title: Drosha, DGCR8, and Dicer mRNAs are down-regulated in human cells infected with dengue virus 4, and play a role in viral pathogenesis.
abstract: Dengue virus (DENV) and its four serotypes (DENV1-4) belong to the Flavivirus genus of the Flaviviridae family. DENV infection is a life-threatening disease, which results in up to 20,000 deaths each year. Viruses have been shown to encode trans-regulatory small RNAs, or microRNAs (miRNAs), which bind to messenger RNA and negatively regulate host or viral gene expression. During DENV infections, miRNAs interact with proteins in the RNAi pathway, and are processed by ribonucleases such as Dicer and Drosha. This study aims to investigate Drosha, DGCR8, and Dicer expression levels in human A-549 cells following DENV4 infection. DENV4 infected A-549 cells were collected daily for 5 days, and RNA was extracted to quantify viral load. Gene expression of Drosha, Dicer, and DGCR8 was determined using quantitative PCR (RT-qPCR). We found that DENV4 infection exhibited the highest viral load 3 days post-infection. Dicer, Drosha, and DGCR8 showed reduced expression following DENV4 infection as compared with negative controls. In addition, we hypothesize that reduced expression of DGCR8 may not only be related to miRNA biogenesis, but also other small RNAs. This study may change our understanding regarding the relationship between host cells and the dengue virus.
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: S M M
authors.initials: SM
authors.lastname: Casseb
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: D B
authors.initials: DB
authors.lastname: Simith
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: K F L
authors.initials: KF
authors.lastname: Melo
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: M H
authors.initials: MH
authors.lastname: Mendonça
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: A C M
authors.initials: AC
authors.lastname: Santos
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: V L
authors.initials: VL
authors.lastname: Carvalho
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: A C R
authors.initials: AC
authors.lastname: Cruz
authors.affiliation: Seção de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
authors.forename: P F C
authors.initials: PF
authors.lastname: Vasconcelos
mesh_terms: D000072283:A549 Cells; D053487:DEAD-box RNA Helicases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D003715:Dengue / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D003716:Dengue Virus / Q000235:genetics* / Q000472:pathogenicity*; D015536:Down-Regulation; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D016601:RNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D019562:Viral Load
chemical_list: C474043:DGCR8 protein, human; D035683:MicroRNAs; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C408087:DICER1 protein, human; C517918:DROSHA protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases