冬凌草甲素增强巨噬细胞对凋亡的U937细胞的吞噬作用

目的：研究具有诱导肿瘤细胞凋亡活性的冬凌草甲素，促进巨噬细胞对因凋亡的肿瘤细胞的吞噬作用。 方法： DNA凝胶电泳检测UV照射（2.4 J/cm2, 4 min）的人组织淋巴瘤U937细胞凋亡；Giemsa染色，Hoechst 33258染色，镜下检测计数吞噬作用。 结果： UV照射（2.4 J/cm2, 4 min）诱导U937细胞发生凋亡，琼脂糖凝胶电泳可见凋亡典型的DNA梯带。2.7 μmol·L^-1的冬凌草甲素具有增强U937分化的巨噬细胞对UV照射诱导凋亡的U937细胞的吞噬作用，并呈时间剂量依赖性，但对非特异性荧光颗粒的吞噬效果较弱。加入抗TNFα和抗IL-1β的抗体，培养12 h, 吞噬增强作用明显受抑制。冬凌草甲素在人外周血来源的巨噬细胞吞噬凋亡的U937细胞过程中同样发挥增强吞噬的效果。 结论： 冬凌草甲素可特异地增强巨噬细胞对凋亡的U937细胞的吞噬作用，其吞噬机制是通过诱导巨噬细胞TNFα和IL-1β的释放。

Oridonin enhances phagocytosis of apoptotic U937 cells by macrophage-like cells

AIM: To study the effect of oridonin on the phagocytosis of apoptotic U937 cells by macrophage-like cells. METHODS: DNA agarose gel electrophoresis, Giemsa staining, Hoechst 33258 staining and photomicroscopical observation were used. RESULTS: UV irradiation (2.4 J/cm2, 4 min) induced U937 cell apoptosis. Marked DNA fragmentation in agarose gel electrophoresis was observed. Oridonin augmented phagocytosis of apoptotic U937 cells by U937 cell-derived macrophages in a time- and dose-dependent manner. However, less effect on synthetic fluoresbrite micropheres was observed. The oridonin-augmented phagocytosis was attenuated by anti-human TNFα or anti-human IL-1β antiserum. In addition, the similar effect of phagocytosis was observed in oridonin-treated human monocyte-derived macrophages at 4 day maturation. CONCLUSION: Oridonin enhances phagocytosis of apoptotic U937 cells by macrophage-like cells. The releases of TNFα and IL-1β are involved in this mechanism.