Limits...
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

A heat map of hierarchical cluster analysis comparing the metabolite changes between PGC-1α-Tg mice and WT mice.Horizontal axis shows sample names corresponding to the samples used in Fig 1 (WT1, WT2, and WT3 for wild-type and Tg1, Tg2, and Tg3 for PGC-1α-Tg mice). The heat map patterns between WT (upper three lanes) and PGC-1α-Tg (lower three lanes) are clearly distinguishable. The color red demonstrates that the relative content of metabolites is high and green demonstrates that they are low.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4482640&req=5

pone.0129084.g002: A heat map of hierarchical cluster analysis comparing the metabolite changes between PGC-1α-Tg mice and WT mice.Horizontal axis shows sample names corresponding to the samples used in Fig 1 (WT1, WT2, and WT3 for wild-type and Tg1, Tg2, and Tg3 for PGC-1α-Tg mice). The heat map patterns between WT (upper three lanes) and PGC-1α-Tg (lower three lanes) are clearly distinguishable. The color red demonstrates that the relative content of metabolites is high and green demonstrates that they are low.

Mentions: Metabolomic analysis was conducted in the skeletal muscle of PGC-1α-Tg mice with age- and sex-matched wild-type (WT) mice littermates. Average body weights were 26.2 ± 3.0 g in PGC-1α-Tg mice and 25.7 ± 2.0 g in WT mice. Average weights of the gastrocnemius muscles were 115 ± 10 mg in PGC-1α-Tg mice and 138 ± 17 mg in WT mice. Consistent with previous reports [4], the weights of the gastrocnemius muscles in PGC-1α-Tg mice were significantly lower than those in WT littermates. Skeletal muscles of PGC-1α-Tg mice showed a red color characteristic of oxidative muscle. In the metabolomic analysis, 211 peaks (126 cations and 85 anions) were detected by the anion and cation modes of CE-TOFMS. The results of principal component analysis (PCA) in these detected peaks are shown in Fig 1. The first principal component effectively and distinctly separated the mice based on genotype (x axis), suggesting that overexpression of PGC-1α in the skeletal muscle caused a significant change in the overall metabolite profile of the muscle. Furthermore, a hierarchical cluster analyses (HCA) was conducted, followed by heat map analysis (Fig 2). As demonstrated from the heat map analysis, skeletal muscle samples from individual WT and PGC-1α-Tg mice segregated into tight clusters, indicating that PGC-1α has profound effects on the systemic metabolite profile of the skeletal muscle. From the results of PCA (Fig 1) and HCA (Fig 2), it was observed that PGC-1α overexpression had a significant influence in the metabolite profiles of the skeletal muscle because the two groups (WT and PGC-1α-Tg) were clearly distinguishable. The relative area values of the detected metabolic products in PGC-1α-Tg mice and WT are listed in S1 Table, sorted in order (PGC-1α-Tg per WT). In the following subsections, we discuss the results of the metabolomic analysis.


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)

A heat map of hierarchical cluster analysis comparing the metabolite changes between PGC-1α-Tg mice and WT mice.Horizontal axis shows sample names corresponding to the samples used in Fig 1 (WT1, WT2, and WT3 for wild-type and Tg1, Tg2, and Tg3 for PGC-1α-Tg mice). The heat map patterns between WT (upper three lanes) and PGC-1α-Tg (lower three lanes) are clearly distinguishable. The color red demonstrates that the relative content of metabolites is high and green demonstrates that they are low.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0129084.g002: A heat map of hierarchical cluster analysis comparing the metabolite changes between PGC-1α-Tg mice and WT mice.Horizontal axis shows sample names corresponding to the samples used in Fig 1 (WT1, WT2, and WT3 for wild-type and Tg1, Tg2, and Tg3 for PGC-1α-Tg mice). The heat map patterns between WT (upper three lanes) and PGC-1α-Tg (lower three lanes) are clearly distinguishable. The color red demonstrates that the relative content of metabolites is high and green demonstrates that they are low.
Mentions: Metabolomic analysis was conducted in the skeletal muscle of PGC-1α-Tg mice with age- and sex-matched wild-type (WT) mice littermates. Average body weights were 26.2 ± 3.0 g in PGC-1α-Tg mice and 25.7 ± 2.0 g in WT mice. Average weights of the gastrocnemius muscles were 115 ± 10 mg in PGC-1α-Tg mice and 138 ± 17 mg in WT mice. Consistent with previous reports [4], the weights of the gastrocnemius muscles in PGC-1α-Tg mice were significantly lower than those in WT littermates. Skeletal muscles of PGC-1α-Tg mice showed a red color characteristic of oxidative muscle. In the metabolomic analysis, 211 peaks (126 cations and 85 anions) were detected by the anion and cation modes of CE-TOFMS. The results of principal component analysis (PCA) in these detected peaks are shown in Fig 1. The first principal component effectively and distinctly separated the mice based on genotype (x axis), suggesting that overexpression of PGC-1α in the skeletal muscle caused a significant change in the overall metabolite profile of the muscle. Furthermore, a hierarchical cluster analyses (HCA) was conducted, followed by heat map analysis (Fig 2). As demonstrated from the heat map analysis, skeletal muscle samples from individual WT and PGC-1α-Tg mice segregated into tight clusters, indicating that PGC-1α has profound effects on the systemic metabolite profile of the skeletal muscle. From the results of PCA (Fig 1) and HCA (Fig 2), it was observed that PGC-1α overexpression had a significant influence in the metabolite profiles of the skeletal muscle because the two groups (WT and PGC-1α-Tg) were clearly distinguishable. The relative area values of the detected metabolic products in PGC-1α-Tg mice and WT are listed in S1 Table, sorted in order (PGC-1α-Tg per WT). In the following subsections, we discuss the results of the metabolomic analysis.

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