Induction of nitric oxide synthase activity in human astrocytes by interleukin-1β and interferon-γ

Lee, Sunhee C.; Dickson, Dennis W.; Liu, Wei; Brosnan, Celia F.

doi:10.1016/0165-5728(93)90229-r

Cited by 360 publications

(235 citation statements)

References 22 publications

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“…In previous studies we have shown that this antibody reacts strongly with primary cultures of human fetal astrocytes that have been activated by cytokines and that can be shown to release high levels of NO as determined by the Griess reaction, and which by Western blot express a single band of ϳ130 kd. 13 In all lesions from seven different cases of MS, iNOS immunoreactivity was detected within lesioned areas of the brain, with levels that correlated with lesion activity (Table 1 and Figure 2). A case of tropical spastic paraparesis was also studied and showed a moderate degree of iNOS expression (Table 1).…”

Section: Inos Immunoreactivity In Ms Lesionsmentioning

confidence: 87%

“…Normal appearing white matter remote from the lesion, as well as white matter from a normal control brain was nonreactive ( Figure 2I). IL-1, which has been implicated in the induction of iNOS in astrocytes, 13 was also prominently expressed in the acute MS lesions ( Figure 2J). …”

Section: Inos Immunoreactivity In Ms Lesionsmentioning

confidence: 94%

“…Slides were dipped in emulsion and incubated for 14 to 21 days at Ϫ80°C before development and counterstaining with hematoxylin. Primary cultures of human fetal astrocytes activated with cytokines as described 13 were used as positive and negative controls for the antisense and sense probes respectively.…”

Section: Tissuementioning

confidence: 99%

“…We would suggest yet a further involvement of activated T cells as a source of IFN-␥, a cytokine that is known to act synergistically with other activators in the sustained production of high levels of iNOS in many different cell types, including astrocytes. 3,9,10,13,38 From this scenario we predict that the production of the highly toxic downstream products of NO would require interactions between appropriately activated lymphocytes, macrophages/microglia, and astrocytes. Such a complex multiple signaling pathway requiring cooperative activity between multiple cell types is encountered frequently in immune-based diseases where the potential for causing irreversible damage to adjacent uninvolved tissues constitutes a significant risk.…”

Section: Nitrotyrosine Immunoreactivity In Ms Lesionsmentioning

confidence: 99%

“…11,12 However, iNOS can be readily induced in human cell types of varying lineages by a combination of cytokines, and in human fetal astrocytes activation by IL-1 in combination with IFN-␥ forms a potent inducing stimulus. 13 Because IL-1 and IFN-␥ are known to be up-regulated in active MS lesions, these data would suggest that astrocytes should be activated to express iNOS at these sites. Two early reports that examined the expression of NADPH diaphorase staining as an indicator of NO production supported a role for astrocytes as a source of NO in MS lesions, 14,15 however, two subsequent studies using a reverse transcriptase in situ polymerase chain reaction (PCR) hybridization and/or immunocytochemical approach failed to detect iNOS in astrocytes, and instead implicated cells of the monocyte/macrophage lineage.…”

mentioning

confidence: 99%

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Expression of Inducible Nitric Oxide Synthase and Nitrotyrosine in Multiple Sclerosis Lesions

Liu

Zhao

Brosnan

et al. 2001

The American Journal of Pathology

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Nitric oxide generated by the inducible form of nitric oxide synthase (iNOS) may contribute to the pathogenesis of multiple sclerosis (MS). In this report, we studied postmortem tissues of MS patients for the expression of iNOS by in situ hybridization and immunocytochemistry. Immunocytochemistry for nitrotyrosine, a putative footprint for peroxynitrite formation was also performed. In acute MS lesions, intense reactivity for iNOS mRNA and protein was detected in reactive astrocytes throughout the lesion and in adjacent normal appearing white matter. Staining of macrophages, inflammatory cell infiltrates, and endothelial cells was variable from case to case, but generally detected only in acute lesions. In chronic MS lesions reactive astrocytes at the lesion edge were positive for iNOS whereas the lesion center was nonreactive. Normal appearing white matter demonstrated little reactivity, as did tissues from noninflamed control brains. Staining for nitrotyrosine was also detected in acute but not chronic MS lesions, and displayed a diffuse parenchymal, membranous, and perivascular pattern of immunoreactivity. These results support the conclusion that iNOS is induced in multiple cell types in MS lesions and that astrocyte-derived nitric oxide could be important in orchestrating inflammatory responses in MS , particularly at the blood-brain barrier. Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) that is thought to be mediated by an autoimmune attack directed against components of the myelin sheath. MS lesions are characterized by loss of myelin, oligodendrocytes, and axons associated with a mononuclear inflammatory infiltrate and a reactive gliosis. Although the mechanisms that lead to loss of function associated with these events remain poorly understood, the activation of T cells and macrophages that secrete freely diffusable factors has been widely implicated. Included in these factors are the proinflammatory cytokines interleukin (IL)-1, tumor necrosis factor-␣, IL-12, and interferon (IFN)-␥, and reactive oxygen and reactive nitrogen species. All of these factors have been shown to be elevated in active MS lesions, and animal models support a role for them in disease pathogenesis. 1,2 The anti-proliferative and/or cytotoxic effects of nitric oxide (NO) have been associated with the persistent production of high levels of NO that occurs after the activation of the inducible form of nitric oxide synthase (iNOS). 3 The expression of this enzyme in various cell types is known to be transcriptionally regulated and to be activated by a combination of pro-inflammatory signals such as ligands that activate toll-like receptors and/or cytokines such as IL-1, tumor necrosis factor-␣, and interferon-␥ (IFN-␥). 3 NO by itself demonstrates only weak toxic activity, but congeners formed by auto-oxidation such as NO 2⅐ , N 2 O 3 , and S-nitrosothiols enhance its cytotoxic potential. The toxicity of NO is also greatly enhanced when it combines with O 2Ϫ to generate peroxynitrite (ONOOϪ),...

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Section: Inos Immunoreactivity In Ms Lesionsmentioning

confidence: 87%

Section: Inos Immunoreactivity In Ms Lesionsmentioning

confidence: 94%

Section: Tissuementioning

confidence: 99%

Section: Nitrotyrosine Immunoreactivity In Ms Lesionsmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Expression of Inducible Nitric Oxide Synthase and Nitrotyrosine in Multiple Sclerosis Lesions

Liu

Zhao

Brosnan

et al. 2001

The American Journal of Pathology

Self Cite

299

180

View full text Add to dashboard Cite

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Inducible nitric oxide synthase and nitric oxide production by oligodendrocytes

Merrill¹,

Murphy

Mitrovic³

et al. 1997

J. Neurosci. Res.

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It has been previously demonstrated that microglia and astrocytes produce micromolar amounts of nitric oxide in vitro. In this study, we demonstrate that primary rat oligodendrocytes can be stimulated to produce iNOS mRNA as detected by Northern blot and in situ hybridization analysis and a 131-kDa iNOS protein by Western blot analysis; protein was also detected in cells by single- and double-label immunohistochemistry for iNOS and the oligodendrocyte-specific marker CNPase. NO/NOS are produced as a consequence of activation of the gene encoding the inducible nitric oxide synthase as determined by inhibition with actinomycin D and cyclohexamide. The iNOS is functional, leading to calcium/calmodulin-independent NO production in these in vitro cultures.

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Inducible nitric oxide synthase expression in cultures enriched for mature oligodendrocytes is due to microglia

Hewett

Winkler

et al. 1999

J. Neurosci. Res.

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Expression of inducible nitric oxide (NO) synthase (NOS-2) occurs during inflammation in the central nervous system (CNS) and has been linked to demyelination accompanying certain CNS inflammatory diseases. Although astrocytes and microglia are thought to be the major sources of NOS-2 expression in the CNS in vivo, recent evidence suggested that the myelin-producing oligodendrocytes (OLs) themselves can express NOS-2 in culture. Given the potentially important pathological implications of this finding, the purpose of this study was to examine further the expression of NOS-2 by OLs in vitro. After exposure to lipopolysaccharide (LPS) and interferon-gamma (IFNgamma), primary cultures enriched for mature OLs released NO in a time-dependent manner, although the amount varied considerably between different culture preparations. Increased NO production was accompanied by expression of NOS-2 mRNA and protein, as determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. Immunofluorescence analysis revealed that the cell-type expressing NOS-2 in these cultures was galactocerebroside (Gal C)-negative but CD11b-positive. Further, NO production could be attenuated in cultures treated with the microglial/macrophage toxin, leucine methyl ester, prior to LPS/IFNgamma stimulation. Thus, microglia were the source of NOS-2 catalytic activity in these cultures. The present results indicate that LPS and IFNgamma are not effective stimuli for induction of NOS-2 in OLs in primary cell culture.

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Induction of nitric oxide synthase activity in human astrocytes by interleukin-1β and interferon-γ

Cited by 360 publications

References 22 publications

Expression of Inducible Nitric Oxide Synthase and Nitrotyrosine in Multiple Sclerosis Lesions

Expression of Inducible Nitric Oxide Synthase and Nitrotyrosine in Multiple Sclerosis Lesions

Inducible nitric oxide synthase and nitric oxide production by oligodendrocytes

Inducible nitric oxide synthase expression in cultures enriched for mature oligodendrocytes is due to microglia

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