骨关节炎(OA)是伴随着软骨细胞过度凋亡的退行性关节软骨致病过程。软骨细胞死亡和OA的发生与自噬减少有关。四面体骨架核酸(TFNA),一种有效的生物活性DNA纳米材料,在各种疾病中发挥抗凋亡和抗氧化作用,导致自噬促进和抑制Wnt/β-catenin信号通路。这里,我们旨在阐明TFNA对OA的治疗作用及其潜在的分子作用机制。合成了TFNA,并通过建立的方法进行了表征。建立白细胞介素(IL)-1β刺激的OA细胞模型并用TFNA处理。通过免疫荧光和流式细胞术检查TFNA的细胞摄取和细胞内活性氧水平。通过细胞计数试剂盒-8(CCK8)测定和流式细胞术记录凋亡细胞死亡。应用透射电子显微镜观察自噬体。BCL2、BAX、caspase-3,Nrf2,HO-1,LC3-II,Beclin1,Atg7,β-连环蛋白,通过免疫荧光和蛋白质印迹检测Lef-1和CyclinD1。在不存在或存在IL-1β的情况下,TFNA成功合成并有效进入软骨细胞,而无需转染剂的帮助。TFNA处理IL-1β诱导的软骨细胞通过激活BCL2/BAX/caspase-3通路减少凋亡,通过调节Nrf2/HO-1信号通路抑制氧化应激,并通过上调LC3-II增强自噬,Beclin1和Atg7.此外,TFNA通过调节Wnt/β-catenin信号通路显示软骨保护作用。总的来说,TFNA可用作OA的治疗性纳米药物。
Osteoarthritis (OA) is a degenerative articular cartilage pathogenic process that is accompanied by excessive chondrocyte apoptosis. The occurrence of chondrocyte death and OA is related to decreased autophagy. Tetrahedral framework nucleic acid (TFNA), a potent bioactive DNA nanomaterial, exerts antiapoptotic and antioxidative effects in various diseases, resulting in autophagy promotion and inhibition of the Wnt/β-catenin-signaling pathway. Here, we aimed to elucidate the therapeutic effects of TFNA on OA and its potential molecular mechanism of action. TFNA was synthesized and characterized by established methods. An interleukin (IL)-1β stimulated OA cell model was established and treated with TFNA. Cellular uptake of TFNA and intracellular reactive oxygen species levels were examined via immunofluorescence and flow cytometry. Apoptotic cell death was documented by the Cell Counting Kit-8 (CCK8) assay and flow cytometry. Transmission electron microscopy was applied to view the autophagosomes. The expression of BCL2, BAX, caspase-3, Nrf2, HO-1, LC3-II, Beclin1, Atg7, β-catenin, Lef-1, and CyclinD1 was detected by immunofluorescence and western blotting. TFNA was successfully synthesized and effectively entered chondrocytes in the absence or presence of IL-1β without the help of transfection agents. TFNA treatment in IL-1β-induced chondrocytes reduced apoptosis by activating the BCL2/BAX/caspase-3 pathway, inhibited oxidative stress by regulating the Nrf2/HO-1-signaling pathway, and enhanced autophagy through upregulated LC3-II, Beclin1, and Atg7. Moreover, TFNA showed chondroprotective effects by regulating the Wnt/β-catenin-signaling pathway. Overall, TFNA may have utility as a therapeutic nanomedicine for OA.