The anti-inflammatory effects of 15-HETE on osteoarthritis during treadmill exercise

Navigating the Global Landscape of Exercise Interventions for Knee Osteoarthritis: Exploring Evolving Trends and Emerging Frontiers From a Bibliometric and Visualization Analysis Perspective (2011-2022)

OBJECTIVES

This study utilizes visual analysis methods to retrospectively examine the evolution and trends in exercise interventions for knee osteoarthritis (KOA) research from 2011 to 2022.

DESIGN

Bibliometric and visualization analysis review.

SETTING AND PARTICIPANTS

Using the Web of Science database, the literature search range is from January 1, 2011, to December 31, 2022, with the language specified as English and document type set to Article.

METHODS

Visual analysis was used to analyze literature in the field of exercise interventions for KOA, with KOA and exercise interventions as the key search terms. Visualization maps for countries/regions were created using Tableau and Scimago Graphica software. Institutional, author, and keyword visualization maps were drawn using CiteSpace and VOSviewer software.

RESULTS

In total, 3137 articles were included in the visual analysis. The United States emerged as the leading country in terms of publication volume and contribution. Moreover, developed countries such as the United States, Australia, United Kingdom, and Canada have established close and stable cooperative relationships. The University of Melbourne stood out as the institution with both the highest publication volume and centrality. At the forefront of research output in this field was Bennell K.L. from the University of Melbourne. The journal with the highest co-citation frequency was Osteoarthritis and Cartilage. The keyword clustering map highlighted an evolution in the field of exercise interventions for KOA, emphasizing 8 key research themes spanning knee osteoarthritis, serum cartilage, osteoarthritis initiative, patellofemoral pain, total knee arthroplasty, exercise-induced hypoalgesia, isometric exercise, and anterior cruciate ligament reconstruction. Burst analysis revealed that older adult was the earliest and most prominent keyword, with contemporary topics such as patellofemoral pain, safety, musculoskeletal disorder, and neuromuscular exercise considered as research hotspots and future directions in this field.

CONCLUSIONS AND IMPLICATIONS

The global attention on exercise interventions for KOA research is expanding, emphasizing the importance of strengthened connections among developing countries and collaborative author groups. Recent trends have shifted toward topics such as neuromuscular training, treatment safety, and musculoskeletal disorders, whereas research interest in patellofemoral pain remains unabated. Neuromuscular training for KOA represents the current frontier in this field. Future research should delve into the effects of diverse types of exercise interventions for KOA on neuromuscular injury and recovery, exploring feasibility and safety to formulate personalized exercise plans for patients with KOA.

Effects of platelet-rich plasma combined with isometric quadriceps contraction on cartilage in a rat model of knee osteoarthritis

Background

Intra-articular injection of platelet-rich plasma (PRP) or isometric contraction of quadriceps (ICQ) has shown positive effects in patients with knee osteoarthritis (KOA). However, the synergistic effect of combining PRP and ICQ intervention (joint intervention) on cartilage repair has not been validated. Thus, this study aimed to explore the reparative effects of joint intervention on cartilage in a KOA rat model.

Methods

Fifty-four 2-month-old female Sprague-Dawley rats were randomly divided into the control group (CG, n = 6) and model group (injected with sodium iodoacetate, n = 48). After 1 week, six rats from the model group were randomly selected for validation. The remaining 42 rats were further divided into seven groups: PRP group (PRPG), ICQ group (ICQG), joint intervention group (JIG), normal saline group (NSG), acupuncture group (AG), normal saline and acupuncture group (NSAG) and model blank group (MBG). The intervention lasted for 4 weeks, with PRPG and JIG receiving PRP injections (twice) and ICQG and JIG undergoing ICQ (five times per week, 15 min each session).

Results

Histological staining with haematoxylin and eosin as well as transmission electron microscopy revealed severe cartilage damage in MBG, AG, NSAG and NSG, followed by PRPG and ICQG. JIG exhibited a more intact cartilage structure. Compared with JIG, the Mankin scores increased remarkably in PRPG, ICQG, AG, NSAG and NSG (P < 0.01). Relative mRNA expression levels showed the upregulation of IL-1β in ICQG, NSAG and NSG compared with JIG (P < 0.05) and the upregulation of IL-6, IL-18 and MMP-13 in AG and NSAG (P < 0.05). Compared with PRPG, IL-1β and IL-6 were upregulated in ICQG, AG, NSAG and NSG (P < 0.05). In addition, IL-18 was upregulated in AG (P < 0.01), and IL-18, MMP-13 and TNF-α were upregulated in NSAG (P < 0.05). Compared with ICQG, IL-1β, IL-18, MMP-13 and TNF-α were upregulated in NSAG (P < 0.05), and IL-1β and IL-18 were upregulated in AG (P < 0.05).

Conclusion

The combination of PRP and ICQ can alleviate inflammatory responses in cartilage, promote chondrocyte regeneration and facilitate matrix tissue repair. Compared with single interventions, a synergistic effect is observed.

Plasma oxylipin profiles reflect Parkinson's disease stage

Derivatives of polyunsaturated fatty acids (PUFAs), also known as oxylipins, are key participants in regulating inflammation. Neuroinflammation is involved in many neurodegenerative diseases, including Parkinson's disease. The development of ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) facilitated the study of oxylipins on a system level, i.e., the analysis of oxylipin profiles. We analyzed oxylipin profiles in the blood plasma of 36 healthy volunteers (HC) and 73 patients with Parkinson's disease (PD), divided into early (L\M, 29 patients) or advanced (H, 44 patients) stages based on the Hoehn and Yahr scale. Among the 40 oxylipins detected, we observed a decrease in the concentration of arachidonic acid (AA) and AA derivatives, including anandamide (AEA) and Leukotriene E4 (LTE4), and an increase in the concentration of hydroxyeicosatetraenoic acids 19-HETE and 12-HETE (PD vs HC). Correlation analysis of gender, age of PD onset, and disease stages revealed 20 compounds the concentration of which changed depending on disease stage. Comparison of the acquired oxylipin profiles to openly available PD patient brain transcriptome datasets showed that plasma oxylipins do not appear to directly reflect changes in brain metabolism at different disease stages. However, both the L\M and H stages are characterized by their own oxylipin profiles - in patients with the H stage oxylipin synthesis is increased, while in patients with L\M stages oxylipin synthesis decreases compared to HC. This suggests that different therapeutic approaches may be more effective for patients at early versus late stages of PD.

Moderate mechanical strain and exercise reduce inflammation and excessive autophagy in osteoarthritis by downregulating mitofusin 2

AIMS

The major pathological mechanisms of osteoarthritis (OA) progression include inflammation, autophagy, and apoptosis, etc. Moderate mechanical strain and exercise effectively improve chondrocyte degeneration by reducing these adverse factors. Mitofusin 2 (MFN2) is a crucial regulatory factor associated with inflammation, autophagy and apoptosis, and its expression is regulated by exercise. This study aims to elucidate the effects of moderate mechanical strain and exercise on MFN2 expression and its influence on OA progression.

MAIN METHODS

Destabilization of the medial meniscus (DMM) surgery was performed on rats to induce an OA rat model. Subsequently, adeno-associated virus (overexpression/knockdown) intra-articular injection or moderate treadmill exercise was administered to evaluate the effects of these treatments on MFN2 expression and OA progression. Overexpressed plasmids and siRNA vectors were used to regulate MFN2 expression in chondrocytes. An inflammatory degeneration cell model was generated by IL-1β stimulation. Moderate mechanical strain was applied to MFN2-overexpressing cells to explore their interactions.

KEY FINDINGS

MFN2 overexpression aggravated inflammation by activating the NF-κB and P38 pathways and induced excessive autophagy by inhibiting the PI3K/AKT/mTOR pathway, thereby causing chondrocyte apoptosis and metabolic disorder. Moderate mechanical strain partially reversed these adverse effects. In the DMM rat model, MFN2 overexpression in articular cartilage exacerbated OA progression, whereas MFN2 knockdown and treadmill exercise alleviated cartilage degeneration, inflammation, and mechanical pain.

SIGNIFICANCE

MFN2 is a critical factor mediating the association between inflammation and excessive autophagy in OA progression. Moderate mechanical strain and treadmill exercise may improve OA through downregulating MFN2 expression. This study may provide a theoretical basis for exercise therapy in OA treatment.

Identification of polyunsaturated fatty acids as potential biomarkers of osteoarthritis after sodium hyaluronate and mesenchymal stem cell treatment through metabolomics

Introduction: Osteoarthritis (OA) is a prevalent joint disorder worldwide. Sodium hyaluronate (SH) and mesenchymal stem cells (MSCs) are promising therapeutic strategies for OA. Previous studies showed they could improve knee function and clinical symptoms of OA. However, the mechanism of the therapeutic effects on the improvement of OA has not been clearly explained. Methods: In our study, we used a technique called 5-(diisopropylamino)amylamine derivatization liquid chromatography coupled with mass spectrometry to find the metabolites in OA synovial fluid under different treatments. Results and Discussion: After looking into the metabolomics, we discovered that SH and MSC treatment led to the downregulation of ω-6 polyunsaturated fatty acids (PUFAs) and the upregulation of ω-3 PUFAs. Significantly, the contents of 5(S)-HETE, PGA2, PGB2, and PGJ2 were lower in the MSC group than in the SH group after quantification using 5-(diisopropylamino)amylamine derivatization-UHPLC-QQQ-MS. This is the first report on the relationship of 11(S)-HETE, PGA2, PGB2, PGF2β, 11β-PGF2α, and DK-PGE2 with OA. Moreover, the correlation analysis of metabolites and inflammation factors showed the positive association of ω-6 PUFAs with pro-inflammation cytokines, and of ω-3 PUFAs with anti-inflammation cytokines. Our results indicated the therapeutic effect of SH and MSCs in patients with OA. In addition, this reliable metabolic approach could uncover novel biomarkers to treat OA.

Exercise induced meteorin-like protects chondrocytes against inflammation and pyroptosis in osteoarthritis by inhibiting PI3K/Akt/NF-κB and NLRP3/caspase-1/GSDMD signaling

The production of metrnl, a novel adipomyokine, is induced upon exercise in adipose tissue and skeletal muscle. In this study, we investigated the anti-inflammatory and antipyroptotic effects of exercise-induced metrnl producted in rats in vitro and in vivo. Forty Sprague-Dawley rats were divided randomly into five groups: control (CG), osteoarthritis (OA) with sedentary lifestyle (OAG), OA with low intensity exercise (OAL), OA with moderate intensity exercise (OAM), and OA with high intensity exercise (OAH). The correlation between the level of metrnl and OA degree was detected using ELISA, X-ray imaging, histology, and immunohistochemistry in vivo. Primary chondrocytes were preincubated with recombinant metrnl before interleukin-1β administration to verify the anti-inflammatory and antipyroptotic effects of metrnl. Western blotting and quantitative reverse transcription (qRT)-PCR were used to evaluate the differences in protein and mRNA expression between groups, respectively. Reactive oxygen species (ROS) assay, immunofluorescence, transmission electron microscopy (TEM), and flow cytometry were used to evaluate morphological changes and pyroptosis in chondrocytes. In the moderate-intensity treadmill exercise group, the severity of OA showed maximum relief and the metrnl levels had the most significant increase. Metrnl exerted its anti-inflammatory effect through the suppression of the PI3K/Akt/NF-κB pathway in IL-1β-induced OA chondrocytes, which was accompanied with the recovery of collagen II expression and the attenuation of MMP13 and ADAMTS5. Moreover, metrnl ameliorated chondrocyte pyroptosis by inhibiting the activation of the nod-like receptor protein-3/caspase-1/gasdermin D cascade. In conclusion, moderate-intensity exercise improves inflammation and pyroptosis by increasing metrnl release, which inhibits the PI3K/Akt/NF-κB and further NLRP3/caspase-1/GSDMD signaling pathways.

Ginsenoside Compound K Ameliorates Osteoarthritis by Inhibiting the Chondrocyte Endoplasmic Reticulum Stress-Mediated IRE1α-TXNIP-NLRP3 Axis and Pyroptosis

Osteoarthritis (OA) is a common joint disease, and studies have reported that the endoplasmic reticulum stress (ERS) in chondrocytes caused by the cartilage tissue damage could mediate the activation of Nod-like receptor protein 3 (NLRP3) inflammasomes through inositol-requiring enzyme 1 alpha (IRE1α) and thioredoxin interacting protein (TXNIP). Ginsenoside compound K (CK) has an inhibitory effect on IRE1α activation. However, the role of IRE1α-TXNIP and its interaction with CK are still unclear. In this study, we examined the role and mechanism of action of CK in OA. We found that CK ameliorated OA and ERS in IL-1β-treated chondrocytes and a monoiodoacetate-induced rat OA model. The effect of CK on inflammation, pyroptosis, and ERS was blocked by the ERS inducer tunicamycin. In conclusion, CK hindered OA progression by inhibiting the ERS-IRE1α-TXNIP-NLRP3 axis. Overall, our data indicate that CK could be useful in the treatment of OA and other chronic inflammatory diseases.

Therapeutic exercise interventions in rat models of arthritis

Arthritis is the leading cause of musculoskeletal pain and disability worldwide. Nearly 50% of individuals over the age of 65 have arthritis, which contributes to limited function, articular pain, physical inactivity, and diminished quality of life. Therapeutic exercise is often recommended in clinical settings for patients experiencing arthritic pain, however, there is little practical guidance regarding the use of therapeutic exercise to alleviate arthritic musculoskeletal pain. Rodent models of arthritis allow researchers to control experimental variables, which cannot be done with human participants, providing an opportunity to test therapeutic approaches in preclinical models. This literature review provides a summary of published findings in therapeutic exercise interventions in rat models of arthritis as well as gaps in the existing literature. We reveal that preclinical research in this field has yet to adequately investigate the impact of experimental variables in therapeutic exercise including their modality, intensity, duration, and frequency on joint pathophysiology and pain outcomes.

The effectiveness of treadmill and swimming exercise in an animal model of osteoarthritis

Introduction: Osteoarthritis (OA) is considered an inflammatory and degenerative joint disease, characterized by loss of hyaline joint cartilage and adjacent bone remodeling with the formation of osteophytes, accompanied by various degrees of functional limitation and reduction in the quality of life of individuals. The objective of this work was to investigate the effects of treatment with physical exercise on the treadmill and swimming in an animal model of osteoarthritis. Methods: Forty-eight male Wistar rats were divided (n=12 per group): Sham (S); Osteoarthritis (OA); Osteoarthritis + Treadmill (OA + T); Osteoarthritis + Swimming (OA + S). The mechanical model of OA was induced by median meniscectomy. Thirty days later, the animals started the physical exercise protocols. Both protocols were performed at moderate intensity. Forty-eight hours after the end of the exercise protocols, all animals were anesthetized and euthanized for histological, molecular, and biochemical parameters analysis. Results: Physical exercise performed on a treadmill was more effective in attenuating the action of pro-inflammatory cytokines (IFN-γ, TNF-α, IL1-β, and IL6) and positively regulating anti-inflammatories such as IL4, IL10, and TGF-β in relation to other groups. Discussion: In addition to maintaining a more balanced oxi-reductive environment within the joint, treadmill exercise provided a more satisfactory morphological outcome regarding the number of chondrocytes in the histological evaluation. As an outcome, better results were found in groups submitted to exercise, mostly treadmill exercise.

Exercise for Osteoarthritis: A Literature Review of Pathology and Mechanism

Osteoarthritis (OA) has a very high incidence worldwide and has become a very common joint disease in the elderly. Currently, the treatment methods for OA include surgery, drug therapy, and exercise therapy. In recent years, the treatment of certain diseases by exercise has received increasing research and attention. Proper exercise can improve the physiological function of various organs of the body. At present, the treatment of OA is usually symptomatic. Limited methods are available for the treatment of OA according to its pathogenesis, and effective intervention has not been developed to slow down the progress of OA from the molecular level. Only by clarifying the mechanism of exercise treatment of OA and the influence of different exercise intensities on OA patients can we choose the appropriate exercise prescription to prevent and treat OA. This review mainly expounds the mechanism that exercise alleviates the pathological changes of OA by affecting the degradation of the ECM, apoptosis, inflammatory response, autophagy, and changes of ncRNA, and summarizes the effects of different exercise types on OA patients. Finally, it is found that different exercise types, exercise intensity, exercise time and exercise frequency have different effects on OA patients. At the same time, suitable exercise prescriptions are recommended for OA patients.

Glycoproteomic and Lipidomic Characterization of Industrially Produced Whey Protein Phospholipid Concentrate with Emphasis on Antimicrobial Xanthine Oxidase, Oxylipins and Small Milk Fat Globules

This work investigates the composition of whey protein phospholipid concentrate (WPPC), an underutilized dairy stream, and reveals that it is a source of many bioactive compounds that can benefit the immune system and gut health. Our glycoproteomics approach uncovered that proteins derived from the milk fat globule membrane (MFGM) represent 23% of the total protein relative abundance and identified 85 N-glycans. Released sialic acid, an additional marker of glycosylation, ranged from 1.2 to 2% of the total weight. Xanthine oxidase, a glycosylated marker of MFG bioactivity, was found in high abundance and displayed higher antimicrobial activity than bovine milk, despite its similar fat and solids content. An average MFG diameter of 2.64 ± 0.01 µm was found in liquid WPPC, compared to 4.78 ± 0.13 µm in bovine milk, which likely explains the unusually high presence of glycosylated membrane-bound proteins and phospholipids, whose total fatty acids accounted for 20% of the WPPC total fatty acid pool. Free and bound oxylipins (mainly derived from linoleic acid) were also identified, together with other less abundant anti-inflammatory lipid mediators derived from eicosapentaenoic acid and docosahexaenoic acid. Our study demonstrates that WPPC represents a promising starting material for bioactive compound extraction and a functional vehicle for the delivery of small MFGs.

Matrix Metalloproteinase 3: A Promoting and Destabilizing Factor in the Pathogenesis of Disease and Cell Differentiation

Cells must alter their expression profiles and morphological characteristics but also reshape the extracellular matrix (ECM) to fulfill their functions throughout their lifespan. Matrix metalloproteinase 3 (MMP-3) is a member of the matrix metalloproteinase (MMP) family, which can degrade multiple ECM components. MMP-3 can activate multiple pro-MMPs and thus initiates the MMP-mediated degradation reactions. In this review, we summarized the function of MMP-3 and discussed its effects on biological activities. From this point of view, we emphasized the positive and negative roles of MMP-3 in the pathogenesis of disease and cell differentiation, highlighting that MMP-3 is especially closely involved in the occurrence and development of osteoarthritis. Then, we discussed some pathways that were shown to regulate MMP-3. By writing this review, we hope to provide new topics of interest for researchers and attract more researchers to investigate MMP-3.

Role of Physical Exercise and Nutraceuticals in Modulating Molecular Pathways of Osteoarthritis

Osteoarthritis (OA) is a painful and disabling disease that affects millions of patients. Its etiology is largely unknown, but it is most likely multifactorial. OA pathogenesis involves the catabolism of the cartilage extracellular matrix and is supported by inflammatory and oxidative signaling pathways and marked epigenetic changes. To delay OA progression, a wide range of exercise programs and naturally derived compounds have been suggested. This literature review aims to analyze the main signaling pathways and the evidence about the synergistic effects of these two interventions to counter OA. The converging nutrigenomic and physiogenomic intervention could slow down and reduce the complex pathological features of OA. This review provides a comprehensive picture of a possible signaling approach for targeting OA molecular pathways, initiation, and progression.