Project description:The objective of this study was to identify novel genes whose expression is sensitive to anabolic stimuli. We used microarrays to detail the change in gene expression within the tibialis anterior muscle following an anabolic stimulus. In this case, the anabolic stimulus was nutrient consumption.
Project description:The aim of the study was to investigate how short-term fasting affects whole-body energy homeostasis and skeletal muscle energy/nutrient-sensing pathways and transcriptome in humans. For this purpose, twelve young healthy men were studied during a 24-hour fast. Skeletal muscle biopsies were collected and analyzed at baseline and after 4, 10 and 24h of fasting. As expected, fasting induced a time-dependent decrease in plasma insulin and leptin levels, whereas levels of ketone bodies and free fatty acids increased. This was associated with a metabolic shift from glucose towards lipid oxidation. Transcriptome profiling identified genes that were significantly regulated by fasting in skeletal muscle at both early and late time-points. Collectively, our study provides a comprehensive map of the main energy/nutrient-sensing pathways and transcriptomic changes during short-term adaptation to fasting in human skeletal muscle
Project description:Microglia are fundamentally important immune cells within the central nervous system (CNS) that respond to environmental challenges to maintain normal physiological processes. Alterations in steady-state cellular function and over-activation of microglia can facilitate the initiation and progression of neuropathological conditions such as Alzheimer’s disease, Multiple Sclerosis, and Major Depressive Disorder. Alcohol consumption disrupts signaling pathways including both innate and adaptive immune responses that are necessary for CNS homeostasis. Unbiased RNA-Seq profiling was used to identify gene expression changes in isolated microglia in response to recurring bouts of voluntary alcohol drinking behavior. Gene coexpression analysis identified a coordinately regulated group of genes, unique to microglia, that collectively are associated with alcohol consumption. Several genes in this group were involved in toll-like receptor signaling and production of the inflammatory cytokine interferon-gamma. Coordinate expression of these genes is not ascertained from an admixture of CNS cell-types, underscoring the importance of examining isolated cellular populations to reveal systematic gene expression changes arising from mature microglia. We identified a distinctive microglial gene expression signature for neuroimmune responses related to alcohol consumption that provides valuable insight into microglia-specific changes underlying the development of substance abuse, as well as related CNS disorders.
Project description:The mechanisms of metabolic improvements following Roux-en-Y gastric bypass (RYGB) surgery are not entirely clear. Therefore, the aim of our study was to investigate the role of obesity and RYGB on the human skeletal muscle proteome.
Project description:Northern elephant seals (NES, Mirounga angustirostris) undergo an annual molt during which they spend ~40 days fasting on land with reduced activity and lose approximately one-quarter of their body mass. Reduced activity and muscle load in stereotypic terrestrial mammalian models results in decreased muscle mass and capacity for force production and aerobic metabolism. However, the majority of lost mass in fasting female NES is from fat while muscle mass is largely preserved. Although muscle mass is preserved, potential changes to the metabolic and contractile capacity are unknown. To assess potential changes in NES skeletal muscle during molt, we collected muscle biopsies from 6 adult female NES at the beginning of the molt and after ~30 days at the end of the molt. Skeletal muscle was assessed for respiratory capacity using high resolution respirometry, and RNA was extracted to assess changes in gene expression. Despite a month of reduced activity, fasting, and weight loss, skeletal muscle respiratory capacity was preserved with no change in OXPHOS respiratory capacity. Molt was associated with 162 upregulated genes including genes favoring lipid metabolism and regulating cell cycles. We identified 172 downregulated genes including those coding for ribosomal proteins and genes associated with skeletal muscle force transduction and glucose metabolism. Following ~30 days of molt, NES skeletal muscle metabolic capacity appears largely preserved although mechanotransduction may be compromised. In the absence of exercise stimulus, fasting-induced shifts in skeletal muscle lipid metabolism may stimulate lipid signaling pathways associated with preserving the mass and metabolic capacity of slow oxidative muscle.
Project description:The objective of this study was to identify novel genes whose expression is sensitive to androgen deprivation. We used microarrays to detail the change in gene expression within the tibialis anterior muscle following castration surgery.
Project description:Recreationally-trained college aged males underwent 10 weeks of moderate volume, high-load resistance exercise with PRE and POST vastus lateralis skeletal muscle biopsies. Protein isolation was performed on tissue samples and the sarcoplasmic protein fraction was analyzed to evaluate changes PRE to POST.