麦胚凝集素诱导小鼠成纤维细胞L929发生凋亡的研究

Induction of apoptosis by wheat germ agglutinin in mouse fibroblast cell line L929

目的 :研究麦胚凝集素 (WGA)是否能够诱导小鼠成纤维细胞L92 9发生凋亡及其可能的分子机制。方法 :分别收集以WGA或琥珀酰化WGA(sWGA)处理 2 4h的L92 9细胞 ,经碘化丙啶染色后 ,以流式细胞仪分析细胞凋亡百分率 ,同时以荧光显微镜观察吖啶橙染色细胞的形态。结果 :WGA处理过的细胞 ,其DNA亚二倍体峰 (Sub -G1)即凋亡峰的百分率明显升高 ,且与WGA剂量呈正相关 ;而sWGA处理的细胞则无此现象。同时 ,荧光显微镜观察发现WGA处理的细胞发生核碎裂 ,但sWGA无此作用。结论 :WGA能诱导L92 9细胞发生凋亡 ,而sWGA不能诱导该细胞凋亡 ,提示WGA结合至细胞表面唾液酸残基是其诱导凋亡所必需 ;WGA诱导细胞凋亡的能力可部分解释其细胞毒性。

AIM: To investigate whether wheat germ agglutinin (WGA) could induce apoptosis in mouse fibroblast cell line L929 and the possible molecular mechanism underlying. METHODS: The cells were exposed to WGA or its succinylated form (sWGA) for 24 h and both attached cells and the cells in supernatant were collected. The percentages of apoptotic cells were estimated by flow cytometry after staining with propidium iodide. Cell morphology was observed under fluorescence microscope after staining the cells with acridine orange. RESULTS: WGA treatment resulted in significant increase of the low DNA content peak (sub-G 1) that representing apoptotic cells, whereas sWGA did not. Morphologic study demonstrated that exposure to WGA induced nuclear fragmentation while sWGA not. CONCLUSION: These results indicate that WGA (specific for both sialic acid and GlcNAc) induces apoptosis in L929 cells, whereas sWGA (specific only for GlcNAc) does not. It is possible that binding to sialic acid residues on the cell surface of L929 is essential for WGA to induce apoptosis. Apoptosis induction may be, at least in part, involved in the cytotoxicity of WGA. [