Lactoferrin inhibits neutrophil apoptosis via blockade of proximal apoptotic signaling events

N Francis, SH Wong, Peter Hampson, K Wang, Stephen Young, HP Deigner, M Salmon, Dagmar Scheel-Toellner, Janet Lord

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)

Abstract

Neutrophils are the most abundant leukocyte and have a short lifespan, dying by apoptosis approximately five days after leaving the bone marrow. Their apoptosis can be delayed at sites of inflammation to extend their functional lifespan, but inappropriate inhibition of apoptosis contributes to chronic inflammatory disease. Levels of the physiological iron chelator lactoferrin are raised at sites of inflammation and we have shown previously that iron-unsaturated lactoferrin inhibited human neutrophil apoptosis, but the mechanisms involved were not determined. Here we report that the anti-apoptotic effect of lactoferrin is dependent upon its iron saturation status as iron-saturated lactoferrin did not affect neutrophil apoptosis. We also show that the effect of lactoferrin is mediated at an early stage in apoptosis as it inhibited activation of sphingomyelinase, generation of ceramide, activation of caspase 8 and Bax and cleavage of Bid. Lactoferrin did not inhibit apoptosis induced by exogenous ceramide, supporting the proposal that it acts upstream of ceramide generation. We therefore conclude that raised lactoferrin levels are likely to contribute to chronic inflammation by delaying neutrophil apoptosis and that this is achieved by inhibiting proximal apoptotic signaling events. (C) 2011 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)1822-1826
Number of pages5
JournalBiochimica et Biophysica Acta. Molecular Cell Research
Volume1813
Issue number10
DOIs
Publication statusPublished - 1 Oct 2011

Keywords

  • apoptotic signaling
  • inflammation
  • apoptosis
  • Neutrophil
  • iron chelator

Fingerprint

Dive into the research topics of 'Lactoferrin inhibits neutrophil apoptosis via blockade of proximal apoptotic signaling events'. Together they form a unique fingerprint.

Cite this