Aims. This study aimed to explore whether serum combined with synovial interleukin-6 (IL-6) measurement can improve the accuracy of prosthetic joint infection (PJI) diagnosis, and to establish the cut-off values of
Aims. Insufficient treatment response in rheumatoid arthritis (RA) patients requires novel treatment strategies to halt disease progression. The potential benefit of combination of cytokine-inhibitors in RA is still unclear and needs further investigation. To explore the impact of combined deficiency of two major cytokines, namely interleukin (IL)-1 and
Purpose: The role of the pro-inflammatory cytokine HMGB1 (alarmins) has not been investigated in the clinical setting. This study aims to assess its relationship to
Aims. In the repair of condylar cartilage injury, synovium-derived mesenchymal stem cells (SMSCs) migrate to an injured site and differentiate into cartilage. This study aimed to confirm that histone deacetylase (HDAC) inhibitors, which alleviate arthritis, can improve chondrogenesis inhibited by IL-1β, and to explore its mechanism. Methods. SMSCs were isolated from synovium specimens of patients undergoing temporomandibular joint (TMJ) surgery. Chondrogenic differentiation potential of SMSCs was evaluated in vitro in the control, IL-1β stimulation, and IL-1β stimulation with HDAC inhibitors groups. The effect of HDAC inhibitors on the synovium and condylar cartilage in a rat TMJ arthritis model was evaluated. Results. Interleukin (IL)-1β inhibited the chondrogenic differentiation potential of SMSCs, while the HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and panobinostat (LBH589), attenuated inhibition of IL-1β-induced SMSC chondrogenesis. Additionally, SAHA attenuated the destruction of condylar cartilage in rat TMJ arthritis model.
Aims. Synovial fluid white blood cell (WBC) count and percentage of polymorphonuclear cells (%PMN) are elevated at periprosthetic joint infection (PJI). Leucocytes produce different interleukins (IL), including
The role of the pro-inflammatory cytokine HMGB1 (alarmins) has not been investigated in the clinical setting. This study aims to assess its relationship to
Introduction: Abnormalities of mesenchymal stem cells and osteoblastic cells (Obs) might play a role in producing bone collapse due to insufficient repair of the necrotic area in osteonecrosis of the femoral head (ON). Osteoblast and osteocyte apoptosis should be increased at the osteonecrotic site. Materials and Methods: We compared the TRAIL (TNF-related apoptosis-inducing ligand) cytotoxicity in primary Obs isolated from femoral heads from patients with ON or osteoarthritis (OA) and on two human osteosarcoma cell lines, MG-63 and SaOS. 2. . Results and Discussion: We showed that ON but also OA Obs were sensitive to TRAIL. We also observed TRAIL cytotoxicity on MG-63 but not SaOS. 2. cells. Moreover, we saw that TRAIL negatively regulated Akt and ERK survival pathways in MG-63 cells. We also investigated the
Aims: As inflammation plays a key role in the etiology of intervertebral disc degeneration, we suggest a possible contribution of pro-inflammatory gene polymorphisms in the pathogenesis of adolescent idiopathic scoliosis (AIS). The nucleus pulposus of scoliotic discs responds to exogenous stimuli by secreting interleukin-6 (IL-6) and other inflammatory cytokines. The association between matrix metalloproteinases (MMPs) and disc degeneration has been reported by several investigators. A human MMP-3 promoter 5A/6A gene polymorphism regulates MMP-3 genes expression, while the G/C polymorphism of the promoter region of
Introduction: After a meniscus trauma, preservation of the meniscus is the most important surgical goal. The use of scaffolds colonized with meniscus cells (fibrochondrocytes) to reconstruct meniscal defects seem to be a promising way for the treatment of a meniscus trauma. The goal of our investigations was the analysis of expression of different anabolic and catabolic factors in human fibrochondrocytes after seeding these cells onto a collagen I scaffold to investigate the regenerative potential of such a construct for the treatment of meniscus tears. Material and Methods: Human meniscus tissue was digested in collagenase and dispase and cells were characterized by immunohistochemistry. To test scaffolds, we used a commercially available bovine collagen I matrix approved for surgical purposes. The scaffold was colonized with human fibrochondrocytes in a density of 106 cells per cm2. Cells expanded at the same ínoculation density w/o scaffold served as mock-controls. After 14 and 28 days in culture, the cells were extracted from the scaffold by aid of collagenase (Sigma, Deisenhofen, FGR) and analyzed for the expression of different factors, including IL-1β,
Osteosarcoma (OS) is an aggressive bone malignancy with a high relapse rate despite combined treatment with surgery and multiagent chemotherapy. As for other cancers, OS-associated microenvironment may contribute to tumor initiation, growth, and metastasis. We consider mesenchymal stromal cells (MSC) as a relevant cellular component of OS microenvironment, and have previously found that the interaction between MSC and tumor cells is bidirectional: tumor cells can modulate their peripheral environment that in turn becomes more favourable to tumor growth through metabolic reprogramming (1). Stem-like cells were derived from HOS osteosarcoma cell line by using the spherogenic system (2). CSC isolated from HOS (HOS-CSC) were co-coltured with MSC isolated from bone marrow. Cell lysates and supernatants were collected for the analysis of RNA expression and of secreted cytokines, by Q-RT-PCR and specific ELISA assays, respectively. Here, we determined the effects of MSC on OS stemness and migration, two major features associated with recurrence and chemoresistance. Recruitment of MSC to the tumor environment leads to enhanced proliferation of OS stem cells, which increase the expression levels of TGFβ1. The latter, in turn, could be responsible for the activation of NF-kB genes and
Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting 350,000 people in the UK. Within synovial joints, synoviocytes form a destructive pannus that degrades articular cartilage and bone. Synovial fluid glutamate levels increase 54 fold in RA patients and are also elevated in animal models of inflammatory and osteoarthritis. To determine whether elevated glutamate levels contribute to RA pathology we investigated which synovial joint tissues express glutamate receptors and whether glutamate stimulation influences synovio-cyte phenotype. Various glutamate receptor mRNAs (NMDAR1, KA1, AMPAGluR2, AMPA GluR3, mGluR4) were expressed in tissues of the rat knee. All receptors were expressed in the patella. The fibrocartilagenous menis-cus and articular cartilage chondrocytes expressed mGluR4 and both AMPA receptor subunits. Human synoviocytes expressed NMDAR1 and KA1 mRNA. To determine whether glutamate receptors were functional in human synoviocytes, cells were preloaded with a fluorescent indicator of intracellular calcium (iCa 2+) and stimulated with glutamate or specific agonists (NMDA or kainate, 500mM). Glutamate stimulated release of iCa2+ in 25% of synoviocytes whereas NMDA and Kainate each stimulated 15% of cells. NMDA responses increased to 57% in the absence of Mg2+ consistent with the inhibitory effect of Mg2+ on this receptor. To determine whether activation of glutamate receptors can influence human synoviocyte phenotype, we cultured synoviocytes in various glutamate concentrations (50mM to 2mM) and measured effects of glutamate receptor antagonists on release of a proinflammatory cytokine (IL-6) and degradative enzymes (MMP2 and 9). In some RA patients, glutamate stimulation increased synoviocyte pro MMP-2 release. TIMP1 and TIMP2 release were not affected by glutamate stimulation or co-treatment with receptor antagonists.
Introduction: The development of periprosthetic osteolysis (OL) in total hip arthroplasty (THA) depends on activation of distinct pathways by wear particles eventually leading to predominance of osteoclasts over osteoblasts at the bone-implant interface. These processes are orchestrated by many cytokines and chemokines. However, interindividual variability in OL was observed even in cases of comparable wear rates and identical prosthesis. To explain it, we hypothesize genetic susceptibility to OL underlined by single nucleotide polymorphisms (SNP) for genes for key signal molecules. Patients and Methods: In this case-control association study we investigated patients with severe OL around THA (n=116). The control group included patients with the same THA and mild OL (n=89). All were Caucasian, all had a single type of cementless THA implanted at a single institution. Healthy subjects without THA (n=150) served as a genetic background. Severity of OL was determined according to the Saleh’s classification. We used the candidate gene approach and overall, 22 cytokine/cytokine receptor SNPs were genotyped by polymerase chain reaction with sequence specific primers (PCR-SSP). Results: The results showed an association of the TNF-238*A allele with severe OL (odds ratio, OR=6.59, p=0.005, population attributable risk percentage, PAR% = 5.2), higher risk of revision (OR=infinity, p=0.017) and poorer survival of THA (p=0.022). In addition, carriers of the IL-6-174*G allele were more frequent among the patients with severe OL (OR=2.51, p=0.007, PAR%=31.5). Finally, the genetic variant IL-2-330*G was associated with lower risk for THA revision (OR=0.44, p=0.02), protection from severe OL (OR=0.55, p=0.043) and longer survival of THA (p=0.018). Conclusions: At least in a Czech population, genetic variants of the pro-inflammatory cytokines TNF-alpha and
Mechanical loading of bone is anabolic, while aseptic loosening of implants is catabolic. In a rat model of mechanically induced aseptic loosening, osteoclast differentiation is increased dramatically but the underlying mechanism is unknown. The objective was to profile molecular pathways in peri-implant bone resorption. Microarrays on cortical bone samples exposed to pressurized fluid flow were performed 3, 6, 12, 24 and 36 hrs, using time 0 as controls. Of a total of 4093 genes that underwent a 1.25-fold change (p<0.05) due to fluid flow only 21 were common for all time points. Signals linked to inflammation and apoptosis were regulated in a biphasic manner at 3 and 12 and/or 24 hrs. The acute response at 3 hrs was associated with increases in the cytokines
Aims. Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant (gynura bicolor), has demonstrated anti-inflammatory properties in various diseases. We aimed to explore the chondroprotective effect of DHCA on OA and its potential mechanism. Methods. In vitro, interleukin-1 beta (IL-1β) was used to establish the mice OA chondrocytes. Cell counting kit-8 evaluated chondrocyte viability. Western blotting analyzed the expression levels of collagen II, aggrecan, SOX9, inducible nitric oxide synthase (iNOS),
Anterior cruciate ligament (ACL) injuries have been increasing, especially amongst adolescents. These injuries can increase the risk for early-onset knee osteoarthritis (OA). The consequences of late-stage knee OA include structural joint change, functional limitations and persistent pain. Interleukin-6 (IL-6) is a pro-inflammatory biomarker reflecting knee joint healing, and increasing evidence suggests that
Aims. Tocilizumab, an interleukin-6 (IL-6) receptor (IL-6R) targeting antibody, enhances the anti-tumour effect of conventional chemotherapy in preclinical models of cancer. We investigated the anti-tumour effect of tocilizumab in osteosarcoma (OS) cell lines. Methods. We used the 143B, HOS, and Saos-2 human OS cell lines. We first analyzed the
Senescent chondrocyte and subchondral osteoclast overburden aggravate inflammatory cytokine and pro-catabolic proteinase overproduction, accelerating extracellular matrix degradation and pain during osteoarthritis (OA). Fibronectin type III domain containing 5 (FNDC5) is found to promote tissue homeostasis and alleviate inflammation. This study aimed to characterize what role Fndc5 may play in chondrocyte aging and OA development. Serum and macroscopically healthy and osteoarthritic cartilage were biopsied from patients with knee OA who received total knee replacement. Murine chondrocytes were transfected with Fndc5 RNAi or cDNA. Mice overexpressing Fndc5 (Fndc5Tg) were operated to have destabilized medial meniscus mediated (DMM) joint injury as an experimental OA model. Cellular senescence was characterized using RT-PCR analysis of p16INK4A, p21CIP1, and p53 expression together with ß-galactosidase activity staining. Articular cartilage damage and synovitis were graded using OARSI scores. Osteophyte formation and mechanical allodynia were quantified using microCT imaging and von Frey filament, respectively. Osteoclast formation was examined using tartrate-resistant acid phosphatase staining. Senescent chondrocyte and subchondral osteoclast overburden together with decreased serum FNDC5 levels were present in human osteoarthritic cartilage. Fndc5 knockdown upregulated senescence program together with increased
Osteoarthritis (OA) is a common cause of chronic pain. Subchondral bone is highly innervated, and bone structural changes directly correlate with pain in OA. Mechanisms underlying skeletal–neural interactions are under-investigated. Bone derived axon guidance molecules are known to regulate bone remodelling. Such signals in the nervous system regulate neural plasticity, branching and neural inflammation. Perturbation of these signals during OA disease progression may disrupt sensory afferents activity, affecting tissue integrity, nociception, and proprioception. Osteocyte mechanical loading and
While cell morphology has been recognized as a fundamental regulator of cell behavior, few studies have measured the complex cell morphological changes of chondrocytes using quantitative cell morphometry descriptors in relation to inflammation and phenotypic outcome. Acute vs. persistent exposure to IL-1β and how IL-1β modulated dynamic changes in cell morphology in relation to the phenotype, donor and OA grade in healthy and osteoarthritis (OA) chondrocytes was investigated. A panel of quantitative cell morphometry descriptors was measured using an automated high-throughput method. Absolute quantification of gene expression was measured by ddPCR followed by correlation analyses. In OA chondrocytes, chronic IL-1β significantly decreased COL2A1, SOX9, and ACAN, increased
Aims. Rheumatoid arthritis (RA), which mainly results from fibroblast-like synoviocyte (FLS) dysfunction, is related to oxidative stress. Advanced oxidation protein products (AOPPs), which are proinflammatory mediators and a novel biomarker of oxidative stress, have been observed to accumulate significantly in the serum of RA patients. Here, we present the first investigation of the effects of AOPPs on RA-FLSs and the signalling pathway involved in AOPP-induced inflammatory responses and invasive behaviour. Methods. We used different concentrations of AOPPs (50 to 200 µg/ml) to treat RA-FLSs. Cell migration and invasion and the expression levels of tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), matrix metalloproteinase-3 (MMP-3), and MMP-13 were investigated. Western blot and immunofluorescence were used to analyze nuclear factor-κB (NF-κB) activation. Results. AOPPs promoted RA-FLS migration and invasion in vitro and significantly induced the messenger RNA (mRNA) and protein expression of TNF-α,