Insulin-like growth factor-I protects cells from ER stress-induced apoptosis via enhancement of the adaptive capacity of endoplasmic reticulum
| Autor: | Derek LeRoith, D. Lann, N Kurshan, Ruslan Novosyadlyy, Shoshana Yakar, Archana Vijayakumar |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
p38 mitogen-activated protein kinases
Apoptosis Biology Endoplasmic Reticulum Wortmannin chemistry.chemical_compound Mice Cell Line Tumor medicine Staurosporine Animals Humans Cycloheximide Enzyme Inhibitors Insulin-Like Growth Factor I STAT3 Molecular Biology Endoplasmic Reticulum Chaperone BiP Protein Kinase Inhibitors PI3K/AKT/mTOR pathway Protein Synthesis Inhibitors Endoplasmic reticulum Cell Biology Recombinant Proteins Cell biology chemistry Unfolded protein response biology.protein NIH 3T3 Cells Thapsigargin Signal transduction medicine.drug Signal Transduction |
| Zdroj: | Cell death and differentiation. 15(8) |
| ISSN: | 1350-9047 |
| Popis: | Disruption of endoplasmic reticulum (ER) homeostasis causes accumulation of unfolded and misfolded proteins in the ER, triggering the ER stress response, which can eventually lead to apoptosis when ER dysfunction is severe or prolonged. Here we demonstrate that human MCF-7 breast cancer cells, as well as murine NIH/3T3 fibroblasts, are rescued from ER stress-initiated apoptosis by insulin-like growth factor-I (IGF-I). IGF-I significantly augments the adaptive capacity of the ER by enhancing compensatory mechanisms such as the IRE1 alpha-, PERK- and ATF6-mediated arms of ER stress signalling. During ER stress, IGF-I stimulates translational recovery and induces expression of the key molecular chaperone protein Grp78/BiP, thereby enhancing the folding capacity of the ER and promoting recovery from ER stress. We also demonstrate that the antiapoptotic activity of IGF-I during ER stress may be mediated by a novel, as yet unidentified, signalling pathway(s). Application of signal transduction inhibitors of MEK (U1026), PI3K (LY294002 and wortmannin), JNK (SP600125), p38 (SB203580), protein kinases A and C (H-89 and staurosporine) and STAT3 (Stattic) does not prevent IGF-I-mediated protection from ER stress-induced apoptosis. Taken together, these data demonstrate that IGF-I protects against ER stress-induced apoptosis by increasing adaptive mechanisms through enhancement of ER stress-signalling pathways, thereby restoring ER homeostasis and preventing apoptosis. |
| Databáze: | OpenAIRE |
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