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Investigating the Expression of Inducible Nitric Oxide Synthase in BV‐2 Microglial Cells: Role of Protein Kinase C in the Expression
Author(s) -
Lawwell Leanne,
Moore D. Blaine,
StevensTruss Regina
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.800.1
Subject(s) - nitric oxide , protein kinase c , nitric oxide synthase , nitrite , chemistry , downregulation and upregulation , microbiology and biotechnology , protein kinase a , biochemistry , kinase , biology , gene , nitrate , organic chemistry
Although the production of high levels of nitric oxide by activated microglial cells has been associated with the Aβ plaques of Alzheimer's disease patients, the exact mechanism by which plaque formation leads to nitric oxide upregulation is not fully understood. This study was done to investigate the molecular mechanisms involved in expression of inducible nitric oxide synthase (iNOS) in BV‐2 cells. BV‐2 cells were treated with several activators believed to affect iNOS expression, specifically PMA, LPS, and γ‐INF, and levels of nitrite (measured using the Griess assay) and iNOS protein (measured by Western analysis) were measured. The role of Protein Kinase C (PKC) in the expression of iNOS was assessed by treating the cells with several PKC inhibitors (Ro‐31‐8220, Go6976, and Go6983) prior to activation. Nitrite and iNOS protein levels were again measured. The data showed a direct correlation between the levels of nitrite and iNOS protein following every treatment. As expected, LPS and γ‐INF increased iNOS expression and corresponding nitrite levels, and additionally were synergistic when used in combination in these cells. PMA showed no activation of iNOS when used alone. However, when used in combination with either LPS or γ‐INF, it produced separate effects. In combination with LPS, LPS activity was reduced; however, with γ‐INF activity was enhanced. Each of the PKC inhibitors differently affected nitrite production and iNOS expression observed with the various treatments, suggesting a role for different PKC isoforms in this action in the cell. These results demonstrate that PKC is involved in the expression of iNOS and that expression is regulated via different cellular pathways.