Bone-derived MSCs encapsulated in alginate hydrogel prevent collagen-induced arthritis in mice through the activation of adenosine A2A/2B receptors in tolerogenic dendritic cells

Tolerogenic dendritic cells (tolDCs) facilitate the suppression of autoimmune responses by differentiating regulatory T cells (Treg). The dysfunction of immunotolerance results in the development of autoimmune diseases, such as rheumatoid arthritis (RA). As multipotent progenitor cells, mesenchymal stem cells (MSCs), can regulate dendritic cells (DCs) to restore their immunosuppressive function and prevent disease development. However, the underlying mechanisms of MSCs in regulating DCs still need to be better defined. Simultaneously, the delivery system for MSCs also influences their function. Herein, MSCs are encapsulated in alginate hydrogel to improve cell survival and retention in situ, maximizing efficacy in vivo. The three-dimensional co-culture of encapsulated MSCs with DCs demonstrates that MSCs can inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines. In the collagen-induced arthritis (CIA) mice model, alginate hydrogel encapsulated MSCs induce a significantly higher expression of CD39+CD73+ on MSCs. These enzymes hydrolyze ATP to adenosine and activate A2A/2B receptors on immature DCs, further promoting the phenotypic transformation of DCs to tolDCs and regulating naïve T cells to Tregs. Therefore, encapsulated MSCs obviously alleviate the inflammatory response and prevent CIA progression. This finding clarifies the mechanism of MSCs-DCs crosstalk in eliciting the immunosuppression effect and provides insights into hydrogel-promoted stem cell therapy for autoimmune diseases.

Lateral septum adenosine A2A receptors control stress-induced depressive-like behaviors via signal-ing to hypothalamus and habenula / 中国药理学与毒理学杂志

Depressive disorder ranks as a major bur-den of disease worldwide,yet the current antidepressant medications are limited by frequent non-responsiveness and significant side effects.The lateral septum(LS)is thought to control of depression,however,the cellular and circuit substrates are largely unknown.Here,we identified a subpopulation of LS GABAergic adenosine A2A receptors(A2AR)-positive neurons mediating depres-sive symptoms via direct projects to the lateral habenula(LHb)and the dorsomedial hypothalamus(DMH).Activa-tion of A2AR in the LS augmented the spiking frequency of A2AR-positive neurons leading to a decreased activation of surrounding neurons and the bi-directional manipula-tion of LS-A2AR activity demonstrated that LS-A2ARs are necessary and sufficient to trigger depressive pheno-types.Thus,the optogenetic modulation(stimulation or inhibition)of LS-A2AR-positive neuronal activity or LS-A2AR-positive neurons projection terminals to the LHb or DMH,phenocopied depressive behaviors.Moreover,A2AR are upregulated in the LS in two male mouse mod-els of repeated stress-induced depression.This identifica-tion that aberrantly increased A2AR signaling in the LS is a critical upstream regulator of repeated stress-induced depressive-like behaviors provides a neurophysiological and circuit-based justification of the antidepressant poten-tial of A2AR antagonists,prompting their clinical transla-tion.

Adenosine A 2A receptor deficiency prevents p38MAPK activation and apoptosis of prefrontal cortex cells in mice with chronic hypoxic hypercapnia / 中华物理医学与康复杂志

Objective:To observe the effect of genetic inactivation of adenosine A 2A receptor on apoptosis in the prefrontal cortex and on the expression of phosphorylated p38 mitogen-active protein kinase (p38MAPK) in mice with chronic hypoxic hypercapnia. Methods:Sixteen male wild-type mice and 16 male mice in which the adenosine A 2A receptor gene had been knocked out were randomly divided into a 4 weeks group (including 4HH+ /+ and 4HH-/- subgroups) and a normal control group (including NC+ /+ and NC-/- subgroups). The 4HH+ /+ and 4HH-/- group mice were exposed to an atmosphere containing 9-11% O 2 and 5-6% CO 2 8 hours a day, 6 days a week for 4 weeks. The apoptosis index (AI) in their prefrontal cortices was then evaluated using terminal-deoxynucleoitide transferase mediated nick end labelling (TUNEL) staining. The expression of p38MAPK protein in the prefrontal cortices was measured using western blotting. Results:The average AI had increased significantly in the 4HH+ /+ and 4HH-/- groups compared with the controls, with significantly more apoptotic cells in the 4HH+ /+ group than in the 4HH-/- group. In the 4HH+ /+ and 4HH-/- groups the average expression of p38 protein in the prefrontal cortex was significantly higher than among their controls. Moreover, the average expression of p-p38MAPK protein in the prefrontal cortex of the 4HH-/- group was significantly lower than in the 4HH+ /+ group.Conclusion:Adenosine A 2A receptor knockout inhibits apoptosis in the prefrontal cortex and down-regulates the p38MAPK activation of mice after exposure to chronic hypoxic hypercapnia.

Mechanism of mental dependence of propofol in rats: adenosine A2A receptor-neurotransmitter-ERK pathway / 中华麻醉学杂志

Objective:To investigate the relationship between the mechanism of mental dependence of propofol and adenosine A2A receptor-neurotransmitter-extracellular signal-regulated kinase (ERK) pathway in rats.Methods:Forty-eight healthy male Sprague-Dawley rats, aged about 7 weeks, weighing 200-300 g, were used in this study.The model of propofol dependence was established by intraperitoneal injection of propofol 40 mg/kg for 14 consecutive days.The rats were divided into 6 groups ( n=8 each) using a random number table method: central control group (group c-C), central agonist group (group c-CGS), central antagonist group (group c-DMPX), peripheral control group (group p-C), peripheral agonist group (group p-CGS) and peripheral antagonist group (group p-DMPX). Adenosine A2A agonist CGS-21680 2.5 ng/0.5 μl was intracranially injected immediately after establishing the model in group c-CGS, while the equal volume of normal saline was given instead in c-C group.CGS-21680 0.1 mg/kg was intraperitoneally injected in group p-CGS, while the equal volume of normal saline was given instead in group p-C.Adenosine A2A receptor antagonist DMPX 50 ng/0.5 μl was intracranially injected at 20 min before each propofol injection in group c-DMPX, and DMPX 0.25 mg/kg was intraperitoneally injected in group p-DMPX.The position preference value (CPP value) was determined before establishing the model, immediately after establishing the model, and after administration of agonist or normal saline (after intervention). The animals were sacrificed at 1 day after establishing the model, and blood samples and brain tissues were obtained for determination of the levels of dopamine (DA) and glutamate (Glu) in plasma and hippocampus and content of serotonin (5-HT) in cerebral cortex (by enzyme-linked immunosorbent assay) and expression of phosphorylated ERK1/2 (p-ERK1/2) in cerebral cortex (by Western blot). Results:Compared with the baseline before establishing the model, CPP value was increased immediately after establishing the model in c-C, c-CGS, p-C and p-CGS groups ( P<0.05), and no significant change was found in CPP value immediately after establishing the model in c-DMPX and p-DMPX groups ( P>0.05). Compared with the value immediately after establishing the model, no significant change was found in CPP value after intervention in c-C and p-C groups ( P>0.05), and CPP value was increased after intervention in c-CGS and p-CGS groups ( P<0.05). Compared with group c-C, the contents of hippocampal DA and Glu were significantly increased in group c-CGS, and the contents of hippocampal Glu were decreased, the content of 5-HT in cerebral cortex was increased, and the expression of p-ERK1/2 was down-regulated in group c-DMPX ( P<0.05). Compared with group p-C, no significant change was found in levels of DA and glutamate (Glu) in plasma and hippocampus and 5-HT and p-ERK1/2 in cerebral cortex in group p-CGS ( P>0.05), and the contents of hippocampal DA and Glu were significantly decreased, the content of 5-HT in cerebral cortex was increased, and the expression of p-ERK1/2 was down-regulated in group p-DMPX ( P<0.05). Conclusion:The mechanism underlying the development of propofol mental dependence may be related to activating adenosine A2A receptors, increasing excitatory neurotransmitters in brain, and thus up-regulating ERK activity in rats.

Sleep Promoting Effect of Luteolin in Mice via Adenosine A1 and A2A Receptors

Luteolin, a widespread flavonoid, has been known to have neuroprotective activity against various neurologic diseases such as epilepsy, and Alzheimer’s disease. However, little information is available regarding the hypnotic effect of luteolin. In this study, we evaluated the hypnotic effect of luteolin and its underlying mechanism. In pentobarbital-induced sleeping mice model, luteolin (1, and 3 mg/kg, p.o.) decreased sleep latency and increased the total sleep time. Through electroencephalogram (EEG) and electromyogram (EMG) recording, we demonstrated that luteolin increased non-rapid eye movement (NREM) sleep time and decreased wake time. To evaluate the underlying mechanism, we examined the effects of various pharmacological antagonists on the hypnotic effect of luteolin. The hypnotic effect of 3 mg/kg of luteolin was not affected by flumazenil, a GABAA receptor-benzodiazepine (GABAAR-BDZ) binding site antagonist, and bicuculine, a GABAAR-GABA binding site antagonist. On the other hand, the hypnotic effect of 3 mg/kg of luteolin was almost completely blocked by caffeine, an antagonist for both adenosine A1 and A2A receptor (A1R and A2AR), 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX), an A1R antagonist, and SCH-58261, an A2AR antagonist. From the binding affinity assay, we have found that luteolin significantly binds to not only A1R but also A2AR with IC₅₀ of 1.19, 0.84 μg/kg, respectively. However, luteolin did not bind to either BDZ-receptor or GABAAR. From these results, it has been suggested that luteolin has hypnotic efficacy through A1R and A2AR binding.

Effect of activating adenosine A2A receptors on myocardial ischemia-reperfusion injury in diabetic rats: the relationship with autophagy / 中华麻醉学杂志

Objective To evaluate the effect of activating adenosine A2A receptors on myocardial is-chemia-reperfusion ( I∕R) injury in diabetic rats and the relationship with autophagy. Methods Clean-grade healthy male Sprague-Dawley rats, aged 6 weeks, weighing 200-250 g, were studied. The diabetic rat model was established by intraperitoneal injection of 1％ streptozotocin 60 mg∕kg. Forty diabetic rats were divided into 4 groups ( n=10 each ) using a random number table method: sham operation group ( group Sham) , I∕R group ( group I∕R) , I∕R plus adenosine A2A receptor agonist CGS21680 group ( group CGS) , and I∕R plus CGS21680 plus adenosine A2A receptor antagonist ZM241385 group ( group CGS+ZM) . Myocardial I∕R was produced by occlusion of the left anterior descending branch of the coronary artery for 30 min followed by 120-min reperfusion. Adenosine A2A receptor agonist CGS2168010μg∕100g was in-travenously injected at 10 min before reperfusion in group CGS. CGS2168010 ug∕100g and ZM2413850. 2 mg∕kg were intravenously injected sequentially at 10 min before reperfusion in group CGS+ZM. Blood sam-ples were obtained at the end of reperfusion for determination of concentrations of creatine kinase-MB ( CK-MB), lactate dehydrogenase (LDH) and cardiac troponin I (cTnI) in serum (by enzyme-linked immu-nosorbent assay). The animals were sacrificed, and myocardial tissues were obtained for measurement of the percentage of myocardial infarct volume ( by TTC staining) and for determination of the expression of mi-crotubule-associated protein 1 light chain 3 Ⅰ ( LC3Ⅰ) , LC3 Ⅱ, p62 and Beclin-1 ( by Western blot) . LC3 Ⅱ∕LC3 Ⅰ ratio was calculated. Results Compared with group Sham, the serum CK-MB, LDH and cTnI concentrations and percentage of myocardial infarct volume were significantly increased, the expression of p62 and Beclin-1 was up-regulated, and the LC3Ⅱ∕LC3Ⅰratio was increased in group I∕R ( P<0. 05) . Compared with group I∕R, the concentrations of serum CK-MB, LDH and cTnI and percentage of myocardial infarct volume were significantly decreased, the expression of p62 and Beclin-1 was down-regulated, and the ratio of LC3Ⅱ∕LC3Ⅰwas increased in group CGS ( P<0. 05) , and no significant change was found in the pa-rameters mentioned above in group CGS+ZM (P>0. 05). Compared with group CGS, the concentrations of serum CK-MB, LDH and cTnI and percentage of myocardial infarct volume were significantly increased, the expression of p62 and Beclin-1 was down-regulated, and the ratio of LC3Ⅱ∕LC3Ⅰwas decreased in group CGS+ZM ( P<0. 05) . Conclusion Activating adenosine A2A receptors can mitigate myocardial I∕R injury, and the mechanism may be related to enhancing autophagy in diabetic rats.

A2AR activation after traumatic brain injury in the role of excessive tau protein phosphorylation and mechanism research / 中国生化药物杂志

Objective To explore the A2AR activation after traumatic brain injury mechanisms and the role of excessive tau protein phosphorylation.Methods With no specific mice experiment research of specific pathogens, position in the left parietal cortex in mice, by the method of controllable cortical against brain trauma model model, 15 min after injury in mice abdominal injection of A2AR specific inhibitors ZM241385 or use A2AR knockout mice, testing the brain neuron loss and tau protein phosphorylation level;Use specific agonists CGS21680 activate the original generation of nerve cells in the hippocampus and the A2AR human neuroblastoma cells, using immunocytochemistry and immunofluorescence test tua protein phosphorylation level of change, to observe axon transport function of mitochondria.Results Immunohistochemical results accumulation of optical density analysis showed that inhibition of A2AR activation can significantly reduce after cerebral trauma Ser404 tua protein loci phosphorylation levels, reduce excessive tua protein phosphorylation with nerve pathological change;A2AR activation after tua phosphorylation of proteins at a Ser404 site level increased significantly, nerve axons per unit length processes in the mitochondria number decreased significantly, resulting in axoplasmic transport dysfunction;To activate the original generation of nerve cells in the hippocampus and after the A2AR human neuroblastoma cells, tua protein phosphorylation Ser404 locus levels increased significantly.Conclusion A2AR activation after cerebral trauma has obvious influence on tua protein phosphorylation levels, may be a function by influencing the axoplasmic transport, eventually forming cognitive dysfunction.

Effect of adenosine A2A receptor agonist combined with bone marrow mesenchymal stem cells transplantation on the negative immune regulation in mice with acute liver failure / 中华传染病杂志

Objective To investigate the therapeutic effect and possible mechanism of adenosine A2A receptor agonist (CGS21680) combined with bone marrow mesenchymal stem cells (BMMSC) transplantation in acute liver failure (ALF).Methods Fifty male C57BL/6 mice, 6-8 weeks old, were fed with standard diet for 1 week and randomly divided into 5 groups according to random number table: healthy control group (n=6), model group (n=11), BMMSC group (n=11), CGS21680/BMMSC group (n=11) and CGS21680 group (n=11).Except healthy control group, the other mice were injected with D-GalN and lipopolysaccharide (LPS) to establish ALF model.Ten hours later, CGS21680/BMMSC group and CGS21680 group were injected intraperitoneally with adenosine A2A receptor agonist CGS21680 (2.1 mg/kg).In addition, the BMMSC group and CGS21680/BMMSC group were injected BMMSC (1×10.6) through tail vein.After 24 hours, pathological changes of liver tissue was observed by hematoxylin and eosin staining.The change of proportion of mouse splenic Treg among CD4+T lymphocytes was detected by flow cytometry.Toll-like receptor (TLR)4 and nuclear factor (NF)-κB expression levels in liver tissue were detected by real-time fluorescence quantitative polymerase chain reaction (PCR) and Western blot.One-way analysis of variance (one-way ANOVA) and SNK-q test was conducted for data analysis.Results Serum IL-6 levels were (23.67±2.97) pg/mL in healthy control group, (151.47±6.03) pg/mL in model control group, (72.10±3.74) pg/mL in BMMSC group, (53.35±2.50) pg/mL in CGS21680/BMMSC group and (84.85±3.25) pg/mL in CGS21680 group.The differences between healthy control group and the other 4 groups were all statistically significant (t=46.02, 25.51, 19.58 and 34.03, respectively, all P<0.01).Serum TNF-ɑ levels were (24.62±3.19) pg/mL in healthy control group, (102.25±2.10) pg/mL in model control group, (54.71±2.23) pg/mL in BMMSC group, (42.20±4.72) pg/mL in CGS21680/BMMSC group and (81.76±3.50) pg/mL in CGS21680 group.The differences between healthy control group and the other 4 groups were all statistically significant (t=46.49, 19.97, 7.72 and 29.57, respectively, all P<0.01).The differences of spleen Treg proportion in healthy control group were statistically significant compared with model control group, BMMSC group, CGS21680/BMMSC group and CGS21680 group (t=51.67, 12.22, 5.91 and 18.21, respectively, all P<0.01).The differences of TLR4 mRNA levels of liver tissue in healthy control group were statistically significant compared with model control group, BMMSC group, CGS21680/BMMSC group and CGS21680 group (t=26.31, 21.33, 13.24 and 27.14, respectively, all P<0.05).The differences of NF-κB mRNA level of liver tissue in healthy control group were statistically significant compared with model control group, BMMSC group, CGS21680/BMMSC group and CGS21680 group (t=16.56, 16.34, 7.83 and 13.11, respectively, all P<0.05).The differences of TLR4 protein level in liver tissue of healthy control group were statistically significant compared with model control group, BMMSC group, CGS21680/BMMSC group and CGS21680 group (t=35.60, 10.38, 6.05 and 18.02, respectively, all P<0.05).The differences of liver NF-κB protein level in the healthy control group were statistically significant compared with model control group, BMMSC group, CGS21680/BMMSC group and CGS21680 group (t=10.80, 7.30, 4.61 and 13.24, respectively, all P<0.05).Conclusions Adenosine A2A receptor agonist combined with BMMSC can significantly up-regulate the proportion of Treg cells in acute liver failure mice and inhibit the TLR4/NF-κB pathway activation, with both coordinated regulation, and further inhibit the liver inflammation.

Effect of adenosine A2A receptor antagonists on motor disorders induced by 6-hydroxydopamine in rat

PURPOSE: To investigate the role of adenosine A2A receptors on 6-OHDA-induced motor disorder in rat. METHODS: In order to induce experimental model of Parkinson's disease, 6-hydoxydopamine (8 μg/rat) was injected unilaterally into the SNc. After three weeks as a recovery period, 6-OHDA-induced bradykinesia and balance disturbances were assessed by using beam traversal test 10, 30 and 60 minutes after intraperitoneal injections of the drugs (caffeine, SCH58261). RESULTS: The results showed that 6-OHDA (8 μg/rat, Intra-SNc) induced motor disorders of Parkinson's disease and increased elapsed time in the beam test (p<0.001). Injection of caffeine (30 mg/kg, i.p.) and SCH58261 (2 mg/kg, i.p.) attenuated elapsed time on beam (p<0.01 and p<0.001). We showed that acute administration of caffeine and SCH 58261 can improve the 6-OHDA-induced bradykinesia and motor disturbance. CONCLUSION: Adenosine A2AR antagonists improve 6-OHDA-motor deficit and this effect seems to be mediated by the inhibition of A2A presynaptic receptors in substantia nigra pars compacta.

Effect of chronic intermittent hypoxia on AMPK pathway in young rats / 中国病理生理杂志

[ ABSTRACT] AIM: To investigate the effect of chronic intermittent hypoxia on AMP-activated protein kinase ( AMPK) pathway in the brain of young rats.METHODS:Part one:SD mice (3~4 weeks old) were randomly divided into 4 groups (n=8): simulated air control group for 2 weeks (2AC), chronic intermittent hypoxia group for 2 weeks (2IH), simulated air control group for 4 weeks (4AC) and chronic intermittent hypoxia group for 4 weeks (4IH).Part two:SD mice (3~4 weeks old) were randomly divided into 2 groups (n=8): chronic intermittent hypoxia group for 4 weeks (4IH) and chronic intermittent hypoxia group treated with AMPK inhibitor for 4 weeks (4IHI).After modeling, the eight-arm maze test was performed.TUNEL method was used to detect the neuronal apoptosis in the hippocampal and pre-frontal cortical tissues.The mRNA expression of adenosine A2a receptor was examined by RT-qPCR, and the protein levels of phosphorylated AMPK (p-AMPK) and mammalian target of rapamycin (p-mTOR) were determined by Western blot. RESULTS:Compared with control group, the numbers of reference memory error ( RME) , working memory error ( WME) and total error (TE) in 2IH group and 4IH group significantly increased (P<0.01).Compared with 2IH group, the num-bers of errors in 4IH group also increased significantly (P<0.01).Compared with 4IH group, the values in 4IHI group significantly decreased.Compared with control group, the neuronal apoptosis of hippocampus and prefrontal cortex in 2IH group and 4IH group increased, and that in 4IH group was more evident (P<0.05).In 4IHI group, the neuronal apopto-sis decreased.The mRNA expression of adenosine A2a receptor in the hippocampal and cortical tissues in 2IH group and 4IH group was higher than that in control group.The protein level of p-AMPK was higher, and p-mTOR was lower in 2IH group and 4IH group, and those in 4IH group were more evident (P<0.05).Compared with 4IH group, the protein level of p-AMPK was lower, and p-mTOR was higher in 4IHI group.CONCLUSION: Chronic intermittent hypoxia induces neuronal apoptosis, resulting in impairment of learning and memory in a time-dependent manner by upregulating adenosine A2a receptor, activating AMPK activity, and inhibiting mTOR phosphorylation in rats.

Adenosine A2 A receptor antagonist SCH58261 attenuates hypoxic-ischemic brain damage in a fetal rabbit model / 中国病理生理杂志

[ ABSTRACT] AIM: To study the effect of adenosine A 2A receptor antagonist SCH58261 on hypoxic-ischemic brain damage ( HIBD) in a mature fetal rabbit model .METHODS:Pregnant New Zealand white rabbits at gestational day 29 were selected and were randomly divided into sham-operated group, hypoxic-ischemic group, SCH58261 0.04 mg/kg group, SCH58261 0.12 mg/kg group and DMSO group.The intrauterine rabbit HIBD model was established .All pregnant rabbits were subjected to cesarean section 24 h after the sham operation or experimental procedure to induce hypoxic-ische-mic injury in the fetus .The survival neonatal rabbits were kept in a neonatal incubator at 35℃.The general conditions of the newborn rabbits were recorded .The degree of neurobehavioral damage in the newborn rabbits was estimated by a neu -robehavioral scoring protocol .The concentration of SCH 58261 in the serum of pregnant rabbits , the serum of neonatal rab-bits and the brain tissues of neonatal rabbits was measured by mass spectrometry .The mRNA expression of Bcl-2/Bax and protein levels of p-P38 mitogen-activated protein kinase (MAPK) in the cortex, hippocampus and striatum area in the brain of the neonatal rabbits were determined by real-time PCR and Western blot .RESULTS:SCH58261 was detected in the se-rum and brain tissues of the newborn rabbits .The SCH58261 concentration was approximately 40 μg/L in the brain tissue of the newborn rabbits .The mRNA expression of Bcl-2 in the cortex , hippocampus and striatum of brain tissues in SCH58261 0.04 mg/kg group and SCH58261 0.12 mg/kg group was higher , and the mRNA expression of Bax was lower than those in HI group (P<0.05).The protein level of p-P38 MAPK in the cortex, hippocampus and striatum of brain tis-sues was reduced in SCH58261 0.04 mg/kg group and SCH58261 0.12 mg/kg group compared with HI group (P<0.05). The protein level of p-P38 MAPK in SCH58261 0.12 mg/kg group was a little lower than that in SCH 58261 0.04 mg/kg group (P<0.05).CONCLUSION: Adenosine A2A receptor antagonist SCH58261 attenuates hypoxia-ischemia induced neonatal brain injury by blocking adenosine A 2A receptor, subsequently inhibiting p-P38 MAPK phosphorylation to reduce neuronal apoptosis .

Proliferation and activation of acetaldehyde-induced HSC-T6 cells through RNA inference targeting adenosine A1 and A2 A receptors / 中国药理学通报

Aim To investigate the influence of down-regulating adenosine A1 receptor and adenosine A2 A receptor gene expression on proliferation and activation of acetaldehyde-induced hepatic stellate cell-T6 cells through siRNA. Methods Alcoholic liver fibrosis in vitro model was constructed by inducing HSC-T6 cells with acetaldehyde. siRNA targeting A1R and A2AR were designed and synthesized according to its mRNA. The siRNA was transfected into rat HSC-T6 cells by li-posome LipofectamineTM 2000. HSC cell proliferation was measured by MTT. The mRNA levels of A1R, A2AR, α-SMA, Collagen I in the supernatant of the cell culture were measured by Quantitative Real-Time PCR. The protein levels of A1R, A2AR, α-SMA, Collagen I were measured by Western blot. Results A1 R and A2 AR siRNA effectively inhibited the cell proliferation, and they also significantly decreased the levels of A1R, A2AR,α-SMA, Collagen I, suggesting that A1 R and A2 AR might be potential target genes in the alcoholic liver fibrosis. Conclusions Silencing A1 R or A2 AR by RNAi can significantly inhibit the HSC proliferation, A1R and A2AR may be potential therapeutic target genes for alcoholic liver fibrosis.

Roles of the unselective adenosine receptor agonist 5'-(N-ethylcarboxamido) adenosine-induced cardio-protection in vitro / 中国药学杂志

OBJECTIVE: To study the roles of adenosine A2A and A2B receptor in 5'-(N-ethylcarboxamido) adenosine (NECA)-induced cardioprotection in vitro against reperfusion injury, and to explore the underlying mechanism. METHODS: Simulated ischemia/reperfusion injury model was developed in cardiac H9c2 cells. NECA, an unselective adenosine receptor agonist, the selective antagonists of adenosine A2A receptor antagonist SCH58261 (SCH) and the selective A2B receptor antagonist MRS1706 (MRS) were used. CCK-8 assay was used to evaluate cell viability. Mitochondrial membrane potential (ΔΨm) was measured with fluorescence microscope using JC-1. Amplex Red Hydrogen Peroxide/Peroxidase Assay Kit was used to detect the level of intracellular H2O2. Intracellular reactive oxygen species (ROS) levels were determined with DCFH-DA. Mitochondrial ROS were detected with MitoSox Red. RESULTS: NECA applied at reperfusion reduced cell death in cells subjected to simulated ischemia/reperfusion. Compared with the ischemia/reperfusion injury group, NECA inhibited the reduction of cell viability and ΔΨm, and the elevation of intracellular and mitochondrial ROS, which were all abolished by adenosine A2A and A2B receptor antagonists(P < 0.01 or P < 0.05). CONCLUSION: Adenosine A2A and A2B receptors work in concert to mediate the cardioprotective effect of NECA presumably by modulating the mPTP opening and mitochondrial ROS generation.

Adenosine A2A receptor and nervous system diseases / 国际药学研究杂志

Adenosine, which arises from the breakdown of adenosine triphosphate, is extensively distributed in mammalian tis-sues and cells. Adenosine exerts its regulating effects on cell function via binding to the specific membrane receptors. Adenosine receptors are belong to G-protein-coupled receptors and can be subdivided into A1, A2A, A2B and A3 receptors in mammals. Among these receptors, A2A has been demonstrated to be related to pathogenesis of many diseases. In the present review, we focus on the recent progress made in investigating the relationship between A2A and nervous system disorders, which may provide new strategies for treatment of these diseases.

Adenosine A2A receptor and nervous system diseases / 国际药学研究杂志

Adenosine, which arises from the breakdown of adenosine triphosphate, is extensively distributed in mammalian tissues and cells. Adenosine exerts its regulating effects on cell function via binding to the specific membrane receptors. Adenosine receptors are belong to G-protein-coupled receptors and can be subdivided into Ai, A2A, A2B and A3 receptors in mammals. Among these receptors, A2A has been demonstrated to be related to pathogenesis of many diseases. In the present review, we focus on the recent progress made in investigating the relationship between A2A and nervous system disorders, which may provide new strategies for treatment of these diseases.

Effect of adenosine A2A receptor on stress response of pituitary-adrenal axis in acute phase of craniocerebral trauma in mice / 中华创伤杂志

Objective To investigate the effect of adenosine A2A receptor on pituitary-adrenal axis response in acute phase of moderate craniocerebral trauma.Methods Eighteen adenosine A2A receptor knock-out mice in a C57BL/6 background and another eighteen their wild-type littermates were divided into normal control group and craniocerebral trauma for 4 hours group,and craniocerebral trauma for 24 hours group according to random number table,with siμ mice per group.Plasma levels of adrenocorticotropic-hormone (ACTH) and corticosterone at hours 4 and 24 postinjury were determined using ELISA method.Results At 4 and 24 hours,brain water content in wild-type mice [(80.950 ± 0.184) ％,(82.178 ± 0.255)％ respectively] was higher than that in gene knock-out mice [(80.006 ± 0.199)％,(81.091 ± 0.295)％ respectively,P ＜ 0.01].Besides,brain water content in both wild-type and gene knock-out mice increased after injury (P ＜ 0.01).Plasma levels of ACTH and corticosterone were higher in geneknock-out sham mice than in wild-type sham mice [(120.214 ± 2.472) ng/L vs (91.767 ±7.395) ng/L,(27.814 ±0.888) μg/L vs (11.430 ±0.644) μg/L respectively,P ＜0.0l].At 4 and 24 hours,plasma levels of ACTH [(174.776-± 5.040) ng/L,(189.613 ± 4.802) ng/L respectively] in geneknock-out mice showed a higher increase than those in wild-type mice [(119.594 ± 6.945) ng/L,(124.93-± 11.001 7) ng/L respectively,P ＜ 0.05].Moreover,plasma levels of corticosterone [(40.138 ±-0.805) μg/L] at 4 hours and [(37.440-0.485)μg/L] at 24 hours in gene knock-out mice showed a same result as compared with that in wild-type mice [(19.702 ± 0.804) μg/L,(17.602 ± 0.743) μg/L respectively,P ＜ 0.05].Conclusions Knock-out of adenosine A2A receptor increases the release of ACTH and corticosterone in acute stage of moderate craniocerebral trauma and promotes pituitary-adrenal stress response.This may provide a novel explanation for the neuroprotective effect of A2A receptor deficiency.

The effects of adenosine A2A receptor antagonist on the behavior and the striatal A2A receptor,metabotropic glutamate receptors protein expression in rats with levodopa-induced dyskinesia / 中华神经科杂志

Objective To study the behavioural changes and biological effects of selective adenosine A2A receptor antagonist (CSC) in a rat model of levodopa(L-DOPA) -induced dyskinesia (LID).Methods The hemi-parkinsonian rat model was produced by stereotaxically injecting 6-OHDA to the right medial forebrain bundle. Rats were randomly divided into 4 treatment groups with a random number generating program to receive intraperitoneal injections twice daily for 21 days (n = 10): saline, L-DOPA at 25 mg/kg with benserazide at 6. 25 mg/kg, CSC at 2. 5 mg/kg alone and CSC at 2.5 mg/kg with L-DOPA at 25 mg/kg plus benserazide at 6. 25 mg/kg. Forepaw adjusting steps, abnormal involuntary movements (AIM) and rotational response duration were observed on 2, 9, 11,18 and 21 d. After sacrifice, the expression of adenosine A2A R and mGluR5 was observed by Western blot. Results Co-administration of LDOPA with CSC significantly increased the forelimb adjusting steps of parkinsonian rats during 21 days of treatment when compared to L-DOPA alone. CSC treatment alone increased the forelimb adjusting steps significantly. Co-administration of L-DOPA with CSC ( ( 11 ± 5 ) score) significantly decreased the AIM scores of limb and orolingual muscles when compared to L-DOPA alone (( 17 ± 4) score; t = 2. 44, P ＜0. 05). The subchronic L-DOPA treatment upregulated the striatal expression of adenosine A2A R and mGluR5. However, co-administration of L-DOPA with CSC reversed the shortening of the rotational motor response duration induced by L-DOPA administration during the period of the treatment and attenuated the LDOPA-induced upregulation of adenosine A2A R and mGluR5 expressions. Conclusions CSC improves motor function in a hemi-parkinson rat model, potentiates the antiparkinsonian effects with L-DOPA and partly attenuates LID. Co-administration of L-DOPA with CSC reverses the L-DOPA-induced upregulated expression of A2A R and mGluR5, indicating the involvement of both A2A R and mGluR5 in the onset and progression of LID. Adenosine A2AR antagonists may be promising drugs for treatment of LID.

The dynamic changes of adenosine receptors imbalance during kindling by lithium chloride-pilocarpine / 中华神经科杂志

Objective To investigate the dynamic changes of adenosine receptors, A1 (A1R) and A2a (A2aR) in the brain from the acute to chronic phase after kindling and to explore the correlation between seizure and expression level of A1R and A2aR. MethodsRats were randomly selected into the testing model, reference and normal control groups.Testing rats were kindled by lithium choride-pilocarpine, reference rats were treated with saline, and no treatment was given in normal control group. The dynamic expression of A1R and A2aR were detected by RT-PCR, immunofluorescence staining and Western blot at time-points of 24 hours, 1 month and 6 months post-kindling. Results In the acute phase of 24 hours after kindling, the A1R expression level (mRNA level was (1. 1483 ±0. 1182); Western blot result was ( 0. 7872± 0. 0621 ) ; immunofluorescence staining count was ( 76. 17 ± 4. 62 )/HP) was increased and A2aR (mRNA level was (0. 8338±0. 0572) ; Western blot result was (0. 2098 ±0. 0257) ; immunofluorescence staining count was (43. 83 ± 5. 12 )/HP) was decreased.The results showed statistically difference compared with the reference and normal groups (P< 0. 05 ). In the later chronic phase of 1 month and 6 months after kindling, the expression level of A1R was decreased and A2aR was increased. These data revealed statistically significant difference (P <0. 01 ). Furthermore, the comparison of the results in 1 month and 6 months after kindling found that the expression of AIR was lower in 6 months (mRNA level was (0. 5682 ±0. 0443) ; Western blot result was (0. 7749 ±0. 0262) ; immunofluorescence staining count was (38. 50 ±4. 81 )/HP) than in 1 month and that of A2aR was higher in 6 months (mRNA level was (1. 2169±0. 0332) ; Western blot result was (0. 7080 ±0. 0371 ); immunofluorescence staining count was (114. 50 ± 4. 04)/HP). The differences were statistical significant (t = - 19. 02--13.28, P < 0. 05). ConclusionsThe expressions of A1R and A2AR during and after kindling presents a bidirectional change. In the acute phas the expression of AR is regulated to suppress seizures. While in the chronic phase, the repeated seizures result in the change of A1R and A2aR expression in the opposite direction. This mechanism plays an important role in refractory seizures.

Adenosine A2A receptor antagonist 8-( 3-Chlorostyryl) caffeine improves motor complication in Parkinson's disease / 中华神经科杂志

Objective To investigate cellular and behavioral effects of adenosine A2A receptor antagonist in a rat model of levodopa-induced motor complications.Methods The hemi-parkinsonian rat model was produced by stereotaxically injecting 6-OHDA to right medial forebmin bundle(MFB).Animals were intraperitoneally treated with levodopa 50 mg/kg plus benserazide 12.5 mg/kg twice a day for 22 days levodopa + vehicle.Rotational duration was estimated.After they were sacrificed,the expression of adenosine A2A receptor was observed by immunohistochemistry and Western blot.Results CSC,reversing the shortened rotational duration induced by levodopa,prolonged the rotational duration.This effect was maintained fil the end of the treatment.The chronic levedopa treatment induced an upregulation of adenosine A2A receptor expression in the lesioned striatum (IOD,(11.55±2.75)×104).The subsequent CSC treatment decreased the adenosine A2A receptor expression to the level of control (IOD,(6.02±1.29)× 104) and PD group (IOD,(5.60±1.83)×104>,F=33.31,P<0.05).Conclusion These results suggest that adenosine A2A receptor is probably involved in the development of levodopa induced motor complications and adenosine A2A receptor antagonist could be useful in the treatment of motor comphcations in parkinsonian patients.

A novel therapy for PD-adenosine A_ (2A) receptor antagonist / 中国药理学通报

Adenosine A_ 2A receptors are selectively localized in basal ganglia and can affect the locomotor activity. Epidemiological and laboratory data have suggested that A_ 2A blockade may confer neuroprotection against the underlying dopaminergic neuron degeneration. A_ 2A receptor antagonist may ameliorate the symptom of Parkinsons disease (PD) and block the disease progress. Thus, the data suggested that A_ 2A receptor antagonist might be effective as a novel therapy for the management of PD.