Low and high molecular weight poly(l‐lysine)s/poly(l‐lysine)–DNA complexes initiate mitochondrial‐mediated apoptosis differently
- 13 October 2005
- journal article
- Published by Wiley in FEBS Letters
- Vol. 579 (27), 6191-6198
- https://doi.org/10.1016/j.febslet.2005.09.092
Abstract
Poly(L-lysine)s, PLLs, are commonly used for DNA compaction and cell transfection. We report that, although PLLs of low (2.9 kDa), L-PLL, and high (27.4 kDa), H-PLL, Mw in free form and DNA-complexed cannot only cause rapid plasma membrane damage in human cell lines, phosphatidylserine "scrambling" and loss of membrane integrity, but later (24 h) initiate stress-induced cell death via mitochondrial permeabilization without the involvement of processed caspase-2. Mitochondrially mediated apoptosis was confirmed by detection of cytochrome c (Cyt c) release, activation of caspases-9 and -3, and subsequent changes in mitochondrial membrane potential. Plasma membrane damage and apoptosis were most prominent with H-PLL. Cytoplasmic level of Cyt c was more elevated following H-PLL treatment, but unlike L-PLL case, inhibition of Bax channel-forming activity reduced the extent of Cyt c release from mitochondria by half. Inhibition of Bax channel-forming activity had no modulatory effect on L-PLL-mediated Cyt c release. Further, functional studies of isolated mitochondria indicate that H-PLL, but not L-PLL, can directly induce Cyt c release, membrane depolarization, and a progressive decline in the rate of uncoupled respiration. Combined, our data suggest that H-PLL and L-PLL are capable of initiating mitochondrially mediated apoptosis differently. The observed PLL-mediated late-phase apoptosis may provide an explanation for previously reported transient gene expression associated with PLL-based transfection vectors. The importance of our data in relation to design of novel and safer cationic non-viral vectors for human gene therapy is discussed.Keywords
This publication has 30 references indexed in Scilit:
- Pro-apoptotic Bid induces membrane perturbation by inserting selected lysolipids into the bilayerBiochemical Journal, 2005
- Caspase-2 Permeabilizes the Outer Mitochondrial Membrane and Disrupts the Binding of Cytochrome c to Anionic PhospholipidsPublished by Elsevier BV ,2004
- Disruption of Mitochondrial Function during Apoptosis Is Mediated by Caspase Cleavage of the p75 Subunit of Complex I of the Electron Transport ChainCell, 2004
- 3,6-Dibromocarbazole Piperazine Derivatives of 2-Propanol as First Inhibitors of Cytochrome c Release via Bax Channel ModulationJournal of Medicinal Chemistry, 2003
- Mitochondria: Releasing Power for Life and Unleashing the Machineries of DeathCell, 2003
- Intracellular rate-limiting steps of gene transfer using glycosylated polylysines in cystic fibrosis airway epithelial cellsGene Therapy, 2002
- Discovery of Small-Molecule Inhibitors of Bcl-2 through Structure-Based Computer ScreeningJournal of Medicinal Chemistry, 2001
- Early redistribution of plasma membrane phosphatidylserine is a general feature of apoptosis regardless of the initiating stimulus: inhibition by overexpression of Bcl-2 and Abl.The Journal of Experimental Medicine, 1995
- Inhibition of mitochondrial phospholipase A2 by mono- and dilysocardiolipinBiochemistry, 1987
- Polycations as prostaglandin synthesis inducers: Stimulation of arachidonic acid release and prostaglandin synthesis in cultured fibroblasts by poly(l-lysine) and other synthetic polycationsBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1984