Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Dependence of reactive oxygen species and FLICE inhibitory protein on lipofectamine-induced apoptosis in human lung epithelial cells.

Authors
Kongkaneramit-L; Sarisuta-N; Azad-N; Lu-Y; Iyer-AKV; Wang-Y; Rojanasakul-Y
Source
J Pharmacol Exp Ther 2008 Jun; 325(3):969-977
NIOSHTIC No.
20033880
Abstract
Cationic liposomes such as Lipofectamine (LF) are widely used as nonviral gene delivery vectors; however, their clinical application is limited by their cytotoxicity. These agents have been shown to induce apoptosis as the primary mode of cell death, but their mechanism of action is not well understood. The present study investigated the mechanism of LF-induced apoptosis and examined the role of reactive oxygen species (ROS) in this process. We found that LF induced apoptosis of human epithelial H460 cells through a mechanism that involves caspase activation and ROS generation. Inhibition of caspase activity by pan-caspase inhibitor (z-VAD-fmk) or by specific caspase-8 inhibitor (z-IETD-fmk) or caspase-9 inhibitor (z-LEHD-fmk) inhibited the apoptotic effect of LF. Overexpression of FLICE-inhibitory protein (FLIP) or B-cell lymphoma-2, which are known inhibitors of the extrinsic and intrinsic death pathways, respectively, similarly inhibited apoptosis by LF. Induction of apoptosis by LF was shown to require ROS generation because its inhibition by ROS scavengers or by ectopic expression of antioxidant enzyme superoxide dismutase and glutathione peroxidase strongly inhibited the apoptotic effect of LF. Electron spin resonance studies showed that LF induced multiple ROS; however, superoxide was found to be the primary ROS responsible for LF-induced apoptosis. The mechanism by which ROS mediate the apoptotic effect of LF involves down-regulation of FLIP through the ubiquitination pathway. In demonstrating the role of FLIP and ROS in LF death signaling, we document a novel mechanism of apoptosis regulation that may be exploited to decrease cytotoxicity and increase gene transfection efficiency of cationic liposomes.
Keywords
Pharmacology; Therapeutic-agents; Antioxidants; Antioxidation; Genes; Genetics; Cytotoxic-effects; Cytotoxins
Contact
Dr. Yon Rojanasakul, West Virginia University, Health Sciences Center, Department of Pharmaceutical Sciences, P.O. Box 9530, Morgantown, WV 26506
CODEN
JPETAB
Publication Date
20080601
Document Type
Journal Article
Email Address
yrojan@hsc.wvu.edu
Fiscal Year
2008
NTIS Accession No.
NTIS Price
Issue of Publication
3
ISSN
0022-3565
NIOSH Division
HELD
Priority Area
Manufacturing
Source Name
Journal of Pharmacology and Experimental Therapeutics
State
WV
TOP