Fig. 4

Leptin modulates LDLR and PCSK9 protein levels and LDL uptake through a p38MAPK-dependent pathway. a Western blot analysis of phosphorylated-p38 and total p38 protein levels in HepG2 cells treated with 50 ng/ml leptin for 0, 5, 15, 30, 60, 120 min. b The normalized intensities of phosphorylated-p38 versus total p38 are presented as the mean ± SD of three independent experiments. c Western blot analysis of LDLR, PCSK9 and HNF1α protein levels in HepG2 cells treated with leptin (50 ng/mL) alone or combined with SB 203580 (10 μM) for 24 h. d The normalized intensities of LDLR, PCSK9 and HNF1α versus GAPDH are presented as the mean ± SD of three independent experiments. e Representative fluorescence microscopy images of cell-associated Dil-LDL (red), Hoechst-stained nuclei (blue), and the overlay. *p < 0.05 represent significant differences compared to the vehicle-treated cells. ^# p < 0.05 represent significant differences compared to the leptin-treated cells