吲哚乙酸结合辣根过氧化物酶诱导K562细胞凋亡机制的探讨

Mechanism of Apoptosis Induced by Indole-3-Acetic Acids Combined with Horseradish Peroxidase in Leukemia Cell Line K562

为探讨吲哚乙酸(indole3aceticacidIAA)和辣根过氧化物酶(horseradishperoxidaseHRP)共同作用诱导k562细胞凋亡的可能机制,应用MTT法和DNA末端标记法(TUNEL)分别检测IAA/HRP对k562细胞增殖及诱导k562细胞凋亡的影响;用化学方法检测了不同IAA浓度结合HRP作用下细胞内超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量的变化;应用DCFHDA探针通过共聚焦显微镜检测药物作用下细胞内自由基的产生情况。研究结果表明:MTT和TUNEL显示IAA/HRP能明显抑制K562细胞的增殖,诱导K562细胞凋亡,其诱导凋亡的作用与IAA浓度呈正相关(r=0.971,P<0.01),且随IAA浓度的增加,细胞内SOD活力、MDA量也随之升高;DCFHDA探针检测表明,胞内自由基水平的荧光强度也随IAA浓度的增加而呈明显上升趋势。结论:IAA结合HRP能抑制K562细胞增殖,并诱导凋亡,其机制可能与IAA/HRP作用下K562细胞内自由基的产生增加有关。

To investigate the possible mechanism of apoptosis induced by indole-3-acetic acid （IAA） combined with horseradish peroxidase in leukemia cell line K562, cell proliferation and apoptosis of K562 cell were examined by MTT assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL）, respectively; the activity of superoxide dismutase （SOD） and the quantitative change of MDA were measured by biochemical method; changes of free radical were determined by 2,7-dichlorofluorescin diacetate （DCFH-DA） probe with confocal microscopy. The results showed that of MTT assay and TUNEL indicated that IAA/HRP could significantly inhibit cell proliferation （ P 〈 0.05） and induce apoptosis of K562 cell （P 〈0.01 ）, at the same time a positive correlation was found between apoptosis rate and IAA concentration （ r = 0. 971, P 〈 0. 01 ）. The activity of SOD and the quantitative of MDA increased, accompanied with a rise in IAA concentration. Results detected by DCFH-DA probe indicated that the flourescence intensity of intracellular free radical increased, as compared with control, and a positive correlation was found. It is concluded that IAA/HRP can inhibit proliferation of K562 cells and induce K562 cell apoptosis, its mechanism may be related with the increase of intracellular free radical due to the effects of IAA/HRP.