Apoptosis

, Volume 14, Issue 10, pp 1176–1189

Partial attenuation of cytotoxicity and apoptosis by SOD1 in ischemic renal epithelial cells

  • Huan Ling Liang
  • Jody Arsenault
  • Jordan Mortensen
  • Frank Park
  • Christopher P. Johnson
  • Vani Nilakantan
Original paper

DOI: 10.1007/s10495-009-0393-z

Cite this article as:
Liang, H.L., Arsenault, J., Mortensen, J. et al. Apoptosis (2009) 14: 1176. doi:10.1007/s10495-009-0393-z

Abstract

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-PK1) 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 (O2•−) 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 O2•− 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-PK1 cells with the mitochondrial antioxidant, MitoTEMPO. Treatment with MitoTEMPO also decreased ATP depletion induced cytotoxicity in LLC-PK1 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.

Keywords

Apoptosis ATP depletion Catalase Lentiviral Reactive oxygen species SOD1 

Abbreviations

EGFP

Enhanced green fluorescent protein

IM

Injury media

IR

Ischemia-reperfusion

LDH

Lactate dehydrogenase

PBS

Phosphate-buffered saline

ROS

Reactive oxygen species

SOD

Superoxide dismutase

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Huan Ling Liang
    • 1
    • 2
  • Jody Arsenault
    • 6
    • 7
  • Jordan Mortensen
    • 1
    • 2
  • Frank Park
    • 2
    • 3
    • 5
  • Christopher P. Johnson
    • 1
    • 2
    • 4
  • Vani Nilakantan
    • 1
    • 2
  1. 1.Division of Transplant SurgeryMedical College of WisconsinMilwaukeeUSA
  2. 2.Kidney Disease Center, H4135Medical College of WisconsinMilwaukeeUSA
  3. 3.Department of PhysiologyMedical College of WisconsinMilwaukeeUSA
  4. 4.VA Medical CenterMedical College of WisconsinMilwaukeeUSA
  5. 5.Department of Medicine (Division of Nephrology)Medical College of WisconsinMilwaukeeUSA
  6. 6.Department of PharmacologyLSU Health Sciences CenterNew OrleansUSA
  7. 7.Eli LillyIndianapolisUSA

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