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Metabolomic Analysis of the Skeletal Muscle of Mice Overexpressing PGC-1α.

Hatazawa Y, Senoo N, Tadaishi M, Ogawa Y, Ezaki O, Kamei Y, Miura S - PLoS ONE (2015)

Bottom Line: Meanwhile, BCAA levels decreased (Val, 0.7-fold; Leu, 0.8-fold; and Ile, 0.7-fold), and Glu (3.1-fold) and Asp (2.2-fold) levels increased.Moreover, our metabolomics data showing the activation of the purine nucleotide pathway, malate-aspartate shuttle, as well as creatine metabolism, which are known to be active during exercise, further suggests that PGC-1α regulates metabolism in exercise.Thus, we demonstrated the roles of PGC-1α in the skeletal muscle at the metabolite level.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan.

ABSTRACT
Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) is a coactivator of various nuclear receptors and other transcription factors whose expression increases in the skeletal muscle during exercise. We have previously made transgenic mice overexpressing PGC-1α in the skeletal muscle (PGC-1α-Tg mice). PGC-1α upregulates the expression of genes associated with red fibers, mitochondrial function, fatty acid oxidation, and branched chain amino acid (BCAA) degradation. However, global analyses of the actual metabolic products have not been investigated. In this study, we conducted metabolomic analysis of the skeletal muscle in PGC-1α-Tg mice by capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry. Principal component analysis and hierarchical cluster analysis showed clearly distinguishable changes in the metabolites between PGC-1α-Tg and wild-type control mice. Changes were observed in metabolite levels of various metabolic pathways such as the TCA cycle, pentose phosphate pathway, nucleotide synthesis, purine nucleotide cycle, and amino acid metabolism, including BCAA and β-alanine. Namely, metabolic products of the TCA cycle increased in PGC-1α-Tg mice, with increased levels of citrate (2.3-fold), succinate (2.2-fold), fumarate (2.8-fold), and malate (2.3-fold) observed. Metabolic products associated with the pentose phosphate pathway and nucleotide biosynthesis also increased in PGC-1α-Tg mice. Meanwhile, BCAA levels decreased (Val, 0.7-fold; Leu, 0.8-fold; and Ile, 0.7-fold), and Glu (3.1-fold) and Asp (2.2-fold) levels increased. Levels of β-alanine and related metabolites were markedly decreased in PGC-1α-Tg mice. Coordinated regulation of the TCA cycle and amino acid metabolism, including BCAA, suggests that PGC-1α plays important roles in energy metabolism. Moreover, our metabolomics data showing the activation of the purine nucleotide pathway, malate-aspartate shuttle, as well as creatine metabolism, which are known to be active during exercise, further suggests that PGC-1α regulates metabolism in exercise. Thus, we demonstrated the roles of PGC-1α in the skeletal muscle at the metabolite level.

No MeSH data available.


Related in: MedlinePlus

Observed metabolite changes mapped onto the pathways associated with β-alanine metabolism.Changes in the metabolite levels in the skeletal muscle of PGC-1α-Tg mice and WT mice are shown. Relative metabolite changes shown in the graphs were obtained by CE-TOFMS (S1 Table). Open bars, WT and filled bars, PGC-1α-Tg (N = 3). Data are expressed as the mean ± SD. Asterisks indicate statistically significant differences (***p < 0.001, **p < 0.01, *p < 0.05). Microarray data of gene expression change of enzymes and transporter in the related metabolic process are shown in the scheme.
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pone.0129084.g009: Observed metabolite changes mapped onto the pathways associated with β-alanine metabolism.Changes in the metabolite levels in the skeletal muscle of PGC-1α-Tg mice and WT mice are shown. Relative metabolite changes shown in the graphs were obtained by CE-TOFMS (S1 Table). Open bars, WT and filled bars, PGC-1α-Tg (N = 3). Data are expressed as the mean ± SD. Asterisks indicate statistically significant differences (***p < 0.001, **p < 0.01, *p < 0.05). Microarray data of gene expression change of enzymes and transporter in the related metabolic process are shown in the scheme.

Mentions: Metabolic products related to β-alanine metabolism decreased in PGC-1α-Tg mice (Fig 9). This includes the levels of β-alanine (0.15-fold), anserine (dipeptide of β-alanine and methylhistidine) (0.08-fold), and carnosine (dipeptide of β-alanine and histidine) (0.04-fold). β-Ala–Lys (dipeptide of β-alanine and lysine) was detected in WT mice but not in PGC-1α-Tg mice (Fig 9 and S1 Table). β-alanine is metabolized by 4-aminobutyrate transaminase (4.0-fold in microarray) to malonate semialdehyde. Furthermore, acetyl-CoA (detected only in PGC-1α-Tg mice, but not in WT mice) is produced from malonate-semialdehyde by malonate-semialdehyde dehydrogenase (the probe for this enzyme was not present in the microarray). Thus, β-alanine is likely to be converted into acetyl-CoA and enter the TCA cycle.


Metabolomic Analysis of the Skeletal Muscle of Mice Overexpressing PGC-1α.

Hatazawa Y, Senoo N, Tadaishi M, Ogawa Y, Ezaki O, Kamei Y, Miura S - PLoS ONE (2015)

Observed metabolite changes mapped onto the pathways associated with β-alanine metabolism.Changes in the metabolite levels in the skeletal muscle of PGC-1α-Tg mice and WT mice are shown. Relative metabolite changes shown in the graphs were obtained by CE-TOFMS (S1 Table). Open bars, WT and filled bars, PGC-1α-Tg (N = 3). Data are expressed as the mean ± SD. Asterisks indicate statistically significant differences (***p < 0.001, **p < 0.01, *p < 0.05). Microarray data of gene expression change of enzymes and transporter in the related metabolic process are shown in the scheme.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482640&req=5

pone.0129084.g009: Observed metabolite changes mapped onto the pathways associated with β-alanine metabolism.Changes in the metabolite levels in the skeletal muscle of PGC-1α-Tg mice and WT mice are shown. Relative metabolite changes shown in the graphs were obtained by CE-TOFMS (S1 Table). Open bars, WT and filled bars, PGC-1α-Tg (N = 3). Data are expressed as the mean ± SD. Asterisks indicate statistically significant differences (***p < 0.001, **p < 0.01, *p < 0.05). Microarray data of gene expression change of enzymes and transporter in the related metabolic process are shown in the scheme.
Mentions: Metabolic products related to β-alanine metabolism decreased in PGC-1α-Tg mice (Fig 9). This includes the levels of β-alanine (0.15-fold), anserine (dipeptide of β-alanine and methylhistidine) (0.08-fold), and carnosine (dipeptide of β-alanine and histidine) (0.04-fold). β-Ala–Lys (dipeptide of β-alanine and lysine) was detected in WT mice but not in PGC-1α-Tg mice (Fig 9 and S1 Table). β-alanine is metabolized by 4-aminobutyrate transaminase (4.0-fold in microarray) to malonate semialdehyde. Furthermore, acetyl-CoA (detected only in PGC-1α-Tg mice, but not in WT mice) is produced from malonate-semialdehyde by malonate-semialdehyde dehydrogenase (the probe for this enzyme was not present in the microarray). Thus, β-alanine is likely to be converted into acetyl-CoA and enter the TCA cycle.

Bottom Line: Meanwhile, BCAA levels decreased (Val, 0.7-fold; Leu, 0.8-fold; and Ile, 0.7-fold), and Glu (3.1-fold) and Asp (2.2-fold) levels increased.Moreover, our metabolomics data showing the activation of the purine nucleotide pathway, malate-aspartate shuttle, as well as creatine metabolism, which are known to be active during exercise, further suggests that PGC-1α regulates metabolism in exercise.Thus, we demonstrated the roles of PGC-1α in the skeletal muscle at the metabolite level.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan.

ABSTRACT
Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) is a coactivator of various nuclear receptors and other transcription factors whose expression increases in the skeletal muscle during exercise. We have previously made transgenic mice overexpressing PGC-1α in the skeletal muscle (PGC-1α-Tg mice). PGC-1α upregulates the expression of genes associated with red fibers, mitochondrial function, fatty acid oxidation, and branched chain amino acid (BCAA) degradation. However, global analyses of the actual metabolic products have not been investigated. In this study, we conducted metabolomic analysis of the skeletal muscle in PGC-1α-Tg mice by capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry. Principal component analysis and hierarchical cluster analysis showed clearly distinguishable changes in the metabolites between PGC-1α-Tg and wild-type control mice. Changes were observed in metabolite levels of various metabolic pathways such as the TCA cycle, pentose phosphate pathway, nucleotide synthesis, purine nucleotide cycle, and amino acid metabolism, including BCAA and β-alanine. Namely, metabolic products of the TCA cycle increased in PGC-1α-Tg mice, with increased levels of citrate (2.3-fold), succinate (2.2-fold), fumarate (2.8-fold), and malate (2.3-fold) observed. Metabolic products associated with the pentose phosphate pathway and nucleotide biosynthesis also increased in PGC-1α-Tg mice. Meanwhile, BCAA levels decreased (Val, 0.7-fold; Leu, 0.8-fold; and Ile, 0.7-fold), and Glu (3.1-fold) and Asp (2.2-fold) levels increased. Levels of β-alanine and related metabolites were markedly decreased in PGC-1α-Tg mice. Coordinated regulation of the TCA cycle and amino acid metabolism, including BCAA, suggests that PGC-1α plays important roles in energy metabolism. Moreover, our metabolomics data showing the activation of the purine nucleotide pathway, malate-aspartate shuttle, as well as creatine metabolism, which are known to be active during exercise, further suggests that PGC-1α regulates metabolism in exercise. Thus, we demonstrated the roles of PGC-1α in the skeletal muscle at the metabolite level.

No MeSH data available.


Related in: MedlinePlus