title: "Super p53" mice display retinal astroglial changes.
abstract: Tumour-suppressor genes, such as the p53 gene, produce proteins that inhibit cell division under adverse conditions, as in the case of DNA damage, radiation, hypoxia, or oxidative stress (OS). The p53 gene can arrest proliferation and trigger death by apoptosis subsequent to several factors. In astrocytes, p53 promotes cell-cycle arrest and is involved in oxidative stress-mediated astrocyte cell death. Increasingly, astrocytic p53 is proving fundamental in orchestrating neurodegenerative disease pathogenesis. In terms of ocular disease, p53 may play a role in hypoxia due to ischaemia and may be involved in the retinal response to oxidative stress (OS). We studied the influence of the p53 gene in the structural and quantitative characteristics of astrocytes in the retina. Adult mice of the C57BL/6 strain (12 months old) were distributed into two groups: 1) mice with two extra copies of p53 ("super p53"; n = 6) and 2) wild-type p53 age-matched control, as the control group (WT; n = 6). Retinas from each group were immunohistochemically processed to locate the glial fibrillary acidic protein (GFAP). GFAP+ astrocytes were manually counted and the mean area occupied for one astrocyte was quantified. Retinal-astrocyte distribution followed established patterns; however, morphological changes were seen through the retinas in relation to p53 availability. The mean GFAP+ area occupied by one astrocyte in "super p53" eyes was significantly higher (p<0.05; Student's t-test) than in the WT. In addition, astroglial density was significantly higher in the "super p53" retinas than in the WT ones, both in the whole-retina (p<0,01 Student's t-test) and in the intermediate and peripheral concentric areas of the retina (p<0.05 Student's t-test). This fact might improve the resistance of the retinal cells against OS and its downstream signalling pathways.
authors.affiliation: Instituto de Investigaciones Oftalmológicas "Ramón Castroviejo", Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Salazar
authors.forename: Roberto
authors.initials: R
authors.lastname: Gallego-Pinazo
authors.forename: Rosa
authors.initials: R
authors.lastname: de Hoz
authors.forename: Maria D
authors.initials: MD
authors.lastname: Pinazo-Durán
authors.forename: Blanca
authors.initials: B
authors.lastname: Rojas
authors.forename: Ana I
authors.initials: AI
authors.lastname: Ramírez
authors.forename: Manuel
authors.initials: M
authors.lastname: Serrano
authors.forename: José M
authors.initials: JM
authors.lastname: Ramírez
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology*; D005455:Fluorescent Antibody Technique; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D012160:Retina / Q000473:pathology*; D013194:Staining and Labeling; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D005904:Glial Fibrillary Acidic Protein; D016159:Tumor Suppressor Protein p53