Upregulation of Phosphodiesterase 7A Contributes to Concurrent Pain and Depression via Inhibition of cAMP-PKA-CREB-BDNF Signaling and Neuroinflammation in the Hippocampus of Mice.

Background: Phosphodiesterases (PDEs) are enzymes that catalyze the hydrolysis of cyclic adenosine monophosphate AMP (cAMP) and/or cyclic guanosine monophosphate (cGMP). PDE inhibitors can mitigate chronic pain and depression when these disorders occur individually; however, there is limited understanding of their role in concurrent chronic pain and depression. We aimed to evaluate the mechanisms of action of PDE using 2 mouse models of concurrent chronic pain and depression.