@article{10902/26768,
year = {2011},
url = {https://hdl.handle.net/10902/26768},
abstract = {DNA repair protects neurons against spontaneous or disease-associated DNA damage. Dysfunctions of this mechanism underlie a growing list of neurodegenerative disorders. The Purkinje cell (PC) degeneration mutation causes the loss of nna1 expression and is associated with the postnatal degeneration of PCs. This PC degeneration dramatically affects nuclear architecture and provides an excellent model to elucidate the nuclear mechanisms involved in a whole array of neurodegenerative disorders. We used immunocytochemistry for histone variants and components of the DNA damage response, an in situ transcription assay, and in situ hybridization for telomeres to analyze changes in chromatin architecture and function. We demonstrate that the phosphorylation of H2AX, a DNA damage signal, and the trimethylation of the histone H4K20, a repressive mark, in extensive domains of genome are epigenetic hallmarks of chromatin in degenerating PCs. These histone modifications are associated with a large scale reorganization of chromatin, telomere clustering, and heterochromatin-induced gene silencing, all of them key factors in PC degeneration. Furthermore, ataxia telangiectasia mutated and 53BP1, two components of the DNA repair pathway, fail to be concentrated in the damaged chromatin compartments, even though the expression levels of their coding genes were slightly up-regulated. Although the mechanism by which Nna1 loss of function leads to PC neurodegeneration is undefined, the progressive accumulation of DNA damage in chromosome territories irreversibly compromises global gene transcription and seems to trigger PC degeneration and death.},
organization = {This work was supported by Dirección General de Investigación Grant BFU2008-00175, Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas Grant CB06/05/0037 from Instituto de Salud Carlos III, Ministerio de Ciencia y Tecnología Grant BFU2010-18284, Ministerio de Sanidad, Política Social e Igualdad (Plan Nacional Sobre Drogas), Instituto de Formación e Investigación Marqués de Valdecilla Grant FMV/UC09-02, Junta de Castilla y León, and Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León.},
publisher = {American Society for Biochemistry and Molecular Biology Inc.},
publisher = {Journal of Biological Chemistry VOL. 286, NO. 32, pp. 28287-28302},
title = {Purkinje cell degeneration in pcd mice reveals large scale chromatin reorganization and gene silencing linked to defective DNA repair},
author = {Baltanás, Fernando C. and Casafont Parra, Íñigo and Lafarga, Vanesa and Weruaga, Eduardo and Alonso, José R. and Berciano Blanco, María Teresa and Lafarga Coscojuela, Miguel Ángel},
}