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Frontiers in Immunology 2021Synovial joints are complex structures that enable normal locomotion. Following injury, they undergo a series of changes, including a prevalent inflammatory response.... (Review)
Review
Synovial joints are complex structures that enable normal locomotion. Following injury, they undergo a series of changes, including a prevalent inflammatory response. This increases the risk for development of osteoarthritis (OA), the most common joint disorder. In healthy joints, macrophages are the predominant immune cells. They regulate bone turnover, constantly scavenge debris from the joint cavity and, together with synovial fibroblasts, form a protective barrier. Macrophages thus work in concert with the non-hematopoietic stroma. In turn, the stroma provides a scaffold as well as molecular signals for macrophage survival and functional imprinting: "a macrophage niche". These intricate cellular interactions are susceptible to perturbations like those induced by joint injury. With this review, we explore how the concepts of local tissue niches apply to synovial joints. We introduce the joint micro-anatomy and cellular players, and discuss their potential interactions in healthy joints, with an emphasis on molecular cues underlying their crosstalk and relevance to joint functionality. We then consider how these interactions are perturbed by joint injury and how they may contribute to OA pathogenesis. We conclude by discussing how understanding these changes might help identify novel therapeutic avenues with the potential of restoring joint function and reducing post-traumatic OA risk.
Topics: Cell Movement; Humans; Knee Joint; Macrophages; Monocytes; Osteoarthritis; Synovial Membrane
PubMed: 34804052
DOI: 10.3389/fimmu.2021.763702 -
Frontiers in Immunology 2023Rheumatoid arthritis (RA) is a complex autoimmune disease characterized by chronic inflammation that affects synovial tissues of multiple joints. Granzymes (Gzms) are... (Review)
Review
Rheumatoid arthritis (RA) is a complex autoimmune disease characterized by chronic inflammation that affects synovial tissues of multiple joints. Granzymes (Gzms) are serine proteases that are released into the immune synapse between cytotoxic lymphocytes and target cells. They enter target cells with the help of perforin to induce programmed cell death in inflammatory and tumor cells. Gzms may have a connection with RA. First, increased levels of Gzms have been found in the serum (GzmB), plasma (GzmA, GzmB), synovial fluid (GzmB, GzmM), and synovial tissue (GzmK) of patients with RA. Moreover, Gzms may contribute to inflammation by degrading the extracellular matrix and promoting cytokine release. They are thought to be involved in RA pathogenesis and have the potential to be used as biomarkers for RA diagnosis, although their exact role is yet to be fully elucidated. The purpose of this review was to summarize the current knowledge regarding the possible role of the granzyme family in RA, with the aim of providing a reference for future research on the mechanisms of RA and the development of new therapies.
Topics: Humans; Granzymes; Arthritis, Rheumatoid; Autoimmune Diseases; Inflammation; Synovial Membrane
PubMed: 36875082
DOI: 10.3389/fimmu.2023.1137918 -
BMC Veterinary Research May 2021Capsulitis leads to the release of inflammatory mediators in the joint, causing capsular fibrosis and osteoarthritis (OA). Strain elastosonography (SE) measures the...
BACKGROUND
Capsulitis leads to the release of inflammatory mediators in the joint, causing capsular fibrosis and osteoarthritis (OA). Strain elastosonography (SE) measures the elasticity of tissue by evaluating its strain in operator-dependent deformation. The aims of the study were to assess the feasibility, repeatability, and reproducibility of SE for imaging the distal attachment of the joint capsule (DJC) of metacarpophalangeal joints in sound horses (Group S) and in horses with metacarpophalangeal OA (Group P) and to evaluate differences in the elastosonographic patterns of these horses. After a whole lameness examination, fore fetlock DJCs were assigned to Group S and Group P and were thereafter examined by two operators using SE. Qualitative (i.e., colour grading score) and semi-quantitative (i.e., elasticity index (EI) and strain ratio (SR)) methods were used to evaluate the elastograms. The inter-rater reliability (IRR), intraclass correlation coefficient (intra-CC) and interclass correlation coefficient (inter-CC) were used to compare colour grading scores and the repeatability and reproducibility of EI and SR outcomes. The same parameters were compared between groups. P < 0.05 indicated a significant finding.
RESULTS
Forty-one horses were included: 11 were in Group S and 30 were in Group P (16 with bilateral OA, 8 with left OA and 6 with right OA). IRR outcomes ranged from good to excellent. For transverse and longitudinal ultrasound scans, the colour grading score of Group S was significantly higher than the metacarpophalangeal DJCs of Group P. Both Inter-CC and intra-CC were higher in Group S than in Group P, with values always > 0.8. Significative differences in EI and SR were detected between groups and between Group S and the affected limb of Group P; values were lower in Group S than in Group P.
CONCLUSIONS
SE can be a useful technique for evaluating DJCs, with good repeatability and reproducibility. DJCs appear softer in sound horses.
Topics: Animals; Elasticity Imaging Techniques; Feasibility Studies; Female; Horse Diseases; Horses; Joint Capsule; Lameness, Animal; Male; Osteoarthritis; Prospective Studies; Reproducibility of Results
PubMed: 34051815
DOI: 10.1186/s12917-021-02897-8 -
The Journal of Physiology Feb 2017Rheumatoid arthritis (RA) is a progressive disease that affects both pediatric and adult populations. The cellular basis for RA has been investigated extensively using... (Review)
Review
Rheumatoid arthritis (RA) is a progressive disease that affects both pediatric and adult populations. The cellular basis for RA has been investigated extensively using animal models, human tissues and isolated cells in culture. However, many aspects of its aetiology and molecular mechanisms remain unknown. Some of the electrophysiological principles that regulate secretion of essential lubricants (hyaluronan and lubricin) and cytokines from synovial fibroblasts have been identified. Data sets describing the main types of ion channels that are expressed in human synovial fibroblast preparations have begun to provide important new insights into the interplay among: (i) ion fluxes, (ii) Ca release from the endoplasmic reticulum, (iii) intercellular coupling, and (iv) both transient and longer duration changes in synovial fibroblast membrane potential. A combination of this information, knowledge of similar patterns of responses in cells that regulate the immune system, and the availability of adult human synovial fibroblasts are likely to provide new pathophysiological insights.
Topics: Animals; Electrophysiological Phenomena; Fibroblasts; Humans; Ion Channels; Synovial Membrane
PubMed: 27079855
DOI: 10.1113/JP270209 -
Scientific Reports Nov 2022Stokes's equation in the fluid domain and Brinkman's equation in the porous media are combined in the current study which is designated by the Stokes-Brinkman coupling....
Stokes's equation in the fluid domain and Brinkman's equation in the porous media are combined in the current study which is designated by the Stokes-Brinkman coupling. The current paper gives a theoretical analysis of the Stokes-Brinkman coupling. It has been shown that such a model is a good match for the knee joint. A flow model has been investigated in order to get a better understanding of the convective diffusion of the viscous flow along the articular surfaces between the joints. The Beavers and Joseph slip conditions which are a specific boundary condition for the synovial fluid are used to solve the governing system of partial differential equations for the synovial fluid and the results are provided here. We develop formulas for the interfacial velocity for both flow through special slip condition and analyse the link between the slip parameters [Formula: see text] and [Formula: see text]. Thus, the damping force due to the porous medium naturally when we non-dimensionalize, some parameter which are controlling the structure like, [Formula: see text] and [Formula: see text]. Through the development of an analytical solution and numerical simulation (using the finite volume approach) it is hoped that the mechanisms of nutritional transport into the synovial joint will be better understood. According to the data the average concentration has a negative connection with both the axial distance and the duration spent in the experiment. Many graphs have been utilized to gain understanding into the problem's various characteristics including velocity and concentration, among others. Hyaluronate (HA) is considered to be present in porous cartilage surfaces and the viscosity of synovial fluid fluctuates in response to the amount of HA present.
Topics: Humans; Porosity; Viscosity; Computer Simulation; Knee Joint; Synovial Fluid
PubMed: 36348000
DOI: 10.1038/s41598-022-23402-7 -
Arthritis Research & Therapy Apr 2021Osteoarthritis (OA) has long been regarded as a disease of cartilage degeneration, whereas mounting evidence implies that low-grade inflammation contributes to OA. Among... (Review)
Review
OBJECTIVE
Osteoarthritis (OA) has long been regarded as a disease of cartilage degeneration, whereas mounting evidence implies that low-grade inflammation contributes to OA. Among inflammatory cells involved, macrophages play a crucial role and are mediated by the local microenvironment to exhibit different phenotypes and polarization states. Therefore, we conducted a systematic review to uncover the phenotypic alterations of macrophages during OA and summarized the potential therapeutic interventions via modulating macrophages.
METHODS
A systematic review of multiple databases (PubMed, Web of Science, ScienceDirect, Medline) was performed up to February 29, 2020. Included articles were discussed and evaluated by two independent reviewers. Relevant information was analyzed with a standardized and well-designed template.
RESULTS
A total of 28 studies were included. Results were subcategorized into two sections depending on sources from human tissue/cell-based studies (12 studies) and animal experiments (16 studies). The overall observation indicated that M1 macrophages elevated in both synovium and circulation during OA development, along with lower numbers of M2 macrophages. The detailed alterations of macrophages in both synovium and circulation were listed and analyzed. Furthermore, interventions against OA via regulating macrophages in animal models were highlighted.
CONCLUSION
This study emphasized the importance of the phenotypic alterations of macrophages in OA development. The classical phenotypic subcategory of M1 and M2 macrophages was questionable due to controversial and conflicting results. Therefore, further efforts are needed to categorize macrophages in an exhaustive manner and to use advanced technologies to identify the individual roles of each subtype of macrophages in OA.
Topics: Animals; Humans; Inflammation; Macrophages; Osteoarthritis; Phenotype; Synovial Membrane
PubMed: 33838669
DOI: 10.1186/s13075-021-02457-3 -
Frontiers in Immunology 2022
Topics: Humans; Synovial Membrane; Osteoarthritis
PubMed: 36304462
DOI: 10.3389/fimmu.2022.1052196 -
European Journal of Applied Physiology Dec 2019The benefits of exercise across the lifespan and for a wide spectrum of health and diseases are well known. However, there remains less clarity as to the effects of both... (Review)
Review
PURPOSE
The benefits of exercise across the lifespan and for a wide spectrum of health and diseases are well known. However, there remains less clarity as to the effects of both acute and chronic exercise on joint health. Serum biomarkers of joint metabolism are sensitive to change and have the potential to differentiate between normal and adverse adaptations to acute and chronic load. Therefore, the primary objective of this review is to evaluate how serum biomarkers can inform our understanding of how exercise affects joint metabolism.
METHODS
A comprehensive literature search was completed to identify joint biomarkers previously used to investigate acute and chronic exercise training.
RESULTS
Identified biomarkers included those related to joint cartilage, bone, synovium, synovial fluid, and inflammation. However, current research has largely focused on the response of serum cartilage oligomeric matrix protein (COMP) to acute loading in healthy young individuals. Studies demonstrate how acute loading transiently increases serum COMP (i.e., cartilage metabolism), which is mostly dependent on the duration of exercise. This response does not appear to be associated with any lasting deleterious changes, cartilage degradation, or osteoarthritis.
CONCLUSION
Several promising biomarkers for assessing joint metabolism exist and may in future enhance our understanding of the physiological response to acute and chronic exercise. Defining 'normal' and 'abnormal' biomarker responses to exercise and methodological standardisation would greatly improve the potential of research in this area to understand mechanisms and inform practice.
Topics: Biomarkers; Cartilage Oligomeric Matrix Protein; Cartilage, Articular; Exercise; Humans; Knee Joint; Synovial Fluid
PubMed: 31650307
DOI: 10.1007/s00421-019-04232-4 -
Orthopaedic Surgery Oct 2021Irreparable massive rotator cuff tear (IMRCT) was one of the causes of shoulder dysfunction, despite technical improvement, the failure rate of IMRCT was still... (Review)
Review
Irreparable massive rotator cuff tear (IMRCT) was one of the causes of shoulder dysfunction, despite technical improvement, the failure rate of IMRCT was still demonstrated to be high. Traditional treatments like non-surgical treatments, partial rotator cuff repair, and tendon transfers could only achieve a slight improvement. A potential cause for high failure rate was the fact that traditional treatments cannot restore the superior stability of glenohumeral joint, and thus restricted the movement of shoulder joint severely. Superior capsular reconstruction (SCR) using a variety of grafts (autograft, allograft, xenograft, or synthetic grafts) provided a promising option for IMRCT. In surgery, graft was fixed medially to superior glenoid and laterally to the footprint of humeral greater tuberosity. SCR could increase the stability of the superior glenohumeral joint, decrease the subacromial pressure and acromiohumeral distance. This review summarized the relevant literature regarding the alternative grafts, surgery indications, operative techniques and clinical outcomes of SCR. we compared the different grafts, key surgical steps, the advantages and disadvantages of different surgical methods to provide clinicians with new surgical insights into the treatments of IMRCT. In conclusion, IMRCT without severe glenohumeral arthritis was the best suitable indication for SCR. The clinical outcomes were positive in the short-term and middle-term following-up. More studies were necessary to determine long-term results of this surgical procedure.
Topics: Arthroscopy; Humans; Joint Capsule; Plastic Surgery Procedures; Rotator Cuff Injuries
PubMed: 34585538
DOI: 10.1111/os.12976 -
International Journal of Biological... 2021Joint capsule fibrosis caused by excessive inflammation results in post-traumatic joint contracture (PTJC). Transforming growth factor (TGF)-β1 plays a key role in PTJC...
Joint capsule fibrosis caused by excessive inflammation results in post-traumatic joint contracture (PTJC). Transforming growth factor (TGF)-β1 plays a key role in PTJC by regulating fibroblast functions, however, cytokine-induced TGF-β1 expression in specific cell types remains poorly characterized. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in inflammation- and fibrosis-associated pathophysiology. In this study, we investigated whether MIF can facilitate TGF-β1 production from fibroblasts and regulate joint capsule fibrosis following PTJC. Our data demonstrated that MIF and TGF-β1 significantly increased in fibroblasts of injured rat posterior joint capsules. Treatment the lesion sites with MIF inhibitor 4-Iodo-6-phenylpyrimidine (4-IPP) reduced TGF-β1 production and relieved joint capsule inflammation and fibrosis. , MIF facilitated TGF-β1 expression in primary joint capsule fibroblasts by activating mitogen-activated protein kinase (MAPK) (P38, ERK) signaling through coupling with membrane surface receptor CD74, which in turn affected fibroblast functions and promoted MIF production. Our results reveal a novel function of trauma-induced MIF in the occurrence and development of joint capsule fibrosis. Further investigation of the underlying mechanism may provide potential therapeutic targets for PTJC.
Topics: Animals; Cells, Cultured; Disease Models, Animal; Fibroblasts; Fibrosis; Intramolecular Oxidoreductases; Joint Capsule; Joint Diseases; Macrophage Migration-Inhibitory Factors; Macrophages; Male; RNA; Rats; Rats, Sprague-Dawley; Signal Transduction; Transforming Growth Factor beta1
PubMed: 33994866
DOI: 10.7150/ijbs.57025