title: Adenosine A2A receptors and brain injury: broad spectrum of neuroprotection, multifaceted actions and "fine tuning" modulation.
abstract: This review summarizes recent developments that have contributed to understand how adenosine receptors, particularly A2A receptors, modulate brain injury in various animal models of neurological disorders, including Parkinson's disease (PD), stroke, Huntington's disease (HD), multiple sclerosis, Alzheimer's disease (AD) and HIV-associated dementia. It is clear that extracellular adenosine acting at adenosine receptors influences the functional outcome in a broad spectrum of brain injuries, indicating that A2A Rs may modulate some general cellular processes to affect neuronal cells death. Pharmacological, neurochemical and molecular/genetic approaches to the complex actions of A2A receptors in different cellular elements suggest that A2A receptor activation can be detrimental or protective after brain insults, depending on the nature of brain injury and associated pathological conditions. An interesting concept that emerges from these studies is A2A R's ability to fine tune neuronal and glial functions to produce neuroprotective effects. While the data presented here clearly highlight the complexity of using adenosinergic agents therapeutically in PD and other neurodegenerative disorders and point out many areas for further inquiry, they also confirm that adenosine receptor ligands, particularly A2A receptor ligands, have many promising characteristics that encourage the pursuit of their therapeutic potential.
authors.affiliation: Department of Neurology, Boston University School of Medicine, 715 Albany Street, C329, Boston, MA 02118, USA. chenjf@bu.edu
authors.forename: Jiang-Fan
authors.initials: JF
authors.lastname: Chen
authors.forename: Patricia K
authors.initials: PK
authors.lastname: Sonsalla
authors.forename: Felicita
authors.initials: F
authors.lastname: Pedata
authors.forename: Alessia
authors.initials: A
authors.lastname: Melani
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Domenici
authors.forename: Patrizia
authors.initials: P
authors.lastname: Popoli
authors.forename: Jonathan
authors.initials: J
authors.lastname: Geiger
authors.forename: Luísa V
authors.initials: LV
authors.lastname: Lopes
authors.forename: Alexandre
authors.initials: A
authors.lastname: de Mendonça
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D001927:Brain Diseases / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D020208:Brain Injury, Chronic / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D009410:Nerve Degeneration / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D018696:Neuroprotective Agents / Q000494:pharmacology; D043705:Receptor, Adenosine A2A / Q000378:metabolism*
chemical_list: D018696:Neuroprotective Agents; D043705:Receptor, Adenosine A2A; D000241:Adenosine