1. Macrophages uptake extracellular mitochondria from apoptotic cells, inducing caspase-1 activation and IL-1β production.
Macrophages uptake extracellular mitochondria from apoptotic cells, inducing caspase-1 activation and IL-1β production. (A) J774A.1 cells were incubated with mitochondria purified from healthy, apoptotic, and necroptotic L929 cells containing DsRed-labeled mitochondria and analyzed by FACS and (B) imaged by confocal microscopy to confirm intracellular localization of the mitochondria. Red staining: mitochondria stained with DsRed; blue staining: nuclei stained with DAPI. Original magnification ×400. (C) LPS-primed J774A.1 cells were stimulated for 16 h with mitochondria (100 mg/ml) purified from healthy, apoptotic, and necroptotic L929 cells, the SN was assayed for IL-1β production, (D) LPS-primed primary murine (C57BL/6) peritoneal macrophages were similarly treated with mitochondria, and the SN was assayed for IL-1β. (E) Caspase-1 activity was measured in LPS-primed J744A.1 macrophages following treatment with purified mitochondria from healthy, apoptotic, or necroptotic cells. ATP (5 mM) served as a positive control. (F and G) Unprimed J774A.1 cells were treated with mitochondria (100 mg/ml) for 16 h, and the SN was assayed for IL-6 and TNF-α. LPS (100 ng/ml) served as a positive control. Comparisons were performed using a Kruskal–Wallis with Dunn multiple comparison test. A p value <0.05 was considered significant.
Minghua Zhu et al. ImmunoHorizons 2018;2:
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