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Proapoptotic Nitric Oxide Production in Amyloid β Protein‐Treated Cerebral Microvascular Endothelial Cells
Author(s) -
KIMURA CHIWAKA,
OIKE MASAHIRO,
WATANABE MICHI,
ITO YUSHI
Publication year - 2007
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1080/10739680601131127
Subject(s) - nitric oxide , apoptosis , enos , nitric oxide synthase , microbiology and biotechnology , lipopolysaccharide , blot , endothelium , endothelial stem cell , cell culture , chemistry , biology , biochemistry , immunology , endocrinology , in vitro , organic chemistry , genetics , gene
Objective: The objective of this study was to investigate the effects of amyloid β protein (Aβ) on cerebral microvascular endothelium, and their possible involvement in Aβ‐induced apoptosis in the neighboring cells. Methods: Cultured bovine brain microvascular endothelial cells (BBECs) were incubated with Aβ for 24 h. Production of nitric oxide (NO) was assessed by nitric oxide‐sensitive fluorescent dye, DAF‐2, and the expression of NO synthase (NOS) proteins was examined by Western blotting. Effects of Aβ‐treated microvascular endothelium on the DNA damage of the neighboring cells were assessed by single‐cell gel electrophoresis. Results: Aβ increased the expression of iNOS protein, but did not affect eNOS and nNOS expressions in BBECs. Aβ‐treated BBECs showed spontaneous NO production in the presence of L‐arginine. The neural cell line PC12 showed marked apoptosis after being co‐cultured with Aβ‐treated BBECs for 48 h, and the apoptosis was as potent as that induced by the inflammatory stimuli lipopolysaccharide and interferon‐γ. The DNA damage of PC12 cells evoked by co‐culture with Aβ‐treated BBECs was prevented by L‐ N G ‐nitroarginine methyl ester, an inhibitor of NOS. Conclusions: These results indicate that Aβ induces the expression of iNOS in BBECs, and that microvascular endothelium‐derived NO may induce apoptosis in neighboring neural cells.