Temporal transcriptomics and molecular dynamics identify a serine-type endopeptidase as a key regulator of dengue virus infection in Aedes aegypti

Abstract

The dengue virus (DENV), a major global pathogen causing over 400 million annual infections, relies on the mosquito Aedes aegypti as its primary vector. Intriguingly, A. aegypti sustains persistent DENV infection without exhibiting apparent pathology, indicating a highly adapted and regulated host-virus relationship. However, the temporal gene expression dynamics that govern this finely balanced interaction remain poorly understood. We performed a comprehensive transcriptomic analysis using 12 paired-end RNA-seq datasets from gene expression omnibus (GEO; GSE222893), comparing naive and DENV-infected A. aegypti samples at Days 1, 2, and 7 post-infection. A robust bioinformatics pipeline (STAR [->] FeatureCounts [->] DESeq2 [->] g:Profiler) was employed to identify differentially expressed genes (DEGs), explore functional annotations, and resolve temporal patterns via principal component analysis. Finally, a molecular dynamics simulation (MDS) was performed to check the molecular stability of the highly expressed gene. Our temporal analysis identified LOC5570687, a gene encoding a serine-type endopeptidase, as the most significantly differentially expressed transcript across all infection time points. Functional annotation confirmed its role in proteolysis, implicating it in the cleavage of flaviviral polyproteins, a critical step in viral replication. Principal component analysis revealed distinct transcriptional divergence at Day 1, immune modulation at Day 2, and convergence by Day 7--marking virion maturation. Downregulation of LOC5570687 in DENV-exposed mosquitoes was temporally associated with enhanced viral replication, indicating its potential role as a molecular switch between antiviral defense and viral exploitation. A 100 ns MDS was proof of the structural stability, compactness, and dynamic properties of the highly expressed protein. This study uncovers the temporally dynamic transcriptional landscape of A. aegypti during DENV infection and the serine-type endopeptidase LOC5570687 as a critical regulator of viral pathogenesis. These findings provide a molecular framework for understanding vector competence and propose the LOC5570687 as a promising target for vector-based intervention strategies to disrupt DENV transmission.