Fig. 5
Serotonin receptors and serotonin reuptake inhibitors (SSRIs) modulate cell steatosis in liver cancer HepG2 cells. a Expression of various serotonin receptors (5-HTrs) in HepG2, SK-Hep1, PLC/PRF5 and Hep3B2 cells were analyzed by RT/qPCR as described in the materials and methods section. b HepG2 cells were grown on coverslips in 6-well plates and treated with serotonin (0.5 mM) or serotonin receptors antagonists, LY272015 (1 μM) and SB216641 (1 μM) (Abcam), alone for 30 h or pretreated with LY272015 and SB216641 for 8 h followed by serotonin treatment for 24 h in presence of LY272015 and SB216641 as indicated. Cells were further treated with vehicle alone or 100 μM OA for an additional 24 h. Cells were fixed, stained with Oil Red O stain and observed under a light microscope using 40X objective and photographed. The number of Oil-Red-O-stained lipid droplets present in each steatotic cell (n = 10) were measured and plotted. c HepG2 cells were grown in 6-well plates and treated with indicated concentrations of serotonin or serotonin receptors antagonists, LY272015 and SB216641 alone for 30 h, or pretreated with LY272015 and SB216641 for 8 h followed by serotonin treatment for 24 h in the presence of LY272015 and SB216641 as indicated. Fifty micrograms of cell lysates were immunoblotted with indicated antibodies. d HepG2 cells were treated with indicated concentrations of serotonin or serotonin re-uptake inhibitors (SSRIs), sertraline and fluvoxamine, alone for 30 h, or pretreated with sertraline and fluvoxamine for 8 h followed by serotonin treatment for 24 h in presence of SSRIs as indicated. Fifty micrograms of cell lysates were immunoblotted with indicated antibodies. e HepG2 cells were grown on coverslips in 6-well plates treated with indicated concentrations of serotonin or SSRIs as indicated in section 5d. Cells were further treated with vehicle alone or 100 μM OA for an additional 18 h. Cells were fixed, stained with Oil Red O stain and observed under a light microscope as described earlier. The number of Oil-Red-O-stained lipid droplets present in steatotic cells (n = 10) were measured and plotted. Data are expressed as the mean ± S.D. ***p < 0.001 compared to OA. # # # p < 0.001 compared to Serot. Serot. - Serotonin. OA- Oleic acid