Project description:Acute physical exercise elicits changes in gene expression in skeletal muscles to promote metabolic changes and to repair exercise-induced muscle injuries. Here, we investigated the impact of a single bout of running exercise until exhaustion on global transcriptional profiles in porcine skeletal muscles. Using a combined microarray and candidate gene approach, we identified a suite of genes that are differentially expressed in muscles during post-exercise recovery. Thus, several members of the heat shock protein family and proteins associated with proteolytic events were significantly up-regulated, suggesting that protein breakdown, prevention of protein aggregation and stabilization of unfolded proteins are important processes for restoring cellular homeostasis. We also detected an up-regulation of genes, which have been reported to be associated with muscle cell proliferation and differentiation, possibly reflecting an activation, differentiation and fusion of satellite cells to facilitate repair of muscle damage. In addition, exercise increased expression of the nuclear hormone receptors, which regulates metabolic functions associated with lipid, carbohydrate and energy homeostasis. Finally, we observed an unanticipated involvement of long non-coding RNA transcripts, which have been implicated in RNA processing and nuclear retention of adenosine-to-inosine edited mRNAs. These findings expand the complexity of pathways affected by acute contractile activity of skeletal muscle, contributing to a better understanding of the molecular processes that occur in muscle tissue in the recovery phase. Gene expression study of the porcine muscle Biceps femoris in regard to exercise, pigs allowed to rest for 0 hours, 1 hour and 3 hours after exercise were compared with pigs that had not been exercising, using in-house printed porcine two-colour oligonucleotide microarrays.
Project description:Acute physical exercise elicits changes in gene expression in skeletal muscles to promote metabolic changes and to repair exercise-induced muscle injuries. Here, we investigated the impact of a single bout of running exercise until exhaustion on global transcriptional profiles in porcine skeletal muscles. Using a combined microarray and candidate gene approach, we identified a suite of genes that are differentially expressed in muscles during post-exercise recovery. Thus, several members of the heat shock protein family and proteins associated with proteolytic events were significantly up-regulated, suggesting that protein breakdown, prevention of protein aggregation and stabilization of unfolded proteins are important processes for restoring cellular homeostasis. We also detected an up-regulation of genes, which have been reported to be associated with muscle cell proliferation and differentiation, possibly reflecting an activation, differentiation and fusion of satellite cells to facilitate repair of muscle damage. In addition, exercise increased expression of the nuclear hormone receptors, which regulates metabolic functions associated with lipid, carbohydrate and energy homeostasis. Finally, we observed an unanticipated involvement of long non-coding RNA transcripts, which have been implicated in RNA processing and nuclear retention of adenosine-to-inosine edited mRNAs. These findings expand the complexity of pathways affected by acute contractile activity of skeletal muscle, contributing to a better understanding of the molecular processes that occur in muscle tissue in the recovery phase. Gene expression study of the porcine muscle Longissimus dorsi in regard to exercise, pigs allowed to rest for 0 hours, 1 hour and 3 hours after exercise were compared with pigs that had not been exercising, using in-house printed porcine two-colour oligonucleotide microarrays.
Project description:Acute physical exercise elicits changes in gene expression in skeletal muscles to promote metabolic changes and to repair exercise-induced muscle injuries. Here, we investigated the impact of a single bout of running exercise until exhaustion on global transcriptional profiles in porcine skeletal muscles. Using a combined microarray and candidate gene approach, we identified a suite of genes that are differentially expressed in muscles during post-exercise recovery. Thus, several members of the heat shock protein family and proteins associated with proteolytic events were significantly up-regulated, suggesting that protein breakdown, prevention of protein aggregation and stabilization of unfolded proteins are important processes for restoring cellular homeostasis. We also detected an up-regulation of genes, which have been reported to be associated with muscle cell proliferation and differentiation, possibly reflecting an activation, differentiation and fusion of satellite cells to facilitate repair of muscle damage. In addition, exercise increased expression of the nuclear hormone receptors, which regulates metabolic functions associated with lipid, carbohydrate and energy homeostasis. Finally, we observed an unanticipated involvement of long non-coding RNA transcripts, which have been implicated in RNA processing and nuclear retention of adenosine-to-inosine edited mRNAs. These findings expand the complexity of pathways affected by acute contractile activity of skeletal muscle, contributing to a better understanding of the molecular processes that occur in muscle tissue in the recovery phase.
Project description:Acute physical exercise elicits changes in gene expression in skeletal muscles to promote metabolic changes and to repair exercise-induced muscle injuries. Here, we investigated the impact of a single bout of running exercise until exhaustion on global transcriptional profiles in porcine skeletal muscles. Using a combined microarray and candidate gene approach, we identified a suite of genes that are differentially expressed in muscles during post-exercise recovery. Thus, several members of the heat shock protein family and proteins associated with proteolytic events were significantly up-regulated, suggesting that protein breakdown, prevention of protein aggregation and stabilization of unfolded proteins are important processes for restoring cellular homeostasis. We also detected an up-regulation of genes, which have been reported to be associated with muscle cell proliferation and differentiation, possibly reflecting an activation, differentiation and fusion of satellite cells to facilitate repair of muscle damage. In addition, exercise increased expression of the nuclear hormone receptors, which regulates metabolic functions associated with lipid, carbohydrate and energy homeostasis. Finally, we observed an unanticipated involvement of long non-coding RNA transcripts, which have been implicated in RNA processing and nuclear retention of adenosine-to-inosine edited mRNAs. These findings expand the complexity of pathways affected by acute contractile activity of skeletal muscle, contributing to a better understanding of the molecular processes that occur in muscle tissue in the recovery phase.
Project description:Besides its substantial role in eye lens, αB-crystallin (HSPB5) retains fundamental function in striated muscle during physiological or pathological modifications. In this study, we aimed to analyse the cellular and molecular factors driving the functional response of HSPB5 protein in different muscles from mice subjected to an acute bout of non-damaging endurance exercise or in C2C12 myocytes upon exposure to pro-oxidant environment, chosen as "in vivo" and "in vitro" models of a physiological stressing conditions, respectively. To this end, red (GR) and white gastrocnemius (GW), as sources of slow-oxidative and fast-glycolytic/oxidative fibers, as well as the soleus (SOL), mainly composed of slow-oxidative type fibers, were obtained from BALB/c mice, before (CTRL) and at different times (0', 15', 30' 120') following 1-h of running. Although the total level of HSPB5 protein was not affected by exercise, we found a significantly increase of phosphorylated HSPB5 (p-HSPB5) only in GR and SOL skeletal muscle with a higher amount of type I and IIA/X myofibers. The fiber-specific activation of HSPB5 was correlated to its interaction with the actin filaments, as well as to an increased level of lipid peroxidation and carbonylated proteins. The role of the pro-oxidant environment in HSPB5 response was investigated in terminally differentiated C2C12 myotubes, where most of HSPB5/pHSPB5 pool was present in the cytosolic compartment in standard culture conditions. As a result of exposure to pro-oxidizing, but not cytotoxic, H2O2 concentration, the p-38MAPK-mediated phosphorylation of HSPB5 resulted functional to promote its interaction with the myofibrillar components, such as β-actin, desmin and filamin 1. This study provides novel information on the molecular pathway underlying the HSPB5 physiological function in skeletal muscle, confirming the contribution of the pro-oxidant environment in HSPB5 activation and interaction with substrate/client myofibrillar proteins, offering new insights for the study of myofibrillar myopathies and cardiomyopathies.
Project description:Age-related declines in cardiorespiratory fitness and physical function are mitigated by regular endurance exercise in older adults. This may be due, in part, to changes in the transcriptional program of skeletal muscle following repeated bouts of exercise. However, the impact of chronic exercise training on the transcriptional response to an acute bout of endurance exercise has not been clearly determined. Here, we characterized baseline differences in muscle transcriptome and exercise-induced response in older adults who were active/endurance trained or sedentary. RNA-sequencing was performed on vastus lateralis biopsy specimens obtained before, immediately after, and 3 h following a bout of endurance exercise (40 min of cycling at 60%-70% of heart rate reserve). Using a recently developed bioinformatics approach, we found that transcript signatures related to type I myofibers, mitochondria, and endothelial cells were higher in active/endurance-trained adults and were associated with key phenotypic features including V̇o2peak, ATPmax, and muscle fiber proportion. Immune cell signatures were elevated in the sedentary group and linked to visceral and intermuscular adipose tissue mass. Following acute exercise, we observed distinct temporal transcriptional signatures that were largely similar among groups. Enrichment analysis revealed catabolic processes were uniquely enriched in the sedentary group at the 3-h postexercise timepoint. In summary, this study revealed key transcriptional signatures that distinguished active and sedentary adults, which were associated with difference in oxidative capacity and depot-specific adiposity. The acute response signatures were consistent with beneficial effects of endurance exercise to improve muscle health in older adults irrespective of exercise history and adiposity.NEW & NOTEWORTHY Muscle transcript signatures associated with oxidative capacity and immune cells underlie important phenotypic and clinical characteristics of older adults who are endurance trained or sedentary. Despite divergent phenotypes, the temporal transcriptional signatures in response to an acute bout of endurance exercise were largely similar among groups. These data provide new insight into the transcriptional programs of aging muscle and the beneficial effects of endurance exercise to promote healthy aging in older adults.
Project description:Middle-aged and master endurance athletes exhibit similar physical performance and long-term muscle adaptation to aerobic exercise. Nevertheless, we hypothesized that the short-term plasticity of the skeletal muscle might be distinctly altered for master athletes when they are challenged by a single bout of prolonged moderate-intensity exercise. Six middle-aged (37Y) and five older (50Y) master highly-trained athletes performed a 24-h treadmill run (24TR). Vastus lateralis muscle biopsies were collected before and after the run and assessed for proteomics, fiber morphometry, intramyocellular lipid droplets (LD), mitochondrial oxidative activity, extracellular matrix (ECM), and micro-vascularisation. Before 24TR, muscle fiber type morphometry, intramyocellular LD, oxidative activity, ECM and micro-vascularisation were similar between master and middle-aged runners. For 37Y runners, 24TR was associated with ECM thickening, increased capillary-to-fiber interface, and an 89% depletion of LD in type-I fibers. In contrast, for 50Y runners, 24TR did not alter ECM and capillarization and poorly depleted LDs. Moreover, an impaired succinate dehydrogenase activity and functional class scoring of proteomes suggested reduced oxidative phosphorylation post-24TR exclusively in 50Y muscle. Collectively, our data support that middle-aged and master endurance athletes exhibit distinct transient plasticity in response to a single bout of ultra-endurance exercise, which may constitute early signs of muscle aging for master athletes.
Project description:Sulforaphane (SFN) plays an important role in preventing oxidative stress by activating the nuclear factor (erythroid derived 2)-like 2 (Nrf2) signalling pathway. SFN may improve exercise endurance capacity by counteracting oxidative stress-induced damage during exercise. We assessed running ability based on an exhaustive treadmill test (progressive-continuous all-out) and examined the expression of markers for oxidative stress and muscle damage. Twelve- to 13-week-old Male wild-type mice (Nrf2 +/+) and Nrf2-null mice (Nrf2 -/-) on C57BL/6J background were intraperitoneally injected with SFN or vehicle prior to the test. The running distance of SFN-injected Nrf2 +/+ mice was significantly greater compared with that of uninjected mice. Enhanced running capacity was accompanied by upregulation of Nrf2 signalling and downstream genes. Marker of oxidative stress in SFN-injected Nrf2 +/+ mice were lower than those in uninjected mice following the test. SFN produced greater protection against muscle damage during exhaustive exercise conditions in Nrf2 +/+ mice than in Nrf2 -/- mice. SFN-induced Nrf2 upregulation, and its antioxidative effects, might play critical roles in attenuating muscle fatigue via reduction of oxidative stress caused by exhaustive exercise. This in turn leads to enhanced exercise endurance capacity. These results provide new insights into SFN-induced upregulation of Nrf2 and its role in improving exercise performance.
Project description:Age-related declines in cardiorespiratory fitness and physical function are mitigated by regular endurance exercise in older adults. This may be due, in part, to changes in the transcriptional program of skeletal muscle following repeated bouts of exercise. However, the impact of chronic exercise training on the transcriptional response to an acute bout of endurance exercise has not been clearly determined. Here, we characterized baseline differences in muscle transcriptome and exercise-induced response in older adults who were active/endurance trained or sedentary. RNA-sequencing was performed on vastus lateralis biopsy specimens obtained before, immediately after, and 3 h following a bout of endurance exercise (40 min of cycling at 60%–70% of heart rate reserve). Using a recently developed bioinformatics approach, we found that transcript signatures related to type I myofibers, mitochondria, and endothelial cells were higher in active/endurance-trained adults and were associated with key phenotypic features including V̇o2peak, ATPmax, and muscle fiber proportion. Immune cell signatures were elevated in the sedentary group and linked to visceral and intermuscular adipose tissue mass. Following acute exercise, we observed distinct temporal transcriptional signatures that were largely similar among groups. Enrichment analysis revealed catabolic processes were uniquely enriched in the sedentary group at the 3-h postexercise timepoint. In summary, this study revealed key transcriptional signatures that distinguished active and sedentary adults, which were associated with difference in oxidative capacity and depot-specific adiposity. The acute response signatures were consistent with beneficial effects of endurance exercise to improve muscle health in older adults irrespective of exercise history and adiposity.