Project description:Fibroblasts can be chemically induced to pluripotent stem cells (CiPSCs) through an extraembryonic endoderm (XEN)-like state or directly converted into other differentiated cell lineages. However, the mechanisms underlying chemically-induced cell fate reprogramming remain unclear. Here, a transcriptome-based screen of biologically active compounds uncovered that CDK8 inhibition was essential to enable chemically-induced reprogramming from fibroblasts into XEN-like cells, then CiPSCs. RNA-seq analysis showed that a CDK8 inhibitor, MSC2530818, inhibited pro-inflammatory pathways that suppress chemical reprogramming, and facilitated the induction of a multi-lineage priming state, indicating the establishment of plasticity in fibroblasts. CDK8 inhibition also resulted in chromatin accessibility profile and Pol II occupation profile similar to that under initial chemical reprogramming. Moreover, CDK8 inhibition greatly promoted transgene-mediated reprogramming of mouse fibroblasts into hepatocyte-like cells, and chemical reprogramming of human fibroblasts into adipocytes. These collective findings thus define CDK8 as a general molecular barrier in multiple cell reprogramming processes, and as a common target for inducing plasticity and cell fate conversion.
Project description:Recent reports have proposed a new paradigm for obtaining mature somatic cell types from fibroblasts without going through a pluripotent state, by briefly expressing canonical iPSC reprogramming factors Oct4, Sox2, Klf4 and c-Myc (abbreviated as OSKM), in cells expanded in lineage differentiation promoting conditions. Here we apply genetic lineage tracing for endogenous Nanog, Oct4 and X chromosome reactivation during OSKM induced trans-differentiation, as these molecular events mark final stages for acquisition of induced pluripotency. Remarkably, the vast majority of reprogrammed cardiomyocytes or neural stem cells derived from mouse fibroblasts via OSKM mediated trans-differentiation were attained after transient acquisition of pluripotency, and followed by rapid differentiation. Our findings underscore a molecular and functional coupling between inducing pluripotency and obtaining “trans-differentiated” somatic cells via OSKM induction, and have implications on defining molecular trajectories assumed during different cell reprogramming methods. poly RNA-Seq and Chromatin accesibility (ATAC-seq) were measured during conversion of mouse embryonic fibroblasts to neural stem cells using OSKM trans-differentiation method, as well as in mouse emrbyonic fibroblasts, iPSCs and mouse ESCs.
Project description:Recent reports have proposed a new paradigm for obtaining mature somatic cell types from fibroblasts without going through a pluripotent state, by briefly expressing canonical iPSC reprogramming factors Oct4, Sox2, Klf4 and c-Myc (abbreviated as OSKM), in cells expanded in lineage differentiation promoting conditions. Here we apply genetic lineage tracing for endogenous Nanog, Oct4 and X chromosome reactivation during OSKM induced trans-differentiation, as these molecular events mark final stages for acquisition of induced pluripotency. Remarkably, the vast majority of reprogrammed cardiomyocytes or neural stem cells derived from mouse fibroblasts via OSKM mediated trans-differentiation were attained after transient acquisition of pluripotency, and followed by rapid differentiation. Our findings underscore a molecular and functional coupling between inducing pluripotency and obtaining “trans-differentiated” somatic cells via OSKM induction, and have implications on defining molecular trajectories assumed during different cell reprogramming methods. WGBS (Whole-Genome-Bisulfite-sequencing) were measured during conversion of mouse embryonic fibroblasts to neural stem cells using OSKM trans-differentiation method, as well as in mouse emrbyonic fibroblasts, and mouse ESCs.
Project description:Expression profiles generated during dissection of the molecular mechanisms underlying direct reprogramming of somatic cells to a pluripotent state (induced pluripotent stem cells, iPS). Experiment Overall Design: 2 technical replicates of B lymphocytes, partially reprogrammed (MCV8, MCV6, BIV1), MEF-iPS(Oct4) and B-iPS(Nanog) cell lines.
Project description:Induced cellular reprogramming to the pluripotent state offers a novel stem cell source for autologous transplantation. While recent studies have explored the role of factors required for induced pluripotent stem cell (iPSC) induction, the cellular and molecular basis of reprogramming from human fibroblasts remains elusive. Here, we have identified a subset of human dermal-derived fibroblasts that shares hallmark molecular and epigenetic features with pluripotent cells. Functional studies demonstrate that these cells contribute to the majority of human iPSCs generated from dermal fibroblasts and are dependent on heterogeneous fibroblast microenvironment for reprogramming competency. Molecular characterization indicated these predisposed fibroblasts were unique to other dermal derived stem cells and possessed features of proliferative selfrenewal. Our study reveals human fibroblasts are not equivalently capable of cellular reprogramming, and suggests that reprogramming factors overcome commitment steps that allow predetermined dermal fibroblasts to establish stable pluripotent state.
Project description:Expression profiles generated during dissection of the molecular mechanisms underlying direct reprogramming of somatic cells to a pluripotent state (induced pluripotent stem cells, iPS). Keywords: Cell type comparison/Timecourse
Project description:Fibroblasts can be chemically induced to pluripotent stem cells (CiPSCs) through an extraembryonic endoderm (XEN)-like state or directly converted into other differentiated cell lineages. However, the mechanisms underlying chemically-induced cell fate reprogramming remain unclear. Here, a transcriptome-based screen of biologically active compounds uncovered that CDK8 inhibition was essential to enable chemically-induced reprogramming from fibroblasts into XEN-like cells, then CiPSCs. RNA-seq analysis showed that a CDK8 inhibitor, MSC2530818, inhibited pro-inflammatory pathways that suppress chemical reprogramming, and facilitated the induction of a multi-lineage priming state, indicating the establishment of plasticity in fibroblasts. CDK8 inhibition also resulted in chromatin accessibility profile and Pol II occupation profile similar to that under initial chemical reprogramming. Moreover, CDK8 inhibition greatly promoted transgene-mediated reprogramming of mouse fibroblasts into hepatocyte-like cells, and chemical reprogramming of human fibroblasts into adipocytes. These collective findings thus define CDK8 as a general molecular barrier in multiple cell reprogramming processes, and as a common target for inducing plasticity and cell fate conversion.
Project description:Fibroblasts can be chemically induced to pluripotent stem cells (CiPSCs) through an extraembryonic endoderm (XEN)-like state or directly converted into other differentiated cell lineages. However, the mechanisms underlying chemically-induced cell fate reprogramming remain unclear. Here, a transcriptome-based screen of biologically active compounds uncovered that CDK8 inhibition was essential to enable chemically-induced reprogramming from fibroblasts into XEN-like cells, then CiPSCs. RNA-seq analysis showed that a CDK8 inhibitor, MSC2530818, inhibited pro-inflammatory pathways that suppress chemical reprogramming, and facilitated the induction of a multi-lineage priming state, indicating the establishment of plasticity in fibroblasts. CDK8 inhibition also resulted in chromatin accessibility profile and Pol II occupation profile similar to that under initial chemical reprogramming. Moreover, CDK8 inhibition greatly promoted transgene-mediated reprogramming of mouse fibroblasts into hepatocyte-like cells, and chemical reprogramming of human fibroblasts into adipocytes. These collective findings thus define CDK8 as a general molecular barrier in multiple cell reprogramming processes, and as a common target for inducing plasticity and cell fate conversion.