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Nucleoporin 50 (Nup50) is a component of nuclear basket in nuclear pore complex. It includes three main domains: N domain binding to importin α, F domain binding to importin β and R domain binding to Ran. The N domain has two importin α-binding segments. There are mainly two models for explaining the role of Nup50 in nuclear import: tri-stable switch and disassemble-recycle model. Nup50 not only participates in nuclear import, but also regulates genome organization and gene expression. In addition, Nup50 is involved in the process of viral infection and replication. There is some evidence that Nup50 is related to hepatitis B virus and human immunodeficiency virus 1 infections. However, there are few researches on the relationship between Nup50 and viral infection. This article summarized the progress in the function of Nup50 and its relationship with viral infection, aiming to provide new ideas for the following in-depth study.
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The global pandemic of COVID-19 caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection confers great threat to the public health. Human breastmilk is an extremely complex with nutritional composition to nourish infants and protect them from different kinds of infection diseases and also SARS-CoV-2 infection. Previous studies have found that breastmilk exhibited potent antiviral activity against SARS-CoV-2 infection. However, it is still unknown which component(s) in the breastmilk is responsible for its antiviral activity. Here, we identified Lactoferrin (LF), MUC1 and -Lactalbumin (-LA) from human breastmilk by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and in vitro confirmation that inhibited SARS-CoV-2 infection and analyzed their antiviral activity using the SARS-CoV-2 pseudovirus system and transcription and replication-competent SARS-CoV-2 virus-like-particles (trVLP) in the Huh7.5, Vero E6 and Caco-2-N cell lines. Additionally, we found that LF and MUC1 could inhibit viral attachment, entry and post-entry replication, while -LA just inhibit viral attachment and entry. Importantly, LF, MUC1 and -LA possess potent antiviral activities towards not only wild-type but also variants such as B.1.1.7 (alpha), B.1.351 (beta), P.1 (gamma) and B.1.617.1 (kappa). Moreover, LF from other species (e.g., bovine and goat) is still capable of blocking viral attachment to cellular heparan sulfate. Taken together, our study provided the first line of evidence that human breastmilk components (LF, MUC1 and -LA) are promising therapeutic candidates warranting further development or treatingVID-19 given their exceedingly safety levels.
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ObjectiveTo investigate the potential mechanism of serum N-glycan alterations in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) by measuring serum N-glycan profile and comparing glycosyltransferase gene expression between HCC tissue and adjacent tissue. MethodsThe samples of HCC tissue, adjacent tissue, and normal liver tissue were collected from 34 patients with HBV-related HCC who were admitted to Chinese PLA General Hospital, and serum samples were also collected. Among these 34 patients, 8 were randomly selected and their serum samples were established as HCC experimental group, and the serum samples of 20 healthy adults were established as control group. DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis was used to analyze serum N-glycan profile in the HCC experimental group and the control group. Quantitative real-time PCR was used to measure the mRNA expression of 8 glycosyltransferase genes (FUT3, FUT4, FUT6, FUT7, FUT8, Gn-TIII, Gn-TIVa, and Gn-TV) in the HCC tissue and adjacent tissue of 34 patients with HBV-related HCC, and Western blot was used to measure the expression of corresponding proteins. The independent samples t-test was used for comparison of continuous data between two groups. ResultsCompared with the control group, the HCC experimental group had a significant increase in the abundance of N-glycan peak9 (NA3Fb) in serum(t=-2.514,P＜0.05). There were significant differences in the mRNA expression of FUT8, Gn-TIVa, and Gn-TV between HCC tissue and adjacent tissue, and the mRNA and protein expression levels of FUT8 and Gn-TV in HCC tissue were significantly higher than those in adjacent tissue (FUT8 mRNA: 1.50±0.34 vs 0.65±0.11, t=-2.354，P=0.022; Gn-TV mRNA: 3.57±0.64 vs 1.33±016, t=-3.384,P=0001; FUT8 protein: 0.70±0.11 vs 0.083±0.017, t=9.555,P=0.001; Gn-TV protein: 1.33±0.19 vs 0.60±0.15, t=5.097,P=0.007). The mRNA expression level of Gn-TIVa in HCC tissue was significantly higher than that in adjacent tissue (2.90±0.47 vs 1.68±0.19, t=-2.403,P=0.019), but there was no significant difference in the protein expression level of Gn-TIVa between HCC tissue and adjacent tissue (052±0.24 vs 0.24±0.11,t=1.833, P=0.141). The changes of glycosyltransferase gene expression in HCC tissue were consistent with the alteration of serum N-glycan profile. ConclusionSerum N-glycan alterations in patients with HBV-related HCC may be closely associated with the upregulated expression of the glycosyltransferase genes FUT8, Gn-TIVa, and Gn-TV in HCC tissue.
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Since the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in several somatic cells, little is known about the infection of SASRS-CoV-2 and its related pangolin coronavirus (GX_P2V). Here we present for the first time that SARS-CoV-2 pseudovirus and GX_P2V could infect lung progenitor and even anterior foregut endoderm cells causing these cells death, which differentiated from human embryonic stem cells (hESCs). The infection and replication of SARS-CoV-2 and GX_P2V were inhibited when treated with whey protein of breastmilk and Remdesivir, confirming that these two viruses could infect lung progenitor and even anterior foregut endoderm. Moreover, we found that SARS-CoV-2 pseudovirus could infect endoderm and ectoderm. We found that whey protein blocked SARS-CoV-2 infecting these cells. In line with the SARS-CoV-2 results, GX_P2V could also infected endoderm and ectoderm, and also was inhibited by Remdesivir treatment. Although expressing coronavirus related receptor such as ACE2 and TMPRSS2, mesoderm cells are not permissive for SARS-CoV-2 and GX_P2V infection, which needed further to study the mechanisms. Interestingly, we also found that hESCs, which also express ACE2 and TMPRSS2 markers, are permissive for GX_P2V but not SARS-CoV-2 pseudovirus infection and replication, indicating the widespread cell types for GX_P2V infection. Heparin treatment blocked efficiently viral infection. These results provided insight that these stem cells maybe provided a stable repository of coronavirus function or genome. The potential consequence of SARS-CoV-2 and animal coronavirus such as GX_P2V infection in hESCs, germ layer and induced progenitors should be closely monitored.
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Since the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human breastmilk, little is known about the antiviral property of human breastmilk to SARS-CoV-2 and its related pangolin coronavirus (GX_P2V). Here we present for the first time that whey protein from human breastmilk effectively inhibited both SARS-CoV-2 and GX_P2V by blocking viral attachment, entry and even post-entry viral replication. Moreover, human whey protein inhibited infectious virus production proved by the plaque assay. We found that whey protein from different species such as cow and goat also showed anti-coronavirus properties. And commercial bovine milk also showed similar activity. Interestingly, the main antimicrobial components of breastmilk, such as Lactoferrin and IgA antibody, showed limited anti-coronavirus activity, indicating that other factors of breastmilk may play the important anti-coronavirus role. Taken together, we reported that whey protein inhibits SARS-CoV-2 and its related virus of GX_P2V. These results rule out whey protein as a direct-acting inhibitor of SARS-CoV-2 and GX_P2V infection and replication and further investigation of its molecular mechanism of action in the context of COVID-19.
