Overview of MMP-13 as a Promising Target for the Treatment of Osteoarthritis

Hydrogen generators-protected mesenchymal stem cells reverse articular redox imbalance-induced immune dysfunction for osteoarthritis treatment

Stem cell therapy has revolutionized the management of osteoarthritis (OA), but the articular dysregulated redox status diminishes cell engraftment efficiency and disrupts immune homeostasis, therefore compromising the overall therapeutic efficacy. Here, we present hydrogen (H2) generators-backpacked mesenchymal stem cells (MSCs) which preserve the biological functions and survival of transplanted cells and reverse articular immune dysfunction, mitigating OA. Specifically, post systemic transplantation, H2 generators-laden MSCs home to OA joints, and upon stimulation in acidic OA environment, H2 produced from the generators remodels articular redox balance, thereby relieving the loss of mitochondrial membrane potential, decreasing cell apoptosis rate, and maintaining pluripotent and paracrine functions of MSCs. Furthermore, the reactive oxygen species scavenging by H2 in combination with paracrine effects of the MSCs promote macrophage polarization towards the anti-inflammatory M2 phenotype, which contributes to reversing synovial immune disorder. In severe OA model, the backpacked MSCs reduce osteoarthritic degeneration, osteophyte formation and joint inflammation, and promote cartilage regeneration. In sum, our work demonstrates that arming with H2 generators effectively boosts the therapeutic efficacy of MSCs, which hold great potential for alleviating redox imbalance-related tissue lesions, including but not limited to OA.

Zn2+-driven metformin conjugated with siRNA attenuates osteoarthritis progression by inhibiting NF-κB signaling and activating autophagy

Osteoarthritis (OA) is a type of joint disease that influences millions of individuals. Regrettably, effective treatment for OA is currently unavailable. The challenge lies in the deep location of chondrocytes within the dense cartilage matrix that hinders the delivery and efficiency of clinical OA drugs. To overcome this obstacle, the present study proposed a hybrid nanodrug by Zinc(II) metal-drug coordination-driven self-assembly as highly efficient delivery system. This nano-assembly formulations possessed the ability to deliver two types of drugs, namely metformin (Met) and therapeutic genes (p65 siRNA). Results showed that this nano-assembly not only exhibited positive charge-driven anchoring to the cartilage matrix and effective drug delivery capacity, but also synergistically inhibited NF-κB activity and activates autophagy of OA chondrocytes, thus safeguarding the cartilage. The successful achievement of this project not only contribute to the advancement of research on bio-nanomaterials for treating OA, but also establish a robust theoretical foundation for realizing promising and functional integration of nanomedicine targeting OA.

Naringin in repairing articular cartilage injury by activating TGF-β/Smad signaling pathway to attenuate inflammatory response

Naringin protects cartilage and attenuates inflammation. This study investigated the mechanism by which naringin activates the TGF-β/Smad signaling pathway to attenuate the inflammatory response and repair rabbit articular cartilage injury. A ring bone extraction drill was used to create a rabbit articular cartilage injury model. Sixteen Japanese white rabbits were divided into Sham, Mod, Nar, and Con groups and treated for 12 weeks. Compared with the Mod group, obvious signs of morphological and structural repair of cartilage injury were observed in the Nar group. The ICRS, BV/TV, and BS/TV scores increased, whereas the Wakitani and Tb.Sp scores decreased. Furthermore, ADAMTS-5 levels were significantly reduced, and TGF-β1 levels were significantly increased. The average light density of P-Smad3 in the repaired tissue was significantly elevated, whereas that of MMP-13 was significantly reduced. Compared with that in the Sham group, the transcription and expression levels of TβRII, type II collagen, P-TβRII, and P-Smad2 in the repair tissues of the Mod group were lower. This was reversed in the Nar group. Therefore, naringin administration can improve the morphology and structure of articular cartilage injury, reduce the concentration and expression levels of pro-inflammatory factors in the joint fluid and repair tissues, and increase the concentrations and expression levels of anti-inflammatory factors in the joint fluid and repair tissues. Thus, naringin exerts a positive effect by reducing the inflammatory response and repairing articular cartilage injury. This mechanism is closely related to the activation of the TGF-β/Smad signaling pathway.

Identification of Differential Fibrocartilage Degradation Between Sexes in a Burn-Synovectomy Temporomandibular Osteoarthritis Mouse Model

BACKGROUND

Temporomandibular joint osteoarthritis is a degenerative disease with a higher prevalence in women, yet its sex-specific mechanisms remain unclear. This study investigates fibrocartilage degradation in a burn-synovectomy TMJ OA mouse model, hypothesizing that female mice exhibit greater cartilage degradation due to differential inflammatory responses.

METHODS

PRG4-CreERT2; Ai9 mice (12-week-old males and females) underwent burn-synovectomy injuries and were euthanized at 1, 3, and 9 weeks for histological and immunofluorescence analyses. PRG4 and MMP-13 expression were assessed to evaluate fibrocartilage integrity and degradation. Statistical significance was determined using ANOVA and post hoc testing.

RESULTS

Female mice showed significantly higher Osteoarthritis Research Society International (OARSI) scores and MMP-13/PRG4 ratios at later time points, indicating sustained degradation. PRG4 expression increased similarly in both sexes in all time points, but MMP-13 expression was significantly higher in females at 9 weeks, suggesting heightened cartilage catabolism.

CONCLUSION

This study highlights sex-based differences in TMJ OA progression, reinforcing the importance of targeted therapeutic strategies. The burn-synovectomy model effectively replicates TMJ OA pathology, making it a valuable tool for future research.

Extracellular vesicles in age-related diseases: disease pathogenesis, intervention, and biomarker

Aging is a multifactorial biological process characterized by the irreversible accumulation of molecular damage, leading to an increased risk of age-related diseases. With the global prominent rise in aging populations, elucidating the mechanisms underlying the aging process and developing strategies to combat age-related diseases have become a pressing priority. Extracellular vesicles (EVs) have gained significant attention due to their role in intercellular communication. EVs are known for their ability to deliver biocargoes, such as miRNA, proteins, and lipids, implicating their involvement in disease pathogenesis and intervention. In this review article, we explore the dual role of EVs in age-related diseases: contributing to the pathogenesis of diseases by transferring deleterious molecules, while also offering therapeutic ability by transferring beneficial molecules. We also highlight the application of EVs as biomarkers for early diagnosis of age-related diseases, paving the way for early intervention and precision medicine. Additionally, we discuss how analysing the composition of EVs cargo can provide insights into disease progression. Finally, we address the challenges and future perspectives of EV-based-therapy in clinical translation, including standardization of EVs isolation methods and improving cargo specificity.

DNA Origami-Based CD44-Targeted Therapy Silences Stat3 Enhances Cartilage Regeneration and Alleviates Osteoarthritis Progression

Osteoarthritis (OA) is a widespread musculoskeletal disorder affecting ≈600 million people globally, and small interfering RNA (siRNA) therapy shows potential in targeting OA progression. However, the efficient and targeted delivery of siRNA remains a major challenge due to issues with tissue specificity and degradation in vivo. In this study, A DNA origami-based chondrocyte-targeted delivery system (OCS) is designed for siRNA delivery to OA-affected cartilage. The DNA origami is engineered to load with siRNA targeting signal transducer and activator of transcription 3 (Stat3), a key regulator of inflammation and cartilage degradation, and is functionalized with anti-CD44 aptamers for selective targeting of OA chondrocytes. In vitro, the DNA origami system effectively delivers siRNA to diseased chondrocytes, silencing matrix metalloproteinases expression and reducing inflammation. In OA rat models, it preserves cartilage integrity, promotes regeneration, and mitigates ECM degradation without evident side effects. These findings highlight DNA origami as a promising platform for siRNA-based OA therapy, offering a promising solution to the challenges of targeted and efficient siRNA delivery.

ETS1 promotes the expression of Ctsb and Mmp13 during the differentiation of septoclasts from pericytes

Septoclasts (SCs), which express both fatty acid-binding protein 5 and platelet-derived growth factor beta, are mononuclear cartilage-resorbing cells predominantly located at the chondro-osseous junction of the growth plate (GP). These cells originate from pericytes (PCs). Cathepsin B (CTSB) and matrix metalloproteinase-13 (MMP13), expressed in SCs, participate in the degradation of collagen and other cartilage matrices. This study aimed to investigate the involvement of the ETS proto-oncogene 1 (ETS1) in the transcription of Ctsb and Mmp13 during the differentiation of SCs from PCs. ETS1 was localized in SCs and a small number of PCs during development and postnatal stages. Upregulation of Ets1, Mmp13, Ctsb, and the Ets1-related genes, specificity protein 1 (Sp-1), jun proto-oncogene (c-Jun), and cAMP response element-binding protein-binding protein (Crebbp) in SCs compared with those in PCs was shown by RNA-seq analysis of samples isolated from the tibiae of 3-week-old postnatal mice. The Ets1-related proteins were localized ubiquitously in SCs and PCs in the GP. In primary SC cultures, the expression levels of Ctsb and Mmp13 were significantly reduced following treatment with Ets1 siRNA. Thus, our results revealed that ETS1 promoted the expression of Ctsb and Mmp13 in SCs during the differentiation of SCs from PCs.

Metformin exhibits inhibitory effects on ferroptosis and alleviates chondrocyte metabolic imbalance in osteoarthritis models, as well as Erastin-induced ferroptosis, through the modulation of the P53/SLC7A11 pathway

Osteoarthritis (OA) is a prevalent degenerative disease, and metformin, the first-line treatment for type 2 diabetes, has shown potential in slowing the progression of OA, although its mechanism of action is not fully understood. This study aims to explore the role of ferroptosis in OA and evaluate the therapeutic effects and mechanisms of metformin on ferroptosis. We identified gene differences associated with OA through RNA-Seq data analysis and predicted potential targets using network pharmacology and molecular docking techniques. In vivo experimental methods, including histological examination, immunofluorescence, Western blotting, real-time quantitative PCR, biochemical analysis, and ELISA, were used to study the effects of metformin in the modified Hulth method and Erastin-induced OA models. The study found that metformin significantly inhibits chondrocyte ferroptosis by upregulating SLC7A11 and downregulating P53 expression, maintaining the balance of synthesis and catabolism in chondrocytes, and effectively slowing down the degeneration of knee joint cartilage in rats. Overall, this study not only provides further evidence for the anti-OA effects of metformin but also identifies its direct targets in the inhibition of ferroptosis in OA.

Theranostics of osteoarthritis: Applications and prospects of precision targeting nanotechnology

Osteoarthritis (OA), a complex degenerative joint disease driven by cartilage degeneration, synovial inflammation, and subchondral bone remodeling, lacks effective disease-modifying therapies. Precision-targeted nanotechnology has emerged as a breakthrough strategy, offering enhanced drug delivery, reduced toxicity, and synergistic diagnostic-therapeutic capabilities. This review summarizes OA pathogenesis, focusing on dysregulated immune networks and self-perpetuating synovial microenvironmental interactions. We discuss advanced nanomedicine approaches, which leverage OA-specific pathological cues for localized treatment. Innovations in cytokine modulation, photothermal therapy, and integrated theranostics (photoacoustic/fluorescence imaging) are highlighted as transformative tools for real-time diagnosis and personalized intervention. Despite progress, challenges such as biocompatibility optimization, clinical translation barriers, OA heterogeneity necessitate further development of multifunctional nanocarriers and rationaldesigns. This work underscores the potential of nanotechnology to advance OA therapeutics, bridging preclinical innovation with clinical applicability in pharmaceutical sciences.

Hand Osteoarthritis: Molecular Mechanisms, Randomized Controlled Trials, and the Future of Targeted Treatment

Hand osteoarthritis (OA) is a prevalent and disabling condition, yet its pathogenesis remains less studied than OA in large weight-bearing joints. Emerging genetic, epigenetic, and microbiome research suggests that hand OA might be biologically distinct, involving joint-specific pathways not shared by knee or hip OA. This review integrates genome-wide association studies specific to hand OA, highlighting key molecular contributors such as inflammatory cytokines. These genetic insights, together with emerging data on epigenetic alterations and gut microbial dysbiosis, point to broader systemic and regulatory influences on hand OA onset and progression. We also assess pharmacologic interventions tested in randomized controlled trials that have attempted to target these pathways. While agents such as TNF and IL-6 inhibitors, hydroxychloroquine, and corticosteroids have shown limited success, emerging evidence supports the potential of methotrexate in synovitis-positive general hand OA, platelet-rich plasma in thumb carpometacarpal (CMC) OA, and prolotherapy in interphalangeal (IP) OA. These findings illustrate the persistent gap between mechanistic understanding and therapeutic success. Future work must prioritize multifactorial strategies for addressing pain and translational frameworks that link molecular mechanisms to treatment response. In summary, this review offers an update on hand OA and identifies key opportunities for more targeted and effective therapy.

Elucidating the transcriptomic response of adult-derived mHypoA-2/12 mouse hypothalamic neuron cell line to cannabidiol (CBD) exposure

Cannabidiol (CBD) is a compound found in Cannabis sativa that is known for its neuroprotective, anti-inflammatory, analgesic, and anxiolytic properties. These properties make it a promising treatment for various neurological conditions. This study aimed to examine the effects of CBD on hypothalamic neurons at the transcriptome level using the adult-derived mHypoA-2/12 mouse cell line. The cells were exposed to four different CBD concentrations (ranging from 0.325 to 3 µM) for 6 and 24 h. Apart from the transcriptome analysis, apoptosis (caspase 3/7 activity) and viability (MTT) assays were performed. The obtained results showed that CBD enhanced cell viability, especially after 24 h of treatment and at lower or intermediate concentrations, and reduced apoptosis, with significant effects at the highest concentration. CBD caused moderate transcriptome profile changes (13 to 69 genes per treatment), with more genes affected at higher concentrations and shorter exposure times, indicating a stronger initial cellular response. Further analysis revealed that CBD affects several biological processes, including: intrinsic apoptosis suppression via p53 modulation, impacting genes like Bbc3, Mdm2, Cdkn1a, and Smad3. Additionally, CBD influenced genes involved in extracellular matrix organization, including metalloproteinases (Mmp-3, Mmp-13) and their inhibitors (Timp1), as well as collagen components (Col11a1) and mitochondrial respiratory chain complexes (mt-Nd5, mt-Nd4). Genes related to serotonin and dopamine biosynthesis, as well as Aldh2, were also impacted, linking CBD's effects in hypothalamic neurons to potential benefits in managing alcohol use disorders. These findings suggest the hypothalamus is a significant target for CBD, warranting further investigation.

Constructing a cross-tissue human knee single-cell atlas identified osteoarthritis reduces regenerative tissue stem cells while increasing inflammatory pain macrophages

Osteoarthritis (OA) affects the entire knee joint; however, cross-tissue molecular mechanisms are poorly understood due to a lack of comprehensive, integrated analysis. We constructed the first comprehensive single-cell RNA sequencing knee OA atlas from articular cartilage, meniscus, synovium, and subchondral bone which showed active communication between them. Healthy synovium and meniscus contain the largest populations of tissue stem cells (TSCs) and immune cells that are altered in OA. The regenerative TSCs expressing SDF1, SOX9, CD146, PDGFRB, and CD105 decrease during OA, whereas osteogenic TSCs expressing osteogenic differentiation-related factor NT5E (CD73) are increased. In OA, the balance between regenerative and osteogenic TSCs shifts in the OA state with an increased number of osteogenic TSCs. We also report an increased level of quadruple-positive inflammatory (IL1B-IL6-NOS2-TNF) and pain marker (P2RX7) specific macrophages in OA. Fibroblasts are enriched in OA-synovium and may contribute to fibrosis. Importantly, OA cartilage contains unique MMP13-producing detrimental chondrocytes along with RUNX2-producing chondrocytes that worsen OA pathophysiology. This atlas provides a novel avenue for potential therapeutic applications in human knee OA and other musculoskeletal diseases and injuries, targeting synovium and meniscus to intervene in OA-specific molecular and cellular alterations.

Naringin Mitigates Chondrocyte Apoptosis in Osteoarthritis by Suppressing the miR-29a-3p-Bax Pathway

The present study aims to explore potential therapeutic effects of Naringin on osteoarthritis (OA) and investigate the underlying mechanism. The chondrocytes in the joint usually undergo detrimental changes during OA progression, including increased apoptosis. miRNAs emerge as crucial regulators in this processes. The study delves into the intricate interplay between miR-29a-3p, BAX-mediated apoptosis, and Naringin intervention. Pro-inflammatory cytokines induce chondrocyte apoptosis in OA, impacting cell viability. Naringin treatment effectively restores cell survivability (1.8-fold change), inhibiting caspase activity (0.54-fold change) and lowering matrix metalloproteinases-9 (MMP-9) (0.50-fold change) and MMP-13 expression (0.50-fold change). Furthermore, COL2A1, Sox9, Runx2, TGF-β1, and BMP-4 levels in cytokines-stimulated chondrocytes were enhanced by Naringin, accompanied by decreased productions of MMP3 and MMP13. In cartilage tissues of OA rats, Osteoarthritis Research Society International (OARSI) scores in Safranin O staining were elevated, Pro-inflammatory cytokine productions and MMP3 and MMP13 expressions were enhanced, and COL2A1, Sox9, Runx2, TGF-β1, and BMP-4 levels were reduced, which were remarkably rescued by Naringin. We further revealed the intricate connection between miR-29a-3p and the chondrocyte fate. Elevated miR-29a-3p expression corresponds to increased apoptotic chondrocytes. Naringin suppresses miR-29a-3p, curbing apoptosis and suggesting a potential therapeutic avenue. Notably, BAX emerges as a key player, with miR-29a-3p influencing its expression. Naringin's mitigation of BAX upregulation underscores its protective role. Overall, we found the potential role of Naringin in addressing chondrocyte apoptosis in OA through miR-29a-3p-BAX modulation, offering insights into innovative OA management strategies.

RNA-binding protein HuR interacts with UFM1 mRNA to ameliorate chondrocyte inflammation, apoptosis and extracellular matrix degradation

OBJECTIVE

To investigate the mechanisms by which the RNA-binding protein HuR /ELAVL1 interacts with UFM1 mRNA to ameliorate chondrocyte inflammation, apoptosis, and extracellular matrix (ECM) degradation in osteoarthritis (OA).

METHODS

OA cartilage tissues were collected. A lipopolysaccharide-induced chondrocyte inflammation model was constructed and transfected with relevant sequences or plasmids, chondrocyte viability was detected by MTT, and chondrocyte apoptosis was detected by flow cytometry. OA was induced in rats via anterior cruciate ligament transection (ACLT), and lentiviral vectors mediating overexpression or silencing of HuR/UFM1 were administered via intra-articular injection following surgery. The pathology of cartilage tissue in rats was observed by hematoxylin and eosin staining and safranin O/fast green staining, apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, and Collagen II, Aggrecan, MMP3, and MMP13 were measured by immunohistochemistry. Western blot was conducted to measure PCNA, Cleaved-caspase 3, Collagen II, Aggrecan, MMP3 and MMP13. Inflammatory factors in chondrocyte supernatant and rat serum were detected using an enzyme-linked immunosorbent assay. HuR and UFM1 detection was performed using real-time fluorescence quantitative PCR and Western blot. Bioinformatics software, RIP, RNA pull down and mRNA stability analysis were combined to study the binding relationship between HuR and UFM1.

RESULTS

HuR expression was down-regulated in OA. HuR overexpression ameliorated OA chondrocyte inflammation, apoptosis, and ECM degradation, and HuR downregulation aggravated these pathologies. HuR regulated UFM1 stability by binding to UFM1 3'UTR. UFM1 expression was downregulated in OA and positively correlated with HuR expression. UFM1 silencing counteracted the ameliorative effect of HuR on OA chondrocyte inflammation, apoptosis, and ECM degradation.

CONCLUSION

HuR ameliorates OA chondrocyte inflammation, apoptosis, and ECM degradation through post-transcriptional regulation of UFM1.

Enhancing the Therapeutic Potential of Human Umbilical Cord Mesenchymal Stem Cells for Osteoarthritis: The Role of Platelet-Rich Plasma and Extracellular Vesicles

Osteoarthritis (OA) is a chronic degenerative joint disease. Our previous study demonstrated that extracellular vesicles (EVs) secreted by human umbilical cord mesenchymal stem cells (HUCMSCs), which play a crucial role in regenerative medicine, have therapeutic effects on OA. Additionally, platelet-rich plasma (PRP) has been widely used in musculoskeletal diseases as it promotes wound healing, angiogenesis, and tissue remodeling; however, its efficacy as a stand-alone therapy remains controversial. Therefore, we investigated the therapeutic effects of combining stem cell-derived EVs with PRP in an OA model. HUCMSC-derived EVs treated with PRP were used as the experimental group, whereas HUCMSC-derived EVs cultured with serum-free (SF) or exosome-depleted fetal bovine serum (exo(-)FBS) and PRP served as controls. PRP-treated HUCMSCs maintained their surface antigen characteristics and potential to differentiate into adipocytes, osteoblasts, and chondrocytes. In the OA model, mice treated with HUCMSCs + 5% PRP-derived EVs showed significantly improved motor function compared to controls and were comparable to those treated with HUCMSCs +SF and +exo(-)FBS-derived EVs. Additionally, increased type II collagen and aggrecan and decreased IL-1β expression were observed in cartilage transplanted with various EVs. In conclusion, PRP enhances HUCMSC differentiation, whereas treatment with EVs improves OA outcomes, providing a promising strategy for future clinical applications.

High glucose induces senescence in synovial mesenchymal stem cells through mitochondrial dysfunction

PURPOSE

To investigate the impact of high glucose on the senescence of synovial mesenchymal stem cells (SMSCs) and to elucidate the role of mitochondrial dysfunction in this process.

METHODS

‌SMSCs were treated with medium containing high glucose (25 mmol/L) or low glucose (5.5 mmol/L) concentrations. The effects of high glucose concentrations on the proliferation, senescence, mitochondrial reactive oxygen species (ROS) levels, mitochondrial fission, and mitophagy of SMSCs were investigated. First, the impact of 24-hour high glucose treatment on SMSCs was investigated‌. After this initial 24-hour exposure, the medium was subsequently changed to low glucose, and the cells were cultivated for an additional 24 h; this was then compared with the effects of continuous 48-hour high-glucose exposure and continuous 48-hour low-glucose exposure.

RESULTS

High glucose concentrations did not promote the proliferation of SMSCs but rather accelerated their senescence by ‌upregulating‌ the mRNA expression of senescence-associated secretory phenotype (SASP) genes and increasing the number of senescence-associated β-galactosidase (SA-β-gal)-positive cells. Additionally, high glucose ‌concentrations elevated‌ ROS levels in mitochondria and ‌facilitated‌ mitochondrial fission; they also ‌inhibited‌ the mitophagy of SMSCs by suppressing the expression of mitophagy-related proteins (PINK1, PARKIN, and LC3B). High glucose-induced suppression of mRNA (Il-6, Cxcl1, Dnm1, Pink1, Prkn, Lc3b) and protein (P21) expression, along with increased SA-β-gal-positive cell numbers and elevated MitoSOX intensity, can be reversed by terminating the high glucose treatment.

CONCLUSION

High glucose concentrations induce senescence in SMSCs via mitochondrial dysfunction, manifested as ROS accumulation, excessive fission, and mitophagy suppression. Glucose normalization reversed senescence phenotypes, accompanied by restored mitophagy and reduced oxidative stress. Mitochondrial dysfunction may be one of the key mechanisms underlying high glucose-induced senescence in SMSCs.

Acupotomy Ameliorates KOA Related Chondrocyte Premature Senescence Through YAP/FOXD1 Pathway

Purpose

Premature senescence of chondrocytes is a typical lesion of knee osteoarthritis (KOA). Abnormal cartilage stress can inhibit the mechanosensitive Yes-associated protein (YAP) / transcription factor forkhead box D1 (FOXD1) pathway, which is related to premature senescence of chondrocytes, thereby accelerating the progression of the lesion. This study aims to investigate whether acupotomy intervention could inhibit the premature senescence of chondrocytes and protect the cartilage of KOA rabbits.

Methods

18 male New Zealand rabbits were randomly divided into 3 groups (n = 6 each): control, KOA, and KOA + acupotomy (KOA+Apo). KOA, KOA+Apo rabbits were modeled by modified Videman's method for 6 weeks. After modeling, the KOA+Apo groups were subjected to acupotomy once a week for 3 weeks on the muscles around the left hind knee. The modified Lequesne MG score and passive range of motion (PROM) were used to evaluate the general condition and exercise ability of rabbits. Cartilage degeneration was detected by safranin O-fast green staining and transmission electron microscope(TEM). Type II collagen (Col-II) and aggrecan by immunohistochemistry (IHC), IL-7 and MMP-13 by Enzyme-Linked Immunosorbent Assay (ELISA), and p53, Rb1, p - YAP, YAP, FOXD1 by IHC, Western blot, or RT - PCR.

Results

Acupotomy effectively curbed cartilage degeneration and chondrocyte premature senescence in KOA rabbits. Mechanistically, it cut IL - 7 and MMP-13 levels, easing the inflammatory milieu and extracellular matrix degradation. It also regulated p53 and Rb1, controlling cell - cycle progression. Crucially, acupotomy upregulated the YAP/FOXD1 pathway, which, by affecting downstream genes, modulated IL - 7, MMP-13, p53, and Rb1 levels, acting as a pivotal molecular link in its regulatory effects.

Conclusion

Acupotomy may protect KOA rabbits' cartilage by inhibiting chondrocytes premature senescence via the YAP/FOXD1 pathway, offering a new theoretical basis for treating mechanically - induced KOA.

Injectable sustainable andrographolide-releasing hydrogel for long-lasting alleviation of osteoarthritis and regulation of chondrocyte autophagy via PRKCA/EGFR

Osteoarthritis is one of the most prevalent age-related joint diseases, with chondrocyte inflammation and autophagy dysregulation serving as pivotal pathogenesis factors. Andrographolide (AD), a phytochemical identified in Andrographis paniculata, exhibits anti-inflammatory properties and regulates autophagy to safeguard cells from damage. Nevertheless, the precise mechanism underlying the influence of AD on autophagy in osteoarthritis (OA) chondrocytes remains unelucidated. Concurrently, sustained efficacy of andrographolide typically necessitates prolonged administration, posing a challenge for its clinical application. We engineered an injectable 4-arm PEG-Mix-Hydrogel/PF system capable of encapsulating lipophilic drugs and achieving sustained release over a period of up to 24 days, substantially reducing the frequency of medication. Our findings indicate that andrographolide augments chondrocyte autophagy via the PRKCA/EGFR pathway and modulates chondrocyte inflammation as well as extracellular matrix degradation. Subsequent experimentation revealed that the injectable 4-arm PEG-Mix-Hydrogel/PF@AD (PHPF@AD) exhibited excellent biocompatibility with chondrocytes, possessed a rapid in-situ gelation time, and a single injection was sufficient to alleviate joint degeneration, abnormal gait, and weakened chondrocyte autophagy in OA mice, while ameliorating inflammation, matrix degradation, and apoptosis levels, and maintaining a certain degree of bone mass around the joints. In summary, this injectable hydrogel with spontaneous andrographolide release is anticipated to be a promising therapeutic modality for OA.

A Novel Curcumin-Loaded Nanoplatform Alleviates Osteoarthritis by Inhibiting Chondrocyte Ferroptosis

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the degradation of articular cartilage. Recent studies have demonstrated that chondrocyte ferroptosis plays a crucial role in the progression of OA. Consequently, developing nanomedicines that suppress chondrocyte ferroptosis is a promising strategy for OA treatment. However, there are few reports on nanomedicines specifically targeting chondrocyte ferroptosis for OA therapy. In this study, Curcumin-loaded nanoparticles (Cur-NPs) are fabricated to suppress chondrocyte ferroptosis by regulating reactive oxygen species (ROS), ferrous ion (Fe2⁺), and Acyl-CoA Synthetase Long-Chain Family Member 4 (ACSL4) levels of chondrocyte. This is achieved by combining the functions of curcumin and an amphiphilic block copolymer with ROS scavenging and iron-chelating properties. The in vitro anti-ferroptotic effects of Cur-NPs are thoroughly investigated. The findings indicate that Cur-NPs decrease the expression of ferroptosis markers such as ROS, Fe2⁺, and ACSL4, while protecting the mitochondrial membrane potential of chondrocytes. Additionally, Cur-NPs attenuated lipid peroxidation in chondrocytes. Furthermore, Cur-NPs significantly reduced the expression of the catabolic factor Matrix Metallopeptidase 13 (MMP13) and increased the expression of the anabolic factor Collagen type II (Col II) in vitro. This study demonstrates that Cur-NPs exhibit enhanced chondroprotective effects through anti-ferroptotic actions, presenting a promising approach for inhibiting chondrocyte ferroptosis using bioactive nanomaterials in OA treatment.

Dynamic compression modulates anabolic and catabolic activity in chondrocyte seeded agarose constructs

Mechanical stimulation is a widely used technique in the development of tissue engineered cartilage. While various regimes can enhance tissue growth and improve construct mechanical properties, existing outcome measures predominantly assess the anabolic effect of mechanical stimuli. Catabolic responses are generally overlooked, and a critical gap remains in how mechanical loading simultaneously affects both anabolic and catabolic processes. In this study, full-thickness articular cartilage was aseptically harvested from the metacarpal-phalangeal joints of skeletally mature bovine. Isolated chondrocytes were encapsulated in agarose gels and subjected to dynamic compressive strains from 0 % to 15 % for either 20 or 60 min using a custom-built mechanical stimulation device. Anabolism was assessed by [3H]-proline and [35S]-sulfate incorporation, while catabolism was evaluated by MMP-13 enzymatic activity. Long-term effects of dynamic loading were assessed through biochemical analyses and histological evaluation. Results showed that low-to-moderate strains (2.5 % and 5 %) induced high anabolic activity relative to control with minimal catabolic response. In contrast, high strains (15 %) resulted in elevated catabolic and reduced anabolic activity relative to control. The application of mechanical stimuli over the long-term elicited comparable responses with lower compressive stains leading to improved cartilaginous extracellular matrix accumulation. This study provides valuable insights into the complex interplay between anabolic and catabolic metabolism in chondrocyte-seeded agarose constructs subjected to dynamic compression. This research underscores the necessity of evaluating both responses to optimize the growth and properties of tissue-engineered cartilage.

Deciphering cartilage neuro-immune interactions and innervation profile through 3D engineered osteoarthritic micropathophysiological system

Osteoarthritis (OA) is an inflammatory musculoskeletal disorder that results in cartilage breakdown and alterations in the surrounding tissue microenvironment. Imbalances caused by inflammation and catabolic processes potentiate pathological nerves and blood vessels outgrowth toward damaged areas leading to pain in the patients. Yet, the precise mechanisms leading the nerve sprouting into the aneural cartilaginous tissue remain elusive. In this work, we aim to recapitulate in vitro the hallmarks of OA pathophysiology, including the sensory innervation profile, and provide a sensitive and reliable analytical tool to monitor the in vitro disease progression at microscale. Leveraging the use of patient-derived cells and bioengineering cutting-edge technologies, we engineered cartilage-like microtissues composed of primary human chondrocytes encapsulated in gelatin methacrylate hydrogel. Engineered constructs patterned inside microfluidic devices show the expression of cartilage markers, namely collagen type II, aggrecan, SOX-9 and glycosaminoglycans. Upon pro-inflammatory triggering, using primary human pro-inflammatory macrophage secretome, hallmarks of OA are recapitulated namely catabolic processes of human chondrocytes and the sensory innervation profile, supported by gene expression and functional assays. To monitor the OA micropathological system, a highly sensitive technology - EliChip™ - is presented to quantitively assess the molecular signature of cytokines and growth factors (interleukin 6 and nerve growth factor) produced from a single microfluidic chip. Herein, we report a miniaturized pathophysiological model and analytical tool to foster the neuro-immune interactions playing a role in cartilage-related disorders.

Effects of Oligomeric Proanthocyanidins on Cadmium-Induced Extracellular Matrix Damage via Inhibiting the ERK1/2 Signaling Pathway in Chicken Chondrocytes

Cadmium (Cd) is a toxic, non-essential metal that primarily enters animal bodies through the digestive and respiratory systems, leading to damage to multiple organs and tissues. Cd can accumulate in cartilage and induce damage to chondrocytes. Procyanidins (PAs), also known as concentrated tannic acid or oligomeric proanthocyanidins (OPCs), exhibit diverse biological and pharmacological activities. However, the mechanism of OPCs alleviates Cd-induced damage to chondrocytes in chickens remains to be further explored in vitro. Chondrocytes were isolated from both ends of the tibia of 17-day-old SPF chicken embryos, and then subsequently treated with various concentrations of Cd (0, 1, 2.5, 5, and 10 μmol/L) or OPCs (0, 5, 10, 20, and 40 μmol/L) to investigate the mechanism underlying extracellular matrix (ECM) degradation and damage. Cd reduced cell viability, glycosaminoglycan (GAG) secretion, and ECM degradation in chondrocytes by decreasing the expression of type II collagen alpha 1 (COL2A1) and aggrecan (ACAN) while increasing the release of cartilage oligomeric matrix protein (COMP), along with elevated levels of matrix-degrading enzymes, such as matrix metalloproteinases 1 (MMP1), MMP10, and MMP13, and a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) and ADAMTS5. Cd induced phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) and the expression of matrix-degrading enzymes, impairing ECM synthesis, an effect that could be alleviated by ERK1/2 inhibitor U0126. Chondrocytes were treated with 5 μmol/L Cd and 10 μmol/L OPCs, and it was found that OPCs inhibited the activation of the ERK1/2 signaling pathway and the expression of matrix-degrading enzymes, while promoting ECM synthesis and alleviating Cd-induced ECM damage in chickens. This study provides a theoretical basis for clinical research on OPCs with respect to the prevention and treatment of Cd-induced chondrogenic diseases in poultry.

MiR-103-3p regulates chondrocyte autophagy, apoptosis, and ECM degradation through the PI3K/Akt/mTOR pathway by targeting CPEB3

BACKGROUND

Chondrocyte apoptosis is associated with the severity of cartilage destruction and matrix degeneration in the progression of osteoarthritis. Increasing evidence indicates that autophagy has a significant cytoprotective effect against chondrocyte apoptosis. Here, we investigated the role of microRNA-103-3p (miR-103-3p) in regulating chondrocyte function and elucidated the underlying mechanism.

METHODS

MiR-103-3p expression in interleukin-1β (IL-1β)-stimulated chondrocytes was evaluated using RT-qPCR. The targets of miR-103-3p predicted by online databases were verified using biotin-based pulldown assay and luciferase reporter assay. IL-1β stimulated-chondrocytes were transfected with miR-103-3p inhibitor along with siRNA targeting cytoplasmic polyadenylation element-binding protein3 (siCPEB3), the autophagy inhibitor 3-MA, or the PI3K agonist 740 Y-P. Chondrocyte proliferation was evaluated using cell counting kit-8. Apoptosis was detected by flow cytometry. The levels of apoptosis-, extracellular matrix (ECM)-, autophagy-, and the PI3K/Akt/mTOR pathway-related proteins in chondrocytes were detected using immunoblotting or immunofluorescence.

RESULTS

We found that IL-1β stimulation upregulated miR-103-3p and downregulated CPEB3 in mouse chondrocytes. Inhibiting miR-103-3p reduced IL-1β-induced apoptosis and ECM macromolecule degradation while enhancing autophagy in chondrocytes. MiR-103-3p targeted CPEB3, and its downregulation rescued the expression of level in IL-1β stimulated-chondrocytes. MiR-103-3p downregulation inhibited the PI3K/Akt/mTOR pathway in IL-1β stimulated-chondrocytes by upregulating CPEB3. 3-MA, 740 Y-P, or CPEB3 knockdown counteracted the effect of miR-103-3p downregulation on chondrocyte apoptosis, ECM macromolecule degradation, and autophagy.

CONCLUSION

Overall, inhibition of miR-103-3p reduces IL-1β-induced apoptosis and ECM macromolecule degradation in chondrocytes by enhancing autophagy through the CPEB3/PI3K/Akt/mTOR pathway.

Low-intensity pulsed ultrasound inhibits chondrocyte senescence by inhibiting PI3K/AKT/mTOR signaling

Cellular senescence is an important cause of age-related degenerative diseases, including osteoarthritis (OA). Chondrocyte senescence is crucial in OA onset and progression. As a non-invasive, safe, and widely used physical rehabilitation factor, the effect and mechanism of low intensity pulsed ultrasound (LIPUS) on chondrocyte senescence remain unclear. This study evaluated the inhibitory effect of LIPUS on OA chondrocyte senescence in vitro and in vivo. The effect of LIPUS on chondrocyte senescence was examined by RT-qPCR, enzyme-linked immunosorbent assay (ELISA), and western blotting. Changes in levels of reactive oxygen species (ROS) and γ-h2ax foci in senescent chondrocytes were detected using fluorescent staining. Chondrocyte senescence was evaluated by senescence-associated β-galactosidase (SA-β-gal) staining. The PI3K inhibitor LY294002 and the PI3K agonist 740Y-P were used to investigate whether PI3K/AKT/mTOR signalling was involved in the effect of LIPUS in senescent chondrocytes. Chondrocyte senescence and cartilage degeneration were analyzed in a destabilization of the medial meniscal (DMM) mouse model by immunohistochemistry, hematoxylin and eosin staining, and safranin-O/fast green staining. LIPUS inhibited the expression of the senescence-associated secretory phenotype (SASP) factors CCL4 and CCL2 and the senescence phenotype in doxorubicin-treated chondrocytes by inhibiting the PI3K/AKT/mTOR pathway. LIPUS alleviated chondrocyte senescence and attenuated OA progression in the DMM mice. These results demonstrated a novel role for LIPUS in inhibiting chondrocyte senescence and the SASP by modulating PI3K/AKT/mTOR signalling. Our findings expanded the clinical application of LIPUS and provide a new, non-invasive, and safe treatment approach to prevent and treat age-related degenerative joint disorders.

Sodium alginate microspheres loaded with Quercetin/Mg nanoparticles as novel drug delivery systems for osteoarthritis therapy

BACKGROUND

Osteoarthritis (OA) is the most prevalent arthritic disease characterized by cartilage degradation and low-grade inflammation, for which there remains a lack of efficacious therapeutic interventions. Notably, mitigating the impact of oxidative stress (OS) and inflammatory factors could help alleviate or hinder the advancement of OA. Given the benefits of both quercetin (Que) and Magnesium ion (Mg2+) in OA treatment, coupled with the structural properties of Que, we have innovatively developed the Que-Mg2+ nanoparticles (NPs), aiming to deliver both Que and Mg2+ simultaneously and achieve enhanced therapeutic outcomes for OA. Moreover, to avoid the adverse reactions linked to frequent injections, sodium alginate (SA) microspheres encapsulating Que-Mg2+ NPs (Que-Mg@SA) were designed to treat the H2O2-induced OA cell model.

METHODS

Que-Mg@SA microspheres were synthesized using the ionotropic gelation technique, with calcium chloride acting as the cross-linking agent. Comprehensive characterization of the Que-Mg@SA was conducted through transmission electron microscope (TEM), dynamic light scattering (DLS), optical microscope, and scanning electron microscope (SEM), which provided detailed insights into their size, zeta potential, morphology, and micromorphology. Additionally, the microsphere swelling rate and Que release were evaluated. The biocompatibility of Que-Mg@SA microspheres, along with their impact on chondrocyte viability, were detected through CCK-8 assay and live/dead cell staining. Furthermore, the antioxidant and anti-inflammatory properties of Que-Mg@SA were evaluated by examining the ROS scavenging ability and pro-inflammatory factors levels, respectively. Finally, the regulatory influence of Que-Mg@SA microspheres on extracellular matrix (ECM) metabolism in OA was assessed by immunofluorescence staining and Western blot.

RESULTS

Characterization results revealed that Que-Mg NPs exhibit nanoscale diameter, exceptional stability, and good dispersibility, while Que-Mg@SA possesses high entrapment efficiency (EE%) and loading efficiency (LE%), pronounced hygroscopic properties, and sustained drug-release capabilities. Additionally, in vitro cellular assays revealed that the biocompatible Que-Mg@SA microspheres significantly restored chondrocyte viability, scavenged H2O2-induced excessive ROS, reduced the levels of inflammatory cytokines, upregulated cartilage anabolic gene expression, downregulated cartilage catabolic protease gene expression, and maintained the metabolic balance of cartilage tissue.

CONCLUSION

The functionalized Que-Mg@SA microspheres developed in our study hold great promise as a drug delivery system for OA and potentially other biomedical applications.

CLINICAL TRIAL NUMBER

Not applicable.

Rethinking Osteoarthritis Management: Synergistic Effects of Chronoexercise, Circadian Rhythm, and Chondroprotective Agents

Osteoarthritis (OA) is a chronic and debilitating joint disease characterized by progressive cartilage degeneration for which no definitive cure exists. Conventional management approaches often rely on fragmented and poorly coordinated pharmacological and non-pharmacological interventions that are inconsistently applied throughout the disease course. Persistent controversies regarding the clinical efficacy of chondroprotective agents, frequently highlighted by pharmacovigilance agencies, underscore the need for a structured evidence-based approach. Emerging evidence suggests that synchronizing pharmacotherapy and exercise regimens with circadian biology may optimize therapeutic outcomes by addressing early pathological processes, including low-grade inflammation, oxidative stress, and matrix degradation. Recognizing the influence of the chondrocyte clock on these processes, this study proposes a 'prototype' for a novel framework that leverages the circadian rhythm-aligned administration of traditional chondroprotective agents along with tailored, accessible exercise protocols to mitigate cartilage breakdown and support joint function. In addition, this model-based framework emphasizes the interdependence between cartilage chronobiology and time-of-day-dependent responses to exercise, where strategically timed joint activity enhances nutrient and waste exchange, mitigates mitochondrial dysfunction, supports cellular metabolism, and promotes tissue maintenance, whereas nighttime rest promotes cartilage rehydration and repair. This time-sensitive, comprehensive approach aims to slow OA progression, reduce structural damage, and delay invasive procedures, particularly in weight-bearing joints such as the knee and hip. However, significant challenges remain, including inter-individual variability in circadian rhythms, a lack of reliable biomarkers for pharmacotherapeutic monitoring, and limited clinical evidence supporting chronoexercise protocols. Future large-scale, longitudinal trials are critical to evaluate the efficacy and scalability of this rational integrative strategy, paving the way for a new era in OA management.

Deficiency of ATF2 retards senescence induced by replication stress and pamidronate in mouse jaw bone marrow stem cells

The aging process is associated with a loss of bone mass and an accumulation of senescent cells, which is under epigenetic control. Morphological and molecular analysis revealed a notable reduction in bone mass and alveolar crest height in aged mice, accompanied by increased levels of senescent mouse jaw bone marrow stem cells (mJBMSCs). To investigate whether specific transcription factors are involved, assay for transposase-accessible chromatin with sequencing (ATAC-seq) was performed on mJBMSCs isolated from 2-, 4-, 8-, and 20-month-old mice. In 20-month-old mJBMSCs, increased chromatin accessibility was observed alongside elevated expression of activating transcription factor 2 (ATF2) in both cells and alveolar bone. Silencing Atf2 in mJBMSCs failed to reverse physiological aging, but delayed replication stress and pamidronate (PAM) induced senescence. The analysis of ATAC-seq and RNA sequencing indicated that the differentially expressed genes upregulated by PAM but downregulated by ATF2 deficiency were related to some key biological processes, including negative regulation of cell proliferation, inflammatory response, adipogenesis, and cellular senescence. The dual-luciferase assay was conducted to demonstrate that ATF2 enhances Cdkn2a transcription by binding to its promoter region. Our findings suggest significant chromatin alterations in aged mJBMSCs, positioning ATF2 as a potential target for combating externally induced senescence.

Upregulating lncRNA GUSBP11 protects chondrocytes from IL-1β-induced inflammatory damage via inhibiting miR-122-5p

Studies have demonstrated that several lncRNAs exhibit abnormal expression levels in patients suffering from osteoarthritis, and in-depth investigation of these aberrantly expressed lncRNAs may pave the way for innovative therapeutic strategies targeting OA. The aim of this study was to examine the expression of glucuronidase beta pseudogene 11 (GUSBP11) in OA patients and to elucidate its potential molecular mechanism. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to detect GUSBP11 levels on cartilage tissues and serum samples obtained from OA patients. To establish an in vitro OA cell model, interleukin-1β (IL-1β) was utilized to induce CHON-001 and ATDC5 cell lines. Cell counting kit-8 (CCK-8) assay and flow cytometry were performed to evaluate cell viability and apoptosis, and enzyme-linked immunosorbent assay (ELISA) was employed to qualify the levels of inflammatory factors. StarBase database predicted that miR-122-5p was the target gene of GUSBP11. Subsequently, luciferase reporter genes were conducted to validate this interaction. Potential target genes of miR-122-5p were predicted, followed by gene function annotation and correlation analysis of these targets. Our findings revealed that GUSBP11 expression was markedly decreased in both the cartilage tissues and serum of OA patients. Diminished levels of GUSBP11 showed high diagnostic accuracy for OA. In the IL-1β-induced OA cell model, GUSBP11 expression was notably reduced, leading to decreased cell viability, an increase in apoptotic cells, and elevated levels of inflammatory factors. Up-regulation of GUSBP11 significantly ameliorated these adverse effects. Luciferase reporter genes confirmed the interaction between GUSBP11 and miR-122-5p, indicating that an increase in miR-122-5p drastically inhibited cell viability while promoting apoptosis and inflammation. In conclusion, within the context of the in vitro OA cell model, GUSBP11 appears to exacerbate IL-1β-induced chondrocyte inflammation through the up-regulation of miR-122-5p. This underscores the potential of GUSBP11 as a novel target and avenue for therapeutic intervention in the treatment of OA.

MMP expression and its clinical significance in intervertebral disc destruction of spinal tuberculosis, Brucellar spondylitis, and pyogenic spondylitis

OBJECTIVE

This study is designed to investigate the roles of MMP-2, MMP-9, and MMP-13 in intervertebral disc destruction resulting from different types of spinal infections and their correlations with clinical quantitative data.

METHODS

Disc tissue samples were collected from 60 patients with spinal infections (20 cases each of STB, BS, and PS in the infection group) and 20 patients with intervertebral disc herniation (control group). The expressions of MMP-2, MMP-9, and MMP-13 were detected by RT-qPCR. Correlation analysis was carried out with clinical quantitative data such as preoperative erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), and related blood routine indicators in the infection group.

RESULTS

In the analysis between the infection group and the control group, MMP-13 was expressed in the diseased intervertebral disc tissue of STB patients, but the result was not statistically significant (P = 0.2172). There was a significant difference in the expression of MMP-13 in the diseased intervertebral discs of BS and PS patients. The expressions of MMP-9 and MMP-2 were markedly increased in the diseased intervertebral disc tissue of STB, BS, and PS patients (all P < 0.05). In the inter-group analysis of the infection group, the expression of MMP-13 in the diseased intervertebral disc tissue of PS patients was significantly different from that of STB and BS (P < 0.0001), while there was no significant difference between the STB and BS groups (P = 0.2393). The expression of MMP-9 in the diseased intervertebral disc tissue of STB patients was significantly different from that of BS and PS (P < 0.0001), but there was no statistically significant difference between the BS and PS groups (P = 0.9643). There was no statistically significant difference in the expression of MMP-2 among the STB, BS, and PS groups. In the correlation analysis with clinical quantitative data, MMP-13 was positively correlated with CRP, ESR, IL-6, WBC, and NEUT levels (r values were 0.7346, 0.3465, 0.3326, 0.6347, and 0.5152 respectively), and negatively correlated with LYM level (r = -0.5152, P < 0.05), and had no correlation with PCT and MXD levels. MMP-9 was positively correlated with ESR level (r = 0.3412, P < 0.05) and had no correlation with CRP, IL-6, PCT, WBC, NEUT, and LYM levels. MMP-2 was positively correlated with NEUT and LYM levels (r values were 0.3021 and 0.3306 respectively, P < 0.05) and had no correlation with ESR, CRP, IL-6, PCT, and WBC levels.

CONCLUSION

MMP-2, MMP-9, and MMP-13 play crucial roles in intervertebral disc destruction due to spinal infections. The differential expression of MMPs may be one of the reasons for the varying degrees of intervertebral disc destruction in different types of spinal infections. Moreover, when clinical indicators such as CRP, ESR, IL-6, WBC, and NEUT increase, it suggests that the expression of MMP-13 in the intervertebral disc at the lesion site significantly rises, and it may become a new target for the treatment of spinal infections in the future.

Potential Chondroprotective Effect of Artemisia annua L. Water Extract on SW1353 Cell

Inflammation plays a critical role in the pathogenesis of osteoarthritis (OA). The objective of this study was to investigate the anti-inflammatory and chondroprotective properties of Artemisia annua L. water extract (AWE) following the induction of inflammation in cartilage cells (SW1353 cell) through the administration of interleukin-1 beta (IL-1β). We demonstrated significant antioxidant activity, as evidenced by elevated total phenolic and flavonoid content, in addition to robust free radical scavenging capacity, as assessed through DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Its cytotoxic effects were assessed at a concentration of 200 μg/mL, where no cytotoxic signs were observed in SW1353 cells treated with IL-1β; the levels of reactive oxygen species (ROS) were notably reduced in a dose-dependent manner. The principal inflammatory markers, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), were significantly diminished by AWE treatment. AWE administration led to a dose-dependent reduction in the expression of key proteins involved in the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathways, ultimately resulting in a decrease in the release of matrix metalloproteinases (MMPs), specifically MMP-1 and MMP-13, which are known to contribute to cartilage degradation. Additionally, the levels of degraded collagen type II in the cartilage cells were restored. These findings suggest that reducing oxidative stress and inflammation, along with inhibiting activated MAPK and NF-κB signaling pathways, may ameliorate the progression of IL-1β-induced OA. Furthermore, a molecular docking analysis revealed a strong binding affinity of MMP-13, a critical mediator in the pathogenesis of OA. Six compounds were identified in AWE, corroborating its potential antioxidant and anti-inflammatory effects. Therefore, AWE may serve as a potentially useful therapeutic agent against OA by modulating inflammation-related mechanisms.

Role of lncRNA XIST/miR-146a Axis in Matrix Degradation and Apoptosis of Osteoarthritic Chondrocytes Through Regulation of MMP-13 and BCL2

Growing evidence demonstrates the critical roles of long non-coding RNAs (lncRNAs) in osteoarthritis (OA) pathogenesis. The lncRNA XIST is one of the most commonly studied; however, its function remains unclear. This study aimed to research the molecular mechanism of XIST in human OA chondrocytes. Cells were transfected with small interfering RNA against XIST or with a microRNA (miR)-146a inhibitor in the presence of interleukin (IL)-1β. Viability was detected using MTT; apoptosis using cytometry; and XIST, miR-146a, B-cell lymphoma (BCL)2, and metalloproteinase (MMP)-13 expression using real-time PCR. The analysis of p50 and p65 nuclear factor (NF)-κB was conducted using PCR and immunofluorescence. Our findings showed that XIST was highly expressed in OA chondrocytes when compared to T/C-28a2 lines. Furthermore, XIST silencing significantly promoted survival and limited apoptosis, with a concomitant over expression of BCL2, reduction in MMP-13 mRNA, and NF-κB activation after IL-1β stimulus. Conversely, miR-146a was significantly down-regulated in OA cells, while its levels were increased following XIST silencing; moreover, miR-146a inhibition induced opposite results to those caused by XIST. Finally, the down-regulation of XIST was correlated to the over-expression of miR-146a, with a consequent modulation of BCL2, MMP-13, and NF-κB. This study suggests an influence of the XIST/miR-146a axis on the viability, apoptosis, and matrix degradation occurring in OA.

MMP13 mRNA Expression Level as a Potential Marker for Knee OA Progression-An Observational Study

Background/Objectives: Osteoarthritis (OA) is a very common degenerative joint disease that has a significant negative impact on patients' lives and which can lead to functional limitations and disability. Matrix metalloproteinase 13 (MMP-13) is a key enzyme responsible for the degenerative changes in cartilage occurring during the pathogenesis of OA. This cohort study analyzed the differences in the expression level of MMP13 mRNA in articular cartilage with subchondral bone and in the synovium of patients with OA, according to the disease stage, in order to develop potential markers for OA progression, as well as for the degree of pain perception, in order to discover a molecular biomarker related to pain. Methods: In thirty-one patients (n = 31), the expression level of the studied gene was assessed in the affected and unaffected areas of the knee joint using the qPCR method. Statistical analysis was performed using the Mann-Whitney U test, the Kruskal-Wallis test, and Spearman's rank correlation coefficient. Results: A significantly higher expression level of MMP13 mRNA was noticed in the OA-affected articular cartilage with subchondral bone compared to the control tissue (p = 0.027, Mann-Whitney U test). The expression level of MMP13 mRNA was higher in patients with stage 4 knee OA than in those with stage 3, but the difference in MMP13 mRNA expression level was statistically insignificant (p > 0.05, Mann-Whitney U test). A higher MMP13 mRNA expression level was noticed in the OA-affected synovium compared to the control tissue (median RQ: 0.068 and 0.037, respectively), but these differences were not significant (p > 0.05, Mann-Whitney U test). A significantly higher MMP13 mRNA expression level was observed in the synovium of stage 4 knee OA patients compared to stage 3 patients (p = 0.015, Mann-Whitney U test). There was no significant difference in the expression level of MMP13 mRNA between both tissues, i.e., the articular cartilage with subchondral bone and the synovium from the stage 3 group and the control tissue (p > 0.05, Mann-Whitney U test); however, a significant difference was found between these tissues in stage 4 and in the control tissue (p = 0.014, Mann-Whitney U test). Conclusions: The results of our pilot study indicated the diagnostic potential of MMP13 mRNA and proved its role in the development and progression of OA. Further studies are needed to verify the potential utility of MMP13 mRNA in the development of molecularly targeted therapy for patients with OA.

Three-dimensional cell culture-derived extracellular vesicles loaded alginate/hyaluronic acid composite scaffold as an optimal therapy for cartilage defect regeneration

Osteoarthritis (OA) is a chronic musculoskeletal disease characterized by joint inflammation and progressive degeneration of articular cartilage. Currently a definitive cure for OA remains to be a challenge due to the very low self-repair capacity of cartilage, thus development of more effective therapies is needed for cartilage repair. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have shown great potential as therapeutic agents for stimulating regeneration of articular cartilage. However, a standardized protocol is still lacking for manufacturing of highly active EVs for clinical applications. This study aimed to investigate the efficient production of highly active EVs by 3-dimensional (3D) MSC culture, verify the reparative efficacy of EVs on cartilage defect and elucidate the repair mechanisms. Umbilical cord MSCs were embedded in alginate to form MSC spheroids for 3D culture in human platelet lysate (hPL)-containing medium, which produced 3D culture-derived EVs (3D-EVs) with a significantly improved yield. The 3D-EVs expressed higher level of VEGF, and appeared superior to two-dimensional (2D) monolayer MSC culture-derived EVs (2D-EVs) to improve migration and proliferation in MSCs and inflammatory chondrocytes, and to suppress expression of cartilage-degrading factors. Importantly, the 3D-EVs and sodium alginate (SA)-hyaluronic acid (HA) composite hydrogel (3D-EVs/SA-HA) demonstrated significantly improved therapeutic efficacy than 2D-EVs/SA-HA hydrogel for repair of cartilage defectin vivo. The underlying mechanisms are associated with the concomitant upregulation of type II collagen and cartilage synthesis and downregulation of MMP13 in cartilage tissues. Collectively, these data showed that highly active MSC EVs could be efficiently manufactured by 3D cell culture with hPL-containing medium, and these EVs were superior to 2D-EVs for the repair of articular cartilage defect.

Low-dose Radiation Therapy (LDRT) in Managing Osteoarthritis: A Comprehensive Review

Osteoarthritis (OA) is the most common degenerative arthropathy, impacting the quality of life for millions worldwide. It typically presents with chronic pain, stiffness, and reduced mobility in the affected joints. Nonsurgical treatments like physiotherapy or pharmacotherapy may provide limited relief and may have adverse effects and complications. Recently, low-dose radiation therapy (LDRT) has emerged as a potential alternative for managing OA, utilizing its anti-inflammatory effects. LDRT's anti-inflammatory effects involve modulating immune responses, reducing pro-inflammatory cytokines, and inducing apoptosis in inflammatory cells. Clinical studies show varying degrees of symptom relief, with some patients experiencing pain reduction and improved joint mobility while others show minimal response. The variability in LDRT treatment designs, radiation dosages, and patient populations complicates standardized treatment protocols and raises concerns about potential carcinogenic risks. Despite these issues, LDRT shows promise as an alternative to other OA treatments, especially for patients who don't respond to other treatments. This review aims to provide updated information on the effectiveness, mechanisms, and safety of LDRT in treating OA. We reviewed the literature of studies on the safety and efficacy of LDRT on affected joints by OA, its biological effects, potential therapeutic and adverse effects, application and contraindications, clinical outcomes, and clinical evidence in subjects with OA.

Application of cell therapy in rheumatoid Arthritis: Focusing on the immunomodulatory strategies of Mesenchymal stem cells

Rheumatoid arthritis (RA) is a common chronic autoimmune disease that primarily affects the joints, leading to synovial inflammation and hyperplasia, which subsequently causes joint pain, swelling, and damage. The microenvironment of RA is characterized by hypoxia, high reactive oxygen species (ROS), low pH, and levels of high inflammatory factors. Traditional treatments only partially alleviate symptoms and often cause various adverse reactions with long-term use. Therefore, there is an urgent need for safer and more effective treatments. In recent years, mesenchymal stem cells (MSCs) have shown significant potential in treating RA due to their diverse immunomodulatory mechanisms. MSCs paracrine a variety of soluble factors to improve the inflammatory microenvironment in RA patients by inhibiting T cell proliferation or inducing T cell differentiation to regulatory T cells (Tregs), inhibiting B cell proliferation and differentiation and immunoglobulin production, prompting macrophage polarization toward an anti-inflammatory phenotype, and inhibiting neutrophil recruitment and preventing the maturation of dendritic cells (DCs). This review summarizes the immunomodulatory effects of MSCs in RA and their application in animal models and clinical trials. Although the immunomodulatory mechanisms of MSCs are not yet fully elucidated, their significant potential in RA treatment has been widely recognized. Future research should further explore the immunomodulatory mechanisms of MSCs and optimize their functions in different pathological microenvironments to develop more effective and safer therapeutic strategies.

Characterization of a chemically induced osteoarthritis model in zebrafish

Osteoarthritis (OA) is characterized by the progressive degeneration of the synovial joint, leading to irreversible damage to articular cartilage and subchondral bone. While animal models have advanced our understanding of OA, numerous unresolved issues still remain. The zebrafish, known for its transparent body, rapid developmental, and impressive regenerative capabilities, offers substantial potential for osteoarthritis research. This study seeks to establish a new OA model utilizing the zebrafish jaw joint, acting as a supplement to traditional animal models. In the future, this model could serve as a valuable platform for delving deeper into the mechanisms of this disease, as well as for advancing drug discovery and therapeutic interventions. Leveraging the skeletal structure of zebrafish, we targeted the largest jaw joint for our research. A custom fixation device was crafted, and a microinjection system was utilized to inject mono-iodoacetate (MIA) or collagenase type II (CTII) into the joint cavity of zebrafish. Subsequent analyses included histological staining, immunohistochemistry, OA research society international (OARSI) scoring, and real-time in vivo imaging were performed at 7, 14, and 28 days post injection. Our results effectively demonstrated the presence of synovial inflammation and cartilage damage within the zebrafish mandible, affirming the feasibility of inducing OA in zebrafish. In conclusion, the local injection of chemical agents into the joint cavity of zebrafish effectively induced the occurrence of OA. Establishing the zebrafish OA model enhances the array of animal models available for OA research. Moreover, zebrafish present distinct advantages, including robust regenerative abilities, genetic editing simplicity, and efficient drug screening. Consequently, this offers a fresh avenue for investigating the pathogenesis, prevention, and potential therapeutic approaches for human OA.

Yiqi Yangxue formula inhibits cartilage degeneration in knee osteoarthritis by regulating LncRNA-UFC1/miR-34a/MMP-13 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Knee osteoarthritis (KOA) is a prevalent and disabling clinical condition affecting joint structures worldwide. The Yiqi Yangxue formula (YQYXF) is frequently prescribed in clinical settings for the treatment of KOA. Existing research has primarily focused on alterations in drug metabolism, with limited investigation into the epigenetic effects of YQYXF, particularly in relation to non-coding RNA.

AIM OF THE STUDY

Exploring the effects of YQYXF on critical factors of long chain non-coding RNA UFC1/miR-34a/matrix metalloproteinase-13 (MMP-13) axis and their interrelationships.

METHODS

UHPLC-QE-MS technology was used to identify the YQYXF ingredients in rat serum. KEGG and GO analysis were performed on the targets of blood components acting on KOA using a database. Simultaneously, a protein interaction network was constructed using target proteins and metabolites to identify the core components and key pathways of YQYXF. The KOA rat model was established using an improved Hulth method. SPF SD rats were randomly divided into normal group, sham surgery group, model group, celecoxib capsules group (18 mg/kg), YQYXF low, medium and high dose groups (4.6 g/kg, 9.2 g/kg, 18.4 g/kg). Observe the synovial and cartilage tissues of rats using pathological methods. RT-PCR was used to detect the levels of UFC1, miR-34a, and MMP-13 in cartilage. Immunohistochemistry was used to detect the levels of MMP-13 and ADAMTS-5 in cartilage. ELISA method was used to detect the levels of MMP-13 and ADAMTS-5 in serum. In addition, we further validated the regulation of crucial factor expression levels of UFC1/miR-34a/MMP-13 axis in rat chondrocytes and degenerative chondrocytes of KOA patients by YQYXF, providing a basis for its treatment of KOA.

RESULTS

The compounds that YQYXF enters the bloodstream mainly contain flavonoids and phenylpropanoid compounds. The core components that act on OA include quercetin, fisetin, and demethylweldelolactone. The main target pathways are the IL-17 signaling pathway, lipid and atherosclerosis, cellular sensitivity, inflammatory mediator regulation of TRP channels, TNF signaling pathway, relaxin signaling pathway and C-type lectin receptor signaling pathway. YQYXF inhibited the expression of miR-34a and MMP-13 mRNA, and reduced the protein levels of MMP-13 and ADAMTS-5. In vitro studies have confirmed that 20% YQYXF serum promoted UFC1 and reduce miR-34a levels. In addition, miR-34a in sh-UFC1+10% YQYXF serum and sh-UFC1+20% YQYXF serum groups significantly decreased compared to the sh-UFC1 group.

CONCLUSION

The anti-KOA cartilage degeneration effect of YQYXF might be related to inhibiting cell apoptosis and promoting cell proliferation, which regulated the lncRNA-UFC1/miR-34a/MMP-13 axis.

Effects of adipose allograft matrix on viability of humeral head cartilage and rotator cuff tendon

BACKGROUND

Rotator cuff repairs may fail because of compromised blood supply, suture anchor pullout, or poor fixation to bone. To augment the repairs and promote healing of the tears, orthobiologics, such a platelet-rich plasma (PRP), and biologic scaffolds have been applied with mixed results. Adipose allograft matrix (AAM), which recruits native cells to damaged tissues, may also be a potential treatment for rotator cuff tears.

METHODS

To assess the potential use of AAM on rotator cuff tears, humeral head cartilage and subscapularis tendon were collected from patients undergoing reverse shoulder arthroplasty (RSA). Punch biopsies of the tissues were used to create explants for tissue culture, and the remaining tissue was digested to isolate the chondrocytes and tenocytes for cell culture. Explants and cells were then cultured in media containing AAM. After 48 h, the tissues and cells were measured for cell viability, cell proliferation, extracellular matrix (ECM) and metalloproteinase (MMP) gene expression and for MMP, inflammatory cytokine, and growth factor concentrations.

RESULTS

Cell viability was increased in humeral head chondrocytes and rotator cuff tenocytes cultured with AAM. Gene expression of the matrix proteoglycan, aggrecan, and of the proteolytic enzyme MMP-13 were downregulated in humeral head chondrocytes. MMP-13 concentrations were increased in subscapularis tenocytes and in humeral head chondrocyte/subscapularis tenocyte co-cultures. The anti-inflammatory cytokine, IL-1ra was increased in cartilage/tendon explant co-cultures. TGF-β1 concentrations were increased in chondrocytes, but decreased in tenocytes.

CONCLUSIONS

Overall, AAM had no significant negative effects on the cells or explants. The results of these experiments provide the basis for the future use of AAM as a scaffolding for tissue engineering, preclinical animal models of rotator cuff tear and glenohumeral osteoarthritis, and clinical models.

CLINICAL TRIAL NUMBER

Not applicable.

Duhuo Jisheng Decoction in reduction of inflammatory response via Transforming growth factor-β/Smad signaling pathway for repairing rabbit articular cartilage Injury: A Randomized Controlled Trial

OBJECTIVE

This study aims to investigate the mechanism underlying the effect of Duhuo Jisheng Decoction on the repair of rabbit articular cartilage injury through a reduction in the inflammatory response mediated by the Transforming growth factor (TGF)-β/Smad signaling pathway.

METHODS

A rabbit articular cartilage injury model was constructed using a ring bone extraction drill. Twenty-four Japanese white rabbits were randomly divided into six groups, namely Sham operation, model, low-dose Duhuo Jisheng Decoction, medium-dose Duhuo Jisheng Decoction, high-dose Duhuo Jisheng Decoction, and positive control groups. The treatment lasted 12 weeks. Gross observation, International Cartilage Repair Society score, Wakitani score, and Micro-computed tomography analysis were used to evaluate the structural repair of cartilage injury. Histology and immunohistochemistry were used to observe the proteoglycan, P-TβRII, P-Smad2, and type II collagen expression levels. Enzyme-linked immunosorbent assay was used to analyze the concentrations of Matrix Metalloproteinase-13 and Syndecan-4 in the joint fluid; and RT-PCR and Western Blot were used to observe the mRNA and protein expressions of ALK5, Sox-9, P-Smad3, and TGF-β1 at the injury repair site.

RESULTS

The repair effect of cartilage injury, as seen through gross observation and quantitative scoring, was better in all the Duhuo Jisheng Decoction treatment groups than in the model group. The medium dose group of Duhuo Jisheng Decoction had the best repair effect. We observed remarkable structural restoration of cartilage injury in the medium-dose Duhuo Jisheng Decoction group, with the subchondral bone presenting a distinct hierarchy, and parameters such as bone volume fraction and trabecular separation/spacing being significantly augmented. We found high expression levels of proteoglycans, P-TβRII, P-Smad2, and type II collagen. The concentrations of Matrix Metalloproteinase-13 and Syndecan-4 in the joint fluid were significantly lower following treatment. The low gene expression levels of ALK5, Sox-9, P-Smad3, and TGF-β1 in the injury site of the model group could be reversed in the medium-dose Duhuo Jisheng Decoction group.

CONCLUSION

Duhuo Jisheng Decoction can repair rabbit cartilage injury and reverse the levels of inflammatory factors in the joint fluid. The mechanism underlying its therapeutic effect is related to the activation of the TGF-β/Smad signaling pathway. This study provides a reliable basis for using Duhuo Jisheng Decoction to treat cartilage injury following knee osteoarthritis.

Inflammatory microenvironment promotes extracellular matrix degradation of chondrocytes through ALKBH5-dependent Runx2 m6A modification in the pathogenesis of osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the breakdown of cartilage and extracellular matrix (ECM). The degradation of ECM in chondrocytes plays a crucial role in OA pathogenesis, but the underlying molecular mechanisms remain largely unclear.

METHODS

A sodium monoiodoacetate (MIA) mouse model was used to mimic OA. ECM integrity was accessed by Hematoxylin and Eosin (H&E) staining, Safranin O/fast green staining, and microcomputerized tomography. Enzyme-linked immunosorbent assay measured circulating proinflammatory cytokines. Reverse transcription-quantitative polymerase chain reaction and western blotting analyzed mRNA and protein expression levels. RNA and chromatin immunoprecipitation evaluated RNA-protein and DNA-protein interactions.

RESULTS

MIA mice showed significant upregulation of the RNA m6A demethylase ALKBH5 (alkylated DNA repair protein AlkB homolog 5), the transcription factor Runx2 (runt-related transcription factor 2), and matrix-degrading enzymes Mmps (matrix metallopeptidase) and Adamts(s) (a disintegrin and metalloproteinase with thrombospondin motifs). In vitro, proinflammatory cytokines induced these proteins in chondrocytes. Mechanically, Alkbh5 cooperated with Ythdf1 (YTH N6-methyladenosine RNA binding protein 1) in the inflammatory microenvironment to regulate the expression and stability of RUNX2 mRNA. Runx2, in turn, activated the expression of MMPs and ADAMTSs, promoting ECM degradation in chondrocytes, thereby contributing to OA progression. Notably, inhibition of Alkbh5 and Runx2 in MIA-treated mice significantly alleviated the pathological progression of OA.

CONCLUSION

Our results reveal a novel mechanism of OA pathogenesis and suggest that targeting Alkbh5 and Runx2 may represent a new therapeutic strategy for OA treatment.

Extracellular Vesicles Derived from Human Umbilical Mesenchymal Stem Cells Transfected with miR-7704 Improved Damaged Cartilage and Reduced Matrix Metallopeptidase 13

We aimed to explore the therapeutic efficacy of miR-7704-modified extracellular vesicles (EVs) derived from human umbilical cord mesenchymal stem cells (HUCMSCs) for osteoarthritis (OA) treatment. In vitro experiments demonstrated the successful transfection of miR-7704 into HUCMSCs and the isolation of EVs from these cells. In vivo experiments used an OA mouse model to assess the effects of the injection of miR-7704-modified EVs intra-articularly. Walking capacity (rotarod test), cartilage morphology, histological scores, and the expression of type II collagen, aggrecan, interleukin-1 beta, and matrix metalloproteinase 13 (MMP13) in the cartilage were evaluated. The EVs were characterized to confirm their suitability for therapeutic use. IL-1beta-treated chondrocytes increased type II collagen and decreased MMP13 after treatment with miR-7704-overexpressed EVs. In vivo experiments revealed that an intra-articular injection of miR-7704-overexpressed EVs significantly improved walking capacity, preserved cartilage morphology, and resulted in higher histological scores compared to in the controls. Furthermore, the decreased expression of MMP13 in the cartilage post treatment suggests a potential mechanism for the observed therapeutic effects. Therefore, miR-7704-overexpressed EVs derived from HUCMSCs showed potential as an innovative therapeutic strategy for treating OA. Further investigations should focus on optimizing dosage, understanding mechanisms, ensuring safety and efficacy, developing advanced delivery systems, and conducting early-phase clinical trials to establish the therapeutic potential of HUCMSC-derived EVs for OA management.

Wharton's Jelly Mesenchymal Stem Cells: Shaping the Future of Osteoarthritis Therapy with Advancements in Chitosan-Hyaluronic Acid Scaffolds

This review explores the potential of Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) in cartilage regeneration and osteoarthritis treatment. It covers key factors influencing chondrogenesis, including growth factors, cytokines, and hypoxia, focusing on precise timing. The effectiveness of three-dimensional cultures and scaffold-based strategies in chondrogenic differentiation is discussed. Specific biomaterials such as chitosan and hyaluronic acid are highlighted for tissue engineering. The document reviews clinical applications, incorporating evidence from animal research and early trials and molecular and histological assessments of chondrogenic differentiation processes. It addresses challenges and strategies for optimizing MSC-derived chondrocyte therapy, emphasizing the immunomodulatory properties of these cells. The review concludes as a comprehensive road map for future research and clinical applications in regenerative medicine.

Early Intervention With Boiogito to Suppress Knee Osteoarthritis Progression: An Experimental Approach Using a Medial Meniscus Instability Rat Model

Background Knee osteoarthritis (KOA) is a prevalent and chronic condition characterized by swelling, pain, and limited range of motion of the knee due to degenerative changes in joint structures, leading to impairment in performing daily activities. Although conservative treatments, such as exercise therapy and nonsteroidal anti-inflammatory drugs are employed, there are few effective therapeutic options for preventing disease progression. During early KOA, there is osteoclast proliferation in the subchondral bone, disruption in cartilage homeostasis, elevation of matrix metalloproteinase-13 (MMP-13) levels, and reduction in tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) levels. Boiogito (BOT), which is a traditional Japanese medicinal formula, attenuates KOA progression, however, its effects when administered after KOA progression remain unclear. This study aimed to assess the therapeutic efficacy of BOT in preventing KOA progression in a rat model by focusing on its effects on motor function, subchondral bone turnover, and cartilage degradation in relation to the timing of administration. Methods A rat KOA model was created by destabilizing the medial meniscus (DMM). Rats were divided into Sham, DMM, DMM + BOT (0w, BOT administered immediately post-surgery), and DMM + BOT (3w, BOT administered 3 weeks post-surgery) groups. BOT was included in the diet at 1% (w/w). Motor function was evaluated biweekly by a treadmill running test, while structural changes in the knee were assessed by measuring the medial meniscus extrusion ratio (MMER) using computed tomography (CT). Histological and immunohistochemical analyses were conducted to evaluate joint degeneration via the Osteoarthritis Research Society International (OARSI) score, osteoclast numbers in subchondral bone through tartrate-resistant acid phosphatase (TRAP) staining, and MMP-13/TIMP-1 ratios in articular cartilage. Results Treadmill testing revealed that the DMM + BOT (0w) had significantly higher running speeds compared with the DMM and DMM + BOT (3w) groups. In all groups that underwent DMM surgery, the MMER was not significantly different. Histological assessments showed that the DMM + BOT (0w) group had lower OARSI scores and reduced osteoclast numbers in the subchondral bone compared with the DMM group. Immunohistochemical analysis showed a significant reduction in MMP-13 expression and MMP-13/TIMP-1 ratios in the DMM + BOT (0w) group, whereas the DMM + BOT (3w) group showed limited efficacy compared with the early intervention. Conclusion Early administration of BOT attenuates KOA progression by preserving motor function, reducing subchondral bone turnover, and mitigating cartilage degradation. These findings highlight the importance of early intervention with BOT to achieve optimal therapeutic outcomes in KOA.

An In Vitro Investigation of Levofloxacin-Induced Cytotoxicity in Rat Bone Marrow Mesenchymal Stem Cells

BACKGROUND

Levofloxacin, a widely used fluoroquinolone antibiotic, has been linked to musculoskeletal complications. However, its impact on bone marrow mesenchymal stem cells (BMSCs), which are vital for tissue repair and regeneration, remains poorly understood.

AIM

This study aims to examine the impact on rat BMSCs following therapy with levofloxacin.

METHODS

 Rat BMSCs were exposed to various doses of levofloxacin (0, 14, 28, 56, 112, and 224 μM) to assess its possible cytotoxic impact on these stem cells. Cell viability was assessed using the MTT assay to evaluate the cytotoxic effects of levofloxacin. Cell apoptosis was calculated with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double staining, along with the expression levels of matrix metalloproteinase-3 (MMP-3), MMP-13, collagen type I alpha 1 (Col1A1), tissue inhibitor of metalloproteinase-1 (TIMP-1), and TIMP-3 messenger RNA (mRNA), which were assessed using RT-PCR. An apoptotic marker, caspase-3, was detected by immunocytochemical analysis.

RESULTS

 In certain concentrations (0-224 μM), as the concentration of levofloxacin increased, the number of apoptotic cells increased. The results demonstrated that levofloxacin significantly upregulated the mRNA levels of MMP-3 as well as MMP-13 in a dose-related manner, simultaneously downregulating TIMP-1 expression. In contrast, the expression of TIMP-3 and Col1A1 remained unaffected. In addition, the expression of caspase-3 was substantially elevated by levofloxacin in a concentration-related manner, between 28 μM and 224 μM, as indicated by immunocytochemistry.

CONCLUSION

 These findings provide evidence that levofloxacin exerts cytotoxicity on BMSCs, shown by increased apoptosis and a reduction in extracellular matrix components, highlighting a potential adverse impact of levofloxacin. Additionally, this cytotoxic effect may negatively affect fracture healing and impair the regenerative capacity of BMSCs.

Milk fat globule-epidermal growth factor 8 exerts anti-osteoarthritis effects by inhibiting apoptosis and inducing autophagy in mouse chondrocytes

Osteoarthritis (OA) is a chronic degenerative joint disease, characterized by cartilage injury. Milk fat globule-epidermal growth factor 8 (MFG-E8) exhibited anti-inflammatory effects, with undefined mechanism in OA. Eighteen C57BL/6 J mice were randomized into Sham and destabilization of medial meniscus (DMM) groups, with DMM surgery for OA model establishment. Subsequently, DMM mice received rmMFG-E8 (50 ng/g) as rmMFG-E8 group (n = 6). HE staining and Safranin O/Fast green staining for cartilage tissue pathological damage, TUNEL staining for apoptosis, ELISA for pro-inflammatory factors, and immunohistochemistry were performed. Following extraction of primary mouse chondrocytes, cells were randomized into Control, OA (10 ng/mL IL-1β), OA + rmMFG-E8 (500 ng/mL), and OA + rmMFG-E8+3-MA (autophagy inhibitor, 5 mM) groups. Cell viability by CCK8, pro-inflammatory factors by qRT-PCR, and apoptosis by flow cytometry were detected. In vivo and in vitro, transmission electron microscopy for autophagy and Western blot for autophagy- and apoptosis-related expression were conducted. In vivo, DMM group showed severe cartilage tissue damage, higher matrix metalloproteinase 13 (MMP13), Cleaved caspase-3, Cleaved PARP, Bax, TNF-α, IL-1β, IL-6 levels, and lower Bcl-2, MFG-E8, Collagen II, LC3II/LC3I, Beclin1, and ATG5 expression. Further rmMFG-E8 intervention improved mobility and pathological damage in DMM mice, with lower MMP13 expression. In vitro, rmMFG-E8 in OA group reduced TNF-α, IL-1β, IL-6, Cleaved caspase-3, Cleaved PARP, Bax, and P62 levels, and enhanced cell viability, Bcl-2, LC3II/LC3I, Beclin1, and ATG5 expression. Further 3-MA treatment up-regulated apoptosis and decreased cell viability and autophagy. Therefore, MFG-E8 exerts anti-OA effects by inhibiting apoptosis and inducing autophagy, offering a new potential target for OA treatment.

Biocompatible ionized air alleviates rat osteoarthritis by modulating polarization from M1 to M2 macrophages

The imbalance in the proportion of M1/M2 macrophage polarization is a crucial contributor to the persistent progression of osteoarthritis (OA). This study aimed to evaluate the effects of low-dose biocompatible ionized air (BIA) on macrophage polarization and its subsequent chondroprotective effects, thereby validating the potential of BIA in slowing the progression of OA. In vitro experiments demonstrated that BIA modulates the polarization of M1 macrophages toward the M2 phenotype via the ROS-mediated STAT6 pathway. This shift reduces the expression of pro-inflammatory mediators while increasing the expression of anti-inflammatory mediators and pro-chondrogenic factors, leading to an improved microenvironment surrounding chondrocytes. The direct benefits of this improved microenvironment include enhanced chondrocyte viability, inhibition of apoptosis, and reduced degradation of the extracellular matrix. In vivo studies in rats showed that BIA inhibited M1 macrophage infiltration in the synovium, upregulated the proportion of M2 macrophages, alleviated cartilage degeneration, and delayed OA progression. This gas-based regulatory strategy may open new avenues for the treatment of OA.

Expanding Horizons of CRISPR/Cas Technology: Clinical Advancements, Therapeutic Applications, and Challenges in Gene Therapy

CRISPR-Cas technology has transformed the field of gene editing, opening new possibilities for treatment of various genetic disorders. Recent years have seen a surge in clinical trials using CRISPR-Cas-based therapies. This review examines the current landscape of CRISPR-Cas implementation in clinical trials, with data from key registries, including the Australian New Zealand Clinical Trials Registry, the Chinese Clinical Trial Register, and ClinicalTrials.gov. Emphasis is placed on the mechanism of action of tested therapies, the delivery method, and the most recent findings of each clinical trial.

MiRNA-34a, miRNA-145, and miRNA-222 Expression, Matrix Metalloproteinases, TNF-α and VEGF in Patients with Different Phenotypes of Coronary Artery Disease

The development of different phenotypes of coronary artery (CA) lesions is regulated via many various factors, such as pro-inflammatory agents, zinc-dependent endopeptidases, growth factors and circulating microRNAs (miRs). To evaluate the expression levels of miR-34a, miR-145 and miR-222, tumor necrosis factor α (TNF-α), matrix metalloproteinases (MMP-1, -9, -13 and -14) and vascular endothelial growth factor (VEGF) in patients with different phenotypes of coronary artery disease (CAD): ischemia/angina with non-obstructive coronary arteries (INOCA/ANOCA) and obstructive CAD (oCAD) compared with a control group. This cross-sectional observational study included 157 subjects with a verified CAD diagnosis (51 patients with INOCA, 76 patients with oCAD and 30 healthy volunteers). The expression of miR-34a, miR-145 and miR-222 (RT-PCR) and the levels of VEGF, TNF-α, MMP-1, MMP-9, MMP-13 and MMP-14 (ELISA) were estimated in plasma samples. A higher concentration of MMP-9 was found in oCAD-group samples compared to the INOCA/ANOCA group. The INOCA/ANOCA group was characterized by higher levels of TNF-α. Based on multivariate regression analysis, a mathematical model predicting the type of CA lesion was constructed. MiR-145 was the independent predictor of INOCA/ANOCA (p = 0.006). Changes in concentrations of MMP-9 and MMP-14 were found in both investigated CAD groups, with MMP-9 levels being significantly higher in obstructive CAD samples than in INOCA/ANOCA, which confirms the role of inflammation in the development of atherosclerosis. A multivariate regression analysis allowed us to achieve a model that can predict the phenotype of stable CAD, and MiR-145 can be assumed as an independent predictor of INOCA/ANOCA.

An Advanced Mechanically Active Osteoarthritis-on-Chip Model to Test Injectable Therapeutic Formulations: The SYN321 Case Study

Current treatments for osteoarthritis (OA) often fail to address the underlying pathophysiology and may have systemic side effects, particularly associated with long-term use of non-steroidal anti-inflammatory drugs (NSAIDs). Thus, researchers are currently directing their efforts toward innovative polymer-drug combinations, such as mixtures of hyaluronic acid viscoelastic hydrogels and NSAIDs like diclofenac, to ensure sustained release of the NSAID within the joint following intra-articular injection. However, the progress of novel injectable therapies for OA is hindered by the absence of preclinical models that accurately represent the pathology of the disease. The uBeat® MultiCompress platform is here presented as a novel approach for studying anti-OA injectable therapeutics on human mechanically-damaged OA cartilage microtissues, in a physiologically relevant environment. This platform can accommodate injectable therapeutic formulations and is successfully tested with SYN321, a novel diclofenac-sodium hyaluronate conjugate under development as a treatment for knee OA. Results indicate the platform's effectiveness in evaluating therapeutic potential, showing downregulation of inflammatory markers and reduction in matrix degradation in OA cartilage micro-tissues treated with SYN321. The uBeat® MultiCompress platform thus represents a valuable tool for OA research, offering a bridge between traditional in vitro studies and potential clinical applications, with implications for future drug discovery.

Development of a Microfluidic Vascularized Osteochondral Model as a Drug Testing Platform for Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease characterized by changes in cartilage and subchondral bone. To date, there are no available drugs that can counteract the progression of OA, partly due to the inadequacy of current models to recapitulate the relevant cellular complexity. In this study, an osteochondral microfluidic model is developed using human primary cells to mimic an OA-like microenvironment and this study validates it as a drug testing platform. In the model, the cartilage compartment is created by embedding articular chondrocytes in fibrin hydrogel while the bone compartment is obtained by embedding osteoblasts, osteoclasts, endothelial cells, and mesenchymal stem cells in a fibrin hydrogel enriched with calcium phosphate nanoparticles. After developing and characterizing the model, Interleukin-1β is applied to induce OA-like conditions. Subsequently, the model potential is evaluated as a drug testing platform by assessing the effect of two anti-inflammatory drugs (Interleukin-1 Receptor antagonist and Celecoxib) on the regulation of inflammation- and matrix degradation-related markers. The model responded to inflammation and demonstrated differences in drug efficacy. Finally, it compares the behavior of the "Cartilage" and "Cartilage+Bone" models, emphasizing the necessity of incorporating both cartilage and bone compartments to capture the complex pathophysiology of OA.