Perspective and Potential of A2A and A3 Adenosine Receptors as Therapeutic Targets for the Treatment of Rheumatoid Arthritis

Adenosine is a purine nucleoside which is an effective controller of inflammation. The inflammatory effect of adenosine is expressed via its four receptor subtypes viz. A(1), A(2A), A(2B) and A(3). The various inflammatory conditions including rheumatoid arthritis (RA) are initiated by adenosine receptors of which A(2A) and A(3) play a vital role. RA primarily is an auto-immune disorder which is manifested as chronic inflammation in the synovial lining of joints. In order to develop an effective treatment, the role of cytokines, IL-1, TNF-alpha and IL-6 is crucial. Besides, the knowledge of PI3K-PKB/Akt and NF-kB signaling pathway is also important to understand the antiinflammatory targets. Methotrexate along with various other molecules like, NSAIDs and DMARDs are presently used as treatment lines for controlling RA. The enhanced knowledge of the preclinical stages and pathogenesis along with recent potent therapeutics raises the hopes that RA can be prevented in the near future.