Central role for endothelial human deneddylase-1/SENP8 in fine-tuning the vascular inflammatory response

J Immunol. 2013 Jan 1;190(1):392-400. doi: 10.4049/jimmunol.1202041. Epub 2012 Dec 3.

Abstract

A deeper understanding of the mechanisms that control responses to inflammation is critical to the development of effective therapies. We sought to define the most proximal regulators of the Cullin (Cul)-RING ligases, which play a central role in the stabilization of NF-κB and hypoxia-inducible factor (HIF). In these studies, we identify the human deneddylase-1 (SENP8) as a key regulator of Cul neddylation response in vitro and in vivo. Using human microvascular endothelial cells (HMECs), we examined inflammatory responses to LPS or TNF-α by assessing Cul neddylation status, NF-κB and HIF-1α stabilization, and inflammatory cytokine secretion. HMECs with an intact neddylation pathway showed a time-dependent induction of Cul-1 neddylation, nuclear translocation of NF-κB, stabilization of HIF-1α, and increased NF-κB/HIF-α promoter activity in response to LPS. HMECs lacking SENP8 were unable to neddylate Cul-1 and subsequently were unable to activate NF-κB or HIF-1α. Pharmacological targeting of neddylation (MLN4924) significantly abrogated NF-κB responses, induced HIF-1α promoter activity, and reduced secretion of TNF-α-elicited proinflammatory cytokines. MLN4924 stabilized HIF and abrogated proinflammatory responses while maintaining anti-inflammatory IL-10 responses in vivo following LPS administration. These studies identify SENP8 as a proximal regulator of Cul neddylation and provide an important role for SENP8 in fine-tuning the inflammatory response. Moreover, our findings provide feasibility for therapeutic targeting of the Culs during inflammation.

Publication types

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

MeSH terms

  • Cells, Cultured
  • Cullin Proteins / metabolism
  • Cullin Proteins / physiology*
  • Endopeptidases / deficiency
  • Endopeptidases / genetics
  • Endopeptidases / physiology*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / enzymology*
  • Endothelium, Vascular / immunology*
  • Enzyme Precursors / metabolism
  • Enzyme Precursors / physiology
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Inflammation Mediators / physiology*
  • Microcirculation / immunology
  • NEDD8 Protein
  • Ubiquitins / metabolism
  • Ubiquitins / physiology*

Substances

  • Cullin Proteins
  • Enzyme Precursors
  • Inflammation Mediators
  • NEDD8 Protein
  • NEDD8 protein, human
  • Ubiquitins
  • Endopeptidases
  • SENP8 protein, human