Identification of phosphodiesterase-7A (PDE7A) as a novel target for reducing ethanol consumption in mice.

BACKGROUND: Ethanol elicits a rapid stimulatory effect and a subsequent, prolonged sedative response, which are potential predictors of EtOH consumption by decreasing adenosine signaling; this phenomenon also reflects the obvious sex difference. cAMP-PKA signaling pathway modulation can influence the stimulatory and sedative effects induced by EtOH in mice. This study's objective is to clarify the role of phosphodiesterase (PDE) in mediating the observed sex differences in ethanol responsiveness between male and female animals.

METHODS: EtOH was administered intraperitoneally (i.p.) for 7 days to identify the changes in PDE isoforms in response to EtOH treatment. Additionally, EtOH consumption and preference of male and female C57BL/6J mice were assessed using the drinking-in-the-dark (DID) and two-bottle choice (2BC) tests. Further, pharmacological inhibition of PDE7A heterozygote knockout mice was performed to investigate its effects on ethanol-induced stimulation and sedation in both male and female mice. Finally, Western blotting analysis was performed to evaluate the alterations in cAMP-PKA/Epac2 pathways.

RESULTS: Ethanol administration resulted in an immediate upregulation in PDE7A expression in female mice, indicating a strong association between PDE7A and ethanol stimulation. Through the pharmacological inhibition of PDE7A KD mice, we have demonstrated, for the first time, that PDE7A selectively attenuates ethanol responsiveness and consumption exclusively in female mice may be associated with the cAMP-PKA/Epac2 pathway and downstream phosphorylation of CREB and ERK1/2.

CONCLUSIONS: PDE7A inhibition or knockdown attenuates EtOH responsiveness and consumption exclusively in female mice associated the change of cAMP-PKA/Epac2 signaling pathways, thereby highlighting its potential as a novel therapeutic target for alcohol use disorder.