Abstract
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. In the current study, a transgenic mouse that produced t10c12-CLA had been generated by inserting 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. 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 fatty acid oxidation and thermogenesis capacity of brown adipose tissues were elevated via CPT1B and UCP1/2 over-expression. 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.
Footnotes
Figure 4b for ITT added; Figure 6 J-K revised; Figure 7F updated
- Abbreviations
- CLA
- conjugated linoleic acid
- LA
- linoleic acid
- t10c12
- trans 10, cis 12
- pai
- Propionibacterium acnes isomerase
- wt
- wild-type
- FGF21
- fibroblast growth factor 21
- UCP
- uncoupling protein
- AMPK
- AMP-activated protein kinase
- BAT
- brown adipose tissue
- WAT
- white adipose tissue
- FAs
- fatty acids