Circular RNAs(circRNAs)are a novel class of non-coding RNA that have recently shown to have huge capabilities in the regulation of gene expression at the posttranscriptional level.Growing evidence has indicated that c...Circular RNAs(circRNAs)are a novel class of non-coding RNA that have recently shown to have huge capabilities in the regulation of gene expression at the posttranscriptional level.Growing evidence has indicated that circRNAs could serve as competing endogenous RNAs(ceRNAs)to sponge microRNAs(miRNAs)and suppress functions of targeted miRNAs.Osteosarcoma(OS)is the most common malignant primary bone cancer.Hsa_circ_0002137 is upregulated in OS.However,the role of hsa_circ_0002137 in OS remains unclear.Using miRNA pull-down assay,we showed that cir_0002137 sponged hsa-miR-1246,and BCL2 apoptosis regulator(BCL2)mRNA was a potential target of hsa-miR-1246 in human osteosarcoma(HOS)cells.Further,we found that hsa_cir_0002137 could enhance the expression of BCL2 hsa-miR-1246 and promote HOS cell growth through sponging hsa-miR-1246.Moreover,RNA binding protein immunoprecip itation(RIP)assay revealed that lin-28 homolog B(LIN28B)protein associated with hsa_circ_0002137,and LIN28B could increase hsa_circ_0002137 stability and thus accelerate OS cell growth.Our work was the first to study the functions of hsa_circ_0002137,has-miR-1246 and LIN28B in OS,and these results may provide novel therapeutic targets for OS treatment.展开更多
目的探讨微小RNA-137(microRNA-137,miR-137)对载脂蛋白E基因敲除小鼠动脉粥样硬化(atherosclerosis,AS)斑块的影响和机制。方法采用高脂饮食喂养12周的载脂蛋白E^(-/-)小鼠60只,建立AS模型,分为AS组、阴性对照组、miR-137组、Ad阴性对...目的探讨微小RNA-137(microRNA-137,miR-137)对载脂蛋白E基因敲除小鼠动脉粥样硬化(atherosclerosis,AS)斑块的影响和机制。方法采用高脂饮食喂养12周的载脂蛋白E^(-/-)小鼠60只,建立AS模型,分为AS组、阴性对照组、miR-137组、Ad阴性对照组、联合组,每组12只;取12只野生型C57BL/6小鼠为对照组,给予普通饲料喂养。全自动生化分析仪检测血清血脂[总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)]水平;酶联免疫吸附法检测血清炎性因子[肿瘤坏死因子α(tumor necrosis factorα,TNF-α)、白细胞介素(interleukin,IL)-4、IL-6、IL-10]水平;苏木精-伊红染色观察主动脉组织形态变化;油红O染色观察整体主动脉斑块形成情况;免疫荧光染色检测主动脉诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)、精氨酸酶1(arginase-1,Arg-1)表达;实时荧光定量聚合酶链反应检测主动脉内miR-137、性别决定区Y框蛋白4(sex determining region Y box protein 4,SOX4)mRNA表达。结果与AS组和阴性对照组比较,miR-137组血清TG、TC、LDL-C、TNF-α、IL-6水平明显降低,HDL-C、IL-10、IL-4水平明显升高(P<0.05);与Ad阴性对照组比较,联合组血清TG、TC、LDL-C、TNF-α、IL-6水平明显升高,HDL-C、IL-10、IL-4水平明显降低(P<0.05)。与对照组比较,AS组主动脉斑块面积、整体主动脉斑块损伤、iNOS荧光强度明显升高(P<0.05);与AS组和阴性对照组比较,miR-137组主动脉斑块面积、整体主动脉斑块损伤、iNOS荧光强度明显降低,Arg-1荧光强度明显升高(P<0.05);与Ad阴性对照组比较,联合组主动脉斑块面积、整体主动脉斑块损伤、iNOS荧光强度明显升高,Arg-1荧光强度明显降低(P<0.05)。双荧光素酶实验结果显示,与转染模拟物阴性对照比较,转染miR-137模拟物后,含有SOX4野生型细胞的荧光素酶活性明显降低(0.37±0.05 vs 1.00±0.08,P<0.05)。结论过表达miR-137可能通过靶向下调SOX4表达,抑制大鼠肉瘤/丝裂原活化蛋白激酶通路激活,抑制M1型巨噬细胞极化,促进M2型巨噬细胞极化,减少炎性反应,减缓AS斑块形成。展开更多
南方红壤丘陵区不同用材林下土壤侵蚀特征及其对有机碳(SOC)含量的影响与机制尚不明确。应用137Cs示踪技术,以桂北低山丘陵区的杂木林、马尾松林和桉树林为研究对象,研究不同林型和坡位下土壤侵蚀特征及其对SOC含量的影响。结果表明,土...南方红壤丘陵区不同用材林下土壤侵蚀特征及其对有机碳(SOC)含量的影响与机制尚不明确。应用137Cs示踪技术,以桂北低山丘陵区的杂木林、马尾松林和桉树林为研究对象,研究不同林型和坡位下土壤侵蚀特征及其对SOC含量的影响。结果表明,土壤侵蚀模数的范围为-3009.29—7472.95 t km^(-2)a^(-1),不同林型间表现为桉树林(4659.56 t km^(-2)a^(-1))>马尾松(938.99 t km^(-2)a^(-1))>杂木林(-1476.90 t km^(-2)a^(-1)),不同坡位为上坡(3416.71 t km^(-2)a^(-1))>中坡(621.80 t km^(-2)a^(-1))>下坡(83.14 t km^(-2)a^(-1))。与背景值相比,3个林地的上坡位均发生了土壤侵蚀,下坡位均发生了土壤沉积,桉树人工林的土壤侵蚀量较大。SOC和粘粒含量分别在不同林型和坡位上具有一致的分布规律,其平均值在不同林型间表现为桉树林<马尾松林<杂木林,不同坡位间表现为上坡<中坡<下坡。土壤侵蚀模数与SOC、粘粒含量均呈显著负相关,与粉粒含量呈显著正相关。结构方程模型表明,土壤侵蚀通过降低土壤粘粒含量从而减小SOC含量。在土壤侵蚀最大的上坡位,应注意防风固土措施的选择,如营造混交林。加强对人工林林下凋落物的保留与林下植被的恢复措施,以减少土壤侵蚀和增加土壤碳固存,充分发挥人工林在水土保持中的作用。展开更多
基金supported by grants from the National Natural Science Foundation of China(81802184)the Natural Science Foundation of Guangdong Province(2017A030310226)the Fundamental Research Funds for the Central Universities(19ykpy22).
文摘Circular RNAs(circRNAs)are a novel class of non-coding RNA that have recently shown to have huge capabilities in the regulation of gene expression at the posttranscriptional level.Growing evidence has indicated that circRNAs could serve as competing endogenous RNAs(ceRNAs)to sponge microRNAs(miRNAs)and suppress functions of targeted miRNAs.Osteosarcoma(OS)is the most common malignant primary bone cancer.Hsa_circ_0002137 is upregulated in OS.However,the role of hsa_circ_0002137 in OS remains unclear.Using miRNA pull-down assay,we showed that cir_0002137 sponged hsa-miR-1246,and BCL2 apoptosis regulator(BCL2)mRNA was a potential target of hsa-miR-1246 in human osteosarcoma(HOS)cells.Further,we found that hsa_cir_0002137 could enhance the expression of BCL2 hsa-miR-1246 and promote HOS cell growth through sponging hsa-miR-1246.Moreover,RNA binding protein immunoprecip itation(RIP)assay revealed that lin-28 homolog B(LIN28B)protein associated with hsa_circ_0002137,and LIN28B could increase hsa_circ_0002137 stability and thus accelerate OS cell growth.Our work was the first to study the functions of hsa_circ_0002137,has-miR-1246 and LIN28B in OS,and these results may provide novel therapeutic targets for OS treatment.
文摘目的探讨微小RNA-137(microRNA-137,miR-137)对载脂蛋白E基因敲除小鼠动脉粥样硬化(atherosclerosis,AS)斑块的影响和机制。方法采用高脂饮食喂养12周的载脂蛋白E^(-/-)小鼠60只,建立AS模型,分为AS组、阴性对照组、miR-137组、Ad阴性对照组、联合组,每组12只;取12只野生型C57BL/6小鼠为对照组,给予普通饲料喂养。全自动生化分析仪检测血清血脂[总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)]水平;酶联免疫吸附法检测血清炎性因子[肿瘤坏死因子α(tumor necrosis factorα,TNF-α)、白细胞介素(interleukin,IL)-4、IL-6、IL-10]水平;苏木精-伊红染色观察主动脉组织形态变化;油红O染色观察整体主动脉斑块形成情况;免疫荧光染色检测主动脉诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)、精氨酸酶1(arginase-1,Arg-1)表达;实时荧光定量聚合酶链反应检测主动脉内miR-137、性别决定区Y框蛋白4(sex determining region Y box protein 4,SOX4)mRNA表达。结果与AS组和阴性对照组比较,miR-137组血清TG、TC、LDL-C、TNF-α、IL-6水平明显降低,HDL-C、IL-10、IL-4水平明显升高(P<0.05);与Ad阴性对照组比较,联合组血清TG、TC、LDL-C、TNF-α、IL-6水平明显升高,HDL-C、IL-10、IL-4水平明显降低(P<0.05)。与对照组比较,AS组主动脉斑块面积、整体主动脉斑块损伤、iNOS荧光强度明显升高(P<0.05);与AS组和阴性对照组比较,miR-137组主动脉斑块面积、整体主动脉斑块损伤、iNOS荧光强度明显降低,Arg-1荧光强度明显升高(P<0.05);与Ad阴性对照组比较,联合组主动脉斑块面积、整体主动脉斑块损伤、iNOS荧光强度明显升高,Arg-1荧光强度明显降低(P<0.05)。双荧光素酶实验结果显示,与转染模拟物阴性对照比较,转染miR-137模拟物后,含有SOX4野生型细胞的荧光素酶活性明显降低(0.37±0.05 vs 1.00±0.08,P<0.05)。结论过表达miR-137可能通过靶向下调SOX4表达,抑制大鼠肉瘤/丝裂原活化蛋白激酶通路激活,抑制M1型巨噬细胞极化,促进M2型巨噬细胞极化,减少炎性反应,减缓AS斑块形成。
文摘南方红壤丘陵区不同用材林下土壤侵蚀特征及其对有机碳(SOC)含量的影响与机制尚不明确。应用137Cs示踪技术,以桂北低山丘陵区的杂木林、马尾松林和桉树林为研究对象,研究不同林型和坡位下土壤侵蚀特征及其对SOC含量的影响。结果表明,土壤侵蚀模数的范围为-3009.29—7472.95 t km^(-2)a^(-1),不同林型间表现为桉树林(4659.56 t km^(-2)a^(-1))>马尾松(938.99 t km^(-2)a^(-1))>杂木林(-1476.90 t km^(-2)a^(-1)),不同坡位为上坡(3416.71 t km^(-2)a^(-1))>中坡(621.80 t km^(-2)a^(-1))>下坡(83.14 t km^(-2)a^(-1))。与背景值相比,3个林地的上坡位均发生了土壤侵蚀,下坡位均发生了土壤沉积,桉树人工林的土壤侵蚀量较大。SOC和粘粒含量分别在不同林型和坡位上具有一致的分布规律,其平均值在不同林型间表现为桉树林<马尾松林<杂木林,不同坡位间表现为上坡<中坡<下坡。土壤侵蚀模数与SOC、粘粒含量均呈显著负相关,与粉粒含量呈显著正相关。结构方程模型表明,土壤侵蚀通过降低土壤粘粒含量从而减小SOC含量。在土壤侵蚀最大的上坡位,应注意防风固土措施的选择,如营造混交林。加强对人工林林下凋落物的保留与林下植被的恢复措施,以减少土壤侵蚀和增加土壤碳固存,充分发挥人工林在水土保持中的作用。
