RNA-seq of triceps brachii muscles from mice after myostatin depletion and wheel running exercise
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ABSTRACT: The purpose of this study was to determine whether postdevelopmental myostatin depletion influenced the changes in skeletal muscle gene expression profiles induced by a long-term increase in physical activity. Myostatin levels in muscles of adult male mice with floxed myostatin genes were reduced ~85% by activating Cre recombinase. Control mice with normal myostatin genes had the same Cre-activating treatment. Some of the mice were housed in ordinary cages throughout the study, limiting their physical activity. Other mice were given free access to running wheels for the final 12 weeks of the study. At the end of the study, comprehensive gene expression profiles of triceps brachii muscles were determined by RNA sequencing (RNA-Seq), with muscles from mice selected for similarity of running behavior throughout the period of wheel access. Wheel running increased expression of hundreds of mRNAs encoding proteins involved in oxidative energy metabolism, and this response was not affected by myostatin deficiency. The running-induced increase in the ratio of Myh1 mRNA (which encodes myosin heavy chain type 2x) to Myh4 mRNA (which encodes myosin heavy chain type 2b) also was not affected by myostatin depletion. At every threshold of P (computed by analysis of variance), the number of transcripts with interactions between activity level and myostatin level was fewer than the number expected by chance. These data suggest that myostatin is not required for transcriptional adaptations to moderate-intensity exercise. 12 samples, 6 from sedentary mice and 6 from active (wheel running) mice. 3 control and 3 myostatin-deficient mice within each activity level.
Project description:This SuperSeries is composed of the following subset Series: GSE31839: Effect of wheel running exercise and myostatin depletion on gene expression in triceps brachii muscles of mice GSE31843: Effect of wheel running exercise on gene expression in skeletal muscles of mice Refer to individual Series
Project description:RNA from 5 mice with postdevelopmental knockout of myostatin and 5 mice with normal myostatin expression was analyzed with comprehensive oligonucleotide microarrays. Myostatin depletion affected the expression of several hundred genes at nominal P < 0.01, but fewer than a hundred effects were statistically significant according to a more stringent criterion (false discovery rate < 5%). Most of the effects were less than 1.5-fold in magnitude. In contrast to previously-reported effects of constitutive myostatin knockout, postdevelopmental knockout did not downregulate expression of genes encoding slow isoforms of contractile proteins or genes encoding proteins involved in energy metabolism. Several collagen genes were expressed at lower levels in the myostatin-deficient muscles, and this led to reduced tissue collagen levels as reflected by hydroxyproline content. Myostatin knockout tended to down-regulate the expression of sets of genes with promoter motifs for Smad3, Smad4, myogenin, NF-κB, serum response factor, and numerous other transcription factors. Main conclusions: in mature muscle, myostatin is a key transcriptional regulator of collagen genes, but not genes encoding contractile proteins or genes encoding proteins involved in energy metabolism. Experiment Overall Design: Comparison of muscle gene expression in 5 mice with postdevelopmental myostatin knockout and 5 control mice
Project description:The purpose of this study was to determine whether postdevelopmental myostatin depletion influenced the changes in skeletal muscle gene expression profiles induced by a long-term increase in physical activity. Myostatin levels in muscles of adult male mice with floxed myostatin genes were reduced ~85% by activating Cre recombinase. Control mice with normal myostatin genes had the same Cre-activating treatment. Some of the mice were housed in ordinary cages throughout the study, limiting their physical activity. Other mice were given free access to running wheels for the final 12 weeks of the study. At the end of the study, comprehensive gene expression profiles of triceps brachii muscles were determined by RNA sequencing (RNA-Seq), with muscles from mice selected for similarity of running behavior throughout the period of wheel access. Wheel running increased expression of hundreds of mRNAs encoding proteins involved in oxidative energy metabolism, and this response was not affected by myostatin deficiency. The running-induced increase in the ratio of Myh1 mRNA (which encodes myosin heavy chain type 2x) to Myh4 mRNA (which encodes myosin heavy chain type 2b) also was not affected by myostatin depletion. At every threshold of P (computed by analysis of variance), the number of transcripts with interactions between activity level and myostatin level was fewer than the number expected by chance. These data suggest that myostatin is not required for transcriptional adaptations to moderate-intensity exercise.
Project description:This analysis was done to determine which muscle group has the most skeletal muscle transcriptional reponses to wheel running activity. Seven male mice with C57BL/6 genetic background were placed individually in cages with running wheels and allowed free access to the wheels 24 hr per day. Access to running wheels began when the mice were 6 months old, and continued for 12 weeks. The morning after the night of running, the mice were euthanized and several muscle groups were snap froze in liquid nitrogen to preserve RNA. The same muscle groups were collected from three age-matched "sedentary" mice that were housed in ordinary cages that did not permit sustained running. For each muscle group, separate pools of polyadenylated RNA from the sedentary and wheel-running mice were prepared for deep sequencing of cDNA with the SOLiD 3 platform. Four muscle groups were examined (quadriceps femoris; gastrocnemius/plantaris; tibialis anterior; triceps brachii). For each muscle, RNA was pooled from 3 sedentary or 7 wheel-running mice (8 pools total).
Project description:To study the combined effect of myostatin/activin inhibition and exercise on muscle mass and pathophysiology, young mdx mice, a model for Duchenne Muscular Dystrophy, were injected with soluble activin receptor-Fc (sActRIIB-Fc) or placebo (PBS) 1x/week for a 7-week period, in combination with or without voluntary running. C57Bl/10ScSnJ mice injected with PBS acted as wildtype controls. Microarray expression analysis from skeletal muscle was performed using m. gastrocnemies as the sample. We found thatexercise or a combination of exercise and sActRIIB-Fc treatment is more effective in correcting gene expression profiles of dystrophic muscles than the sActRIIB-Fc treatment alone. We also identified several pathways and proteins that were affected by exercise and sActRIIB-Fc together or independently. Total RNA obtained from gastrocnemius muscle of mdx mice divided into four groups: 1) control (injected with PBS, n=5), 2) runners (voluntary wheel running for 7 weeks, injected with PBS, n=5), 3) sActRIIB-Fc -treated (n=5), and 4) runners with sActRIIB-Fc-treatment (n=5). sActRIIB-Fc or PBS was injected intraperitoneally once a week with a 5-mg/kg dose of sActRIIB-Fc. In addition, wildtype mice served as healthy controls (n=4).
Project description:Aged mice (22-24 mo) underwent Progressive weighted wheel running (PoWeR) for 8 weeks. RNA-seq on soleus and plantaris muscles was conducted on untrained and PoWeR trained mice. RNA from soleus and plantaris of young mice (4-6 months old) was used as a comparator (Englund et al. 2021 Function)
Project description:Although skeletal muscle metabolism is a well-studied physiological process, little is known about how it is regulated at the transcriptional level. The myogenic transcription factor myogenin is required for skeletal muscle development during embryonic and fetal life, but myogeninâs role in adult skeletal muscle is unclear. We sought to determine myogeninâs function in adult muscle metabolism. A Myog conditional allele and Cre-ER transgene were used to delete Myog in adult mice. Mice were analyzed for exercise capacity by involuntary treadmill running. To assess oxidative and glycolytic metabolism, we monitored blood glucose and lactate levels and performed histochemical analysis on muscle fibers. Surprisingly, we found that Myog-deleted mice performed significantly better than controls in high- and low-intensity treadmill running. This enhanced exercise capacity was due to more efficient oxidative metabolism during low-intensity exercise and more efficient glycolytic metabolism during high-intensity exercise. Furthermore, Myog-deleted mice had an enhanced response to long-term voluntary exercise training on running wheels. We identified several candidate genes whose expression was altered in exercise-stressed muscle of mice lacking myogenin. The results suggest that myogenin plays a critical role as a high-level transcriptional regulator to control the energy balance between aerobic and anaerobic metabolism in adult skeletal muscle. We used microarrays to detail the global program of gene expression underlying enhanced exercise endurance associated with myog-deletion and long-term exercise training. Mouse gastrocnemius muscles were selected after 6 months of myog-deletion and exercise training for RNA extraction and hybridization on Affymetrix microarrays. We chose 3 wild type and 3 myog-deleted mice that best represented the average of each larger group that was tested during our mouse exercise studies.
Project description:Transcription profiling of skeletal muscle (tibialis anterior) of 5-week-old male wild type and myostatin null mice given ad libitum access to 20ppm clenbuterol hydrochloride in drinking water or plain tap water for 2 weeks. The objective of the study was to determine overlap in the mechanisms of muscle hypertrophy of the two models. 2x2 factorial arrangement of genotype (wild type and myostatin null) and clenbuterol treatment (control and clenbuterol at 20 ppm) with 4 replicates.