title: Effects of X-ray and carbon ion beam irradiation on membrane permeability and integrity in Saccharomyces cerevisiae cells.
abstract: Saccharomyces cerevisiae has served as a eukaryotic model in radiation biology studies of cellular responses to ionizing radiation (IR). Research in this field has thus far mainly been focused on DNA strand breaks, DNA base damage, or inhibition of protein activity. However, the effects of IR on S. cerevisiae cell membranes have barely been studied. Here, we investigated the changes in the permeability and integrity of S. cerevisiae cell membranes induced by high-linear energy transfer carbon ion (CI) beam or low-linear energy transfer X-ray. After CI exposure, protein elution and nucleotide diffusion were more pronounced than after X-ray treatment at the same doses, although these features were most prevalent following irradiation doses of 25-175 Gy. Flow cytometry of forward scatter light versus side scatter light and double-staining with fluorescein diacetate and propidium iodide showed that CI and X-ray irradiation significantly affected S. cerevisiae cell membrane integrity and cellular enzyme activity compared with untreated control cells. The extent of lesions in CI-irradiated cells, which exhibited markedly altered morphology and size, was greater than that in X-ray-irradiated cells. The relationships between permeabilized cells, esterase activity, and non-viable cell numbers furthermore indicated that irradiation-induced increases in cell permeabilization and decreases in esterase activity are dependent on the type of radiation and that these parameters correspond well with cell viability. These results also indicate that the patterns of cell inactivity due to X-ray or CI irradiation may be similar in terms of cell membrane damage.
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China School of Pharmacy, Lanzhou University, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China.
authors.forename: Guozhen
authors.initials: G
authors.lastname: Cao
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China.
authors.forename: Jianshun
authors.initials: J
authors.lastname: Miao
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China.
authors.forename: Wenjian
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China.
authors.forename: Jufang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China LD@impcas.ac.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Lu
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lan zhou 730000, China School of Pharmacy, Lanzhou University, Lan zhou 730000, China Key Laboratory of Microbial Resources Exploition and Application, Lan zhou 730000, China.
authors.forename: Jiefang
authors.initials: J
authors.lastname: Xia
mesh_terms: D002244:Carbon; D002463:Cell Membrane Permeability / Q000502:physiology* / Q000528:radiation effects*; D002470:Cell Survival / Q000502:physiology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D020450:Heavy Ions; D011829:Radiation Dosage; D012441:Saccharomyces cerevisiae / Q000502:physiology* / Q000528:radiation effects*; D014965:X-Rays
chemical_list: D002244:Carbon
keywords: Saccharomyces cerevisiae; X-ray; carbon ion; cell membrane permeability; flow cytometry