Project description:Myeloproliferative neoplasms (MPN) are a clonal hematological disease which harbors different driver mutations, including JAK2 V617F, and there is clear evidence that MPN is associated with aberrant DNA methylation (DNAm). However, it is unclear whether the driver mutation alone is sufficient to recapitulate the MPN phenotype and the global DNA methylation changes observed in patients. For this purpose, we utilized three established induced pluripotent stem cell (iPSC) clones carrying the JAK2 V617F mutation, both heterozygous and homozygous genotypes along with their wild type (WT) counterparts. These iPSCs were differentiated towards hematopoietic stem and progenitor differentiation (iHPCs) to capture the mutant phenotype. Genome wide methylation analysis of JAK2 mutated iPSCs and iHPCs showed no significant methylation differences compared to wild type cells. The iPSC model only partially recapitulated the DNAm changes observed in patients with JAK2 mutation, suggesting that epigenetic changes are not directly evoked by the driver mutation, but rather accumulate over the course of disease development.
Project description:Reprogramming of somatic cells into induced pluripotent stem cells (iPSC) is an epigenetic phenomenon. It has been suggested that iPSC retain some tissue-specific memory whereas little is known about inter-individual epigenetic variation of iPSC clones. In this study we have reprogrammed mesenchymal stromal cells (MSC) from human bone marrow by retrovirus-mediated overexpression of OCT-3/4, SOX2, c-MYC, and KLF4. Global DNA-methylation profiles of the initial MSC, MSC-derived iPSC (iP-MSC) and embryonic stem cells (ESC) were then compared using a high density DNA-methylation array covering more than 450,000 CpG sites. Overall, DNA-methylation patterns of iP-MSC and ESC were similar whereas some CpG sites revealed highly significant differences, which were not related to parental MSC. Furthermore, hypermethylation in iP-MSC versus ESC was particularly enriched in developmental genes as well as shore regions next to CpG islands indicating that these differences are not due to tissue-specific memory or random de novo methylation. Subsequently, we searched for CpG sites with donor-specific variation in MSC preparations. These “epigenetic fingerprints” were highly enriched in non-promoter regions and outside of CpG islands – and they were maintained upon reprogramming into iP-MSC. In conclusion, DNA methylation profiles of iP-MSC clones from the same donor were closely related despite heterogeneity of MSC. On the other hand, iP-MSC maintain donor-derived epigenetic differences. In the absence of isogenic controls for disease modeling applications, it would therefore be more appropriate to compare iPSC from different donors rather than a high number of different clones from the same patient. 16 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:Currently, cardiomyocytes differentiated from human induced pluripotent stem cells (iPSCs) are routinely generated for disease research and drug development as an alternative to animal models. Although iPSC-derived cardiomyocytes (iPSC-CMs) are generally assumed to resemble myocytes in the fetal heart, a systematic global comparison is still lacking. We established a robust differentiation protocol to generate mature cardiomyocytes from male and female iPSC lines, and investigated their gene expression and splicing profiles, compared to that of human hearts at different stages of development.
Project description:A heterogeneous genetic subtype of B-cell precursor acute lymphoblastic leukemia is driven by constitutive kinase-activation, including patients with JAK2 fusions. In our study, we model the impact of a novel JAK2 fusion protein on hematopoietic development in human induced pluripotent stem cells (hiPSCs). We insert the RUNX1-JAK2 fusion into one endogenous RUNX1 allele through employing in trans paired nicking genome editing. Tagging of the fusion with a degron facilitates protein depletion using the heterobifunctional compound dTAG-13. Throughout in vitro hematopoietic differentiation, the expression of RUNX1-JAK2 is driven by endogenous RUNX1 regulatory elements at physiological levels. Functional analysis reveals that RUNX1-JAK2 knock-in cell lines yield fewer hematopoietic progenitors, due to RUNX1 haploinsufficiency. Nevertheless, these progenitors further differen-tiate toward myeloid lineages to a similar extent as wild-type cells. The expression of the RUNX1-JAK2 fusion protein only elicits subtle effects on myeloid differentiation, and is unable to transform early hematopoietic progenitors. However, phosphoprotein and transcriptome analyses reveal that RUNX1-JAK2 constitutively activates JAK-STAT signaling in differentiating hiPSCs and at the same time upregulates MYC targets—confirming the interaction between these pathways. This proof-of-principle study indicates that conditional expression of oncogenic fusion proteins in combination with hematopoietic differentiation of hiPSCs may be applicable to leukemia-relevant disease modeling.
Project description:Reprogramming of somatic cells into induced pluripotent stem cells (iPSC) is an epigenetic phenomenon. It has been suggested that iPSC retain some tissue-specific memory whereas little is known about inter-individual epigenetic variation of iPSC clones. In this study we have reprogrammed mesenchymal stromal cells (MSC) from human bone marrow by retrovirus-mediated overexpression of OCT-3/4, SOX2, c-MYC, and KLF4. Global DNA-methylation profiles of the initial MSC, MSC-derived iPSC (iP-MSC) and embryonic stem cells (ESC) were then compared using a high density DNA-methylation array covering more than 450,000 CpG sites. Overall, DNA-methylation patterns of iP-MSC and ESC were similar whereas some CpG sites revealed highly significant differences, which were not related to parental MSC. Furthermore, hypermethylation in iP-MSC versus ESC was particularly enriched in developmental genes as well as shore regions next to CpG islands indicating that these differences are not due to tissue-specific memory or random de novo methylation. Subsequently, we searched for CpG sites with donor-specific variation in MSC preparations. These “epigenetic fingerprints” were highly enriched in non-promoter regions and outside of CpG islands – and they were maintained upon reprogramming into iP-MSC. In conclusion, DNA methylation profiles of iP-MSC clones from the same donor were closely related despite heterogeneity of MSC. On the other hand, iP-MSC maintain donor-derived epigenetic differences. In the absence of isogenic controls for disease modeling applications, it would therefore be more appropriate to compare iPSC from different donors rather than a high number of different clones from the same patient.
Project description:Macrophages (Mɸ) are highly heterogenous and versatile innate immune cells involved in homeostatic and immune responses. Activated Mɸ can exist in two extreme phenotypes: pro-inflammatory (M1) and anti-inflammatory (M2) Mɸ and these phenotypes can be recapitulated in vitro by using lipopolysaccharide (LPS) plus IFNγ and IL-4, respectively. In the recent years, human induced pluripotent stem cells (iPSC) derived-Mɸ have gained major attention since they are functionally similar to human monocyte derived-Mɸ and are receptive to genome editing. In this study, we used quantitative proteomics to address whether the plasticity of iPSC-derived Mɸ (iPSDM) are similar to human monocyte derived Mɸ. Our analyses suggest that iPSC Mɸ are promising tools to understand Mɸ biology since they exhibit similar polarisation profiles and functions as monocyte-derived Mɸ. We believe this comprehensive proteome data set will be a useful resource in the Mɸ field.
Project description:Detailed comparison of human pluripotent stem cells, to determine how hESC and iPSC differ in their protein expression profiles. The data was acquired in a TMT 10-plex SPS-MS3. 4 replicates of hESC compared to 4 replicates of HipSci human iPSCs.
Project description:Macrophages (Mɸ) are highly heterogenous and versatile innate immune cells involved in homeostatic and immune responses. Activated Mɸ can exist in two extreme phenotypes: pro-inflammatory (M1) and anti-inflammatory (M2) Mɸ and these phenotypes can be recapitulated in vitro by using lipopolysaccharide (LPS) plus IFNγ and IL-4, respectively. In the recent years, human induced pluripotent stem cells (iPSC) derived-Mɸ have gained major attention since they are functionally similar to human monocyte derived-Mɸ and are receptive to genome editing. We performed quantitative proteomics of culture supernatants to identify soluble factors released from differentially polarised iPSC-derived Mɸ (iPSDM). Our analysis suggests that the cytokine/chemokine profiles released from polarised iPSDM are similar to monocyte-derived Mɸ.
Project description:In this dataset, we determine the global gene expression in human induced pluripotent stem (iPS) cell-derived CD61+ megakaryocytes carrying homozygous JAK2 V617F mutation or the JAK2 wildtype gene.