Cardiac and Soleus muscles following exposure of rats to heat acclimation and exercise training
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ABSTRACT: The processes of adaptation to environmental heat and aerobic exercise training improve efficiency in various body systems and bring about acclimatory homeostasis. In order to examine the global genomic responses of the soleus and heart following exposure of rats to these stressors, nylon cDNA Atlas Array was used. Male rats were exposed to one of the following stressors: heat acclimation, aerobic training (treadmill), and combined heat acclimation and aerobic training for short (2, 3 days) and long (1 mo) time period. The study comprised seven experimental groups: Controls-untreated. Heat acclimated groups (2dac, Acc)â exposure to environmental heat at 34C for 2 or 30 days. Exercise groups (3dex, Ex)â graduated training protocol under normothermic conditions for 3 and 30 days at 24C. Exercise training and heat acclimation â (3dexac, ExAc)- exposed to both environmental heat and aerobic exercise as above. The Series data tables appended below: 1) Heart - normalized log2 ratio of geomeans defined as treatment/control 2) Soleus - normalized log2 ratio of geomeans defined as treatment/control 21 samples, 3 pool each, of: 1)Â Control untreated rats 2)Â Long-term heat acclimated rats 3)Â Long-term aerobic-exercised trained rats. 4)Â Rats exposed to long-term heat acclimation and exercise training. 5)Â Short term heat acclimated rats. 6)Â Short term aerobic exercised trained rats 7)Â Rats exposed to short-term heat acclimation and exercise training.
Project description:The processes of adaptation to environmental heat and aerobic exercise training improve efficiency in various body systems and bring about acclimatory homeostasis. In order to examine the global genomic responses of the soleus and heart following exposure of rats to these stressors, nylon cDNA Atlas Array was used. Male rats were exposed to one of the following stressors: heat acclimation, aerobic training (treadmill), and combined heat acclimation and aerobic training for short (2, 3 days) and long (1 mo) time period. The study comprised seven experimental groups: Controls-untreated. Heat acclimated groups (2dac, Acc)– exposure to environmental heat at 34C for 2 or 30 days. Exercise groups (3dex, Ex)– graduated training protocol under normothermic conditions for 3 and 30 days at 24C. Exercise training and heat acclimation – (3dexac, ExAc)- exposed to both environmental heat and aerobic exercise as above. The Series data tables appended below: 1) Heart - normalized log2 ratio of geomeans defined as treatment/control 2) Soleus - normalized log2 ratio of geomeans defined as treatment/control Keywords: stress response
Project description:To determine the efficacy and potential protective mechanism of canagliflozin combined with aerobic exercise in treating chronic heart failure (CHF).During 10 days, isoproterenol (5 mg/kg/d) was injected into rats to create CHF models. The rats were then randomized into four groups and administered with saline, canagliflozin (3 mg/kg/d), aerobic exercise training, and canagliflozin combined with aerobic exercise training. Then, we performed gene expression profiling using the data obtained by RNA-seq in the Control, HF, LC and LC-AE groups.
Project description:Low aerobic exercise capacity is a risk factor for diabetes and strong predictor of mortality; yet some individuals are exercise resistant, and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease-risk, we used selective breeding for 15 generation to develop rat models of low- and high-aerobic response to training. Before exercise training, rats selected as low- and high-responders had similar exercise capacities. However, after 8-wks of treadmill training low-responders failed to improve their exercise capacity, while high-responders improved by 54%. Remarkably, low-responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise resistant phenotype segregates with disease risk. Low-responders had impaired exercise-induced angiogenes0is in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low-responders. Low-responders had increased stress/inflammatory signaling and altered TGFM-NM-2 signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease. Cardiac and skeletal muscle from 3 high and 3 low responder rats were examined for differential miRNA expression using Exiqon microarrays
Project description:Low aerobic exercise capacity is a risk factor for diabetes and strong predictor of mortality; yet some individuals are exercise resistant, and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease-risk, we used selective breeding for 15 generation to develop rat models of low- and high-aerobic response to training. Before exercise training, rats selected as low- and high-responders had similar exercise capacities. However, after 8-wks of treadmill training low-responders failed to improve their exercise capacity, while high-responders improved by 54%. Remarkably, low-responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise resistant phenotype segregates with disease risk. Low-responders had impaired exercise-induced angiogenes0is in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low-responders. Low-responders had increased stress/inflammatory signaling and altered TGFβ signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease.
Project description:In our study, we investigated for contractile activity-specific changes in the transcriptome in untrained and trained (after an aerobic training programme) human skeletal muscle. The second goal was to examine effect of aerobic training on gene expression in muscle at baseline (after long term training). Seven untrained males performed the one-legged knee extension exercise (for 60 min) with the same relative intensity before and after a 2 month aerobic training programme (1 h/day, 5/week). Biopsy samples were taken at rest (baseline condition, 48 h after exercise), 1 and 4 h after the one-legged exercise from m. vastus lateralis of either leg. Comparison of gene expression in exercised leg with that in non-exercised [control] leg allowed us to identify contractile activity-specific genes in both untrained and trained skeletal muscle, i.e., genes that play a key role in adapting to acute exercise, regardless of the level of fitness. RNA-sequencing (84 samples in total; ~47 million reads/sample) was performed by NextSeq 500 and HiSeq 2500 (Illumina). Two months aerobic training increased the aerobic capacity of the knee-extensor muscles (power at anaerobic threshold in the incremental one-legged and cycling tests), the maximum rate of ADP-stimulated mitochondrial respiration in permeabilized muscle fibres and amounts of oxidative phosphorylation proteins. Contractile activity-specific changes in the transcriptome in untrained and trained human skeletal muscle were revealed for the first time. After 2 month aerobic training, transcriptome responses specific for contractile activity in trained muscle substantially decreased relative to those in untrained muscle. We found out that adaptation of skeletal muscle to regular exercise is associated not only with a transient change in the transcriptome after each stress (acute exercise), but also with a marked change in baseline expression of many genes after repeated stress (e.g., long term training).
Project description:Seventy two rats were randomized to twelve independent groups of rats (n = 6 in all groups) where half of the rats were chosen for training (treadmill exercise training 1.5 hour 5 days a week, in 1, 4, 24, 48 days and for 4 and 8 weeks) or sedentary (no training) as described in detail by Wisloff et al. (Intensity-controlled treadmill running in rats: VO(2 max) and cardiac hypertrophy. Am J Physiol Heart Circ Physiol. 2001 Mar;280(3):H1301-10.) or Kemi et al.(Aerobic fitness is associated with cardiomyocyte contractile capacity and endothelial function in exercise training and detraining. Circulation. 2004 Jun 15;109(23):2897-904. Epub 2004 Jun 1.). The rats were scarified one hour after training (1, 4, 24 and 48 days) or 24 hours after training (4 and 8 weeks). Biopsies form left ventricle was taken form all rats and stored on -80°C for preparation of RNA. The same procedures were performed for the control/sedentary rats which were sacrificed at the same time as the exercised rats.
Project description:Background: Cold acclimation and exercise training were previously shown to increase peripheral insulin sensitivity in human volunteers with type 2 diabetes. Although cold is a potent activator of brown adipose tissue, the increase in peripheral insulin sensitivity by cold is largely mediated by events occurring in skeletal muscle and at least partly involves GLUT4 translocation, as is also observed for exercise training. Results: To investigate if cold acclimation and exercise training overlap in the molecular adaptive response in skeletal muscle, we performed transcriptomics analysis on vastus lateralis muscle collected from human subjects before and after 10 days of cold acclimation, as well as before and after a 12-week exercise training intervention. Methods: Cold acclimation altered the expression of 756 genes (422 up, 334 down, P<0.01), while exercise training altered the expression of 665 genes (444 up, 221 down, P<0.01). Principal Component Analysis, Venn diagram, similarity analysis and Rank–rank Hypergeometric Overlap all indicated significant overlap between cold acclimation and exercise training in upregulated genes, but not in downregulated genes. Overlapping gene regulation was especially evident for genes and pathways associated with extracellular matrix remodeling. Interestingly, the genes most highly induced by cold acclimation were involved in contraction and in signal transduction between nerve and muscle cells, while no significant changes were observed in genes and pathways related to insulin signaling or glucose metabolism. Conclusions: Overall, our results indicate that cold acclimation and exercise training have overlapping effects on gene expression in human skeletal muscle, but strikingly these overlapping genes are designated to pathways related to cell remodeling rather than metabolic pathways.
Project description:Background: Cold acclimation and exercise training were previously shown to increase peripheral insulin sensitivity in human volunteers with type 2 diabetes. Although cold is a potent activator of brown adipose tissue, the increase in peripheral insulin sensitivity by cold is largely mediated by events occurring in skeletal muscle and at least partly involves GLUT4 translocation, as is also observed for exercise training. Results: To investigate if cold acclimation and exercise training overlap in the molecular adaptive response in skeletal muscle, we performed transcriptomics analysis on vastus lateralis muscle collected from human subjects before and after 10 days of cold acclimation, as well as before and after a 12-week exercise training intervention. Methods: Cold acclimation altered the expression of 756 genes (422 up, 334 down, P<0.01), while exercise training altered the expression of 665 genes (444 up, 221 down, P<0.01). Principal Component Analysis, Venn diagram, similarity analysis and Rank–rank Hypergeometric Overlap all indicated significant overlap between cold acclimation and exercise training in upregulated genes, but not in downregulated genes. Overlapping gene regulation was especially evident for genes and pathways associated with extracellular matrix remodeling. Interestingly, the genes most highly induced by cold acclimation were involved in contraction and in signal transduction between nerve and muscle cells, while no significant changes were observed in genes and pathways related to insulin signaling or glucose metabolism. Conclusions: Overall, our results indicate that cold acclimation and exercise training have overlapping effects on gene expression in human skeletal muscle, but strikingly these overlapping genes are designated to pathways related to cell remodeling rather than metabolic pathways.
Project description:Maximal aerobic exercise capacity (V̇O2max) is one of the strongest predictors of morbidity and mortality. Aerobic exercise training can increase V̇O2max, but inter-individual variability is marked and unexplained physiologically. The mechanisms underlying this variability have major clinical implications for extending human healthspan. Here, we report the first comprehensive, RNA-seq study of circulating transcriptome signatures related to ΔV̇O2max. We used RNA-seq to characterize transcriptomic predictors of ΔV̇O2max in healthy women who completed a 16-week, randomized controlled trial comparing higher vs. lower aerobic exercise training volume and intensity (four training groups, fully crossed). We found striking baseline gene expression differences in subjects who responded to aerobic exercise training with robust (R) vs. little/no (NR) ΔV̇O2max.