Cyanidin attenuates the high hydrostatic pressure-induced degradation of cellular matrix of nucleus pulposus cell via blocking the Wnt/β-catenin signaling

Purpose: The treatment of intervertebral disc degeneration is limited, cyanidin can protect chondrocytes from degeneration. This research investigated the effect of cyanidin on human nucleus pulposus cells (HNPC) metabolism and its mechanism. Methods: HNPC were treated with cyanidin, XAV-939 (inhibitor of Wnt/beta-catenin signaling) and SKL2001 (activator of Wnt/beta-catenin signaling), and pressurized at 1, 3, and 30 atm. Quantitative real-time PCR and Western blot were used to assess the expressions of matrix metalloproteinase-3 (MMP-3), matrix metalloproteinase-13 (MMP-13), Collagen-II, Aggrecan, Wnt-3a and beta-catenin in treated HNPC. Cell counting kit-8 was used to detect the HNPC cell viability. Radioisotope incorporation method was used to assess the proteoglycan synthesis rate of HNPC. The level of cell matrix was detected by toluidine blue staining. Results: Proper hydrostatic pressure of 3 atm could elevate cell viability, proteoglycan synthesis and the level of cell matrix of HNPC, while high hydrostatic pressure of 30 atm reduced the above effects. Cyanidin and XAV-939 reversed the promoting effect of 30 atm pressure on Wnt/beta-catenin signaling pathway and the inhibiting effect on cell viability, proteoglycan synthesis and the level of cell matrix. Subsequently, SKL2001 further reversed the function of cyanidin on HNPC. Conclusion: Cyanidin attenuated the high hydrostatic pressure-induced degradation of cellular matrix of HNPC via blocking the Wnt/beta-catenin signaling pathway. Our findings in this research provided a basis for in vitro experiment of cyanidin and a theoretical fundament on this disease.