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International Journal of Molecular... Apr 2024Adenosine A receptor (AR) antagonists are the leading nondopaminergic therapy to manage Parkinson's disease (PD) since they afford both motor benefits and...
Adenosine A receptor (AR) antagonists are the leading nondopaminergic therapy to manage Parkinson's disease (PD) since they afford both motor benefits and neuroprotection. PD begins with a synaptic dysfunction and damage in the striatum evolving to an overt neuronal damage of dopaminergic neurons in the substantia nigra. We tested if AR antagonists are equally effective in controlling these two degenerative processes. We used a slow intracerebroventricular infusion of the toxin MPP in male rats for 15 days, which caused an initial loss of synaptic markers in the striatum within 10 days, followed by a neuronal loss in the substantia nigra within 30 days. Interestingly, the initial loss of striatal nerve terminals involved a loss of both dopaminergic and glutamatergic synaptic markers, while GABAergic markers were preserved. The daily administration of the AR antagonist SCH58261 (0.1 mg/kg, i.p.) in the first 10 days after MPP infusion markedly attenuated both the initial loss of striatal synaptic markers and the subsequent loss of nigra dopaminergic neurons. Strikingly, the administration of SCH58261 (0.1 mg/kg, i.p. for 10 days) starting 20 days after MPP infusion was less efficacious to attenuate the loss of nigra dopaminergic neurons. This prominent AR-mediated control of synaptotoxicity was directly confirmed by showing that the MPTP-induced dysfunction (MTT assay) and damage (lactate dehydrogenase release assay) of striatal synaptosomes were prevented by 50 nM SCH58261. This suggests that AR antagonists may be more effective to counteract the onset rather than the evolution of PD pathology.
Topics: Animals; Adenosine A2 Receptor Antagonists; Rats; Male; Disease Models, Animal; Parkinson Disease; Receptor, Adenosine A2A; Corpus Striatum; Dopaminergic Neurons; Pyrimidines; Triazoles; Substantia Nigra; Neuroprotective Agents; Rats, Sprague-Dawley
PubMed: 38732120
DOI: 10.3390/ijms25094903 -
International Journal of Molecular... Apr 2024ADORA2A (adenosine A2a receptor) and ADORA2B propagate immunoregulatory signals, including restricting both innate and adaptive immunity, though recent data also suggest...
ADORA2A (adenosine A2a receptor) and ADORA2B propagate immunoregulatory signals, including restricting both innate and adaptive immunity, though recent data also suggest a tumor suppressor effect in certain settings. We evaluated the RNA expression from 514 tumors in a clinical-grade laboratory; 489 patients with advanced/metastatic disease had clinical outcome correlates. Transcript expression was standardized to internal housekeeping genes and ranked (0-100 scale) relative to 735 specimens from 35 different cancer types. Transcript abundance rank values were defined as "low/moderate" (0-74) or "high" (75-100) percentile RNA expression ranks. Overall, 20.8% of tumors had high ADORA2A (≥75 percentile RNA rank). The greatest proportion of high ADORA2A expressors was found in neuroendocrine and breast cancers and sarcomas, whereas the lowest was found in colorectal and ovarian cancers, albeit with patient-to-patient variability. In multivariable logistic regression analysis, there was a significant positive correlation between high ADORA2A RNA expression and a high expression of the immune checkpoint-related molecules PD-1 ( = 0.015), VISTA ( ≤ 0.001), CD38 ( = 0.031), and CD39 ( ≤ 0.001). In 217 immunotherapy-treated patients, high ADORA2A did not correlate significantly with progression-free ( = 0.51) or overall survival (OS) ( = 0.09) from the initiation of the checkpoint blockade. However, high versus not-high ADORA2A transcript expression correlated with longer OS from the time of advanced/metastatic disease (N = 489 patients; (HR 0.69 (95% CI 0.51-0.95) ( = 0.02)). Therefore, high ADORA2A transcript levels may be a favorable prognostic factor, unrelated to immunotherapy. Importantly, ascertaining co-expression patterns of ADORA2A with PD-1 and VISTA in individual tumors as a basis for the precision co-targeting of ADORA2A and these other checkpoint-related molecules warrants investigation in clinical trials.
Topics: Humans; Neoplasms; Female; Male; Receptor, Adenosine A2A; Gene Expression Regulation, Neoplastic; Transcriptome; Middle Aged; Biomarkers, Tumor; Prognosis; Aged; Programmed Cell Death 1 Receptor; Adult; Apyrase
PubMed: 38731962
DOI: 10.3390/ijms25094742 -
International Journal of Molecular... Apr 2024Numerous studies suggest the involvement of adenosine-5'-triphosphate (ATP) and similar nucleotides in the pathophysiology of asthma. Androgens, such as testosterone...
Numerous studies suggest the involvement of adenosine-5'-triphosphate (ATP) and similar nucleotides in the pathophysiology of asthma. Androgens, such as testosterone (TES), are proposed to alleviate asthma symptoms in young men. ATP and uridine-5'-triphosphate (UTP) relax the airway smooth muscle (ASM) via purinergic P2Y and P2Y receptors and K channel opening. We previously demonstrated that TES increased the expression of voltage-dependent K (K) channels in ASM. This study investigates how TES may potentiate ASM relaxation induced by ATP and UTP. Tracheal tissues treated with or without TES (control group) from young male guinea pigs were used. In organ baths, tracheas exposed to TES (40 nM for 48 h) showed enhanced ATP- and UTP-evoked relaxation. Tetraethylammonium, a K channel blocker, annulled this effect. Patch-clamp experiments in tracheal myocytes showed that TES also increased ATP- and UTP-induced K currents, and this effect was abolished with flutamide (an androgen receptor antagonist). K channels were involved in this phenomenon, which was demonstrated by inhibition with 4-aminopyridine. RB2 (an antagonist of almost all P2Y receptors except for P2Y), as well as N-ethylmaleimide and SQ 22,536 (inhibitors of G proteins and adenylyl cyclase, respectively), attenuated the enhancement of the K currents induced by TES. Immunofluorescence and immunohistochemistry studies revealed that TES did not modify the expression of P2Y receptors or COX-1 and COX-2, while we have demonstrated that this androgen augmented the expression of K1.2 and K1.5 channels in ASM. Thus, TES leads to the upregulation of P2Y signaling and K channels in guinea pig ASM, enhancing ATP and UTP relaxation responses, which likely limits the severity of bronchospasm in young males.
Topics: Animals; Uridine Triphosphate; Guinea Pigs; Muscle Relaxation; Male; Adenosine Triphosphate; Trachea; Testosterone; Adenylyl Cyclases; Muscle, Smooth; Potassium Channels, Voltage-Gated; Signal Transduction; Receptors, Purinergic P2
PubMed: 38731872
DOI: 10.3390/ijms25094652 -
Brazilian Journal of Medical and... 2024Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic...
Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic system and physical exercise modulate the gastrointestinal (GI) tract. In the current study, we investigated the role of ATP, physical exercise, and P2X7 receptor blocking on GE delay induced by cisplatin in rats. Male rats were divided into the following groups: control (C), cisplatin (Cis), exercise (Ex), Brilliant Blue G (BBG), ATP, Cis+Ex, Cis+ATP, Cis+BBG, Cis+Ex+BBG, Cis+Ex+BBG+ATP, and Cis+ATP+BBG. GE delay was induced by treatment with 1 mg/kg cisplatin (1 time/week for 5 weeks, ip). The moderate physical exercise was swimming (1 h/day, 5 days/week for 5 weeks). At the end of the treatment or exercise and 30 min before the GE assessment, some groups received BBG (50 mg/kg, sc) or ATP (2 mg/kg, sc). Then, GE was assessed after a 10-min postprandial period. Chronic use of Cis decreased GE delay (P<0.05) compared to the control group. Both exercise and ATP prevented (P<0.05) GE delay compared to Cis. The pretreatment with BBG significantly inhibited (P<0.05) the effect of exercise and ATP. On the other hand, the association between exercise and ATP reversed (P<0.05) the effect of the BBG and prevented GE delay. Therefore, we suggest that both exercise and treatment with ATP activate P2X7 receptors and prevent GE delay induced by cisplatin in rats.
Topics: Animals; Cisplatin; Male; Adenosine Triphosphate; Gastric Emptying; Receptors, Purinergic P2X7; Physical Conditioning, Animal; Rats, Wistar; Antineoplastic Agents; Rats; Purinergic P2X Receptor Antagonists
PubMed: 38716980
DOI: 10.1590/1414-431X2024e13234 -
CNS Neuroscience & Therapeutics May 2024Adenosine A3 receptor (ADORA3) belongs to the adenosine receptor families and the role of ADORA3 in vascular dementia (VaD) is largely unexplored. The present study...
BACKGROUND
Adenosine A3 receptor (ADORA3) belongs to the adenosine receptor families and the role of ADORA3 in vascular dementia (VaD) is largely unexplored. The present study sought to determine the therapeutic role of ADORA3 antagonist in a mouse model of VaD.
METHODS
The GSE122063 dataset was selected to screen the differential expression genes and pathways between VaD patients and controls. A mouse model of bilateral carotid artery stenosis (BCAS) was established. The cognitive functions were examined by the novel object recognition test, Y maze test, and fear of conditioning test. The white matter injury (WMI) was examined by 9.4 T MRI, western blot, and immunofluorescence staining. The mechanisms of ADORA3-regulated phagocytosis by microglia were examined using qPCR, western blot, dual immunofluorescence staining, and flow cytometry.
RESULTS
The expression of ADORA3 was elevated in brain tissues of VaD patients and ADORA3 was indicated as a key gene for VaD in the GSE122063. In BCAS mice, the expression of ADORA3 was predominantly elevated in microglia in the corpus callosum. ADORA3 antagonist promotes microglial phagocytosis to myelin debris by facilitating cAMP/PKA/p-CREB pathway and thereby ameliorates WMI and cognitive impairment in BCAS mice. The therapeutic effect of ADORA3 antagonist was partially reversed by the inhibition of the cAMP/PKA pathway.
CONCLUSIONS
ADORA3 antagonist alleviates chronic ischemic WMI by modulating myelin clearance of microglia, which may be a potential therapeutic target for the treatment of VaD.
Topics: Animals; Humans; Male; Mice; Brain Ischemia; Carotid Stenosis; Dementia, Vascular; Mice, Inbred C57BL; Microglia; Organic Chemicals; Phagocytosis; Receptor, Adenosine A3; White Matter
PubMed: 38715283
DOI: 10.1111/cns.14742 -
CNS Neuroscience & Therapeutics May 2024The preoptic area (POA) of the hypothalamus, crucial in thermoregulation, has long been implicated in the pain process. However, whether nociceptive stimulation affects...
AIMS
The preoptic area (POA) of the hypothalamus, crucial in thermoregulation, has long been implicated in the pain process. However, whether nociceptive stimulation affects body temperature and its mechanism remains poorly studied.
METHODS
We used capsaicin, formalin, and surgery to induce acute nociceptive stimulation and monitored rectal temperature. Optical fiber recording, chemical genetics, confocal imaging, and pharmacology assays were employed to confirm the role and interaction of POA astrocytes and extracellular adenosine. Immunofluorescence was utilized for further validation.
RESULTS
Acute nociception could activate POA astrocytes and induce a decrease in body temperature. Manipulation of astrocytes allowed bidirectional control of body temperature. Furthermore, acute nociception and astrocyte activation led to increased extracellular adenosine concentration within the POA. Activation of adenosine A1 or A2A receptors contributed to decreased body temperature, while inhibition of these receptors mitigated the thermo-lowering effect of astrocytes.
CONCLUSION
Our results elucidate the interplay between acute nociception and thermoregulation, specifically highlighting POA astrocyte activation. This enriches our understanding of physiological responses to painful stimuli and contributes to the analysis of the anatomical basis involved in the process.
Topics: Animals; Preoptic Area; Astrocytes; Nociception; Hypothermia; Male; Mice; Receptors, Purinergic P1; Mice, Inbred C57BL; Adenosine; Capsaicin; Formaldehyde
PubMed: 38715251
DOI: 10.1111/cns.14726 -
Frontiers in Physiology 2024Interleukin 13 (IL-13) is an important effector molecule in allergic asthma. IL-13-mediated mucin hypersecretion requires conversion of secretoglobin-positive club...
Interleukin 13 (IL-13) is an important effector molecule in allergic asthma. IL-13-mediated mucin hypersecretion requires conversion of secretoglobin-positive club cells into goblet cells through suppression of () and induction of (). IL-13-mediated mucin hypersecretion may also include modulation of purinergic and muscarinic receptors that control basal and stimulated mucin secretion. We recently found that the transcription factor cAMP response element-binding protein (Creb1) inhibits and modulates mucus secretion in mice. We tested the hypothesis that loss of club cell Creb1 mitigates the pro-mucin effects of IL-13. We challenged male and female mice with conditional loss of club cell Creb1 and wild type littermates with intra-airway IL-13 or vehicle. We also studied human "club cell-like" NCI-H322 cells. Loss of club cell Creb1 augmented IL-13-mediated increases in mRNA for the gel-forming mucins and and prevented IL-13-mediated decreases in () mRNA in male airways. In female airways, loss of club cell Creb1 reduced mRNA and significantly blunted IL-13-mediated increases in () mRNA but did not impact and mRNA. Despite changes in mucins and secretion machinery, goblet cell density following cholinergic stimulation was not impacted by loss of club cell Creb1 in either sex. IL-13 treatment decreased basal airway resistance across sexes in mice with loss of club cell Creb1, whereas loss of club cell Creb1 augmented IL-13-mediated increases in airway elastance in response to methacholine. NCI-H322 cells displayed IL-13 signaling components, including IL-13Rα1 and . Pharmacologic inhibition of CREB reduced IL-13Rα1 mRNA, whereas recombinant CREB decreased mRNA. Application of IL-13 to NCI-H322 cells increased concentrations of cAMP in a delayed manner, thus linking IL-13 signaling to CREB signaling. These data highlight sex-specific regulation of club cell Creb1 on IL-13-mediated mucin hypersecretion and airway mechanics.
PubMed: 38711951
DOI: 10.3389/fphys.2024.1392443 -
Frontiers in Immunology 2024Modified Vaccinia Virus Ankara (MVA) is a safe vaccine vector inducing long- lasting and potent immune responses. MVA-mediated CD8T cell responses are optimally induced,...
INTRODUCTION
Modified Vaccinia Virus Ankara (MVA) is a safe vaccine vector inducing long- lasting and potent immune responses. MVA-mediated CD8T cell responses are optimally induced, if both, direct- and cross-presentation of viral or recombinant antigens by dendritic cells are contributing.
METHODS
To improve the adaptive immune responses, we investigated the role of the purinergic receptor P2X7 (P2RX7) in MVA-infected feeder cells as a modulator of cross-presentation by non-infected dendritic cells. The infected feeder cells serve as source of antigen and provide signals that help to attract dendritic cells for antigen take up and to license these cells for cross-presentation.
RESULTS
We demonstrate that presence of an active P2RX7 in major histocompatibility complex (MHC) class I (MHCI) mismatched feeder cells significantly enhanced MVA-mediated antigen cross-presentation. This was partly regulated by P2RX7-specific processes, such as the increased availability of extracellular particles as well as the altered cellular energy metabolism by mitochondria in the feeder cells. Furthermore, functional P2RX7 in feeder cells resulted in a delayed but also prolonged antigen expression after infection.
DISCUSSION
We conclude that a combination of the above mentioned P2RX7-depending processes leads to significantly increased T cell activation via cross- presentation of MVA-derived antigens. To this day, P2RX7 has been mostly investigated in regards to neuroinflammatory diseases and cancer progression. However, we report for the first time the crucial role of P2RX7 for antigen- specific T cell immunity in a viral infection model.
Topics: Animals; Humans; Mice; Antigen Presentation; Antigens, Viral; CD8-Positive T-Lymphocytes; Cross-Priming; Dendritic Cells; Genetic Vectors; Mice, Inbred C57BL; Receptors, Purinergic P2X7; Vaccinia virus
PubMed: 38711513
DOI: 10.3389/fimmu.2024.1360140 -
Biological Research Apr 2024Astrocytes Ca signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during...
BACKGROUND
Astrocytes Ca signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during an increase in synaptic activity triggers coordinated Ca signals in astrocytes. Importantly, astrocytes express the Ca-dependent nitric oxide (NO)-synthetizing enzymes eNOS and nNOS, which might contribute to the Ca signals by triggering Ca influx or ATP release through the activation of connexin 43 (Cx43) hemichannels, pannexin-1 (Panx-1) channels or Ca homeostasis modulator 1 (CALHM1) channels. Hence, we aim to evaluate the participation of NO in the astrocytic Ca signaling initiated by stimulation of mGluR in primary cultures of astrocytes from rat brain cortex.
RESULTS
Astrocytes were stimulated with glutamate or t-ACPD and NO-dependent changes in [Ca] and ATP release were evaluated. In addition, the activity of Cx43 hemichannels, Panx-1 channels and CALHM1 channels was also analyzed. The expression of Cx43, Panx-1 and CALHM1 in astrocytes was confirmed by immunofluorescence analysis and both glutamate and t-ACPD induced NO-mediated activation of CALHM1 channels via direct S-nitrosylation, which was further confirmed by assessing CALHM1-mediated current using the two-electrode voltage clamp technique in Xenopus oocytes. Pharmacological blockade or siRNA-mediated inhibition of CALHM1 expression revealed that the opening of these channels provides a pathway for ATP release and the subsequent purinergic receptor-dependent activation of Cx43 hemichannels and Panx-1 channels, which further contributes to the astrocytic Ca signaling.
CONCLUSIONS
Our findings demonstrate that activation of CALHM1 channels through NO-mediated S-nitrosylation in astrocytes in vitro is critical for the generation of glutamate-initiated astrocytic Ca signaling.
Topics: Animals; Rats; Astrocytes; Calcium; Calcium Channels; Calcium Signaling; Cells, Cultured; Connexin 43; Glutamic Acid; Nitric Oxide; Rats, Wistar
PubMed: 38689353
DOI: 10.1186/s40659-024-00503-3 -
Nature Communications Apr 2024Optochemistry, an emerging pharmacologic approach in which light is used to selectively activate or deactivate molecules, has the potential to alleviate symptoms, cure...
Optochemistry, an emerging pharmacologic approach in which light is used to selectively activate or deactivate molecules, has the potential to alleviate symptoms, cure diseases, and improve quality of life while preventing uncontrolled drug effects. The development of in-vivo applications for optochemistry to render brain cells photoresponsive without relying on genetic engineering has been progressing slowly. The nucleus accumbens (NAc) is a region for the regulation of slow-wave sleep (SWS) through the integration of motivational stimuli. Adenosine emerges as a promising candidate molecule for activating indirect pathway neurons of the NAc expressing adenosine A receptors (ARs) to induce SWS. Here, we developed a brain-permeable positive allosteric modulator of ARs (AR PAM) that can be rapidly photoactivated with visible light (λ > 400 nm) and used it optoallosterically to induce SWS in the NAc of freely behaving male mice by increasing the activity of extracellular adenosine derived from astrocytic and neuronal activity.
Topics: Animals; Nucleus Accumbens; Male; Receptor, Adenosine A2A; Mice; Adenosine; Allosteric Regulation; Sleep, Slow-Wave; Astrocytes; Light; Neurons; Mice, Inbred C57BL; Humans; Adenosine A2 Receptor Agonists
PubMed: 38688901
DOI: 10.1038/s41467-024-47964-4