Identification of microRNAs expressed in the midgut of Aedes albopictus during dengue infection.
The midgut is the first barrier to dengue virus (DENV) infections of mosquitoes and therefore is a major bottleneck for the subsequent development of vector competence. However, the molecular mechanisms responsible for this barrier are unknown.



We constructed three small RNA libraries from the midguts of adult Aedes albopictus females that had been fed on either sugar solution, an uninfected blood meal, or a blood meal infected with DENV-2, and112 conserved microRNAs represented by 173 miRNA sequences were identified, with 34 novel microRNAs predicted by Mireap, RNAfold and Sfold software. In addition, the expression of aal-miR-1174, aal-miR-2951 and aal-miR-956 was confirmed via stem-loop quantitative real-time PCR (qRT-PCR). Compared with microRNA expression profiles of mosquitoes that had ingested a regular blood meal, 43 microRNAs were upregulated and 4were downregulated in mosquitoes that had ingested a DENV-2-infected blood meal. Among the differentially expressed microRNAs, miR-1767, miR-276-3p, miR-4448 and miR-4728-5p were verified via stem-loop qRT-PCR.



Analyses indicated that the changing patterns in miRNA expression during DENV-2 infection were significant and varied at different time points post infection. Most miRNA were upregulated at 24 h but were downregulated at 48 h post DENV-2 intake. The aal-miR-4728-5p was chosen for an in vitro transient transfection assay, and the results show that this miRNA enhances DENV replication in C6/36 cells. This study provides the first information on microRNAs expressed in the midgut of Ae. albopictus and describes species-specific changes in their expression levels following infection by DENV-2.
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.|Center for Disease Control and Prevention of Guangzhou Military Region, Guangzhou, 510507, People's Republic of China.
Jianxin
J
Su
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Chunxiao
C
Li
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Yingmei
Y
Zhang
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Ting
T
Yan
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Xiaojuan
X
Zhu
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Minghui
M
Zhao
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Dan
D
Xing
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
Yande
Y
Dong
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China. guoxx99@163.com.
Xiaoxia
X
Guo
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China. tongyanzhao@126.com.
Tongyan
T
Zhao
D000330:Aedes / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D000818:Animals; D003715:Dengue / Q000635:transmission / Q000821:virology; D003716:Dengue Virus / Q000235:genetics* / Q000502:physiology; D004064:Digestive System / Q000378:metabolism / Q000821:virology; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
D035683:MicroRNAs
Aedes albopictus; Dengue virus (DENV); MicroRNA (miRNA); Midgut