Figure 1.

Psoralen alleviates insulin resistance in sodium oleate-induced L02 cells by enhancing the expression of GLUT4 and promoting the GLUT4 membrane translocation. L02 cells except the control group were induced with sodium oleate (100 μM) for 24 h to induce lipid deposition. Then, all cells were stimulated by insulin (10 μg/mL) for 30 min and then incubated with psoralen at 0, 0.37, 1.1, and 3.3 μM for 24 h. (A) The glucose content was measured by the glucose content assay kit. (B) The expression of GLUT4 and GLUT2 was detected by Western blotting. (C) The expression of INSR, p-INSR, IRS1, and p-IRS1 were measured by Western blotting. (D) The expression of GLUT4 and F-actin was detected by immunofluorescence and images captured by confocal microscopy (scale bar = 10 μm). (E) Colocalization efficiency of GLUT4 and F-actin in multiple cells (n ≥ 3 cells) within the field of view was quantified by line scan analysis (160 pixels with two ends on the membrane) by observing the overlap of fluorescence intensity peaks along the spanning contour. (F) The expression of GLUT2 and F-actin was detected by immunofluorescence and images captured by confocal microscopy (scale bar = 10 μm). (G) Colocalization efficiency of GLUT2 and F-actin in multiple cells (n ≥ 3 cells) within the field of view was quantified by line scan analysis (250 pixels with two ends on the membrane) by observing the overlap of fluorescence intensity peaks along spanning profiles. All values were expressed as the mean ± SD from three independent experiments. # p < 0.05, ## p < 0.01, vs. the control group; ** p < 0.01 vs. sodium oleate-induced group. Abbreviations: INS, insulin; Pso, psoralen; INSR, insulin receptor; IRS1, insulin receptor substrate 1.