Interesterified Fats Induce Deleterious Effects on Adipose Tissue and Liver in LDLr-KO Mice

Interesterified fatsare being widely used by the food industry in an attempt to replace trans fatty acids. The effect of interesterified fatscontaining palmiticor stearic acids on lipid metabolismand inflammatory signaling pathways in adipose and hepatic tissues was evaluated. Male LDLr-KO mice were fed a high-fat diet containing polyunsaturated (PUFA), palmitic( PALM), palmiticinteresterified ( PALMINTER), stearic (STEAR), or stearic interesterified (STEAR INTER) fats for 16 weeks. The expression of genes and protein levels involved in lipid metabolismand inflammatory processes in liver and white adipose tissuewas determined by quantitative RT-PCR and by Western blot, respectively. The infiltration of inflammatory cells in hepatic and adipose tissues was determined by eosin and hematoxylin, while liver collagen content was determined by Sirius Redstaining. Both interesterified fatsincreased liver collagen content and JNK phosphorylation. Additionally, the STEAR INTER group developednonalcoholic steatohepatitis(NASH) associated with higher neutrophil infiltration. PALMINTER induced adipose tissue expansionand enlargement of adipocytes. Furthermore, PALMINTER triggered increased IKK phosphorylation and TNFα protein content, conditions associated with the upstream activation of the NFkB signaling pathway. STEAR INTER induced NASH, while PALMINTER triggered hepatic fibrosis and adipocyte hypertrophy with inflammatory response in LDLr-KO mice.