Intertwisted superhydrophilic and superhydrophobic collagen fibers enabled anti-fouling high-performance separation of emulsion wastewater.

Oil-contaminated wastewater has been one of the most concerned environmental issues. Superwetting materials-enabled remediation of oil contamination in wastewater faces the critical challenge of fouling problems due to the formation of intercepted phase. Herein, high-performance separation of emulsions wastewater was accomplished by developing collagen fibers (CFs)-derived water-oil dual-channels that were comprised of intertwisted superhydrophilic and superhydrophobic CFs. The dual-channels relied on the superhydrophilic CFs to accomplish efficient demulsifying, which played the role as water-channel to enable fast transportation of water, while the superhydrophobic CFs served as the oil-transport channel to permit oil transportation. The mutual repellency between water-channel and oil-channel was essential to guarantee the stability of established dual-channels. The unique dual-channel separation mechanism fundamentally resolved the intercepted phase-caused fouling problem frequently engaged by the superwetting materials that provided single-channel separation capability. Long-lasting (1440 min) anti-fouling separations were achieved by the superwetting CFs-derived dual-channels with separation efficiency high up to 99.99%, and more than 4-fold of stable separation flux as compared with that of superhydrophilic CFs with single-channel separation capability. Our investigations demonstrated a novel strategy by using superwetting CFs to develop water-oil dual-channels for achieving high-performance anti-fouling separation of emulsions wastewater. ENVIRONMENTAL IMPLICATION: Industrial processes discard a large amount of emulsion wastewater, which seriously imperils the aquatic ecosystem. This work demonstrated a conceptual-new strategy to achieve effective remediation of emulsion wastewater via the water-oil dual-channels established by the intertwisted superhydrophilic and superhydrophobic collagen fibers (CFs). The superhydrophilic CFs enabled efficient demulsification of emulsions and played the role of water-channel for the rapid transportation of water, while the superhydrophobic CFs worked as oil-channel to permit the efficient transportation of oil pollutants. Consequently, the long-term (1440 min) anti-fouling high-performance separation of emulsion wastewater was achieved.

Effectiveness of an integrative programme in reducing hypertension incidence among the population at risk for hypertension: A community-based randomized intervention study in Shanghai, China.

Background: We aimed to evaluate the effectiveness of a community-based integrative programme in reducing hypertension incidence among populations at high risk for hypertension in Shanghai, Eastern China. Methods: We conducted a cluster-randomized intervention trial with a total of 607 participants (intervention, n = 303; control, n = 304) between October 2019 and October 2020. A total of 605 participants (intervention, n = 302; control, n = 303) completed the follow-up survey. The intervention group received an integrative programme that included health education, physician follow-up, and self-management, while the control group received usual care only. We used questionnaires to investigate risk factors, knowledge, attitudes, and behaviours regarding hypertension prevention for all participants at baseline and follow-up. We measured the incidence of hypertension according to the predefined protocol based on the national definition during the four follow-ups (only applicable to the intervention group) and the physical examination at the end of the intervention/programme/study. The difference-in-difference (DID) effects of the intervention were estimated using Generalized Estimating Equations. Results: There were no significant differences in age group, gender, and educational level between intervention and control groups at baseline. The integrative programme reduced the incidence of hypertension in the intervention group compared to the control group (odds ratio (OR) = 0.27, 95% confidence interval (CI) = 0.12-0.61). The DID analysis found that the one-year intervention has improved the level of hypertension-related knowledge and attitudes regarding diagnostic criteria, complications of hypertension, and lifestyle modification (P < 0.05). The intervention was also associated with a 3.7% increase in the behaviour change rate of "not smoking" (OR = 2.50, 95% CI = 1.45-4.30) and a 34.8% increase in the rate of "monitoring blood pressure regularly" (OR = 29.61, 95% CI = 13.02-67.35). Conclusions: The integrative programme could reduce the risk for hypertension and improve the level of hypertension-related knowledge and attitudes, affecting the formation of healthy behaviours in high-risk populations. The community-based management for high-risk groups should be scaled up and incorporated into national hypertension control programmes, which may potentially reduce the substantial burden of hypertension and cardiovascular disease in China. Registration: ISRCTN registration number: ISRCTN74154693.

(cRGD)2 peptides modified nanoparticles increase tumor-targeting therapeutic effects by co-delivery of albendazole and iodine-131.

Albendazole (ABZ), a clinical antiparasitic drug, has shown potential antitumor effects in various tumors. Herein, we prepared dimeric cRGD [(cRGD)2] modified human serum albumin (HSA) nanosystem to co-delivery of albendazole (ABZ) and iodine-131 (131I) for chemoradiotherapy of triple-negative breast cancer (TNBC). HSA@ABZ NPs were synthesized by the self-assembly method. 131I-(cRGD)2/HSA@ABZ NPs were fabricated through covalently binding HSA@ABZ NPs with (cRGD)2 peptides, followed by chloramine T direct labeling with 131I. In vitro therapeutic effects on TNBC (MDA-MB-231 and 4T1 cells) were determined using MTT assay, crystal violet assay, wound-healing assay and western blotting analysis. In vivo treatment was performed using 4T1-bearing mice, and the tumor-targeting efficacy was assessed by gamma imaging. The distribution of NPs was quantitatively analyzed by detecting the gamma counts in tumor and main organs. The nanoparticles possessed negative charge, moderate size and good polydispersity index. Dual responding to pH and redox, the in vitro release rate of ABZ was more than 80% in 72 h. In vitro, NPs inhibited the proliferation of TNBC cells in a concentration-dependent manner and decreased cell migration. Western blotting analysis showed that the NPs, as well as free ABZ, cell-dependently induced autophagy and apoptosis by restraining or promoting the expression of p-p38 and p-JNK MAPK. In vivo, gamma imaging exhibited an earlier and denser radioactivity accumulation in tumor of 131I-(cRGD)2/HSA@ABZ NPs compared to NPs free of (cRGD)2 conjugating. Furthermore, 131I-(cRGD)2/HSA@ABZ NPs significantly suppressed tumor growth by restraining proliferation and promoting apoptosis in vivo. Our study suggested that the nanoparticles we developed enhanced tumor-targeting of ABZ and increased antitumor effects by combination of chemotherapy and radiotherapy.

Low dose inocula of SARS-CoV-2 Alpha variant transmits more efficiently than earlier variants in hamsters.

Emerging variants of SARS-CoV-2 have been shown to rapidly replace original circulating strains in humans soon after they emerged. There is a lack of experimental evidence to explain how these natural occurring variants spread more efficiently than existing strains of SARS-CoV-2 in transmission. We found that the Alpha variant (B.1.1.7) increased competitive fitness over earlier parental D614G lineages in in-vitro and in-vivo systems. Using hamster transmission model, we further demonstrated that the Alpha variant is able to replicate and shed more efficiently in the nasal cavity of hamsters than other variants with low dose and short duration of exposure. The capability to initiate effective infection with low inocula may be one of the key factors leading to the rapid transmission of emerging variants of SARS-CoV-2.

Mammalian cells use the autophagy process to restrict avian influenza virus replication.

Host adaptive mutations in the influenza A virus (IAV) PB2 protein are critical for human infection, but their molecular action is not well understood. We observe that when IAV containing avian PB2 infects mammalian cells, viral ribonucleoprotein (vRNP) aggregates that localize to the microtubule-organizing center (MTOC) are formed. These vRNP aggregates resemble LC3B-associated autophagosome structures, with aggresome-like properties, in that they cause the re-distribution of vimentin. However, electron microscopy reveals that these aggregates represent an accumulation of autophagic vacuoles. Compared to mammalian-PB2 virus, avian-PB2 virus induces higher autophagic flux in infected cells, indicating an increased rate of autophagosomes containing avian vRNPs fusing with lysosomes. We found that p62 is essential for the formation of vRNP aggregates and that the Raptor-interacting region of p62 is required for interaction with vRNPs through the PB2 polymerase subunit. Selective autophagic sequestration during late-stage virus replication is thus an additional strategy for host restriction of avian-PB2 IAV.

TOP1 inhibition therapy protects against SARS-CoV-2-induced lethal inflammation.

The ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently affecting millions of lives worldwide. Large retrospective studies indicate that an elevated level of inflammatory cytokines and pro-inflammatory factors are associated with both increased disease severity and mortality. Here, using multidimensional epigenetic, transcriptional, in vitro, and in vivo analyses, we report that topoisomerase 1 (TOP1) inhibition suppresses lethal inflammation induced by SARS-CoV-2. Therapeutic treatment with two doses of topotecan (TPT), an FDA-approved TOP1 inhibitor, suppresses infection-induced inflammation in hamsters. TPT treatment as late as 4 days post-infection reduces morbidity and rescues mortality in a transgenic mouse model. These results support the potential of TOP1 inhibition as an effective host-directed therapy against severe SARS-CoV-2 infection. TPT and its derivatives are inexpensive clinical-grade inhibitors available in most countries. Clinical trials are needed to evaluate the efficacy of repurposing TOP1 inhibitors for severe coronavirus disease 2019 (COVID-19) in humans.

Corrigendum to "Trend of HIV-1 drug resistance in China: A systematic review and meta-analysis of data accumulated over 17 years (2001-2017)" [EClinicalMedicine 18 (2020) 100238].

[This corrects the article DOI: 10.1016/j.eclinm.2019.100238.].

A Novel 2-dimensional Multiplex qPCR Assay for Single-Tube Detection of Nine Human Herpesviruses.

Human herpesviruses are double-stranded DNA viruses that are classified into nine species. More than 90% of adults are ever infected with one or more herpesviruses. The symptoms of infection with different herpesviruses are diverse ranging from mild or asymptomatic infections to deadly diseases such as aggressive lymphomas and sarcomas. Timely and accurate detection of herpesvirus infection is critical for clinical management and treatment. In this study, we established a single-tube nonuple qPCR assay for detection of all nine herpesviruses using a 2-D multiplex qPCR method with a house-keeping gene as the internal control. The novel assay can detect and distinguish different herpesviruses with 30 to 300 copies per 25 µL single-tube reaction, and does not cross-react with 20 other human viruses, including DNA and RNA viruses. The robustness of the novel assay was evaluated using 170 clinical samples. The novel assay showed a high consistency (100%) with the single qPCR assay for HHVs detection. The features of simple, rapid, high sensitivity, specificity, and low cost make this assay a high potential to be widely used in clinical diagnosis and patient treatment.

Zoledronic acid re­sensitises gefitinib­resistant lung cancer cells by inhibiting the JAK/STAT3 signalling pathway and reversing epithelial­mesenchymal transition.

Studies have shown that suppression of both the JAK/STAT3 pathway and epithelial­mesenchymal transition (EMT) may overturn the resistance of non­small cell lung cancer (NSCLC) cells to gefitinib. Zoledronic acid (ZA) injection is used to treat and prevent multiple forms of osteoporosis, hypercalcemia and bone metastasis­related complications of malignancy. Clinical research has shown that ZA may exert antitumour effects and delay the progression of NSCLC. In the present study, we investigated whether ZA combined with gefitinib could re­sensitise NSCLC cells to gefitinib in vitro and in vivo through inhibition of the JAK/STAT3 signalling pathway and EMT reversal. The results revealed that ZA potently increased the sensitivity of gefitinib­resistant lung cancer cells to gefitinib. ZA decreased activation of JAK/STAT3 signalling and reversed EMT in the H1975 and HCC827GR cell lines. Furthermore, addition of IL­6 to ZA­pretreated gefitinib­resistant cell lines abrogated the effect of ZA and restored the cellular resistance to tyrosine kinase inhibitors. Finally, ZA­based combinatorial therapy effectively inhibited the growth of xenografts derived from gefitinib­resistant cancer cells, which was correlated with the inhibition of the JAK/STAT3 signalling pathway and EMT reversal. In conclusion, ZA re­sensitised gefitinib­resistant lung cancer cells through inhibition of the JAK/STAT3 signalling pathway and EMT reversal. The combination of ZA and gefitinib may be a promising therapeutic strategy to reverse gefitinib resistance and prolong the survival of patients with NSCLC.

Topoisomerase 1 inhibition therapy protects against SARS-CoV-2-induced inflammation and death in animal models.

The ongoing pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is currently affecting millions of lives worldwide. Large retrospective studies indicate that an elevated level of inflammatory cytokines and pro-inflammatory factors are associated with both increased disease severity and mortality. Here, using multidimensional epigenetic, transcriptional, in vitro and in vivo analyses, we report that Topoisomerase 1 (Top1) inhibition suppresses lethal inflammation induced by SARS-CoV-2. Therapeutic treatment with two doses of Topotecan (TPT), a FDA-approved Top1 inhibitor, suppresses infection-induced inflammation in hamsters. TPT treatment as late as four days post-infection reduces morbidity and rescues mortality in a transgenic mouse model. These results support the potential of Top1 inhibition as an effective host-directed therapy against severe SARS-CoV-2 infection. TPT and its derivatives are inexpensive clinical-grade inhibitors available in most countries. Clinical trials are needed to evaluate the efficacy of repurposing Top1 inhibitors for COVID-19 in humans.

Trend of HIV-1 drug resistance in China: A systematic review and meta-analysis of data accumulated over 17 years (2001-2017).

BACKGROUND: The emergence and spread of HIV-1 drug resistance may compromise HIV control globally. In response to HIV/AIDS epidemic, China launched national HIV/AIDS treatment program in 2003, and started to accumulate drug resistance data since 2001. In this study we aimed to assess the level, trend and distribution of HIV-1 drug resistance during a period of 17 years from 2001 to 2017, and to characterize crucial drug resistance mutations. METHODS: We systematically reviewed 4737 studies published between January 1, 2001 and March 31, 2019 in PubMed, Embase, China National Knowledge Infrastructure (CNKI), WanFang Database, Web of Science, conference abstracts from the Chinese Medical Association and the Chinese AIDS Academic Conferences, and selected 170 studies that met our study criteria. To assess the prevalence of drug resistance in whole country or a local region, we performed pooled analyses of raw data. The transformed proportions were pooled using the inverse variance fixed effects methods or the DerSimonian-Laired random effects methods. The temporal trend of transmitted drug resistance (TDR) was determined using generalized additive model implemented in the Mgcv version 1.8 package. HIV-1 genotypic resistance was analyzed using the Stanford HIVdb algorithm. FINDINGS: We assembled 218 datasets from 170 selected studies (129 in Chinese and 41 in English), covering 21,451 ART-naïve and 30,475 ART-treated individuals with HIV-1 infection. The pooled prevalence of TDR was 3.0% (95%CI: 2.8-3.2), including 0.7% (95%CI: 0.4-1.0), 1.4% (95%CI: 1.3-1.6) and 0.5% (95%CI: 0.4-0.6) for nucleoside reverse transcriptase inhibitor (NRTI), non-NRTI (NNRTI) and protease inhibitor (PI) resistance, respectively. The acquired drug resistance (ADR) prevalence was 44.7% (95%CI: 39.3-50.2), including 31.4% (95%CI: 28.2-34.6), 39.5% (95%CI: 35.6-43.5) and 1.0% (95%CI: 0.8-1.2) for NRTI, NNRTI and PI resistance, respectively. TDR and ADR prevalence had characteristic regional patterns. The worst prevalence of drug resistance occurred in Central China, and higher ADR prevalence occurred in South China than North China. TDR in whole country has risen since 2012, and this rise was driven mainly by NNRTI resistance. One NRTI-associated (M184V/I) and three NNRTI-associated (K103N/S, Y181C/I and G190A/S) mutations had high percentages in ART-naïve and ART-treated individuals, and these mutations conferred high-level resistance to 3TC, EFV and/or NVP. INTERPRETATION: These findings suggest that the current available first-line ART regimens containing 3TC and/or EFV or NVP need to be revised. In addition, scale-up of multiple viral load measurements per year and drug resistance testing prior to ART initiation are recommended. Furthermore, implementation of pre-treatment education and counseling to improve patient adherence to ART is encouraged. FUNDING: This work was supported by grants from the National Natural Science Foundation of China (81672033, U1302224, and 81271888) and Open Research Fund Program of the State Key Laboratory of Virology of China (2019IOV002).

18F-FDG PET imaging for monitoring the early anti-tumor effect of albendazole on triple-negative breast cancer.

BACKGROUND: Multiple studies have indicated that albendazole (ABZ) can disrupt the microtubule in worms and have anti-tumor potential in a variety of tumors. However, the therapeutic effect of ABZ on triple-negative breast cancer (TNBC) is largely unknown, and the therapeutic evaluation of ABZ by 18F-FDG PET imaging remains relatively unexplored. METHODS: The effects of ABZ on TNBC cell lines (MDA-MB-231 cells) were investigated in vitro using MTT, wound-healing, transwell migration, flow cytometry and Western blotting analyses. In vivo treatment was conducted in an MDA-MB-231 tumor-bearing nude mouse model. Mouse body weight loss was also evaluated. PET imaging was performed before and after 3 days of treatment. Tumor tissues were harvested for immunofluorescence analysis. RESULTS: ABZ treatment inhibited the proliferation and migration and triggered the apoptosis in MDA-MB-231 cells. Furthermore, Western blotting analysis showed that ABZ induced the apoptosis in MDA-MB-231 cells via GLUT1/AMPK/P53 signaling pathway. Long-term treatment studies found that the tumor volume of the treatment group was smaller compared with the control group, and the survival time was prolonged. In vivo 18F-FDG PET imaging showed that 3-day ABZ treatment reduced standardized uptake value (SUV) values in MDA-MB-231 xenografts compared with the controls, and immunofluorescence analysis showed more TUNEL-positive cells in the ABZ-treated mice. CONCLUSIONS: Our study suggested that ABZ induced the apoptosis of MDA-MB-231 cells by inhibiting glucose uptake, and it could be considered as a potential drug for TNBC cells. Moreover, 18F-FDG PET imaging could be used to monitor the early anti-tumor effect of ABZ on MDA-MB-231 tumors.

Generation of DelNS1 Influenza Viruses: a Strategy for Optimizing Live Attenuated Influenza Vaccines.

Nonstructural protein 1 (NS1) of influenza virus is a key virulence element with multifunctional roles in virus replication and a potent antagonist of host immune response. Deletion of NS1 (DelNS1) would create a safer and more extensively immunogenic live attenuated influenza virus (LAIV) vaccine. However, DelNS1 viruses are very difficult to grow in regular vaccine-producing systems, which has hampered the application of DelNS1 LAIV vaccines in humans. We have developed two master backbones of deleted-NS1 (DelNS1) viral genomes from influenza A or B viruses which contain novel adaptive mutations to support DelNS1-LAIV replication. These DelNS1-LAIVs are highly attenuated in human cells in vitro and nonpathogenic in mice but replicate well in vaccine-producing cells. Both influenza A and influenza B DelNS1 LAIVs grow better at 33°C than at 37 to 39°C. Vaccination with DelNS1 LAIV performed once is enough to provide potent protection against lethal challenge with homologous virus and strong long-lasting cross protection against heterosubtypic or antigenically distantly related influenza viruses in mice. Mechanistic investigations revealed that DelNS1-LAIVs induce cross protective neutralizing antibody and CD8+ and CD4+ T cell immunities. Importantly, it has been shown that DelNS1-LAIV can be used to enhance specific anti-influenza immunity through expression of additional antigens from the deleted-NS1 site. Generation of DelNS1 viruses which are nonpathogenic and able to grow in vaccine-producing systems is an important strategy for making highly immunogenic LAIV vaccines that induce broad cross protective immunity against seasonal and emerging influenza.IMPORTANCE Current seasonal influenza vaccines are suboptimal and low in immunogenicity and do not provide long-lasting immunity and cross protection against influenza virus strains that have antigenically drifted. More-effective influenza vaccines which can induce both humoral immunity and T cell immunity are needed. The NS1 protein of influenza virus is a virulence element and the critical factor for regulation of the host immune response during virus infection. Deletion of the NS1 protein is a strategy to make an optimal LAIV vaccine. However, DelNS1 viruses are very difficult to grow in regular vaccine-producing systems, hampering the application of DelNS1 LAIV vaccines in humans. We have generated a panel of both influenza A and influenza B DelNS1 LAIVs which are able to grow in regular vaccine-producing cells. These DelNS1 LAIV vaccines are completely nonpathogenic, exhibit potent and long-lasting immunity, and can be used to express extra viral antigen to induce cross protective immunity against seasonal and emerging influenza.

The PB2 Polymerase Host Adaptation Substitutions Prime Avian Indonesia Sub Clade 2.1 H5N1 Viruses for Infecting Humans.

Significantly higher numbers of human infections with H5N1 virus have occurred in Indonesia and Egypt, compared with other affected areas, and it is speculated that there are specific viral factors for human infection with avian H5N1 viruses in these locations. We previously showed PB2-K526R is present in 80% of Indonesian H5N1 human isolates, which lack the more common PB2-E627K substitution. Testing the hypothesis that this mutation may prime avian H5N1 virus for human infection, we showed that: (1) K526R is rarely found in avian influenza viruses but was identified in H5N1 viruses 2⁻3 years after the virus emerged in Indonesia, coincident with the emergence of H5N1 human infections in Indonesia; (2) K526R is required for efficient replication of Indonesia H5N1 virus in mammalian cells in vitro and in vivo and reverse substitution to 526K in human isolates abolishes this ability; (3) Indonesian H5N1 virus, which contains K526R-PB2, is stable and does not further acquire E627K following replication in infected mice; and (4) virus containing K526R-PB2 shows no fitness deficit in avian species. These findings illustrate an important mechanism in which a host adaptive mutation that predisposes avian H5N1 virus towards infecting humans has arisen with the virus becoming prevalent in avian species prior to human infections occurring. A similar mechanism is observed in the Qinghai-lineage H5N1 viruses that have caused many human cases in Egypt; here, E627K predisposes towards human infections. Surveillance should focus on the detection of adaptation markers in avian strains that prime for human infection.

Radiolabeled ultra-small Fe3O4 nanoprobes for tumor-targeted multimodal imaging.

AIM: In the present study, we aimed to characterize the tumor-targeting properties of ultra-small iron oxide nanoparticles (IONPs) as multimodality imaging contrast agent. METHODS: The dimeric cRGD peptides [cyclic(Cys-Arg-Gly-Asp-dSer-Cys)-Tyr-dSer-Lys-Tyr-cyclic(Cys-Arg-Gly-Asp-dSer-Cys)], which specifically targeted integrin-αvß3 receptor highly overexpressed in tumor vasculature and tumor cells, were covalently conjugated onto the surface of ultra-small IONPs followed by the labeling of nuclide 125I- through the chloramine-T method to afford the desired 125I-(cRGD)2-IONPs nanoprobe.125I-(cRGD)2-IONPs were injected into tumor-bearing mice for magnetic resonance (MR) and single photon emission computed tomography (SPECT) multi-modality imaging of tumors. RESULTS: The prepared IONPs demonstrated were very useful for T1/T2 and SPECT imaging of tumors in vivo, exhibiting a high tumor uptake of a clinically useful target-to-background ratio in a short time. CONCLUSION: We successfully developed a novel integrin-αvß3 receptor-targeted ultra-small IONPs, which could be successfully used as T1-T2-MRI/SPECT contrast agents for high-resolution and high-sensitivity of tumor imaging in vivo.

The role of nuclear NS1 protein in highly pathogenic H5N1 influenza viruses.

The non-structural protein (NS1) of influenza A viruses (IAV) performs multiple functions during viral infection. NS1 contains two nuclear localization signals (NLS): NLS1 and NLS2. The NS1 protein is located predominantly in the nucleus during the early stages of infection and subsequently exported to the cytoplasm. A nonsense mutation that results in a large deletion in the carboxy-terminal region of the NS1 protein that contains the NLS2 domain was found in some IAV subtypes, including highly pathogenic avian influenza (HPAI) H7N9 and H5N1 viruses. We introduced different mutations into the NLS domains of NS1 proteins in various strains of IAV, and demonstrated that mutation of the NLS2 region in the NS1 protein of HPAI H5N1 viruses severely affects its nuclear localization pattern. H5N1 viruses expressing NS1 protein that is unable to localize to the nucleus are less potent in antagonizing cellular antiviral responses than viruses expressing wild-type NS1. However, no significant difference was observed with respect to viral replication and pathogenesis. In contrast, the replication and antiviral defenses of H1N1 viruses are greatly attenuated when nuclear localization of the NS1 protein is blocked. Our data reveals a novel functional plasticity for NS1 proteins among different IAV subtypes.

An NS-segment exonic splicing enhancer regulates influenza A virus replication in mammalian cells.

Influenza virus utilizes host splicing machinery to process viral mRNAs expressed from both M and NS segments. Through genetic analysis and functional characterization, we here show that the NS segment of H7N9 virus contains a unique G540A substitution, located within a previously undefined exonic splicing enhancer (ESE) motif present in the NEP mRNA of influenza A viruses. G540A supports virus replication in mammalian cells while retaining replication ability in avian cells. Host splicing regulator, SF2, interacts with this ESE to regulate splicing of NEP/NS1 mRNA and G540A substitution affects SF2-ESE interaction. The NS1 protein directly interacts with SF2 in the nucleus and modulates splicing of NS mRNAs during virus replication. We demonstrate that splicing of NEP/NS1 mRNA is regulated through a cis NEP-ESE motif and suggest a unique NEP-ESE may contribute to provide H7N9 virus with the ability to both circulate efficiently in avian hosts and replicate in mammalian cells.

Functional characterization of two novel scorpion sodium channel toxins from Lychas mucronatus.

The diverse α-scorpion toxins are invaluable pharmacological tools and potential drugs targeting sodium channels, but the pharmacological profiles of most toxins remains unknown so far. Here, we reported pharmacological activities of two novel α-scorpion toxins LmαTX3 and LmαTX5 from the Lychas mucronatus. Using the expression vector pET-28a, the recombinant LmαTX3 and LmαTX5 were separated by RP-HPLC and identified by MALDI-TOF-MS. Subsequently, sodium channels rNav1.2, mNav1.4, hNav1.5 and hNav1.7 were used for evaluating the pharmacological activities of LmαTX3 and LmαTX5 toxins. The electrophysiological experiments showed that both 10 µM recombinant LmαTX3 and LmαTX5 seriously inhibited the fast inactivation of mNav1.4 and hNav1.5 channels, moderately affected hNav1.7 channel, and hardly modulated rNav1.2 channel. The dose-response experiments further indicated the EC50 values of LmαTX3 were 4.98 ± 0.79 µM for mNav1.4, 1.23 ± 0.31 µM for hNav1.5 and 31.46 ± 2.32 µM for hNav1.7 channels, respectively. Similar pharmacological profiles of recombinant LmαTX5 were also observed, and its EC50 values were 4.53 ± 1.38 µM, 1.03 ± 0.43 µM and 67.62 ± 2.31 µM for mNav1.4, hNav1.5 and hNav1.7, respectively. In addition, the recombinant LmαTX3 from the vector pET-14b had much less effect on the fast inactivation of mNav1.4, hNav1.5 and hNav1.7 channels, which indicated that the expression vector pET-14b likely played a critical role in toxin function. Together, these findings first highlighted that scorpion toxins from L. mucronatus were a new molecular resource of discovering pharmacological probes and prospective drugs targeting sodium channels in the future.

Characterization of a novel BmαTX47 toxin modulating sodium channels: the crucial role of expression vectors in toxin pharmacological activity.

Long-chain scorpion toxins with four disulfide bridges exhibit various pharmacological features towards the different voltage-gated sodium channel subtypes. However, the toxin production still remains a huge challenge. Here, we reported the effects of different expression vectors on the pharmacological properties of a novel toxin BmαTX47 from the scorpion Buthus martensii Karsch. The recombinant BmαTX47 was obtained using the expression vector pET-14b and pET-28a, respectively. Pharmacological experiments showed that the recombinant BmαTX47 was a new α-scorpion toxin which could inhibit the fast inactivation of rNa(v)1.2, mNa(v)1.4 and hNa(v)1.5 channels. Importantly, the different expression vectors were found to strongly affect BmαTX47 pharmacological activities while toxins were obtained by the same expression and purification procedures. When 10 µM recombinant BmαTX47 from the pET-28a vector was applied, the values of I(5ms)/I(peak) for rNa(v)1.2, mNa(v)1.4 and hNa(v)1.5 channels were 44.12% ± 3.17%, 25.40% ± 4.89% and 65.34% ± 3.86%, respectively, which were better than those values of 11.33% ± 1.46%, 15.96% ± 1.87% and 5.24% ± 2.38% for rNa(v)1.2, mNa(v)1.4 and hNa(v)1.5 channels delayed by 10 µM recombinant BmαTX47 from the pET-14b vector. The dose-response experiments further indicated the EC50 values of recombinant BmαTX47 from the pET-28a vector were 7262.9 ± 755.9 nM for rNa(v)1.2 channel and 1005.8 ± 118.6 nM for hNa(v)1.5 channel, respectively. Together, these findings highlighted the important role of expression vectors in scorpion toxin pharmacological properties, which would accelerate the understanding of the structure-function relationships of scorpion toxins and promote the potential application of toxins in the near future.

[Investigation of measles, rubella and varicella IgG antibody levels among migrant and native pupils in Changning District of Shanghai].

OBJECTIVE: To define the measles, rubella and varicella immunoglobulin G (IgG) anti-body levels among migrant and native pupils so as to advise effective measures for measles control and prevention. METHODS: 241 pupils at four or five grade were recruited from 3 primary schools in Changning District. Measles, rubella and varicella IgG antibody levels were tested. RESULTS: The positive rates of measles, rubella and varicella IgG antibodies of the 241 pupils were 96.68%, 79.67% and 57.68% respectively. The positive rates of IgG antibodies of meales and rubella were not significant difference between the migrant and native groups, but the concentrations of IgG antibodies of measles and rubella in migrant group were higher than those of native group. The positive rate of varicella IgG antibody in migrant group was also higher than that of native group. CONCLUSION: There was a high potential to outbreak of varicella in primary schools. Surveillance and prevention for infectious diseases and health education should be reinforced in schools. The pupils who have no varicella history are recommended to administer varicella vaccine.