Vitamin D deficiency down-regulates Notch pathway contributing to skeletal muscle atrophy in old wistar rats

• Published in: Nutrition & metabolism 2014-09, Vol.11 (1), p.47-47, Article 47
• Main Authors: Domingues-Faria, Carla, Chanet, Audrey, Salles, Jérôme, Berry, Alexandre, Giraudet, Christophe, Patrac, Véronique, Denis, Philippe, Bouton, Katia, Goncalves-Mendes, Nicolas, Vasson, Marie-Paule, Boirie, Yves, Walrand, Stéphane
• Format: Article
• Language: English
• Subjects: Age; Aging; Analysis; Cell cycle; Cell growth; cell proliferation; correlation; elderly; Food and Nutrition; Gene expression; genes; Health aspects; Hypotheses; Life Sciences; messenger RNA; muscle strength; muscles; Musculoskeletal system; Nutrition; Older people; proliferating cell nuclear antigen; protein synthesis; Proteins; quantitative polymerase chain reaction; rats; Rodents; sarcopenia; skeletal muscle; Studies; t-test; Transcription factors; Vitamin D; Vitamin D deficiency; Vitamin deficiency; vitamin status; Western blotting
• ISSN: 1743-7075; 1743-7075
• DOI: 10.1186/1743-7075-11-47

BACKGROUND: The diminished ability of aged muscle to self-repair is a factor behind sarcopenia and contributes to muscle atrophy. Muscle repair depends on satellite cells whose pool size is diminished with aging. A reduction in Notch pathway activity may explain the age-related decrease in satellite cell proliferation, as this pathway has been implicated in satellite cell self-renewal. Skeletal muscle is a target of vitamin D which modulates muscle cell proliferation and differentiation in vitro and stimulates muscle regeneration in vivo. Vitamin D status is positively correlated to muscle strength/function, and elderly populations develop a vitamin D deficiency. The aim of this study was to evaluate how vitamin D deficiency induces skeletal muscle atrophy in old rats through a reduction in Notch pathway activity and proliferation potential in muscle. METHODS: 15-month-old male rats were vitamin D-depleted or not (control) for 9 months (n = 10 per group). Rats were 24-month-old at the end of the experiment. Gene and/or protein expression of markers of proliferation, or modulating proliferation, and of Notch signalling pathway were studied in the tibialis anterior muscle by qPCR and western blot. An unpaired student’s t-test was performed to test the effect of the experimental conditions. RESULTS: Vitamin D depletion led to a drop in concentrations of plasma 25-hydroxyvitamin D in depleted rats compared to controls (-74%, p