BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC ...BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC tissues,and might be involved in the development of GC by regulating its downstream winglessrelated integration site(WNT)/β-catenin signaling.AIM To clarify the expression of HNF4α/WNT5a/β-catenin signaling proteins in clinical GC tissues.METHODS We immunohistochemically stained pathological blocks of GC and matched paracancerous tissues.The intensity of HNF4α,WNT5a andβ-catenin staining in the tumor cells was determined according to cell rates and staining intensity.The correlations between GC and HNF4α,WNT5a,andβ-catenin expression using chisquare and paired chi-square tests.Relationships between double-positive HNF4αand WNT5a expression and types of gastric tumor tissues were assessed using regression analysis.Correlations between HNF4αand WNT5a expression at the RNA level in GC tissues found in the TCGA database were analyzed using Pearson correlation coefficients.RESULTS We found more abundant HNF4αand WNT5a proteins in GC,especially in mucinous adenocarcinoma and mixed GC than in adjacent tissues(P<0.001).Low and high levels of cytoplasmicβ-catenin respectively expressed in GC and adjacent tissues(P<0.001)were not significantly associated with pathological parameters.CONCLUSION The expressions of HNF4αand WNT5a could serve as early diagnostic biomarkers for GC.展开更多
Early antiretroviral therapy(ART)initiation is known to limit the establishment of the HIV reservoir,with studies suggesting benefits such as a reduced number of infected cells and a smaller latent reservoir.However,t...Early antiretroviral therapy(ART)initiation is known to limit the establishment of the HIV reservoir,with studies suggesting benefits such as a reduced number of infected cells and a smaller latent reservoir.However,the long-term impact of early ART initiation on the dynamics of the infected cell pool remains unclear,and clinical evidence directly comparing proviral integration site counts between early and late ART initiation is limited.In this study,we used Linear Target Amplification-PCR(LTA-PCR)and Next Generation Sequencing to compare unique integration site(UIS)clonal counts between individuals who initiated ART during acute HIV infection stage(Acute-ART group)and those in the AIDS stage(AIDS-ART group).Our analysis revealed distinct clonal distribution patterns,with greater UIS heterogeneity in Acute-ART group and more homogeneity in AIDS-ART group.Monoclonal UIS accumulation,predominantly in-gene regions,was influenced by ART timing and duration,with early treatment delaying this process.Host cell genes integrated by HIV provirus as monoclonal types were enriched in cell cycle and lymphocyte activation pathways.Tumor suppressor genes(TSGs)were more frequently integrated as monoclonal types in AIDS-ART group,suggesting potential risk factors.Overall,we introduced a sequencing method to assess provirus size in human peripheral blood and identified the widespread presence of monoclonal distribution of UIS in AIDS-ART group after long-term treatment.The early intervention helps slow the progress of clonal expansion of infected cells,reducing the formation of stable and persistent reservoirs,and ultimately posing fewer barriers to achieving a functional cure.展开更多
Pichia pastoris,a methylotrophic yeast,can utilize methanol as a carbon source and energy source to synthesize high-value chemicals,and is an ideal host for biomanufacturing.Constructing the P.pastoris cell factory is...Pichia pastoris,a methylotrophic yeast,can utilize methanol as a carbon source and energy source to synthesize high-value chemicals,and is an ideal host for biomanufacturing.Constructing the P.pastoris cell factory is somewhat impeded due to the absence of genetic tools for manipulating multi-gene biosynthetic pathways.To broaden its application in the field of metabolic engineering,this study identified and screened 15 novel integration sites in P.pastoris using CRISPR-Cpf1 genome editing technology,with EGFP serving the reporter protein.These integration sites have integration efficiencies of 10-100%and varying expression strengths,which allow for selection based on the expression levels of genes as needed.Additionally,these integrated sites are applied in the heterologous biosynthesis of P.pastoris,such as the astaxanthin biosynthetic pathway and the carbon dioxide fixation pathway of the Calvin-Benson-Bassham(CBB)cycle.During the three-site integration process,the 8 genes of the CBB cycle were integrated into the genome of P.pastoris.This indicates the potential of these integration sites for integrating large fragments and suggests their successful application in metabolic engineering of P.pastoris.This may lead to improved efficiency of genetic engineering in P.pastoris.展开更多
Integration of oncogenic DNA viruses into the human genome is a key step in most virusinduced carcinogenesis.Here,we constructed a virus integration site(VIS)Atlas database,an extensive collection of integration break...Integration of oncogenic DNA viruses into the human genome is a key step in most virusinduced carcinogenesis.Here,we constructed a virus integration site(VIS)Atlas database,an extensive collection of integration breakpoints for three most prevalent oncoviruses,human papillomavirus,hepatitis B virus,and Epstein-Barr virus based on the next-generation sequencing(NGS)data,literature,and experimental data.There are 63,179 breakpoints and 47,411 junctional sequences with full annotations deposited in the VIS Atlas database,comprising 47 virus genotypes and 17 disease types.The VIS Atlas database provides(1)a genome browser for NGS breakpoint quality check,visualization of VISs,and the local genomic context;(2)a novel platform to discover integration patterns;and(3)a statistics interface for a comprehensive investigation of genotypespecific integration features.Data collected in the VIS Atlas aid to provide insights into virus pathogenic mechanisms and the development of novel antitumor drugs.展开更多
CRISPR/Cas9-mediated homology-directed recombination is an efficient method to express target genes.Based on the above method,providing ideal neutral integration sites can ensure the reliable,stable,and high expressio...CRISPR/Cas9-mediated homology-directed recombination is an efficient method to express target genes.Based on the above method,providing ideal neutral integration sites can ensure the reliable,stable,and high expression of target genes.In this study,we obtained a fluorescent transformant with neutral integration and high expression of the GFP expression cassette from the constructed GFP expression library and named strain FS.The integration site mapped at 4886 bp upstream of the gene FVRRES_00686 was identified in strain FS based on a Y-shaped adaptor-dependent extension,and the sequence containing 600 bp upstream and downstream of this site was selected as the candidate region for designing sgRNAs(Sites)for CRISPR/Cas9-mediated homology-directed recombination.PCR analysis showed that the integration efficiency of CRISPR/Cas9-mediated integration of target genes in designed sites reached 100%.Further expression stability and applicability analysis revealed that the integration of the target gene into the above designed sites can be stably inherited and expressed and has no negative effect on the growth of F.venenatum TB01.These results indicate the above designed neutral sites have the potential to accelerate the development of F.venenatum TB01 through overexpression of target genes in metabolic engineering.展开更多
Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways...Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review.展开更多
The wingless-related integration site(WNT)proteins are a family of secreted glycoproteins that are evolutionarily conserved and are believed to be involved in evolution in vertebrates and invertebrates.WNT signaling p...The wingless-related integration site(WNT)proteins are a family of secreted glycoproteins that are evolutionarily conserved and are believed to be involved in evolution in vertebrates and invertebrates.WNT signaling pathways may be associated with limb regeneration and development in crustaceans.However,the detail mechanisms remain unclear.Therefore,the distribution of WNT4 in the hepatopancreas,muscle,hemocyte,ganglion,heart,eyestalk,gill tissue,and diff erent larvae development stages of the swimming crab(Portunus trituberculatus)were characterized using immunofl uorescence,real-time PCR,and Western blotting.Signifi cant PtWNT4 expression was detected in heart and eyestalk.In addition,PtWNT4 was expressed in all larval stages of P.trituberculatus with a dynamic expression pattern,especially in the eyestalk and other organs in the carapace area.The injection of WNT4 dsRNA into regenerative limbs signifi cantly decreased PtWNT4 mRNA levels in the eyestalk,heart,and muscle,resulting in 1.9-fold,2.2-fold,and 2.7-fold decreases compared with those detected in the group injected with crab saline(P<0.05),respectively,indicating successful gene silencing.Overall,expression analysis on the WNT4 using RNAi provides an insight to its functional mechanism during limb regeneration in P.trituberculatus.The results not only demonstrated the requirement for WNT4 in limb regeneration of Crustaceans,but also suggested its ability to promote larval development at specifi c stages.展开更多
Hepatocellular carcinoma(HCC)is the fifth most widespread cancer responsible for one fourth of cancer-related deaths globally.Persistent infection with hepatitis B virus(HBV)remains the main cause of HCC summing up to...Hepatocellular carcinoma(HCC)is the fifth most widespread cancer responsible for one fourth of cancer-related deaths globally.Persistent infection with hepatitis B virus(HBV)remains the main cause of HCC summing up to 50%of its causative etiology.Our recent studies,supported by findings from others,uncovered that HBV and its close relative woodchuck hepatitis virus(WHV)integrate into hepatocyte genome almost immediately,hence in minutes after infection.Retrotransposons and genes with translocation potential were found to be frequent sites of HBV insertions,suggesting a mechanism of HBV DNA spread across liver genome from the earliest stages after virus invasion.Many other genes were identified as the sites of early hepadnavirus merges in human hepatocyte-like lines infected de novo with HBV and in natural woodchuck WHV infection model.It was uncovered that head-to-tail joins(HTJs)prevail among the earliest virus-host fusions,implying their formation via the non-homologous-end-joining(NHEJ)pathway.Overlapping homologous junctions resulting from the micro-homology-mediated-overlapping-joining(MHMOJ)were rarely detected.Formation of the initial HTJs coincided with strong induction of reactive oxygen species(ROS)and transient appearance of inducible nitric oxide(iNOS).This was accompanied by cell DNA damage and activation of the poly(ADP-ribose)polymerase 1(PARP1)-mediated host DNA repair machinery,which may explain predominant HTJ format of the first virushost fusions.Identification of initial integration sites and resulting alterations in hepatocyte phenotype may pave a way to discovery of reliable markers of HBV-triggered HCC,including HCC resulting from occult HBV infection.Our research strongly argues that HBV is an ultimate human carcinogen capable of initiation of a pro-oncogenic process immediately after first contact with a susceptible host.展开更多
The genetic stability and expression efficiency of exogenous genes in transgenic animals are closely related to integration site and copy number. In our laboratory, by transgenic manipulation and subsequent test cross...The genetic stability and expression efficiency of exogenous genes in transgenic animals are closely related to integration site and copy number. In our laboratory, by transgenic manipulation and subsequent test crosses, we established an ‘‘all-fish'' growth hormone(GH)transgenic common carp family that exhibits fast growth.In this present study, genome walking, real-time quantitative polymerase chain reaction, and fluorescence in situ hybridization techniques were applied to identify the integration characteristics of the exogenous grass carp GH gene in the transgenic common carp. The exogenous GH genes, in the form of two complete and one incomplete tandem repeats, were found to have integrated into an ATrich region near the end of a chromosome pair. We hypothesize that the high efficiency of exogenous GH gene expression might be due to the low copy number in the genome and the AT-rich integration site.展开更多
The chromosomal position effect can significantly affect the transgene expression,which may provide an efficient strategy for the inauguration of alien genes in new hosts,but has been less explored rationally.The bact...The chromosomal position effect can significantly affect the transgene expression,which may provide an efficient strategy for the inauguration of alien genes in new hosts,but has been less explored rationally.The bacterium Myxococcus xanthus harbors a large circular high-GC genome,and the position effect in this chassis may result in a thousand-fold expression variation of alien natural products.In this study,we conducted transposon insertion at TA sites on the M.xanthus genome,and used enrichment and dilution indexes to respectively appraise high and low expression potentials of alien genes at insertion sites.The enrichment sites are characteristically distributed along the genome,and the dilution sites are overlapped well with the horizontal transfer genes.We experimentally demonstrated the enrichment sites as high expression integration sites(HEISs),and the dilution sites unsuitable for gene integration expression.This work highlights that HEISs are the plug-and-play sites for efficient expression of integrated genes.展开更多
Antiretroviral therapy(ART)can effectively inhibit human immunodeficiency virus-1(HIV-1)replication,but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruse...Antiretroviral therapy(ART)can effectively inhibit human immunodeficiency virus-1(HIV-1)replication,but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruses.In order to reduce or eliminate the HIV-1 latent reservoir,characteristics of the latently infected cells need to be intensively studied,and a comprehensive understanding of the heterogenous nature of the latent reservoir will be critical to develop novel therapeutic strategies.Here,we discuss the different cell types and mechanisms contributing to the complexity and heterogeneity of HIV-1 latent reservoirs,and summarize the key challenges to the development of cure strategies for acquired immunodeficiency syndrome(AIDS).展开更多
基金Supported by National Natural Science Foundation of China,No.81673757.
文摘BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC tissues,and might be involved in the development of GC by regulating its downstream winglessrelated integration site(WNT)/β-catenin signaling.AIM To clarify the expression of HNF4α/WNT5a/β-catenin signaling proteins in clinical GC tissues.METHODS We immunohistochemically stained pathological blocks of GC and matched paracancerous tissues.The intensity of HNF4α,WNT5a andβ-catenin staining in the tumor cells was determined according to cell rates and staining intensity.The correlations between GC and HNF4α,WNT5a,andβ-catenin expression using chisquare and paired chi-square tests.Relationships between double-positive HNF4αand WNT5a expression and types of gastric tumor tissues were assessed using regression analysis.Correlations between HNF4αand WNT5a expression at the RNA level in GC tissues found in the TCGA database were analyzed using Pearson correlation coefficients.RESULTS We found more abundant HNF4αand WNT5a proteins in GC,especially in mucinous adenocarcinoma and mixed GC than in adjacent tissues(P<0.001).Low and high levels of cytoplasmicβ-catenin respectively expressed in GC and adjacent tissues(P<0.001)were not significantly associated with pathological parameters.CONCLUSION The expressions of HNF4αand WNT5a could serve as early diagnostic biomarkers for GC.
基金supported by the China’s National Key R&D Programs(No.2023YFC2306700)National Science Foundation of China(No.82301973)+11 种基金the Chinesisch-Deutsches Mobilitats programm(No.M-0569)Basic and Applied Basic Research Fund of Guangdong Province:Regional Joint Fund-Youth Fund Project(No.2021A1515110831No.2022 A1515111163)the China Post-Doctoral Science Foundation(No.2022M721473)the Shenzhen Third People’s Hospital project(No.21250G1001No.22240G1005No.XKJS-CRGRK-008)Shenzhen Science and Technology Innovations Committee(No.JSGGZD20220822095200001,No.JCYJ20220530163406014)the Top Talent Support Program for young and middle-aged people of Wuxi Health Committee(No.BJ2023093)Research Projects of Wuxi Health Committee(No.M202203)the Wuxi Science and Technology Fund Project(No.Y20222008)We also extend our gratitude to Daniel Hoffmann from the Department of Bioinformatics and Computational Biophysics,University of Duisburg-Essen,Essen 45147,Germany,for his invaluable guidance in bioinformatic analysis.
文摘Early antiretroviral therapy(ART)initiation is known to limit the establishment of the HIV reservoir,with studies suggesting benefits such as a reduced number of infected cells and a smaller latent reservoir.However,the long-term impact of early ART initiation on the dynamics of the infected cell pool remains unclear,and clinical evidence directly comparing proviral integration site counts between early and late ART initiation is limited.In this study,we used Linear Target Amplification-PCR(LTA-PCR)and Next Generation Sequencing to compare unique integration site(UIS)clonal counts between individuals who initiated ART during acute HIV infection stage(Acute-ART group)and those in the AIDS stage(AIDS-ART group).Our analysis revealed distinct clonal distribution patterns,with greater UIS heterogeneity in Acute-ART group and more homogeneity in AIDS-ART group.Monoclonal UIS accumulation,predominantly in-gene regions,was influenced by ART timing and duration,with early treatment delaying this process.Host cell genes integrated by HIV provirus as monoclonal types were enriched in cell cycle and lymphocyte activation pathways.Tumor suppressor genes(TSGs)were more frequently integrated as monoclonal types in AIDS-ART group,suggesting potential risk factors.Overall,we introduced a sequencing method to assess provirus size in human peripheral blood and identified the widespread presence of monoclonal distribution of UIS in AIDS-ART group after long-term treatment.The early intervention helps slow the progress of clonal expansion of infected cells,reducing the formation of stable and persistent reservoirs,and ultimately posing fewer barriers to achieving a functional cure.
基金supported by the National Key Research and Development Program(2021YFC2104000)the National Natural Science Foundation of China(32272276)the Fundamental Research Funds for the Central Universities.
文摘Pichia pastoris,a methylotrophic yeast,can utilize methanol as a carbon source and energy source to synthesize high-value chemicals,and is an ideal host for biomanufacturing.Constructing the P.pastoris cell factory is somewhat impeded due to the absence of genetic tools for manipulating multi-gene biosynthetic pathways.To broaden its application in the field of metabolic engineering,this study identified and screened 15 novel integration sites in P.pastoris using CRISPR-Cpf1 genome editing technology,with EGFP serving the reporter protein.These integration sites have integration efficiencies of 10-100%and varying expression strengths,which allow for selection based on the expression levels of genes as needed.Additionally,these integrated sites are applied in the heterologous biosynthesis of P.pastoris,such as the astaxanthin biosynthetic pathway and the carbon dioxide fixation pathway of the Calvin-Benson-Bassham(CBB)cycle.During the three-site integration process,the 8 genes of the CBB cycle were integrated into the genome of P.pastoris.This indicates the potential of these integration sites for integrating large fragments and suggests their successful application in metabolic engineering of P.pastoris.This may lead to improved efficiency of genetic engineering in P.pastoris.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2018ZX10301402)the National Natural Science Foundation of China(Grant No.81761148025)+6 种基金the Major Projects of Guangzhou Science and Technology Bureau,China(Grant No.201704020093)the National Ten Thousands Plan for Young Top Talents,Young Pearl River Scholar,International Cooperation and Exchange Projects of the National Natural Science Foundation of China(China&Russian)(Grant No.17-54-80078)the Major Projects of Wuhan Municipal Health Commission of China(Grant No.WX19M02)the Major Projects of Hubei Provincial Health Commission of China(Grant No.WJ2019H312)the Dongguan Social Development Key Project of China(Grant No.202050715007221)the Regional Joint Fund Project of Guangdong Basic and Applied Basic Research Foundation of China(Regional Cultivation Project,Grant No.2021B1515140063)the Dongguan Social Development Key Project of China(Grant No.20221800905772).
文摘Integration of oncogenic DNA viruses into the human genome is a key step in most virusinduced carcinogenesis.Here,we constructed a virus integration site(VIS)Atlas database,an extensive collection of integration breakpoints for three most prevalent oncoviruses,human papillomavirus,hepatitis B virus,and Epstein-Barr virus based on the next-generation sequencing(NGS)data,literature,and experimental data.There are 63,179 breakpoints and 47,411 junctional sequences with full annotations deposited in the VIS Atlas database,comprising 47 virus genotypes and 17 disease types.The VIS Atlas database provides(1)a genome browser for NGS breakpoint quality check,visualization of VISs,and the local genomic context;(2)a novel platform to discover integration patterns;and(3)a statistics interface for a comprehensive investigation of genotypespecific integration features.Data collected in the VIS Atlas aid to provide insights into virus pathogenic mechanisms and the development of novel antitumor drugs.
基金supported by the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project (TSBICIP-CXRC-050 and TSBICIP-KJGG-004-20)the China Postdoctoral Science Foundation (2022M713329).
文摘CRISPR/Cas9-mediated homology-directed recombination is an efficient method to express target genes.Based on the above method,providing ideal neutral integration sites can ensure the reliable,stable,and high expression of target genes.In this study,we obtained a fluorescent transformant with neutral integration and high expression of the GFP expression cassette from the constructed GFP expression library and named strain FS.The integration site mapped at 4886 bp upstream of the gene FVRRES_00686 was identified in strain FS based on a Y-shaped adaptor-dependent extension,and the sequence containing 600 bp upstream and downstream of this site was selected as the candidate region for designing sgRNAs(Sites)for CRISPR/Cas9-mediated homology-directed recombination.PCR analysis showed that the integration efficiency of CRISPR/Cas9-mediated integration of target genes in designed sites reached 100%.Further expression stability and applicability analysis revealed that the integration of the target gene into the above designed sites can be stably inherited and expressed and has no negative effect on the growth of F.venenatum TB01.These results indicate the above designed neutral sites have the potential to accelerate the development of F.venenatum TB01 through overexpression of target genes in metabolic engineering.
基金supported by the German Research Council(Deutsche Forschungsgemeinschaft,HA3309/3-1/2,HA3309/6-1,HA3309/7-1)。
文摘Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review.
基金Supported by the National Natural Science Foundation of China(No.31602152)the Major Agriculture Program of Ningbo(No.2017C110007)the K.C.Wong Magana Fund in Ningbo University.The funding body had no role in the study design,experimental implementation,interpretation of data,or writing of the manuscript。
文摘The wingless-related integration site(WNT)proteins are a family of secreted glycoproteins that are evolutionarily conserved and are believed to be involved in evolution in vertebrates and invertebrates.WNT signaling pathways may be associated with limb regeneration and development in crustaceans.However,the detail mechanisms remain unclear.Therefore,the distribution of WNT4 in the hepatopancreas,muscle,hemocyte,ganglion,heart,eyestalk,gill tissue,and diff erent larvae development stages of the swimming crab(Portunus trituberculatus)were characterized using immunofl uorescence,real-time PCR,and Western blotting.Signifi cant PtWNT4 expression was detected in heart and eyestalk.In addition,PtWNT4 was expressed in all larval stages of P.trituberculatus with a dynamic expression pattern,especially in the eyestalk and other organs in the carapace area.The injection of WNT4 dsRNA into regenerative limbs signifi cantly decreased PtWNT4 mRNA levels in the eyestalk,heart,and muscle,resulting in 1.9-fold,2.2-fold,and 2.7-fold decreases compared with those detected in the group injected with crab saline(P<0.05),respectively,indicating successful gene silencing.Overall,expression analysis on the WNT4 using RNAi provides an insight to its functional mechanism during limb regeneration in P.trituberculatus.The results not only demonstrated the requirement for WNT4 in limb regeneration of Crustaceans,but also suggested its ability to promote larval development at specifi c stages.
基金supported by an operating grant(PIN 22346)from the Cancer Research Society Inc.,Canada and the Environmental Cancer Fund-Read for the Cure,Canada and in part by an operating grant(PJT-153001)from the Canadian Institutes of Health Research awarded to Michalak TI.
文摘Hepatocellular carcinoma(HCC)is the fifth most widespread cancer responsible for one fourth of cancer-related deaths globally.Persistent infection with hepatitis B virus(HBV)remains the main cause of HCC summing up to 50%of its causative etiology.Our recent studies,supported by findings from others,uncovered that HBV and its close relative woodchuck hepatitis virus(WHV)integrate into hepatocyte genome almost immediately,hence in minutes after infection.Retrotransposons and genes with translocation potential were found to be frequent sites of HBV insertions,suggesting a mechanism of HBV DNA spread across liver genome from the earliest stages after virus invasion.Many other genes were identified as the sites of early hepadnavirus merges in human hepatocyte-like lines infected de novo with HBV and in natural woodchuck WHV infection model.It was uncovered that head-to-tail joins(HTJs)prevail among the earliest virus-host fusions,implying their formation via the non-homologous-end-joining(NHEJ)pathway.Overlapping homologous junctions resulting from the micro-homology-mediated-overlapping-joining(MHMOJ)were rarely detected.Formation of the initial HTJs coincided with strong induction of reactive oxygen species(ROS)and transient appearance of inducible nitric oxide(iNOS).This was accompanied by cell DNA damage and activation of the poly(ADP-ribose)polymerase 1(PARP1)-mediated host DNA repair machinery,which may explain predominant HTJ format of the first virushost fusions.Identification of initial integration sites and resulting alterations in hepatocyte phenotype may pave a way to discovery of reliable markers of HBV-triggered HCC,including HCC resulting from occult HBV infection.Our research strongly argues that HBV is an ultimate human carcinogen capable of initiation of a pro-oncogenic process immediately after first contact with a susceptible host.
基金supported by the National High Technology Research and Development Program of China(‘‘863’’Program)(2011AA100404,2011AA100403)the National Natural Science Foundation of China(31325026,31272649)
文摘The genetic stability and expression efficiency of exogenous genes in transgenic animals are closely related to integration site and copy number. In our laboratory, by transgenic manipulation and subsequent test crosses, we established an ‘‘all-fish'' growth hormone(GH)transgenic common carp family that exhibits fast growth.In this present study, genome walking, real-time quantitative polymerase chain reaction, and fluorescence in situ hybridization techniques were applied to identify the integration characteristics of the exogenous grass carp GH gene in the transgenic common carp. The exogenous GH genes, in the form of two complete and one incomplete tandem repeats, were found to have integrated into an ATrich region near the end of a chromosome pair. We hypothesize that the high efficiency of exogenous GH gene expression might be due to the low copy number in the genome and the AT-rich integration site.
基金the National Key Research and Development Program of China(2021YFC2101000)the National Natural Science Foundation of China(32301220).
文摘The chromosomal position effect can significantly affect the transgene expression,which may provide an efficient strategy for the inauguration of alien genes in new hosts,but has been less explored rationally.The bacterium Myxococcus xanthus harbors a large circular high-GC genome,and the position effect in this chassis may result in a thousand-fold expression variation of alien natural products.In this study,we conducted transposon insertion at TA sites on the M.xanthus genome,and used enrichment and dilution indexes to respectively appraise high and low expression potentials of alien genes at insertion sites.The enrichment sites are characteristically distributed along the genome,and the dilution sites are overlapped well with the horizontal transfer genes.We experimentally demonstrated the enrichment sites as high expression integration sites(HEISs),and the dilution sites unsuitable for gene integration expression.This work highlights that HEISs are the plug-and-play sites for efficient expression of integrated genes.
基金This work was supported by grants from the National Special Research Program of China for Important Infectious Diseases(No.2018ZX10302103 and No.2017ZX10202102)National Natural Science Foundation of China(No.81672024)+1 种基金Natural Science Foundation of Guangdong Province of China(No.2017A030306005)Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06S638)。
文摘Antiretroviral therapy(ART)can effectively inhibit human immunodeficiency virus-1(HIV-1)replication,but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruses.In order to reduce or eliminate the HIV-1 latent reservoir,characteristics of the latently infected cells need to be intensively studied,and a comprehensive understanding of the heterogenous nature of the latent reservoir will be critical to develop novel therapeutic strategies.Here,we discuss the different cell types and mechanisms contributing to the complexity and heterogeneity of HIV-1 latent reservoirs,and summarize the key challenges to the development of cure strategies for acquired immunodeficiency syndrome(AIDS).
