Extracellular mitochondria interact with neutrophils. (A) Intravenously injected fluorescence-labeled mitochondria (MitoTracker Deep Red) associate with mouse neutrophils (Gr1+ cells) in vivo as measured by flow cytometry (n = 6; data are mean ± SEM, ***P < .001, Student t test). (B) Intravenous injection of mitochondria induces neutrophil rolling in LysM-eGFP mice. (Center and right) Neutrophil (green) velocity is significantly reduced (n = 89; supplemental Movie 3) in blood (red) following intravenous injection of mitochondria compared with (left) Tyrode buffer as vehicle (n = 51; data are mean ± SEM, ***P < .001, Student t test) (C) Scanning electronic micrographs of mitochondria in association with (left) freshly isolated human neutrophil and (right) ensuing neutrophil structural change (29.2 ± 2.11%, n = 3) after a 30-minute incubation in the presence of human recombinant sPLA2-IIA.
