甘露聚糖结合凝集素诱导人白血病细胞系U937细胞凋亡

目的研究甘露聚糖结合凝集素（MBL）对白血病细胞系U937凋亡的影响。方法不同浓度MBL处理U937细胞后,应用CCK-8法分析细胞增殖情况,Hoechst33258染色观察细胞核及染色质,AnnexinV/PI双染流式细胞术分析细胞凋亡率,real-timePCR和免疫印迹分析凋亡相关基因及蛋白表达。结果 30～50μg/mlMBL培养72h,U937细胞增殖明显受抑,出现不同程度核固缩、核碎裂;随MBL浓度升高或作用时间延长,凋亡细胞数逐渐增多;Fas、Caspase-3mRNA、Fas和FasL蛋白表达量升高,Caspase-3和多腺苷二磷酸多聚酶（PARP）蛋白被剪切激活或失活。结论 MBL可诱导白血病细胞U937细胞凋亡,其机制与上调Fas表达、剪切Caspase-3和PAPR有关。

Mannan-binding lectin induces apoptosis of human leukemia U937 cells

Objective To investigate the effects of mannan-binding lectin（MBL） on the induction of apoptosis of human leukemia U937 cells.Methods U937 cells were treated with different concentrations of MBL.Cellular proliferation was measured using the Cell Counting Kit-8.Cell apoptosis was analyzed by Hoechst 33258 staining and flow cytometry with Annexin V-FITC/PI staining.The expression of apoptosis-relative genes and proteins was analyzed by real-time PCR and Western blot.Results Within the concentrations of 30-50 μg/ml and at 72 hours after the treatment,the proliferation of U937 cell was inhibited.Condensed or fragmented nuclei were observed in the treated U937 cells.The percentage of apoptotic cells was increased in a MBL concentration and time dependent manner.The expressions of Fas and Caspase-3 mRNAs,Fas and FasL proteins were up-regulated.Caspase-3 and poly ADP-ribose polymerase（PARP） proteins were also cleaved and activated.Conclusion MBL can induce apoptosis of U937 cells and the mechanism may associate with the up-regulation of Fas expression and cleave of Caspase-3 and PARP.