Evidence of nuclear localization of neuronal nitric oxide synthase in cultured astrocytes of rats.
With immunocytochemistry, we have observed the nuclear localization of neuronal nitric oxide synthase (nNOS) in cultured cerebral cortical astrocytes of rats. During the early six days in the subcultures of these cells, nNOS-immunoreactivity was mainly distributed in the cytoplasm. However, nNOS-immunoreactivity was mainly distributed in the nucleus at day 7, and this nuclear localization lasted about ten hours. Meanwhile, inducible nitric oxide synthase expression was significantly inhibited in these cells. Thereafter, nNOS-immunoreactivity was mainly distributed in the cytoplasm again. By confocal microscopy and western blot analysis, the phenomenon of nNOS nuclear localization was further confirmed; and the activity of nNOS in nuclear protein extracts from astrocytes of day 7-subculture could be detected using electron spin resonance (ESR) technique. These results may represent a new pathway of nitric oxide/nNOS participating in inducible nitric oxide synthase gene transcription regulation.
Yuan
Zhongrui
Z
State Key Laboratory of Natural and Biomimetic Drugs, Health Science Center for Peking University, Beijing, China. zhongruiyuan@hotmail.com
Liu
Baoyi
B
Yuan
Lan
L
Zhang
Ye
Y
Dong
Xiaomin
X
Lu
Jingfen
J
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000201:enzymology*; D015153:Blotting, Western; D002467:Cell Nucleus / Q000201:enzymology*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000201:enzymology; D004578:Electron Spin Resonance Spectroscopy; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000201:enzymology
D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; C496322:Nos1 protein, rat; C496318:Nos2 protein, rat