横断山区是我国长江上游重要的生态屏障区,对周边区域乃至我国中西部地区气候和生态环境有着深刻的影响。NPP作为碳收支和气候变化研究的核心内容,是判定生态系统健康状况和可持续发展水平的重要指标。基于MODIS C6的NPP数据、1∶100万...横断山区是我国长江上游重要的生态屏障区,对周边区域乃至我国中西部地区气候和生态环境有着深刻的影响。NPP作为碳收支和气候变化研究的核心内容,是判定生态系统健康状况和可持续发展水平的重要指标。基于MODIS C6的NPP数据、1∶100万植被类型图、气象数据和地形数据,采用趋势线分析法和相关分析法对横断地区2004—2014年植被NPP时空格局、变化规律以及驱动因子进行了研究。结果表明:(1)2004—2014年横断山区植被年NPP总量的介于183.768—223.239 Tg C之间,多年平均为208.498 Tg C,单位面积下的植被年NPP均值为463 g C m^(-2)a^(-1)。整体上,植被NPP呈增加趋势,但局部差异明显。(2)植被NPP平均值的年际变化率在-53—97 g C m^(-2)a^(-1)之间,NPP呈增加趋势的区域分布在北部与中部的东侧以及南部的东、西两侧地区,而减少趋势的区域主要集中在西北部、中部的汶川—映秀一带以及南部攀枝花地区。(3)横断山区植被NPP变化受气候因子驱动影响的区域占比8.42%,主要集中在中部的大雪山-沙鲁里山地区,而非气候因子占比91.58%,分布在北部的阿坝地区以及南部的低海拔广大地区。该研究将对横断山区生态环境建设和可持续发展起到指导作用。展开更多
天山北坡是中国农牧业发展基地,也是“一带一路”开发重点区域。气候变化和人类活动是影响天山北坡净初级生产力(Net Primary Productivity,NPP)的2个重要因素,定量评估气候变化和人类活动对天山北坡草场可持续性利用具有重要意义。该...天山北坡是中国农牧业发展基地,也是“一带一路”开发重点区域。气候变化和人类活动是影响天山北坡净初级生产力(Net Primary Productivity,NPP)的2个重要因素,定量评估气候变化和人类活动对天山北坡草场可持续性利用具有重要意义。该研究采用MODIS C6遥感数据、气象数据和野外实测数据,分析2004-2015年气候变化和人类活动对天山北坡NPP变化的影响。结果表明:2004-2015年天山北坡实际净初级生产力(Actual Net Primary Productivity,NPPA)介于128.67~170.49 g/(m^2·a)之间,总体呈现增加趋势;西部区域NPPA年均值最高,天山北坡NPPA的主要供给区是中西部区域。天山北坡不同区域年均温度及降水量呈现明显差异,降水对NPPA的影响大于温度。同时,人类活动对NPP的影响(Human Activities on Net Primary Productivity,NPPH),总体上由负作用逐渐向正作用转变,正作用增强区域主要分布在奇台县、木垒县和天山北坡东部部分地区,负作用逐渐增强区域主要分布在奎屯市及乌苏市部分地区。展开更多
The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 ℃ for 30 min, recovery for 12h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their mol...The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 ℃ for 30 min, recovery for 12h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their molecular masses, isoelectric points (pI), pH-optima and other properties were analyzed by native proteinase gels.It was shown that the 65 kDa ATP-BPase is specifically induced by heat shock and not detectable in control cells.Its N-terminal 1-9 amino acid sequence was determined by Edman degradation, but no homologies to other proteins in the protein data bases were found. 30 and 31 kDa proteinases can be cleaved from the 45, 55 and 65 kDa proteinases to which they are linked. A possible relationship of the heat-induced 65 kDa ATP-BPase with the ATP-dependent proteinases (ATP-DPases) in prokaryotes and eukaryotes is discussed.展开更多
Previous studies have shown that baicalin prevented iron accumulation after substantia nigra injury, reduced divalent metal transporter 1 expression, and increased ferroportin 1 expression in the substantia nigra of r...Previous studies have shown that baicalin prevented iron accumulation after substantia nigra injury, reduced divalent metal transporter 1 expression, and increased ferroportin 1 expression in the substantia nigra of rotenone-induced Parkinson＇s disease rats. In the current study, we investigated the relationship between iron accumulation and transferrin expression in C6 cells, to explore the mechanisms of the inhibitory effect of baicalin on iron accumulation observed in Parkinson＇s disease rats. Iron content was detected using inductively coupled plasma-atomic emission spectroscopy. Results showed that iron content decreased 41% after blocking divalent metal transporter 1 and ferroportin 1 proteins. After treatment with ferric ammonium citrate of differing concentrations （10, 50, 100, 400 ktg/mL） in C6 glioma cells, cell survival rate and ferroportin 1 expression were negatively correlated with ferric ammonium citrate concentration, but divalent metal transporter 1 expression positively correlated with ferric ammonium citrate concentration. Baicalin or deferoxamine reduced divalent metal transporter 1 expression, but increased ferroportin 1 expression in the 100 μg/mL ferric ammonium citrate-loaded C6 cells. These results indicate that baicalin down-regulated iron concentration, which positively regulat- ed divalent metal transporter 1 expression and negatively regulated ferroportin 1 expression, and decreased iron accumulation in the substantia nigra.展开更多
Background：Orthotopic liver transplantation （OLT） improves the prognosis of patients with hepatocellular carcinoma （HCC）.Moreover,the complement system is a powerful immune effector that can affect liver function...Background：Orthotopic liver transplantation （OLT） improves the prognosis of patients with hepatocellular carcinoma （HCC）.Moreover,the complement system is a powerful immune effector that can affect liver function and process of liver cirrhosis.However,studies correlating the complement system with tacrolimus metabolism after OLT are scarce.In this study,the role of single nucleotide polymorphisms （SNPs） associated with the sixth complement component （C6） in tacrolimus metabolism was investigated during the early stages of liver transplantation.Methods：The study enrolled 135 adult patients treated with OLT for HCC between August 2011 and October 2013.Ten SNPs in C6 gene and rs776746 in cytochrome P450 3A5 （CYP3A5） gene were investigated.The tacrolilnus levels were monitored daily during 4 weeks after transplantation.Results：Both donor and recipient CYP3A5 rs776746 allele A were correlated with decreased concentration/dose （C/D） ratios.Recipient C6 rs9200 allele G and donor C6 rs10052999 homozygotes were correlated with lower C/D ratios.Recipient CYP3A5 rs776746 allele A （yielded median tacrolimus C/D ratios of 225.90 at week 1 and 123.61 at week 2）,C6 rs9200 allele G （exhibited median tacrolimus C/D ratios of 211.31 at week l,110.23 at week 2,and 99.88 at week 3）,and donor CYP3A5 rs776746 allele A （exhibited median C/D ratios of 210.82 at week l,111.06 at week 2,77.49 at week 3,and 85.60 at week 4） and C6 rs 10052999 homozygote （exhibited median C/D ratios of 167.59 at week 2,157.99 at week 3,and 155.36 at week 4） were associated with rapid tacrolimus metabolism.With increasing number of these alleles,patients were found to have lower tacrolimus C/D ratios at various time points during the 4 weeks after transplantation.In multiple linear regression analysis,recipient C6 rs9200 group （AA vs.GG/GA） was found to be related to tacrolimus metabolism at weeks 1,2,and 3 （P =0.005,P =0.045,and P =0.033,respectively）,whereas donor C6 rs10052999 group （CC/TT vs.TC） w展开更多
Background The glioblastoma has served as a valuable experimental model system for investigating the growth and invasive properties of glioblastoma.Aquaporin-1(AQP1)in facilitating cell migration and potentially contr...Background The glioblastoma has served as a valuable experimental model system for investigating the growth and invasive properties of glioblastoma.Aquaporin-1(AQP1)in facilitating cell migration and potentially contributing to tumor progression.In this study,we analyzed the role of AQP1 overexpression in glioblastoma and elucidated the main mechanisms involved.Methods AQP1 overexpression recombinant vector was introduced into C6 rat glioma cells to construct an AQP1 overexpression C6 cell line,and its effect on cell viability and migration ability was detected by MTT and Transwell.RNA was extracted by Trizol method for gene sequencing and transcriptomics analysis,and the differentially expressed genes(DEGs)were enriched for up-and downregulated genes by Principal component analysis(PCA),and the molecular mechanism of AQP1 overexpression was analyzed in comparison with the control group using the NCBI GEO database.Statistical analysis was performed using Mann-Whitney paired two tailed t test.Results The cell viability of AQP1-transfected cell lines increased by 23%and the mean distance traveled increased by 67%compared with the control group.Quantitative analysis of gene expression showed that there were 12,121 genes with an average transcripts per million(TPM)value greater than 1.DEGs accounted for 13%of the genes expressed,with the highest correlation with upregulated genes being FOXO4 and MAZ,and the highest with down-regulated genes being E2F TFs.Conclusions AQP1 may be implicated in glioma formation by interacting with the transcriptional regulation networks involving the FOXO4,MAZ,and E2F1/2.These findings shed light on the potential significance of AQP1 in glioma pathogenesis and warrant further investigations to unravel the underlying molecular mechanisms.展开更多
Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To in...Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To investigate the mechanism of gJioblastoma treatment by neural stem ceiJ trans- plantation with respect to the Ras/Raf/Mek/Erk pathway, C6 glioma cells were prepared in sus- pension and then infused into the rat brain to establish a glioblastoma model. Neural stem cells isolated from fetal rats were then injected into the brain of this glioblastoma model. Results showed that Raf-1, Erk and Bcl-2 protein expression significantly increased, while Caspase-3 protein expression decreased. After transplantation of neural stem cells, Raf-1, Erk and Bcl-2 protein expression significantly decreased, while Caspase-3 protein expression significantly in-creased. Our findings indicate that transplantation of neural stem cells may promote apoptosis of glioma cells by inhibiting Ras/Raf/Mek/Erk signaling, and thus may represent a novel treatment approach for glioblastoma.展开更多
文摘横断山区是我国长江上游重要的生态屏障区,对周边区域乃至我国中西部地区气候和生态环境有着深刻的影响。NPP作为碳收支和气候变化研究的核心内容,是判定生态系统健康状况和可持续发展水平的重要指标。基于MODIS C6的NPP数据、1∶100万植被类型图、气象数据和地形数据,采用趋势线分析法和相关分析法对横断地区2004—2014年植被NPP时空格局、变化规律以及驱动因子进行了研究。结果表明:(1)2004—2014年横断山区植被年NPP总量的介于183.768—223.239 Tg C之间,多年平均为208.498 Tg C,单位面积下的植被年NPP均值为463 g C m^(-2)a^(-1)。整体上,植被NPP呈增加趋势,但局部差异明显。(2)植被NPP平均值的年际变化率在-53—97 g C m^(-2)a^(-1)之间,NPP呈增加趋势的区域分布在北部与中部的东侧以及南部的东、西两侧地区,而减少趋势的区域主要集中在西北部、中部的汶川—映秀一带以及南部攀枝花地区。(3)横断山区植被NPP变化受气候因子驱动影响的区域占比8.42%,主要集中在中部的大雪山-沙鲁里山地区,而非气候因子占比91.58%,分布在北部的阿坝地区以及南部的低海拔广大地区。该研究将对横断山区生态环境建设和可持续发展起到指导作用。
文摘天山北坡是中国农牧业发展基地,也是“一带一路”开发重点区域。气候变化和人类活动是影响天山北坡净初级生产力(Net Primary Productivity,NPP)的2个重要因素,定量评估气候变化和人类活动对天山北坡草场可持续性利用具有重要意义。该研究采用MODIS C6遥感数据、气象数据和野外实测数据,分析2004-2015年气候变化和人类活动对天山北坡NPP变化的影响。结果表明:2004-2015年天山北坡实际净初级生产力(Actual Net Primary Productivity,NPPA)介于128.67~170.49 g/(m^2·a)之间,总体呈现增加趋势;西部区域NPPA年均值最高,天山北坡NPPA的主要供给区是中西部区域。天山北坡不同区域年均温度及降水量呈现明显差异,降水对NPPA的影响大于温度。同时,人类活动对NPP的影响(Human Activities on Net Primary Productivity,NPPH),总体上由负作用逐渐向正作用转变,正作用增强区域主要分布在奇台县、木垒县和天山北坡东部部分地区,负作用逐渐增强区域主要分布在奎屯市及乌苏市部分地区。
文摘The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 ℃ for 30 min, recovery for 12h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their molecular masses, isoelectric points (pI), pH-optima and other properties were analyzed by native proteinase gels.It was shown that the 65 kDa ATP-BPase is specifically induced by heat shock and not detectable in control cells.Its N-terminal 1-9 amino acid sequence was determined by Edman degradation, but no homologies to other proteins in the protein data bases were found. 30 and 31 kDa proteinases can be cleaved from the 45, 55 and 65 kDa proteinases to which they are linked. A possible relationship of the heat-induced 65 kDa ATP-BPase with the ATP-dependent proteinases (ATP-DPases) in prokaryotes and eukaryotes is discussed.
基金supported by the Scientific Research Common Program of Beijing Municipal Commission of Education,No.KM20110025010
文摘Previous studies have shown that baicalin prevented iron accumulation after substantia nigra injury, reduced divalent metal transporter 1 expression, and increased ferroportin 1 expression in the substantia nigra of rotenone-induced Parkinson＇s disease rats. In the current study, we investigated the relationship between iron accumulation and transferrin expression in C6 cells, to explore the mechanisms of the inhibitory effect of baicalin on iron accumulation observed in Parkinson＇s disease rats. Iron content was detected using inductively coupled plasma-atomic emission spectroscopy. Results showed that iron content decreased 41% after blocking divalent metal transporter 1 and ferroportin 1 proteins. After treatment with ferric ammonium citrate of differing concentrations （10, 50, 100, 400 ktg/mL） in C6 glioma cells, cell survival rate and ferroportin 1 expression were negatively correlated with ferric ammonium citrate concentration, but divalent metal transporter 1 expression positively correlated with ferric ammonium citrate concentration. Baicalin or deferoxamine reduced divalent metal transporter 1 expression, but increased ferroportin 1 expression in the 100 μg/mL ferric ammonium citrate-loaded C6 cells. These results indicate that baicalin down-regulated iron concentration, which positively regulat- ed divalent metal transporter 1 expression and negatively regulated ferroportin 1 expression, and decreased iron accumulation in the substantia nigra.
基金This study was supported by grants from the National Natural Science Foundation of China （No. 81370579） and the Science and Technology Commission of Shanghai Municipality, China （No. 134119a6300）.
文摘Background：Orthotopic liver transplantation （OLT） improves the prognosis of patients with hepatocellular carcinoma （HCC）.Moreover,the complement system is a powerful immune effector that can affect liver function and process of liver cirrhosis.However,studies correlating the complement system with tacrolimus metabolism after OLT are scarce.In this study,the role of single nucleotide polymorphisms （SNPs） associated with the sixth complement component （C6） in tacrolimus metabolism was investigated during the early stages of liver transplantation.Methods：The study enrolled 135 adult patients treated with OLT for HCC between August 2011 and October 2013.Ten SNPs in C6 gene and rs776746 in cytochrome P450 3A5 （CYP3A5） gene were investigated.The tacrolilnus levels were monitored daily during 4 weeks after transplantation.Results：Both donor and recipient CYP3A5 rs776746 allele A were correlated with decreased concentration/dose （C/D） ratios.Recipient C6 rs9200 allele G and donor C6 rs10052999 homozygotes were correlated with lower C/D ratios.Recipient CYP3A5 rs776746 allele A （yielded median tacrolimus C/D ratios of 225.90 at week 1 and 123.61 at week 2）,C6 rs9200 allele G （exhibited median tacrolimus C/D ratios of 211.31 at week l,110.23 at week 2,and 99.88 at week 3）,and donor CYP3A5 rs776746 allele A （exhibited median C/D ratios of 210.82 at week l,111.06 at week 2,77.49 at week 3,and 85.60 at week 4） and C6 rs 10052999 homozygote （exhibited median C/D ratios of 167.59 at week 2,157.99 at week 3,and 155.36 at week 4） were associated with rapid tacrolimus metabolism.With increasing number of these alleles,patients were found to have lower tacrolimus C/D ratios at various time points during the 4 weeks after transplantation.In multiple linear regression analysis,recipient C6 rs9200 group （AA vs.GG/GA） was found to be related to tacrolimus metabolism at weeks 1,2,and 3 （P =0.005,P =0.045,and P =0.033,respectively）,whereas donor C6 rs10052999 group （CC/TT vs.TC） w
基金supported by Natural Science Foundation of Hainan Province(821RC692)Hainan Provincial Health Industry Research Project(20A200136)Hainan Natural Science Foundation(2019RC388)
文摘Background The glioblastoma has served as a valuable experimental model system for investigating the growth and invasive properties of glioblastoma.Aquaporin-1(AQP1)in facilitating cell migration and potentially contributing to tumor progression.In this study,we analyzed the role of AQP1 overexpression in glioblastoma and elucidated the main mechanisms involved.Methods AQP1 overexpression recombinant vector was introduced into C6 rat glioma cells to construct an AQP1 overexpression C6 cell line,and its effect on cell viability and migration ability was detected by MTT and Transwell.RNA was extracted by Trizol method for gene sequencing and transcriptomics analysis,and the differentially expressed genes(DEGs)were enriched for up-and downregulated genes by Principal component analysis(PCA),and the molecular mechanism of AQP1 overexpression was analyzed in comparison with the control group using the NCBI GEO database.Statistical analysis was performed using Mann-Whitney paired two tailed t test.Results The cell viability of AQP1-transfected cell lines increased by 23%and the mean distance traveled increased by 67%compared with the control group.Quantitative analysis of gene expression showed that there were 12,121 genes with an average transcripts per million(TPM)value greater than 1.DEGs accounted for 13%of the genes expressed,with the highest correlation with upregulated genes being FOXO4 and MAZ,and the highest with down-regulated genes being E2F TFs.Conclusions AQP1 may be implicated in glioma formation by interacting with the transcriptional regulation networks involving the FOXO4,MAZ,and E2F1/2.These findings shed light on the potential significance of AQP1 in glioma pathogenesis and warrant further investigations to unravel the underlying molecular mechanisms.
文摘Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To investigate the mechanism of gJioblastoma treatment by neural stem ceiJ trans- plantation with respect to the Ras/Raf/Mek/Erk pathway, C6 glioma cells were prepared in sus- pension and then infused into the rat brain to establish a glioblastoma model. Neural stem cells isolated from fetal rats were then injected into the brain of this glioblastoma model. Results showed that Raf-1, Erk and Bcl-2 protein expression significantly increased, while Caspase-3 protein expression decreased. After transplantation of neural stem cells, Raf-1, Erk and Bcl-2 protein expression significantly decreased, while Caspase-3 protein expression significantly in-creased. Our findings indicate that transplantation of neural stem cells may promote apoptosis of glioma cells by inhibiting Ras/Raf/Mek/Erk signaling, and thus may represent a novel treatment approach for glioblastoma.
