Project description:AlkB homolog 1 (ALKBH1) is one of nine members of the AlkB homologs in mammals. Most Alkbh1-deficient mice die during embryonic development, and survivors have severe defects in tissues originating from the ectodermal lineage. We hypothesized the phenotype to rely upon aberrant epigenetic regulation and provided evidence for ALKBH1 to be a histone H2A demethylase. We used a whole genome expression microarray to detail differentially expressed genes in embryonic stem cells lacking the Alkbh1 gene and identified distinct classes of up- and down-regulated genes during this process.
Project description:AlkB homolog 1 (ALKBH1) is one of nine members of the AlkB homologs in mammals. Most Alkbh1-deficient mice die during embryonic development, and survivors have severe defects in tissues originating from the ectodermal lineage. We hypothesized the phenotype to rely upon aberrant epigenetic regulation and provided evidence for ALKBH1 to be a histone H2A demethylase. We used a whole genome expression microarray to detail differentially expressed genes in embryonic stem cells lacking the Alkbh1 gene and identified distinct classes of up- and down-regulated genes during this process. Wild type and Alkbh-/- embryonic stem cells were established to identify differentially expressed genes at day 0, undifferentiated cells. We sought to obtain a subset of genes possibly explaining the observed phenotype. Total RNA was extracted and hybridized on Affymetrix GeneChips. 3 parallels were analyzed from each of the two genotypes.
Project description:DNA N6-methyladenosine (6mA) in eukaryotic genomes has recently been observed in diverse species. 6mA has been reported to associate with multiple physiological processes including embryonic development and tumorigenesis, and ALKBH1 is a primary 6mA demethylase in mouse and human cells. To research the roles of 6mA and its putative regulators such as putative ALKBH1 in the homeostatic maintenance of human stem cells and their differentiated derivatives, We generated ALKBH1-deficient human embryonic stem cells (hESCs) via CRISPR/Cas9-mediated non-homologous end joining (NHEJ). We next differentiated ALKBH1+/+ and ALKBH1-/- hESCs into human mesenchymal stem cells (hMSCs) and vascular smooth muscle cells (hVSMCs). Early-onset growth arrest of ALKBH1-/- hMSCs was observed, and increased apoptosis and enhanced migration ability were observed in ALKBH1-/- hVSMCs. However, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis revealed no change in 6mA levels between ALKBH1+/+ and ALKBH1-/- hESCs, between ALKBH1+/+ and ALKBH1-/- hMSCs, and between ALKBH1+/+ and ALKBH1-/- hVSMCs, respectively. These data demonstrate that depletion of ALKBH1 exerts minimal impact on 6mA levels in hESCs and their differentiated derivatives and that ALKBH1 regulates the homeostasis of hMSCs and hVSMCs possibly in a DNA 6mA-independent manner.
