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Effect of a chronic intake of high dietary glycated proteins on skeletal muscle protein metabolism during aging in normal rats
Author(s) -
Murakami Hitoshi,
Henry Gwenaele,
Leonil Joelle,
Galmier MarieJosephe,
Giraudet Christophe,
Rousset Paulette,
Masgrau Aurelie,
Walrand Stephane,
Boirie Yves,
Guillet Christelle
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.233.2
Subject(s) - endocrinology , medicine , glycation , skeletal muscle , insulin resistance , anabolism , insulin receptor , protein kinase b , pi3k/akt/mtor pathway , rage (emotion) , insulin , phosphorylation , biology , signal transduction , diabetes mellitus , biochemistry , neuroscience
Chronic exposure of advanced glycation end products (AGEs) is associated with development of insulin resistance in mammals and in L6 skeletal muscle cells. AGEs increase oxidative stress and inflammation through receptor for AGEs (RAGE). We hypothesized that a chronic intake of dietary high AGEs may affect skeletal muscle protein metabolism and muscle mass in aging. To elucidate this hypothesis, phosphorylation of anabolic signaling pathway (Akt, mTOR, p70S6K, 4E‐BP1) and RAGE expression were measured by Western‐blot in tibialis in young (5month old), adult (13month old) and old (25month old) rats fed a diet containing heated casein (high‐AGEs) or non heated casein (low‐AGE) for 3 months. Insulin sensitivity was also evaluated by OGTT. Muscle loss and insulin resistance were observed in old ( P <0.05, 0.57±0.08, 2.66±1.32 fold from young, respectively), without any effect of high‐AGEs. Phosphorylation of mTOR, p70S6K increased in old rats ( P <0.05, 1.59±0.06, 10.59±2.58 fold from young rats, respectively). Interestingly, phosphorylation of p70S6K and RAGE expression were enhanced by high‐AGEs in old rats ( P <0.05, 4.19±1.02, 1.86±0.28 fold, respectively). Glycated proteins might stimulate signaling pathway of muscle protein synthesis through RAGE. Consequently, chronic intake of glycated proteins does not affect muscle anabolic response during aging.