Rapid phosphorylation of histone H2A.X following ionotropic glutamate receptor activation
- 16 May 2006
- journal article
- research article
- Published by Wiley in European Journal of Neuroscience
- Vol. 23 (9), 2351-2361
- https://doi.org/10.1111/j.1460-9568.2006.04768.x
Abstract
Excessive activation of ionotropic glutamate receptors increases oxidative stress, contributing to the neuronal death observed following neurological insults such as ischemia and seizures. Post‐translational histone modifications may be key mediators in the detection and repair of damage resulting from oxidative stress, including DNA damage, and may thus affect neuronal survival in the aftermath of insults characterized by excessive glutamate release. In non‐neuronal cells, phosphorylation of histone variant H2A.X (termed γ‐H2AX) occurs rapidly following DNA double‐strand breaks. We investigated γ‐H2AX formation in rat cortical neurons (days in vitro 14) following activation of N‐methyl‐d‐aspartate (NMDA) or α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazolepropionic acid (AMPA)/kainate glutamate receptors using fluorescent immunohistochemical techniques. Moreover, we evaluated the co‐localization of γ‐H2AX ‘foci’ with Mre11, a double‐strand break repair protein, to provide further evidence for the activation of this DNA damage response pathway. Here we show that minimally cytotoxic stimulation of ionotropic glutamate receptors was sufficient to evoke γ‐H2AX in neurons, and that NMDA‐induced γ‐H2AX foci formation was attenuated by pretreatment with the antioxidant, Vitamin E, and the intracellular calcium chelator, BAPTA‐AM. Moreover, a subset of γ‐H2AX foci co‐localized with Mre11, indicating that at least a portion of γ‐H2AX foci is damage dependent. The extent of γ‐H2AX induction following glutamate receptor activation corresponded to the increases we observed following conventional DNA damaging agents [i.e. non‐lethal doses of gamma‐radiation (1 Gy) and hydrogen peroxide (10 µm)]. These data suggest that insults not necessarily resulting in neuronal death induce the DNA damage‐evoked chromatin modification, γ‐H2AX, and implicate a role for histone alterations in determining neuronal vulnerability following neurological insults.Keywords
This publication has 62 references indexed in Scilit:
- An epigenetic code for DNA damage repair pathways?Biochemistry and Cell Biology, 2005
- Replication protein A and γ-H2AX foci assembly is triggered by cellular response to DNA double-strand breaksExperimental Cell Research, 2004
- γ-H2AX Expression Pattern in Non-Irradiated Neonatal Mouse Germ Cells and after Low-Dose γ-Radiation: Relationships Between Chromatid Breaks and DNA Double-Strand Breaks1Biology of Reproduction, 2004
- MGLuR5 activation reduces β‐amyloid‐induced cell death in primary neuronal cultures and attenuates translocation of cytochrome c and apoptosis‐inducing factorJournal of Neurochemistry, 2004
- Assessment of histone H2AX phosphorylation induced by DNA topoisomerase I and II inhibitors topotecan and mitoxantrone and by the DNA cross‐linking agent cisplatinCytometry Part A, 2004
- Neurodegenerative diseases and oxidative stressNature Reviews Drug Discovery, 2004
- The role of p53 in determining sensitivity to radiotherapyNature Reviews Cancer, 2003
- Elevated DNA double strand breaks and apoptosis in the CNS of scid mutant miceCell Death & Differentiation, 2001
- Requirement for Atm in Ionizing Radiation-Induced Cell Death in the Developing Central Nervous SystemScience, 1998
- Oxidative stress aspects of the cytotoxicity of carbamide peroxide: in vitro studiesToxicology Letters, 1995