Project description:Low-intensity neuromuscular electrical stimulation (NMES) is often used as an alternative to exercise and high-intensity electrical stimulation to prevent the loss of muscle mass, strength, and endurance in spaceflight and in patients with severe chronic diseases. This study assessed the efficiency of low-intensity (~10% of maximal voluntary contraction) combined (low- and high-frequency) electrical stimulation in preventing the negative effects of weekly disuse (dry immersion without [DI, see a related dataset GSE271607] and with [DI+NMES] daily stimulation; 10 males in each group) on the strength and aerobic performance of the ankle plantar flexors and knee extensors, mitochondrial function in permeabilized muscle fibers, and the proteomic (quantitative mass spectrometry-based analysis) and transcriptomic (RNA-sequencing) profiles of the soleus muscle and vastus lateralis muscle. Application of electrical stimulation during dry immersion prevented a decrease in the maximal strength and a slight reduction in aerobic performance of knee extensors, as well as a decrease in maximal ADP-stimulated mitochondrial respiration and changes in the expression of genes encoding mitochondrial, extracellular matrix, and membrane proteins in the vastus lateralis muscle. In contrast, for the ankle plantar flexors/soleus muscle, electrical stimulation had a positive effect only on maximal mitochondrial respiration, but accelerated the decline in the maximal strength and muscle fiber cross-sectional area, which appears to be associated with the activation of genes regulating the inflammatory response. The data obtained open up broad prospects for the use of low-intensity combined electrical stimulation to prevent the negative effects of disuse for “mixed” muscles, meanwhile, the optimization of the stimulation protocol is required for “slow” muscles.
Project description:Purpose: The goal of this study was to determine the gene expression changes that occur over 7 days in parralyzed muscle in response to isometric contraction elicited by electrical stimulation initiated 4 months after spinal cord injury and to compare such changes to those observed in a normal muscle subjected to overload. Methods: Electrical stimulation of the soleus and plantaris muscle was stimulated in female rats with complete transection of the spinal cord at the interspace between the 9th and 10th thoracic vertebrae. Stimulation was begun 16 weeks after spinal cord transection and produced near-isometric contraction of soleus, plantaris and tibialis anterior. Muscle was analyzed at 1, 2 and 7 days after starting exercise with electrical stimulation. To provide a baseline reference for gene expression at 16 weeks after spinal cord injury, muscle was also analysed from an additional group of spinal cord transected animals. One additional group of animals with a sham-spinal cord injury was included to provide information about gene expression in neurologically intact animals of similar age. In parallel studies, rats underwent bilateral gastrocnemius ablation to overload soleus and plantaris, or a sham ablation as a control. Muscle was analyzed at 1, 3 and 7 days after gastrocnemius ablation or sham-ablation. Gene expression was determined using Affymetrix Rat Exon microarrays. For each group of animals, microarray analysis was performed for soleus muscle for each of 3 separate animals, using one array per animal. Control sammples for the spinal cord injured groups included a group of animals with a Sham-spinal cord injury, and a group of spinal cord injured animals that did not get electrical stimulation. The comparator for determining fold-change expression values was the spinal cord injured group that did not receive electrical stimulation. For each day after gastrocnemius ablation, a control was included that received all procedures needed for this ablation except cutting the distal insertion of the gastrocnemius into the Achilles tendon to control for effects of the surgery on gene expression.
Project description:We recently identified C18ORF25 as a new exercise-regulated phophoprotein. To investigate potential in vivo functions of C18ORF25, we used CRISPR/Cas9 to generate a whole-body knock-out (KO) mouse model on a C57BL/6J background. Proteomic analysis was performed to identify potental changes in the proteome. To gain further insights into the possible signalling pathways regulated by C18ORF25, Soleus muscles from WT and KO mice (n=4) were isolated, and the muscle from one leg was maintained at resting tension with no stimulation as a control while the muscle from the contralateral leg was subject to electrical stimulation ex vivo. Muscles were quickly snap frozen and subject to single-shot label-free phosphoproteomic analysis to compare the signalling responses between the genotypes.
Project description:Muscle (M), myotendinous (J) and tendon (T) tissues were isolated from murine wild-type soleus muscle-tendon units. Tissues were either: 1) fractionated prior to LC-MS/MS analysis of the CS and IN fractions; or 2) homogenized prior to LC-MS/MS analysis of the homogenate. Samples were analyzed by Q Exactive (Thermo Scientific).
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)