Objective: To investigate the methylation rate of tuberous sclerosis complex 1 (Tsc1) promoter and expression of mammalian target of rapamycin (mTOR) in food-induced rat hypothalamus.
Methods: 16 male SD rats were divided into high fat diet induced group (8 rats) and normal control group (8 rats) feeding for 12 weeks. Body mass, mass of celiac fat, celiac fat/body mass were measured. Methylation of Tsc1 promoter, mRNA and protein expression of mTOR were detected by bisulfite sequencing method, RT-PCR and Western blot, respectively.
Results: Mass of celiac fat, celiac fat/body mass were higher in food-induced rat than that in control group. There were 11 methylation sites in SD rat hypothalamus. Obese group has significantly higher methylation rates (94.50% +/- 4.66%) than that of control group (86.60% +/- 3.49%) (P<0.002). The mRNA and protein expression of mTOR were noted lower in control group than in obese group (P<0.05).
Conclusion: The increased methylation rate of Tsc1 promoter in food-induced rat hypothalamus and up-regulated expression of mTOR, downstream gene of Tsc1 may promote the obesity.