Matrix metalloproteinases in rheumatoid arthritis and osteoarthritis: a state of the art review

Mechanistic Exploration of Smilax glabra Roxb. in Osteoarthritis: Insights from Network Pharmacology, Molecular Docking, and In Vitro Validation

Background: Arthritis, a debilitating joint disease, remains a significant global health burden. This study uncovers the therapeutic potential of the medicinal plant Smilax glabra Roxb. (SGR) in attenuating progression of disease by modulating immune responses. Methods: Through computational approaches, key bioactive compounds in SGR were identified by using freely available databases: TCMSP, TCMID, HIT2.0, HERB, and INPUT in order to elucidate their underlying mechanisms of action. Therapeutic targets for the disease have been retrieved by TTD, GeneCard, and OMIM databases. The STRING database was used to analyze the protein-protein interactions (PPI) of intersecting genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to reveal the functional roles of genes. Mcule was used for molecular docking and binding affinity of compounds and targets were evaluated by DeepPurpose model. ALP activity, cell viability assay, TRAP staining were also performed. Results: A total of 14 active SGR compounds with 59 common targets for arthritis have been identified. These targets have a major role in controlling biological processes such as wound healing, oxygen responses, and chemical stimuli. Molecular docking by Mcule platform demonstrated that quercetin and β-sitosterol showed higher binding energy affinities with TNF, TP53, PTGS2, and JUN as compared to other targets. To explore the complex relationship between compounds and targets, pre-trained Davis and KIBA models were used to predict the affinity values of selected compounds. In MC3T3-E1 cells, ALP activity was significantly increased and bone marrow macrophages (BMM) showed a low number of TRAP-positive cells in SGR-treated cells. Conclusions: Our findings demonstrate that SGR effectively inhibits/regulates inflammatory responses, prevents cartilage degradation, promotes bone regeneration, and can be used as a promising candidate for the development of novel arthritis treatment.

Network medicine based approach for identifying the type 2 diabetes, osteoarthritis and triple negative breast cancer interactome: Finding the hub of hub genes

The increasing prevalence of multi-morbidities, particularly the incidence of breast cancer in diabetic/osteoarthritic patients emphasize on the need for exploring the underlying molecular mechanisms resulting in carcinogenesis. To address this, present study employed a systems biology approach to identify switch genes pivotal to the crosstalk between diseased states resulting in multi-morbid conditions. Hub genes previously reported for type 2 diabetes mellitus (T2DM), osteoarthritis (OA), and triple negative breast cancer (TNBC), were extracted from published literature and fed into an integrated bioinformatics analyses pipeline. Thirty-one hub genes common to all three diseases were identified. Functional enrichment analyses showed these were mainly enriched for immune and metabolism associated terms including advanced glycation end products (AGE) pathways, cancer pathways, particularly breast neoplasm, immune system signalling and adipose tissue. The T2DM-OA-TNBC interactome was subjected to protein-protein interaction network analyses to identify meta hub/clustered genes. These were prioritized and wired into a three disease signalling map presenting the enriched molecular crosstalk on T2DM-OA-TNBC axes to gain insight into the molecular mechanisms underlying disease-disease interactions. Deciphering the molecular bases for the intertwined metabolic and immune states may potentiate the discovery of biomarkers critical for identifying and targeting the immuno-metabolic origin of disease.

PH-sensitive BSA-modified resveratrol micelles targeting macrophages alleviate symptoms of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease, leading to severe inflammatory infiltration and joint damage, accompanied by a decrease in pH of joint microenvironment. Macrophages play an important role in the pathogenesis of RA, with high expression of bovine serum albumin (BSA) receptors on the surface of macrophages. Resveratrol (Res) has strong anti-inflammatory effects, but its application is limited due to its poor water solubility and low bioavailability. Therefore, we constructed pH-sensitive micelles by encapsulating Res and modifying BSA on the surface of the micelles (BSA-Res@Ms), thereby greatly improving the therapeutic effect of RA. Our research results indicated that BSA-Res@Ms had a smooth and uniform appearance, small particle size, high drug encapsulation efficiency, good stability, and pH-sensitive properties. In vitro, BSA-Res@Ms increased the uptake of Res by RAW264.7 cells, reduced the levels of pro-inflammatory cytokines and cleared excess ROS produced by activated RAW264.7 cells, and inhibited the generation of osteoclasts. In vivo, BSA-Res@Ms could target inflamed joint sites, significantly alleviate joint inflammation symptoms, inhibit activated macrophages, improve synovial hyperplasia and inflammatory cell infiltration, and protect cartilage. BSA-Res@Ms provide a very promising method for the treatment of RA, which can effectively improve the inflammatory manifestations of RA.

(Chemical) Roles of HOCl in Rheumatic Diseases

Chronic rheumatic diseases such as rheumatoid arthritis (RA) are characterized by a dysregulated immune response and persistent inflammation. The large number of neutrophilic granulocytes in the synovial fluid (SF) from RA patients leads to elevated enzyme activities, for example, from myeloperoxidase (MPO) and elastase. Hypochlorous acid (HOCl), as the most important MPO-derived product, is a strong reactive oxygen species (ROS) and known to be involved in the processes of cartilage destruction (particularly regarding the glycosaminoglycans). This review will discuss open questions about the contribution of HOCl in RA in order to improve the understanding of oxidative tissue damaging. First, the (chemical) composition of articular cartilage and SF and the mechanisms of cartilage degradation will be discussed. Afterwards, the products released by neutrophils during inflammation will be summarized and their effects towards the individual, most abundant cartilage compounds (collagen, proteoglycans) and selected cellular components (lipids, DNA) discussed. New developments about neutrophil extracellular traps (NETs) and the use of antioxidants as drugs will be outlined, too. Finally, we will try to estimate the effects induced by these different agents and their contributions in RA.

A Review of Advances in Molecular Imaging of Rheumatoid Arthritis: From In Vitro to Clinic Applications Using Radiolabeled Targeting Vectors with Technetium-99m

Rheumatoid arthritis (RA) is a systemic autoimmune disorder caused by inflammation of cartilaginous diarthrodial joints that destroys joints and cartilage, resulting in synovitis and pannus formation. Timely detection and effective management of RA are pivotal for mitigating inflammatory arthritis consequences, potentially influencing disease progression. Nuclear medicine using radiolabeled targeted vectors presents a promising avenue for RA diagnosis and response to treatment assessment. Radiopharmaceutical such as technetium-99m (99mTc), combined with single photon emission computed tomography (SPECT) combined with CT (SPECT/CT), introduces a more refined diagnostic approach, enhancing accuracy through precise anatomical localization, representing a notable advancement in hybrid molecular imaging for RA evaluation. This comprehensive review discusses existing research, encompassing in vitro, in vivo, and clinical studies to explore the application of 99mTc radiolabeled targeting vectors with SPECT imaging for RA diagnosis. The purpose of this review is to highlight the potential of this strategy to enhance patient outcomes by improving the early detection and management of RA.

Senolytic therapeutics: An emerging treatment modality for osteoarthritis

Osteoarthritis (OA), a chronic joint disease affecting millions of people aged over 65 years, is the main musculoskeletal cause of diminished joint mobility in the elderly. It is characterized by lingering pain and increasing deterioration of articular cartilage. Aging and accumulation of senescent cells (SCs) in the joints are frequently associated with OA. Apoptosis resistance; irreversible cell cycle arrest; increased p16INK4a expression, secretion of senescence-associated secretory phenotype factors, senescence-associated β-galactosidase levels, secretion of extracellular vesicles, and levels of reactive oxygen and reactive nitrogen species; and mitochondrial dysregulation are some common changes in cellular senescence in joint tissues. Development of OA correlates with an increase in the density of SCs in joint tissues. Senescence-associated secretory phenotype has been linked to OA and cartilage breakdown. Senolytics and therapeutic pharmaceuticals are being focused upon for OA management. SCs can be selectively eliminated or killed by senolytics to halt the pathogenesis and progression of OA. Comprehensive understanding of how aging affects joint dysfunction will benefit OA patients. Here, we discuss age-related mechanisms associated with OA pathogenesis and senolytics as an emerging modality in the management of age-related SCs and pathogenesis of OA in preclinical and clinical studies.

Lipid mediators obtained from docosahexaenoic acid by soybean lipoxygenase attenuate RANKL-induced osteoclast differentiation and rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease characterized by persistent inflammation and joint destruction. A lipid mediator (LM, namely, 17S-monohydroxy docosahexaenoic acid, resolvin D5, and protectin DX in a ratio of 3:47:50) produced by soybean lipoxygenase from DHA, exhibits anti-inflammatory activity. In this study, we determined the effect of LM on collagen antibody-induced arthritis (CAIA) in mice and receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation in RAW264.7 cells. LM effectively downregulated the expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K, inhibited osteoclast formation, and suppressed the NF-κB signaling pathway in vitro. In vivo, LM at 10 μg/kg/day significantly decreased paw swelling and inhibited progression of arthritis in CAIA mice. Moreover, proinflammatory cytokine (tumor necrosis factor-α, interleukin (IL)-6, IL-1β, IL-17, and interferon-γ) levels in serum were decreased, whereas IL-10 levels were increased following LM treatment. Furthermore, LM alleviated joint inflammation, cartilage erosion, and bone destruction in the ankles, which may be related to matrix metalloproteinase and Janus kinase (JAK)-signal transducer and activators of transcription (STAT) signaling pathway. Our findings suggest that LM attenuates arthritis severity, restores serum imbalances, and modifies joint damage. Thus, LM represents a promising therapy for relieving RA symptoms.

A Review of Cyclic Phosphatidic Acid and Other Potential Therapeutic Targets for Treating Osteoarthritis

Osteoarthritis (OA), a chronic degenerative joint disease, is the most common form of arthritis. OA occurs when the protective cartilage that cushions the ends of bones gradually breaks down. This leads to the rubbing of bones against each other, resulting in pain and stiffness. Cyclic phosphatidic acid (cPA) shows promise as a treatment for OA. In this article, we review the most recent findings regarding the biological functions of cPA signaling in mammalian systems, specifically in relation to OA. cPA is a naturally occurring phospholipid mediator with unique cyclic phosphate rings at the sn-2 and sn-3 positions in the glycerol backbone. cPA promotes various responses, including cell proliferation, migration, and survival. cPA possesses physiological activities that are distinct from those elicited by lysophosphatidic acid; however, its biochemical origin has rarely been studied. Although there is currently no cure for OA, advances in medical research may lead to new therapies or strategies in the future, and cPA has potential therapeutic applications.

Total Flavonoids of Rhizoma Drynariae Treat Osteoarthritis by Inhibiting Arachidonic Acid Metabolites Through AMPK/NFκB Pathway

Objective

Previous clinical studies have found that total flavonoids of Rhizoma Drynariae (TFRD) have a good therapeutic effect on osteoarthritis (OA), but its therapeutic mechanism needs further research.

Methods

OA rat model was established by Hulth method and was intervened by TFRD. Pathological assessments were conducted to assess the protective effect of TFRD on cartilage. Serum metabolomics and network pharmacology were detected to predict the mechanism of TFRD treating OA. In further experiments, molecular biology experiment was carried out to confirm the predicted mechanisms in vivo and in vitro.

Results

TFRD can effectively reduce chondrocyte apoptosis and cartilage degeneration in OA model rats. Serum metabolomics revealed that the intervention effect may be closely related to arachidonic acid metabolism pathway. Network pharmacologic prediction showed that COX-2 was the key target of TFRD in treating OA, and its mechanism might be related with NFκB, apoptosis, AMPK and arachidonic acid metabolism pathway. In vivo experiments indicated that TFRD can inhibit the abnormal expression of COX-2 mRNA in OA model rats. In the in vitro studies, the expression of COX-2 mRNA and protein increased, AMPK phosphorylation was inhibited, and NFκB signaling pathway was activated in IL-1β-induced chondrocytes, and these changes can be reversed by TFRD. After the activation of AMPK signaling pathway or the block-down of NFκB signaling pathway, the effect of TFRD on COX-2 mRNA expression was significantly weakened.

Conclusion

TFRD can inhibit COX-2-mediated arachidonic acid metabolites, and its mechanism is closely related to AMPK/NFκB pathway, which may be a key mechanism in the treatment of OA.

Medermycin Inhibits TNFα-Promoted Inflammatory Reaction in Human Synovial Fibroblasts

Synovial inflammation plays a crucial role in the destruction of joints and the experience of pain in osteoarthritis (OA). Emerging evidence suggests that certain antibiotic agents and their derivatives possess anti-inflammatory properties. Medermycin (MED) has been identified as a potent antibiotic, specifically active against Gram-positive bacteria. In this study, we aimed to investigate the impact of MED on TNFα-induced inflammatory reactions in a synovial cell line, SW-982, as well as primary human synovial fibroblasts (HSF) using RNA sequencing, rtRT-PCR, ELISA, and western blotting. Through the analysis of differentially expressed genes (DEGs), we identified a total of 1478 significantly upregulated genes in SW-982 cells stimulated with TNFα compared to the vehicle control. Among these upregulated genes, MED treatment led to a reduction in 1167 genes, including those encoding proinflammatory cytokines such as IL1B, IL6, and IL8. Pathway analysis revealed the enrichment of DEGs in the TNF and NFκB signaling pathway, further supporting the involvement of MED in modulating inflammatory responses. Subsequent experiments demonstrated that MED inhibited the expression of IL6 and IL8 at both the mRNA and protein levels in both SW982 cells and HSF. Additionally, MED treatment resulted in a reduction in p65 phosphorylation in both cell types, indicating its inhibitory effect on NFκB activation. Interestingly, MED also inhibited Akt phosphorylation in SW982 cells, but not in HSF. Overall, our findings suggest that MED suppresses TNFα-mediated inflammatory cytokine production and p65 phosphorylation. These results highlight the potential therapeutic value of MED in managing inflammatory conditions in OA. Further investigations utilizing articular chondrocytes and animal models of OA may provide valuable insights into the therapeutic potential of MED for this disease.

Rehmannia alcohol extract inhibits neuropeptide secretion and alleviates osteoarthritis pain through cartilage protection

Osteoarthritis (OA) is a common joint disease characterized by chronic pain, and the perception of pain is closely associated with brain function and neuropeptide regulation. Rehmannia is common plant herb with anti-inflammatory and analgesic properties that is used to treat OA. However, it is unclear whether Rehmannia alleviates OA-related pain via regulation of neuropeptides and brain function. We examined the pain relief regulatory pathway in OA after treatment with Rehmannia by verifying the therapeutic effect of Rehmannia alcohol extract in vivo and vitro and exploring of the potential mechanism underlying the analgesic effect of Rahmanian using functional magnetic resonance imaging and measuring neuropeptide secretion. Our results showed that Rehmannia alcohol extract and the related active ingredient, Rehmannioside D, can delay cartilage degradation and alleviate inflammation in OA rats. The Rehmannia alcohol extract can also relieve OA pain, reduce the secretion of calcitonin gene-related peptide (CGRP) and substance P (SP), and reverse the pathological changes in the cerebral cortex and hippocampus. Our research results demonstrate that Rehmannia alleviates OA pain by protecting cartilage, preventing the stimulation of inflammatory factors on neuropeptide secretion, and influencing the relevant functional areas of the brain.