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Suppression of nitric oxide formation by tyrosine kinase inhibitors in murine N9 microglia.
Br J Pharmacol. 1998 Mar; 123(5):879-89.BJ

Abstract

1. Microglial cells represent the first line of defence in the brain against infection and damage. However, under conditions of chronic inflammation and neurodegeneration, excessive activation of microglia can contribute to the neurodegenerative process by releasing a cornucopia of potentially cytotoxic substances including the cytotoxic free radical nitric oxide (NO). Although the cell signalling events implicated in NO formation in peripheral macrophages are well defined, events occurring in the phenotypically homologous cerebral microglial cell are not yet fully characterized. 2. In the present study, a cloned murine microglial cell line (N9), stimulated with combined lipopolysaccharide/interferon-gamma (LPS/IFN) incubation, was shown to produce a significant increase in NO formation, as measured by medium nitrite levels, during 8-72 h exposure. 3. LPS/IFN-stimulated NO production was partially inhibited with the nitric oxide synthase (NOS) competitive antagonists; N(omega)-nitro-L-arginine methyl ester and N(omega)-nitro-L-arginine. The ability of the selective inducible (iNOS) inhibitor, aminoguanidine, but not the selective 'neuronal-type' constitutive (cNOS) inhibitor 7-nitroindazole, to inhibit NO production suggested a primary role of iNOS in this response and was confirmed by immunolabelling of activated cells with a specific iNOS antibody. 4. A series of tyrosine kinase inhibitors, herbimycin A, genestein, tyrphostins, AG-126, AG-556 and the tyrosine phosphatase inhibitors, sodium orthovanadate and phenylarsine oxide, significantly attenuated LPS/IFN-mediated NO production. The serine/threonine kinase inhibitors, staursporine (protein kinase C), H-9 (cyclic GMP/cyclic AMP-dependent kinase) or serine/threonine phosphatase inhibitors, cyclosporin A (phosphatase 2B) and okadaic acid (phosphatase 1/2A), reduced NO formation by an apparent cytostatic mechanism, as determined by cellular reduction of 3-(4,5-dimethylthiazol-2-yi)-2,5-diphenyl-tetrazolium bromide (MTT). 5. The present results suggest that the co-ordinated activation of protein tyrosine kinases/phosphatases, and proximal signalling events implicating the interplay between serine-threonine kinases/phosphatases, is intricately linked with inflammatory mediated mechanisms of iNOS activation in microglial cells by regulating the activation of the transcription factor NFkappaB.

Authors+Show Affiliations

Institut de Recherches Servier, Division of Cerebral Pathology, Servier Laboratories, Croissy-sur-Seine, France.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9535016

Citation

Lockhart, B P., et al. "Suppression of Nitric Oxide Formation By Tyrosine Kinase Inhibitors in Murine N9 Microglia." British Journal of Pharmacology, vol. 123, no. 5, 1998, pp. 879-89.
Lockhart BP, Cressey KC, Lepagnol JM. Suppression of nitric oxide formation by tyrosine kinase inhibitors in murine N9 microglia. Br J Pharmacol. 1998;123(5):879-89.
Lockhart, B. P., Cressey, K. C., & Lepagnol, J. M. (1998). Suppression of nitric oxide formation by tyrosine kinase inhibitors in murine N9 microglia. British Journal of Pharmacology, 123(5), 879-89.
Lockhart BP, Cressey KC, Lepagnol JM. Suppression of Nitric Oxide Formation By Tyrosine Kinase Inhibitors in Murine N9 Microglia. Br J Pharmacol. 1998;123(5):879-89. PubMed PMID: 9535016.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Suppression of nitric oxide formation by tyrosine kinase inhibitors in murine N9 microglia. AU - Lockhart,B P, AU - Cressey,K C, AU - Lepagnol,J M, PY - 1998/4/16/pubmed PY - 1998/4/16/medline PY - 1998/4/16/entrez SP - 879 EP - 89 JF - British journal of pharmacology JO - Br J Pharmacol VL - 123 IS - 5 N2 - 1. Microglial cells represent the first line of defence in the brain against infection and damage. However, under conditions of chronic inflammation and neurodegeneration, excessive activation of microglia can contribute to the neurodegenerative process by releasing a cornucopia of potentially cytotoxic substances including the cytotoxic free radical nitric oxide (NO). Although the cell signalling events implicated in NO formation in peripheral macrophages are well defined, events occurring in the phenotypically homologous cerebral microglial cell are not yet fully characterized. 2. In the present study, a cloned murine microglial cell line (N9), stimulated with combined lipopolysaccharide/interferon-gamma (LPS/IFN) incubation, was shown to produce a significant increase in NO formation, as measured by medium nitrite levels, during 8-72 h exposure. 3. LPS/IFN-stimulated NO production was partially inhibited with the nitric oxide synthase (NOS) competitive antagonists; N(omega)-nitro-L-arginine methyl ester and N(omega)-nitro-L-arginine. The ability of the selective inducible (iNOS) inhibitor, aminoguanidine, but not the selective 'neuronal-type' constitutive (cNOS) inhibitor 7-nitroindazole, to inhibit NO production suggested a primary role of iNOS in this response and was confirmed by immunolabelling of activated cells with a specific iNOS antibody. 4. A series of tyrosine kinase inhibitors, herbimycin A, genestein, tyrphostins, AG-126, AG-556 and the tyrosine phosphatase inhibitors, sodium orthovanadate and phenylarsine oxide, significantly attenuated LPS/IFN-mediated NO production. The serine/threonine kinase inhibitors, staursporine (protein kinase C), H-9 (cyclic GMP/cyclic AMP-dependent kinase) or serine/threonine phosphatase inhibitors, cyclosporin A (phosphatase 2B) and okadaic acid (phosphatase 1/2A), reduced NO formation by an apparent cytostatic mechanism, as determined by cellular reduction of 3-(4,5-dimethylthiazol-2-yi)-2,5-diphenyl-tetrazolium bromide (MTT). 5. The present results suggest that the co-ordinated activation of protein tyrosine kinases/phosphatases, and proximal signalling events implicating the interplay between serine-threonine kinases/phosphatases, is intricately linked with inflammatory mediated mechanisms of iNOS activation in microglial cells by regulating the activation of the transcription factor NFkappaB. SN - 0007-1188 UR - https://www.unboundmedicine.com/medline/citation/9535016/Suppression_of_nitric_oxide_formation_by_tyrosine_kinase_inhibitors_in_murine_N9_microglia_ L2 - https://doi.org/10.1038/sj.bjp.0701664 DB - PRIME DP - Unbound Medicine ER -