Liyuan Sun1,2, Liangjing Chen1, Lina Bai1, Yongpeng Xia1, Xiaobo Yang1, Wei Jiang3, Wenjun Sun1,3. 1. a Bioelectromagnetics Key Laboratory, Zhejiang University School of Medicine , Hangzhou , China. 2. b The Second Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou , China. 3. c Institute of Environmental Medicine, Zhejiang University School of Medicine , Hangzhou , China.
Abstract
PURPOSE: Exposure to extremely low frequency electromagnetic fields (ELF-EMFs) could elicit biological effects including carcinogenesis. However, the detailed mechanisms by which these ELF-EMFs interact with biological system are currently unclear. Previously, we found that a 50-Hz magnetic field (MF) exposure could induce epidermal growth factor receptor (EGFR) clustering and phosphorylation on cell membranes. In the present experiment, the possible roles of reactive oxygen species (ROS) in MF-induced EGFR clustering were investigated. MATERIALS AND METHODS: Human amnion epithelial (FL) cells were exposed to a 50-Hz MF with or without N-acetyl-l-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC). EGFR clustering on cellular membrane surface was analyzed using confocal microscopy after indirect immunofluorescence staining. The intracellular ROS level and acid sphingomyelinase (ASMase) activity were detected using an ROS assay kit and an Amplex® Red Sphingomyelinase Assay Kit, respectively. RESULTS: Results showed that exposure of FL cells to a 50-Hz MF at 0.4 mT for 15 min significantly enhanced the ROS level, induced EGFR clustering and increased ASMase activity. However, pretreatment with NAC or PDTC, the scavenger of ROS, not only counteracted the effects of a 50-Hz MF on ROS level and AMS activity, but also inhibited the EGFR clustering induced by MF exposure. CONCLUSIONS: The present and previous data suggest that ROS mediates the MF-induced EGFR clustering via ASMase activation.
PURPOSE: Exposure to extremely low frequency electromagnetic fields (ELF-EMFs) could elicit biological effects including carcinogenesis. However, the detailed mechanisms by which these ELF-EMFs interact with biological system are currently unclear. Previously, we found that a 50-Hz magnetic field (MF) exposure could induce epidermal growth factor receptor (EGFR) clustering and phosphorylation on cell membranes. In the present experiment, the possible roles of reactive oxygen species (ROS) in MF-induced EGFR clustering were investigated. MATERIALS AND METHODS:Human amnion epithelial (FL) cells were exposed to a 50-Hz MF with or without N-acetyl-l-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC). EGFR clustering on cellular membrane surface was analyzed using confocal microscopy after indirect immunofluorescence staining. The intracellular ROS level and acid sphingomyelinase (ASMase) activity were detected using an ROS assay kit and an Amplex® Red Sphingomyelinase Assay Kit, respectively. RESULTS: Results showed that exposure of FL cells to a 50-Hz MF at 0.4 mT for 15 min significantly enhanced the ROS level, induced EGFR clustering and increased ASMase activity. However, pretreatment with NAC or PDTC, the scavenger of ROS, not only counteracted the effects of a 50-Hz MF on ROS level and AMS activity, but also inhibited the EGFR clustering induced by MF exposure. CONCLUSIONS: The present and previous data suggest that ROS mediates the MF-induced EGFR clustering via ASMase activation.
Entities:
Keywords:
50-Hz magnetic field; acid sphingomyelinase (ASMase); epidermal growth factor receptor; reactive oxygen species (ROS)
Authors: Jemima Ho; Don N Wickramasinghe; Spyridoula-Angeliki Nikou; Bernhard Hube; Jonathan P Richardson; Julian R Naglik Journal: Cells Date: 2020-03-12 Impact factor: 6.600