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Salt is a necessary condition to produce a surimi product that is based on the gelation of salt-soluble myofibrillar proteins. Recently, there has been a growing concern among consumers to consume healthy foods due to the threat of several chronic diseases caused by an unhealthy diet. Methods of reducing salt content out of concern for health issues caused by excessive sodium intake may affect the gel properties of surimi, as can many health-oriented food additives. Several studies have investigated different strategies to improve the health characteristics of surimi products without decreasing gel properties. This review reports recent developments in this area and how the gel properties were successfully maintained under reduced-salt conditions and the use of additives. This review of recent studies presents a great deal of progress made in the health benefits of surimi and can be used as a reference for further development in the surimi product processing industry.

Starch and protein are common polymers in food, and their phase separation often occurs during food processing. Protein-fortified starch dough can be considered as a triple phase separation system, and the effect of phase separation on dough rheology warrants further research. In this study, starch doughs fortified with fish actomyosin were used, and their rheological properties were researched and explained with respect to phase separation. The results suggested that the phase separation of actomyosin-binder-starch granules in the raw dough affected the quality of dough. The addition of actomyosin significantly decreased stiffness and shear sensitivity but increased the fluidity of the blended dough. Moreover, it was found that the interaction between mung bean starch and actomyosin was very weak. The polymer molecules were connected by physical links. Owing to phase separation, it was presumed that “wall slip” occurred between the binder, starch granule, and actomyosin. The blended dough containing 30% of the added actomyosin (R3) showed the best recovery ability and the weakest molecular interaction (interaction type Z′ = 0.40 for storage modulus G′ and 0.31 for loss modulus G′′). Additionally, the phase structure of the model doughs was investigated. It was found that the starch network played a dominant role when 10% (R1) actomyosin was added. With the addition of actomyosin, the protein network formed gradually. A bicontinuous phase structure with interpenetrating network was observed in R3 (actomyosin = 30%). In summary, our findings demonstrate the feasibility to make blended doughs by mixing fish actomyosin and mung bean starch. Moreover, in terms of use in traditional noodle making, the blended R3 dough was found to be the best in terms of recovery ability and flow characteristics.

Edible coatings and films based on chitosan, and containing grape seed extract (GSE), were developed and their activities tested against murine norovirus (MNV‐1), Listeria innocua and Escherichia coli K12. Grape seed extract concentrations of 1%, 1.5%, and 2.5% dissolved in deionized water resulted in MNV‐1 plaque reductions (p

Background Ancient civilizations used natural products as food and as resources to treat various diseases. Today, food ingredients, especially those derived from plants, still play important roles in human nutrition and drug discovery. The health-promoting bioactive compounds or drug candidates need to be identified systematically and efficiently, for developing healthy diets and for alleviating the burden of chronic diseases worldwide. Scope and approach In this multi-disciplinary process, the separation and identification of diverse molecules, the analysis of their interactions with cellular targets, the chemical synthesis, and the animal and clinical trials, are all equally important. The focus of this mini-review is on the initial stage of the process, which is critical to future trends of health foods and food-derived drug discoveries. Through the strategy of targeting the critical proteins involved in many chronic diseases, the bioactive components can be fished out and studied further. Key findings and conclusions Three of the major methodologies to accelerate the discovery of the bioactive components: high throughput screening, phage display technique and virtual screening, are summarized with successful examples. The efficient strategy to identify and further validate the cellular targets, the in silico target prediction and the mass spectroscopy-based proteomics, are also highlighted. To achieve this very promising research goals, through the strategy of targeting the critical proteins involved in many chronic diseases, the establishment of an International Food Ingredients Consortium (IFIC) is proposed.

This study aimed to identify novel ACEI peptides from Larimichthys crocea titin using in silico approaches and to clarify the molecular interaction mechanism. The hydrolyzed peptides of titin were compared with known ACEI peptides in the AHTPDB and BIOPEP-UWM database. Furthermore, peptides were evaluated for their solubility, ADMET properties, △G (kcal/mol) values, and in vitro ACEI activity. Molecular mechanism of ACE-peptide was performed by molecular interactions and binding orientation study. The results revealed that IC50 values of Trp-Ala-Arg(WAR) and Trp-Gln-Arg(WQR) were (31.2 ± 0.8) and (231.33 ± 0.02) μmol/L, respectively. The docking interactions result suggested that ACE-WAR and ACE-WQR complexes have same binding site, including the residues LYS511, TYR520, TYR523, HIS353, and HIS513. Molecular docking of two tripeptides WAR and WQR with ACE studies predicted their binding site and clarified the interaction between ACE and its inhibitors. The molecular docking data are consistent with the ACE inhibitory activity of the studied peptides. The results showed that Larimichthys crocea titin may be a valuable source for developing nutraceutical food.

This study examined the effects on conformation and oxidation of myofibrillar protein in largemouth bass by different thawing methods. The conventional thawing, microwave thawing, microwave (MVT) or ultrasound combined with vacuum thawing, microwave or far-infrared thawing (FMT) combined with magnetic nanoparticles were used in this experiment. The physicochemical changes were analyzed by differential scanning calorimetry and dynamic rheology. The protein structure changes were measured by Raman, intrinsic fluorescence, and second-derivative ultraviolet spectrometry. The degree of protein aggregation was evaluated by surface hydrophobicity, particle size, and zeta-potential measurements. Total sulfhydryl content, protein carbonyl content, Ca2+ -ATPase activity, and SDS-PAGE were used to analyze the degree of protein oxidation. Results showed that MVT and FMT samples had better thermal stability, more stable protein conformation, and a lower degree of protein oxidation. Thus, these two methods would be beneficial to sustain the quality of thawed fillets. PRACTICAL APPLICATIONS: In the market circulation, largemouth bass (Micropterus salmoides) need to be frozen. The thawing methods can directly affect the quality of frozen fish, thus causing the changes in the conformation of the myofibrillar protein in fish, and also affecting the degree of protein oxidation. The results showed that the microwave combined with vacuum and the magnetic nanoparticles combined with far-infrared thawing had less effect on myofibrillar protein of fish and were a better thawing method.

Background Interactions between flavor compounds and proteins during food processing are critical to flavor perception of the final product. Here, we investigated the effect of the duration of heat treatment on the interaction between bighead carp myosin and selected flavor compounds including hexanal, heptanal, octanal, nonanal, (E)-2-heptenal, and 1-octen-3-ol. Results The binding of flavor compounds to native myosin was strong and decreased in the order nonanal > octanal > (E)-2-heptenal > heptanal > hexanal >1-octen-3-ol. The aldehydes, especially trans-2-undecenal, were more conducive to hydrophobic binding to myosin than alcohols. Within the initial 5 min of heating, the surface hydrophobicity and total sulfhydryl exposure increased, while α-helix turned into β-sheets, β-turns, and random coils. However, upon further heating, the hydrophobicity and sulfhydryl contents declined, β-sheets, β-turns and random coils shifted to α-helix. Throughout the heating process, the particle size increased, and the absolute zeta potential decreased continuously, indicating that thermal aggregation of myosin occurred simultaneously. Changes in binding capacities of flavor compounds to myosin were consistent with changes in hydrophobicity and sulfhydryl contents. Conclusion The initial enhancement of the flavor-binding capacity of myosin was attributed to the unfolding of secondary structures by exposing more hydrophobic bonding sites and hydrogen bonding sites. The rebuilding and aggregating of myosin was enhanced upon prolonged heating, thus favoring hydrophobic protein-protein interactions and weakening the resultant flavor binding capacity of myosin.

Inhibition of beta-site APP cleaving enzyme1 (BACE1) is one of the most promising therapeutic approaches for Alzheimer’s disease. To find natural products for the treatment of Alzheimer's disease, absorption, distribution, metabolism, excretion and toxicity (ADMET) properties and in vitro BACE1 inhibitory activity of the peptides isolated from egg albumin were evaluated. Then, molecular docking and molecular dynamics simulation were used to explain the molecular mechanism of the interactions between BACE1 and peptides. The IC50 value of peptide KLPGF, with satisfactory ADMET properties, against BACE1 was (8.30 ± 0.56) mmol/L. Molecular docking revealed that KLPGF contacted with the residues of BACE1’s active sites through twelve hydrogen bonds interactions, two hydrophobic interactions, one electrostatic interaction, and two Pi-cation interactions. The 5 ns molecular dynamics simulations confirmed that the structure of KLPGF with BACE1 was stable. Peptide KLPGF contacted the residues Lys321, Asp228, and Asn233 with stable hydrogen bonds. KLPGF may be a potential anti-BACE1 candidate.

This study investigated the effects of different concentrations (0, 5, 10, 20, 50, and 100 μmol/g protein) of tea polyphenols (TP) on the oxidative modification and the physicochemical, structural, and gelling properties of myofibrillar protein (MP) from grass carp (Ctenopharyngodon idellus) oxidized by a hydroxyl radical-generating system. The results showed that low concentrations (5 and 10 μmol/g protein) of TP could effectively inhibit the formation of carbonyl groups and dityrosine, the loss of sulfhydryl groups and α-helix conformation, and the change of the tertiary structure of MP caused by hydroxyl radicals. Moreover, the presence of TP in all concentrations decreased the surface hydrophobicity of MP. TP at 10 μmol/g protein had better effects on preventing the oxidation-induced cross-linking and aggregation of myosin heavy chain (MHC) and actin of MP, keeping the stability of MP solutions with lower turbiscan stability index (TSI) values, and improving gelling properties characterized by higher hardness and gel strength of MP gels. By contrast, excessive presence of TP (20, 50, and 100 μmol/g protein) showed pro-oxidative effects on oxidatively stressed MP, which was detrimental to the MP and contributed to the denaturation and irregular aggregation of MP, the loss of MP solution stability, and lower gelling capacity with poor texture and gel strength. The concentration-dependent effects of TP on MP depended on the extent of MP oxidative modification and MP-TP interactions, indicating that a proper amount of TP has the potential to protect MP from oxidation and to enhance the gelling capacity of surimi during processing.

In the present study, we characterized CF-14, a novel antimicrobial peptide derived from the catfish skin mucus. The objective of this study was to explore the antimicrobial mechanism of CF-14 against Escherichia coli. The agar-diffusion assay and the microdilution method were used to evaluate the antimicrobial activity and the minimum inhibitory concentration (MIC) of CF-14 against E. coli, respectively. In addition, the absorbance of the bacterial suspension filtrate at 260 nm was measured to quantify the leakage of bacterial cytoplasmic components. The bacterial morphological changes were observed by scanning electron microscopy, while confocal microscopy was used to investigate the localization site of CF-14 in E.coli. The DNA binding ability of CF-14 was evaluated using gel retardation assay and the binding of CF-14 to DnaK was evaluated using Discovery Studio. The results demonstrated that CF-14 exhibited strong antimicrobial activity against E.coli with an MIC of 31.3 μg/mL. Unlike common cationic anti-microbial peptides (AMPs) that target the cellmembrane, CF-14 penetrated the E.coli cell membrane and induced only minormembrane perturbations. Furthermore, the antimicrobial mechanism of CF-14 against E.coli involved DNA binding and competitive inhibition of bacterial DnaK. Finally, by deleting or replacing the amino acid sequence, the antibacterial activity of CF-14 was affected, which helped the optimization of amino acid sequence. Therefore, CF-14 can be a potential antimicrobial peptide.

Significance Myeloid lineage cells are suspected of having an integral role in pathophysiological processes of multiple sclerosis (MS), but the molecular mechanism(s) governing their effector function remains incompletely understood. We show that STAT3 is activated in myeloid cells near active MS lesions. Conditional deletion of Stat3 in myeloid cells abolished symptoms of experimental autoimmune encephalomyelitis (EAE) by suppressing the generation of pathogenic T cells. Functional and transcriptomic analyses of myeloid cells from wild-type and conditional knockout mice implicated antigen processing/presentation and inflammatory cytokine production as the mechanism underlying the effects of STAT3 deletion on impaired T cell activation. Our data indicate that targeting STAT3 in myeloid cells might be a viable treatment option for autoimmune demyelinating disease., Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the central nervous system. Dysregulation of STAT3, a transcription factor pivotal to various cellular processes including Th17 cell differentiation, has been implicated in MS. Here, we report that STAT3 is activated in infiltrating monocytic cells near active MS lesions and that activation of STAT3 in myeloid cells is essential for leukocyte infiltration, neuroinflammation, and demyelination in experimental autoimmune encephalomyelitis (EAE). Genetic disruption of Stat3 in peripheral myeloid lineage cells abrogated EAE, which was associated with decreased antigen-specific T helper cell responses. Myeloid cells from immunized Stat3 mutant mice exhibited impaired antigen-presenting functions and were ineffective in driving encephalitogenic T cell differentiation. Single-cell transcriptome analyses of myeloid lineage cells from preclinical wild-type and mutant mice revealed that loss of myeloid STAT3 signaling disrupted antigen-dependent cross-activation of myeloid cells and T helper cells. This study identifies a previously unrecognized requisite for myeloid cell STAT3 in the activation of myelin-reactive T cells and suggests myeloid STAT3 as a potential therapeutic target for autoimmune demyelinating disease.

Internal N6-methyladenosine (m6A) modification is one of the most common and abundant modifications of RNA. However, the biological roles of viral RNA m6A remain elusive. Here, using human metapneumovirus (HMPV) as a model, we demonstrate that m6A serves as a molecular marker for innate immune discrimination of self from non-self RNAs. We show that HMPV RNAs are m6A methylated and that viral m6A methylation promotes HMPV replication and gene expression. Inactivating m6A addition sites with synonymous mutations or demethylase resulted in m6A-deficient recombinant HMPVs and virion RNAs that induced increased expression of type I interferon, which was dependent on the cytoplasmic RNA sensor RIG-I, and not on melanoma differentiation-associated protein 5 (MDA5). Mechanistically, m6A-deficient virion RNA induces higher expression of RIG-I, binds more efficiently to RIG-I and facilitates the conformational change of RIG-I, leading to enhanced interferon expression. Furthermore, m6A-deficient recombinant HMPVs triggered increased interferon in vivo and were attenuated in cotton rats but retained high immunogenicity. Collectively, our results highlight that (1) viruses acquire m6A in their RNA as a means of mimicking cellular RNA to avoid detection by innate immunity and (2) viral RNA m6A can serve as a target to attenuate HMPV for vaccine purposes. This study reports a novel function for the N6-methyladenosine RNA modification in allowing RIG-I to discriminate self from non-self RNA and shows that human metapneumovirus induces this modification of its RNA to evade recognition in vivo.

Acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and beta-secretase 1 (BACE 1) play vital roles in the development and progression of Alzheimer's disease (AD). The objective of the present study was to identify fish roe-derived anti-AD peptides with activities against AChE, BChE, and BACE 1. Fish roe proteins were cleaved in silico by gastrointestinal proteases, and the released peptides were collected. Subsequently, the toxicity, solubility, and biological properties of these novel di- and tri-peptides were predicted and validated. Finally, potential anti-AD peptides were docked to targets, i.e., AChE, BChE, and BACE 1. A novel anti-AD tripeptide WIR with potent inhibition of AChE and BACE 1 was identified, with IC50 values of 43.32 ± 1.22 μM and 2.27 ± 0.35 mM, respectively. In addition, the inhibition rate of WIR (at a concentration of 1.06 ± 0.87 μM) against BChE was 33.5%, and the peptide WIR was able to simultaneously interact with AChE, BChE, and BACE 1. Residues Ser286 of AChE, Asp70 of BChE, and Thr231, Arg235 of BACE 1 played key roles in the interaction with peptide WIR. In summary, peptide WIR exhibits the potential to be an effective treatment for AD.

Background The present study investigated the effect of two-step heat treatments on the structure of grass carp myofibrillar proteins (MPs) and their binding ability for selected aldehydes (hexanal, heptanal, octanal and nonanal). Results Within 30 min of the first heating step at 40 °C and 5-10 min of the second heating step at 90 °C, the enhancement of the flavor-binding ability was likely explained by the increases in surface hydrophobicity and total sulfhydryl content due to the unfolding of secondary structures of MPs through exposure of hydrophobic amino acids and sulfhydryl groups. Nevertheless, lengthy heating at 90 °C accelerated the aggregation of unfolded MPs and reduced the hydrophobic bonding sites, thus weakening the hydrophobic interactions and decreasing the resultant binding ability of MPs with aldehydes. Conclusion The binding ability of aldehydes to MPs was found to be strongly influenced by changes in protein structure and surface during the two-step heating process. The results provided insight into improving the flavor characteristics of freshwater fish surimi products. © 2019 Society of Chemical Industry.

Among over 150 distinct RNA modifications, N6-methyladenosine (m6A) and adenosine-to-inosine (A-to-I) RNA editing represent 2 of the most studied modifications on mammalian mRNAs. Although both modifications occur on adenosine residues, knowledge on potential functional crosstalk between these 2 modifications is still limited. Here, we show that the m6A modification promotes expression levels of the ADAR1, which encodes an A-to-I RNA editing enzyme, in response to interferon (IFN) stimulation. We reveal that YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) mediates up-regulation of ADAR1; YTHDF1 is a reader protein that can preferentially bind m6A-modified transcripts and promote translation. Knockdown of YTHDF1 reduces the overall levels of IFN-induced A-to-I RNA editing, which consequently activates dsRNA-sensing pathway and increases expression of various IFN-stimulated genes. Physiologically, YTHDF1 deficiency inhibits virus replication in cells through regulating IFN responses. The A-to-I RNA editing activity of ADAR1 plays important roles in the YTHDF1-dependent IFN responses. Therefore, we uncover that m6A and YTHDF1 affect innate immune responses through modulating the ADAR1-mediated A-to-I RNA editing., A study of the epitranscriptomic landscape reveals a functional role of the RNA modification N6-methyladenosine in suppressing aberrant innate antiviral immune responses by modulating A-to-I RNA editing and RNA secondary structure.

Aims Pseudomonas fluorescens are important psychrotrophic food spoilage bacteria that are frequently detected in dairy, meat and aquatic products. Quorum sensing (QS) is an intercellular communication and gene regulation mechanism that enables bacteria to monitor their cell densities and regulate a variety of physiological processes. Hence, targeting the bacterial QS system might be a feasible approach to improve food quality and safety by regulating the spoilage caused by P. fluorescens. Methods and results In this study, we screened a food-derived three-dimensional (3D) compound database to search for potential QS inhibitors (QSIs) with higher security. The 3D structures of LuxI- and LuxR-type proteins of P. fluorescens P07 were used as targets to screen for QSIs. A total of 25 compounds with high docking scores were tested for their anti-QS activities by indicator strains. The results show that 19 compounds possessed anti-QS activities. Among them, (+)-catechin had the strongest anti-QS activity. The results show that (+)-catechin significantly inhibited the production of extracellular enzymes, swimming motility, biofilm formation, acyl-homoserine lactones and extracellular polymeric substances (EPSs) of P. fluorescens P07. The inhibitory mechanism of (+)-catechin on the QS system of P. fluorescens P07 was discussed in the context of molecular docking analysis and real-time quantitative PCR (RT-qPCR). Conclusions Virtual screening was useful in finding novel QSIs with high security of P. fluorescens P07 from a food-derived 3D compound database. The high hit rate suggested that foods are rich sources of QSIs, and have great potential for exploration. Significance and impact of the study The modelled LuxI- and LuxR-type proteins could be used as targets to discover P. fluorescens P07 QSIs. (+)-catechin, (-)-epicatechin, propyl gallate, hesperidin and lycopene which were identified as potent QSIs, and may be applied in food preservation and biofilm elimination.

The environment of marine occupies about 95% biosphere of the world and it can be a critical source of bioactive compounds for humans to be explored. Special environment such as high salt, high pressure, low temperature, low nutrition and no light, etc. has made the production of bioactive substances different from terrestrial organisms. Natural ingredients secreted by marine-derived bacteria, fungi, actinomycetes, Cyanobacteria and other organisms have been separated as active pharmacophore. A number of evidences have demonstrated that bioactive ingredients isolated from marine organisms can be other means to discover novel medicines, since enormous natural compounds from marine environment were specified to be anticancer, antibacterial, antifungal, antitumor, cytotoxic, cytostatic, anti-inflammatory, antiviral agents, etc. Although considerable progress is being made within the field of chemical synthesis and engineering biosynthesis of bioactive compounds, marine environment still remains the richest and the most diverse sources for new drugs. This paper reviewed the natural compounds discovered recently from metabolites of marine organisms, which possess distinct chemical structures that may form the basis for the synthesis of new drugs to combat resistant pathogens of human life. With developing sciences and technologies, marine-derived bioactive compounds are still being found, showing the hope of solving the problems of human survival and sustainable development of resources and environment.

Background Forty-two percent of patients experience disease comorbidity, contributing substantially to mortality rates and increased healthcare costs. Yet, the possibility of underlying shared mechanisms for diseases remains not well established, and few studies have confirmed their molecular predictions with clinical datasets. Methods In this work, we integrated genome-wide association study (GWAS) associating diseases and single nucleotide polymorphisms (SNPs) with transcript regulatory activity from expression quantitative trait loci (eQTL). This allowed novel mechanistic insights for noncoding and intergenic regions. We then analyzed pairs of SNPs across diseases to identify shared molecular effectors robust to multiple test correction (False Discovery Rate FDReRNA 1.5, FDRcomorbidity

N(6)-Methyladenosine (m(6)A) is the most abundant internal RNA modification catalyzed by host RNA methyltransferases. As obligate intracellular parasites, many viruses acquire m(6)A methylation in their RNAs. However, the biological functions of viral m(6)A methylation are poorly understood. Here, we found that viral m(6)A methylation serves as a molecular marker for host innate immunity to discriminate self from nonself RNA and that this novel biological function of viral m(6)A methylation is universally conserved in several families in nonsegmented negative-sense (NNS) RNA viruses. Using m(6)A methyltransferase (METTL3) knockout cells, we produced m(6)A-deficient virion RNAs from the representative members of the families Pneumoviridae, Paramyxoviridae, and Rhabdoviridae and found that these m(6)A-deficient viral RNAs triggered significantly higher levels of type I interferon compared to the m(6)A-sufficient viral RNAs, in a RIG-I-dependent manner. Reconstitution of the RIG-I pathway revealed that m(6)A-deficient virion RNA induced higher expression of RIG-I, bound to RIG-I more efficiently, enhanced RIG-I ubiquitination, and facilitated RIG-I conformational rearrangement and oligomerization. Furthermore, the m(6)A binding protein YTHDF2 is essential for suppression of the type I interferon signaling pathway, including by virion RNA. Collectively, our results suggest that several families in NNS RNA viruses acquire m(6)A in viral RNA as a common strategy to evade host innate immunity. IMPORTANCE The nonsegmented negative-sense (NNS) RNA viruses share many common replication and gene expression strategies. There are no vaccines or antiviral drugs for many of these viruses. We found that representative members of the families Pneumoviridae, Paramyxoviridae, and Rhabdoviridae among the NNS RNA viruses acquire m(6)A methylation in their genome and antigenome as a means to escape recognition by host innate immunity via a RIG-I-dependent signaling pathway. Viral RNA lacking m(6)A methylation induces a significantly higher type I interferon response than m(6)A-sufficient viral RNA. In addition to uncovering m(6)A methylation as a common mechanism for many NNS RNA viruses to evade host innate immunity, this study discovered a novel strategy to enhance type I interferon responses, which may have important applications in vaccine development, as robust innate immunity will likely promote the subsequent adaptive immunity.

Significance Measles virus (MeV) vaccine is one of the safest and most efficient vaccines with a track record in children. Here, we generated a panel of rMeV-based vaccines with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S antigens inserted near 3′ of the MeV genome. The rMeV expressing a soluble stabilized, prefusion spike (preS) is much more potent in triggering SARS-CoV-2–specific neutralizing antibody than rMeV-based full-length S vaccine candidate. A single dose of rMeV-preS is sufficient to induce high levels of SARS-CoV-2 antibody in animals. Furthermore, rMeV-preS induces high levels of Th1-biased immunity. Hamsters immunized with rMeV-preS were completely protected against SARS-CoV-2 challenge. Our results demonstrate rMeV-preS is a safe and highly efficacious bivalent vaccine candidate for SARS-CoV-2 and MeV., The current pandemic of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights an urgent need to develop a safe, efficacious, and durable vaccine. Using a measles virus (rMeV) vaccine strain as the backbone, we developed a series of recombinant attenuated vaccine candidates expressing various forms of the SARS-CoV-2 spike (S) protein and its receptor binding domain (RBD) and evaluated their efficacy in cotton rat, IFNAR−/−mice, IFNAR−/−-hCD46 mice, and golden Syrian hamsters. We found that rMeV expressing stabilized prefusion S protein (rMeV-preS) was more potent in inducing SARS-CoV-2–specific neutralizing antibodies than rMeV expressing full-length S protein (rMeV-S), while the rMeVs expressing different lengths of RBD (rMeV-RBD) were the least potent. Animals immunized with rMeV-preS produced higher levels of neutralizing antibody than found in convalescent sera from COVID-19 patients and a strong Th1-biased T cell response. The rMeV-preS also provided complete protection of hamsters from challenge with SARS-CoV-2, preventing replication in lungs and nasal turbinates, body weight loss, cytokine storm, and lung pathology. These data demonstrate that rMeV-preS is a safe and highly efficacious vaccine candidate, supporting its further development as a SARS-CoV-2 vaccine.

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract (LRT) infections, with increased severity in high-risk human populations, such as infants, the immunocompromised, and the elderly. Although the virus was identified more than 60 years ago, there is still no licensed vaccine available. Over the years, several vaccine delivery strategies have been evaluated. In this study, we developed two recombinant vesicular stomatitis virus (rVSV) vector-based vaccine candidates expressing the RSV-G (attachment) protein (rVSV-G) or F (fusion) protein (rVSV-F). All vectors were evaluated in the cotton rat animal model for their in vivo immunogenicity and protective efficacy against an RSV-A2 virus challenge. Intranasal (i.n.) delivery of rVSV-G and rVSV-F together completely protected the lower respiratory tract (lungs) at doses as low as 10(3) PFU. In contrast, doses greater than 10(6) PFU were required to protect the upper respiratory tract (URT) completely. Reimmunization of RSV-immune cotton rats was most effective with rVSV-F. In immunized animals, overall antibody responses were sufficient for protection, whereas CD4 and CD8 T cells were not necessary. A prime-boost immunization regimen increased both protection and neutralizing antibody titers. Overall, mucosally delivered rVSV-vector-based RSV vaccine candidates induce protective immunity and therefore represent a promising immunization regimen against RSV infection. IMPORTANCE Even after decades of intensive research efforts, a safe and efficacious RSV vaccine remains elusive. Expression of heterologous antigens from rVSV vectors has demonstrated several practical and safety advantages over other virus vector systems and live attenuated vaccines. In this study, we developed safe and efficacious vaccine candidates by expressing the two major immunogenic RSV surface proteins in rVSV vectors and delivering them mucosally in a prime-boost regimen. The main immune parameter responsible for protection was the antibody response. These vaccine candidates induced complete protection of both the upper and lower respiratory tracts.

Weak gelation ability and simple nutrient composition of squid myofibril protein limits its further development in surimi production. Millet flour is rich in nutrients and has a good viscoelasticity after heating. Physicochemical properties of Peruvian squid myofibril protein based blend gel fortified with millet four were studied. Rheological test results showed that all blend gels exhibit solid-like characters. With the addition of millet flour, the composite modulus of all the samples showed a trend of decreasing first and then increasing. The minimum value appeared around 48oC. Moreover, it was found that gel strength, water holding capacity, hardness, gumminess and chewiness showed a trend of increasing at first and then decreasing. The blend gel with 4% millet flour addition exhibit good performance in those testing. The subsequent analysis of water distribution further explained and proved the mechanism. In summary, the blend gel of squid myofibril protein fortified with 4% of millet flour addition was considered the most suitable amount for enhancing the quality of blend gel.

Protamex was selected to prepare the hydrolysate. E-tongue, free amino acid combined with soluble peptide analysis were used to detect the flavor changes of Aloididae aloidi during enzymolysis. Degree of proteolysis increased with the prolongation of enzymolysis time, and reached the maximum value at 8 hours. The content of soluble peptide of hydrolysate increased firstly and then decreased in the later process. The E-tongue could effectively distinguish the taste difference of hydrolysates at different enzymolysis time, and the hydrolysate presented strong bitterness and astringency during the whole enzymolysis. The total amount of free amino acids in the hydrolysate increased gradually, and some sweet, umami and bitter amino acids increased in varying degrees during the process of enzymolysis.

Background Flavor loss is a common problem when manufacturing apple juice and is closely related to the properties of the colloidal pectin particles in cloudy juice. The flavor changes and particle properties of three varieties of apple juice ('Ralls', 'Golden Delicious' and 'Fuji') during processing were investigated. Results Compared with manually pressed juice, juice made by industrial pulping and filtration contained larger particles, resulting in the 'sweet and sour' taste of the juice being relatively weak and the diversity of aromas narrower, as determined by E-nose analysis. Pulping and filtration, however, released some important flavor esters, such as butyl butyrate, hexyl-2-methyl butyrate, and hexyl butyrate. The transformation of volatile compounds during apple juice processing was closely related to the apple cultivar but, in all three varieties, the content of 1-hexanal and (E)-2-hexenal in the juice gradually decreased during processing. Pectinase treatment reduced the colloid particle size and increased the ζ-potential of the juice, resulting in better uniformity and stability, as well as increasing the content of nonanal. After pasteurization, the colloidal particles tended to aggregate and the ζ-potential decreased. Many volatile compounds decreased in concentration or disappeared after heat treatment. Conclusion The flavor and colloidal properties of cloudy apple juice changed markedly during processing and the effect of each processing step was different. © 2020 Society of Chemical Industry.

Human respiratory syncytial virus (RSV) is the leading viral cause of lower respiratory tract disease in infants and children worldwide. Currently, there are no FDA-approved vaccines to combat this virus. The large (L) polymerase protein of RSV replicates the viral genome and transcribes viral mRNAs. The L protein is organized as a core ring-like domain containing the RNA-dependent RNA polymerase and an appendage of globular domains containing an mRNA capping region and a cap methyltransferase region, which are linked by a flexible hinge region. Here, we found that the flexible hinge region of RSV L protein is tolerant to amino acid deletion or insertion. Recombinant RSVs carrying a single or double deletion or a single alanine insertion were genetically stable, highly attenuated in immortalized cells, had defects in replication and spread, and had a delay in innate immune cytokine responses in primary, well-differentiated, human bronchial epithelial (HBE) cultures. The replication of these recombinant viruses was highly attenuated in the upper and lower respiratory tracts of cotton rats. Importantly, these recombinant viruses elicited high levels of neutralizing antibody and provided complete protection against RSV replication. Taken together, amino acid deletions or insertions in the hinge region of the L protein can serve as a novel approach to rationally design genetically stable, highly attenuated, and immunogenic live virus vaccine candidates for RSV. IMPORTANCE Despite tremendous efforts, there are no FDA-approved vaccines for human respiratory syncytial virus (RSV). A live attenuated RSV vaccine is one of the most promising vaccine strategies for RSV. However, it has been a challenge to identify an RSV vaccine strain that has an optimal balance between attenuation and immunogenicity. In this study, we generated a panel of recombinant RSVs carrying a single and double deletion or a single alanine insertion in the large (L) polymerase protein that are genetically stable, sufficiently attenuated, and grow to high titer in cultured cells, while retaining high immunogenicity. Thus, these recombinant viruses may be promising vaccine candidates for RSV.

Background Fish sauce has a subtle flavor with prominent umami and salty taste, and is accompanied by a certain sweetness and bitterness. In order to identify a wider range of umami peptides, Chinese southern and northern anchovy sauce were selected for the study. Results Seventeen peptides were obtained by separation and purification, and their taste activity was predicted. Through the taste characterization and descriptive analysis, it was found that the synthesized peptides were umami and umami-enhancing peptides. Seventeen umami peptides were simulated and embedded into the umami receptor T1R1/T1R3 by inserting into the Venus flytrap domain (VFTD) of the T1R3 subunit; the interaction forces were mainly hydrogen bonding, electrostatic interaction, van der Waals force and hydrophobic interaction. According to the docking interaction energies, long-chain peptides may be easier to bind to the receptor than short-chain peptides. Asp196, Glu128 and Glu197 were the main binding sites for docking, and could affect umami synergism. Conclusion For the first time, novel umami peptides in Chinese anchovy sauce have been reported. This study is helpful for discovering umami marine resource peptides, and can provide a basis for further understanding the flavor system of anchovy sauce. © 2020 Society of Chemical Industry.

Phenoloxidase (PO) is a typical metal enzyme, which requires metal ions as prosthetic groups to enable the full exertion of its activity. To study how metal ions affected the activity and structure of PO enzymes, while providing reference materials for in-depth investigations, we examined the effects of different metal ions (Cu2+, Zn2+, Mg2+, Ca2+, and Ba2+) on their activities. Furthermore, Cu2+ and Mg2+ were selected for further investigation through UV spectra, intrinsic fluorescence spectroscopy, AFM, and FTIR. It was revealed that Cu2+ had a more obvious effect on PO compared to Mg2+. The PO could be activated when the concentrations of Cu2+ and Mg2+ were lower than 10−3 and 10−2 mol/L, respectively, and maximum PO activities (182.14% and 141.02%) were observed at 10−4 mol/L concentrations of Cu2+ and Mg2+. When the concentrations of Cu2+ and Mg2+ were higher than 10−2 and 10−1 mol/L, the activities PO were inhibited. The results of the UV–vis and fluorescence spectra revealed that Cu2+ shaped the tertiary structure of PO, whereas the effect of Mg2+ was slight. The AFM results demonstrated that high concentrations of Cu2+ and Mg2+ resulted in PO aggregation. FTIR analysis indicated that the total content of PO α-helices and β-sheets decreased with higher concentrations of Cu2+ and Mg2+.

The nonstructural protein 1 (NS1) of several flaviviruses, including West Nile, dengue, and yellow fever viruses, is capable of inducing variable degrees of protection against flavivirus infection in animal models. However, the immunogenicity of NS1 protein of Zika virus (ZIKV) is less understood. Here, we determined the efficacy of ZIKV NS1-based vaccine candidates using two delivery platforms, methyltransferase-defective recombinant vesicular stomatitis virus (mtdVSV) and a DNA vaccine. We first show that expression of ZIKV NS1 could be significantly enhanced by optimizing the signal peptide. A single dose of mtdVSV-NS1-based vaccine or two doses of DNA vaccine induced high levels of NS1-specfic antibody and T cell immune responses but provided only partial protection against ZIKV viremia in BALB/c mice. In Ifnar1(−/−) mice, neither NS1-based vaccine provided protection against a lethal high dose (10(5) PFU) ZIKV challenge, but mtdVSV-NS1-based vaccine prevented deaths from a low dose (10(3) PFU) challenge, though they experienced viremia and body weight loss. We conclude that ZIKV NS1 alone conferred substantial, but not complete, protection against ZIKV infection. Nevertheless, these results highlight the value of ZIKV NS1 for vaccine development. IMPORTANCE Most Zika virus (ZIKV) vaccine research has focused on the E or prM-E proteins and the induction of high levels of neutralizing antibodies. However, these ZIKV neutralizing antibodies cross-react with other flaviviruses, which may aggravate the disease via an antibody-dependent enhancement (ADE) mechanism. ZIKV NS1 protein may be an alternative antigen for vaccine development, since antibodies to NS1 do not bind to the virion, thereby eliminating the risk of ADE. Here, we show that recombinant VSV and DNA vaccines expressing NS1, alone, confer partial protection against ZIKV infection in both immunocompetent and immunodeficient mice, highlighting the value of NS1 as a potential vaccine candidate.

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in children of

The 5′ cap methylation of viral RNA plays important roles in RNA stability, efficient translation, and immune evasion. Thus, RNA cap methylation is an attractive target for antiviral discovery and development of new live attenuated vaccines. For coronaviruses, RNA cap structure is first methylated at the guanine-N-7 (G-N-7) position by nonstructural protein 14 (nsp14), which facilitates and precedes the subsequent ribose 2′-O methylation by the nsp16-nsp10 complex. Using porcine epidemic diarrhea virus (PEDV), an Alphacoronavirus, as a model, we showed that G-N-7 methyltransferase (G-N-7 MTase) of PEDV nsp14 methylated RNA substrates in a sequence-unspecific manner. PEDV nsp14 can efficiently methylate RNA substrates with various lengths in both neutral and alkaline pH environments and can methylate cap analogs (GpppA and GpppG) and single-nucleotide GTP but not ATP, CTP, or UTP. Mutations to the S-adenosyl-l-methionine (SAM) binding motif in the nsp14 abolished the G-N-7 MTase activity and were lethal to PEDV. However, recombinant rPEDV-D350A with a single mutation (D350A) in nsp14, which retained 29.0% of G-N-7 MTase activity, was viable. Recombinant rPEDV-D350A formed a significantly smaller plaque and had significant defects in viral protein synthesis and viral replication in Vero CCL-81 cells and intestinal porcine epithelial cells (IPEC-DQ). Notably, rPEDV-D350A induced significantly higher expression of both type I and III interferons in IPEC-DQ cells than the parental rPEDV. Collectively, our results demonstrate that G-N-7 MTase activity of PEDV modulates viral replication, gene expression, and innate immune responses. IMPORTANCE Coronaviruses (CoVs) include a wide range of important human and animal pathogens. Examples of human CoVs include severe acute respiratory syndrome coronavirus (SARS-CoV-1), Middle East respiratory syndrome coronavirus (MERS-CoV), and the most recently emerged SARS-CoV-2. Examples of pig CoVs include porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine enteric alphacoronavirus (SeACoV). There are no vaccines or antiviral drugs for most of these viruses. All known CoVs encode a bifunctional nsp14 protein which possesses ExoN and guanine-N-7 methyltransferase (G-N-7 MTase) activities, responsible for replication fidelity and RNA cap G-N-7 methylation, respectively. Here, we biochemically characterized G-N-7 MTase of PEDV nsp14 and found that G-N-7 MTase-deficient PEDV was defective in replication and induced greater responses of type I and III interferons. These findings highlight that CoV G-N-7 MTase may be a novel target for rational design of live attenuated vaccines and antiviral drugs.

Anchovy sauce shows different taste profiles under different fermentation time. The change rules of free amino acids was measured by amino acid analyzer, and other taste substances, such as nucleotides and organic acids in anchovy sauce under different fermentation time were also investigated. Moreover, the correlation between protease activity and taste substances in anchovy sauce fermentation was analyzed by orthogonal partial least squares. Throughout the fermentation process, the taste substances in anchovy sauce increased during early months and then decreased as time increased. The content of amino acid nitrogen, TCA-soluble peptides, 5′-nucleotides (AMP, GMP, IMP) and organic acids (lactic acid, succinic acid) in anchovy sauce increased by 26%, 33%, (45%, 35%, 68%) and (27%, 2%) respectively in comparison with 6 months fermentation. Total amino acid content reached its maximum after 18 months fermentation. Results of electronic tongue demonstrated that the umami of anchovy sauce after 12 months fermentation increased by 17% in comparison with 6 months fermentation. A model correlating changes in protease activity with taste formation suggested that protease activity impacted the content of Ala, Glu, Lys, Asp, Leu, TCA-soluble peptides and succinic acid. This study can provide empirical evidence to guide the efficient processing of anchovy sauce.

Aims Cyclophosphamide (CTX) is an effective anti-tumor and immunosuppressive agent, but it induces nephrotoxicity in clinical applications. The present study aimed to evaluate the protective effect of pyrroloquinoline quinone (PQQ) on CTX-induced nephrotoxicity. Main methods We injected male ICR mice with CTX (80 mg/kg/day), and determined nephrotoxicity indices, MDA and antioxidant defenses, inflammatory cytokines, and the levels of main proteins in the Nrf2-HO-1 and NLRP3 signaling pathways. Key findings PQQ has significantly decreased the serum levels of creatinine and urea compared to Model group. When treated with PQQ, MDA, IL-1β, IL-6, and TNF-α levels have decreased, and SOD, GSH-Px, and CAT activity have increased in the kidney tissues of CTX-induced mice. PQQ activated the Nrf2-mediated signaling pathway, as indicated by the increased expression of Nrf2, HO-1, GCLM, and NQO1. Moreover, PQQ inhibited the NLRP3 inflammatory pathway, as indicated by the reduced expression of NLRP3, ASC, and Caspase-1. Significance Our results suggest that PQQ protects against CTX-induced nephrotoxicity, probably by activating the Nrf2-mediated antioxidant pathway and inhibiting the NLRP3 inflammatory pathway.

The dedicator of cytokinesis (DOCK) family proteins consist of 11 members, each of which contains 2 domains, DOCK homology region (DHR)-1 and DHR-2, and as guanine nucleotide exchange factors, they mediate activation of small GTPases. Both DOCK2 and DOCK8 deficiencies in humans can cause severe combined immunodeficiency, but they have different characteristics. DOCK8 defect mainly causes high IgE, allergic disease, refractory skin virus infection, and increased incidence of malignant tumor, whereas DOCK2 defect mainly causes early-onset, invasive infection with less atopy and increased IgE. However, the underlying molecular mechanisms causing the disease remain unclear. This paper discusses the role of DOCK family proteins in regulating B and T cells, including development, survival, migration, activation, immune tolerance, and immune functions. Moreover, related signal pathways or molecule mechanisms are also described in this review. A greater understanding of DOCK family proteins and their regulation of lymphocyte functions may facilitate the development of new therapeutics for immunodeficient patients and improve their prognosis.

Human papillomaviruses 16 (HPV16) is the primary causative agent of cervical cancer (CC). E6 oncoprotein plays a crucial role in cervical carcinogenesis and commonly cause the dysregulation of the long noncoding RNAs (lncRNAs) expression. However, the biological function of lncRNAs in HPV16-related CC remains largely unexplored. In the present study HPV16 E6-induced differential expression of lncRNAs, miRNA, and mRNA were identified using microarray-based analysis and verified in tumor r cell lines and tumor tissues, and the function of lncRNA in CC was investigated in vitro and in vivo. We found that an lncRNA, named GABPB1-AS1, was significantly upregulated in HPV16-positive CC tissues and cell lines. GABPB1-AS1 expression in HPV16-positive CC tissues was positively associated with tumor size, lymph node metastasis, and FIGO stage. High expression of GABPB1-AS1 was correlated with a poor prognosis for HPV16-positive CC patients. Functionally, E6-induced GABPB1-AS1 overexpression facilitated CC cells proliferation and invasion in vitro and in vivo. Mechanistically, GABPB1-AS1 acted as a competing endogenous RNA (ceRNA) by sponging miR-519e-5p, resulting in the de-repression of its target gene Notch2 which is well known as an oncogene. Therefore, GABPB1-AS1 functioned as a tumor activator in CC pathogenesis by binding to miR-519e-5p and destroying its tumor suppressive function. Collectively, current results demonstrate that GABPB1-AS1 is associated with CC progression, and may be a promising biomarker or target for the clinical management of CC.

Purpose We aimed to further clarify the epidemiological and clinical characteristics of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Methods We identified close contacts of confirmed coronavirus disease 2019 (COVID-19) cases in northeast Chongqing, China, who were confirmed by real-time reverse transcription polymerase chain reaction-positive (RT-PCR+). We stratified this cohort by normal vs abnormal findings on chest computed tomography (CT) and compared the strata regarding comorbidities, demographics, laboratory findings, viral transmission and other factors. Results Between January 2020 and March 2020, we identified and hospitalized 279 RT-PCR+ contacts of COVID-19 patients. 63 (23%) remained asymptomatic until discharge; 29 had abnormal and 34 had normal chest CT findings. The mean cohort age was 39.3 years, and 87.3% had no comorbidities. Mean time to diagnosis after close contact with a COVID-19 index patient was 16.0 days, and it was 13.4 days and 18.7 days for those with abnormal and normal CT findings, respectively (P < .05). Nine patients (14.3%) transmitted the virus to others; 4 and 5 were in the abnormal and normal CT strata, respectively. The median length of time for nucleic acid to turn negative was 13 days compared with 10.4 days in those with normal chest CT scans (P < .05). Conclusions A portion of asymptomatic individuals were capable of transmitting the virus to others. Given the frequency and potential infectiousness of asymptomatic infections, testing of traced contacts is essential. Studies of the impact of treatment of asymptomatic RT-PCR+ individuals on disease progression and transmission should be undertaken.

Enteric viruses are shed in fecal material by humans and other animals and are common contaminants in wastewater and surface water. Wastewater treatment plants often disinfect this effluent with low-pressure and medium-pressure UV lamps, which emit 254-nm and 220- to 280-nm irradiation, respectively. It is not known whether this treatment is efficacious against enteric viruses or how such treatments may inactivate these enteric viruses. This study examined UV disinfection for two enteric viruses: rotavirus (RV) (strain OSU with double-stranded RNA and a three-layer capsid) and Tulane virus (TV) (a cultivable surrogate for human norovirus with single-stranded RNA and a single-layer capsid). Viruses were treated with UV irradiation at 220 or 254 nm under conditions relevant to wastewater stabilization ponds, whose water is often used for irrigation. TV was susceptible to 220- or 254-nm UV at similar levels. It appears that UV irradiation inactivated TV by mutagenizing both its genome and capsid binding proteins. RV was more susceptible to UV at 220 nm than to UV at 254 nm. UV irradiation of RV at either 220 or 254 nm resulted in a virus that retained its ability to bind to its host cell receptor. After 220-nm treatment, the VP7 segment of the RV genome could not be amplified by PCR, suggesting that this treatment mutagenized the viral genome. However, this correlation was not observed when UV at 254 nm was used. Thus, RV and TV, with different genome and capsid contents, are targeted by UV irradiation in different ways. IMPORTANCE UV irradiation is becoming common for disinfection in water treatment plants, but little is known about the effectiveness of this treatment for enteric RNA viruses. Here, we observed that 220-nm UV irradiation was efficacious against rotavirus (RV) and Tulane virus (TV). UV irradiation at 254 nm inactivated TV to a greater extent than RV. Additional assays showed that UV irradiation compromised different portions of the RV and TV life cycles. UV irradiation decreased the binding of TV to its host receptor and mutagenized the TV genome. UV irradiation at 220 nm appeared to allow RV–host receptor interaction but halted RV genome replication. These findings provide knowledge about the disinfection of waterborne viruses, information that is important for the safe reuse or release of treated wastewater.

BACKGROUND Implants with platform-switching (PS) design have been demonstrated to reduce marginal bone loss. However, the influence on peri-implant soft tissue healing is unclear. This study was designed to investigate its effect on peri-implant soft tissue healing after implant uncovery. METHODS Non-smokers needing two implants in different quadrants were recruited in this study. For each individual, one PS and one platform-matching (PM) implants were placed using two-stage protocol. Following 2 to 8 months of healing, all implants were uncovered and connected to the corresponding healing abutments. Clinical measurements and peri-implant crevicular fluid (PICF) were taken at 1-, 2-, 4-, and 6-week after 2nd stage surgery. The cytokine concentrations in PICF were analyzed. Peri-implant mucosa (1 × 2 × 2 mm) was harvested around the healing abutment for the analysis of gene expression at uncovery and 6-week post-uncovery. RESULTS Eighteen participants (nine males; 51.7 ± 14.9 years) were recruited. Compared to PM, PS showed significantly lower probing depth (PD) at 1- and 2-week as well as modified sulcus bleeding index (mSBI) at 1-, 4-, and 6-week (P

Edible films can be designed to serve as carriers of antimicrobial agents and be used to control pathogenic foodborne viruses and bacteria. This research tested this concept by dissolving green tea extract (GTE) in chitosan film-forming solutions (FFS) and using it to prepare dried chitosan edible films. As a control, the GTE was also dissolved in deionized water (DW). The FFS and the dried chitosan films with the GTE and the DW without chitosan were all evaluated against murine norovirus (MNV-1), Escherichia coli K12, and Listeria innocua. Both the FFS and the DW with GTE were incubated with ~107 PFU/ml of the virus suspensions for 3 h. The chitosan films with GTE were incubated for 4 and 24 h at 23±1°C. The results showed that the DW containing 1, 1.5, and 2.5% aqueous GTE, significantly (p<0.05) reduced MNV-1 plaques by 1.7, 2.5, and 3.3 logs after 3 h exposure, respectively. Similarly, FFS containing 2.5 and 5.0% GTE reduced MNV-1 counts by 2.5 and 4.0 logs, respectively, after 3 h exposure. The dried chitosan films with 5, 10, and 15% GTE were also effective against MNV-1 infectivity. After 24 h incubation, the 5 and 10% chitosan GTE films produced significant (p<0.05) titer reductions of 1.6 and 4.5 logs, respectively. Chitosan films containing 15% GTE reduced MNV-1 plaques to undetectable levels in 24 h. All chitosan GTE films reduced E. coli K12 and L. innocua populations to undetectable levels in tryptic soy broth after 24 h exposure. The results of this study showed that edible films enriched with GTE have potential to reduce both foodborne viruses and bacteria.

Quorum sensing (QS) is a signal sensing system by which bacteria monitor the density of their population, thus, targeting to QS system may be an alternative approach to control diverse cellular processes including the microbial contamination and the virulence of human and plant pathogens as bacteria have been evolving resistance to antibiotics. In this study, curcumin liposomes were prepared by film dispersion method to increase its bioavailability against QS systems of food-borne epathogenic bacteria, i.e. Aeromonas hydrophila and Serratia grimesii. And their physicochemical properties were measured including particle size, zeta-potential entrapment rate as well as drug-loading rate. Meanwhile, the effects of curcumin liposomes on QS phenomenon of food-borne pathogens including biofilm formation, extracellular protease, swimming motility et al. were determined. Results showed that the average diameter of curcumin liposomes was (207 ± 8.2) nm and the entrapment rate and drug-loading rate were 82.71% and 23.33%. The zeta-potential of curcumin liposomes were (−37 ± 1.56) mv. Curcumin liposomes showed uniform structures by scanning electron microscopy (SEM). The curcumin liposomes could significantly inhibit QS systems of the two pathogens and the biological availability of curcumin has been improved.

Background Human papillomavirus (HPV) infection and viral proteins expression cause a number of epigenetic alterations leading to cervical carcinogenesis. The recent discovery of a large amount of histone methylation modifiers reveals important roles of these enzymes in regulating tumor progression. Methods The changes in expression of 48 histone methylation modifiers were assessed following knockdown of HPV16 E7 in CaSki cells. Lysine-specific demethylase 2A (KDM2A)-regulated microRNAs (miRNAs) in cervical cancer pathogenesis were disclosed using quantitative real-time polymerase chain reaction. The function of KDM2A-miRNAs on cervical cancer was investigated in vitro and in vivo. Results Upregulation of KDM2A induced by HPV16 E7 promotes cervical cancer cell proliferation and invasion and is correlated with poor prognosis in patients with cervical cancer. KDM2A physically interacts with the promoter of miR-132 and suppresses its expression by removing the mono or dimethyl group from H3K36 at the miR-132 locus. Functionally, miR-132 represses cancer cell proliferation and invasion by inhibiting radixin (RDX). Upregulated KDM2A promotes cervical cancer progression by repressing miR-132, which results in a derepression of RDX. Therefore, KDM2A functions as a tumor activator in cervical cancer pathogenesis by binding miR-132 promoter and abrogating its tumor suppressive function. Conclusion Our results suggest a function for KDM2A in cervical cancer progression and suggest its candidacy as a new prognostic biomarker and target for clinical management of cervical cancer.

Current efforts to develop Zika virus (ZIKV) subunit vaccines have been focused on pre-membrane (prM) and envelope (E) proteins, but the role of NS1 in ZIKV-specific immune response and protection is poorly understood. Here, we develop an attenuated recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing ZIKV prM-E-NS1 as a polyprotein. This vectored vaccine candidate is attenuated in mice, where a single immunization induces ZIKV-specific antibody and T cell immune responses that provide protection against ZIKV challenge. Co-expression of prM, E, and NS1 induces significantly higher levels of Th2 and Th17 cytokine responses than prM-E. In addition, NS1 alone is capable of conferring partial protection against ZIKV infection in mice even though it does not induce neutralizing antibodies. These results demonstrate that attenuated rVSV co-expressing prM, E, and NS1 is a promising vaccine candidate for protection against ZIKV infection and highlights an important role for NS1 in ZIKV-specific cellular immune responses., Current Zika virus (ZIKV) subunit vaccine development largely focuses on prM and E proteins, and the role of NS1 for immune response and protection is unclear. Here, Li et al. develop an attenuated VSV-based vaccine expressing a ZIKV prM-E-NS1 polyprotein and characterize immune response and protection in mice.

Pseudomonas fluorescens, a Gram-negative psychrotrophic bacteria, is the main microorganism causing spoilage of chilled raw milk and aquatic products. Quorum sensing (QS) widely exists in bacteria to monitor their population densities and regulate numerous physiological activities, such as the secretion of siderophores, swarming motility and biofilm formation. Thus, searching for quorum sensing inhibitors (QSIs) may be another promising way to control the deterioration of food caused by P. fluorescens. Here, we screened a traditional Chinese medicine (TCM) database to discover potential QSIs with lesser toxicity. The gene sequences of LuxI- and LuxR-type proteins of P. fluorescens P07 were obtained through whole-genome sequencing. In addition, the protein structures built by homology modelling were used as targets to screen for QSIs. Twenty-one compounds with a dock score greater than 6 were purchased and tested by biosensor strains (Chromobacterium violaceum CV026 and Agrobacterium tumefaciens A136). The results showed that 10 of the compounds were determined as hits (hit rate: 66.67%). Benzyl alcohol, rhodinyl formate and houttuynine were effective QSIs. The impact of the most active compound (benzyl alcohol) on the phenotypes of P. fluorescens P07, including swimming and swarming motility, production of extracellular enzymes and siderophores, N-acylhomoserine lactone (AHLs) content and biofilm formation were determined. The inhibitory mechanism of benzyl alcohol on the QS system of P. fluorescens P07 is further discussed. This study reveals the feasibility of searching for novel QSIs through virtual screening.

Some bacteria can modulate their spoilage potential by responding to environmental signaling molecules via the quorum sensing (QS) system. However, the ability of Pseudomonas fluorescens, the specific spoilage organism (SSO) of turbot, to response to environmental signaling molecules remains unclear. This study investigated the effects of six synthetic N-acyl homoserine lactones (AHLs) on typical behaviors mediated by QS in P. fluorescens, such as biofilm formation and extracellular protease activity. Total volatile basic nitrogen (TVB-N) was used as a spoilage indicator to evaluate quality changes in AHL-treated turbot filets during storage. The results confirm the enhancing effect of environmental AHLs on QS-dependent factors of P. fluorescens and quality deterioration of turbot filets, with C4-HSL and C14-HSL being the most effective. Moreover, the content decrease of exogenous AHLs was also validated by gas chromatography–mass spectrometry analysis. Further, changes in rhlR transcription levels in P. fluorescens suggest that this bacterium can sense environmental AHLs. Finally, molecular docking analysis demonstrates the potential interactions of RhlR protein with various exogenous AHLs. These findings strongly implicate environmental AHLs in turbot spoilage caused by P. fluorescens, suggesting preservation of turbot should not exclusively consider the elimination of SSO-secreted AHLs.

Introduction Duchenne muscular dystrophy (DMD) and golden retriever muscular dystrophy (GRMD) are X-linked disorders caused by mutations in the DMD gene. Autophagy was recently identified as a secondary therapeutic target for DMD. We hypothesized that autophagy would be reduced in GRMD. Methods Autophagic gene and protein expression was assessed in normal and GRMD skeletal muscles and correlated with phenotypic biomarkers. Results Muscles were differentially affected. Autophagy gene levels were lower than normal in the GRMD cranial sartorius (CS) but similar in the vastus lateralis (VL). Protein markers of autophagic flux, LC3B-II and p62, were higher in both GRMD muscles, in keeping with impaired autophagy. Protein levels correlated with a more severe phenotype. Autophagic structures were found in necrotic, fast-twitch GRMD myofibers. Discussion Our data suggest that autophagy is impaired in certain GRMD muscles. Differential GRMD CS involvement emphasizes that therapeutic modulation of autophagy could require specific muscle targeting. Muscle Nerve 58: 418-426, 2018.

Microorganism activities are considered the main cause of most food spoilage, leading to great economic losses. Pseudomonas fluorescens is a Gram-negative bacterium that is widely found in food and has high spoilage activity. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Thus, it is very possible that RpoS plays an important role in spoilage regulation in P. fluorescens. In this study an in-frame deletion mutation of rpoS was constructed to explore its function in P. fluorescens. The results showed that RpoS positively regulated the resistance of P. fluorescens to H2O2, heat, ethanol and crystal violet, negatively regulated the resistance to acetic acid, and had no effect on the resistance to NaCl. Further studies indicated that acylated homoserine lactone (AHL) production and the transcription levels of five AHL-related genes were significantly decreased in the rpoS mutant compared with those in the wild-type strain. Interestingly, the two homologous genes coding for AHL synthases contained RpoS-dependent −10 elements, suggesting that AHL quorum sensing is directly regulated by RpoS. RpoS also contributed to the spoilage activities of P. fluorescens by regulating extracellular protease and total volatile basic nitrogen (TVB-N) production in sterilized salmon juice. Our results reveal that RpoS was a key regulatory factor involved in stress resistance, the AHL quorum sensing system, and spoilage potential of P. fluorescens. Our study may benefit food safety control and food preservation.

In order to circumvent some challenges of the classical approach, the in silico method has been applied to the discovery of angiotensin-converting enzyme (ACE) inhibitory peptides from food proteins. In this study, some convenient and efficient in silico tools were utilized to identify novel ACE inhibitory peptides from Salmo salar.; Results: Collagen from Salmo salar was digested in silico into hundreds of peptides. Results revealed that tetrapeptides PGAR and IGPR showed potent ACE inhibitory activity, with IC50 values of 0.598 ± 0.12 and 0.43 ± 0.09 mmol L-1 , respectively. The molecular docking result showed that PGAR and IGPR interact with ACE mostly via hydrogen bonds and attractive charge. Peptide IGPR interacts with Zn+ at the ACE active site, showing high inhibitory activity.; Conclusion: Interaction with Zn+ in ACE may lead to higher inhibitory activity of peptides, and Pi interactions may promote the effect of peptides on ACE. The in silico method can be an effective method to predict potent ACE inhibitory peptides from food proteins. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Pseudomonas fluorescens, an important food spoiling bacteria, uses quorum sensing to control biofilm formation and motility. To date, only a few compounds targeting the LuxR-based quorum sensing system of P. fluorescens have been identified. In the present study, the quorum sensing inhibitory effect of cinnamaldehyde at sublethal concentrations was investigated in terms of inhibition of the extracellular protease, biofilm formation, and swimming and swarming motility. The total volatile basic nitrogen value was also measured to evaluate the effect of cinnamaldehyde on quality preservation of turbot fillets stored at 4 ± 1 °C for 15 days. The results showed that cinnamaldehyde significantly inhibited quorum sensing-dependent factors in P. fluorescens and extended the storage life of turbot. Unexpectedly, cinnamaldehyde did not interfere with production of AHLs (N­acylhomoserine lactones) by P. fluorescens, as shown by measurement of AHL production using GC–MS. Molecular docking analysis revealed that cinnamaldehyde can interact with the LuxR-type protein of P. fluorescens, which could constitute the molecular basis of the quorum sensing inhibition observed. These findings strongly suggest that cinnamaldehyde is a quorum sensing inhibitor with great potential for the preservation of aquatic products to guarantee food safety.

Optimizing the physicochemical properties of microwave-cooked meat needs a better understanding of the mechanisms responsible for protein changes. This paper explored the causes of aggregation of the denatured fish protein in ready-to-eat food by determining the changes in sarcoplasmic and myofibril proteins, which includes the effects of different microwave power levels (300, 600, and 900 W) and heating times (0–60 s) on the aggregation kinetics and physiochemical properties. The determination of aggregation kinetics that accurately describes microwave cooking characteristics is crucial for the optimization of operating parameters, performance improvement of the cooked food system, and product quality. The aggregation rate and turbidity of proteins increased with increasing microwave power and time. A negative correlation was observed between the protein solubility and microwave power and time. Protein aggregation induced by microwave showed a reliable and reproducible characterization of particle size distributions. At longer microwave heating time or higher microwave power, these protein particles formed larger aggregates.

Aim: This study aimed to characterize plasmid-mediated antimicrobial resistance in clinical Klebsiella pneumoniae 1220 carrying bla CTX-M-14 and qnrB4. Materials & methods: Plasmid p1220-CTXM was transformed from the 1220 isolate into Escherichia coli through conjugal transfer and then fully sequenced. Antimicrobial susceptibility was determined by VITEK. Results: p1220-CTXM was an IncFIIK plasmid genetically closely related to pKP048 and carried resistance markers including bla CTX-M-14, bla DHA-1, qnrB4, sul1 and qacEΔ1, all of which were harbored in a 35.7-kb multidrug-resistant region. bla CTX-M-14 was located in a truncated ISEcp1-bla CTX-M-14-orf477 transposition unit, and qnrB4 and bla DHA-1 were in a truncated qnrB4-bla DHA-1 region. Conclusion: This study provided the insight into the co-occurrence of bla CTX-M-14 and qnrB4 and the evolution of pKP048-related IncFIIK plasmids.