title: Loss of H3K9me3 Correlates with ATM Activation and Histone H2AX Phosphorylation Deficiencies in Hutchinson-Gilford Progeria Syndrome.
abstract: Compelling evidence suggests that defective DNA damage response (DDR) plays a key role in the premature aging phenotypes in Hutchinson-Gilford progeria syndrome (HGPS). Studies document widespread alterations in histone modifications in HGPS cells, especially, the global loss of histone H3 trimethylated on lysine 9 (H3K9me3). In this study, we explore the potential connection(s) between H3K9me3 loss and the impaired DDR in HGPS. When cells are exposed to a DNA-damaging agent Doxorubicin (Dox), double strand breaks (DSBs) are generated that result in the phosphorylation of histone H2A variant H2AX (gammaH2AX) within an hour. We find that the intensities of gammaH2AX foci appear significantly weaker in the G0/G1 phase HGPS cells compared to control cells. This reduction is associated with a delay in the recruitment of essential DDR factors. We further demonstrate that ataxia-telangiectasia mutated (ATM) is responsible for the amplification of gammaH2AX signals at DSBs during G0/G1 phase, and its activation is inhibited in the HGPS cells that display significant loss of H3K9me3. Moreover, methylene (MB) blue treatment, which is known to save heterochromatin loss in HGPS, restores H3K9me3, stimulates ATM activity, increases gammaH2AX signals and rescues deficient DDR. In summary, this study demonstrates an early DDR defect of attenuated gammaH2AX signals in G0/G1 phase HGPS cells and provides a plausible connection between H3K9me3 loss and DDR deficiency.
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.
authors.forename: Haoyue
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.
authors.forename: Linlin
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.|Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD, United States of America.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.
authors.forename: Mason
authors.initials: M
authors.lastname: Trappio
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.
authors.forename: Celeste
authors.initials: C
authors.lastname: Witting
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States of America.
authors.forename: Kan
authors.initials: K
authors.lastname: Cao
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D004249:DNA Damage; D059766:DNA End-Joining Repair; D004317:Doxorubicin / Q000494:pharmacology; D004789:Enzyme Activation; D005347:Fibroblasts / Q000378:metabolism; D017353:Gene Deletion; D056726:Genetic Association Studies; D006657:Histones / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D011371:Progeria / Q000235:genetics*
chemical_list: D006657:Histones; D004317:Doxorubicin; D064007:Ataxia Telangiectasia Mutated Proteins