Long Noncoding RNA NRAV Promotes Respiratory Syncytial Virus Replication by Targeting the MicroRNA miR-509-3p/Rab5c Axis To Regulate Vesicle Transportation.

Respiratory syncytial virus (RSV) is an enveloped RNA virus which is responsible for approximately 80% of lower respiratory tract infections in children. Current lines of evidence have supported the functional involvement of long noncoding RNA (lncRNA) in many viral infectious diseases. However, the overall biological effect and clinical role of lncRNAs in RSV infection remain unclear. In this study, lncRNAs related to respiratory virus infection were obtained from the lncRNA database, and we collected 144 clinical sputum specimens to identify lncRNAs related to RSV infection. Quantitative PCR (qPCR) detection indicated that the expression of lncRNA negative regulator of antiviral response (NRAV) in RSV-positive patients was significantly lower than that in uninfected patients, but lncRNA psoriasis-associated non-protein coding RNA induced by stress (PRINS), nuclear paraspeckle assembly transcript 1 (NEAT1), and Nettoie Salmonella pas Theiler's (NeST) showed no difference in vivo and in vitro Meanwhile, overexpression of NRAV promoted RSV proliferation in A549 and BEAS-2B cells, and vice versa, indicating that the downregulation of NRAV was part of the host antiviral defense. RNA fluorescent in situ hybridization (FISH) confirmed that NRAV was mainly located in the cytoplasm. Through RNA sequencing, we found that Rab5c, which is a vesicle transporting protein, showed the same change trend as NRAV. Subsequent investigation revealed that NRAV was able to favor RSV production indirectly by sponging microRNA miR-509-3p so as to release Rab5c and facilitate vesicle transportation. The study provides a new insight into virus-host interaction through noncoding RNA, which may contribute to exploring potential antivirus targets for respiratory virus.IMPORTANCE The mechanism of interaction between RSV and host noncoding RNAs is not fully understood. In this study, we found that the expression of long noncoding RNA (lncRNA) negative regulator of antiviral response (NRAV) was reduced in RSV-infected patients, and overexpression of NRAV facilitated RSV production in vitro, suggesting that the reduction of NRAV in RSV infection was part of the host antiviral response. We also found that NRAV competed with vesicle protein Rab5c for microRNA miR509-3p in cytoplasm to promote RSV vesicle transport and accelerate RSV proliferation, thereby improving our understanding of the pathogenic mechanism of RSV infection.

Li J ，Li M ，Wang X ，Sun M ，Ma C ，Liang W ，Gao X ，Wei L ... -  《-》

Long noncoding RNA negative regulator of antiviral response contributes to pancreatic ductal adenocarcinoma progression via targeting miR-299-3p.

Pancreatic ductal cancer (PDAC) has high malignancy and poor prognosis. Long noncoding RNAs (lncRNAs) are associated with high levels of malignancy, including PDAC. However, the biological and clinical significance of negative regulator of antiviral response (NRAV) in PDAC is unclear. To study the regulatory role of lncRNA NRAV in PDAC. GEPIA analyzed lncRNA NRAV and miRNA (miR-299-3p) expression levels in PDAC tissues and measured them in PDAC cells by quantitative measurements in real time. The specific role of NRAV and miR-299-3p in cell proliferation and transfer potential was evaluated by cell formation analysis, Cell Counting Kit-8 and Transwell analysis. The relationship between NRAV and miR-299-3p was studied by predictive bioinformatics, RNA immunoassay, and fluorescence enzyme analysis. In vivo experiments included transplantation of simulated tumor cells under naked mice. The expression level of lncRNA NRAV was higher in both tumor tissues and cell lines of PDAC and was negatively associated with the clinical survival of PDAC patients. Functionally, overexpression of NRAV promoted cell proliferation and metastasis of PDAC cells, while knockdown of NRAV reversed these effects. Finally, NRAV was performed as a molecular sponge of miR-299-3p. Moreover, overexpression of miR-299-3p could reverse the promoting effects of NRAV on cell proliferation and metastasis of PDAC cells. NRAV facilitates progression of PDAC as a molecular sponge of miR-299-3p and may be a potential molecular marker for diagnosis and treatment of PDAC.

Wang HQ ，Qian CH ，Guo ZY ，Li PM ，Qiu ZJ ... -  《-》

Rab5c promotes RSV and ADV replication by autophagy in respiratory epithelial cells.

Wang X ，Cheng J ，Shen L ，Chen M ，Sun K ，Li J ，Li M ，Ma C ，Wei L ... -  《-》

Luteolin inhibits respiratory syncytial virus replication by regulating the MiR-155/SOCS1/STAT1 signaling pathway.

Wang S ，Ling Y ，Yao Y ，Zheng G ，Chen W ... -  《Virology Journal》

Respiratory Syncytial Virus-Induced Oxidative Stress Leads to an Increase in Labile Zinc Pools in Lung Epithelial Cells.

Zinc supplementation in cell culture has been shown to inhibit various viruses, like herpes simplex virus, rotavirus, severe acute respiratory syndrome (SARS) coronavirus, rhinovirus, and respiratory syncytial virus (RSV). However, whether zinc plays a direct antiviral role in viral infections and whether viruses have adopted strategies to modulate zinc homeostasis have not been investigated. Results from clinical trials of zinc supplementation in infections indicate that zinc supplementation may be beneficial in a pathogen- or disease-specific manner, further underscoring the importance of understanding the interaction between zinc homeostasis and virus infections at the molecular level. We investigated the effect of RSV infection on zinc homeostasis and show that RSV infection in lung epithelial cells leads to modulation of zinc homeostasis. The intracellular labile zinc pool increases upon RSV infection in a multiplicity of infection (MOI)-dependent fashion. Small interfering RNA (siRNA)-mediated knockdown of the ubiquitous zinc uptake transporter ZIP1 suggests that labile zinc levels are increased due to the increased uptake by RSV-infected cells as an antiviral response. Adding zinc to culture medium after RSV infection led to significant inhibition of RSV titers, whereas depletion of zinc by a zinc chelator, N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) led to an increase in RSV titers. The inhibitory effect of zinc was specific, as other divalent cations had no effect on RSV titers. Both RSV infection and zinc chelation by TPEN led to reactive oxygen species (ROS) induction, whereas addition of zinc blocked ROS induction. These results suggest a molecular link between RSV infection, zinc homeostasis, and oxidative-stress pathways and provide new insights for developing strategies to counter RSV infection.IMPORTANCE Zinc deficiency rates in developing countries range from 20 to 30%, and zinc supplementation trials have been shown to correct clinical manifestations attributed to zinc deficiency, but the outcomes in the case of respiratory infections have been inconsistent. We aimed at understanding the role of zinc homeostasis in respiratory syncytial virus (RSV) infection. Infection of lung epithelial cell lines or primary small-airway epithelial cells led to an increase in labile zinc pools, which was due to increased uptake of zinc. Zinc supplementation inhibited RSV replication, whereas zinc chelation had an opposing effect, leading to increases in RSV titers. Increases in labile zinc in RSV-infected cells coincided with induction of reactive oxygen species (ROS). Both zinc depletion and addition of exogenous ROS led to enhanced RSV infection, whereas addition of the antioxidant inhibited RSV, suggesting that zinc is part of an interplay between RSV-induced oxidative stress and the host response to maintain redox balance.

Khan NA ，Singla M ，Samal S ，Lodha R ，Medigeshi GR ... -  《mSphere》