IL-21 Receptor Expression in Human Tendinopathy

The pathogenetic mechanisms underlying tendinopathy remain unclear, with much debate as to whether inflammation or degradation has the prominent role. Increasing evidence points toward an early inflammatory infiltrate and associated inflammatory cytokine production in human and animal models of tend...

Full description

Saved in:
Bibliographic Details
Main Authors: Abigail L. Campbell, Nicola C. Smith, James H. Reilly, Shauna C. Kerr, William J. Leach, Umberto G. Fazzi, Brian P. Rooney, George A. C. Murrell, Neal L. Millar
Format: Article
Language:English
Published: Wiley 2014-01-01
Series:Mediators of Inflammation
Online Access:http://dx.doi.org/10.1155/2014/481206
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The pathogenetic mechanisms underlying tendinopathy remain unclear, with much debate as to whether inflammation or degradation has the prominent role. Increasing evidence points toward an early inflammatory infiltrate and associated inflammatory cytokine production in human and animal models of tendon disease. The IL-21/IL-21R axis is a proinflammatory cytokine complex that has been associated with chronic inflammatory diseases including rheumatoid arthritis and inflammatory bowel disease. This project aimed to investigate the role and expression of the cytokine/receptor pair IL-21/IL-21R in human tendinopathy. We found significantly elevated expression of IL-21 receptor message and protein in human tendon samples but found no convincing evidence of the presence of IL-21 at message or protein level. The level of expression of IL-21R message/protein in human tenocytes was significantly upregulated by proinflammatory cytokines (TNFα/IL-1β) in vitro. These findings demonstrate that IL-21R is present in early human tendinopathy mainly expressed by tenocytes and macrophages. Despite a lack of IL-21 expression, these data again suggest that early tendinopathy has an inflammatory/cytokine phenotype, which may provide novel translational targets in the treatment of tendinopathy.
ISSN:0962-9351
1466-1861