Prostaglandin E2 as an immunomodulating factor released in vitro by human glioma cells

Lauro, Giuliana M.; Lorenzo, N. Alcorta; Grossi, Milena; Maleci, Alberto; Guidetti, B

doi:10.1007/bf00688305

Cited by 52 publications

(26 citation statements)

References 24 publications

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“…Preparation of Astrocytoma Cells-Human astrocytoma T67 cells were obtained from explant of III WHO gemistocytic astrocytoma and were characterized in our laboratory, as described previously (9).…”

Section: Methodsmentioning

confidence: 99%

Rapid Inactivation of NOS-I by Lipopolysaccharide Plus Interferon-γ-induced Tyrosine Phosphorylation

Colasanti

Persichini

Cavalieri

et al. 1999

Journal of Biological Chemistry

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Human astrocytoma T67 cells constitutively express a neuronal NO synthase (NOS-I) and, following administration of lipopolysaccharide (LPS) plus interferon-␥ (IFN␥), an inducible NOS isoform (NOS-II). Previous results indicated that a treatment of T67 cells with the combination of LPS plus IFN␥, by affecting NOS-I activity, also inhibited NO production in a very short time. Here, we report that under basal conditions, a NOS-I protein of about 150 kDa was weakly and partially tyrosine-phosphorylated, as verified by immunoprecipitation and Western blotting. Furthermore, LPS plus IFN␥ increased the tyrosine phosphorylation of NOS-I, with a concomitant inhibition of its enzyme activity. The same effect was observed in the presence of vanadate, an inhibitor of phosphotyrosine-specific phosphatases. On the contrary, genistein, an inhibitor of protein-tyrosine kinases, reduced tyrosine phosphorylation of NOS-I, enhancing its enzyme activity. Finally, using reverse transcriptase-polymerase chain reaction, we have observed that a suboptimal induction of NOS-II mRNA expression in T67 cells was enhanced by vanadate (or L-NAME) and inhibited by genistein. Because exogenous NO has been found to suppress NOS-II expression, the decrease of NO production that we have obtained from the inactivation of NOS-I by LPS/IFN␥-induced tyrosine phosphorylation provides the best conditions for NOS-II expression in human astrocytoma T67 cells.

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Section: Methodsmentioning

confidence: 99%

Rapid Inactivation of NOS-I by Lipopolysaccharide Plus Interferon-γ-induced Tyrosine Phosphorylation

Colasanti

Persichini

Cavalieri

et al. 1999

Journal of Biological Chemistry

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Section: Methodsmentioning

confidence: 99%

Bacterial Lipopolysaccharide Plus Interferon-Ɣ Elicit a Very Fast Inhibition of a Ca2+-dependent Nitric-oxide Synthase Activity in Human Astrocytoma Cells

Colasanti¹,

Cavalieri

Persichini³

et al. 1997

Journal of Biological Chemistry

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Previous results indicate that induction of inducible nitric-oxide synthase (iNOS) expression may be kept suppressed by the endogenous NO level as produced by a constitutive NOS (cNOS) enzyme. In cell types possessing both cNOS and iNOS, this may represent an evident paradox. Here, we report that lipopolysaccharide and interferon-␥, which are able to strongly induce iNOS in astrocytoma cells, can rapidly inhibit the NO production generated by the constitutive NOS isoform, thus obtaining the best conditions for iNOS induction and resolving the apparent paradox. In fact, a 30-min treatment of T67 cells with the combination of lipopolysaccharide plus interferon-␥ (MIX) strongly inhibits the cNOS activity, as determined by measuring [ 3 H]citrulline production. In addition, the effect of MIX is also observed by measuring nitrite, the stable breakdown product of NO: a 30-min pretreatment of T67 cells with MIX is able to reduce significantly the N-methyl-D-aspartate-induced nitrite production. Finally, using reverse transcriptasepolymerase chain reaction, we have observed that a 30-min treatment of T67 cells with MIX does not affect expression of mRNA coding for the neuronal NOS-I isoform. These results suggest the novel concept of a possible role of a cNOS isoform in astrocytes as a control function on iNOS induction.

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“…In order to check this possibility, we stimulated two human-established astroglial cell lines, namely T67, derived from a human III WHO gemistocytic astrocytoma, and T70, derived from a human glioblastoma (Lauro et al, 1986), with MBP. Briefly, 5 ϫ 10 5 cells were seeded into T25 tissue culture flasks in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal calf serum (FCS) and 40 g/ml gentamicin.…”

Section: ϩmentioning

confidence: 99%

Myelin basic protein induces heme oxygenase‐1 in human astroglial cells

Businaro

Fabrizi

Caronti

et al. 2001

Glia

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Heme oxygenase-1 (HO-1), also known as heat-shock protein 32 (HSP-32), is induced in many cells by a large variety of stimuli. Its induction in nervous system cells following toxic and oxidative stress was suggested to play a protective role. Its presence was recently detected by immunohistochemical studies at the level of inflammatory lesions of rat experimental autoimmune encephalomyelitis. In the present study, we demonstrate that myelin basic protein (MBP) induces HO-1 in human astroglial cells, as shown by Western blots and RT-PCR. Proteolytic fragments derived from the whole MBP show a different behavior in the HO-1 induction: MBP152-167 was able to produce a light but still significant increase in HO-1 mRNA and protein levels, whereas MBP68-84 was not. The increase in HO-1 production seems to be mediated by a Ca(2+)-dependent mechanism, since MBP addition to astrocytoma cultures induced a strong and immediate increment of [Ca(2+)](i) increase; MBP152-167 elicited a delayed and less pronounced [Ca(2+)](i) increase; no [Ca(2+)](i) changes were induced following cell treatment with MBP68-84. NO pathway involvement in the induction of HO-1 by MBP was ruled out since the expression of the inducible isoform of nitric oxide synthase was not upregulated in treated cells, neither nitrite levels were modified, as demonstrated by Greiss reaction. The possible significance of HO-1 induction following MBP stimulation is discussed.

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Prostaglandin E2 as an immunomodulating factor released in vitro by human glioma cells

Cited by 52 publications

References 24 publications

Rapid Inactivation of NOS-I by Lipopolysaccharide Plus Interferon-γ-induced Tyrosine Phosphorylation

Rapid Inactivation of NOS-I by Lipopolysaccharide Plus Interferon-γ-induced Tyrosine Phosphorylation

Bacterial Lipopolysaccharide Plus Interferon-Ɣ Elicit a Very Fast Inhibition of a Ca2+-dependent Nitric-oxide Synthase Activity in Human Astrocytoma Cells

Myelin basic protein induces heme oxygenase‐1 in human astroglial cells

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