Format

Send to

Choose Destination
Tissue Eng Part A. 2009 Oct;15(10):2825-35. doi: 10.1089/ten.TEA.2008.0663.

ERK1/2 activation induced by inflammatory cytokines compromises effective host tissue integration of engineered cartilage.

Author information

1
Cartilage Biology and Orthopaedics Branch, National Institute of Arthritis, and Musculoskeletal and Skin Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892-8022, USA.

Abstract

OBJECTIVE:

Proinflammatory cytokines are known to provoke degradative signaling cascades that promote extracellular matrix disintegration in articular cartilage. Because integration of the repair tissue into the surrounding native cartilage to produce a mechanically stable interface has a profound impact on the viability and functionality of the restored joint surface, this study examined the effects of proinflammatory cytokines on the properties of tissue-engineered cartilage in the context of integration.

METHODS:

Using an established in vitro cartilage defect model, we examined the integration of chondrocyte-laden agarose constructs into native articular cartilage and the biochemical and biomechanical alterations of these implants upon treatment with interleukin 1-beta (IL1-beta) and tumor necrosis factor-alpha (TNF-alpha). Additionally, we probed extracellular regulated kinase (ERK) signaling involvement in response to proinflammatory cytokines.

RESULTS:

The time-dependent accumulation of extracellular matrix and concomitant increase in Young's modulus observed in the absence of cytokines was significantly decreased upon IL1-beta and TNF-alpha treatment. Push-out test showed the highest interface strength in hybrid cultures maintained without cytokines, which was significantly lowered with IL1-beta and TNF-alpha treatment. Histological characteristics of the interface region are consistent with the biochemical findings. Treatment with an inhibitor of ERK pathway antagonized the deleterious effects caused by both cytokines.

CONCLUSION:

This study is the first to show the functional catastrophic effects of IL1-beta and TNF-alpha on the biochemical, structural, and integrative properties of tissue-engineered cartilage and their significant counteraction by the blockade of ERK signaling pathway. With the discovery of new potential chemical entities, ERK inhibitor may emerge as a new therapeutic approach for functional integration and mechanical integrity of an engineered cartilage to the host tissue and, therefore, enhance long-term viability and functionality of the restored joint surface.

PMID:
19243242
PMCID:
PMC2792059
DOI:
10.1089/ten.TEA.2008.0663
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center