Rabbit model for osteoarthrosis of the temporomandibular joint as a basis for assessment of outcomes after intervention

Screening chondrocyte necroptosis-related genes in the diagnosis and treatment of osteoarthritis

Background

Osteoarthritis (OA) is the most common form of joint diseases, with hallmark of cartilage degeneration. Recent studies have shown that the pathogenesis of OA is associated with chondrocyte necroptosis.

Methods

In this study, we used single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing data to analyze necroptosis regulation in OA chondrocytes. We performed enrichment analysis, carried out experimental validation, constructed machine learning models, and docked drug molecules.

Results

After least absolute shrinkage and selection operator (LASSO) algorithm screening, 4 hub genes (RIPK3, CYBB, HSP90AB1, and TRAF5) with diagnostic characteristics were obtained. Following the comparison of multiple models, the Bayesian model with an average area under curve (AUC) value of 0.944 was finally selected. We found that nimesulide exhibited strong binding affinity to CYBB and HSP90AB1, and experimentally verified that nimesulide reduced the expression of RIPK3 and CYBB, suggesting its potential as an inhibitor of chondrocyte necroptosis. Furthermore, scRNA-seq results showed that necroptosis in OA was significantly upregulated on regulatory chondrocytes (RegC) compared to other chondrocyte subtypes.

Conclusions

The results indicate that nimesulide might be used to treat OA by inhibiting chondrocyte necroptosis through down-regulation of RIK3 and CYBB genes. This study reveals the role of chondrocyte necroptosis in OA, and suggests a potential therapeutic strategy by regulating necroptosis with nimesulide.

Can treatment with chondroitin and glucosamine sulphate prevent changes in the articular disc caused by temporomandibular joint osteoarthritis?

BACKGROUND

Chondroitin and glucosamine sulphates (CGS) are considered structure-modifying drugs and have been studied in the prevention, delay or reversal of structural morphological changes in joints caused by osteoarthritis.

OBJECTIVE

The aim of the present study was to investigate the action of CGS on the progression of chemically induced osteoarthritis in the temporomandibular joint (TMJ) of rabbits by evaluating the serum levels of tumour necrosis factor (TNF-α) and collagen in the articular discs.

MATERIALS AND METHODS

A sample of 36 male rabbits was divided into three groups: control (CG), osteoarthritis (OG) and treatment (TG). The disease was induced by intra-articular injection of sodium monoiodoacetate (10 mg/mL) in the OG and TG groups bilaterally. After 10 days, the TG animals received subcutaneous injection of chondroitin sulphates and glucosamine (7.5 mg/kg) and the OG and CG received saline solution (50 μL). Euthanasia times were subdivided into 40 and 100 days. Collagen quantification was performed by biochemical and histological analysis and for the quantification of serum levels of TNF-α, an enzyme immunoassay was used.

RESULTS

The TG showed an increase in the collagen area of the articular disc when compared to the CG and the OG. The increase collagen concentration in the discs did not show a statistically significant difference between the groups. Post-treatment TNF-α levels were significantly lower in TG compared to OG.

CONCLUSIONS

The results indicate that CGS treatment delayed the degeneration of the collagen in the TMJ articular disc and reduced serum TNF-α levels, indicating a preventive effect on OA progression.

Temporomandibular joint osteoarthritis: A review of animal models induced by surgical interventions

OBJECTIVES

The pathological mechanism of temporomandibular joint osteoarthritis (TMJOA) is still unclear. Animal models induced by surgical interventions are one of the most ideal tools to imitate human pathological conditions. This review aims to define the similarities and differences of different surgical animal models.

METHODS

Articles of TMJOA surgical animal models were collected including anterior disc displacement, disc perforation, and discectomy. We analyzed their experiments strategies based on comparing preoperative selection, intraoperative methodology, and postoperative manifestations.

RESULTS

No matter which surgical intervention is selected, abnormal stress forces the whole joint to remodel its structure so that it could adapt to functional requirements, resulting in TMJOA eventually. However, anterior disc displacement needs more than 16 weeks to obtain typical manifestations, where the methodology is complicated. The course of perforation and discectomy is around 12-16 weeks, but they could cause excessive damage to the TMJ structure.

CONCLUSIONS

All surgical interventions can cause TMJOA, but the extent of pathology varies from each other. This review will assist future experiments to better understand the pathogenesis of TMJOA and choose the most appropriate model.

Animal Models of Temporomandibular Disorder

Temporomandibular disorders (TMD) are a group of diseases in the oral and maxillofacial region that can manifest as acute or chronic persistent pain, affecting millions of people worldwide. Although hundreds of studies have explored mechanisms and treatments underlying TMD, multiple pathogenic factors and diverse clinical manifestations make it still poorly managed. Appropriate animal models are helpful to study the pathogenesis of TMD and explore effective treatment measures. At present, due to the high cost of obtaining large animals, rodents and rabbits are often used to prepare TMD animal models. Over the past decade, various animal models have been intensively developed to understand neurobiological and molecular mechanisms of TMD, and seek effective treatments. Although these models cannot carry out all clinical features, they are valuable in revealing the mechanisms of TMD and creating curative access. Currently, there are multitudinous animal models of TMD research. They can be constructed in different means and summarized into four ways according to the various causes and symptoms, including chemical induction (intra-articular injection of ovalbumin, collagenase, formalin, vascular endothelial growth factor, intramuscular injection of complete Freund’s adjuvant, etc.), mechanical stress stimulation (passive mouth opening, change of chewing load), surgical operation (partial disc resection, joint disc perforation) and psychological stress induction. Here, we summarize and discuss different approaches of animal models for determining neurophysiological and mechanical mechanisms of TMD and assess their advantages and limitations, respectively.

Reduction of osteoarthritis severity in the temporomandibular joint of rabbits treated with chondroitin sulfate and glucosamine

Osteoarthritis is a degenerative disease that causes substantial changes in joint tissues, such as cartilage degeneration and subchondral bone sclerosis. Chondroitin sulfate and glucosamine are commonly used products for the symptomatic treatment of osteoarthritis. The aim of the present study was to investigate the effects of these products when used as structure-modifying drugs on the progression of osteoarthritis in the rabbit temporomandibular joint. Thirty-six New Zealand rabbits were divided into 3 groups (n = 12/group): control (no disease); osteoarthritis (disease induction); and treatment (disease induction and administration of chondroitin sulfate and glucosamine). Osteoarthritis was induced by intra-articular injection of monosodium iodoacetate. Animals were killed at 30 and 90 days after initiation of therapy. The treatment was effective in reducing disease severity, with late effects and changes in the concentration of glycosaminoglycans in the articular disc. The results indicate that chondroitin sulfate and glucosamine may have a structure-modifying effect on the tissues of rabbit temporomandibular joints altered by osteoarthritis.

Condylotomy to Reverse Temporomandibular Joint Osteoarthritis in Rabbits

PURPOSE

Osteoarthritis (OA) of the temporomandibular joint (TMJ) is characterized by local tissue degeneration and pain. Treatments have been aimed at reducing symptoms, and only some can interfere with the progression of pathophysiologic changes caused by OA. Condylotomy is an alternative treatment for patients with OA refractory to conventional treatment. The aim of the present animal study was to investigate the influence of condylotomy on TMJ OA in New Zealand rabbits.

MATERIALS AND METHODS

The 36 rabbits were divided into 3 groups: the osteoarthritis group (OG; induced OA), treatment group (TG; induced OA plus condylotomy), and control group (CG; neither OA nor surgery). OA was induced using intra-articular monosodium iodoacetate injection for 40 days. The rabbits in the TG underwent condylotomy and were killed 20, 40, and 60 days after treatment. The rabbits in the CG and OG were killed at the same points.

RESULTS

The articular joint condition was better in the TG 60 days after surgery (P = .032). A direct comparison revealed regression of TMJ OA over time among the treated rabbits (P = .008). Surgical treatment promoted mandibular condylar remodeling in the TG, reversing the tissue degeneration caused by OA.

CONCLUSIONS

Our findings suggest that condylotomy could be an option for the treatment of OA and prevent damage to TMJ structures. This could be of particular importance for patients without satisfactory responses to more conservative treatment.

A Macaca Fascicularis Knee Osteoarthritis Model Developed by Modified Hulth Combined with Joint Scratches

BACKGROUND Osteoarthritis is a common degenerative disease of joints, and animal models have important significance in the investigation of this disease. The aim of this study was to develop a better method for developing osteoarthritis models in primates by comparing the modified Hulth score combined with joint scratches modeling method with others. MATERIAL AND METHODS We randomly divided 15 young male Macaca fascicularis and 3 old male Macaca fascicularis into 6 groups (n=3). Knee osteoarthritis (KOA) models were developed with different methods: modified Hulth combined with joint scratches (Group A), modified Hulth (Group B), Hulth (Group C), spontaneous models (Group D); sham-operated (Group E), and blank control (Group F). Morphology and pathology of knee joints were observed at the 8th week after surgery. The levels of WBC, IL-1b, and TGF-b1 in synovial fluid were detected by ELISA. The levels of COL-II, ACAN, and MMP-13 in articular cartilage were examined by RT-qPCR and Western blot. RESULTS In Brittberg and modified Mankin score, Group A was higher than B (P<0.05) and lower than C (P<0.05), and there was no statistically significant difference between Group A and D (P>0.05). Except for Group E and F, the differences were statistically significant among others in WBC, IL-1β, and TGF-β1 (P<0.05). COL-II and ACAN decreased and MMP-13 increased, and there was no significant difference between Groups A and D (P>0.05) or between Groups E and F (P>0.05). There were statistically significant differences among other groups (P<0.05). CONCLUSIONS The models developed by modified Hulth combined with joint scratches were the closet to spontaneous models at the 8th week after surgery.