目的:研究雷公藤红素对人肥大细胞系 HMC-1细胞凋亡的诱导作用。方法:HMC-1细胞与雷公藤红素(0.125～1.0μmol/L)共育不同时间,经 DNA 琼脂糖电泳和流式细胞仪 DNA 含量分析。结果:(1)雷公藤红素能有效地诱导 HMC-1细胞凋亡,细胞呈凋亡...目的:研究雷公藤红素对人肥大细胞系 HMC-1细胞凋亡的诱导作用。方法:HMC-1细胞与雷公藤红素(0.125～1.0μmol/L)共育不同时间,经 DNA 琼脂糖电泳和流式细胞仪 DNA 含量分析。结果:(1)雷公藤红素能有效地诱导 HMC-1细胞凋亡,细胞呈凋亡形态学改变,DNA 琼脂糖电泳出现梯形条带,流式细胞仪分析,在 G_1期峰前出现凋亡峰。(2)凋亡程度随药物浓度增加和作用时间的延长而提高。(3)凋亡率随 S 期细胞比例的下降而升高,二者呈显著负相关(P<0.01)。结论:雷公藤红素可以诱导 HMC-1细胞凋亡,凋亡主要发生在 S期。展开更多
Objective: Apoptosis of human mast cell line HMC-1 can be induced by tripterine, a monomer extracted from Tripterygium Wilfordii Hook, f.. This paper is to describe the typical morphologic changes accompanying apoptot...Objective: Apoptosis of human mast cell line HMC-1 can be induced by tripterine, a monomer extracted from Tripterygium Wilfordii Hook, f.. This paper is to describe the typical morphologic changes accompanying apoptotic process, explore the possible mechanism underlying and discuss the significance of using it as hallmark of apoptosis. Methods: On or after exposure to tripterine, cells were analyzed with light microscopy, electromicroscope, flow cytometry, ferminal trans- ferase dUTP nick and end labeling (TFUNEL). Results: Under light microscopy, Cell with patterns like sunflower: Cellular main body surrounded by clusters of small small (resembling the petals of sunflower), could be seen in the apoptotic pro cess. The sunflower-like cells (SLCs), negative to trypan blue staining, wb or without the accompaniment of chromatin condense, could occur as soon as20 min after the addition of tripterine and survive for several hours. Drug-baced SLC was time- and dose-dependent. The apoptosis were significantly correlated with results of TUNEL or PI/FCM in the for & h of induction. The SLCs could be easily discriminated under reverse light microscopy. The number of SLC at different time from different persons was consistent. Conclusion: The results suggested that SLC is a characteristic morphologic chane of apop totic cells, it can be a useful mark for quantifying apoptotic HMC-l cell.展开更多
In plants, demethylation of 5-methylcytosine (5 mC) residues is controlled by DNA glycosylases, while in mammals it requires oxidation of 5 mC by TET proteins, a group of Fe(II)/2-oxoglutaratedependent dioxygenases. W...In plants, demethylation of 5-methylcytosine (5 mC) residues is controlled by DNA glycosylases, while in mammals it requires oxidation of 5 mC by TET proteins, a group of Fe(II)/2-oxoglutaratedependent dioxygenases. We analysed the effects of expressing the C-terminal catalytic domain of the human TET3 gene (TET3c) in Arabidopsis thaliana, using an rDNA region as a methylation reporter. In TET3c transformants, epialleles with hypomethylation or hypermethylation patterns can be induced, which is each stably retained in progeny lines even after removal of the TET3c transgene. In TET3c transformants, 5-hydroxymethylcytosine (5 hmC) marks are detected, indicative of the oxidative activity of the transgenic enzyme. 5-formylcytosine (5 fC) is only detectable in TET3c transformants with a DNA glycosylase mutant background suggesting further oxidation of 5 hmC residues to 5 fC by TET3c, and efficient recognition and removal of 5 fC by plant glycosylases. The results suggest that TET3c can be employed to induce heritable locus-specific changes in DNA methylation, and that accumulation of 5 hmC can be used as a marker for TET3c target regions.展开更多
文摘目的:研究雷公藤红素对人肥大细胞系 HMC-1细胞凋亡的诱导作用。方法:HMC-1细胞与雷公藤红素(0.125～1.0μmol/L)共育不同时间,经 DNA 琼脂糖电泳和流式细胞仪 DNA 含量分析。结果:(1)雷公藤红素能有效地诱导 HMC-1细胞凋亡,细胞呈凋亡形态学改变,DNA 琼脂糖电泳出现梯形条带,流式细胞仪分析,在 G_1期峰前出现凋亡峰。(2)凋亡程度随药物浓度增加和作用时间的延长而提高。(3)凋亡率随 S 期细胞比例的下降而升高,二者呈显著负相关(P<0.01)。结论:雷公藤红素可以诱导 HMC-1细胞凋亡,凋亡主要发生在 S期。
文摘Objective: Apoptosis of human mast cell line HMC-1 can be induced by tripterine, a monomer extracted from Tripterygium Wilfordii Hook, f.. This paper is to describe the typical morphologic changes accompanying apoptotic process, explore the possible mechanism underlying and discuss the significance of using it as hallmark of apoptosis. Methods: On or after exposure to tripterine, cells were analyzed with light microscopy, electromicroscope, flow cytometry, ferminal trans- ferase dUTP nick and end labeling (TFUNEL). Results: Under light microscopy, Cell with patterns like sunflower: Cellular main body surrounded by clusters of small small (resembling the petals of sunflower), could be seen in the apoptotic pro cess. The sunflower-like cells (SLCs), negative to trypan blue staining, wb or without the accompaniment of chromatin condense, could occur as soon as20 min after the addition of tripterine and survive for several hours. Drug-baced SLC was time- and dose-dependent. The apoptosis were significantly correlated with results of TUNEL or PI/FCM in the for & h of induction. The SLCs could be easily discriminated under reverse light microscopy. The number of SLC at different time from different persons was consistent. Conclusion: The results suggested that SLC is a characteristic morphologic chane of apop totic cells, it can be a useful mark for quantifying apoptotic HMC-l cell.
文摘In plants, demethylation of 5-methylcytosine (5 mC) residues is controlled by DNA glycosylases, while in mammals it requires oxidation of 5 mC by TET proteins, a group of Fe(II)/2-oxoglutaratedependent dioxygenases. We analysed the effects of expressing the C-terminal catalytic domain of the human TET3 gene (TET3c) in Arabidopsis thaliana, using an rDNA region as a methylation reporter. In TET3c transformants, epialleles with hypomethylation or hypermethylation patterns can be induced, which is each stably retained in progeny lines even after removal of the TET3c transgene. In TET3c transformants, 5-hydroxymethylcytosine (5 hmC) marks are detected, indicative of the oxidative activity of the transgenic enzyme. 5-formylcytosine (5 fC) is only detectable in TET3c transformants with a DNA glycosylase mutant background suggesting further oxidation of 5 hmC residues to 5 fC by TET3c, and efficient recognition and removal of 5 fC by plant glycosylases. The results suggest that TET3c can be employed to induce heritable locus-specific changes in DNA methylation, and that accumulation of 5 hmC can be used as a marker for TET3c target regions.
