Project description:Expression profiles of 7-day cultured HSPCs in the presence or absence of valproic acid and/or lithium. Two small molecules, valproic acid (VPA) and lithium (Li), were tested to inhibit differentiation of hematopoietic stem/progenitor (HSPC) cells in culture. HSPCs exposed to VPA and Li during differentiation-inducing culture preserved an immature cell phenotype, provided radioprotection to lethally irradiated recipients and enhanced in vivo repopulating potential. Furthermore, VPA and Li synergistically preserved expression of stem cell-related genes and repressed genes involved in differentiation. Target genes were collectively co-regulated during normal hematopoietic differentiation. Additionally, transcription factor networks were identified as possible primary regulators. Our results demonstrate that the combination of VPA and Li potently prevents differentiation at the biological and the molecular level, and provide evidence to suggest that combinatorial screening of chemical compounds may uncover possible additive/synergistic effects to modulate stem cell fate decisions. These data consist of total mRNA obtained from hematopoietic cells cultured for 7 days in the presence or absence of valproic acid and/or lithium. All samples were analyzed in independent biological triplicates.
Project description:Two small molecules, valproic acid (VPA) and lithium (Li), were tested to inhibit differentiation of hematopoietic stem/progenitor (HSPC) cells in culture. HSPCs exposed to VPA and Li during differentiation-inducing culture preserved an immature cell phenotype, provided radioprotection to lethally irradiated recipients and enhanced in vivo repopulating potential. Furthermore, VPA and Li synergistically preserved expression of stem cell-related genes and repressed genes involved in differentiation. Target genes were collectively co-regulated during normal hematopoietic differentiation. Additionally, transcription factor networks were identified as possible primary regulators. Our results demonstrate that the combination of VPA and Li potently prevents differentiation at the biological and the molecular level, and provide evidence to suggest that combinatorial screening of chemical compounds may uncover possible additive/synergistic effects to modulate stem cell fate decisions. These data consist of total mRNA obtained from hematopoietic cells cultured for 7 days in the presence or absence of valproic acid and/or lithium. All samples were analyzed in independent biological triplicates.
Project description:The combination of valproic acid and lithium delays hematopoietic stem\progenitor differentiation Microarray-based microRNA profiling study was peformed of four developmentally related hematopoietic cell types isolated from the BM of B6 and D2 mice. Total RNA isolated from purified LSK multilineage cells, committed LS−K+ cells, erythroid TER-119+ cells and myeloid Gr-1+ cells was hybridized to Single Color Illumina mouse WG-6_V2 mRNA arrays. Triplicates were generated for each of the 8 conditions (4 cell types, 2 mouse strains).
Project description:Two small molecules, valproic acid (VPA) and lithium (Li), were tested to inhibit differentiation of hematopoietic stem/progenitor (HSPC) cells in culture. HSPCs exposed to VPA and Li during differentiation-inducing culture preserved an immature cell phenotype, provided radioprotection to lethally irradiated recipients and enhanced in vivo repopulating potential. Furthermore, VPA and Li synergistically preserved expression of stem cell-related genes and repressed genes involved in differentiation. Target genes were collectively co-regulated during normal hematopoietic differentiation. Additionally, transcription factor networks were identified as possible primary regulators. Our results demonstrate that the combination of VPA and Li potently prevents differentiation at the biological and the molecular level, and provide evidence to suggest that combinatorial screening of chemical compounds may uncover possible additive/synergistic effects to modulate stem cell fate decisions.
Project description:Analysis of the effects of valproic acid (VPA) on chronic myelogenous leukemia K562 cells. This study attempts to elucidate the effects of VPA on cell homeostasis and hematopoietic differentiation pathways in this cell line. We used ten experimental conditions comparing valproic acid-treated and untreated cells at time points 2, 6, 10, 48 and 72 hrs respectively. Experiments were performed in three biological replicates including a dye swap (represented by replicate 3, for each timepoint).
Project description:Analysis of the effects of valproic acid (VPA) on chronic myelogenous leukemia K562 cells. This study attempts to elucidate the effects of VPA on cell homeostasis and hematopoietic differentiation pathways in this cell line.
Project description:Expression profiles of LSK cells stimulated for 24h in the presence or in the absence of of valproic acid (VPA) The molecular process that underlies the biological effects of valproic acid (VPA), a widely used histone deacetylase inhibitor, on HSPCs was investigated by studying the early-response genes of VPA. Genome-wide gene expression studies revealed overrepresentation of genes involved in glutathione metabolism, receptor and signal transducer activity and changes in the HSPCs surface profile following short, 24h VPA treatment. Sca-1, a well-known and widely used stem cell surface marker, was identified as a prominent VPA target.VPA strongly preserved Sca-1 expression on LSK cells, but also re-activated Sca-1 on committed progenitor cells that were Sca-1 negative, thereby reverting them to the LSK phenotype. We demonstrated that re-acquired Sca-1 expression coincided with induced self-renewal capacity as measured by in vitro re-plating assays, while Sca-1 itself was not required for the biological effects of VPA as demonstrated using Sca-1 deficient progenitor cells. We show that VPA can induce several genes involved in signal transduction of which Sca-1 was shown to mark cells with increased self-renewal capacity. These data consist of total mRNA obtained from hematopoietic cells cultured for 24h in the presence or absence of valproic acid. All samples were analyzed in independent biological triplicates.
Project description:Hematopoietic differentiation from human pluripotent stem cell in vitro is an important approach for the research of hematopoietic stem cell regeneration. Small molecules that can maintenance low ROS level and inhibit cell apoptosis or autophagy are benifit for the maintenance or expansion of hematopoietic stem cells. Lipoic acid (ALA) as a small antioxidant molecule can regulate the ROS level and apoptosis of cells. This study found that lipoic acid promoted the production of hemogenic endothelial cells and hematopoietic progenitor cells. Transcriptome analysis of hemogenic endothelial cells showed that ALA upregulated the endothelial to hematopoietic transition (EHT) related genes and downregulated the EHT negative regulated genes. ALA also up-regulated ROS and apoptosis related genes to inhibit the apoptosis of hematopoietic stem/progenitor cells.These results indicated that ALA might have an important role in the regeneration of hematopoietic stem progenitor cell in vitro.