Project description:After tissue injury mesenchymal progenitor subsets undergo a transient proliferative expansion, morphological transition and migration from their perivascular niche. Some of these subsets contribute enduring populations to connective tissue structures adjacent to muscle. To gain insights into gene accessibility to complement the single cell RNA seq expression data previously obtained and to uncover the lineage potential of MPs in this context, tdTomato positive cells were profiled by single cell ATAC sequencing.
Project description:New potential sources of stem cells for clinical application include bone marrow mesenchymal stem cells (BMMSCs), human embryonic stem cells (hESCs), and induced pluripotent stem cells (iPS). However, each source is not without its own concerns. While research continues in an effort overcome these problems, the generation of mesenchymal progenitors from existing hESC lines may circumvent many of these issues. We report here a comparison of the transcriptome of hESC-derived mesenchymal progenitors (EMPs), its parental hESC line, and 2 donors of adult BMMSCs. A custom-designed oligo-microarray of just over 11,000 highly-expressed genes in stem cells was used to profile the transcriptome of BMMSCs, EMPs, and hESCs.
Project description:Memory B cells represent one of the pillar of humoral protection and are found in the circulation and secondary lymphoid organs several decades after initial pathogen or vaccine encounter. The exact cellular and biological mechanisms allowing long-term survival of quiescent cells in such a fluctuating microenvironment remain poorly understood. scRNA-seq analysis of long-lived Vaccinia-specific and total IgG+ memory B cells had helped us identify two subsets of quiescent switched memory B cells in the spleen of adult donors, separated by the expression of CR2(CD21). To better understand the relationship between these two resting splenic memory B cell subsets, we sorted CD21hiCD20hi and CD21intCD20int IgG+ memory B cells from the live IgD-CD27+IgG+CD20+CD3-CD14-CD16- compartment of the spleen of four organ donors, collected between 2015 and 2019. For all donors, both IgG+ memory B cell subsets were sorted alongside naïve B cells (IgD+CD27-CD38-CD24-CD20+CD3-CD14-CD16-). Assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-seq) was performed on 50000 cells of each sorted population, according to published methods (Buenrostro, Nature Methods, 2013, PMID: 24097267) and sent for library sequencing by Integragen (Evry, France). In parallel, RNA was extracted from remaining cells and sent for library preparation and sequencing by Integragen (Evry, France) (see related accession number).
Project description:Skeletal muscle possesses the ability to adapt its size in response to milieus, which is called plasticity. Resistance training induces the increment of muscle mass called muscle hypertrophy. Muscle stem cells (MuSC; also known as muscle stem cells) function to supply new nuclei for myofiber during the overload in muscle. We found that Yap1 and Taz in mesenchymal progenitors (also called FAPs) are critical for MuSC proliferation in overloaded muscles. We hypothsize that Yap1/Taz-dependent mesenchymal progenitors derived factor induces MuSC proliferation. In order to identify such factors, RNA-seq of overloaded FAPs were performed.
Project description:Human induced pluripotent stem cells provide an unlimited, scalable source of youthful tissue progenitors and secretome for regenerative therapies. The aim of our study was to assess the potential of conditioned medium (CM) derived from hiPSC-mesenchymal progenitors (hiPSC-MPs) to stimulate osteogenic differentiation of adult and aged human bone marrow-mesenchymal stromal cells (MSCs). In addition, we evaluated whether extended cultivation or osteogenic pre-differentiation of hiPSC-MPs could enhance the CM stimulatory activity.