目的:探讨凋亡相关斑点样蛋白(Apoptosis-associated speck-like protein,ASC)在ONO-AE-248所诱发的中性粒细胞非凋亡、非坏死性死亡中的作用及意义。方法:TUNEL法标记凋亡细胞,结合激光共聚焦扫描显微镜观察细胞核形态以及DNA片段化发生的情况;Western blot法检测不同药物刺激组(LPS延迟凋亡组、TNF-α促进凋亡组、ONO-AE-248刺激组以及自发性凋亡组)的ASC蛋白的表达差异性。结果:TUNEL法检测ONO-AE-248培养12小时后的中性粒细胞,未见TUNEL阳性细胞。Western blot结果显示ONO-AE-248刺激后中性粒细胞ASC蛋白的表达一直处于下调状态。结论:ONO-AE-248诱导人中性粒细胞死亡过程中细胞核DNA断裂方式明显不同于自发性凋亡组,核内染色体可能只发生DNA较大片段的断裂,而没有发生小片段化。ONO-AE-248引起的ASC表达的下调可能是这种新型细胞死亡方式区别于自发性凋亡的重要差异点。
Objective:To investigate the role of apoptosis-associated speck-like protein(ASC) in non-apoptotic,non-necrotic cell death of neutrophils induced by ONO-AE-248.Methods:The morphological changes of neutrophil nuclei and DNA fragmentation of the cells were examined by confocal microscopy and terminal-deoxynucleotidyl transferase mediated nick end labeling(TUNEL).Neutrophils were stimulated with medium alone,LPS,TNF-α or ONO-AE248 respectively.Then expression of ASC was detected by Western blot.Results:ONO-AE-248-induced neutrophil death was negative in TUNEL assay.Western blot showed that the expression of ASC protein was down-regulated by ONO-AE-248.Conclusion:The DNA degradation of the neutrophils when stimulated by ONO-AE-248 is probably different from that of the typical apoptosis.ASC might be a crosslink point between the ONO-AE-248-induced neutrophil death and spontaneous apoptosis of neutrophils.