Srebp 2 (sterol - regulatory - binding - protein 2) pathway in testis and liver of hypercholesterolemic rabbits promoted by fat diet protection by olibe oil adittion

Abstract

Fat diet promotes hypercholesterolemia and infertility in adult male rabbits without obesity. This metabolic-reproductive disorder is corrected with a decrease in fat diet accompanied with the intake of extra virgin olive oil (AOVE). The underlying cellular and molecular mechanisms are still under research. The general regulation of cholesterol also relies on intracellular regulation. The cellular / molecular balance of cholesterol levels depends on the SREBP 2 pathway and its dependent molecules, such as LDLr or Methyl-Coenzyme A, which are involved in de novo synthesis of this lipid. The high fat diet promoted a decrease in the expression of SREBP 2 (mRNA and protein), in rabbits after 3 months compared to control animals that consumed balanced diet for rabbits (GEPSA ®), in both liver and testicle. This drop in expression is more pronounced at 6 months of diet. Interestingly, the addition of AOVE to the diet promoted an increase in the expression of SREBP 2 (both mRNA and protein) in both tissues, hepatic and seminiferous tubule. In addition, it was possible to observe the subcellular localization of the SREBP-2 protein in testes and hepatocytes by immunofluorescence (IFI). In the testicle, the SREBP 2 protein was located in interstitial cells and, depending on the stage of the seminiferous epithelial cycle, Sertoli and/or germline cells. We can infer that dietary fat / circulating cholesterol affects the hepatic and testicular levels, generating alterations such as fatty liver and germinal disorders with abnormal sperm cells observed in previous studies. These changes are due to an imbalance of the intracellular cholesterol regulatory pathway. The AOVE contributes in the correction of the hepatic and testicular histo-physiology.