Platelet-rich plasma alleviates knee arthritis in rats by inhibiting p65.

Knee osteoarthritis (KOA) is a chronic joint disease characterized by the degeneration of articular cartilage. In this study, we explored the potential therapeutic effects of platelet-rich plasma (PRP) and identified molecular targets for treating KOA. A rat model of KOA was established via the Hulth method and primary knee joint chondrocytes were isolated to evaluate the effects of PRP and shRNA targeting p65 (sh-p65). ELISA was used to detect inflammatory factors, including IL-6, IL-1ß, and TNF-α. HE staining, Safranin O/Fast Green staining and Masson staining were performed to evaluate the morphology of articular cartilage, followed by detection of p65, COL2A1, ACAN, MMP13, and ADAMTS5 expression. The proliferation and apoptosis of primary knee chondrocytes were detected by the CCK-8 assay and TUNEL staining, respectively. Treatment with either PRP or sh-p65 decreased IL-6, IL-1ß, and TNF-α levels in the peripheral blood of KOA rats and chondrocyte culture supernatants, increased COL2A1 and ACAN levels, and decreased MMP13 and ADAMTS5 expression. Furthermore, administration of PRP or sh-p65 exerted protective effects on articular cartilage, enhanced the vitality of knee joint chondrocytes, and inhibited apoptosis. Collectively, PRP inhibited inflammation, promoted chondrocyte proliferation and cartilage matrix secretion, and induced cartilage regeneration by suppressing p65 expression; these effects allow PRP to alleviate KOA progression. P65-based targeted therapy administered in combination with PRP might be a promising strategy for treating KOA.

Germacrone alleviates collagen-induced arthritis via regulating Th1/Th2 balance and NF-κB activation.

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease. The imbalance of T helper type 1 (Th1) and Th2 immune responses contributes to the pathogenesis of this disease. Germacrone is a major bioactive component isolated from Rhizoma Curcuma with multiple bioactivities including anti-inflammation. However, the role and mechanism of germacrone in RA are still unknown. Collagen-induced arthritis (CIA) model was established in male DBA/1 J mice by two immunizations with chicken collagen II. Germacrone was orally administered once per day starting on the day of second immunization for 3 weeks. Arthritis scoring was evaluated every 3 days after second immunization. H&E staining was used for histopathological examination. Levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-4 in serum and synovial tissues of mice were detected by ELISA. Th1 and Th2 cell percentage in mouse spleens was analyzed by flow cytometry. IκB and phosphorylation of NF-κB p65 (p-p65) expression in mouse synovial tissues was assayed by Western blot. We found germacrone treatment significantly reduced arthritis score and inflammation in CIA mice. Levels of TNF-α and IFN-γ were elevated, and IL-4 reduced, in the serum and synovial tissues of CIA mice. Germacrone partially reversed levels of these cytokines. Moreover, germacrone decreased the ratio of Th1 to Th2 cells in mouse spleens. Additionally, germacrone remarkably enhanced IκB expression, but suppressed p-p65 level in CIA mice. Taken together, these results suggest that germacrone alleviated the progression of arthritis that might be related to the regulation of Th1/Th2 balance and inactivation of NF-κB pathway.

Long non-coding RNA highly up-regulated in liver cancer protects tumor necrosis factor-alpha-induced inflammatory injury by down-regulation of microRNA-101 in ATDC5 cells.

BACKGROUND: Osteoarthritis (OA) is a familiar joint degenerative disease. Long non-coding RNAs (lncRNAs) play vital roles in the pathogenesis of OA. Nevertheless, the regulatory impacts of lncRNA highly up-regulated in liver cancer (lncRNA-HULC) on OA remain dimness. The study tried to probe the protective effect of HULC on ATDC5 cells against tumor necrosis factor-alpha (TNF-α)-induced inflammatory injury. METHODS: Relative expression levels of pro-inflammatory cytokines (IL-6, IL-8 and MCP-1) and HULC in OA cartilage tissues and normal cartilage tissues were determined by RT-qPCR. TNF-α induced inflammatory injury model in ATDC5 cells was constructed, and the biological functions of HULC overexpression or suppression in TNF-α-injured ATDC5 cells were assessed. The relevancy between miR-101 and HULC was investigated by utilizing bioinformatics prediction, luciferase reporter assay, RNA pull-down and immunoprecipitation. MiR-101 mimic and inhibitor were transfected into ATDC5 cells, and its regulatory effect on TNF-α-injured ATDC5 cells was examined. Further, NF-κB and MAPK signaling pathways were finally detected by western blot. RESULTS: Enhancement of IL-6, IL-8 and MCP-1 were observated in OA cartilage tissues, but repression of HULC was discovered in OA cartilage tissues. HULC expression was decreased by TNF-α treatment, and overexpressed HULC significantly relieved TNF-α-induced ATDC5 cells injury. Additionally, miR-101 was mutual repressed with HULC, and overexpressed miR-101 reversed the protective effect of HULC in TNF-α-injured ATDC5 cells. Besides, HULC blocked NF-κB and MAPK pathways via repression of miR-101. CONCLUSIONS: The discoveries testified that HULC protected ATDC5 cells against TNF-α-induced inflammatory injury by repression of miR-101.