Aim: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen ...Aim: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen and the stability of DNA was examined by adding lipofection reagents. Methods: A PCR fragment (249 bp) of pEGFPN-1 vector was used as the DNA substrate and was incubated with the seminal plasma at 40 ℃ for 30 min. Then, the whole reaction solution was subjected to agarose gel electrophoresis and the DNA size was evaluated under UV light. Results: The DNA substrate was completely diminished after incubation with seminal plasma. However, the substrate was intact after incubation with heat-treated seminal plasma or incubation with seminal plasma in the presence of 0.5 mmol/L -5 mmol/L EDTA. The substrate was stabilized in the seminal plasma by the addition of commercially available lipofection reagents. Conclusion: The DNase activity is present in the seminal plasma of ejaculated chicken semen. However, DNA is stable in the liposomal-DNA complex.展开更多
Background Previous studies have suggested that interrupted clearance of nuclear DNA-protein complexes after cell death might initiate and propagate systemic lupus erythematosus (SLE). Deoxyribonuclease Ⅰ (DNaseⅠ) ...Background Previous studies have suggested that interrupted clearance of nuclear DNA-protein complexes after cell death might initiate and propagate systemic lupus erythematosus (SLE). Deoxyribonuclease Ⅰ (DNaseⅠ) may be responsible for the removal of DNA from nuclear antigens at sites of high cell turnover, thus preventing the onset of SLE. The purpose of this study was to genotype the single nucleotide polymorphisms (SNPs) of DNase1 and characterize its gene expression and alternatively spliced transcripts in Chinese patients with SLE in order to unde rstand the pathogenic role of DNase1 in human SLE.Methods Four SNPs located at the 3’ end of the DNase1 gene, as listed on the SNP website, were selected for analysis. Those SNPs with relatively high heterozygosity were chosen for genotyping in 312 Chinese SLE families using the Taqman minor groove binder (MGB) allelic discrimination method. Haplotypes were constructed and linkage disequilibrium tests were performed using GeneHunter. DNase1 mRNA expression was detected using real-time polymerase chain reaction (PCR), and alternatively spliced transcripts were isolated using capillary electrophoresis. Any effects the specific SNP haplotypes had on DNase1 gene expression and the alternatively spliced transcripts were also assessed.Results rs179982 and rs1053874 had high heterozygosity, about 0.5 in this Chinese cohort, while rs1059857 was also found to be heterozygous. Analysis of the haplotype combining rs179982-rs1030874 (C-G) and rs179982-rs1030874-rs1059857 (C-G-G) revealed a skewed transmission in favor of affected offspring. DNase1 gene expression was higher in SLE patients than in normal controls (P<0.001), but this was not related to disease activity or SNP haplotype. Capillary electrophoresis revealed that the pattern of alternatively spliced transcripts in patients differed from that of normal controls. Furthermore, different SNP haplotype combinations generated different transcript patterns in SLE patients. Conclusions The SNP haplotypes are in linkage disequilibrium in Chinese SLE patients and may induce the disease through a modification of DNase1 mRNA splicing rather than at the level of mRNA expression. There is a relatively unique transcript band in SLE patients independent of special haplotype, which suggests that other unknown factors might be involved in adjusting gene expression.展开更多
Background:Traumatic injury is associated with increased concentrations of cell-free DNA(cfDNA)in the circulation,which contribute to post-injury complications.The endonuclease deoxyribonuclease 1(DNase-1)is responsib...Background:Traumatic injury is associated with increased concentrations of cell-free DNA(cfDNA)in the circulation,which contribute to post-injury complications.The endonuclease deoxyribonuclease 1(DNase-1)is responsible for removing 90%of circulating cfDNA.Recently,DNase activity was reported to be significantly reduced following major non-traumatic brain injury(TBI),but the processes responsible were not investigated.Moreover,it is not known how quickly following injury DNase activity is reduced and whether this also occurs after TBI.Methods:At 3 post-injury time points(≤1,4–12 and 48–72 hours),blood samples were obtained from 155 adult trauma patients that had sustained an isolated TBI(n=21),TBI with accompanying extracranial injury(TBI^(+))(n=53)or an extracranial injury only(ECI)(n=81).In addition to measuring cfDNA levels and the activity and expression of DNase,circulating concentrations of monomeric globular action(G-actin),an inhibitor of DNase-1,and the actin scavenging proteins gelsolin(GSN)and vitamin D binding protein(VDBP)were determined and values compared to a cohort of healthy controls.Results:Significantly elevated concentrations of plasma cfDNA were seen in TBI,TBI^(+)and ECI patients at all study time points when compared to healthy controls.cfDNA levels were significantly higher at≤1 hour post-injury in ECI patients who subsequently developed multiple organ dysfunction syndrome when compared to those who did not.Plasma DNase-1 protein was significantly elevated in all patient groups at all sampling time points.In contrast,DNase enzyme activity was significantly reduced,with this impaired function evident in TBI^(+)patients within minutes of injury.Circulating concentrations of G-actin were elevated in all patient cohorts in the immediate aftermath of injury and this was accompanied by a significant reduction in the levels of GSN and VDBP.Conclusions:The post-traumatic increase in circulating cfDNA that occurs following extracranial trauma and TBI is accompanied by reduced DNase activity.We propose that,secondary to reduced GSN and VDBP levels,elevated circulating concentrations of G-actin underlie the post-injury reduction in DNase activity.Reducing circulating cfDNA levels via therapeutic restoration of DNase-1 activity may improve clinical outcomes post-injury.展开更多
通过(NH4)2SO4沉淀,利用Blue Sepharose 6 Fast Flow和SP Sepharose Fast Flow层析方法从灵芝中分离纯化了一种脱氧核糖核酸酶,命名为GLDNase.通过质谱分析确定GLDNase精确分子质量为13807 u.SDS-PAGE电泳表明GLDNase为单亚基多肽,其N-...通过(NH4)2SO4沉淀,利用Blue Sepharose 6 Fast Flow和SP Sepharose Fast Flow层析方法从灵芝中分离纯化了一种脱氧核糖核酸酶,命名为GLDNase.通过质谱分析确定GLDNase精确分子质量为13807 u.SDS-PAGE电泳表明GLDNase为单亚基多肽,其N-端氨基酸序列为PLDTGRYHIYTW/T/CDGG.GLDNase可作用于ssDNA和dsDNA,是一种非限制性内切酶,酶活性依赖于二价金属阳离子Mg2+,10 mmol.L-1EDTA可完全抑制其活性.最适pH值为8.4,40℃时相对活性最高.GLDNase水解DNA的产物末端的基团为3′-OH、5′-磷酸.展开更多
文摘Aim: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen and the stability of DNA was examined by adding lipofection reagents. Methods: A PCR fragment (249 bp) of pEGFPN-1 vector was used as the DNA substrate and was incubated with the seminal plasma at 40 ℃ for 30 min. Then, the whole reaction solution was subjected to agarose gel electrophoresis and the DNA size was evaluated under UV light. Results: The DNA substrate was completely diminished after incubation with seminal plasma. However, the substrate was intact after incubation with heat-treated seminal plasma or incubation with seminal plasma in the presence of 0.5 mmol/L -5 mmol/L EDTA. The substrate was stabilized in the seminal plasma by the addition of commercially available lipofection reagents. Conclusion: The DNase activity is present in the seminal plasma of ejaculated chicken semen. However, DNA is stable in the liposomal-DNA complex.
文摘Background Previous studies have suggested that interrupted clearance of nuclear DNA-protein complexes after cell death might initiate and propagate systemic lupus erythematosus (SLE). Deoxyribonuclease Ⅰ (DNaseⅠ) may be responsible for the removal of DNA from nuclear antigens at sites of high cell turnover, thus preventing the onset of SLE. The purpose of this study was to genotype the single nucleotide polymorphisms (SNPs) of DNase1 and characterize its gene expression and alternatively spliced transcripts in Chinese patients with SLE in order to unde rstand the pathogenic role of DNase1 in human SLE.Methods Four SNPs located at the 3’ end of the DNase1 gene, as listed on the SNP website, were selected for analysis. Those SNPs with relatively high heterozygosity were chosen for genotyping in 312 Chinese SLE families using the Taqman minor groove binder (MGB) allelic discrimination method. Haplotypes were constructed and linkage disequilibrium tests were performed using GeneHunter. DNase1 mRNA expression was detected using real-time polymerase chain reaction (PCR), and alternatively spliced transcripts were isolated using capillary electrophoresis. Any effects the specific SNP haplotypes had on DNase1 gene expression and the alternatively spliced transcripts were also assessed.Results rs179982 and rs1053874 had high heterozygosity, about 0.5 in this Chinese cohort, while rs1059857 was also found to be heterozygous. Analysis of the haplotype combining rs179982-rs1030874 (C-G) and rs179982-rs1030874-rs1059857 (C-G-G) revealed a skewed transmission in favor of affected offspring. DNase1 gene expression was higher in SLE patients than in normal controls (P<0.001), but this was not related to disease activity or SNP haplotype. Capillary electrophoresis revealed that the pattern of alternatively spliced transcripts in patients differed from that of normal controls. Furthermore, different SNP haplotype combinations generated different transcript patterns in SLE patients. Conclusions The SNP haplotypes are in linkage disequilibrium in Chinese SLE patients and may induce the disease through a modification of DNase1 mRNA splicing rather than at the level of mRNA expression. There is a relatively unique transcript band in SLE patients independent of special haplotype, which suggests that other unknown factors might be involved in adjusting gene expression.
基金funded by the National Institute for Health Research(NIHR)Surgical Reconstruction and Microbiology Research Centre and the Scar Free Foundation.JML is supported by the NIHR Birmingham Biomedical Research Centre and the Medical Research Council(MRC)Versus Arthritis Centre for Musculoskeletal Ageing Research.The funding bodies had no role in the design of the study,the collection,analysis or interpretation of the data or in the writing of the manuscript.
文摘Background:Traumatic injury is associated with increased concentrations of cell-free DNA(cfDNA)in the circulation,which contribute to post-injury complications.The endonuclease deoxyribonuclease 1(DNase-1)is responsible for removing 90%of circulating cfDNA.Recently,DNase activity was reported to be significantly reduced following major non-traumatic brain injury(TBI),but the processes responsible were not investigated.Moreover,it is not known how quickly following injury DNase activity is reduced and whether this also occurs after TBI.Methods:At 3 post-injury time points(≤1,4–12 and 48–72 hours),blood samples were obtained from 155 adult trauma patients that had sustained an isolated TBI(n=21),TBI with accompanying extracranial injury(TBI^(+))(n=53)or an extracranial injury only(ECI)(n=81).In addition to measuring cfDNA levels and the activity and expression of DNase,circulating concentrations of monomeric globular action(G-actin),an inhibitor of DNase-1,and the actin scavenging proteins gelsolin(GSN)and vitamin D binding protein(VDBP)were determined and values compared to a cohort of healthy controls.Results:Significantly elevated concentrations of plasma cfDNA were seen in TBI,TBI^(+)and ECI patients at all study time points when compared to healthy controls.cfDNA levels were significantly higher at≤1 hour post-injury in ECI patients who subsequently developed multiple organ dysfunction syndrome when compared to those who did not.Plasma DNase-1 protein was significantly elevated in all patient groups at all sampling time points.In contrast,DNase enzyme activity was significantly reduced,with this impaired function evident in TBI^(+)patients within minutes of injury.Circulating concentrations of G-actin were elevated in all patient cohorts in the immediate aftermath of injury and this was accompanied by a significant reduction in the levels of GSN and VDBP.Conclusions:The post-traumatic increase in circulating cfDNA that occurs following extracranial trauma and TBI is accompanied by reduced DNase activity.We propose that,secondary to reduced GSN and VDBP levels,elevated circulating concentrations of G-actin underlie the post-injury reduction in DNase activity.Reducing circulating cfDNA levels via therapeutic restoration of DNase-1 activity may improve clinical outcomes post-injury.
文摘通过(NH4)2SO4沉淀,利用Blue Sepharose 6 Fast Flow和SP Sepharose Fast Flow层析方法从灵芝中分离纯化了一种脱氧核糖核酸酶,命名为GLDNase.通过质谱分析确定GLDNase精确分子质量为13807 u.SDS-PAGE电泳表明GLDNase为单亚基多肽,其N-端氨基酸序列为PLDTGRYHIYTW/T/CDGG.GLDNase可作用于ssDNA和dsDNA,是一种非限制性内切酶,酶活性依赖于二价金属阳离子Mg2+,10 mmol.L-1EDTA可完全抑制其活性.最适pH值为8.4,40℃时相对活性最高.GLDNase水解DNA的产物末端的基团为3′-OH、5′-磷酸.
