Abstract: Objective To investigate the effect of high glucose treatment on apoptosis and extracellular matrix (ECM) metabolism in rat nucleus pulposus cells (NPC) and to preliminarily explorepossible underlying mechanisms. Methods NPC were isolated from lumbar spine tissues of maleWistar rats. NPC were divided into 6 groups: Control group, Glucose-treated groups (treated with 5mmol / L, 15 mmol / L, and 25 mmol / L glucose, respectively), high glucose + NAC group (treated with 25 mmol / L glucose and 3 mmol / L antioxidant NAC), high glucose + PDTC group (treated with 25 mmol / L glucose and 10 μmol / L NF-κB pathway inhibitor PDTC) . Cell viability and apoptosis were detected by cell counting kit-8 and flow cytometry, respectively. Fluorescent probes were used to detect intracellular reactive oxygen species ( ROS) levels. Enzyme-linked immunosorbent assay was used to detect IL-1β, IL-6 and TNF-α levels. Western blotting was used to detect relevant protein expression levels. Results Compared to the cell viability and apoptosis in the control group, no significant change was observed in the 5 mmol / L and 15 mmol / L glucose groups, however, a significant decrease in cell viability and a significant increase in apoptosis were seen in the 25 mmol / L glucosegroup (P< 0. 05). The expression levels of Bcl-2-associated X protein (Bax), Caspase-3, MMP-3,MMP-9, MMP-13, A disintegrin and metalloproteinase with thrombospondin 4 (ADAMTS-4), and ADAMTS-5 were significantly decreased in the glucose + NAC and glucose + PDTC groups when compared with those in the 25 mmol / L glucose group, whereas the expression levels of Bcl-2, collagenⅡ (COLⅡ), and aggrecan were significantly increased (P< 0. 05). The intracellular ROS levelsand supernatant levels of the IL-1β, IL-6, and TNF-α in the glucose + NAC and glucose + PDTCgroups were significantly lower when compared with those in the 25 mmol / L glucose group (P< 0. 05). In addition, the cellular levels of p-P65 / P65 and p-IκBα / IκBα were significantly reduced in the glucose + NAC and glucose + PDTC groups when compared with those in the 25 mmol / L glucosegroup (P< 0. 05). Conclusion High glucose treatment promotes NPC apoptosis and ECM degradation by inducing oxidative stress and inflammatory responses, which involves the activation of ROS / NF-κB signaling pathway.

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