Effects of dexmedetomidine on ADAMTS5 mediated matrix degradation in chondrocytes and expressions of related factors / 西安交通大学学报(医学版)

ABSTRACT

【Objective】 To investigate the effects of dexmedetomidine (DEX) intervention on the expressions of chondrocytes and related factors in vitro and its possible molecular mechanisms. 【Methods】 C28/I2 normal human chondrocyte lines were cultured in vitro, and dexmedetomidine at the concentration of 1 μmol/L was selected to intervene for 24 h and 48 h, respectively. The morphology and cell density of chondrocytes were observed after DEX culture at different time points. Immunofluorescence technique was used to detect the expression levels of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) in chondrocytes in each group. The expression levels of Adamts5, aggrecan (Acan), versican (Vcan), Furin, proprotein convertase subtilisin/kexin type 6 (Pcsk6), collagen type Ⅰ alpha 1 (Col1a1), collagen type Ⅱ alpha 1 (Col2a1), collagen type X alpha 1 (Col10a1), and SRY2 related high mobility group box gene9 (Sox9) were detected by RT-PCR. Adamts5 gene knockout chondrocytes were constructed by lentivirus transfection technology and treated with DEX; RT-PCR was used to detect the effects of DEX on the expression levels of Acan, Vcan, Furin, Pcsk6 and Sox9 after Adamts5 gene knockout. 【Results】 After 24 and 48 h of intervention with 1 μmol/L DEX, the morphology and size of chondrocytes did not change significantly, but the cell density increased slightly. Immunofluorescence assay showed that the expression of ADAMTS5 increased at first and then decreased after DEX treatment for 24 and 48h, respectively (P=0.032). RT-PCR results showed that with the extension of intervention time, the expression of Adamts5 first increased and then decreased. The expression difference between 48 and 24 h after culture was statistically significant (P=0.032). The change trend of Pcsk6 was the same as that of Adamts5, while the change trend of Acan expression was opposite that of Adamts5. Chondrocytes knocked out Adamts5 gene and intervened with DEX for 24 and 48 h. The results of RT-PCR showed that the expression of Pcsk6 decreased while that of Acan increased and the changes were significant. 【Conclusion】 Dexmedetomidine may activate ADAMTS5 zymogen through Pcsk6, thereby promoting proteoglycan degradation in chondrocytes.