Proteomic profiling of proteins with altered expression in fluoxetine‐treated HEK293A‐TREK‐2 cells

TREK channels, which are mechanosensitive tandem‐pore potassium channel family with four transmembrane segments have been known to inhibit their activities by selective serotonin reuptake inhibitor (SSRI) antidepressants such as fluoxetine and paroxetine. Although there are reports for the interactions between TREK channel and depression, the underlying mechanisms are still unclear. To identify and elucidate proteins involved between SSRI antidepressant and TREK protein, proteomic analysis was introduced after fluoxetine treatment in TREK‐2 over‐expressed HEK293A cells. The cells were processed for two‐dimensional electrophoresis and subsequent MALDI‐TOF/mass spectrometry with different time points after fluoxetine treatment. After 24 h of drug treatment, two proteins including protein disulfide isomerase are up‐regulated in fluoxetine (25 μM)‐treated 293A‐TREK‐2 cells. Four proteins such as heterogeneous nuclear ribonucleoproteins C1/C2 were up‐regulated and five proteins were down‐regulated after 36 h of the treatment. In the 48 h of treatment, nine proteins, that is, heterogeneous nuclear ribonucleoprotein K and stress‐70 protein were up‐regulated and eight proteins like vimentin were down‐regulated. The observed proteins could be utilized as biomarkers involved in the TREK‐2 channel after fluoxetine treatment. KOSEF grant for MRC (R13‐2005‐012‐01003‐0) and grant for the NRF of Korea (2009‐0072300).