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Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
Published on: June 29, 2011
Apoptotic cell death and nitric oxide: activating and antagonistic transducing pathways
B Brüne1, K Sandau, A von Knethen
1University of Erlangen-Nürnberg, Faculty of Medicine, Department of Medicine IV-Experimental Division, Erlangen, 91054, Germany. mfm423@rzmail.uni-erlangen.de
Biochemistry. Biokhimiia
|August 29, 1998
Summary
Nitric oxide (NO) plays dual roles in cell death and survival. NO can trigger apoptosis, but also protect cells from damage through complex signaling pathways.
Area of Science:
- Cellular Biology
- Biochemistry
- Immunology
Background:
- Nitric oxide (NO) is a critical signaling molecule in mammalian pathophysiology.
- NO has a dual role in host defense, capable of eliminating pathogens and tumors, but also inducing cell death.
Purpose of the Study:
- To elucidate the complex mechanisms by which nitric oxide (NO) mediates both apoptosis and cell protection.
- To understand the signaling pathways and molecular interactions involved in NO-induced cell death and survival.
Main Methods:
- Investigated NO-mediated apoptosis through examining p53, caspases, and Bcl-2 family proteins.
- Utilized NO-synthase inhibitors to block NO effects and assessed cell rescue via anti-apoptotic protein overexpression.
- Explored protective mechanisms involving NO/superoxide interactions and the role of reduced glutathione.
- Analyzed gene transcription of protective proteins like heat shock proteins and hemeoxygenase-1.
Main Results:
- NO-induced apoptosis involves p53 upregulation, caspase activation, and alterations in Bcl-2 family proteins.
- NO-synthase inhibition reversed NO-induced cytotoxicity, while Bcl-2 overexpression conferred protection.
- Cellular protection from NO can occur via NO/superoxide interaction, especially when oxidative stress is managed by reduced glutathione.
- NO also induces protective proteins, such as heat shock proteins and hemeoxygenase-1, contributing to cell survival.
Conclusions:
- The role of NO in cell injury is determined by the balance between its cytotoxic and protective signaling pathways.
- Cellular fate (apoptosis or survival) in response to NO depends on the dynamic interplay of pro- and anti-apoptotic mechanisms.
- Understanding this balance is crucial for comprehending NO's impact on cellular health and disease.
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