Sterol regulatory element binding protein 2 overexpression is associated with reduced adipogenesis and ectopic fat accumulation in transgenic spontaneously hypertensive rats

Physiol Res. 2014;63(5):587-90. doi: 10.33549/physiolres.932751. Epub 2014 Jun 5.

Abstract

It has been reported that the major function of the sterol regulatory element binding protein 2 (SREBP-2) is to activate preferentially cholesterol biosynthesis in liver and adipose tissue rather than fatty acid synthesis. In the current study, we analyzed the effects of overexpression of human dominant-positive SREBP-2 transgene under control of PEPCK promoter in the spontaneously hypertensive rat (SHR) on lipid and glucose metabolism. Transgenic overexpression of SREBP-2 was associated with significantly higher hepatic triglycerides (20.4+/-0.9 vs. 17.0+/-0.05 micromol/g, P<0.05) but not cholesterol (10.6+/-0.4 vs. 10.9+/-0.4 micromol/g) and decreased relative weight of epididymal fat pad (0.73+/-0.03 vs. 0.83+/-0.03, P<0.05). In addition, muscle triglyceride (15.8+/-3.7 vs. 8.5+/-1.2 micromol/g, P<0.001) and cholesterol (3.6+/-0.5 vs. 2.1+/-0.1 micromol/g, P<0.05) concentrations were significantly increased in transgenic rats when compared to SHR controls. Ectopic fat accumulation was associated with significantly increased serum glucose levels (6.4+/-0.1 vs. 5.9+/-0.1 mmol/l, P<0.005) and reduced insulin levels (1.78+/-0.33 vs. 2.73+/-0.37 nmol/l, P<0.05) in transgenic rats. These results provide evidence for important role of SREBP-2 in regulation of lipid and glucose metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipogenesis*
  • Adipose Tissue / metabolism*
  • Adipose Tissue / physiopathology
  • Adiposity*
  • Animals
  • Blood Glucose / metabolism
  • Cholesterol / metabolism
  • Disease Models, Animal
  • Humans
  • Hypertension / blood
  • Hypertension / genetics
  • Hypertension / metabolism*
  • Hypertension / physiopathology
  • Insulin / blood
  • Intracellular Signaling Peptides and Proteins / genetics
  • Liver / metabolism
  • Phosphoenolpyruvate Carboxykinase (GTP) / genetics
  • Promoter Regions, Genetic
  • Rats, Inbred SHR
  • Rats, Transgenic
  • Sterol Regulatory Element Binding Protein 2 / genetics
  • Sterol Regulatory Element Binding Protein 2 / metabolism*
  • Triglycerides / metabolism

Substances

  • Blood Glucose
  • Insulin
  • Intracellular Signaling Peptides and Proteins
  • SREBF2 protein, human
  • Sterol Regulatory Element Binding Protein 2
  • Triglycerides
  • Cholesterol
  • Pck1 protein, rat
  • Phosphoenolpyruvate Carboxykinase (GTP)