title: Modulation of the mitochondrial large-conductance calcium-regulated potassium channel by polyunsaturated fatty acids.
abstract: 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 Ca(2+)-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 10μM ETYA. Po increased, however, after adding 10μM AA. The application of 30μM DHA or 10μM EPA also increased the Po of the channel. Additionally, the number of open channels in the patch increased in the presence of 30μM EPA. Collectively, our results indicate that PUFAs regulate the BKCa channel from the inner mitochondrial membrane.
authors.affiliation: Department of Biochemistry, Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Warsaw, Poland. Electronic address: a.kajma@nencki.gov.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Olszewska
authors.affiliation: Department of Biochemistry, Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Warsaw, Poland; Department of Biophysics, Warsaw University of Life Sciences, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Bednarczyk
authors.affiliation: Department of Neurology, Otto-von-Guericke Universität Magdeburg, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Siemen
authors.affiliation: Department of Biochemistry, Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Szewczyk
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D045744:Cell Line, Tumor; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D006801:Humans; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000187:drug effects* / Q000378:metabolism; D018408:Patch-Clamp Techniques
chemical_list: D000447:Aldehydes; D005231:Fatty Acids, Unsaturated; D051036:Large-Conductance Calcium-Activated Potassium Channels; C027576:4-hydroxy-2-nonenal
keywords: Fatty acids; Large-conductance calcium-activated potassium channel; Mitochondria