Fig 2: Inhibition of SREBP2 by 25-HC in HaCaT keratinocytes. Gene-expression analysis of the samples treated with HA-atRA or HA-C18:1 combined with 25-hydroxycholesterol (1 µM). The bars represent the mean ± SD of four independent experiments. The decreases in SREBF2, HMGCS1 and LDLR after the addition of 25-HC were significant (* p < 0.05, t-test) compared to respective HA-atRA and HA-C18:1 treatments.

Fig 3: SEMA3C upregulates lipogenic and cholesterogenic enzymes. (A) LNCaP cells treated with recombinant SEMA3C 1 μM in 5% CSS-supplemented phenol red-free RPMI for 24 h. mRNA expression of genes involved in cholesterol pathway by RT-qPCR method. SEMA3C was silenced in (B) C4-2 cells and (C) 22Rv1 cells by siRNA and mRNA expression of cholesterogenic genes was quantified in siSEMA3C-treated cells compared to respective control cells. (D) Increased activity of SREBP-responsive element in transiently transfected luciferase reporter plasmid into LNCaP cells followed by recombinant SEMA3C 1 μM or vehicle treatment (n = 6). (E) LNCaP cells were treated with erlotinib 2 μM approximately 2 h prior to the treatment with recombinant SEMA3C 1 μM. After 24 h, SREBP-responsive promoter activity was assessed by luciferase assay. (F) qPCR was performed to quantify relative mRNA expression of a panel of SREBP targets in LNCaP cells in the presence of erlotinib 2 μM. Only HMGCS1 mRNA expression level was affected. (G) The whole protein of LNCaPSEMA3C and LNCaPvector was immunoblotted to examine the protein level of genes involved in the cholesterol pathway. (mean ± s.d.; *P < 0.05, **P < 0.01, ***P < 0.001).