Project description:Skeletal muscle biopsies were obtained from humans before (rest), immediately after (3hr_post) and 48 hours (48hr_post) after a training bout.
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:We report RNA-seq of skeletal muscle (quadriceps) of young (6-month), old (24-month), and senolytic (Dasatinib + quercetin) treated mice
Project description:We investigated age-related changes in the transcriptional profile of skeletal muscle in 5 month old (young) and 25 month old (old) C57BL/6NHsd mice using high density oligonucleotide arrays (22,690 transcripts probed). We identified 712 transcripts that are differentially expressed in young (5 month old) and old (25-month old) mouse skeletal muscle. Caloric restriction (CR) completely or partially reversed 87% of the changes in expression. Examination of individual genes revealed a transcriptional profile indicative of increased p53 activity in the older muscle. To determine whether the increase in p53 activity is associated with transcriptional activation of apoptotic targets, we performed RT-PCR on four well known mediators of p53-induced apoptosis: puma, noxa, tnfrsf10b and bok. Expression levels for these proapoptotic genes increased significantly with age (P<0.05), while CR significantly lowered expression levels for these genes as compared to control fed old mice (P<0.05). Age-related induction of p53-related genes was observed in multiple tissues, but was not observed in SOD2+/- and GPX4+/- mice, suggesting that oxidative stress does not mediate the observed age-related increase in expression. Western blot analysis confirmed that protein levels for both p21 and GADD45a, two established transcriptional targets of p53, were higher in the older muscle tissue. These observations support a role for p53-mediated apoptotic activity in mammalian aging. Keywords: aging, calorie restriction, muscle, p53
Project description:Both aging and physical activity can influence the amount of connective tissue in skeletal muscle, but the impact of these upon specific extracellular matrix (ECM) proteins in skeletal muscle is unknown. We investigated the proteome profile of connective tissue in skeletal muscle by label-free proteomic analysis of on cellular protein-depleted extracts from lateral gastrocnemius muscle of old (22-23 months old) and middle-aged mice (11 months old) subjected to three different levels of regular physical activity for 10 weeks (high resistance wheel running, low resistance wheel running or sedentary controls). We hypothesized that aging is correlated with increased amount of connective tissue proteins in skeletal muscle, and that regular physical activity can counteract these age-related changes. We found that dominating cellular proteins were diminished in the urea/thiourea extract, which was therefore used for proteomics. Proteomic analysis identified 482 proteins and showed enrichment for ECM proteins. Statistical analysis revealed that the abundances of 86 proteins were changed with age. Twenty-three of these differentially abundant proteins were identified as structural ECM proteins (e.g., collagens and laminins) and all of these were significantly more abundant with aging. No significant effect of training or interaction between training and advance in age was found for any proteins. Finally, we found a lower protein concentration in the urea/thiourea extracts from the old compared to middle-aged mice. These findings indicate that intramuscular connective tissue alters its protein content with age but is unaffected by training.
Project description:Combining resistance and endurance exercises in a training regime (concurrent training) can impair improvements in muscle hypertrophy, strength, and power compared to resistance training alone. Here we aimed to characterize skeletal muscle transcriptomic changes following chronic concurrent training to determine whether contraction-induced gene expression may reveal molecular underpinnings explaining impaired adaptations. Eighteen young, healthy male participants underwent 12 weeks of resistance, endurance, or concurrent training. Maximal strength, aerobic capacity, and anaerobic power were assessed. Transcriptomics were performed on skeletal muscle biopsies obtained pre and post-intervention. Improvements to maximal anaerobic power are impaired with concurrent and endurance training. Gene expression related to plasma membrane structures was enriched while gene expression related to regulation of mRNA processing and protein degradation was suppressed with concurrent training. Considerable overlap of gene expression related to extracellular matrix remodeling was observed between concurrent and endurance training. Our results provide the first comprehensive comparison of unique and overlapping gene sets enriched following chronic resistance, endurance, and concurrent training, and reveals pathways that may have implications in relation to impaired adaptations when undertaking concurrent training.
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.