M6PR interacts with the HA2 subunit of influenza A virus to facilitate the fusion of viral and endosomal membranes

Influenza A virus(IAV) commandeers numerous host cellular factors for successful replication. However, very few host factors have been revealed to be involved in the fusion of viral envelope and late endosomal membranes. In this study, we identified cation-dependent mannose-6-phosphate receptor(M6PR) as a crucial host factor for the replication of IAV. We found that siRNA knockdown of M6PR expression significantly reduced the growth titers of different subtypes of IAV, and that the inhibitory effect of M6PR siRNA treatment on IAV growth was overcome by the complement of exogenously expressed M6PR. When A549 cells were treated with siRNA targeting M6PR,the nuclear accumulation of viral nucleoprotein(NP) was dramatically inhibited at early timepoints post-infection, indicating that M6PR engages in the early stage of the IAV replication cycle. By investigating the role of M6PR in the individual entry and post-entry steps of IAV replication, we found that the downregulation of M6PR expression had no effect on attachment, internalization, early endosome trafficking,or late endosome acidification. However, we found that M6PR expression was critical for the fusion of viral envelope and late endosomal membranes. Of note, M6PR interacted with the hemagglutinin(HA) protein of IAV, and further studies showed that the lumenal domain of M6PR and the ectodomain of HA2 mediated the interaction and directly promoted the fusion of the viral and late endosomal membranes,thereby facilitating IAV replication. Together, our findings highlight the importance of the M6PR–HA interaction in the fusion of viral and late endosomal membranes during IAV replication.

Fast Zn^(2+)mobility enabled by sucrose modified Zn^(2+)solvation structure for dendrite-free aqueous zinc battery

Aqueous zinc battery has been regarded as one of the most promising energy storage systems due to its low cost and environmental benignity.However,the safety concern on Zn anodes caused by uncontrolled Zn dendrite growth in aqueous electrolyte hinders their application.Herein,sucrose with multi-hydroxyl groups has been introduced into aqueous electrolyte to modify Zn^(2+)solvation environment and create a protection layer on Zn anode,thus effectively retarding the growth of zinc dendrites.Atomistic simulations and experiments confirm that sucrose molecules can enter into the solvation sheath of Zn^(2+),and the as-formed unique solvation structure enhances the mobility of Zn^(2+).Such fast Zn^(2+)kinetics in sucrose-modified electrolyte can successfully suppress the dendrite growth.With this sucrose-modified aqueous electrolyte,Zn/Zn symmetric cells present more stable cycle performance than those using pure aqueous electrolyte;Zn/C cells also deliver an impressive higher energy density of 129.7 Wh·kg^(−1)and improved stability,suggesting a great potential application of sucrose-modified electrolytes for future Zn batteries.

Inhalation treatment of primary lung cancer using liposomal curcumin dry powder inhalers

Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low water solubility, poor bioavailability and rapid metabolism significantly limits clinical applications. Here we developed a liposomal curcumin dry powder inhaler(LCD) for inhalation treatment of primary lung cancer. LCDs were obtained from curcumin liposomes after freeze-drying. The LCDs had a mass mean aerodynamic diameter of 5.81 μm and a fine particle fraction of 46.71%, suitable for pulmonary delivery. The uptake of curcumin liposomes by human lung cancer A549 cells was markedly greater and faster than that of free curcumin. The high cytotoxicity on A549 cells and the low cytotoxicity of curcumin liposomes on normal human bronchial BEAS-2B epithelial cells yielded a high selection index partly due to increased cell apoptosis. Curcumin powders, LCDs and gemcitabine were directly sprayed into the lungs of rats with lung cancer through the trachea. LCDs showed higher anticancer effects than the other two medications with regard to pathology and the expression of many cancer-related markers including VEGF, malondialdehyde, TNF-α, caspase-3 and BCL-2. LCDs are a promising medication for inhalation treatment of lung cancer with high therapeutic efficiency.

Influenza A virus use of BinCARD1 to facilitate the binding of viral NP to importinα7 is counteracted by TBK1-p62 axis-mediated autophagy

As a major component of the viral ribonucleoprotein(vRNP)complex in influenza A virus(IAV),nucleoprotein(NP)interacts with isoforms of importinαfamily members,leading to the import of itself and vRNP complex into the nucleus,a process pivotal in the replication cycle of IAV.In this study,we found that BinCARD1,an isoform of Bcl10-interacting protein with CARD(BinCARD),was leveraged by IAV for efficient viral replication.BinCARD1 promoted the nuclear import of the vRNP complex and newly synthesized NP and thus enhanced vRNP complex activity.Moreover,we found that BinCARD1 interacted with NP to promote NP binding to importinα7,an adaptor in the host nuclear import pathway.However,we also found that BinCARD1 promoted RIG-I-mediated innate immune signaling by mediating Lys63-linked polyubiquitination of TRAF3,and that TBK1 appeared to degrade BinCARD1.We showed that BinCARD1 was polyubiquitinated at residue K103 through a Lys63 linkage,which was recognized by the TBK1-p62 axis for autophagic degradation.Overall,our data demonstrate that IAV leverages BinCARD1 as an important host factor that promotes viral replication,and two mechanisms in the host defense system are triggered—innate immune signaling and autophagic degradation—to mitigate the promoting effect of BinCARD1 on the life cycle of IAV.