title: Bystander autophagy mediated by radiation-induced exosomal miR-7-5p in non-targeted human bronchial epithelial cells.
abstract: Radiation-induced bystander effect (RIBE) describes a set of biological effects in non-targeted cells that receive bystander signals from the irradiated cells. RIBE brings potential hazards to adjacent normal tissues in radiotherapy, and imparts a higher risk than previously thought. Excessive release of some substances from irradiated cells into extracellular microenvironment has a deleterious effect. For example, cytokines and reactive oxygen species have been confirmed to be involved in RIBE process via extracellular medium or gap junctions. However, RIBE-mediating signals and intercellular communication pathways are incompletely characterized. Here, we first identified a set of differentially expressed miRNAs in the exosomes collected from 2 Gy irradiated human bronchial epithelial BEP2D cells, from which miR-7-5p was found to induce autophagy in recipient cells. This exosome-mediated autophagy was significantly attenuated by miR-7-5p inhibitor. Moreover, our data demonstrated that autophagy induced by exosomal miR-7-5p was associated with EGFR/Akt/mTOR signaling pathway. Together, our results support the involvement of secretive exosomes in propagation of RIBE signals to bystander cells. The exosomes-containing miR-7-5p is a crucial mediator of bystander autophagy.
authors.affiliation: School of Radiation Medicine and Protection, Medical College of Soochow University, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P R China.|Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Man
authors.initials: M
authors.lastname: Song
authors.affiliation: Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Radiation Medicine and Protection, Medical College of Soochow University, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P R China.
authors.forename: Zeng-Fu
authors.initials: ZF
authors.lastname: Shang
authors.affiliation: Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Liu
authors.affiliation: Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Da-Fei
authors.initials: DF
authors.lastname: Xie
authors.affiliation: Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Hua
authors.initials: H
authors.lastname: Guan
authors.affiliation: School of Radiation Medicine and Protection, Medical College of Soochow University, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, P R China.|Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P R China.
authors.forename: Ping-Kun
authors.initials: PK
authors.lastname: Zhou
mesh_terms: D001343:Autophagy / Q000502:physiology*; D001980:Bronchi / Q000378:metabolism*; D024201:Bystander Effect / Q000502:physiology*; D002460:Cell Line; D004847:Epithelial Cells / Q000378:metabolism*; D055354:Exosomes / Q000378:metabolism*; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D011839:Radiation, Ionizing; D015398:Signal Transduction / Q000502:physiology
chemical_list: D035683:MicroRNAs; C549242:MIRN7-1 microRNA, human