In eukaryote, nuclear structure is a key component forthe functions of eukaryotic cells. More and more evidencesshow that the nuclear structure plays important role in re-gulating DNA replication. The nuclear structur...In eukaryote, nuclear structure is a key component forthe functions of eukaryotic cells. More and more evidencesshow that the nuclear structure plays important role in re-gulating DNA replication. The nuclear structure providesa physical barrier for the replication licensing, participatesin the decision where DNA replication initiates, and orga-nizes replication proteins as replication factory for DNAreplication. Through these works, new concepts on theregulation of DNA replication have emerged, which willbe discussed in this minireview.展开更多
Single-stranded DNA-binding proteins(SSBs)play essential roles in the replication,recombination and repair processes of organellar DNA molecules.In Arabidopsis thaliana,SSBs are encoded by a small family of two genes(...Single-stranded DNA-binding proteins(SSBs)play essential roles in the replication,recombination and repair processes of organellar DNA molecules.In Arabidopsis thaliana,SSBs are encoded by a small family of two genes(SSB1 and SSB2).However,the functional divergence of these two SSB copies in plants remains largely unknown,and detailed studies regarding their roles in the replication and recombination of organellar genomes are still incomplete.In this study,phylogenetic,gene structure and protein motif analyses all suggested that SSB1 and SSB2 probably diverged during the early evolution of seed plants.Based on accurate long-read sequencing results,ssb1 and ssb2 mutants had decreased copy numbers for both mitochondrial DNA(mtDNA)and plastid DNA(ptDNA),accompanied by a slight increase in structural rearrangements mediated by intermediate-sized repeats in mt genome and small-scale variants in both genomes.Our findings provide an important foundation for further investigating the effects of DNA dosage in the regulation of mutation frequencies in plant organellar genomes.展开更多
Cloud computing has become an essential technology for the management and processing of large datasets,offering scalability,high availability,and fault tolerance.However,optimizing data replication across multiple dat...Cloud computing has become an essential technology for the management and processing of large datasets,offering scalability,high availability,and fault tolerance.However,optimizing data replication across multiple data centers poses a significant challenge,especially when balancing opposing goals such as latency,storage costs,energy consumption,and network efficiency.This study introduces a novel Dynamic Optimization Algorithm called Dynamic Multi-Objective Gannet Optimization(DMGO),designed to enhance data replication efficiency in cloud environments.Unlike traditional static replication systems,DMGO adapts dynamically to variations in network conditions,system demand,and resource availability.The approach utilizes multi-objective optimization approaches to efficiently balance data access latency,storage efficiency,and operational costs.DMGO consistently evaluates data center performance and adjusts replication algorithms in real time to guarantee optimal system efficiency.Experimental evaluations conducted in a simulated cloud environment demonstrate that DMGO significantly outperforms conventional static algorithms,achieving faster data access,lower storage overhead,reduced energy consumption,and improved scalability.The proposed methodology offers a robust and adaptable solution for modern cloud systems,ensuring efficient resource consumption while maintaining high performance.展开更多
The DNA replication stress(RS)response is crucial for maintaining cellular homeostasis and promoting physiological longevity.However,the mechanisms by which long-lived species,such as bats,regulate RS to maintain geno...The DNA replication stress(RS)response is crucial for maintaining cellular homeostasis and promoting physiological longevity.However,the mechanisms by which long-lived species,such as bats,regulate RS to maintain genomic stability remain unclear.Also,recent studies have uncovered noncanonical roles of ribosome-associated factors in maintaining genomic stability.In this study,somatic skin fibroblasts from the long-lived big-footed bat(Myotis pilosus)were examined,with results showing that bat cells exhibited enhanced RS tolerance compared to mouse cells.Comparative transcriptome analysis under RS conditions revealed pronounced species-specific transcriptional differences,including robust up-regulation of ribosome biogenesis genes in bat cells and a markedly reduced activation of the P53 signaling pathway.These features emphasize a distinct homeostatic strategy in bat cells.Nuclear fragile X mental retardation-interacting protein 1(Nufip1),a ribosome-associated factor highly expressed in bat fibroblasts,was identified as a potential integrator of ribosomal and P53 signaling via its association with ribosomal protein S27-like(Rps27l).These findings provide direct cellular and molecular evidence for a noncanonical RS response in bats,highlighting a deeper understanding of the biological characteristics and genomic maintenance mechanisms of long-lived species.展开更多
Virus-encoding RNA-dependent RNA polymerase(RdRp)is essential for genome replication and gene transcription of human coronaviruses(HCoVs),including severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).We previo...Virus-encoding RNA-dependent RNA polymerase(RdRp)is essential for genome replication and gene transcription of human coronaviruses(HCoVs),including severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).We previously identified the interaction between the catalytic subunit NSP12 of SARS-CoV-2 RdRp and the host protein CREB-regulated transcription coactivator 3(CRTC3),a member of the CRTC family that regulates cyclic AMP response element-binding protein(CREB)-mediated transcriptional activation.Currently,the implication of CRTC3 in the pathogenesis of HCoVs is poorly understood.Herein,we demonstrated that CRTC3 attenuates RdRp activity and SARS-CoV-2 genome replication,therefore reducing the production of progeny viruses.The interaction of CRTC3 with NSP12 contributes to its inhibitory effect on RdRp activity.Furthermore,we expanded the suppressive effects of two other CRTC family members(CRTC1 and CRTC2)on the RdRp activities of lethal HCoVs,including SARS-CoV-2 and Middle East respiratory syndrome coronavirus(MERS-CoV),along with the CREB antagonization.Overall,our research suggests that CRTCs restrict the replication of HCoVs and are antagonized by CREB,which not only provides new insights into the replication regulation of HCoVs,but also offers important information for the development of anti-HCoV interventions.展开更多
Data replication is a key way to design a disaster tolerance system. This paper presents a replication driver layer-based data replication system on FreeBSD （FRS）. The system is embedded into the replication device ...Data replication is a key way to design a disaster tolerance system. This paper presents a replication driver layer-based data replication system on FreeBSD （FRS）. The system is embedded into the replication device driver layer, does not depend on specific storage devices and logical volume manager, and can achieve replication on data block level. The design considerations and decisions in defining FRS are described in detail.展开更多
Human parainfluenza virus type 3(HPIV3),a member of the Paramyxoviridae family,can cause lower respiratory disease in infants and young children.The phosphoprotein(P)of HPIV3 is an essential cofactor of the viral RNA-...Human parainfluenza virus type 3(HPIV3),a member of the Paramyxoviridae family,can cause lower respiratory disease in infants and young children.The phosphoprotein(P)of HPIV3 is an essential cofactor of the viral RNA-dependent RNA polymerase large protein(L).P connects nucleocapsid protein(N)with L to initiate genome transcription and replication.Sumoylation influences many important pathways of the target proteins,and many viral proteins are also themselves sumoylated.In this study,we found that the P of HPIV3 could be sumoylated,and mutation of K492 and K532 to arginine(PK492 R/K532 R)failed to be sumoylated within P,which enhances HPIV3 minigenome activity.Biochemical studies showed that PK492 R/K532 Rhad no effect on its interactions with N,formation of homo-tetramers and formation of inclusion bodies.Finally,we found that incorporation of K492 R/K532 R into a recombinant HPIV3(rHPIV3-PK492 R/K532 R)increased viral production in culture cells,suggesting that sumoylation attenuates functions of P and down-regulates viral replication.展开更多
As the amount of data continues to grow rapidly,the variety of data produced by applications is becoming more affluent than ever.Cloud computing is the best technology evolving today to provide multi-services for the ...As the amount of data continues to grow rapidly,the variety of data produced by applications is becoming more affluent than ever.Cloud computing is the best technology evolving today to provide multi-services for the mass and variety of data.The cloud computing features are capable of processing,managing,and storing all sorts of data.Although data is stored in many high-end nodes,either in the same data centers or across many data centers in cloud,performance issues are still inevitable.The cloud replication strategy is one of best solutions to address risk of performance degradation in the cloud environment.The real challenge here is developing the right data replication strategy with minimal data movement that guarantees efficient network usage,low fault tolerance,and minimal replication frequency.The key problem discussed in this research is inefficient network usage discovered during selecting a suitable data center to store replica copies induced by inadequate data center selection criteria.Hence,to mitigate the issue,we proposed Replication Strategy with a comprehensive Data Center Selection Method(RS-DCSM),which can determine the appropriate data center to place replicas by considering three key factors:Popularity,space availability,and centrality.The proposed RS-DCSM was simulated using CloudSim and the results proved that data movement between data centers is significantly reduced by 14%reduction in overall replication frequency and 20%decrement in network usage,which outperformed the current replication strategy,known as Dynamic Popularity aware Replication Strategy(DPRS)algorithm.展开更多
Dynamic data replication is a technique used in data grid environments that helps to reduce access latency and network bandwidth utilization. Replication also increases data availability thereby enhancing system relia...Dynamic data replication is a technique used in data grid environments that helps to reduce access latency and network bandwidth utilization. Replication also increases data availability thereby enhancing system reliability. In this paper we discuss the issues with single-location strategies in large-scale data integration applications, and examine potential multiple-location schemes. Dynamic multiple-location replication is NP-complete in nature. We therefore transform the multiple-location problem into several classical mathematical problems with different parameter settings, to which efficient approximation algorithms apply experimental results indicate that unlike single-location strategies our multiple-location schemes are efficient with respect to access latency and bandwidth consumption, especially when the requesters of a data set are distributed over a large scale of locations.展开更多
AIM:To determine the antiviral mechanism or target of oxymatrine against hepatitis B virus(HBV).METHODS:HepG2.2.15 cells were incubated with culture medium containing 500 μg/mL of oxymatrine for 2 and 5 d.The surface...AIM:To determine the antiviral mechanism or target of oxymatrine against hepatitis B virus(HBV).METHODS:HepG2.2.15 cells were incubated with culture medium containing 500 μg/mL of oxymatrine for 2 and 5 d.The surface antigen of HBV(HBsAg) and e antigen of HBV(HBeAg) in supernatant were determined by ELISA.HBV DNA in supernatant,and intracellular covalently closed circular DNA(cccDNA),relaxed circular DNA(rcDNA) and pregenomic RNA(pgRNA) were quantif ied by specif ic real-time polymerase chain reaction(PCR) or reverse transcription(RT)-PCR.RESULTS:Treatment with oxymatrine for 2 d and 5 d reduced the production of HBV by the cell line,as indicated by the decline of HBsAg(22.67%,t = 5.439,P = 0.0322 and 22.39%,t = 5.376,P = 0.0329,respectively),HBeAg(55.34%,t = 9.859,P = 0.0101 and 43.97%,t = 14.080,P = 0.0050) and HBV DNA(40.75%,t = 4.570,P = 0.0447 and 75.32%,t = 14.460,P = 0.0047) in the supernatant.Intracellular cccDNA was also markedly reduced by 63.98%(t = 6.152,P = 0.0254) and 80.83%(t = 10.270,P = 0.0093),and intracellular rcDNA by 34.35%(t = 4.776,P = 0.0413) and 39.24%(t = 10.050,P = 0.0097).In contrast,intracellular pgRNA increased by 6.90-fold(t = 8.941,P = 0.0123) and 3.18-fold(t = 7.432,P = 0.0176) after 500 μg/mL of oxymatrine treatment for 2 d and 5 d,respectively.CONCLUSION:Oxymatrine may inhibit the replication of HBV by interfering with the process of packaging pgRNA into the nucleocapsid,or inhibiting the activity of the viral DNA polymerase.展开更多
Chronic infection with the hepatitis B virus(HBV) is the leading risk factor for the development of hepatocellular carcinoma(HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause...Chronic infection with the hepatitis B virus(HBV) is the leading risk factor for the development of hepatocellular carcinoma(HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, micro RNAs(mi RNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of mi RNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between mi RNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some mi RNAs, such as mi R-122, and mi R-125 and mi R-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and mi RNAs, including how HBV affects cellular mi RNAs, how these mi RNAs impact HBV replication, and the relationship between HBV-mediated mi RNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and mi RNAs, and proposepotential applications of mi RNA-related techniques that could enhance our understanding of the role mi RNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes.展开更多
AIM: To analyze the association of HCV-RNA with peripheral blood mononuclear cells (PBMC) and to answer the question whether HCV-RNA positivity in PBMC is due to viral replication. METHODS: HCV-RNA was monitored in se...AIM: To analyze the association of HCV-RNA with peripheral blood mononuclear cells (PBMC) and to answer the question whether HCV-RNA positivity in PBMC is due to viral replication. METHODS: HCV-RNA was monitored in serum and PBMC preparations from 15 patients with chronic HCV infection before, during and after an IFN-alpha therapy using a nested RT/PCR technique. In a second approach, PBMC from healthy donors were incubated in HCV positive plasma. RESULTS: In the IFN-alpha responding patients,HCV-RNA disappeared first from total RNA preparations of PBMC and then from serum. In contrast, in relapsing patients, HCV-RNA reappeared first in serum and then in PBMC. A quantitative analysis of the HCV-RNA concentration in serum was performed before and after transition from detectable to non detectable HCV-RNA in PBMC-RNA and vice versa. When HCV-RNA was detectable in PBMC preparations, the HCV concentration in serum was significantly higher than the serum HCV-RNA concentration when HCV-RNA in PBMC was not detectable. Furthermore, at no time during the observation period was HCV specific RNA observed in PBMC, if HCV-RNA in serum was under the detection limit. Incubation of PBMC from healthy donors with several dilutions of HCV positive plasma for two hours showed a concentration dependent PCR positivity for HCV-RNA in reisolated PBMC. CONCLUSION: The detectability of HCV-RNA in total RNA from PBMC seems to depend on the HCV concentration in serum. Contamination or passive adsorption by circulating virus could be the reason for detection of HCV-RNA in PBMC preparations of chronically infected patients.展开更多
AIM： To establish a rapid and convenient animal model with hepatitis B virus （HBV） replication.METHODS： A naked DNA solution of HBV-replicationcompetent plasmid was transferred to BALB/C mice via the tail vein, us...AIM： To establish a rapid and convenient animal model with hepatitis B virus （HBV） replication.METHODS： A naked DNA solution of HBV-replicationcompetent plasmid was transferred to BALB/C mice via the tail vein, using a hydrodynamic in vivo transfection procedure. After injection, these mice were sacrificed on d 1, 3, 4, 5, 7 and 10. HBV DNA replication intermediates in the liver were analyzed by Southern blot hybridization. The expression of hepatitis B core antigen （HBcAg） and hepatitis B surface antigen （HBsAg） in the liver was checked by immunohistochemistry. Serum HBsAg and hepatitis B e antigen （HBeAg） was detected by enzyme- linked immunosorbent assay （ELISA）. Inhibition of HBV replication was compared in HBV replication model mice treated intraperitoneally with polyinosinic-polytidylin acid （polyIC） or phosphate-buffered saline （PBS）.RESULTS： After hydrodynamic in vivo transfection, HBV DNA replication intermediates in the mouse liver were detectable on d 1 and abundant on d 3 and 4, the levels were slightly decreased and remained relatively stable between d 5 and 7, and were almost undetectable on d 10. The expression patterns of HBcAg and HBsAg were similar to that of HBV replication intermediate DNA, except that they reached a peak on d 1 after injection. No obvious differences in HBV DNA replication intermediates were observed in the left, right and middle lobes of the liver. After treatment with polyIC, the level of HBV intermediate DNA in the liver was lower than that in the control mice injected with PBS.CONCLUSION： A rapid and convenient mouse model with a high level of HBV replication was developed and used to investigate the inhibitory effect of polyIC on HBV replication, which provides a useful tool for future functional studies of the HBV genome.展开更多
Viruses depend on host cellular metabolism to provide the energy and biosynthetic building blocks required for their replication. In this study, we observed that influenza A virus(H1N1), a single-stranded, negative-se...Viruses depend on host cellular metabolism to provide the energy and biosynthetic building blocks required for their replication. In this study, we observed that influenza A virus(H1N1), a single-stranded, negative-sense RNA virus with an eight-segmented genome, enhanced glycolysis both in mouse lung tissues and in human lung epithelial(A549) cells. In detail, the expression of hexokinase 2(HK2), the first enzyme in glycolysis, was upregulated in H1N1-infected A549 cells,and the expression of pyruvate kinase M2(PKM2) and pyruvate dehydrogenase kinase 3(PDK3) was upregulated in H1N1-infected mouse lung tissues. Pharmacologically inhibiting the glycolytic pathway or targeting hypoxia-inducible factor 1(HIF-1), the central transcriptional factor critical for glycolysis, significantly reduced H1N1 replication, revealing a requirement for glycolysis during H1N1 infection. In addition, pharmacologically enhancing the glycolytic pathway further promoted H1N1 replication. Furthermore, the change of H1N1 replication upon glycolysis inhibition or enhancement was independent of interferon signaling. Taken together, these findings suggest that influenza A virus induces the glycolytic pathway and thus facilitates efficient viral replication. This study raises the possibility that metabolic inhibitors, such as those that target glycolysis, could be used to treat influenza A virus infection in the future.展开更多
Dengue virus(DENV) belongs to the genus Flavivirus of the family Flaviviridae and it is primarily transmitted via Aedes aegypti and Aedes albopictus mosquitoes. The life cycle of DENV includes attachment, endocytosis,...Dengue virus(DENV) belongs to the genus Flavivirus of the family Flaviviridae and it is primarily transmitted via Aedes aegypti and Aedes albopictus mosquitoes. The life cycle of DENV includes attachment, endocytosis, protein translation, RNA synthesis, assembly, egress, and maturation.Recent researches have indicated that a variety of host factors, including cellular proteins and micro RNAs, positively or negatively regulate the DENV replication process. This review summarizes the latest findings(from 2014 to 2016) in the identification of the host factors involved in the DENV life cycle and Dengue infection.展开更多
文摘In eukaryote, nuclear structure is a key component forthe functions of eukaryotic cells. More and more evidencesshow that the nuclear structure plays important role in re-gulating DNA replication. The nuclear structure providesa physical barrier for the replication licensing, participatesin the decision where DNA replication initiates, and orga-nizes replication proteins as replication factory for DNAreplication. Through these works, new concepts on theregulation of DNA replication have emerged, which willbe discussed in this minireview.
基金supported by grants from the National Natural Science Foundation of China(32170238,32400191)Guangdong Basic and Applied Basic Research Foundation(2023A1515111029)+2 种基金the Science,Technology and Innovation Commission of Shenzhen Municipality(RCYX20200714114538196)the Chinese Academy of Agricultural Sciences Elite Youth Program(grant 110243160001007)the Guangdong Pearl River Talent Program(2021QN02N792)。
文摘Single-stranded DNA-binding proteins(SSBs)play essential roles in the replication,recombination and repair processes of organellar DNA molecules.In Arabidopsis thaliana,SSBs are encoded by a small family of two genes(SSB1 and SSB2).However,the functional divergence of these two SSB copies in plants remains largely unknown,and detailed studies regarding their roles in the replication and recombination of organellar genomes are still incomplete.In this study,phylogenetic,gene structure and protein motif analyses all suggested that SSB1 and SSB2 probably diverged during the early evolution of seed plants.Based on accurate long-read sequencing results,ssb1 and ssb2 mutants had decreased copy numbers for both mitochondrial DNA(mtDNA)and plastid DNA(ptDNA),accompanied by a slight increase in structural rearrangements mediated by intermediate-sized repeats in mt genome and small-scale variants in both genomes.Our findings provide an important foundation for further investigating the effects of DNA dosage in the regulation of mutation frequencies in plant organellar genomes.
文摘Cloud computing has become an essential technology for the management and processing of large datasets,offering scalability,high availability,and fault tolerance.However,optimizing data replication across multiple data centers poses a significant challenge,especially when balancing opposing goals such as latency,storage costs,energy consumption,and network efficiency.This study introduces a novel Dynamic Optimization Algorithm called Dynamic Multi-Objective Gannet Optimization(DMGO),designed to enhance data replication efficiency in cloud environments.Unlike traditional static replication systems,DMGO adapts dynamically to variations in network conditions,system demand,and resource availability.The approach utilizes multi-objective optimization approaches to efficiently balance data access latency,storage efficiency,and operational costs.DMGO consistently evaluates data center performance and adjusts replication algorithms in real time to guarantee optimal system efficiency.Experimental evaluations conducted in a simulated cloud environment demonstrate that DMGO significantly outperforms conventional static algorithms,achieving faster data access,lower storage overhead,reduced energy consumption,and improved scalability.The proposed methodology offers a robust and adaptable solution for modern cloud systems,ensuring efficient resource consumption while maintaining high performance.
基金supported by the Applied Basic Research Programs of Science and Technology Commission Foundation of Yunnan Province(202401AT070186 to K.Q.L.,202201AS070044 to B.Z.)Yunnan Province(202305AH340006 to B.Z.)Kunming Science and Technology Bureau(2022SCP007 to B.Z.)。
文摘The DNA replication stress(RS)response is crucial for maintaining cellular homeostasis and promoting physiological longevity.However,the mechanisms by which long-lived species,such as bats,regulate RS to maintain genomic stability remain unclear.Also,recent studies have uncovered noncanonical roles of ribosome-associated factors in maintaining genomic stability.In this study,somatic skin fibroblasts from the long-lived big-footed bat(Myotis pilosus)were examined,with results showing that bat cells exhibited enhanced RS tolerance compared to mouse cells.Comparative transcriptome analysis under RS conditions revealed pronounced species-specific transcriptional differences,including robust up-regulation of ribosome biogenesis genes in bat cells and a markedly reduced activation of the P53 signaling pathway.These features emphasize a distinct homeostatic strategy in bat cells.Nuclear fragile X mental retardation-interacting protein 1(Nufip1),a ribosome-associated factor highly expressed in bat fibroblasts,was identified as a potential integrator of ribosomal and P53 signaling via its association with ribosomal protein S27-like(Rps27l).These findings provide direct cellular and molecular evidence for a noncanonical RS response in bats,highlighting a deeper understanding of the biological characteristics and genomic maintenance mechanisms of long-lived species.
基金supported by grants from the National Natural Science Foundation of China(32071236)the National Science Fund for Distinguished Young Scholars(32225001)+6 种基金the 1.3.5 Project for Disciplines Excellence of West China Hospital,Sichuan University(ZYGD23018)Key Science and Technology Research Projects in Key Areas of the Corps(2023AB053)the National Key Research and Development Program of China(2022YFC2303700)the Joint Project of Pengzhou People's Hospital with Southwest Medical University(2024PZXNYD02)Project funded by China Postdoctoral Science Foundation(2020M683304)Sichuan Science and Technology Support Project(2021YJ0502)Post-Doctor Research Project,West China Hospital,Sichuan University(2020HXBH082).
文摘Virus-encoding RNA-dependent RNA polymerase(RdRp)is essential for genome replication and gene transcription of human coronaviruses(HCoVs),including severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).We previously identified the interaction between the catalytic subunit NSP12 of SARS-CoV-2 RdRp and the host protein CREB-regulated transcription coactivator 3(CRTC3),a member of the CRTC family that regulates cyclic AMP response element-binding protein(CREB)-mediated transcriptional activation.Currently,the implication of CRTC3 in the pathogenesis of HCoVs is poorly understood.Herein,we demonstrated that CRTC3 attenuates RdRp activity and SARS-CoV-2 genome replication,therefore reducing the production of progeny viruses.The interaction of CRTC3 with NSP12 contributes to its inhibitory effect on RdRp activity.Furthermore,we expanded the suppressive effects of two other CRTC family members(CRTC1 and CRTC2)on the RdRp activities of lethal HCoVs,including SARS-CoV-2 and Middle East respiratory syndrome coronavirus(MERS-CoV),along with the CREB antagonization.Overall,our research suggests that CRTCs restrict the replication of HCoVs and are antagonized by CREB,which not only provides new insights into the replication regulation of HCoVs,but also offers important information for the development of anti-HCoV interventions.
基金supported by 863 Program under Grant No. 2009AA01A404
文摘Data replication is a key way to design a disaster tolerance system. This paper presents a replication driver layer-based data replication system on FreeBSD （FRS）. The system is embedded into the replication device driver layer, does not depend on specific storage devices and logical volume manager, and can achieve replication on data block level. The design considerations and decisions in defining FRS are described in detail.
基金supported by grants from National Key R&D Program of China(2017YFA0505801)the National Natural Science Foundation of China(81825015,81871650 and 31630086)+2 种基金National Science and Technology Major Project(2018ZX10101004)the Natural Science Foundation of Hubei Province Innovation Group(2017CFA022)Advanced Customer Cultivation Project of Wuhan National Biosafety Laboratory(2019ACCP-MS06)。
文摘Human parainfluenza virus type 3(HPIV3),a member of the Paramyxoviridae family,can cause lower respiratory disease in infants and young children.The phosphoprotein(P)of HPIV3 is an essential cofactor of the viral RNA-dependent RNA polymerase large protein(L).P connects nucleocapsid protein(N)with L to initiate genome transcription and replication.Sumoylation influences many important pathways of the target proteins,and many viral proteins are also themselves sumoylated.In this study,we found that the P of HPIV3 could be sumoylated,and mutation of K492 and K532 to arginine(PK492 R/K532 R)failed to be sumoylated within P,which enhances HPIV3 minigenome activity.Biochemical studies showed that PK492 R/K532 Rhad no effect on its interactions with N,formation of homo-tetramers and formation of inclusion bodies.Finally,we found that incorporation of K492 R/K532 R into a recombinant HPIV3(rHPIV3-PK492 R/K532 R)increased viral production in culture cells,suggesting that sumoylation attenuates functions of P and down-regulates viral replication.
基金supported by Universiti Putra Malaysia and the Ministry of Education(MOE).
文摘As the amount of data continues to grow rapidly,the variety of data produced by applications is becoming more affluent than ever.Cloud computing is the best technology evolving today to provide multi-services for the mass and variety of data.The cloud computing features are capable of processing,managing,and storing all sorts of data.Although data is stored in many high-end nodes,either in the same data centers or across many data centers in cloud,performance issues are still inevitable.The cloud replication strategy is one of best solutions to address risk of performance degradation in the cloud environment.The real challenge here is developing the right data replication strategy with minimal data movement that guarantees efficient network usage,low fault tolerance,and minimal replication frequency.The key problem discussed in this research is inefficient network usage discovered during selecting a suitable data center to store replica copies induced by inadequate data center selection criteria.Hence,to mitigate the issue,we proposed Replication Strategy with a comprehensive Data Center Selection Method(RS-DCSM),which can determine the appropriate data center to place replicas by considering three key factors:Popularity,space availability,and centrality.The proposed RS-DCSM was simulated using CloudSim and the results proved that data movement between data centers is significantly reduced by 14%reduction in overall replication frequency and 20%decrement in network usage,which outperformed the current replication strategy,known as Dynamic Popularity aware Replication Strategy(DPRS)algorithm.
基金the National Natural Science Foundation of China (70671011)the National High-Technology Research and Development Program of China (863 Program) (2007AA04Z1B1)the Social Science Youth Foundation of Chongqing University ( CDSK2007-37)
文摘Dynamic data replication is a technique used in data grid environments that helps to reduce access latency and network bandwidth utilization. Replication also increases data availability thereby enhancing system reliability. In this paper we discuss the issues with single-location strategies in large-scale data integration applications, and examine potential multiple-location schemes. Dynamic multiple-location replication is NP-complete in nature. We therefore transform the multiple-location problem into several classical mathematical problems with different parameter settings, to which efficient approximation algorithms apply experimental results indicate that unlike single-location strategies our multiple-location schemes are efficient with respect to access latency and bandwidth consumption, especially when the requesters of a data set are distributed over a large scale of locations.
基金Supported by The National Natural Scientifi c Foundation of China,No. 30070958The National Key Technologies Research and Development Program of China during the 11th Five-year Plan Period,No. 2008zx1002-006
文摘AIM:To determine the antiviral mechanism or target of oxymatrine against hepatitis B virus(HBV).METHODS:HepG2.2.15 cells were incubated with culture medium containing 500 μg/mL of oxymatrine for 2 and 5 d.The surface antigen of HBV(HBsAg) and e antigen of HBV(HBeAg) in supernatant were determined by ELISA.HBV DNA in supernatant,and intracellular covalently closed circular DNA(cccDNA),relaxed circular DNA(rcDNA) and pregenomic RNA(pgRNA) were quantif ied by specif ic real-time polymerase chain reaction(PCR) or reverse transcription(RT)-PCR.RESULTS:Treatment with oxymatrine for 2 d and 5 d reduced the production of HBV by the cell line,as indicated by the decline of HBsAg(22.67%,t = 5.439,P = 0.0322 and 22.39%,t = 5.376,P = 0.0329,respectively),HBeAg(55.34%,t = 9.859,P = 0.0101 and 43.97%,t = 14.080,P = 0.0050) and HBV DNA(40.75%,t = 4.570,P = 0.0447 and 75.32%,t = 14.460,P = 0.0047) in the supernatant.Intracellular cccDNA was also markedly reduced by 63.98%(t = 6.152,P = 0.0254) and 80.83%(t = 10.270,P = 0.0093),and intracellular rcDNA by 34.35%(t = 4.776,P = 0.0413) and 39.24%(t = 10.050,P = 0.0097).In contrast,intracellular pgRNA increased by 6.90-fold(t = 8.941,P = 0.0123) and 3.18-fold(t = 7.432,P = 0.0176) after 500 μg/mL of oxymatrine treatment for 2 d and 5 d,respectively.CONCLUSION:Oxymatrine may inhibit the replication of HBV by interfering with the process of packaging pgRNA into the nucleocapsid,or inhibiting the activity of the viral DNA polymerase.
基金Supported by Pennsylvania state CURE grant,No.4100057658,[to Steel LF and Bouchard MJ(partially)]a Ruth L Kirschstein(F31)Predoctoral Fellowship,No.5F31CA171712-03,[to Lamontagne J(partially)]
文摘Chronic infection with the hepatitis B virus(HBV) is the leading risk factor for the development of hepatocellular carcinoma(HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, micro RNAs(mi RNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of mi RNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between mi RNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some mi RNAs, such as mi R-122, and mi R-125 and mi R-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and mi RNAs, including how HBV affects cellular mi RNAs, how these mi RNAs impact HBV replication, and the relationship between HBV-mediated mi RNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and mi RNAs, and proposepotential applications of mi RNA-related techniques that could enhance our understanding of the role mi RNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes.
基金Supported by a grant of DFG (SFB 402 Teilprojekt C1 (Mihm))by a grant of Hoffmann La Roche (Grenzach-Wyhden, Germany)Part of the data has been presented as poster at the 1999 EASL-meeting in Neaples
文摘AIM: To analyze the association of HCV-RNA with peripheral blood mononuclear cells (PBMC) and to answer the question whether HCV-RNA positivity in PBMC is due to viral replication. METHODS: HCV-RNA was monitored in serum and PBMC preparations from 15 patients with chronic HCV infection before, during and after an IFN-alpha therapy using a nested RT/PCR technique. In a second approach, PBMC from healthy donors were incubated in HCV positive plasma. RESULTS: In the IFN-alpha responding patients,HCV-RNA disappeared first from total RNA preparations of PBMC and then from serum. In contrast, in relapsing patients, HCV-RNA reappeared first in serum and then in PBMC. A quantitative analysis of the HCV-RNA concentration in serum was performed before and after transition from detectable to non detectable HCV-RNA in PBMC-RNA and vice versa. When HCV-RNA was detectable in PBMC preparations, the HCV concentration in serum was significantly higher than the serum HCV-RNA concentration when HCV-RNA in PBMC was not detectable. Furthermore, at no time during the observation period was HCV specific RNA observed in PBMC, if HCV-RNA in serum was under the detection limit. Incubation of PBMC from healthy donors with several dilutions of HCV positive plasma for two hours showed a concentration dependent PCR positivity for HCV-RNA in reisolated PBMC. CONCLUSION: The detectability of HCV-RNA in total RNA from PBMC seems to depend on the HCV concentration in serum. Contamination or passive adsorption by circulating virus could be the reason for detection of HCV-RNA in PBMC preparations of chronically infected patients.
基金Supported by the National Science Fund for Distinguished Young Scholars from the National Natural Science Foundation of China,No.30325036a grant from the National Natural Science Foundation of China,No.30571640
文摘AIM： To establish a rapid and convenient animal model with hepatitis B virus （HBV） replication.METHODS： A naked DNA solution of HBV-replicationcompetent plasmid was transferred to BALB/C mice via the tail vein, using a hydrodynamic in vivo transfection procedure. After injection, these mice were sacrificed on d 1, 3, 4, 5, 7 and 10. HBV DNA replication intermediates in the liver were analyzed by Southern blot hybridization. The expression of hepatitis B core antigen （HBcAg） and hepatitis B surface antigen （HBsAg） in the liver was checked by immunohistochemistry. Serum HBsAg and hepatitis B e antigen （HBeAg） was detected by enzyme- linked immunosorbent assay （ELISA）. Inhibition of HBV replication was compared in HBV replication model mice treated intraperitoneally with polyinosinic-polytidylin acid （polyIC） or phosphate-buffered saline （PBS）.RESULTS： After hydrodynamic in vivo transfection, HBV DNA replication intermediates in the mouse liver were detectable on d 1 and abundant on d 3 and 4, the levels were slightly decreased and remained relatively stable between d 5 and 7, and were almost undetectable on d 10. The expression patterns of HBcAg and HBsAg were similar to that of HBV replication intermediate DNA, except that they reached a peak on d 1 after injection. No obvious differences in HBV DNA replication intermediates were observed in the left, right and middle lobes of the liver. After treatment with polyIC, the level of HBV intermediate DNA in the liver was lower than that in the control mice injected with PBS.CONCLUSION： A rapid and convenient mouse model with a high level of HBV replication was developed and used to investigate the inhibitory effect of polyIC on HBV replication, which provides a useful tool for future functional studies of the HBV genome.
基金This work was supported by the National Natural Science Funds of China under Grant 81471891 and 82000022Key and Weak Subject Construction Project of Shanghai Health and Family Planning System under Grant 2016ZB0205Natural Science Foundation of Shanghai under Grant 18ZR1431900。
文摘Viruses depend on host cellular metabolism to provide the energy and biosynthetic building blocks required for their replication. In this study, we observed that influenza A virus(H1N1), a single-stranded, negative-sense RNA virus with an eight-segmented genome, enhanced glycolysis both in mouse lung tissues and in human lung epithelial(A549) cells. In detail, the expression of hexokinase 2(HK2), the first enzyme in glycolysis, was upregulated in H1N1-infected A549 cells,and the expression of pyruvate kinase M2(PKM2) and pyruvate dehydrogenase kinase 3(PDK3) was upregulated in H1N1-infected mouse lung tissues. Pharmacologically inhibiting the glycolytic pathway or targeting hypoxia-inducible factor 1(HIF-1), the central transcriptional factor critical for glycolysis, significantly reduced H1N1 replication, revealing a requirement for glycolysis during H1N1 infection. In addition, pharmacologically enhancing the glycolytic pathway further promoted H1N1 replication. Furthermore, the change of H1N1 replication upon glycolysis inhibition or enhancement was independent of interferon signaling. Taken together, these findings suggest that influenza A virus induces the glycolytic pathway and thus facilitates efficient viral replication. This study raises the possibility that metabolic inhibitors, such as those that target glycolysis, could be used to treat influenza A virus infection in the future.
基金supported by the National Natural Science Foundation of China (81371794)Guangdong Natural Science Foundation (2014A030311007)
文摘Dengue virus(DENV) belongs to the genus Flavivirus of the family Flaviviridae and it is primarily transmitted via Aedes aegypti and Aedes albopictus mosquitoes. The life cycle of DENV includes attachment, endocytosis, protein translation, RNA synthesis, assembly, egress, and maturation.Recent researches have indicated that a variety of host factors, including cellular proteins and micro RNAs, positively or negatively regulate the DENV replication process. This review summarizes the latest findings(from 2014 to 2016) in the identification of the host factors involved in the DENV life cycle and Dengue infection.
