title: Radiation adaptive response of glial cells.
abstract: There are various types of radiation in space including high energy particles. It is, therefore, becoming to be important to study the low dose and low dose-rate effects in space radiation biology. Radiation adaptive response (RAR) for cell growth and its mechanism were examined using cultured glial cells. The cells from hippocampus of Wistar rats were irradiated with a low dose (0.1 Gy) of X-rays and 3 h after with a high dose (2 Gy). Decrease in the rate of cell growth with 2 Gy was suppressed by the 0.1 Gy preirradiation, when cells were counted 2 days after irradiation. The inhibitors of protein kinase C (PKC) and DNA-dependent protein kinase (DNAPK) or phosphatidylinositol 3-kinase (PI3K) suppressed RAR. The treatment with the activators of PKC instead of 0.1 Gy-preirradiation also caused adaptive response to 2 Gy-irradiation. Moreover, glial cells cultured from severe combined immunodeficiency (scid) mice, which have lost DNAPK activity, and AT-2KY cells, fibroblasts of an ataxia-telangiectasia (AT) patient, showed no RAR. These results indicated that PKC, ATtM, DNAPK and/or PI3K were involved in RAR for growth of cultured glial cells. Proteomics [correction of preteomics] analysis of these cells exposed to low dose irradiation in now underway.
authors.affiliation: Redox Regulation Research Group, Tokyo Metro. Inst. of Gerontol., Tokyo, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Miura
authors.forename: Shozo
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000528:radiation effects; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D004307:Dose-Response Relationship, Radiation; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D051379:Mice; D009457:Neuroglia / Q000187:drug effects / Q000528:radiation effects*; D009687:Nuclear Proteins; D019869:Phosphatidylinositol 3-Kinases / Q000187:drug effects / Q000502:physiology*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D011836:Radiation Tolerance / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D016511:Severe Combined Immunodeficiency
chemical_list: D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C; D017346:Protein Serine-Threonine Kinases; C497263:PRKDC protein, human