Phosphodiesterase inhibition in the treatment of autoimmune and inflammatory diseases: current status and potential

Cyclic nucleotide second messengers adenosine-3′,5′-cyclic monophosphate (cAMP) and guanosine-3′,5′-cyclic monophosphate (cGMP) influence numerous cellular functions, including inflammatory and immune responses. Intracellular levels of these nucleotides are regulated by a diverse group of phosphodiesterase enzymes. Inhibition of the various types of phosphodiesterase enzymes may offer a novel means to manage both inflammatory and autoimmune disorders. Recently, progress has been made in the development of phosphodiesterase inhibitors for a variety of conditions. This article reviews recent developments in the search for phosphodiesterase inhibitors as novel therapeutic agents for inflammatory and autoimmune conditions.