Project description:We identified the target genes of FTO ("fat mass and obesity associated") in primary cultures of human skeletal muscle cells using adenoviral vectors expressing FTO or GFP and oligonucleotide microarrays. Human myotubes were prepared from 4 different skeletal muscle biopsies. After differentiation, myotubes were infected for 48 hours with recombinant adenovirus expressing either GFP or FTO. Each FTO-infected myotubes culture was compared to GFP-infected myotubes culture. GFP-infected myotubes were regarded as the control. Four biological replicates were processed.
Project description:In this study we have identified the target genes of BHLHB2 and BHLHB3 in primary cultures of human skeletal muscle cells using adenoviral vectors expressing either BHLHB2 or BHLHB3, and oligonucleotide microarrays. Human myotubes were prepared from 4 different skeletal muscle biopsies. After 7 days of differentiation, myotubes were infected for 48 hours with recombinant adenovirus expressing either GFP, BHLHB2 or BHLHB3. Each BHLHB2- or BHLHB3-infected myotubes culture was compared to GFP-infected myotubes culture. GFP-infected myotubes were considered the control. Four biological replicates were processed.
Project description:Skeletal muscle is a major contributor to whole-body glucose homeostasis and is an important endocrine organ. To date, few studies have undertaken the large-scale identification of skeletal muscle-derived secreted proteins (myokines), particularly in response to stimuli that activate pathways governing energy metabolism in health and disease. Whereas the AMP-activated protein kinase (AMPK) and insulin-signaling pathways have received notable attention for their ability to independently regulate skeletal muscle substrate metabolism, little work has examined their ability to re-pattern the secretome. The present study coupled the use of high-resolution MS-based proteomics and bioinformatics analysis of conditioned media derived from 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR – an AMPK activator)- and insulin-treated differentiated C2C12 myotubes. We quantified 858 secreted proteins, including cytokines and growth factors such as fibroblast growth factor-21 (Fgf21). We identified 377 and 118 proteins that were significantly altered by Insulin and AICAR treatment, respectively. Notably, the family of insulin growth factor binding-proteins (Igfbp) was differentially regulated by each treatment. Insulin- but not AICAR-induced conditioned media increased the mitochondrial respiratory capacity of myotubes, potentially via secreted factors. These findings may serve as an important resource to elucidate secondary metabolic effects of insulin and AICAR stimulation in skeletal muscle.
Project description:RNA was sequenced from differentiated C2C12 mouse myotubes that were treated with S2-013 conditioned media with or without resveratrol in comparison to control media
Project description:We hypothesized that muscle contraction produces a cellular stress signal capable to increase lipolysis to sustain fuel availability during exercise. The aim of the present study was to identify novel exercise-regulated myokines, aka exerkines, able to promote lipolysis in human adipocytes. To this end, human primary myotubes from lean healthy volunteers were submitted to electrical pulse stimulation to mimic either acute intense or chronic moderate exercise. Conditioned media experiments with hMADS adipocytes were performed. Unbiased proteomic and ELISA analyses were applied in conditioned media and human plasma samples. Real-time qPCR was performed in cultured myotubes and muscle biopsy samples.
Project description:We recently identified C18ORF25 as a new exercise-regulated phophoprotein. To investigate potential in vivo functions of C18ORF25, we used CRISPR/Cas9 to generate a whole-body knock-out (KO) mouse model on a C57BL/6J background. Proteomic analysis was performed to identify potental changes in the proteome. To gain further insights into the possible signalling pathways regulated by C18ORF25, Soleus muscles from WT and KO mice (n=4) were isolated, and the muscle from one leg was maintained at resting tension with no stimulation as a control while the muscle from the contralateral leg was subject to electrical stimulation ex vivo. Muscles were quickly snap frozen and subject to single-shot label-free phosphoproteomic analysis to compare the signalling responses between the genotypes.
Project description:We performed DIA-MS based proteomic analysis of Hela cells conditioned media containing fetal bovine serum by albumin (Alb)-depletion and non-depletion. In addition, we attempted to enrich secreted proteins by reducing the volume of culture medium (10mL, 5mL and 2mL). The supernatants of each culture condition were subjected to albumin depletion followed by DIA-MS. We further analyzed proteins in the conditioned media of HeLa cells with and without tumor necrosis factor (TNF) stimulation.
Project description:Skeletal muscle is a highly organized and regenerative tissue that maintains its homeostasis primarily by activation and differentiation of muscle stem cells. Mimicking an in vitro skeletal muscle differentiation program that contains self-renewing adult muscle stem cells and aligned myotubes has been challenging. Here, we set out to engineer a biomimetic skeletal muscle construct that can self-regenerate and produce aligned myotubes using induced myogenic progenitor cells (iMPCs), a heterogeneous culture consisting of skeletal muscle stem, progenitor and differentiated cells. Utilizing electrospinning, we fabricated polycaprolactone (PCL) substrates that enabled iMPC-differentiation into aligned myotubes by controlling PCL fiber orientation. Newly-conceived constructs contained highly organized multinucleated myotubes in conjunction with self-renewing muscle stem cells, whose differentiation capacity was augmented by Matrigel supplementation. Additionally, we demonstrate using single cell RNA sequencing (scRNA-seq) that iMPC-derived constructs faithfully recapitulate a step-wise myogenic differentiation program. Notably, when the constructs were subjected to a damaging myonecrotic agent, self-renewing muscle stem cells rapidly differentiated into aligned myotubes, akin to skeletal muscle repair in vivo. Taken together, we report on a novel in vitro system that mirrors myogenic regeneration and muscle fiber alignment, and can serve as a platform to study myogenesis, model muscular dystrophies or perform drug screens.