c-Jun N-terminal kinases differentially regulate TNF- and TLRs-mediated necroptosis through their kinase-dependent and -independent activities

Cell Death Dis. 2018 Nov 15;9(12):1140. doi: 10.1038/s41419-018-1189-2.


Tumor necrosis factor (TNF) and Toll-like receptor (TLR)3/TLR4 activation trigger necroptotic cell death through downstream signaling complex containing receptor-interacting protein kinase 1 (RIPK1), RIPK3, and pseudokinase mixed lineage kinase-domain-like (MLKL). However, the regulation of necroptotic signaling pathway is far less investigated. Here we showed that c-Jun N-terminal kinases (JNK1 and JNK2) displayed kinase-dependent and -independent functions in regulating TNF- and TLRs-mediated necroptosis. We found that RIPK1 and RIPK3 promoted cell-death-independent JNK activation in macrophages, which contributed to pro-inflammatory cytokines production. Meanwhile, blocking the kinase activity of JNK dramatically reduced TNF and TLRs-induced necroptotic cell death. Consistently, inhibition of JNK activity protected mice from TNF-induced death and Staphylococcus aureus-mediated lung damage. However, depletion of JNK protein using siRNA sensitized macrophages to necroptosis that was triggered by LPS or poly I:C but still inhibited TNF-induced necroptosis. Mechanistic studies revealed that RIPK1 recruited JNK to the necrosome complex and their kinase activity was required for necrosome formation and the phosphorylation of MLKL in TNF- and TLRs-induced necroptosis. Loss of JNK protein consistently suppressed the phosphorylation of MLKL and necrosome formation in TNF-triggered necroptosis, but differentially promoted the phosphorylation of MLKL and necrosome formation in poly I:C-triggered necroptosis by promoting the oligomeration of TRIF. In conclusion, our findings define a differential role for JNK in regulating TNF- and TLRs-mediated necroptosis by their kinase or scaffolding activities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / genetics
  • Animals
  • Apoptosis / genetics
  • Cell Death / genetics
  • Humans
  • Inflammation / genetics*
  • Inflammation / microbiology
  • Inflammation / pathology
  • Mice
  • Mitogen-Activated Protein Kinase 8 / genetics*
  • Mitogen-Activated Protein Kinase 9 / genetics*
  • Phosphorylation
  • Poly I-C / genetics
  • Protein Kinases / genetics
  • RAW 264.7 Cells
  • Receptor-Interacting Protein Serine-Threonine Kinases / genetics*
  • Signal Transduction / genetics
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / pathogenicity
  • Toll-Like Receptor 3 / genetics
  • Toll-Like Receptor 4 / genetics
  • Tumor Necrosis Factor-alpha / genetics


  • Adaptor Proteins, Vesicular Transport
  • TICAM-1 protein, mouse
  • Toll-Like Receptor 3
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha
  • MLKL protein, mouse
  • Protein Kinases
  • Mitogen-Activated Protein Kinase 9
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Ripk1 protein, mouse
  • Ripk3 protein, mouse
  • Mitogen-Activated Protein Kinase 8
  • Poly I-C