Disruption of A2AR-D2R Heteroreceptor Complexes After A2AR Transmembrane 5 Peptide Administration Enhances Cocaine Self-Administration in Rats

Abstract

Antagonistic allosteric A2AR-D2R receptor-receptor interactions in heteroreceptor complexes counteract cocaine self-administration and cocaine seeking in rats as seen in biochemical and behavioral experiments. It was shown that the human A2AR transmembrane five (TM5) was part of the interface of the human A2AR-D2R receptor heteromer. In the current paper, the rat A2AR synthetic TM5 (synthTM5) peptide disrupts the A2AR-D2R heteroreceptor complex in HEK293 cells as shown by the bioluminescence resonance energy transfer method. Rat A2AR synthTM5 peptide, microinjected into the nucleus accumbens, produced a complete counteraction of the inhibitory effects of the A2AR agonist CGS21680 on cocaine self-administration. It was linked to a disappearance of the accumbal A2AR-D2R heteroreceptor complexes and the A2AR agonist induced inhibition of D2R recognition using proximity ligation assay and biochemical binding techniques. However, possible effects of the A2AR synthTM5 peptide on accumbal A2AR-D3R and A2AR-D4R heteroreceptor complexes remain to be excluded. Evidence is provided that accumbal A2AR-D2R-like heteroreceptor complexes with their antagonistic receptor-receptor interactions can be major targets for treatment of cocaine use disorder.Electronic supplementary materialThe online version of this article (10.1007/s12035-018-0887-1) contains supplementary material, which is available to authorized users.

Effects of intra-accumbal or intra-prefrontal cortex microinjections of adenosine 2A receptor ligands on responses to cocaine reward and seeking in rats

“…The above functional interaction has been raised on tasks involving effort-related processes (Mingote et al 2008; Pardo et al 2012), in motivational disruptions of mother-infant interactions (Pereira et al 2011) or in excessive ethanol drinking (Nam et al 2013). The latter hypothesis needs, however, to be verify with the local injection of pharmacological tools or with the recently available A 2A transmembrane peptide that disrupts the A 2A -D 2 heteroreceptor complexes (Borroto-Escuela et al 2018). …”

Adenosine-Related Mechanisms in Non-Adenosine Receptor Drugs

“…These direct GPCR interactions enable allosteric pharmacological interactions to occur. For example, disruption of the A 2A AR-D 2 R complex by an A 2A AR agonist blocks the inhibition of cocaine self-administration [113]. Thus, there can potentially be MoA interactions between ARs and any of the numerous other GPCRs with which they heterodimerize or oligomerize (reviewed in Vecchio et al [114,115]).…”

OSU-6162, a Sigma1R Ligand in Low Doses, Can Further Increase the Effects of Cocaine Self-Administration on Accumbal D2R Heteroreceptor Complexes

“…Free-floating formalin-fixed brain sections (30 μmthick, cut using a cryostat) at Bregma level (1.0 0mm) from rats after cocaine self-administration were employed using the following primary antibodies: rabbit monoclonal anti-A2AR (AB1559F, 1:250; Millipore, Sweden), mouse monoclonal anti-D2R (MABN53, 1:600, Millipore, Sweden), and rabbit monoclonal anti-sigma1R (ab53852, 1:500, Abcam, Sweden). Primary antibodies were validated previously by means of immunohistochemistry in both rat brain tissue and HEK293 cell line ((Borroto-Escuela et al 2017;Borroto-Escuela et al 2018c;Feltmann et al 2018)). Control experiments for in situ PLA procedures were performed in free-floating formalinfixed rat brain sections employing only one primary antibody (mouse monoclonal anti-D2R (MABN53, 1:600, Millipore, Sweden).…”

“…In fact, highly significant antagonistic A2AR-D2R interactions were found in the ventral striatum associated with significant increases in A2AR-D2R and Sigma1R-D2R heteroreceptor complexes during cocaine self-administration Borroto-Escuela et al 2017;Pintsuk et al 2016). The inhibition of cocaine self-administration by the A2AR agonist was blocked by a receptor interface interfering peptide (A2AR-TM5) disrupting the A2AR-D2R complex (Borroto-Escuela et al 2018c). However, in cell lines expressing A2AR-D2R-Sigma1R heteroreceptor complexes, cocaine markedly enhanced the A2AR agonist-induced inhibition of Gi/o-mediated signaling of the D2R as studied in a CREB (cAMP response element-binding protein) assay .…”