Active immunization of fatty acid translocase specifically decreased visceral fat deposition in male broilers

Lipid accumulation of avian adipocytes is mainly dependent upon the fatty acid transmembrane uptake process mediated by membrane proteins, such as fatty acid translocase (FAT/CD36), fatty acid transport protein 1, and caveolin-2. To examine the effects of FAT/CD36 on spatial-specific fat deposition, 60 broiler chickens were randomly allocated to 2 groups by sex. Each male or female group contained 2 subgroups (n = 14-15) inoculated by intramuscular injection with chicken FAT/CD36 or BSA (control) immunogens at 34, 49, and 63 d. The subcutaneous and visceral fat deposits were measured, as were levels of plasma triglyceride and free fatty acid. Serum antibody titer was measured by ELISA. The mRNA expression levels of fatty acid transport-related genes in the adipose tissue of the male broilers were investigated to reveal the relationships among various fatty acid transporters. The results showed that active immunization with FAT/CD36 could significantly decrease the visceral fat of the male broilers by up to 40%, but it had no effect on subcutaneous fat stores of male broilers or on either site of fat deposition in female broilers. The concentration of plasma free fatty acids increased in the experimental groups for both male and female broilers. After the FAT/CD36 immunization, very low density lipoprotein receptor mRNA expression was upregulated in both the subcutaneous and visceral fat of male broilers, whereas peroxisome proliferator-activated receptor γ, FAT/CD36, and acyl-CoA binding protein mRNA expression levels were upregulated only in the visceral fat of male broilers. These results indicated a novel role of chicken FAT/CD36 in fat deposition, with sex- and spatial-specific effects.