The purpose of the present study was to investigate the effect of glutamate scavenger oxaloacetate (OA) combined with CGS21680, an adenosine A2A receptor (A2AR) agonist, on acute traumatic brain injury (TBI), and to elucidate the underlying mechanisms. C57BL/6J mice were subjected to moderate-level TBI by controlled cortical impact, and then were treated with OA, CGS21680, or OA combined with CGS21680 at acute stage of TBI. At 24 h post TBI, neurological severity score, brain water content, glutamate concentration in cerebrospinal fluid (CSF), mRNA and protein levels of IL-1β and TNF-α, mRNA level and activity of glutamate oxaloacetate aminotransferase (GOT), and ATP level of brain tissue were detected. The results showed that neurological deficit, brain water content, glutamate concentration in CSF, and the inflammatory cytokine IL-1β and TNF-α production were exacerbated in CGS21680 treated mice. Administrating OA suppressed the rise of both glutamate concentration in CSF and brain water content, and elevated the ATP level of cerebral tissue. More interestingly, neurological deficit, brain edema, glutamate concentration, IL-1β and TNF-α levels were ameliorated significantly in mice treated with OA combined with CGS21680. The combined treatment exhibited better therapeutic effects than single OA treatment. We also observed that GOT activity was enhanced in single CGS21680 treatment group, and both the GOT mRNA level and GOT activity were up-regulated in early-stage combined treatment group. These results suggest that A2AR can improve the efficiency of GOT and potentiate the ability of OA to metabolize glutamate. This may be the mechanism that A2AR activation in combination group augmented the neuroprotective effect of OA rather than aggravated the brain damages. Taken together, the present study provides a new insight for the clinical treatment of TBI with A2AR agonists and OA.
Adenosine A2 Receptor Agonists/therapeutic use* ; Adenosine Triphosphate ; Animals ; Brain Injuries/metabolism* ; Brain Injuries, Traumatic/metabolism* ; Glutamic Acid ; Mice ; Mice, Inbred C57BL ; Neuroprotective Agents/therapeutic use* ; Oxaloacetic Acid/therapeutic use* ; RNA, Messenger ; Receptor, Adenosine A2A/metabolism* ; Tumor Necrosis Factor-alpha/genetics* ; Water

Adenosine is a metabolite produced abundantly in the tumor microenvironment, dampening immune response in inflamed tissues via adenosine A2A receptor (A2AR) which is widely expressed on immune cells, inhibiting anti-tumor immune response accordingly. Therefore, blocking adenosine signaling pathway is of potential to promote anti-tumor immunity. This review briefly introduces adenosine signaling pathway, describes its role in regulating tumor immunity and highlights A2AR blockade in cancer therapy. Prospective anti-tumor activity of adenosine/A2AR inhibition has been revealed by preclinical data, and a number of clinical trials of A2AR antagonists are under way. Primary results from clinical trials suggest that A2AR antagonists are well tolerated in cancer patients and are effective both as monotherapy and in combination with other therapies. In the future, finding predictive biomarkers are critical to identify patients most likely to benefit from adenosine pathway blockade, and further researches are needed to rationally combine A2AR antagonists with other anti-tumor therapies.
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Adenosine/therapeutic use* ; Adenosine A2 Receptor Antagonists/therapeutic use* ; Humans ; Lung Neoplasms ; Receptor, Adenosine A2A/metabolism* ; Tumor Microenvironment

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.
Adenosine ; Animals ; Binding Sites ; Caffeine ; Electroencephalography ; Epilepsy ; Eye Movements ; Flumazenil ; Hand ; Hypnotics and Sedatives ; Luteolin ; Mice ; Receptor, Adenosine A1 ; Receptor, Adenosine A2A ; Sleep Initiation and Maintenance Disorders

OBJECTIVE: To explore the role of the low-affinity A2b adenosine receptors (Adora2b) in pulmonary microvascular endothelial inflammation induced by lipopolysaccharide and its mechanism. METHODS: Rat pulmonary microvascular endothelial cells (PMVECs) were isolated and cultured in vitro. After serum deprivation for 24 hours, cells were pretreated with Adora2b specific agonist BAY60-6583 (0.1, 1, 10 μmol/L) or Adora2b specific antagonist PSB1115 (1 μmol/L) for 1 hour, respectively, and then challenged with LPS (100 μg/L). Cells without treatment were served as the control group, and those treated with LPS, BAY60-6583 or PSB1115 alone were served as single challenge groups. After incubation with specific drugs for 24 hours, the apoptosis of PMVECs was analyzed by flow cytometry using Annexin V/propidium iodide (PI) technique. The levels of early inflammatory factors in cultured medium were measured using enzyme linked immunosorbent assay (ELISA). The mRNA expressions of chemotactic factors and adhesion molecules were determined by real-time quantitative-polymerase chain reaction (RT-qPCR). Polymorph nuclear neutrophils (PMNs) from venous blood of healthy rats were isolated, and PMN migration through PMVECs monolayer under stimulation of drugs was observed in transwell inserts. The monolayer permeability of PMVECs after adhesion of PMNs was determined by fluorescein isothiocyanate (FITC)-albumin assay. Oxidative stress was detected by DCFH-DA assay. RESULTS: Compared with the control group, more cells entered into the apoptosis stage after LPS challenge. Meanwhile, the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in cultured medium were significantly increased, as well as the mRNA expressions of chemotactic factors [C-X-C motif chemokine ligand 1 (CXCL-1), CXCL-3 and monocyte chemoattractant protein-1 (MCP-1)] and adhesion molecules [E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1)]. More PMNs migrated through PMVECs following adhesion and the monolayer permeability of PMVECs was rapidly enhanced. The oxidative stress was upregulated. Compared with LPS group, BAY60-6583 pretreatment could dose-dependently decrease the rate of apoptosis, attenuate trans-endothelial migration of PMNs and decrease the endothelial cell barrier leakage. There were significant differences even after incubation of 0.1 μmol/L BAY60-6583 [apoptosis rate: (21.12±2.12)% vs. (27.66±3.57)%, number of migrated PMNs/HP: 260.60±18.24 vs. 290.20±16.48, permeability coefficient (Pd, ×10^-6 cm/s): 28.28±2.04 vs. 32.55±2.13, all P < 0.05]. Meanwhile, BAY60-6583 pretreatment also downregulated the levels of early proinflammatory factors in a dose-dependent manner as well as the mRNA expressions of chemotactic factors and adhesion molecules. The statistic difference was significant while treated with 1 μmol/L BAY60-6583 [IL-1β (ng/L): 475.75±63.15 vs. 755.25±67.42, TNF-α (ng/L): 560.25±69.96 vs. 818.75±60.92, CXCL-1 mRNA (2^-ΔΔCt): 3.57±0.28 vs. 5.27±0.69, CXCL-3 mRNA (2^-ΔΔCt): 4.56±0.48 vs. 7.32±0.54, MCP-1 mRNA (2^-ΔΔCt): 2.21±0.31 vs. 3.35±0.21, E-selectin mRNA (2^-ΔΔCt): 4.64±0.09 vs. 7.28±0.73, ICAM-1 mRNA (2^-ΔΔCt): 4.14±0.30 vs. 5.89±0.25, VCAM-1 mRNA (2^-ΔΔCt): 2.23±0.19 vs. 2.92±0.33, all P < 0.05]. Furthermore, pretreatment of 10 μmol/L BAY60-6583 could decrease the oxidative stress [reactive oxygen species (RFU): 629.05±33.10 vs. 781.45±64.59, P < 0.05]. Contrast, PSB1115 pretreatment aggravated apoptosis of PMVECs after LPS incubation [(34.36±4.57)% vs. (27.66±3.57)%], upregulated expressions of proinflammatory and chemotactic factors as well as adhesion molecules [IL-1β (ng/L): 889.00±63.11 vs. 755.25±67.42, TNF-α (ng/L): 939.00±43.44 vs. 818.75±60.92, CXCL-1 mRNA (2^-ΔΔCt): 6.66±0.65 vs. 5.27±0.69, CXCL-3 mRNA (2^-ΔΔCt): 10.42±0.51 vs. 7.32±0.54, MCP-1 mRNA (2^-ΔΔCt): 4.85±0.34 vs. 3.35±0.21, E-selectin mRNA (2^-ΔΔCt): 8.42±0.47 vs. 7.28±0.73, ICAM-1 mRNA (2^-ΔΔCt): 7.46±0.72 vs. 5.89±0.25, VCAM-1 mRNA (2^-ΔΔCt): 4.35±0.26 vs. 2.92±0.33], aggravated trans-endothelial migration of PMNs (cells/HP: 348.40±22.68 vs. 290.20±16.48), enhanced the leakage of PMVECs monolayer [Pd (×10^-6 cm/s): 39.65±2.69 vs. 32.55±2.13] and increased oxidative stress in PMVECs [reactive oxygen species (RFU): 847.04±29.26 vs. 781.45±64.59], with statistically significant difference (all P < 0.05). CONCLUSIONS Activation of endothelial Adora2b attenuates LPS-induced pulmonary microvascular inflammation by decreasing the release of early inflammatory factors, downregulating expressions of chemotactic factors and adhesion molecules, attenuating trans-endothelial migration of PMNs and oxidative stress in PMVECs, which suggest endothelial Adora2b is apotential anti-inflammatory target in the treatment of LPS-induced acute lung injury.
Animals ; Endothelial Cells ; Inflammation ; Lipopolysaccharides/metabolism* ; Pneumonia ; Rats ; Receptor, Adenosine A2B/metabolism* ; Tumor Necrosis Factor-alpha

Polydeoxyribonucleotide (PDRN) is safe and effective in wound healing, cellular growth, synthesis of extracellular matrix protein, and inflammation reduction via activation of adenosine A2 receptors. We report a 28-year-old male patient treated with PDRN injections for chronic non-healing wound refractory to negative pressure wound therapy, skin graft, or growth factors. Three injections of PDRN were administered at the wound site into the anterior and medial sides of the left stump on the 1st, 4th, and 9th days of hospitalization. The PDRN ameliorated wound healing by enhancing cell growth, tissue repair, and angiogenesis. PDRN application represents a potential treatment for non-healing wounds obviating the need for additional therapies, and hospitalization, as well as improve patient’s activities of daily living.
Activities of Daily Living ; Adult ; Amputees* ; Extracellular Matrix ; Hospitalization ; Humans ; Inflammation ; Intercellular Signaling Peptides and Proteins ; Male ; Negative-Pressure Wound Therapy ; Polydeoxyribonucleotides ; Receptors, Adenosine A2 ; Skin ; Transplants ; Wound Healing ; Wounds and Injuries*

PURPOSE: Polydeoxyribonucleotide (PDRN), consisting of a mixture of deoxyribonucleotide polymers, has been suggested to have anti-inflammatory effects and enhance angiogenesis as an adenosine A(2A) receptor agonist. The aim of this study was to report the effectiveness of PDRN as an adjuvant therapy after surgical debridement in MRONJ (medication-related osteonecrosis of the jaw) patients. MATERIALS AND METHODS: Five patients (1 male, 4 females, age 65~79 years) who were diagnosed with MRONJ stage 2 or 3 underwent surgical debridement and PDRN mucosal injection. After surgical debridement, patients were subject to daily injection with 1 ml of PDRN around the surgical wound for 14 days. RESULT: The patients' symptoms gradually disappeared. The surgical wound uneventfully healed, and no recurrence was observed during the follow-up period. CONCLUSION: Although further studies are required, the present study first describes the possibility of PDRN as a useful option for MRONJ treatment.
Debridement ; Female ; Follow-Up Studies ; Humans ; Jaw ; Male ; Observational Study ; Osteonecrosis ; Polymers ; Receptor, Adenosine A2A ; Recurrence ; Wounds and Injuries

OBJECTIVE: To elucidate the action mechanism of Xingnaojing Injection (, XNJI) for sepsis, and to target screen the potential bioactive ingredients. METHODS: An integrated protocol that combines in silico target screen (molecular docking) and database mapping was employed to find the potential inhibitors from XNJI for the sepsis-related targets and to establish the compound-target (C-T) interaction network. The XNJI's bioactive components database was investigated and the sepsis-associated targets were comprehensively constructed; the 3D structure of adenosine receptor A2a and 5-lipoxygenase proteins were established and evaluated with homology modeling method; system network pharmacology for sepsis treatment was studied between the bioactive ingredients and the sepsis targets using computational biology methods to distinguish inhibitors from non inhibitors for the selected sepsis-related targets and C-T network construction. RESULTS: Multiple bioactive compounds in the XNJI were found to interact with multiple sepsis targets. The 32 bioactive ingredients were generated from XNJI in pharmacological system, and 21 potential targets were predicted to the sepsis disease; the biological activities for some potential inhibitors had been experimentally confirmed, highlighting the reliability of in silico target screen. Further integrated C-T network showed that these bioactive components together probably display synergistic action for sepsis treatment. CONCLUSIONS The uncovered mechanism may offer a superior insight for understanding the theory of the Chinese herbal medicine for combating sepsis. Moreover, the potential inhibitors for the sepsis-related targets may provide a good source to find new lead compounds against sepsis disease.
Arachidonate 5-Lipoxygenase ; metabolism ; Computer Simulation ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; therapeutic use ; Humans ; Injections ; Phytochemicals ; therapeutic use ; Receptor, Adenosine A2A ; metabolism ; Reproducibility of Results ; Sepsis ; drug therapy ; metabolism

OBJECTIVETo study the effects of caffeine citrate on myelin basic protein (MBP) expression in the cerebral white matter of neonatal rats with hypoxic-ischemic brain damage (HIBD) and the related mechanism.

METHODSForty-eight seven-day-old Sprague-Dawley neonatal rats were randomly assigned to 3 groups: sham operation (n=16), HIBD (n=16) and HIBD+caffeine citrate (n=16). The rats in the HIBD and HIBD+caffeine citrate groups were subjected to left common carotid artery ligation, and then were exposed to 80 mL/L oxygen and 920 mL/L nitrogen for 2 hours to induce HIBD. The rats in the sham operation group were only subjected to a sham operation, without the left common carotid artery ligation or hypoxia exposure. Caffeine citrate (20 mg/kg) was injected intraperitoneally before hypoxia ischemia (HI) and immediately, 24 hours, 48 hours and 72 hours after HI. The other two groups were injected intraperitoneally with an equal volume of normal saline at the corresponding time points. On postnatal day 12, the expression of MBP in the left subcortical white matter was detected by immunohistochemistry, and the levels of adenosine A1 receptor mRNA and A2a receptor mRNA in the left brain were detected by real-time PCR.

RESULTSThe expression of MBP in the left subcortical white matter in the HIBD group was lower than in the sham operation group (P<0.05). The MBP expression in the HIBD+caffeine citrate group was significantly higher than in the HIBD group, but was still lower than the sham operation group (P<0.05). Real-time PCR showed that the adenosine A1 receptor mRNA expression was significantly higher in the HIBD group than in the sham operation group, and it was significantly lower in the HIBD+caffeine citrate group than in the HIBD group (P<0.05).

CONCLUSIONSCaffeine citrate can improve brain white matter damage following HIBD in neonatal rats and the protection mechanism might be related with the down-regulation of adenosine A1 receptor expression.

Animals ; Animals, Newborn ; Caffeine ; pharmacology ; Citrates ; pharmacology ; Female ; Hypoxia-Ischemia, Brain ; drug therapy ; metabolism ; pathology ; Male ; Myelin Basic Protein ; analysis ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Receptor, Adenosine A1 ; genetics ; Receptor, Adenosine A2A ; genetics ; White Matter ; chemistry

OBJECTIVETo investigate the effect of adenosine A2A receptor knockout (A(2A)RKO) on relationship between continuous activation of phospho-c-Jun N-terminal kinase (P-JNK) and expression of nerve cell apoptosis in hippocampus CA1 domain of newborn mice after hypoxia/ischemia brain damage(HIBD) and its potential mechanism.

METHODSA(2A)RKO mice and adenosine A2A receptor wildtype (A(2A)RWT) littermates (n = 80) were divided into Sham operation group (S) and model group (M), 1, 3 and 7 day after HIBD, totally 8 groups. HIBD was developed with 7 day-old neonatal mice according classical Rice-Vannucci method. It was tested the effect of A(2A)RKO on short-term neurofunctional outcomes consisted of three developmental reflexes (righting, geotaxis and cliff aversion), the changes of brain pathology with hematoxylin-eosin (HE) staining and Nissl staining, the expressions of nerve cell apoptosis with terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeling(TUNEL) staining and P-JNK were observed by immunohistochemistry.

RESULTSThe neurological behavior injuries and brain histopathological damages and nerve apoptosis cells were aggravated in A(2A)RKO newborn mice after HIBD. The positive expressions of P-JNK were significantly higher in the ischemic hippocampus CA1 domain after HIBD than ones in group S respectively (P < 0.01), reaching to peak at 1 day and then began gradually decreasing. P-JNK expression in model knockout(MKO) at 1, 3 and 7 day increased greatly compared to those in the previous time point of corresponding model wildtype (MWT) (P < 0.01, P < 0.05, P > 0.05); there was a positive correlation between the expressions of P-JNK and nerve cell apoptosis after HIBD in newborn mice(r = 0.837, P < 0.01).

CONCLUSIONEarly continuous activation of P-JNK might be involved in the aggravated nerve apoptosis cells and brain damage induced by A(2A) RKO newborn mice after HIBD.

Animals ; Animals, Newborn ; Apoptosis ; Hypoxia-Ischemia, Brain ; metabolism ; pathology ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Mice ; Mice, Knockout ; Neurons ; drug effects ; metabolism ; pathology ; Receptor, Adenosine A2A ; genetics

Numerous studies have shown that adenosine or adenosine agonists can stimulate angiogenesis. However, the effect of caffeine (a known adenosine receptor antagonist) on angiogenesis has not been previously studied. Accordingly, this study was undertaken to examine the effect of caffeine on angiogenesis and to clarify the mechanism involved. Chick chorioallantoic membrane assays were used to investigate the effect of caffeine on angiogenesis and proliferation assays using human umbilical vein endothelial cells (HUVECs), were used to study its effects on specific aspects of angiogenesis. The expressions of caspase-3 and Bcl-2 were examined by western blotting, immunofluorescence staining was used to identify HUVEC morphological changes, and fluorescence activated cell sorting (FACS) and DAPI staining were used to detect HUVEC apoptosis. Caffeine was found to inhibit blood vessel formation dose-dependently and to inhibit the proliferation of HUVECs time- and dose-dependently. FACS analysis and DAPI staining showed that inhibitory effect of caffeine on HUVEC proliferation was the result of apoptosis and the up-regulation of thrombospondin-1 (TSP-1). Furthermore, TSP-1 levels were down-regulated by NECA but were unaffected by CGS21680, indicating that caffeine regulated TSP-1 expression via adenosine A2B receptor. In addition, caffeine up-regulated caspase-3 and down-regulated Bcl-2 at the protein level. These results suggest that the inhibitory effect of caffeine on angiogenesis is associated, at least in part, with its induction of endothelial cell apoptosis, probably mediated by a caspase-3 dependent mechanism.
Adenosine ; Adenosine-5'-(N-ethylcarboxamide) ; Apoptosis ; Blood Vessels ; Blotting, Western ; Caffeine ; Caspase 3 ; Chorioallantoic Membrane ; Endothelial Cells ; Flow Cytometry ; Fluorescent Antibody Technique ; Glycosaminoglycans ; Human Umbilical Vein Endothelial Cells ; Indoles ; Phenethylamines ; Receptor, Adenosine A2B ; Receptors, Purinergic P1 ; Thrombospondin 1 ; Up-Regulation