Heterologous ferredoxin reductase and flavodoxin protect Cos-7 cells from oxidative stress.
BACKGROUND
Ferredoxin-NADP(H) reductase (FNR) from Pisum sativum and Flavodoxin (Fld) from Anabaena PCC 7119 have been reported to protect a variety of cells and organisms from oxidative insults. In this work, these two proteins were expressed in mitochondria of Cos-7 cells and tested for their efficacy to protect these cells from oxidative stress in vitro.


RESULTS
Cos-7/pFNR and Cos-7/pFld cell lines expressing FNR and Fld, respectively, showed a significantly higher resistance to 24 h exposure to 300-600 µM hydrogen peroxide measured by LDH retention, MTT reduction, malondialdehyde (MDA) levels and lipid peroxide (LPO; FOX assay) levels. However, FNR and Fld did not exhibit any protection at shorter incubation times (2 h and 4 h) to 4 mM hydrogen peroxide or to a 48 h exposure to 300 µM methyl viologen. We found enhanced methyl viologen damage exerted by FNR that may be due to depletion of NADPH pools through NADPH-MV diaphorase activity as previously observed for other overexpressed enzymes.


CONCLUSIONS
The results presented are a first report of antioxidant function of these heterologous enzymes of vegetal and cyanobacterial origin in mammalian cells.
Mediavilla
María G
MG
Centro Binacional Argentina-Italia de Investigaciones en Criobiología Clínica y Aplicada CAIC and Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina. mmediavi@fbioyf.unr.edu.ar
Di Venanzio
Gisela A
GA
Guibert
Edgardo E
EE
Tiribelli
Claudio
C
D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D017931:DNA Primers; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism*; D005418:Flavodoxin / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D019076:Transgenes
D017931:DNA Primers; D005418:Flavodoxin; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D005287:Ferredoxin-NADP Reductase