Osteoarthritis year in review 2019: epidemiology and therapy

In vitro and in vivo studies of the therapeutic potential of Tinospora crispa extracts in osteoarthritis: Targeting oxidation, inflammation, and chondroprotection

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing incidence of osteoarthritis (OA), especially among the elderly population, highlights the need for more efficacious treatments that go beyond mere symptomatic relief. Tinospora crispa (L.) Hook. f. & Thomson (TC) boasts a rich traditional heritage, widespread use in Ayurveda, traditional Chinese medicine (TCM), and diverse indigenous healing practices throughout Southeast Asia for treating arthritis, rheumatism, fever, and inflammation.

AIM OF THE STUDY

This study investigates the anti-inflammatory and chondroprotective potential of TC stem extracts, including ethanolic TC extract (ETCE) and aqueous TC extract (ATCE), in modulating OA pathogenesis through in vitro and in vivo approaches.

MATERIALS AND METHODS

The study utilized LC-MS/MS to identify key compounds in TC stem extracts. In vitro experiments assessed the antioxidative and anti-inflammatory properties of ETCE and ATCE in activated macrophages, while an in vivo monoiodoacetate (MIA)-induced OA rat model evaluated the efficacy of ETCE treatment. Key markers of oxidative stress, such as superoxide dismutase (SOD) and catalase (CAT), were assessed alongside pro-inflammatory cytokines TNF-α and IL-1β, and matrix-degrading enzymes, matrix metalloproteinase (MMP 13 and MMP 3), to evaluate the therapeutic effects of TC stem extracts on OA.

RESULTS

Chemical profiling of the extracts was conducted using LC-MS/MS in positive ionization, identifying seven compounds, including pseudolaric acid B, stylopine, and reticuline, which were reported for the first time in this species. The study utilized varying concentrations of TC stem extracts, specifically 6.25-25 μg/mL for in vitro assays and 500 mg/kg for in vivo studies. Our findings also revealed that both ETCE and ATCE exhibit dose-dependent reduction in reactive oxygen species (41%-52%) and nitric oxide (NO) levels (50% and 72%), with ETCE displaying superior antioxidative efficacy and marked anti-inflammatory properties, significantly reducing TNF-α and IL-6 at concentrations above 12.5 μg/mL. In the MIA-induced OA rat model, ETCE treatment notably outperformed ATCE, markedly lowering TNF-α (1.91 ± 0.37 pg/mL) and IL-1β (26.30 ± 3.68 pg/mL) levels and effectively inhibiting MMP 13 and MMP 3 enzymes. Furthermore, macroscopic and histopathological assessments, including ICRS scoring and OARSI grading, indicate that TC stem extracts reduce articular damage and proteoglycan loss in rat knee cartilage. These results suggest that TC stem extracts may play a role in preventing cartilage degradation and potentially alleviating inflammation and pain associated with OA, though further studies are needed to confirm these effects.

CONCLUSION

This study highlights the potential of TC stem extracts as a novel, chondroprotective therapeutic avenue for OA management. By targeting oxidative stress, pro-inflammatory cytokines, and cartilage-degrading enzymes, TC stem extracts promise to prevent cartilage degradation and alleviate inflammation and pain associated with OA.

Severity and progression of structural hand OA is not associated with progression of structural knee OA: The IMI-APPROACH cohort

Objective

To investigate whether structural hand OA or its progression is associated with structural knee OA progression after two years in a population with symptomatic knee OA.

Methods

We used baseline and two-year follow-up data from the IMI-APPROACH cohort. Symptomatic hand and knee OA were defined using ACR criteria. Radiographs of hands and knees were scored semi-quantitatively for osteophytes and joint space narrowing (JSN) following the OARSI atlas, and Kellgren-Lawrence (KL) scale. Knee images were also scored quantitatively with the Knee Image Digital Analysis (KIDA). Progression was defined as change above the minimal detectable change on patient level, except for KIDA (most affected knee compartment level). With logistic regression analyses the severity or progression of hand OA was associated with knee OA progression.

Results

In 221 participants (mean age 66, 77% women, mean BMI 27.7, 19% hand OA), OA progression occurred in 18%-28%, and 9%-38% in hands and knees respectively, depending on features. Baseline structural hand OA features were not significantly associated with knee OA progression, except for hand osteophytes with KIDA osteophytes progression (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.06). Progression of structural hand OA features was not significantly associated with knee OA progression, except for hand osteophyte or JSN progression, which was significantly associated with knee osteophyte progression (OR 0.44, 95%CI 0.22-0.84 and OR 0.43, 95%CI 0.18-0.94, respectively), and hand osteophyte progression for knee JSN (OR 2.51, 95%CI 1.15-5.48).

Conclusions

In patients with symptomatic knee OA, no consistent associations between baseline structural hand OA or hand OA progression and knee OA progression were shown.

Strategies for the Codelivery of Osteoclasts and Mesenchymal Stem Cells in 3D-Printable Osteochondral Scaffolds

Osteochondral defects, characterized by structural compromises to articular cartilage and subchondral bone, can cause pain and lead to progressive cartilage damage and eventual osteoarthritis. Unfortunately, repairing these defects remains difficult because of the poor regenerative properties of cartilage and complex mechanical demands of the joint. As such, the field of tissue engineering aims to develop multiphasic implants that replace pathological cartilage and bone tissue and restore mechanical functionality to the joint. Recent bone physiology investigations have demonstrated that osteoclast (OC) lineage cells are inextricably involved in osteoblastic bone formation through an extensive network of anabolic signaling pathways, and so the codelivery OC and osteoblast (OB) lineage cells within scaffolds is being actively explored for bone tissue engineering purposes. However, it remains unclear how these cells can be incorporated into the design of multiphasic osteochondral scaffolds to potentially enhance subchondral bone formation and subsequent implant osseointegration. To explore this question, we examined direct surface seeding and hydrogel encapsulation as potential scaffold cellularization strategies. First, we examined how OC precursor cells and peripheral blood monocytes (PBMCs) influence early-stage bone matrix development and osteogenesis in 2D coculture. Then, we evaluated the osteogenic potential of mesenchymal stem cells (MSCs) and PBMCs cocultures encapsulated within a gelatin methacrylate (GelMA) hydrogel system. Our findings demonstrate that coculturing PBMCs with MSCs in 2D cultures significantly enhanced cell proliferation, early bone matrix deposition, and the formation of cell clusters by Day 28. However, we observed no significant difference in type I collagen deposition between GelMA hydrogel scaffolds cultured in basal and OC conditions during the same period. In addition, we found that the GelMA hydrogel system with MSC/PBMC cocultures in OC conditions exhibited decreased osteogenic activity by Day 28. Collectively, our findings support the osteogenic potential of OC-lineage cells in 2D culture conditions, and the potential benefits of surface-seeding for the codelivery of OC-lineage cells and MSCs in osteo-scaffolds for enhanced osteochondral regeneration and broader bone tissue engineering purposes.

Zwitterion-Lubricated Hydrogel Microspheres Encapsulated with Metformin Ameliorate Age-Associated Osteoarthritis

Chondrocyte senescence and reduced lubrication play pivotal roles in the pathogenesis of age-related osteoarthritis (OA). In the present study, highly lubricated and drug-loaded hydrogel microspheres are designed and fabricated through the radical polymerization of sulfobetaine (SB)-modified hyaluronic acid methacrylate using microfluidic technology. The copolymer contains a large number of SB and carboxyl groups that can provide a high degree of lubrication through hydration and form electrostatic loading interactions with metformin (Met@SBHA), producing a high drug load for anti-chondrocyte senescence. Mechanical, tribological, and drug release analyses demonstrated enhanced lubricative properties and prolonged drug dissemination of the Met@SBHA microspheres. RNA sequencing (RNA-seq) analysis, network pharmacology, and in vitro assays revealed the extraordinary capacity of Met@SBHA to combat chondrocyte senescence. Additionally, inducible nitric oxide synthase (iNOS) has been identified as a promising protein modulated by Met in senescent chondrocytes, thereby exerting a significant influence on the iNOS/ONOO-/P53 pathway. Notably, the intra-articular administration of Met@SBHA in aged mice ameliorated cartilage senescence and OA pathogenesis. Based on the findings of this study, Met@SBHA emerges as an innovative and promising strategy in tackling age-related OA serving the dual function of enhancing joint lubrication and mitigating cartilage senescence.

A synoptic literature review of animal models for investigating the biomechanics of knee osteoarthritis

Osteoarthritis (OA) is a common chronic disease largely driven by mechanical factors, causing significant health and economic burdens worldwide. Early detection is challenging, making animal models a key tool for studying its onset and mechanically-relevant pathogenesis. This review evaluate current use of preclinical in vivo models and progressive measurement techniques for analysing biomechanical factors in the specific context of the clinical OA phenotypes. It categorizes preclinical in vivo models into naturally occurring, genetically modified, chemically-induced, surgically-induced, and non-invasive types, linking each to clinical phenotypes like chronic pain, inflammation, and mechanical overload. Specifically, we discriminate between mechanical and biological factors, give a new explanation of the mechanical overload OA phenotype and propose that it should be further subcategorized into two subtypes, post-traumatic and chronic overloading OA. This review then summarises the representative models and tools in biomechanical studies of OA. We highlight and identify how to develop a mechanical model without inflammatory sequelae and how to induce OA without significant experimental trauma and so enable the detection of changes indicative of early-stage OA in the absence of such sequelae. We propose that the most popular post-traumatic OA biomechanical models are not representative of all types of mechanical overloading OA and, in particular, identify a deficiency of current rodent models to represent the chronic overloading OA phenotype without requiring intraarticular surgery. We therefore pinpoint well standardized and reproducible chronic overloading models that are being developed to enable the study of early OA changes in non-trauma related, slowly-progressive OA. In particular, non-invasive models (repetitive small compression loading model and exercise model) and an extra-articular surgical model (osteotomy) are attractive ways to present the chronic natural course of primary OA. Use of these models and quantitative mechanical behaviour tools such as gait analysis and non-invasive imaging techniques show great promise in understanding the mechanical aspects of the onset and progression of OA in the context of chronic knee joint overloading. Further development of these models and the advanced characterisation tools will enable better replication of the human chronic overloading OA phenotype and thus facilitate mechanically-driven clinical questions to be answered.

Ameliorative effects of undifferentiated and differentiated BM-MSCs in MIA-induced osteoarthritic Wistar rats: roles of NF-κB and MMPs signaling pathways

OBJECTIVES

Osteoarthritis (OA) is a degenerative joint condition that is persistent. OA affects millions of people throughout the world. Both people and society are heavily economically burdened by osteoarthritis. There is currently no medication that can structurally alter the OA processes or stop the disease from progressing. Stem cells have the potential to revolutionize medicine due to their capacity to differentiate into chondrocytes, capacity to heal tissues and organs including osteoarthritic joints, and immunomodulatory capabilities. Therefore, the goal of the current investigation was to determine how bone marrow-derived mesenchymal stem cells (BM-MSCs) and chondrogenic differentiated mesenchymal stem cells (CD-MSCs) affected the treatment of OA in rats with monosodium iodoacetate (MIA)-induced osteoarthritis.

METHODS

Male Wistar rats were injected three times with MIA (1 mg)/100 µL isotonic saline to induce osteoarthritis in the ankle joint of the right hind leg. Following the MIA injection, the osteoarthritic rats were given weekly treatments of 1 × 106 BM-MSCs and CD-MSCs into the tail vein for three weeks.

RESULTS

The obtained results showed that in osteoarthritic rats, BM-MSCs and CD-MSCs dramatically decreased ankle diameter measurements, decreased oxidized glutathione (GSSG) level, and boosted glutathione peroxidase (GPx) and glutathione reductase (GR) activities. Additionally, in rats with MIA-induced OA, BM-MSCs and CD-MSCs dramatically boosted interleukin-10 (IL-10) serum levels while considerably decreasing serum anticitrullinated protein antibodies (ACPA), tumour necrosis factor-α (TNF-α), and interleukin-17 (IL-17) levels as well as ankle transforming growth factor-β1 (TGF-β1) expression. Analysis of histology, immunohistochemistry, and western blots in osteoarthritic joints showed that cartilage breakdown and joint inflammation gradually decreased over time.

CONCLUSIONS

It is possible to conclude from these results that BM-MSCs and CD-MSCs have anti-arthritic potential in MIA-induced OA, which may be mediated via inhibitory effects on oxidative stress, MMPs and inflammation through suppressing the NF-κB pathway. In osteoarthritis, using CD-MSCs as a treatment is more beneficial therapeutically than using BM-MSCs.

Nano-enzyme hydrogels for cartilage repair effectiveness based on ternary strategy therapy

Designing artificial nano-enzymes for scavenging reactive oxygen species (ROS) in chondrocytes (CHOs) is considered the most feasible pathway for the treatment of osteoarthritis (OA). However, the accumulation of ROS due to the amount of nano-enzymatic catalytic site exposure and insufficient oxygen supply seriously threatens the clinical application of this therapy. Although metal-organic framework (MOF) immobilization of artificial nano-enzymes to enhance active site exposure has been extensively studied, artificial nano-enzymes/MOFs for ROS scavenging in OA treatment are still lacking. In this study, a biocompatible lubricating hydrogel-loaded iron-doped zeolitic imidazolate framework-8 (Fe/ZIF-8/Gel) centrase was engineered to scavenge endogenous overexpressed ROS synergistically generating dissolved oxygen and enhancing sustained lubrication for CHOs as a ternary artificial nano-enzyme. This property enabled the nano-enzymatic hydrogels to mitigate OA hypoxia and inhibit oxidative stress damage successfully. Ternary strategy-based therapies show excellent cartilage repair in vivo. The experimental results suggest that nano-enzyme-enhanced lubricating hydrogels are a potentially effective OA treatment and a novel strategy.

The effect of mindfulness and motivational interviewing along with neuromuscular exercises on pain, function, and balance of women affected by knee osteoarthritis: a rater-blinded randomized controlled clinical trial

PURPOSE

This study aimed to evaluate the effect of motivational interviewing (MI) and mindfulness (MF) added to neuromuscular (NM) exercises on improving pain, function, balance, and quality of life in patients with knee osteoarthritis (KOA).

METHODS

This randomized clinical trial was conducted on sixty patients who were randomly assigned to the MI + NM, MF + NM, and NM groups. The groups received four training sessions for six weeks. Physical function with Western Ontario and McMaster Universities Arthritis Index timed up and go, going up and down eight stairs, pain with visual analogue scale, quality of life with SF36, and balance with Biodex were evaluated before and after interventions.

RESULTS

Within-group comparisons showed that NM + MI, NM + MF, and NM groups experienced significant improvement in all factors after six-week (p < 0.05). However, between groups, comparisons in the post-test revealed that the MI + NM group had a more significant effect on pain, function, and static balance than the MF + NM group. Nevertheless, the MF + NM group improved the quality of life better than the MI + NM and NM groups (p < 0.05).

CONCLUSION

Adding psychological interventions to physical exercises had a better effect on improving the symptoms of patients. Additionally, the MI showed more effectiveness in improving the symptoms of patients.

The effects of combined transcranial direct Current stimulation with physiotherapy for physical function in subjects with knee osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Transcranial Direct Current Stimulation (tDCS) emerges as a promising therapeutic intervention for knee osteoarthritis (KOA), yet its impact on physical function remains insufficiently explored.

OBJECTIVES

To evaluate the relative effects of tDCS for physical function in patients with KOA.

METHODS

Pubmed, Web of Science, Scopus and Cochrane Database were explored as of August 2023 to identify studies to be included in the current systematic review and metaanalysis. Randomized controlled trials in patients with KOA comparing tDCS with placebo were included. The outcomes defined were measures of physical function (questionnaires, gait, or physical performance). The Risk of Bias tool was used to assess bias in the randomized controlled trials, whereas the PEDro scale was applied for methodological quality, and the certainty of evidence for each outcome was assessed through GRADE. Results for each outcome were synthesized using meta-analysis (random-effects model, I2-test for heterogeneity) and a subgroup analysis was performed to improve the sensitivity of the results and to explore potential moderating factors of the effect sizes.

RESULTS

Ten studies with good to excellent quality were included, analyzing a total of 628 participants. Regarding physical function, tDCS showed a favorable effect (ES: -0.58; 95%CI -0.82, -0.33; I2: 52.1%) with a low risk of bias and low to moderate certainty of evidence. The concurrent application of physiotherapy interventions and tDCS improved the effects on pain and function. Applying physiotherapy interventions, as well as adding peripheral currents, increased the effect sizes (ES: -0.95, k = 3, p = .018; ES: -0.95, k = 4 p = .001, respectively). The pattern of application of the tDCS, either daily or in alternate days, did not moderate the effect size (p = .619). Meta-regression revealed that the number of tDCS sessions did not moderate the effect size either (p = .242).

CONCLUSION

The tDCS might be a promising therapeutic approach to enhance physical function in subjects affected with KOA. However, further systematic reviews with meta-analyses should be performed with standardized and proven-efficacy physiotherapy programs, as well as with long-term results, to ascertain whether the improvement may be sustained over time. This study provides valuable insights into optimizing tDCS interventions for enhanced outcomes in the management of KOA.Protocol available via PROSPERO [CRD42023440676].

Hyaluronic Acid Viscosupplement Modulates Inflammatory Mediators in Chondrocyte and Macrophage Coculture via MAPK and NF-κB Signaling Pathways

Osteoarthritis (OA) is a chronic musculoskeletal disorder characterized by cartilage degeneration and synovial inflammation. Paracrine interactions between chondrocytes and macrophages play an essential role in the onset and progression of OA. In this study, in replicating the inflammatory response during OA pathogenesis, chondrocytes were treated with interleukin-1β (IL-1β), and macrophages were treated with lipopolysaccharide and interferon-γ. In addition, a coculture system was developed to simulate the biological situation in the joint. In this study, we examined the impact of hyaluronic acid (HA) viscosupplement, particularly Hyruan Plus, on chondrocytes and macrophages. Notably, this viscosupplement has demonstrated promising outcomes in reducing inflammation; however, the underlying mechanism of action remains elusive. The viscosupplement attenuated inflammation, showing an inhibitory effect on nitric oxide production, downregulating proinflammatory cytokines such as matrix metalloproteinases (MMP13 and MMP3), and upregulating the expression levels of type II collagen and aggrecan in chondrocytes. HA also reduced the expression level of inflammatory cytokines such as IL-1β, TNF-α, and IL-6 in macrophages, and HA exerted an overall protective effect by partially suppressing the MAPK pathway in chondrocytes and p65/NF-κB signaling in macrophages. Therefore, HA shows potential as a viscosupplement for treating arthritic joints.

Autogenous structural bone graft reconstruction of ≥ 10-mm-deep uncontained medial proximal tibial defects in primary total knee arthroplasty

BACKGROUND

Management of uncontained medial proximal tibial defects during primary total knee arthroplasty (TKA) can be challenging, especially for defects ≥ 10 mm in depth. This study sought to assess the outcomes of autogenous structural bone grafts to address these defects.

MATERIALS AND METHODS

In this prospective study, patients with uncontained medial proximal tibial defects ≥ 10 mm in depth undergoing TKA were managed by autogenous structural bone grafts fixed by screws and were followed up for at least 36 months. Patients were followed-up clinically with Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Additionally, radiological follow-up was done to assess bone graft union and implant stability.

RESULTS

The study included 48 patients with a mean age of 69.2 ± 4.5 years. The mean body mass index (BMI) was 31.4 ± 3.7 kg/m2. The mean defect depth was 17 ± 3.6 mm. With a mean follow-up period of 52.2 ± 12.3 months, the median KSS improved significantly from 30 preoperatively to 89, P < 0.001. The median WOMAC score reduced significantly from 85 preoperatively to 30.5, P < 0.001. The mean ROM increased significantly from 73 ± 12.4 preoperatively to 124 ± 8.4 degrees, P < 0.001. The mean graft union time was 4.9 ± 1 months. No significant complications were reported.

CONCLUSIONS

Autogenous bone graft reconstruction is a safe and effective method of addressing uncontained medial proximal tibial defects in primary TKA.

LEVEL OF EVIDENCE

Level IV.

The mechanistic role of curcumin on matrix metalloproteinases in osteoarthritis

A systematic mechanistic review was performed to determine mechanistic evidence for curcumin on pro-inflammatory matrix metalloproteinases and Osteoarthritis to understand the underlying pathophysiology, and to evaluate available human intervention evidence to inform clinical decision making. The systematic literature search was performed in 3 tranches (reviews, mechanistic, intervention studies) using PubMed, with no date limitations and using specific search terms. 65 out of 393 screened papers were accepted based on detailed inclusion and exclusion criteria. The mechanistic search was divided into three searches and the intervention searches were subdivided into four searches. Curcumin demonstrated significant inhibition of matrix metalloproteinases linked to cartilage degradation in Osteoarthritis through reduced activation of the nuclear factor kappa-B signaling pathway via suppressing phosphorylation of Iκβa and p65 nuclear translocation. Mechanistic evidence implicated matrix metalloproteinases in Osteoarthritis by decreasing Type II collagen, leading to cartilage damage. As a potential nutritional intervention for Osteoarthritis, curcumin could reduce inflammatory markers and improve pain and function scores. The evidence indicates most formulations of turmeric extract and curcumin extract, bio-enhanced and non-bio-enhanced, are effective at improving inflammatory markers and pain and function to a greater or lesser extent. Due to the high heterogeneity of the formulations, dosage, and duration of the studies, further research is needed to fully understand curcumin's potential as a promising non-pharmaceutical intervention for Osteoarthritis. This mechanism review identifies a gap in current research for the mechanism by which Type II collagen is mediated.

Suppressive Activity of Boiogito, a Japanese Traditional Kampo Medicine, on Periostin Secretion in Human Fibroblast-Like Synoviocytes In Vitro

Background Knee osteoarthritis (KOA) is a prevalent degenerative disease that affects the knee joints, particularly among individuals aged over 40 years. It leads to pain, stiffness, and reduced quality of life; affects approximately 300 million individuals worldwide; and is increasing, particularly in developed nations. Although treatments for KOA range from conservative measures to surgical interventions, such as total knee arthroplasty (TKA), the financial burden of TKA in many countries underscores the urgent need for effective conservative therapies. The pathophysiology of KOA involves articular cartilage degeneration, increased subchondral bone turnover, synovitis, and periarticular soft tissue contracture. Abnormal bone turnover, intensified by factors, such as weight gain and knee injury, precedes cartilage degeneration. Synovitis, characterized by inflammation in the synovial tissue, plays a crucial role in perpetuating the disease by triggering a cascade of catabolic and proinflammatory mediators, including cytokines, such as interleukin (IL)-1 beta, tumor necrosis factor-alpha, and IL-13. Periostin, an extracellular matrix protein, is implicated in KOA progression, with its levels increasing with disease severity. Materials & methods In this study, the preventive effect of boiogito (BOT), a traditional herbal medicine, on periostin secretion in human fibroblast-like synoviocytes (hFLS) stimulated by IL-13 was investigated. Synoviocyte Growth Medium and recombinant human IL-13 were used for cell culture and stimulation. BOT was dissolved in phosphate-buffered saline and applied to cell cultures. Periostin secretion and mRNA expression were measured using enzyme-linked immunosorbent assay and quantitative reverse transcription polymerase chain reaction, respectively. Cell viability was assessed using an MTT assay, and signal transducer and activator of transcription factor 6 (STAT6) phosphorylation was examined using Western blotting. Results IL-13 stimulation of hFLS significantly increased periostin secretion, with levels rising above 20 ng/mL after 72 h of stimulation. Pretreatment with BOT dose-dependently suppressed periostin secretion, with doses of 1,000 μg/mL significantly reducing periostin levels. Furthermore, BOT inhibited periostin mRNA expression and STAT6 phosphorylation in IL-13-stimulated hFLS, suggesting its potential in modulating IL-13-mediated inflammatory pathways in KOA. Conclusion This study demonstrated the preventive effect of BOT on periostin secretion in IL-13-stimulated hFLS, highlighting its potential as a therapeutic agent for KOA. By inhibiting periostin production and downstream signaling pathways, BOT may offer a promising conservative treatment option for KOA, addressing the inflammatory cascade implicated in disease progression. Further research is warranted to elucidate the specific herbal components responsible for the therapeutic effects of BOT and to validate its efficacy in clinical settings.

Enzymatic digestion does not compromise sliding-mediated cartilage lubrication

Articular cartilage's remarkable low-friction properties are essential to joint function. In osteoarthritis (OA), cartilage degeneration (e.g., proteoglycan loss and collagen damage) decreases tissue modulus and increases permeability. Although these changes impair lubrication in fully depressurized and slowly slid cartilage, new evidence suggests such relationships may not hold under biofidelic sliding conditions more representative of those encountered in vivo. Our recent studies using the convergent stationary contact area (cSCA) configuration demonstrate that articulation (i.e., sliding) generates interfacial hydrodynamic pressures capable of replenishing cartilage interstitial fluid/pressure lost to compressive loading through a mechanism termed tribological rehydration. This fluid recovery sustains in vivo-like kinetic friction coefficients (µk<0.02 in PBS and <0.005 in synovial fluid) with little sensitivity to mechanical properties in healthy tissue. However, the tribomechanical function of compromised cartilage under biofidelic sliding conditions remains unknown. Here, we investigated the effects of OA-like changes in cartilage mechanical properties, modeled via enzymatic digestion of mature bovine cartilage, on its tribomechanical function during cSCA sliding. We found no differences in sliding-driven tribological rehydration behaviors or µk between naïve and digested cSCA cartilage (in PBS or synovial fluid). This suggests that OA-like cartilage retains sufficient functional properties to support naïve-like fluid recovery and lubrication under biofidelic sliding conditions. However, OA-like cartilage accumulated greater total tissue strains due to elevated strain accrual during initial load application. Together, these results suggest that elevated total tissue strains-as opposed to activity-mediated strains or friction-driven wear-might be the key biomechanical mediator of OA pathology in cartilage. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) decreases cartilage's modulus and increases its permeability. While these changes compromise frictional performance in benchtop testing under low fluid load support (FLS) conditions, whether such observations hold under sliding conditions that better represent the joints' dynamic FLS conditions in vivo is unclear. Here, we leveraged biofidelic benchtop sliding experiments-that is, those mimicking joints' native sliding environment-to examine how OA-like changes in mechanical properties effect cartilage's natural lubrication. We found no differences in sliding-mediated fluid recovery or kinetic friction behaviors between naïve and OA-like cartilage. However, OA-like cartilage experienced greater strain accumulation during load application, suggesting that elevated tissue strains (not friction-driven wear) may be the primary biomechanical mediator of OA pathology.

Effectiveness of Rehabilitation for Osteoarthritis of the Knee: A Scoping Review of Network Meta-Analyses

BACKGROUND

 Although an increasing number of network meta-analyses have been conducted on the effectiveness of conservative therapy for knee osteoarthritis, these may have been poorly planned and executed.We aimed to review the qualities of a comprehensive set of network meta-analyses on rehabilitation therapies for knee osteoarthritis and provide an overview of the effectiveness of each therapy.

METHODS

The eligibility criteria were as follows: (i) conservative rehabilitation was the primary treatment in the intervention group, (ii) included patients were diagnosed with knee osteoarthritis, and (iii) patient groups were aged ≤75 years, and rehabilitation interventions comprised exercise, orthotic, or physical therapies or patient education. Two independent reviewers screened the titles and abstracts of the identified records and selected the eligible reviews; their full texts were further assessed for eligibility. Then, a checklist derived from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension statement for the reporting of systematic reviews incorporating network meta-analyses of healthcare Interventions was used to validate the completeness of the reporting of each network meta-analysis. Furthermore, the statistical and outcome data regarding the quality of life, knee joint function and pain, adverse events, and physical functions were extracted using a customized spreadsheet.

RESULTS

Overall, 2701 titles and abstracts were screened, and eight network meta-analyses were ultimately selected. Nearly all reviews adequately addressed the PRISMA extension checklist, and the completeness of reporting was adequate; therefore, all expected information could be extracted. However, the methodology used to confirm the transitivity assumption was insufficient in many reviews. The following interventions were effective in reducing pain and improving physical function: (i) strengthening, flexibility, aerobic, and mind-body exercises, (ii) pulsed ultrasound, (iii) focused and radial extracorporeal shockwave therapy, and (iv) continuous ultrasound. The following interventions were effective in improving the quality of life: (i) strengthening, (ii) mixed, and (iii) mind-body exercises.

CONCLUSIONS

Our results suggested that exercise therapies, including muscle-strengthening, aerobic, flexibility, and mind-body exercises, are likely to be effective for pain relief and functional improvement in knee osteoarthritis. This may be the first review to provide a comprehensive perspective for considering priorities for future rehabilitation interventions for knee osteoarthritis.

Prognostic Factors in Intra-articular Platelet-Rich Plasma Treatment for Knee Osteoarthritis: A Comparative Analysis of Responders and Nonresponders

BACKGROUND

Knee osteoarthritis (KOA) is a chronic joint disease affecting activities of daily living (ADL) and quality of life due to pain and limited range of motion, afflicting a large number of patients worldwide. However, it is difficult to prevent the progression of the disease. Therapeutic strategies for KOA aim to maintain ADL and QOL by alleviating pain or managing locomotive function. Recently, intra-articular injection of platelet-rich plasma (PRP) has been gaining attention. In this study, the clinical results of PRP treatment in our institution were reported and compared between responders and non-responders using patient characteristics and imaging data assessed from plain X-rays and magnetic resonance imaging (MRI).

METHODS

Participants in the study were KOA patients with varus deformity assessed as grade 2 or higher in the Kellgren-Lawrence classification who received PRP treatment from January 2022 to November 2023 and were followed up for at least three months. PRP was prepared with 27 mL of blood collected from the patient, and 2.7 mL of PRP was prepared using the PEAK©︎PRP System from DePuy Synthes (Raynham, MA). Intra-articular injections of PRP were performed under echo-guided procedures, and responders or non-responders were determined using the Osteoarthritis Research Society International Standing Committee for Clinical Trials Response Criteria Initiative (OMERACT-OARSI) criteria evaluated by the Japanese Knee Injury and Osteoarthritis Outcome Score (J-KOOS) at three months after PRP injection. The clinical efficacy of PRP treatment for KOA was assessed in this study, and a dichotomous analysis was performed comparing the responder group and the non-responder group using patient characteristics and assessed data from plain X-ray images and MRI to determine prognostic factors for PRP treatment.

RESULTS

The study population included 36 knees with a mean age of 70.6. ± 9.2 years, comprising six knees in men and 30 knees in women. The responder group consisted of 16 knees (44.4%), and the non-responder group consisted of 20 knees (55.6%). J-KOOS subscores at pre-treatment elicited that each subscale in the R group was significantly lower than that in the NR group at pretreatment. A dichotomous analysis for the two groups revealed the distribution of sex and past medical history of hyperlipidemia to be significantly different between the two groups. Multivariable logistic regression analysis showed that the coexistence of hyperlipidemia was the main prognostic factor for the efficacy of PRP therapy.

DISCUSSION

In this study, comparisons were conducted between responders and non-responders to estimate prognostic factors for the efficacy of PRP therapy. Surprisingly, responders to the treatment tended to show lower J-KOOS scores and to have hyperlipidemia. A literature review revealed conflicting reports on prognostic factors for PRP therapy in KOA, highlighting the need for further research.

Elucidating Cyathula Officinals' mechanism in osteoarthritis treatment: Network pharmacology and empirical evidence on anti-inflammatory actions

In this study, we explored the therapeutic potential of Cyathula Officinals (CNX) in Knee Osteoarthritis (KOA) treatment. Utilizing network pharmacology and in vitro experiments, we identified active ingredients, action targets and pathways in CNX. Our analysis, integrating databases like TCMSP, SwissTarget Prediction, Genecards, CTD, STRING, and DAVID, highlighted 396 action targets and 283 disease targets, pinpointing 64 intersection genes linked to KOA. The significant involvement of the MAPK and NF-κB pathways in CNX's anti-inflammatory action was validated through qPCR, which might underlie CNX's efficacy in inhibiting chondrocyte apoptosis and IL-6 expression. These findings suggest CNX's potential in KOA management, offering insights for its clinical application.

Diagnostic value of serum COMP and ADAMTS7 for intervertebral disc degeneration

OBJECTIVE

Intervertebral disc degeneration (IVDD) is a major cause of morbidity and disability. Our study aimed to investigate the potential of cartilage oligomeric matrix protein (COMP) and ADAMTS7 (A disintegrin and metalloproteinases with thrombospondin motifs 7) as biomarkers for IVDD together with their functional relationship.

METHODS

IVD tissues and peripheral blood samples were collected from IVDD rabbit models over 1-4 weeks. Tissues and blood samples were also collected from clinical patients those were stratified into four equal groups according to Pfirrmann IVDD grading (I-V) with baseline data collected for each participant. COMP and ADAMTS7 expression were analyzed and biomarker characteristics were assessed using linear regression and receiver operating curve (ROC) analyses.

RESULTS

COMP and ADAMTS7 expression increased in tissues and serum during IVDD progression. Serum COMP (sCOMP) and serum ADAMTS7 (sADAMTS7) levels increased in a time-dependent manner following IVD damage in the rabbit model while significant positive correlations were detected between sCOMP and sADAMTS7 and Pfirrmann grade in human subjects. ROC analysis showed that combining sCOMP and sADAMTS7 assay results produced an improved diagnostic measure for IVDD compared to individual sCOMP or sADAMTS7 tests. In vitro assays conducted on human cell isolates revealed that COMP prevented extracellular matrix degradation and antagonized ADAMTS7 expression although this protective role was uncoupled under microenvironmental conditions mimicking IVDD.

CONCLUSIONS

Increases in circulating COMP and ADAMTS7 correlate with IVDD progression and may play regulatory roles. Assays for sCOMP and/or sADAMTS7 levels can discriminate between healthy subjects and IVDD patients, warranting further clinical assessment.

Modified Mesenchymal stem cell, platelet-rich plasma, and hyaluronic acid intervention in early stage osteoarthritis: A systematic review, meta-analysis, and meta-regression of arthroscopic-guided intra-articular approaches

BACKGROUND

Mesenchymal stem cells (MSCs) hold promise for osteoarthritis (OA) treatment, potentially enhanced by combining them with platelet-rich plasma (PRP) and hyaluronic acid (HA). This study aimed to assess the synergy of MSCs, PRP, and varying HA doses, and determine optimal MSC sources to treat early-stage OA in the perspective of Lysholm score, VAS Score, KSS score, and WOMAC score.

METHOD

Original articles from 2013 to 2023 were screened from four databases, focusing on clinical trials and randomized controlled trials. The Risk of Bias in Non-randomized Studies-of Interventions (ROB-2) tool evaluated bias, and a PICOS criteria table guided result construction. Revman 5.4 analyzed outcomes such as Lysholm score, VAS score, KSS, WOMAC score, cartilage volume, and defect size using MRI. This systematic review adhered to PRISMA guidelines.

RESULT

Nine studies met the final inclusion criteria. Meta-analysis revealed a significant improvement in Lysholm score (MD: 17.89; 95% CI: 16.01, 19.77; I2 = 0%, P = 0.56), a notable reduction in VAS score (MD: -2.62; 95% CI: -2.83, -2.41; I2 = 99%, P < 0.00001), elevated KSS (MD: 29.59; 95% CI: 27.66, 31.52; I2 = 95%, P < 0.0001), and reduced WOMAC score (MD: -12.38; 95% CI: -13.75, -11.01; I2 = 99%, P < 0.0001).

CONCLUSIONS

Arthroscopic guided high-dose subchondral application of primary cultured synovial MSCs in popliteal PRP media with HA effectively regenerates cartilage defects and improves clinical outcomes in early-stage osteoarthritis. Clarification of MSC sources and quantities enhances the understanding of this promising treatment modality.

Efficacy of the newly designed "SkyWalker" robot compared to the MAKO robotic system in primary total knee arthroplasty: a one-year follow-up study

PURPOSE

Robot-assisted surgical systems for performing total knee arthroplasty (TKA) have gained significant attention. This study was designed to compare the surgical outcomes in primary TKA surgery between the recently developed "SkyWalker" robot system and the more commonly used MAKO robot.

METHODS

A total of 75 patients undergoing primary TKA surgery by the same surgical team were included in this study, with 30 patients in the "SkyWalker" group and 45 patients in the "MAKO" group. We documented the osteotomy plan for both robotic systems. The lower limb alignment angles were evaluated by postoperative radiographic assessment. The operation time, estimated blood loss, postoperative hospital stays, and changes in laboratory indexes were collected during hospitalization. In addition, a comparative evaluation of knee functional assessments and complications was conducted during six month and one year follow-ups.

RESULTS

There were no significant differences between the two groups in terms of the accuracy of restoring lower limb alignment, estimated blood loss, or operation time. The knee function assessments at six months and one year postoperatively were similar in both groups. Except for day three after surgery, the level of interleukin-6 (IL-6) and the change in IL-6 (∆IL-6) from preoperative baseline were higher in the "SkyWalker" group than in the MAKO group (median: 20.53 vs. 14.17, P=0.050 and median: 17.30 vs. 10.09, P=0.042, respectively). Additionally, one patient from the MAKO group underwent revision surgery at nine months postoperatively due to ongoing periprosthetic discomfort.

CONCLUSIONS

The newly developed "SkyWalker" robot showed comparable efficacy to the MAKO robot in terms of lower limb alignment accuracy and postoperative six month and one year follow-up of clinically assessed resumption of knee function.

Mitochondrial-targeting and NIR-responsive Mn3O4@PDA@Pd-SS31 nanozymes reduce oxidative stress and reverse mitochondrial dysfunction to alleviate osteoarthritis

Mitochondrial reactive oxygen species (mROS) play a crucial role in the process of osteoarthritis (OA), which may be a promising target for therapy of OA. In this study, novel mitochondrial-targeting and SOD-mimic Mn3O4@PDA@Pd-SS31 nanozymes with near-infrared (NIR) responsiveness and synergistic cascade to scavenge mROS were designed for the therapy of OA. Results showed that the nanozymes accelerated the release of Pd and Mn3O4 under NIR irradiation, exhibiting enhanced activities of SOD and CAT mimic enzymes with reversed mitochondrial dysfunction and promoted mitophagy to effectively scavenge mROS from chondrocytes, modulate the microenvironment of oxidative stress, and eventually inhibit the inflammatory response. Nanozymes were excreted in vivo through intestinal metabolic pathway and had good biocompatibility, effectively reducing the inflammatory response and relieving articular cartilage degeneration in OA joints, with a reduction of 93.7 % and 93.8 % in OARSCI scores for 4 and 8 weeks respectively. Thus, this study demonstrated that the mitochondria targeting and NIR responsive Mn3O4@PDA@Pd-SS31 nanozymes could efficiently scavenge mROS, repair damaged mitochondrial function and promote cartilage regeneration, which are promising for the treatment of OA in clinical applications.

a comparison of intra-articular hyaluronic acid and platelet-rich plasma for knee osteoarthritis: a systematic review

Introduction

Knee osteoarthritis (KOA), the most common chronic degenerative condition in an older population, accounts for many disabilities around the world. One of the most popular treatments is intra-articular injection of hyaluronic acid (HA) and platelet-rich plasma (PRP).

Objective

Prior studies have found that both HA and PRP had a therapeutic effect on KOA. This study aims to perform a systematic review regarding whether PRP is superior to HA for KOA.

Method

We conducted a comprehensive literature search using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for prospective randomized control trials (pRCTs) in three international databases PubMed, Google Scholar, and ScienceDirect from 2019-2022. Two researchers independently searched the reviews, extracted, and cross-checked the data. The disparity when choosing the literature was resolved by discussion. The modified Jadad was scale used to assess the quality of the included studies. Cochrane risk of bias 2 tool (RoB-2) was used for determininzg risk of bias.

Results

Twenty three studies were eligible for inclusion. Four pRCT with the highest Jadad score were selected as best evidence. Risk of bias assesment concluded two studies having a low risk of bias, one is high risk of bias, and the other possesses some concerns.. Three studies found no difference in patient-reported outcomes between PRP and HA group and one study concluded that PRP is more effective than HA in treating KOA.

Conclusion

Intra-articular injections of PRP and HA are effective interventions for KOA. However, there is not enough evidence of PRP superiority over HA.

Gamma-oryzanol alleviates osteoarthritis development by targeting Keap1-Nrf2 binding to interfere with chondrocyte ferroptosis

Osteoarthritis (OA) is a prevalent joint disorder pathologically correlated to chondrocyte ferroptosis. Gamma-oryzanol (γ-Ory), as a first-line drug for autonomic disorders, aroused our interest because of its antioxidant, lipid-lowering, and hypoglycemic potential. The purpose of this study was to investigate the potential impact and mechanism of γ-Ory in treating OA. And the inhibition of γ-Ory in extracellular matrix molecule (ECM) degradation, ferroptosis, and Keap1-Nrf2 binding in IL-1β-exposed chondrocytes was detected via immunoblotting, immunofluorescence, and co-immunoprecipitation. Micro-CT, SO staining, and immunofluorescence have been conducted to assess the impact of γ-Ory treatment on ACLT-mediated OA in rats at both imaging and histological stages. We found that γ-Ory dose-dependently suppressed IL-1β-induced ECM deterioration and chondrocyte ferroptosis. Our animal experiments revealed that γ-Ory delayed ACLT-mediated OA development. Mechanistically, γ-Ory interfered with the binding of Keap1 to Nrf2 to promote the latter's nuclear import, thereby increasing the expression of detoxification enzymes. Summarily, our works support γ-Ory's potential as a candidate drug for the treatment of OA.

Management and Amelioration of Knee Joint Osteoarthritis in Adults Using a Novel High-Functional Bovine Collagen Peptide as a Nutritional Therapy: A Double-Blind, Prospective, Multicentric, Randomized, Active and Placebo Controlled, Five-Arm, Clinical Study to Evaluate the Efficacy, Safety, and Tolerability

OBJECTIVE

The various functionalities of collagen peptides have generated a large interest in utilizing the bioactive peptides as a nutritional therapy to ameliorate various physiological degenerative conditions. Collagen peptides are observed to reduce the pain and aligned difficulties with respect to osteoarthritis. Here we report the enhanced ameliorating property of novel high-functional "Wellnex" Type J collagen peptides following a double-blind randomized active and placebo-controlled 5-arm clinical trial (n = 100) by using it as a nutritional supplement in subjects with knee joint osteoarthritis in comparison with conventional bovine collagen peptides. The efficacy, safety, and tolerability were also studied.

DESIGN

Dosages of 2.5, 5.0, and 10.0 g of high-functional Type J bovine collagen peptides, 10.0 g of conventional collagen peptides, and 10.0 g of placebo were given to the 5 groups for a period of 90 days. The Western Ontario McMaster Universities Arthritis Index (WOMAC) score, Pain Scale, Quality of Life (QoL), Physician's Impression of change Score (PICS), serum C-terminal cross-linked telopeptide of type II collagen (CTX-II) levels and Magnetic Resonance Imaging Osteoarthritis Knee Score (MOAKS) parameters were monitored.

RESULTS

Type J 2.5 g showed significant improvement in WOMAC, QoL, CTX, and MOAKS and observed to be equivalent to conventional collagen peptide 10-g supplementation in terms of efficacy.

CONCLUSION

The two significant outcomes of the study were that Type J 10.0 g, Type J 5.0 g, Type J 2.5 g and conventional collagen peptides 10.0 g supplementation were observed to be beneficial nutraceutical therapies for knee joint osteoarthritis, and Type J 2.5 g supplementation was equivalent to conventional collagen peptides 10.0-g supplementation in terms of efficacy.

Predictors Associated with Forgotten Knee in Patients with Total Knee Arthroplasty Based on Multivariable Linear Regression

OBJECTIVE

Existing studies have conflicting results about the predictors of forgotten joints in patients with total knee arthroplasty (TKA), and the relationship between psychosocial factors and forgotten knees is unknown. The purpose of this study was to confirm predictors for the forgotten joint in TKA patients.

METHODS

This was an observational, prospective longitudinal study. A total of 205 patients who underwent TKA and a 6-month follow-up were included between August 2020 and September 2021. Demographic characteristics, clinical characteristics, and psychosocial variables were collected before TKA surgery (T0). The forgotten joint score (FJS) was taken before TKA surgery (T0) and at 1 month (T1), 3 months (T3), and 6 months (T6) after TKA surgery. The psychosocial variables were also completed at T6. Bivariate and multivariable linear regressions (LR) were performed to screen the predictors associated with FJS (T6).

RESULTS

Patients who underwent TKA in our study had a mean FJS of 20.3 ± 12.2 before surgery, 15.9 ± 10.3 at 1 month, 28.7 ± 12.6 at 3 months, and 40.3 ± 12.5 at 6 months. The predictors were sex, combined musculoskeletal disorders (MSD), operation time, FJS (T3), range of motion (ROM) (T6), pain score (T6), Groningen orthopaedic social support scale (GO-SSS) score (T6), and the generalized anxiety disorder scale (GAD) score (T6). The data satisfied the assumptions of multivariable linear regressions. The multiple R2 of LR was 0.71, and the adjusted R2 was 0.70. The F-statistic of the LR model was 59.5 (p < 0.000).

CONCLUSION

Our study revealed the level of forgotten knee decreased slightly from preoperation to 1 month postoperatively and then increased from 1 month postoperatively to 6 months postoperatively in TKA patients. The main predictors associated with the FJS at 6 months after surgery were sex, combined MSD, operation time, FJS (T3), ROM (T6), pain score (T6), GO-SSS score (T6), and anxiety (T6).

Exploring needs, barriers to, and facilitators of rehabilitation exercise following revision hip replacement - A grounded theory study

PURPOSE

Evidence on rehabilitation after revision total hip replacement (THR) is inadequate and development of rehabilitation interventions is warranted. Even so, little is known about patients' experiences with revision THR rehabilitation. This study aimed to explore patients' rehabilitation exercise experiences after revision THR.

MATERIALS AND METHODS

Using constructivist grounded theory, we conducted semi-structured qualitative interviews with twelve patients with completed or almost completed rehabilitation exercise after revision THR. Data collection and analysis were a constant comparative process conducted in three phases; initial, focused, and theoretical.

FINDINGS

From the data, we generated a substantial theory of the participant's circumstances and ability to integrate rehabilitation exercise into their everyday life after revision THR. Four categories were constructed based on patients' experiences in different contexts: hesitance, fear avoidance, self-commitment, and fidelity.

CONCLUSIONS

This study highlighted that patients' expectations, past experiences, attitudes, trusts, and circumstances interact to influence engagement and adherence to rehabilitation exercise and described four categories relating to the integration of revision THR rehabilitation exercise into their everyday life. Clinicians should be aware of and account for these categories during rehabilitation exercise. Tailored individual rehabilitation exercise interventions and clinician approaches to optimize engagement and adherence are needed among patients with revision THR.

HOXA10 promotes Gdf5 expression in articular chondrocytes

Growth differentiation factor 5 (GDF5), a BMP family member, is highly expressed in the surface layer of articular cartilage. The GDF5 gene is a key risk locus for osteoarthritis and Gdf5-deficient mice show abnormal joint development, indicating that GDF5 is essential in joint development and homeostasis. In this study, we aimed to identify transcription factors involved in Gdf5 expression by performing two-step screening. We first performed microarray analyses to find transcription factors specifically and highly expressed in the superficial zone (SFZ) cells of articular cartilage, and isolated 11 transcription factors highly expressed in SFZ cells but not in costal chondrocytes. To further proceed with the identification, we generated Gdf5-HiBiT knock-in (Gdf5-HiBiT KI) mice, by which we can easily and reproducibly monitor Gdf5 expression, using CRISPR/Cas9 genome editing. Among the 11 transcription factors, Hoxa10 clearly upregulated HiBiT activity in the SFZ cells isolated from Gdf5-HiBiT KI mice. Hoxa10 overexpression increased Gdf5 expression while Hoxa10 knockdown decreased it in the SFZ cells. Moreover, ChIP and promoter assays proved the direct regulation of Gdf5 expression by HOXA10. Thus, our results indicate the important role played by HOXA10 in Gdf5 regulation and the usefulness of Gdf5-HiBiT KI mice for monitoring Gdf5 expression.

MiR-203a-3p attenuates apoptosis and pyroptosis of chondrocytes by regulating the MYD88/NF-κB pathway to alleviate osteoarthritis progression

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease that imposes a significant socioeconomic burden worldwide. Our previous studies revealed a down-regulation of miR-203a-3p in the knee tissues of OA patients. However, the underlying mechanism through which miR-203a-3p mediates the pathological process of OA remains unknown. Thus, we aimed to determine the effects of miR-203a-3p in the progression of OA.

METHODS

Rat primary chondrocytes were stimulated with 10 μg/mL lipopolysaccharide (LPS) for 24 hours, followed by transfection with 50 nM miR-203a-3p mimic, inhibitor, and siRNA for MYD88 or consistent negative controls for 48 hours. To evaluate the effects of miR-203a-3p on cartilage matrix degradation, oxidative stress, apoptosis, and pyroptosis in chondrocytes, various techniques such as immunofluorescence staining, biochemical analysis, Western blotting, and the TUNEL staining were utilized. In the rat OA model, all rats were randomly divided into four groups: Sham, OA, OA+Agomir negative control (NC), and OA+Agomir. They received intra-articular injections of 25 nmol miR-203a-3p agomir, agomir NC, or normal saline twice a week for the duration of 8 weeks after OA induction. Immunofluorescence staining was performed to evaluate the effects of miR-203a-3p on cartilage matrix degradation in rats.

RESULTS

MiR-203a-3p was down-regulated in LPS-treated rat chondrocytes and OA cartilage, and directly targeted MYD88. Moreover, miR-203a-3p significantly inhibited LPS-induced cartilage matrix degradation, oxidative stress, apoptosis, and pyroptosis of chondrocytes via targeting MYD88. Mechanistically, miR-203a-3p exerted protective effects via the inhibition of the MYD88/NF-κB pathway. In the rat OA model, intra-articular injections of miR-203a-3p agomir also significantly inhibited cartilage matrix degradation, thereby alleviating OA progression. Furthermore, the miR-203a-3p agomir-treated arthritic rat dramatically exhibited better articular tissue morphology and lower OARSI scores.

CONCLUSIONS

MiR-203a-3p plays a role in alleviating the progression of OA by regulating the MYD88/NF-κB pathway, thereby inhibiting cartilage matrix degradation, oxidative stress, apoptosis, and pyroptosis of chondrocytes. It highlights the potential significance of miR-203a-3p as an important regulator of OA.

New insight of the pathogenesis in osteoarthritis: the intricate interplay of ferroptosis and autophagy mediated by mitophagy/chaperone-mediated autophagy

Ferroptosis, characterized by iron accumulation and lipid peroxidation, is a form of iron-driven cell death. Mitophagy is a type of selective autophagy, where degradation of damaged mitochondria is the key mechanism for maintaining mitochondrial homeostasis. Additionally, Chaperone-mediated autophagy (CMA) is a biological process that transports individual cytoplasmic proteins to lysosomes for degradation through companion molecules such as heat shock proteins. Research has demonstrated the involvement of ferroptosis, mitophagy, and CMA in the pathological progression of Osteoarthritis (OA). Furthermore, research has indicated a significant correlation between alterations in the expression of reactive oxygen species (ROS), adenosine monophosphate (AMP)-activated protein kinase (AMPK), and hypoxia-inducible factors (HIFs) and the occurrence of OA, particularly in relation to ferroptosis and mitophagy. In light of these findings, our study aims to assess the regulatory functions of ferroptosis and mitophagy/CMA in the pathogenesis of OA. Additionally, we propose a mechanism of crosstalk between ferroptosis and mitophagy, while also examining potential pharmacological interventions for targeted therapy in OA. Ultimately, our research endeavors to offer novel insights and directions for the prevention and treatment of OA.

Mechanical stress in the urbanized Roman Phoenician coast

OBJECTIVE

Skeletal populations from Byblos, Beirut, and Tyre were studied to assess mechanical stress along the Roman Phoenician coast.

MATERIALS

The sample included 153 adult skeletons.

METHODS

Skeletal remains were macroscopically assessed for osteoarthritis, intervertebral disc disease (IDD), and Schmorl's nodes.

RESULTS

The Byblos population experienced higher levels of mechanical stress than the Beirut and Tyre ones. Sex-based differences were also found in all skeletal assemblages with males likely engaging in physically more demanding tasks.

CONCLUSIONS

The variation in mechanical stress, and associated physically demanding tasks, between these populations can be attributed to their differing political and economic status during the Roman period; textual sources highlight the economic and political dominance of Beirut and Tyre, emanating from their status as coloniae.

SIGNIFICANCE

This study represents one of the first attempts to investigate mechanical stress in coastal Phoenicia during the Roman period. It provides valuable insights into the biocultural structure of understudied communities at the periphery of the Roman world, and can serve as a basis for further future research into the occupational patterns of Phoenician communities.

LIMITATIONS

The contextual information for these skeletal populations is very limited and does not allow secure conclusions regarding their representativeness. The sample sizes are also rather small, especially when divided per sex and age.

SUGGESTIONS FOR FURTHER RESEARCH

Further investigation employing complementary methods such as cross-sectional geometric properties and entheseal changes is needed to reconstruct the occupational patterns of these communities, taking into account cultural, environmental, and temporal factors.

Emerging role and therapeutic implications of p53 in intervertebral disc degeneration

Lower back pain (LBP) is a common degenerative musculoskeletal disease that imposes a huge economic burden on both individuals and society. With the aggravation of social aging, the incidence of LBP has increased globally. Intervertebral disc degeneration (IDD) is the primary cause of LBP. Currently, IDD treatment strategies include physiotherapy, medication, and surgery; however, none can address the root cause by ending the degeneration of intervertebral discs (IVDs). However, in recent years, targeted therapy based on specific molecules has brought hope for treating IDD. The tumor suppressor gene p53 produces a transcription factor that regulates cell metabolism and survival. Recently, p53 was shown to play an important role in maintaining IVD microenvironment homeostasis by regulating IVD cell senescence, apoptosis, and metabolism by activating downstream target genes. This study reviews research progress regarding the potential role of p53 in IDD and discusses the challenges of targeting p53 in the treatment of IDD. This review will help to elucidate the pathogenesis of IDD and provide insights for the future development of precision treatments.

Streamlining quantitative joint-wide medial femoro-tibial histopathological scoring of mouse post-traumatic knee osteoarthritis models

OBJECTIVES

Histological scoring remains the gold-standard for quantifying post-traumatic osteoarthritis (ptOA) in animal models, allowing concurrent evaluation of numerous joint tissues. Available systems require scoring multiple sections/joint making analysis laborious and expensive. We investigated if a single section allowed equivalent quantitation of pathology in different joint tissues and disease stages, in three ptOA models.

METHOD

Male 10-12-week-old C57BL/6 mice underwent surgical medial-meniscal-destabilization, anterior-cruciate-ligament (ACL) transection, non-invasive-ACL-rupture, or served as sham-surgical, non-invasive-ACL-strain, or naïve/non-operated controls. Mice (n = 12/group) were harvested 1-, 4-, 8-, and 16-week post-intervention. Serial sagittal toluidine-blue/fast-green stained sections of the medial-femoro-tibial joint (n = 7/joint, 84 µm apart) underwent blinded scoring of 40 histology-outcomes. We evaluated agreement between single-slide versus entire slide-set maximum or median scores (weighted-kappa), and sensitivity/specificity of single-slide versus median/maximum to detect OA pathology.

RESULTS

A single optimal mid-sagittal section showed excellent agreement with median (weighted-kappa 0.960) and maximum (weighted-kappa 0.926) scores. Agreement for individual histology-outcomes was high with only 19/240 median and 15/240 maximum scores having a weighted-kappa ≤0.4, the majority of these (16/19 and 11/15) in control groups. Statistically-significant histology-outcome differences between ptOA models and their controls detected with the entire slide-set were reliably reproduced using a single slide (sensitivity >93.15%, specificity >93.10%). The majority of false-negatives with single-slide scoring were meniscal and subchondral bone histology-outcomes (89%) and occurred in weeks 1-4 post-injury (84%).

CONCLUSION

A single mid-sagittal slide reduced the time needed to score diverse histopathological changes by 87% without compromising the sensitivity or specificity of the analysis, across a variety of ptOA models and time-points.

Efficacy of transcranial direct current stimulation in patients with knee osteoarthritis: A systematic review

OBJECTIVE

Transcranial direct current stimulation (tDCS) has demonstrated its efficacy in alleviating pain among individuals with musculoskeletal disorders. This review focuses on the application of tDCS as a therapeutic intervention for managing knee osteoarthritis (OA), a prevalent musculoskeletal condition. The primary objective is to assess the effectiveness of tDCS(add-on tDCS and /or stand-alone tDCS), whether as an add-on to existing treatments or as a standalone therapy, in reducing pain and enhancing functional capacity in patients with knee OA.

METHODS

A comprehensive search was conducted across multiple databases, including PubMed, Science Direct, OVID, MEDLINE, CINAHL, EMBASE, ProQuest, and Google Scholar, and Web of Science. The search terms employed were "Transcranial direct current stimulation" or "tDCS" in combination with "Osteoarthritis" or "OA" and "knee." After eliminating duplicates and studies that did not meet the inclusion criteria, a total of 14 relevant articles were identified for review.

RESULTS

Among the included studies, twelve reported statistically significant improvements in pain levels when comparing the active tDCS group to the sham tDCS group. Only two studies reported no significant difference in pain intensity between the active tDCS and sham tDCS groups. Findings regarding functional abilities were diverse, with some studies demonstrating a significant enhancement in functional outcomes in the active tDCS group, while others observed no statistically significant differences.

CONCLUSION

The results of this review suggest that tDCS holds promise as a pain management intervention for individuals with knee OA. Notably, anodal tDCS applied over the primary motor cortex (M1) appears to be particularly effective in alleviating pain in patients with knee OA. However, the impact of tDCS on functional performance appears to be limited.

Integrin α10β1-Selected Mesenchymal Stem Cells Reduce Pain and Cartilage Degradation and Increase Immunomodulation in an Equine Osteoarthritis Model

OBJECTIVE

Integrin α10β1-selected mesenchymal stem cells (integrin α10-MSCs) have previously shown potential in treating cartilage damage and osteoarthritis (OA) in vitro and in animal models in vivo. The aim of this study was to further investigate disease-modifying effects of integrin α10-MSCs.

DESIGN

OA was surgically induced in 17 horses. Eighteen days after surgery, horses received 2 × 107 integrin α10-MSCs intra-articularly or were left untreated. Lameness and response to carpal flexion was assessed weekly along with synovial fluid (SF) analysis. On day 52 after treatment, horses were euthanized, and carpi were evaluated by computed tomography (CT), MRI, histology, and for macroscopic pathology and integrin α10-MSCs were traced in the joint tissues.

RESULTS

Lameness and response to carpal flexion significantly improved over time following integrin α10-MSC treatment. Treated horses had milder macroscopic cartilage pathology and lower cartilage histology scores than the untreated group. Prostaglandin E2 and interleukin-10 increased in the SF after integrin α10-MSC injection. Integrin α10-MSCs were found in SF from treated horses up to day 17 after treatment, and in the articular cartilage and subchondral bone from 5 of 8 treated horses after euthanasia at 52 days after treatment. The integrin α10-MSC injection did not cause joint flare.

CONCLUSION

This study demonstrates that intra-articular (IA) injection of integrin α10-MSCs appears to be safe, alleviate pathological changes in the joint, and improve joint function in an equine post-traumatic osteoarthritis (PTOA) model. The results suggest that integrin α10-MSCs hold promise as a disease-modifying osteoarthritis drug (DMOAD).

Risk factors for contralateral total knee arthroplasty after unilateral total knee arthroplasty

BACKGROUND

Little attention has been focused on risk factors for undergoing bilateral total knee arthroplasty (TKA) after primary unilateral TKA among patients with knee osteoarthritis (OA). This study investigated the differences in characteristics between groups with and without additional TKA for the contralateral knee among patients with knee OA who underwent primary unilateral TKA.

METHODS

Seventy-six patients who underwent primary unilateral TKA were included in this study. We defined patients who underwent additional TKA for the contralateral knee within one year of the primary TKA as a bilateral TKA group, and patients who did not undergo bilateral TKA as a unilateral TKA group. Femorotibial angle (FTA), percentage of mechanical axis (%MA), Kellgren-Lawrence (KL) grade, range of motion, Japan Orthopaedic Association (JOA) score, 10 m-walking time, C-reactive protein, estimated glomerular filtration rate, and serum albumin levels were selected as independent variables including covariates of age, sex, and body mass index for predicting bilateral TKA. We compared differences in variables between the two groups using the t-test or Mann-Whitney U-test and general linear models. A multivariate stepwise logistic regression model was also used to determine which variables correlated with bailateral TKA.

RESULTS

In pairwise comparisons, the KL grade, FTA, %MA, JOA score, and knee flexion angle in the contralateral knee were significantly worse in the bilateral TKA group than in the unilateral TKA group after controlling for covariates (P < 0.01, respectively). A stepwise logistic regression revealed that significant contributors to undergoing the contralateral TKA were FTA (OR = 1.47, P < 0.001) and knee flexion angle (OR = 0.96, P = 0.022) of the contralateral knee.

CONCLUSIONS

Severe varus deformity and limitations of flexion in the contralateral knee were found to be risk factors for undergoing additional TKA within one year of primary unilateral TKA among patients with knee OA.

Associations of preoperative anemia and postoperative hemoglobin values with hospital costs in total knee arthroplasty (TKA)

BACKGROUND

Total knee arthroplasty are among the most frequently conducted surgeries, due to an aging society. Since hospital costs are subsequently rising, adequate preparation of patients and reimbursement becomes more and more important. Recent literature revealed anemia as a risk factor for enhanced length of stay (LOS) and complications. This study analyzed whether preoperative hemoglobin (Hb) and postoperative Hb were associated with total hospital costs and general ward costs.

METHODS

The study comprised 367 patients from a single high-volume hospital in Germany. Hospital costs were calculated with standardized cost accounting methods. Generalized linear models were applied to account for confounders, such as age, comorbidities, body mass index, insurance status, health-related quality of life, implant types, incision-suture-time and tranexamic acid.

RESULTS

Preoperative anemic women had 426 Euros higher general ward costs (p < 0.01), due to increased LOS. For men, 1 g/dl less Hb loss between the preoperative value and the value before discharge reduced total costs by 292 Euros (p < 0.001) and 161 Euros fewer general ward costs (p < 0.001). Total hospital costs were reduced by 144 Euros with 1 g/dl higher Hb on day 2 postoperatively for women (p < 0.01).

CONCLUSION

Preoperative anemia was associated with increased general ward costs for women and Hb loss with decreasing total hospital costs for men and women. Cost containment, especially reduced utilization of the general ward, may be feasible with the correction of anemia for women. Postoperative Hb values may be a factor for adjustments of reimbursement systems.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

Potential of thermoresponsive hydrogel as an alternative therapy for rat knee osteoarthritis

Osteoarthritis is a degenerative condition that is highly prevalent and primarily affects the joints. The knee is the most commonly affected site, impacting the lives of over 300 million individuals worldwide. This study presents a potential solution to address the unmet need for a minimally invasive technique in the treatment of osteoarthritis: a biocompatible, injectable, and thermoresponsive hydrogel. In comparison to commercially available products such as lyophilized platelets, dextrose, and triamcinolone, the thermoresponsive hydrogel exhibits significantly superior performance in dynamic behaviors, including print area, stability, and step cycle, when tested on rats with knee osteoarthritis. However, it demonstrates similar treatment efficacy to these products in static behaviors, as observed through histopathological and immunohistochemical analysis. Therefore, the thermoresponsive hydrogel holds promise as an effective alternative therapy for osteoarthritis. Moreover, by blending the hydrogel with drugs, controlled and sustained release can be achieved, thereby facilitating the long-term management of osteoarthritis symptoms.

The Preventive Effects of Platelet-Rich Plasma Against Knee Osteoarthritis Progression in Rats

BACKGROUND

In recent years, the intra-articular administration of platelet-rich plasma (PRP), a novel therapeutic strategy for knee osteoarthritis (KOA), has gained attention. However, the efficacy of PRP in inhibiting degenerative joint changes remains unclear. The current study aimed to evaluate the therapeutic effect of the intra-articular administration of PRP in rats with induced KOA.

MATERIALS AND METHODS

PRP was prepared from the whole blood of nine-week-old male Wistar rats via centrifugation at 25°C, 200 × g, for seven minutes. KOA was induced in the right knees of the rats via destabilization of the medial meniscus (DMM) surgery. The animals were divided into the control, sham, DMM, and DMM + PRP groups (n = 5 each). The rats in the DMM + PRP group received 50 μL of intra-articular PRP in the right knee joint four weeks after surgery. The rotarod test was conducted to assess locomotive function. Eight weeks after DMM surgery, the degree of medial meniscus extrusion was measured via computed tomography (CT) images on the right knee. Then, a histological analysis of the harvested knees was conducted. KOA progression was assessed using the Osteoarthritis Research Society International (OARSI) score. The number of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in the subchondral bone was counted via histological analysis.

RESULTS

The degree of medial meniscus extrusion did not significantly differ between the DMM and DMM + PRP groups. Similarly, there were no significant differences in the walking time based on the rotarod test between the DMM and DMM + PRP groups. However, the DMM group had a significantly higher OARSI score than the DMM + PRP group. The number of TRAP-positive osteoclasts in the subchondral bone of the DMM group increased over time, peaking four weeks after surgery. The DMM + PRP group had a higher number of TRAP-positive osteoclasts in the subchondral bone than the control group. However, there was no significant difference between the number of TRAP-positive osteoclasts between the DMM group and the control and sham groups.

CONCLUSION

The intra-articular administration of PRP may inhibit KOA progression in a rat model, especially in the articular cartilage degradation and osteophyte formation. The results can provide further evidence about the efficacy of PRP against KOA progression and can contribute to the current practice of healthcare professionals based on accurate knowledge.

Silenced LASP1 interacts with DNMT1 to promote TJP2 expression and attenuate articular cartilage injury in mice by suppressing TJP2 methylation

To investigate the regulatory mechanisms and effects of LIM and SH3 protein 1 (LASP1) on osteoarthritis (OA). IL-1β was used to induce OA in cell models. Viability and apoptosis of chondrocytes were assessed. The expressions of tumor necrsis factor-α (TNF-α) and IL-6 were measured by ELISA kit, and Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were performed to test the expression of related proteins. The STRING database was used to predict the relationship between LASP1 and DNA methyltransferase 1 (DNMT1). The tight junction protein 2 (TJP2) and Gene Expression Omnibus data were analyzed for differential OA genes. Methylation-specific PCR detected methylation of the TJP2 promoter region, and chromatin immunoprecipitation detected the enrichment of DNMT1 in the TJP2 promoter region. Safranin O-Fast Green staining and hematoxylin and eosin staining were used to determine the OARSI score and evaluate the pathological conditions of the joint tissues. LASP1 was highly expressed in IL-1β-induced cell models. Silencing of LASP1 promoted chondrocyte proliferation and expression of Collagen II and Aggrecan and inhibited chondrocyte apoptosis, inflammatory factors, and matrix metalloprotein expression. TJP2 is weakly expressed in OA models, and LASP1 promotes methylation of the TJP2 promoter region by interacting with DNMT1. Silencing of LASP1 attenuated IL-1β-induced chondrocyte degeneration by promoting TJP2 expression. Similarly, silencing LASP1 promotes TJP2 expression to alleviate articular cartilage injury in mice with OA. Silencing of LASP1 inhibited the methylation of the TJP2 promoter region by interacting with DNMT1, thereby alleviating articular cartilage damage in OA mice.

The Effects of Ultrasound-Guided Intra-Articular Injections with Hyaluronic Acid and Corticosteroids in Patients with Hip Osteoarthritis: A Long-Term Real-World Analysis

Intra-articular (IA) ultrasound-guided hip injections are currently considered a cornerstone of the conservative management of symptomatic hip osteoarthritis (HOA), although their effect on clinical outcomes has not been fully elucidated.The purpose of this study is to investigate the effectiveness of ultrasound-guided IA hip injections of hyaluronic acid (HA) with or without corticosteroids (CS) on pain relief and functional improvement in patients with HOA. In total, 167 patients with HOA were assessed at baseline (T0) and 12 months after injection (T1) using the VAS and GLFS scores. The sample consisted mainly of female subjects (58.1%), presenting an average age of 70.6 ± 12.2 years and grade 3 HOA (63.9%) according to the Kellgren-Lawrence classification. Most of the patients (76.2%) underwent unilateral hip injection with a combination of medium-high molecular weight HA (1500-2000 kDa) and CS. At T1, lower use of anti-inflammatory drugs, an increase in the consumption of chondroprotectors, and an overall reduction of instrumental physical therapies and therapeutic exercise were recorded. In addition, a statistically significant intragroup and between-group decrease observed at T1 for both the VAS and GLFS. Study results suggested that intra-articular hip injections with HA alone and with CS could represent a useful therapeutic tool for pain reduction and functional improvement for patients with hip osteoarthritis.

Berberine oleanolic acid complex salt grafted hyaluronic acid/silk fibroin (BOA-g-HA/SF) composite scaffold promotes cartilage tissue regeneration under IL-1β caused stress

Since inflammatory cytokines cause stress to chondrocytes and the failure of cartilage defects repair with cartilage tissue engineering, it is necessary to develop a scaffold to maintain cartilage regeneration under inflammatory factors caused stress. Following a berberine-oleanolic acid (OA) complex salt (BOA) was grafted to hyaluronic acid (HA) to obtain water soluble BOA-g-HA, it mixed with silk fibroin (SF) to prepared 4 solutions, which contained 30 mg/mL SF and 0.75, 1.5, 2.25, and 3.0 mg/mL BOA-g-HA respectively. They were lyophilized to fabricate BOA-g-HA/SF-1, BOA-g-HA/SF-2, BOA-g-HA/SF-3, and BOA-g-HA/SF-4 composite scaffolds respectively. All prepared scaffolds displayed porous network structure and exhibited promising mechanical properties for tissue engineering applications. Among them, the BOA-g-HA/SF-3 composite scaffold showed the highest influence on maintaining chondrocytic phenotype of chondrocytes under IL-1β induced stress. Following SF, HA/SF, and BOA-g-HA/SF-3 composite scaffolds with seeded chondrocytes were treated with IL-1β induction for 1 week, specimens were incubated with cell culture medium for 3 week or were subcutaneously implanted into nude mice for 4 weeks. The results demonstrated that the BOA-g-HA/SF-3 composite scaffold promotes cartilage tissue regeneration in vitro and in vivo under IL-1β caused stress, suggesting that it can be potential applied for repairing cartilage defects in osteoarthritis patients.

Suramin analogues protect cartilage against osteoarthritic breakdown by increasing levels of tissue inhibitor of metalloproteinases 3 (TIMP-3) in the tissue

Osteoarthritis is a chronic degenerative joint disease affecting millions of people worldwide, with no disease-modifying drugs currently available to treat the disease. Tissue inhibitor of metalloproteinases 3 (TIMP-3) is a potential therapeutic target in osteoarthritis because of its ability to inhibit the catabolic metalloproteinases that drive joint damage by degrading the cartilage extracellular matrix. We previously found that suramin inhibits cartilage degradation through its ability to block endocytosis and intracellular degradation of TIMP-3 by low-density lipoprotein receptor-related protein 1 (LRP1), and analysis of commercially available suramin analogues indicated the importance of the 1,3,5-trisulfonic acid substitutions on the terminal naphthalene rings for this activity. Here we describe synthesis and structure-activity relationship analysis of additional suramin analogues using ex vivo models of TIMP-3 trafficking and cartilage degradation. This showed that 1,3,6-trisulfonic acid substitution of the terminal naphthalene rings was also effective, and that the protective activity of suramin analogues depended on the presence of a rigid phenyl-containing central region, with para/para substitution of these phenyl rings being most favourable. Truncated analogues lost protective activity. The physicochemical characteristics of suramin and its analogues indicate that approaches such as intra-articular injection would be required to develop them for therapeutic use.

Targeting regulated chondrocyte death in osteoarthritis therapy

In vivo articular cartilage degeneration is an essential hallmark of osteoarthritis (OA), involving chondrocyte senescence, extracellular matrix degradation, chondrocyte death, cartilage loss, and bone erosion. Among them, chondrocyte death is one of the major factors leading to cartilage degeneration. Many studies have reported that various cell death modes, including apoptosis, ferroptosis, and autophagy, play a key role in OA chondrocyte death. Currently, there is insufficient understanding of OA pathogenesis, and there remains a lack of treatment methods to prevent OA and inhibit its progression. Studies suggest that OA prevention and treatment are mainly directed to arrest premature or excessive chondrocyte death. In this review, we a) discuss the forms of death of chondrocytes and the associations between them, b) summarize the critical factors in chondrocyte death, c) discuss the vital role of chondrocyte death in OA, d) and, explore new approaches for targeting the regulation of chondrocyte death in OA treatment.

Identification of EGFR as an essential regulator in chondrocytes ferroptosis of osteoarthritis using bioinformatics, in vivo, and in vitro study

Objective

The mechanisms of chondrocytes ferroptosis in osteoarthritis (OA) have not yet been fully elucidated. This study aimed to identify key ferroptosis related genes (FRGs) involved in chondrocytes ferroptosis.

Methods

LASSO, SVM-RFE, and receiver operating characteristic curve (ROC) were performed to screen key differentially expressed FRGs (DEFRGs). Functional analyses were conducted using GO, and KEGG analyses. Unsupervised clustering analysis was used to identify ferroptosis related patterns. The CeRNA network was constructed to predict the upstream miRNAs and lncRNAs. Finally, we validated the role of EGFR in chondrocytes ferroptosis using in vivo and in vitro experiments.

Results

A total of 42 DEFRGs were identified between OA and normal cartilages. GO and KEGG analyses indicated that these DEFRGs were significantly engaged in ferroptosis related biological processes and pathways, such as cellular response to oxidative stress, positive regulation of programmed cell death, MAPK and PI3K-Akt signaling pathways. Moreover, four key DEFRGs, including ACSF2, AURKA, EGFR, and KLHL24, were considered as potential biomarkers of OA. Moreover, two distinct ferroptosis related patterns were determined, and a total of 882 differentially expressed genes were identified which might participate in extracellular matrix degradation and inflammatory response. In addition, the CeRNA network showed that EGFR could be competitively regulated by 3 lncRNAs and 4 miRNAs. Significantly, the expression of EGFR was downregulated in human OA cartilages, OA mouse model, and erastin induced chondrocytes. EGFR inhibition could induce the occurrence of chondrocytes ferroptosis and ECM degradation which could be reversed by the addition of Ferrostatin-1.

Conclusion

Our study has identified ACSF2, AURKA, EGFR, and KLHL24 as ferroptosis-related biomarkers in OA. Furthermore, we have conducted a preliminary investigation into the role of EGFR in regulating chondrocytes ferroptosis. These findings offer novel insights into the molecular mechanisms underlying OA.

Tizoxanide as a novel theraputic candidate for osteoarthritis

Osteoarthritis (OA) is a frequently seen degenerative joint disease in the elderly. Its pathogenesis is highly related to the local inflammatory reaction and autophagy. Tizoxanide (Tiz), the main active metabolite of nitazoxanide, has proved its anti-inflammatory properties in several diseases. However, the exact role of Tiz in OA remains to explore. In this study, we investigated the anti-arthritic effects and the underlying molecular mechanisms of Tiz on rat OA. The results showed that Tiz could attenuate the IL-1β-induced inflammatory disorders, cartilage matrix damage and autophagy reduction in rat chondrocytes. Moreover, employment of autophagy inhibitor 3-methyladenine (3-MA) could antagonize the protective effects of Tiz in IL-1β-treated rat chondrocytes. Additionally, Tiz also inhibited the IL-1β-induced PI3K/AKT/mTOR and P38/JNK phosphorylation in chondrocytes. In vivo, intra-articular injection of Tiz could significantly alleviate the progression of cartilage damage in rat OA model. Briefly, our study demonstrated the therapeutic potential of Tiz in OA, suggesting that Tiz administration might serve as a promising strategy in OA therapy.

Relations between Structure/Composition and Mechanics in Osteoarthritic Regenerated Articular Tissue: A Machine Learning Approach

In the context of a large animal model of early osteoarthritis (OA) treated by orthobiologics, the purpose of this study was to reveal relations between articular tissues structure/composition and cartilage viscoelasticity. Twenty-four sheep, with induced knee OA, were treated by mesenchymal stem cells in various preparations-adipose-derived mesenchymal stem cells (ADSCs), stromal vascular fraction (SVF), and amniotic endothelial cells (AECs)-and euthanized at 3 or 6 months to evaluate the (i) biochemistry of synovial fluid; (ii) histology, immunohistochemistry, and histomorphometry of articular cartilage; and (iii) viscoelasticity of articular cartilage. After performing an initial analysis to evaluate the correlation and multicollinearity between the investigated variables, this study used machine learning (ML) models-Variable Selection Using Random Forests (VSURF) and Extreme Gradient Boosting (XGB)-to classify variables according to their importance and employ them for interpretation and prediction. The experimental setup revealed a potential relation between cartilage elastic modulus and cartilage thickness (CT), synovial fluid interleukin 6 (IL6), and prostaglandin E2 (PGE2), and between cartilage relaxation time and CT and PGE2. SVF treatment was the only limit on the deleterious OA effect on cartilage viscoelastic properties. This work provides indications to future studies aiming to highlight these and other relationships and focusing on advanced regeneration targets.

Lipid peroxidation in osteoarthritis: focusing on 4-hydroxynonenal, malondialdehyde, and ferroptosis

Osteoarthritis (OA) is a multifactorial and increasingly prevalent degenerative disease that affects the whole joint. The pathogenesis of OA is poorly understood and there is a lack of therapeutic interventions to reverse the pathological process of this disease. Accumulating studies have shown that the overproduction of reactive oxygen species (ROS) and ROS-induced lipid peroxidation are involved in the pathogenesis of OA. 4-Hydroxy-2-nonenal (4-HNE) and malondialdehyde (MDA) have received considerable attention for their role in cartilage degeneration and subchondral bone remodeling during OA development. Ferroptosis is a form of cell death characterized by a lack of control of membrane lipid peroxidation and recent studies have suggested that chondrocyte ferroptosis contributes to OA progression. In this review, we aim to discuss lipid peroxidation-derived 4-HNE and MDA in the progression of OA. In addition, the therapeutic potential for OA by controlling the accumulation of lipid peroxidation and inhibiting chondrocyte ferroptosis are discussed.

Treatment with CR500® improves algofunctional scores in patients with knee osteoarthritis: a post-market confirmatory interventional, single arm clinical investigation

BACKGROUND

Knee osteoarthritis (OA) is a progressive and degenerative condition. Several pharmacological and non-pharmacological treatments are able to improve the OA symptoms and the structural characteristics of the affected joints. Among these, infiltrative therapy with hyaluronic acid (HA) is the most used and consolidated procedure for the pain management. The addition of skin conditioning peptides to HA promotes the cartilage remodeling processes and a better permeation of the HA-based gel containing a peptide mixture, CR500®. Furthermore, the topic route of administration is convenient over the routinely used intra-articular injective procedures. In this study, the effectiveness of CR500® was evaluated in terms of improvement of the algo-functional symptoms related to unilateral knee OA.

METHODS

38 mild and moderate OA patients were enrolled at a screening visit (V-1), treated at baseline visit (V1), and then continued the topical application of CR500® twice a week for 4 weeks, and followed-up for 3 visits (V2-V4) from week 2 to 4. Lequesne Knee Index (LKI) and Knee injury and Osteoarthritis Outcome Score (KOOS) were collected. Synovial fluid was collected and used for the quantification of neoepitope of type II collagen (C2C), C-terminal telopeptide of type II collagen (CTX-II), type II collagen propeptide (CPII), tumor necrosis factor alpha (TNFα) and HA. The expression of CD11c and CD206 was evaluated on cell pellets.

RESULTS

Three patients were excluded, thus 35 patients were included in the analysis. The treatment with CR500® was safe and well tolerated, with 7.9% patients had mild adverse events, not related to the device. The LKI total score showed a significant decrease from V1 to V4. KOOS score also showed a significant improvement of patient condition at V2, V3 and V4 in comparison with V1 for all subscales, except for KOOS sport subscale which improved only from V3. At V1 a negative correlation among KOOS pain subscale values and C2C, CPII and TNFα levels was observed, as well as a positive correlation between KOOS pain subscale and CD11c/CD206 ratio.

CONCLUSION

CR500® is safe and appear to be effective in improving pain and function in OA patients during the 4 weeks of treatment.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT05661162. This trial was registered on 22/12/2022.

Effects of genus Epimedium in the treatment of osteoarthritis and relevant signaling pathways

Osteoarthritis (OA) is a common chronic degenerative joint disease in clinical practice with a high prevalence, especially in the elderly. Traditional Chinese Medicine (TCM) believes that OA belongs to the category of "Bi syndrome" and the "bone Bi syndrome". The etiology and pathogenesis lie in the deficiency of the liver and kidney, the deficiency of Qi and blood, and external exposure to wind, cold, and dampness. Epimedium is a yang-reinforcing herb in TCM, which can tonify the liver and kidney, strengthen muscles and bones, dispel wind, cold and dampness, and can treat both the symptoms and the root cause of "bone Bi syndrome". In addition, Epimedium contains a large number of ingredients. Through modern science and technology, more than 270 compounds have been found in Epimedium, among which flavonoids are the main active ingredients. Therefore, our study will review the effects and mechanisms of genus Epimedium in treating OA from two aspects: (1) Introduction of Epimedium and its main active ingredients; (2) Effects of Epimedium and its active ingredients in treating OA and relevant signaling pathways, in order to provide more ideas for OA treatment.