[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.

[Mechanism of aqueous extract of Strychni Semen in improving pain in rats with rheumatoid arthritis based on TLR4/TNF-α/MMP-9 signaling pathway].

This study aims to explore the mechanism of aqueous extract of Strychni Semen(SA) in relieving pain in the rat model of rheumatoid arthritis(RA) via Toll-like receptor 4(TLR4)/tumor necrosis factor-α(TNF-α)/matrix metalloproteinase-9(MMP-9) signaling pathway. Firstly, the main chemical components of Strychni Semen were searched against TCMSP, TCMID, ETCM, and related literature, and the main targets of the chemical components were retrieved from TargetNet and SwissTargetPrediction. The main targets of RA and pain were searched against GeneCards, Online Mendelian Inheritance in Man(OMIM), and Therapeutic Target Database(TTD). Venny 2.1.0 was used to obtain the common targets shared by Strychni Semen, RA, and pain, and STRING and Cytoscape 3.6.1 were used to build the protein-protein interaction network. Then, molecular docking was carried out in AutoDock Vina. Finally, the rat model of type Ⅱ collagen-induced arthritis(CIA) was established. The up-down method and acetone method were employed to examine the mechanical pain threshold and cold pain threshold of rats, and the pain-relieving effect of SA on CIA rats was evaluated comprehensively. Hematoxylin-eosin(HE) staining was employed to evaluate the histopathological changes of joints in CIA rats. The expression levels of key target proteins was determined by immunohistochemistry and Western blot, and the mRNA levels of key targets were determined by real-time fluorescence quantitative polymerase chain reaction(real-time PCR). The results of network prediction showed that Strychni Semen may act on the TLR4/TNF-α/MMP-9 signaling pathway to exert the pain-relieving effect. The results of molecular docking showed that brucine, the main active component of SA, had strong binding ability to TLR4, TNF-α, and MMP-9. The results of animal experiments showed that SA improved the mechanical and cold pain sensitivity(P<0.05, P<0.01) and reduced the joint histopathological score of CIA rats(P<0.01). In addition, medium and high doses of SA down-regulated the protein and mRNA levels of TNF-α, TLR4, and MMP-9(P<0.05,P<0.01). In conclusion, SA alleviated the mechanical pain sensitivity, cold pain sensitivity, and joint histopathological changes in CIA rats by inhibiting the over activation of TLR4/TNF-α/MMP-9 signaling pathway.