|
Title
|
|
|
|
Caspase inhibitors promote alternative cell death pathways
| |
|
Author
|
|
|
|
| |
|
Abstract
|
|
|
|
| The use of caspase inhibitors has revealed the existence of alternative backup cell death programs for apoptosis. The broad-spectrum caspase inhibitor zVAD-fmk modulates the three major types of cell death. Addition of zVAD-fmk blocks apoptotic cell death, sensitizes cells to necrotic cell death, and induces autophagic cell death. Several studies have shown a crucial role for the kinase RIP1 and the adenosine nucleotide translocator (ANT)cyclophilin D (CypD) complex in necrotic cell death. The underlying mechanism of zVAD-fmkmediated sensitization to necrotic cell death involves the inhibition of caspase-8mediated proteolysis of RIP1 and disturbance of the ANT-CypD interaction. RIP1 is also involved in autophagic cell death. Caspase inhibitors and knockdown studies have revealed negative roles for catalase and caspase-8 in autophagic cell death. The positive role of RIP1 and the negative role of caspase-8 in both necrotic and autophagic cell death suggest that the pathways of these two types of cell death are interconnected. Necrotic cell death represents a rapid cellular response involving mitochondrial reactive oxygen species (ROS) production, decreased adenosine triphosphate concentration, and other cellular insults, whereas autophagic cell death first starts as a survival attempt by cleaning up ROS-damaged mitochondria. However, when this process occurs in excess, autophagy itself becomes cytotoxic and eventually leads to autophagic cell death. A better understanding of the molecular mechanisms of these alternative cell death pathways may provide therapeutic tools to combat cell death associated with neurodegenerative diseases, ischemia-reperfusion pathologies, and infectious diseases, and may also facilitate the development of alternative cytotoxic strategies in cancer treatment. |
| |
|
Language
|
|
|
|
English
| |
|
Source (journal)
|
|
|
|
STKE : Signal Transduction Knowledge Environment
| |
|
Publication
|
|
|
|
2006
| |
|
ISSN
|
|
|
|
1525-8882
| |
|
Volume/pages
|
|
|
|
358
(2006)
| |
|
Article Reference
|
|
|
|
pe44
| |
|
Medium
|
|
|
|
E-only publicatie
| |
|
Full text (Publisher's DOI)
|
|
|
|
| |
|