Fig. 6: Methylmalonic acid inhibits HMGCR activity and increases SREBP2-mediated gene expression and DiI-LDL uptake.

a, b Flow cytometry analysis of DiI-LDL specific binding (a) and uptake (b) in Huh7 cells treated with vehicle, 50 μM methylmalonic acid (MMA), 100 μM propionic acid (PA) or 5 μM statin for 24 h and incubated with 30 μg/ml DiI-LDL for 2 h at 37 °C (uptake) or 90 min at 4 °C (binding). Data are mean ± s.e.m. of three independent experiments in duplicate. Statistical comparisons by one-way ANOVA with Bonferroni correction for multiple comparisons. c Western blot analysis of SREBP2-responsive genes in Huh7 cells incubated in LPDS for 24 h and treated with vehicle, 100 μM propionic acid (PA), or 5 μM statin for 24 h. HSP90 was used as a loading control; quantification is shown to the right of the blots. Data are mean ± s.e.m. of three independent experiments in duplicate. Statistical comparisons by two-way ANOVA with Bonferroni correction for multiple comparisons. d HMGCR activity in liver microsomes treated with increasing doses (10 μM, 100 μM, 1 mM, 10 mM, 100 mM) of propionic acid or vehicle control. Data are mean ± s.e.m. of three independent experiments in duplicate. e Western blot analysis of SREBP2-responsive genes in Huh7 cells incubated in LPDS for 24 h and treated with vehicle, 50 μM methylmalonic acid (MMA), or 5 μM statin for 24 h. HSP90 was used as a loading control; quantification is shown to the right of the blots. Data are mean ± s.e.m. of three independent experiments in duplicate. Statistical comparisons by two-way ANOVA with Bonferroni correction for multiple comparisons. f HMGCR activity in liver microsomes treated with increasing doses (10 μM, 25 μM, 50 μM, 75 μM, 100 μM, 1 mM, 10 mM) of methylmalonic acid (MMA) or vehicle control. Data are mean ± s.e.m. of three independent experiments in duplicate. Statistical comparisons by one-way ANOVA with Bonferroni correction for multiple comparisons.