Project description:The two vertebrate Gsk-3 isoforms, Gsk-3a and Gsk-3b, are encoded by distinct genetic loci and exhibit mostly redundant function in murine embryonic stem cells (ESCs). Here we report that deletion of both Gsk-3a and Gsk-3b in mouse ESCs results in significant changes in gene expression. In contrast, deletion of either Gsk-3a or Gsk-3b individually had little effect on gene expression. These data support the notion that Gsk-3 isoforms are functionally redundant in embryonic stem cells. In addition, we did not find the expected upregulation of known Wnt target genes. Our data suggests that Gsk-3-meidated regulation of gene expression in embryonic stem cells is complex, and likely involves affects on numerous signaling pathways. The study was designed to examine the changes in gene expression between wild-type, Gsk-3a-/-, Gsk-3b-/-, and Gsk-3a-/-;Gsk-3b-/- mouse embryonic stem cells.
Project description:Decitabine (DEC) has a known DNA demethylating activity but also cause cytotoxicity through DNA damage. The two differing mechanisms of action confound studies investigating the effect of DNA demethylation in cancer treatment. The novel DNA methyltransferase 1 specific inhibitor GSK-3685032 causes loss of DNA methylation without DNA damage and offers the possibility to examine the molecular consequences of global loss of DNA methylation. EM-seq was used to evaluate the DNA demethylating effects of DEC and GSK-3685032 in LOUCY and SUP-T1 cells treated with 10 nM Decitabine for 3 days or 300 nM of GSK-3685032 for 3 and 7 days.
Project description:The two vertebrate Gsk-3 isoforms, Gsk-3a and Gsk-3b, are encoded by distinct genetic loci and exhibit mostly redundant function in murine embryonic stem cells (ESCs). Here we report that deletion of both Gsk-3a and Gsk-3b in mouse ESCs results in misregulated expression of imprinted genes and hypomethylation of corresponding imprinted loci. Treatment of wild-type ESCs with small molecule inhibitors of Gsk-3 phenocopies the DNA hypomethylation of imprinted loci observed in Gsk-3 null ESCs. We provide evidence that DNA hypomethylation in Gsk-3 null ESCs is due to a reduction in the levels of the de novo DNA methyltransferase, Dnmt3a2. Gsk-3 activity serves as a node for several signal transduction pathways, and its regulation of Dnmt3a2 expression raises the possibility that DNA methylation could be transiently affected by different types of environmental stimuli. Our data suggest that modulating Gsk-3 activity could have further reaching effects in the regulation of the epigenome. Keywords: Gene expression array-based The study was designed to examine the changes in gene expression between wild-type and Gsk-3a-/-;Gsk-3b-/- mouse embryonic stem cells.