maniac phase symptoms, once it was able to prevent the hyperlocomotion induced by ketamine in rats.
Asunto(s)
Hipercinesia/inducido químicamente , Hipercinesia/prevención & control , Inosina/administración & dosificación , Ketamina/administración & dosificación , Locomoción/efectos de los fármacos , Manía/inducido químicamente , Animales , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipercinesia/metabolismo , Masculino , Manía/metabolismo , Ratas Wistar , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismoRESUMEN
Injured retinas in mammals do not regenerate and heal with loss of function. The adult retina of zebrafish self-repairs after damage by activating cell-intrinsic mechanisms, which are regulated by extrinsic signal interactions. Among relevant regulatory extrinsic systems, purinergic signaling regulates progenitor proliferation during retinogenesis and regeneration and glia proliferation in proliferative retinopathies. ATP-activated P2X7 (P2RX7) and adenosine (P1R) receptors are involved in the progression of almost all retinopathies leading to blindness. Here, we examined P2RX7 and P1R participation in the retina regenerative response induced by photoreceptor damage caused by a specific dose of CoCl2 . First, we found that treatment of uninjured retinas with a potent agonist of P2RX7 (BzATP) provoked photoreceptor damage and mitotic activation of multipotent progenitors. In CoCl2 -injured retinas, blockade of endogenous extracellular ATP activity on P2RX7 caused further neurodegeneration, Müller cell gliosis, progenitor proliferation, and microglia reactivity. P2RX7 inhibition in injured retinas also increased the expression of lin28a and tnfα genes, which are related to multipotent progenitor proliferation. Levels of hif1α, vegf3r, and vegfaa mRNA were enhanced by blockade of P2RX7 immediately after injury, indicating hypoxic like damage and endothelial cell growth and proliferation. Complete depletion of extracellular nucleotides with an apyrase treatment strongly potentiated cell death and progenitor proliferation induced with CoCl2 . Blockade of adenosine P1 and A2A receptors (A2A R) had deleterious effects and deregulated normal timing for progenitor and precursor cell proliferation following photoreceptor damage. ATP via P2RX7 and adenosine via A2A R are survival extracellular signals key for retina regeneration in zebrafish.
Asunto(s)
Regeneración Nerviosa/fisiología , Neuronas/patología , Células Fotorreceptoras de Vertebrados/metabolismo , Receptor de Adenosina A2A/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animales , Muerte Celular/fisiología , Cobalto/toxicidad , Degeneración Nerviosa/inducido químicamente , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Células Fotorreceptoras de Vertebrados/efectos de los fármacos , Células Fotorreceptoras de Vertebrados/patología , Pez CebraRESUMEN
Hypoxia is a condition that together with low pH, high amounts of reactive oxygen species (ROS), and increased adenosine levels characterize tumor microenvironment. Mast cells (MCs) are part of tumor microenvironment, but the effect of hypoxia on the production of MC-derived cytokines has not been fully described. Using the hypoxia marker pimonidazole in vivo, we found that MCs were largely located in the low-oxygen areas within B16-F1 mice melanoma tumors. In vitro, hypoxia promoted ROS production, a ROS-dependent increase of intracellular calcium, and the production of MCP 1 (CCL-2) in murine bone marrow-derived MCs. Hypoxia-induced CCL-2 production was sensitive to the antioxidant trolox and to nifedipine, a blocker of L-type voltage-dependent Ca2+ channels (LVDCCs). Simultaneously with CCL-2 production, hypoxia caused the ROS-dependent glutathionylation and membrane translocation of the α1c subunit of Cav1.2 LVDCCs. Relationship between ROS production, calcium rise, and CCL-2 synthesis was also observed when cells were treated with H2O2 In vivo, high CCL-2 production was detected on hypoxic zones of melanoma tumors (where tryptase-positive MCs were also found). Pimonidazole and CCL-2 positive staining diminished when B16-F1 cell-inoculated animals were treated with trolox, nifedipine, or the adenosine receptor 2A antagonist KW6002. Our results show that MCs are located preferentially in hypoxic zones of melanoma tumors, hypoxia-induced CCL-2 production in MCs requires calcium rise mediated by glutathionylation and membrane translocation of LVDCCs, and this mechanism of CCL-2 synthesis seems to operate in other cells inside melanoma tumors, with the participation of the adenosine receptor 2A.
Asunto(s)
Canales de Calcio Tipo L/metabolismo , Quimiocina CCL2/metabolismo , Mastocitos/inmunología , Melanoma Experimental/inmunología , Microambiente Tumoral/inmunología , Antagonistas del Receptor de Adenosina A2/farmacología , Animales , Antioxidantes/farmacología , Biopsia , Bloqueadores de los Canales de Calcio/farmacología , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/inmunología , Línea Celular Tumoral/trasplante , Quimiocina CCL2/inmunología , Peróxido de Hidrógeno/farmacología , Mastocitos/efectos de los fármacos , Mastocitos/metabolismo , Melanoma Experimental/patología , Ratones , Especies Reactivas de Oxígeno/metabolismo , Receptor de Adenosina A2A/metabolismo , Microambiente Tumoral/efectos de los fármacosAsunto(s)
Depresión/metabolismo , Receptor de Adenosina A2A/metabolismo , Suicidio/psicología , Adenosina/metabolismo , Depresión/fisiopatología , Trastorno Depresivo/metabolismo , Trastorno Depresivo/fisiopatología , Humanos , Conducta Impulsiva/fisiología , Receptor de Adenosina A2A/efectos de los fármacos , Receptores Purinérgicos/metabolismo , Ideación SuicidaRESUMEN
Guanosine, a guanine-based purine nucleoside, has been described as a neuromodulator that exerts neuroprotective effects in animal and cellular ischemia models. However, guanosine's exact mechanism of action and molecular targets have not yet been identified. Here, we aimed to elucidate a role of adenosine receptors (ARs) in mediating guanosine effects. We investigated the neuroprotective effects of guanosine in hippocampal slices from A2AR-deficient mice (A2AR-/-) subjected to oxygen/glucose deprivation (OGD). Next, we assessed guanosine binding at ARs taking advantage of a fluorescent-selective A2AR antagonist (MRS7396) which could engage in a bioluminescence resonance energy transfer (BRET) process with NanoLuc-tagged A2AR. Next, we evaluated functional AR activation by determining cAMP and calcium accumulation. Finally, we assessed the impact of A1R and A2AR co-expression in guanosine-mediated impedance responses in living cells. Guanosine prevented the reduction of cellular viability and increased reactive oxygen species generation induced by OGD in hippocampal slices from wild-type, but not from A2AR-/- mice. Notably, while guanosine was not able to modify MRS7396 binding to A2AR-expressing cells, a partial blockade was observed in cells co-expressing A1R and A2AR. The relevance of the A1R and A2AR interaction in guanosine effects was further substantiated by means of functional assays (i.e., cAMP and calcium determinations), since guanosine only blocked A2AR agonist-mediated effects in doubly expressing A1R and A2AR cells. Interestingly, while guanosine did not affect A1R/A2AR heteromer formation, it reduced A2AR agonist-mediated cell impedance responses. Our results indicate that guanosine-induced effects may require both A1R and A2AR co-expression, thus identifying a molecular substrate that may allow fine tuning of guanosine-mediated responses.
Asunto(s)
AMP Cíclico/metabolismo , Guanosina/farmacología , Hipocampo/metabolismo , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismo , Agonistas del Receptor de Adenosina A2/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , AMP Cíclico/genética , Femenino , Células HEK293 , Humanos , Masculino , Ratones , Ratones Mutantes , Plásmidos , Unión Proteica/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
2-Allylphenol (2-AP) is a synthetic phenylpropanoid, structurally related to cardanol, thymol, and ortho-eugenol. Phenylpropanoids are described in the literature as being capable of promoting biological activity. Due to the similarity between 2-AP and other bioactive phenylpropanoids, the present research aims at evaluating the antioxidant, antinociceptive, and anti-inflammatory potential of 2-AP in silico, in vitro, and in vivo. At 30 min prior to the start of in vivo pharmacological testing, administration of 2-AP (25, 50, 75, and 100 mg/kg i.p.), morphine (6 mg/kg i.p.), dexamethasone (2 mg/kg s.c.), or vehicle alone was performed. In the acetic acid-induced abdominal writhing tests, pretreatment with 2-AP significantly reduced the number of abdominal writhes, as well as decreased licking times in the glutamate and formalin tests. Investigation of the mechanism of action using the formalin model led to the conclusion that the opioid system does not participate in its activity. However, the adenosinergic system is involved. In the peritonitis tests, 2-AP inhibited leukocyte migration and reduced releases of proinflammatory mediators TNF-α and IL-1ß. In vitro antioxidant assays demonstrated that 2-AP presents significant ability to sequester superoxide radicals. In silico docking studies confirmed interaction between 2-AP and the adenosine A2a receptor through hydrogen bonds with the critical asparagine 253 residues present in the active site. Investigation of 2-AP demonstrated its nociception inhibition and ability to reduce reactive oxygen species. Its interaction with A2a receptors may well be related to proinflammatory cytokines TNF-α and IL-1ß reduction activity, corroborating its antinociceptive effect.
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Analgésicos/farmacología , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Interleucina-1beta/metabolismo , Fenoles/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Masculino , Ratones , Simulación del Acoplamiento Molecular , Peritonitis/tratamiento farmacológico , Peritonitis/metabolismo , Peritonitis/patología , Fenoles/química , Receptor de Adenosina A2A/química , Receptor de Adenosina A2A/metabolismoRESUMEN
Cannabidiol (CBD) is a natural compound with psychoactive therapeutic properties well described. Conversely, the immunological effects of CBD are still poorly explored. In this study, the potential anti-inflammatory effects and underlying mechanisms of CBD and its analog Dimethyl-Heptyl-Cannabidiol (DMH-CBD) were investigated using RAW 264.7 macrophages. CBD and DMH-CBD suppressed LPS-induced TNF production and NF-kB activity in a concentration-dependent manner. Both compounds reduced the NF-kB activity in a µM concentration range: CBD (IC50â¯=â¯15⯵M) and DMH-CBD (IC50â¯=â¯38⯵M). However, the concentrations of CBD that mediated NF-kB inhibition were similar to those that cause cytotoxicity (LC50â¯=â¯58⯵M). Differently, DMH-CBD inhibited the NF-kB activation without cytotoxic effects at the same concentrations, although it provokes cytotoxicity at long-term exposure. The inhibitory action of the DMH-CBD on NF-kB activity was not related to the reduction in IkBα degradation or either p65 (NF-kB) translocation to the nucleus, although it decreased p38 MAP kinase phosphorylation. Additionally, 8-(3-Chlorostyryl) caffeine (CSC), an A2A antagonist, reversed the effect of DMH-CBD on NF-kB activity in a concentration-dependent manner. Collectively, our results demonstrated that CBD reduces NF-kB activity at concentrations intimately associated with those that cause cell death, whereas DMH-CBD decreases NF-kB activity at non-toxic concentrations in an A2A receptor dependent-manner.
Asunto(s)
Agonistas del Receptor de Adenosina A2/farmacología , Cannabidiol/análogos & derivados , Cannabidiol/farmacología , Macrófagos/efectos de los fármacos , FN-kappa B/metabolismo , Receptor de Adenosina A2A/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Agonistas del Receptor de Adenosina A2/toxicidad , Animales , Cannabidiol/química , Cannabidiol/toxicidad , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Concentración 50 Inhibidora , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Fosforilación , Células RAW 264.7 , Receptor de Adenosina A2A/metabolismo , Vías Secretoras , Transducción de Señal , Células THP-1 , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Adenosine receptors (ARs) belong to family A of GPCRs that are involved in many diseases, including cerebral and cardiac ischemic diseases, immune and inflammatory disorders, etc. Thus, they represent important therapeutic targets to treat these conditions. Computational techniques such as molecular dynamics (MD) simulations permit researchers to obtain structural information about these proteins, and principal component analysis (PCA) allows for the identification of collective motions. There are available structures for the active form (3QAK) and the inactive form (3EML) of A2AR which permit us to gain insight about their activation/inactivation mechanism. In this work, we have proposed an inverse strategy using MD simulations where the active form was coupled to the antagonist caffeine and the inactive form was coupled to adenosine agonist. Moreover, we have included four reported thermostabilizing mutations in the inactive form to study A2AR structural differences under different conditions. Some observations stand out from the PCA studies. For instance, the apo structures showed remarkable similarities, and the principal components (PCs) were rearranged in a ligand-dependent manner. Additionally, the active conformation was less stable compared to the inactive one. Some PCs inverted their direction in the presence of a ligand, and comparison of the PCs between 3EML and 3EML_ADN showed that adenosine induced major changes in the structure of A2AR. Rearrangement of PCs precedes and drives conformational changes that occur after ligand binding. Knowledge about these conformational changes provides important insights about the activity of A2AR.