[ Objective] The study aimed to lay a foundation for the further studies on function mechanism of NS1 protein in the interspecies transmission of waterfowl influenza virus. [Method] Using the serologic assay and the s...[ Objective] The study aimed to lay a foundation for the further studies on function mechanism of NS1 protein in the interspecies transmission of waterfowl influenza virus. [Method] Using the serologic assay and the specific RT-PCR method, some strains of H9 subtype waterfowl influenza virus were isolated from the 12 to 20 day-old muscovy duck flocks without any clinical symptoms in different areas of Guangdong Province. Four of these strains, including A/duck/ZQ/303/2007（H9N2） （A3 for short）, A/Duck/FJ/301/2007 （H9N2） （C1 for short）, A/Duck/NH/306/2007（H9N2） （ D6 for short）, A/duck/SS/402/2007（H9N2） （ E2 for short）, and a strain named A/duck/ZC/2007（H9N2） （L1 for short） from a muscovy duck died of avian influenza virus （AIV）, were used for NSl gene cloning and sequencing. Subsequently, the obtained NSl gene sequences were compared with other NS1 sequences registered in GenBank, and the phylogenetic analysis was also conducted. [Result] When compared with the H9N2 AIV NS1 sequences in GenBank, the NSl genes of the four AIV strains A3, C1, 136 and E2 displayed homologies ranging from 99% to 100% at nucleotide level, and 95% to 100% at amino acid level; while the NSl gene of L1 strain displayed homology ranging from 94% to 97% at nucleotide level, and 93% to 98% at amino acid level. The phylogenetic tree demonstrated that A3, C1, D6 and E2 were highly resemblant, and L1 was closest to AY66473 （chicken, 2003）. By comparison with the NS1 gene sequences of L1, AF523514 （duck）, AY664743 （chicken） and EF155262.1 （quail） using DNAstar, A3, C1, D6 and E.2 presented nucleotide variations at site 21 （ R→Q）, 70, 71 （ KE→EG）, 86 （ A→S）, 124 （V→M） and 225 （ S→N）, and amino acid variations at site 21,70, 71 and 86 in dsRNA- dependent protein kinase （PKR） binding domain of NSl gene, which induced the evident variations of antigenic determinant and surface proba- bility plot of NS1 protein. [ Conclusion] This study suggested that the amino acid sequence variation in PKR binding domain of NS1 protein had something to do with the virus pathogenicity.展开更多
Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone...Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.展开更多
Age-related macular degeneration(AMD) is the leading cause of irreversible blindness in the developed world. The quality of life of both patients and families is impacted by this prevalent disease. Previously, macular...Age-related macular degeneration(AMD) is the leading cause of irreversible blindness in the developed world. The quality of life of both patients and families is impacted by this prevalent disease. Previously, macular degeneration had no known effective treatment. Today, vitamins for non-exudative AMD and intravitreal injection of medications for its exudative form are primary forms of current treatment. Modern advances in molecular science give rise to new possibilities of disease management. In the year 2003 the sequencing of the entire human genome was completed. Since that time, genes such as complement factor H, high-temperature requirement factor A1, and age-relateed maculopathy susceptibility 2 have been discovered and associated with a higher risk of AMD. A patient's genetic make-up may dictate the effectiveness of current or future therapeutic options. In addition, utilizing genetic data and incorporating it into new treatments(such as viral vectors) may lead to longer-lasting(or permanent) VEGF blockade and specific targeting of complement related genes. There have also been considerable advances in stem cell directed treatment of AMD. Retinal pigment epithelial(RPE) cells can be derived from human embryonic stem cells, induced pluripotent stem cells, or adult human RPE stem cells. Utilizing animal models of RPE and retinal degeneration, stem cell-derived RPE cells have been successfully implanted into the subretinal space. They have been injected as a cell mass or as a pre-prepared monolayer on a thin membrane. Visual recovery has been demonstrated in a retinal dystrophic rat model. Preliminary data on 2 human subjects also demonstrates possible early visual benefit from transplantation of stem cell-derived RPE. As more data is published, and as differentiation and implantation techniques are optimized, the stabilization and possible improvement of vision in individuals with non-exudative macular becomes a real possibility. We conclude that the technologic advances that continue to unfold in both genetic and stem cell research offer optimism in the future treatment of AMD.展开更多
Incorporation of the histone variant H2A.Z into nucleosomes by the SWR1 chromatin remodeling complex is a critical step in eukaryotic gene regulation. In Arabidopsis, SWRlc and H2A.Z have been shown to con- trol gene ...Incorporation of the histone variant H2A.Z into nucleosomes by the SWR1 chromatin remodeling complex is a critical step in eukaryotic gene regulation. In Arabidopsis, SWRlc and H2A.Z have been shown to con- trol gene expression underlying development and environmental responses. Although they have been implicated in defense, the specific roles of the complex subunits and H2A.Z in immunity are not well under- stood. In this study, we analyzed the roles of the SWRlc subunits, PHOTOPERIOD-INDEPENDENT EARLY FLOWERING1 （PIE1）, ACTIN-RELATED PROTEIN6 （ARP6）, and SWR1 COMPLEX 6 （SWC6）, as well as H2A.Z, in defense and gene regulation. We found that SWRlc components play different roles in resistance to different pathogens. Loss of PIE1 and SWC6 function as well as depletion of H2A.Z led to reduced basal resistance, while loss of ARP6 fucntion resulted in enhanced resistance. We found that mutations in PIE1 and SWC6 resulted in impaired effector-triggered immunity. Mutation in SWRlc components and H2A.Z also resulted in compromised jasmonic acid/ethylene-mediated immunity. Genome-wide expres- sion analyses similarly reveal distinct roles for H2A.Z and SWRlc components in gene regulation, and sug- gest a potential role for PIE1 in the regulation of the cross talk between defense signaling pathways. Our data show that although they are part of the same complex, Arabidopsis SWRlc components could have non-redundant functions in plant immunity and gene regulation.展开更多
Dear Editor,Influenza A viruses cause pandemics at an interval of approximately 10-40 years,and pigs are regarded as a＂mixing vessel＂because they are easily infected with avian and human influenza viruses（Ito et al...Dear Editor,Influenza A viruses cause pandemics at an interval of approximately 10-40 years,and pigs are regarded as a＂mixing vessel＂because they are easily infected with avian and human influenza viruses（Ito et al.,1998）.According to previous studies,H3N2,H1N2,and H1N1 subtypes o（swine influenza viruses have been detected in Korean pigs （Pascua et al., 2013; Kim et al., 2014; Song et al., 2007）. Moreover, a novel H3N2 influenza virus containing the matrix （34） gene from a 2009 pandemic influenza virus was detected in Korean pigs in 2013 （Pascua et al., 2013）, an H1N2 influenza virus con- taining the internal genes from a 2009 pandemic influ- enza virus was found in Korean pigs in 2014 （Kim et al., 2014）, and an H1N1 influenza virus containing all genes from the classical swine influenza viruses was isolated from Korean pigs in 2007 （Song et al., 2007）.展开更多
From mammals to plants, the Polycomb Group （PcG） machinery plays a crucial role in maintaining the repres- sion of genes that are not required in a specific differentiation status. However, the mechanism by which Pe...From mammals to plants, the Polycomb Group （PcG） machinery plays a crucial role in maintaining the repres- sion of genes that are not required in a specific differentiation status. However, the mechanism by which PeG machinery mediates gene repression is still largely unknown in plants. Compared to animals, few PcG proteins have been identi- fied in plants, not only because just some of these proteins are clearly conserved to their animal counterparts, but also because some PcG functions are carried out by plant-specific proteins, most of them as yet uncharacterized. For a long time, the apparent lack of Polycomb Repressive Complex （PRC）I components in plants was interpreted according to the idea that plants, as sessile organisms, do not need a long-term repression, as they must be able to respond rapidly to environmental signals; however, some PRC1 components have been recently identified, indicating that this may not be the case. Furthermore, new data regarding the recruitment of PcG complexes and maintenance of PcG repression in plants have revealed important differences to what has been reported so far. This review highlights recent progress in plant PcG function, focusing on the role of the putative PRC1 components.展开更多
基金Supported by Key Specific Program for Science and Technology of Guangdong Province (2008B020700003 A2007A020400006)~~
文摘[ Objective] The study aimed to lay a foundation for the further studies on function mechanism of NS1 protein in the interspecies transmission of waterfowl influenza virus. [Method] Using the serologic assay and the specific RT-PCR method, some strains of H9 subtype waterfowl influenza virus were isolated from the 12 to 20 day-old muscovy duck flocks without any clinical symptoms in different areas of Guangdong Province. Four of these strains, including A/duck/ZQ/303/2007（H9N2） （A3 for short）, A/Duck/FJ/301/2007 （H9N2） （C1 for short）, A/Duck/NH/306/2007（H9N2） （ D6 for short）, A/duck/SS/402/2007（H9N2） （ E2 for short）, and a strain named A/duck/ZC/2007（H9N2） （L1 for short） from a muscovy duck died of avian influenza virus （AIV）, were used for NSl gene cloning and sequencing. Subsequently, the obtained NSl gene sequences were compared with other NS1 sequences registered in GenBank, and the phylogenetic analysis was also conducted. [Result] When compared with the H9N2 AIV NS1 sequences in GenBank, the NSl genes of the four AIV strains A3, C1, 136 and E2 displayed homologies ranging from 99% to 100% at nucleotide level, and 95% to 100% at amino acid level; while the NSl gene of L1 strain displayed homology ranging from 94% to 97% at nucleotide level, and 93% to 98% at amino acid level. The phylogenetic tree demonstrated that A3, C1, D6 and E2 were highly resemblant, and L1 was closest to AY66473 （chicken, 2003）. By comparison with the NS1 gene sequences of L1, AF523514 （duck）, AY664743 （chicken） and EF155262.1 （quail） using DNAstar, A3, C1, D6 and E.2 presented nucleotide variations at site 21 （ R→Q）, 70, 71 （ KE→EG）, 86 （ A→S）, 124 （V→M） and 225 （ S→N）, and amino acid variations at site 21,70, 71 and 86 in dsRNA- dependent protein kinase （PKR） binding domain of NSl gene, which induced the evident variations of antigenic determinant and surface proba- bility plot of NS1 protein. [ Conclusion] This study suggested that the amino acid sequence variation in PKR binding domain of NS1 protein had something to do with the virus pathogenicity.
基金Supported by National Natural Science Foundation of China (30721063)National Basic Research Program of China (973 Program) (2005CB522402, 2006CB910403)+1 种基金National Laboratory of Medical Molecular Biology grant (2060204)Beijing municipal government grant (YB20081002301)
文摘Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.
文摘Age-related macular degeneration(AMD) is the leading cause of irreversible blindness in the developed world. The quality of life of both patients and families is impacted by this prevalent disease. Previously, macular degeneration had no known effective treatment. Today, vitamins for non-exudative AMD and intravitreal injection of medications for its exudative form are primary forms of current treatment. Modern advances in molecular science give rise to new possibilities of disease management. In the year 2003 the sequencing of the entire human genome was completed. Since that time, genes such as complement factor H, high-temperature requirement factor A1, and age-relateed maculopathy susceptibility 2 have been discovered and associated with a higher risk of AMD. A patient's genetic make-up may dictate the effectiveness of current or future therapeutic options. In addition, utilizing genetic data and incorporating it into new treatments(such as viral vectors) may lead to longer-lasting(or permanent) VEGF blockade and specific targeting of complement related genes. There have also been considerable advances in stem cell directed treatment of AMD. Retinal pigment epithelial(RPE) cells can be derived from human embryonic stem cells, induced pluripotent stem cells, or adult human RPE stem cells. Utilizing animal models of RPE and retinal degeneration, stem cell-derived RPE cells have been successfully implanted into the subretinal space. They have been injected as a cell mass or as a pre-prepared monolayer on a thin membrane. Visual recovery has been demonstrated in a retinal dystrophic rat model. Preliminary data on 2 human subjects also demonstrates possible early visual benefit from transplantation of stem cell-derived RPE. As more data is published, and as differentiation and implantation techniques are optimized, the stabilization and possible improvement of vision in individuals with non-exudative macular becomes a real possibility. We conclude that the technologic advances that continue to unfold in both genetic and stem cell research offer optimism in the future treatment of AMD.
文摘Incorporation of the histone variant H2A.Z into nucleosomes by the SWR1 chromatin remodeling complex is a critical step in eukaryotic gene regulation. In Arabidopsis, SWRlc and H2A.Z have been shown to con- trol gene expression underlying development and environmental responses. Although they have been implicated in defense, the specific roles of the complex subunits and H2A.Z in immunity are not well under- stood. In this study, we analyzed the roles of the SWRlc subunits, PHOTOPERIOD-INDEPENDENT EARLY FLOWERING1 （PIE1）, ACTIN-RELATED PROTEIN6 （ARP6）, and SWR1 COMPLEX 6 （SWC6）, as well as H2A.Z, in defense and gene regulation. We found that SWRlc components play different roles in resistance to different pathogens. Loss of PIE1 and SWC6 function as well as depletion of H2A.Z led to reduced basal resistance, while loss of ARP6 fucntion resulted in enhanced resistance. We found that mutations in PIE1 and SWC6 resulted in impaired effector-triggered immunity. Mutation in SWRlc components and H2A.Z also resulted in compromised jasmonic acid/ethylene-mediated immunity. Genome-wide expres- sion analyses similarly reveal distinct roles for H2A.Z and SWRlc components in gene regulation, and sug- gest a potential role for PIE1 in the regulation of the cross talk between defense signaling pathways. Our data show that although they are part of the same complex, Arabidopsis SWRlc components could have non-redundant functions in plant immunity and gene regulation.
基金in part funded by a 2015 research fund from Chungnam National University
文摘Dear Editor,Influenza A viruses cause pandemics at an interval of approximately 10-40 years,and pigs are regarded as a＂mixing vessel＂because they are easily infected with avian and human influenza viruses（Ito et al.,1998）.According to previous studies,H3N2,H1N2,and H1N1 subtypes o（swine influenza viruses have been detected in Korean pigs （Pascua et al., 2013; Kim et al., 2014; Song et al., 2007）. Moreover, a novel H3N2 influenza virus containing the matrix （34） gene from a 2009 pandemic influenza virus was detected in Korean pigs in 2013 （Pascua et al., 2013）, an H1N2 influenza virus con- taining the internal genes from a 2009 pandemic influ- enza virus was found in Korean pigs in 2014 （Kim et al., 2014）, and an H1N1 influenza virus containing all genes from the classical swine influenza viruses was isolated from Korean pigs in 2007 （Song et al., 2007）.
文摘From mammals to plants, the Polycomb Group （PcG） machinery plays a crucial role in maintaining the repres- sion of genes that are not required in a specific differentiation status. However, the mechanism by which PeG machinery mediates gene repression is still largely unknown in plants. Compared to animals, few PcG proteins have been identi- fied in plants, not only because just some of these proteins are clearly conserved to their animal counterparts, but also because some PcG functions are carried out by plant-specific proteins, most of them as yet uncharacterized. For a long time, the apparent lack of Polycomb Repressive Complex （PRC）I components in plants was interpreted according to the idea that plants, as sessile organisms, do not need a long-term repression, as they must be able to respond rapidly to environmental signals; however, some PRC1 components have been recently identified, indicating that this may not be the case. Furthermore, new data regarding the recruitment of PcG complexes and maintenance of PcG repression in plants have revealed important differences to what has been reported so far. This review highlights recent progress in plant PcG function, focusing on the role of the putative PRC1 components.
