AdipoRon reduces TGFβ1-mediated collagen deposition in vitro and alleviates knee stiffness in vivo

Arthrofibrosis, which causes joint motion restrictions, is a common complication following total knee arthroplasty (TKA). Key features associated with arthrofibrosis include myofibroblast activation, knee stiffness, and excessive scar tissue formation. We previously demonstrated that adiponectin levels are suppressed within the knee tissues of patients affected by arthrofibrosis and showed that AdipoRon, an adiponectin receptor agonist, exhibited anti-fibrotic properties in human mesenchymal stem cells. In this study, the therapeutic potential of AdipoRon was evaluated on TGFβ1-mediated myofibroblast differentiation of primary human knee fibroblasts and in a mouse model of knee stiffness. Picrosirius red staining revealed that AdipoRon reduced TGFβ1-induced collagen deposition in primary knee fibroblasts derived from patients undergoing primary TKA and revision TKA for arthrofibrosis. AdipoRon also reduced mRNA and protein levels of ACTA2, a key myofibroblast marker. RNA-seq analysis corroborated the anti-myofibrogenic effects of AdipoRon. In our knee stiffness mouse model, 6 weeks of knee immobilization, to induce a knee contracture, in conjunction with daily vehicle (DMSO) or AdipoRon (1, 5, and 25 mg/kg) via intraperitoneal injections were well tolerated based on animal behavior and weight measurements. Biomechanical testing demonstrated that passive extension angles (PEAs) of experimental knees were similar between vehicle and AdipoRon treatment groups in mice evaluated immediately following immobilization. Interestingly, relative to vehicle-treated mice, 5 mg/kg AdipoRon therapy improved the PEA of the experimental knees in mice that underwent 4 weeks of knee remobilization following the immobilization and therapy. Together, these studies revealed that AdipoRon may be an effective therapeutic modality for arthrofibrosis.

Identification of Lipid Biomarkers for Chronic Joint Pain Associated with Different Joint Diseases

Lipids, especially lysophosphatidylcholine LPC16:0, have been shown to be involved in chronic joint pain through the activation of acid-sensing ion channels (ASIC3). The aim of the present study was to investigate the lipid contents of the synovial fluids from controls and patients suffering from chronic joint pain in order to identify characteristic lipid signatures associated with specific joint diseases. For this purpose, lipids were extracted from the synovial fluids and analyzed by mass spectrometry. Lipidomic analyses identified certain choline-containing lipid classes and molecular species as biomarkers of chronic joint pain, regardless of the pathology, with significantly higher levels detected in the patient samples. Moreover, correlations were observed between certain lipid levels and the type of joint pathologies. Interestingly, LPC16:0 levels appeared to correlate with the metabolic status of patients while other choline-containing lipids were more specifically associated with the inflammatory state. Overall, these data point at selective lipid species in synovial fluid as being strong predictors of specific joint pathologies which could help in the selection of the most adapted treatment.

Proteomics identifies novel biomarkers of synovial joint disease in a canine model of mucopolysaccharidosis I

Mucopolysaccharidosis I is a lysosomal storage disorder characterized by deficient alpha-L-iduronidase activity, leading to abnormal accumulation of glycosaminoglycans in cells and tissues. Synovial joint disease is prevalent and significantly reduces patient quality of life. There is a critical need for improved understanding of joint disease pathophysiology in MPS I, including specific biomarkers to predict and monitor joint disease progression, and response to treatment. The objective of this study was to leverage the naturally-occurring MPS I canine model and undertake an unbiased proteomic screen to identify systemic biomarkers predictive of local joint disease in MPS I. Synovial fluid and serum samples were collected from MPS I and healthy dogs at 12 months-of-age, and protein abundance characterized using liquid chromatography tandem mass spectrometry. Stifle joints were evaluated postmortem using magnetic resonance imaging (MRI) and histology. Proteomics identified 40 proteins for which abundance was significantly correlated between serum and synovial fluid, including markers of inflammatory joint disease and lysosomal dysfunction. Elevated expression of three biomarker candidates, matrix metalloproteinase 19, inter-alpha-trypsin inhibitor heavy-chain 3 and alpha-1-microglobulin, was confirmed in MPS I cartilage, and serum abundance of these molecules was found to correlate with MRI and histological degenerative grades. The candidate biomarkers identified have the potential to improve patient care by facilitating minimally-invasive, specific assessment of joint disease progression and response to therapeutic intervention.

Correlations between metabolites in the synovial fluid and serum: A mouse injury study

Osteoarthritis occurs frequently after joint injury. Currently, osteoarthritis is diagnosed by radiographic changes that are typically found after the disease has progressed to multiple tissues. The primary objective was to compare potential metabolomic biomarkers of joint injury between synovial fluid and serum in a mouse model of posttraumatic osteoarthritis. The secondary objective was to gain insight into the pathophysiology of osteoarthritis by examining metabolomic profiles after joint injury. Twelve-week-old adult female C57BL/6 mice (n = 12) were randomly assigned to control, Day 1, or Day 8 postinjury groups. Randomly selected stifle joints were subjected to a single rapid compression. At Days 1 and 8 postinjury, serum was extracted before mice were euthanized for synovial fluid collection. Metabolomic profiling detected ~2500 metabolites across serum and synovial fluid. Of these, 179 were positively correlated and 51 were negatively correlated between synovial fluid and serum, indicating the potential for the development of metabolomic biomarkers. Synovial fluid captured injury-induced differences in metabolomic profiles at both Days 1 and 8 after injury whereas serum did not. However, synovial fluid and serum were distinct at both time points after injury. In synovial fluid, pathways of interest mapped to amino acid synthesis and degradation, bupropion degradation, and transfer RNA (tRNA) charging. In serum, pathways were amino acid synthesis and degradation, the phospholipase pathway, and nicotine degradation. These results provide a rich picture of the injury response at early time points after joint injury. Furthermore, the correlations between synovial fluid and serum metabolites suggest the potential to gain insight into intra-articular pathophysiology through analysis of serum metabolites.

E8002 Reduces Adhesion Formation and Improves Joint Mobility in a Rat Model of Knee Arthrofibrosis

Knee arthrofibrosis is a common complication of knee surgery, caused by excessive scar tissue, which results in functional disability. However, no curative treatment has been established. E8002 is an anti-adhesion material that contains L-ascorbic acid, an antioxidant. We aimed to evaluate the efficacy of E8002 for the prevention of knee arthrofibrosis in a rat model, comprising injury to the surface of the femur and quadriceps muscle 1 cm proximal to the patella. Sixteen male, 8-week-old Sprague Dawley rats were studied: in the Adhesion group, haemorrhagic injury was induced to the quadriceps and bone, and in the E8002 group, an adhesion-preventing film was implanted between the quadriceps and femur after injury. Six weeks following injury, the restriction of knee flexion owing to fibrotic scarring had not worsened in the E8002 group but had worsened in the Adhesion group. The area of fibrotic scarring was smaller in the E8002 group than in the Adhesion group (p < 0.05). In addition, the numbers of fibroblasts (p < 0.05) and myofibroblasts (p < 0.01) in the fibrotic scar were lower in the E8002 group. Thus, E8002 reduces myofibroblast proliferation and fibrotic scar formation and improves the range of motion of the joint in a model of knee injury.

Human Mesenchymal Stromal Cells Enhance Cartilage Healing in a Murine Joint Surface Injury Model

Human umbilical cord (hUC)- or bone marrow (hBM)-derived mesenchymal stromal cells (MSCs) were evaluated as an allogeneic source of cells for cartilage repair. We aimed to determine if they could enhance healing of chondral defects with or without the recruitment of endogenous cells. hMSCs were applied into a focal joint surface injury in knees of adult mice expressing tdTomato fluorescent protein in cells descending from Gdf5-expressing embryonic joint interzone cells. Three experimental groups were used: (i) hUC-MSCs, (ii) hBM-MSCs and (iii) PBS (vehicle) without cells. Cartilage repair was assessed after 8 weeks and tdTomato-expressing cells were detected by immunostaining. Plasma levels of pro-inflammatory mediators and other markers were measured by electrochemiluminescence. Both hUC-MSC (n = 14, p = 0.009) and hBM-MSC (n = 13, p = 0.006) treatment groups had significantly improved cartilage repair compared to controls (n = 18). While hMSCs were not detectable in the repair tissue at 8 weeks post-implantation, increased endogenous Gdf5-lineage cells were detected in repair tissue of hUC-MSC-treated mice. This xenogeneic study indicates that hMSCs enhance intrinsic cartilage repair mechanisms in mice. Hence, hMSCs, particularly the more proliferative hUC-MSCs, could represent an attractive allogeneic cell population for treating patients with chondral defects and perhaps prevent the onset and progression of osteoarthritis.

Effects of triangle grass decoction on bone metabolism in rats with chronic kidney disease complicated with mineral and bone abnormalities

ETHNOPHARMACOLOGICAL RELEVANCE

Triangle grass is a liliaceous Chlorophytum perennial herb of ChlorophytumlaxumR.Br. It is distributed mainly in Guangdong and Guangxi Provinces of China. The initial use of triangle grass was mainly to treat bone pain and swelling caused by a fall injury. Triangle grass tablets (NO. Z20070544) are also used as a preparation in our hospital because of their analgesic, anti-inflammatory, anti-snake venom and microcirculation improvement properties and other pharmacological effects (Mei et al., 2006). Triangle grass tablets have been widely used in our hospital to treat patients with bone pain from chronic kidney disease-mineral and bone disorder (CKD-MBD). However, the effects and mechanism of triangle grass on bone metabolism in chronic kidney disease complicated with mineral and bone abnormalities are unclear.

AIM OF THE STUDY

The aim of the present study was to investigate the effects of a triangle grass decoction on bone metabolism in CKD-MBD rats.

MATERIALS AND METHODS

CKD-MBD model rats were subjected to 5/6 nephrectomy combined with 0.5 g NaH2PO4/rat. Serum blood urea nitrogen (BUN), creatinine (Cr), phosphorus (P), calcium (Ca), and intact parathyroid hormone (iPTH) levels were measured with an automatic biochemical analyser. Bone mineral density was determined with a Viva CT 40 system. Bone morphogenetic protein 7(BMP-7),runt-related transcription factor 2 (Runx2) and Osterix protein levels were measured by Western blot analysis. Kidney, vertebra and thoracic aorta tissue samples were assessed by histopathology and immunohistochemistry (IHC).

RESULTS

The degrees of membrane thickening, necrosis, swelling and cast deposition were significantly reduced in high-dose rats and Low-dose rats. Serum BUN levels were significantly reduced in the Pre-H group (P < 0.05). Hypocalcaemia and hyperphos phataemia were detected in triangle grass (P < 0.05, P < 0.05). In addition, iPTH levels were significantly increased in the Pre-H group (P < 0.05). Alkaline phosphatase (ALP)levels were significantly decreased in the Pre-H group (P < 0.05). The bone mineral density was improved in the Pre-H and Pre-L groups. BMP-7 protein levels were significantly increased in the Pre-H group (P < 0.05). The pathological changes in muscle fibres in the thoracic aorta middle membranes were significantly alleviated in rats in the Pre-H and Pre-L groups. Changes in SM22α and SMα-act in protein levels were significantly attenuated in the Pre-H group (P < 0.05, P < 0.05). Changes in Runx2 and Osterix protein levels were also significantly attenuated in the Pre-H and Pre-L groups (P < 0.05, P < 0.05).

CONCLUSIONS

Triangle grass can simultaneously ameliorate vertebral bone loss and abnormal calcification in the thoracic aorta. Triangle grass has a definite effect on bone metabolism disorder in CKD-MBD rats.

Manjarix attenuated pain and joint swelling in a rat model of monosodium iodoacetate-induced osteoarthritis

Osteoarthritis (OA) is a joint disease characterized by degeneration of cartilage, intra-articular inflammation, remodeling of subchondral bone and joint pain. The present study was designed to assess the therapeutic effects and the possible underlying mechanism of action of Manjarix, a herbal combination composed of ginger and turmeric powder extracts, on chemically induced osteoarthritis in rats. An OA model was generated by intra-articular injection of 50 μL (40 mg mL-1) of monosodium iodoacetate (MIA) into the right knee joint of rats. After one week of osteoarthritis induction, a comparison of the anti-inflammatory efficacy of indomethacin at an oral dose of 2 mg kg-1 daily for 4 successive weeks versus five decremental dose levels of Manjarix (1000, 500, 250, 125, and 62.5 mg kg-1) was performed. Serum inflammatory cytokines, interleukin 6, interleukin 8, and tumor necrosis factor alpha; C-telopeptide of type II collagen (CTX-II) and hyaluronic acid (HA) were measured, along with weekly assessment of the knee joint swelling. Pain-like behavior was assessed and knee radiographic and histological examination were performed to understand the extent of pain due to cartilage degradation. Manjarix significantly reduced the knee joint swelling, decreased the serum levels of IL6, TNF-α, CTX-II and HA, and reduced the pathological injury in joints, with no evidence of osteo-reactivity in the radiographic examination. Manjarix also significantly prevented MIA-induced pain behavior. These results demonstrate that Manjarix exhibits chondroprotective effects and can inhibit the OA pain induced by MIA, and thus it can be used as a potential therapeutic product for OA.

Strain-specific joint invasion and colonization by Lyme disease spirochetes is promoted by outer surface protein C

Lyme disease, caused by Borrelia burgdorferi, B. afzelii and B. garinii, is a chronic, multi-systemic infection and the spectrum of tissues affected can vary with the Lyme disease strain. For example, whereas B. garinii infection is associated with neurologic manifestations, B. burgdorferi infection is associated with arthritis. The basis for tissue tropism is poorly understood, but has been long hypothesized to involve strain-specific interactions with host components in the target tissue. OspC (outer surface protein C) is a highly variable outer surface protein required for infectivity, and sequence differences in OspC are associated with variation in tissue invasiveness, but whether OspC directly influences tropism is unknown. We found that OspC binds to the extracellular matrix (ECM) components fibronectin and/or dermatan sulfate in an OspC variant-dependent manner. Murine infection by isogenic B. burgdorferi strains differing only in their ospC coding region revealed that two OspC variants capable of binding dermatan sulfate promoted colonization of all tissues tested, including joints. However, an isogenic strain producing OspC from B. garinii strain PBr, which binds fibronectin but not dermatan sulfate, colonized the skin, heart and bladder, but not joints. Moreover, a strain producing an OspC altered to recognize neither fibronectin nor dermatan sulfate displayed dramatically reduced levels of tissue colonization that were indistinguishable from a strain entirely deficient in OspC. Finally, intravital microscopy revealed that this OspC mutant, in contrast to a strain producing wild type OspC, was defective in promoting joint invasion by B. burgdorferi in living mice. We conclude that OspC functions as an ECM-binding adhesin that is required for joint invasion, and that variation in OspC sequence contributes to strain-specific differences in tissue tropism displayed among Lyme disease spirochetes.

Infection by different Lyme disease bacteria is associated with different manifestations, such as cardiac, neurologic, or, in the case of B. burgdorferi, the major cause of Lyme disease in the U.S., joint disease. The basis for these differences is unknown, but likely involve strain-specific interactions with host components in the target tissue. The sequence of the outer surface lipoprotein OspC varies with the strains, and we found that this variation influences the spectrum of host extracellular matrix components recognized. Infection of mice with strains that are identical except for ospC revealed that OspC variants that differ in binding spectrum promote infection of different tissues. A strain producing OspC invaded and colonized the joint in living animals, but an altered OspC protein incapable of binding tissue components did not. Thus, tissue-binding by OspC is critical for infection and joint invasion, and OspC variation directly influences tissue tropism.

Role of Microparticles in the Pathogenesis of Inflammatory Joint Diseases

Rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) make up a group of chronic immune-mediated inflammatory diseases (IMIDs). The course of these diseases involves chronic inflammation of joints and enthesopathies, which can result in joint damage and disability. Microparticles (MPs) are a group of small spherical membranous vesicles. The structure and cellular origin of MPs, mechanisms that stimulate their secretion and the place of their production, determine their biological properties, which could become manifest in the pathogenesis of immune-mediated inflammatory diseases. Microparticles can stimulate synovitis with proinflammatory cytokines and chemokines. MPs may also contribute to the pathogenesis of rheumatic diseases by the formation of immune complexes and complement activation, pro-coagulation activity, activation of vascular endothelium cells, and stimulation of metalloproteinase production. It seems that in the future, microparticles can become a modern marker of disease activity, a response to treatment, and, possibly, they can be used in the prognosis of the course of arthritis. The knowledge of the complexity of MPs biology remains incomplete and it requires further comprehensive studies to explain how they affect the development of rheumatic diseases. This review focuses on the immunopathogenic and therapeutic role of MPs in chronic immune-mediated inflammatory joint diseases.

Skeletal phenotype/genotype in progressive pseudorheumatoid chondrodysplasia

BACKGROUND

Axial and extra-axial deceleration in function and progressive joint pain with subsequent development of antalgic gait associated with swellings, and stiffness of the joints with loss of the physiological spine biomechanics were the natural history in this group of patients. Clinical and radiological phenotypes have been analysed carefully to further understand the aetiology behind.

METHODS

Seven patients (three children around the age of 9-11 and one child of 17 years old). Three adults aging 25, 30, 33 and 40 years old were seen and examined. The paediatric group of patients were initially diagnosed with myopathy followed later by juvenile rheumatoid arthritis in other institutions. Clinical and imaging documentation were collected in our departments, followed by mutation screening, was carried out by bidirectional sequencing of the WISP3 gene.

RESULTS

Clinical and radiological phenotypic studies confirmed the diagnosis of progressive pseudorheumatoid chondrodysplasia. A constellation of abnormalities such as early senile hyperostosis of the spine (Forestier disease), osteoarthritis of the hips showed progressive diminution and irregularities of the hip joint spaces associated with progressive capital femoral epiphyseal dysplasia and coxa vara have been encountered. Loss-of-function homozygous mutations (c.667T>G, p.Cys223Gly) and (c.170C>A, p.Ser57*) in the WISP3 gene were identified in our patients.

CONCLUSION

The definite diagnosis was not defined via vigorous myopathic and rheumatologic investigations. Detailed clinical examination and skeletal survey, followed by genotypic confirmation, were our fundamental pointers to rule out the false diagnosis of juvenile rheumatoid arthritis and rheumatoid polyarthritis in the adult group of patients. We wish to stress that the clinical/radiological phenotype is the baseline tool to establish a definite diagnosis and to guide the geneticist toward proper genotype.Key Points•Joint pain and difficulties in walking/climbing the stairs are characteristic features encountered in early childhood. False diagnosis of juvenile rheumatoid arthritis can be made at this point.•False positive-like muscular wasting resembling myopathy results in ensuing vigorous troublesome investigations.•Flattened vertebral bodies associated with defective ossification of the anterior end plates are characteristic features of progressive pseudorheumatoid chondrodysplasia.•Joint expansions, which are usually accompanied by narrowing of the articular ends of the appendicular skeletal system, show a clear radiological phenotype of pseudorheumatoid chondrodysplasia.

Substance P and fibrotic diseases

Substance P (SP) is an undecapeptide encoding the tachykinin 1 (TAC1) gene and belongs to the tachykinin family. SP is widely distributed in the central nervous system and the peripheral nervous system. SP is also produced by nonneuronal cells, such as inflammatory cells and endothelial cells. The biological activities of SP are mainly regulated through the high-affinity neurokinin 1 receptor (NK-1R). The SP/NK-1R system plays an important role in the molecular bases of many human pathophysiologic processes, such as pain, infectious and inflammatory diseases, and cancer. In addition, this system has been implicated in fibrotic diseases and processes such as wound healing, myocardial fibrosis, bowel fibrosis, myelofibrosis, renal fibrosis, and lung fibrosis. Recently, studies have shown that SP plays an important role in liver fibrosis and that NK-1R antagonists can inhibit the progression of fibrosis. NK-1R receptor antagonists could provide clinical solutions for fibrotic diseases. This review summarizes the structure and function of SP and its involvement in fibrotic diseases.

Inflammatory joint diseases and atherosclerosis: time to look beyond the 'lipid paradox'

PURPOSE OF REVIEW

Uncertainty persists about the contribution of lipids to the increased risk of cardiovascular disease (CVD) among rheumatoid arthritis and other inflammatory joint disease (IJD) patients. In reviewing recent research, we consider potential insights gained by quantifying lipoprotein particles directly, rather than by their lipid content.

RECENT FINDINGS

Although inflammation often decreases LDL cholesterol (LDL-C), and anti-inflammatory medications often increase LDL-C, both inflammation and anti-inflammatory medications can increase atherogenic Apolipoprotein B (ApoB)-containing lipoprotein particles, attenuated by statins. CVD risk factors, that is, smoking, obesity, ApoB, may increase years prior to IJD diagnosis. Increased risks of nonatherosclerotic myocardial and pulmonary disease, heart failure and mortality may be directly related to disease activity, inflammation, and possibly to HDL particles and function.

SUMMARY

For IJD patients, higher cumulative lifetime exposure to CVD risk factors accelerates atherosclerosis and subsequent CVD risk that is underestimated by current risk factor levels. CVD risk reduction in IJD requires aggressive and earlier reduction in CVD risk factors (ApoB lipoproteins, smoking, hypertension, diabetes, lack of physical activity), in addition to control of disease activity and inflammation. Lipid-lowering medications can attenuate anti-inflammatory medication-induced increases in ApoB and LDL-C, but can also reduce CVD risk due to cumulative lifetime exposure.

Synovial Fluid Metabolites Differentiate between Septic and Nonseptic Joint Pathologies

Osteoarthritis (OA), osteochondrosis (OC), and synovial sepsis in horses cause loss of function and pain. Reliable biomarkers are required to achieve accurate and rapid diagnosis, with synovial fluid (SF) holding a unique source of biochemical information. Nuclear magnetic resonance (NMR) spectroscopy allows global metabolite analysis of a small volume of SF, with minimal sample preprocessing using a noninvasive and nondestructive method. Equine SF metabolic profiles from both nonseptic joints (OA and OC) and septic joints were analyzed using 1D 1H NMR spectroscopy. Univariate and multivariate statistical analyses were used to identify differential metabolite abundance between groups. Metabolites were annotated via 1H NMR using 1D NMR identification software Chenomx, with identities confirmed using 1D 1H and 2D 1H 13C NMR. Multivariate analysis identified separation between septic and nonseptic groups. Acetate, alanine, citrate, creatine phosphate, creatinine, glucose, glutamate, glutamine, glycine, phenylalanine, pyruvate, and valine were higher in the nonseptic group, while glycylproline was higher in sepsis. Multivariate separation was primarily driven by glucose; however, partial-least-squares discriminant analysis plots with glucose excluded demonstrated the remaining metabolites were still able to discriminate the groups. This study demonstrates that a panel of synovial metabolites can distinguish between septic and nonseptic equine SF, with glucose the principal discriminator.

Emerging Role of Exosomes in the Joint Diseases

Exosomes are a subset of small, membrane-bound extracellular vesicles that are important for communication among cells. They originate from the cell membrane during endocytic internalization, and are stable in biological fluids, including blood and synovial fluids. Increasing knowledge is emerging about exosomes in joint diseases, including osteoarthritis, rheumatoid arthritis, osteonecrosis of the femoral head, and others. Exosomes in synovial fluid can lead to inflammation, degeneration of cartilage, and destruction of joints. Exosomes in blood have diagnostic value in the early disease stage or for complicated conditions of joint diseases. Exosomes from stem cells could delay diseases and repair joints. For a comprehensive understanding about the emerging role of exosomes in joint diseases, we introduced the isolation and verification of exosomes from synovial fluid, reviewed the physiological and pathological effects of exosomes on joints, and discussed the diagnostic value and therapeutic potential of exosomes in joint diseases. In the future, immunologically active exosomes and engineered exosomes will of interest in the joint diseases. Challenges in the field of exosomes in joint-disease research include complex and expensive isolation, detection of contributing molecular, effectiveness and safety evaluation. In summary, challenges remain, but the field of exosomes in joint diseases has potential, including in mechanisms, diagnoses and therapies.

[Joint disease and energy metabolism.]

Recently, it has been found that systemic metabolic disorders are associated with the onset and progression of various joint diseases. Although osteoarthritis(OA)is mainly a degradative condition of the articular cartilage induced by mechanical stress, there is a growing body of data demonstrating the involvement of metabolic factors including fat metabolism. Recent studies have revealed that adipokines including adiponectin and leptin are associated with inflammation of rheumatoid arthritis. A better understanding of these relationships may lead to new strategies to treat or prevent joint disease such as OA.

Role of Galectin-3 in Bone Cell Differentiation, Bone Pathophysiology and Vascular Osteogenesis

Galectin-3 is expressed in various tissues, including the bone, where it is considered a marker of chondrogenic and osteogenic cell lineages. Galectin-3 protein was found to be increased in the differentiated chondrocytes of the metaphyseal plate cartilage, where it favors chondrocyte survival and cartilage matrix mineralization. It was also shown to be highly expressed in differentiating osteoblasts and osteoclasts, in concomitance with expression of osteogenic markers and Runt-related transcription factor 2 and with the appearance of a mature phenotype. Galectin-3 is expressed also by osteocytes, though its function in these cells has not been fully elucidated. The effects of galectin-3 on bone cells were also investigated in galectin-3 null mice, further supporting its role in all stages of bone biology, from development to remodeling. Galectin-3 was also shown to act as a receptor for advanced glycation endproducts, which have been implicated in age-dependent and diabetes-associated bone fragility. Moreover, its regulatory role in inflammatory bone and joint disorders entitles galectin-3 as a possible therapeutic target. Finally, galectin-3 capacity to commit mesenchymal stem cells to the osteoblastic lineage and to favor transdifferentiation of vascular smooth muscle cells into an osteoblast-like phenotype open a new area of interest in bone and vascular pathologies.

Magnetic resonance imaging of posterolateral plica of the elbow joint: Asymptomatic vs. symptomatic subjects

Background

Magnetic resonance imaging (MRI) may be useful to diagnose a posterolateral plica syndrome of the elbow joint because this syndrome has less clear clinical features. The purposes of this study were to document mediolateral and sagittal dimensions of a posterolateral synovial fold and to determine the proportion of subjects with the posterolateral plica in asymptomatic elbows. We also aimed to determine whether the dimensions of the posterolateral synovial fold and the prevalence of the plica differ between symptomatic and asymptomatic subjects.

Materials and methods

This retrospective review of prospectively collected data included 50 asymptomatic elbows (asymptomatic group) and 14 elbows with arthroscopically confirmed posterolateral plicae (plica group). The mediolateral and sagittal dimensions of the posterolateral synovial fold were measured. In addition, the criteria for the prevalence of posterolateral plica was determined with conventional MRI as synovial fold dimension ≥ 3 mm and coverage of radial head by synovial fold ≥ 30%.

Results

The plica group showed larger posterolateral synovial fold dimensions compared to the asymptomatic group. The median mediolateral and sagittal dimensions of the synovial fold in the asymptomatic group were 3.8 mm and 4.7 mm, respectively. Dimensions in the plica group were 7.0 mm and 7.4 mm, respectively. When the presence of posterolateral plica was determined using the dimension criteria, there was no difference in the prevalence of the plica between the asymptomatic and the plica group. However, using the coverage criteria, the prevalence of posterolateral elbow plica was significantly greater in the plica group than the asymptomatic group (64% vs. 18%; p < 0.001).

Conclusions

The patients who underwent arthroscopic surgery for posterolateral plica syndrome had larger dimensions of the posterolateral synovial fold and higher prevalence of the posterolateral plica on conventional MRI compared to the asymptomatic subjects.

[CONNECTIVE TISSUE METABOLIC FEATURES IN CLIMACTERIC SYNDROME'S PATIENTS WITH VARIOUS TYPES OF MENOPAUSE]

The purpose of the study was investigation of the connective tissue metabolic features among women with menopausal syndrome (MS) and MS, in which the arthropathic syndrome is leading and comparative analysis of the connective tissue indicators exchange during menopause caused in a surgical and natural way. We examined 70 women in total, menopause duration they accounted for 1,95±1,1 years, it came both as natural, and as a result of a surgery. The main group included 40 women with MS with leading arthropathic syndrome. The patients' modified menopausal index was calculated (MMI), the functional condition of the joints was assessed on a scale-questionnaire with the calculation of the clinical-functional index of WOMAC; the quantitative content and qualitative composition of glycosaminoglycans in the serum, the urinary excretion of hydroxyproline and uronic acids were determined. To determine the degree of deviation from the control (standard) indicators was used non-parametric Mann-Whitney criterion and factor analysis (main components method). It was revealed that all patients have an increased content of glycosaminoglycans and glycoprotein in the blood, which corresponds to the general age-related rearrangement of connective tissue metabolism, but the patients of the main group have more expressed indictors, which corresponds to more severe dystrophic changes and the severity of clinical symptoms. Redistribution of the fractional composition of glycosaminoglycans towards the increase of chondroitin-6 sulfate in patients of the main group indicates the presence of pre-emptive destruction of cartilage. The arthropathic syndrome availability also confirms the significant reduction CI-6s / CI-4s ratio and an increased content of chondroitin sulfates. Patients with a natural type of menopause showed more pronounced changes in connective tissue metabolites, in contrast to patients with surgical menopause еhat indicates a longer and more invasive pathologic course of natural menopause.

Cartilage biomarkers in the osteoarthropathy of alkaptonuria reveal low turnover and accelerated ageing

OBJECTIVE

Alkaptonuria (AKU) is a rare autosomal recessive disease resulting from a single enzyme deficiency in tyrosine metabolism. As a result, homogentisic acid cannot be metabolized, causing systemic increases. Over time, homogentisic acid polymerizes and deposits in collagenous tissues, leading to ochronosis. Typically, this occurs in joint cartilages, leading to an early onset, rapidly progressing osteoarthropathy. The aim of this study was to examine tissue turnover in cartilage affected by ochronosis and its role in disease initiation and progression.

METHODS

With informed patient consent, hip and knee cartilages were obtained at surgery for arthropathy due to AKU (n = 6; 2 knees/4 hips) and OA (n = 12; 5 knees/7 hips); healthy non-arthritic (non-OA n = 6; 1 knee/5 hips) cartilages were obtained as waste from trauma surgery. We measured cartilage concentrations (normalized to dry weight) of racemized aspartate, GAG, COMP and deamidated COMP (D-COMP). Unpaired AKU, OA and non-OA samples were compared by non-parametric Mann-Whitney U test.

RESULTS

Despite more extractable total protein being obtained from AKU cartilage than from OA or non-OA cartilage, there was significantly less extractable GAG, COMP and D-COMP in AKU samples compared with OA and non-OA comparators. Racemized Asx (aspartate and asparagine) was significantly enriched in AKU cartilage compared with in OA cartilage.

CONCLUSIONS

These novel data represent the first examination of cartilage matrix components in a sample of patients with AKU, representing almost 10% of the known UK alkaptonuric population. Compared with OA and non-OA, AKU cartilage demonstrates a very low turnover state and has low levels of extractable matrix proteins.

An Analysis of Pathological Activities of CCN Proteins in Joint Disorders: Mechanical Stretch-Mediated CCN2 Expression in Cultured Meniscus Cells

The multifunctional growth factor CYR61/CTGF/NOV (CCN) 2, also known as connective tissue growth factor, regulates cellular proliferation, differentiation, and tissue regeneration. Recent literatures have described important roles of CCN2 in the meniscus metabolism. However, the mechanical stress-mediated transcriptional regulation of CCN2 in the meniscus remains unclear. The meniscus is a fibrocartilaginous tissue that controls complex biomechanics of the knee joint. Therefore, the injured unstable meniscus has a poor healing potential especially in the avascular inner region. In addition, dysfunction of the meniscus correlates with the progression of degenerative knee joint disorders and joint space narrowing. Here, we describe an experimental approach that investigates the distinct cellular behavior of inner and outer meniscus cells in response to mechanical stretch. Our experimental model can analyze the relationships between stretch-induced CCN2 expression and its functional role in the meniscus homeostasis.

Osteonecrosis diagnosed on MR images of the knee: Relationship to reduced bone mineral density determined by high resolution peripheral quantitative CT

Purpose: To evaluate if osteonecrosis diagnosed on MR images of the knee relates to reduced bone mineral density (BMD) and may be caused by an insufficiency fracture.

Material and Methods: Thirty-two consecutive patients (8 men, 24 women; age range 27–82 years, mean 62 years) with MR findings of osteonecrosis of the femoral or tibial condyle were prospectively included. Trabecular and cortical BMD were measured with high resolution peripheral quantitative CT in the non-dominant distal radius and the tibia of the involved extremity. One tibia was not measured due to posttraumatic deformity.

Results: The mean trabecular BMD of the radius was 81% of the young-adult average peak BMD (range 19–160%). The mean cortical BMD in the radius was 86% (range 63–108%). The mean trabecular BMD in the tibia was 92% (range 28–160%). The mean cortical BMD in the tibia was 86% (range 49–132%). The values of the trabecular bone of the distal radius (tibia) were normal in 11 (15) patients, osteopenic in 12 (4), and osteoporotic in 9 (12), respectively. The cortical bone values of the distal radius (tibia) were normal in 12 (13) patients, osteopenic in 12 (12), and osteoporotic in 8 (6), respectively.

Conclusion: Osteoporosis and osteopenia are commonly found in patients with osteonecrosis of the knee as diagnosed on MR images. This indicates that for some patients an insufficiency mechanism may be responsible for the MR findings. However, in the patients with normal bone density other reasons for osteonecrosis may be present.

Effect of Vitamin D on Joint Replacement Outcomes

Vitamin D is a steroid hormone that affects not only bone metabolism and strength but also a variety of musculoskeletal health and surgical outcomes that are relevant to orthopaedic medicine. Risk factors for vitamin D deficiency include sex, age, skin pigmentation, obesity, and preexisting conditions such as nephritic syndrome and malabsorption syndrome. Furthermore, vitamin D deficiency is associated with the development of postoperative complications, such as an increased risk of infection, morbidity, and mortality. The standardization of vitamin D terminology as well as a thorough understanding of the medical considerations associated with vitamin D deficiency can improve preoperative planning and clearance, and, ultimately, patient outcomes and satisfaction.

Inflammatory signaling induced bone loss

A broad spectrum of inflammatory disorders have the capacity to target the skeleton and to de-regulate the processes of physiological bone remodeling. This review will focus on the systemic inflammatory rheumatologic disorders, which target articular and peri-articular bone tissues. Many of these disorders also affect extra-articular tissues and organs, and in addition, have the capacity to produce systemic bone loss and increased risk of osteoporotic fractures. Attention will focus on rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and the seronegative spondyloarthropathies (SpAs), which include ankylosing spondylitis (AS), reactive arthritis (formerly designated as Reiter's syndrome), the arthritis of inflammatory bowel disease, juvenile onset spondyloarthropathy and psoriatic arthritis. The discussion will principally focus on RA, which is a prototypical model of an inflammatory disorder that de-regulates bone remodeling, but also will review the other forms of inflammatory joint disease to highlight the differential effects of inflammation on bone remodeling in these conditions. This article is part of a Special Issue entitled "Muscle Bone Interactions".

Human xylosyltransferases--mediators of arthrofibrosis? New pathomechanistic insights into arthrofibrotic remodeling after knee replacement therapy

Total knee replacement (TKR) is a common therapeutic option to restore joint functionality in chronic inflammatory joint diseases. Subsequent arthrofibrotic remodeling occurs in 10%, but the underlying pathomechanisms remain unclear. We evaluated the association of xylosyltransferases (XT), fibrotic mediators catalyzing glycosaminoglycan biosynthesis, leading to arthrofibrosis as well as the feasibility of using serum XT activity as a diagnostic marker. For this purpose, synovial fibroblasts (SF) were isolated from arthrofibrotic and control synovial biopsies. Basal α-smooth muscle actin expression revealed a high fibroblast-myofibroblast transition rate in arthrofibrotic fibroblasts. Fibrotic remodeling marked by enhanced XT activity, α-SMA protein expression as well as xylosyltransferase-I, collagen type III-alpha-1 and ACTA2 mRNA expression was stronger in arthrofibrotic than in control fibroblasts treated with transforming growth factor-β1 (TGF-β1). Otherwise, no differences between serum levels of XT-I activity or common fibrosis markers (galectin-3 and growth differentiation factor-15 levels (GDF-15)) were found between 95 patients with arthrofibrosis and 132 controls after TKR. In summary, XT-I was initially investigated as a key cellular mediator of arthrofibrosis and a target for therapeutic intervention. However, the blood-synovial-barrier makes arthrofibrotic molecular changes undetectable in serum. Future studies on monitoring or preventing arthrofibrotic remodeling should therefore rely on local instead of systemic parameters.

Articular nodular fasciitis of the right shoulder joint: report of an unusual case with focus on immunohistochemical differential diagnosis

The mesenchymal lesion nodular fasciitis (NF) can affect various sites of the body but usually arises in subcutaneous tissue or occasionally skeletal muscle. NF is not commonly known to arise in joints, and articular NF is extremely rare. Herein, we present a case of a 54-year-old woman with articular NF. No sign of recurrence was observed after surgical piecemeal removal with a suspected positive surgical margin. In our case, a differential diagnosis of NF, desmoid-type fibromatosis, and low-grade myofibroblastic sarcoma was considered. Stromal hyalinization, a characteristic of articular NF, made the diagnosis somewhat difficult, although typical NF morphology was present. Immunohistochemical analysis of α-smooth muscle actin, desmin, β-catenin, and protein gene product 9.5 expression along with close morphological examination provided a reliable distinction.

Novel cartilage oligomeric matrix protein (COMP) neoepitopes identified in synovial fluids from patients with joint diseases using affinity chromatography and mass spectrometry

To identify patients at risk for progressive joint damage, there is a need for early diagnostic tools to detect molecular events leading to cartilage destruction. Isolation and characterization of distinct cartilage oligomeric matrix protein (COMP) fragments derived from cartilage and released into synovial fluid will allow discrimination between different pathological conditions and monitoring of disease progression. Early detection of disease and processes in the tissue as well as an understanding of the pathologic mechanisms will also open the way for novel treatment strategies. Disease-specific COMP fragments were isolated by affinity chromatography of synovial fluids from patients with rheumatoid arthritis, osteoarthritis, or acute trauma. Enriched COMP fragments were separated by SDSPAGE followed by in-gel digestion and mass spectrometric identification and characterization.Using the enzymes trypsin, chymotrypsin, and Asp-N for the digestions, an extensive analysis of the enriched fragments could be accomplished. Twelve different neoepitopes were identified and characterized within the enriched COMP fragments. For one of the neoepitopes, Ser77, an inhibition ELISA was developed. This ELISA quantifies COMP fragments clearly distinguishable from total COMP. Furthermore, fragments containing the neoepitope Ser77 were released into the culture medium of cytokine (TNF-α and IL-6/soluble IL-6 receptor)-stimulated human cartilage explants. The identified neoepitopes provide a complement to the currently available commercial assays for cartilage markers. Through neoepitope assays, tools to pinpoint disease progression, evaluation methods for therapy, and means to elucidate disease mechanisms will be provided.

A naturally occurring single amino acid replacement in multiple gene regulator of group A Streptococcus significantly increases virulence

Single-nucleotide polymorphisms (SNPs) are the most common source of genetic variation within a species; however, few investigations demonstrate how naturally occurring SNPs may increase strain virulence. We recently used group A Streptococcus as a model pathogen to study bacteria strain genotype-patient disease phenotype relationships. Whole-genome sequencing of approximately 800 serotype M59 group A Streptococcus strains, recovered during an outbreak of severe invasive infections across North America, identified a disproportionate number of SNPs in the gene encoding multiple gene regulator of group A Streptococcus (mga). Herein, we report results of studies designed to test the hypothesis that the most commonly occurring SNP, encoding a replacement of arginine for histidine at codon 201 of Mga (H201R), significantly increases virulence. Whole transcriptome analysis revealed that the H201R replacement significantly increased expression of mga and 54 other genes, including many proven virulence factors. Compared to the wild-type strain, a H201R isogenic mutant strain caused significantly larger skin lesions in mice. Serial quantitative bacterial culture and noninvasive magnetic resonance imaging also demonstrated that the isogenic H201R strain was significantly more virulent in a nonhuman primate model of joint infection. These findings show that the H201R replacement in Mga increases the virulence of M59 group A Streptococcus and provide new insight to how a naturally occurring SNP in bacteria contributes to human disease phenotypes.

[Progress on microRNA in aseptic loosening of prostheses]

MicroRNA(miRNA) is a class of non-coding RNA that plays an important role in gene expression and controlling. In recent years,the role of miRNA in the development of the disease has aroused great interest. Abnormal osteoclastogenesis and persistent inflammatory response induced by wear particles or osteoblast differentiation and maturation is the main cause of aseptic loosening in joint replacements. New researches shows that persistent inflammatory response, osteoclastogenesis and osteoblast differentiation are closely associated with miRNA, suggesting that there are certain relations between miRNA and aseptic loosening of prostheses. Additionally, the alteration of the expression levels of some miRNA may be curative for aseptic loosening. With the findings of the new miRNA targets, the important role of miRNA is further confirmed.

Characterization of joint disease in mucopolysaccharidosis type I mice

Mucopolysaccharidoses (MPS) are lysosomal storage disorders characterized by mutations in enzymes that degrade glycosaminoglycans (GAGs). Joint disease is present in most forms of MPS, including MPS I. This work aimed to describe the joint disease progression in the murine model of MPS I. Normal (wild-type) and MPS I mice were sacrificed at different time points (from 2 to 12 months). The knee joints were collected, and haematoxylin-eosin staining was used to evaluate the articular architecture. Safranin-O and Sirius Red staining was used to analyse the proteoglycan and collagen content. Additionally, we analysed the expression of the matrix-degrading metalloproteinases (MMPs), MMP-2 and MMP-9, using immunohistochemistry. We observed progressive joint alterations from 6 months, including the presence of synovial inflammatory infiltrate, the destruction and thickening of the cartilage extracellular matrix, as well as proteoglycan and collagen depletion. Furthermore, we observed an increase in the expression of MMP-2 and MMP-9, which could conceivably explain the degenerative changes. Our results suggest that the joint disease in MPS I mice may be caused by a degenerative process due to increase in proteases expression, leading to loss of collagen and proteoglycans. These results may guide the development of ancillary therapies for joint disease in MPS I.

Histomorphologic changes of the long head of the biceps tendon in common shoulder pathologies

PURPOSE

To assess molecular and histologic differences between the proximal (intra-articular) and distal (extra-articular) portions of the long head of the biceps (LHB) tendon in 3 different disease states (biceps instability, tendinosis, and degenerative joint disease [DJD]) compared with a healthy tendon (fresh frozen).

METHODS

We used 32 LHB tendons of patients undergoing tenodesis (mean age, 54.7 ± 10.1 years) and 9 harvested tissue donors. Tendons were divided according to 4 diagnostic groups: (1) biceps instability, (2) tendinosis, (3) DJD, and (4) normal control. After sectioning, tendons were fixed in formalin and stained with H&E and alcian blue for histologic analysis. Measurements of collagen organization by use of polarized light microscopy was then performed, and protein expression for type I and type III collagen, tenascin C, and decorin was determined.

RESULTS

There were no statistical differences found for protein expression of type I or type III collagen, tenascin C, or decorin. The proximal and distal regions of the tendons had statistically significant differences in alcian blue staining, with the proximal portion containing a higher amount of proteoglycan (instability, P = .001; tendinosis, P = .005; DJD, P = .008; control, P = .011). When compared with the nonpathologic control tendons, a significant increase in alcian blue staining for the proximal region was seen in all 3 groups. Total polarized light analysis showed that the distal tendon had a significantly higher intensity (organization) compared with the proximal tendon (P < .001); this was also seen in all of the diagnostic groups (instability, P = .010; tendinosis, P = .013; DJD, P = .07; control, P = .028).

CONCLUSIONS

This study showed a greater degree of degeneration of the proximal (intra-articular) regions of the LHB tendon when compared with the distal regions in all pathologic groups. However, no major differences at the cellular level were found among groups.

CLINICAL RELEVANCE

The pathomechanisms of the various forms of known LHB diagnoses are not yet fully understood and basic science studies may help in understanding their etiology and therefore optimizing treatment options.

[Effects of Yiqi Huayu prescription on knee cartilage degeneration in HIF-1alpha gene knockout mice]

OBJECTIVE

To study the role of hypoxia-inducible factor 1 alpha (HIF1alpha) on knee cartilage degeneration,and to explore the effects and mechanisms of Chinese herbal compound Yiqi Huayu prescription on HIF-1alpha gene knockout mice on knee cartilage degeneration.

METHODS

The 4-month and 6-month HIF-1alpha gene knock out mice were obtained by interbreeding, and divided into HIF-1alpha +/+ 4-month mice group,HIF-1alpha -/- 4-month mice group,HIF-1alpha +/+ 6-month mice group and HIF-1alpha -/- 6-month mice group, 3 mice in each group. And then the 2-month-old HIF-1alpha gene knock out mice were randomly divided into Yiqi Huayu prescription group and physiological saline group. There were 6 mice in each group. After 2 months' drug administration, the knee joint of mice was collected, and the Mankin score were evaluated; Safranine-fast green staining, HE Staining, and immunohistochemistry analysis for VEGF, Col X, Col II, MMP-13 and Sox-9 were performed erespectively.

RESULTS

(1) Compared to the results in the HIF-1alpha+/+ mice groups, the HIF-1alpha-/- mice developed aging related cartilage loss and bony tissue appearance, cartilage defects increased,and cells reduced. In HIF-1alpha-/-4-month mice and 6-month mice group, the expresion of Col II and Sox9 decreased, and the expression of Col X, MMP-13 and VEGF increased. (2) Compared to the physiological saline group, the ossification and defect of knee joint cartilage reduced of mice in the Yiqi Huayu prescription group, the cartilage cell distribution was more uniform, and the total number of cells increased. The expression of type II collagen and Sox9 protein increased, expression of Col X, MMP-13 and VEGF protein decreased of mice in the Yiqi Huayu prescription group.

CONCLUSION

The knee cartilage degenerates in the HIF-1alpha cKO mice, and the degeneration increased with age adding. The Yiqi Huayu prescription can delay the degeneration of knee cartilage of HIF-1alpha cKO mice.

Levels of Cr, Co, Ni and Mo in erythrocytes, serum and urine after hip resurfacing arthroplasty

BACKGROUND

Hip resurfacing arthroplasty is known to increase the metal ion concentration in the serum, urine and whole blood, with potentially adverse effects on the organism. However, only few data are available about the metal ion concentrations in erythrocytes, although they are directly exposed to the higher concentrations of the serum.

METHODS

The ion levels of chromium, cobalt, nickel and molybdenum in erythrocytes of 25 patients with a hip resurfacing implant were analysed with high resolution ICP-sf-MS (inductively-coupled-plasma-sector-field-mass-spectrometry). The results were compared to the ion levels in the serum and urine of the patients, and also to the ion levels of 27 control persons without an implant.

RESULTS

Compared to the control group, ion levels in the erythrocytes of the hip resurfacing group were markedly increased for cobalt (0.10 vs. 3.26 microg/kg) and slightly for chromium (6.04 vs. 7.38 microg/kg). In contrast, ion levels in the serum of the hip resurfacing group were increased for cobalt (0.21 vs. 1.92 microg/l), chromium (1.48 vs. 5.64 microg/l), nickel (1.53 vs. 4.25 microg/l) and molybdenum (2.17 vs. 3.78 microg/l).

CONCLUSION

Ion concentrations of cobalt and chromium are also increased in erythrocytes after hip resurfacing arthroplasty. Further research is required to evaluate the impact of the elevated ion levels on the erythrocytes, and to evaluate if metal ions also accumulate in other tissues of the body.

Limited joint mobility in childhood diabetes: discovery, description, and decline

CONTEXT

The discovery of limited joint mobility (LJM) as the earliest clinically apparent complication of diabetes in children and adolescents nearly 40 years ago provided insights into the mechanism of diabetes complications.

RESULTS

LJM, due to periarticular connective tissue thickening and stiffness, varied from single joint involvement bilaterally to obvious hand deformity and limitation of movement of the spine. Thick, tight, waxy skin was apparent with more severe changes; biopsy indicated thickening of the dermis and epidermis with accumulation of collagen and loss of skin appendages. Substantial growth impairment was associated with all levels of LJM. Risk for microvascular disease over a 16-year period was actuarially increased nearly 4-fold by the presence of LJM. Long-term glycemic control influenced the onset of LJM; for every unit increase in average glycated hemoglobin from onset there was a 46% increase in the risk of LJM. Between 1976-78 and 1998, the prevalence of LJM decreased from 30 to 7%, and the portion with moderate to severe changes decreased from 33 to 14%, with the disappearance of severely affected individuals. Furthermore, growth data markedly improved for those with and without LJM; 30% without LJM and 77% with LJM had been less than the 25th percentile for height, whereas the more contemporary group had 22% without LJM and 33% with LJM in this quartile.

CONCLUSIONS

The elucidation of LJM as a novel and informative early complication of pediatric diabetes has provided insights into the evolution of the severe long-term complications of diabetes. The marked decrease in the frequency of LJM and statural deficit in children and youth with diabetes in the 20 years between the late 1970s and 1990s can be attributed to improved metabolic control of children and adolescents. The prevalence of LJM in a population may serve as a measure of quality of diabetes control.

Increased BMP expression in arthrofibrosis after TKA

PURPOSE

Because of the multiple possible aetiologies of painful total knee arthroplasty (TKA), the diagnosis and treatment of such patients are challenging. In a considerable number of patients, an intraarticular pathology is present, although not verifiable with clinical and diagnostic imaging techniques as in cases of primary arthrofibrosis. In these patients, the differentiation between intra- and extraarticular causes of pain remains difficult. Until now, little attention has been paid to changes of the synovial fluid and tissue in these knees. The objective of this study was to analyse the changes of the synovial environment in patients suffering from arthrofibrosis after TKA in comparison with knees with referred pain suffering from hip arthritis. The changes of the synovial environment probably provide additional diagnostic information to verify an intraarticular pathology.

METHODS

The synovial fluid of 10 consecutive knees in 10 patients presenting with a primary arthrofibrosis after TKA without signs of infection, instability, malalignment, or loosening was analysed and compared to the synovial fluid of 10 knees with referred pain serving as controls. The BMP-2 concentration was measured in the synovial fluid, and the presence of cytokines leading to an overexpression of BMP-2 was detected by measuring the change of BMP-2 expression in a synoviocyte cell line following exposing to the synovial fluid of the patients.

RESULTS

The concentration of BMP-2 in the synovial fluid was significantly higher in arthrofibrotic TKA knees (24.3 ± 6.9 pg/mL), compared with the control group 5.9 ± 4.8 pg/mL (P < 0.001). Corresponding to this finding, BMP-2 expression in synoviocytes was upregulated 11.5-fold (P < 0.05) by synovial fluid of patients suffering from arthrofibrosis after TKA, compared with the control group with referred pain.

CONCLUSION

BMP-2 is overexpressed and its concentrations are consequently higher in patients suffering from arthrofibrosis after TKA. The synovial BMP-2 concentration may be a potential marker for differentiating between intra- and extraarticular causes of pain.

LEVEL OF EVIDENCE

II.

Kirenol exerts a potent anti-arthritic effect in collagen-induced arthritis by modifying the T cells balance

Rheumatoid arthritis is characterized by the imbalance of T cells, which leads to increased pro-inflammatory and reduced anti-inflammatory cytokines. Modulating the balance among T cells is crucial for the treatment of RA. Kirenol is a major diterpenoid components of Herba Siegesbeckiae, which has been applied for arthritic therapy for centuries. Since prior research showed Kirenol exhibited anti-inflammatory effect in rats, in this study we have evaluated the effect and mechanism of bioactive Kirenol in a rat model of collagen-induced arthritis (CIA) on modulation of T cells. After immunization with bovine type II collagen (CII), Wistar rats were orally administered saline (CIA group), 2 mg/kg Kirenol or 2 mg/kg prednisolone daily for 30 days. The severity of arthritis was clinically and histologically assessed. The numbers of CD4⁺CD25⁺Foxp3⁺ T regulatory cells (Tregs) and IFNγ⁺CD4⁺ and IL4⁺CD4⁺ T cells were determined by flow cytometry, the mRNA expression level of Foxp3 was quantified by RT-PCR, cytokine levels were measured by ELISA and CII-induced cell proliferation was quantified in vitro. Kirenol significantly delayed the occurrence and reduced the disease severity of CIA. Histological analysis confirmed Kirenol suppressed joint inflammation and inhibited cartilage and bone destruction, compared to the CIA group. Kirenol also upregulated the mRNA expression of Foxp3, increased the numbers of CD4⁺CD25⁺Foxp3⁺ and IL4⁺CD4⁺ T cells, and reduced the number of IFNγ⁺CD4⁺ T cells. Kirenol reduced the levels of TNF-α, IL-17A and IL-6 in synovial fluid and TNF-α, IL-17A and IFN-γ in serum, and increased the serum levels of IL-4, IL-10 and TGF-β1. In addition, Kirenol inhibited the ability of CII to induce splenocyte, PBMC and lymph node cell proliferation in vitro, compared to cells from CIA rats. In conclusion, these results suggest that Kirenol may be a potential immunosuppressant for the treatment for rheumatoid arthritis.

Glucocorticoids in bone and joint disease: the good, the bad and the uncertain

Therapeutic glucocorticoids are widely used to treat a variety of inflammatory conditions. However, the beneficial anti-inflammatory effects of glucocorticoids are limited by their detrimental effects on bone, including decreased bone density and increased fracture risk. Glucocorticoids adversely affect bone because they inhibit the amount of bone formed by osteoblasts. Surprisingly, through the expression of the 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) enzyme, osteoblasts can generate active glucocorticoids (cortisol and/or prednisolone) from their inactive counterparts (cortisone and/or prednisone). 11beta-HSD1 activity in an individual predicts the impact of glucocorticoids on bone. 11beta-HSD1 expression within bone also increases with age and inflammation. This implicates locally produced glucocorticoids in age-related and inflammation-associated osteoporosis. Glucocorticoids are also generated by synovial tissue through the expression of 11beta-HSD1. Activity increases with joint inflammation and could represent a local anti-inflammatory system. The recognition that peripheral tissues generate glucocorticoids suggests that, for conditions associated with ageing or inflammation, one should consider glucocorticoid activity beyond the circulation.

The role of selected metalloproteinases in cheiroarthropathy in children with type 1 diabetes - a pilotage study

BACKGROUND

Metalloproteinases of the external matrix play an important role in ethiopatogenesis of diabetic complications especially in microangiopathy and also in fibrosing processes with occurrence the cheiroarthropathy, but clinical data are insufficient.

AIMS

The aim of the study was to assess the influence of metalloproteinases such as gelatinase A (MMP2) and gelatinase B (MMP9), and their tissue inhibitors (TIMP2, TIMP9) in ethiopathogenesis of cheiroatrhopathy in children with diabetes type 1.

MATERIALS AND METHODS

  Forty one children were observed in average age of 14.98 years (±3.03 years), with the average duration of diabetes 6.78 years (±3.21 years), and with average HbA1c within all diabetes duration time 7.1% (6.47-7.5%). In all patients, the occurrence of cheiroarthropathy was checked, and concentration of metalloproteinase's and their inhibitors in serum were measured using ELISA method. Probe was divided into two groups because of presence of cheiroarthropathy. The comparing analysis of these two groups was conducted, and the correlation between metalloproteinase's concentration and their tissue inhibitors with selected parameters was done.

RESULTS

  When comparing group with cheiroarthropathy (n = 19) with the group without cheiroarthropathy (n = 22), the statistically significant elevated levels of metalloproteinase's were proved such as: MMP2 - 202 ng/ml (193-207) vs. 138 ng/ml (130-158), p < 0.001; MMP9 - 462 ng/ml (426-505) vs. 288 ng/ml (251-313), 0.001; TIMP2 - 182 ng/ml (177-190) vs. 104 ng/ml (88-165), p < 0.001); TIMP9 - 85 ng/ml (68-95) vs. 55 ng/ml (50-60), p < 0.001. There was no correlation between occurrence of cheiroarthropathy and age of the diabetes onset, duration of diabetes, grade of metabolic compensation, insulin dosages, weight and height.

CONCLUSION

  In children with long-term diabetes, although relatively metabolic compensation, the cheiroarthropathy has been occurred accompanying by elevated concentrations of metalloproteinase's and their tissue inhibitors. The presence of cheiroarthropathy could be treated as a simple test to identification the patients endangered to develop chronic vascular complication.

Quantitative genetic study of amphiregulin and fractalkine circulating levels--potential markers of arthropathies

OBJECTIVE

Amphiregulin (AREG) and Fractalkine (FRACT), are involved in a variety of normal and pathological processes, and are both suggested to be relevant to joint degeneration. The aims of the present study included (1) testing association between circulating levels of these biomarkers and joint pathologies, (2) evaluation of the putative genetic and familial factors' effect on AREG and FRACT variability.

DESIGN

The study was conducted in the family-based sample of 923 Caucasian individuals. Variance component analysis was used to assess contribution of genetic and environmental factors to variability of AREG and FRACT concentration.

RESULTS

The mean levels of FRACT were significantly higher in the affected group with arthropathies (synovial joints osteoarthritis (OA) and disc degenerative disease, DDD) then in the control group (P<0.0004). Circulating AREG levels were higher in DDD (P=0.0272). Genetic factors constituted the main source of the interindividual differences of the AREG and FRACT levels in our sample, and explained 29.68% and 41.68% of the total variation, respectively. The phenotypic correlation between AREG and FRACT was substantial (r=0.55, P=0.0001) and was associated with both common genetic and environmental factors. Specifically, 30% of the phenotypic correlation between AREG and FRACT was due to common genetic effects.

CONCLUSIONS

Further studies are required to assess relevancy of FRACT to clinical diagnosis and prognosis of arthropathies, to investigate the mechanisms behind the observed phenotypic and genetic covariation among the studied biomarkers, and to explore specific genetic polymorphisms affecting AREG and FRACT variation.

Alkaptonuria

A 69-year-old woman presented with a 30-year history of lower back and large joint pain of the hips and shoulders. On examination blue-grey, pigmented macules were present over the cartilaginous portions of the ears and on the sclera. Past medical history included aortic stenosis. Urine homogentisic acid level was elevated, which is diagnostic for alkaptonuria. Alkaptonuria is an autosomal recessive disorder that results in deficiency of homogentisic acid oxidase and in the accumulation of homogentisic acid in connective tissue. Disease can result in blue-grey pigmentation of the cartilage, sclerae, face, and hands as well as severe arthropathy and cardiac valve disease. Treatment is limited at this time. Promising early reports of the use of nitisinone have prompted ongoing trials of this therapeutic agent.

Upper limb musculoskeletal abnormalities and poor metabolic control in diabetes

INTRODUCTION

An increased prevalence of musculoskeletal disease is recognised in diabetes and is a common source of disability. It is known to predominantly affect the upper limbs especially the hand and shoulder. The relationship with other complications of diabetes and glycaemic control is uncertain. We designed this study to clarify these relationships, and to assess differences between types 1 and 2 diabetes.

METHODS

We identified a group of 96 people with established diabetes and examined them for the presence of locomotor disease focussing on the upper limbs. We recorded the mean HbA1c and the presence of diabetic complications, together with the health assessment questionnaire (HAQ) score. We explored correlations between locomotor disease and these variables using logistic regression. We compared data between type 1 and type 2 diabetics and contrasted the amalgamated data with that of a matched control population of medical out patients using Students t tests.

RESULTS

Locomotor disease was present in 75% of diabetics with the upper limb the commonest site for abnormalities. This prevalence was significantly higher than that seen in the controls (53%) [p=0.02]. Shoulder capsulitis (25%), carpal tunnel syndrome (20%), tenosynovitis (29%), limited joint mobility (28%) and Dupuytrens contracture (13%) were the most frequent findings and were much commoner than in controls. Capsulitis usually coexisted with other upper limb abnormalities and best predicted the presence of retinopathy and/or neuropathy. The mean HbA1c was significantly higher in patients with combined shoulder and hand problems (9.1%) than in those with no upper limb problems (8.0%) [p=0.018]. The pattern of results was similar in type 1 and type 2 diabetes, although the prevalence of abnormalities and mean HAQ were significantly greater in type 2 patients, which may be in part a function of their greater mean age.

CONCLUSION

Upper limb locomotor abnormalities are very common in diabetes and are associated with worse glycaemic control and more diabetic complications. Assessment of upper limb locomotor disease in diabetes should include an estimate of glycaemic control and a search for other complications.

Adipokines in the skeleton: influence on cartilage function and joint degenerative diseases

The discovery of leptin in 1994 marked the beginning of a new understanding about white adipose tissue (WAT) and modified a static vision of this tissue which was viewed up to the end of the 20th century as an inert tissue, devoted to body protection from heat loss and to passively storing energy. The identification of the product of the gene obese accentuated the role of adipose tissue in the physiopathology of obesity-linked diseases, and led to the discovery of various adipokines, many of a pro-inflammatory nature. It has become progressively manifest that WAT-derived adipokines can now be considered as the fulcrum between obesity-related environmental causes, such as nutrition and lifestyle, and the biochemical shifts that lead to metabolic syndrome, inflammatory and/or autoimmune conditions, and rheumatic diseases. Herein, we review recent adipokine research, with particular emphasis to the role of leptin, adiponectin, resistin, and visfatin in chondrocyte function and skeleton, as well as in inflammatory and degenerative cartilage joint diseases.

Mechanism of glycosaminoglycan-mediated bone and joint disease: implications for the mucopolysaccharidoses and other connective tissue diseases

We have previously shown that glycosaminoglycan (GAG) storage in animal models of the mucopolysaccharidoses (MPS) leads to inflammation and apoptosis within cartilage. We have now extended these findings to synovial tissue and further explored the mechanism underlying GAG-mediated disease. Analysis of MPS rats, cats, and/or dogs revealed that MPS synovial fibroblasts and fluid displayed elevated expression of numerous inflammatory molecules, including several proteins important for lipopolysaccharide signaling (eg, Toll-like receptor 4 and lipoprotein-binding protein). The expression of tumor necrosis factor, in particular, was elevated up to 50-fold, leading to up-regulation of the osteoclast survival factor, receptor activator of nuclear factor-kappaB ligand, and the appearance of multinucleated osteoclast-like cells in the MPS bone marrow. Treatment of normal synovial fibroblasts with GAGs also led to production of the prosurvival lipid sphingosine-1-phosphate, resulting in enhanced cell proliferation, consistent with the hyperplastic synovial tissue observed in MPS patients. In contrast, GAG treatment of normal chondrocytes led to production of the proapoptotic lipid ceramide, confirming the enhanced cell death we had previously observed in MPS cartilage. These findings have important implications for the pathogenesis and treatment of MPS and have further defined the mechanism of GAG-stimulated disease.

Enhanced alpha 1(I) mRNA expression in frozen shoulder and dupuytren tissue

The purpose of this study has been to investigate collagen I and III synthesis during the fibrosing stage of frozen shoulder and Dupuytren samples in comparison to normal capsule tissue. - By using the quantitative PCR significantly increased levels of alpha 1(I) mRNA transcription in samples of frozen shoulder (p = 0.016) and Duypuytren (p = 0.041) could be demonstrated, whereas alpha 2(I) and alpha 1(III) chains have shown the same mRNA levels as in normal capsule tissue. - Despite an enhancement of alpha 1(I) mRNA transcription in frozen shoulder and Dupuytren samples the intracellular precursor procollagen I and extracellular mature collagen I was detected immunohistochemically in reduced levels. - The structural alteration of collagen I assembly might be caused by disturbed post-translation from the polypeptide chains into the triple helices procollagen I though alpha 1(I) mRNA transcription was significantly increased and alpha 2(I) mRNA transcription was in normal range. Fibroblasts might release high quantities of free alpha 1(I) polypeptide chains or (alpha 1(I)) 3 homotrimer into the extracellular space during the fibrosing stage of frozen shoulder and Dupuytren disease. - In all samples neither differences of alpha 1(III) mRNA transcription nor differences of immunohistochemical staining intensity of collagen III could be seen. This might result from apoptosis of myofibroblasts in the final phase of the fibrosing processes. - The stimulating effect of insulin-like growth factor type I (IGF-I) to induce fibrosis in connective tissue such as scarlet is known. In all patients suffering from frozen shoulder and Dupuytren disease the serum IGF-I level was in a normal range and the IGF-I receptor - (IGFR-I) mRNA transcription in the samples was also in the same level compared with normal capsule tissue.

A simplified method of determining synovial fluid chondroitin sulfate chain length

OBJECTIVE

To determine whether dimethylmethylene blue (DMMB) analysis, when combined with agarose gel filtration chromatography (Superose 6), can be performed instead of fluorophore-assisted carbohydrate electrophoresis (FACE) to determine chondroitin sulfate (CS) chain length in synovial fluid (SF).

METHODS

SF was obtained from (1) normal horses after 8 weeks of rest, (2) the same horses after 9 months of treadmill training, and (3) horses with osteochondral (OC) injury from racing. SF CS concentrations and chain lengths were determined by gel chromatography and DMMB analysis and compared with previous results determined by FACE analysis on the same samples.

RESULTS

DMMB analysis showed that SF CS peak chain length in the OC injury group increased significantly (18.7 kDa) when compared to rested and exercised normal horses (15.6 kDa). The assay had a positive predictive value of 71% and a negative predictive value of 75% for discriminating between normal and injured joints.

CONCLUSIONS

We report a simple and inexpensive DMMB analysis of SF CS chain length, which, when coupled with Superose 6 chromatography, discriminates between normal and post-injury joints. Similar to our previous FACE analysis results [Brown MP, Trumble TN, Plaas AHK, Sandy JD, Romano M, Hernandez J, et-al. Exercise and injury increase chondroitin sulfate chain length and decrease hyaluronan chain length in synovial fluid. Osteoarthritis Cartilage 2007;15], our DMMB results show an increase in the chain length of the CS in the SF of injured joints.

Cytokine mRNA expression in synovial fluid of affected and contralateral stifle joints and the left shoulder joint in dogs with unilateral disease of the stifle joint

OBJECTIVE

To examine mRNA expression of cytokines in synovial fluid (SF) cells from dogs with cranial cruciate ligament (CrCL) rupture and medial patellar luxation (MPL) and determine mRNA expression for 3 joints (affected stifle, unaffected contralateral stifle, and left shoulder joints) in dogs with unilateral CrCL rupture.

SAMPLE POPULATION

29 stifle joints with CrCL rupture (29 dogs), 8 stifle joints with MPL (7 dogs), and 24 normal stifle joints (16 clinically normal dogs).

PROCEDURES

Immediately before reconstructive surgery, SF was aspirated from the cruciate-deficient stifle joint or stifle joint with MPL. Fourteen of 29 dogs had unilateral CrCL rupture; SF was also aspirated from the unaffected contralateral stifle joint and left shoulder joint. Those 14 dogs were examined 6 and 12 months after reconstructive surgery. Total RNA was extracted from SF cells and reverse transcription-PCR assay was performed to obtain cDNA. Canine-specific cytokine mRNA expression was determined by use of a real-time PCR assay.

RESULTS

Interleukin (IL)-8 and -10 and interferon-gamma expression differed significantly between dogs with arthropathies and dogs with normal stifle joints. For the 14 dogs with unilateral CrCL rupture, a significant difference was found for IL-8 expression. Before reconstructive surgery, IL-8 expression differed significantly between the affected stifle joint and left shoulder joint or contralateral stifle joint. Six months after surgery, IL-8 expression was significantly increased in the unaffected contralateral stifle joint, compared with the shoulder joint.

CONCLUSIONS AND CLINICAL RELEVANCE

No conclusions can be made regarding the role of the examined cytokines in initiation of CrCL disease.

Changes in hyaluronan concentration in tissues and body fluids in disease states

Proteins which specifically bind hyaluronan have been used to develop sensitive immunoassay-like analytical techniques. These assays have made it possible to analyse hyaluronan concentrations in nanogram amounts in tissues and body fluids. The normal adult human circulating level of hyaluronan varies between 10 and 100 micrograms/l. Increased levels of serum hyaluronan (greater than 1 mg/l) have been found in inflammatory rheumatic diseases such as rheumatoid arthritis, scleroderma and psoriatic arthritis. Even higher levels occur in serum from patients with cirrhotic liver diseases and in patients with malignant mesothelioma. Elevated serum hyaluronan levels are a sign either of increased production and/or outflow from the tissues or of decreased elimination of the polysaccharide in the liver endothelial cells or in other parts of the reticuloendothelial system or through the kidneys. The serum concentration is also influenced by increased age and by the degree of physical activity. Important information on pathological processes has been gained by analysing the hyaluronan concentration in other body fluids such as urine, perfusion fluid from the intestine and bronchoalveolar lavage fluid. In the future these analyses should also be useful in clinical work.