Project description:The establishment of in vitro naïve human pluripotent stem cell cultures opened new perspectives for the study of early events in human development. The role of several transcription factors and signalling pathways during maintenance of human naïve pluripotency have been characterized. However, little is known about the role exerted by the extracellular matrix (ECM) and its three-dimensional (3D) organization. Here, using an unbiased and integrated approach combining transcriptional, proteomic and secretome analyses, we found that naïve, but not primed, hiPSC colonies are characterized by a self-organized ECM-rich microenvironment. Based on this, we developed a 3D culture system that supports robust long-term feeder-free self-renewal of naïve hiPSCs, and also allows direct and timely developmental morphogenesis simply by modulating the signalling environment. Our study opens new perspectives for future applications of naïve hiPSCs to study critical stages of human development in 3D starting from a single cell.
Project description:The establishment of in vitro naïve human pluripotent stem cell cultures opened new perspectives for the study of early events in human development. In the last 5 years the signalling environment promoting human naïve pluripotency has been extensively investigated. However, little is known about the role exerted by the extracellular matrix and three-dimensional organization in naïve maintenance. Here, by using an unbiased and integrated approach we found that naïve, but not primed, hiPSC colonies are characterized by an extracellular matrix-rich microenvironment, and by a specific extracellular matrix fingerprint at transcriptional, proteomic and secretome levels. Based on this, we developed a 3D culture system which supports robust long-term feeder-free expansion of naïve hiPSCs. In this same 3D ECM-rich environment, we can recapitulate timely developmental morphogenesis simply by modulating the signalling environment. Our study opens new perspectives for future applications of naïve hiPSCs to study critical stages of human development in three-dimensions starting from a single cell.
Project description:The establishment of in vitro naïve human pluripotent stem cell cultures opened new perspectives for the study of early events in human development. The role of several transcription factors and signaling pathways during maintenance of human naïve pluripotency has been characterized. However, little is known about the role exerted by the extracellular matrix and its three-dimensional organization. Here, using an unbiased and integrated approach combining transcriptional, proteomic and secretome analyses, we found that naïve, but not primed, hiPSC colonies are characterized by a self-organized extracellular matrix (ECM)-rich microenvironment. Based on this, we developed a 3D culture system that supports robust long-term feeder-free self-renewal of naïve hiPSCs, and also allows direct and timely developmental morphogenesis simply by modulating the signalling environment. Our study opens new perspectives for future applications of naïve hiPSCs to study critical stages of human development in 3D starting from a single cell
Project description:The establishment of in vitro naïve human pluripotent stem cell cultures opened new perspectives for the study of early events in human development. The role of several transcription factors and signaling pathways during maintenance of human naïve pluripotency has been characterized. However, little is known about the role exerted by the extracellular matrix and its three-dimensional organization. Here, using an unbiased and integrated approach combining transcriptional, proteomic and secretome analyses, we found that naïve, but not primed, hiPSC colonies are characterized by a self-organized extracellular matrix (ECM)-rich microenvironment. Based on this, we developed a 3D culture system that supports robust long-term feeder-free self-renewal of naïve hiPSCs, and also allows direct and timely developmental morphogenesis simply by modulating the signalling environment. Our study opens new perspectives for future applications of naïve hiPSCs to study critical stages of human development in 3D starting from a single cell
Project description:The establishment of in vitro naïve human pluripotent stem cell cultures opened new perspectives for the study of early events in human development. In the last 5 years the signalling environment promoting human naïve pluripotency has been extensively investigated. However, little is known about the role exerted by the extracellular matrix and three-dimensional organization in naïve maintenance. Here, by using an unbiased and integrated approach we found that naïve, but not primed, hiPSC colonies are characterized by an extracellular matrix-rich microenvironment, and by a specific extracellular matrix fingerprint at transcriptional, proteomic and secretome levels. Based on this, we developed a 3D culture system which supports robust long-term feeder-free expansion of naïve hiPSCs. In this same 3D ECM-rich environment, we can recapitulate timely developmental morphogenesis simply by modulating the signalling environment. Our study opens new perspectives for future applications of naïve hiPSCs to study critical stages of human development in three-dimensions starting from a single cell.
Project description:It is well established that the expression profiles of multiple and possibly redundant matrix remodeling proteases (e.g. collagenases) strongly differ in health, disease and development. Although enzymatic redundancy might be inferred from their close similarity in structure, their in-vivo activity can lead to extremely diverse tissue-remodeling outcomes. We observed that proteolysis of collagen-rich natural extracellular matrix (ECM), generated uniquely by individual homologous proteases, leads to specific combinatorial events, which eventually affects overall ECM topography, visco-elastic properties and composition. We reveal striking differences in the movement and signaling patterns, morphology, and gene expression profiles of cells interacting with natural collagen-rich ECM degraded by different collagenases. Thus, unlike envisioned before matrix-remodeling systems are not redundant and give rise to precise ECM-cell crosstalk. As ECM proteolysis is an abundant biochemical process critical to tissue homoeostasis, these results improve our fundamental understanding of combinatorial factors dictating cell behavior.
Project description:A critical step in metastasis is cancer cell dissemination. Dissemination and metastasis are associated with specific genetic changes and changes in extracellular matrix (ECM), but how these changes interact to enable dissemination remains unclear. Here we tested the importance of ECM to dissemination in both normal and malignant mammary epithelium. By time-lapse imaging, we observed collective invasion and dissemination directly in 3D culture. Our results reveal that the pattern of epithelial migration and local dissemination are constrained by the local ECM microenvironment. To identify RNA expression changes that could regulate these changes in cell behavior, we conducted whole genome RNA expression profiling from normal and malignant mammary epithelium in 3D culture. We collected RNA from normal and malignant epithelium during active growth at 4 days in culture in either Matrigel or collagen I. We hybridized the resulting RNA to Agilent single color microarrays with a minimum of three biologically independent microarray replicates per condition. We observed significant gene expression differences between normal and malignant epithelium, even when cultured in the same ECM. In contrast, the ECM microenvironment had a relatively small impact on RNA expression, despite its large effects on migratory strategy and local dissemination. Gene expression was measured in normal and malignant mammary epithelial fragments cultured in one of two 3D matrices (laminin-rich basement membrane gel or collagen I) and collected at day 4, which we observed to have peak invasion and dissemination. At least three independent experiments were performed at each time using different mice for each experiment.
Project description:This SuperSeries is composed of the following subset Series: GSE36346: The histone demethylase KDM1A sustains the oncogenic potential of MLL-AF9 leukemia stem cells (ChIP-Seq data) GSE36347: The histone demethylase KDM1A sustains the oncogenic potential of MLL-AF9 leukemia stem cells (expression data) Refer to individual Series
Project description:Corneal endothelial cells (CECs) are critical to maintaining clarity of the cornea. This study was initiated to develop peripheral blood mononuclear cells (PBMC)-originated induced pluripotent stem cells (iPSCs)-derived CECs. We isolated PBMC and programmed the mononuclear cells to generate iPSCs. Subsequently, the PBMC-originated iPSCs were differentiated to CECs. The morphology of differentiating iPSCs was examined at regular intervals by phase contrast microscopy. In parallel, the expression of pluripotent, and CECs-associated markers was investigated by quantitative real-time PCR (qRT-PCR). The molecular architecture of the iPSCs-derived CECs and human corneal endothelium (CE) were examined by mass spectrometry-based proteome sequencing. The PBMC-originated iPSCs expressed pluripotent-specific markers at levels similar to expression in H9 human embryonic stem cells (hESCs). Phase contrast microscopy illustrated that iPSCs-derived CECs are tightly adherent, exhibiting a hexagonal-like shape, one of the cardinal characteristics of CECs. The CECs-associated markers were expressed at many orders of magnitude higher in iPSCs-derived CECs at days 13, 20, and 30 compared to their respective levels in iPSCs. Importantly, only residual expression levels of pluripotency markers were detected in iPSCs-derived CECs. Mass spectrometry-based proteome profiling identified 10,575 proteins in iPSCs-derived CECs. In parallel, we completed proteome profiling of the human CE identifying 6345 proteins. Of these, 5763 proteins were identified in the iPSCs-derived CECs suggesting a 90.82% overlap between the iPSCs-derived CECs and human CE proteomes. Importantly, cryopreservation of iPSCs-derived CECs did not affect the tight adherence of CECs, and their hexagonal-like shape while expressing high levels of CECs-associated markers. We have successfully developed a personalized approach to generate CECs that closely mimic the molecular architecture of the human CE. To the best of our knowledge, this is the first report describing the development of PBMC-originated, iPSCs-derived CECs.