Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China.
Biomaterials. 2011 Nov;32(33):8613-25. doi: 10.1016/j.biomaterials.2011.07.047. Epub 2011 Sep 7.
Polyethylenimine (PEI) is one of the most effective and widely used cationic macromolecules in experimental gene transfer/therapy protocols. However, the further clinical application of PEI is largely impeded by its cytotoxicity. Here we performed a fundamental investigation on the mechanism of PEI-induced cytotoxicity in both hepatic and nephritic cell lines. It was demonstrated that besides necrosis and apoptosis, autophagy was apparently associated with PEI-induced cytotoxicity and contributed to aggravated cell damage. Specifically, at the early stage (3 h) of PEI-induced cytotoxicity, autophagy was mainly correlated with lysosome damage, but in the later phase (after a 24-h recovery), autophagy was mainly related with mitochondrial injury. Modulation of Rab5, Rab7 expression and inhibition of clathrin-mediated endocytosis pathway significantly affected the formation of autophagosome, which suggested that the endolysosome transport pathway especially the clathrin-mediated endocytosis at least partly facilitated PEI-induced autophagy. As PEI-induced autophagy played a causative role in its cytotoxicity, it's highly recommended to design PEI-based gene-carriers that could avoid the endolysosome transport pathway.
聚乙烯亚胺 (PEI) 是实验性基因转染/治疗方案中最有效和应用最广泛的阳离子高分子之一。然而，PEI 的进一步临床应用在很大程度上受到其细胞毒性的阻碍。在这里，我们对 PEI 在肝和肾细胞系中诱导细胞毒性的机制进行了基础研究。结果表明，除了坏死和凋亡外，自噬与 PEI 诱导的细胞毒性明显相关，并导致细胞损伤加重。具体而言，在 PEI 诱导的细胞毒性的早期阶段（3 h），自噬主要与溶酶体损伤相关，但在后期阶段（24 小时恢复后），自噬主要与线粒体损伤相关。Rab5、Rab7 表达的调节和网格蛋白介导的内吞作用途径的抑制显著影响自噬体的形成，这表明内溶酶体转运途径，特别是网格蛋白介导的内吞作用至少部分促进了 PEI 诱导的自噬。由于 PEI 诱导的自噬在其细胞毒性中起因果作用，强烈建议设计基于 PEI 的基因载体，以避免内溶酶体转运途径。
