Cyclic AMP-specific 3',5'-cyclic phosphodiesterase 4 (PDE4)

Cyclic AMP-specific 3',5'-cyclic phosphodiesterase 4 (PDE4) is a member of the cyclic nucleotide phosphodiesterase enzyme superfamily that specifically hydrolyzes the second messenger cyclic adenosine monophosphate (cAMP) into its inactive form. By regulating cellular concentrations of cAMP—a key mediator in signal transduction—PDE4 plays a central role in controlling various physiological processes including inflammation, immune response modulation, cognition, and emotional memory. The human genome encodes several isoforms within the PDE4 family—PDE4A, PDE4B, PDE4C, and PDE4D—which differ in tissue distribution and regulatory properties. Due to its pivotal function in modulating inflammatory cell activity and neuronal signaling pathways via control of cAMP levels, inhibition or activation of specific isoforms has therapeutic potential for diseases such as asthma, COPD, atopic dermatitis, certain neuropsychiatric conditions like schizophrenia or bipolar disorder—and possibly autosomal dominant polycystic kidney disease. Several drugs targeting this enzyme have been developed for clinical use or are under investigation.[1][3][6][7]

Other names

cAMP-specific phosphodiesterase 4Phosphodiesterase type 4PDE4APDE4BPDE4CPDE4D (refers to gene family members)DPDE2PDE46[5][7]

Inhibition increases intracellular cAMP by blocking its hydrolysis; this modulates immune and inflammatory responses and can affect neuronal signaling.