毛兰素对IL-1β诱导软骨细胞损伤的保护作用及机制OA

Objective To investigate the protective effect of erianin,a natural extract from Dendrobium,against interleukin-1β(IL-1β)-induced chondrocyte injury and its mechanism.Methods An IL-1β(10 ng/mL)-induced chondrocyte injury model was established to simulate osteoarthritis.The cells were divided into six groups:the control group,cultured in normal medium,and erianin concentration gradient treatment groups(5,10,20,40,and 80 nmol/L).Western blotting was used to detect the expression levels of the inflammatory proteins inducible nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2).Enzyme-linked immunosorbent assay(ELISA)was used to measure the secretion levels of IL-6,tumor necrosis factor-α(TNF-α),prostaglandin E2(PGE2),and nitric oxide(NO)in the cell supernatant.Real-time quantitative PCR(qRT-PCR)was used to analyze the mRNA expression of extracellular matrix metabolism-related genes,including Aggrecan,CollagenⅡ,matrix metalloproteinase 13(MMP13),and a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5).Senescence-associated β-galactosidase(SA-β-gal)staining was used to observe chondrocyte senescence.Immunofluorescence was used to detect the nuclear translocation of nuclear factor-κB(NF-κB)signaling and to analyze the effect of erianin on the NF-κB pathway.Results Within the concentration range of 0-40 nmol/L,erianin showed no obvious toxicity to chondrocytes,and there was no statistically significant difference in chondrocyte viability compared with the control group(all P＞0.05).Therefore,40 nmol/L was selected as the non-toxic concentration.Compared with the control group,IL-1β increased the expression of iNOS and COX-2 in chondrocytes(both P＜0.01),and elevated the levels of PGE2,NO,IL-6,and TNF-α in the supernatant(all P＜0.01).Treatment with 40 nmol/L erianin reversed the expression of the above inflammatory indicators(all P＜0.01).In addition,erianin upregulated the mRNA expression of the extracellular matrix-related genes Aggrecan and CollageⅡ,downregulated the mRNA levels of ADAMTS5 and MMP13,and reduced the proportion of senescent chondrocytes(all P＜0.01).Compared with the IL-1β group,the intensity of NF-κB signaling in the nucleus was significantly weakened after erianin treatment(P＜0.01).Conclusions Erianin effectively alleviates IL-1β-induced inflammatory responses in chondrocytes,reduces extracellular matrix degradation,and attenuates chondrocyte senescence by inhibiting the NF-κB signaling pathway.