Biochemical and Biophysical Research Communications
AP-1 mediates β-amyloid-induced iNOS expression in PC12 cells via the ERK2 and p38 MAPK signaling pathways
Section snippets
Experimental procedures
Chemical and biochemical reagents. Dulbecco’s modified Eagle’s medium (DMEM), fetal bovine serum, horse serum, F-12, and N-2 supplement were provided from Gibco (Grand Island, NY, USA). Aβ25–35 was supplied from Bachem (Torrance, CA, USA). Aβ25–35 was dissolved in deionized distilled water at a concentration of 1 mM and stored at −20 °C. The stock solution was diluted to desired concentrations immediately before use and added to culture medium without the aging procedure. We note that both fresh
Aβ25–35-mediated iNOS expression and NO production in PC12 cells
We have previously reported that Aβ25–35 induces apoptosis in PC12 cells by provoking oxidative stress [25], [26]. To explore the possible involvement of nitrosative stress as an alternative mechanism responsible for Aβ25–35-induced PC12 cell death, expression of iNOS was measured at protein and mRNA levels by Western blot analysis and RT-PCR, respectively. Significantly elevated iNOS protein expression was detected at 12 h after the Aβ25–35 treatment, which steadily increased up to 36 h after Aβ
Discussion
Aβ is the major component of senile plaques, which has been considered to play a causal role in the development and progress of AD. The molecular mechanisms underlying Aβ-mediated neurotoxicity still remain to be elucidated, but there is convincing evidence for the involvement of nitrosative stress caused by increased accumulation of reactive nitrogen species (RNS), such as NO and peroxynitrite [28], [29]. In this study, exposure of PC12 cells to Aβ25–35 resulted in elevated iNOS protein and
Acknowledgment
This work was supported by the Korea Research Foundation Grant ES0022.
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