Expression of a short antibody heavy chain peptide effectively antagonizes adenosine 2A receptor in vitro and in vivo.

BACKGROUND

Adenosine 2A receptor (AR) is involved in many physiological and pathological functions and serves as an important drug target. Inhibition of AR may alleviate symptoms associated with a variety of neuropsychiatric disorders. However, the currently used AR antagonists have specificity limitations.

RESEARCH DESIGN AND METHODS

A Fab fragment (Fab2838) of an AR mouse monoclonal antibody can specifically bind to AR to form a complex and inhibit the activity of its receptor. We constructed the vector AntiAR, a small-molecule peptide that binds to and inhibits AR based on Fab2838.

RESULTS

Experiments in HEK293T cells showed that peptide AntiAR of 29 peptides was the most effective among the synthesized peptides in inhibiting the AR downstream signal cAMP/PKA/CREB. In neurons, the AntiAR reversed the calcium flow change induced by the AR agonist CGS21680 (1 μM). Furthermore, AntiAR expression in the mice striatum weakened the p-PKA/p-CREB signal, enhanced locomotor abilities and increased time spent in the center area in the home-cage observation experiment and increased anxiolytic behavior in the elevated-plus maze test.

CONCLUSIONS

Antagonistic peptide AntiAR can effectively block the AR signaling pathway. This provides a new strategy for the specific inhibition of AR and provides information needed for drug development.