Research progress of phosphodiesterases and phosphodiesterase inhibitors

Intracellular levels of ubiquitous transduction signal cyclic adenosine 3′, 5′-monophosphate (cAMP) and cyclic guanosine 3′, 5′-monophosphate (cGMP) are partly determined by the hydrolysis by phosphodiesterases (PDEs). So far, the superfamily of PDE is composed of at least 11 isoforms and each family is characterized with unique cellular distribution, expression, regulation mode and inhibitor sensitivity, and PDEs are considered to be involved in a variety of pathological processes, such as inflammation, asthma, depression, and erectile dysfunction, etc. Currently, these characteristics draw PDEs more and more attention as great targets for drugs. In this review, the basic biochemical properties, cellular regulation, expression pattern, physiological functions and inhibitors of different PDE isoforms will be briefly discussed.