Proinflammatory gene expression and renal lipogenesis are modulated by dietary protein content in obese Zucker fa/fa rats

Am J Physiol Renal Physiol. 2011 Jan;300(1):F263-71. doi: 10.1152/ajprenal.00171.2010. Epub 2010 Oct 20.


Obesity is a risk factor for the development of chronic kidney disease (CKD) and end-stage renal disease. It is not clear whether the adoption of a high-protein diet in obese patients affects renal lipid metabolism or kidney function. Thus the aims of this study were to assess in obese Zuckerfa/fa rats the effects of different types and amounts of dietary protein on the expression of lipogenic and inflammatory genes, as well as renal lipid concentration and biochemical parameters of kidney function. Rats were fed different concentrations of soy protein or casein (20, 30, 45%) for 2 mo. Independent of the type of protein ingested, higher dietary protein intake led to higher serum triglycerides (TG) than rats fed adequate concentrations of protein. Additionally, the soy protein diet significantly increased serum TG compared with the casein diet. However, rats fed soy protein had significantly decreased serum cholesterol concentrations compared with those fed a casein diet. No significant differences in renal TG and cholesterol concentrations were observed between rats fed with either protein diets. Renal expression of sterol-regulatory element binding protein 2 (SREBP-2) and its target gene HMG-CoA reductase was significantly increased as the concentration of dietary protein increased. The highest protein diets were associated with greater expression of proinflammatory cytokines in the kidney, independent of the type of dietary protein. These results indicate that high soy or casein protein diets upregulate the expression of lipogenic and proinflammatory genes in the kidney.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose / metabolism
  • Caseins / administration & dosage*
  • Caseins / pharmacology
  • Cholesterol / blood
  • Collagen Type IV / biosynthesis
  • Dietary Proteins / administration & dosage*
  • Dietary Proteins / pharmacology
  • Hydrogen Peroxide / urine
  • Hydroxymethylglutaryl CoA Reductases / biosynthesis
  • Insulin / blood
  • Interleukin-6 / biosynthesis
  • Kidney / anatomy & histology
  • Kidney / drug effects
  • Kidney / physiology*
  • Lipogenesis
  • Obesity / metabolism*
  • Organ Size
  • Oxidative Stress
  • Rats
  • Rats, Zucker
  • Soybean Proteins / administration & dosage*
  • Soybean Proteins / pharmacology
  • Sterol Regulatory Element Binding Protein 1 / biosynthesis
  • Sterol Regulatory Element Binding Protein 2 / biosynthesis
  • Transforming Growth Factor beta / biosynthesis
  • Triglycerides / blood
  • Tumor Necrosis Factor-alpha / biosynthesis


  • Blood Glucose
  • Caseins
  • Collagen Type IV
  • Dietary Proteins
  • Insulin
  • Interleukin-6
  • Soybean Proteins
  • Srebf1 protein, rat
  • Sterol Regulatory Element Binding Protein 1
  • Sterol Regulatory Element Binding Protein 2
  • Transforming Growth Factor beta
  • Triglycerides
  • Tumor Necrosis Factor-alpha
  • Cholesterol
  • Hydrogen Peroxide
  • Hydroxymethylglutaryl CoA Reductases