The University of Southampton
University of Southampton Institutional Repository

Epigenetic regulation of interleukin-8, an inflammatory chemokine, in osteoarthritis

Epigenetic regulation of interleukin-8, an inflammatory chemokine, in osteoarthritis
Epigenetic regulation of interleukin-8, an inflammatory chemokine, in osteoarthritis
Objective

To determine whether altered IL8 methylation status is associated with increased expression of IL8 in human osteoarthritic (OA) chondrocytes.

Methods

IL8 expression levels and the percentage CpG methylation in human chondrocytes were quantified by qRT-PCR and pyrosequencing in OA patients and in non-OA osteoporotic controls. The effect of CpG methylation on IL8 promoter activity was determined using a CpG-free vector; co-transfections with expression vectors encoding nuclear factor-kappa B (NF-?B), AP-1 and C/EBP were subsequently undertaken to analyse for IL8 promoter activity in response to changes in methylation status.

Results

IL8 expression in OA patients was 37-fold higher than in osteoporotic controls. Three CpG sites in the IL8 promoter were significantly demethylated in OA patients. Multiple regression analysis revealed that the degree of methylation of the CpG site located at ?116-bp was the strongest predictor of IL8 expression. In vitro DNA methylation was noted to decrease IL8 promoter basal activity. Furthermore, NF-?B, AP-1 and C/EBP strongly enhanced IL8 promoter activity whilst DNA methylation inhibited the effects of these three transcription factors.

Conclusions

The present study demonstrates the key role of DNA methylation status on the expression of IL8 in human chondrocytes. We demonstrate a quantitative relationship between percentage methylation and gene expression within clinical samples. These studies provide direct evidence linking the activation of IL8, DNA demethylation and the induction of the OA process with important therapeutic implications therein for patients with this debilitating disease.
interlukin-8, chemokine, dna methylation, epigenetics, inflammation, osteoarthritis
1063-4584
1946-1954
Takahashi, A.
03e3dc19-ed43-4c2f-a3a6-2bd09fedd59a
de Andrés, M.C.
54e87e8a-1aa2-4907-a8a0-25d0c15e5e40
Hashimoto, K.
4589dbf6-e5a6-429d-b5cd-c348f88d6c40
Itoi, E.
1ac8819d-7b0b-4f66-90f0-bd41b2806c0e
Oreffo, R.O.C.
ff9fff72-6855-4d0f-bfb2-311d0e8f3778
Takahashi, A.
03e3dc19-ed43-4c2f-a3a6-2bd09fedd59a
de Andrés, M.C.
54e87e8a-1aa2-4907-a8a0-25d0c15e5e40
Hashimoto, K.
4589dbf6-e5a6-429d-b5cd-c348f88d6c40
Itoi, E.
1ac8819d-7b0b-4f66-90f0-bd41b2806c0e
Oreffo, R.O.C.
ff9fff72-6855-4d0f-bfb2-311d0e8f3778

Takahashi, A., de Andrés, M.C., Hashimoto, K., Itoi, E. and Oreffo, R.O.C. (2015) Epigenetic regulation of interleukin-8, an inflammatory chemokine, in osteoarthritis. Osteoarthritis and Cartilage, 23 (11), 1946-1954. (doi:10.1016/j.joca.2015.02.168). (PMID:26521741)

Record type: Article

Abstract

Objective

To determine whether altered IL8 methylation status is associated with increased expression of IL8 in human osteoarthritic (OA) chondrocytes.

Methods

IL8 expression levels and the percentage CpG methylation in human chondrocytes were quantified by qRT-PCR and pyrosequencing in OA patients and in non-OA osteoporotic controls. The effect of CpG methylation on IL8 promoter activity was determined using a CpG-free vector; co-transfections with expression vectors encoding nuclear factor-kappa B (NF-?B), AP-1 and C/EBP were subsequently undertaken to analyse for IL8 promoter activity in response to changes in methylation status.

Results

IL8 expression in OA patients was 37-fold higher than in osteoporotic controls. Three CpG sites in the IL8 promoter were significantly demethylated in OA patients. Multiple regression analysis revealed that the degree of methylation of the CpG site located at ?116-bp was the strongest predictor of IL8 expression. In vitro DNA methylation was noted to decrease IL8 promoter basal activity. Furthermore, NF-?B, AP-1 and C/EBP strongly enhanced IL8 promoter activity whilst DNA methylation inhibited the effects of these three transcription factors.

Conclusions

The present study demonstrates the key role of DNA methylation status on the expression of IL8 in human chondrocytes. We demonstrate a quantitative relationship between percentage methylation and gene expression within clinical samples. These studies provide direct evidence linking the activation of IL8, DNA demethylation and the induction of the OA process with important therapeutic implications therein for patients with this debilitating disease.

Text
__userfiles.soton.ac.uk_Users_slb1_mydesktop_1-s2.0-S1063458415002125-main.pdf - Other
Available under License Creative Commons Attribution.
Download (1MB)

More information

Published date: 2015
Keywords: interlukin-8, chemokine, dna methylation, epigenetics, inflammation, osteoarthritis
Organisations: Human Development & Health

Identifiers

Local EPrints ID: 383501
URI: http://eprints.soton.ac.uk/id/eprint/383501
ISSN: 1063-4584
PURE UUID: 620eb2b9-11a3-4c75-822d-d0e5c248ffcc
ORCID for R.O.C. Oreffo: ORCID iD orcid.org/0000-0001-5995-6726

Catalogue record

Date deposited: 17 Nov 2015 12:24
Last modified: 15 Mar 2024 03:04

Export record

Altmetrics

Contributors

Author: A. Takahashi
Author: M.C. de Andrés
Author: K. Hashimoto
Author: E. Itoi
Author: R.O.C. Oreffo ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×