Figure 5.

DMSO results in an increase in cAMP levels, which in turn increases cell surface human NTCP expression in a PI3 K/CREB-dependent manner. (a,b) Impact of DMSO, as well as MDL12—an inhibitor of adenylyl cyclase—on intracellular levels of cAMP. (b,c) Impact of DMSO or exogenously added cAMP on cellular NTCP levels as determined by (b) western blot and (c) immunofluorescence microscopy. (d) Activation of PI3 K signalling, as determined by phosphorylation analysis of p38α and CREB in the presence of 2% DMSO, exogenous cAMP or the p38 inhibitor Wortmannin, performed by phospho-kinase arrays. Numbers under western blot lanes indicate densitometric analysis normalized to loading controls. Data shown are mean (s.d.) of three independent experiments.