The cell surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34 + cells freshly isolated from CB displayed ...The cell surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34 + cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF+FL could up regulate the expression of CD95 in vitro culture and tumor necrosis factor α (TNF α) and interon γ (IFN γ) further increased the CD95 expression induced by positive cytokines. The functional status of CD95 mediated apoptosis were analyzed by incubation of CD34 +CB cells in the presence of anti CD95 monoclonal antibodies (McAbs). The effects of anti CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU C assays. A decrease of viable cells, CFU C and LTIC numbers were observed in the presence of anti CD95 McAbs and TNF α or IFN γ. However, growth factor deprivation or the early acting cytokine such as SCF and FL cross linking to CD95 caused low apoptosis of CD34 + cells. The correlation of increased intracytoplasmic levels of bcl 2 and the presence of CD95 on fresh CB CD34 + cells suggested that bcl 2 might be involved in protecting against CD95 mediated apoptosis of CB CD34 + cells.展开更多
The rapid actions of androgen on synaptic plasticity have been extensively studied.However,the underlying mechanisms remain controversial.In this study,we used mouse hippocampal neuron cell line HT22 cells as a cell r...The rapid actions of androgen on synaptic plasticity have been extensively studied.However,the underlying mechanisms remain controversial.In this study,we used mouse hippocampal neuron cell line HT22 cells as a cell research model to investigate whether Ca^(2+)/CaMKII mediates androgen rapid actions on synaptic plasticity,especially for synaptic protein PSD95 expression.Using calcium imaging,we verified incubation with 100 nmol/L testosterone for 20 min had the most significant effect on intracellular Ca^(2+)level.In addition,the depolarization of resting membrane potential after testosterone stimulation was observed by patch clamp.We found that the depolarization of resting membrane potential was to-40 mV.展开更多
目的检测脑挫伤修复过程中突触后致密蛋白(postsynaptic density protein 95,PSD-95)的表达,探讨其变化规律与损伤时间的相关性。方法雄性SD大鼠50只,随机分为8个实验组,1个对照组,每组5只。制作大鼠脑挫伤模型,于伤后3、6、12h和3、5、...目的检测脑挫伤修复过程中突触后致密蛋白(postsynaptic density protein 95,PSD-95)的表达,探讨其变化规律与损伤时间的相关性。方法雄性SD大鼠50只,随机分为8个实验组,1个对照组,每组5只。制作大鼠脑挫伤模型,于伤后3、6、12h和3、5、7、10d取脑组织,应用免疫组织化学技术和免疫蛋白印迹(Western blot)方法检测脑挫伤后不同时间脑组织中PSD-95的表达变化。结果对照组脑组织仅有少量PSD-95阳性细胞;实验组中,伤后3h、6h组脑组织出现较多PSD-95阳性细胞,12h组阳性细胞数量持续升高,伤后1d阳性细胞数下降,5d后又升高并达到高峰,7d、10d恢复;计算阳性率,统计分析结果显示,阳性细胞数与相邻上组比较,存在显著性差异。Western blot结果:挫伤后,3～12h表达量上升,1d下降,随后又逐步上升,5d达到高峰,7d、10d下降;应用Fluorchem V2.0 Stand Alone软件获取感光条带的平均灰度值,经统计分析,各组与相邻上组比较,存在显著性差异。结论大鼠脑损伤后损伤周边区PSD-95呈现升高→下降→再升高→再下降的表达规律,对损伤时间推断有一定的参考意义。展开更多
基金This project was supported by a grant from National Na-ture Science Foundation of China (No.3992 80 10 )
文摘The cell surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34 + cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF+FL could up regulate the expression of CD95 in vitro culture and tumor necrosis factor α (TNF α) and interon γ (IFN γ) further increased the CD95 expression induced by positive cytokines. The functional status of CD95 mediated apoptosis were analyzed by incubation of CD34 +CB cells in the presence of anti CD95 monoclonal antibodies (McAbs). The effects of anti CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU C assays. A decrease of viable cells, CFU C and LTIC numbers were observed in the presence of anti CD95 McAbs and TNF α or IFN γ. However, growth factor deprivation or the early acting cytokine such as SCF and FL cross linking to CD95 caused low apoptosis of CD34 + cells. The correlation of increased intracytoplasmic levels of bcl 2 and the presence of CD95 on fresh CB CD34 + cells suggested that bcl 2 might be involved in protecting against CD95 mediated apoptosis of CB CD34 + cells.
文摘The rapid actions of androgen on synaptic plasticity have been extensively studied.However,the underlying mechanisms remain controversial.In this study,we used mouse hippocampal neuron cell line HT22 cells as a cell research model to investigate whether Ca^(2+)/CaMKII mediates androgen rapid actions on synaptic plasticity,especially for synaptic protein PSD95 expression.Using calcium imaging,we verified incubation with 100 nmol/L testosterone for 20 min had the most significant effect on intracellular Ca^(2+)level.In addition,the depolarization of resting membrane potential after testosterone stimulation was observed by patch clamp.We found that the depolarization of resting membrane potential was to-40 mV.
文摘目的检测脑挫伤修复过程中突触后致密蛋白(postsynaptic density protein 95,PSD-95)的表达,探讨其变化规律与损伤时间的相关性。方法雄性SD大鼠50只,随机分为8个实验组,1个对照组,每组5只。制作大鼠脑挫伤模型,于伤后3、6、12h和3、5、7、10d取脑组织,应用免疫组织化学技术和免疫蛋白印迹(Western blot)方法检测脑挫伤后不同时间脑组织中PSD-95的表达变化。结果对照组脑组织仅有少量PSD-95阳性细胞;实验组中,伤后3h、6h组脑组织出现较多PSD-95阳性细胞,12h组阳性细胞数量持续升高,伤后1d阳性细胞数下降,5d后又升高并达到高峰,7d、10d恢复;计算阳性率,统计分析结果显示,阳性细胞数与相邻上组比较,存在显著性差异。Western blot结果:挫伤后,3～12h表达量上升,1d下降,随后又逐步上升,5d达到高峰,7d、10d下降;应用Fluorchem V2.0 Stand Alone软件获取感光条带的平均灰度值,经统计分析,各组与相邻上组比较,存在显著性差异。结论大鼠脑损伤后损伤周边区PSD-95呈现升高→下降→再升高→再下降的表达规律,对损伤时间推断有一定的参考意义。
