title: Upregulation of miR-34a-5p antagonizes AFB1-induced genotoxicity in F344 rat liver.
abstract: Aflatoxin B1 (AFB1) is a well-known human hepatotoxicant and genotoxicant. Recent studies demonstrated that aberrant miRNA expression patterns were correlated with the cellular and genetic lesions induced by chemicals. To explore the role of miRNAs in AFB1-induced hepatotoxicity and genotoxicity, we examined alterations in miRNA expression patterns in F334 rat livers after exposure to 100 μg/kg or 200 μg/kg AFB1 for 28 days. Using high-throughput sequencing, we discovered that rno-miR-34a-5p, rno-miR-200b-3p, and rno-miR-429 were up-regulated and that rno-miR-130a-3p was down-regulated in liver tissue from rats that received 200 μg/kg of AFB1; this finding was validated by real-time PCR. AFB1 treatment resulted in the upregulation of rno-miR-34a-5p and rno-miR-200b-3p in the rat H-4-II-E cell line similar to our in vivo observations. Moreover, rno-miR-34a-5p was transcriptionally elevated via p53 activation after AFB1 exposure. Upregulation of rno-miR-34a-5p suppressed the expression of the cell cycle-related genes CCND1, CCNE2 and MET and led to cell cycle arrest in the G0-G1 phase. The CBMN assay indicated that inhibition of rno-miR-34a-5p and p53 expression aggravated the DNA damage induced by AFB1, which might be associated with shortening of the DNA damage repair period. Circulating miR-34a-5p in rat sera preceded a significant increase in ALT activity and other miRNAs in the 100 μg/kg AFB1 group. These observations demonstrated that rno-miR-34a-5p responded sensitively to AFB1 exposure and facilitated p53 repair of DNA damage by impacting the cell cycle. Thus, circulating rno-miR-34a-5p may be a sensitive indicator for the induction of hepatic genotoxicity by AFB1 in rats.
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China; Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong Province, China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Liu
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China; Department of Hospital Infection Control, The First Affiliated Hospital of Jinan University, Guangzhou, China.
authors.forename: Haohui
authors.initials: H
authors.lastname: Yu
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Daochuan
authors.initials: D
authors.lastname: Li
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Xing
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Chen
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Xu
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Qiming
authors.initials: Q
authors.lastname: Fan
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Chen
authors.affiliation: Faculty of Preventive Medicine, A Key Laboratory of Guangzhou Environmental Pollution and Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou, China. Electronic address: wangq27@mail.sysu.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
mesh_terms: D016604:Aflatoxin B1 / Q000037:antagonists & inhibitors* / Q000633:toxicity; D000818:Animals; D015415:Biomarkers / Q000097:blood; D045744:Cell Line, Tumor; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D019927:Cyclin E / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects; D020869:Gene Expression Profiling; D008099:Liver / Q000187:drug effects*; D035683:MicroRNAs / Q000097:blood / Q000235:genetics / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; C530106:Ccnd1 protein, rat; C503690:Ccne2 protein, rat; D019927:Cyclin E; C560944:MIRN34 microRNA, rat; D035683:MicroRNAs; D016159:Tumor Suppressor Protein p53; D019938:Cyclin D1; D016604:Aflatoxin B1
keywords: Aflatoxin B1; DNA damage; Genotoxicity; P53; miR-34a-5p