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Attenuated phagocytosis of secondary necrotic neutrophils by macrophages in aged and SMP30 knockout mice
Author(s) -
Takahashi Rei,
Totsuka Sayuri,
Ishigami Akihito,
Kobayashi Yoshiro,
Nagata Kisaburo
Publication year - 2016
Publication title -
geriatrics and gerontology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.823
H-Index - 57
eISSN - 1447-0594
pISSN - 1444-1586
DOI - 10.1111/ggi.12436
Subject(s) - phagocytosis , infiltration (hvac) , peritoneal cavity , macrophage , in vivo , inflammation , knockout mouse , necrosis , immunology , in vitro , cellular infiltration , medicine , pathology , biology , receptor , anatomy , biochemistry , physics , microbiology and biotechnology , thermodynamics
Aim Secondary necrotic cells generated in vivo induce inflammatory responses; for example, the production of macrophage inflammatory protein‐2 ( MIP ‐2) and subsequent infiltration of neutrophils. The aim of the present study was to elucidate the effect of aging on the phagocytosis of secondary necrotic cells and the inflammatory responses by using either wild‐type ( WT ) young mice, WT aged mice or senescence‐accelerated mice ( SMP 30 −/− mice). Methods The phagocytosis of secondary necrotic neutrophils with resident macrophage from either WT young mice, WT aged mice or SMP 30 −/− mice was examined by coculturing macrophages with secondary necrotic neutrophils in vitro . To investigate the inflammatory response induced by secondary necrotic cells, time‐dependent infiltration of neutrophils and production of MIP ‐2 were determined in the peritoneal cavity on the injection of secondary necrotic cells. Results The phagocytosis of secondary necrotic cells by macrophages from WT aged and SMP 30 −/− mice was significantly reduced as compared with that by macrophages from WT young mice. On peritoneal injection of secondary necrotic cells, the peak time of neutrophil infiltration was earlier in SMP 30 −/− mice than in WT young mice. The number of neutrophils in SMP 30 −/− mice at the peak time was also greater than that in WT young mice. Conclusions Our findings showed that the phagocytosis of secondary necrotic cells was attenuated in aged mice and SMP 30 −/− mice, and that the MIP ‐2 production was enhanced and subsequently neutrophil infiltration was exaggerated on peritoneal injection of secondary necrotic cells into those mice. Geriatr Gerontol Int 2016; 16: 135–142.