Project description:The goal of this project was to use a randomized, cross over design to determine the amino acid blood and muscle response to the acute ingestion of cheddar cheese in comparison to that of bovine milk and to investigate the skeletal muscle mTORC1 response.
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:Skeletal muscle weakness is linked to many adverse health outcomes. Current research to identify new drugs has often been inconclusive due to lack of adequate cellular models. We have previously developed a scalable monolayer system to differentiate human embryonic stem cell (hESC) into mature skeletal muscle cells (SkMCs) within 26 days without cell sorting or genetic manipulation. Here, building on our previous work, we show that differentiation and fusion of myotubes can be further enhanced using the anabolic factors testosterone (T) and follistatin (F) in combination with a cocktail of myokines (C). Importantly, combined TFC treatment significantly enhanced both hESC-SkMC fusion index and expression of various skeletal muscle markers including the motor protein Myosin Heavy Chain (MyHC). Transcriptomic and proteomic analysis revealed oxidative phosphorylation as the most up-regulated pathway, suggesting energy metabolism is coupled to enhanced muscle differentiation. This cellular model will be a powerful tool for studying in vitro myogenesis and for drug discovery to further enhance muscle development or treat muscle diseases.
Project description:Skeletal muscle weakness is linked to many adverse health outcomes. Current research to identify new drugs has often been inconclusive due to lack of adequate cellular models. We have previously developed a scalable monolayer system to differentiate human embryonic stem cell (hESC) into mature skeletal muscle cells (SkMCs) within 26 days without cell sorting or genetic manipulation. Here, building on our previous work, we show that differentiation and fusion of myotubes can be further enhanced using the anabolic factors testosterone (T) and follistatin (F) in combination with a cocktail of myokines (C). Importantly, combined TFC treatment significantly enhanced both hESC-SkMC fusion index and expression of various skeletal muscle markers including the protein Myosin Heavy Chain (MyHC). Transcriptomic and proteomic analysis revealed oxidative phosphorylation as the most up-regulated pathway, suggesting energy metabolism is coupled to enhanced muscle differentiation. This cellular model will be a powerful tool for studying in vitro myogenesis and for drug discovery to further enhance muscle development or treat muscle diseases.
Project description:During lactation, mothers initiate cycles of bone formation followed by significant bone loss to meet the high calcium (Ca2+) demand by progeny. While estrogen functions typically as an anabolic driver of bone remodeling, this sex steroid is absent in postpartum females. Here, we report that a brain-derived secreted from neurons of the arcuate nucleus (ARC) fills this void and functions as a potent osteogenic factor to promote bone mass in lactating females. We previously reported an extraordinarily sex-specific high bone mass phenotype in female mice that persists with aging and is central in origin after eliminating estrogen receptor alpha signaling in ARCKISS1 neurons. Parabiosis and bone transplant studies established that a humoral factor in mutant females accounts for this unusual skeletal phenotype. High bone mass in mutant females could be traced back to the skeletal stem cell (SSC) level, reflected by their increased frequency and osteochondrogenic potential. Based on ex-vivo, in vivo, and in vitro assays, one protein emerged as the most promising secreted pro-osteogenic factor from the ARC, acting in mice and human SSCs at low concentrations (<nM) independent of age and sex. The role of this brain-derived factor in bone formation was confirmed by in vivo gain and loss of function studies. Unexpectedly, in wild-type females, a transient spike of this protein appears in ARCKISS1 neurons coincident with lactation when bone remodeling and high calcium demand intensify in estrogen-depleted mothers. Our findings establish a potentially new therapeutic anabolic bone hormone that functions in a novel female-specific brain-bone axis to ensure mammalian species survival.
Project description:Background: Periods of inactivity experienced by older adults induce nutrient anabolic resistance creating a cascade of skeletal muscle transcriptional and translational aberrations contributing to muscle dysfunction. Objective: To identify how inactivity alters leucine-stimulated translation of molecules and pathways within the skeletal muscle of older adults.