Dear Editor,The pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),continues despite extensive efforts to control viral transmission.Meanwhile,the emerg...Dear Editor,The pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),continues despite extensive efforts to control viral transmission.Meanwhile,the emergence of SARS-CoV-2 variants with antigenically divergence in viral protein dampens the efficacy of authorized vaccines,leading to the breakthrough infections in vaccinated population(Cao et al.,2021,2022;Tuekprakhon et al.,2022;Xiang et al.,2022).Moreover,diverse sarbecoviruses in bats and pangolins have been discovered and isolated(Ge et al.,2013;Xiao et al.,2020).Some of these viruses have exhibited efficient binding to human angiotensin-converting enzyme 2(hACE2)(Xiao et al.,2020;Liu et al.,2021;Temmam et al.,2022),highlighting the risk of spillover from wild animals to human.Thus,the development of pan-sarbecovirus vaccines is of high priority.展开更多
A switch from avian-typeα-2,3 to human-typeα-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus.Some H9N2 viruses exhibit a preference for binding to human-typeα-2,...A switch from avian-typeα-2,3 to human-typeα-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus.Some H9N2 viruses exhibit a preference for binding to human-typeα-2,6 receptors.This identifies their potential threat to public health.However,our understanding of the molecular basis for the switch of receptor preference is still limited.In this study,we employed the random forest algorithm to identify the potentially key amino acid sites within hemagglutinin(HA),which are associated with the receptor binding ability of H9N2 avian influenza virus(AIV).Subsequently,these sites were further verified by receptor binding assays.A total of 12 substitutions in the HA protein(N158D,N158S,A160 N,A160D,A160T,T163I,T163V,V190T,V190A,D193 N,D193G,and N231D)were predicted to prefer binding toα-2,6 receptors.Except for the V190T substitution,the other substitutions were demonstrated to display an affinity for preferential binding toα-2,6 receptors by receptor binding assays.Especially,the A160T substitution caused a significant upregulation of immune-response genes and an increased mortality rate in mice.Our findings provide novel insights into understanding the genetic basis of receptor preference of the H9N2 AIV.展开更多
Coronavirus disease 2019(COVID-19),caused by the novel human coronavirus SARS-CoV-2,is currently a major threat to public health worldwide.The viral spike protein binds the host receptor angiotensin-converting enzyme ...Coronavirus disease 2019(COVID-19),caused by the novel human coronavirus SARS-CoV-2,is currently a major threat to public health worldwide.The viral spike protein binds the host receptor angiotensin-converting enzyme 2(ACE2)via the receptor-binding domain(RBD),and thus is believed to be a major target to block viral entry.Both SARS-CoV-2 and SARS-CoV share this mechanism.Here we functionally analyzed the key amino acid residues located within receptor binding motif of RBD that may interact with human ACE2 and available neutralizing antibodies.The in vivo experiments showed that immunization with either the SARS-CoV RBD or SARS-CoV-2 RBD was able to induce strong clade-specific neutralizing antibodies in mice;however,the cross-neutralizing activity was much weaker,indicating that there are distinct antigenic features in the RBDs of the two viruses.This finding was confirmed with the available neutralizing monoclonal antibodies against SARS-CoV or SARS-CoV-2.It is worth noting that a newly developed SARS-CoV-2 human antibody,HA001,was able to neutralize SARS-CoV-2,but failed to recognize SARS-CoV.Moreover,the potential epitope residues of HA001 were identified as A475 and F486 in the SARS-CoV-2 RBD,representing new binding sites for neutralizing antibodies.Overall,our study has revealed the presence of different key epitopes between SARS-CoV and SARSCoV-2,which indicates the necessity to develop new prophylactic vaccine and antibody drugs for specific control of the COVID-19 pandemic although the available agents obtained from the SARS-CoV study are unneglectable.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused many deaths and contributed to a tremendous public health concern worldwide since 2020.Angiotensin-converting enzyme 2(ACE2)binds to the SARS-CoV-2...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused many deaths and contributed to a tremendous public health concern worldwide since 2020.Angiotensin-converting enzyme 2(ACE2)binds to the SARS-CoV-2 virus as a receptor.The challenge of different nonhuman primate(NHP)species by SARSCoV-2 virus demonstrated different effects on virus replication and disease pathology.This study characterizes differences between host ACE2 sequences of three NHP species:Macaca mulatta,Macaca fascicularis,and Chlorocebus sabaeus.In addition,the binding affinity between the ACE2 ectodomain and the SARS-CoV-2 S receptor-binding domain(RBD)was analyzed.Variation of ACE2 sequence among NHP species and the binding affinity may account for different susceptibility and responses to SARS-CoV-2 infection.展开更多
A novel avian-origin H7N9 influenza virus was discovered in March in China and has caused a total of131 people infected including 39 deaths in China as of June 9, 2013. Adaptation of avian viruses to efficiently infec...A novel avian-origin H7N9 influenza virus was discovered in March in China and has caused a total of131 people infected including 39 deaths in China as of June 9, 2013. Adaptation of avian viruses to efficiently infect humans requires the viral hemagglutinin（HA） binding switches from avian to human type receptors with help of some mutations in HA. As such it is critical for pandemic assessment to discover these mutations as hallmarks of adaptation. To continue our previous study of this novel H7N9 virus, we identified two sets of mutations in HA. The first set of mutations are present in the current circulating strains of 2013 H7N9 in China, and the second set are potential mutations that were found when compared to the HAs of previous human H7 subtype. These two sets of mutations exhibited unique features. The first group of mutations, on average, enhanced the HA binding to human type receptors whereas reduced that to avian types. Further the reduction of avian binding was almost three times of the increase of the human binding. The second group increased the binding to both human and avian types.But the increase in human types was almost three times of that in the avian types. Though different in their way of changing the binding preference, these two sets of mutations both contained more mutations to decrease the avian binding and increase the human binding than those that did the opposite. Our research highlighted the pandemic potential of this novel virus by showing the important mutations that could potentially help it to adapt to human hosts. Our findings offered new insights into the current state of evolution of this virus, which might be helpful for the continued surveillance of the emergence of H7N9 strains having the ability of human-to-human transmission.展开更多
Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3（15/85, v/v）demonstrated that the...Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3（15/85, v/v）demonstrated that the short oligo （aryltriazole）s backbone 1 could not bind halide anions unless that amide H-bond donors were incorporated at the termini of the oligomer. Terminal substituents on oligo（aryltriazoleamide）s foldamers 2–4 display a considerable influence on the binding affinities of the foldamers for halide anions. Large steric hindrance of the terminal substituents was found to be unfavorable for binding halide anions, but aromatic π-π interactions between two terminal substituents are capable of stabilizing the conformation of foldamers thus giving rise to an enhancement in the binding strengths. However, the terminal substituents were found to hardly affect the binding selectivity in the studied cases.展开更多
Influenza,a highly contagious respiratory infectious disease caused by an influenza virus,is a threat to public health worldwide.Avian influenza viruses(AIVs)have the potential to cause the next pandemic by crossing t...Influenza,a highly contagious respiratory infectious disease caused by an influenza virus,is a threat to public health worldwide.Avian influenza viruses(AIVs)have the potential to cause the next pandemic by crossing the species barrier through mutation of viral genome.Here,we investigated the pathogenicity of AIVs obtained from South Korea and Mongolia during 2018–2019 by measuring viral titers in the lungs and extrapulmonary organs of mouse models.In addition,we assessed the pathogenicity of AIVs in ferret models.Moreover,we compared the ability of viruses to replicate in mammalian cells,as well as the receptor-binding preferences of AIV isolates.Genetic analyses were finally performed to identify the genetic relationships and amino acid substitutions between viral proteins during mammalian adaptation.Of the 24 AIV isolates tested,A/Mallard/South Korea/KNU2019-34/2019(KNU19-34;H1N1)caused severe bodyweight loss and high mortality in mice.The virus replicated in the lungs,kidneys,and heart.Importantly,KNU19-34-infected ferrets showed high viral loads in both nasal washes and lungs.KNU19-34 replicated rapidly in A549 and bound preferentially to human likeα2,6-linked sialic acids rather than to avian-likeα2,3-linked sialic acids,similar to the pandemic A/California/04/2009(H1N1)strain.Gene segments of KNU19-34 were distributed in Egypt and Asia lineages from 2015 to 2018,and the virus had several amino acid substitutions compared to H1N1 AIV isolates that were non-pathogenic in mice.Collectively,the data suggest that KNU19-34 has zoonotic potential and the possibility of new mutations responsible for mammalian adaptation.展开更多
Remodeling plant intracellular nucleotide-binding leucine-rich repeat immune receptors(NLRs)to engineer synthetic disease-resistance genes has emerged as a promising approach to achieving broad-spectrum disease resist...Remodeling plant intracellular nucleotide-binding leucine-rich repeat immune receptors(NLRs)to engineer synthetic disease-resistance genes has emerged as a promising approach to achieving broad-spectrum disease resistance.But strategies for expanding NLR recognition spectra[[1],[2],[3],[4],[5]]are often limited by the rapid evolution of pathogens and pests.In our recent study,we developed an innovative strategy to engineer broad-spectrum,durable and complete disease resistance in plants by remodeling autoactive NLRs into protease-activated switches[6].展开更多
Avian infl uenza A virus continues to pose a global threat with occasional H5N1 human infections,which is em-phasized by a recent severe human infection caused by avian-origin H7N9 in China.Luckily these viruses do no...Avian infl uenza A virus continues to pose a global threat with occasional H5N1 human infections,which is em-phasized by a recent severe human infection caused by avian-origin H7N9 in China.Luckily these viruses do not transmit effi ciently in human populations.With a few ami-no acid substitutions of the hemagglutinin H5 protein in the laboratory,two H5 mutants have been shown to obtain an air-borne transmission in a mammalian ferret model.Here in this study one of the mutant H5 proteins devel-oped by Kawaoka’s group(VN1203mut)was expressed in a baculovirus system and its receptor-binding properties were assessed.We herein show that the VN1203mut had a dramatically reduced binding affi nity for the avianα2,3-linkage receptor compared to wild type but showed no detectable increase in affi nity for the humanα2,6-linkage receptor,using Surface Plasmon Resonance techonology.Further,the crystal structures of the VN1203mut and its complexes with either human or avian receptors demon-strate that the VN1203mut binds the human receptor in the same binding manner(cis conformation)as seen for the HAs of previously reported 1957 and 1968 pandemic influenza viruses.Our receptor binding and crystallo-graphic data shown here further confi rm that the ability to bind the avian receptor has to decrease for a higher hu-man receptor binding affi nity.As the Q226L substitution is shown important for obtaining human receptor binding,we suspect that the newly emerged H7N9 binds human receptor as H7 has a Q226L substitution.展开更多
This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone （r-fGH） was expressed by Escherichia coli in form of inclusion body or as ...This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone （r-fGH） was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield （2.605 mg L^-1） than that from soluble protein （1.964 mg L^-l）. Of the tested recovery methods, addition of renaturing buffer （pH 8.5） into denatured inclusion body yielded the best recovery rate （17.9%）. This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.展开更多
Current understanding about how the virus that causes COVID-19 spreads is largely based on what is known about similar coronaviruses.Some of the Natural products are suitable drugs against SARS-CoV-2 main protease.For...Current understanding about how the virus that causes COVID-19 spreads is largely based on what is known about similar coronaviruses.Some of the Natural products are suitable drugs against SARS-CoV-2 main protease.For recognizing a strong inhibitor,we have accomplished dock-ing studies on the major virus protease with 4 natural product species as anti COVID-19(SARS-CoV-2),namely“Vidarabine”,“Cytarabine”,“Gem-citabine”and“Matrine”which have been extracted fromGillan’s leaves plants.These are known as Chuchaq,Trshvash,Cote-Couto and Khlvash in Iran.Among these four studied compounds,Cytarabine appears as a suitable com-pound with high effectiveness inhibitors to this protease.Finally by this work we present a method on the Computational Prediction of Protein Structure Associated with COVID-19 Based Ligand Design and Molecular Modeling.By this investigation,auto dock software(iGEM-DOCK)has been used and via this tool,the suitable receptors can be distinguished in whole COVID-19 component structures for forming a complex.“iGEMDOCK”is suitable to define the binding site quickly.With docking simulation and NMR inves-tigation,we have demonstrated these compounds exhibit a suitable binding energy around 9 Kcal/mol with various ligand proteins modes in the bind-ing to COVID-19 viruses.However,these data need further evaluation for repurposing these drugs against COVID-19 viruses,in both vivo&vitro.展开更多
Adapter proteins can regulate the gene transcriptions in disparate signaling pathway by interacting with multiple signaling molecules, including T cell activation signaling. Nuclear receptor binding protein （NRBP）, ...Adapter proteins can regulate the gene transcriptions in disparate signaling pathway by interacting with multiple signaling molecules, including T cell activation signaling. Nuclear receptor binding protein （NRBP）, a novel adapter protein, represents a small family of evolutionarily conserved proteins with homologs in Caenorhabditis elegans （C. elegans）, Drosophila melanogaster （i）. melanogaster）, mouse and human. Here, we demonstrated that overexpression of NRBP in Jurkat TAg cells specifically impairs T cell receptor （TCR） or phorbol myristate acetate （PMA） /ionomycin-mediated signaling leading to nuclear factor of activated T cells （NFAT） promoter activation. Furthermore, the N-terminal of NRBP is necessary for its regulation of NFAT activation. Finally, we showed that NRBP has minimal effect on both TCR- and PMA-induced CD69 up-regulation in Jurkat TAg cells, which suggests that NRBP may function downstream of protein kinase C （PKC） /Ras pathway.展开更多
BACKGROUND Sotos syndrome is an autosomal dominant disorder,whereas attention-deficit/hyperactivity disorder(ADHD)is a neurodevelopmental condition.This report aimed to summarize the clinical and genetic features of a...BACKGROUND Sotos syndrome is an autosomal dominant disorder,whereas attention-deficit/hyperactivity disorder(ADHD)is a neurodevelopmental condition.This report aimed to summarize the clinical and genetic features of a pediatric case of Soros syndrome and ADHD in a child exhibiting precocious puberty.CASE SUMMARY The patient presented with accelerated growth and advanced skeletal maturation;however,she lacked any distinct facial characteristics related to specific genetic disorders.Genetic analyses revealed a paternally inherited heterozygous synonymous mutation[c.4605C>T(p.Arg1535Arg)].Functional analyses suggested that this mutation may disrupt splicing,and bioinformatics analyses predicted that this mutation was likely pathogenic.After an initial diagnosis of Sotos syndrome,the patient was diagnosed with ADHD during the follow-up period at the age of 8 years and 7 months.CONCLUSION The potential for comorbid ADHD in Sotos syndrome patients should be considered to avoid the risk of a missed diagnosis.展开更多
The surface glycoproteins of coronaviruses play an important role in receptor binding and cell entry. Different coronaviruses interact with their specific receptors to enter host cells. Lentiviruses pseudotyped with t...The surface glycoproteins of coronaviruses play an important role in receptor binding and cell entry. Different coronaviruses interact with their specific receptors to enter host cells. Lentiviruses pseudotyped with their spike proteins(S) were compared to analyze the entry efficiency of various coronaviruses. Our results indicated that S proteins from different coronaviruses displayed varied abilities to mediate pseudotyped virus infection. Furthermore, the cell tropisms of porcine epidemic diarrhea virus(PEDV) and transmissible gastroenteritis virus(TGEV) have been characterized by live and pseudotyped viruses. Both live and pseudoviruses could infected VeroCCL-81(monkey kidney), Huh-7(human liver), and PK-15(pig kidney) cells efficiently. CCL94(cat kidney) cells could be infected efficiently by TGEV but not PEDV. Overall, our study provides new insights into the mechanisms of viral entry and forms a basis for antiviral drug screening.展开更多
Molecular dynamics(MD)simulation is a computational technique that analyzes the movement of a system of particles over a given period.MD can provide detailed information about the fluctuations and conformational chang...Molecular dynamics(MD)simulation is a computational technique that analyzes the movement of a system of particles over a given period.MD can provide detailed information about the fluctuations and conformational changes of biomolecules at the atomic level over time.In recent years,MD has been widely applied to the discovery of peptides and peptide-like molecules that may serve as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)inhibitors.This review summarizes recent advances in such explorations,focusing on four protein targets:angiotensin-converting enzyme 2(ACE2),spike protein(S protein),main protease(M^(pro)),and papain-like protease(PL^(pro)).These four proteins are important druggable targets of SARS-CoV-2 because of their roles in viral entry,maturation,and infectivity of the virus.A review of the literature revealed that ACE2,S protein,and M^(pro) have received more attention in MD research than PL^(pro).Inhibitors of the four targets identified by MD simulations included peptides derived from food and other bioresources,peptides designed using the targets as templates,and peptide-like molecules retrieved from databases.Many of the inhibitors have yet to be validated in experimental assays for potency.Nevertheless,the role of MD simulation as an efficient tool in the early stages of anti-SARS-CoV-2 drug discovery agents has been demonstrated.展开更多
Objective To review the recent developments in and research into binding receptors of hepatitis C virus (HCV) and especially the role of dendritic cell-specitic adhesion receptor (DC-SIGN) in HCV.Data sources Both C...Objective To review the recent developments in and research into binding receptors of hepatitis C virus (HCV) and especially the role of dendritic cell-specitic adhesion receptor (DC-SIGN) in HCV.Data sources Both Chinese- and English-languge literature was searched using MEDLINE (2000-2003) and the databank of Chinese-language literature (2000-2003).Study selection Relevant articles on DC-SIGN and HCV binding receptors in recent domestic and foreign literature were selected.Data extraction Data were mainly extracted from 40 articles which are listed in the references section of this review. Results DC-SIGN, a dendritic cell-specific adhesion receptor and a type Ⅱ transmembrane mannose-binding C-type lectin, is very important in the function of dendritic cells (DC), both in mediating nave T cell interactions through ICAM-3 and as a rolling receptor that mediates the DC-specific ICAM-2-dependent migration processes. It can be used by HCV and other viral and bacterial pathogens including human immunodeficiency virus (HIV), Ebola virus, CMV and Mycobacterium tuberculosis to facilitate infection. Both DC-SIGN and DC-SIGNR can act either in cis, by concentrating virus on target cells, or in trans, by transmission of bound virus to a target cell expressing appropriate entry receptors. Recent report showed that DC-SIGN not only plays a role in entry into DC, HCV E2 interaction with DC-SIGN might also be detrimental to the interaction of DC with T cells during antigen presentation. Conclusions DC-SIGNs are high-affinity binding receptors for HCV.The clinical strategies that target DC-SIGN may be successful in restricting HCV dissemination and pathogenesis as well as directing the migration of DCs to manipulate appropriate immune responses in autoimmunity and tumorigenic situations.展开更多
Activated nucleotide binding to the oligonucleotide receptor protein 3（NLRP3） inflammasome is possibly involved in the pathogenesis of Alzheimer＇s disease through oxidative stress and neurogenic inflammation. Low e...Activated nucleotide binding to the oligonucleotide receptor protein 3（NLRP3） inflammasome is possibly involved in the pathogenesis of Alzheimer＇s disease through oxidative stress and neurogenic inflammation. Low expression of the signal transducer and activator of transcription 3（STAT3） gene may promote the occurrence of neurodegenerative diseases to some extent. To clarify the roles of the NLRP3 inflammasome and STAT3 expression in oxidative stress,（1） SHSY5 Y cells were incubated with 1 mM H2 O2 to induce oxidative stress injury, and the expression of human-cell-specific signal transduction, STAT3-shRNA silencing signal transduction and STAT3 were detected. Cells were pretreated with Ca2＋ chelator BAPATA-AM（0.1 mM） for 30 minutes as a control.（2） Western blot assay was used to analyze the expression of caspase-1, NLRP3, signal transduction and STAT3. Enzyme-linked immunosorbent assay was used to analyze interleukin-1β levels. Flow cytometry was carried out to calculate the number of apoptotic cells. We found that H2 O2 treatment activated NLRP3 inflammasomes and decreased phosphorylation of signal transduction and STAT3 serine 727. BAPTA-AM pretreatment abolished the H2 O2-induced activation of NLRP3 inflammasomes, caspase-1 expression, interleukin-1β expression and apoptosis in SHSY5 Y cells, and had no effect in cells with downregulated STAT3 expression by RNAi. The findings suggest that downregulation of signal transduction and STAT3 expression may enhance the oxidative stress mediated by NLRP3, which may not depend on the Ca2^＋ signaling pathway.展开更多
Objective: Chronic atrophic gastritis(CAG) is a complex and burdensome disease. However, side effects and compliance issues cannot be ignored due to the long treatment cycle. Numerous studies have confirmed the effect...Objective: Chronic atrophic gastritis(CAG) is a complex and burdensome disease. However, side effects and compliance issues cannot be ignored due to the long treatment cycle. Numerous studies have confirmed the effectiveness of rutaecarpine(RUT) for treating digestive dysfunction. However, the potential mechanism of action of RUT in the context of CAG treatment remains unclear. This study aimed to explore the therapeutic effects and mechanisms of RUT in 1-methyl-3-nitro-1-nitrosoguanidine-induced CAG using network pharmacology,metabolomics, and traditional pharmacological approaches. Materials and Methods: Pathological tests and ELISA assays were used to observe the therapeutic effects of RUT treatment on CAG. Differential metabolites were identified using ultra-high-performance liquid chromatography-tandem mass spectrometry, and metabolism-related target genes were enriched. The same target genes were identified between RUT and CAG diseases. The intersectional target genes were uploaded to Cytoscape for enrichment, and the nucleotide-binding oligomerization domain(NOD)-like receptor signaling pathway was selected to validate the mechanisms of the study. Finally, cell pyroptosis status was evaluated using the terminal deoxynucleotidyl transferase-mediated d UTP nick end labeling assay, and the expressions of associated proteins of the NOD-like receptor signaling pathway were assessed by Western blotting and immunohistochemistry. Results: RUT alleviated gastric mucosal damage and significantly downregulated indicators associated with infiammation and gastric atrophy. A total of 29 intersection target genes was identified, and core pathways were obtained. The NOD-like receptor signaling pathway and pyroptosis status were selected to validate the mechanisms of RUT treatment in CAG rats. The expression of NOD-related proteins and downstream factors was downregulated in the RUT group. Conclusions: RUT exerts a pharmacological effect on relieving gastric damage in CAG rats by inhibiting NOD-like receptors and infiammasomes.展开更多
基金supported by the National Key Research and Development Program of China(2021YFC2302400)the National Natural Science Foundation of China(82241069 and 82350801)+2 种基金supported by the National Science Fund for Distinguished Young Scholar(81925025)the Innovation Fund for Medical Sciences(2019-I2M-5-049)from the Chinese Academy of Medical Sciencessponsored by Beijing Nova Program(20240484525).
文摘Dear Editor,The pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),continues despite extensive efforts to control viral transmission.Meanwhile,the emergence of SARS-CoV-2 variants with antigenically divergence in viral protein dampens the efficacy of authorized vaccines,leading to the breakthrough infections in vaccinated population(Cao et al.,2021,2022;Tuekprakhon et al.,2022;Xiang et al.,2022).Moreover,diverse sarbecoviruses in bats and pangolins have been discovered and isolated(Ge et al.,2013;Xiao et al.,2020).Some of these viruses have exhibited efficient binding to human angiotensin-converting enzyme 2(hACE2)(Xiao et al.,2020;Liu et al.,2021;Temmam et al.,2022),highlighting the risk of spillover from wild animals to human.Thus,the development of pan-sarbecovirus vaccines is of high priority.
基金supported by the National Natural Science Foundation of China(32273037 and 32102636)the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030007)+4 种基金Laboratory of Lingnan Modern Agriculture Project(NT2021007)the Guangdong Science and Technology Innovation Leading Talent Program(2019TX05N098)the 111 Center(D20008)the double first-class discipline promotion project(2023B10564003)the Department of Education of Guangdong Province(2019KZDXM004 and 2019KCXTD001).
文摘A switch from avian-typeα-2,3 to human-typeα-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus.Some H9N2 viruses exhibit a preference for binding to human-typeα-2,6 receptors.This identifies their potential threat to public health.However,our understanding of the molecular basis for the switch of receptor preference is still limited.In this study,we employed the random forest algorithm to identify the potentially key amino acid sites within hemagglutinin(HA),which are associated with the receptor binding ability of H9N2 avian influenza virus(AIV).Subsequently,these sites were further verified by receptor binding assays.A total of 12 substitutions in the HA protein(N158D,N158S,A160 N,A160D,A160T,T163I,T163V,V190T,V190A,D193 N,D193G,and N231D)were predicted to prefer binding toα-2,6 receptors.Except for the V190T substitution,the other substitutions were demonstrated to display an affinity for preferential binding toα-2,6 receptors by receptor binding assays.Especially,the A160T substitution caused a significant upregulation of immune-response genes and an increased mortality rate in mice.Our findings provide novel insights into understanding the genetic basis of receptor preference of the H9N2 AIV.
基金supported by the National Natural Science Foundation of China(82041015)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19000000)+1 种基金the Key International Partnership Program of the Chinese Academy of Sciences(153D31KYSB20180055)the National Major Science and Technology Projects of China(2018ZX10301403).
文摘Coronavirus disease 2019(COVID-19),caused by the novel human coronavirus SARS-CoV-2,is currently a major threat to public health worldwide.The viral spike protein binds the host receptor angiotensin-converting enzyme 2(ACE2)via the receptor-binding domain(RBD),and thus is believed to be a major target to block viral entry.Both SARS-CoV-2 and SARS-CoV share this mechanism.Here we functionally analyzed the key amino acid residues located within receptor binding motif of RBD that may interact with human ACE2 and available neutralizing antibodies.The in vivo experiments showed that immunization with either the SARS-CoV RBD or SARS-CoV-2 RBD was able to induce strong clade-specific neutralizing antibodies in mice;however,the cross-neutralizing activity was much weaker,indicating that there are distinct antigenic features in the RBDs of the two viruses.This finding was confirmed with the available neutralizing monoclonal antibodies against SARS-CoV or SARS-CoV-2.It is worth noting that a newly developed SARS-CoV-2 human antibody,HA001,was able to neutralize SARS-CoV-2,but failed to recognize SARS-CoV.Moreover,the potential epitope residues of HA001 were identified as A475 and F486 in the SARS-CoV-2 RBD,representing new binding sites for neutralizing antibodies.Overall,our study has revealed the presence of different key epitopes between SARS-CoV and SARSCoV-2,which indicates the necessity to develop new prophylactic vaccine and antibody drugs for specific control of the COVID-19 pandemic although the available agents obtained from the SARS-CoV study are unneglectable.
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused many deaths and contributed to a tremendous public health concern worldwide since 2020.Angiotensin-converting enzyme 2(ACE2)binds to the SARS-CoV-2 virus as a receptor.The challenge of different nonhuman primate(NHP)species by SARSCoV-2 virus demonstrated different effects on virus replication and disease pathology.This study characterizes differences between host ACE2 sequences of three NHP species:Macaca mulatta,Macaca fascicularis,and Chlorocebus sabaeus.In addition,the binding affinity between the ACE2 ectodomain and the SARS-CoV-2 S receptor-binding domain(RBD)was analyzed.Variation of ACE2 sequence among NHP species and the binding affinity may account for different susceptibility and responses to SARS-CoV-2 infection.
文摘A novel avian-origin H7N9 influenza virus was discovered in March in China and has caused a total of131 people infected including 39 deaths in China as of June 9, 2013. Adaptation of avian viruses to efficiently infect humans requires the viral hemagglutinin（HA） binding switches from avian to human type receptors with help of some mutations in HA. As such it is critical for pandemic assessment to discover these mutations as hallmarks of adaptation. To continue our previous study of this novel H7N9 virus, we identified two sets of mutations in HA. The first set of mutations are present in the current circulating strains of 2013 H7N9 in China, and the second set are potential mutations that were found when compared to the HAs of previous human H7 subtype. These two sets of mutations exhibited unique features. The first group of mutations, on average, enhanced the HA binding to human type receptors whereas reduced that to avian types. Further the reduction of avian binding was almost three times of the increase of the human binding. The second group increased the binding to both human and avian types.But the increase in human types was almost three times of that in the avian types. Though different in their way of changing the binding preference, these two sets of mutations both contained more mutations to decrease the avian binding and increase the human binding than those that did the opposite. Our research highlighted the pandemic potential of this novel virus by showing the important mutations that could potentially help it to adapt to human hosts. Our findings offered new insights into the current state of evolution of this virus, which might be helpful for the continued surveillance of the emergence of H7N9 strains having the ability of human-to-human transmission.
基金the National Natural Science Foundation of China(Nos.21332008 and 21472015)
文摘Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3（15/85, v/v）demonstrated that the short oligo （aryltriazole）s backbone 1 could not bind halide anions unless that amide H-bond donors were incorporated at the termini of the oligomer. Terminal substituents on oligo（aryltriazoleamide）s foldamers 2–4 display a considerable influence on the binding affinities of the foldamers for halide anions. Large steric hindrance of the terminal substituents was found to be unfavorable for binding halide anions, but aromatic π-π interactions between two terminal substituents are capable of stabilizing the conformation of foldamers thus giving rise to an enhancement in the binding strengths. However, the terminal substituents were found to hardly affect the binding selectivity in the studied cases.
基金funded by grants from the National Research Foundation of Korea(NRF)grant funded by the Korea government(2018M3A9H4055203 and 2023R1A2C2003679)from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea(HV23C1857)from KRIBB Research Initiative Program(KGM9942421).
文摘Influenza,a highly contagious respiratory infectious disease caused by an influenza virus,is a threat to public health worldwide.Avian influenza viruses(AIVs)have the potential to cause the next pandemic by crossing the species barrier through mutation of viral genome.Here,we investigated the pathogenicity of AIVs obtained from South Korea and Mongolia during 2018–2019 by measuring viral titers in the lungs and extrapulmonary organs of mouse models.In addition,we assessed the pathogenicity of AIVs in ferret models.Moreover,we compared the ability of viruses to replicate in mammalian cells,as well as the receptor-binding preferences of AIV isolates.Genetic analyses were finally performed to identify the genetic relationships and amino acid substitutions between viral proteins during mammalian adaptation.Of the 24 AIV isolates tested,A/Mallard/South Korea/KNU2019-34/2019(KNU19-34;H1N1)caused severe bodyweight loss and high mortality in mice.The virus replicated in the lungs,kidneys,and heart.Importantly,KNU19-34-infected ferrets showed high viral loads in both nasal washes and lungs.KNU19-34 replicated rapidly in A549 and bound preferentially to human likeα2,6-linked sialic acids rather than to avian-likeα2,3-linked sialic acids,similar to the pandemic A/California/04/2009(H1N1)strain.Gene segments of KNU19-34 were distributed in Egypt and Asia lineages from 2015 to 2018,and the virus had several amino acid substitutions compared to H1N1 AIV isolates that were non-pathogenic in mice.Collectively,the data suggest that KNU19-34 has zoonotic potential and the possibility of new mutations responsible for mammalian adaptation.
基金supported by the Biological Breeding-National Science and Technology Major Project(2024ZD04077).
文摘Remodeling plant intracellular nucleotide-binding leucine-rich repeat immune receptors(NLRs)to engineer synthetic disease-resistance genes has emerged as a promising approach to achieving broad-spectrum disease resistance.But strategies for expanding NLR recognition spectra[[1],[2],[3],[4],[5]]are often limited by the rapid evolution of pathogens and pests.In our recent study,we developed an innovative strategy to engineer broad-spectrum,durable and complete disease resistance in plants by remodeling autoactive NLRs into protease-activated switches[6].
基金the National Basic Research Program(973 Program)(No.2011CB504703)the National Natural Sci-ence Foundation of China(Grant No.81290342).G.F.G.is a leading principal investigator of the NSFC Innovative Research Group(Grant No.81021003)。
文摘Avian infl uenza A virus continues to pose a global threat with occasional H5N1 human infections,which is em-phasized by a recent severe human infection caused by avian-origin H7N9 in China.Luckily these viruses do not transmit effi ciently in human populations.With a few ami-no acid substitutions of the hemagglutinin H5 protein in the laboratory,two H5 mutants have been shown to obtain an air-borne transmission in a mammalian ferret model.Here in this study one of the mutant H5 proteins devel-oped by Kawaoka’s group(VN1203mut)was expressed in a baculovirus system and its receptor-binding properties were assessed.We herein show that the VN1203mut had a dramatically reduced binding affi nity for the avianα2,3-linkage receptor compared to wild type but showed no detectable increase in affi nity for the humanα2,6-linkage receptor,using Surface Plasmon Resonance techonology.Further,the crystal structures of the VN1203mut and its complexes with either human or avian receptors demon-strate that the VN1203mut binds the human receptor in the same binding manner(cis conformation)as seen for the HAs of previously reported 1957 and 1968 pandemic influenza viruses.Our receptor binding and crystallo-graphic data shown here further confi rm that the ability to bind the avian receptor has to decrease for a higher hu-man receptor binding affi nity.As the Q226L substitution is shown important for obtaining human receptor binding,we suspect that the newly emerged H7N9 binds human receptor as H7 has a Q226L substitution.
基金supported by the National Natural Science Foundation of China (No.30901111)the China Agriculture Research System (CARS-50)the key Project of Chinese Ministry of Education (No.108083)
文摘This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone （r-fGH） was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield （2.605 mg L^-1） than that from soluble protein （1.964 mg L^-l）. Of the tested recovery methods, addition of renaturing buffer （pH 8.5） into denatured inclusion body yielded the best recovery rate （17.9%）. This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.
文摘Current understanding about how the virus that causes COVID-19 spreads is largely based on what is known about similar coronaviruses.Some of the Natural products are suitable drugs against SARS-CoV-2 main protease.For recognizing a strong inhibitor,we have accomplished dock-ing studies on the major virus protease with 4 natural product species as anti COVID-19(SARS-CoV-2),namely“Vidarabine”,“Cytarabine”,“Gem-citabine”and“Matrine”which have been extracted fromGillan’s leaves plants.These are known as Chuchaq,Trshvash,Cote-Couto and Khlvash in Iran.Among these four studied compounds,Cytarabine appears as a suitable com-pound with high effectiveness inhibitors to this protease.Finally by this work we present a method on the Computational Prediction of Protein Structure Associated with COVID-19 Based Ligand Design and Molecular Modeling.By this investigation,auto dock software(iGEM-DOCK)has been used and via this tool,the suitable receptors can be distinguished in whole COVID-19 component structures for forming a complex.“iGEMDOCK”is suitable to define the binding site quickly.With docking simulation and NMR inves-tigation,we have demonstrated these compounds exhibit a suitable binding energy around 9 Kcal/mol with various ligand proteins modes in the bind-ing to COVID-19 viruses.However,these data need further evaluation for repurposing these drugs against COVID-19 viruses,in both vivo&vitro.
基金Foundation item: the National Natural Science Foundation (No. 30430630)
文摘Adapter proteins can regulate the gene transcriptions in disparate signaling pathway by interacting with multiple signaling molecules, including T cell activation signaling. Nuclear receptor binding protein （NRBP）, a novel adapter protein, represents a small family of evolutionarily conserved proteins with homologs in Caenorhabditis elegans （C. elegans）, Drosophila melanogaster （i）. melanogaster）, mouse and human. Here, we demonstrated that overexpression of NRBP in Jurkat TAg cells specifically impairs T cell receptor （TCR） or phorbol myristate acetate （PMA） /ionomycin-mediated signaling leading to nuclear factor of activated T cells （NFAT） promoter activation. Furthermore, the N-terminal of NRBP is necessary for its regulation of NFAT activation. Finally, we showed that NRBP has minimal effect on both TCR- and PMA-induced CD69 up-regulation in Jurkat TAg cells, which suggests that NRBP may function downstream of protein kinase C （PKC） /Ras pathway.
文摘BACKGROUND Sotos syndrome is an autosomal dominant disorder,whereas attention-deficit/hyperactivity disorder(ADHD)is a neurodevelopmental condition.This report aimed to summarize the clinical and genetic features of a pediatric case of Soros syndrome and ADHD in a child exhibiting precocious puberty.CASE SUMMARY The patient presented with accelerated growth and advanced skeletal maturation;however,she lacked any distinct facial characteristics related to specific genetic disorders.Genetic analyses revealed a paternally inherited heterozygous synonymous mutation[c.4605C>T(p.Arg1535Arg)].Functional analyses suggested that this mutation may disrupt splicing,and bioinformatics analyses predicted that this mutation was likely pathogenic.After an initial diagnosis of Sotos syndrome,the patient was diagnosed with ADHD during the follow-up period at the age of 8 years and 7 months.CONCLUSION The potential for comorbid ADHD in Sotos syndrome patients should be considered to avoid the risk of a missed diagnosis.
基金supported by the National Natural Science Foundation of China (Grant No.31372440)
文摘The surface glycoproteins of coronaviruses play an important role in receptor binding and cell entry. Different coronaviruses interact with their specific receptors to enter host cells. Lentiviruses pseudotyped with their spike proteins(S) were compared to analyze the entry efficiency of various coronaviruses. Our results indicated that S proteins from different coronaviruses displayed varied abilities to mediate pseudotyped virus infection. Furthermore, the cell tropisms of porcine epidemic diarrhea virus(PEDV) and transmissible gastroenteritis virus(TGEV) have been characterized by live and pseudotyped viruses. Both live and pseudoviruses could infected VeroCCL-81(monkey kidney), Huh-7(human liver), and PK-15(pig kidney) cells efficiently. CCL94(cat kidney) cells could be infected efficiently by TGEV but not PEDV. Overall, our study provides new insights into the mechanisms of viral entry and forms a basis for antiviral drug screening.
文摘Molecular dynamics(MD)simulation is a computational technique that analyzes the movement of a system of particles over a given period.MD can provide detailed information about the fluctuations and conformational changes of biomolecules at the atomic level over time.In recent years,MD has been widely applied to the discovery of peptides and peptide-like molecules that may serve as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)inhibitors.This review summarizes recent advances in such explorations,focusing on four protein targets:angiotensin-converting enzyme 2(ACE2),spike protein(S protein),main protease(M^(pro)),and papain-like protease(PL^(pro)).These four proteins are important druggable targets of SARS-CoV-2 because of their roles in viral entry,maturation,and infectivity of the virus.A review of the literature revealed that ACE2,S protein,and M^(pro) have received more attention in MD research than PL^(pro).Inhibitors of the four targets identified by MD simulations included peptides derived from food and other bioresources,peptides designed using the targets as templates,and peptide-like molecules retrieved from databases.Many of the inhibitors have yet to be validated in experimental assays for potency.Nevertheless,the role of MD simulation as an efficient tool in the early stages of anti-SARS-CoV-2 drug discovery agents has been demonstrated.
基金ThisprojectwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No 3 0 170 82 2 )
文摘Objective To review the recent developments in and research into binding receptors of hepatitis C virus (HCV) and especially the role of dendritic cell-specitic adhesion receptor (DC-SIGN) in HCV.Data sources Both Chinese- and English-languge literature was searched using MEDLINE (2000-2003) and the databank of Chinese-language literature (2000-2003).Study selection Relevant articles on DC-SIGN and HCV binding receptors in recent domestic and foreign literature were selected.Data extraction Data were mainly extracted from 40 articles which are listed in the references section of this review. Results DC-SIGN, a dendritic cell-specific adhesion receptor and a type Ⅱ transmembrane mannose-binding C-type lectin, is very important in the function of dendritic cells (DC), both in mediating nave T cell interactions through ICAM-3 and as a rolling receptor that mediates the DC-specific ICAM-2-dependent migration processes. It can be used by HCV and other viral and bacterial pathogens including human immunodeficiency virus (HIV), Ebola virus, CMV and Mycobacterium tuberculosis to facilitate infection. Both DC-SIGN and DC-SIGNR can act either in cis, by concentrating virus on target cells, or in trans, by transmission of bound virus to a target cell expressing appropriate entry receptors. Recent report showed that DC-SIGN not only plays a role in entry into DC, HCV E2 interaction with DC-SIGN might also be detrimental to the interaction of DC with T cells during antigen presentation. Conclusions DC-SIGNs are high-affinity binding receptors for HCV.The clinical strategies that target DC-SIGN may be successful in restricting HCV dissemination and pathogenesis as well as directing the migration of DCs to manipulate appropriate immune responses in autoimmunity and tumorigenic situations.
基金supported by Department of Science and Technology in Guizhou Province of China,No.Basic [2016]1131(to QianKe-He to HB)+2 种基金Department of Health and Family Planning Commission in Guizhou Province of China,No.2015-326(to HB)Less Developed Regions of the National Natural Science Foundation of China,No.81560482the Research Foundation for Creative Research Groups of Education Bureau of Guizhou Province of China,No.KY[2016]033(to QFZ)
文摘Activated nucleotide binding to the oligonucleotide receptor protein 3（NLRP3） inflammasome is possibly involved in the pathogenesis of Alzheimer＇s disease through oxidative stress and neurogenic inflammation. Low expression of the signal transducer and activator of transcription 3（STAT3） gene may promote the occurrence of neurodegenerative diseases to some extent. To clarify the roles of the NLRP3 inflammasome and STAT3 expression in oxidative stress,（1） SHSY5 Y cells were incubated with 1 mM H2 O2 to induce oxidative stress injury, and the expression of human-cell-specific signal transduction, STAT3-shRNA silencing signal transduction and STAT3 were detected. Cells were pretreated with Ca2＋ chelator BAPATA-AM（0.1 mM） for 30 minutes as a control.（2） Western blot assay was used to analyze the expression of caspase-1, NLRP3, signal transduction and STAT3. Enzyme-linked immunosorbent assay was used to analyze interleukin-1β levels. Flow cytometry was carried out to calculate the number of apoptotic cells. We found that H2 O2 treatment activated NLRP3 inflammasomes and decreased phosphorylation of signal transduction and STAT3 serine 727. BAPTA-AM pretreatment abolished the H2 O2-induced activation of NLRP3 inflammasomes, caspase-1 expression, interleukin-1β expression and apoptosis in SHSY5 Y cells, and had no effect in cells with downregulated STAT3 expression by RNAi. The findings suggest that downregulation of signal transduction and STAT3 expression may enhance the oxidative stress mediated by NLRP3, which may not depend on the Ca2^＋ signaling pathway.
基金supported by the Major Program of the National Natural Science Foundation of China (No. 82192915)the National Key Research and Development Program (No. 2018YFC1704500)
文摘Objective: Chronic atrophic gastritis(CAG) is a complex and burdensome disease. However, side effects and compliance issues cannot be ignored due to the long treatment cycle. Numerous studies have confirmed the effectiveness of rutaecarpine(RUT) for treating digestive dysfunction. However, the potential mechanism of action of RUT in the context of CAG treatment remains unclear. This study aimed to explore the therapeutic effects and mechanisms of RUT in 1-methyl-3-nitro-1-nitrosoguanidine-induced CAG using network pharmacology,metabolomics, and traditional pharmacological approaches. Materials and Methods: Pathological tests and ELISA assays were used to observe the therapeutic effects of RUT treatment on CAG. Differential metabolites were identified using ultra-high-performance liquid chromatography-tandem mass spectrometry, and metabolism-related target genes were enriched. The same target genes were identified between RUT and CAG diseases. The intersectional target genes were uploaded to Cytoscape for enrichment, and the nucleotide-binding oligomerization domain(NOD)-like receptor signaling pathway was selected to validate the mechanisms of the study. Finally, cell pyroptosis status was evaluated using the terminal deoxynucleotidyl transferase-mediated d UTP nick end labeling assay, and the expressions of associated proteins of the NOD-like receptor signaling pathway were assessed by Western blotting and immunohistochemistry. Results: RUT alleviated gastric mucosal damage and significantly downregulated indicators associated with infiammation and gastric atrophy. A total of 29 intersection target genes was identified, and core pathways were obtained. The NOD-like receptor signaling pathway and pyroptosis status were selected to validate the mechanisms of RUT treatment in CAG rats. The expression of NOD-related proteins and downstream factors was downregulated in the RUT group. Conclusions: RUT exerts a pharmacological effect on relieving gastric damage in CAG rats by inhibiting NOD-like receptors and infiammasomes.
