title: Overexpression of miR-26b-5p regulates the cell cycle by targeting CCND2 in GC-2 cells under exposure to extremely low frequency electromagnetic fields.
abstract: The increasing prevalence of extremely low frequency electromagnetic fields (ELF-EMFs) exposure has raised considerable public concern regarding the potential hazardous effects of ELF-EMFs on male reproductive function. Increasing evidence indicates that miRNAs are necessary for spermatogenesis and male fertility. However, the regulation of miRNA expression and the roles of miRNAs in response to ELF-EMFs remain unclear. In our study, mouse spermatocyte-derived GC-2 cells were intermittently exposed to a 50 Hz ELF-EMF for 72 h (5 min on/10 min off) at magnetic field intensities of 1 mT, 2 mT and 3 mT. MiR-26b-5p was differentially expressed in response to different magnetic field intensities of ELF-EMFs. The host gene CTDSP1 showed an unmethylation status in GC-2 cells at different magnetic field intensities of ELF-EMF exposure. MiR-26b-5p had no significant, obvious influence on the cell viability, apoptosis or cell cycle of GC-2 cells. However, the overexpression of miR-26b-5p significantly decreased the percentage of G0/G1 phase cells and slightly increased the percentage of S phase cells compared to the sham group that was exposed to a 50 Hz ELF-EMF. Computational algorithms identified Cyclin D2 (CCND2) as a direct target of miR-26b-5p. MiR-26b-5p and a 50 Hz ELF-EMF altered the expression of CCND2 at both the mRNA and protein levels. Overexpressed miR-26b-5p in GC-2 cells can change the mRNA expression of CCND2 following 50 Hz ELF-EMF at 3 mT. These findings demonstrate that miR-26b-5p could serve as a potential biomarker following 50 Hz ELF-EMF exposure, and miR-26b-5p-CCND2-mediated cell cycle regulation might play a pivotal role in the biological effects of ELF-EMFs.
authors.affiliation: a College of Bioengineering, Chongqing University , Chongqing , China.|b Institute of Toxicology, College of Preventive Medicine, Third Military Medical University , Chongqing , China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: b Institute of Toxicology, College of Preventive Medicine, Third Military Medical University , Chongqing , China.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Liu
authors.affiliation: b Institute of Toxicology, College of Preventive Medicine, Third Military Medical University , Chongqing , China.
authors.forename: Kai-Jun
authors.initials: KJ
authors.lastname: Liu
authors.affiliation: b Institute of Toxicology, College of Preventive Medicine, Third Military Medical University , Chongqing , China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ao
authors.affiliation: b Institute of Toxicology, College of Preventive Medicine, Third Military Medical University , Chongqing , China.
authors.forename: Jia
authors.initials: J
authors.lastname: Cao
authors.affiliation: a College of Bioengineering, Chongqing University , Chongqing , China.
authors.forename: Julia Li
authors.initials: JL
authors.lastname: Zhong
authors.affiliation: b Institute of Toxicology, College of Preventive Medicine, Third Military Medical University , Chongqing , China.
authors.forename: Jin-Yi
authors.initials: JY
authors.lastname: Liu
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D056742:Cyclin D2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004574:Electromagnetic Fields; D059585:G1 Phase Cell Cycle Checkpoints / Q000528:radiation effects; D051379:Mice; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D020413:3' Untranslated Regions; C486196:Ccnd2 protein, mouse; D056742:Cyclin D2; D035683:MicroRNAs; C543693:Mirn26 microRNA, mouse; D016376:Oligonucleotides, Antisense; D010749:Phosphoprotein Phosphatases
keywords: CCND2; cell cycle; extremely low frequency electromagnetic fields; miR-26b-5p; reproductive toxicity