Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 83
Filter
1.
PLoS One ; 19(5): e0302829, 2024.
Article in English | MEDLINE | ID: mdl-38728342

ABSTRACT

Restless Legs Syndrome (RLS) is a common sleep disorder characterized by an urge to move the legs that is responsive to movement (particularly during rest), periodic leg movements during sleep, and hyperarousal. Recent evidence suggests that the involvement of the adenosine system may establish a connection between dopamine and glutamate dysfunction in RLS. Transcranial magnetic stimulation (TMS) is a non-invasive electrophysiological technique widely applied to explore brain electrophysiology and neurochemistry under different experimental conditions. In this pilot study protocol, we aim to investigate the effects of dipyridamole (a well-known enhancer of adenosinergic transmission) and caffeine (an adenosine receptor antagonist) on measures of cortical excitation and inhibition in response to TMS in patients with primary RLS. Initially, we will assess cortical excitability using both single- and paired-pulse TMS in patients with RLS. Then, based on the measures obtained, we will explore the effects of dipyridamole and caffeine, in comparison to placebo, on various TMS parameters related to cortical excitation and inhibition. Finally, we will evaluate the psycho-cognitive performance of RLS patients to screen them for cognitive impairment and/or mood-behavioral dysfunction, thus aiming to correlate psycho-cognitive findings with TMS data. Overall, this study protocol will be the first to shed lights on the neurophysiological mechanisms of RLS involving the modulation of the adenosine system, thus potentially providing a foundation for innovative "pharmaco-TMS"-based treatments. The distinctive TMS profile observed in RLS holds indeed the potential utility for both diagnosis and treatment, as well as for patient monitoring. As such, it can be considered a target for both novel pharmacological (i.e., drug) and non-pharmacological (e.g., neuromodulatory), "TMS-guided", interventions.


Subject(s)
Caffeine , Dipyridamole , Restless Legs Syndrome , Transcranial Magnetic Stimulation , Humans , Restless Legs Syndrome/drug therapy , Restless Legs Syndrome/physiopathology , Transcranial Magnetic Stimulation/methods , Caffeine/pharmacology , Caffeine/therapeutic use , Pilot Projects , Dipyridamole/pharmacology , Dipyridamole/therapeutic use , Male , Adenosine/metabolism , Adult , Female , Purinergic P1 Receptor Antagonists/therapeutic use , Purinergic P1 Receptor Antagonists/pharmacology , Middle Aged , Proof of Concept Study
2.
Hum Immunol ; 85(3): 110774, 2024 May.
Article in English | MEDLINE | ID: mdl-38521664

ABSTRACT

One of the ways in which macrophages support tumorigenic growth is by producing adenosine, which acts to dampen antitumor immune responses and is generated by both tumor and immune cells in the tumor microenvironment (TME). Two cell surface expressed molecules, CD73 and CD39, boost catalytic adenosine triphosphate, leading to further increased adenosine synthesis, under hypoxic circumstances in the TME. There are four receptors (A1, A2A, A2B, and A3) expressed on macrophages that allow adenosine to perform its immunomodulatory effect. Researchers have shown that adenosine signaling is a key factor in tumor progression and an attractive therapeutic target for treating cancer. Several antagonistic adenosine-targeting biological therapies that decrease the suppressive action of tumor-associated macrophages have been produced and explored to transform this result from basic research into a therapeutic advantage. Here, we'll review the newest findings from studies of pharmacological compounds that target adenosine receptors, and their potential therapeutic value based on blocking the suppressive action of macrophages in tumors.


Subject(s)
Adenosine , Immunotherapy , Neoplasms , Receptors, Purinergic P1 , Signal Transduction , Tumor Microenvironment , Humans , Adenosine/metabolism , Neoplasms/immunology , Neoplasms/therapy , Neoplasms/metabolism , Neoplasms/drug therapy , Immunotherapy/methods , Tumor Microenvironment/immunology , Animals , Receptors, Purinergic P1/metabolism , Macrophages/immunology , Macrophages/metabolism , Tumor-Associated Macrophages/immunology , Tumor-Associated Macrophages/metabolism , Molecular Targeted Therapy , Purinergic P1 Receptor Antagonists/pharmacology , Purinergic P1 Receptor Antagonists/therapeutic use
3.
Mol Neurobiol ; 60(10): 5987-6000, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37391647

ABSTRACT

All biological tissues and bodily fluids include the autacoid adenosine. The P1 class of purinergic receptors includes adenosine receptors. Four distinct G-protein-coupled receptors on the cellular membrane mediate the effects of adenosine, whose cytoplasmic content is regulated by producing/degrading enzymes and nucleoside transporters. A2A receptor has received a great deal of attention in recent years because it has a wide range of potential therapeutic uses. A2B and, more significantly, A2A receptors regulate numerous physiological mechanisms in the central nervous system (CNS). The inferior targetability of A2B receptors towards adenosine points that they might portray a promising medicinal target since they are triggered only under pharmacological circumstances (when adenosine levels rise up to micromolar concentrations). The accessibility of specific ligands for A2B receptors would permit the exploration of such a theory. A2A receptors mediate both potentially neurotoxic and neuroprotective actions. Hence, it is debatable to what extent they play a role in neurodegenerative illnesses. However, A2A receptor blockers have demonstrated clear antiparkinsonian consequences, and a significant attraction exists in the role of A2A receptors in other neurodegenerative disorders. Amyloid peptide extracellular accumulation and tau hyperphosphorylation are the pathogenic components of AD that lead to neuronal cell death, cognitive impairment, and memory loss. Interestingly, in vitro and in vivo research has shown that A2A adenosine receptor antagonists may block each of these clinical symptoms, offering a crucial new approach to combat a condition for which, regrettably, only symptomatic medications are currently available. At least two requirements must be met to determine whether such receptors are a target for diseases of the CNS: a complete understanding of the mechanisms governing A2A-dependent processes and the availability of ligands that can distinguish between the various receptor populations. This review concisely summarises the biological effects mediated by A2A adenosine receptors in neurodegenerative disorders and discusses the chemical characteristics of A2A adenosine receptor antagonists undergoing clinical trials. Selective A2A receptor blocker against neurodegenerative disorders.


Subject(s)
Adenosine , Neurodegenerative Diseases , Humans , Adenosine/pharmacology , Receptor, Adenosine A2A/metabolism , Ligands , Neurodegenerative Diseases/drug therapy , Purinergic P1 Receptor Antagonists/therapeutic use , Receptors, Purinergic P1
4.
Int J Mol Sci ; 23(21)2022 Nov 03.
Article in English | MEDLINE | ID: mdl-36362227

ABSTRACT

The adenosine A2A and A2B receptors are promising therapeutic targets in the treatment of obesity and diabetes since the agonists and antagonists of these receptors have the potential to positively affect metabolic disorders. The present study investigated the link between body weight reduction, glucose homeostasis, and anti-inflammatory activity induced by a highly potent and specific adenosine A2B receptor antagonist, compound PSB-603. Mice were fed a high-fat diet for 14 weeks, and after 12 weeks, they were treated for 14 days intraperitoneally with the test compound. The A1/A2A/A2B receptor antagonist theophylline was used as a reference. Following two weeks of treatment, different biochemical parameters were determined, including total cholesterol, triglycerides, glucose, TNF-α, and IL-6 blood levels, as well as glucose and insulin tolerance. To avoid false positive results, mouse locomotor and spontaneous activities were assessed. Both theophylline and PSB-603 significantly reduced body weight in obese mice. Both compounds had no effects on glucose levels in the obese state; however, PSB-603, contrary to theophylline, significantly reduced triglycerides and total cholesterol blood levels. Thus, our observations showed that selective A2B adenosine receptor blockade has a more favourable effect on the lipid profile than nonselective inhibition.


Subject(s)
Metabolic Diseases , Purinergic P1 Receptor Antagonists , Animals , Mice , Adenosine/pharmacology , Adenosine A2 Receptor Antagonists/pharmacology , Adenosine A2 Receptor Antagonists/therapeutic use , Adenosine A2 Receptor Antagonists/metabolism , Body Weight , Cholesterol/therapeutic use , Glucose/metabolism , Obesity/drug therapy , Obesity/metabolism , Purine Nucleosides , Purinergic P1 Receptor Antagonists/therapeutic use , Receptor, Adenosine A2B/metabolism , Theophylline , Triglycerides/therapeutic use
5.
In Vivo ; 36(5): 2186-2193, 2022.
Article in English | MEDLINE | ID: mdl-36099145

ABSTRACT

BACKGROUND/AIM: Adenosine and 4 G-protein-associated membrane receptors (A1, A2A, A2B, and A3) and their derivatives regulate the central nervous, cardiovascular, peripheral, and immune system. We developed a novel selective A3 AR antagonist, HL3501, and examined its anti-fibrotic effects across various models. MATERIALS AND METHODS: The anti-fibrotic activity of HL3501 was evaluated in three cell lines (HK2, LX2, and Primary hepatic stellate cell) and a methionine-choline-deficient (MCD) model including use of mouse pharmacokinetics (PK). RESULTS: HL3501 decreased alpha-smooth muscle actin (α-SMA) and collagen 1 in TGF-ß1-induced pro-fibrotic activation in HK2 cells. HL3501 also inhibited TGF-ß1-induced HSC activation, which resulted in reduction of α-SMA and fibronectin in LX2 and human primary HSCs. In the nonalcoholic fatty liver disease activity score (NAS) analysis, HL3501 showed improved anti-steatosis and anti-inflammatory activity. The mouse PK study revealed the oral bioavailability (%F) of HL3501 at 30 mg/kg and 60 mg/kg as 92.5 and 107.2%, respectively. CONCLUSION: HL3501 presents anti-fibrotic effects in in vitro and in vivo studies. We also demonstrated that HL3501 is orally available and has a good bioavailability (BA >90%) profile from in mouse PK. HL3501, therefore, has a therapeutic potential for various fibrotic diseases, including those of liver and kidney tissues.


Subject(s)
Kidney Diseases , Liver Cirrhosis , Adenosine/pharmacology , Animals , Fibrosis , Humans , Liver Cirrhosis/drug therapy , Liver Cirrhosis/metabolism , Mice , Purinergic P1 Receptor Antagonists/therapeutic use , Transforming Growth Factor beta1/metabolism
6.
Front Immunol ; 13: 996446, 2022.
Article in English | MEDLINE | ID: mdl-36148230

ABSTRACT

Adenosine shows a significant immunosuppressive effect in sepsis via binding to the adenosine 2a receptor (A2aR). Both genetic deletion and pharmacological inhibition of the A2aR may improve survival in sepsis. However, available research on this protective mechanism is quite limited. We used an A2aR antagonist (ZM241385) to treat a cecal ligation and puncture model of normal mice or regulatory T-cell (Treg)-depletion mice and found that the protective effect of ZM241385 is dependent on Tregs. Mechanically, A2aR inactivation was associated with decreased frequencies and reduced function of Foxp3+ Tregs, as evidenced by Foxp3 and CTLA-4 expression and classical effector T-cell proliferative assays, suggesting Treg modulation is a potential protective mechanism against sepsis. Simultaneously, the function and quantity of abdominal neutrophils were improved with ZM241385 treatment. To see if a link exists between them, Tregs and neutrophils were co-cultured, and it was found that ZM241385 blocked the inhibitory effect of Tregs on neutrophils. According to our research, Tregs play a key role in how A2aR antagonists improve sepsis prognosis and bacterial clearance.


Subject(s)
Sepsis , T-Lymphocytes, Regulatory , Adenosine/metabolism , Animals , CTLA-4 Antigen/metabolism , Forkhead Transcription Factors/metabolism , Mice , Purinergic P1 Receptor Antagonists/metabolism , Purinergic P1 Receptor Antagonists/pharmacology , Purinergic P1 Receptor Antagonists/therapeutic use , Survival Rate
7.
Clin Cancer Res ; 28(22): 4871-4884, 2022 11 14.
Article in English | MEDLINE | ID: mdl-36044531

ABSTRACT

PURPOSE: To evaluate AZD4635, an adenosine A2A receptor antagonist, as monotherapy or in combination with durvalumab in patients with advanced solid tumors. PATIENTS AND METHODS: In phase Ia (dose escalation), patients had relapsed/refractory solid tumors; in phase Ib (dose expansion), patients had checkpoint inhibitor-naïve metastatic castration-resistant prostate cancer (mCRPC) or colorectal carcinoma, non-small cell lung cancer with prior anti-PD-1/PD-L1 exposure, or other solid tumors (checkpoint-naïve or prior anti-PD-1/PD-L1 exposure). Patients received AZD4635 monotherapy (75-200 mg once daily or 125 mg twice daily) or in combination with durvalumab (AZD4635 75 or 100 mg once daily). The primary objective was safety; secondary objectives included antitumor activity and pharmacokinetics; exploratory objectives included evaluation of an adenosine gene signature in patients with mCRPC. RESULTS: As of September 8, 2020, 250 patients were treated (AZD4635, n = 161; AZD4635+durvalumab, n = 89). In phase Ia, DLTs were observed with monotherapy (125 mg twice daily; n = 2) and with combination treatment (75 mg; n = 1) in patients receiving nanosuspension. The most common treatment-related adverse events included nausea, fatigue, vomiting, decreased appetite, dizziness, and diarrhea. The RP2D of the AZD4635 capsule formulation was 75 mg once daily, as monotherapy or in combination with durvalumab. The pharmacokinetic profile was dose-proportional, and exposure was adequate to cover target with 100 mg nanosuspension or 75 mg capsule once daily. In patients with mCRPC receiving monotherapy or combination treatment, tumor responses (2/39 and 6/37, respectively) and prostate-specific antigen responses (3/60 and 10/45, respectively) were observed. High versus low blood-based adenosine signature was associated with median progression-free survival of 21 weeks versus 8.7 weeks. CONCLUSIONS: AZD4635 monotherapy or combination therapy was well tolerated. Objective responses support additional phase II combination studies in patients with mCRPC.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Prostatic Neoplasms, Castration-Resistant , Male , Humans , B7-H1 Antigen , Carcinoma, Non-Small-Cell Lung/drug therapy , Adenosine A2 Receptor Antagonists/adverse effects , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/etiology , Purinergic P1 Receptor Antagonists/therapeutic use , Receptor, Adenosine A2A/genetics , Receptor, Adenosine A2A/therapeutic use , Lung Neoplasms/drug therapy , Adenosine , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics
8.
Br J Pharmacol ; 179(22): 5074-5088, 2022 11.
Article in English | MEDLINE | ID: mdl-35861684

ABSTRACT

BACKGROUND AND PURPOSE: Recently pentoxifylline, a non-selective phosphodiesterase inhibitor and adenosine receptor antagonist, has attracted much interest for the treatment of the increased vascular resistance and endothelial dysfunction in pre-eclampsia. We therefore investigated the placental transfer, vascular effects and anti-inflammatory actions of pentoxifylline in healthy and pre-eclamptic human placentas. EXPERIMENTAL APPROACH: The placental transfer and metabolism of pentoxifylline were studied using ex vivo placenta perfusion experiments. In wire myography experiments with chorionic plate arteries, pentoxifyllines vasodilator properties were investigated, focusing on the cGMP and cAMP pathways and adenosine receptors. Its effects on inflammatory factors were also studied in placental explants. KEY RESULTS: Pentoxifylline transferred from the maternal to foetal circulation, reaching identical concentrations. The placenta metabolized pentoxifylline into its active metabolite lisofylline (M1), which was released into both circulations. In healthy placentas, pentoxifylline potentiated cAMP- and cGMP-induced vasodilation, as well as causing vasodilation by adenosine A1 antagonism and via NO synthase and PKG. Pentoxifylline also reduced inflammatory factors secretion. In pre-eclamptic placentas, we observed that its vasodilator capacity was preserved, however not via NO-PKG but likely through adenosine signalling. Pentoxifylline neither potentiated vasodilation through cAMP and cGMP, nor suppressed the release of inflammatory factors from these placentas. CONCLUSION AND IMPLICATIONS: Pentoxifylline is transferred across and metabolized by the placenta. Its beneficial effects on the NO pathway and inflammation are not retained in pre-eclampsia, limiting its application in this disease, although it could be useful for other placenta-related disorders. Future studies might focus on selective A1 receptor antagonists as a new treatment for pre-eclampsia.


Subject(s)
Pentoxifylline , Pre-Eclampsia , Adenosine/pharmacology , Anti-Inflammatory Agents/pharmacology , Cyclic GMP/metabolism , Female , Humans , Nitric Oxide Synthase/metabolism , Pentoxifylline/metabolism , Pentoxifylline/pharmacology , Pentoxifylline/therapeutic use , Phosphodiesterase Inhibitors/pharmacology , Phosphodiesterase Inhibitors/therapeutic use , Placenta/metabolism , Pre-Eclampsia/drug therapy , Pregnancy , Purinergic P1 Receptor Antagonists/metabolism , Purinergic P1 Receptor Antagonists/pharmacology , Purinergic P1 Receptor Antagonists/therapeutic use , Vasodilator Agents/pharmacology
9.
Curr Med Chem ; 29(28): 4780-4795, 2022 08 06.
Article in English | MEDLINE | ID: mdl-35184706

ABSTRACT

Endogenous nucleoside adenosine modulates a number of physiological effects through interaction with P1 purinergic receptors. All of them are G protein-coupled receptors, and, to date, four subtypes have been characterized and named A1, A2A, A2B, and A3. In recent years, adenosine receptors, particularly the A2A subtype, have become attractive targets for the treatment of several neurodegenerative disorders, known to involve neuroinflammation, like Parkinson's and Alzheimer's diseases, multiple sclerosis, and neuropsychiatric conditions. In fact, it has been demonstrated that inhibition of A2A adenosine receptors exerts neuroprotective effects counteracting neuroinflammatory processes and astroglial and microglial activation. The A2A adenosine receptor antagonist istradefylline, developed by Kyowa Hakko Kirin Inc., was approved in Japan as adjunctive therapy for the treatment of Parkinson's disease, and very recently, it was also approved by the US Food and Drug Administration. These findings pave the way for new therapeutic opportunities, so, in this review, a summary of the most relevant and promising A2A adenosine receptor antagonists will be presented along with their preclinical and clinical studies in neuroinflammation related diseases.


Subject(s)
Neuroprotective Agents , Parkinson Disease , Adenosine/therapeutic use , Adenosine A2 Receptor Antagonists/pharmacology , Adenosine A2 Receptor Antagonists/therapeutic use , Humans , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Parkinson Disease/drug therapy , Purinergic P1 Receptor Antagonists/therapeutic use , Receptor, Adenosine A2A
10.
Curr Med Chem ; 29(24): 4138-4151, 2022.
Article in English | MEDLINE | ID: mdl-34844537

ABSTRACT

BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia worldwide, with approximately 6 million cases reported in America in 2020. The clinical signs of AD include cognitive dysfunction, apathy, anxiety and neuropsychiatric signs, and pathogenetic mechanisms that involve amyloid peptide-ß extracellular accumulation and tau hyperphosphorylation. Unfortunately, current drugs to treat AD can provide only symptomatic relief but are not disease-modifying molecules able to revert AD progression. The endogenous modulator adenosine, through A2A receptor activation, plays a role in synaptic loss and neuroinflammation, which are crucial for cognitive impairment and memory damage. OBJECTIVE: In this review, recent advances covering A2A adenosine receptor antagonists will be extensively reviewed, providing a basis for the rational design of future A2A inhibitors. METHODS: Herein, the literature on A2A adenosine receptors and their role in synaptic plasticity and neuroinflammation, as well as the effects of A2A antagonism in animal models of AD and in humans, are reviewed. Furthermore, current chemical and structure-based strategies are presented. RESULTS: Caffeine, the most widely consumed natural product stimulant and an A2A antagonist, improves human memory. Similarly, synthetic A2A receptor antagonists, as described in this review, may provide a means to fight AD. CONCLUSION: This review highlights the clinical potential of A2A adenosine receptor antagonists as a novel approach to treat patients with AD.


Subject(s)
Alzheimer Disease , Neurodegenerative Diseases , Adenosine A2 Receptor Antagonists/pharmacology , Adenosine A2 Receptor Antagonists/therapeutic use , Alzheimer Disease/drug therapy , Amyloid beta-Peptides , Animals , Caffeine/therapeutic use , Humans , Neurodegenerative Diseases/drug therapy , Purinergic P1 Receptor Antagonists/therapeutic use , Receptor, Adenosine A2A
11.
Cells ; 10(11)2021 10 21.
Article in English | MEDLINE | ID: mdl-34831054

ABSTRACT

Extracellular adenosine accumulates in the environment of numerous tumors. For years, this fact has fueled preclinical research to determine whether adenosine receptors (ARs) could be the target to fight cancer. The four ARs discovered so far, A1, A2A, A2B and A3, belong to the class A family of G protein-coupled receptors (GPCRs) and all four have been involved in one way or another in regulating tumor progression. Prompted by the successful anti-cancer immunotherapy, the focus was placed on the ARs more involved in regulation of immune cell differentiation and activation and that are able to establish molecular and functional interactions. This review focuses on the potential of A2A and A2B receptor antagonists in cancer control and in boosting anti-cancer chemotherapy and immunotherapy. The article also overviews the ongoing clinical trials in which A2AR and A2BR ligands are being tested in anti-cancer therapy.


Subject(s)
Antineoplastic Agents/therapeutic use , Immunotherapy , Neoplasms/drug therapy , Purinergic P1 Receptor Antagonists/therapeutic use , Animals , Antineoplastic Agents/pharmacology , Clinical Trials as Topic , Humans , Immune System/drug effects , Immune System/metabolism , Purinergic P1 Receptor Antagonists/pharmacology
12.
ACS Chem Neurosci ; 12(23): 4438-4448, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34672533

ABSTRACT

Respiratory dysfunction is a major cause of death in people with spinal cord injury (SCI). A remaining unsolved problem in treating SCI is the intolerable side effects of the drugs to patients. In a significant departure from conventional targeted nanotherapeutics to overcome the blood-brain barrier (BBB), this work pursues a drug-delivery approach that uses neural tracing retrograde transport proteins to bypass the BBB and deliver an adenosine A1 receptor antagonist drug, 1,3-dipropyl-8-cyclopentyl xanthine, exclusively to the respiratory motoneurons in the spinal cord and the brainstem. A single intradiaphragmatic injection at one thousandth of the native drug dosage induces prolonged respiratory recovery in a hemisection animal model. To translate the discovery into new treatments for respiratory dysfunction, we carry out this study to characterize the purity and quality of synthesis, stability, and drug-release properties of the neural tracing protein (wheat germ agglutinin chemically conjugated to horseradish peroxidase)-coupled nanoconjugate. We show that the batch-to-batch particle size and drug dosage variations are less than 10%. We evaluate the nanoconjugate size against the spatial constraints imposed by transsynaptic transport from pre to postsynaptic neurons. We determine that the nanoconjugate formulation is capable of sustained drug release lasting for days at physiologic pH, a prerequisite for long-distance transport of the drug from the diaphragm muscle to the brainstem. We model the drug-release profiles using a first-order reaction model and the Noyes-Whitney diffusion model. We confirm via biological electron microscopy that the nanoconjugate particles do not accumulate in the tissues at the injection site. We define the nanoconjugate storage conditions after monitoring the solution dispersion stability under various conditions for 4 months. This study supports further development of neural tracing protein-enabled nanotherapeutics for treating respiratory problems associated with SCI.


Subject(s)
Pharmaceutical Preparations , Spinal Cord Injuries , Animals , Drug Liberation , Humans , Motor Neurons , Nanoconjugates , Purinergic P1 Receptor Antagonists/therapeutic use , Spinal Cord Injuries/drug therapy
13.
Trends Cancer ; 7(8): 731-750, 2021 08.
Article in English | MEDLINE | ID: mdl-34074623

ABSTRACT

ATP hydrolysis and downstream signaling pathways in the extracellular space have a major impact upon tumor progression and metastasis. The complexity and interdependence of various cell types in the extracellular space have been increasingly appreciated in recent years. With increased awareness of the importance of this signaling pathway in the pathogenic development and progression of malignancies, there has been attention to therapeutic strategies targeting extracellular adenosine metabolism and signaling. This review summarizes the molecular and physiologic roles of extracellular ATP and adenosine in normal and disease states, and potential therapeutic applications.


Subject(s)
Adenosine Triphosphate/metabolism , Adenosine/metabolism , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Neoplasms/drug therapy , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Cell Line, Tumor , Clinical Trials as Topic , Disease Models, Animal , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/immunology , Humans , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , Neoplasms/immunology , Neoplasms/metabolism , Neoplasms/pathology , Progression-Free Survival , Purinergic P1 Receptor Antagonists/pharmacology , Purinergic P1 Receptor Antagonists/therapeutic use , Purinergic P2 Receptor Antagonists/pharmacology , Purinergic P2 Receptor Antagonists/therapeutic use , Receptors, Purinergic P1/metabolism , Receptors, Purinergic P2/metabolism , Signal Transduction/drug effects , Signal Transduction/immunology , Xenograft Model Antitumor Assays
14.
J Med Chem ; 64(11): 7156-7178, 2021 06 10.
Article in English | MEDLINE | ID: mdl-34019396

ABSTRACT

The purine alkaloid caffeine is the most widely consumed psychostimulant drug in the world and has multiple beneficial pharmacological activities, for example, in neurodegenerative diseases. However, despite being an extensively studied bioactive natural product, the mechanistic understanding of caffeine's pharmacological effects is incomplete. While several molecular targets of caffeine such as adenosine receptors and phosphodiesterases have been known for decades and inspired numerous medicinal chemistry programs, new protein interactions of the xanthine are continuously discovered providing potentially improved pharmacological understanding and a molecular basis for future medicinal chemistry. In this Perspective, we gather knowledge on the confirmed protein interactions, structure activity relationship, and chemical biology of caffeine on well-known and upcoming targets. The diversity of caffeine's molecular activities on receptors and enzymes, many of which are abundant in the CNS, indicates a complex interplay of several mechanisms contributing to neuroprotective effects and highlights new targets as attractive subjects for drug discovery.


Subject(s)
Caffeine/metabolism , Chemistry, Pharmaceutical , 3',5'-Cyclic-AMP Phosphodiesterases/antagonists & inhibitors , 3',5'-Cyclic-AMP Phosphodiesterases/metabolism , Caffeine/chemistry , Caffeine/therapeutic use , Glycogen Phosphorylase/antagonists & inhibitors , Glycogen Phosphorylase/metabolism , Humans , Neurodegenerative Diseases/drug therapy , Neurodegenerative Diseases/pathology , Neuroprotective Agents/chemistry , Neuroprotective Agents/metabolism , Neuroprotective Agents/therapeutic use , Pain/drug therapy , Pain/pathology , Purinergic P1 Receptor Antagonists/chemistry , Purinergic P1 Receptor Antagonists/metabolism , Purinergic P1 Receptor Antagonists/therapeutic use , Receptors, Purinergic P1/chemistry , Receptors, Purinergic P1/metabolism
15.
Clin Transl Oncol ; 23(10): 1979-1994, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33871826

ABSTRACT

The year 2019 witnessed the first approval of an immune checkpoint inhibitor (ICI) for the management of triple negative breast cancers (TNBC) that are metastatic and programmed death ligand (PD)-L1 positive. Extensive research has focused on testing ICI-based combinatorial strategies, with the ultimate goal of enhancing the response of breast tumors to immunotherapy to increase the number of breast cancer patients benefiting from this transformative treatment. The promising investigational strategies included immunotherapy combinations with monoclonal antibodies (mAbs) against human epidermal growth factor receptor (HER)-2 for the HER2 + tumors versus cyclin-dependent kinase (CDK)4/6 inhibitors in the estrogen receptor (ER) + disease. Multiple approaches are showing signals of success in advanced TNBC include employing Poly (ADP-ribose) polymerase (PARP) inhibitors, tyrosine kinase inhibitors, MEK inhibitors, phosphatidylinositol 3­kinase (PI3K)/protein kinase B (AKT) signaling inhibitors or inhibitors of adenosine receptor, in combination with the classical PD-1/PD-L1 immune checkpoint inhibitors. Co-treatment with chemotherapy, high intensity focused ultrasound (HIFU) or interleukin-2-ßÉ£ agonist have also produced promising outcomes. This review highlights the latest combinatorial strategies under development for overcoming cancer immune evasion and enhancing the percentage of immunotherapy responders in the different subsets of advanced breast cancers.


Subject(s)
Antineoplastic Agents/therapeutic use , Immune Checkpoint Inhibitors/therapeutic use , Immunotherapy/methods , Triple Negative Breast Neoplasms/therapy , Ado-Trastuzumab Emtansine/therapeutic use , Antibodies, Monoclonal/therapeutic use , Camptothecin/analogs & derivatives , Camptothecin/therapeutic use , Cyclin-Dependent Kinase Inhibitor Proteins/therapeutic use , Drug Therapy, Combination/methods , Female , Furans/therapeutic use , High-Intensity Focused Ultrasound Ablation , Humans , Immunoconjugates/therapeutic use , Ketones/therapeutic use , Phosphoinositide-3 Kinase Inhibitors/therapeutic use , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Programmed Cell Death 1 Receptor , Protein Kinase Inhibitors/therapeutic use , Purinergic P1 Receptor Antagonists/therapeutic use , Receptor, ErbB-2/antagonists & inhibitors , Trastuzumab/therapeutic use , Triple Negative Breast Neoplasms/pathology
16.
Biomed Pharmacother ; 137: 111273, 2021 May.
Article in English | MEDLINE | ID: mdl-33524787

ABSTRACT

Diabetes mellitus (DM) and hypertension are highly prevalent worldwide health problems and frequently associated with severe clinical complications, such as diabetic cardiomyopathy, nephropathy, retinopathy, neuropathy, stroke, and cardiac arrhythmia, among others. Despite all existing research results and reasonable speculations, knowledge about the role of purinergic system in individuals with DM and hypertension remains restricted. Purinergic signaling accounts for a complex network of receptors and extracellular enzymes responsible for the recognition and degradation of extracellular nucleotides and adenosine. The main components of this system that will be presented in this review are: P1 and P2 receptors and the enzymatic cascade composed by CD39 (NTPDase; with ATP and ADP as a substrate), CD73 (5'-nucleotidase; with AMP as a substrate), and adenosine deaminase (ADA; with adenosine as a substrate). The purinergic system has recently emerged as a central player in several physiopathological conditions, particularly those linked to inflammatory responses such as diabetes and hypertension. Therefore, the present review focuses on changes in both purinergic P1 and P2 receptor expression as well as the activities of CD39, CD73, and ADA in diabetes and hypertension conditions. It can be postulated that the manipulation of the purinergic axis at different levels can prevent or exacerbate the insurgency and evolution of diabetes and hypertension working as a compensatory mechanism.


Subject(s)
Diabetes Mellitus/metabolism , Hypertension/metabolism , Purines/metabolism , Receptors, Purinergic P1/metabolism , Receptors, Purinergic P2/metabolism , 5'-Nucleotidase/metabolism , Adenosine Deaminase/metabolism , Animals , Antigens, CD/metabolism , Apyrase/metabolism , Cell Communication , Diabetes Mellitus/epidemiology , Diabetes Mellitus/physiopathology , Diabetes Mellitus/therapy , Diet, Healthy , Exercise , Humans , Hypertension/epidemiology , Hypertension/physiopathology , Hypertension/therapy , Purinergic P1 Receptor Antagonists/therapeutic use , Purinergic P2 Receptor Antagonists/therapeutic use , Signal Transduction
17.
Heart ; 107(11): 864-873, 2021 06.
Article in English | MEDLINE | ID: mdl-33462120

ABSTRACT

This article aims to give advice on how to identify and manage patients with syncope who are at risk of severe outcomes, that is, at risk of trauma, potentially life-threatening episodes or frequent recurrences reducing quality of life. The first step of syncope diagnostic assessment is to identify patients with cardiac syncope, and once established, these patients must receive the adequate mechanism-specific treatment. If cardiac syncope is unlikely, reflex (neurally mediated) syncope and orthostatic hypotension are the most frequent causes of transient loss of consciousness. For these presentations, efficacy of therapy is largely determined by the mechanism of syncope rather than its aetiology or clinical features. The identified mechanism of syncope should be carefully assessed and assigned either to hypotensive or bradycardic phenotype, which will determine the choice of therapy (counteracting hypotension or counteracting bradycardia). The results of recent trials indicate that 'mechanism-specific therapy' is highly effective in preventing recurrences. Established mechanism-specific treatment strategies include withdrawal of hypotensive drugs, applying fludrocortisone and midodrine for the hypotensive phenotype and cardiac pacing in the bradycardic phenotype.


Subject(s)
Syncope/etiology , Syncope/prevention & control , Accidental Falls , Adenosine/blood , Antihypertensive Agents/adverse effects , Atomoxetine Hydrochloride/therapeutic use , Atrioventricular Node/innervation , Atrioventricular Node/surgery , Bradycardia/complications , Bradycardia/therapy , Cardiac Pacing, Artificial , Decision Trees , Deprescriptions , Fludrocortisone/therapeutic use , Humans , Hypotension/complications , Hypotension/prevention & control , Midodrine/therapeutic use , Parasympathectomy , Purinergic P1 Receptor Antagonists/therapeutic use , Risk Assessment , Sinoatrial Node/innervation , Sinoatrial Node/surgery , Theophylline/therapeutic use
19.
Arch Iran Med ; 23(5): 312-318, 2020 05 01.
Article in English | MEDLINE | ID: mdl-32383615

ABSTRACT

BACKGROUND: As there are different views on the effects of aminophylline on neonatal renal function, we intended to observe the effects of aminophylline on renal dysfunction in neonates with prenatal asphyxia. METHODS: This randomized trial was conducted in the Obstetrics and Gynecology Hospital, Tehran, Iran, from June 2016 to May 2017, in neonates with moderate to severe asphyxia during birth. Fifty-six neonates were divided randomly into two groups. The intervention group received one dose of 5mg/kg slow intravenous aminophylline injection and the placebo group received 2 mL/kg of intravenous 10% solution of dextrose saline during the first hour of life. They were monitored and compared for renal functional indices, electrolytes, and complications of asphyxia during the three days of life. RESULTS: The mean of Cr (37.9 ± 8.8 vs 38.5 ± 9.4 and 20.8 ± 4.8 vs 30.1 ± 5.2 µmol/L), GFR (21.55 ± 4.7 vs 20.25 ± 4.4 and 30.8 ± 7.1 vs 20.1 ± 6.5 mL/minute/1.73 m2), Na (135.1 ± 12.4 vs134.5 ± 11.2 and 128.9 ± 11.5 vs 134.2 ± 10.9 mEq/L), and urine output (98.2 ± 25 vs 96.8 ± 23 and 148.7 ± 35 vs 108.8 ± 20 cc) were in the aminophylline treated and placebo group on the 1st and 3rd days, respectively. The mean difference of Cr (-9.3 (-8.9; -9.7) µmol/L); (P = 0.02), GFR (10.7 (10.1; 11.3) mL/minute/1.73 m2) (P = 0.009), Na (-5.3 (-5.9; -4.7) mEq/L) (P = 0.002), and urine volume (39.9 (24.9; 54.9) cc) (P = 0.001) presented statistically significant differences on the third day between the intervention and placebo group. CONCLUSION: Aminophylline was effective in preventing renal dysfunction in neonates with asphyxia. Neonates who received aminophylline indicated a significant improvement in GFR and urine output on the first day of life.


Subject(s)
Acute Kidney Injury/prevention & control , Aminophylline/therapeutic use , Asphyxia Neonatorum/drug therapy , Purinergic P1 Receptor Antagonists/therapeutic use , Acute Kidney Injury/physiopathology , Double-Blind Method , Female , Glomerular Filtration Rate , Humans , Infant, Newborn , Iran , Male , Urine
20.
Pharmacol Ther ; 210: 107513, 2020 06.
Article in English | MEDLINE | ID: mdl-32109489

ABSTRACT

Adenosine is an endogenous purine nucleoside ubiquitously distributed throughout the body that interacts with G protein-coupled receptors, classified in four subtypes: A1R, A2AR, A2BR and A3R. Among the plethora of functions of adenosine, it has been increasingly recognized as a key mediator of the immune response. Neuroinflammation is a feature of chronic neurodegenerative diseases and contributes to the pathophysiology of several retinal degenerative diseases. Animal models of retinal diseases are helping to elucidate the regulatory roles of adenosine receptors in the development and progression of those diseases. Mounting evidence demonstrates that the adenosinergic system is altered in the retina during pathological conditions, compromising retinal physiology. This review focuses on the roles played by adenosine and the elements of the adenosinergic system (receptors, enzymes, transporters) in the neuroinflammatory processes occurring in the retina. An improved understanding of the molecular and cellular mechanisms of the signalling pathways mediated by adenosine underlying the onset and progression of retinal diseases will pave the way towards the identification of new therapeutic approaches.


Subject(s)
Adenosine/metabolism , Inflammation Mediators/metabolism , Receptors, Purinergic P1/metabolism , Retina/metabolism , Retinitis/metabolism , Animals , Anti-Inflammatory Agents/therapeutic use , Humans , Ligands , Purinergic P1 Receptor Antagonists/therapeutic use , Retina/drug effects , Retina/immunology , Retinitis/drug therapy , Retinitis/immunology , Signal Transduction
SELECTION OF CITATIONS
SEARCH DETAIL
...