Sterol Regulatory Element-Binding Proteins Are Regulators of the Rat Thyroid Peroxidase Gene in Thyroid Cells
Figure 12
Evaluation of the transactivation activity of the identified SREBP-responsive cis-elements of the rat TPO gene.
HepG2 cells were transiently transfected with either wild-type or mutated reporter gene constructs of rTPO 2xSRE/InvSRE-Luc, rTPO 2xSRE+640-Luc, rTPO 2xInvSRE-like+654-Luc and co-transfected with either pcDNA3.1 (empty vector) or plasmids expressing nuclear forms of rat SREBP-1c and rat SREBP-2 for 12 h. After transfection, medium was changed to RPMI1640 medium supplemented with 10% FBS for 24 h. Afterwards, cells were lysed, and luciferase activities were measured. Bars represent means ± SD from at least three independent experiments each performed in quadruplicate. The wild-type (upper strand) and mutated (lower strand) sequences of the putative SREBP-responsive cis-elements are indicated. The lower-case letters represents the substituted nucleotides.