Fig. 7: G3BP1 is required for de novo lipogenesis.

A Male 8-week-old WT and G3BP1 LKO mice fed HFD for 20 weeks (MASLD model, n = 6 mice per group). Liver cryosections were fixed in 4% paraformaldehyde and subjected to immunofluorescence staining using TFE3 antibody. Nuclei were counterstained with DAPI. Scale bar: 10 μm. B Cytoplasmic and nuclear fractions were isolated from livers of male 8-week-old WT and G3BP1 LKO mice fed HFD for 20 weeks. Fraction purity was validated by immunoblotting with anti-Histone H3 for nuclear markers. Parallel blots were probed with anti-TFE3, anti-Tubulin, and anti-G3BP1. Each experiment was repeated independently at least three times. C Liver lysates from male 8-week-old WT and G3BP1 LKO mice fed HFD for 20 weeks were resolved by SDS-PAGE for Western blot analysis (n = 4). Membranes were probed with anti-INSIG2, anti-SREBP1 and anti-G3BP1. ACTIN served as loading control. D 8-week-old G3BP1 LKO male mice were intravenously injected with AAV8-Control or AAV8-TFE3 (2 × 10¹¹ viral genomes/mouse) and maintained on HFD for 20 weeks. Representative liver sections stained with H&E (left panels) and Oil Red O (right panels) are shown. Scale bars: 50 μm. n = 6 biologically independent mice per group. Hepatic triglyceride (TG, E) and total cholesterol (TC, F) levels in AAV8-treated G3BP1 LKO mice (n = 6 mice per group). All values are presented as means ± S.E.M. Statistical significance was assessed using unpaired two-tailed Student’s t-test. Exact P value for TG (Panel E), *P = 0.012; TC (Panel F), **P = 0.0042. Serum ALT (G) and AST (H) activities in the indicated groups (n = 6 mice per group). All values are presented as means ± S.E.M. Statistical significance was assessed using unpaired two-tailed Student’s t-test. Exact P value for ALT (panel G), **P = 0.0062; for AST (panel H), **P = 0.0012.