Figure 3

Effect of carnosine on the level of HIF-1α. HIF-1α protein level was increased in hypoxic HeLa cells cultured in the presence of 20 mM carnosine for 48 h as demonstrated by western blot (A) and immunofluorescence (scale bar, 10 μm) (B). (C) Carnosine treatment increased expression of HIF-1α mRNA and its target genes VEGF and GLUT-1 under hypoxic conditions. Concurrently, the mRNA level of VBP1, a protein that binds to VHL and is involved in HIF-1α degradation, was decreased. (D) Chromatin immunoprecipitation assay performed under the same conditions demonstrated that HIF-1α bound to hypoxia-responsive elements in the promoter region of VEGF and CA9 genes.