Song Fei 1 , 2 , Fan Xuefei3 , Liu Nannan3 , Chen Suhuan3 , Jiang Min2 , Chen Guangyi4 , Chen Wuqi4 , Chen Xiaoyu3 , Zhou Jian1
DOI: DOI:10.19405/j.cnki.issn1000-1492.2024.11.003
abstract:
To investigate the inhibitory effect of curcumin ( Cur) on IL-1β-induced cartilage damage and to study the relationship between the regulatory mechanisms of the DUSP1 /p38 MAPK signalling pathway in the above process . Methods Chondrocytes (C28/I2) and postoperative primary chondrocytes from osteoarthritis pa- tients were divided into control and experimental groups , and the experimental group was treated with different con- centrations of Cur (0 , 10 , 20 , 40 , 60 , 80 μmol/L) after applying the inflammatory induction treatment with IL- 1β(10 μg/L) . The cell proliferation inhibition rate was determined by cell viability assay (CCK-8) , the apoptosis rate was detected by flow cytometry assay . Real-time fluorescence quantitative PCR ( qRT-PCR) , Western blot , and immunofluorescence assay were used to detect type II collagen α1 chain (Collagen Ⅱ ) , matrix metallopeptid- ase 13 (MMP13) , interleukin-1β(IL-1β) , BCL2-related X protein ( Bax) , B lymphocytoma-2 ( Bcl-2) , dual- specificity phosphatase 1 (DUSP1) , p38 mitogen-activated protein kinase ( p38) , and phosphorylated p38 mito- gen-activated protein kinase (p-p38) RNA and protein expression levels . The role of the DUSP1 /p38 MAPK axis in the inhibition of chondrocyte oxidative stress , apoptosis and inflammation by Cur was further validated using DUSP1 interfering RNA and p38 MAPK pathway inhibitor (SB) . Results Cur significantly inhibited the IL-1β-in- duced decrease in chondrocyte viability and significantly reduced the levels of oxidative stress , apoptosis , and in- flammation in chondrocytes; Cur inhibited the expression of MMP13 , IL-1β, Bax , and p-p38 proteins , while the
expression of Collagen II , Bcl-2 , and DUSP1 proteins significantly increased; IL-1βand interfering RNA silencing DUSP1 activated the p38 pathway , while Cur inhibited the activation of the p38 pathway; the use of p38 MAPK pathway inhibitors reduced cellular inflammation . Conclusion Cur attenuates IL-1β-induced oxidative stress , ap- optosis and inflammation in chondrocytes by promoting the expression of DUSP1 protein and inhibiting the activation of p38 MAPK pathway .