EFFECT OF A TYPE II COLLAGEN FRAGMENT ON CELLS OF THE INTERVERTEBRAL DISC

Abstract

Purpose: Knowledge of factors regulating the turnover, repair, and degeneration of the intervertebral disc (IVD) is lacking. Although type II collagen (CII) fragments accumulate in the degenerative IVD, little is known of how they affect the degenerative process. In this study, the effect of a CII fragment, CII-(245–270), known to be critical in arthritis was investigated on gene expression of proteinases, collagen, and proteoglycan by bovine disc cells to determine its role in matrix turnover.

Methods: Cells isolated from the nucleus pulposus (NP) and annulus fibrosus (AF) of adult bovine tails were cultured in the absence (control) or presence of the fragment. The fragment CII-(245–270) (US Biological, Massachusetts) was dissolved in culture medium to a final concentration of 1& #956;g/ml. PCR was performed and products were visualized by ethidium bromide staining.

Results: Addition of the CII-(245–270) peptide at 1& #956;g/ml to NP and AF cells enhanced expression of genes for MMP-1, cathepsin K, and aggrecan after 48 hours compared with the control. MMP-13 was also upregulated in the NP. In contrast, the effect in the AF was time dependent. Type II collagen was upregulated throughout the culture time in the NP as opposed to the AF where its expression was enhanced only on day 2.

Conclusions: We have shown that the CII-(245–270) peptide can alter gene expression of proteinases, collagen, and proteoglycan in bovine disc cells. The present study reveals the complex interrelationships of gene expression in the disc that accompany fragmentation of type II collagen. This new information suggests that increased levels of these fragments, in degenerated discs, may stimulate disc breakdown but may also attempt to protect the disc, by unknown mechanisms Funding: Other Education Grant Funding Parties: AO foundation, Switzerland