Project description:Human skeletal muscle disuse-atrophy is one of the main problems associated with spaceflight, bed rest, lower limb unloading, or immobilization. This study investigates the effects of 10-day unilateral lower limb suspension (ULLS) followed by 21 days of active recovery (AR) in young healthy men.
Project description:Skeletal muscle unloading due to joint immobilization induces skeletal muscle atrophy. However, the skeletal muscle proteome response to limb immobilization has not been investigated using SWATH methods. This study quantitatively characterized the muscle proteome at baseline, and after 3 and 14 d of unilateral lower limb (knee-brace) immobilization in 18 healthy young men (25.4 ±5.5 y, 81.2 ±11.6 kg). All muscle biopsies were obtained from the vastus lateralis muscle. Unilateral lower limb immobilization was preceded by four-weeks of exercise training to standardise acute training history, and 7 days of dietary provision to standardise energy/macronutrient intake. Dietary intake was also standardised/provided throughout the 14 d immobilization period.
Project description:Gene expression changes induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, fibre-type switching, and loss of ability to transition between lipid and glucose as energy source (metabolic inflexibility), was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28â32 g body wt; Harlan, Indianapolis, IN). Agilent Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the soleus muscle and the gastrocnemius muscle in the hindlimbs of freely ambulating control and 24h HLS treated mice. Experiment Overall Design: Five independent biological replicates of this experiment (Control and HLS) were carried out.
Project description:Gene expression changes in femur bone induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, weakness and results in bone remodelling and subsequent loss of bone mass, was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28–32 g body wt; Harlan, Indianapolis, IN). AgilentTM Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the femur bone in the hindlimbs of freely ambulating control and 24h HLS treated mice. Five independent biological replicates of this experiment were carried out. Five independent biological replicates of this experiment (Control and HLS) were carried out.
Project description:Rodent hind limb unloading was used as a model for reduced muscle activity and eventual atrophy. After a 10 day period of unloading, mice in this study were “reloaded” for 3 days and regained use of their hind limbs. We report the application of Next-generation sequencing (NGS) technology for high-throughput profiling of mRNA in soleus muscle of adult (6 mo) and aged (22-24 mo) mice. Our goal was to determine the effects of hind limb unloading and reloading on mRNA profiles in soleus muscle and compare between adult and aged mice. We find that there are distinct response in the profile of fatty acid oxidation, TCA cycle, ETC oxidative phosphorylation gene expression patterns in response to unloading and reloading. The repsonses are generally simialr between young and old mice.
Project description:Gene expression changes induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, fibre-type switching, and loss of ability to transition between lipid and glucose as energy source (metabolic inflexibility), was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28–32 g body wt; Harlan, Indianapolis, IN). Agilent Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the soleus muscle and the gastrocnemius muscle in the hindlimbs of freely ambulating control and 24h HLS treated mice. Keywords: treatment vs control, tissue type comparison
Project description:Although short-term disuse does not result in measurable muscle atrophy, studies suggest that molecular changes associated with protein degradation may be initiated within days of the onset of a disuse stimulus. We examined the global gene expression patterns in sedentary men (n = 7, mean age ± S.D = 22.1 ± 3.7 yr) following 48h unloading (UL) via unilateral lower limb suspension and 24h reloading (RL). Biopsy samples of the left vastus lateralis muscle were collected at baseline, 48h UL, and 24h RL. Expression changes were measured by microarray and gene clustering; identification of enriched functions and canonical pathways were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA). Four genes were validated with qRT-PCR, and protein levels were measured with Western blot. Of the upregulated genes after UL, the most enriched functional group and highest ranked canonical pathway were related to protein ubiquitination. The oxidative stress response pathway was the second highest ranked canonical pathway. Of the downregulated genes, functions related to mitochondrial metabolism were the mostly highly enriched. In general, gene expression patterns following UL persisted following RL. qRT-PCR confirmed increases in mRNA for UPP-related E3 ligase Atrogin1 (but not accompanying increases in protein products) and stress response gene heme oxygenase-1 (HMOX, which showed a trend towards increases in protein products at 48h UL) as well as extracellular matrix (ECM) component COL4. The gene expression patterns were not readily reversed upon RL suggesting that molecular responses to short-term periods of skeletal muscle inactivity may persist after activity resumes. Biopsies were taken of the left vastus lateralis of healthy, sedentary men (N = 7) at baseline, immediately following 48h UL and 24h RL. A 5mm Berstrom biopsy needle was used. Biopsy samples were immediately snap-frozen in liquid nitrogen upon excision. All samples were stored at -80° C until analysis.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.