Influence of Phosphodiesterase-Inhibitor PDE4 Roflumilast N-Oxide on Surfactant Protein of human Alveolar Epithelial Cell Type II

Surfactant Proteins (SPs) are surface active lipoproteins, essential for the integrity of the lung and important for host defence. All four Surfactant Proteins (A-D) and their isoforms are mainly expressed by alveolar epithelial cells type II (AECII). It has been shown that SP gene transcription is regulated by intracellular cyclic adenosine monophosphate (cAMP). Phosphodiesterase 4 is the major hydrolysing phosphodiesterase in AECII reducing cAMP levels. To investigate the effect of phosphodiesterase inhibition on SP mRNA and protein expression, we stimulated freshly isolated human AECII with two different conc…