Project description:Global microarray (HG U133 Plus 2.0) was used to investigate the effects of resistance exercise and resistance training on the skeletal muscle transcriptome profile of 28 young and old adults. Vastus lateralis muscle biopsies were obtained pre and 4hrs post resistance exercise in the beginning (untrained state) and at the end (trained state) of a 12 wk progressive resistance training program.
Project description:Global microarray (HG U133 Plus 2.0) was used to investigate the effects of resistance exercise and resistance training on the skeletal muscle transcriptome profile of 28 young and old adults. Vastus lateralis muscle biopsies were obtained pre and 4hrs post resistance exercise in the beginning (untrained state) and at the end (trained state) of a 12 wk progressive resistance training program. A total of 28 subjects were included in this investigation. The young (n=16, 24±1y) participants included 8 males and 8 females. The old (n=12, 84±1y) participants included 6 males and 6 females. All subjects participated in 12 wks of progressive resistance training consisting of bilateral knee extensions with 3x10 reps at 70% of 1-RM, and 3d/wk for a total of 36 training sessions. Vastus lateralis biopsies were obtained in conjunction with the 1st and 36th (last) training session and included a basal biopsy and another biopsy 4hrs post the resistance exercise session (for a total of 4 biopsies per subject). The RNA integrity for all samples was very good with an average RIN number of 7.6. All 110 samples were analyzed on a separate microarray chip, and samples were not pooled between subjects. The study design allowed us to examine the acute effects of resistance exercise on the skeletal muscle transcriptome in the untrained and trained state. The design also provided information on the effects of resistance training on basal level gene expression and the effects of age on basal level gene expression
Project description:The skeletal muscle system plays an important role in the independence of older adults. In this study we examine differences in the skeletal muscle transcriptome between healthy young and older subjects and (pre‐)frail older adults. Additionally, we examine the effect of resistance‐type exercise training on the muscle transcriptome in healthy older subjects and (pre‐)frail older adults. Baseline transcriptome profiles were measured in muscle biopsies collected from 53 young, 73 healthy older subjects, and 61 frail older subjects. Follow‐up samples from these frail older subjects (31 samples) and healthy older subjects (41 samples) were collected after 6 months of progressive resistance‐type exercise training. Frail older subjects trained twice per week and the healthy older subjects trained three times per week. At baseline genes related to mitochondrial function and energy metabolism were differentially expressed between older and young subjects, as well as between healthy and frail older subjects. Three hundred seven genes were differentially expressed after training in both groups. Training affected expression levels of genes related to extracellular matrix, glucose metabolism, and vascularization. Expression of genes that were modulated by exercise training was indicative of muscle strength at baseline. Genes that strongly correlated with strength belonged to the protocadherin gamma gene cluster (r = −0.73). Our data suggest significant remaining plasticity of ageing skeletal muscle to adapt to resistance‐type exercise training. Some age‐related changes in skeletal muscle gene expression appear to be partially reversed by prolonged resistance‐type exercise training. The protocadherin gamma gene cluster may be related to muscle denervation and re‐innervation in ageing muscle.
Project description:Human aging is associated with skeletal muscle atrophy and functional impairment (sarcopenia). Multiple lines of evidence suggest that mitochondrial dysfunction is a major contributor to sarcopenia. We evaluated whether healthy aging was associated with a transcriptional profile reflecting mitochondrial impairment and whether resistance exercise could reverse this signature to that approximating a younger physiological age. Skeletal muscle biopsies from healthy older (N = 25) and younger (N = 26) adult men and women were compared using gene expression profiling, and a subset of these were related to measurements of muscle strength. 14 of the older adults had muscle samples taken before and after a six-month resistance exercise-training program. Before exercise training, older adults were 59% weaker than younger, but after six months of training in older adults, strength improved significantly (P<0.001) such that they were only 38% lower than young adults. As a consequence of age, we found 596 genes differentially expressed using a false discovery rate cut-off of 5%. Prior to the exercise training, the transcriptome profile showed a dramatic enrichment of genes associated with mitochondrial function with age. However, following exercise training the transcriptional signature of aging was markedly reversed back to that of younger levels for most genes that were affected by both age and exercise. We conclude that healthy older adults show evidence of mitochondrial impairment and muscle weakness, but that this can be partially reversed at the phenotypic level, and substantially reversed at the transcriptome level, following six months of resistance exercise training. Keywords: resistance exercise, muscle, aging
Project description:Global microarray (HG U133 Plus 2.0) was used for the first time to investigate the effects of resistance exercise on the transcriptome in slow-twitch myosin heavy chain (MHC) I and fast-twitch MHC IIa muscle fibers of young and old women. Vastus lateralis muscle biopsies were obtained pre and 4hrs post resistance exercise in the beginning (untrained state) and at the end (trained state) of a 12 wk progressive resistance training program. A total of 14 females were included in this investigation. The participants included 8 young (23±2y) and 6 old (85±1y) females. All subjects participated in 12 wks of progressive resistance training consisting of bilateral knee extensions with 3x10 reps at 70% of 1-RM, and 3d/wk for a total of 36 training sessions. Vastus lateralis biopsies were obtained in conjunction with the 1st and 36th (last) training session and included a basal biopsy and another biopsy 4hrs post the resistance exercise session. From each biopsy sample, we isolated individual muscle fibers. After myosin isoform identification of isolated fibers (SDS-PAGE), RNA extraction of 20 MHC I and 20 MHC IIa muscle fibers per biopsy sample followed. Thus, each resulting sample contained total RNA from 20 muscle fibers of identical fiber type (MHC I or MHC IIa). A total of 70 samples were analyzed on separate microarray chips, and samples were not pooled between subjects. The study design allowed us to examine the acute effects of resistance exercise on the transcriptome in MHC I and MHC IIa muscle fibers in the untrained and trained state.
Project description:Global microarray (HG U133 Plus 2.0) was used for the first time to investigate the effects of resistance exercise on the transcriptome in slow-twitch myosin heavy chain (MHC) I and fast-twitch MHC IIa muscle fibers of young and old women. Vastus lateralis muscle biopsies were obtained pre and 4hrs post resistance exercise in the beginning (untrained state) and at the end (trained state) of a 12 wk progressive resistance training program.
Project description:Background: Exercise has a positive effect on overall health. This study was performed to get an overview of the effects of mixed exercise training on skeletal muscl 18 middle-aged men performed 12 weeks of exercise training (2x endurance training and 1x resistance training), muscle biopsies were taken at baseline and 3 days after the last training session
Project description:How skeletal muscle adapts to different types of exercise intensity with age is not known. Adult and old C57BL/6 male mice were assigned to one of three groups: sedentary, daily high-intensity intermittent training (HIIT), or moderate intensity continuous training (MICT) for 4 weeks, compatible with the older group’s exercise capacity. Improvements in body composition, fasting blood glucose, and muscle strength were mostly observed in the MICT old group, while effects of HIIT training in adult and old animals was less clear. Skeletal muscle exhibited structural and functional adaptations to exercise training, as revealed by electron microscopy, OXPHOS assays, respirometry, and muscle protein biomarkers. Transcriptomics analysis of gastrocnemius muscle combined with liver and serum metabolomics unveiled an age-dependent metabolic remodeling in response to exercise training. These results support a tailored exercise prescription approach aimed at improving health and ameliorating age-associated loss of muscle strength and function in the elderly.
Project description:The aim of this investigation was to evaluate the effect of training on the global transcriptional response of skeletal muscle to an acute bout of resistance exercise. Seven young healthy men and women underwent a 12-week supervised progressive unilateral arm resistance exercise (RE) training program. One week after the last session of training, subjects performed an acute bout of bilateral arm RE in which the trained and the untrained arm exercised at the same relative intensity. A muscle biopsy was obtained 4h post exercise from the biceps brachii of the trained and untrained arm. Trained and untrained muscle samples were analyzed for mRNA levels of over 20,000 annotated genes using Affymetrix U133 Plus 2.0 microarrays.
Project description:Shatavari is a herbal dietary supplement that may increase skeletal muscle strength in younger and older adults. Shatavari contains compounds with both estradiol-like and antioxidant properties, which could enhance muscle function. Postmenopausal women may derive the greatest benefit, as estrogen deficiency adversely impacts skeletal muscle function. However, mechanistic insights are limited and the effects of shatavari on muscle function require further characterization. In this randomised, double-blind trial, 17 young (23 ±5yr) and 22 older (63±5yr) women completed an eight-week leg resistance training programme. They consumed either a placebo or shatavari (1000mg/d, equivalent to 26,500 mg/d fresh weight) supplement throughout. Pre and post training, measures of leg strength, neuromuscular function and vastus lateralis (VL) biopsies were obtained. Tandem-mass-tagged VL proteomic analyses were performed. Additionally, resistance training (RT) is the gold standard intervention for ameliorating sarcopenia. Outstanding mechanistic questions remain regarding the malleability of the molecular determinants of skeletal muscle function in older age. Discovery proteomics can expand such knowledge. We further aimed to compare the effect of RT on the skeletal muscle proteome and neuromuscular function (NMF) in older and younger women.