ABSTRACT
AIM: To investigate the effects of the c-Jun N-terminal kinase (JNK1/2) on the inflammation cytokine tumour necrosis factor-alpha (TNF-α)-enhanced production of matrix metalloproteinase-3 (MMP-3) in human dental pulp fibroblast-like cells (HPFs). METHODOLOGY: HPFs were grown from pulp explants from healthy donors. Primary cultures were established by culturing the cells for 20 to 30 days. The experiments with HPFs were performed between passages 3 and 10. The HPFs were incubated in serum-free medium containing TNF-α for 24 h. The medium in each well was prepared in SDS sample buffer and was analysed for MMP-3 by Western blotting. RESULTS: JNK inhibitor SP601245 markedly inhibited the production of MMP-3 in TNF-α-stimulated human dental pulp fibroblasts. MMP-3 production was enhanced by TNF-α in HPFs; silencing JNK1 and JNK2 expression inhibited this activation. cAMP response element-binding protein (CREB) was activated by TNF-α in HPFs; silencing JNK1 and JNK2 expression inhibited this activation. CONCLUSION: The activation of CREB via JNK pathways in the presence of TNF-α occurred with enhancement of MMP-3 production in dental pulp fibroblasts.
