Molecular characterization and functional analysis of four teleostean K+ channels in macrophages of sea perch (Lateolabrax japonicas)

Potassium ion channels are one of the most diversely and widely distributed channels, which are involved in all kinds of physiological functions in both excitable and non-excitable cells. The expression of voltage-gated potassium ion (Kv) channels is highly variable according to the state of macrophages activation. Macrophages have an important function in innate immunity against intruding pathogens. They produce a variety of inflammatory and immunoactive molecules that modulate imflammatory responses. Here we show that blockade of K+ channels by non-selective Kv channel inhibitor tetraethylammonium chloride (TEA), and 4-aminopyridine (4-AP) inhibited proinflammatory cytokines expression, cell proliferation, and reactive oxygen species (ROS) production in LPS-stimulated macrophages of Sea perch (Lateolabrax japonicas). Then we isolated four Kv channels genes (spKv1.1, spKv1.2, spKv1.5 and spKv3.1) in LPS-activated fish macrophages. These channels genes were up-regulated after LPS stimulation except spKv3.1, which remained unchanged during the test. The results of this study indicate that Kv channels could be required for modulating the immune function of fish macrophages.