Fig. 5: Redox signaling regulates LBP-induced LD accumulation via phospholipid biogenesis and the LBP chaperone function of PRDX4.
a The bar graph compares the hepatic TG levels in WT mice and LBPKI/KI mice, with/without NAC treatment. Means ± s.d., 2way ANOVA (n = 5–6, biologically independent). b Bright-field microscope image of LDs in LBPKI/KI mice, fasted for 24 h and treated with/without NAC treatment for 3 h. Scale bar = 10 µm Experiments repeated three times independently with similar results. c A pie chart representing the difference in lipid composition between WT mice that were fasted for 24 h (n = 3) and those treated with NAC for 3 h (n = 3). d MSEA analysis for the lipidomic data in (c). e Changes in LBP content within LDs extracted from liver tissue with/without NAC treatment for 3 h in 24 h fasting mice (n = 3, biologically independent). f Confocal microscopy images (upper panel) and quantification (lower panel) of LBP (blue) co-stained with PRDX4 (violet) at different ratios of Bodipy C12 (orange) and FL-HPC (green). Scale bar = 5 µm, magnified area scale bar = 1 µm. Experiments repeated three times independently with similar results. g Staining of LBP (green) and PRDX4 (violet) co-localized with Bodipy C12 (orange) in HepG2 cells after 16 h of Bodipy C12 treatment and 3 h of starvation. Scale bar = 5 µm. Experiments repeated two times independently with similar results. h Confocal images show that knockdown of PRDX4 does not affect the localization of LBP in LD, but increases LD size, whereas knockdown of LBP affects PRDX4 localization in LD. The shRNA scaffold plasmid with dual promoters for expressing green fluorescent protein; red represents LBP; violet denotes PRDX4, while Bodipy C12 is orange. Scale bar = 5 µm. Experiments repeated three times independently with similar results. i Effects of PRDX4-knockdown on LBP-mediated regulation of TG accumulation. Means ± s.d., one-way ANOVA (n = 3, biologically independent). j Effects of PRDX4-knockdown on LBP-mediated regulation of lipolysis. Means ± s.d., one-way ANOVA (n = 3, biologically independent). k Representative confocal image shows that shPRDX4 (green) reduces the ability of LBP (violet) to leave the LD (Bodipy C12, orange) after 3 h of PC treatment. Scale bar = 5 µm, magnified area scale bar =1 µm. Experiments repeated three times independently with similar results.
