Metabolic impact of trans 10, cis 12-conjugated linoleic acid in pai transgenic mice

Introduction: Trans 10, cis 12-conjugated linoleic acid (t10c12-CLA) from ruminant-derived foodstuffs can induce body fat loss in mammals after oral administration, while its mechanism on fat reduction has yet to be clarified fully until now. Methods: In the current study, a transgenic mouse that produces t10c12-CLA has been generated via the insertion of the Propionibacterium acnes isomerase (Pai) expression cassette into the Rosa26 locus, and its male offspring were used to decipher an irreversible long-term impact of t10c12-CLA on health and its mechanism of action. Results: Compared to their wild-type C57BL/6J littermates, comprehensive phenotype profiling of biallelic pai/pai mice indicated that white fat was decreased while brown fat was increased reversely; meanwhile, more heat was released and the central activities were reduced. Besides decreased plasma triglycerides in both pai genotypes and increased serum FGF21 in pai/wt mice, RNA and protein analysis revealed that the thermogenesis capacity of brown adipose tissues was increased via pAMPK and UCP2 over-expression. Conclusion: The results indicate that the t10c12-CLA-induced fat loss might be caused by the excess FGF21 and the increased mass and extra thermogenesis of brown adipose tissue in transgenic mice. ### Competing Interest Statement The authors have declared no competing interest.