Unknown

Dataset Information

0

Oestrogens inhibit interleukin 1beta-mediated nitric oxide synthase expression in articular chondrocytes through nuclear factor-kappa B impairment.


ABSTRACT:

Objectives

To investigate the presence and functionality of oestrogen receptor alpha (ERalpha) in interleukin (IL)1beta-treated rabbit articular chondrocytes in culture, and to determine the mechanisms of 17beta oestradiol (E2) effects on IL1beta-induced inducible nitric oxide synthase (iNOS) expression.

Methods

The presence and functionality of ERalpha were investigated by immunocytochemistry and transient expression of an E2-responsive reporter construct. iNOS expression and production were determined by transient expression of a chimeric iNOS promoter-luciferase construct and protein immunoblotting. Nitric oxide (NO) production was determined by the Griess reaction. DNA-binding activities of nuclear factor-kappaB (NF-kappaB) and activated protein 1 were determined by electrophoretic mobility shift assay (EMSA)-ELISA assays. Nuclear translocation of p65 was studied by immunocytochemistry.

Results

ERalpha was identified in the nucleus of chondrocytes. ERalpha efficiently transactivated a transiently expressed E2-responsive construct. On IL1beta treatment, ERalpha partially diffused from its nuclear localisation into the cytoplasm and its transactivation ability was impaired. Nevertheless, E2, tamoxifen and raloxifene efficiently inhibited IL1beta-induced NO production (-34%, -31% and -36%, respectively). E2 decreased IL1beta-induced iNOS protein expression (-40%). Transient expression of an iNOS promoter construct strongly suggested that iNOS expression was inhibited at the transcriptional level, and EMSA-ELISA assays showed that E2 reduced (-60%) the IL1beta-induced p65 DNA-binding capacity. Finally, the p65 nuclear translocation induced by IL1beta was also strongly decreased by E2.

Conclusions

Our data support a reciprocal antagonism between oestrogens and IL1beta, ultimately resulting in the decrease of cytokine-dependent NO production through transcriptional inhibition of iNOS expression. This effect was associated with selective inhibition of p65 DNA binding and nuclear translocation.

SUBMITTER: Richette P 

PROVIDER: S-EPMC1856006 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature

altmetric image

Publications

Oestrogens inhibit interleukin 1beta-mediated nitric oxide synthase expression in articular chondrocytes through nuclear factor-kappa B impairment.

Richette Pascal P   Dumontier Marie-France MF   Tahiri Khadija K   Widerak Magdalena M   Torre Antoine A   Benallaoua Mourad M   Rannou François F   Corvol Marie-Therese MT   Savouret Jean-François JF  

Annals of the rheumatic diseases 20061026 3


<h4>Objectives</h4>To investigate the presence and functionality of oestrogen receptor alpha (ERalpha) in interleukin (IL)1beta-treated rabbit articular chondrocytes in culture, and to determine the mechanisms of 17beta oestradiol (E2) effects on IL1beta-induced inducible nitric oxide synthase (iNOS) expression.<h4>Methods</h4>The presence and functionality of ERalpha were investigated by immunocytochemistry and transient expression of an E2-responsive reporter construct. iNOS expression and pro  ...[more]

Similar Datasets

| S-EPMC2626196 | biostudies-literature
| S-EPMC3151103 | biostudies-literature
| S-EPMC101760 | biostudies-literature
| S-EPMC1754923 | biostudies-literature
| S-EPMC1222396 | biostudies-other
2017-10-10 | GSE104793 | GEO
| S-EPMC111027 | biostudies-literature
| S-EPMC64850 | biostudies-literature
| S-EPMC1906809 | biostudies-other
| S-EPMC1174950 | biostudies-literature