Conclusions
RhTSG-6 can attenuate ECM degradation and apoptosis in IL-1b-induced NP cells by inhibiting the p38, JNK and ERK pathways, which may contribute to its potential application in the therapy of IDD.
Methods
Experimental human NP cells were isolated from the patients with idiopathic scoliosis and treated with culture medium containing IL-1b (10 ng/mL) for 24 hours to induce extracellular matrix degradation and apoptosis, simulating an IDD model in vitro. The viability of NP cells was analyzed by the CCK-8 assay. The relevant mRNA and protein levels were measured by RT-qPCR and western blot. The apoptosis of NP cells was determined by flow cytometry analysis and western blot.
Results
Compared with the NP cells without IL-1b treatment, IL-1b caused approximately 70% reduction in the viability of NP cells, while RhTSG-6 partly increased the decrease of IL-1b on cell viabilities. Moreover, treatment with rhTSG-6 considerably attenuated the upregulation of extracellular matrix (ECM)-catabolic factors (MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5), and increased the downregulation of ECM-anabolic factor (collagen II) in NP cells induced by IL-1b, indicating that ECM degradation was suppressed. Furthermore, rhTSG-6 also protected NP cells from IL-1b-induced apoptosis. Mechanically, rhTSG-6 inhibited the activation of members of mitogen-activated protein kinase (MAPK) pathway by blocking the phosphorylation of p38, c-Jun N-terminal kinase (JNK) and ERK in IL-1b-induced NP cells. Conclusions: RhTSG-6 can attenuate ECM degradation and apoptosis in IL-1b-induced NP cells by inhibiting the p38, JNK and ERK pathways, which may contribute to its potential application in the therapy of IDD.