Frontline Science: Activation of metabolic nuclear receptors restores periodontal tissue homeostasis in mice with leukocyte adhesion deficiency-1

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Tetsuhiro Kajikawa - , University of Pennsylvania (Author)
  • Baomei Wang - , University of Pennsylvania (Author)
  • Xiaofei Li - , University of Pennsylvania (Author)
  • Hui Wang - , University of Pennsylvania (Author)
  • Triantafyllos Chavakis - , Institute of Clinical Chemistry and Laboratory Medicine (Author)
  • Niki M. Moutsopoulos - , National Institutes of Health (NIH) (Author)
  • George Hajishengallis - , University of Pennsylvania (Author)

Abstract

β2 Integrins mediate neutrophil-endothelial adhesion and recruitment of neutrophils to sites of inflammation. The diminished expression of β2 integrins in patients with mutations in the ITGB2 (CD18) gene (leukocyte adhesion deficiency-Type 1; LAD1) results in few or no neutrophils in peripheral tissues. In the periodontium, neutrophil paucity is associated with up-regulation of IL-23 and IL-17, which drive inflammatory bone loss. Using a relevant mouse model, we investigated whether diminished efferocytosis (owing to neutrophil scarcity) is associated with LAD1 periodontitis pathogenesis and aimed to develop approaches to restore the missing efferocytosis signals. We first showed that CD18−/− mice phenocopied human LAD1 in terms of IL-23/IL-17-driven inflammatory bone loss. Ab-mediated blockade of c-Mer tyrosine kinase (Mer), a major efferocytic receptor, mimicked LAD1-associated up-regulation of gingival IL-23 and IL-17 mRNA expression in wild-type (WT) mice. Consistently, soluble Mer-Fc reversed the inhibitory effect of efferocytosis on IL-23 expression in LPS-activated Mϕs. Adoptive transfer of WT neutrophils to CD18−/− mice down-regulated IL-23 and IL-17 expression to normal levels, but not when CD18−/− mice were treated with blocking anti-Mer Ab. Synthetic agonist-induced activation of liver X receptors (LXR) and peroxisome proliferator-activated receptors (PPAR), which link efferocytosis to generation of homeostatic signals, inhibited the expression of IL-23 and IL-17 and favorably affected the bone levels of CD18−/− mice. Therefore, our data link diminished efferocytosis-associated signaling due to impaired neutrophil recruitment to dysregulation of the IL-23–IL-17 axis and, moreover, suggest LXR and PPAR as potential therapeutic targets for treating LAD1 periodontitis.

Details

Original languageEnglish
Pages (from-to)1501-1514
Number of pages14
JournalJournal of leukocyte biology
Volume108
Issue number5
Publication statusPublished - 1 Nov 2020
Peer-reviewedYes

External IDs

PubMed 32421906

Keywords

Keywords

  • interleukin-17, leukocyte adhesion deficiency, liver X receptors, neutrophils, peroxisome proliferator-activated receptors, β2-integrins

Library keywords