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

Domingues-Faria C, Chanet A, Salles J, Berry A, Giraudet C, Patrac V, Denis P, Bouton K, Goncalves-Mendes N, Vasson MP, Boirie Y, Walrand S - Nutr Metab (Lond) (2014)

Bottom Line: 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.An unpaired student's t-test was performed to test the effect of the experimental conditions.The D-depleted group showed -39%, -31% drops in expression of two markers known to modulate proliferation (Bmp4, Fgf-2 mRNA levels) and -56% drop in one marker of cell proliferation (PCNA protein expression) compared to controls (p < 0.05).

View Article: PubMed Central - PubMed

Affiliation: Université d'Auvergne, Unité de Nutrition Humaine, Equipe ECREIN, CLARA, CRNH Auvergne; INRA, UMR 1019, UNH, CRNH Auvergne, Clermont Université, 63000 Clermont-Ferrand, France ; Université d'Auvergne, Unité de Nutrition Humaine, Equipe NuTriM, CRNH Auvergne; INRA, UMR 1019, UNH, CRNH Auvergne, Clermont Université, 63000 Clermont-Ferrand, France ; INRA, UMR1019, UNH, CRNH Auvergne, 63000 Clermont-Ferrand, France.

ABSTRACT

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 < 0.01). Tibialis anterior weight was decreased in D-depleted rats (-25%, p < 0.05). The D-depleted group showed -39%, -31% drops in expression of two markers known to modulate proliferation (Bmp4, Fgf-2 mRNA levels) and -56% drop in one marker of cell proliferation (PCNA protein expression) compared to controls (p < 0.05). Notch pathway activity was blunted in tibialis anterior of D-depleted rats compared to controls, seen as a down-regulation of cleaved Notch (-53%, p < 0.05) and its target Hes1 (-35%, p < 0.05).

Conclusions: A 9-month vitamin D depletion induced vitamin D deficiency in old rats. Vitamin D depletion induces skeletal muscle atrophy in old rats through a reduction in Notch pathway activity and proliferation potential. Vitamin D deficiency could aggravate the age-related decrease in muscle regeneration capacity.

No MeSH data available.


Related in: MedlinePlus

Effect of vitamin D depletion on expression of proliferation markers and regulators in old rats. (A) mRNA expression of Bmp4 and (B) Fgf-2 in tibialis anterior of control and depleted rats was analyzed using a RT2 Profiler Custom PCR Array following the manufacturer’s protocol. Bmp4 and Fgf-2 mRNA in control and vitamin D depleted samples was normalized using expression of Tbp as a housekeeping gene and was relative to control group according to the 2-ΔΔCT method (n = 7 for control group and n = 9 for depleted group). mRNA expression levels of Bmp4 and Fgf-2 were significantly decreased in vitamin D-depleted rats versus controls. Data presented are means ± SEM; *p < 0.05. (C) Protein expression of PCNA in tibialis anterior was analyzed by western blotting and quantified using Multi Gauge V3.2 software. Expression of the total amount of p38 was used to normalize protein loading between samples (n = 7 for control group and n = 9 for depleted group). The expression of PCNA protein decreased in old rats after dietary vitamin D depletion compared to control. A.U = arbitrary units. Data presented are means ± SEM; *p < 0.05.
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Fig4: Effect of vitamin D depletion on expression of proliferation markers and regulators in old rats. (A) mRNA expression of Bmp4 and (B) Fgf-2 in tibialis anterior of control and depleted rats was analyzed using a RT2 Profiler Custom PCR Array following the manufacturer’s protocol. Bmp4 and Fgf-2 mRNA in control and vitamin D depleted samples was normalized using expression of Tbp as a housekeeping gene and was relative to control group according to the 2-ΔΔCT method (n = 7 for control group and n = 9 for depleted group). mRNA expression levels of Bmp4 and Fgf-2 were significantly decreased in vitamin D-depleted rats versus controls. Data presented are means ± SEM; *p < 0.05. (C) Protein expression of PCNA in tibialis anterior was analyzed by western blotting and quantified using Multi Gauge V3.2 software. Expression of the total amount of p38 was used to normalize protein loading between samples (n = 7 for control group and n = 9 for depleted group). The expression of PCNA protein decreased in old rats after dietary vitamin D depletion compared to control. A.U = arbitrary units. Data presented are means ± SEM; *p < 0.05.

Mentions: Concerning genes related to cell proliferation, mRNA expression levels of Bmp4 (Figure 4A) and Fgf-2 (Figure 4B) were also significantly decreased by 39% and 31% in vitamin D-depleted rats versus controls (p < 0.05). These data were confirmed by the decreased expression of PCNA protein in old rats after dietary vitamin D depletion (-56%, p < 0.05, Figure 4C).Figure 4


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

Domingues-Faria C, Chanet A, Salles J, Berry A, Giraudet C, Patrac V, Denis P, Bouton K, Goncalves-Mendes N, Vasson MP, Boirie Y, Walrand S - Nutr Metab (Lond) (2014)

Effect of vitamin D depletion on expression of proliferation markers and regulators in old rats. (A) mRNA expression of Bmp4 and (B) Fgf-2 in tibialis anterior of control and depleted rats was analyzed using a RT2 Profiler Custom PCR Array following the manufacturer’s protocol. Bmp4 and Fgf-2 mRNA in control and vitamin D depleted samples was normalized using expression of Tbp as a housekeeping gene and was relative to control group according to the 2-ΔΔCT method (n = 7 for control group and n = 9 for depleted group). mRNA expression levels of Bmp4 and Fgf-2 were significantly decreased in vitamin D-depleted rats versus controls. Data presented are means ± SEM; *p < 0.05. (C) Protein expression of PCNA in tibialis anterior was analyzed by western blotting and quantified using Multi Gauge V3.2 software. Expression of the total amount of p38 was used to normalize protein loading between samples (n = 7 for control group and n = 9 for depleted group). The expression of PCNA protein decreased in old rats after dietary vitamin D depletion compared to control. A.U = arbitrary units. Data presented are means ± SEM; *p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC4195890&req=5

Fig4: Effect of vitamin D depletion on expression of proliferation markers and regulators in old rats. (A) mRNA expression of Bmp4 and (B) Fgf-2 in tibialis anterior of control and depleted rats was analyzed using a RT2 Profiler Custom PCR Array following the manufacturer’s protocol. Bmp4 and Fgf-2 mRNA in control and vitamin D depleted samples was normalized using expression of Tbp as a housekeeping gene and was relative to control group according to the 2-ΔΔCT method (n = 7 for control group and n = 9 for depleted group). mRNA expression levels of Bmp4 and Fgf-2 were significantly decreased in vitamin D-depleted rats versus controls. Data presented are means ± SEM; *p < 0.05. (C) Protein expression of PCNA in tibialis anterior was analyzed by western blotting and quantified using Multi Gauge V3.2 software. Expression of the total amount of p38 was used to normalize protein loading between samples (n = 7 for control group and n = 9 for depleted group). The expression of PCNA protein decreased in old rats after dietary vitamin D depletion compared to control. A.U = arbitrary units. Data presented are means ± SEM; *p < 0.05.
Mentions: Concerning genes related to cell proliferation, mRNA expression levels of Bmp4 (Figure 4A) and Fgf-2 (Figure 4B) were also significantly decreased by 39% and 31% in vitamin D-depleted rats versus controls (p < 0.05). These data were confirmed by the decreased expression of PCNA protein in old rats after dietary vitamin D depletion (-56%, p < 0.05, Figure 4C).Figure 4

Bottom Line: 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.An unpaired student's t-test was performed to test the effect of the experimental conditions.The D-depleted group showed -39%, -31% drops in expression of two markers known to modulate proliferation (Bmp4, Fgf-2 mRNA levels) and -56% drop in one marker of cell proliferation (PCNA protein expression) compared to controls (p < 0.05).

View Article: PubMed Central - PubMed

Affiliation: Université d'Auvergne, Unité de Nutrition Humaine, Equipe ECREIN, CLARA, CRNH Auvergne; INRA, UMR 1019, UNH, CRNH Auvergne, Clermont Université, 63000 Clermont-Ferrand, France ; Université d'Auvergne, Unité de Nutrition Humaine, Equipe NuTriM, CRNH Auvergne; INRA, UMR 1019, UNH, CRNH Auvergne, Clermont Université, 63000 Clermont-Ferrand, France ; INRA, UMR1019, UNH, CRNH Auvergne, 63000 Clermont-Ferrand, France.

ABSTRACT

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 < 0.01). Tibialis anterior weight was decreased in D-depleted rats (-25%, p < 0.05). The D-depleted group showed -39%, -31% drops in expression of two markers known to modulate proliferation (Bmp4, Fgf-2 mRNA levels) and -56% drop in one marker of cell proliferation (PCNA protein expression) compared to controls (p < 0.05). Notch pathway activity was blunted in tibialis anterior of D-depleted rats compared to controls, seen as a down-regulation of cleaved Notch (-53%, p < 0.05) and its target Hes1 (-35%, p < 0.05).

Conclusions: A 9-month vitamin D depletion induced vitamin D deficiency in old rats. Vitamin D depletion induces skeletal muscle atrophy in old rats through a reduction in Notch pathway activity and proliferation potential. Vitamin D deficiency could aggravate the age-related decrease in muscle regeneration capacity.

No MeSH data available.


Related in: MedlinePlus