Project description:The capacity of muscle to grow or to regenerate is provided by adult stem cells, called satellite cells. Satellite cells can generate proliferating myoblasts, sensitive to MP signaling. To understand the role of this signaling pathway in adult myogenesis, we analyzed the changes in gene expression following treatment of primary myoblasts with BMP4 agonist or GREM1 antogonist. Here we used microarrays and to clarify BMP4/GREM1 signaling and we identified several pathways and cellular processes affected.
Project description:Expression profiling of proliferating primary myoblasts obtained from vastus lateralis muscle biopsises from healthy individuals and stimulated with Vitamin D (100 nM 1,25(OH)2D3) or vehicle for 24h.
Project description:Chromatin immunoprecipitation in combination with sequencing (ChIP-seq) was used to identify the interactions of CRMs with key regulators of Grem1 expression, namely SMAD4 (mediating response to BMP signal transduction) and GLI3 (SHH signal transduction). This analysis revealed the presence of a single significantly enriched SMAD4 ChIP-seq peak in CRM2 during initiation of forelimb bud development, when BMP4 is required to initiate/upregulate the Grem1 transcription. During progression of limb development, GLI3 chromatin complexes interact with all enhancers except CRM5. which agrees with the predominant role of SHH-mediated Grem1 regulation during outgrowth and/or GLI3R-mediated repression during termination. Thus, the Grem1 TAD encodes an array of CRM enhancers that integrate inputs from BMP and SHH signaling into the dynamic regulation of Grem1 during limb bud outgrowth.
Project description:This experiment was carried out to identify the short-term effects of Activin A and BMP4 stimulation on gene expression in human embryonic stem cells grown in a chemically defined medium. Keywords: Growth factor stimulation experiment
Project description:The gene expression of bone marrow cells of mice enriched for Gremlin1 vs control was measured (n=3). It is not known if endogenous adult mesenchymal stem cells (MSCs) exist.Following culture,perisinusoidal mesenchymal cells can clonally recapitulate the skeletal microenvironment, but this fails to confirm their endogenous lineage repertoire. Multipotential MSCs in vitro may be fate-restricted in vivo and specific perisinusoidal recombination does not trace bone or cartilage Reconciling in vitro MSCs with their in vivo potential has been challenging and remains untested outside of the bone. We prove that expression of the bone morphogenetic protein (BMP)-antagonist gremlin 1 (Grem1) identifies a population of self-renewing, multipotent bone, cartilage and stromal-primed MSCs in both health and healing that are completely distinct from the established Nes-GFP niche-supporting mesenchymal cells. Grem1 recombination also identifies small intestinal MSCs (siMSCs) that can be transplanted and clonally trace the self-renewing, multilineage periepithelial mesenchymal sheath. Our findings prove the existence of adult MSCs that are regionally and functionally distinct from perisinusoidal Nes-GFP cells. We also established that the mesenchyme undergoes ordered turnover outside of the bone and may help to preserve regional niches. Grem1 MSCs provide a new focus for investigating mesenchymal renewal and repair. a.Adult (6-8 weeks) Grem1;TdTomato mice were induced by oral tamoxifen and their bone marrow harvested by digestion sorted for Non-recombined CD45/CD31/Ter-119 triple negative bone marrow cells (n=3). b.Adult (6-8 weeks) Grem1;TdTomato mice were induced by oral tamoxifen and their bone marrow harvested by digestion sorted for Grem1 (n=3). Same mice as in a so that samples are matched.
Project description:Backround: Several microRNAs have been characterized to regulate the process of angiogenesis. Previously, bone morphogenetic protein 4 (BMP4) was shown to increase the proangiogenic activity of endothelial cells. Aim: In this project we investigated how the proangiogenic BMP4 effect is mediated by microRNAs. Experimental design: To investigate changes in the microRNA transcriptome in HUVECs a time course experiment (12, 18 and 24 h) was performed. HUVECs were kept in endothelial basal medium either with BMP4 (25 ng/ml) stimulation or buffer control (4 mM HCL with 0.1% bovine serum albumin). Comparison between stimulated vs. unstimulated cells at different time points. followed by a miRNA microarray analysis was performed.