During brain ischemia,excitotoxicity and peri-infarct depolarization injuries occur and cause cerebral tissue damage.Indeed,anoxic depolarization,consisting of massive neuronal depolarization due to the loss of membra...During brain ischemia,excitotoxicity and peri-infarct depolarization injuries occur and cause cerebral tissue damage.Indeed,anoxic depolarization,consisting of massive neuronal depolarization due to the loss of membrane ion gradients,occurs in vivo or in vitro during an energy failure.The neuromodulator adenosine is released in huge amounts during cerebral ischemia and exerts its effects by activating specific metabotropic receptors,namely:A_(1),A_(2A),A_(2B),and A_(3).The A_(2A)receptor subtype is highly expressed in striatal medium spiny neurons,which are particularly susceptible to ischemic damage.Evidence indicates that the A2Areceptors are upregulated in the rat striatum after stroke and the selective antagonist SCH58261 protects from exaggerated glutamate release within the first 4 hours from the insult and alleviates neurological impairment and histological injury in the following 24 hours.We recently added new knowledge to the mechanisms by which the adenosine A2Areceptor subtype participates in ischemia-induced neuronal death by performing patch-clamp recordings from medium spiny neurons in rat striatal brain slices exposed to oxygen and glucose deprivation.We demonstrated that the selective block of A2Areceptors by SCH58261 significantly reduced ionic imbalance and delayed the anoxic depolarization in medium spiny neurons during oxygen and glucose deprivation and that the mechanism involves voltage-gated K+channel modulation and a presynaptic inhibition of glutamate release by the A2Areceptor antagonist.The present review summarizes the latest findings in the literature about the possibility of developing selective ligands of A2Areceptors as advantageous therapeutic tools that may contribute to counteracting neurodegeneration after brain ischemia.展开更多
An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease prog...An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control.展开更多
BACKGROUND Immunological dysfunction-induced low-grade inflammation is regarded as one of the predominant pathogenetic mechanisms in post-infectious irritable bowel syndrome(PI-IBS).γδT cells play a crucial role in ...BACKGROUND Immunological dysfunction-induced low-grade inflammation is regarded as one of the predominant pathogenetic mechanisms in post-infectious irritable bowel syndrome(PI-IBS).γδT cells play a crucial role in innate and adaptive immunity.Adenosine receptors expressed on the surface ofγδT cells participate in intestinal inflammation and immunity regulation.AIM To investigate the role ofγδT cell regulated by adenosine 2A receptor(A2AR)in PI-IBS.METHODS The PI-IBS mouse model has been established with Trichinella spiralis(T.spiralis)infection.The intestinal A2AR and A2AR inγδT cells were detected by immunohistochemistry,and the inflammatory cytokines were measured by western blot.The role of A2AR on the isolatedγδT cells,including proliferation,apoptosis,and cytokine production,were evaluated in vitro.Their A2AR expression was measured by western blot and reverse transcription polymerase chain reaction(RT-PCR).The animals were administered with A2AR agonist,or A2AR antagonist.Besides,γδT cells were also injected back into the animals,and the parameters described above were examined,as well as the clinical features.Furthermore,the A2AR-associated signaling pathway molecules were assessed by western blot and RT-PCR.RESULTS PI-IBS mice exhibited elevated ATP content and A2AR expression(P<0.05),and suppression of A2AR enhanced PI-IBS clinical characteristics,indicated by the abdominal withdrawal reflex and colon transportation test.PI-IBS was associated with an increase in intestinal T cells,and cytokine levels of interleukin-1(IL-1),IL-6,IL-17A,and interferon-α(IFN-α).Also,γδT cells expressed A2AR in vitro and generated IL-1,IL-6,IL-17A,and IFN-α,which can be controlled by A2AR agonist and antagonist.Mechanistic studies demonstrated that the A2AR antagonist improved the function ofγδT cells through the PKA/CREB/NF-κB signaling pathway.CONCLUSION Our results revealed that A2AR contributes to the facilitation of PI-IBS by regulating the function ofγδT cells via the PKA/CREB/NF-κB signaling pathway.展开更多
AIM： To determine whether a specific adenosine A2A receptor agonist （ATL-146e） can ameliorate aspirin-induced gastric mucosal lesions in rats, and reduce neutrophil accumulation and production of pro-inflammatory c...AIM： To determine whether a specific adenosine A2A receptor agonist （ATL-146e） can ameliorate aspirin-induced gastric mucosal lesions in rats, and reduce neutrophil accumulation and production of pro-inflammatory cytokines. METHODS： Gastric lesions were produced by oral gavage of aspirin （200 mg/kg） and HCI （0.15 mol/L, 8.0 mL/kg）. 4-{3-[6-Amino-9-（5-ethylcarbamoyl-3,4- dihydroxy-tetrahydro-furan-2-yl）-9H-purin-2-yl]-prop-2- ynyl}-cyclohexanecarboxylic acid methyl ester （ATL-146e, 2.5-5μg/kg, IP） was injected 30 min before the administration of aspirin. Tissue myeloperoxidase （MPO） concentration in gastric mucosa was measured as an index of neutrophil infiltration. Gastric mucosal concentrations of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） were determined by ELISA. Also, we examined the effect of ATL-146e on tissue prostaglandin E2 （PGE2） production and gastric secretion. RESULTS： Intragastric administration of aspirin induced multiple hemorrhagic erosions in rat gastric mucosa. The total length of gastric erosions （ulcer index） in control rats was 29.8±7.75 mm and was reduced to 3.8±1.42 mm alter pretreatment with 5.0 g/kg ATL-146e （P〈 0.01）. The gastric contents of MPO and pro-inflammatory cytokines were all increased after the administration of aspirin and reduced to nearly normal levels by ATL-146e. Gastric mucosal PGE2 concentration was not affected by intraperitoneal injection of ATL-146e. CONCLUSION： The specific adenosine A2A receptor agonist, ATL-146e, has potent anti-ulcer effects presumably mediated by its anti-inflammatory properties.展开更多
BACKGROUND Post-infectious irritable bowel syndrome(PI-IBS)is generally regarded as a functional disease.Several recent studies have reported the involvement of lowgrade inflammation and immunological dysfunction in P...BACKGROUND Post-infectious irritable bowel syndrome(PI-IBS)is generally regarded as a functional disease.Several recent studies have reported the involvement of lowgrade inflammation and immunological dysfunction in PI-IBS.T helper 17(Th17)polarization occurs in IBS.Adenosine and its receptors participate in intestinal inflammation and immune regulation.AIM To investigate the role of Th17 polarization of CD4+T cells regulated by adenosine 2A receptor(A2AR)in PI-IBS.METHODS A PI-IBS model was established by infecting mice with Trichinella spiralis.The intestinal A2AR and CD4+T lymphocytes were detected by immunohistochemistry,and the inflammatory cytokines were detected by enzyme-linked immunoassay.CD4+T lymphocytes present in the animal’s spleen were separated and cultured with or without A2AR agonist and antagonist.Western blotting and real-time quantitative polymerase chain reaction were performed to determine the effect of A2AR on the cells and intestinal tissue.Cytokine production was determined.The protein and mRNA levels of A2AR associated signaling pathway molecules were also evaluated.Furthermore,A2AR agonist and antagonist were injected into the mouse model and the clinical features were observed.RESULTS The PI-IBS mouse model showed increased expression of ATP and A2AR(P<0.05),and inhibition of A2AR improved the clinical features in PI-IBS,including the abdominal withdrawal reflex and colon transportation test(P<0.05).The number of intestinal CD4+T cells and interleukin-17(IL-17)protein levels increased during PI-IBS,which was reversed by administration of the A2AR antagonist(P<0.05).CD4+T cells expressed A2AR and produced IL-17 in vitro,which was regulated by the A2AR agonist and antagonist.The A2AR antagonist increased the production of IL-17 by CD4+T cells via the Janus kinase-signal transducer and activator of transcriptionreceptor-related orphan receptorγsignaling pathway.CONCLUSION The results of the present study suggested that the upregulation of A2AR increases PI-IBS by promoting the Th17 polarization of CD4+T cells.展开更多
Typical antipsychotics, potent D2 dopamine receptor antagonists, are the most commonly used drugs in the treatment of bipolar disorders. In the central nervous system, the discovery of antagonistic interactions betwee...Typical antipsychotics, potent D2 dopamine receptor antagonists, are the most commonly used drugs in the treatment of bipolar disorders. In the central nervous system, the discovery of antagonistic interactions between A2A adenosine receptors and D2 dopamine receptors suggests that the adenosine system may be involved in the pathogenesis of different psychiatric disorders and in the therapeutic effectiveness of antipsychotic drugs. Previously, we have demonstrated an increase in A2A receptor expression and agonist affinity in platelets from psychotic patients treated with haloperidol. This result suggests that there is also a structural and functional interaction between A2A and D2 receptors in peripheral cells. In this work, we investigated the effect of different doses of typical drugs on A2A adenosine receptor binding and correlated these parameters with the severity of symptoms. We demonstrated, for the first time, that there was a strong correlation between A2A receptor affinity constant values (Kd) and drug doses in psychotic patients with a moderate severity of illness and moderate psychotic symptoms. The correlation was completely lost in patients with severe illness and severe psychotic symptoms. These results demonstrated that in platelets of patients affected by psychosis, typical antipsychotics modulated A2A receptor binding parameters;this regulation is dependent on the degree of D2 receptor occupancy in relation to the severity of psychotic symptoms, suggesting A2A receptors are a peripheral marker for individual therapy effectiveness.展开更多
The adenosine subfamily G protein-coupled receptors A_(2A)R and A_(2B)R have been identified as promising cancer immunotherapy candidates.One of the A_(2A)R/A_(2B)R dual antagonists,AB928,has progressed to a phaseⅡcl...The adenosine subfamily G protein-coupled receptors A_(2A)R and A_(2B)R have been identified as promising cancer immunotherapy candidates.One of the A_(2A)R/A_(2B)R dual antagonists,AB928,has progressed to a phaseⅡclinical trial to treat rectal cancer.However,the precise mechanism underlying its dual-antagonistic properties remains elusive.Herein,we report crystal structures of the A_(2A)R complexed with AB928 and a selective A_(2A)R antagonist 2-118.The structures revealed a common binding mode on A_(2A)R,wherein the ligands established extensive interactions with residues from the orthosteric and secondary pockets.In contrast,the cAMP assay and A_(2A)R and A_(2B)R molecular dynamics simulations indicated that the ligands adopted distinct binding modes on A_(2B)R.Detailed analysis of their chemical structures suggested that AB928 readily adapted to the A_(2B)R pocket,while 2-118 did not due to intrinsic differences.This disparity potentially accounted for the difference in inhibitory efficacy between A_(2B)R and A_(2A)R.This study serves as a valuable structural template for the future development of selective or dual inhibitors targeting A_(2A)R/A_(2B)R for cancer therapy.展开更多
Adenosine exerts its dual functions of homeostasis and neuromodulation in the brain by acting at mainly 2 G-protein coupled receptors,called A1 and A2A receptors.The adenosine A2A receptor(A2AR)antagonists have been c...Adenosine exerts its dual functions of homeostasis and neuromodulation in the brain by acting at mainly 2 G-protein coupled receptors,called A1 and A2A receptors.The adenosine A2A receptor(A2AR)antagonists have been clinically pursued for the last 2 decades,leading to final approval of the istradefylline,an A2AR antagonist,for the treatment of OFF-Parkinson's disease(PD)patients.The approval paves the way to develop novel therapeutic methods for A2AR antagonists to address 2 major unmet medical needs in PD and traumatic brain injury(TBI),namely neuroprotection or improving cognition.In this review,we first consider the evidence for aberrantly increased adenosine signaling in PD and TBI and the sufficiency of the increased A2AR signaling to trigger neurotoxicity and cognitive impairment.We further discuss the increasing preclinical data on the reversal of cognitive deficits in PD and TBI by A2AR antagonists through control of degenerative proteins and synaptotoxicity,and on protection against TBI and PD pathologies by A2AR antagonists through control of neuroinflammation.Moreover,we provide the supporting evidence from multiple human prospective epidemiological studies which revealed an inverse relation between the consumption of caffeine and the risk of developing PD and cognitive decline in aging population and Alzheimer's disease patients.Collectively,the convergence of clinical,epidemiological and experimental evidence supports the validity of A2AR as a new therapeutic target and facilitates the design of A2AR antagonists in clinical trials for disease-modifying and cognitive benefit in PD and TBI patients.展开更多
Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was app...Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.展开更多
基金supported by University of Florence RICATEN 2023 to EC.Grant/Award Numbers 58514_InternazionalizzazioneUniversity of Florence,to EC.Parkinson’s UK,Grant/Award Number:H-0902 to AJGWellcome Trust,Grant/Award Number:0926/Z/10/Z to AJG。
文摘During brain ischemia,excitotoxicity and peri-infarct depolarization injuries occur and cause cerebral tissue damage.Indeed,anoxic depolarization,consisting of massive neuronal depolarization due to the loss of membrane ion gradients,occurs in vivo or in vitro during an energy failure.The neuromodulator adenosine is released in huge amounts during cerebral ischemia and exerts its effects by activating specific metabotropic receptors,namely:A_(1),A_(2A),A_(2B),and A_(3).The A_(2A)receptor subtype is highly expressed in striatal medium spiny neurons,which are particularly susceptible to ischemic damage.Evidence indicates that the A2Areceptors are upregulated in the rat striatum after stroke and the selective antagonist SCH58261 protects from exaggerated glutamate release within the first 4 hours from the insult and alleviates neurological impairment and histological injury in the following 24 hours.We recently added new knowledge to the mechanisms by which the adenosine A2Areceptor subtype participates in ischemia-induced neuronal death by performing patch-clamp recordings from medium spiny neurons in rat striatal brain slices exposed to oxygen and glucose deprivation.We demonstrated that the selective block of A2Areceptors by SCH58261 significantly reduced ionic imbalance and delayed the anoxic depolarization in medium spiny neurons during oxygen and glucose deprivation and that the mechanism involves voltage-gated K+channel modulation and a presynaptic inhibition of glutamate release by the A2Areceptor antagonist.The present review summarizes the latest findings in the literature about the possibility of developing selective ligands of A2Areceptors as advantageous therapeutic tools that may contribute to counteracting neurodegeneration after brain ischemia.
基金supported by a grant from Ministry of Science,Technological Development and Innovation,Serbia,No.451-03-68/2022-14/200178(to NN)University of Defence,No.MFVMA/02/22-24(to MN)。
文摘An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control.
基金Supported by National Natural Science Foundation of China,No.81160057,No.81860102,and No.82060102Natural Science Foundation of Hainan Province,High-level Personnel Program,No.821RC1116+1 种基金Research Project of Health Industry in Hainan Province,No.20A200066Hainan Provincial Clinical Medical Center.
文摘BACKGROUND Immunological dysfunction-induced low-grade inflammation is regarded as one of the predominant pathogenetic mechanisms in post-infectious irritable bowel syndrome(PI-IBS).γδT cells play a crucial role in innate and adaptive immunity.Adenosine receptors expressed on the surface ofγδT cells participate in intestinal inflammation and immunity regulation.AIM To investigate the role ofγδT cell regulated by adenosine 2A receptor(A2AR)in PI-IBS.METHODS The PI-IBS mouse model has been established with Trichinella spiralis(T.spiralis)infection.The intestinal A2AR and A2AR inγδT cells were detected by immunohistochemistry,and the inflammatory cytokines were measured by western blot.The role of A2AR on the isolatedγδT cells,including proliferation,apoptosis,and cytokine production,were evaluated in vitro.Their A2AR expression was measured by western blot and reverse transcription polymerase chain reaction(RT-PCR).The animals were administered with A2AR agonist,or A2AR antagonist.Besides,γδT cells were also injected back into the animals,and the parameters described above were examined,as well as the clinical features.Furthermore,the A2AR-associated signaling pathway molecules were assessed by western blot and RT-PCR.RESULTS PI-IBS mice exhibited elevated ATP content and A2AR expression(P<0.05),and suppression of A2AR enhanced PI-IBS clinical characteristics,indicated by the abdominal withdrawal reflex and colon transportation test.PI-IBS was associated with an increase in intestinal T cells,and cytokine levels of interleukin-1(IL-1),IL-6,IL-17A,and interferon-α(IFN-α).Also,γδT cells expressed A2AR in vitro and generated IL-1,IL-6,IL-17A,and IFN-α,which can be controlled by A2AR agonist and antagonist.Mechanistic studies demonstrated that the A2AR antagonist improved the function ofγδT cells through the PKA/CREB/NF-κB signaling pathway.CONCLUSION Our results revealed that A2AR contributes to the facilitation of PI-IBS by regulating the function ofγδT cells via the PKA/CREB/NF-κB signaling pathway.
文摘AIM： To determine whether a specific adenosine A2A receptor agonist （ATL-146e） can ameliorate aspirin-induced gastric mucosal lesions in rats, and reduce neutrophil accumulation and production of pro-inflammatory cytokines. METHODS： Gastric lesions were produced by oral gavage of aspirin （200 mg/kg） and HCI （0.15 mol/L, 8.0 mL/kg）. 4-{3-[6-Amino-9-（5-ethylcarbamoyl-3,4- dihydroxy-tetrahydro-furan-2-yl）-9H-purin-2-yl]-prop-2- ynyl}-cyclohexanecarboxylic acid methyl ester （ATL-146e, 2.5-5μg/kg, IP） was injected 30 min before the administration of aspirin. Tissue myeloperoxidase （MPO） concentration in gastric mucosa was measured as an index of neutrophil infiltration. Gastric mucosal concentrations of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） were determined by ELISA. Also, we examined the effect of ATL-146e on tissue prostaglandin E2 （PGE2） production and gastric secretion. RESULTS： Intragastric administration of aspirin induced multiple hemorrhagic erosions in rat gastric mucosa. The total length of gastric erosions （ulcer index） in control rats was 29.8±7.75 mm and was reduced to 3.8±1.42 mm alter pretreatment with 5.0 g/kg ATL-146e （P〈 0.01）. The gastric contents of MPO and pro-inflammatory cytokines were all increased after the administration of aspirin and reduced to nearly normal levels by ATL-146e. Gastric mucosal PGE2 concentration was not affected by intraperitoneal injection of ATL-146e. CONCLUSION： The specific adenosine A2A receptor agonist, ATL-146e, has potent anti-ulcer effects presumably mediated by its anti-inflammatory properties.
基金Supported by National Natural Science Foundation of China,No.81160057,No.81860102,and No.82060102.
文摘BACKGROUND Post-infectious irritable bowel syndrome(PI-IBS)is generally regarded as a functional disease.Several recent studies have reported the involvement of lowgrade inflammation and immunological dysfunction in PI-IBS.T helper 17(Th17)polarization occurs in IBS.Adenosine and its receptors participate in intestinal inflammation and immune regulation.AIM To investigate the role of Th17 polarization of CD4+T cells regulated by adenosine 2A receptor(A2AR)in PI-IBS.METHODS A PI-IBS model was established by infecting mice with Trichinella spiralis.The intestinal A2AR and CD4+T lymphocytes were detected by immunohistochemistry,and the inflammatory cytokines were detected by enzyme-linked immunoassay.CD4+T lymphocytes present in the animal’s spleen were separated and cultured with or without A2AR agonist and antagonist.Western blotting and real-time quantitative polymerase chain reaction were performed to determine the effect of A2AR on the cells and intestinal tissue.Cytokine production was determined.The protein and mRNA levels of A2AR associated signaling pathway molecules were also evaluated.Furthermore,A2AR agonist and antagonist were injected into the mouse model and the clinical features were observed.RESULTS The PI-IBS mouse model showed increased expression of ATP and A2AR(P<0.05),and inhibition of A2AR improved the clinical features in PI-IBS,including the abdominal withdrawal reflex and colon transportation test(P<0.05).The number of intestinal CD4+T cells and interleukin-17(IL-17)protein levels increased during PI-IBS,which was reversed by administration of the A2AR antagonist(P<0.05).CD4+T cells expressed A2AR and produced IL-17 in vitro,which was regulated by the A2AR agonist and antagonist.The A2AR antagonist increased the production of IL-17 by CD4+T cells via the Janus kinase-signal transducer and activator of transcriptionreceptor-related orphan receptorγsignaling pathway.CONCLUSION The results of the present study suggested that the upregulation of A2AR increases PI-IBS by promoting the Th17 polarization of CD4+T cells.
文摘Typical antipsychotics, potent D2 dopamine receptor antagonists, are the most commonly used drugs in the treatment of bipolar disorders. In the central nervous system, the discovery of antagonistic interactions between A2A adenosine receptors and D2 dopamine receptors suggests that the adenosine system may be involved in the pathogenesis of different psychiatric disorders and in the therapeutic effectiveness of antipsychotic drugs. Previously, we have demonstrated an increase in A2A receptor expression and agonist affinity in platelets from psychotic patients treated with haloperidol. This result suggests that there is also a structural and functional interaction between A2A and D2 receptors in peripheral cells. In this work, we investigated the effect of different doses of typical drugs on A2A adenosine receptor binding and correlated these parameters with the severity of symptoms. We demonstrated, for the first time, that there was a strong correlation between A2A receptor affinity constant values (Kd) and drug doses in psychotic patients with a moderate severity of illness and moderate psychotic symptoms. The correlation was completely lost in patients with severe illness and severe psychotic symptoms. These results demonstrated that in platelets of patients affected by psychosis, typical antipsychotics modulated A2A receptor binding parameters;this regulation is dependent on the degree of D2 receptor occupancy in relation to the severity of psychotic symptoms, suggesting A2A receptors are a peripheral marker for individual therapy effectiveness.
基金supported by the National Key Research and Development Program of China(2018YFA0507001)the Basic Research Program of Science and Technology Commission of Shanghai Municipality(21JC1402400)+1 种基金the National Natural Science Foundation of China(32171215,81972828,82172644,82273857 and 81830083)the National Key Scientific Infrastructure for Translational Medicine(Shanghai)(TMSK-2021-120)。
文摘The adenosine subfamily G protein-coupled receptors A_(2A)R and A_(2B)R have been identified as promising cancer immunotherapy candidates.One of the A_(2A)R/A_(2B)R dual antagonists,AB928,has progressed to a phaseⅡclinical trial to treat rectal cancer.However,the precise mechanism underlying its dual-antagonistic properties remains elusive.Herein,we report crystal structures of the A_(2A)R complexed with AB928 and a selective A_(2A)R antagonist 2-118.The structures revealed a common binding mode on A_(2A)R,wherein the ligands established extensive interactions with residues from the orthosteric and secondary pockets.In contrast,the cAMP assay and A_(2A)R and A_(2B)R molecular dynamics simulations indicated that the ligands adopted distinct binding modes on A_(2B)R.Detailed analysis of their chemical structures suggested that AB928 readily adapted to the A_(2B)R pocket,while 2-118 did not due to intrinsic differences.This disparity potentially accounted for the difference in inhibitory efficacy between A_(2B)R and A_(2A)R.This study serves as a valuable structural template for the future development of selective or dual inhibitors targeting A_(2A)R/A_(2B)R for cancer therapy.
基金supported in part by the grants from the National Natural Science Foundation of China[grant numbers 81771176 for Zhao Y,82150710558 and 82151308 for Chen JF]by the Startup Funds from the Oujiang Laboratory (the Zhejiang Provincial Key Laboratory for Regenerative Medicine and Eye-Brain Disorders)[grant number OJQDSP2022007 for Chen JF]Wenzhou,China。
文摘Adenosine exerts its dual functions of homeostasis and neuromodulation in the brain by acting at mainly 2 G-protein coupled receptors,called A1 and A2A receptors.The adenosine A2A receptor(A2AR)antagonists have been clinically pursued for the last 2 decades,leading to final approval of the istradefylline,an A2AR antagonist,for the treatment of OFF-Parkinson's disease(PD)patients.The approval paves the way to develop novel therapeutic methods for A2AR antagonists to address 2 major unmet medical needs in PD and traumatic brain injury(TBI),namely neuroprotection or improving cognition.In this review,we first consider the evidence for aberrantly increased adenosine signaling in PD and TBI and the sufficiency of the increased A2AR signaling to trigger neurotoxicity and cognitive impairment.We further discuss the increasing preclinical data on the reversal of cognitive deficits in PD and TBI by A2AR antagonists through control of degenerative proteins and synaptotoxicity,and on protection against TBI and PD pathologies by A2AR antagonists through control of neuroinflammation.Moreover,we provide the supporting evidence from multiple human prospective epidemiological studies which revealed an inverse relation between the consumption of caffeine and the risk of developing PD and cognitive decline in aging population and Alzheimer's disease patients.Collectively,the convergence of clinical,epidemiological and experimental evidence supports the validity of A2AR as a new therapeutic target and facilitates the design of A2AR antagonists in clinical trials for disease-modifying and cognitive benefit in PD and TBI patients.
文摘Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.
