Adenosine A_2A receptors (A_2ARs) are highly expressed in the human striatum, and at lower densities in the cerebral cortex, the hippocampus, and cells of the immune system. Antagonists of these receptors are potentially useful for the treatment of motor fluctuations, epilepsy, postischemic brain damage, or cognitive impairment, and for the control of an immune checkpoint during immunotherapy of cancer. A_2AR agonists may suppress transplant rejection and graft‐versus‐host disease; be used to treat inflammatory disorders such as asthma, inflammatory bowel disease, and rheumatoid arthritis; be locally applied to promote wound healing and be employed in a strategy for transient opening of the blood–brain barrier (BBB) so that therapeutic drugs and monoclonal antibodies can enter the brain. Increasing A_2AR signaling in adipose tissue is also a potential strategy to combat obesity. Several radioligands for positron emission tomography (PET) imaging of A_2ARs have been developed in recent years. This review article presents a critical overview of the potential therapeutic applications of A_2AR ligands, the use of A_2AR imaging in drug development, and opportunities and limitations of PET imaging in future research.

中文翻译：

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腺苷A2A受体配体的潜在治疗应用和A2A受体成像的机会

腺苷A _2A受体（A _2A Rs）在人纹状体中高表达，在大脑皮层，海马和免疫系统细胞中的密度较低。这些受体的拮抗剂可潜在地用于治疗运动波动，癫痫，缺血性脑损伤或认知障碍，以及在癌症免疫治疗期间控制免疫检查点。A _2AR激动剂可以抑制移植排斥反应和移植物抗宿主病；用于治疗炎症性疾病，例如哮喘，炎症性肠病和类风湿关节炎；局部应用以促进伤口愈合，并采用暂时开放血脑屏障（BBB）的策略，以便治疗药物和单克隆抗体可以进入大脑。在脂肪组织中增加A _2A R信号传导也是对抗肥胖的潜在策略。近年来，已开发出几种用于A _2A Rs的正电子发射断层扫描（PET）成像的放射性配体。该评论文章提出了一个潜在的治疗应用的关键概述_2A [R配体，使用A _2AR成像在药物开发中的应用，以及PET成像在未来研究中的机会和局限性。