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Updated: Sep 28, 2025
RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes
Published on: July 14, 2012
Coupled small molecules target RNA interference and JAK/STAT signaling to reduce Zika virus infection in Aedes
Chasity E Trammell1, Gabriela Ramirez2, Irma Sanchez-Vargas2
1School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America.
Abstract:
The recent global Zika epidemics have revealed the significant threat that mosquito-borne viruses pose. There are currently no effective vaccines or prophylactics to prevent Zika virus (ZIKV) infection. Limiting exposure to infected mosquitoes is the best way to reduce disease incidence. Recent studies have focused on targeting mosquito reproduction and immune responses to reduce transmission. Previous work has evaluated the effect of insulin signaling on antiviral JAK/STAT and RNAi in vector mosquitoes. Specifically, insulin-fed mosquitoes resulted in reduced virus replication in an RNAi-independent, ERK-mediated JAK/STAT-dependent mechanism. In this work, we demonstrate that targeting insulin signaling through the repurposing of small molecule drugs results in the activation of both RNAi and JAK/STAT antiviral pathways. ZIKV-infected Aedes aegypti were fed blood containing demethylasterriquinone B1 (DMAQ-B1), a potent insulin mimetic, in combination with AKT inhibitor VIII. Activation of this coordinated response additively reduced ZIKV levels in Aedes aegypti. This effect included a quantitatively greater reduction in salivary gland ZIKV levels up to 11 d post-bloodmeal ingestion, relative to single pathway activation. Together, our study indicates the potential for field delivery of these small molecules to substantially reduce virus transmission from mosquito to human. As infections like Zika virus are becoming more burdensome and prevalent, understanding how to control this family of viruses in the insect vector is an important issue in public health.
Insights
Repurposing drugs to target mosquito insulin signaling activates antiviral pathways, significantly reducing Zika virus (ZIKV) replication and transmission potential. This offers a novel public health strategy against mosquito-borne diseases.
Area of Science:
- Vector-borne disease control
- Mosquito immunology
- Viral pathogenesis
Background:
- Zika virus (ZIKV) epidemics highlight the threat of mosquito-borne viruses.
- No current vaccines or prophylactics exist for ZIKV infection.
- Targeting mosquito reproduction and immune responses is crucial for reducing disease transmission.
Purpose of the Study:
- To investigate the potential of repurposing small molecule drugs to activate antiviral pathways in mosquitoes.
- To evaluate the combined effect of targeting insulin signaling on ZIKV replication in Aedes aegypti.
- To assess the impact on ZIKV levels in salivary glands for transmission potential.
Main Methods:
- Mosquitoes (Aedes aegypti) infected with ZIKV were fed blood containing demethylasterriquinone B1 (DMAQ-B1) and AKT inhibitor VIII.
- Insulin signaling pathways and antiviral responses (RNAi and JAK/STAT) were analyzed.
- ZIKV levels in whole mosquitoes and salivary glands were quantified over time.
Main Results:
- Targeting insulin signaling with DMAQ-B1 and AKT inhibitor VIII activated both RNAi and JAK/STAT antiviral pathways.
- Combined drug treatment additively reduced ZIKV levels in Aedes aegypti.
- A quantitatively greater reduction in salivary gland ZIKV was observed up to 11 days post-feeding compared to single pathway activation.
Conclusions:
- Repurposing small molecule drugs to modulate insulin signaling offers a promising strategy to control ZIKV in the insect vector.
- This approach can substantially reduce ZIKV transmission from mosquitoes to humans.
- Understanding and manipulating insect vector immunity is critical for public health in the face of emerging infectious diseases.
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