The Relationship Between High-Fat Diet and Fibronect？n Type III Doma？n Containing Protein 5 mRNA Expression

Aim: Fibronectin type III domain containing protein 5 (FNDC5) is located in both muscle and brown adipose tissue. It is expressed that FNDC5 and irisin (fragment of FNDC5) may be use as a therapeutic molecule due to their effects for metabolic disease (related to obesity). Since irisin/FNDC5, a membrane protein, was recently revealed, there are limited number of studies about them. The purpose of this study was to assess the relationship between FNDC5 assosiated with metabolic disease and high-fat diet in muscle and brown adipose tissue. Materials and Methods: In the study, 18 male Sprague-Dawley rats, 1.5-2 months old were used. Rats were randomly chosen, and divided into 3 groups consisting of 6 rats. Rats were fed 85 days with low-fat standard diet or high-fat diet. In both the brown adipose tissue and muscle tissue, FNDC5 mRNA expressions were measured. Results: When the FNDC5 mRNA levels of control and obese groups were compared, it was determined that the FNDC5 mRNA levels of obese group was higher than that of the control group in the brown adipose tissue (p=0.016). When the FNDC5 mRNA levels of antioxidant and obese groups were examined, obese group’s levels was higher than that of the antioksidant group in the brown adipose tissue (p=0.010). As for the muscle tissue, FNDC5 mRNA levels were determined to be lower in the antioxidant group than in the control group (p=0.006). Discussion and Conclusion: Our study indicated that FNDC5 mRNA expression changed in the brown adipose tissue due to high-fat diet, but doesn’t change in the muscle tissue. Therefore, it is understood that high-fat diet may be effective in the regulation of FNDC5 mRNA expression in BAT