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Published on: October 5, 2012
Hydrogen peroxide-induced Akt phosphorylation regulates Bax activation
Mahdieh Sadidi1, Stephen I Lentz, Eva L Feldman
1Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, USA.
Biochimie
|March 13, 2009
Summary
Hydrogen peroxide (H2O2) activates survival pathways by phosphorylating the Bax protein via PI3K/Akt signaling in neuroblastoma cells. This prevents apoptosis, but inhibition blocks this protective effect, leading to cell death.
Area of Science:
- Cell Biology
- Molecular Biology
- Neuroscience
Background:
- Reactive oxygen species, like hydrogen peroxide (H2O2), play critical roles in cellular signaling and fate regulation.
- H2O2 acts as an intracellular messenger, activating phosphatidylinositol-3 kinase (PI3K)/Akt pathways, which are known to promote cell survival.
Purpose of the Study:
- To elucidate the specific molecular mechanism by which the PI3K/Akt signaling pathway confers cell survival in SH-SY5Y neuroblastoma cells under H2O2 exposure.
Main Methods:
- Investigated the role of PI3K/Akt signaling in H2O2-induced cell survival in SH-SY5Y cells.
- Utilized LY294002, a PI3K inhibitor, to block signaling pathways.
- Assessed Bax protein phosphorylation, mitochondrial translocation, cytochrome c release, caspase-3 activation, and cell death.
Main Results:
- H2O2-induced cell survival was mediated by PI3K/Akt signaling, leading to Bax phosphorylation.
- Phosphorylation of Bax by PI3K/Akt suppressed its pro-apoptotic function.
- LY294002 treatment inhibited Bax phosphorylation, induced Bax mitochondrial translocation, cytochrome c release, caspase-3 activation, and subsequent cell death.
Conclusions:
- H2O2 activates PI3K/Akt signaling to promote neuroblastoma cell survival through the post-translational modification (phosphorylation) of Bax.
- This mechanism effectively inactivates Bax, a key component of the intrinsic apoptotic pathway, thereby preventing cell death.
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