Kuo Jung-hua Steven, Jan Ming-shiou, Chiu Hsuan Wen
Graduate Institute of Pharmaceutical Science, Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Sec. 1, Jen-Te, Tainan, 717, Taiwan.
Pharm Res. 2006 Jul;23(7):1509-16. doi: 10.1007/s11095-006-0281-y. Epub 2006 Jun 21.
Tyloxapol, a viscous polymer of the alkyl aryl polyether alcohol type, is classified as a nonionic surfactant and is widely used in biomedical applications. Although tyloxapol has been reported to be cytotoxic in various cell lines, there is no published information about its possible mechanisms of cell death. Hence, the objective of this study was to determine whether tyloxapol causes apoptosis or necrosis. These data could be helpful for a better understanding of the action of tyloxapol in cellular systems.
RAW 264.7 (murine macrophage-like) cells and NIH/3T3 (mouse fibroblast) cells were treated with tyloxapol, and the activity of dehydrogenases in those cells, an indicator of cell viability, was assessed. The cell morphology changes induced by tyloxapol treatment were detected using propidium iodide nuclear staining. The hallmarks of apoptotic cells were characterized using DNA fragmentation assays, DNA fluorescence staining, and then flow analysis.
Tyloxapol treatment produced dose- and time-dependent cytotoxicity. Tyloxapol treatment damaged RAW 264.7 cells more than it damaged NIH/3T3 cells. All the cells exposed to tyloxapol showed some morphological features of apoptosis, such as chromatin condensation and cell shrinkage. Typical apoptotic ladders were observed in DNA extracted from tyloxapol-treated cells. Flow cytometric analysis revealed an increase in the hypodiploid DNA population (sub-G1), indicating that DNA cleavage occurred after tyloxapol treatment. In addition, we showed that pretreating cells with zVAD-fmk, a general caspase inhibitor, did not prevent tyloxapol-induced apoptosis. The cytotoxicity of tyloxapol can be reduced by adding a nontoxic lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine to attenuate the interaction of tyloxapol with the cell membrane.
Our results indicate that tyloxapol induces apoptosis in RAW 264.7 and NIH/3T3 cells. These data provide a novel insight into the cytotoxic action of tyloxapol at the molecular level.
泰洛沙泊是一种烷基芳基聚醚醇型粘性聚合物，属于非离子表面活性剂，广泛应用于生物医学领域。尽管有报道称泰洛沙泊在多种细胞系中具有细胞毒性，但关于其可能的细胞死亡机制尚无公开信息。因此，本研究的目的是确定泰洛沙泊是否会导致细胞凋亡或坏死。这些数据有助于更好地理解泰洛沙泊在细胞系统中的作用。
用泰洛沙泊处理RAW 264.7（鼠巨噬细胞样）细胞和NIH/3T3（小鼠成纤维细胞）细胞，并评估这些细胞中脱氢酶的活性，该活性是细胞活力的指标。使用碘化丙啶核染色检测泰洛沙泊处理诱导的细胞形态变化。使用DNA片段化分析、DNA荧光染色，然后进行流式分析来表征凋亡细胞的特征。
泰洛沙泊处理产生剂量和时间依赖性细胞毒性。泰洛沙泊对RAW 264.7细胞的损伤比对NIH/3T3细胞的损伤更大。所有暴露于泰洛沙泊的细胞都表现出一些凋亡的形态特征，如染色质浓缩和细胞收缩。在从泰洛沙泊处理的细胞中提取的DNA中观察到典型的凋亡梯带。流式细胞术分析显示亚二倍体DNA群体（亚G1）增加，表明泰洛沙泊处理后发生了DNA裂解。此外，我们表明用一种通用的半胱天冬酶抑制剂zVAD-fmk预处理细胞并不能阻止泰洛沙泊诱导的细胞凋亡。通过添加无毒脂质1,2-二棕榈酰-sn-甘油-3-磷酸胆碱来减弱泰洛沙泊与细胞膜的相互作用，可以降低泰洛沙泊的细胞毒性。
我们的结果表明泰洛沙泊在RAW 264.7和NIH/3T3细胞中诱导细胞凋亡。这些数据在分子水平上为泰洛沙泊的细胞毒性作用提供了新的见解。
