PDGF-BB inhibits F-actin formation and chondrocyte dedifferentiation in osteoarthritis via oxygen-dependent HIF-1α/SCIN regulation and RhoA/ROCK signaling inhibition.

Hyaluronans in the treatment of osteoarthritis of the knee: evidence for disease-modifying activity

Objective To study the expression of tumor necrosis factor-α(TNF-α), interleukin(IL)-6, matrix metalloproteinase-3 (MMP-3) in the articular cartilage of rabbits with knee osteoarthritis (KOA) treated by Danshen injection, and to explore the molecular mechanism of Danshen injection in the treatment of knee osteoarthritis. Methods Forty healthy white rabbits were randomly divided into four groups: sham operation group, KOA model(KOA) group, KOA+ sodium hyaluronate (SH) group and KOA+ Danshen group.Sham operation group only made incision without cutting meniscus.The other groups all used cutting meniscus of rabbit right knee joint to establish an experimental animal model of joint instability.The KOA group was given 0.9% normal saline (0.7 mL/d), the KOA+ SH treatment group was given intra-articular injection of SH (0.4 mL/d), and the KOA+ Danshen treatment group was given Danshen injection (0.7 mL/d) for 5 weeks.The field experiment was used to verify whether the instability model of rabbits could affect the motor ability of rabbits.The mRNA content and the protein expression of TNF-α, IL-6 and MMP-3 were detected separately by polymerase chain reaction(PCR) and Western blot.The contents of TNF-α, IL-6 and MMP-3 in knee joint fluid were detected by enzyme linked immunosorbent assay(ELISA) kit. Results Before the establishment of KOA model, there was no significant difference in motor ability among the groups. After the establishment of the model, the movement distance of rabbits in the KOA group was significantly lower than that in the sham operation group[(150±5) vs (580±9), t=60.610, P<0.05]. The walking distance in the KOA+ Danshen group was significantly increased than that in the KOA group[(438±27) vs (150±5), t=16.730, P<0.05]. In rabbit joint fluid, the contents of TNF-α, IL-6, MMP-3 in KOA group were significantly higher than those in sham operation group [(22.62±2.18)mg/mL vs (11.74±2.09)mg/mL, (4.01±0.14)mg/mL vs (1.76±0.11)mg/mL, (0.57±0.05)mg/mL vs(0.27±0.03)mg/mL, t values were 4.413, 17.620 and 6.495 respectively, all P values<0.05], while, compared with KOA group, the content of TNF-α, IL-6, MMP-3 in KOA+ Danshen group were significantly lower [(22.62±2.18)mg/mL vs (15.01±2.37)mg/mL, (4.01±0.14)mg/mL vs (2.47±0.19)mg/mL, (0.57±0.05)mg/mL vs (0.40 ±0.02)mg/mL, t values were 3.725, 8.803 and 9.185 respectively, all P values<0.05]. In the mRNA detection of rabbit knee cartilage, the mRNA expression of TNF-α, IL-6, MMP-3 in KOA group was significantly higher than that in the sham operation group [(1.90±0.02) vs (1.00±0.15), (1.70±0.02) vs (1.00±0.07), (1.60±0.20) vs (1.00±0.13), t values were 11.050, 24.250 and 14.850 respectively, all P values< 0.05], and the mRNA expression of TNF-α, IL-6, MMP-3 in KOA+ Danshen group was significantly lower than that in KOA group [(1.09±0.05) vs (1.90±0.02), (1.13±0.09) vs (1.70±0.02), (1.04±0.08) vs (1.60±0.20), t values were 32.190, 8.822 and 5.868 respectively, all P values<0.05]. In the protein detection of rabbit knee cartilage, the protein expression of TNF-α, IL-6, MMP-3 in KOA group was increased significantly compared with sham operation group (t values were 65.280, 12.320 and 22.280 respectively, all P values<0.05), and the protein expression of TNF-α, IL-6, MMP-3 in KOA+ Danshen group was decreased significantly compared with KOA group (t values were 26.15, 9.053 and 24.670 respectively, all P values<0.05). Conclusion Danshen injection could obviously improve the motor ability of rabbits in KOA group, and also reduce the levels of TNF-α, IL-6 and MMP-3.Therefore, Danshen injection may inhibit the release of osteoarthritis matrix protease and the degradation of articular cartilage in the treatment of knee osteoarthritis, which can control the degenerative lesion of articular cartilage, and ultimately improve the symptoms of knee osteoarthritis. Key words: Knee osteoarthritis; Danshen injection; Tumor necrosis factor-α; Interleukin-6; Matrix metalloproteinase-3

MiR-214-3p, a novel possible therapeutic target for the pathogenesis of osteoarthritis

Accumulation of beta-catenin and subsequent stimulation of beta-catenin-T cell-factor (Tcf)/lymphoid-enhancerfactor (Lef) transcriptional activity causes dedifferentiation of articular chondrocytes, which is characterized by decreased type II collagen expression and initiation of type I collagen expression. This study examined the mechanisms of alpha-catenin degradation, the role of alpha-catenin in beta-catenin signaling, and the physiological significance of alpha-catenin regulation of beta-catenin signaling in articular chondrocytes. We found that both alpha- and beta-catenin accumulated during dedifferentiation of chondrocytes by escaping from proteasomal degradation. Beta-catenin degradation was ubiquitination-dependent, whereas alpha-catenin was proteasomally degraded in a ubiquitination-independent fashion. The accumulated alpha- and beta-catenin existed as complexes in the cytosol and nucleus. The complex formation between alpha- and beta-catenin blocked proteasomal degradation of alpha-catenin and also inhibited beta-catenin-Tcf/Lef transcriptional activity and the suppression of type II collagen expression associated with ectopic expression of beta-catenin, the inhibition of proteasome, or Wnt signaling. Collectively, our results indicate that ubiquitin-independent degradation of alpha-catenin regulates beta-catenin signaling and maintenance of the differentiated phenotype of articular chondrocytes.

CEMIP (for “Cell migration-inducing protein” also called KIAA1199 and Hybid for “Hyaluronan-binding protein”) expression is increased in cancers and described as a regulator of cell survival, growth and invasion. In rheumatoid arthritis, CEMIP is referred to as an angiogenic marker and participates in hyaluronic acid degradation. In this study, CEMIP expression is investigated in healthy and osteoarthritis (OA) cartilage from human and mouse. Its role in OA physiopathology is deciphered, specifically in chondrocytes proliferation and dedifferentiation and in the extracellular matrix remodeling. To this end, CEMIP, αSMA and types I and III collagen expressions were assessed in human OA and non-OA cartilage. CEMIP expression was also investigated in a mouse OA model. CEMIP expression was studied in vitro using a chondrocyte dedifferentiation model. High-throughput RNA sequencing was performed on chondrocytes after CEMIP silencing. Results showed that CEMIP was overexpressed in human and murine OA cartilage and along chondrocytes dedifferentiation. Most of genes deregulated in CEMIP-depleted cells were involved in cartilage turnover (e.g., collagens), mesenchymal transition and fibrosis. CEMIP regulated β-catenin protein level. Moreover, CEMIP was essential for chondrocytes proliferation and promoted αSMA expression, a fibrosis marker, and TGFβ signaling towards the p-Smad2/3 (Alk5/PAI-1) pathway. Interestingly, CEMIP was induced by the pSmad1/5 (Alk1) pathway. αSMA and type III collagen expressions were overexpressed in human OA cartilage and along chondrocytes dedifferentiation. Finally, CEMIP was co-expressed in situ with αSMA in all OA cartilage layers. In conclusion, CEMIP was sharply overexpressed in human and mouse OA cartilage and along chondrocytes dedifferentiation. CEMIP-regulated transdifferentiation of chondrocytes into “chondro-myo-fibroblasts” expressing α-SMA and type III collagen, two fibrosis markers. Moreover, these “chondro-myo-fibroblasts” were found in OA cartilage but not in healthy cartilage.

Chronic pancreatitis (CP), a progressive inflammatory disease, poses diagnostic challenges due to its initially asymptomatic nature. While CP's impact on exocrine and endocrine functions is well-recognized, its potential influence on other body systems, particularly in young individuals, remains underexplored. This study investigates the hypothesis that CP in growing pigs leads to alterations in articular cartilage and subchondral bone, potentially contributing to osteoarthritis (OA) development. Utilizing a pig model of cerulein-induced CP, we examined the structural and compositional changes in subchondral bone, articular cartilage, and synovial fluid. Histological analyses, including Picrosirius Red and Safranin-O staining, were employed alongside immuno-histochemistry and Western blotting techniques. Our findings reveal significant changes in the subchondral bone, including reduced bone volume and alterations in collagen fiber composition. Articular cartilage in CP pigs exhibited decreased proteoglycan content and alterations in key proteins such as MMP-13 and TGF-β1, indicative of early cartilage degradation. These changes suggest a link between CP and musculoskeletal alterations, underscoring the need for further research into CP's systemic effects. Our study provides foundational insights into the relationship between CP and skeletal health, potentially guiding future pediatric healthcare strategies for early CP diagnosis and management.

Nitric oxide is an important mediator in Osteoarthritis (OA), and causes apoptosis and dedifferentiation in articular chondrocytes. Protein kinase Calpha is involved in modulating apoptosis and dedifferentiation of articular chondrocytes induced by nitric oxide. Hyaluronic acid is widely used in the treatment of osteoarthritis and exerts significant chondroprotective effects. The exact mechanisms of its chondroprotective action are not yet fully elucidated. The present study was performed to investigate the effects and mechanisms of hyaluronic acid in NO-induced apoptosis and dedifferentiation of chondrocytes. The ratio of apoptotic cell and cell viability was surveyed by TUNEL, MTT assay and flow cytometry. The expression of aggrecan, type II collagen, and PKCalpha were determined by real-time PCR and Western blot. The expression changes of caspase-3 and bcl-2 was detected by Western blot. The mitochondrial membrane potential (DeltaPsim) was evaluated by Rhodamine-123 fluorescence. HA reduces the TUNEL positive cell, nuclei fragment and the impairment of DeltaPsim. NO-induced chondrocyte dedifferentiation was blocked by HA, which restores expression of aggrecan and type II collagen of chondrocytes and cell viability. HA can block inhibition of PKC-alpha by NO. Our results show that HA blocks NO-induced apoptosis and dedifferentiation of articular chondrocytes by modulation of DeltaPsim and PKCalpha.

Osteoarthritis (OA) is the most prevalent chronic degenerative joint disease among the aged population. However, current treatments for OA are limited to alleviating symptoms, with no therapies that prevent and regenerate cartilage deterioration. To assess the effects of platelet-derived exosomes (Plt-exos) on OA and then to explore the potential molecular mechanism. Controlled laboratory study. Exosomes derived from human apheresis platelets were isolated and identified. The effects of Plt-exos in protecting chondrocytes under interleukin 1β stimulation were evaluated by analyzing the proliferation and migration in human primary chondrocytes. RNA sequencing was later performed in vitro for primary chondrocytes to reveal the underlying mechanisms of Plt-exo treatment. Anterior cruciate ligament transection was used to construct an OA mice model, and intra-articular injection of Plt-exos was given once a week for 6 weeks. Mice were sacrificed 4 weeks after the last injection. Histologic and immunohistochemistry staining and micro-computed tomography analysis were performed to assess alterations of articular cartilage and subchondral bone. Plt-exos significantly promoted proliferation and migration of chondrocytes within a dose-dependent manner, as well as dramatically promoted cartilage regeneration and attenuated abnormal tibial subchondral bone remodeling, thus slowing the progression of OA. After being treated with Plt-exos, 1797 genes were differentially expressed in chondrocytes (923 upregulated and 874 downregulated genes). Functional enrichment results and hub genes were mainly involved in anti-inflammatory effects, mediating cell adhesion, stimulating cartilage repair, promoting anabolism, and inhibiting catabolism. Our results demonstrated that Plt-exos promoted chondrocyte proliferation and migration in vitro, as well as attenuated cartilage degeneration, improved the microarchitecture of subchondral bone, and retarded OA progression in vivo. Our study illustrated that the administered Plt-exos could alleviate knee OA by attenuating cartilage degeneration and subchondral bone loss, possibly serving as a novel promising treatment for OA in the future.

IL-17, IL-1β and TNF-α stimulate VEGF production by dedifferentiated chondrocytes

Osteoarthritis (OA) is a debilitating disease that predominantly impacts the hip, hand, and knee joints. Its pathology is defined by the progressive degradation of articular cartilage, formation of bone spurs, and synovial inflammation, resulting in pain, joint function limitations, and substantial societal and familial burdens. Current treatment strategies primarily target pain alleviation, yet improved interventions addressing the underlying disease pathology are scarce. Recently, exosomes have emerged as a subject of growing interest in OA therapy. Numerous studies have investigated exosomes to offer promising therapeutic approaches for OA through diverse in vivo and in vitro models, elucidating the mechanisms by which exosomes from various cell sources modulate the cartilage microenvironment and promote cartilage repair. Preclinical investigations have demonstrated the regulatory effects of exosomes originating from human cells, including mesenchymal stem cells (MSC), synovial fibroblasts, chondrocytes, macrophages, and exosomes derived from Chinese herbal medicines, on the modulation of the cartilage microenvironment and cartilage repair through diverse signaling pathways. Additionally, therapeutic mechanisms encompass cartilage inflammation, degradation of the cartilage matrix, proliferation and migration of chondrocytes, autophagy, apoptosis, and mitigation of oxidative stress. An increasing number of exosome carrier scaffolds are under development. Our review adopts a multidimensional approach to enhance comprehension of the pivotal therapeutic functions exerted by exosomes sourced from diverse cell types in OA. Ultimately, our aim is to pinpoint therapeutic targets capable of regulating the cartilage microenvironment and facilitating cartilage repair in OA.

Objective To observe the short-term efficacy of intra-articular injection of platelet-rich plasma(PRP) and umbilical cord mesenchymal stem cells(MSCs) in the treatment of mild to moderate knee osteoarthritis. Methods A total of 200 cases of osteoarthritis of knee joint in Liaocheng People′s Hospital were collected. Inclusion creteria: Kellgren- Lawrence grade Ⅰ to Ⅲ patients with osteoarthritis of knee joint. Exclusion criteria: Kelgren-Lawrence grade Ⅳ osteoarthritis patients and inflammatory arthritis patients. According to the pseudo-random numbers generated by the computer, the patients with knee osteoarthritis were randomly divided into PRP+ MSC group, PRP group, MSC group and sodium hyaluronate (SH) group, 50 cases in each group. In PRP+ MSC group, 5 ml PRP and umbilical cord MSCs mixture were injected into articular cavity; in PRP group, 5 ml PRP was injected into articular cavity; in MSC group, 5 ml umbilical cord MSCs were injected into articular cavity; in SH group, 2.5 ml SH and triamcinolone acetonide injection were injected into articular cavity. After one, three, six and 12 months of treatment, the improvement of knee joint function was evaluated by visual analogue scale (VAS) and American Knee Association score (AKS); the changes of cytokines in joint fluid were detected by enzyme-linked immunosorbent assay (ELISA), and the Changes in articular cartilage before and after were evaluated by T2 Map sequence of MRI. Measurement data such as age, course, VAS score, AKS score, and cytokine content were analyzed by one-way ANOVA. Enumeration data such as sex ratio and disease degree of patients were analyzed by chi-square test. Results Among the 200 patients, 175 were followed up, 45 in PRP+ MSC group, 44 in PRP group, 43 in MSC group and 43 in SH group. There was no significant difference in the expression of cytokines in VAS, AKS and synovial fluid between the four groups before treatment (P >0.05). One month after treatment, the VAS scores of the four groups were lower than before, and the AKS scores were higher than before. There was significant difference between the groups (t=6.45, P 0.05). Three months later, VAS and AKS in SH group tended to be in the pre-treatment state, while no rebound was found in the other three groups. PRP+ MSC combined injection group was superior to PRP alone and MSC treatment groups. The difference between the four groups was statistically significant (F=7.84, 4.35; P <0.01). Three weeks after treatment, there was no significant change of cytokines in the joint fluid of SH group. The level of cytokines in the joint fluid of PRP+ MSC group was higher than that of PRP and MSC group (F=39.21, P <0.01). Six months after treatment, the average cartilage T2 values of PRP+ MSC group, PRP group, MSC group and SH group were (54.1±2.6)ms, (56.6±1.4)ms, (56.4±1.6)ms, (58.0±2.0)ms, respectively (F=30.63; P <0.05). Conclusion Intra-articular injection of platelet-rich plasma and umbilical cord mesenchymal stem cells can significantly improve the symptoms of patients with knee osteoarthritis and delay the progress of osteoarthritis. Key words: Osteoarthritis; Mesenchymal stromal cells; Platelet-rich plasma

Objective To identify the effectiveness of arthroscopic debridement(AD) in moderate knee OA on pain and function. Methods 87 patients with moderate degenerative osteoarthritis of knees diagonocised according to ARA,were randomly assigned to two groups:43 patients in therapy group were subjected to AD in combine with sodium hyaluronate injection and physiotherapy,44 patients in the control group only received so-dium hyaluronate injection and physiotherapy. The relief of joint pain, swell, fluidity, and the improvement of joint range of motion before and after the treatment were evaluated by score of Lysholm. Results There is no si-ganificant different between in the therapy group and the control group in the score of Lysholm(P<0.05). Con-clusion The sodium hyaluronate injection combined with physiotherapy can relieve clinical symptoms and im-prove joint function in the patients with moderate degenerative osteoarthritis of knees, arthroscopic surgery for moderate osteoarthritis of the knee provides no additional benefit to optimized physical and HA therapy. Key words: Moderate osteoarthritis of knees; AD; Sodium hyaluronate; Intraarticular injection; Physio-therapy

A multi-centre randomized, double-blind, parallel-group clinical trial was carried out in 63 patients with osteoarthritis of the knee to compare the efficacy and tolerability of a course of intra-articular injections of 20 mg sodium hyaluronate with a similar course of injections of placebo. Treatment consisted of up to 11 injections over a 23-week period. Evaluation was by means of subjective symptom and activity assessments, serially during the course of treatment and also 25 weeks thereafter. Ten patients (5 of 30 on active treatment; 5 of 33 on placebo) were withdrawn prematurely. Pain on movement, assessed by visual analogue scale (VAS) showed statistically significant (p less than 0.05 to p less than 0.0001) reductions in mean scores throughout the first 11 weeks of treatment with sodium hyaluronate but smaller, non-significant, reductions with placebo treatment. The difference between treatments was significant (p less than 0.05) at 5 weeks. Pain at rest, also assessed by VAS, showed little change in mean scores with placebo but with sodium hyaluronate there was a progressive reduction which was significant (p less than 0.01) throughout the period from 5 to 23 weeks. The difference between sodium hyaluronate and placebo was significant (p less than 0.05 to p less than 0.002) at Weeks 5, 11, 15, 19 and 23. 'Activities of daily living' were assessed using a standard scale. There were small improvements with both treatments, significant at some assessments and somewhat greater with sodium hyaluronate than placebo, but there were no statistically significant differences between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Osteoarthritis (OA) is the most common type of arthritis and is one of leading causes of chronic disability among older individuals. The occurrence of OA is increasing because of increasing prevalence of obesity and the aging of the community OA is a disease affecting synovial joints and is characterized by degradation and loss of articular cartilage with subchondral bone remodeling，osteophyte formation and synovial membrane inflammation. Genetic, biologic, biochemical, nutritional and mechanical factors besides degeneration of cartilage contribute to the process of OA. The targets of therapy in OA include inflammation, cartilage breakdown, chondrocyte apoptosis, and subchondral bone remodeling. There are no curative agents, and the current goals of the treatment of OA are to relieve pain and minimized loss of function. Therapeutic development must consider that OA is a complex disease with wide variety of clinical presentations. In spite of intensive research in disease-modifying agents, there is limited evidence to support their use in routine clinical practice. This article reviews existing data on the current treatments for OA.

Experimental arthritis : in vitro and in vivo models