Premium
Effects of transient overexpression or knockdown of cytochrome P450 reductase on reactive oxygen species generation and hypoxia reoxygenation injury in liver cells
Author(s) -
Pillai Venkateswaran C,
Snyder Russell O,
Gumaste Upendra,
Thekkumkara Thomas J,
Mehvar Reza
Publication year - 2011
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.2011.05622.x
Subject(s) - gene knockdown , reactive oxygen species , reperfusion injury , oxidative stress , liver injury , apoptosis , biology , hypoxia (environmental) , microbiology and biotechnology , chemistry , ischemia , biochemistry , pharmacology , oxygen , medicine , organic chemistry
Summary 1. Literature data suggest that the electron‐donating enzyme, cytochrome P450 reductase (CPR), might act as a source of reactive oxygen species (ROS). However, the role of CPR in pathophysiological conditions associated with oxidative stress is unknown. The aim of the present study was to study the role of CPR in the generation of ROS and cellular injury under basal conditions, and after simulated in vitro ischaemia–reperfusion (IR). 2. Plasmid DNA or siRNA approaches were used to transiently overexpress or knockdown the human CPR gene in rat liver epithelial (WB‐F344) or human hepatoblastoma (HepG2) cells, respectively. The generation of ROS and/or cellular injury was then studied under the basal conditions and after simulated IR (4 h of ischaemia plus 30 min of reoxygenation). 3. Under the basal conditions, transient overexpression of CPR protein in WB‐F344 cells caused a 90% increase in the CPR activity, which was associated with a 100% increase in the ROS production. In contrast, after simulated IR, a 2.5‐fold higher CPR activity did not significantly affect the magnitude of ROS generation or cell death. Similarly, although the knockdown of CPR protein resulted in a significant reduction (∼30%) in the CPR activity, the ROS production was not substantially altered after simulated IR in HepG2 cells. 4. Our data suggest that CPR plays a major role in the ROS generation by liver cells under the basal conditions. However, the role of CPR in the ROS generation during simulated in vitro IR injury in these cells is minimal, if any.