Prolonged exposure to hypoxia induces an autophagy-like cell survival program in human neutrophils.

Prolonged exposure to hypoxia induces an autophagy-like cell survival program in human neutrophils.
J Leukoc Biol. 2019 Aug 14;:
Authors: Talla U, Bozonet SM, Parker HA, Hampton MB, Vissers MCM
Abstract
Neutrophils contribute to low oxygen availability at inflammatory sites through the generation of reactive oxidants. They are also functionally affected by hypoxia, which delays neutrophil apoptosis. However, the eventual fate of neutrophils in hypoxic conditions is unknown and this is important for their effective clearance and the resolution of inflammation. We have monitored the survival and function of normal human neutrophils exposed to hypoxia over a 48 h period. Apoptosis was delayed, and the cells remained intact even at 48 h. However, hypoxia promoted significant changes in neutrophil morphology with the appearance of many new cytoplasmic vesicles, often containing cell material, within 5 hours of exposure to low O2 . This coincided with an increase in LC3B-II expression, indicative of autophagosome formation and an autophagy-like process. In hypoxic conditions, neutrophils preferentially lost myeloperoxidase, a marker of azurophil granules. Short-term (2 h) hypoxic exposure resulted in sustained potential to generate superoxide when O2 was restored, but the capacity for oxidant production was lost with longer periods of hypoxia. Phagocytic ability was unchanged by hypoxia, and bacterial killing by neutrophils in both normox...

Source: Journal of Leukocyte Biology - August 13, 2019 Category: Hematology Authors: Talla U, Bozonet SM, Parker HA, Hampton MB, Vissers MCM Tags: J Leukoc Biol Source Type: research