Novel isatin-based hybrids as potential anti-rheumatoid arthritis drug candidates: Synthesis and biological evaluation

Columbianadin ameliorates rheumatoid arthritis by attenuating synoviocyte hyperplasia through targeted vimentin to inhibit the VAV2/Rac-1 signaling pathway

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease pathologically characterized by synovial inflammation. The abnormal activation of synoviocytes seems to accompany the progression of RA. The role and exact molecular mechanism in RA of columbianadin (CBN) which is a natural coumarin is still unclear.

OBJECTIVES

The present research aimed to investigate the effect of vimentin on the abnormal growth characteristics of RA synoviocytes and the targeted regulatory role of CBN.

METHODS

Cell migration and invasion were detected using the wound healing and transwell method. Mechanistically, the direct molecular targets of CBN were screened and identified by activity-based protein profiling. The expression of relevant proteins and mRNA in cells and mouse synovium was detected by western blotting and qRT-PCR. Changes in the degree of paw swelling and body weight of mice were recorded. H&E staining, toluidine blue staining, and micro-CT were used to visualize the degree of pathological damage in the ankle joints of mice. Small interfering RNA and plasmid overexpression of vimentin were used to observe their effects on MH7A cell proliferation, migration, apoptosis, and downstream molecular signaling.

RESULTS

The TNF-α-induced proliferation and migration of MH7A cells could be significantly repressed by CBN (25,50 μM), and the expression of apoptosis and autophagy-associated proteins could be modulated. Furthermore, CBN could directly bind to vimentin and inhibit its expression and function in synoviocytes, thereby ameliorating foot and paw swelling and joint damage in CIA mice. Silencing and overexpression of vimentin might be involved in developing RA synovial hyperplasia and invasive cartilage by activating VAV2 phosphorylation-mediated expression of Rac-1, which affects abnormal growth characteristics, such as synoviocyte invasion and migration.

CONCLUSION

CBN-targeted vimentin restrains the overactivation of RA synoviocytes thereby delaying the pathological process in CIA mice, which provides valuable targets and insights for understanding the pathological mechanisms of RA synovial hyperplasia.

Human embryonic stem cell-derived mesenchymal stromal cells suppress inflammation in mouse models of rheumatoid arthritis and lung fibrosis by regulating T-cell function

BACKGROUND AIMS

Rheumatoid arthritis (RA) is characterized by an overactive immune system, with limited treatment options beyond immunosuppressive drugs or biological response modifiers. Human embryonic stem cell-derived mesenchymal stromal cells (hESC-MSCs) represent a novel alternative, possessing diverse immunomodulatory effects. In this study, we aimed to elucidate the therapeutic effects and underlying mechanisms of hESC-MSCs in treating RA.

METHODS

MSC-like cells were differentiated from hESC (hESC-MSCs) and cultured in vitro. Cell proliferation was assessed using Cell Counting Kit-8 assay and Ki-67 staining. Flow cytometry was used to analyze cell surface markers, T-cell proliferation and immune cell infiltration. The collagen-induced arthritis (CIA) mouse model and bleomycin-induced model of lung fibrosis (BLE) were established and treated with hESC-MSCs intravenously for in vivo assessment. Pathological analyses, reverse transcription-quantitative polymerase chain reaction and Western blotting were conducted to evaluate the efficacy of hESC-MSCs treatment.

RESULTS

Intravenous transplantation of hESC-MSCs effectively reduced inflammation in CIA mice in this study. Furthermore, hESC-MSC administration enhanced regulatory T cell infiltration and activation. Additional findings suggest that hESC-MSCs may reduce lung fibrosis in BLE mouse models, indicating their potential to mitigate complications associated with RA progression. In vitro experiments revealed a significant inhibition of T-cell activation and proliferation during co-culture with hESC-MSCs. In addition, hESC-MSCs demonstrated enhanced proliferative capacity compared with traditional primary MSCs.

CONCLUSIONS

Transplantation of hESC-MSCs represents a promising therapeutic strategy for RA, potentially regulating T-cell proliferation and differentiation.

Novel artesunate and isatin hybrid CT3-1 suppresses collagen-induced arthritis through abrogating dendritic cell chemotaxis-induced by CCR5

BACKGROUND

Chemotaxis and trafficking of dendritic cells (DCs) induced by cytokine receptors are crucial steps in rheumatoid arthritis (RA) pathogenesis. C-C chemokine receptor type 5 (CCR5) plays a key role in DC movement and has been implicated in multitudinous inflammatory and immunology diseases. Thus, targeting CCR5 to suppress DC chemotaxis is considered as a potential strategy for the management of RA.

METHODS

Herein, we first synthesized a new hybrid named CT3-1 which based on artesunate and isatin. Besides, we studied the regulating effectiveness of CT3-1 on bone marrow-derived DCs (BMDCs) and on collagen-induced arthritis (CIA) through RNA-seq analysis, cell function experiments in vitro and mice model in vivo.

RESULTS

The results shown that CT3-1 mainly reduced CCR5 expression of immature BMDCs and importantly inhibited immature BMDC migration induced by CCR5 in vitro, with no or minor influence on other functions of DCs, such as phagocytosis and maturation. In the mouse model, CT3-1 relieved arthritis severity and inhibited CIA development. Furthermore, CT3-1 intervention decreased the expression of CCR5 in DCs and reduced the proportion of DCs in the peripheral blood of CIA mice.

CONCLUSIONS

Our findings suggest that CCR5-induced chemotaxis and trafficking of immature DCs are important in RA. Targeting CCR5 and inhibiting immature DC chemotaxis may provide a novel choice for the treatment of RA and other similar autoimmune diseases. Moreover, we synthesized a new hybrid compound CT3-1 that could inhibit immature DC trafficking and effectively relieve RA by directly reducing the CCR5 expression of immature DCs.

Delivery Strategies, Structural Modification, and Pharmacological Mechanisms of Honokiol: A Comprehensive Review

Honokiol (HK) is a traditional Chinese herbal bioactive compound that originates mainly from the Magnolia species, traditionally used to treat anxiety and stroke, as well as alleviation of flu symptoms. This natural product and its derivatives displayed diverse biological activities, including anticancer, antioxidant, anti-inflammatory, neuroprotective, and antimicrobial activities. However, its poor bioavailability and pharmacological activity require primary consideration in the development of HK-based drugs. Recent innovative HK formulations based on the nanotechnology approach allowed for improvement in both bioavailability and therapeutic efficacy. Chemical derivation and drug combination are also effective strategies to ameliorate the drawbacks of HK. In recent years, studies on HK derivatives and compositions have made great progress in the treatment of cancer, inflammation, bacterial infection, cardiovascular, and cerebrovascular diseases, demonstrating better activity than HK. The objective of this review is an examination of the recent developments in the field of pharmacological activity of HK and its drug-related issues, and approaches to improve its physicochemical and biological properties, including solubility, stability, and bioavailability. Recent patents and the ongoing clinical trials in HK are also summarized.

Exosomes in Action: Unraveling Their Role in Autoimmune Diseases and Exploring Potential Therapeutic Applications

Exosomes are double phospholipid membrane vesicles that are synthesized and secreted by a variety of cells, including T cells, B cells, dendritic cells, immune cells, are extracellular vesicles. Recent studies have revealed that exosomes can play a significant role in under both physiological and pathological conditions. They have been implicated in regulation of inflammatory responses, immune response, angiogenesis, tissue repair, and antioxidant activities, particularly in modulating immunity in autoimmune diseases (AIDs). Moreover, variations in the expression of exosome-related substances, such as miRNA and proteins, may not only offer valuable perspectives for the early warning, and prognostic assessment of various AIDs, but may also serve as novel markers for disease diagnosis. This article examines the impact of exosomes on the development of AIDs and explores their potential for therapeutic application.

CT2-3 induces cell cycle arrest and apoptosis in rheumatoid arthritis fibroblast-like synoviocytes through regulating PI3K/AKT pathway

Rheumatoid arthritis (RA) is a kind of chronic autoimmune disease. The existing therapies encountered several challenges. Therefore, continued novel anti-RA drug discovery remains necessary for RA therapy. Recently, our group reported a novel compound named CT2-3, which could be realized as a hybrid of the natural product magnolol and phthalimide and exhibited anti-lung cancer activity. However, the effect of CT2-3 on RA is unclear. Here, we aim to explore the effect and potential mechanism of CT2-3 on the abnormal functions of RA-fibroblast-like synoviocytes (RA-FLSs). In this study, we identified the important role of the dysregulated cell cycle and apoptosis of RA-FLSs in RA progression. Interestingly, we found that CT2-3 inhibited the proliferation and DNA replication of primary RA-FLSs and immortalized RA-FLSs namely MH7A. In addition, CT2-3 downregulated the mRNA and protein expression of cyclin-dependent kinase 2 (CDK2), cyclin A2, and cyclin B1, resulting in cell cycle arrest of primary RA-FLSs and MH7A cells. Also, CT2-3 downregulated the level of B-cell lymphoma-2 (Bcl-2), and increased the level of Bcl-2 associated X (Bax), contributing to apoptosis of primary RA-FLSs and MH7A cells. Furthermore, differential analyses of RNA-sequencing, Western blot, and network pharmacological analysis confirmed that CT2-3 inhibited phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway of primary RA-FLSs and MH7A cells. In conclusion, CT2-3 induces cell cycle arrest and apoptosis in RA-FLSs through modulating PI3K/AKT pathway, which may serve as a potential lead compound for further novel small molecule anti-RA drug development.

Identification and experimental validation of ferroptosis-related gene SLC2A3 is involved in rheumatoid arthritis

BACKGROUND

Ferroptosis, an iron-dependent manner of lipid peroxidative cell death, has recently been reported to be strongly associated with rheumatoid arthritis (RA). Targeted ferroptosis may be a potential treatment for RA.

METHODS

We combined bioinformatics analysis and machine learning algorithm to screen the characteristic gene of RA. Moreover, we used gene set enrichment analysis (GSEA) to investigate the biological function of feature gene and CIBERSORT algorithm to analyze the correlation between selected hub gene and immune cells. The CellMiner database was used to predict potential drugs for RA. Finally, it was further verified by in vitro cell experiment.

RESULTS

SLC2A3 was identified as an important potential biomarker based on bioinformatics methods and machine learning algorithms. SLC2A3 encodes the predominantly neuronal glucose transporter 3 (GLUT3). GSEA showed that SLC2A3 high-expression group was correlated with metabolic pathways. Immune cell infiltration analysis showed that SLC2A3 was positively correlated with activated mast cell expression. RSL3 is an activator of ferroptosis that binds to and inactivates GPX4, mediating ferroptosis regulated by GPX4. In our experiment, we treated synovial fibroblast-like cells of RA (RA-FLS) with RSL3 (Ferroptosis inducers) and found that RSL3 can downregulate SLC2A3 expression and induce ferroptosis in RA-FLS.

CONCLUSIONS

Our study identifies and validates ferroptosis-related gene SLC2A3 as a potential biomarker for the diagnosis and treatment of RA. It was also found that RSL3 can induce ferroptosis in RA-FLS via lead to the downregulation of SLC2A3.

Akuammiline alkaloid derivatives: divergent synthesis and effect on the proliferation of rheumatoid arthritis fibroblast-like synoviocytes

During the past decades, rheumatoid arthritis had become a serious problem, torturing millions of patients because of unclear pathogenesis and no ideal therapies. Natural products remain an important source of medicines to treat various major diseases such as rheumatoid arthritis (RA) given their excellent biocompatibility and structural diversity. Herein, we have developed a versatile synthetic method for constructing various skeletons of akuammiline alkaloid analogs based on our previous research on the total synthesis of the related indole alkaloids. We have also evaluated the effect of these analogs on the proliferation of RA fibroblast-like synoviocytes (FLSs) in vitro and analyzed the corresponding structure-activity relationship (SAR). Among these analogs, compounds 9 and 17c have demonstrated a promising inhibitory effect on the proliferation of RA-FLSs, with IC₅₀ values of 3.22 ± 0.29 μM and 3.21 ± 0.31 μM, respectively. Our findings provide a solid foundation for future pharmacological studies on akuammiline alkaloid derivatives and inspiration for the development of anti-RA small molecule drugs derived from natural products.

Artemisitene suppresses rheumatoid arthritis progression via modulating METTL3-mediated N6-methyladenosine modification of ICAM2 mRNA in fibroblast-like synoviocytes

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease. We previously revealed that the natural compound artemisitene (ATT) exhibits excellent broad anticancer activities without toxicity on normal tissues. Nevertheless, the effect of ATT on RA is undiscovered. Herein, we aim to study the effect and potential mechanism of ATT on RA management.

METHODS

A collagen-induced arthritis (CIA) mouse model was employed to confirm the anti-RA potential of ATT. Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays, cell cycle and apoptosis analysis, immunofluorescence, migration and invasion assays, quantitative real-time PCR (RT-qPCR), Western blot, RNA-sequencing (RNA-seq) analysis, plasmid construction and lentivirus infection, and methylated RNA immunoprecipitation and chromatin immunoprecipitation assays, were carried out to confirm the effect and potential mechanism of ATT on RA management.

RESULTS

ATT relieved CIA in mice. ATT inhibited proliferation and induced apoptosis of RA-fibroblast-like synoviocytes (FLSs). ATT restrained RA-FLSs migration and invasion via suppressing epithelial-mesenchymal transition. RNA-sequencing analysis and bioinformatics analysis identified intercellular adhesion molecule 2 (ICAM2) as a promoter of RA progression in RA-FLSs. ATT inhibits RA progression by suppressing ICAM2/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/p300 pathway in RA-FLSs. Moreover, ATT inhibited methyltransferase-like 3 (METTL3)-mediated N6-methyladenosine methylation of ICAM2 mRNA in RA-FLSs. Interestingly, p300 directly facilitated METTL3 transcription, which could be restrained by ATT in RA-FLSs. Importantly, METTL3, ICAM2 and p300 expressions in synovium tissues of RA patients were related to clinical characteristics and therapy response.

CONCLUSIONS

We provided strong evidence that ATT has therapeutic potential for RA management by suppressing proliferation, migration and invasion, in addition to inducing apoptosis of RA-FLSs through modulating METTL3/ICAM2/PI3K/AKT/p300 feedback loop, supplying the fundamental basis for the clinical application of ATT in RA therapy. Moreover, METTL3, ICAM2 and p300 might serve as biomarkers for the therapy response of RA patients.