Abstract
Introduction
It is established that Interleukin-1 (IL-1) is expressed by native nucleus pulposus (NP) cells and that disregulated expression is associated with the pathogenesis of IVD degeneration1. IL-1 has been shown to regulate diverse cellular functions within the IVD including those related to catabolic and anabolic activities2. Here the regulatory potential of IL-1 on chemokines that we have previously identified within the human IVD is investigated to address the hypothesis that regulatory interrelationships exist between cytokines and chemokines in the IVD.
Materials and Methods
Primary human NP cells cultured in alginate beads were subjected to 48 hours treatment with IL-1. RNA extracted from these cultures was used in qRT-PCR gene expression analysis to determine the effects of treatment on the expression of selected target chemokine genes. Cell culture supernatants from these cultures were used to determine the effects of treatment on protein production of selected chemokines.
Results
Constitutive expression of CXCL8, CCL2, and CCL7 was observed in alginate bead cultured primary human NP cells. Following 48 hours IL-1 treatment expression of CXCL8 and CCL2 was upregulated (Fig. 1A). Constitutive expression of IL-1 and CCL3 was not observed in alginate cultured primary human NP cells however, expression was induced following 48 hours IL-1 treatment (Fig. 1B).
Conclusion
This study demonstrates the regulatory potential of IL-1 in relation to a number of chemokines some of which have not been shown previously and adds to the body of evidence implicating IL-1 as a key regulator of NP cell biology.
Yes
None declared
Le Maitre et al. Arthritis Research and Therapy 2007;7:R732-R745
Le Maitre et al. Arthritis Research and Therapy 2007;9:R77