Intra-articular treatment options for knee osteoarthritis

Clinical effect of intramuscular calcitonin compared with oral celecoxib in the treatment of knee bone marrow lesions: a retrospective study

BACKGROUND

Bone marrow lesions (BMLs) are a common finding in patients with osteoarthritis (OA), which are predictors of progression and pain related to cartilage damage in OA. The objective of the present research was to compare the short-term clinical effect of intramuscular calcitonin and oral celecoxib in treating knee BMLs.

PATIENTS AND METHODS

Between January 2016 and December 2018, the medical records of patients with knee BMLs treated by intramuscular calcitonin or oral celecoxib were reviewed. Visual analog scale (VAS) and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) were used to assess knee pain and function, respectively. BMLs were assessed by MRI scans and were scored by the modified Whole-Organ MRI Score (WORMS). The safety of these two medications was also evaluated.

RESULTS

A total of 123 eligible patients who received calcitonin treatment (n = 66) or celecoxib treatment (n = 57) were included. All patients were followed up clinically and radiographically for 3 months. The VAS and WOMAC scores were lower statistically in calcitonin group than celecoxib group at 4-week and 3-month follow-up. For BMLs, the WORMS scores in the calcitonin group were significantly lower than the celecoxib group. Besides, statistically higher MRI improvement rates were found in the calcitonin group compared with the celecoxib group at 4-week follow-up (21.21% vs. 7.01%; P = 0.039) and 3-month follow-up (37.88% vs. 15.79%; P = 0.006).

CONCLUSION

Intramuscular calcitonin 50 IU once daily demonstrated a better short-term effect for knee BML patients compared with oral celecoxib 200 mg twice per day.

The role of indoleamine 2,3 dioxygenase 1 in the osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease and a leading cause of disability. It involves articular cartilage destruction and a whole joint inflammation. In spite of OA pathogenesis is still unclear, new studies on the OA pathophysiological aetiology and immunomodulation therapy continuously achieve significant advances with new concepts. Here, we focus on the indoleamine-2,3-dioxygenase1 (IDO1) activity in the osteoarthritis (OA), which is one of the noticeable enzymes in the synovial fluid of arthritis patients. It was recognized as an essential mediator of autoreactive B and T cell responses in rheumatoid arthritis (RA) and an interesting therapeutic target against RA. However, the role IDO1 plays in the OA pathogenesis hasn't been discussed. The new OA experimental analysis evidenced IDO1 overexpression in the synovial fluid of OA patients, and recent studies reported that IDO1 metabolites were found higher in the OA synovial fluid than RA and spondyloarthropathies (SpA) patients. Moreover, the positive relation of IDO1 metabolites with OA pain and joint stiffness has been confirmed. Thus, the IDO1 plays a pivotal role in the pathogenesis of OA. In this review, the role IDO1 plays in the OA pathogenesis has been deeply discussed. It could be a promising target in the immunotherapy of OA disease.

Intra-articular etanercept attenuates pain and hypoxia from TMJ loading in the rat

Mechanical overloading of the temporomandibular joint (TMJ) and biochemical changes, like inflammation and hypoxia, contribute to cartilage degeneration and pain associated with osteoarthritis (OA). Yet, how overloading contributes to early dysregulation of chondrocytes is not understood, limiting the development of diagnostics and treatments for TMJ OA. Hypoxia-inducible factors (HIF)-1α/2α in chondrocytes were evaluated at Days 8 and 15 in a rat TMJ pain model induced by jaw loading (1 h/day for 7 days) using immunohistochemistry and compared between cases that induce persistent (3.5 N), acute (2 N), or no (0 N) sensitivity. Hypoxia was measured on Day 8 by immunolabeling of the tracer EF5 and 18 F-EF5 PET imaging. To assess the role of tumor necrosis factor (TNF) in painful TMJ loading, intra-articular etanercept was given before loading. Orofacial sensitivity was evaluated during and after loading. Facial grimace, TNF-α, HIF-2α, and hypoxia levels in the TMJ were measured after loading. HIF-2α was elevated (P = .03) after 3.5 N loading at Day 8, but HIF-1α was unchanged. EF5 uptake increased on Day 8 in the 3.5 N group (P < .048) by tissue assay and 18 F-EF5 PET. At Day 8, both HIF-2α (P = .01) and EF5 uptake (P = .005) were correlated with loading magnitude. Etanercept attenuated sensitivity (P < .01) and the facial grimace on Day 7 (P = .01). It also reduced (P < .01) HIF-2α and EF5 uptake on Day 8; but TNF-α levels were not different from controls at that time. Findings suggest that TMJ loading that induces persistent sensitivity upregulates the catabolic factor HIF-2α and reduces oxygen levels in the cartilage, which may be TNF-driven.

Ethical and Practical Considerations for Integrating Cellular ("Stem Cell") Therapy into Clinical Practice

PURPOSE OF REVIEW

Cellular therapies, also known as "stem cell" interventions (SCI), have undergone a rapid popularization in the USA and worldwide. The current review aimed at outlining (1) the ethical challenges facing the implementation of SCI; (2) the applicability of the currently available SCI; and (3) recommendations to achieve ethical, well-regulated incorporation of SCI in the clinical setting.

RECENT FINDINGS

Concerns regarding the inadequate characterization, poor adverse effects disclosure, and unorthodox, often inappropriate, market practices have engendered a genuine concern regarding the SCI compliance with ethical standards. Six instances of litigation on the basis of misrepresentation or inappropriate informed consent were recorded between 2012 and 2018. Such concerns have been furthered by the loopholes in the regulatory aspect governing the use of SCI coupled with the unclear literature-reported efficacy and diverse spectrum of profess indications. Similarly, the application of SCI in the clinical field is yet to prove its value. The uncertain efficacy, coupled with obscure true-costs of utilization, impedes a value-based assessment. A multidisciplinary approach involving legislative and medical professional societies should continue to advance regulations that govern SCI. A well-regulated system that allows for the ethical integration of SCI with appositely evidenced-based described benefits and risks should be sought.

Dextran sulfate-triamcinolone acetonide conjugate nanoparticles for targeted treatment of osteoarthritis

Osteoarthritis (OA) is a synovial inflammatory condition characterized by cartilage destruction and osteophyte formation. Macrophages play a central role in OA pathogenesis by producing proinflammatory cytokines. Intra-articular corticosteroid administration can relieve refractory pain and inflamed effusion of knee joints. However, limitations, such as rapid clearance from the joint space, potential damage to articular cartilage, and accelerated joint degeneration, may hamper the clinical application of corticosteroids. In this study, we reported the design and preparation of dextran sulfate-triamcinolone acetonide conjugate (DS-TA) nanoparticles (NPs) for treating OA by specifically targeting scavenger receptor class A (SR-A) on activated macrophages. We verified the excellent targeting specificity of DS-TA NPs to SR-A by flow cytometry and confocal laser scanning microscopy. DS-TA NPs were found to effectively reduce the viability of activated macrophages (RAW 264.7 cells) and the expression of proinflammatory cytokines. Intra-articular injection of DS-TA NPs effectively alleviated the structural damages to the joint cartilage, as confirmed in histopathological analysis. Additionally, DS-TA NPs decreased the expression of proinflammatory cytokines, including IL-1β, IL-6, and TNF-α, in the cartilage tissue. Thus, DS-TA NPs are a potential therapeutic nanomedicine for the targeted treatment of OA.

A technological overview of cooled radiofrequency ablation and its effectiveness in the management of chronic knee pain

Knee osteoarthritis (OA) is a painful and sometimes debilitating condition affecting an estimated 14 million people in the USA alone. Management of knee OA begins with conservative medical treatments and progresses to total knee arthroplasty. Managing pain until a patient is eligible for arthroplasty remains a key part of the treatment algorithm for knee OA. Cooled radiofrequency ablation has shown clinical effectiveness in managing knee OA pain, with a majority of patients experiencing upwards of 12 months of analgesic effect. Herein is presented an overview of the technology of cooled radiofrequency ablation and a summary of current clinical trials demonstrating the treatments effectiveness.

REG-O3 chimeric peptide combining growth hormone and somatostatin sequences improves joint function and prevents cartilage degradation in rat model of traumatic knee osteoarthritis

Objective

REG-O3 is a 24-aminoacid chimeric peptide combining a sequence derived from growth hormone (GH) and an analog of somatostatin (SST), molecules displaying cartilage repair and anti-inflammatory properties, respectively. This study aimed to investigate the disease-modifying osteoarthritis drug (DMOAD) potential of REG-O3 by analyzing its effect on pain, joint function and structure, upon injection into osteoarthritic rat knee joint.

Design

Osteoarthritis was induced in the right knee of mature male Lewis rats (n = 12/group) by surgical transection of the anterior cruciate ligament (ACLT) combined with partial medial meniscectomy (pMMx). Treatments were administered intra-articularly from fourteen days after surgery through three consecutive injections one week apart. The effect of REG-O3, solubilized in a liposomal solution and injected at either 5, 25 or 50 μg/50 μL, was compared to liposomal (LIP), dexamethasone and hyaluronic acid (HA) solutions. The study endpoints were the pain/function measured once a week throughout the entire study, and the joint structure evaluated eight weeks after surgery using OARSI score.

Results

ACLT/pMMx surgery induced a significant modification of weight bearing in all groups. When compared to liposomal solution, REG-O3 was able to significantly improve weight bearing as efficiently as dexamethasone and HA. REG-O3 (25 μg) was also able to significantly decrease OARSI histological global score as well as degeneration of both cartilage and matrix while the other treatments did not.

Conclusion

This study provides evidence of a remarkable protecting effect of REG-O3 on pain/knee joint function and cartilage/matrix degradation in ACLT/pMMx model of rat osteoarthritis. REG-O3 thus displays an interesting profile as a DMOAD.

Nanotechnological Strategies for Osteoarthritis Diagnosis, Monitoring, Clinical Management, and Regenerative Medicine: Recent Advances and Future Opportunities

PURPOSE OF REVIEW

In this review article, we discuss the potential for employing nanotechnological strategies for the diagnosis, monitoring, and clinical management of osteoarthritis (OA) and explore how nanotechnology is being integrated rapidly into regenerative medicine for OA and related osteoarticular disorders.

RECENT FINDINGS

We review recent advances in this rapidly emerging field and discuss future opportunities for innovations in enhanced diagnosis, prognosis, and treatment of OA and other osteoarticular disorders, the smart delivery of drugs and biological agents, and the development of biomimetic regenerative platforms to support cell and gene therapies for arresting OA and promoting cartilage and bone repair. Nanotubes, magnetic nanoparticles, and other nanotechnology-based drug and gene delivery systems may be used for targeting molecular pathways and pathogenic mechanisms involved in OA development. Nanocomposites are also being explored as potential tools for promoting cartilage repair. Nanotechnology platforms may be combined with cell, gene, and biological therapies for the development of a new generation of future OA therapeutics. Graphical Abstract.

Combined Experimental Approach and Finite Element Modeling of Small Molecule Transport Through Joint Synovium to Measure Effective Diffusivity

Trans-synovial solute transport plays a critical role in the clearance of intra-articularly (IA) delivered drugs. In this study, we present a computational finite element model (FEM) of solute transport through the synovium validated by experiments on synovial explants. Unsteady diffusion of urea, a small uncharged molecule, was measured through devitalized porcine and human synovium using custom-built diffusion chambers. A multiphasic computational model was constructed and optimized with the experimental data to extract effective diffusivity for urea within the synovium. A monotonic decrease in urea concentration was observed in the donor bath over time, with an effective diffusivity found to be an order of magnitude lower in synovium versus that measured in free solution. Parametric studies incorporating an intimal cell layer with varying thickness and varying effective diffusivities were performed, revealing a dependence of drug clearance kinetics on both parameters. The findings of this study indicate that the synovial matrix impedes urea solute transport out of the joint with little retention of the solute in the matrix.

Effects of Sprifermin, IGF1, IGF2, BMP7, or CNP on Bovine Chondrocytes in Monolayer and 3D Culture

One possible approach to treat osteoarthritis (OA) is to counteract cartilage degeneration with anabolic compounds that stimulate chondrocyte proliferation and/or extracellular matrix (ECM) production. Several molecules including sprifermin (recombinant human fibroblast growth factor [FGF18]), insulin-like growth factor-1 [IGF1] and -2 [IGF2], C-type natriuretic peptide [CNP], and bone metamorphic protein 7 [BMP7] have been shown to have these characteristics both in vitro and in vivo. However, it is not known how these molecules compare each other regarding their effect on phenotype and stimulation of ECM production in primary chondrocytes. The effects of sprifermin, IGF1, IGF2, CNP, and BMP7 were evaluated on bovine articular chondrocytes, first in monolayer to determine their effective concentrations, and then in three-dimensional (3D) culture at concentrations of 100 ng/ml for sprifermin; 300 ng/ml for IGF1, IGF2, and BMP7; and 10 nM for CNP. In 3D culture, the effects of a permanent exposure or a cyclic exposure consisting of 24 h incubation per week with the compounds were evaluated. All growth factors increased ECM production and cell proliferation to a similar extent but CNP had almost no effect on bovine chondrocytes. Sprifermin was more effective with cyclic exposure, IGF1, and IGF2 with permanent exposure, and BMP7 showed similar results with both exposures. Regarding the cell phenotype, sprifermin appeared to be the only compound favoring the chondrocyte phenotype; it decreased type I collagen expression and had no hypertrophic effect. Together, these results confirmed that sprifermin is a promising disease-modifying OA drug. © 2019 The Authors. Journal of Orthopaedic Research^® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:653-662, 2020.

Anti‑inflammatory and anti‑catabolic effect of non‑animal stabilized hyaluronic acid and mesenchymal stem cell‑conditioned medium in an osteoarthritis coculture model

Previous clinical studies have reported the clinical effectiveness of non‑animal stabilized hyaluronic acid (NASHA) and adipose‑derived mesenchymal stromal/stem cells (MSC) in the treatment of knee osteoarthritis (OA). Unlike MSC secreted mediators, in vitro anti‑inflammatory effects of NASHA have not been evaluated. We aimed to evaluate and compare the anti‑inflammatory effect of NASHA and MSC conditioned medium (stem cell‑conditioned medium; SC‑CM), in an explant‑based coculture model of OA. Cartilage and synovial membrane from seven patients undergoing total knee arthroplasty were used to create a coculture system. Recombinant IL‑1β was added to the cocultures to induce inflammation. Four experimental groups were generated: i) Basal; ii) IL‑1β; iii) NASHA (NASHA + IL‑1β); and iv) SC‑CM (SC‑CM + IL‑1β). Glycosaminoglycans (GAG) released in the culture medium and of nitric oxide (NO) production were quantified. Gene expression in cartilage and synovium of IL‑1β, matrix metallopeptidase 13 (MMP13), ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS5) and tissue inhibitor of metalloproteinases 1 (TIMP1) was measured by reverse transcription‑quantitative PCR. Media GAG concentration was decreased in cocultures with NASHA and SC‑CM (48 h, P<0.05; 72 h, P<0.01) compared with IL‑1β. Production of NO was significantly lower only in SC‑CM after 72 h (P<0.01). In cartilage, SC‑CM inhibited the expression of IL‑1β, MMP13 and ADAMTS5, while NASHA had this effect only in MMP13 and ADAMTS5. In synovium, SC‑CM decreased the expression level of MMP13 and ADAMTS5, while NASHA only decreased ADAMTS5 expression. Both NASHA and SC‑CM increased TIMP1 expression in cartilage and synovium. Treatments with NASHA and SC‑CM were shown to be a therapeutic option that may help counteract the catabolism produced by the inflammatory state in knee OA. The anti‑inflammatory mediators produced by MSC promote a lower expression of inflammatory targets in our study model.

Procedural Treatments for Knee Osteoarthritis: A Review of Current Injectable Therapies

Knee osteoarthritis is a common painful degenerative condition affecting the aging Canadian population. In addition to pain and disability, osteoarthritis is associated with depression, comorbid conditions such as diabetes, and increased caregiver burden. It is predicted to cost the Canadian healthcare system $7.6 billion dollars by 2031. Despite its high cost and prevalence, controversy persists in the medical community regarding optimal therapies to treat knee osteoarthritis. A variety of medications like nonsteroidal anti-inflammatories and opioids can cause severe side effects with limited benefits. Total knee arthroplasty, although a definitive management, comes with risk such as postoperative infections, revisions, and chronic pain. Newer injectable therapies are gaining attention as alternatives to medications because of a safer side effect profile and are much less invasive than a joint replacement. Platelet-rich plasma is beginning to replace the more common injectable therapies of intra-articular corticosteroids and hyaluronic acid, but larger trials are needed to confirm this effect. Small studies have examined prolotherapy and stem cell therapy and demonstrate some benefits. Trials involving genicular nerve block procedures have been successful. As treatments evolve, injectable therapies may offer a safe and effective pathway for patients suffering from knee osteoarthritis.

Comparison of analgesic effect, knee joint function recovery, and safety profiles between pre-operative and post-operative administrations of meloxicam in knee osteoarthritis patients who underwent total knee arthroplasty

AIMS

This study aimed to compare the efficacy and safety of pre-operative and post-operative meloxicam administration regarding post-operative pain control and knee joint function recovery in knee osteoarthritis (KOA) patients who underwent total knee arthroplasty (TKA).

METHODS

Totally, 196 KOA patients who underwent TKA were consecutively enrolled and randomly assigned into pre-operative (N = 98) and post-operative administration group (N = 98) as 1:1 ratio. Pre-operative administration group received meloxicam 15 mg at 24 h pre-operation and 7.5 mg at 4 h, 24 h, 48 h, and 72 h post-operation, respectively. Post-operative administration group received meloxicam 15 mg at 4 h post-operation and 7.5 mg at 24 h, 48 h, and 72 h post-operation, respectively. Pain visual analog scale (VAS) at rest and at flexion, patient's global assessment (PGA), patient-controlled analgesia (PCA) consumption, hospital for special surgery (HSS), knee score, and adverse events were assessed.

RESULTS

Pre-operative meloxicam administration attenuated pain VAS score at rest at 6 h, 12 h, and 24 h; and pain VAS score at flexion at 6 h, 12 h, 24 h, and 48 h; as well as PGA score at 6 h, 12 h, 48 h post-TKA compared with post-operative meloxicam administration. Additional and total consumption of PCA were both decreased in pre-operative meloxicam administration group than post-operative meloxicam administration group, while HSS knee score at 3 months post-TKA was similar between pre-operative and post-operative meloxicam administration groups. Regarding safety, the incidence of adverse events was of no difference between the two groups.

CONCLUSION

Pre-operative administration of meloxicam might assist the post-operative pain management and care in KOA patients who underwent TKA.

The influence of sample size and gender composition on the meta-analysis conclusion of platelet-rich plasma treatment for osteoarthritis

Objective

The magnitude of the therapeutic effects of intra-articular injection of platelet-rich plasma (PRP) on osteoarthritis (OA) is still under debate. The goal of this study that was a systematic review of randomised controlled trials ​of PRP injections for the treatment of OA was to elucidate the therapeutic efficacy of PRP.

Methods

Electronic databases of PubMed, CENTRAL, EMBASE, EBSCO, ClinicalTrials.gov, and International Clinical Trials Registry Platform ​were searched from inception to June 2018 for RCTs that compared PRP injections to controls in patients with OA. A random-effects approach was used to compile data and subgroups according to trial size (large trials versus small trials), patient profile (age and gender), and PRP preparation method was performed.

Results

Thirty trials met the inclusion criteria and were analysed. All results had unexplained statistical heterogeneity. Patients treated with PRP compared with control showed statistically relevant pain relief and function improvement at short term (standardised mean difference [SMD] ​= ​−0.62, 95% confidence interval [CI]: −0.98 to −0.27, P ​= ​0.0006, SMD ​= ​−0.74, 95% CI: −1.11 to 0.36, P ​= ​0.0001, respectively), medium term (SMD ​= ​−0.53, 95% CI: −0.83 to −0.23, P ​= ​0.0006, SMD ​= ​−0.50, 95% CI: −0.75 to −0.25, P ​= ​0.0006), and long term (SMD ​= ​−0.69, 95% CI: −1.08 to −0.30, P ​= ​0.0006, SMD ​= ​−0.68, 95% CI: −0.1.09 to −0.27, P ​= ​0.001, respectively). A subgroup analysis of the data from large trials and from trials composed of less than 50% female patients revealed that therapeutic effects of the treatment are insignificant.

Conclusions

According to the currently available data, PRP injections are beneficial for pain relief and function improvement in patients with OA. This meta-analysis, however, demonstrated that the efficacy of PRP is related to sample size and gender composition. Thus, more randomised controlled trials of high quality and larger patient size, also including gender aspects, are required to understand this phenomenon.

The translational potential of this article

The translation potential of this meta-analysis is that provided another perspective to analyse the treatment effect of PRP for OA. In future research, phenotypes subpopulation and gender difference of OA patient should be considered for PRP treatment.

Intra-articular injection of etoricoxib-loaded PLGA-PEG-PLGA triblock copolymeric nanoparticles attenuates osteoarthritis progression

The current pharmacological therapies for osteoarthritis (OA) are mainly focused on symptomatic relief of pain and inflammation through the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Etoricoxib is a cyclooxygenase-2 (COX-2) selective NSAID with a higher cyclooxygenase-1 (COX-1) to COX-2 selectivity ratio than the other COX-2 selective NSAIDs and a lower risk of gastrointestinal toxicity compared to traditional NSAIDs. In this study, we first evaluated the anti-inflammatory and chondro-protective effects of etoricoxib on interlecukin-1β-stimulated human osteoarthritic chondrocytes. We found that etoricoxib not only inhibited the expression of inflammation mediators COX-2, prostaglandin E₂ (PGE₂), and nitric oxide, but also had a similar chondro-protective effect to celecoxib through down-regulating matrix degrading enzymes matrix metalloproteinase-13 (MMP-13) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-5). We then used PLGA-PEG-PLGA triblock copolymeric nanoparticles (NPs) as a drug delivery system to locally deliver etoricoxib into the articular cavity to reduce the risk of cardiovascular toxicity of etoricoxib when administered systemically or orally. The etoricoxib-loaded NPs showed a sustained drug release over 28 days in vitro; in rat OA model, the intra-articular injection of etoricoxib-loaded NPs alleviated the symptoms of subchondral bone, synovium, and cartilage. In conclusion, our study confirmed the chondro-protective role of etoricoxib in OA, and proved the curative effects of etoricoxib-loaded PLGA-PEG-PLGA NPs in vivo.

Pharmacodynamics, efficacy, safety and administration of intra-articular therapies for knee osteoarthritis

Introduction: Osteoarthritis (OA) is the leading cause of disability in the elderly, usually presenting with mono-or oligo-arthritis where local drug delivery by intra-articular (IA) injection may be more effective in terms of increased bioavailability, less systemic exposure and reduced adverse events. Several intra-articular medications for symptomatic are available on the market while the new disease-modifying drugs (DMOADs) are progressing into phase 3 pipeline of drug development.Areas covered: This narrative review covered the pharmacokinetic and pharmacodynamics of clinically available IA drugs which include corticosteroids, hyaluronic acid as well as injection techniques, efficacy, adverse effects and contraindications. In addition, the authors briefly describe the newer disease-modifying OA drugs (DMOAD) which are undergoing phase 3 pipeline of development such as Fibroblast growth factor (FGF-18) and Wnt inhibitor.Expert opinion: This is a rapidly evolving area with both new products and new trials regularly emerging. It is also a critically important area in a disease field that lacks for safe and effective treatments, where intra-articular delivery may enhance both local efficacy and reduce systemic toxicity.

Mangiferin Prevents TBHP-Induced Apoptosis and ECM Degradation in Mouse Osteoarthritic Chondrocytes via Restoring Autophagy and Ameliorates Murine Osteoarthritis

Osteoarthritis (OA) is an age-related degenerative disease with complicated pathology involving chondrocyte apoptosis and extracellular matrix (ECM) degradation. Previous studies have shown that moderate autophagy has a protective effect against apoptosis in chondrocyte. Mangiferin is a natural polyphenol and exerts multiple pharmacological effects on different diseases in various preclinical studies. In this study, we investigated the effects of mangiferin on OA and delineated a potential molecular mechanism. In vitro, mangiferin treatment inhibited the expression of proapoptotic proteins induced by tert-butyl hydroperoxide (TBHP), increased the expression of antiapoptotic Bcl-2, and prevented ECM degradation by inhibiting the production of matrix-degrading enzyme. Mechanistically, mangiferin enhanced autophagy by activating the AMP-activated protein kinase (AMPK) signaling pathway. On the contrary, inhibition of autophagy partly abolished the protective effects of mangiferin on antiapoptosis and ECM synthesis in TBHP-treated chondrocyte. Correspondingly, the protective effect of mangiferin was also found in a mouse OA model. In conclusion, our results suggested that mangiferin serves as a potentially applicable candidate for treating OA.

Autologous Micro-Fragmented Adipose Tissue as Stem Cell-Based Natural Scaffold for Cartilage Defect Repair

Osteoarthritis (OA) poses a tough challenge worldwide. Adipose-derived stem cells (ASCs) have been proved to play a promising role in cartilage repair. However, enzymatic digestion, ex vivo culture and expansion, with significant senescence and decline in multipotency, limit their application. The present study was designed to obtain micro-fragmented adipose tissue (MFAT) through gentle mechanical force and determine the effect of this stem cell-based natural scaffold on repair of full-thickness cartilage defects. In this study, ASCs sprouted from MFAT were characterized by multi-differentiation induction and flow cytometry. Scratch and transwell migration assays were operated to determine whether MFAT could promote migration of chondrocytes in vitro. In a rat model, cartilage defects were created on the femoral groove and treated with intra-articular injection of MFAT or PBS for 6 weeks and 12 weeks (n = 12). At the time points, the degree of cartilage repair was evaluated by histological staining, immunohistochemistry and scoring, respectively. Two unoperated age-matched animals served as native controls. ASCs derived from MFAT possessed properties to differentiate into adipocytes, osteocytes and chondrocytes, with expression of mesenchymal stem cell markers (CD29, 44, 90) and no expression of hematopoietic markers (CD31, 34, 45). In addition, MFAT could significantly promote migration of chondrocytes. MFAT-treated defects showed improved macroscopic appearance and histological evaluation compared with PBS-treated defects at both time points. After 12 weeks of treatment, MFAT-treated defects displayed regular surface, high amount of hyaline cartilage, intact subchondral bone reconstruction and corresponding formation of type I, II, and VI collagen, which resembled the normal cartilage. This study demonstrates the efficacy of MFAT on cartilage repair in an animal model for the first time, and the utility of MFAT as a ready-to-use therapeutic alternative to traditional stem cell therapy.

Involvement of TLR4 in the protective effect of intra-articular administration of curcumin on rat experimental osteoarthritis

PURPOSE

In view of the principal role of Toll-like receptor 4 (TLR4) in mediating sterile inflammatory response contributing to osteoarthritis (OA) pathogenesis, we used lipopolysaccharide (LPS), a known TLR4 activator, to clarify whether modulation of TLR4 contributed to the protective actions of intra-articular administration of curcumin in a classical rat OA model surgically induced by anterior cruciate ligament transection (ACLT).

METHODS

The rats underwent ACLT and received 50μl of curcumin at the concentration of 1 mg mL-1 and 10 μg LPS by intra-articular injection once a week for 8 weeks. Morphological changes of the cartilage and synovial tissues were observed. Apoptotic chondrocytes were detected using TUNEL assay. The concentrations of IL-1β and TNF-ɑ in synovial fluid were determined using ELISA kits. The mRNA and protein expression levels of TLR4 and NF-κB p65 were detected by real-time PCR and Western blotting, respectively.

RESULTS

Intra-articular administration of curcumin significantly improved articular cartilage injury, suppressed synovial inflammation and down-regulated the overexpression of TLR4 and its downstream NF-κB caused by LPS-induced TLR4 activation in rat osteoarthritic knees.

CONCLUSION

The data suggested that the inhibition of TLR4 signal might be an important mechanism underlying a protective effect of local curcumin administration on OA.

Recent Advances in the Pharmacological Activities of Dioscin

Dioscin is a typical saponin with multiple pharmacological activities. The past few years have seen an emerging interest in and growing research on this pleiotropic saponin. Here, we review the emerging pharmacological activities reported recently, with foci on its antitumor, antimicrobial, anti-inflammatory, antioxidative, and tissue-protective properties. The potential use of dioscin in therapies of diverse clinical disorders is also discussed.

NF-κB Signaling Pathways in Osteoarthritic Cartilage Destruction

Osteoarthritis (OA) is a type of joint disease associated with wear and tear, inflammation, and aging. Mechanical stress along with synovial inflammation promotes the degradation of the extracellular matrix in the cartilage, leading to the breakdown of joint cartilage. The nuclear factor-kappaB (NF-κB) transcription factor has long been recognized as a disease-contributing factor and, thus, has become a therapeutic target for OA. Because NF-κB is a versatile and multi-functional transcription factor involved in various biological processes, a comprehensive understanding of the functions or regulation of NF-κB in the OA pathology will aid in the development of targeted therapeutic strategies to protect the cartilage from OA damage and reduce the risk of potential side-effects. In this review, we discuss the roles of NF-κB in OA chondrocytes and related signaling pathways, including recent findings, to better understand pathological cartilage remodeling and provide potential therapeutic targets that can interfere with NF-κB signaling for OA treatment.

The polymorphism of SMAD3 rs1065080 is associated with increased risk for knee osteoarthritis

The mechanism of knee osteoarthritis (OA) is still not clearly elucidated. SMAD3 gene polymorphisms are considered to play a vital role in OA pathogenesis. We thus investigated the relationship of SMAD3 rs1065080 gene polymorphism and susceptibility to knee osteoarthritis in a Chinese Han population. A total of 237 patients and 142 healthy control participants were enrolled in a case-control study. DNA was extracted from peripheral blood samples and genotyped by using the Mass-ARRAY method. Our results revealed that there was a significant difference between patients and healthy controls in the genotype of A and G (p = 0.019); those with a GG genotype had a significant increase in OA risk (OR 2.881, 95% CI 1.993-7.353, p = 0.025). In addition, logistic regression analysis showed that the recessive genetic model decreased OA morbidity (OR 0.648, 95% CI 0.416-0.911, p = 0.046). In conclusion, the GG genotype of rs1065080 was associated with a higher risk of OA and the recessive genetic model decreased the risk of OA.

Scientific Papers and Patents on Substances with Unproven Effects. Part 2

Several examples are discussed in this review, where substances without proven effects were proposed for practical use within the scope of evidence-based medicines. The following is discussed here: generalizations of the hormesis concept and its use in support of homeopathy; phytoestrogens and soy products potentially having feminizing effects; glycosaminoglycans for the treatment of osteoarthritis and possibilities of their replacement by diet modifications; flavonoids recommended for the treatment of chronic venous insufficiency and varicose veins; acetylcysteine as a mucolytic agent and its questionable efficiency especially by an oral intake; stem cells and cell therapies. In conclusion, placebo therapies can be beneficial and ethically justifiable but it is not a sufficient reason to publish biased information. Importantly, placebo must be devoid of adverse effects, otherwise, it is named pseudo-placebo. Therapeutic methods with unproven effects should be tested in high-quality research shielded from the funding bias. Some issues discussed in this review are not entirely clear, and the arguments provided here can initiate a constructive discussion.