RIP1-dependent and independent effects of necrostatin-1 in necrosis and T cell activation
Document Type
Journal ArticlePublication Date
2011-08-01Keywords
AnimalsApoptosis
Caspases
Cell Proliferation
Cyclic AMP-Dependent Protein Kinases
Extracellular Signal-Regulated MAP Kinases
Gene Knockdown Techniques
Humans
Imidazoles
Indoles
JNK Mitogen-Activated Protein Kinases
Jurkat Cells
Lymphocyte Activation
Mice
NIH 3T3 Cells
Necrosis
Phosphorylation
Receptor-Interacting Protein Serine-Threonine Kinases
T-Lymphocytes
Tumor Necrosis Factor-alpha
Immunology and Infectious Disease
Life Sciences
Medicine and Health Sciences
Pathology
Metadata
Show full item recordAbstract
BACKGROUND: Programmed necrosis/necroptosis is an emerging form of cell death that plays important roles in mammalian development and the immune system. The pro-necrotic kinases in the receptor interacting protein (RIP) family are crucial mediators of programmed necrosis. Recent advances in necrosis research have been greatly aided by the identification of chemical inhibitors that block programmed necrosis. Necrostatin-1 (Nec-1) and its derivatives were previously shown to target the pro-necrotic kinase RIP1/RIPK1. The protective effect conferred by Nec-1 and its derivatives in many experimental model systems was often attributed to the inhibition of RIP1 function. METHODOLOGY/PRINCIPAL FINDINGS: We compared the effect of Nec-1 and siRNA-mediated silencing of RIP1 in the murine fibrosarcoma cell line L929. Treatment of L929 cells with the pan-caspase inhibitor zVAD-fmk or exogenous TNF induces necrosis. Strikingly, we found that siRNA-mediated silencing of RIP1 inhibited zVAD-fmk induced necrosis, but not TNF-induced necrosis. TNF-induced cell death in RIP1 knocked down L929 cells was inhibited by Nec-1, but not the caspase inhibitor zVAD-fmk. We found that PKA-C section sign expression, but not Jnk or Erk activation, was moderately inhibited by Nec-1. Moreover, we found that Nec-1 inhibits proximal T cell receptor signaling independent of RIP1, leading to inhibition of T cell proliferation. CONCLUSIONS/SIGNIFICANCE: Our results reveal that besides RIP1, Nec-1 also targets other factors crucial for necrosis induction in L929 cells. In addition, high doses of Nec-1 inhibit other signal transduction pathways such as that for T cell receptor activation. These results highlight the importance to independently validate results obtained using Nec-1 with other approaches such as siRNA-mediated gene silencing. We propose that some of the previous published results obtained using Nec-1 should be re-evaluated in light of our findings.Source
Cho Y, McQuade T, Zhang H, Zhang J, Chan FK-M (2011) RIP1-Dependent and Independent Effects of Necrostatin-1 in Necrosis and T Cell Activation. PLoS ONE 6(8): e23209. doi:10.1371/journal.pone.0023209. Link to article on publisher's siteDOI
10.1371/journal.pone.0023209Permanent Link to this Item
http://hdl.handle.net/20.500.14038/39561PubMed ID
21853090Related Resources
Link to Article in PubMedRights
Copyright: © 2011 Cho et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.ae974a485f413a2113503eed53cd6c53
10.1371/journal.pone.0023209