Modulation of the mitochondrial large-conductance calcium-regulated potassium channel by polyunsaturated fatty acids

Polyunsaturated fatty acids (PUFAs) and their metabolites can modulate several biochemical processes in the cell and thus prevent various diseases. PUFAs have a number of cellular targets, including membrane proteins. They can interact with plasma membrane and intracellular potassium channels. The goal of this work was to verify the interaction between PUFAs and the most common and intensively studied mitochondrial large conductance Ca2+-regulated potassium channel (mitoBKCa). For this purpose human astrocytoma U87 MG cell lines were investigated using a patch-clamp technique. We analyzed the effects of arachidonic acid (AA); eicosatetraynoic acid (ETYA), which is a non-metabolizable analog of AA; docosahexaenoic acid (DHA); and eicosapentaenoic acid (EPA). The open probability (Po) of the channel did not change significantly after application of 10 μM ETYA. Po increased, however, after adding 10 μM AA. The application of 30 μM DHA or 10 μM EPA also increased the Po of the channel. Additionally, the number of open channels in the patch increased in the presence of 30 μM EPA. Collectively, our results indicate that PUFAs regulate the BKCa channel from the inner mitochondrial membrane.