Necroptosis promotes cell-autonomous activation of proinflammatory cytokine gene expression

Cell Death Dis. 2018 May 1;9(5):500. doi: 10.1038/s41419-018-0524-y.

Abstract

Necroptosis, a form of regulated necrotic cell death, is mediated by receptor interacting protein 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like protein (MLKL). However, the mechanism by which necroptosis promotes inflammation is still unclear. Here we report that the expression of cytokines is robustly upregulated in a cell-autonomous manner during necroptosis induced by tumor necrosis factor alpha (TNFα). We demonstrate that TNFα-induced necroptosis leads to two waves of cytokine production. The first wave, more transient and weaker than the second, is in response to TNFα alone; whereas the second wave depends upon the necroptotic signaling. We show that necroptosis promotes the transcription of TNFα-target genes in a cell-intrinsic manner. The activation of both NF-κB and p38 by the necroptotic machinery, RIPK1, RIPK3, and MLKL, is involved in mediating the robust induction of cytokine expression in the second wave. In contrast, necroptosis induced by direct oligomerization of MLKL promotes cytokine production at much lower levels than that of necroptosis induced with TNFα. Thus, we conclude that TNFα-induced necroptosis signaling events mediated by RIPK1 and RIPK3 activation, in addition to the MLKL oligomerization, promotes the expression of cytokines involving multiple intracellular signaling mechanisms including NF-κB pathway and p38. These findings reveal that the necroptotic cell death machinery mounts an immune response by promoting cell-autonomous production of cytokines. Our study provides insights into the mechanism by which necroptosis promotes inflammation in human diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Apoptosis / immunology
  • Cell Line
  • Chemokine CXCL1 / agonists
  • Chemokine CXCL1 / genetics*
  • Chemokine CXCL1 / immunology
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / immunology
  • Gene Expression Regulation / immunology*
  • HEK293 Cells
  • HT29 Cells
  • Humans
  • Mice
  • Necrosis / genetics*
  • Necrosis / immunology
  • Protein Isoforms / agonists
  • Protein Isoforms / genetics
  • Protein Isoforms / immunology
  • Protein Kinases / genetics*
  • Protein Kinases / immunology
  • Protein Multimerization
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / immunology
  • Receptor-Interacting Protein Serine-Threonine Kinases / genetics*
  • Receptor-Interacting Protein Serine-Threonine Kinases / immunology
  • Signal Transduction
  • Transcription Factor RelA / antagonists & inhibitors
  • Transcription Factor RelA / genetics
  • Transcription Factor RelA / immunology
  • Tumor Necrosis Factor-alpha / pharmacology
  • p38 Mitogen-Activated Protein Kinases / genetics
  • p38 Mitogen-Activated Protein Kinases / immunology

Substances

  • CXCL1 protein, human
  • Chemokine CXCL1
  • Protein Isoforms
  • RNA, Small Interfering
  • Transcription Factor RelA
  • Tumor Necrosis Factor-alpha
  • MLKL protein, human
  • Protein Kinases
  • RIPK1 protein, human
  • RIPK3 protein, human
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • p38 Mitogen-Activated Protein Kinases