Bone Abstracts

Introduction: Hypertrophy of ligamentum flavum (LF) induces narrowing of spinal canal which develops neurogenic claudication. Several mechanisms of LF hypertrophy have been suggested. Among them inflammatory cytokine play a crucial role in LF hypertrophy by increasing collagen synthesis. Cyclooxygenase-2 (COX-2) pathway shares inflammatory reaction from infection and arthritis. Selective COX-2 inhibitor (COX-2si) might modulates collagen synthesis via suppressing inflammatory pathway. Hence, the current study examined the effect of COX-2si in collagen synthesis of inflammatory cytokine induced LF cells.

Materials and methods: Fibroblast and LF cells were harvested and cultured. Inflammatory cytokines (IL-1, TNF-s) were utilized to stimulate collagen synthesis of LF cells. Then COX-2si was administered to stimulated fibroblasts and LF cells. Collagen synthesis, RT-PCR for COX-2 and various collagens, were performed.

Results: Fibroblasts and LF cells stimulated by inflammatory cytokines showed increase in collagen synthesis in translational and transcriptional level. Stimulated fibroblasts and LF cells with COX-2si demonstrated down-regulation of COX-2, various collagens mRNA, and finally collagen synthesis.

Summary and conclusion: In stimulated fibroblasts and LF cells, COX-2si provided therapeutic mechanism in reducing collagen synthesis. Hence COX-2si might be useful in preventing LF hypertrophy, which opens new therapeutic, preventive measures in symptomatic lumbar spinal stenosis.

Keywords: COX-2, ligamentum flavum, fibroblast, spinal stenosi