IL-10 affects mechanism of intervertebral disc degenerative lesions treated with curcumin by regulating the MAPK signaling pathway

BACKGROUND: The pathogenesis of intervertebral disc degenerative disease (IDDD) remains unclear. While the anti-inflammatory role of IL-10 and the therapeutic potential of curcumin are well recognized, their specific interplay in IDDD remains poorly understood. OBJECTIVES: This study aimed to investigate whether curcumin alleviates IDDD by upregulating IL-10 to suppress MAPK pathway overactivation, thereby exerting anti-inflammatory, anti-apoptotic and pro-anabolic effects on nucleus pulposus cells. METHODS: Nucleus pulposus cells were isolated from patients with IDDD and divided into the following groups: control, varying concentrations of curcumin (10-80) μmol/L, varying concentrations of IL-10 (30-60) mM and a combination group of curcumin and IL-10. Cell proliferation and gene/protein expression were assessed using MTT assay, qPCR, Western blot and ELISA. RESULTS: IL-10 promoted myeloid cell proliferation, upregulated Bax and GAG expression, enhanced collagen II synthesis and ERK1/2 phosphorylation, while downregulating Bcl-2 expression and reducing TNF-α and IL-6 secretion (P<0.05). These effects exhibited a dose-dependent enhancement, with high-dose IL-10 showing significantly greater efficacy compared to the low-dose group (P<0.05). CONCLUSION: IL-10 mitigates disc degeneration by modulating MAPK signaling, reducing inflammation and apoptosis and promoting matrix synthesis in nucleus pulposus cells.