RESUMO
The role of adenosine receptors in fascial manipulation-induced analgesia has not yet been investigated. The purpose of this study was to evaluate the involvement of the adenosine A1 receptor (A1R) in the antihyperalgesic effect of plantar fascia manipulation (PFM), specifically in mice with peripheral inflammation. Mice injected with Complete Freund's Adjuvant (CFA) underwent behavioral, i.e. mechanical hyperalgesia and edema. The mice underwent PFM for either 3, 9 or 15 min. Response frequency to mechanical stimuli was then assessed at 24 and 96 h after plantar CFA injection. The adenosinergic receptors were assessed by systemic (intraperitoneal, i.p.), central (intrathecal, i.t.), and peripheral (intraplantar, i.pl.) administration of caffeine. The participation of the A1R was investigated using the 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), a selective A1R subtype antagonist. PFM inhibited mechanical hyperalgesia induced by CFA injection and did not reduce paw edema. Furthermore, the antihyperalgesic effect of PFM was prevented by pretreatment of the animals with caffeine given by i.p., i.pl., and i.t. routes. In addition, i.pl. and i.t. administrations of DPCPX blocked the antihyperalgesia caused by PFM. These observations indicate that adenosine receptors mediate the antihyperalgesic effect of PFM. Caffeine's inhibition of PFM-induced antihyperalgesia suggests that a more precise understanding of how fascia-manipulation and caffeine interact is warranted.
Assuntos
Modelos Animais de Doenças , Adjuvante de Freund , Hiperalgesia , Inflamação , Receptor A1 de Adenosina , Xantinas , Animais , Receptor A1 de Adenosina/metabolismo , Receptor A1 de Adenosina/efeitos dos fármacos , Camundongos , Masculino , Hiperalgesia/tratamento farmacológico , Hiperalgesia/metabolismo , Inflamação/metabolismo , Inflamação/tratamento farmacológico , Xantinas/farmacologia , Fáscia/efeitos dos fármacos , Cafeína/farmacologia , Cafeína/administração & dosagem , Analgesia/métodos , Medula Espinal/metabolismo , Medula Espinal/efeitos dos fármacos , Antagonistas do Receptor A1 de Adenosina/farmacologiaRESUMO
Peripheral tramadol's delivery in the temporomandibular joint (TMJ) leads to significant analgesic outcomes and inflammatory process's resolvent actions. Mechanistically, these properties are apart from the opioid system. Nevertheless, the molecular mechanisms behind these effects are still unclear. Therefore, the present study investigated the hypothesis that adenosine A1 receptors are involved in the tramadol-induced analgesic and anti-inflammatory effects in the TMJ. Animals were pretreated with an intra-TMJ injection of DPCPX (antagonist of A1 receptor) or tramadol and subsequent nociceptive challenge with an intra-TMJ injection of 1.5% formalin. For over 45 min, the nociceptive behavior was quantitated, and by the end of this assessment, the animals were euthanized, and the periarticular tissue was collected. Lastly, an in vitro assay of BMDM (Bone Marrow-Derived Macrophages) was performed to investigate tramadol activity in macrophages. The intra-TMJ injection of tramadol ameliorates formalin-induced hypernociception along with inhibiting leukocyte migration. The tramadol's peripheral anti-inflammatory effect was mediated by the adenosine A1 receptor and was associated with increased protein expression of α2a-adrenoceptor in the periarticular tissues (p < 0.05: ANOVA, Tukey's test). Also, tramadol inhibits formalin-induced leukocyte migration and protein expression of P2X7 receptors in the periarticular tissue (p < 0.05); however, DPCPX did not alter this effect (p > 0.05). Moreover, DPCPX significantly reduced the protein expression of the M2 macrophage marker, MRC1. In BMDM, tramadol significantly reduces inflammatory cytokines release, and DPCPX abrogated this effect (p < 0.05). We identify tramadol's peripheral effect is mediated by adenosine A1 receptor, possibly expressed in macrophages in the TMJ tissue. We also determined an important discovery related to the activation of A1R/α2a receptors in the tramadol action.
Assuntos
Agonistas do Receptor A1 de Adenosina/administração & dosagem , Artralgia/tratamento farmacológico , Receptor A1 de Adenosina/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Tramadol/administração & dosagem , Analgésicos Opioides/administração & dosagem , Animais , Anti-Inflamatórios/administração & dosagem , Artralgia/induzido quimicamente , Artralgia/imunologia , Artralgia/patologia , Modelos Animais de Doenças , Formaldeído/administração & dosagem , Formaldeído/toxicidade , Humanos , Injeções Intra-Articulares , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Nociceptividade/efeitos dos fármacos , Ratos , Articulação Temporomandibular/efeitos dos fármacos , Articulação Temporomandibular/imunologia , Articulação Temporomandibular/patologia , Xantinas/administração & dosagem , Xantinas/toxicidadeRESUMO
The role of peripheral adenosine receptors in pain is a controversial issue and seems to be quite different from the roles of spinal and central adenosine receptors. The present study is aimed at clarifying the role of these receptors in peripheral nociception. To clarify this, studies were done on Swiss mice with adenosine receptor agonists and antagonists. Nociceptive behavior was induced by subcutaneous injection of glutamate (10 µmol) into the ventral surface of the hind paw of mice. Statistical analyses were performed by one-way ANOVA followed by the Student-Newman-Keuls post hoc test. Results showed that intraplantar (i.pl.) administration of N6-cyclohexyl-adenosine (CHA), an adenosine A1 receptor agonist, at 1 or 10 µg/paw significantly reduced glutamate-induced nociception (p<0.01 and p<0.001 vs. vehicle, respectively, n=8-10). In contrast, i.pl. injection of hydrochloride hydrate (CGS21680, an adenosine A2A receptor agonist) (1 µg/paw) induced a significant increase in glutamate-induced nociception compared to the vehicle (p<0.05, n=8), while 4-(-2-[7-amino-2-{2-furyl}{1,2,4}triazolo{2,3-a} {1,3,5}triazin-5-yl-amino]ethyl)phenol (ZM241385, an adenosine A2A receptor antagonist) (20 µg/paw) caused a significant reduction (p<0.05, n=7-8). There were no significant effects on i.pl. administration of four additional adenosine receptor drugs-8-cyclopentyl-1,3-dipropylxanthine (DPCPX, an A1 antagonist, 1-10 µg/paw), N(6)-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl]adenosine (DPMA, an A2B agonist, 1-100 µg/paw), alloxazine (an A2B antagonist, 0.1-3 µg/paw), and 2-hexyn-1-yl-N(6)-methyladenosine (HEMADO) (an A3 agonist, 1-100 µg/paw) (p>0.05 vs. vehicle for all tests). We also found that prior administration of DPCPX (3 µg/paw) significantly blocked the anti-nociceptive effect of CHA (1 µg/paw) (p<0.05, n=7-9). Similarly, ZM241385 (20 µg/paw) administered prior to CGS21680 (1 µg/paw) significantly blocked CGS21680-induced exacerbation of nociception (p<0.05, n=8). Finally, inosine (10 and 100 µg/paw), a novel endogenous adenosine A1 receptor agonist recently reported by our research group, was also able to reduce glutamate-induced nociception (p<0.001 vs. vehicle, n=7-8). Interestingly, as an A1 adenosine receptor agonist, the inosine effect was significantly blocked by the A1 antagonist DPCPX (3 µg/paw) (p<0.05, n=7-9) but not by the A2A antagonist ZM241385 (10 µg/paw, p>0.05). In summary, these results demonstrate for the first time that i.pl administration of inosine induces an anti-nociceptive effect, similar to that elicited by CHA and possibly mediated by peripheral adenosine A1 receptor activation. Moreover, our results suggest that peripheral adenosine A2A receptor activation presents a pro-nociceptive effect, exacerbating glutamate-induced nociception independent of inosine-induced anti-nociceptive effects.
Assuntos
Glutamatos , Nociceptividade/efeitos dos fármacos , Dor/induzido quimicamente , Dor/psicologia , Sistema Nervoso Periférico/efeitos dos fármacos , Receptores Purinérgicos P1/efeitos dos fármacos , Agonistas do Receptor A1 de Adenosina/farmacologia , Antagonistas do Receptor A1 de Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Feminino , Pé , Glutamatos/administração & dosagem , Injeções , Inosina/farmacologia , Masculino , Camundongos , Medição da Dor/efeitos dos fármacos , Receptor A2A de Adenosina/efeitos dos fármacosRESUMO
Extracellular adenosine plays important roles in modulating the immune responses. We have previously demonstrated that infection of dendritic cells (DC) by Leishmania amazonensis leads to increased expression of CD39 and CD73 and to the selective activation of the low affinity A2B receptors (A2B R), which contributes to DC inhibition, without involvement of the high affinity A2A R. To understand this apparent paradox, we now characterized the alterations of both adenosine receptors in infected cells. With this aim, bone marrow-derived DC from C57BL/6J mice were infected with metacyclic promastigotes of L. amazonensis. Fluorescence microscopy revealed that L. amazonensis infection stimulates the recruitment of A2B R, but not of A2A R, to the surface of infected DC, without altering the amount of mRNA or the total A2B R density, an effect dependent on lipophosphoglycan (LPG). Log-phase promastigotes or axenic amastigotes of L. amazonensis do not stimulate A2B R recruitment. A2B R clusters are localized in caveolin-rich lipid rafts and the disruption of these membrane domains impairs A2B R recruitment and activation. More importantly, our results show that A2B R co-localize with CD39 and CD73 forming a "purinergic cluster" that allows for the production of extracellular adenosine in close proximity with these receptors. We conclude that A2B R activation by locally produced adenosine constitutes an elegant and powerful evasion mechanism used by L. amazonensis to down-modulate the DC activation.
Assuntos
5'-Nucleotidase/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Caveolina 1/metabolismo , Células Dendríticas/imunologia , Leishmaniose/imunologia , Microdomínios da Membrana/imunologia , Receptor A2B de Adenosina/metabolismo , Animais , Células Dendríticas/metabolismo , Células Dendríticas/parasitologia , Células Dendríticas/patologia , Imunidade , Imunomodulação , Leishmania/imunologia , Leishmaniose/metabolismo , Leishmaniose/parasitologia , Leishmaniose/patologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/parasitologia , Macrófagos/patologia , Masculino , Microdomínios da Membrana/parasitologia , Microdomínios da Membrana/patologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
This study aimed to evaluate the effect of a single administration of IB-MECA, an A3 adenosine receptor agonist, upon the nociceptive response and central biomarkers of rats submitted to chronic pain models. A total of 136 adult male Wistar rats were divided into two protocols: (1) chronic inflammatory pain (CIP) using complete Freund's adjuvant and (2) neuropathic pain (NP) by chronic constriction injury of the sciatic nerve. Thermal and mechanical hyperalgesia was measured using von Frey (VF), Randal-Selitto (RS), and hot plate (HP) tests. Rats were treated with a single dose of IB-MECA (0.5 µmol/kg i.p.), a vehicle (dimethyl sulfoxide-DMSO), or positive control (morphine, 5 mg/kg i.p.). Interleukin 1ß (IL-1ß), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) levels were measured in the brainstem and spinal cord using enzyme-linked immunosorbent assay (ELISA). The establishment of the chronic pain (CIP or NP) model was observed 14 days after induction by a decreased nociceptive threshold in all three tests (GEE, P < 0.05). The antinociceptive effect of a single dose of IB-MECA was observed in both chronic pain models, but this was more effective in NP model. There was an increase in IL-1ß levels promoted by CIP. NP model promoted increase in the brainstem BDNF levels, which was reversed by IB-MECA.
Assuntos
Adenosina/análogos & derivados , Analgésicos/farmacologia , Dor Crônica/metabolismo , Adenosina/farmacologia , Animais , Modelos Animais de Doenças , Inflamação/metabolismo , Masculino , Neuralgia/metabolismo , Ratos , Ratos WistarRESUMO
This review aims to analyze and contrast the neurological effects associated with the use of caffeine on neurobehavior and neuroprotection in animal models. Caffeine belongs to the group of methylxanthines that exert a direct effect on adenosine receptors associated with inhibitory or excitatory G proteins, generating modification of cyclic AMP activity and intracellular calcium flow which produces alterations in the modulation system of the neurotransmitters dopamine and glutamate. The regulation of the neurotransmission systems generates protection against the inflammation of the central nervous system, by activation of the microglia and reinforcement of the blood-brain barrier. This drug will also restore cognition or prevent memory loss in Parkinson's or Alzheimer's diseases. It is important to establish new study models in other species to assess whether the behavior of the molecule is similar and to obtain other clinical applications in its behavioral and neuroprotective effects.(AU)
Assuntos
Animais , Hipotálamo/efeitos dos fármacos , Hipotálamo/fisiopatologia , Estimulantes do Sistema Nervoso Central/análise , Estimulantes do Sistema Nervoso Central/farmacologia , Estimulantes do Sistema Nervoso Central/uso terapêutico , Cafeína , Doenças NeurodegenerativasRESUMO
This review aims to analyze and contrast the neurological effects associated with the use of caffeine on neurobehavior and neuroprotection in animal models. Caffeine belongs to the group of methylxanthines that exert a direct effect on adenosine receptors associated with inhibitory or excitatory G proteins, generating modification of cyclic AMP activity and intracellular calcium flow which produces alterations in the modulation system of the neurotransmitters dopamine and glutamate. The regulation of the neurotransmission systems generates protection against the inflammation of the central nervous system, by activation of the microglia and reinforcement of the blood-brain barrier. This drug will also restore cognition or prevent memory loss in Parkinson's or Alzheimer's diseases. It is important to establish new study models in other species to assess whether the behavior of the molecule is similar and to obtain other clinical applications in its behavioral and neuroprotective effects.
Assuntos
Animais , Estimulantes do Sistema Nervoso Central/análise , Estimulantes do Sistema Nervoso Central/farmacologia , Estimulantes do Sistema Nervoso Central/uso terapêutico , Hipotálamo/efeitos dos fármacos , Hipotálamo/fisiopatologia , Cafeína , Doenças NeurodegenerativasRESUMO
Diabetic nephropathy (DN) is considered the main cause of kidney disease in which myofibroblasts lead to renal fibrosis. Macrophages were recently identified as the major source of myofibroblasts in a process known as macrophage-myofibroblast transition (MMT). Adenosine levels increase during DN and in vivo administration of MRS1754, an antagonist of the A2B adenosine receptor (A2BAR), attenuated glomerular fibrosis (glomerulosclerosis). We aimed to investigate the association between A2BAR and MMT in glomerulosclerosis during DN. Kidneys/glomeruli of non-diabetic, diabetic, and MRS1754-treated diabetic (DM+MRS1754) rats were processed for histopathologic, transcriptomic, flow cytometry, and cellular in vitro analyses. Macrophages were used for in vitro cell migration/transmigration assays and MMT studies. In vivo MRS1754 treatment attenuated the clinical and histopathological signs of glomerulosclerosis in DN rats. Transcriptomic analysis demonstrated a decrease in chemokine-chemoattractants/cell-adhesion genes of monocytes/macrophages in DM+MRS1754 glomeruli. The number of intraglomerular infiltrated macrophages and MMT cells increased in diabetic rats. This was reverted by MRS1754 treatment. In vitro cell migration/transmigration decreased in macrophages treated with MRS1754. Human macrophages cultured with adenosine and/or TGF-ß induced MMT, a process which was reduced by MRS1754. We concluded that pharmacologic blockade of A2BAR attenuated some clinical signs of renal dysfunction and glomerulosclerosis, and decreased intraglomerular macrophage infiltration and MMT in DN rats.
Assuntos
Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Macrófagos/patologia , Monócitos/patologia , Miofibroblastos/patologia , Receptor A2B de Adenosina/metabolismo , Acetamidas/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Biomarcadores/metabolismo , Moléculas de Adesão Celular/metabolismo , Quimiocinas/metabolismo , Fatores Quimiotáticos/farmacologia , Fibrose , Humanos , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/metabolismo , Purinas/farmacologia , Ratos Sprague-Dawley , Transcrição Gênica/efeitos dos fármacosRESUMO
Clostridium difficile causes intestinal inflammation, which increases adenosine. We compared the expression of adenosine receptors (AR) subtypes A1, A2A, A2B, and A3 in HCT-8, IEC-6 cells, and isolated intestinal epithelial cells, challenged or not with Clostridium difficile toxin A and B (TcdA and TcdB) or infection (CDI). In HCT-8, TcdB induced an early A2BR expression at 6 h and a late A2AR expression at 6 and 24 h. In addition, both TcdA and TcdB increased IL-6 expression at all time-points (peak at 6 h) and PSB603, an A2BR antagonist, decreased IL-6 expression and production. In isolated cecum epithelial cells, TcdA induced an early expression of A2BR at 2s and 6 h, followed by a late expression of A2AR at 6 and 24 h and of A1R at 24 h. In CDI, A2AR and A2BR expressions were increased at day 3, but not at day 7. ARs play a role in regulating inflammation during CDI by inducing an early pro-inflammatory and a late anti-inflammatory response. The timing of interventions with AR antagonist or agonists may be of relevance in treatment of CDI.
Assuntos
Animais , Toxinas Bacterianas , Clostridioides difficile , Infecções por Clostridium , Receptores Purinérgicos P1/metabolismo , Proteínas de Bactérias , Regulação para Cima , Interleucina-6 , Modelos Animais de Doenças , Enterotoxinas , Infecções , Anti-InflamatóriosRESUMO
Diabetic nephropathy (DN) is the main cause of end-stage renal disease, which remains incurable. The progression of DN is associated with progressive and irreversible renal fibrosis and also high levels of adenosine. Our aim was to evaluate the effects of ADORA3 antagonism on renal injury in streptozotocin-induced diabetic rats. An ADORA3 antagonist that was administered in diabetic rats greatly inhibited the levels of inflammatory interleukins IL-1ß and IL-18, meanwhile when adenosine deaminase was administered, there was a non-selective attenuation of the inflammatory mediators IL-1ß, IL-18, IL-6, and induction of IL-10. The ADORA3 antagonist attenuated the high glucose-induced activation of caspase 1 in HK2 cells in vitro. Additionally, ADORA3 antagonisms blocked the increase in caspase 1 and the nuclear localization of NFκB in the renal tubular epithelium of diabetic rats, both events that are involved in regulating the production and activation of IL-1ß and IL-18. The effects of the A3 receptor antagonist resulted in the attenuation of kidney injury, as evidenced by decreased levels of the pro-fibrotic marker α-SMA at histological levels and the restoration of proteinuria in diabetic rats. We conclude that ADORA3 antagonism represents a potential therapeutic target that mechanistically works through the selective blockade of the NLRP3 inflammasome.
Assuntos
Antagonistas do Receptor A3 de Adenosina/administração & dosagem , Caspase 1/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Antagonistas do Receptor A3 de Adenosina/farmacologia , Adenosina Desaminase/efeitos adversos , Animais , Linhagem Celular , Diabetes Mellitus Experimental/enzimologia , Nefropatias Diabéticas/induzido quimicamente , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Injeções Intraperitoneais , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/enzimologia , Masculino , Ratos , EstreptozocinaRESUMO
Cigarette smoking is directly associated with lung cancer. Non-small cell lung carcinoma (NSCLC) represents approximately 80% from all types of lung cancer. This latter is hard to diagnose and to treat due to the lack of symptoms in early stages of the disease. The aim of this study was to evaluate ADA activity and the expression of P2X7, A1, and A2A receptors and in lymphocytes. In addition, the profile of pro-inflammatory and anti-inflammatory cytokines serum levels of patients with lung cancer in advanced stage was evaluated. Patients (n = 13) previously treated for lung cancer at stage IV (UICC) with chemotherapy had their blood collected. Cancer patients showed a decrease in ADA activity and an increase in A1 receptor expression in lymphocytes when compared to the control group. Moreover, patients exhibited an increase in IL-6 and TNF-α, while IL-17 and INF-Ï serum levels were lower in patients with lung cancer. The decreased ADA activity and the increase in A1 receptor expression may contribute to adenosine pro-tumor effects by increasing IL-6 and TNF-α and decreasing IL-17 and INF-γ serum levels. Our data show an indirect evidence that purinergic signaling may have a role in promoting a profile of cytokines levels that favors tumor progression.
Assuntos
Adenosina Desaminase/metabolismo , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Linfócitos/enzimologia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Citocinas/sangue , Feminino , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/metabolismo , Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Receptores Purinérgicos/metabolismo , Transdução de SinaisRESUMO
Glioblastoma (GBM) is the brain tumor with the worst prognosis composed of a cell subpopulation called Glioblastoma Stem-like Cells (GSCs) responsible for tumor recurrence mediated by cell invasion. GSCs persist in a hypoxic microenvironment which promotes extracellular adenosine production and activation of the A3 Adenosine Receptor (A3AR), therefore, the aim of this study was to determine the role of extracellular adenosine and A3AR on GSCs invasion under hypoxia. GSCs were obtained from a U87MG cell line and primary cultures of GBM patients, and then incubated under normoxia or hypoxia. Gene expression was evaluated by RNAseq, RT-qPCR, and western blot. Cell migration was measured by spreading and transwell boyden chamber assays; cell invasion was evaluated by Matrigel-coated transwell, ex vivo brain slice, and in vivo xenograft assays. The contribution of A3AR on cell migration/invasion was evaluated using the A3AR antagonist, MRS1220. Extracellular adenosine production was higher under hypoxia than normoxia, mainly by the catalytic action of the prostatic acid phosphatase (PAP), promoting cell migration/invasion in a HIF-2-dependent process. A3AR blockade decreased cell migration/invasion and the expression of Epithelial-Mesenchymal Transition markers. In conclusion, high levels of extracellular adenosine production enhance cell migration/invasion of GSCs, through HIF-2/PAP-dependent activation of A3AR under hypoxia.
Assuntos
Adenosina/metabolismo , Neoplasias Encefálicas/metabolismo , Movimento Celular , Glioblastoma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Receptor A3 de Adenosina/metabolismo , Fosfatase Ácida/genética , Fosfatase Ácida/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Camundongos Endogâmicos NOD , Camundongos SCID , Invasividade Neoplásica , Células-Tronco Neoplásicas/patologia , Receptor A3 de Adenosina/genética , Transdução de Sinais , Células Tumorais Cultivadas , Hipóxia Tumoral , Microambiente TumoralRESUMO
Genetic variants involved in adenosine metabolism and its receptors were associated with increased risk for psychiatric disorders, including anxiety, depression, and schizophrenia. Here, we examined an association between a single nucleotide polymorphism in A2A receptor gene (ADORA2A, rs2298383 SNP) with current depressive episode and symptom profile. A total of 1253 individuals from a cross-sectional population-based study were analyzed by the Mini International Neuropsychiatric Interview 5.0. Our data showed that the TT genotype of ADORA2A rs2298383 SNP was associated with reduced risk for depression when compared to the CC/CT genotypes (p = 0.020). This association remained significant after adjusting for confounding variables such as smoking, gender, socioeconomic class, and ethnicity (OR = 0.631 (95% CI 0.425-0.937); p = 0.022). Regarding the symptoms associated with depression, we evaluated the impact of the ADORA2A SNP in the occurrence of sad/discouraged mood, anhedonia, appetite changes, sleep disturbances, motion changes, energy loss, feelings of worthless or guilty, difficulty in concentrating, and presence of bad thoughts. Notably, the TT genotype was independently associated with reduced sleep disturbances (OR = 0.438 (95% CI 0.258-0.743); p = 0.002) and less difficulty in concentrating (OR = 0.534 (95% CI 0.316-0.901; p = 0.019). The cross-sectional design cannot evaluate the cause-effect relationship and did not evaluate the functional consequences of this polymorphism. Our data support an important role for ADORA2A rs2298383 SNP in clinical heterogeneity associated with depression. The presence of the TT genotype was associated with decrease risk for current depression and disturbances in sleep and attention, two of the most common symptoms associated with this disorder.
Assuntos
Depressão/genética , Predisposição Genética para Doença/genética , Receptor A2A de Adenosina/genética , Adolescente , Adulto , Estudos Transversais , Feminino , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
Glioblastoma (GBM) is a neoplasm characterized by an extensive blood vessel network. Hypoxic niches of GBM can induce tumorigenic properties of a small cell subpopulation called Glioblastoma stem-like cells (GSCs) and can also increase extracellular adenosine generation which activates the A3 adenosine receptor (A3AR). Moreover, GSCs potentiates the persistent neovascularization in GBM. The aim of this study was to determine if A3AR blockade can reduce the vasculogenesis mediated by the differentiation of GSCs to Endothelial Cells (ECs) under hypoxia. We evaluated the expression of endothelial cell markers (CD31, CD34, CD144, and vWF) by fluorescence-activated cell sorting (FACS), and vascular endothelial growth factor (VEGF) secretion by ELISA using MRS1220 (A3AR antagonist) under hypoxia. We validate our results using U87MG-GSCs A3AR knockout (GSCsA3-KO). The effect of MRS1220 on blood vessel formation was evaluated in vivo using a subcutaneous GSCs-tumor model. GSCs increased extracellular adenosine production and A3AR expression under hypoxia. Hypoxia also increased the percentage of GSCs positive for endothelial cell markers and VEGF secretion, which was in turn prevented when using MRS1220 and in GSCsA3-KO. Finally, in vivo treatment with MRS1220 reduced tumor size and blood vessel formation. Blockade of A3AR decreases the differentiation of GSCs to ECs under hypoxia and in vivo blood vessel formation.
Assuntos
Diferenciação Celular , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Glioblastoma/metabolismo , Glioblastoma/patologia , Receptor A3 de Adenosina/metabolismo , Adenosina/farmacologia , Antagonistas do Receptor A3 de Adenosina/farmacologia , Animais , Biomarcadores Tumorais/metabolismo , Diferenciação Celular/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Células Endoteliais/efeitos dos fármacos , Humanos , Masculino , Modelos Biológicos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Ratos Sprague-DawleyRESUMO
Hypertension is a risk factor for cardiovascular diseases, which have been associated with dysfunction of sympathetic and purinergic neurotransmission. Therefore, herein, we evaluated whether modifications of adenosine receptor signaling may contribute to the cardiac dysfunction observed in hypertension. Isolated right atria from spontaneously hypertensive (SHR) or normotensive Wistar rats (NWR) were used to investigate the influence of adenosine receptor signaling cascade in the cardiac chronotropism. Our results showed that adenosine, the endogenous agonist of adenosine receptors, and CPA, a selective agonist of A1 receptor, decreased the atrial chronotropism of NWR and SHR in a concentration- and time-dependent manner, culminating in cardiac arrest (0 bpm). Interestingly, a 3-fold lower concentration of adenosine was required to induce the negative chronotropic effect in SHR atria. Pre-incubation of tissues from both strains with DPCPX, a selective A1 receptor antagonist, inhibited the negative chronotropic effect of CPA, while simultaneous inhibition of A2 and A3 receptors, with ZM241385 and MRS1523, did not change the adenosine chronotropic effects. Moreover, 1 µg/ml pertussis toxin, which inactivates the Gαi protein subunit, reduced by 80% the negative chronotropic effects of adenosine in the NWR atrium, with minor effects in SHR tissue. These data indicate that the negative chronotropic effect of adenosine in right atrium depends exclusively on the activation of A1 receptors. Moreover, the distinct responsiveness of NWR and SHR atria to pertussis toxin reveals that the enhanced negative chronotropic response of SHR right atrium is probably due to an increased activity of Gαi protein-mediated.
Assuntos
Adenosina/fisiologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/fisiologia , Átrios do Coração/fisiopatologia , Hipertensão/fisiopatologia , Receptor A1 de Adenosina/fisiologia , Animais , Masculino , Ratos Endogâmicos SHR , Ratos Wistar , Transdução de SinaisRESUMO
In the right atrium (RA), adenosine and acetylcholine inhibit the pacemaker function of the sinoatrial node and induce cardiac arrest. Pre-incubation of receptor antagonists is known to inhibit the cardiac arrest induced by these agonists; however, the effect of antagonist administration after established cardiac arrest has not been described. Therefore, we assessed whether specific receptor antagonists could revert cardiac arrest induced by adenosine and muscarinic receptors activation. RA isolated from adults Wistar rats were mounted in an organ bath containing Krebs solution. Cardiac arrest was induced by adenosine or ATP (1mM), the A1 adenosine receptor agonist CPA (0.1-1µM), and muscarinic receptor agonists, carbachol (0.3-1µM) and acetylcholine (1mM). After establishing the cardiac arrest, the A1 adenosine receptor antagonist DPCPX (0.3-30µM), the muscarinic receptor antagonist atropine (10nM to 100µM) or the phosphodiesterase inhibitor IBMX (10-300µM) were incubated in order to check for the return of spontaneous contractions. DPCPX reversed the cardiac arrest induced by adenosine, ATP and CPA. In addition, atropine reversed the cardiac arrest induced by carbachol. Unexpectedly, DPCPX also reversed the cardiac arrest induced by carbachol. Similarly to DPCPX, the phosphodiesterase inhibitor IBMX reversed the cardiac arrest induced by adenosine, CPA and carbachol. The antagonism of adenosine and acetylcholine receptors activation, as well as phosphodiesterase inhibition, are able to revert cardiac arrest. DPCPX restore spontaneous contractions via the selective antagonism of A1 adenosine receptor and through a secondary mechanism likely related to phosphodiesterase inhibition.
Assuntos
Agonistas do Receptor A1 de Adenosina/farmacologia , Parada Cardíaca/induzido quimicamente , Parada Cardíaca/tratamento farmacológico , Agonistas Muscarínicos/farmacologia , Receptor A1 de Adenosina/metabolismo , Receptores Muscarínicos/metabolismo , Xantinas/farmacologia , Animais , Carbacol/farmacologia , Masculino , Ratos , Ratos Wistar , Xantinas/uso terapêuticoRESUMO
Sleep loss induces a low-grade inflammatory status characterized by a subtle but sustained increase of pro-inflammatory mediators, which are key regulators of blood-brain barrier function. To investigate the influence of inflammatory status on blood-brain barrier dysfunction induced by sleep restriction we performed an experiment using two strains of mice with different immunological backgrounds, C57BL/6 mice that have a predominant pro-inflammatory response and BALB/c mice that have a predominant anti-inflammatory response. Mice were sleep-restricted during 10â¯days using the flowerpot technique during 20â¯h per day with 4â¯h of daily sleep opportunity. The systemic inflammatory status, blood-brain barrier permeability, and the hippocampal expression of neuroinflammatory markers were characterized at the 10thâ¯day. Serum levels of TNF and IFN-γ increased in sleep-restricted C57BL/6 but not in BALB/c mice; no changes in other cytokines were found. Sleep restriction increased blood-brain barrier permeability in C57BL/6 strain but not in BALB/c. The hippocampus of sleep-restricted C57BL/6 mice exhibited an increase in the expression of the neuroinflammatory markers Iba-1, A2A adenosine receptor, and MMP-9; meanwhile in sleep-restricted BALB/c mice the expression of this markers was lesser than the control group. These data suggest that cytokines may be playing a key role in modulating blood-brain barrier function during sleep restriction, and probably the effects are related to Iba-1, MMP-9 and A2A adenosine receptor overexpression.
Assuntos
Barreira Hematoencefálica/metabolismo , Hipocampo/metabolismo , Inflamação/metabolismo , Privação do Sono/metabolismo , Sono/fisiologia , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Mediadores da Inflamação/metabolismo , Interferon gama/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Permeabilidade , Receptor A2A de Adenosina/metabolismo , Fator de Necrose Tumoral alfa/sangueRESUMO
Differently from others Leishmania species, infection by the protozoan parasite L. amazonensis is associated with a lack of antigen-specific T-cell responses. Dendritic cells (DC) are essential for the innate immune response and for directing the differentiation of T-helper lymphocytes. Previously, we showed that L. amazonensis infection impairs DC activation through the activation of adenosine A2B receptor, and here, we evaluated the intracellular events triggered by this receptor in infected cells. To this aim, bone marrow-derived DC from C57BL/6J mice were infected with metacyclic promastigotes of L. amazonensis. Our results show, for the first time, that L. amazonensis increases the production of cAMP and the phosphorylation of extracellular signal-regulated protein kinases 1/2 (ERK1/2) in infected DC by a mechanism dependent on the A2B receptor. Furthermore, L. amazonensis impairs CD40 expression and IL-12 production by DC, and the inhibition of adenylate cyclase, phosphoinositide 3-kinase (PI3K), and ERK1/2 prevent these effects. The increase of ERK1/2 phosphorylation and the inhibition of DC activation by L. amazonensis are independent of protein kinase A (PKA). In addition, C57BL/6J mice were inoculated in the ears with metacyclic promastigotes, in the presence of PSB1115, an A2B receptor antagonist. PSB1115 treatment increases the percentage of CD40+ DC on ears and draining lymph nodes. Furthermore, this treatment reduces lesion size and tissue parasitism. Lymph node cells from treated mice produce higher levels of IFN-γ than control mice, without altering the production of IL-10. In conclusion, we suggest a new pathway used by the parasite (A2B receptor â cAMP â PI3K â ERK1/2) to suppress DC activation, which may contribute to the decrease of IFN-γ production following by the deficiency in immune response characteristic of L. amazonensis infection.
RESUMO
Adenosine receptors are expressed in adipose tissue and control physiological and pathological events such as lipolysis and inflammation. The aim of this study was to evaluate the activity of N6-cyclopentyladenosine (CPA), a potent and selective A1 adenosine receptor agonist; 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxyamidoadenosine hydrochloride (CGS-21680), an A2A adenosine receptor agonist; and 5'-N-ethylcarboxamidoadenosine (NECA), a potent non-selective adenosine receptor agonist on adipose tissue inflammatory alterations induced by obesity in mice. Swiss mice were fed with a high-fat diet for 12 weeks and agonists were administered in the last two weeks. Body weight, adiposity and glucose homeostasis were evaluated. Inflammation in adipose tissue was assessed by evaluation of adipokine production and macrophage infiltration. Adenosine receptor signaling in adipose tissue was also evaluated. Mice that received CGS21680 presented an improvement in glucose homeostasis in association with systemically reduced inflammatory markers (TNF-α, PAI-1) and in the visceral adipose tissue (TNF-α, MCP-1, macrophage infiltration). Activation of p38 signaling was found in adipose tissue of this group of mice. NECA-treated mice presented some improvements in glucose homeostasis associated with an observed weight loss. Mice that received CPA presented only a reduction in the ex vivo basal lipolysis rate measured within visceral adipose tissue. In conclusion, administration of the A2A receptor agonist to obese mice resulted in improvements in glucose homeostasis and adipose tissue inflammation, corroborating the idea that new therapeutics to treat obesity could emerge from these compounds.
Assuntos
Agonistas do Receptor A1 de Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Tecido Adiposo/efeitos dos fármacos , Obesidade/tratamento farmacológico , Obesidade/patologia , Receptor A1 de Adenosina/metabolismo , Receptor A2A de Adenosina/metabolismo , Agonistas do Receptor A1 de Adenosina/uso terapêutico , Agonistas do Receptor A2 de Adenosina/uso terapêutico , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Adiposidade/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Peso Corporal/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Inflamação/complicações , Lipólise/efeitos dos fármacos , Masculino , Camundongos , Obesidade/complicações , Obesidade/metabolismoRESUMO
OBJECTIVE: To verify the association between c.1083T>C polymorphism in the adenosine receptor A2A gene (ADORA2A) and objective sleep, as well as the correlation between caffeine consumption, sleep parameters, and electroencephalographic spectral power in a large, population-based sample from São Paulo, Brazil. METHODS: This study was conducted in participants of the São Paulo Epidemiologic Sleep Study (EPISONO), a large, population-based survey consisting of a representative sample of the inhabitants of the city from São Paulo, Brazil, according to sex, age (20-80 years), and socioeconomic status in the year 2007. Questionnaires, polysomnography, spectral analysis of sleep electroencephalogram, and c.1083T>C polymorphism genotyping were performed in this study. RESULTS: We found that caffeine consumption was positively correlated with sleep latency and α spectral power, as well as negatively correlated with percentage of N3 stage and δ spectral power in this stage. However, this association was identified only in T allele carriers and not in CC genotype. CONCLUSION: Our data support an important aspect of this polymorphism in ADORA2A gene, showing that the variant affects the association between caffeine consumption and objective sleep parameters in a large population-based cohort. CLINICAL TRIAL INFORMATION: Name: Epidemiology of sleep disturbances among adult population of the Sao Paulo City. URL: http://www.clinicaltrials.gov/ct2/show/NCT00596713?term = NCT00596713&rank = 1. Number: NCT00596713.