Redox state and altered pyruvate metabolism contribute to a dose-dependent metformin-induced lactate production of human myotubes
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE229658 | GEO | 2023/09/04
REPOSITORIES: GEO
Similar Datasets
Project description:Redox state and altered pyruvate metabolism contribute to a dose-dependent metformin-induced lactate production of human myotubes
| PRJNA955241 | ENA
Project description:This experiment was conducted to identify target genes of the peroxisome proliferator-activated receptor beta (PPARb) in skeletal muscle of transgenic mice that overexpressed PPARb. The following abstract from the submitted manuscript describes the major findings of this work. The Nuclear Receptor Transcription Factor PPARbeta/delta Programs Muscle Glucose Metabolism. Zhenji Gan, Eileen Burkart-Hartman, Dong-Ho Han, Brian Finck, Teresa C. Leone, John Holloszy, and Daniel P. Kelly. To identify new gene regulatory pathways controlling skeletal muscle energy metabolism, comparative studies were conducted on muscle-specific transgenic mouse lines expressing the nuclear receptors, PPARalpha (MCK-PPARalpha) or PPARbeta/delta (MCK-PPARbeta/delta). MCK-PPARbeta/delta mice are known to have enhanced exercise performance whereas MCK-PPARalpha mice perform at low levels. Transcriptional profiling revealed that the lactate dehydrogenase (Ldh)b/Ldha gene expression ratio is increased in MCK-PPARbeta/delta muscle, an isoenzyme shift that diverts pyruvate into the mitochondrion for the final steps of glucose oxidation. PPARbeta/delta gain- and loss-of-function studies in skeletal myotubes demonstrated that PPARbeta/delta, but not PPARalpha, interacts with the exercise inducible kinase, AMP-activated protein kinase (AMPK), to synergistically activate Ldhb gene transcription by cooperating with myocyte enhancer factor 2A (MEF2A), in a PPARbeta/delta ligand-independent manner. MCK-PPARbeta/delta muscle was shown to have high glycogen stores, increased levels of GLUT4, and augmented capacity for mitochondrial pyruvate oxidation suggesting a broad reprogramming of glucose utilization pathways. Lastly, exercise studies demonstrated that MCK-PPARbeta/delta mice had lower circulating levels of lactate compared to non-transgenic controls, while exhibiting supranormal performance on a high intensity exercise regimen. These results identify a transcriptional regulatory mechanism that increases capacity for muscle glucose utilization in a pattern that resembles the effects of exercise training. Keywords: muscle, exercise, nuclear receptors, glucose metabolism, gene regulation RNA from two wild-type (non-transgenic (NTG)) and two PPARbeta overexpressing (MCK-PPARb) mice was analyzed. Two replicates of each are provided.
2011-12-12 | E-GEOD-29055 | biostudies-arrayexpress
Project description:Skeletal muscle atrophy is dictated by the balance between protein synthesis and protein breakdown, known as proteostasis. With advanced age, muscle atrophy contributes to development of co-morbidities, loss of strength and independence, and all-cause mortality. Aging also coincides with the accumulation of senescent cells within skeletal muscle that produce inflammatory products, known as the senescence associated secretory phenotype. Previously, we found that a metformin + leucine (MET+LEU) combination treatment had synergistic effects in aged mice to improve skeletal muscle structure and function during disuse atrophy. Therefore, the objective of this study was to determine the mechanisms by which MET+LEU exhibits muscle atrophy protection in vitro and if this occurs through cellular senescence. C2C12 myoblasts differentiated into myotubes were used to determine MET+LEU mechanisms during serum-deprivation (SD) atrophy. Single myofibers were isolated from aged (22-23 mo) C57Bl6/J mice, and human primary myoblasts were extracted from a healthy older adult donor. 25 + 125 µM MET+LEU treatment increased differentiation of myotubes and prevented SD induced atrophy. Low concentration (0.1 + 0.5 µM) MET+LEU had unique effects to prevent myotube atrophy and cause transcriptional reprogramming compared to individual therapies. SD increased inflammatory and cellular senescence pathways that was reversed with MET+LEU treatment. SD resulted in dysregulated proteostasis that was rescued with MET+LEU, and proteasome inhibition with MG-132 also rescued myotube atrophy. Cellular senescence transcriptional pathways and markers increased by SD were reversed with MET+LEU treatment, and dasatinib + quercetin (D+Q) senolytic treatment prevented myotube atrophy similar to MET+LEU. In aged myofibers, MET+LEU prevented SD atrophy, and in human primary myotubes MET+LEU prevented reductions in myonuclei fusion. These data provide evidence that MET+LEU has muscle cell intrinsic properties to prevent atrophy by reversing senescence and improving proteostasis
2023-04-19 | GSE221941 | GEO
Project description:Cannabidiol (CBD), a cannabinoid from the cannabis plant, is widely used in sports for recovery, pain management, and sleep improvement, yet its effects on muscle are not well understood. This study aimed to determine the transcriptional response of murine skeletal muscle myotubes to broad-spectrum CBD and synthetic CBD (sCBD), hypothesizing significant changes in metabolism, myogenesis, and inflammation, with unique gene expression profiles for broad-spectrum CBD due to its additional compounds. Differentiated C2C12 myotubes were treated with 10 µM CBD, sCBD, or vehicle control (DMSO) for 24 hours before RNA extraction. Poly-A tail enriched mRNA libraries were constructed and sequenced using 2x50 bp paired-end sequencing. CBD and sCBD treatment induced 4489 and 1979 differentially expressed genes (DEGs; p <0.001, FDR step-up <0.05), respectively, with common upregulation of 857 genes and common downregulation of 648 genes. Common upregulated DEGs were associated with “response to unfolded protein”, “cell redox homeostasis”, “endoplasmic reticulum stress”, “oxidative stress” and “cellular response to hypoxia”. Common downregulated DEGs were linked to “sarcomere organization”, “skeletal muscle tissue development”, “regulation of muscle contraction”, “skeletal muscle contraction” and “muscle contraction”. CBD treatment induced 1342 unique upregulated DEGs and 1137 unique downregulated DEGs, compared to 154 and 152 unique up- and downregulated DEGs in sCBD. The transcriptional data indicate that CBD may induce mild cellular stress, activating pathways associated with altered redox balance, unfolded protein response, and endoplasmic reticulum stress. We hypothesize that CBD interacts with muscle and may elicit a ‘mitohormetic’ effect that warrants further investigation.
2024-09-25 | GSE272113 | GEO
Project description:This experiment was conducted to identify target genes of the peroxisome proliferator-activated receptor beta (PPARb) in skeletal muscle of transgenic mice that overexpressed PPARb. The following abstract from the submitted manuscript describes the major findings of this work. The Nuclear Receptor Transcription Factor PPARbeta/delta Programs Muscle Glucose Metabolism. Zhenji Gan, Eileen Burkart-Hartman, Dong-Ho Han, Brian Finck, Teresa C. Leone, John Holloszy, and Daniel P. Kelly. To identify new gene regulatory pathways controlling skeletal muscle energy metabolism, comparative studies were conducted on muscle-specific transgenic mouse lines expressing the nuclear receptors, PPARalpha (MCK-PPARalpha) or PPARbeta/delta (MCK-PPARbeta/delta). MCK-PPARbeta/delta mice are known to have enhanced exercise performance whereas MCK-PPARalpha mice perform at low levels. Transcriptional profiling revealed that the lactate dehydrogenase (Ldh)b/Ldha gene expression ratio is increased in MCK-PPARbeta/delta muscle, an isoenzyme shift that diverts pyruvate into the mitochondrion for the final steps of glucose oxidation. PPARbeta/delta gain- and loss-of-function studies in skeletal myotubes demonstrated that PPARbeta/delta, but not PPARalpha, interacts with the exercise inducible kinase, AMP-activated protein kinase (AMPK), to synergistically activate Ldhb gene transcription by cooperating with myocyte enhancer factor 2A (MEF2A), in a PPARbeta/delta ligand-independent manner. MCK-PPARbeta/delta muscle was shown to have high glycogen stores, increased levels of GLUT4, and augmented capacity for mitochondrial pyruvate oxidation suggesting a broad reprogramming of glucose utilization pathways. Lastly, exercise studies demonstrated that MCK-PPARbeta/delta mice had lower circulating levels of lactate compared to non-transgenic controls, while exhibiting supranormal performance on a high intensity exercise regimen. These results identify a transcriptional regulatory mechanism that increases capacity for muscle glucose utilization in a pattern that resembles the effects of exercise training. Keywords: muscle, exercise, nuclear receptors, glucose metabolism, gene regulation
2011-12-12 | GSE29055 | GEO
Project description:In muscle, reactive oxygen species (ROS) generation increases with strenuous activity, chronic unloading, and inflammatory stimuli; skeletal muscle function is very sensitive to ROS; and there are redox-sensitive signaling pathways. Using myogenic cell cultures, we asked whether hydrogen peroxide (H2O2) induces adaptive changes in skeletal muscle gene expression. H2O2 downregulated or failed to induce antioxidant or apoptotic genes in the myotubes. Instead, H2O2 changed the expression of genes for cytosolic and mitochondrial enzymes, and upregulated inflammatory mediators. Finally, H2O2 had a mostly inhibitory effect on the expression of many transcription factors. The results indicate that mild oxidative stress may induce an adaptive response in skeletal muscle without antioxidant upregulation or apoptosis. Keywords: Gene Expression, C2C12 Myotubes, Oxidative Stress, Adaptation
2005-08-11 | GSE3078 | GEO
Project description:Mesenchymal progenitor cells can be differentiated in vitro into myotubes that exhibit many characteristic features of primary mammalian skeletal muscle fibers. However, in general, they do not show the functional excitation-contraction coupling or the striated sarcomere arrangement typical of mature myofibers. Epigenetic modifications have been shown to play a key role in regulating the progressional changes in transcription necessary for muscle differentiation. In this study, we demonstrate that treatment of murine C2C12 mesenchymal progenitor cells with 10 µM of the DNA methylation inhibitor 5-azacytidine (5AC) promotes myogenesis, resulting in myotubes with enhanced maturity as compared to untreated myotubes. Specifically, 5AC treatment resulted in the upregulation of muscle genes at the myoblast stage while at later stages nearly 50 % of the 5AC-treated myotubes displayed a mature, well-defined sarcomere organization as well as spontaneous contractions that coincided with action potentials and intracellular calcium transients. Both the percentage of striated myotubes and their contractile activity could be inhibited by 20 nM TTX, 10 µM ryanodine and 100 µM nifedipine, suggesting that action potential-induced calcium transients are responsible for these characteristics. Our data suggest that genomic demethylation induced by 5AC overcomes an epigenetic barrier that prevents untreated C2C12 myotubes from reaching full maturity.
2012-01-01 | GSE30192 | GEO
Project description:Metabolically healthy skeletal muscle is characterized by the ability to switch easily between glucose and fat oxidation, whereas loss of this ability seems to be related to insulin resistance. The aim of this study was to investigate whether different fatty acids (FAs) and the LXR ligand T0901317 affected metabolic switching in human skeletal muscle cells (myotubes). Pretreatment of myotubes with eicosapentaenoic acid (EPA) increased suppressibility, the ability of glucose to suppress FA oxidation, and metabolic flexibility, the ability to increase FA oxidation when changing from “fed” to “fasted” state. Adaptability, the capacity to increase FA oxidation with increasing FA availability, was increased after pretreatment with EPA, linoleic acid (LA) and palmitic acid (PA). T0901317 counteracted the effect of EPA on suppressibility and adaptability, but did not affect these parameters alone. EPA itself accumulated less, however, EPA, LA, OA and T0901317 increased the number of lipid droplets (LDs) in myotubes, whereas LD size and mitochondria amount were independent of pretreatment. Microarray analysis showed that EPA regulated more genes than the other FAs. Some pathways involved in carbohydrate metabolism were induced only by EPA. The present study suggests a possible favorable effect of EPA on skeletal muscle metabolic switching and glucose utilization. Keywords: Analysis of target gene regulation by using microarrays. Primary human myotubes, derived from 3 healthy, female donors, were preincubated with different fatty acids (oleic acid [OA], palmitic acid [PA], eicosapentaenoic acid [EPA] or linoleic acid [LA], each at 100 µM) or bovine serum albumin [BSA] (40 µM) for 24 h.
2010-06-23 | E-GEOD-18589 | biostudies-arrayexpress
Project description:Mesenchymal progenitor cells can be differentiated in vitro into myotubes that exhibit many characteristic features of primary mammalian skeletal muscle fibers. However, in general, they do not show the functional excitation-contraction coupling or the striated sarcomere arrangement typical of mature myofibers. Epigenetic modifications have been shown to play a key role in regulating the progressional changes in transcription necessary for muscle differentiation. In this study, we demonstrate that treatment of murine C2C12 mesenchymal progenitor cells with 10 µM of the DNA methylation inhibitor 5-azacytidine (5AC) promotes myogenesis, resulting in myotubes with enhanced maturity as compared to untreated myotubes. Specifically, 5AC treatment resulted in the upregulation of muscle genes at the myoblast stage while at later stages nearly 50 % of the 5AC-treated myotubes displayed a mature, well-defined sarcomere organization as well as spontaneous contractions that coincided with action potentials and intracellular calcium transients. Both the percentage of striated myotubes and their contractile activity could be inhibited by 20 nM TTX, 10 µM ryanodine and 100 µM nifedipine, suggesting that action potential-induced calcium transients are responsible for these characteristics. Our data suggest that genomic demethylation induced by 5AC overcomes an epigenetic barrier that prevents untreated C2C12 myotubes from reaching full maturity. C2C12 cells were plated at 1500 cells/cm2 (day -1), cultured for 1 day in DMEM 10%NCS, then treated (d0) with or without 10uM 5-azacytidine (5AC) for an additional 3 days. RNA was extracted on day 3 and hybridized to GeneChip Mouse Genome 430 2.0 array (Affymetrix).
2012-01-01 | E-GEOD-30192 | biostudies-arrayexpress
Project description:In order to genetically determine the essential components of electron flow during respiration of sulfate by the anaerobe Desulfovibrio desulfuricans G20, a growth mode independent of sulfate is needed. However, a mutant of the G20 strain, I2, lacking the abundant type-1 tetraheme cytochrome c3 (TpI-c3), was found to be altered in growth with sulfate. Here we report that I2 does not reduce sulfate with electrons from pyruvate. In contrast, in the absence of sulfate, fermentative growth of I2 on pyruvate actually yielded slightly greater cellular protein than G20. When provided lactate with sulfate or when fermenting pyruvate, I2 produced more hydrogen and accumulated little if any succinate. G20 grows by fumarate dismutation and accumulates the theoretical 2:1 ratio of the end products, succinate and acetate, respectively. In contrast, I2 did not grow on fumarate alone. We inferred that TpI-c3 might be required for transfer of electrons to the membrane-bound fumarate reductase or for establishing a redox environment needed to trigger synthesis of the enzymes for succinate production. Microarray and proteomic analyses of gene and protein expression in I2 compared with G20 were consistent with increases in those enzymes predicted to be necessary for the generation of end products measured. These results support a role for the periplasmic TpI-c3 in electron flow from pyruvate to sulfate and in establishing conditions for enzyme production for fumarate dismutation. In addition, evidence for the simultaneous operation of respiratory electron flow and substrate-level phosphorylation was obtained from end product analysis. Strains I2 and G20 of Desulfovibrio desulfuricans were grown in different media. Four biological replicates of G20 on lactate media, and two biological replicates of G20 on Pyruvate media were compared with three replicates of I2 on lactate media and two replicates of I2 on pyruvate media.
2010-04-25 | E-GEOD-21287 | biostudies-arrayexpress