Disentangling the role of PI3K/Akt, Rho GTPase and the actin cytoskeleton on dengue virus infection

• Published in: Virus research 2018-09, Vol.256, p.153-165
• Main Authors: Cuartas-López, Alexandra Milena, Hernández-Cuellar, Camilo Eduardo, Gallego-Gómez, Juan Carlos
• Format: Article
• Language: English
• Subjects: Actin cytoskeleton; Actin Cytoskeleton - metabolism; Animals; Blotting, Western; Cell Line; Cercopithecus aethiops; Dengue virus; Dengue Virus - growth & development; Enzyme Inhibitors - metabolism; Epithelial Cells - virology; Gene Knockdown Techniques; Hepatocytes - virology; Host-Pathogen Interactions; Humans; Microscopy, Fluorescence; Phosphatidylinositol 3-Kinases - metabolism; PI3K/Akt signaling; Proto-Oncogene Proteins c-akt - metabolism; rho GTP-Binding Proteins - metabolism; Rho GTPases; Signal Transduction; Viral Load; Viral replication
• ISSN: 0168-1702; 1872-7492
• DOI: 10.1016/j.virusres.2018.08.013

•DENV-2 infection induces AKT phosphorylation with consequent activation of RhoGTPases and actin reorganization in Huh7 cells.•Blocking this signal pathway in three levels PI3K-AKT, RhoGTPases and actin microfilaments, produces crucial effects in DENV-2 virus infection.•The Inhibition of PI3K-Akt decrease viral titer, and changes in perinuclear redistribution of Envelope viral protein.•DENV-2 viral infection decreased are coincident with colocalization of actin microfilaments with Envelope viral protein.•PI3K-Akt signaling pathways are related with RhoGTPases, in the remodeling of the actin cytoskeleton on DENV-2 infection. Infection generated by Dengue Virus (DENV) does not have a specific pharmacologic treatment. Therefore, it is necessary to investigate research strategies departing from traditional approaches. Studying cellular mechanisms during early DENV infection may allow the design of a host-based approach to antivirals. Herein, we describe early/late events of DENV infection in mammalian cells related to PI3K/Akt, Rho GTPases, and the actin cytoskeleton. To evaluate whether PI3K/Akt/Rho GTPases and the actin cytoskeleton participate in DENV replication in Huh7 cells, chemical and genetic inhibition were performed over 24 h.p.i., including early (1–12 h.p.i.) and late (12–24 h.p.i.) infection. Effects were evidenced by quantification of viral titers, activation of kinases assayed by western blot and In-Cell Western and subcellular patterns registered by quantitative fluorescence microscopy. DENV infections induced activation of PI3K/Akt with concomitant reorganization of the actin cytoskeleton, which was confirmed using specific chemical inhibitors. Additionally, inhibition of PI3K/Akt/Rho GTPases and actin microfilaments significantly reduced new viral progeny. Blocking the downstream effectors (ROCK and Rac1) of this pathway mimicked the cellular phenotype of PI3K/Akt/Rho GTPases inhibition. Furthermore, blockage of the final executor (i.e., actin) of this cellular process in infected cells also elicited molecular and viral effects. Finally, combined PI3K/Akt inhibition and Rho GTPases knockdown (Rac1, Rac2 and Cdc42), showed a similar effect on DENV-2 titer to that observed by individual treatment. Taken together, these findings suggest that the PI3K/Akt pathway is involved in DENV-2 infection in a Rho GTPase- and actin-dependent manner and that DENV-2 uses this signaling cascade to efficiently replicate in cells.