Figure 5.

miR-378a-3p knockdown promoted degradation of ApoB100 and impaired secretion of ApoB100 by increasing SORT1. (A-B) CP-10447 inhibited secretion of ApoB100, which was reflected by almost undetectable ³⁵S-ApoB100 in the medium among three groups of HepG2-miR cells. HepG2-miR cells were transfected with scramble (control), miR-378a-3p-ASO or a combination of miR-378a-3p-ASO and SORT1 shRNA. 48 hours post-transfection, cells were starved for one hour in cysteine and methionine free medium and then labeled with ³⁵S-methionine/cysteine for 3 hours in the presence of CP-10447. (C-D) miR-378a-3p knockdown reduced intracellular ³⁵S-ApoB100, while additional treatment of SORT1 shRNA offset the effect of miR-378a-3p-ASO. (E) No significant change was observed in total ³⁵S-ApoB100 (intracellular and medium) among three groups of HepG2-miR cells transfected with scramble (control), miR-378a-3p-ASO or a combination of miR-378a-3p-ASO and SORT1 shRNA. HepG2-miR cells were transfected with scramble (control), miR-378a-3p-ASO or a combination of miR-378a-3p-ASO and SORT1 shRNA. 48 hour post transfection, cells were starved for one hour in cysteine and methionine free median and then labeled with ³⁵S-methionine/cysteine for 3 hours in the presence of MG132. (F-G) miR-378a-3p knockdown reduced secreted ³⁵S-ApoB100 in the medium of HepG2-miR cells; while additional treatment of SORT1 shRNA counteracted the effect of miR-378a-3p-ASO. Data represent mean ± SEM. **p < 0.01 (AVONA test).