Macrophage Precursor Cells from the Left Atrial Appendage of the Adult Heart Spontaneously Reprogram into a C-kit+/CD45- Stem Cell-Like Phenotype [Array analysis]
ABSTRACT: The developmental origin of the c-kit expressing progenitor cell pool in the adult heart has remained elusive. Recently, it has been discovered that the injured heart is enriched with c-kit+ cells, which also express the hematopoietic marker CD45. In this study, we characterize the phenotype and transcriptome of the c-kit+/CD45+ cell population, originating from the left atrial appendage. These cells are defined as cardiac macrophage progenitors. We also demonstrate that the c-kit+/CD45+ progenitor cell population activates heart development, neural crest and pluripotency associated pathways in vitro, in conjunction with CD45 down-regulation, and acquire a c-kit+/lin- phenotype. This spontaneous reprogramming progresses further to a highly proliferative, partially myogenic phenotype. Our data suggests that c-kit+/lin- cells and cardiac macrophages have a common lineage origin possibly resolving some current conundrums in the field of cardiac regeneration. Two different stem cell types were grown by altering the tissue digestion protocol. To investigate their transcriptional profiles we prepared RNA from two cell sorted replicates per cell type and from two left ventricular biopsy samples as controls.
Project description:The developmental origin of the c-kit expressing progenitor cell pool in the adult heart has remained elusive. Recently, it has been discovered that the injured heart is enriched with c-kit+ cells, which also express the hematopoietic marker CD45. In this study, we characterize the phenotype and transcriptome of the c-kit+/CD45+ cell population, originating from the left atrial appendage. These cells are defined as cardiac macrophage progenitors. We also demonstrate that the c-kit+/CD45+ progenitor cell population activates heart development, neural crest and pluripotency associated pathways in vitro, in conjunction with CD45 down-regulation, and acquire a c-kit+/lin- phenotype. This spontaneous reprogramming progresses further to a highly proliferative, partially myogenic phenotype. Our data suggests that c-kit+/lin- cells and cardiac macrophages have a common lineage origin possibly resolving some current conundrums in the field of cardiac regeneration. Two different stem cell types were grown by altering the tissue digestion protocol, from which one type was spontaneously transdifferentiating to other cell types. To investigate their transcriptional profiles we prepared RNA from two cell sorted replicates per cell type (A, B, C1, C2, C3).
Project description:Cardiac fibroblasts are critical to proper heart function through multiple interactions with the myocardial compartment. Loosely defined based on their mesenchymal origin, capacity to adhere to plastic and to secrete extracellular matrix, cardiac fibroblasts have been largely neglected due to heterogeneity and lack of proper markers. Objective: To identify genes uniquely expressed in the cardiac fibroblast pool, we performed an unbiased comparative analysis between cardiac and tail fibroblasts, and tracked cardiac fibroblasts after injury to determine their contribution to myocardial regeneration. Methods and Results: High-throughput cell surface and intracellular profiling identified homogeneously expressed MSC markers in cardiac fibroblasts, as well as a surprising number of cardiogenic markers, some expressed at higher levels than in cardiomyocytes. Genetically marked fibroblasts contributed to interstitial but not cardiomyocyte compartments in infarcted hearts. Conclusions: The core transcriptional identity of cardiac fibroblasts reflects their embryological origin, provoking novel interpretations for studies on more specialized cardiac progenitors, and offering a novel perspective for reinterpreting cardiac regenerative therapies 3 biological replicates plated over 5 days after isolation pooled out of 2 animals were used for both tail and heart fibroblasts (6 total samples analysed)
Project description:The herbicide linuron is an endocrine disruptor with a suspected anti-androgenic mode of action (MOA) but the complete MOA for LIN is not fully characterized. The objectives of this study were to better characterize the MOA of LIN in the fathead minnow (FHMs) ovary by comparing expression profiles of LIN to dihydrotestosterone (DHT) and flutamide (FLUT), both model compounds with well defined androgenic and anti-androgenic MOAs respectively. Ovarian explants from vitellogenic FHMs were exposed to 10-6 M, 10-7 M, and 10-8 M of DHT, FLUT, and LIN in vitro in a12 hour incubation experiment. Ovary explants exposed to DHT showed a significant increase in E2 production compared to controls but FLUT and LIN did not affect E2 production. Microarray analysis and support vector machine classification revealed that expression patterns of FLUT and LIN in the ovary were more similar to each other compared to DHT and other androgens. Gene set enrichment analysis identified the notch signaling cascade was affected by all three chemicals. DHT down-regulated the WNT-Frizzled pathway while LIN down-regulated angiopoietin receptor signaling and increased biosynthesis of cholesterol. LIN shared 27 expression sub-networks (e.g. beta-3 adrenergic receptor, MAP3K1, interleukin, signlaing) in common with FLUT, and only 4 sub-networks with DHT. A reciprocal gene expression network was constructed using DHT and FLUT data, and the network revealed that steroid metabolism, translation, and DNA replication are potentially regulated through AR signaling. This study characterizes cell pathways associated with E2 production and identifies cell signaling cascades that may be disrupted by ureic-based herbicides in the ovary. 16 samples total; 4 control, 4 DHT, 4 Flutamide, 4 LIN
Project description:Development of systems allowing the maintenance of native properties of mesenchymal stromal cells (MSC) is a critical challenge for studying physiological functions of skeletal progenitors, as well as towards cellular therapy and regenerative medicine applications. Conventional stem cell culture in monolayer on plastic dishes (2D) is associated with progressive loss of functionality, likely due to the absence of a biomimetic microenvironment and the selection of adherent populations. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow cells within the pores of 3D scaffolds in a perfusion-based bioreactor system, followed by enzymatic digestion for cell retrieval. The 3D-perfusion system supported MSC growth while maintaining cells of the hematopoietic lineage, and thus generated a cellular environment mimicking some features of the bone marrow stroma. As compared to 2D-expansion, sorted CD45- cells derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7-8 doublings) maintained a 4.3-fold higher clonogenicity and exhibited a superior differentiation capacity towards all typical mesenchymal lineages, with similar immunomodulatory function in vitro. Transcriptomic analysis performed on MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability as well as a significant upregulation of multipotency-related gene clusters following 3D-perfusion as compared to 2D expansion. The described system offers a model to study how factors of a 3D engineered niche may regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems. Nucleated cells were isolated from 5 fresh human bone marrow aspirates by means of red blood cells lyses buffer and then were seeded into a 3D perfusion bioreactor system using a pure hydroxyapatite 3D scaffold and in conventional Petri dishes (2D). After culture for 19 days, cells from both systems were enzymatically retrieved and sorted using anti-CD45-coated magnetic beads. Total RNA was extracted from CD45- cells, QCed and hybridized to Affymetrix microarrays.
Project description:To investigate roles for Tbx20 in endocardium, we ablated Tbx20 utilizing Tie2Cre. Tie2Cre;Tbx20 mutants died at E14, exhibiting defects in multiple aspects of cardiac septation. Although endocardial cells lacking Tbx20 were able to undergo endothelial-to-mesenchymal transition, cushion mesenchymal cells lacking Tbx20 did not disperse normally. Non-cell autonomous roles of endocardial Tbx20 were also revealed, as evidenced by decreased myocardialization of outflow tract and failure of dorsal mesenchymal protrusion formation in mutants. To examine how ablation of Tbx20 in endocardial lineages affected gene expression, we performed global gene expression analysis on purified endocardial lineages. E12.5 hearts were dissociated, and Tie2Cre;RosatdTom lineage traced cells of controls and mutants were isolated by fluorescence activated cell sorting (FACS), after exclusion of blood cells (Ter119+, CD41+ and/or CD45+). Mutant endocardial lineages exhibited decreased expression of genes associated with extracellular matrix and cell migration. E12.5 hearts were dissociated, and Tie2Cre;RosatdTom lineage traced cells of controls and mutants were isolated by fluorescence activated cell sorting (FACS), after exclusion of blood cells (Ter119+, CD41+ and/or CD45+). FACS sorted Tie2Cre lineage from E12.5 hearts: Tie2Cre;Tbx20 +/loxP Control hearts versus Tie2Cre;Tbx20 loxP/- mutant hearts
Project description:Hematopoietic Stem Cells (HSC) are originated during embryonic development from endothelial-like cells located in the ventral side of the dorsal aorta around day E10-12 of murine development. This region is called AGM for Aorta/Gonad/Mesonephros and refers to the tissues around the hemogenic aorta. Cells that emerge from the endothelium and show hematopoietic traits can be distinguished by the expression of the c-kit receptor and finally acquire the CD45 marker. AGM regions were obtained from E11.5 embryos by dissection and digested with 0.1% collagenase. Cells were stained with anti-CD31, anti-ckit, anti-CD45 and anti-Ter119 antibodies. Sorting of the CD31+CD45-Ter119- population was performed, and cells were separated into c-kit+ and c-kit-. 3 replicates each of c-kit+ and c-kit- cells.
Project description:Neural crest defects lead to congenital heart disease involving outflow tract (OFT) malformation. Integrin-linked-Kinase (ILK) plays important roles in multiple cellular processes and embryogenesis. ILK is expressed in neural crest cells (NCC), but its role in NCC and OFT morphogenesis remains unknown. We used microarrays to detail the global programme of gene expression underlying the morphogenesis of the cardiac neural crest and outflow tract. The outflow tract of control and ILK mutant mouse embryos at E10.5 were dissected and dissociated. Neural crest cells were FACS sorted and used for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Lineage-specific differentiation potential varies among different human pluripotent stem cell (hPSC) lines. A stem cell bank may advice researchers on which hPSCs exhibit the highest differentiation potential for a certain lineage. In this study, we aimed at characterizing the hematopoietic differentiation potential from 14 hESC/iPSC lines through the embryoid body (hEB) differentiation system. We carried out gene expression profiling on six different hESC lines grouped according to their ability to differentiate towards hematopoietic lineage: SHEF1, AND1 and H1 were considered as good (high CD45 expression and high CFU potential), whereas H9, HS181 and VAL3 were selected as poor-blood differentiating lines (low CD45 expression and low CFU potential). Human ESC samples were collected during the exponential cell growth phase and stabilized in RNA later. 500 ng of each total RNA sample was labelled with Cy3 using the Quick-Amp Labelling kit and hybridized with the Gene Expression Hybridization kit to a Whole Human Genome Oligo Microarray (Agilent Technologies) following the Manufacturer’s instructions. Each cell line was analyzed as independent duplicates. H9 hESC line was used as the baseline.
Project description:We describe a novel population of human adult cardiac resident stem cells (CRSCs), which are positive for W8B2 antigen, originating from human adult atrial appendages. W8B2+ CRSCs exhibit a spindle-shaped morphology, are clonogenic and able to self-renew. W8B2+ CRSCs show high expression of mesenchymal but not hematopoietic nor endothelial markers. W8B2+ CRSCs expressed GATA4, HAND2, and TBX5, but not C-KIT, SCA-1, NKX2.5, PDGFRα, ISL1 or Wilm’s tumor gene-1 (WT1). W8B2+ CRSCs can differentiate into the cardiovascular lineages and secrete various cytokines. Comparative RNA sequencing was performed using W8B2+ cell from human atrial appendages (passage 2 from 3 different patients), c-Kit+ cell from human atrial appendages (passage 2 from 3 different patients) and W8B2+ cell from bone marrow (passage 3 from 2 different patients, from PromoCell, Heidelberg, Germany).