title: X-irradiation reduces the proliferation of astrocytes by cell cycle arrest.
abstract: Reactive astrogliosis is one of the key components of the cellular response to CNS injury and is considered a major impediment to axonal regeneration. Our previous study demonstrated that cell cycle inhibition treatment can reduce astrocyte activation and proliferation in vivo. In this study, we examined whether reactive astrogliosis can be suppressed by X-irradiation in vitro by modulating cell cycle progression. X-irradiation with low dose (4 Gy) suppressed astrocyte proliferation as demonstrated by immunofluorescence staining with BrdU and Ki67 in monolayer astrocyte cultures and those in scratch-wound model. The proportions of BrdU (+) and Ki67 (+) cells at 12, 24, and 48 h after 4 Gy irradiation were significantly lower than those in control group. FACS analysis of monolayer astrocyte cultures showed that X-irradiation decreased the proportion of astrocytes in S phase at 12 and 24h after irradiation with a dose-dependent manner. Furthermore, after X-irradiation, higher levels of p53 were observed by western blot as compared to control astrocyte cultures. Taken together, these data support that X-irradiation can decrease astrogliosis via arresting the cell cycle progression, which might constitute an effective therapeutic intervention in diseases characterized by excessive proliferation of glial cells.
authors.affiliation: Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Wuhan 430030, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.forename: Min-Jie
authors.initials: MJ
authors.lastname: Xie
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Yu
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Qin
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Zhou
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000528:radiation effects*; D015153:Blotting, Western; D002453:Cell Cycle / Q000528:radiation effects*; D049109:Cell Proliferation / Q000528:radiation effects*; D002469:Cell Separation; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005911:Gliosis / Q000517:prevention & control*; D051381:Rats; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000528:radiation effects; D014965:X-Rays
chemical_list: D016159:Tumor Suppressor Protein p53