Maternal protein restriction changes structural and metabolic gene expression in the skeletal muscle of aging offspring rats.
Level 5 - mechanism / opinion, no new human data
Animal research without human data.
PubMed 33843034 · doi:10.14670/HH-18-337
What was done
Researchers examined the soleus (SOL, oxidative) and extensor digitorum longus (EDL, glycolytic) skeletal muscles of 540-day-old aged male rats born to dams fed a low-protein diet (6% protein) during pregnancy and lactation. They evaluated muscle fiber cross-sectional area (CSA; n=8), fiber type frequency (n=5), global transcriptomics (n=3), and gene expression of metabolic markers (Sdha, CS, Ldha) and differentially expressed genes (n=8) using morphological, immunohistochemical, and molecular analyses.
What was found
In the oxidative SOL muscle, maternal protein restriction significantly decreased muscle fiber CSA (p<0.05) and down-regulated the oxidative marker Sdha (p<0.001) and Hspb7 (p<0.01). It up-regulated anabolic and structural genes, including Igf-1 (p<0.01), Chad (p<0.01), and Fmod (p<0.05). In the glycolytic EDL muscle, maternal restriction decreased type IIA fiber frequency (p<0.05) and increased type IIB frequency (p<0.05), with no changes in CSA or oxidative markers. EDL muscle also showed up-regulation of Chad (p<0.01) and down-regulation of Myog (p<0.01). Absolute numerical values and effect sizes were not reported in the abstract.
Why it matters
This study demonstrates that early-life nutritional deficits can exert lifelong programming effects on skeletal muscle architecture and metabolic gene expression into senility, primarily affecting oxidative muscle fibers.
Limits
The study was conducted in a rodent model, limiting direct translation to human aging. Sample sizes were small across all assays (n=3 to 8 per group). Only male offspring were evaluated, and functional outcomes (such as muscle strength or endurance) were not reported in the abstract.
Cited by
- supports Animal studies show maternal protein restriction during pregnancy triggers epigenetic changes that program offspring to have smaller muscle mass throughout life.