目的通过磁共振R2*mapping技术示踪及动态监测NSCLC裸鼠模型给药后不同时间点R2*值的变化趋势,阐明R2*mapping在评价F/A-PLGA@DOX/SPIO纳米载药体系在肿瘤成像中的应用价值及影像学基础。方法成功构建NSCLC裸鼠移植瘤模型24只,随机分为G...目的通过磁共振R2*mapping技术示踪及动态监测NSCLC裸鼠模型给药后不同时间点R2*值的变化趋势,阐明R2*mapping在评价F/A-PLGA@DOX/SPIO纳米载药体系在肿瘤成像中的应用价值及影像学基础。方法成功构建NSCLC裸鼠移植瘤模型24只,随机分为G1、G2两组,每组12只。分别尾静脉注射单纯SPIO以及F/A-PLGA@DOX/SPIO纳米载药体系,并采用1.5 T MR和动物专用小鼠线圈对建模成功荷瘤裸鼠皮下移植瘤模型进行R2*扫描获得肿瘤区域R2*值。实验结束后全部肿瘤组织及肝脏、脾脏普鲁士蓝染色。结果G2组每个时间点的R2*值均高于G1组(P<0.05)。相对于G1组,G2组肿瘤R2*值在早期上升趋势明显,且在给药后60h时明显高于G1组(P<0.05)。G1组排泄期较G2组明显提前。普鲁士蓝染色结果显示,G2组肿瘤的蓝色铁沉积高于SPIO组,而肝脏、脾脏组织的蓝色铁沉积低于G1。结论R2*值与肿瘤组织内的SPIO含量存在较高敏感性,R2*mapping技术提供了一种SPIO的肿瘤示踪成像方法。展开更多
目的基于T2^(*)mapping定量分析业余马拉松运动员足踝部关节软骨的T2^(*)值,并分析其与性别、年龄、身体质量指数(body mass index,BMI)、跑龄、跑量之间的相关性。材料与方法于2023年7月份至2023年9月份招募重庆市长跑运动爱好者48名,...目的基于T2^(*)mapping定量分析业余马拉松运动员足踝部关节软骨的T2^(*)值,并分析其与性别、年龄、身体质量指数(body mass index,BMI)、跑龄、跑量之间的相关性。材料与方法于2023年7月份至2023年9月份招募重庆市长跑运动爱好者48名,其中跑量<300 km/月的36例(中低跑量组),跑量≥300 km/月的12例(高跑量组)。所有受试者均进行单侧无症状踝关节的MRI扫描,扫描序列包括T2^(*)mapping多回波自旋回波(spin echo,SE)序列矢状位、质子密度加权成像脂肪抑制(proton density-weighted imaging fat-saturated,PDWI-FS)序列矢状位、冠状位、横轴位以及T1加权脂肪抑制成像(T1-weighted imaging fat-saturated,T1WI-FS)序列横轴位。沿关节软骨轮廓边缘勾画距骨穹窿、跟骰关节跟骨面、骰骨面及后距下关节跟骨面、距骨面软骨作为感兴趣区(region of interest,ROI),获得相应的T2^(*)值。采用线性回归分析软骨T2^(*)值与年龄、BMI、跑龄的相关性,采用独立样本t检验分析不同跑量及不同性别间的软骨T2^(*)值差异。结果(1)距骨穹窿、跟骰关节跟骨面及骰骨面、后距下关节跟骨面及距骨面软骨T2^(*)值在性别上的差异均具有统计学意义(P=0.001、P<0.001、P=0.002、P=0.008、P=0.004);(2)高跑量组的距骨穹窿、后距下关节跟骨面软骨T2^(*)值高于中低跑量组(P=0.014、0.023),不同跑量的跟骰关节跟骨面及骰骨面、后距下关节距骨面软骨T2^(*)值的差异均无统计学意义(P=0.987、0.072、0.724);(3)距骨穹窿、跟骰关节跟骨面及骰骨面、后距下关节跟骨面、距骨面软骨T2^(*)值均与BMI呈正相关(r=0.376、0.384、0.300、0.422、0.455,P=0.005、0.004、0.019、0.001、0.001)。结论在业余马拉松运动员这一跑步群体中,与中低跑量相比,高跑量更有可能导致距骨穹窿、后距下关节跟骨面软骨损伤;而与较低的BMI相比,高BMI增加了距骨穹窿、跟骰关节跟骨面、骰骨面及后距下关节跟骨面、距骨面软骨损伤的风险。展开更多
Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell walls.The presence of stone cells has a negative influence on fruit texture and taste,and thus the reductio...Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell walls.The presence of stone cells has a negative influence on fruit texture and taste,and thus the reduction of stone cell content in pear fruit is a key goal of breeding efforts.However,research into the key transcription factors and regulatory networks associated with pear fruit stone cell formation have been limited.We here used a combination of co-expression network and expression quantitative trait locus(eQTL)analyses in 206 pear cultivars with different stone cell contents to identify relevant genes;these analyses uncovered the gene PbrMYB4,a R2R3 MYB transcription factor gene.There was a strong positive correlation between relative PbrMYB4 expression levels in the fruit flesh and stone cell/lignin contents.Overexpression of PbrMYB4 significantly increased the lignin contents,whereas silencing of PbrMYB4 had the opposite effect,decreasing the contents of lignin.PbrMYB4 overexpression in pear calli significantly promoted lignin biosynthesis.In Arabidopsis thaliana,PbrMYB4 overexpression resulted in increasing lignin deposition,cell wall thickness of vessels and xylary fiber,and accelerating expression level of lignin biosynthetic genes.PbrMYB4 was found to activate 4-Coumarate:Coenzyme A Ligase(Pbr4CL1)by binding to AC-I elements in the promoter regions,as demonstrated with dual-luciferase reporter assays and a yeast one-hybrid assay.These results demonstrated that PbrMYB4 positively regulated lignin biosynthesis in pear fruit stone cells by activating lignin biosynthesis genes.This study improves our understanding of the gene regulatory networks associated with stone cell formation in pear fruit,providing guidance for molecular breeding of pear varieties with low stone cell content.展开更多
文摘目的通过磁共振R2*mapping技术示踪及动态监测NSCLC裸鼠模型给药后不同时间点R2*值的变化趋势,阐明R2*mapping在评价F/A-PLGA@DOX/SPIO纳米载药体系在肿瘤成像中的应用价值及影像学基础。方法成功构建NSCLC裸鼠移植瘤模型24只,随机分为G1、G2两组,每组12只。分别尾静脉注射单纯SPIO以及F/A-PLGA@DOX/SPIO纳米载药体系,并采用1.5 T MR和动物专用小鼠线圈对建模成功荷瘤裸鼠皮下移植瘤模型进行R2*扫描获得肿瘤区域R2*值。实验结束后全部肿瘤组织及肝脏、脾脏普鲁士蓝染色。结果G2组每个时间点的R2*值均高于G1组(P<0.05)。相对于G1组,G2组肿瘤R2*值在早期上升趋势明显,且在给药后60h时明显高于G1组(P<0.05)。G1组排泄期较G2组明显提前。普鲁士蓝染色结果显示,G2组肿瘤的蓝色铁沉积高于SPIO组,而肝脏、脾脏组织的蓝色铁沉积低于G1。结论R2*值与肿瘤组织内的SPIO含量存在较高敏感性,R2*mapping技术提供了一种SPIO的肿瘤示踪成像方法。
基金funded by the Science Foundation of China(Grant No.32230097)Earmarked Fund for China Agriculture Research System(Grant No.CARS-28)+2 种基金the Earmarked Fund for Jiangsu Agricultural Industry Technology System(Grant No.JATS[2023]412)Natural Science Foundation of Jiangsu Province for Young Scholar(Grant No.BK20221010)supported by the high-performance computing platform of Bioinformatics Center,Nanjing Agricultural University。
文摘Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell walls.The presence of stone cells has a negative influence on fruit texture and taste,and thus the reduction of stone cell content in pear fruit is a key goal of breeding efforts.However,research into the key transcription factors and regulatory networks associated with pear fruit stone cell formation have been limited.We here used a combination of co-expression network and expression quantitative trait locus(eQTL)analyses in 206 pear cultivars with different stone cell contents to identify relevant genes;these analyses uncovered the gene PbrMYB4,a R2R3 MYB transcription factor gene.There was a strong positive correlation between relative PbrMYB4 expression levels in the fruit flesh and stone cell/lignin contents.Overexpression of PbrMYB4 significantly increased the lignin contents,whereas silencing of PbrMYB4 had the opposite effect,decreasing the contents of lignin.PbrMYB4 overexpression in pear calli significantly promoted lignin biosynthesis.In Arabidopsis thaliana,PbrMYB4 overexpression resulted in increasing lignin deposition,cell wall thickness of vessels and xylary fiber,and accelerating expression level of lignin biosynthetic genes.PbrMYB4 was found to activate 4-Coumarate:Coenzyme A Ligase(Pbr4CL1)by binding to AC-I elements in the promoter regions,as demonstrated with dual-luciferase reporter assays and a yeast one-hybrid assay.These results demonstrated that PbrMYB4 positively regulated lignin biosynthesis in pear fruit stone cells by activating lignin biosynthesis genes.This study improves our understanding of the gene regulatory networks associated with stone cell formation in pear fruit,providing guidance for molecular breeding of pear varieties with low stone cell content.
