Matrix metalloproteinases in arthritis: towards precision medicine

Glycosylation-driven interactions of nanoparticles with the extracellular matrix: Implications for inflammation and drug delivery

Cationic nanoparticles (NPs) are emerging as promising carriers for intra-articular drug delivery, particularly for osteoarthritis (OA) where treatment options are limited. However, the clinical translation is challenged by an incomplete understanding of NP interactions within pathological environments. While the influence of the protein coronas on NP behavior has been extensively studied, the specific role of glycoproteins in the extracellular matrix (ECM) remains underexplored, representing a significant knowledge gap. This study investigates how glycosylation-driven interactions between polymeric NPs and enzyme-degraded cartilage biomolecules such as glycosaminoglycans (GAGs) affect NP-ECM aggregate formation and subsequent inflammatory responses. Using an ex vivo model of cartilage degradation induced by catabolic enzymes- hyaluronidase, ADAMTS5 and collagenase- a novel model system was developed to specifically study the behavior of small (<10 nm) and large (∼270 nm) cationic NPs in glycoprotein-enriched environments. Atomic force microscopy and dynamic light scattering revealed distinct mesh-like structures formed by the NP aggregates following different enzymatic treatments, confirming the adsorption of glycosylated fragments onto the particles. While total protein content showed minimal differences between NP samples, smaller NPs demonstrated a prominent association with GAGs such as hyaluronic acid and aggrecan, as demonstrated by circular dichroism. These ECM-NP interactions significantly influenced the immunological response, as evidenced by differential cytokine production from macrophages exposed to the aggregates. Our findings underscore the crucial, yet underappreciated, role of glycoproteins in determining NP behavior in pathological environments. Accounting for glycoprotein interactions into the design of nanomaterial and drug delivery systems could significantly improve therapeutic outcomes by enhanced targeting precision, optimized delivery, and effectively modulating immune responses in OA and other complex diseases.

Rapgef3 modulates macrophage reprogramming and exacerbates synovitis and osteoarthritis under excessive mechanical loading

Evidence indicates that mechanical loading plays an important role in osteoarthritis (OA) progression, while the specific pathological changes of the synovium under excessive mechanical loading are unclear. Results showed that excessive mechanical loading caused pro-inflammation of synovial macrophages, which has been confirmed to exist in OA. High Rapgef3 expression level was found in RNA sequencing of RAW246.7 subjected to 0.5 Hz and 20% cyclic tensile strain. We verified this in the synovium of patients with OA and destabilization of the medial meniscus (DMM)-OA mice. Interestingly, the Rapgef3 content of chondrocytes was very low. Primary chondrocytes treated with Rapgef3 alone did not show metabolic phenotype, but an OA phenotype appeared when treated with Rapgef3-stimulated macrophage culture supernatant. Mechanically, excessive mechanical loading activated p65-nuclear factor κB (NF-κB) pathway through Rapgef3, which promoted the inflammation of macrophage, resulting in severe articular cartilage injury. Intra-articular Rapgef3 knockout reversed synovitis and cartilage degeneration, which might provide a therapeutic target for OA.

A versatile platform based on matrix metalloproteinase-sensitive peptides for novel diagnostic and therapeutic strategies in arthritis

Matrix metalloproteinases (MMPs), coupled with other proteinases and glycanases, can degrade proteoglycans, collagens, and other extracellular matrix (ECM) components in inflammatory and non-inflammatory arthritis, making them important pathogenic molecules and ideal disease indicators and pharmaceutical intervention triggers. For MMP responsiveness, MMP-sensitive peptides (MSPs) are among the most easily synthesized and cost-effective substrates, with free terminal amine and/or carboxyl groups extensively employed in multiple designs. We hereby provide a comprehensive review over the mechanisms and advances in MSP applications for the management of arthritis. These applications include early and precise diagnosis of MMP activity via fluorescence probe technologies; acting as nanodrug carriers to enable on-demand drug release triggered by pathological microenvironments; and facilitating cartilage engineering through MMP-mediated degradation, which promotes cell migration, matrix synthesis, and tissue integration. Specifically, the ultra-sensitive MSP diagnostic probes could significantly advance the early diagnosis and detection of osteoarthritis (OA), while MSP-based drug carriers for rheumatoid arthritis (RA) can intelligently release anti-inflammatory drugs effectively during flare-ups, or even before symptoms manifest. The continuous progress in MSP development may acceleratedly lead to novel management regimens for arthropathy in the future.

Synergistic effects of matrix metalloproteinases on the degradation of collagen in abalone (Haliotis discus hannai)

Endogenous proteases, such as matrix metalloproteinase 1 (MMP-1), play critical roles in abalone muscle softening (myomalacia) via the decomposition of extracellular matrix, particularly collagen. However, the synergistic effect of endogenous proteases in collagen degradation remains unknown. In this study, the catalytic domain of MMP-14, namely rMMP14c, was firstly expressed and evaluated for its performance in abalone collagen degradation. SDS-PAGE and scanning electron microscopy revealed that rMMP14c completely degraded the γ-β-α chains of type I collagen within 8 h and effectively depolymerized collagen fibers. The synergistic effects of MMPs on collagen degradation was further examined. Notably, rMMP14c and rMMP1c showed enhanced effect on type I collagen degradation even within 1 h, along with significant release of collagen fiber-originated water-soluble substances. Therefore, the present study elucidates the potential mechanism underlying abalone muscle softening by which MMPs synergistically degrade collagen, providing practical insights for abalone storage during food processing.

Serum extracellular matrix biomarkers in rheumatoid arthritis, psoriatic arthritis and psoriasis and their association with hand function

Inflammatory arthritis, including rheumatoid arthritis and psoriatic arthritis, is characterized by physical function impairment. This becomes apparent even before arthritis onset, as in psoriasis (PsO). Chronic inflammation triggers an accelerated remodeling of the extracellular matrix (ECM), resulting in released ECM fragments detectable in blood. We aimed to investigate levels of blood-based ECM biomarkers in patients with RA, PsA, PsO, and healthy controls and to explore the association of ECM biomarkers with hand function impairments. Patients with RA (n = 85), PsA (n = 115), PsO (n = 102) and controls (n = 110) were included in this cross-sectional study. ECM catabolic (C1M, C2M, C3M, C4M, PRO-C4, C6M, ARG), formation (PRO-C1, PRO-C3, PRO-C6) and inflammation biomarkers (VICM) were measured in serum from all patients. Objective hand function (fine motor skills (Moberg-Picking-Up Test), isometric grip strength (dynamometer) and patient-perceived hand function (Michigan Hand Questionnaire (MHQ)) were assessed. Patients with RA and PsA received treatment with disease-modifying anti-rheumatic drugs. VICM levels were higher in RA, PsA, and PsO than in controls (p < 0.0001). PsA and PsO showed higher C4M levels compared to controls (p < 0.0001, p < 0.0001), while C6M was lower in patients with RA, PsA and PsO than in controls (p < 0.0001, p < 0.001, p < 0.01). PsO presented with higher levels of C1M compared to controls and to RA (p < 0.001 and p < 0.0001). PRO-C6 correlated negatively with MHQ (ρ = -0.39, p < 0.01) and grip strength (ρ = -0.31, p < 0.05) in PsO, while only weak correlations were observed between biomarkers and hand function scores for RA and PsA patients (all ρ <  ± 0.2-0.3). Patients with RA, PsA, and PsO showed significant alterations in ECM remodeling biomarkers. Especially PsA and PsO had higher levels of inflammatory biomarkers compared to RA and controls, likely due to modulation by treatment. Predominantly in PsO, ECM formation biomarkers were associated with hand function impairments.

Identification of osteoarthritis-associated chondrocyte subpopulations and key gene-regulating drugs based on multi-omics analysis

The mechanism by which chondrocytes respond to mechanical stress in joints significantly affects the balance and function of cartilage. This study aims to characterize osteoarthritis-associated chondrocyte subpopulations and key gene targets for regulatory drugs. To begin, single-cell and transcriptome datasets were obtained from the Gene Expression Omnibus (GEO) database. Cell communication and pseudo-temporal analysis, as well as High-dimensional Weighted Gene Co-expression Network Analysis (hdWGCNA), were conducted on the single-cell data to identify key chondrocyte subtypes and module genes. Subsequently, Consensus Cluster Plus analysis was utilized to identify distinct disease subgroups within the osteoarthritis (OA) training dataset based on the key module genes. Furthermore, differential gene expression analysis and GO/KEGG pathway enrichment analysis were performed on the identified subgroups. To screen for hub genes associated with OA, a combination of 10 machine learning algorithms and 113 algorithm compositions was integrated. Additionally, the immune and pathway scores of the training dataset samples were evaluated using the ESTIMATE, MCP-counter, and ssGSEA algorithms to establish the relationship between the hub genes and immune and pathways. Following this, a network depicting the interaction between the hub genes and transcription factors was constructed based on the Network Analyst database. Moreover, the hub genes were subjected to drug prediction and molecular docking using the RNAactDrug database and AutoDockTools. Finally, real-time fluorescence quantitative PCR (RT-qPCR) was employed to detect the expression of hub genes in the plasma samples collected from osteoarthritis patients and healthy adults. In the OA sample, there is a significant increase in the proportion of prehypertrophic chondrocytes (preHTC), particularly in subgroups 6, 7, and 9. We defined these subgroups as OA_PreHTC subgroups. The OA_PreHTC subgroup exhibits a higher communication intensity with proliferative-related pathways such as ANGPTL and TGF-β. Furthermore, two OA disease subgroups were identified in the training set samples. This led to the identification of 411 differentially expressed genes (DEGs) related to osteoarthritis, 2485 DEGs among subgroups, as well as 238 intersecting genes and 5 hub genes (MMP13, FAM26F, CHI3L1, TAC1, and CKS2). RT-qPCR results indicate significant differences in the expression levels of five hub genes and their related TFs in the clinical blood samples of OA patients compared to the healthy control group (NC). Moreover, these five hub genes are positively associated with inflammatory pathways such as TNF-α, JAK-STAT3, and inflammatory response, while being negatively associated with proliferation pathways like WNT and KRAS. Additionally, the five hub genes are positively associated with neutrophils, activated CD4 T cell, gamma delta T cell, and regulatory T cell, while being negatively associated with CD56dim natural killer cell and Type 17T helper cell. Molecular docking results reveal that CAY10603, Tenulin, T0901317, and Nonactin exhibit high binding activity to CHI3L1, suggesting their potential as therapeutic drugs for OA. The OA_PreHTC subgroups plays a crucial role in the occurrence and development of osteoarthritis (OA). Five hub genes may exert their effects on OA through interactions with PreHTC cells, other chondrocytes, and immune cells, playing a role in inhibiting cell proliferation and stimulating inflammation, thus having high diagnostic value for OA. Additionally, CAY10603, Tenulin, T0901317, and Nonactin have potential therapeutic effects for OA patients.

Metabolic reprogramming of macrophages by a nano-sized opsonization strategy to restore M1/M2 balance for osteoarthritis therapy

Osteoarthritis is a chronic and progressive joint disease accompanied by cartilage degeneration and synovial inflammation. It is associated with an imbalance of synovial macrophage M1/M2 ratio tilting more towards the pro-inflammatory M1 than the anti-inflammatory M2. The M1-macrophages rely on aerobic glycolysis for energy whereas the M2-macrophages derive energy from oxidative phosphorylation. Therefore, inhibiting aerobic glycolysis to induce metabolic reprogramming of macrophages and consequently promote the shift from M1 type to M2 type is a therapeutic strategy for osteoarthritis. Here we developed a macrophage-targeting strategy based on opsonization, using nanoparticles self-assembled to incorporate Chrysin (an anti-inflammatory flavonoid) and V-9302 (an inhibitor of glutamine uptake), and the outer layer modified by immunoglobulin IgG by electrostatic adsorption into IgG/Fe-CV NPs. In vitro studies showed that IgG/Fe-CV NPs effectively target M1 macrophages and inhibit HIF-1α and GLUT-1 essential for aerobic glycolysis and promote polarization from M1 to M2-type macrophages. In vivo, IgG/Fe-CV NPs inhibit inflammation and protect against cartilage damage. The metabolic reprogramming strategy with IgG/Fe-CV NPs to shift macrophage polarization from inflammatory to anti-inflammatory phenotype by inhibiting aerobic glycolysis and glutamine delivery may open up new avenues to treat osteoarthritis.

Tibetan medicine Wuwei Leze powder improves inflammatory mediated metabolic disorders and bone damage in collagen-induced arthritis rats

ETHNOPHARMACOLOGICAL RELEVANCE

Wuwei Leze Powder (WLP, སླྱེ་ཏྱེསལྔ་ཐང།) is a classic Traditional Tibetan medicine formula, which has certain clinical efficacy for rheumatoid arthritis (RA). Nevertheless, the pharmacological effects and potential therapeutic mechanisms of WLP on RA remain unclear.

AIM OF THE STUDY

The present study aimed to investigate the potential pharmacological mechanisms of anti- RA effect of WLP.

MATERIALS AND METHODS

The chemical constituents of WLP were analyzed by UPLC-Q-TOF-MS. A collagen-induced arthritis (CIA) rat model was established to evaluate the swelling, arthritis index. Pathohistological staining and micro-CT were employed to evaluate the therapeutic effects of WLP. Subsequently, serum metabolomic analysis was conducted to elucidate the potential biomarkers and pathways. Finally, an enzyme-linked immunosorbent assay, along with immunofluorescence, RT-qPCR and western blotting, were utilized to verify the anti-RA mechanism of WLP.

RESULTS

A total of 109 chemical constituents from WLP were identified by UPLC-Q-TOF-MS. WLP reduced paw swelling, arthritis scores and organ index in the CIA rat model. Histopathological staining and micro-CT observed WLP possesses both anti-inflammatory and bone-protective properties. Subsequently, serum metabolomics identified 12 potential biomarkers, mainly related to amino acid metabolism and the mTOR signaling pathway. ELISA showed that WLP can regulate abnormal levels of inflammatory cytokines (IL-4, IL-10, TNF-α, IL-6, INF-γ and IL-17). Immunofluorescence demonstrated that WLP could regulate the expression of MMP-1, MMP-9, MMP-13 and RANKL. The effect of WLP on the expression of Wnt3a, Wnt10b, β-catenin, RANKL, OPG, p65 and MMP-9 were verified using RT-qPCR and WB, thereby elucidating the anti-arthritis mechanism of WLP.

CONCLUSION

The possible mechanism underlying the anti-RA of WLP involves the downregulation of the Wnt/RANKL/NF-κB axis, the restoration of abnormal host metabolite levels, the suppression of synovitis responses, and the attenuation of bone erosion. Considering the high variability of plant materials, the present study takes a batch of WLP as an example, which inevitably has limitations.

ECM-binding properties of extracellular vesicles: advanced delivery strategies for therapeutic applications in bone and joint diseases

Extracellular vesicles (EVs) and the extracellular matrix (ECM) are essential in maintaining bone and joint health by facilitating intercellular communication, regulating tissue processes and providing structural support. EVs with a large surface area carry diverse biomolecules to steer the function of cells in their surroundings. To understand how EVs localize to specific sites, we here review the available knowledge on EV surface biomolecules and their interactions with ECM components that are crucial for regulating bone remodeling, cartilage maintenance, and immune responses, playing roles in both tissue homeostasis and pathological conditions, such as arthritis and osteoporosis. More importantly, using analyses of animal experimental data, we illustrate the effect of ECM-based biomaterials (e.g. hydrogels, decellularized matrices, and ECM-mimetic scaffolds) as carriers for EVs toward effective EV delivery in regenerative and immunomodulatory therapies in bone and joint tissue. These biomaterials enable sustained release and targeted delivery of EVs, promoting bone and cartilage regeneration. The insights of this review can be utilized to advance the development of cutting-edge therapies for skeletal tissue regeneration and disease management.

Sequential drug release nanocomposites for synergistic therapy in disease treatment

Time-sequenced drug release, or sequential drug release, represents a pivotal strategy in the synergistic treatment of diseases using nanocomposites. Achieving this requires the rational integration of multiple therapeutic agents within a single nanocomposite, coupled with precise time-controlled release mechanisms. These nanocomposites offer many advantages, including enhanced therapeutic synergy, reduced side effects, attenuated adverse interactions, improved stability and optimized drug utilization. Consequently, research in the field of drug delivery and synergistic therapy has become increasingly important. Currently, sequential drug release research is still in the data collection and basic research stages, and its potential has not yet been fully explored. Although prior studies have explored the sequential drug release strategy in various contexts, a comprehensive review of the underlying mechanisms and their applications in nanocomposites remains scarce. This review categorizes different types of sequential drug release strategies and summarizes diverse nanocomposites, focusing on both physical approaches driven by structural variations and chemical methods based on stimulus-responsive mechanisms. Furthermore, we highlight the major applications of sequential drug release strategies in the treatment of various diseases and detail their therapeutic efficacy. Finally, emerging trends and challenges in advancing sequential drug release strategies based on nanocomposites for disease treatment are also discussed.

Poria cocos: traditional uses, triterpenoid components and their renoprotective pharmacology

Poria cocos and its surface layer of Poria cocos (Schw.) Wolf (Polyporaceae), are used in traditional Chinese medicine for its diuretic and renoprotective effects. Phytochemical studies have shown that lanostane and 3,4-seco-lanostane tetracyclic triterpenoids are the main components of P. cocos and its surface layer. Accumulating evidence shows that triterpenoid components in P. cocos and its surface layer contribute to their renoprotective effect. The surface layer of P. cocos showed a stronger diuretic effect than P. cocos. The ethanol extract of the surface layer and its components improved acute kidney injury, acute kidney injury-to-chronic kidney disease transition and chronic kidney disease such as diabetic kidney disease, nephrotic syndrome and tubulointerstitial nephropathy, and protected against renal fibrosis. It has been elucidated that P. cocos and its surface layer exert a diuretic effect and improve kidney diseases through a variety of molecular mechanisms such as aberrant pathways TGF-β1/Smad, Wnt/β-catenin, IκB/NF-κB and Keap1/Nrf2 signaling as well as the activation of renin-angiotensin system, matrix metalloproteinases, aryl hydrocarbon receptor and endogenous metabolites. These studies further confirm the renoprotective effect of P. cocos and its surface layer and provide a beneficial basis to its clinical use in traditional medicine.

Fibroblast growth factor 7 (FGF7) causes cartilage destruction, subchondral bone remodeling, and the premature growth plate closure in mice

OBJECTIVE

Fibroblast growth factor (FGF) signaling plays a significant role in osteoarthritis (OA) pathogenesis, though the OA-related functions of only a few FGFs have been fully elucidated. This study investigates the specific roles of FGF7 in OA development.

METHODS

FGF7 expression was analyzed in human (n=6) and mouse (n=10) cartilage. Experimental OA was induced by destabilization of the medial meniscus (DMM). The roles of FGF7 were explored using intra-articular (IA) injection of recombinant FGF7 (rFGF7) and whole-body Fgf7 knockout mice (Fgf7-/-). Subchondral bone remodeling and growth plate morphology were assessed micro computed tomography (µCT) and histological analysis.

RESULTS

FGF7 was upregulated in OA cartilage. IA injection of rFGF7 led to OA cartilage destruction (OARSI [Osteoarthritis Research Society International] grade; 0.61 [95% CI 0.00-5.33]), while Fgf7-/- mice showed reduced DMM-induced cartilage erosion (OARSI grade; 1.89 [95% CI 1.08-3.00]) compared to wild-type mice (4.92 [95% CI 3.83-5.33]). These effects were associated with changes in matrix-degrading enzyme expression in chondrocytes. Mice receiving IA injection of rFGF7 (20 μg) exhibited increased subchondral bone thickness (68.01 µm [95% CI 61.55-74.46]) and decreased osteoclastogenesis (tartrate-resistant acid phosphatase positivity; 1.94% [95% CI 1.41-2.47]) compared to controls (38.33 µm [95% CI 33.71-42.96]) and (4.23% [95% CI 3.28-5.19]), respectively. Additionally, rFGF7 treatment caused premature closure of growth plates, whereas Fgf7-/- mice exhibited significantly increased growth plate thickness.

CONCLUSIONS

FGF7 exerts multiple functions in various joint tissues, including promoting cartilage destruction, inducing subchondral bone remodeling (SBP thickening), and triggering premature growth plate closure.

Secretory leukocyte protease inhibitor influences periarticular joint inflammation in B. burgdorferi-infected mice

Lyme disease, caused by Borrelia burgdorferi, is the most common tick-borne infection in the United States. Arthritis is a major clinical manifestation of infection, and synovial tissue damage has been attributed to the excessive pro-inflammatory responses. The secretory leukocyte protease inhibitor (SLPI) promotes tissue repair and exerts anti-inflammatory effects. The role of SLPI in the development of Lyme arthritis in C57BL/6 mice, which can be infected with B. burgdorferi, but only develop mild joint inflammation, was therefore examined. SLPI-deficient C57BL/6 mice challenged with B. burgdorferi had a higher infection load in the tibiotarsal joints and marked periarticular swelling, compared to infected wild type control mice. The ankle joint tissues of B. burgdorferi-infected SLPI-deficient mice contained significantly higher percentages of infiltrating neutrophils and macrophages. B. burgdorferi-infected SLPI-deficient mice also exhibited elevated serum levels of IL-6, neutrophil elastase, and MMP-8. Moreover, using a recently developed BASEHIT (BActerial Selection to Elucidate Host-microbe Interactions in high Throughput) library, we found that SLPI directly interacts with B. burgdorferi. These data demonstrate the importance of SLPI in suppressing periarticular joint inflammation in Lyme disease.

Synergistic therapeutic effect of parecoxib and ilomastat combination in osteoarthritis via inhibition of IL-17/PI3K/AKT/NF-κB activity

BACKGROUND

Osteoarthritis is a degenerative disease, and current drug treatment is to give nonsteroidal anti-inflammatory drugs to relieve symptoms. The anti-inflammatory ability of parecoxib and ilomastat has been confirmed, but the synergistic effect of combined administration in osteoarthritis has not been clear.

METHODS

Mouse primary chondrocytes stimulated with IL-1β were cultured. The expression levels of inflammatory cytokines and matrix metalloproteinases were investigated by western blotting, quantitative real-time polymerase chain reaction and ELISA. The effects of parecoxib and ilomastat on chondrocyte apoptosis were evaluated by flow cytometry. In addition, the rat model of osteoarthritis was established by meniscal instability, and the morphological changes of cartilage and the expression levels of related molecules were monitored using Safranin O-Fast green and immunohistochemical staining after intra-articular injection of parecoxib, ilomastat, and the combination of the two.

RESULTS

In vitro experiments showed that the combined administration of parecoxib and ilomastat more effectively inhibited the expression of proinflammatory factors and matrix metalloproteinases compared with single drug administration. The combined drug treatment could more effectively inhibit IL-1β-induced chondrocyte apoptosis. The combined drug treatment alleviated the progression of osteoarthritis by inhibiting the IL-17/PI3K/AKT/NF-κB pathway. In addition, in vivo experiments showed that the combined administration could improve the further deterioration of the osteoarthritis rat model.

CONCLUSIONS

The combined administration of parecoxib and ilomastat to inhibit IL-17/PI3K/AKT/NF-κB transduction is beneficial to reduce the infiltration of inflammatory factors and matrix metalloproteinases in osteoarthritis.

The regulatory role of BMP9 on lipopolysaccharide-induced matrix metalloproteinases in human stem cells from the apical papilla

OBJECTIVE

The aim of this study was to investigate changes in the expression of members of the matrix metalloproteinases (MMPs) family in response to lipopolysaccharide (LPS) stimulation and to investigate the regulatory effects of BMP9 on MMPs.

DESIGN

The extracted human stem cells from the apical papilla (hSCAPs) were identified by flow cytometry, Alizarin Red staining, Oil Red O staining, and alkaline phosphatase staining. The appropriate LPS concentration for inducing inflammation in hSCAPs was determined using real-time quantitative PCR (RT-qPCR) and Cell Counting Kit-8 (CCK-8) assays. MMP expression in LPS-stimulated hSCAPs was evaluated by RT-qPCR. BMP9 was overexpressed in hSCAPs via recombinant adenovirus, and its effects on MMP regulation were assessed using RT-qPCR, Western blotting, and ELISA. All experiments were conducted in vitro. Data were analyzed by one-way ANOVA followed by Tukey's post-hoc comparison, with p < 0.05 considered significant.

RESULTS

The results showed that on the 3rd and 5th day after LPS stimulation, the expression of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-12, and MMP-13 in hSCAPs was significantly upregulated. On the 7th day after LPS induction, the expression of MMP-3, MMP-8, MMP-9 and MMP-13 in hSCAPs was significantly increased. When BMP9 was overexpressed in hSCAPs, the elevated MMPs were inhibited to varying degrees.

CONCLUSIONS

In the LPS-induced inflammatory environment, certain MMPs are elevated in hSCAP, with MMP-13 being the most significant. Overexpression of BMP9 can significantly inhibit elevated MMPs, suggesting that BMP9 may provide new insights and targets for the treatment of periapical periodontitis.

RECK as a Potential Crucial Molecule for the Targeted Treatment of Sepsis

Reversion inducing cysteine rich protein with kazal motifs (RECK), a Kazal motif-containing protein, regulates pro-inflammatory cytokines production, migration of inflammatory cells, vascular endothelial growth factor (VEGF) and Wnt pathways and plays critical roles in septic inflammatory storms and vascular endothelial dysfunction. Recently, RECK has been defined as the negative regulator of adisintegrin and metalloproteinases (ADAMs) and matrix metalloproteinases (MMPs), which are both membrane "molecular scissors" and aggravate the poor prognosis of sepsis. To better understand the roles of RECK and the related mechanisms, we make here a systematic and in-depth review of RECK. We first summarize the findings on structural characteristics of RECK protein and the regulation at the transcription, post-transcription, or protein level of RECK. Then, we discuss the roles of RECK in inflammation, infection, and vascular injury by focusing on the RECK function on ADAMs and MMPs, as well as the pathways of VEGF, WNT, angiopoietin, and notch signaling. In conclusion, RECK participation as a guardian in the development of sepsis provides insight into the strategies of precisely intervening in RECK dysregulationfor the treatment of sepsis.

An overview of matrix metalloproteinase-12 in multiple disease conditions, potential selective inhibitors, and drug designing strategies

Matrix metalloproteases (MMPs) are the proteolytic enzymes accountable for extracellular matrix (ECM) modification through their Zn2+-dependent catalytic activity. Among these, MMP-12 is one of the crucial MMPs that contributes to various disease states including different types of cancers and other major pathophysiological conditions including COPD, asthma, emphysema, skin diseases, arthritis, vascular diseases, and neurological disorders. The majority of the MMP-12 inhibitors should have three constitutional pharmacophoric features (i.e., a hydrophobic group to occupy the S1' pocket, a zinc-binding motif for chelating to the catalytic Zn2+ ion present at the catalytic site, and a flexible and hydrogen bond forming linker region between the S1' pocket substituent and the zinc chelating group for interacting with the catalytic and Ω-loop amino acid residues). This review mainly focuses on the various roles of MMP-12 in different diseases along with the structural comparison with other MMPs as well as promising and MMP-12-selective inhibitors and molecular modeling studies performed on MMP-12 inhibitors. Therefore, this review will provide comprehensive information to the researchers for designing effective and MMP-12-selective inhibitors for therapeutic advancement in the future.

Dipeptidyl Peptidase 4 (DPP4) Exacerbates Osteoarthritis Progression in an Enzyme-Independent Manner

Chondrocyte senescence is a key driver of osteoarthritis (OA). Mitochondrial dysfunction and oxidative stress can induce chondrocyte senescence. However, the specific mechanisms by which senescence contributes to OA progression are not fully understood. Here, it is attested that Dipeptidyl peptidase 4 (DPP4) is significantly upregulated in osteoarthritic chondrocytes in both humans and mice. DPP4 promotes oxidative stress and cellular senescence in chondrocytes through excessive mitochondrial fission in an enzyme-independent manner. Intra-articular injection of adeno-associated virus 2 to upregulate DPP4 in chondrocytes promotes post-traumatic and aging-induced OA in mice in an enzyme-independent manner. Mechanistically, DPP4 competitively binds to Myosin heavy chain 9 (MYH9), interfering with its E3 ubiquitin ligase Carboxyl terminus of Hsc70-interacting protein (CHIP), and thereby upregulates MYH9 expression. Finally, a small molecule, 4,5-Dicaffeoylquinic acid is identified, which disrupts the interaction between DPP4 and MYH9, thereby ameliorating post-traumatic and aging-induced OA in mice caused by DPP4 upregulation. The study indicates that the non-enzymatic activity of DPP4 is a promising target for OA treatment.

Matrikine stimulation of equine synovial fibroblasts and chondrocytes results in an in vitro osteoarthritis phenotype

Osteoarthritis (OA) is a debilitating disease that impacts millions of individuals and has limited therapeutic options. A significant hindrance to therapeutic discovery is the lack of in vitro OA models that translate reliably to in vivo preclinical animal models. An alternative to traditional inflammatory cytokine models is the matrikine stimulation model, in which fragments of matrix proteins naturally found in OA tissues and synovial fluid, are used to stimulate cells of the joint. The objective of this study was to determine if matrikine stimulation of equine synovial fibroblasts and chondrocytes with fibronectin fragments (FN7-10) would result in an OA phenotype. We hypothesized that FN7-10 stimulation of equine articular cells would result in an OA phenotype with gene and protein expression changes similar to those previously described for human chondrocytes stimulated with FN7-10. Synovial fibroblasts and chondrocytes isolated from four horses were stimulated in monolayer culture for 6 or 18 h with 1 µM purified recombinant 42 kD FN7-10 in serum-free media. At the conclusion of stimulation, RNA was collected for targeted gene expression analysis and media for targeted protein production analysis. Consistent with our hypothesis, FN7-10 stimulation resulted in significant alterations to many important genes that are involved in OA pathogenesis including increased expression of IL-1β, IL-4, IL-6, CCL2/MCP-1, CCL5/RANTES, CXCL6/GCP-2, MMP-1, MMP-3, and MMP13. The results of this study suggest that the equine matrikine stimulation model of OA may prove useful for in vitro experiments leading up to preclinical trials.

Super-activated platelet lysate promotes mesenchymal stem cell proliferation, migration, and chondrogenic differentiation: an in vitro study

OBJECTIVE

This study aimed to investigate the effects of super-activated platelet lysate (sPL) on the proliferation, migration, and chondrogenic differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).

METHODS

Cell proliferation and migration assay, enzyme-linked immunosorbent analysis, RT-qPCR, chondrogenic differentiation, and Western blot were performed on sPL-treated hUCMSCs.

RESULTS

The extraction of sPL from PRP yielded a significant release of growth factors. The proliferation of hUCMSCs was significantly enhanced by both 5% and 10% sPL, and the 5% sPL showed the most promising results. Additionally, 10% sPL demonstrated the strongest positive effect on hUCMSC migration. The 20% sPL group showed a significant decrease in inflammatory factor levels compared to the 0% sPL group when hIL-1β was added to the differentiation system. Notably, hUCMSCs in the 5% sPL, 10% sPL and 20% sPL groups displayed excellent chondrogenic differentiation.

CONCLUSION

In summary, sPL demonstrates the ability to promote stem cell proliferation, migration, and chondrogenic differentiation, while also suppressing inflammation.

Highly Efficient Dual-Probe Strategy toward Single-Cell Metabolite Analysis

As cancer progresses, detached cancer cells metastasize through the circulatory system, followed by intricate metabolic rewiring for adaptation and propagation. The dynamic process of metastasis, despite being responsible for the majority of cancer-related deaths, still remains inadequately comprehended. Here, we proposed a microfluidic platform combining the dual-probe strategy for the detection of metastasize-related metabolic levels at single-cell resolution. Unique design facilitates intracellular and extracellular detection within the same cell captured at individual chambers, promoting the understanding of single-cell correlation metabolites analyses. Metabolite profiling of the model cells verified the positive correlation between upregulated intracellular NAD(P)H and the increased secretion of matrix metalloproteinases (MMPs). Furthermore, Zn2+-mediated metabolite analysis demonstrated the correlation in single cells, which could be utilized as a reference for the development of zinc-based antitumor therapies. The strategy provides valuable evidence of a relatively higher risk of metastasis for malignancies through unraveling the intricate metabolic heterogeneities arising from both intrinsic and extrinsic factors within individual cells.

Biomarkers in the diagnosis, prognosis and management of rheumatoid arthritis: A comprehensive review

Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune condition that primarily affects the joints and periarticular soft tissues. In the past two decades, the discovery of new biomarkers has contributed to advances in the understanding of the pathogenesis and natural history of RA. These biomarkers, including genetic, clinical, serological and imaging biomarkers, play a key role in the different stages and aspects of RA, from the so called 'pre-clinical RA', which is characterized by subclinical pathological events, such as autoimmunity and inflammation, to diagnosis (including differential diagnosis), treatment decision making and disease monitoring.This review will provide an overview on the current role of traditional and newer biomarkers in the main aspects of RA management, from the identification of individuals 'at-risk' of RA who are likely to progress to clinically evident disease, to 'early' diagnosis of RA, prognosis, precision medicine, and prediction of response to treatment.

Reactive oxygen species-sensitive fenofibrate-loaded dextran nanoparticles in alleviation of osteoarthritis

Osteoarthritis (OA) stands as a prevalent chronic joint pathology, emerging as a leading cause of disability on a global scale. However, the current therapeutic efficacy in OA treatment remains unsatisfactory. Chondrocyte ferroptosis has become to a critical target for OA treatment, while the fabrication of nanomedicines emerges as a promising strategy for OA treatment. Nevertheless, there exists a paucity of reported nanomedicine systems designed to combat chondrocyte ferroptosis for OA alleviation. In light of this, our study introduced a reactive oxygen species (ROS)-sensitive fenofibrate-loaded targeted nanoparticle (FN-CNPs) as a means of alleviating OA by suppressing chondrocyte ferroptosis. In vitro investigations demonstrated the FN-CNPs can achieve this through the reduction of lipid peroxidation and ROS levels, as well as the elevation of anti-ferroptosis markers (GPX4, FSP1, and ACSL3). Consequently, FN-CNPs exhibited significant anti-inflammatory effects and downregulated the expression of key catabolic mediators in vitro. Furthermore, in vivo studies underscored the ability of FN-CNPs to alleviate OA progression and protect cartilage. Collectively, these findings highlight the efficacy of FN-CNPs in mitigating OA progression by suppressing chondrocyte ferroptosis via regulating ROS levels, antioxidant systems and lipid metabolism of chondrocytes.

Osteoarthritis year in review 2024: Biology

Osteoarthritis (OA) research is a fast-growing and extremely wide field, in which a substantial increase in knowledge has been achieved over the last year. It covers many different topics, however, a PubMed search using the terms 'osteoarthritis' and 'biology' resulted in only a limited number of studies that were published between April 2023 and April 2024. In order to identify OA-relevant studies that focus on mechanistic studies of biological processes at the tissue, cellular, and molecular level, the following keywords were included as search terms: tissue interactions, single cell sequencing, transcriptomics, extracellular matrix, signaling, ion channels, and pain. The final selection of publications presented in this 'year in review' was influenced by the personal preferences of the authors, and eventually three larger key themes emerged: 1) Joint tissue interactions covering meniscus, subchondral bone, fat tissue, synovium, and synovial fluid. 2) Degeneration of the cartilage extracellular matrix and generation of bioactive fragments. 3) Receptors, ion channels, signaling pathways, and cellular metabolism. Many of the studies summarized here identified novel potential targets for OA treatment, and promising results were already obtained addressing these targets in different animal models. It will be exciting to see which findings can be translated into future clinical studies and eventually lead to novel treatment approaches for human OA.

Network Pharmacology, Molecular Docking and in vivo-based Analysis on the Effects of the MBZM-N-IBT for Arthritis

INTRODUCTION

Arthritis is the cause of morbidity associated with Chikungunya virus (CHIKV) infection. It persists even after the virus has been cleared from the body. MBZM-NIBT was earlier shown to inhibit (CHIKV) infection in vitro and in vivo.

OBJECTIVES

The objective of this study is to determine the ability of MBZM-N-IBT to manage arthritis independent of CHIKV infection.

METHODS

The acute toxicity of MBZM-N-IBT was determined to find a permissible oral dose. Effects against inflammation and arthritis were determined in relevant preclinical models. Network pharmacology was used to propose possible modes of action.

RESULTS

It showed no acute toxicity orally, with an estimated LD50 of more than 5000 mg/kg in rats. It significantly reduced inflammation. Its effect against Complete Freund's Adjuvant (CFA) induced arthritis was comparable to that of Diclofenac sodium. Network pharmacology analysis revealed that MBZM-N-IBT can potentially interfere with multiple targets and pathways. MMP12 and CTSD were found to be the most probable hub targets of MBZM-N-IBT for its effect against arthritis.

CONCLUSION

In conclusion, MBZM-N-IBT is safe at 50 mg/kg and can manage arthritis independent of CHIKV infection through modulation of multiple pathways and arthritis-associated targets.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

Jing-Si Herbal Tea Suppresses H2O2 -Instigated Inflammation and Apoptosis by Inhibiting Bax and Mitochondrial Cytochrome C Release in HIG-82 Synoviocytes

Inflammation is an intrinsic protective mechanism against various forms of cellular injuries in humans; however, its undesired activation results in tissue damage and cell death. The onset of chronic inflammation and oxidative stress are the key characteristics of autoimmune inflammatory diseases such as rheumatoid arthritis (RA), for which an effective treatment is yet to be developed. Therefore, in this study, we investigated the protective effects and molecular mechanisms of a novel herbal preparation, Jing-Si herbal tea (JS), against H2O2-induced inflammation and cellular damage in HIG-82 synoviocytes. We found that JS did not show any significant alterations in cell viability at <188 μg/mL; however, a cytotoxic effect was observed at 188-1883 μg/mL concentrations tested. We found that expressions of inflammation associated extracellular matrix (ECM)-degrading proteases MMP-13, ADAMTS-2, -8, and -17 were abnormally enhanced under H2O2-induced pathological oxidative stress (ROS) in HIG-82 cells. Interestingly, JS treatment not only reduced the ROS levels but also significantly repressed the protein expressions of collagen degrading proteases in a dose-dependent manner. Treatment with JS showed enhanced cell viability against H2O2-induced toxic ROS levels. The expressions of cell protective aggrecan, Collagen II, and Bcl-2 were increased, whereas MMP-13, ADAMTS-2, Cytochrome C, and cleaved Caspase 3 were decreased by JS under inflammatory agents H2O2, MIA, LPS, and TNF-α treatment, respectively, in HIG-82 cells. Interestingly, the cytoprotective effect of JS treatment was attributed to a decreased mitochondrial localization of Bax and a reduction of Cytochrome C release into the cytoplasm of H2O2-treated HIG-82 cells. Collectively, our results suggest a novel protective mechanism of JS for RA treatment, which could be potentially applied as a complementary treatment or as an alternative therapeutic approach to mitigate inflammatory diseases.

The cereblon-AMPK (AMP-activated protein kinase) axis in chondrocytes regulates the pathogenesis of osteoarthritis

OBJECTIVE

AMP-activated protein kinase (AMPK) dysregulation is implicated in osteoarthritis (OA), but the mechanisms underlying this dysregulation remain unclear. We investigated the role of cereblon, a substrate-recognition protein within the E3-ligase ubiquitin complex, in AMPK dysregulation and OA pathogenesis.

METHODS

Cereblon expression was examined in human (n = 5) and mouse (n = 10) OA cartilage. The role of cereblon was investigated through its adenoviral overexpression (n = 10) or knockout (KO, n = 15) in the destabilization of the medial meniscus (DMM)-operated mice. The therapeutic potentials of the chemical cereblon degrader, TD-165, and the AMPK activator, metformin, were assessed through intra-articular (IA) injection to mice (n = 15).

RESULTS

Immunostaining revealed that cereblon is upregulated in human and mouse OA cartilage. In DMM model mice, cartilage destruction was exacerbated by overexpression of cereblon in mouse joint tissues (OARSI grade; 1.11 [95% CI: 0.50 to 2.75]), but inhibited in global (-2.50 [95% CI: -3.00 to -1.17]) and chondrocyte-specific (-2.17 [95% CI: -3.14 to -1.06]) cereblon KO mice. The inhibitory effects were more pronounced in mice fed a high-fat diet compared to a regular diet. The degradation of cereblon through IA injection of TD-165 inhibited OA cartilage destruction (-2.47 [95% CI: -3.22 to -1.56]). Mechanistically, cereblon exerts its catabolic effects by negatively modulating AMPK activity within chondrocytes. Consistently, activation of AMPK by IA injection of metformin inhibited posttraumatic OA cartilage destruction (-1.20 ([95% CI: -1.89 to -0.45]).

CONCLUSIONS

The cereblon-AMPK axis acts as a catabolic regulator of OA pathogenesis and seems to be a promising therapeutic target in animal models of OA.

Patterns of antibiotic resistance genes and virulence factor genes in the gut microbiome of patients with osteoarthritis and rheumatoid arthritis

Background

The gut microbiome compositions of osteoarthritis (OA) and rheumatoid arthritis (RA) patients have been revealed; however, the functional genomics, particularly antibiotic resistance genes (ARGs) and virulence factor genes (VFGs), have not yet been explored.

Methods

We used gut metagenomic data to elucidate the distribution of ARGs and VFGs. Building on these differences in gut microbiome, we developed a diagnostic model using a random forest classifier based on ARG and VFG abundances.

Results

Our results indicated that both OA and RA patients exhibit significantly higher alpha diversity in ARGs, as measured by observed genes, the Shannon index, and the Simpson index, compared to healthy controls. However, this increased diversity is not significantly different between OA and RA patients. In contrast, VFGs showed higher diversity in RA patients than in healthy individuals, which was not as pronounced in OA patients. An analysis of the top 20 ARGs and VFGs revealed a largely similar composition between the three groups, with notable exceptions of certain genes that were uniquely enriched in either OA or RA patients. This suggests unique microbial patterns associated with each condition. Our beta diversity analysis further demonstrated distinct distributions of ARG and VFG profiles across the three groups, with several genes significantly enriched in both OA and RA patients, indicating potential markers for these diseases. The model achieved high accuracy (74.7-83.6%) when distinguishing both OA and RA from healthy controls using ARG profiles and substantial accuracy using VFG profiles.

Conclusion

These results support the potential of ARGs and VFGs as reliable biomarkers for diagnosing OA and RA.

Single-Cell Multi-Dimensional data analysis reveals the role of ARL4C in driving rheumatoid arthritis progression and Macrophage polarization dynamics

Rheumatoid arthritis (RA) is an enduring autoimmune inflammatory condition distinguished by continual joint inflammation, hyperplasia of the synovium, erosion of bone, and deterioration of cartilage.Fibroblast-like synoviocytes (FLSs) exhibiting "tumor-like" traits are central to this mechanism.ADP-ribosylation factor-like 4c (ARL4C) functions as a Ras-like small GTP-binding protein, significantly impacting tumor migration, invasion, and proliferation.However, it remains uncertain if ARL4C participates in the stimulation of RA FLSs exhibiting "tumor-like" features, thereby fostering the advancement of RA. In our investigation, we unveiled, for the inaugural instance, via the amalgamated scrutiny of single-cell RNA sequencing (scRNA-seq) and Bulk RNA sequencing (Bulk-seq) datasets, that activated fibroblast-like synoviocytes (FLSs) showcase high expression of ARL4C, and the ARL4C protein expression in FLSs derived from RA patients significantly surpasses that observed in individuals with osteoarthritis (OA) and traumatic injury (trauma).Silencing of the ARL4C gene markedly impeded the proliferation of RA FLSs by hindered the transition of cells from the G0/G1 phase to the S phase, and intensified cell apoptosis and diminished the migratory and invasive capabilities. Co-culture of ARL4C gene-silenced RA FLSs with monocytes/macrophages significantly inhibited the polarization of monocytes/macrophages toward M1 and the repolarization of M2 to M1.Furthermore, intra-articular injection of shARL4C significantly alleviated synovial inflammation and cartilage erosion in collagen-induced arthritis (CIA) rats. In conclusion, our discoveries propose that ARL4C assumes a central role in the synovial inflammation, cartilage degradation, and bone erosion associated with RA by triggering the PI3K/AKT and MAPK signaling pathways within RA FLSs.ARL4C holds promise as a prospective target for the development of pharmaceutical agents targeting FLSs, with the aim of addressing RA.

Challenges in tendon-bone healing: emphasizing inflammatory modulation mechanisms and treatment

Tendons are fibrous connective tissues that transmit force from muscles to bones. Despite their ability to withstand various loads, tendons are susceptible to significant damage. The healing process of tendons and ligaments connected to bone surfaces after injury presents a clinical challenge due to the intricate structure, composition, cellular populations, and mechanics of the interface. Inflammation plays a pivotal role in tendon healing, creating an inflammatory microenvironment through cytokines and immune cells that aid in debris clearance, tendon cell proliferation, and collagen fiber formation. However, uncontrolled inflammation can lead to tissue damage, and adhesions, and impede proper tendon healing, culminating in scar tissue formation. Therefore, precise regulation of inflammation is crucial. This review offers insights into the impact of inflammation on tendon-bone healing and its underlying mechanisms. Understanding the inflammatory microenvironment, cellular interactions, and extracellular matrix dynamics is essential for promoting optimal healing of tendon-bone injuries. The roles of fibroblasts, inflammatory cytokines, chemokines, and growth factors in promoting healing, inhibiting scar formation, and facilitating tissue regeneration are discussed, highlighting the necessity of balancing the suppression of detrimental inflammatory responses with the promotion of beneficial aspects to enhance tendon healing outcomes. Additionally, the review explores the significant implications and translational potential of targeted inflammatory modulation therapies in refining strategies for tendon-bone healing treatments.

Mechanisms of assembly and remodelling of the extracellular matrix

The extracellular matrix (ECM) is the complex meshwork of proteins and glycans that forms the scaffold that surrounds and supports cells. It exerts key roles in all aspects of metazoan physiology, from conferring physical and mechanical properties on tissues and organs to modulating cellular processes such as proliferation, differentiation and migration. Understanding the mechanisms that orchestrate the assembly of the ECM scaffold is thus crucial to understand ECM functions in health and disease. This Review discusses novel insights into the compositional diversity of matrisome components and the mechanisms that lead to tissue-specific assemblies and architectures tailored to support specific functions. The Review then highlights recently discovered mechanisms, including post-translational modifications and metabolic pathways such as amino acid availability and the circadian clock, that modulate ECM secretion, assembly and remodelling in homeostasis and human diseases. Last, the Review explores the potential of 'matritherapies', that is, strategies to normalize ECM composition and architecture to achieve a therapeutic benefit.

Inhibitory Effects of Reynoutria japonica Houtt. on Pain and Cartilage Breakdown in Osteoarthritis Based on Its Multifaceted Anti-Inflammatory Activity: An In Vivo and In Vitro Approach

In the past 30 years, the number of years lived with disability due to osteoarthritis (OA) has doubled, making it an increasing global health burden. To address this issue, interventions that inhibit the progressive pathology driven by age-related low-grade inflammation, the primary mechanism of OA, are being actively pursued. Recent investigations have focused on modulating the age-related low-grade inflammatory pathology of this disease as a therapeutic target. However, no agent has successfully halted the disease's progression or reversed its irreversible course. Reynoutria japonica Houtt. (RJ), a promising East Asian herbal medicine, has been utilized for several diseases due to its potent anti-inflammatory activity. This study aims to determine RJ's capacity to inhibit OA symptoms and associated inflammation, exploring its potential for further development. In vivo and in vitro experiments demonstrated RJ's anti-OA activity and modulation of multifaceted inflammatory targets. RJ significantly inhibited pain, gait deterioration, and cartilage destruction in a monosodium iodoacetate-induced OA rat model, with its analgesic effect further confirmed in an acetic acid-induced writhing model. RJ exhibited consistent anti-inflammatory activity against multiple targets in serum and cartilage of the OA rat model and lipopolysaccharide-induced RAW 264.7 cells. The inhibition of inflammatory cytokines, including interleukin-1β, interleukin-6, matrix metalloproteinase-13, tumor necrosis factor-α, and nitric oxide synthase 2, suggests that RJ's alleviation of OA manifestations relates to its multifaceted anti-inflammatory activity. These results indicate that RJ merits further investigation as a disease-modifying drug candidate targeting OA's inflammatory pathology. To further characterize the pharmacological properties of RJ, future studies with expanded designs are warranted.

Spermidine attenuates chondrocyte inflammation and cellular pyroptosis through the AhR/NF-κB axis and the NLRP3/caspase-1/GSDMD pathway

Introduction

Osteoarthritis (OA) is a prevalent chronic degenerative disease, marked by a complex interplay of mechanical stress, inflammation, and metabolic imbalances. Recent studies have highlighted the potential of spermidine (SPD), a naturally occurring polyamine known for its anti-inflammatory and antioxidant properties, as a promising therapeutic agent for OA. This study delves into the therapeutic efficacy and mechanistic pathways of SPD in mitigating OA symptoms.

Methods

Forty Sprague-Dawley rats were randomly assigned to four groups, including the CG (sham operation), model (anterior cruciate ligament transection [ACLT], and treatment (ACLT + two different doses of SPD) groups. In vivo, correlations between OA severity and different interventions were assessed by ELISA, X-rays, CT imaging, histological staining, and immunohistochemistry. In vitro, IL-1β was used to trigger chondrocyte inflammation, and SPD's cytotoxicity was assessed in primary rat chondrocytes. Next, inflammatory markers, extracellular matrix (ECM) proteins, and pathway marker proteins were detected in chondrocytes administered IL-1β alone, SPD, or aryl hydrocarbon receptor (AhR) silencing, by qRT-PCR, Griess reaction, ELISA, Western blot, and immunofluorescence. Morphological alterations and pyroptosis in chondrocytes were examined by transmission electron microscopy (TEM) and flow cytometry.

Results

Our research reveals that SPD exerts significant anti-inflammatory and antipyroptotic effects on IL-1β-treated chondrocytes and in anterior cruciate ligament transection (ACLT) rat models of OA, primarily through interaction with the Aryl hydrocarbon receptor (AhR). Specifically, SPD's binding to AhR plays a crucial role in modulating the inflammatory response and cellular pyroptosis by inhibiting both the AhR/NF-κB and NLRP3/caspase-1/GSDMD signaling pathways. Furthermore, the knockdown of AhR was found to negate the beneficial effects of SPD, underscoring the centrality of the AhR pathway in SPD's action mechanism. Additionally, SPD was observed to promote the preservation of cartilage integrity and suppress ECM degradation, further supporting its potential as an effective intervention for OA.

Discussion

Collectively, our findings propose SPD as a novel therapeutic approach for OA treatment, targeting the AhR pathway to counteract the disease's progression and highlighting the need for further clinical evaluation to fully establish its therapeutic utility.

Tumor‑associated macrophages activated in the tumor environment of hepatocellular carcinoma: Characterization and treatment (Review)

Hepatocellular carcinoma (HCC) tissue is rich in dendritic cells, T cells, B cells, macrophages, natural killer cells and cellular stroma. Together they form the tumor microenvironment (TME), which is also rich in numerous cytokines. Tumor‑associated macrophages (TAMs) are involved in the regulation of tumor development. TAMs in HCC receive stimuli in different directions, polarize in different directions and release different cytokines to regulate the development of HCC. TAMs are mostly divided into two cell phenotypes: M1 and M2. M1 TAMs secrete pro‑inflammatory mediators, and M2 TAMs secrete a variety of anti‑inflammatory and pro‑tumorigenic substances. The TAM polarization in HCC tumors is M2. Both direct and indirect methods for TAMs to regulate the development of HCC are discussed. TAMs indirectly support HCC development by promoting peripheral angiogenesis and regulating the immune microenvironment of the TME. In terms of the direct regulation between TAMs and HCC cells, the present review mainly focuses on the molecular mechanism. TAMs are involved in both the proliferation and apoptosis of HCC cells to regulate the quantitative changes of HCC, and stimulate the related invasive migratory ability and cell stemness of HCC cells. The present review aims to identify immunotherapeutic options based on the mechanisms of TAMs in the TME of HCC.

The role of vascular and lymphatic networks in bone and joint homeostasis and pathology

The vascular and lymphatic systems are integral to maintaining skeletal homeostasis and responding to pathological conditions in bone and joint tissues. This review explores the interplay between blood vessels and lymphatic vessels in bones and joints, focusing on their roles in homeostasis, regeneration, and disease progression. Type H blood vessels, characterized by high expression of CD31 and endomucin, are crucial for coupling angiogenesis with osteogenesis, thus supporting bone homeostasis and repair. These vessels facilitate nutrient delivery and waste removal, and their dysfunction can lead to conditions such as ischemia and arthritis. Recent discoveries have highlighted the presence and significance of lymphatic vessels within bone tissue, challenging the traditional view that bones are devoid of lymphatics. Lymphatic vessels contribute to interstitial fluid regulation, immune cell trafficking, and tissue repair through lymphangiocrine signaling. The pathological alterations in these networks are closely linked to inflammatory joint diseases, emphasizing the need for further research into their co-regulatory mechanisms. This comprehensive review summarizes the current understanding of the structural and functional aspects of vascular and lymphatic networks in bone and joint tissues, their roles in homeostasis, and the implications of their dysfunction in disease. By elucidating the dynamic interactions between these systems, we aim to enhance the understanding of their contributions to skeletal health and disease, potentially informing the development of targeted therapeutic strategies.

Dihydroartemisinin Regulated the MMP-Mediated Cellular Microenvironment to Alleviate Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with features of synovial inflammation, cartilage erosion, bone destruction, and pain and is currently lacking a satisfactory treatment strategy. Dihydroartemisinin (DHA), the active metabolite of artemisinin, has exhibited outstanding suppressive effects on RA without obvious side effects. However, the underlying mechanisms remain unclear, which limits its further clinical application. The purpose of this study is to reveal the pharmacodynamic mechanism of DHA against RA by means of a combination of single-cell RNA sequencing (RNA-seq), proteomics, as well as transcriptomics both in vivo and in vitro. In our results, DHA effectively reduced the degree of redness, swelling, and pain in RA rats and dramatically changed the synovial tissue microenvironment under the pathological state. Within this microenvironment, fibroblasts, macrophages, B cells, and endothelial cells were the major affected cell types, primarily through DHA targeting the extracellular matrix (ECM) structural constituent signaling pathway. In addition, we confirmed that DHA regulated the ECM by modulating matrix metalloproteinase 2 (MMP2) and MMP3 in the synovial tissue of RA rats. Moreover, DHA induced apoptosis in MH7A cells, further validating the bioinformatics data. In conclusion, DHA effectively reduced the inflammatory response and improved the immune microenvironment in synovial tissue by inhibiting MMP2 and MMP3. Our findings provide a basis for the application of DHA in the treatment of RA.

Investigating the Anti-Inflammatory, Analgesic, and Chondroprotective Effects of Gynostemma pentaphyllum (Thunb.) Makino in Osteoarthritis: An In Vitro and In Vivo Study

Osteoarthritis (OA) is an age-related disease characterized by inflammation, pain, articular cartilage damage, synovitis, and irreversible disability. Gynostemma pentaphyllum (Thunb.) Makino (GP), a herbal medicine traditionally used in East Asia for its anti-inflammatory properties, was investigated for its potential to modulate OA pathology and symptoms. This study evaluated GP's efficacy in inhibiting pain, functional decline, and cartilage destruction in monosodium iodoacetate-induced OA and acetic acid-induced writhing models. Additionally, the effects of GP on OA-related inflammatory targets were assessed via mRNA and protein expression in rat knee cartilage and lipopolysaccharide-induced RAW 264.7 cells. The GP group demonstrated significant pain relief, functional improvement, and cartilage protection. Notably, GP inhibited key inflammatory mediators, including interleukin (IL)-1β, IL-6, matrix metalloproteinases (MMP)-3 and MMP-13, cyclooxygenase-2, and prostaglandin E receptor 2, surpassing the effects of active controls. These findings suggest that GP is a promising candidate for disease-modifying OA drugs and warrants further comprehensive studies.

The role of neutrophils in autoimmune diseases

Historically, neutrophils have been primarily regarded as short-lived immune cells that act as initial responders to antibacterial immunity by swiftly neutralizing pathogens and facilitating the activation of adaptive immunity. However, recent evidence indicates that their roles are considerably more complex than previously recognized. Neutrophils comprise distinct subpopulations and can interact with various immune cells, release granular proteins, and form neutrophil extracellular traps. These functions are increasingly recognized as contributing factors to tissue damage in autoimmune diseases. This review comprehensively examines the physiological functions and heterogeneity of neutrophils, their interactions with other immune cells, and their significance in autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, antiphospholipid syndrome, antineutrophil cytoplasmic antibody-associated vasculitis, multiple sclerosis, and others. This review aims to provide a deeper understanding of the function of neutrophils in the development and progression of autoimmune disorders.

Construction of mitochondrial-targeting nano-prodrug for enhanced Rhein delivery and treatment for osteoarthritis in vitro

Rhein, a natural anthraquinone compound derived from traditional Chinese medicine, exhibits potent anti-inflammatory properties via modulating the level of Reactive oxygen or nitrogen species (RONS). Nevertheless, its limited solubility in water, brief duration of plasma presence, as well as its significant systemic toxicity, pose obstacles to its in vivo usage, necessitating the creation of a reliable drug delivery platform to circumvent these difficulties. In this study, an esterase-responsive and mitochondria-targeted nano-prodrug was synthesized by conjugating Rhein with the polyethylene glycol (PEG)-modified triphenyl phosphonium (TPP) molecule, forming TPP-PEG-RH, which could spontaneously self-assemble into RPT NPs when dispersed in aqueous media. The TPP outer layer of these nanoparticles enhances their pharmacokinetic profile, facilitates efficient delivery to mitochondria, and promotes cellular uptake, thereby enabling enhanced accumulation in mitochondria and improved therapeutic effects in vitro. The decline in RONS was observed in IL-1β-stimulated chondrocyte after RPT NPs treating. RPT NPs also exert excellent anti-inflammatory (IL-1β, TNF-α, IL-6 and MMP-13) and antioxidative effects (Cat and Sod) via the Nrf2 signalling pathway, upregulation of cartilage related genes (Col2a1 and Acan). Moreover, RPT NPs shows protection of mitochondrial membrane potential and inhibition of chondrocyte apoptosis. Moreover, These findings suggest that the mitochondria-targeted polymer-Rhein conjugate may offer a therapeutic solution for patients suffering from chronic joint disorders, by attenuating the progression of osteoarthritis (OA).

Effect of the novel anti-NGF monoclonal antibody DS002 on the metabolomics of pain mediators, cartilage and bone

The anti-nerve growth factor antibody class of drugs interrupts signaling by blocking NGF binding to TrkA receptors for the treatment of pain; however, this target class of drugs has been associated with serious adverse effects in the joints during clinical trials. DS002 is a novel anti-nerve growth factor antibody drug independently developed by Guangdong Dashi Pharmaceuticals. The main purpose of this study is to explore the correlation between DS002 and pain as well as cartilage and bone metabolism with the help of metabolomics technology and the principle of enzyme-linked reaction, and to examine whether DS002 will produce serious adverse effects in joints caused by its same target class of drugs, in order to provide more scientific basis for the safety and efficacy of DS002. Our results showed that DS002 mainly affected the metabolism of aromatic amino acids and other metabolites, of which six metabolites, l -phenylalanine, 5-hydroxytryptophan, 5-hydroxytryptamine hydrochloride, 3-indolepropionic acid, kynuric acid, and kynurenine, were significantly altered, which may be related to the effectiveness of DS002 in treating pain. In addition, there were no significant changes in biological indicators related to cartilage and bone metabolism in vivo, suggesting that DS002 would not have a significant effect on cartilage and bone metabolism, so we hypothesize that DS002 may not produce the serious adverse effects in joints caused by its fellow target analogs. Therefore, the Anti-NGF analgesic drug DS002 has the potential to become a promising drug in the field of analgesia, providing pain patients with an efficient treatment option without adverse effects.

Intra-articular hydrogel formulation prolongs the in vivo stability of Toll-like receptor antagonistic peptides for rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is an autoimmune disease characterized by systemic inflammation that primarily affects joint tissue and requires frequent medication. Recently, we developed cyclic phage-display-derived inhibitory peptides (CPs), which act as Toll-like Receptor 4 antagonists. These CPs exhibited therapeutic efficacy against joint diseases by alleviating inflammatory factors. Nonetheless, CP exhibits in vivo instability and a short half-life. Therefore, this study sought to improve the in vivo stability of CP, thereby reducing the frequency of CP administration through the development of an injectable hydrogel depot formulation. To improve in vivo stability, CP was chemically conjugated to hyaluronic acid (HA-CP) and subsequently mixed into a temperature-sensitive hydrogel [methoxy polyethylene glycol-b-poly(ε-caprolactone)-ran-poly(lactide) (PC)] as an injectable depot (PC+(HA-CP)). For comparison, CP was physically mixed with HA and PC (PC+(HA+CP)). Both PC+(HA-CP) and PC+(HA+CP) were found to rapidly form depots upon injection into the joint space. Cell viability assays confirmed the non-toxic nature of PC+(HA-CP) and PC+(HA+CP), whereas both formulations exhibited inhibition of inflammatory factors. Furthermore, PC+(HA-CP) retained CP for a longer duration compared to PC+(HA+CP) in the presence of hyaluronidase and within the RA joint space. Following intra-articular injection, both the PC+(HA-CP) and PC+(HA+CP) depots exhibited reductions in RA symptoms, cartilage regeneration, and suppression of pro-inflammatory cytokine levels. Specifically, by extending the in vivo retention of CP, PC+(HA-CP) demonstrated superior RA treatment efficacy compared to PC+(HA+CP). In conclusion, intra-articular injection of PC+(HA-CP) was validated as an effective strategy for treating RA, owing to its ability to prolong the in vivo retention of CP. This approach holds promise for improving RA management and patient outcomes.

Pain Relief, Functional Recovery, and Chondroprotective Effects of Angelica gigas Nakai in Osteoarthritis Due to Its Anti-Inflammatory Property: An In Vitro and In Vivo Study

Osteoarthritis (OA), characterized by chronic pain and joint degradation, is a progressive joint disease primarily induced by age-related systemic inflammation. Angelica gigas Nakai (AG), a medicinal plant widely used in East Asia, exhibits promising results for such conditions. This study aimed to evaluate the potential of AG as a drug candidate for modulating the multifaceted pathology of OA based on its anti-inflammatory properties. We evaluated the efficacy of AG in pain relief, functional improvement, and cartilage erosion delay using monosodium iodoacetate-induced OA rats and acetic acid-induced writhing mice, along with its anti-inflammatory effects on multiple targets in the serum and cartilage of in vivo models and lipopolysaccharide-stimulated RAW 264.7 cells. In vivo experiments demonstrated significant analgesic and chondroprotective effects of AG, along with functional recovery, in model animals compared with the active controls. AG dose-dependently modulated inflammatory OA pathology-related targets, including interleukin-1β, tumor necrosis factor-α, matrix metalloproteinase-13, and cyclooxygenase-2, both in vitro and in vivo. In conclusion, AG could be a potential drug candidate for modulating the multifaceted pathology of OA. Nevertheless, further comprehensive investigations, involving a broader range of compounds, pathologies, and mechanisms, are warranted to validate these findings.

Logic-Based Strategy for Spatiotemporal Release of Dual Extracellular Vesicles in Osteoarthritis Treatment

To effectively treat osteoarthritis (OA), the existing inflammation must be reduced before the cartilage damage can be repaired; this cannot be achieved with a single type of extracellular vesicles (EVs). Here, a hydrogel complex with logic-gates function is proposed that can spatiotemporally controlled release two types of EVs: interleukin 10 (IL-10)+ EVs to promote M2 polarization of macrophage, and SRY-box transcription factor 9 (SOX9)+ EVs to increase cartilage matrix synthesis. Following dose-of-action screening, the dual EVs are loaded into a matrix metalloporoteinase 13 (MMP13)-sensitive self-assembled peptide hydrogel (KM13E) and polyethylene glycol diacrylate/gelatin methacryloyl-hydrogel microspheres (PGE), respectively. These materials are mixed to form a "microspheres-in-gel" KM13E@PGE system. In vitro, KM13E@PGE abruptly released IL-10+ EVs after 3 days and slowly released SOX9+ EVs for more than 30 days. In vivo, KM13E@PGE increased the CD206+ M2 macrophage proportion in the synovial tissue and decreased the tumor necrosis factor-α and IL-1β levels. The aggrecan and SOX9 expressions in the cartilage tissues are significantly elevated following inflammation subsidence. This performance is not achieved using anti-inflammatory or cartilage repair therapy alone. The present study provides an injectable, integrated delivery system with spatiotemporal control release of dual EVs, and may inspire logic-gates strategies for OA treatment.

Polymer-drug and polymer-protein conjugated nanocarriers: Design, drug delivery, imaging, therapy, and clinical applications

Polymer-drug conjugates and polymer-protein conjugates have been pivotal in the realm of drug delivery systems for over half a century. These polymeric drugs are characterized by the conjugation of therapeutic molecules or functional moieties to polymers, enabling a range of benefits including extended circulation times, targeted delivery, controlled release, and decreased immunogenicity. This review delves into recent advancements and challenges in the clinical translations and preclinical studies of polymer-drug conjugates and polymer-protein conjugates. The design principles and functionalization strategies crucial for the development of these polymeric drugs were explored followed by the review of structural properties and characteristics of various polymer carriers. This review also identifies significant obstacles in the clinical translation of polymer-drug conjugates and provides insights into the directions for their future development. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Intron retention in PI-PLC γ1 mRNA as a key mechanism affecting MMP expression in human primary fibroblast-like synovial cells

The intron retention (IR) is a phenomenon utilized by cells to allow diverse fates at the same mRNA, leading to a different pattern of synthesis of the same protein. In this study, we analyzed the modulation of phosphoinositide-specific phospholipase C (PI-PLC) enzymes by Harpagophytum procumbens extract (HPE) in synoviocytes from joins of osteoarthritis (OA) patients. In some samples, the PI-PLC γ1 isoform mature mRNA showed the IR and, in these synoviocytes, the HPE treatment increased the phenomenon. Moreover, we highlighted that as a consequence of IR, a lower amount of PI-PLC γ1 was produced. The decrease of PI-PLC γ1 was associated with the decrease of metalloprotease-3 (MMP-3), and MMP-13, and ADAMTS-5 after HPE treatment. The altered expression of MMPs is a hallmark of the onset and progression of OA, thus substances able to decrease their expression are very desirable. The interesting outcomes of this study are that 35% of analyzed synovial tissues showed the IR phenomenon in the PI-PLC γ1 mRNA and that the HPE treatment increased this phenomenon. For the first time, we found that the decrease of PI-PLC γ1 protein in synoviocytes interferes with MMP production, thus affecting the pathways involved in the MMP expression. This finding was validated by the silencing of PI-PLC γ1 in synoviocytes where the IR phenomenon was not present. Our results shed new light on the biochemical mechanisms involved in the degrading enzyme production in the joint of OA patients, suggesting a new therapeutic target and highlighting the importance of personalized medicine.

Fibroblast-like synoviocytes orchestrate daily rhythmic inflammation in arthritis

Rheumatoid arthritis is a chronic inflammatory disease that shows characteristic diurnal variation in symptom severity, where joint resident fibroblast-like synoviocytes (FLS) act as important mediators of arthritis pathology. We investigate the role of FLS circadian clock function in directing rhythmic joint inflammation in a murine model of inflammatory arthritis. We demonstrate FLS time-of-day-dependent gene expression is attenuated in arthritic joints, except for a subset of disease-modifying genes. The deletion of essential clock gene Bmal1 in FLS reduced susceptibility to collagen-induced arthritis but did not impact symptomatic severity in affected mice. Notably, FLS Bmal1 deletion resulted in loss of diurnal expression of disease-modulating genes across the joint, and elevated production of MMP3, a prognostic marker of joint damage in inflammatory arthritis. This work identifies the FLS circadian clock as an influential driver of daily oscillations in joint inflammation, and a potential regulator of destructive pathology in chronic inflammatory arthritis.

Exploring the Early Molecular Pathogenesis of Osteoarthritis Using Differential Network Analysis of Human Synovial Fluid

The molecular mechanisms that drive the onset and development of osteoarthritis (OA) remain largely unknown. In this exploratory study, we used a proteomic platform (SOMAscan assay) to measure the relative abundance of more than 6000 proteins in synovial fluid (SF) from knees of human donors with healthy or mildly degenerated tissues, and knees with late-stage OA from patients undergoing knee replacement surgery. Using a linear mixed effects model, we estimated the differential abundance of 6251 proteins between the three groups. We found 583 proteins upregulated in the late-stage OA, including MMP1, collagenase 3 and interleukin-6. Further, we selected 760 proteins (800 aptamers) based on absolute fold changes between the healthy and mild degeneration groups. To those, we applied Gaussian Graphical Models (GGMs) to analyze the conditional dependence of proteins and to identify key proteins and subnetworks involved in early OA pathogenesis. After regularization and stability selection, we identified 102 proteins involved in GGM networks. Notably, network complexity was lost in the protein graph for mild degeneration when compared to controls, suggesting a disruption in the regular protein interplay. Furthermore, among our main findings were several downregulated (in mild degeneration versus healthy) proteins with unique interactions in the healthy group, one of which, SLCO5A1, has not previously been associated with OA. Our results suggest that this protein is important for healthy joint function. Further, our data suggests that SF proteomics, combined with GGMs, can reveal novel insights into the molecular pathogenesis and identification of biomarker candidates for early-stage OA.

Chondrocyte-Targeted Delivery System of Sortase A-Engineered Extracellular Vesicles Silencing MMP13 for Osteoarthritis Therapy

Targeted drug delivery and the reduction of off-target effects are crucial for the promising clinical application of nucleic acid drugs. To address this challenge, a new approach for treating osteoarthritis (OA) that accurately delivers antisense oligonucleotides (ASO) targeting matrix metalloproteinase-13 (ASO-MMP13) to chondrocytes, is developed. Small extracellular vesicles (exos) are ligated with chondrocyte affinity peptide (CAP) using Sortase A and subsequently incubated with cholesterol-modified ASO-MMP13 to construct a chondrocyte-targeted drug delivery exo (CAP-exoASO). Compared with exos without CAP (ExoASO), CAP-exoASOs attenuate IL-1β-induced chondrocyte damage and prolong the retention time of ASO-MMP13 in the joint without distribution in major organs following intra-articular injection. Notably, CAP-exoASOs decrease MMP13 expression (P < 0.001) and upregulate COL2A1 expression (P = 0.006), resulting in reorganization of the cartilage matrix and alleviation of progression in the OA model. Furthermore, the Osteoarthritis Research Society International (OARSI) score of articular cartilage tissues treated with CAP-exoASO is comparable with that of healthy rats (P = 0.148). A mechanistic study demonstrates that CAP-exoASO may reduce inflammation by suppressing the IL-17 and TNF signaling pathways. Based on the targeted delivery effect, CAP-exoASOs successfully accomplish cartilage repair and have considerable potential for development as a promising therapeutic modality for satisfactory OA therapy.

Combined ROS Sensitive Folate Receptor Targeted Micellar Formulations of Curcumin Effective Against Rheumatoid Arthritis in Rat Model

Introduction

Rheumatoid arthritis (RA) is an inflammatory immune-mediated disease that involves synovitis, cartilage destruction, and even joint damage. Traditional agents used for RA therapy remain unsatisfactory because of their low efficiency and obvious adverse effects. Therefore, we here established RA microenvironment-responsive targeted micelles that can respond to the increase in reactive oxygen species (ROS) levels in the joint and improve macrophage-specific targeting of loaded drugs.

Methods

We here prepared ROS-responsive folate-modified curcumin micelles (TK-FA-Cur-Ms) in which thioketal (TK) was used as a ROS-responsive linker for modifying polyethylene glycol 5000 (PEG5000) on the micellar surface. When micelles were in the ROS-overexpressing inflammatory microenvironment, the PEG5000 hydration layer was shed, and the targeting ligand FA was exposed, thereby enhancing cellular uptake by macrophages through active targeting. The targeting, ROS sensitivity and anti-inflammatory properties of the micelles were assessed in vitro. Collagen-induced arthritis (CIA) rats model was utilized to investigate the targeting, expression of serum inflammatory factors and histology change of the articular cartilage by micelles in vivo.

Results

TK-FA-Cur-Ms had a particle size of 90.07 ± 3.44 nm, which decreased to 78.87 ± 2.41 nm after incubation with H2O2. The micelles exhibited in vitro targeting of RAW264.7 cells and significantly inhibited inflammatory cytokine levels. Pharmacodynamic studies have revealed that TK-FA-Cur-Ms prolonged the drug circulation and exhibited augmented cartilage-protective and anti-inflammatory effects in vivo.

Conclusion

The unique ROS-responsive targeted micelles with targeting, ROS sensitivity and anti-inflammatory properties were successfully prepared and may offer an effective therapeutic strategy against RA.