[Mechanism of bulleyaconitine A in inhibiting bone destruction of rheumatoid arthritis via Src/PI3K/Akt signaling pathway].

Based on the sarcoma receptor coactivator(Src)/phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt) signaling pathway, the mechanism of action of bulleyaconitine A in the treatment of bone destruction of experimental rheumatoid arthritis(RA) was explored. Firstly, key targets of RA bone destruction were collected through GeneCards, PharmGKB, and OMIM databa-ses. Potential targets of bulleyaconitine A were collected using SwissTargetPrediction and PharmMapper databases. Next, intersection targets were obtained by the Venny 2.1.0 platform. Protein-protein interaction(PPI) network and topology analysis were managed by utilizing the STRING database and Cytoscape 3.8.0. Then, Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were conducted in the DAVID database. AutoDock Vina was applied to predict the molecular docking and binding ability of bulleyaconitine A with key targets. Finally, a receptor activator of nuclear factor-κB(RANKL)-induced osteoclast differentiation model was established in vitro. Quantitative real-time polymerase chain reaction(qRT-PCR) was used to detect the mRNA expression levels of related targets, and immunofluorescence and Western blot were adopted to detect the protein expression level of key targets. It displayed that there was a total of 29 drug-disease targets, and Src was the core target of bulleyaconitine A in anti-RA bone destruction. Furthermore, KEGG enrichment analysis revealed that bulleyaconitine A may exert an anti-RA bone destruction effect by regulating the Src/PI3K/Akt signaling pathway. The molecular docking results showed that bulleyaconitine A had better bin-ding ability with Src, phosphatidylinositol-4,5-diphosphate 3-kinase(PIK3CA), and Akt1. The result of the experiment indicated that bulleyaconitine A not only dose-dependently inhibited the mRNA expression levels of osteoclast differentiation-related genes cathepsin K(CTSK) and matrix metalloproteinase-9(MMP-9)(P<0.01), but also significantly reduced the expression of p-c-Src, PI3K, as well as p-Akt in vitro osteoclasts(P<0.01). In summary, bulleyaconitine A may inhibit RA bone destruction by regulating the Src/PI3K/Akt signaling pathway. This study provides experimental support for the treatment of RA bone destruction with bulleyaconitine A and lays a foundation for the clinical application of bulleyaconitine A.

[Inhibitory effect of artesunate on bone destruction in rheumatoid arthritis: an exploration based on AhR/ARNT/NQO1 signaling pathway].

This study aimed to explore the effect of artesunate(ARS) on bone destruction in rheumatoid arthritis(RA) based on the aryl hydrocarbon receptor(AhR)/AhR nucleart ranslocator(ARNT)/NAD(P)H quinone dehydrogenase 1(NQO1) signaling pathway. Macrophage-colony stimulating factor(M-CSF) and receptor activator of nuclear factor-κB(RANKL) were used to induce the differentiation of primary bone marrow-derived mouse macrophages into osteoclasts. After intervention with ARS(0.2, 0.4, and 0.8 µmol·L~(-1)), the formation and differentiation of osteoclasts were observed by tartrate-resistant acid phosphatase(TRAP) and F-actin staining. The protein expression levels of AhR and NQO1 were detected by Western blot, and their distribution in osteoclasts was observed by immunofluorescence localization. Simultaneously, the collagen induced arthritis(CIA) rat model was established using type Ⅱ bovine collagen emulsion and then treated with ARS(7.5, 15, and 30 mg·kg~(-1)) by gavage for 30 days. Following the observation of spinal cord and bone destruction in CIA rats by Masson staining, the expression of AhR and ARNT in rat knee joint tissue was measured by immunohistochemistry and the NQO1 protein expression in the knee joint tissue by Western blot. The results showed that a large number of TRAP-positive cells were present in RANKL-induced rats. Compared with the RANKL-induced group, ARS(0.2, 0.4, and 0.8 µmol·L~(-1)) inhibited the number of TRAP-positive cells in a dose-dependent manner. F-actin staining results showed that the inhibition of F-actin formation was enhanced with the increase in ARS dose. As revealed by Western blot and immunofluorescence assay, ARS significantly promoted the expression of AhR and its transfer to the nucleus, thereby activating the protein expression of downstream ARNT and antioxidant enzyme NQO1. At the same time, the CIA rat model was successfully established. Masson staining revealed serious joint destruction in the model group, manifested by the failed staining of surface cartilage, disordered arrangement of collagen fibers, and unclear boundaries of cartilage and bone. The positive drug and ARS at different doses all improved cartilage and bone destruction to varying degrees, with the best efficacy detected in the high-dose ARS group. According to immunohistochemistry, ARS promoted AhR and ARNT protein expression in knee cartilage and bone of CIA rats and also NQO1 protein expression in rat knee and ankle joint tissues. In conclusion, ARS inhibited osteoclast differentiation by activating the AhR/ARNT/NQO1 signaling pathway, thus alleviating RA.