Strain-specific metabolic responses to long-term caloric restriction in female ILSXISS recombinant inbred mice.
Level 5 - mechanism / opinion, no new human data
Animal research
PubMed 34246728 · doi:10.1016/j.mce.2021.111376
What was done
Female recombinant inbred ILSXISS mouse strains with known divergent lifespan responses to 40% caloric restriction (CR)—TejJ89 (lifespan extension), TejJ48 (unaffected lifespan), and TejJ114 (lifespan shortening)—were assessed after 10 months of 40% CR compared to ad libitum controls. Measures included body mass, gonadal white adipose tissue (gWAT) mass, brown adipose tissue (BAT) mass, glucose tolerance, insulin levels, and untargeted metabolomics of gWAT and BAT in strains TejJ89 and TejJ114.
What was found
Body mass and gWAT mass decreased across all strains with 40% CR, with greater relative body mass loss in TejJ114 (no exact numeric values reported in abstract). BAT mass increased only in TejJ89 and TejJ48. TejJ114 showed the most notable improvement in glucose tolerance, but both TejJ89 and TejJ114 exhibited hyperinsulinemia following CR compared to controls. Metabolomics revealed significant decreases in several long-chain unsaturated fatty acids in gWAT and elevated phosphatidylethanolamines with reduced phosphatidylglycerols in BAT of TejJ89, whereas gWAT and BAT in TejJ114 showed minimal metabolic changes.
Why it matters
The study demonstrates that metabolic, glycemic, and adipose lipidomic responses to long-term caloric restriction depend heavily on genetic background, helping explain why identical dietary restriction regimens produce divergent longevity outcomes across genotypes.
Limits
The study was conducted entirely in female mice from three inbred strains, so findings may not generalize to males or other genotypes. The abstract does not report sample sizes (n), baseline data, or exact numeric measurements and effect sizes. As an animal model, direct translation to human dietary restriction remains uncertain.
Cited by
- supports Studies in rodents show that different genetic backgrounds respond differently to caloric restriction, and some mouse strains experience worse health or lifespan outcomes.