Association of Matrix Metalloproteinase (MMP) Gene Polymorphisms With Knee Osteoarthritis: A Review of the Literature

Effects of metformin phonophoresis and exercise therapy on pain, range of motion, and physical function in chronic knee osteoarthritis: randomized clinical trial

BACKGROUND

Knee osteoarthritis (KOA) is a common musculoskeletal disorder. Therapeutic ultrasound (US) is a safe and effective treatment for KOA. It relieves knee pain and enhances function. Metformin (MF) regulates chondrocytes, hence providing chondroprotection. Furthermore, it efficiently reduces knee articular cartilage degeneration and retards the progression of osteoarthritis. However, the localized administration of MF by phonophoresis for KOA has yet to be studied.

PURPOSE

To assess the possible effects of metformin phonophoresis (MFPH) plus exercise therapy (EX) compared to MFPH alone or the US on knee pain, function, and range of motion (ROM) in chronic KOA patients.

METHODS

Seventy-eight patients with unilateral mild to moderate chronic KOA were included. Patients were randomly assigned to three groups: group A (MFPH + EX), group B (MFPH alone), and group C (US). The US group used an acoustic-neutral gel, while the MFPH group used a gel containing 1.2% MF. The exercises included hamstring stretches, calf stretches, and knee strengthening exercises. Treatment in the three groups continued for four weeks (three sessions per week). The Visual Analog Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the goniometer were used to assess knee pain, function disability, and ROM, respectively. All measures were recorded before, 2 weeks, and 4 weeks after the intervention in all groups. Multivariate Analysis of Variance (MNOVA) was performed to compare the effects within and between groups for knee ROM and function disability. The Kruskal-Wallis test and the Friedman test analyzed the pain intensity.

RESULTS

When the baseline patient characteristics were compared, there were no significant differences in means of age, gender, body mass index (BMI), or lower limb dominance across the three groups (p > 0.05). After 4 weeks of intervention, clinical outcomes significantly improved in all three groups (p < 0.05). However, patients in the MFPH + EX group improved significantly in all outcomes compared to the MFPH and US groups (p < 0.05).

CONCLUSION

Post-treatment results showed a statistically and clinically significant improvement in pain intensity, knee ROM, and function in the MFPH group; however, combining MFPH with exercises is more beneficial in reducing KOA symptoms.

TRIAL REGISTRATION

Clinical Trial Registry at (pactr.samrc.ac.za) database. NO: PACTR202311507335269. Date: November 9, 2023 (retrospectively registered).

ENO1 regulates IL-1β-induced chondrocyte inflammation, apoptosis and matrix degradation possibly through the potential binding to CRLF1

In this study, we aim to investigate the role of enolase 1 (ENO1) in osteoarthritis (OA) pathogenic process and to uncover the underlying mechanism. To this end, we used IL-1β to induce an in vitro OA‑like chondrocyte model in human immortalized chondrocyte C-28/I2 cells. We manipulated the expression of ENO1 and cytokine receptor-like factor 1 (CRLF1) in IL-1β-induced C-28/I2 cells using siRNA and/or overexpression and tested their effects on IL-1β-induced pathologies including cell viability, apoptosis and inflammatory cytokine levels (IL-6 and TNF-α), and the expression of extracellular matrix-related enzymes and major mediators in the NF-κB signaling pathway (p-p65, p65, p-IκBα and IκBα). We used co-immunoprecipitation and immunofluorescence imaging to study a possible binding between ENO1 and CRLF1. Our data showed that IL-1β induction elevated ENO1 and CRLF1 expression in C-28/I2 cells. Silencing ENO1 or CRLF1 inhibited the IL-1β-induced cell viability damage, apoptosis, inflammation, and extracellular matrix degradation. The inhibitory effect of silencing ENO1 was reversed by CRLF1 overexpression, suggesting a functional connection between ENO1 and CRLF1, which could be attributed to a binding between these two partners. Our study could help validate the role of ENO1 in OA pathogenies and identify novel therapeutic targets for OA treatment.

The role of inflammatory mediators and matrix metalloproteinases (MMPs) in the progression of osteoarthritis

Osteoarthritis (OA) is a chronic musculoskeletal disorder characterized by an imbalance between (synthesis) and catabolism (degradation) in altered homeostasis of articular cartilage mediated primarily by the innate immune system. OA degenerates the joints resulting in synovial hyperplasia, degradation of articular cartilage with damage of the structural and functional integrity of the cartilage extracellular matrix, subchondral sclerosis, osteophyte formation, and is characterized by chronic pain, stiffness, and loss of function. Inflammation triggered by factors like biomechanical stress is involved in the development of osteoarthritis. In OA apart from catabolic effects, anti-inflammatory anabolic processes also occur continually. There is also an underlying chronic inflammation present, not only in cartilage tissue but also within the synovium, which perpetuates tissue destruction of the OA joint. The consideration of inflammation in OA considers synovitis and/or other cellular and molecular events in the synovium during the progression of OA. In this review, we have presented the progression of joint degradation that results in OA. The critical role of inflammation in the pathogenesis of OA is discussed in detail along with the dysregulation within the cytokine networks composed of inflammatory and anti-inflammatory cytokines that drive catabolic pathways, inhibit matrix synthesis, and promote cellular apoptosis. OA pathogenesis, fluctuation of synovitis, and its clinical impact on disease progression are presented here along with the role of synovial macrophages in promoting inflammatory and destructive responses in OA. The role of interplay between different cytokines, structure, and function of their receptors in the inter-cellular signaling pathway is further explored. The effect of cytokines in the increased synthesis and release of matrix-decomposing proteolytic enzymes, such as matrix metalloproteinase (MMPs) and a disintegrin-like and metalloproteinase with thrombospondin motif (ADAMTS), is elaborated emphasizing the potential impact of MMPs on the chondrocytes, synovial cells, articular and periarticular tissues, and other immune system cells migrating to the site of inflammation. We also shed light on the pathogenesis of OA via oxidative damage particularly due to nitric oxide (NO) via its angiogenic response to inflammation. We concluded by presenting the current knowledge about the tissue inhibitors of metalloproteinases (TIMPs). Synthetic MMP inhibitors include zinc binding group (ZBG), non-ZBG, and mechanism-based inhibitors, all of which have the potential to be therapeutically beneficial in the treatment of osteoarthritis. Improving our understanding of the signaling pathways and molecular mechanisms that regulate the MMP gene expression, may open up new avenues for the creation of therapies that can stop the joint damage associated with OA.

Genetic polymorphism of WNT9A is functionally associated with thumb osteoarthritis in the Chinese population

BACKGROUND

In a recent genome-wide association study, novel genetic variations of WNT9A were reported to be involved in the etiopathogenesis of thumb osteoarthritis (TOA) in Caucasians. Our purposes were to replicate the association of WNT9A with the development of TOA in the Chinese population and to further unveil the functional role of the risk variants.

METHODS

SNP rs11588850 of WNT9A were genotyped in 953 TOA patients and 1124 healthy controls. The differences of genotype and allele distributions between the patients and healthy controls were evaluated using the Chi-square test. Luciferase Reporter Assay was performed to investigate the influence of variant on the gene expression.

RESULTS

There was significantly lower frequency of genotype AA in TOA patients than in the controls 74.9% vs. 81.9%, p < 0.001). The frequency of allele A was remarkably lower in the patients than in the controls (86.3% vs. 90.5%, p < 0.001), with an odds ratio of 0.66 (95% CI = 0.54-0.80). Luciferase Reporter Assay showed that the construct containing mutant allele G of rs11588850 displayed 29.1% higher enhancer activity than the wild allele A construct (p < 0.05).

CONCLUSIONS

Allele G of rs11588850 was associated with the increased risk of TOA possibly via up-regulation of WNT9A expression. Further functional analysis into the regulatory role of rs11588850 in WNT9A expression can shed new light on the genetic architecture of TOA.

Correlation Between Synovial Fluid Levels of Matrix Metalloproteinase's (MMP-1, MMP-3, and MMP-9) and TNF-α with the Severity of Osteoarthritis Knee in Rural Indian Population

Background

In India, 22% to 39% of the ageing population suffers from degenerative knee osteoarthritis (OA), making it the most prevalent joint disorder in the knee. MMP-1, MMP-3, and MMP-9 protein expression levels have all been associated with OA. The aim of the present study was to establish a relationship between synovial fluid levels of matrix metalloproteinases (MMP-1, MMP-3, and MMP-9), and tumour necrosis factor-alpha (TNF-α) with different Kellgren-Lawrence Grading scale as per the severity of knee osteoarthritis (OA).

Methods

This hospital-based observational study included 87 individuals with knee osteoarthritis examined at the orthopaedics department outpatient clinic at the tertiary care teaching hospital in rural area of north India. In-person interviews were conducted to gather data, through a semi-structured, pretested interview schedule. To determine the degree and severity of OA, the levels of the enzymes matrix metalloproteinase MMP-1, MMP-3, and MMP-9 as well as tumour necrosis factor (TNF-α) were assessed in the synovial fluid of knee of each study participant.

Results

The levels of MMP-1, MMP-3, MMP-9, and TNF-α in synovial fluid were significantly correlated with the severity of osteoarthritis as determined by the Kellgren-Lawrence Grading Scale. Age, duration of symptoms and BMI showed a strong positive and significant correlation with biochemical markers (MMP-1, MMP-3, MMP-9, and TNF-α) in synovial fluid of Knee.

Conclusion

Level of biochemical markers (MMP-1, -3, -9, and TNF-α) in synovial fluid act as diagnostic markers and have a positive correlation with the severity of osteoarthritis knee, age, weight/BMI and duration of disease. However, no significant correlation was found between the level of aforementioned biochemical markers with sex, height, inflammation of the knee, morning stiffness, and age of onset of disease.

Study on the protective effect of chondroitin sulfate from sturgeons on rat chondrocytes and its potential mechanisms

OBJECTIVE

To investigate the protective effect of Chondroitin Sulfate from Sturgeons on rat chondrocytes and its possible mechanism.

METHODS

The model of chondrocyte injury induced by hydrogen peroxide was established and chondrocytes were cultured and divided into the following groups: control group, sham group, model group, Sofast group, Low dose of Chondroitin Sulfate from Sturgeon B (CSSB-L) group, Moderate dose of Chondroitin Sulfate from Sturgeon B (CSSB-M) group and High dose of Chondroitin Sulfate from Sturgeon B (CSSB-H) group. The cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8) assay. The cell apoptosis was detected by flow cytometer. The expression levels of Interleukin-6 (IL-6), Interleukin-8 (IL-8) and Interferon gamma (IFN-γ) in cell supernatants were examined by Enzyme-linked immunosorbent assay (ELISA). Western blot analysis was used to detect the levels of proteins associated with Wnt signal pathway in chondrocytes.

RESULTS

Compared with the control group and sham group, the cell proliferation was decreased significantly, cell apoptosis was increased obviously, and the levels of IL-6, IL-8 and IFN-γ were remarkably increased in the model group. For Wnt signal pathway related proteins, the levels of Wnt3a, Frizzled5, Dsh, β-Catenin and C-myc proteins in the model group were significantly reduced, and p-GSK3β expression level was obviously increased (all P<0.05). Compared with the model group, CSSB could promote cell viability, and inhibit cell apoptosis and the levels of IL-6, IL-8 and IFN-γ (all P<0.05). The levels of Wnt signaling pathways related proteins in the CSSB-M group and CSSB-H group were obviously expressed.

CONCLUSIONS

Chondroitin sulfate from sturgeons protected rat chondrocytes from injuries induced by hydrogen peroxide, which may be associated with the Wnt signaling pathway.

[Developments in Research on the Relationship Between Matrix Metalloproteinases and Osteoarthritis]

Matrix metalloproteinases (MMPs) acquired their names because they depend on metal ions such as Ca 2+ and Zn 2+ as their cofactors. Members of this family of proteins share a similar structure consisting of five functionally distinct structural domains. MMPs, including MMP-1, MMP-3, MMP-9, and MMP-13, are key substances that promote cartilage matrix degradation and play an important role in the occurrence and progression of osteoarthritis (OA). MMPs boost the development of OA through the degradation of extracellular matrix proteins of chondrocytes, the promotion of inflammation, and other mechanisms, and are hence attracting extensive and increasing attention from the medical community. OA is a common degenerative disease that occurs in the joints and is associated with aging, metabolism, infections, genetics, exercise, and other predisposing factors. The pathological changes it causes can lead to a series of clinical symptoms such as joint pain, morning stiffness, and restricted joint movement, severely affecting patients' quality of life. The pathogenic mechanism of this highly prevalent disease is still unclear. At present, there is no effective treatment available for disease improvement. In the future, selective inhibition of MMPs, the key enzymes, may become an effective therapeutic approach. Focusing on the pathogenic effects of MMPs in OA, we herein reviewed the latest findings on the role of MMPs in the occurrence and progression of OA.

A Study on the Potential Mechanism of Shujin Dingtong Recipe against Osteoarthritis Based on Network Pharmacology and Molecular Docking

Background. With the aging of the social population, Osteoarthritis (OA) has already become a vital health and economic problem globally. Shujin Dingtong recipe (SJDTR) is an effective formula to treat OA in China. Although studies have shown that SJDTR can significantly alleviate OA symptoms, its mechanism still remains unclear. Purpose. This study is aimed at investigating the potential mechanism of SJDTR for the treatment of OA based on network pharmacology and molecular docking. Methods. Main ingredients of SJDTR were retrieved from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. OA disease targets were obtained from the Gene Expression Omnibus (GEO) database. The overlapped targets and signaling pathways were explored using Protein-Protein Interaction (PPI) network, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG). Following this, the core targets were employed to dock with corresponding components via molecular docking in order to further explore the mechanism of SJDTR in the treatment of OA. Results. From network pharmacology, we found 100 active components of SJDTR, 31 drug and OA-related targets, 1161 GO items, and 91 signaling pathways. Based on the analysis with PPI network and molecular docking, TP53, CCNB1, and MMP-2 were selected for the core targets of SJDTR against OA. Molecular docking demonstrated that Quercetin, Baicalein, and Luteolin, had good binding with the TP53, CCNB1, and MMP-2 protein, respectively. Conclusion. To conclude, our study suggested the main ingredients of SJDTR might alleviate the progression of OA through multiple targets and pathways. Additionally, network pharmacology and molecular docking, as new approaches, were adopted for systematically exploring the potential mechanism of SJDTR for the treatment of OA.

Long-term intake of Lilium lancifolium mitigated osteoarthritic effects by suppressing inflammatory cytokines in a dog model

Background and Aim: Osteoarthritis (OA) is a chronic, painful, degenerative inflammatory disease of the synovial joints. Regular use of nonsteroidal anti-inflammatory drugs to decrease OA pain can have severe side effects, such as gastric irritation, ulcers, and heart problems. Natural products are extensively used to minimize OA-associated pain and inflammatory reactions. Lilium lancifolium is commonly used to alleviate several diseases through its anti-inflammatory effects. This study examined the impact of L. lancifolium extract on alleviating pain and inflammation associated with articular cartilage damage. Materials and Methods: Hydro-ethanol extracts of the L. lancifolium bulb were used. The experimental animals (adult beagle dogs) were divided into four groups: sham, which received neither treatment nor surgery; placebo, which received an empty gelatin capsule; glucosamine, which received glutamine (60 mg/kg); and L. lancifolium, which received an L. lancifolium extract-filled (60 mg/kg) gelatin capsule for 8 weeks. OA was induced by an expert orthopedic surgeon in 2-year-old dogs through resection of cranial cruciate ligament and lateral collateral ligament. Inflammatory cytokines, enzymes, lameness score, radiology, and histological changes were assessed. Results: Our experiments showed that long-term oral therapy with L. lancifolium alleviated inflammation and increased histological damage. L. lancifolium treatment effectively reduced cytokines, such as interleukin-6, metalloproteinase-9, leukotriene-4, prostaglandin, and cyclo-oxygenase in dogs with OA, suggesting the potential to minimize inflammatory reactions in OA. L. lancifolium showed anti-inflammatory qualities in dogs with OA. This effect was comparable with that of glucosamine OA treatment. Conclusion: L. lancifolium supplementation represents a possible therapeutic and management option in this model of OA.

Joint Cartilage in Long-Duration Spaceflight

This review summarizes the current literature available on joint cartilage alterations in long-duration spaceflight. Evidence from spaceflight participants is currently limited to serum biomarker data in only a few astronauts. Findings from analogue model research, such as bed rest studies, as well as data from animal and cell research in real microgravity indicate that unloading and radiation exposure are associated with joint degeneration in terms of cartilage thinning and changes in cartilage composition. It is currently unknown how much the individual cartilage regions in the different joints of the human body will be affected on long-term missions beyond the Low Earth Orbit. Given the fact that, apart from total joint replacement or joint resurfacing, currently no treatment exists for late-stage osteoarthritis, countermeasures might be needed to avoid cartilage damage during long-duration missions. To plan countermeasures, it is important to know if and how joint cartilage and the adjacent structures, such as the subchondral bone, are affected by long-term unloading, reloading, and radiation. The use of countermeasures that put either load and shear, or other stimuli on the joints, shields them from radiation or helps by supporting cartilage physiology, or by removing oxidative stress possibly help to avoid OA in later life following long-duration space missions. There is a high demand for research on the efficacy of such countermeasures to judge their suitability for their implementation in long-duration missions.

Generation of Matrix Degradation Products Using an In Vitro MMP Cleavage Assay

Matrix metalloproteinases (MMPs) play crucial roles in tissue homeostasis and pathologies by remodeling the extracellular matrix. Previous studies have demonstrated the biological activities of MMP-derived cleavage products. Furthermore, specific fragments can serve as biomarkers. Therefore, an in vitro cleavage assay to identify substrates and characterize cleavage patterns could provide important insight in disease-relevant mechanisms and the identification of novel biomarkers. In the pathogenesis of osteoarthritis (OA), MMP-2, -8, -9 and -13 are of vital importance. However, it is unclear which protease can cleave which matrix component. To address this question, we established an in vitro cleavage assay using recombinantly expressed MMPs and the two cartilage matrix components, COMP and thrombospondin-4. We found a time- and concentration-dependent degradation and an MMP-specific cleavage pattern for both proteins. Cleavage products can now be enriched and purified to investigate their biological activity. To verify the in vivo relevance, we compared the in vitro cleavage patterns with serum and synovial fluid from OA patients and could indeed detect fragments of similar size in the human samples. The cleavage assay can be adapted to other MMPs and substrates, making it a valuable tool for many research fields.