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3 讨论
磷脂酰乙醇胺是维持细胞膜不对称性的重要磷脂成分。在正常细胞膜上，PE分布于细胞膜的内侧，而在细胞凋亡的过程中，其与PS一起外翻到细胞膜外侧[10]。目前，大量研究认为PS外翻是细胞早期凋亡的信号，并参与细胞凋亡的发生。关于PE在细胞凋亡过程中的作用尚不清晰。本研究首次研究证明，外源PE可以显著抑制Hela细胞的增殖，并发现PE对SMMC7721、HEK293以及HepG2具有相同的作用，表明PE细胞增殖抑制作用没有细胞特异性(数据未显)。
细胞增殖抑制受细胞增殖周期和细胞凋亡的双重影响。细胞增殖检测显示PE在不同浓度下均不引起Hela细胞周期的改变，提示PE未通过细胞周期调控Hela细胞的生长抑制。凋亡检测结果证明，PE明显诱导了Hela细胞凋亡的发生。细胞凋亡指标与细胞生长抑制的结果一致。实验表明，细胞凋亡是PE抑制细胞生长的主要方式医.学全.在.线www.lindalemus.com。
PE是细胞膜不对称分布的磷脂成分，在培养细胞时，提供外源PE，可能会引起细胞膜稳定性下降，并诱导细胞凋亡。我们对HepG2进行研究时发现，PE处理细胞后，线粒体Δψm下降的细胞比例明显增加，引起Bcl2表达下调以及Bax上调，以及caspase3的激活。体外实验证明，酸性磷脂和中性磷脂组成的脂质体进行细胞色素c跨膜运送时，PE具有关键的作用。在PA∶PE∶PC体系中随着PE 含量的增加, 细胞色素c跨膜运送增加[11]。关于PE是否通过线粒体通路诱导细胞凋亡，有待进一步的研究。
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