An alkaloid from Menispermum dauricum, dauricine mediates Ca2+ influx and inhibits NF-κB pathway to protect chondrocytes from IL-1β-induced inflammation and catabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Dauricine (DA) is a natural plant-derived alkaloid extracted from Menispermum dauricum. Menispermum dauricum has been used in traditional Chinese medicine as a classic remedy for rheumatoid arthropathy and is believed to be effective in alleviating swelling and pain in the limbs.

AIM OF THE STUDY

Osteoarthritis (OA) is a classic degenerative disease involving chondrocyte death, and there is still a lack of effective therapeutic agents that can reverse the progression of the disease. Here we explored the therapeutic effects of DA against OA and further explored the mechanism.

MATERIALS AND METHODS

The effect of DA on cell viability was assessed by CCK-8. IL-1β-treated mouse chondrocytes were used as an in vitro model of OA, and apoptosis was detected by flow cytometry. QRT-PCR, western blotting, cell staining, and immunofluorescence were used to detect relevant inflammatory factors and cartilage-specific expression. RNA sequencing was used to identify pertinent signaling pathways. The therapeutic effect of DA was verified by micro-CT, histological analysis and immunohistochemical analysis in a mouse OA model.

RESULTS

DA demonstrated a high safety profile on chondrocytes, significantly reversing the inflammatory response induced by IL-1β, and promoting factors associated with cartilage regeneration. Moreover, DA exhibited a significant protective effect on the knee joints of mice undergoing ACLT-DMM, effectively preventing cartilage degeneration and subchondral bone tissue destruction. These positive therapeutic effects were achieved through the modulation of the NF-κB pathway and the Ca2+ signaling pathway by DA.

CONCLUSION

Being derived from a traditional herb, DA exhibits remarkable therapeutic potential and safety in OA treatment, presenting a promising option for patients dealing with osteoarthritis.

Nanocarrier-based activation of necroptotic cell death potentiates cancer immunotherapy

Even though immunological checkpoint inhibitors have demonstrated a potent anti-tumor effect in clinical practice, the low immunogenicity of the majority of tumors still results in a lower response rate and a higher resistance to mono-immunotherapy. Recent studies revealed that immunogenic cell death (ICD) augments T cell responses against some cancers, thus indicating that this combination therapy may further improve the anti-tumor immunity produced by anti-PD-1/PD-L1. Herein a robust synergetic strategy is reported to integrate the activation of necroptotic cell death and the subsequent using of immune checkpoint inhibitors. Liposomes have good biocompatibility and are widely used as drug carriers. Using liposomes as TNF-α-loaded nanoplatforms achieves in vivo tumor targeting and long-term retention in the tumor microenvironment. Tumor cells treated with TNF-α-loaded liposomes exhibited the hallmarks of ICD including the release of high mobility group box 1 (HMGB1) and lactate dehydrogenase (LDH). Additionally, the tumor cell necrosis caused by TNF-α induces the in situ release of tumor-specific antigens, thus increasing the dendritic cell (DC) activation and T cell infiltration when combined with the checkpoint blockade therapy. Collectively, significant tumor reduction is accomplishable by this synergetic strategy, in which TNF-α-loaded liposomes convert the tumor cell into an endogenous vaccine and improve the anti-tumor immunity of anti-PD-1/PD-L1.

Hyaluronic acid-chitosan nanoparticles encoding CrmA attenuate interleukin-1β induced inflammation in synoviocytes in vitro

Osteoarthritis (OA) is a common degenerative joint disease characterized by inflammation of synoviocytes and degradation of cartilage. In the present study, hyaluronic acid/chitosan (HA/CS) nanoparticles were used as a vehicle for gene therapy of OA, and the cytokine response modifier A (CrmA) pDNA was proposed as the target gene. The HA/CS/pCrmA nanoparticles were prepared and the characteristics of the nanoparticles were examined. The nanoparticles were spherical, and the smallest size was obtained with the HA:CS weight ratio of 1:4. The release analysis exhibited a constant release over 29 days. The pDNA was completely combined with HA/CS nanoparticles and the HA/CS nanoparticles protected pDNA from degradation. Subsequently, rat synoviocytes were transfected with HA/CS/pDNA nanoparticles, and the results demonstrated that the HA/CS nanoparticles were able to improve the transfection capacity of pDNA. The cytotoxicity of the HA/CS/pDNA nanoparticles was additionally detected using a MTS assay to ensure that the HA/CS nanoparticle was a safe carrier. To additionally investigate the effects of HA/CS/pCrmA nanoparticles on synoviocytes in OA, the MMP‑3 and MMP‑13 gene expression levels were detected at the gene and protein expression levels. These results indicated that the HA/CS/pCrmA nanoparticles attenuated interleukin‑1β‑mediated inflammation in synoviocytes. It was concluded that the HA/CS/pCrmA nanoparticles may provide a novel approach to the treatment of OA.