Iridoid from Eucommia ulmoides Oliv. Exerts Antiarthritis Effects by Inhibiting the JAK2/STAT3 Signaling Pathway In Vivo and In Vitro.

The purpose of this study was to investigate the anti-inflammatory effects of EU-Idd both in vivo and in vitro. In vivo, we used the collagen-induced arthritis (CIA) rat model to investigate the efficacy of EU-Idd on rheumatoid arthritis. Hematoxylin-eosin staining and Safranin O-fast green staining were used to evaluate the pathological status of the ankle joints in CIA rats. Micro-CT scanning was used to investigate bone erosion of the ankle joints. In vitro, the effect of EU-Idd on Th17 cell differentiation was identified by flow cytometry. TRAP staining was used to detect osteoclast cells. HFLS-RA model cells, induced by tumor necrosis factor-α(TNF-α), were used to evaluate the anti-inflammatory effects of EU-Idd while the levels of related inflammatory cytokines and JAK2/STAT3 proteins were detected by RT-qPCR and western blotting. EU-Idd alleviated joint inflammation in CIA rats and exerted protective effects on the ankle joints. EU-Idd also prevented the differentiation of CD4+ T cells into Th17 cells, reduced the number of osteoclasts, and improved the expression levels of bone metabolism-related proteins including OPG and RANKL. Moreover, EU-Idd inhibited the invasion and migration of HFLS-RA cells and downregulated the expression of related inflammatory cytokine genes and the protein expression levels of p-JAK2 and p-STAT3, both in vivo and in vitro. EU-Idd exerts anti-inflammatory and osteoprotective effects by regulating the JAK2/STAT3 pathway in rheumatoid arthritis. These results are beneficial to excavate new pharmaceutical ingredients for rheumatoid arthritis from iridoid.

Potential diagnostic markers and therapeutic targets for rheumatoid arthritis with comorbid depression based on bioinformatics analysis.

Background: Rheumatoid arthritis (RA) and depression are prevalent diseases that have a negative impact on the quality of life and place a significant economic burden on society. There is increasing evidence that the two diseases are closely related, which could make the disease outcomes worse. In this study, we aimed to identify diagnostic markers and analyzed the therapeutic potential of key genes. Methods: We assessed the differentially expressed genes (DEGs) specific for RA and Major depressive disorder (MDD) and used weighted gene co-expression network analysis (WGCNA) to identify co-expressed gene modules by obtaining the Gene expression profile data from Gene Expression Omnibus (GEO) database. By using the STRING database, a protein-protein interaction (PPI) network constructed and identified key genes. We also employed two types of machine learning techniques to derive diagnostic markers, which were assessed for their association with immune cells and potential therapeutic effects. Molecular docking and in vitro experiments were used to validate these analytical results. Results: In total, 48 DEGs were identified in RA with comorbid MDD. The PPI network was combined with WGCNA to identify 26 key genes of RA with comorbid MDD. Machine learning-based methods indicated that RA combined with MDD is likely related to six diagnostic markers: AURKA, BTN3A2, CXCL10, ERAP2, MARCO, and PLA2G7. CXCL10 and MARCO are closely associated with diverse immune cells in RA. However, apart from PLA2G7, the expression levels of the other five genes were associated with the composition of the majority of immune cells in MDD. Molecular docking and in vitro studies have revealed that Aucubin (AU) exerts the therapeutic effect through the downregulation of CXCL10 and BTN3A2 gene expression in PC12 cells. Conclusion: Our study indicates that six diagnostic markers were the basis of the comorbidity mechanism of RA and MDD and may also be potential therapeutic targets. Further mechanistic studies of the pathogenesis and treatment of RA and MDD may be able to identify new targets using these shared pathways.

[Effects of triterpenoid and iridoid of Eucommiae Cortex on collagen-induced arthritis in rats].

The ethyl acetate fraction of ethanol extract of Eucommiae Cortex can effectively inhibit joint inflammation and bone destruction in rats with collagen-induced arthritis(CIA) and has a potential therapeutic effect on rheumatoid arthritis. The triterpenoid(EU-Tid) and iridoid(EU-Idd) of Eucommiae Cortex are derivatives isolated from the ethyl acetate fraction of the ethanol extract of Eucommiae Cortex, and it is not clear whether they have inhibitory effects on joint inflammation and bone erosion in CIA rats. Therefore, based on the CIA model, the effects of EU-Tid, EU-Idd, and their combination(EU-TP) on arthritis in rats were observed, and the material basis of Eucommiae Cortex against arthritis was further clarified. The samples were collected two and four weeks after administration to observe the pathological changes in different stages of arthritis in CIA rats. For the rats in the model control group, with the prolongation of the disease course, the paw volume and arthritis score increased and histopathological lesions aggravated. Compared with the model control group, the drug administration groups showed reduced paw volumes and arthritis scores, and improved joint lesions and cartilage destruction. Additionally, the mRNA expression levels of tumor necrosis factor-α(TNF-α), interleukin-17(IL-17), and interleukin-23(IL-23) in the spleen were down-regulated in the drug administration groups. EU-TP and EU-Tid at concentrations of 160 and 320 µg·mL~(-1) could significantly inhibit the proliferation of human fibroblast-like synoviocytes-RA(HFLS-RA) and nitric oxide(NO) release in the supernatant of RAW264.7 cells induced by lipopolysaccharide(LPS) at the concentration range of 10-80 µg·mL~(-1) in vitro. EU-Idd had no effect on the proliferation of HFLS-RA but could reduce the NO release at concentrations of 40 and 80 µg·mL~(-1). The results indicated that the terpenoids of Eucommiae Cortex had great potential in the treatment of rheumatoid arthritis.

Anti-inflammatory effects of aucubin in cellular and animal models of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. It is known that aucubin (AU) exerts anti-inflammatory activity, but its effects and mechanisms in RA are unclear. This study investigated the anti-inflammatory effects and mechanisms of AU in vivo and in vitro. Human fibroblast-like synoviocyte cells from patients with RA (HFLS-RA), RAW264.7 cells, and MC3T3-E1 cells were used to evaluate the effects of AU on migration, invasion, apoptosis, osteoclast differentiation and production. Immunofluorescence was used to observe nuclear translocation of nuclear factor (NF)-κB, the double luciferase reporter gene method was used to observe NF-κB-p65 activity in AU-treated MC3T3-E1 cells. RT-qPCR was used to measure expression of bone metabolism and inflammation-related genes, and western blot was used to measure bone metabolism and NF-κB protein expression levels. Collagen-induced arthritis (CIA) rat model was used for pharmacodynamics study. Arthritis indexes were measured in the ankle and knee, histological staining and Micro-computed tomography were performed on the ankle joints. Also, inflammatory factor gene expression and the levels of NF-κB-related proteins were detected as in vitro. AU effectively inhibited HFLS-RA cell migration and invasion, promoted apoptosis, and inhibited RAW264.7 cell differentiation into osteoclasts, as well as inhibited NF-κB-p65 activity in MC3T3-E1 cells. Notably, AU significantly reduced the gene expression levels of three cell-related inflammatory factors and bone metabolism factors, effectively inhibited the expression of p-Iκκα ß, p-IκBα, and p-p65 proteins. In vivo, AU relieved joint inflammation, reduced related inflammatory factors, and inhibited NF-κB signaling. It could be used to treat RA-related synovial inflammation and bone destruction through the NF-κB pathway.