Peroxiredoxin 2 (PRDX2) has been known to act as an antioxidant enzyme whose 
main function is H(2)O(2) reduction in cells. We aimed to study the expression 
patterns of PRDX2 in mouse ovaries and explore the function of this protein in 
apoptosis of granulosa cells (GCs). We found that the expression of the PRDX2 
protein in atretic follicle GCs was markedly higher than in healthy follicle 
GCs. In vitro, the transfection of siRNA targeting the Prdx2 gene inhibited the 
proliferation and induced the apoptosis of primary cultured GCs. Furthermore, 
suppression of PRDX2 resulted in the augmentation of endogenous H(2)O(2), and 
the ability to eliminate the exogenous H(2)O(2) was attenuated. The expression 
of PRDX2 and nuclear factor kappa-light-chain-enhancer of activated B cells 
(NFKB), whose activity was inhibited by binding to IKB, increased in GCs treated 
with various concentrations of H(2)O(2) for 30 min. However, no significant 
change in cytoplasmic IKB expression was observed. At 2 h after treatment with 
H(2)O(2), nuclear NFKB expression level was reduced, cytoplasmic IKB expression 
was increased, and PRDX2 expression was unchanged. Silencing of the Prdx2 gene 
caused early changes in NFKB and IKB expression in the primary cultured GCs 
compared to that in control cells. Taken together, these data suggest that PRDX2 
plays an important role in inhibiting apoptosis in GCs and that PRDX2 actions 
may be related to the expression of NFKB and IKB.