Intra-articular zoledronic acid in a rat osteoarthritis model: significant reduced synovitis may indicate chondroprotective effect

Expression of semaphorin-3A in the joint and role in osteoarthritis

Osteoarthritis (OA) is characterised by the deterioration of cartilage in the joints and pain. We hypothesise that semaphorin-3A (sema-3A), a chemorepellent for sensory nerves, plays a role in joint degradation and pain. We used the mechanical joint loading (MJL) model of OA to investigate sema-3A expression in the joint and examine its association with the development of OA and pain. We also analyse its effect on chondrocyte differentiation using the ATDC5 cell line. We demonstrate that sema-3A is present in most tissues in the healthy joint and its expression increases in highly innervated tissues, such as cruciate ligaments, synovial lining and subchondral bone, in loaded compared to nonloaded control joints. In contrast, sema-3A expression in cartilage was decreased in the severe OA induced by the application of high loads. There was a significant increase in circulating sema-3A, 6 weeks after MJL compared to the nonloaded mice. mRNA for sema-3A and its receptor Plexin A1 were upregulated in the dorsal root ganglia of mice submitted to MJL. These increases were supressed by zoledronate, an inhibitor of bone pain. Sema-3A was expressed at all stages of Chondrocyte maturation and, when added exogenously, stimulated expression of markers of chondrocyte differentiation. This indicates that sema-3A could affect joint tissues distinctively during the development of OA. In highly innervated joint tissues, sema-3A could control innervation and/or induce pain-associated neuronal changes. In cartilage, sema-3A could favour its degeneration by modifying chondrocyte differentiation.

Therapeutic effect of alendronate in an experimental temporomandibular joint osteoarthritis

BACKGROUND

Temporomandibular joint osteoarthritis is a common degenerative joint disease. This disease negatively affects the daily life, speech and chewing functions of patients.

OBJECTIVE

This study aimed to evaluate the effects of intra-articular injection of alendronate to osteoarthritis, which has a protective effect on bone and cartilage tissue and helps reduce inflammation in temporomandibular joint osteoarthritis.

METHODS

A total of 24 Wistar albino rats were used in the study. Rats were divided into four groups: study, saline, control and sham. In both saline and control groups, monosodium iodoacetate was injected intra-articularly to induce osteoarthritis. Alendronate was administered intra-articularly to the study group weekly for 4 weeks. In the saline group, saline was administered by intra-articular injection. At the end of the 12th week, all groups were sacrificed. Mandibular condyle tissues were examined histopathologically.

RESULTS

According to the results, osteoarthritic changes in the control group were higher than those in the study group (p < .05). No significant reduction in osteoarthritic changes was observed in the saline group (p > .05). Significant osteoarthritis findings were observed in all groups compared with the sham group (p < .05).

CONCLUSION

Intra-articular injection of alendronate was found to have positive results on TMJ osteoarthritis. In addition, it was seen that alendronate has effects on reducing cartilage tissue degeneration and loss of matrix proteins.

The effects of alendronate on the suppression of bone resorption and the promotion of cartilage formation in the human mosaicplasty donor site: A randomized, double-blind, placebo-controlled prospective study

BACKGROUND

We previously reported that early alendronate administration accelerated bone formation and improved the quality of repaired cartilage in the donor site in rabbits. To investigate whether alendronate administration has effects in humans similar to those observed in rabbits.

METHODS

The study cohort included 35 patients over the age of 12-years old who underwent mosaicplasty without osteoporotic therapy from March 2011 to October 2012. The donor sites were medial or lateral in the patellofemoral joint. Placebo (P) or Bonalon containing 35 mg of alendronate (A) was administered orally every week for 8 weeks. The cohort comprised 15 male and 20 female, including 14 right and 21 left knees. The mean age at the time of surgery was 57.1 years. Bone formation was examined using computer tomography and lateral knee radiography, and cartilage formation was examined using magnetic resonance imaging (MRI), second-look assessment, and intraoperative acoustic evaluation. The clinical outcomes were assessed using the Japanese Orthopaedic Association knee score and visual analog scale (VAS). Bone and cartilage formation in the donor site and clinical outcomes were assessed at 3, 6, and 12 months after mosaicplasty.

RESULTS

The ratio of TRAP-5b in group A was significantly smaller than that in group P at 2 and 8 weeks after mosaicplasty. The extent of bone formation in the donor sites in group A was significantly greater than that in group P at 3 and 6 months after mosaicplasty. Cartilage formation did not differ significantly between the two groups as determined by MRI, macroscopic assessment, and intraoperative acoustic evaluation. Clinical outcomes did not differ significantly between the two groups, and no negative clinical outcomes were observed.

CONCLUSION

Early alendronate administration accelerated bone formation but not cartilage formation in the mosaicplasty donor site in humans.

Zoledronate promotes ECM degradation and apoptosis via Wnt/β-catenin

This study examined the potential mechanism of zoledronate on interleukin (IL)-1β-induced temporomandibular joint osteoarthritis (TMJOA) chondrocytes, using IL-1β-induced rabbit immortalized mandibular condylar chondrocytes cultured with zoledronate. Cell viability, apoptosis, mRNA, and protein expression of relevant genes involved in extracellular matrix (ECM) degradation, apoptosis, and Wnt/β-catenin signaling were examined. The involvement of the Wnt/β-catenin signaling was examined using Wnt/β-catenin inhibitor (2-(4-(trifluoromethyl)phenyl)-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidin-4-ol (XAV-939)) and activator lithium chloride (LiCl). Aggrecan and type II collagen were downregulated by zoledronate, especially with 100 nM for 48 h (p < 0.01), consistently with the upregulation of A disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) (p < 0.001), matrix metalloprotease-9 (MMP-9) (p < 0.01), caspase-3 (p < 0.001) and downregulation of proliferating cell nuclear antigen (PCNA) (p < 0.01). The apoptotic rate increased from 34.1% to 45.7% with 100 nM zoledronate for 48 h (p < 0.01). The effects of zoledronate on ADAMTs4 (p < 0.001), MMP-9 (p < 0.001), caspase-3 (p < 0.001), and PCNA (p < 0.01) were reversed by XAV-939, while LiCl increased caspase-3 expression (p < 0.01). In conclusion, zoledronate enhances IL-1β-induced ECM degradation and cell apoptosis in TMJOA chondrocytes. Wnt/β-catenin signaling might be involved in this process, but additional studies are necessary to determine the exact involvement of Wnt/β-catenin signaling in chondrocytes after zoledronate treatment.

Terminal sterilization influences the efficacy of an extracellular matrix-blood composite for treating posttraumatic osteoarthritis in the rat model

The objective was to determine if an intra-articular injection of an extracellular matrix (ECM) powder and blood composite (ECM-B) after anterior cruciate ligament (ACL) injury would have a mitigating effect on posttraumatic osteoarthritis and if that effect would be different with terminal sterilization of the ECM powder before use. Eighty Lewis rats underwent ACL transection and were divided into four groups: (1) intra-articular injection with phosphate-buffered saline (PBS; n = 20), (2) intra-articular injection of ECM-B using aseptically processed ECM (ASEPTIC; n = 20), (3) intra-articular injection of the ECM-busing ECM powder sterilized with 15 kGy electron beam irradiation (EBEAM; n = 20), and (4) intra-articular injection of the ECM-B using ECM powder sterilized with ethylene oxide (EO; n = 20). Twenty additional animals received capsulotomy only (SHAM). The animals were followed for 6 weeks and evaluations of gait, radiographs, and joint cartilage histology were performed. At 6 weeks, when compared to the SHAM group, the group treated with PBS had significantly worse gait and histologic changes, while the ASEPTIC group was not different from SHAM for either of these outcomes. When compared to the SHAM group, the EO group had similar gait outcomes, but greater histologic damage, and the EBEAM group had significantly worse gait and histological outcomes. The ECM-B composite produced using aseptically processed ECM powder mitigated the gait and histologic changes associated with osteoarthritis after ACL transection in the rat; however, care must be taken when selecting a terminal sterilization method as this may affect the effectiveness of treatment.

Bisphosphonates as disease-modifying drugs in osteoarthritis preclinical studies: a systematic review from 2000 to 2020

Bisphosphonates have been proposed as possible disease-modifying drugs in osteoarthritis. However, the evidence of their efficacy is poor and their outcomes presented a great heterogeneity. Therefore, the aim of this study is to systematically review the main effects of bisphosphonate use on synovial joint tissues and biochemical markers in preclinical studies over the past two decades (2000-2020). Three databases (Pubmed, Scopus, and Web of Science) were searched, and after screening, twenty-six studies with five different types of bisphosphonates were included in the review. The animal model selected, the type of bisphosphonate used, the therapy duration, and the main effects of individual drugs on synovial tissues were evaluated. Additionally, the quality and risk of bias assessments were performed using the Animals in Research Reporting In Vivo Experiments guidelines and the Systematic Review Centre for Laboratory animal Experimentation tool. Studies showed high variability in experimental designs. Consequently, the comparison of the findings in order to draw specific conclusions about the effectiveness of the drugs is complicated. However, the results of this systematic review suggested that bisphosphonates seemed to reduce the osteoarthritic changes in a dose-dependent manner showing better chondroprotective effects at high doses. Besides, a time-dependent efficacy was also detected in terms of cartilage status. One can conclude that the disease stage of the time-point of treatment initiation may constitute a key factor in the antiresorptive drug efficacy. Generally, we noted that bisphosphonate administration seemed to show positive subchondral bone conservation and fewer biomarker alterations. However, they did not appear to suppress the osteophyte development and their chondroprotective effect is highly variable among the studies. Bisphosphonates appeared to show a positive anti-inflammatory effect on the synovial membrane. However, only a few included publications were focused on their investigation. Regarding the therapy duration, there is a significant lack of evidence on evaluating their effectiveness in preclinical long-term studies and further experimental studies may be needed to examine the pharmacological response in these circumstances. This systematic review might help to clarify the efficacy of bisphosphonates and their function as disease-modifying treatments in osteoarthritis.

Bisphosphonates as a treatment modality in osteoarthritis

Osteoarthritis (OA) is affecting large proportions of the population worldwide. So far, no effective disease modifying drug has been developed for this disease, limiting the therapeutic options to pain medications, physiotherapy and ultimately surgical approaches, mainly joint implant surgery. In vitro and animal studies have demonstrated that bisphosphonates have the potential to become effective modalities for the treatment of OA. This group of pharmacological agents modulates crucial aspects of OA pathogenesis (subchondral bone turnover and loss, bone marrow edema formation, cartilage degeneration and synovitis), and have shown clear efficacy in animal models of OA. Human studies have, however, so far been disappointing with only one of six clinical studies showing clear short-term efficacy. Possible reasons for these discrepancies will be discussed.

Antioxidative nanofullerol inhibits macrophage activation and development of osteoarthritis in rats

Background: There is emerging evidence which suggests that cellular ROS including nitric oxide (NO) are important mediators for inflammation and osteoarthritis (OA). Water-soluble polyhydroxylated fullerene C60 (fullerol) nanoparticle has been demonstrated to have an outstanding ability to scavenge ROS.

Purpose: The objective of this study is to assess the effects of fullerol on inflammation and OA by in vitro and in vivo studies.

Methods: For in vitro experiments, primary mouse peritoneal macrophages and a macrophage cell line RAW264.7 were stimulated to inflammatory phenotypes by lipopolysaccharide (LPS) in the presence of fullerol. For the animal study, OA model was created by intra-articular injection of monoiodoacetate into the knee joints of rats and fullerol was intravenously injected immediately after OA induction.

Results: NO production and pro-inflammatory gene expression induced by LPS was significantly diminished by fullerol in both macrophage cell types. Meanwhile, fullerol could remarkably reduce phosphorylation of p38 mitogen-activated protein kinase, and protein level of transcription factors nuclear factor-kappaB and forkhead box transcription factor 1 within the nucleus. The animal study delineated that systematic administration of fullerol prevented OA, inhibiting inflammation of synovial membranes and the damage toward the cartilage chondrocytes in the OA joints.

Conclusion: Antioxidative fullerol may have a potential therapeutic application for OA.

Pirfenidone reduces subchondral bone loss and fibrosis after murine knee cartilage injury

Pirfenidone is an anti-inflammatory and anti-fibrotic drug that has shown efficacy in lung and kidney fibrosis. Because inflammation and fibrosis have been linked to the progression of osteoarthritis, we investigated the effects of oral Pirfenidone in a mouse model of cartilage injury, which results in chronic inflammation and joint-wide fibrosis in mice that lack hyaluronan synthase 1 (Has1^-/- ) in comparison to wild-type. Femoral cartilage was surgically injured in wild-type and Has1^-/- mice, and Pirfenidone was administered in food starting after 3 days. At 4 weeks, Pirfenidone reduced the appearance, on micro-computed tomography, of pitting in subchondral bone at, and cortical bone surrounding, the site of cartilage injury. This corresponded with a reduction in fibrotic tissue deposits as observed with gross joint surface photography. Pirfenidone resulted in significant recovery of trabecular bone parameters affected by joint injury in Has1^-/- mice, although the effect in wild-type was less pronounced. Pirfenidone also increased Safranin-O staining of growth plate cartilage after cartilage injury and sham operation in both genotypes. Taken together with the expression of selected extracellular matrix, inflammation, and fibrosis genes, these results indicate that Pirfenidone may confer chondrogenic and bone-protective effects, although the well-known anti-fibrotic effects of Pirfenidone may occur earlier in the wound-healing response than the time point examined in this study. Further investigations to identify the specific cell populations in the joint and signaling pathways that are responsive to Pirfenidone are warranted, as Pirfenidone and other anti-fibrotic drugs may encourage tissue repair and prevent progression of post-traumatic osteoarthritis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:365-376, 2018.

Measuring and realizing the translational significance of preclinical in vivo studies of painful osteoarthritis

In this communication, we discuss some key issues surrounding the translation of preclinical efficacy studies in models of painful osteoarthritis (OA) to the clinical arena. We highlight potential pitfalls which could negatively impact successful translation. These include lack of alignment between a model + endpoint and the intended clinical population, employing testing strategies in animals that are not appropriate for the targeted human population such as pre-emptive treatment and lastly, underestimating the magnitude of the efficacy signal in animals that may be needed to see an effect in the clinical population. Through careful analysis, we highlight the importance of each pitfall by providing relevant examples that will hopefully improve future chances of optimizing translation in the area of OA pain research. We advocate advancing publications directed at comparing methods, outcomes and conclusions between preclinical and clinical studies, regardless of whether the findings are positive or negative, are important for improving the potential for a desired successful translation from the bench to bedside.

Effect of antiresorptive and anabolic bone therapy on development of osteoarthritis in a posttraumatic rat model of OA

Introduction

Osteoarthritis (OA) is a leading cause of disability, but despite the high unmet clinical need and extensive research seeking dependable therapeutic interventions, no proven disease-modifying treatment for OA is currently available. Due to the close interaction and interplay between the articular cartilage and the subchondral bone plate, it has been hypothesized that antiresorptive drugs can also reduce cartilage degradation, inhibit excessive turnover of the subchondral bone plate, prevent osteophyte formation, and/or that bone anabolic drugs might also stimulate cartilage synthesis by chondrocytes and preserve cartilage integrity. The benefit of intensive zoledronate (Zol) and parathyroid hormone (PTH) therapy for bone and cartilage metabolism was evaluated in a rat model of OA.

Methods

Medial meniscectomy (MM) was used to induce OA in male Lewis rats. Therapy with Zol and human PTH was initiated immediately after surgery. A dynamic weight-bearing (DWB) system was deployed to evaluate the weight-bearing capacity of the front and hind legs. At the end of the 10-week study, the rats were euthanized and the cartilage pathology was evaluated by contrast (Hexabrix)-enhanced μCT imaging and traditional histology. Bone tissue was evaluated at the tibial metaphysis and epiphysis, including the subchondral bone. Histological techniques and dynamic histomorphometry were used to evaluate cartilage morphology and bone mineralization.

Results

The results of this study highlight the complex changes in bone metabolism in different bone compartments influenced by local factors, including inflammation, pain and mechanical loads. Surgery caused severe and extensive deterioration of the articular cartilage at the medial tibial plateau, as evidenced by contrast-enhanced μCT and histology. The study results showed the negative impact of MM surgery on the weight-bearing capacity of the operated limb, which was not corrected by treatment. Although both Zol and PTH improved subchondral bone mass and Zol reduced serum CTX-II level, both treatments failed to prevent or correct cartilage deterioration, osteophyte formation and mechanical incapacity.

Conclusions

The various methods utilized in this study showed that aggressive treatment with Zol and PTH did not have the capacity to prevent or correct the deterioration of the hyaline cartilage, thickening of the subchondral bone plate, osteophyte formation or the mechanical incapacity of the osteoarthritic knee.

MiR-210 inhibits NF-κB signaling pathway by targeting DR6 in osteoarthritis

Osteoarthritis (OA) is characterized by degradation of articular cartilage and joint inflammation. MicroRNAs have been proved to play an important role in the regulation of chondrogenesis. Previous study showed that microRNA-210 (miR-210) was probably associated with osteoarthritis, while the function of miR-210 in osteoarthritis still remains unknown. The aim of the present study was to investigate the protective effect of miR-210 on osteoarthritis. In the in vitro study, miR-210 level in chondrocytes was decreased after treatment with lipopolysaccharide (LPS). Transfection with miR-210 mimic inhibited LPS-induced pro-inflammatory cytokines production, cell viability reduction and cell apoptosis. Results of luciferase activity assay showed that miR-210 targeted 3′-UTR of death receptor 6 (DR6) to inhibit its expression. MiR-210 mimic and DR6 siRNA transfection inhibited the activation of NF-κB pathway and cell apoptosis of chondrocytes. For the in vivo study, OA model was established on rats by anterior cruciate ligament transection (ACLT). MiR-210 expression is reduced in OA rats. MiR-210 over-expressing lentivirus was injected into the OA rats. Cytokines production, and NF-κB and DR6 expression in OA rats was inhibited by miR-210 overexpression. The results demonstrated that miR-210 decreased inflammation in articular cavity in OA rats by targeting DR6 and inhibiting NF-κB signaling pathway.

Effects of intra-articular clodronate in the treatment of knee osteoarthritis: results of a double-blind, randomized placebo-controlled trial

Aim of this study was to evaluate the efficacy and tolerability of intra-articular (IA) clodronate, compared to saline solution, in patients with symptomatic knee osteoarthritis (KOA). In this double-blind phase 3 randomized clinical trial, patients were randomized to receive once weekly IA injection of 2 mg clodronate or placebo for 4 weeks with 12 weeks of follow-up. The primary objective was the sum of spontaneous, on passive movement, and at digital pressing pain relief assessed by visual analogue score (VAS) of 0-100 at 5 weeks after the final injection. Improving in Western Ontario MacMaster (WOMAC) scale, Lequesne index, consumption of acetaminophen, and physician or patient overall judgment were secondary objectives. Study population included 80 patients, 67 women and 13 men aged 66 ± 6 (SD) years. A significant improvement for all efficacy parameters was observed at all-time points in both groups. A significant difference in favor to clodronate in VAS for pain was observed 5 weeks after the last injection (-114.6 vs. -87.2 for clodronate and placebo group, respectively; p < 0.05). The improvements in Lequesne index, global KOA evaluation from both patients and investigators, and the WOMAC pain subscale were significantly greater in the clodronate group. The proportion of patients that did not require acetaminophen was significantly greater in the clodronate group (about 10 vs. 30 % for clodronate and placebo group, respectively; p < 0.05). IA 2 mg clodronate is associated with small and transient symptomatic and functional benefits and it is safe in KOA patients.