Expression of non-structural-1A binding protein in lung epithelial cells is modulated by miRNA-548an on exposure to influenza A virus

Abstract

Understanding the host response to influenza A virus infection is essential for developing intervention approaches. We show that infection of human alveolar epithelial cells and human bronchial epithelial cells with influenza A for 3 h resulted in down-regulation of host hsa-miRNA-548an (miRNA-548an) which triggered the overexpression of influenza non-structural-1A binding protein (IVNS1ABP, herein referred to as NS1ABP). Reduced NS1ABP mRNA and NS1ABP protein expression after transfection of miRNA-548an mimic or increased NS1ABP mRNA and NS1ABP protein expression after transfection of miRNA-548an inhibitor provided evidence that miRNA-548an is involved in the regulation of NS1ABP. Transfection of cells with inhibitor led to reduced apoptosis of infected cells while transfection of mimic led to increased apoptosis and reduced influenza copy number suggesting that NS1ABP has a role in viral maintenance. Thus, miRNA-548an may be an important target in controlling the early stage infection of influenza A.

ICAM-1 regulates the survival of influenza virus in lung epithelial cells during the early stages of infection

“…Subsequently, cells were washed with PBS, and fixed with 4% methanol-free formaldehyde (Polysciences Inc., Warrington, PA). Immunofluorescent staining was done as described earlier (Othumpangat et al, 2013) and stained with rabbit anti-ICAM1 antibody (Millipore, Billerica, MA) for 1 h, followed by Alexa-488 conjugated anti-rabbit secondary antibody and Phalloidin (Life Technologies). The slides were mounted with DAPI-Prolong Gold anti-fade reagent (Life Technologies) and protected with cover slips.…”

MicroRNA Regulation of RNA Virus Replication and Pathogenesis

“…For example, influenza virus infection has been shown to downregulate miR-24 in A549 cells leading to increased furin protease levels and, thus, increased cleavage of the influenza hemagglutinin protein, leading to increased numbers of infectious influenza particles [68] . Also in A549 cells, influenza virus downregulation of miR-548an was shown to lead to increased NS1-binding protein levels and increased RNA stability by decreasing cellular apoptosis [69] . In another study EV71 infection increased miR-141 levels in human rhabdomyosarcoma cells, leading to the downregulation of eukaryotic translation initiation factor 4E protein and thus contributing to the switch from cap-dependent translation of cellular mRNAs to cap-independent translation of virus RNAs [70] .…”

Lung epithelial cells resist influenza A infection by inducing the expression of cytochrome c oxidase VIc which is modulated by miRNA 4276

“…In our previous studies (Othumpangat et al, 2013), we found that infection with influenza virus induced apoptosis. We examined 4 apoptotic pathway genes associated with the intrinsic pathway, and found caspase-9 level was significantly ( p <0.01) increased in HBEpC cells infected with either H1N1 or H3N2 (Fig.…”

“…Previous studies from our laboratory (Othumpangat et al, 2013) have shown that the levels of influenza non-structural 1A binding protein (IVNS1ABP) changed significantly in A549 cells exposed to influenza virus for 3 h. Examining early stage infection addresses the primary response of the host cells in defending the invading virus. MicroRNA expression profiling using locked nucleic acid (LNA) based miRNA array on A549 cells infected with influenza virus (MOI 3) showed significantly lower expression of several miRNAs in infected cells (Fig.…”