1
|
Vezzani A, Ravizza T, Bedner P, Aronica E, Steinhäuser C, Boison D. Astrocytes in the initiation and progression of epilepsy. Nat Rev Neurol 2022; 18:707-722. [PMID: 36280704 PMCID: PMC10368155 DOI: 10.1038/s41582-022-00727-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2022] [Indexed: 11/09/2022]
Abstract
Epilepsy affects ~65 million people worldwide. First-line treatment options include >20 antiseizure medications, but seizure control is not achieved in approximately one-third of patients. Antiseizure medications act primarily on neurons and can provide symptomatic control of seizures, but do not alter the onset and progression of epilepsy and can cause serious adverse effects. Therefore, medications with new cellular and molecular targets and mechanisms of action are needed. Accumulating evidence indicates that astrocytes are crucial to the pathophysiological mechanisms of epilepsy, raising the possibility that these cells could be novel therapeutic targets. In this Review, we discuss how dysregulation of key astrocyte functions - gliotransmission, cell metabolism and immune function - contribute to the development and progression of hyperexcitability in epilepsy. We consider strategies to mitigate astrocyte dysfunction in each of these areas, and provide an overview of how astrocyte activation states can be monitored in vivo not only to assess their contribution to disease but also to identify markers of disease processes and treatment effects. Improved understanding of the roles of astrocytes in epilepsy has the potential to lead to novel therapies to prevent the initiation and progression of epilepsy.
Collapse
Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy.
| | - Teresa Ravizza
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA
| |
Collapse
|
2
|
Pathophysiological Role and Medicinal Chemistry of A 2A Adenosine Receptor Antagonists in Alzheimer's Disease. Molecules 2022; 27:molecules27092680. [PMID: 35566035 PMCID: PMC9102440 DOI: 10.3390/molecules27092680] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/14/2022] [Accepted: 04/18/2022] [Indexed: 12/20/2022] Open
Abstract
The A2A adenosine receptor is a protein belonging to a family of four GPCR adenosine receptors. It is involved in the regulation of several pathophysiological conditions in both the central nervous system and periphery. In the brain, its localization at pre- and postsynaptic level in striatum, cortex, hippocampus and its effects on glutamate release, microglia and astrocyte activation account for a crucial role in neurodegenerative diseases, including Alzheimer’s disease (AD). This ailment is considered the main form of dementia and is expected to exponentially increase in coming years. The pathological tracts of AD include amyloid peptide-β extracellular accumulation and tau hyperphosphorylation, causing neuronal cell death, cognitive deficit, and memory loss. Interestingly, in vitro and in vivo studies have demonstrated that A2A adenosine receptor antagonists may counteract each of these clinical signs, representing an important new strategy to fight a disease for which unfortunately only symptomatic drugs are available. This review offers a brief overview of the biological effects mediated by A2A adenosine receptors in AD animal and human studies and reports the state of the art of A2A adenosine receptor antagonists currently in clinical trials. As an original approach, it focuses on the crucial role of pharmacokinetics and ability to pass the blood–brain barrier in the discovery of new agents for treating CNS disorders. Considering that A2A receptor antagonist istradefylline is already commercially available for Parkinson’s disease treatment, if the proof of concept of these ligands in AD is confirmed and reinforced, it will be easier to offer a new hope for AD patients.
Collapse
|
3
|
Merighi S, Borea PA, Varani K, Vincenzi F, Jacobson KA, Gessi S. A 2A Adenosine Receptor Antagonists in Neurodegenerative Diseases. Curr Med Chem 2022; 29:4138-4151. [PMID: 34844537 PMCID: PMC9148371 DOI: 10.2174/0929867328666211129122550] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/01/2021] [Accepted: 10/07/2021] [Indexed: 01/03/2023]
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-β 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.
Collapse
Affiliation(s)
- Stefania Merighi
- Department of Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy;,Address correspondence to these authors at the Department Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy; ; ; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States;
| | | | - Katia Varani
- Department of Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy
| | - Fabrizio Vincenzi
- Department of Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States,Address correspondence to these authors at the Department Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy; ; ; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States;
| | - Stefania Gessi
- Department of Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy;,Address correspondence to these authors at the Department Translational Medicine and for Romagna, University of Ferrara, 44121, Ferrara, Italy; ; ; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States;
| |
Collapse
|
4
|
Moreira-de-Sá A, Lourenço VS, Canas PM, Cunha RA. Adenosine A 2A Receptors as Biomarkers of Brain Diseases. Front Neurosci 2021; 15:702581. [PMID: 34335174 PMCID: PMC8322233 DOI: 10.3389/fnins.2021.702581] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022] Open
Abstract
Extracellular adenosine is produced with increased metabolic activity or stress, acting as a paracrine signal of cellular effort. Adenosine receptors are most abundant in the brain, where adenosine acts through inhibitory A1 receptors to decrease activity/noise and through facilitatory A2A receptors (A2AR) to promote plastic changes in physiological conditions. By bolstering glutamate excitotoxicity and neuroinflammation, A2AR also contribute to synaptic and neuronal damage, as heralded by the neuroprotection afforded by the genetic or pharmacological blockade of A2AR in animal models of ischemia, traumatic brain injury, convulsions/epilepsy, repeated stress or Alzheimer's or Parkinson's diseases. A2AR overfunction is not only necessary for the expression of brain damage but is actually sufficient to trigger brain dysfunction in the absence of brain insults or other disease triggers. Furthermore, A2AR overfunction seems to be an early event in the demise of brain diseases, which involves an increased formation of ATP-derived adenosine and an up-regulation of A2AR. This prompts the novel hypothesis that the evaluation of A2AR density in afflicted brain circuits may become an important biomarker of susceptibility and evolution of brain diseases once faithful PET ligands are optimized. Additional relevant biomarkers would be measuring the extracellular ATP and/or adenosine levels with selective dyes, to identify stressed regions in the brain. A2AR display several polymorphisms in humans and preliminary studies have associated different A2AR polymorphisms with altered morphofunctional brain endpoints associated with neuropsychiatric diseases. This further prompts the interest in exploiting A2AR polymorphic analysis as an ancillary biomarker of susceptibility/evolution of brain diseases.
Collapse
Affiliation(s)
- Ana Moreira-de-Sá
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Vanessa S Lourenço
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Paula M Canas
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| |
Collapse
|