NF-ĸβ upregulates ADAMTS5 expression by direct binding after TNF-α treatment in OUMS-27 chondrosarcoma cell line

OSTF1 knockdown mitigates IL-1β-induced chondrocyte injury via inhibiting the NF-κB signaling pathway

Osteoarthritis (OA) is an age-related joint disease characterized by progressive heterogeneous changes in articular cartilage and subchondral bone. Osteoclast stimulating factor 1 (OSTF1) is a small intracellular protein involved in bone formation and bone resorption. However, to our best knowledge, its role in OA is still unclear. In this study, an OA rat model was established by anterior cruciate ligament transection (ALCT). OSTF1 was increased in the cartilage tissues of OA patients and OA rats. Next, the role of OSTF1 in interleukin-1β (IL-1β)-induced chondrocyte apoptosis, inflammation and extracellular matrix degradation was explored through loss of function assays. Strikingly, OSTF1 knockdown relieved IL-1β-induced chondrocyte apoptosis, with decreased cleaved caspase-3 and cleaved PARP levels. Besides, OSTF1 knockdown restrained IL-1β-induced inflammation and degradation of extracellular matrix of chondrocytes. Subsequently, the molecular mechanism of OSTF1 was explored. Transcriptomic analysis revealed the potential gene network map regulated by OSTF1 knockdown. Some differentially expressed genes (DEGs) were involved in regulating the NF-κB signaling pathway. Furthermore, our results demonstrated that OSTF1 knockdown inhibited IL-1β-activated the NF-κB signaling pathway. Ultimately, we analyzed the potential gene network map regulated by OSTF1 and its downstream NF-κB. Bioinformatics analysis showed that 18 DEGs in OSTF1-silenced chondrocytes overlapped with the NF-κB downstream targets. Collectively, our findings indicate that OSTF1 knockdown mitigates IL-1β-induced chondrocyte injury via inhibiting the NF-κB signaling pathway.

Osthole Suppresses Knee Osteoarthritis Development by Enhancing Autophagy Activated via the AMPK/ULK1 Pathway

Knee osteoarthritis (KOA) is an increasingly prevalent heterogeneous disease characterized by cartilage erosion and inflammation. As the main chemical constituent of Angelicae Pubescentis Radix (APR), an anti-inflammatory herbal medicine, the potential biological effects and underlying mechanism of osthole on chondrocytes and KOA progression remain elusive. In this study, the potential effect and mechanism of osthole on KOA were investigated in vitro and in vivo. We found that osthole inhibited IL-1β-induced apoptosis and cartilage matrix degeneration by activating autophagy in rat chondrocytes. In addition, osthole could activate autophagy through phosphorylation of AMPK/ULK1, and AMPK serves as a positive upstream regulator of ULK1. Furthermore, KOA rats treated with osthole showed phosphorylation of the AMPK/ULK1 pathway and autophagy activation, as well as cartilage protection. Collectively, the AMPK/ULK1 signaling pathway can be activated by osthole to enhance autophagy, thereby suppressing KOA development. Osthole may be a novel and effective therapeutic agent for the clinical treatment of KOA.

IL-33 induces ADAMTS5 expression and cell migration in glioblastoma multiforme

Glioblastoma multiforme (GBM), characterized by a high rate of proliferation and migration capacity, is an incurable brain tumor in adults. Interleukin-33 (IL-33), a member of the IL-1 cytokine superfamily, and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5), a family of zinc dependent metalloproteinases, are known to have essential roles in GBM migration and invasion. Previous studies have separately revealed elevated expressions of IL-33 and ADAMTS5 in GBM; however, the interaction between IL-33 and ADAMTS5 in GBM remains unclear. Here, using publically available GlioVis and GEPIA programs, we showed that mRNA expressions of IL-33 and ADAMTS5 are significantly high in GBM cells, and a positive correlation between IL-33 and ADAMTS5 was also determined in these cells. In parallel with the mRNA data of IL-33 and ADAMTS5, by Western blot analysis, protein levels were found to be elevated in GBM tissues and increased gradually with the disease progression. Primary GBM cells and low-grade glioma cells were then treated with IL-33 to examine its stimulating effect on ADAMTS5 expression. Exposure to IL-33 raised ADAMTS5 protein levels in a dose-dependent manner. Finally, the wound-healing method was performed to confirm the impact of IL-33 on migration in primary GBM cells. IL-33 promoted migration of primary GBM cells three times higher than untreated GBM cells. Thus, the current study suggests for the first time that IL-33 might have a role in playing a part in GBM progression through induction of ADAMTS5 expression and promotion of migration in GBM cells.