Effect of GEX1A on NPC1 protein expression. A) Lysates derived from human wild-type (GM05659) fibroblasts were subjected to treatment with endoglycosidase H, and the expression of NPC1 was analyzed using SDS-PAGE and Western blotting with a rabbit anti-NPC1 antibody. B) Human NPC1 mutant (GM18453) fibroblasts were incubated with DMSO, SAHA (5 μM), or GEX1A (50 nM) for 48 hours. Cell lysates were treated with endoglycosidase H, and the expression of NPC1 was analyzed through immunoblotting with a rabbit anti-NPC1 antibody. C) NPC1 isoforms resulting from endoglycosidase H treatment were quantified using densitometry. Relative expression levels represent results from four independent experiments, and error bars represent standard deviation between experiments. * p < 0.05. D) Human NPC1 mutant (GM18453) fibroblasts were incubated with DMSO, SAHA (5 μM), or GEX1A (50 nM) for 48 hours. Cell lysates were treated with peptide:N-glycosidase F, and the expression of NPC1 was analyzed through immunoblotting with a rabbit anti-NPC1 antibody. E) NPC1 isoforms resulting from peptide:N-glycosidase F treatment were quantified using densitometry. Relative expression levels represent results from four independent experiments, and error bars represent standard deviation between experiments. * p < 0.05.