Development and characterization of a humanized mouse model of osteoarthritis

Enhancing the Therapeutic Potential of Human Umbilical Cord Mesenchymal Stem Cells for Osteoarthritis: The Role of Platelet-Rich Plasma and Extracellular Vesicles

Osteoarthritis (OA) is a chronic degenerative joint disease. Our previous study demonstrated that extracellular vesicles (EVs) secreted by human umbilical cord mesenchymal stem cells (HUCMSCs), which play a crucial role in regenerative medicine, have therapeutic effects on OA. Additionally, platelet-rich plasma (PRP) has been widely used in musculoskeletal diseases as it promotes wound healing, angiogenesis, and tissue remodeling; however, its efficacy as a stand-alone therapy remains controversial. Therefore, we investigated the therapeutic effects of combining stem cell-derived EVs with PRP in an OA model. HUCMSC-derived EVs treated with PRP were used as the experimental group, whereas HUCMSC-derived EVs cultured with serum-free (SF) or exosome-depleted fetal bovine serum (exo(-)FBS) and PRP served as controls. PRP-treated HUCMSCs maintained their surface antigen characteristics and potential to differentiate into adipocytes, osteoblasts, and chondrocytes. In the OA model, mice treated with HUCMSCs + 5% PRP-derived EVs showed significantly improved motor function compared to controls and were comparable to those treated with HUCMSCs +SF and +exo(-)FBS-derived EVs. Additionally, increased type II collagen and aggrecan and decreased IL-1β expression were observed in cartilage transplanted with various EVs. In conclusion, PRP enhances HUCMSC differentiation, whereas treatment with EVs improves OA outcomes, providing a promising strategy for future clinical applications.

Denosumab ameliorates osteoarthritis by protecting cartilage against degradation and modulating subchondral bone remodeling

Osteoarthritis (OA) is the most prevalent degenerative joint disease worldwide. Effective management for early-stage OA is crucial. Denosumab (DS) has been widely used to treat osteoporosis (OP) and rheumatoid arthritis, but its potential for managing OA remains clear. We assessed the effects of DS on osteoclast activity and chondrocyte apoptosis using tartrate-resistant acid phosphatase (TRAP) assay, quantitative real-time polymerase chain reaction (qRT-PCR), flow cytometry, and TUNEL staining. To assess the impact of DS on the NF-κB pathway, we performed Western blot and immunofluorescence staining. Additionally, we used an OA model to explore the influence of DS on subchondral bone remodeling and cartilage degeneration in vivo. We found that DS hindered receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis by inhibiting the activity of the NF-κB pathway. Besides, DS alleviated reactive oxygen species (ROS)-induced apoptosis in chondrocytes by regulating the expression of genes related to apoptosis. Moreover, we observed an attenuation of OA-related subchondral bone remodeling and cartilage degeneration in vivo. Our findings indicate that DS could effectively suppress osteoclast activity and chondrocyte apoptosis, thereby mitigating OA-related subchondral bone remodeling and cartilage degeneration. These results provide a mechanistic basis for using DS to treat OA.

Cathelicidin-BF regulates the AMPK/SIRT1/NF-κB pathway to ameliorate murine osteoarthritis: In vitro and in vivo studie

Osteoarthritis (OA) is a chronic degenerative disease with a significant prevalence that causes cartilage damage and can lead to disability. The main factors contributing to the onset and progression of OA include inflammation and degeneration of the extracellular matrix. Cathelicidin-BF (BF-30), a natural peptide derived from Bungarus fasciatus venom, has shown multiple important pharmacological effects. However, the action mechanism of BF-30 in OA treatment remains to be elucidated. In this research, X-ray and Safranin O staining were employed to evaluate the imageology and histomorphology differences in the knee joints of mice in vivo. Techniques such as Western blot analysis, RT-qPCR, ELISA, and immunofluorescence staining were applied to examine gene and protein level changes in in vitro experiments. It was found that BF-30 significantly decreased inflammation and enhanced extracellular matrix metabolism. For the first time, it was demonstrated that the positive effects of BF-30 are mediated through the activation of the AMPK/SIRT1/NF-κB pathway. Moreover, when BF-30 was co-administered with Compound C, an AMPK inhibitor, the therapeutic benefits of BF-30 were reversed in both in vivo and in vitro settings. In conclusion, the findings suggest that BF-30 could be a novel therapeutic agent for OA improvement.