Faculty Collaboration Database

Expression of a dominant-negative mutant of p21(ras) inhibits induction of nitric oxide synthase and activation of nuclear factor-kappaB in primary astrocytes. J Neurochem 2000 Jun;74(6):2288-95

Date

05/23/2000

Pubmed ID

10820188

DOI

10.1046/j.1471-4159.2000.0742288.x

Scopus ID

2-s2.0-0034025512 (requires institutional sign-in at Scopus site)   91 Citations

Abstract

The present study underlines the importance of p21(ras) in regulating the inducible nitric oxide synthase (iNOS) in primary astrocytes. Bacterial lipopolysaccharides induced the GTP loading of p21(ras), and the expression of a dominant-negative mutant of p21(ras) (Deltap21(ras)) inhibited lipopolysaccharide-induced GTP loading in rat primary astrocytes. To delineate the role of p21(ras) in the induction of iNOS, we examined the effect of Deltap21(ras) on the expression of iNOS and the production of nitric oxide. It is interesting that expression of Deltap21(ras) markedly inhibited the production of nitric oxide and the expression of iNOS in lipopolysaccharide- and proinflammatory cytokine (tumor necrosis factor-alpha, interleukin-1beta; interferon-gamma)-stimulated rat and human primary astrocytes. Inhibition of iNOS promoter-derived chloramphenicol acetyltransferase activity by Deltap21(ras) suggests that p21(ras) is involved in the transcription of iNOS. As activation of nuclear factor-kappaB (NF-kappaB) is necessary for the transcription of iNOS, we examined the effect of Deltap21(ras) on the activation of NF-kappaB. Expression of Deltap21(ras) inhibited the DNA binding as well as the transcriptional activity of NF-kappaB in activated astrocytes, suggesting that Deltap21(ras) inhibits the expression of iNOS by inhibiting the activation of NF-kappaB. These studies also suggest that inhibitors of p21(ras) may be used as therapeutics in nitric oxide- and cytokine-mediated neuroinflammatory diseases.

Author List

Pahan K, Liu X, McKinney MJ, Wood C, Sheikh FG, Raymond JR

Author

John R. Raymond MD President, CEO, Professor in the President department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Astrocytes
Cells, Cultured
Cerebral Cortex
Fetus
Gene Expression Regulation, Enzymologic
Genes, Dominant
Humans
Interferon-gamma
Interleukin-1
Lipopolysaccharides
NF-kappa B
Neuritis
Nitric Oxide Synthase
Nitric Oxide Synthase Type II
Promoter Regions, Genetic
Proto-Oncogene Proteins p21(ras)
RNA, Messenger
Rats
Tumor Necrosis Factor-alpha