Induction of genuine autophagy by cationic lipids in mammalian cells.
Autophagy is a cellular stress response that results in the activation of a lysosomal degradation pathway. In this report, we showed that cationic lipids, a common-used class of transfection reagents, induced genuine autophagy in mammalian cells. Extensive LC3 dot formation was observed by treatment with cationic lipids (with or without DNA), but not neutral lipids, in a HeLa cell line stably expressing GFP-LC3 (HeLa-LC3). Further proofs for autophagy were obtained by the co-localization of the LC3 dots with lysosome-specific staining patterns, observation of LC3-I to LC3-II form conversion and appearance of autophagic vacuoles under TEM. The autophagic flux assay with bafilomycin A1 and degradation of p62/SQSTM1 suggested that the autophagy induced by cationic lipids was primarily due to increased formation of autophagosomes and not decreased turnover. Moreover, cationic lipids induced autophagy in an mTOR-independent manner.
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Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science & Technology of China, Hefei, Anhui China.
Chen
Yong
Y
Zheng
Fang
F
Zhou
Wei
W
Wen
Long-Ping
LP
D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D002412:Cations; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008055:Lipids / Q000494:pharmacology*; D008322:Mammals / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure
D002412:Cations; D008055:Lipids; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D049452:Green Fluorescent Proteins