title: Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells.
abstract: Autophagy is one of the major processes involved in the degradation of intracellular materials. Here, we examined the potential impact of heavy ion irradiation on the induction of autophagy in irradiated C2C12 mouse myoblasts and their non-targeted bystander cells. In irradiated cells, ultrastructural analysis revealed the accumulation of autophagic structures at various stages of autophagy (i.e. phagophores, autophagosomes and autolysosomes) within 20 min after irradiation. Multivesicular bodies (MVBs) and autolysosomes containing MVBs (amphisomes) were also observed. Heavy ion irradiation increased the staining of microtubule-associated protein 1 light chain 3 and LysoTracker Red (LTR). Such enhanced staining was suppressed by an autophagy inhibitor 3-methyladenine. In addition to irradiated cells, bystander cells were also positive with LTR staining. Altogether, these results suggest that heavy ion irradiation induces autophagy not only in irradiated myoblasts but also in their bystander cells.
authors.affiliation: Department of Anatomy, Division of Bioregulatory Medicine, Graduate School of Medicine, Gunma University, Maebashi, Gunma 371-8511, Japan.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Hino
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamada
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tajika
authors.forename: Tomoo
authors.initials: T
authors.lastname: Funayama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Morimura
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakashita
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yokota
authors.forename: Kana
authors.initials: K
authors.lastname: Fukamoto
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Mutou
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yorifuji
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D024201:Bystander Effect / Q000528:radiation effects*; D002460:Cell Line; D020450:Heavy Ions; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D057146:Multivesicular Bodies; D032446:Myoblasts / Q000528:radiation effects* / Q000648:ultrastructure
chemical_list: D008869:Microtubule-Associated Proteins; C025946:3-methyladenine; D000225:Adenine