Partial attenuation of cytotoxicity and apoptosis by SOD1 in ischemic renal epithelial cells. Apoptosis 2009 Oct;14(10):1176-89
Date
08/18/2009Pubmed ID
19685188Pubmed Central ID
PMC3146066DOI
10.1007/s10495-009-0393-zScopus ID
2-s2.0-69949147576 (requires institutional sign-in at Scopus site) 20 CitationsAbstract
Reactive oxygen species (ROS) contribute significantly to apoptosis in renal ischemia-reperfusion (IR) injury, however the exact mechanisms are not well understood. We used novel lentiviral vectors to over-express superoxide dismutase 1 (SOD1) in proximal tubular epithelial (LLC-PK(1)) cells and determined effects of SOD1 following ATP depletion-recovery, used as a model to simulate renal IR. SOD1 over-expression partially protected against cytotoxicity (P < 0.001) and decreased superoxide (O(2) (*-)) in ATP depleted cells. The ATP depletion-mediated increase in nuclear fragmentation, an index of apoptosis and activation of caspase-3 was also partially blocked by SOD1 (P < 0.05). However, SOD1 over-expression was insufficient to completely attenuate caspase-3, indicating that ROS other than cytoplasmic O(2) (*-) are involved in ATP depletion mediated injury. To test the contribution of hydrogen peroxide, a subset of enhanced green fluorescent protein (EGFP) and SOD1 (serum free and injured) cells were treated with polyethylene glycol-catalase (PEG-catalase). As expected there was 50% reduction in cytotoxicity and caspase-3 in SOD1 cells compared to EGFP cells; catalase treatment decreased both indices by an additional 28% following ATP depletion. To test the role of mitochondrial derived superoxide, we also treated a subset of LLC-PK(1) cells with the mitochondrial antioxidant, MitoTEMPO. Treatment with MitoTEMPO also decreased ATP depletion induced cytotoxicity in LLC-PK(1) cells in a dose dependant manner. These studies indicate that both SOD1 dependent and independent pathways are integral in protection against ATP depletion-recovery mediated cytotoxicity and apoptosis, however more studies are needed to delineate the signaling mechanisms involved.
Author List
Liang HL, Arsenault J, Mortensen J, Park F, Johnson CP, Nilakantan VAuthor
Christopher P. Johnson MD Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adenosine TriphosphateAnimals
Apoptosis
Caspase 3
Catalase
DNA Fragmentation
Enzyme Activation
Epithelial Cells
Genetic Vectors
Green Fluorescent Proteins
Humans
Hydrogen Peroxide
Ischemia
Kidney Tubules, Proximal
L-Lactate Dehydrogenase
LLC-PK1 Cells
Lentivirus
Piperidines
Reproducibility of Results
Superoxide Dismutase
Superoxide Dismutase-1
Superoxides
Swine
Time Factors