title: miR-281, an abundant midgut-specific miRNA of the vector mosquito Aedes albopictus enhances dengue virus replication.
abstract: BACKGROUND
  Emerging evidence indicates that microRNAs (miRNAs) are involved in host-virus interaction. We previously reported that some miRNAs were differentially expressed in sugar-fed and blood-fed females of Aedes albopictus (Ae. albopictus). Here, we analysis the role in the host-virus system of an abundant midgut-specific miRNA in the mosquito Ae. albopictus.
  
  
  METHODS
  The expression profiles of miR-281 in different body parts of Ae. albopictus and following dengue virus infection were determined using RT-qPCR and Northern blot. miR-281 mimics, antagomiRs and corresponding negative controls were designed and their overexpression and knock-down efficiency were analyzed by qRT-PCR after transfecting the mosquito cell lines C6/36, and also by injecting female mosquitoes. Dengue virus serotype-2 (DENV-2) viral genomic RNA abundance was determined by RT-qPCR. The levels of DENV-2 E protein were detected using Western blot. Virus titers were tested using TCID50. RNAhybrid was used to predict targets of miR-281 in the DENV-2 genome. The EGFP plasmid-based reporter system was used to investigate the interaction between miR-281 and the predicted binding site in the C6/36 cell line.
  
  
  RESULTS
  miR-281 is specifically expressed in the female midgut where dengue virus first invades. After DENV-2 infection, this miRNA is up-regulated in response to viral infection. Functional intervention analyses in vitro with specifically designed miR-281 mimics and corresponding antagomiRs indicated that miR-281 enhances DENV-2 viral replication. Further depletion of miR-281 in female mosquitoes by injection of its specific antagomiRs led to a significant reduction in DENV-2 abundance. The interaction between miR-281 and its predicted target sequence, the DENV-2 genomic 5'-untranslated region (UTR), is confirmed in the context of a plasmid-based reporter system.
  
  
  CONCLUSIONS
  These findings confirm that miR-281, an abundant midgut-specific miRNA, facilitates DENV-2 replication.
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. zhou-yuanhe@163.com.
authors.forename: Yanhe
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. muguchencun@163.com.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. yh7346@yeah.net.
authors.forename: Hui
authors.initials: H
authors.lastname: Yan
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. bdlyj06@163.com.
authors.forename: Yiji
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. zhanghao20091001@sina.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. xujiabao007@gmail.com.
authors.forename: Jiabao
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. santhoshpk73@hotmail.com.
authors.forename: Santhosh
authors.initials: S
authors.lastname: Puthiyakunnon
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. xgchen2001@hotmail.com.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Chen
mesh_terms: D000330:Aedes / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D003716:Dengue Virus / Q000502:physiology*; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006790:Host-Parasite Interactions; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D014779:Virus Replication / Q000502:physiology*
chemical_list: D035683:MicroRNAs