Rotavirus-Induced Early Activation of the RhoA/ROCK/MLC Signaling Pathway Mediates the Disruption of Tight Junctions in Polarized MDCK Cells

Abstract

Intestinal epithelial tight junctions (TJ) are a major barrier restricting the entry of various harmful factors including pathogens; however, they also represent an important entry portal for pathogens. Although the rotavirus-induced early disruption of TJ integrity and targeting of TJ proteins as coreceptors are well-defined, the precise molecular mechanisms involved remain unknown. In the present study, infection of polarized MDCK cells with the species A rotavirus (RVA) strains human DS-1 and bovine NCDV induced a redistribution of TJ proteins into the cytoplasm, a reversible decrease in transepithelial resistance, and an increase in paracellular permeability. RhoA/ROCK/MLC signaling was identified as activated at an early stage of infection, while inhibition of this pathway prevented the rotavirus-induced early disruption of TJ integrity and alteration of TJ protein distribution. Activation of pMYPT, PKC, or MLCK, which are known to participate in TJ dissociation, was not observed in MDCK cells infected with either rotavirus strain. Our data demonstrated that binding of RVA virions or cogent VP8* proteins to cellular receptors activates RhoA/ROCK/MLC signaling, which alters TJ protein distribution and disrupts TJ integrity via contraction of the perijunctional actomyosin ring, facilitating virion access to coreceptors and entry into cells.

Meningitic Escherichia coli Induction of ANGPTL4 in Brain Microvascular Endothelial Cells Contributes to Blood–Brain Barrier Disruption via ARHGAP5/RhoA/MYL5 Signaling Cascade

“…ARHGAP5 is a proto-oncogene that encodes Rho GTPase-activating protein 5, a main negative regulator of the Rho-dependent signaling processes which participates in multiple cellular processes such as cell adhesion, migration, invasion, and cytokinesis [31]. In contrast, the MLC proteins are reported to be the key downstream effector of RhoA signaling [41,45]. Via regulating RhoA signaling activity, the expression of ARHGAP5 in cells was shown to affect actin cytoskeleton-based stress fibers formation [31], and this actin cytoskeleton rearrangement or movement has been evidenced in our previous work to lead to alteration of cell permeability [46].…”

The actin cytoskeleton is important for rotavirus internalization and RNA genome replication

“…Since it has been reported that rotavirus requires JAM-A, occludin and ZO-1 for entry into MA104 cells (Torres-Flores et al, 2015), it is possible that Cdc42 and RhoA could improve rotavirus internalization through their influence on the tight junction establishment. A recent study by Soliman et al supports this last hypothesis; they demonstrated that RhoA/Rock signaling is modulated by rotavirus, disrupting tight junctions integrity to enter cells (Soliman et al, 2018). Further studies are necessary, however, to determine the mechanisms involved, and how these GTPases regulate these cellular pathways.…”

Alteration of cell junctions during viral infection

“…39 Meanwhile, MDCKII cells were infected with RV through the basal surface, suggesting that this area harbors RV receptors. 40 The primary site of RV infection is along the edge of intestinal epithelial cells. 41,42 The binding of the RV coat protein viral protein 8 to receptors located on the intestinal cell surface leads to the destruction of tight junctions by activating the host cell RhoA/ROCK / MLC signaling pathway, which stimulates the translocation of viral receptors from the basolateral to the apical surface and further increases RV invasion.…”

“…In Caco‐2 cells, the distribution of the tight junction proteins occludin and claudin‐1 was altered by incubation with RV . Meanwhile, MDCKII cells were infected with RV through the basal surface, suggesting that this area harbors RV receptors . The primary site of RV infection is along the edge of intestinal epithelial cells .…”