Project description:Muscle satellite cells are a self-renewing pool of stem cells that give rise to daughter myogenic precursor cells in adult skeletal muscle. Published and preliminary data indicated that MyoD and p53 genes are involved in satellite cell differentiation. We would like to know what downstream genes of both transcription factors are affected in satellite cell-derived myoblasts (MyoD-/-, p53 -/-). Experiment Overall Design: this experiment include 3 samples and 25 replicates
Project description:Muscle satellite cells are a self-renewing pool of stem cells that give rise to daughter myogenic precursor cells in adult skeletal muscle. Published and preliminary data indicated that MyoD and p53 genes are involved in satellite cell differentiation. We would like to know what downstream genes of both transcription factors are affected in satellite cell-derived myoblasts (MyoD-/-, p53 -/-). Keywords: other
Project description:Skeletal muscle growth and regeneration rely on myogenic progenitor and satellite cells, the stem cells of postnatal muscle. Elimination of Notch signals during mouse development results in premature differentiation of myogenic progenitors and formation of very small muscle groups. Here we show that this drastic effect is rescued by mutation of the muscle differentiation factor MyoD. However, rescued myogenic progenitors do not assume a satellite cell position and contribute poorly to myofiber growth. The disrupted homing is due to a deficit in basal lamina assembly around emerging satellite cells and to their impaired adhesion to myofibers. On a molecular level, emerging satellite deregulate the expression of basal lamina components and adhesion molecules like integrin a7, collagen XVIIIa1, Megf10 and Mcam. We conclude that Notch signals control homing of satellite cells, stimulating them to contribute to their own microenvironment and to adhere to myofibers. Gene expression analysis using total RNA from FACS-isolated Vcam-1+/CD31-/CD45-/Sca1- embryonic muscle progenitor cells from E17.5 back muscle tissue of MyoD-/-, Pax3cre/+;Rbpjflox/flox;MyoD-/- and Pax3cre/+;DnMamlflox/flox;MyoD-/- mice.
Project description:Deletion of Klf5 in satellite cells impaired muscle regeneration due to a failure of differentiation. Mechanistically, Klf5 controls transcription of muscle genes by interacting with MyoD and Mef2. These findings provide a potential intervention into the process of muscle regeneration through modulation of Klf5.
Project description:Direct lineage reprogramming provides a unique system to study cell fate transitions and unearth molecular mechanisms that safeguard cellular identity. We previously reported on direct conversion of mouse fibroblasts into induced myogenic progenitor cells (iMPCs) by transient MyoD overexpression in concert with small molecules treatment. Here we employed integrative multi-omic approaches to delineate the molecular landscape of fibroblast reprogramming into iMPCs in comparison to transdifferentiation into myogenic cells solely by MyoD overexpression. Utilizing bulk RNA-sequencing and mass spectrometry, we uncovered molecular regulators and pathways that endow a myogenic stem cell identity on fibroblasts only in the presence of small molecule treatment. In addition, we demonstrate that Pax7+ cells in iMPCs share molecular attributes with myoblasts, however in addition express unique genes, proteins and pathways that are indicative of a more activated satellite cell-like state in vitro. Collectively, this study charts a molecular blueprint for reprogramming fibroblasts into muscle stem and progenitor cells and further establishes the fidelity of stable iMPC cultures in capturing skeletal muscle regeneration in vitro for disease modeling and basic research applications.
Project description:Satellite cells are resident skeletal muscle stem cells responsible for muscle maintenance and repair. In resting muscle, satellite cells are maintained in a quiescent state. Satellite cell activation induces the myogenic commitment factor, MyoD, and cell cycle entry to facilitate transition to a population of proliferating myoblasts that eventually exit the cycle and regenerate muscle tissue. The molecular mechanism involved in the transition of a quiescent satellite cell to a transit-amplifying myoblast is poorly understood. We used microarrays to detail the global program of gene expression of in vivo satellite cell activation through muscle injury and identified RNA post-transcriptional regulation as a key component of satellite cell activation. Wild type or Sdc4-/- satellite cells were FACS isolated from resting muscle or from muscle 12h and 48h following barium chloride-induced muscle injury. 5000 cell equivalents of RNA was labeled and hybridized to MOE430v2 GeneChips (Affymetrix) and scanned as per manufacturers protocol. Probeset intensities were GCRMA normalized for further analysis including UPGMA hierarchical clustering, analysis of variance (ANOVA), and fold change.
Project description:Satellite cells are resident skeletal muscle stem cells responsible for muscle maintenance and repair. In resting muscle, satellite cells are maintained in a quiescent state. Satellite cell activation induces the myogenic commitment factor, MyoD, and cell cycle entry to facilitate transition to a population of proliferating myoblasts that eventually exit the cycle and regenerate muscle tissue. The molecular mechanism involved in the transition of a quiescent satellite cell to a transit-amplifying myoblast is poorly understood. We used microarrays to detail the global program of gene expression of in vivo satellite cell activation through muscle injury and identified RNA post-transcriptional regulation as a key component of satellite cell activation.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)