Transcriptomic analysis of porcine muscle Biceps femoris (BF) exposed to a single bout of endurance exercise
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ABSTRACT: 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. 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:We have previously shown in sheep that 10 days of modest chronic increase in maternal cortisol result in fetal heart enlargement and Purkinje cell apoptosis. In subsequent studies in which we extended the duration of cortisol infusion (1mg/kg/d) to term, we found a dramatic incidence of stillbirth in the pregnancies with chronically increased cortisol and associated maternal hyperglycemia. In previous studies of the intraventricular septum from these fetuses we found significantly differentially regulated genes in the term fetuses (ie after ~25 days of cortisol) in pathways consistent with altered metabolism in the heart, particularly in mitochondria, associated with responses to hypoxia and to nutrient. Analysis of mitochondrial number by quantitative real-time PCR confirmed a significant decrease. To investigate the effects on skeletal muscle, we extended the transcriptomic analyses to biceps femoralis. Transcriptomic modelling revealed that pathways related to mitochondrial metabolism were downregulated, whereas pathways suggestive of positive regulation of reactive oxygen species and activation of the apoptotic cascade were upregulated. Mitochondrial DNA (mt-DNA) and the protein levels of cytochrome C was significantly decreased in the biceps. RT- PCR validation of the pathways showed significant decrease in SLC2A4 mRNA levels, and a significant increase in PDK4, TXNIP, ANGPTL4 mRNA levels, consistent with reduced insulin sensitivity of the bicep muscles. Comparison of the change in gene expression in biceps to that in cardiac intraventricular septum and left ventricle showed few common genes with little overlap in specific metabolic or signaling pathways, despite reduction in mitochondria in both heart and biceps. Our results suggest that glucocorticoid exposure affects nuclear genes important to mitochondrial activity and reactive oxygen in both cardiac and skeletal muscle tissues in a tissue specific manner.
Project description:Background: The aim of this study is to improve our understanding of the mechanisms underlying the sparing of masticatory muscles relative to limb muscles in ICU patients with acute quadriplegic myopathy (AQM) by using a unique porcine ICU model, i.e., 5-day longitudinal experiments where animals are sedated, mechanically ventilated and exposed to factors triggering AQM, such as muscle unloading, endotoxin-induced sepsis, and systemic exposure to CS and NMBA. Results: An altered expression was notably observed in heat-shock proteins genes, sarcomeric proteins and myostatin genes were noticed. Hence, modifications in heat-shock proteins, sarcomeric proteins and myostatin genes are in sharp contrast to alterations in the limb muscles and it is postulated that elevated heat-shock proteins and decreased sarcomeric protein and myostatin genes play a protective role in the masticatory muscle relative to limb muscle in ICU patients with AQM. Conclusions: This intervention had no significant effect on masseter muscle fiber size or force-generation capacity. This is in sharp contrast to the dramatic decrease observed in specific force in limb muscle fibers from the same animals. However, significant differences were observed between the craniofacial and the limb muscle with a masseter muscle specific regulation of i) transcriptional and growth factors like RUNX1, FOXO1A, TBX1, PGC1-β and myostatin, ii) several heat shock protein genes like HSP 90, HSP 105/110 and αB-crystallin, iii) a matrix metalloproteinase inhibitor (TIMP2) and iv) oxidative stress responsive elements such as SRXN1 and SOD2. These muscle-type specific differences, the alterations in heat shock protein, sarcomeric protein and myostatin genes are forwarded as important factors underlying the sparing of masticatory muscles compared with limb muscles in critically ill ICU patients with Acute Quadriplegic Myopathy. Keywords: Treatment, immobilization, muscle function.
Project description:The health benefits of physical activity are well documented, but several exercise response parameters are attenuated in obese individuals. The goal of this study was to identify molecular mechanisms that may influence exercise response in skeletal muscle of obese individuals. We performed comparison of the transcriptome in muscle from lean and obese individuals before and after an acute exercise bout.
Project description:We performed gene expression microarray analysis of skeletal muscle biopsies from normal glucose tolerant subjects and type 2 diabetes subjects obtained during a 60 min bicycle ergometer exercise and the 180 min of recovery phase We analysed skeletal mucle biopsies from patients with T2D and from control subjects (n=7 each) at three time points during exercise and recovery
Project description:Aging animals display a decline in a multitude of physical and physiological functions, including muscle function and strength. Muscle gene expression in dogs has been evaluated for a few select genes under pathogenic or varying dietary conditions, but global gene expression profiles of aged animals has not been performed. Because the mechanisms contributing to age-related decline in muscle function are poorly defined, we used canine microarrays to compare gene expression profiles of muscle tissue from geriatric and young adult dogs. Skeletal muscle (biceps femoris) samples were collected from 6 geriatric (12 yr-old) and 6 young adult (1 yr-old) female beagles after being fed one of two diets (animal protein-based versus plant-protein based) for 12 months. RNA samples were hybridized to Affymetrix GeneChip Canine Genome Arrays. Statistical analyses indicated that age had the greatest impact on gene expression, with 262 genes differentially expressed in geriatric dogs. Although not as robust as age, diet affected mRNA abundance of 22 genes. The effect of age was most notable in genes related to metabolism, cell cycle and cell development, and transcription function, with all of these functional groups being predominantly down-regulated in older animals. The effect of diet on gene expression was mostly limited to the geriatric animals, but interactions between age and diet do not allow for a clear-cut pattern of gene expression to be observed. Keywords: age; diet
Project description:Understanding the relationship between physical exercise, reactive oxygen species and skeletal muscle modification is important in order to better identify the benefits or the damages that appropriate or inappropriate exercise can induce. Heart and skeletal muscles have a high density of mitochondria with robust energetic demands and mitochondria plasticity has an important role in both cardiovascular system and skeletal muscle responses. The aim of this study was to investigate the influence of regular physical activity on oxidation profiles of mitochondrial proteins from heart and tibialis anterior muscles. To this end, we used mouse as animal model. Mice were divided in two groups: untrained and regularly trained. The carbonylated protein pattern was studied by two-dimensional gel electrophoresis followed by Western Blot with anti-dinitrophenyl hydrazone antibodies. Mass spectrometry analysis allowed the identifications of several different protein oxidation sites including methionine, cysteine, proline and leucine residues. A large number of oxidized protein were found in both untrained and trained animals. Moreover, mitochondria from skeletal muscles and heart showed almost the same carbonylation pattern. Interestingly, exercise training seems to increase carbonylation level mostly of mitochondrial protein from skeletal muscle.
Project description:Exercise induces skeletal muscle adaptation, and the p38 mitogen-activated protein kinase signaling pathway is thought to play an important role in the adaptive processes. We have obtained new evidence that the gamma isoform of p38 is required for exercise-induced metabolic adaptation in skeletal muscle; however, the neuromuscular activity-dependent target genes of p38gamma remain to be defined. We used microarrays to detail the global programme of gene expression underlying the skeletal muscle genetic reprogramming in response to increased contractile activity and identified distinct classes of up-regulated genes during this process that are dependent on the functional activity of the p38gamma isoform. Skeletal muscle-specific p38gamma knockout mice and the wild type littermates are subject to motor nerve stimulation of one of the tibialis anterior muscles followed by microarray analysis of both the stimulated and the contralateral control muscles.