Fig. 2
The insulin resistance in Huh7 cells is suppressed by silencing of SAA1. a, insulin-stimulated 2DG uptake in response to the treatment of PA, insulin and insulin + PA; *, p < 0.05 vs. the blank group; #, p < 0.05 vs. the insulin group; b, Huh7 cell images after PA treatment by oil red O staining (× 200); c, the contents of triglycerides after PA treatment; d, the mRNA expression of SAA1 in PA-treated Huh7 cells according to RT-qPCR; *, p < 0.05 vs. the 0-h group; e, the gray value of SAA1 and β-actin protein bands measured by western blot analysis; f, the protein expression of SAA1 in PA-treated Huh7 cells according to western blot analysis; *, p < 0.05 vs. the 0-h group; g, the mRNA expression of SAA1, IRS1 and SOCS3 in response to the treatment of PA + sh-SAA1, PA + pcDNA3, PA + pcDNA3-SAA1 tested by RT-qPCR; *, p < 0.05 vs. the blank group; #, p < 0.05 vs. the PA + sh-NC group; &, p < 0.05 vs. the PA + pcDNA3 group; h, the gray value of SAA1, IRS1, SOCS3, and p-IRS1 protein bands evaluated by western blot analysis; i, the protein expression of SAA1, IRS1 and SOCS3, and the extent of IRS1 phosphorylation in response to the treatment of PA + sh-SAA1, PA + pcDNA3, PA + pcDNA3-SAA1 according to western blot analysis; *, p < 0.05 vs. the blank group; #, p < 0.05 vs. the PA + sh-NC group; &, p < 0.05 vs. the PA + pcDNA3 group; j, insulin-stimulated 2DG uptake in response to the treatment of insulin + PA + sh-SAA1, insulin + PA + pcDNA3, insulin + PA + pcDNA3-SAA1; *, p < 0.05 vs. the insulin group; #, p < 0.05 vs. the insulin + PA + sh-NC group; data were expressed by means ± standard deviation; differences between two groups were compared by the t test; multiple groups were compared by one-way analysis of variance; the experiment was repeated 3 times; SAA1, serum amyloid A protein 1; 2DG, [3H]2-deoxyglucose uptake; PA, palmitate; RT-qPCR, reverse transcription quantitative polymerase chain reaction; SOCS3, suppressor of cytokine signaling 3; IRS1, insulin receptor substrate 1; p-IRS1, phosphorylation level of IRS1; NC, negative control