cAMP-specific 3',5'-cyclic phosphodiesterase 4B (PDE4B)

cAMP-specific 3',5'-cyclic phosphodiesterase 4B (PDE4B) is an enzyme encoded by the *PDE4B* gene in humans. It belongs to the type IV family of cyclic nucleotide phosphodiesterases, which specifically hydrolyze cyclic adenosine monophosphate (cAMP), a key second messenger involved in numerous cellular processes. By regulating cellular concentrations of cAMP, PDE4B plays a critical role in signal transduction pathways that mediate responses to hormones, neurotransmitters, and other extracellular signals. The enzyme is expressed in tissues including heart, brain, skeletal muscle, and lung. Altered activity or expression of PDE4B has been associated with neuropsychiatric conditions such as schizophrenia and bipolar disorder. It also modulates cognition—reduced activity improves memory and synaptic plasticity in animal models—and participates in dopamine-associated behaviors. Clinically relevant inhibitors include crisaborole (approved for atopic dermatitis) and rolipram; these drugs act by inhibiting the enzymatic breakdown of cAMP. Therapeutic targeting of PDE4 subtypes like PDE4B aims to treat inflammation-related diseases while minimizing side effects typical for broader-spectrum inhibitors. However, challenges remain regarding selectivity and tolerability due to adverse events such as nausea commonly seen with earlier generation compounds.

Other names

Phosphodiesterase 4BPDE4BcAMP-specific phosphodiesterase type 4BDPDE4 (previous/unofficial)

Inhibition of PDE4B increases intracellular cAMP by preventing its hydrolysis, leading to modulation of inflammatory responses and neuronal signaling pathways.