Effects of 48h Lower Limb Unloading in Human Skeletal Muscle
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE21496 | GEO | 2010/10/23
SECONDARY ACCESSION(S): PRJNA126009
REPOSITORIES: GEO
Similar Datasets
Project description:Although short-term disuse does not result in measurable muscle atrophy, studies suggest that molecular changes associated with protein degradation may be initiated within days of the onset of a disuse stimulus. We examined the global gene expression patterns in sedentary men (n = 7, mean age ± S.D = 22.1 ± 3.7 yr) following 48h unloading (UL) via unilateral lower limb suspension and 24h reloading (RL). Biopsy samples of the left vastus lateralis muscle were collected at baseline, 48h UL, and 24h RL. Expression changes were measured by microarray and gene clustering; identification of enriched functions and canonical pathways were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA). Four genes were validated with qRT-PCR, and protein levels were measured with Western blot. Of the upregulated genes after UL, the most enriched functional group and highest ranked canonical pathway were related to protein ubiquitination. The oxidative stress response pathway was the second highest ranked canonical pathway. Of the downregulated genes, functions related to mitochondrial metabolism were the mostly highly enriched. In general, gene expression patterns following UL persisted following RL. qRT-PCR confirmed increases in mRNA for UPP-related E3 ligase Atrogin1 (but not accompanying increases in protein products) and stress response gene heme oxygenase-1 (HMOX, which showed a trend towards increases in protein products at 48h UL) as well as extracellular matrix (ECM) component COL4. The gene expression patterns were not readily reversed upon RL suggesting that molecular responses to short-term periods of skeletal muscle inactivity may persist after activity resumes. Biopsies were taken of the left vastus lateralis of healthy, sedentary men (N = 7) at baseline, immediately following 48h UL and 24h RL. A 5mm Berstrom biopsy needle was used. Biopsy samples were immediately snap-frozen in liquid nitrogen upon excision. All samples were stored at -80° C until analysis.
2010-10-23 | E-GEOD-21496 | biostudies-arrayexpress
Project description:Loss of muscle mass and strength following disuse followed by impaired muscle recovery likely contribute to sarcopenia in older adults. Metformin and leucine individually have shown positive effects in skeletal muscle during atrophy conditions but have not been evaluated in combination nor under the conditions of disuse atrophy and recovery in aging. The purpose of this study was to determine if a dual treatment of metformin and leucine (MET+LEU) would prevent disuse-induced atrophy and/or promote muscle recovery in aged mice (22-24 mo). We were also interested if these muscle responses correspond to changes in satellite cells and ECM abundance. Aged mice were subjected to 14 days of hindlimb unloading (HU) followed by 7 or 14 days of reloading (7 or 14d RL). Metformin (MET), leucine (LEU), or MET+LEU was administered via drinking water and were compared to Vehicle-treated mice. We observed that MET+LEU increased whole body grip strength, muscle specific force and satellite cell abundance during HU but did not alter muscle size during HU or RL. Moreover, MET+LEU treatment increased ECM turnover driven by a decrease in collagen IV content during 7 and 14d RL. Transcriptome analysis revealed that MET+LEU altered Gene Set Enrichment Analysis hallmark pathways related to inflammation and myogenesis during HU. Together , MET+LEU was able to improve muscle quality during disuse and recovery in aging possibly by increasing muscle satellite cell content and reducing excessive ECM accumulation.
2021-09-01 | GSE167462 | GEO
Project description:Hibernation is energy saving adaptation involving suppression of activity to survive in highly seasonal environments. Immobility and disuse generate muscle loss in most mammalian species. In contrast to other mammals, bears and ground squirrels demonstrate limited muscle atrophy over the physical inactivity of winter hibernation. This suggests that hibernating mammals have adaptive mechanisms to prevent disuse muscle atrophy. To identify common transcriptional program underlying molecular mechanisms preventing muscle loss, we conducted a large-scale gene expression screening in hind limb muscles comparing hibernating and summer active black bears and arctic ground squirrels by the use of custom 9,600 probe cDNA microarrays. The molecular pathway analysis showed an elevated proportion of overexpressed genes involved in all stages of protein biosynthesis and ribosome biogenesis in muscle of both species during hibernation that implies induction of translation at different hibernation states. The induction of protein biosynthesis likely contributes to attenuation of disuse muscle atrophy through prolonged periods of immobility and starvation. This adaptive mechanism allows hibernating mammals to maintain full musculoskeletal function and preserve mobility during and immediately after hibernation, thus promoting survival. The lack of directional changes in genes of protein catabolic pathways does not support the importance of metabolic suppression for preserving muscle mass during winter. Coordinated reduction of multiply genes involved in oxidation reduction and glucose metabolism detected in both species is consistent with metabolic suppression and lower energy demand in skeletal muscle during inactivity of hibernation. Black bears sampled during winter hibernation were compared with the animals sampled during summer. Muscle tissue were hybridized on a custom 12,800 cDNA probe nylon membrane microarray platform . Six hibernating and six summer active bears were studied in the experiment.
2014-10-16 | E-GEOD-62220 | biostudies-arrayexpress
Project description:Hibernation is energy saving adaptation involving suppression of activity to survive in highly seasonal environments. Immobility and disuse generate muscle loss in most mammalian species. In contrast to other mammals, bears and ground squirrels demonstrate limited muscle atrophy over the physical inactivity of winter hibernation. This suggests that hibernating mammals have adaptive mechanisms to prevent disuse muscle atrophy. To identify common transcriptional program underlying molecular mechanisms preventing muscle loss, we conducted a large-scale gene expression screening in hind limb muscles comparing hibernating and summer active black bears and arctic ground squirrels by the use of custom 9,600 probe cDNA microarrays. The molecular pathway analysis showed an elevated proportion of overexpressed genes involved in all stages of protein biosynthesis and ribosome biogenesis in muscle of both species during hibernation that implies induction of translation at different hibernation states. The induction of protein biosynthesis likely contributes to attenuation of disuse muscle atrophy through prolonged periods of immobility and starvation. This adaptive mechanism allows hibernating mammals to maintain full musculoskeletal function and preserve mobility during and immediately after hibernation, thus promoting survival. The lack of directional changes in genes of protein catabolic pathways does not support the importance of metabolic suppression for preserving muscle mass during winter. Coordinated reduction of multiply genes involved in oxidation reduction and glucose metabolism detected in both species is consistent with metabolic suppression and lower energy demand in skeletal muscle during inactivity of hibernation. Arctic ground squirrels sampled during winter hibernation were compared with the animals sampled during summer. Muscle was hybridized on a custom 9,600 probes nylon membrane microarray platform. Ten in late torpor, four in early arousal, then in late arousal were studied in experiments.
2014-10-16 | E-GEOD-62377 | biostudies-arrayexpress
Project description:Studies of skeletal muscle disuse either in patients on bed rest or experimentally in animals(immobilization) have demonstrated that decreased protein synthesis is common, with transient parallel increases in protein degradation. Muscle disuse atrophy involves a process of transition from slow to fast myosin fiber types 6 . A shift toward glycolysis, decreased capacity for fat oxidation, and substrate accumulation in atrophied muscles have been reported as has accommodation of the liver with an increased gluconeogenic capacity. Recent studies have modeled skeletal muscle disuse by using cyclic stretch of differentiated myotubes (C2C12), which mimics the loading pattern of mature skeletal muscle, followed by cessation of stretch.We utilized this model to determine the metabolic changes using non-targeted metabolomics analysis of the media. We identified increases in amino acids resulting from protein degradation (largely sarcomere) that occurs with muscle atrophy that are involved in feeding the Kreb’s cycle through anaplerosis. Specifically, we identified increased alanine/proline metabolism (significantly elevated proline, alanine, glutamine, and asparagine) and increased -ketoglutaric acid, the proposed Kreb’s cycle intermediate being fed by the alanine/proline metabolic anaplerotic mechanism. Additionally, several unique pathways not clearly delineated in previous studies of muscle unloading were seen, including: 1) elevated ethanolamine and elevated keto-acids (e.g. 2-ketoleucine and 2-keovaline) represent intermediates in the Ehlrich amino acid degradation pathway, which feeds into a metabolic pathway supplying acetyl-CoA and 2-hydroxybutyrate (also significantly increased); and 2) elevated guanine, an intermediate of purine metabolism, was seen at 12 hours unloading. Given the interest in targeting different aspects of the ubiquitin proteasome system to inhibit protein degradation, this C2C12 system may allow the identification of direct and indirect alterations in metabolism due to anaplerosis or through other yet to be identified mechanisms using a non-targeted metabolomics approach.
2016-08-19 | ST000452 | MetabolomicsWorkbench
Project description:Studies of skeletal muscle disuse either in patients on bed rest or experimentally in animals(immobilization) have demonstrated that decreased protein synthesis is common, with transient parallel increases in protein degradation. Muscle disuse atrophy involves a process of transition from slow to fast myosin fiber types 6 . A shift toward glycolysis, decreased capacity for fat oxidation, and substrate accumulation in atrophied muscles have been reported as has accommodation of the liver with an increased gluconeogenic capacity. Recent studies have modeled skeletal muscle disuse by using cyclic stretch of differentiated myotubes (C2C12), which mimics the loading pattern of mature skeletal muscle, followed by cessation of stretch.We utilized this model to determine the metabolic changes using non-targeted metabolomics analysis of the media. We identified increases in amino acids resulting from protein degradation (largely sarcomere) that occurs with muscle atrophy that are involved in feeding the Kreb’s cycle through anaplerosis. Specifically, we identified increased alanine/proline metabolism (significantly elevated proline, alanine, glutamine, and asparagine) and increased -ketoglutaric acid, the proposed Kreb’s cycle intermediate being fed by the alanine/proline metabolic anaplerotic mechanism. Additionally, several unique pathways not clearly delineated in previous studies of muscle unloading were seen, including: 1) elevated ethanolamine and elevated keto-acids (e.g. 2-ketoleucine and 2-keovaline) represent intermediates in the Ehlrich amino acid degradation pathway, which feeds into a metabolic pathway supplying acetyl-CoA and 2-hydroxybutyrate (also significantly increased); and 2) elevated guanine, an intermediate of purine metabolism, was seen at 12 hours unloading. Given the interest in targeting different aspects of the ubiquitin proteasome system to inhibit protein degradation, this C2C12 system may allow the identification of direct and indirect alterations in metabolism due to anaplerosis or through other yet to be identified mechanisms using a non-targeted metabolomics approach.
2016-05-28 | ST000431 | MetabolomicsWorkbench
Project description:Studies of skeletal muscle disuse either in patients on bed rest or experimentally in animals(immobilization) have demonstrated that decreased protein synthesis is common, with transient parallel increases in protein degradation. Muscle disuse atrophy involves a process of transition from slow to fast myosin fiber types 6 . A shift toward glycolysis, decreased capacity for fat oxidation, and substrate accumulation in atrophied muscles have been reported as has accommodation of the liver with an increased gluconeogenic capacity. Recent studies have modeled skeletal muscle disuse by using cyclic stretch of differentiated myotubes (C2C12), which mimics the loading pattern of mature skeletal muscle, followed by cessation of stretch.We utilized this model to determine the metabolic changes using non-targeted metabolomics analysis of the media. We identified increases in amino acids resulting from protein degradation (largely sarcomere) that occurs with muscle atrophy that are involved in feeding the Kreb’s cycle through anaplerosis. Specifically, we identified increased alanine/proline metabolism (significantly elevated proline, alanine, glutamine, and asparagine) and increased -ketoglutaric acid, the proposed Kreb’s cycle intermediate being fed by the alanine/proline metabolic anaplerotic mechanism. Additionally, several unique pathways not clearly delineated in previous studies of muscle unloading were seen, including: 1) elevated ethanolamine and elevated keto-acids (e.g. 2-ketoleucine and 2-keovaline) represent intermediates in the Ehlrich amino acid degradation pathway, which feeds into a metabolic pathway supplying acetyl-CoA and 2-hydroxybutyrate (also significantly increased); and 2) elevated guanine, an intermediate of purine metabolism, was seen at 12 hours unloading. Given the interest in targeting different aspects of the ubiquitin proteasome system to inhibit protein degradation, this C2C12 system may allow the identification of direct and indirect alterations in metabolism due to anaplerosis or through other yet to be identified mechanisms using a non-targeted metabolomics approach.
2016-08-17 | ST000451 | MetabolomicsWorkbench
Project description:Following spinal cord injury, skeletal muscle loss is rapid. This severe atrophy is attributed to declines in protein synthesis and increases in protein breakdown. However, the signaling mechanisms controlling these changes are not well understood. Nine male patients and one female patient with spinal cord injury (SCI) (Mean ± SEM = 43.9 ± 6.7 yrs) were recruited for this study. Six patients were quadriplegics and four patients were paraplegics. Inclusion criteria were as follows: patients above the age of 18 yrs, absence of severe brain injury (Glasgow Coma Scale > 13), absence of muscle-crush injury or compartment syndrome, absence of all of the following conditions: hypoxic injury, systemic sepsis, systemic inflammatory or autoimmune disease, and malignancy. Muscle biopsies were obtained from the vastus lateralis muscles of the SCI patients two days and five days post-SCI. Biopsies collected two days post-SCI were included in the current analysis. Expression changes were measured by microarray and gene clustering; identification of enriched functions and canonical pathways were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA). Functional analysis found that 48h following SCI expression, gene expression changes were related to decreases in metabolic functions such as the tricarboxylic acid cycle and oxidative phosphorylation as well as increases in functions associated with protein degradation such as proteasome activity and ubiquitination. Furthermore, increases in expression of metallothioneins were found to be the most over-represented functional group in the DAVID analysis. Results from this study showed that functional categories of gene expression changes in human skeletal muscle are consistent with previous findings in animals. Muscle biopsies were obtained from the vastus lateralis muscles of the SCI patients two days and five days post-SCI. (N = 10). A 5mm Berstrom biopsy needle was used. Biopsy samples were immediately snap-frozen in liquid nitrogen upon excision. All samples were stored at -80° C until analysis.
2010-10-23 | E-GEOD-21497 | biostudies-arrayexpress
Project description:Our results suggest that 48h of immobilization increases expression of mRNA for components of the UPP and MT function while decreasing mRNA and protein for components involved in ECM integrity. We hypothesized that 48h of immobilization would increase gene expression and respective protein products for components of the ubiquitin proteasome pathway (UPP). Keywords: stimulus or stress design
2006-06-20 | GSE5110 | GEO
Project description:Hibernation is energy saving adaptation involving suppression of activity to survive in highly seasonal environments. Immobility and disuse generate muscle loss in most mammalian species. In contrast to other mammals, bears and ground squirrels demonstrate limited muscle atrophy over the physical inactivity of winter hibernation. This suggests that hibernating mammals have adaptive mechanisms to prevent disuse muscle atrophy. To identify common transcriptional program underlying molecular mechanisms preventing muscle loss, we conducted a large-scale gene expression screening in hind limb muscles comparing hibernating and summer active black bears and arctic ground squirrels by the use of custom 9,600 probe cDNA microarrays. The molecular pathway analysis showed an elevated proportion of overexpressed genes involved in all stages of protein biosynthesis and ribosome biogenesis in muscle of both species during hibernation that implies induction of translation at different hibernation states. The induction of protein biosynthesis likely contributes to attenuation of disuse muscle atrophy through prolonged periods of immobility and starvation. This adaptive mechanism allows hibernating mammals to maintain full musculoskeletal function and preserve mobility during and immediately after hibernation, thus promoting survival. The lack of directional changes in genes of protein catabolic pathways does not support the importance of metabolic suppression for preserving muscle mass during winter. Coordinated reduction of multiply genes involved in oxidation reduction and glucose metabolism detected in both species is consistent with metabolic suppression and lower energy demand in skeletal muscle during inactivity of hibernation.
2014-10-16 | GSE62377 | GEO