Repair of articular cartilage defect using adipose-derived stem cell-loaded scaffold derived from native cartilage extracellular matrix.

The purpose of this study was to investigate the feasibility of adipose-derived stem cells (ADSCs) as the seed cells of cartilage tissue engineering. ADSCs were isolated from adipose tissue that was harvested under sterile conditions from the inguen fold of porcines and cultured in vitro. Acellular cartilage extracellular matrix (ACECM) scaffolds of pigs were then constructed. Moreover, inflammatory cells, as well as cellular and humoral immune responses, were detected using hematoxylin and eosin staining staining, immunohistochemical staining, and western blot analysis. The results showed that the cartilage complex constructed by ADSCs and ACECM through tissue engineering successfully repaired the cartilage defect of the pig knee joint. The in vivo repair experiment showed no significant difference between chondrocytes, ADSCs, and induced ADSCs, indicating that ADSCs do not require in vitro induction and have the potential for chondrogenic differentiation in the environment around the knee joint. In addition, pig-derived acellular cartilage scaffolds possess no obvious immune inflammatory response when used in xenotransplantation. ADSCs may serve as viable seed cells for cartilage tissue engineering.

A Clinical Update and Global Economic Burden of Rheumatoid Arthritis.

BACKGROUND AND OBJECTIVE: Rheumatoid arthritis (RA) is a predominant inflammatory autoimmune disorder. The incidence and prevalence of RA is increasing with considerable morbidity and mortality worldwide. The pathophysiology of RA has become clearer due to many significant research outputs during the last two decades. Many inflammatory cytokines involved in RA pathophysiology and the presence of autoantibodies are being used as potential biomarkers via the use of effective diagnostic techniques for the early diagnosis of RA. Currently, several disease-modifying anti-rheumatic drugs are being prescribed targeting RA pathophysiology, which have shown significant contributions in improving the disease outcomes. DISCUSSION: Even though innovations in treatment strategies and monitoring are helping the patients to achieve early and sustained clinical and radiographic remission, the high cost of drugs and limited health care budgets are restricting the easy access of RA treatment. Both direct and indirect high cost of treatment are creating economic burden for the patients and affecting their quality of life. CONCLUSION: The aim of this review is to describe the updated concept of RA pathophysiology and highlight current diagnostic tools used for the early detection as well as prognosis - targeting several biomarkers of RA. Additionally, we explored the updated treatment options with side effects besides discussing the global economic burden.

[Mechanism of bone and cartilage damage in rheumatoid arthritis].

Rheumatoid arthritis(RA)is an autoimmune diseases characterized by inflammation and destruction of bone and cartilage. Bone destruction in RA is triggered by abnormal activation of immune system and osteoclasts induced by RANKL. Advances in osteoimmunology clarified that immune-factors such as inflammatory cytokines and antibodies promote not only inflammation but also bone destruction in RA. Importantly, a newly identified Th17 subset induces osteoclastogenesis potently by upregulating RANKL on synovial fibroblasts, indicating a synergy between T-synovial fibroblast plays a primary role in the inflammatory bone destruction. Recently, novel bone-regulating factors are identified and can be attractive therapeutic targets for destruct ion of bone and cartilage in RA.

[The "treat-to-target" strategies for rheumatoid arthritis and managing for bone cartilage destructions].

Sometime ago, there was little choice for the treatment of rheumatoid arthritis(RA)that was regarded as an untreateble disease but supportive analgesics and mild disease modified drugs. The advent of biological agents with abundant clinical researches regarding remarkable efficacy has cased dramatically the paradigm shift in the treatment of RA. The strategy for medical care to RA has now entered a new era in that treatment target should be clarified and shared between patient and rheumatologist aiming the prevention of structural damage and the maintain of long-term quality of life(QOL)by tight-control. In this review, we summarize the "treat to target"(T2T)strategies for RA and its impact to manage for bone and cartilage destructions.

[Biomarker of bone and cartilage destruction in rheumatoid arthritis].

Recent progress in treatment and imaging enables us to aim the clinical remission in rheumatoid arthritis. In terms of achieving deep remission (structural remission) and predicting prognosis, useful serological biomarkers are now expected. Recently, some of the serological biomarkers, such as RANKL (receptor activator of NF-κB ligand) and TRACP (tartrate-resistant acid phopshatate)-5b, are used to assess the activity of rheumatoid arthritis. The levels of these biomarkers well reflect bone erosion but are less affected by age or physiological variation.

[Anti-RANKL antibody for the treatment of bone and cartilage destruction in rheumatoid arthritis].

Rheumatoid arthritis (RA) is characterized by chronic synovitis and RANKL-dependent osteoclastogenesis leading to bone damage, which causes severe physical disability. Focal and systemic bone and cartilage destruction including secondary osteoporosis contributes to the morbidity associated with RA. The biologics targeting TNF and IL-6 has revolutionized the treatment of RA, producing significant improvements in clinical and structural outcomes. Furthermore, an anti-RANKL antibody denosumab possesses a potential to inhibit joint destruction as well as systemic osteoporosis. Targeting RANKL therapy will most likely enlarge the possibilities of osteoporosis treatment and improve the prognosis in RA patients.

[Semaphorins as treatment targets for cartilage and bone damage caused by rheumatoid arthritis].

Semaphorins family consists of more than 20 proteins, categorized into 8 subclasses. Semaphorins play critical roles in neural development, immune response, and bone metabolism. Rheumatoid arthritis (RA) is a disease which shows abnormality in immunity and bone homeostasis. Therefore, semaphorins are suggested to be relevant to RA. Here, we described the role of semaphorins in bone metabolism and the association with semaphorins and RA which are found by basic and translational research.

[The regulation of CTLA4-Ig in bone and cartilage destruction of rheumatoid arthritis].

CTLA4-Ig is a regulator of co-stimulation and inhibits the activation of T cells through interfering with the interaction of CD80/86 on antigen-presenting cells with CD28. Recently CTLA4-Ig has shown additional effect beyond T cell inhibition, such as direct inhibition of differentiation of osteoclast, enhancement of osteogenesis. These effects may contribute to prevention of bone destruction in rheumatoid arthritis.

IL-1ß, in contrast to TNFα, is pivotal in blood-induced cartilage damage and is a potential target for therapy.

Joint bleeding after (sports) trauma, after major joint surgery, or as seen in hemophilia in general leads to arthropathy. Joint degeneration is considered to result from the direct effects of blood components on cartilage and indirectly from synovial inflammation. Blood-provided proinflammatory cytokines trigger chondrocytes and induce the production of cartilage-degrading proteases. In the presence of erythrocyte-derived iron, cytokines stimulate radical formation in the vicinity of chondrocytes inducing apoptosis. To unravel the role of interleukin (IL) 1ß and tumor necrosis factor (TNF) α in the pathogenesis of this blood-induced cartilage damage, the effect of antagonizing these cytokines was examined in human in vitro cultures. Addition of recombinant human IL-1ß monoclonal antibody or IL-1 receptor antagonist resulted in a dose- and time-dependent protection of cartilage from blood-induced damage. In higher concentrations, almost complete normalization of cartilage matrix proteoglycan turnover was achieved. This was accompanied by a reduction in IL-1ß and IL-6 production in whole blood cultures, whereas TNFα production remained unaffected. Interestingly, addition of a TNFα monoclonal antibody, although demonstrated to inhibit the direct (transient) effects of TNFα on cartilage, exhibited no effect on blood-induced (prolonged) cartilage damage. It is demonstrated that IL-1ß is crucial in the development of blood-induced joint damage, whereas TNFα is not. This hierarchical position of IL-1ß in blood-induced joint damage warrants studies on targeting IL-1ß to potentially prevent joint degeneration after a joint bleed.

Chondropenia: current concept review.

The term "chondropenia" indicates the early stage of degenerative cartilage disease, and it has been identified by carefully monitoring early-stage osteoarthritis (OA). Not only is it the loss of articular cartilage volume, but it is also a rearrangement of biomechanical, ultrastructural, biochemical and molecular properties typical of healthy cartilage tissue. Diagnosing OA at an early stage or an advanced stage is valuable in terms of clinical and therapeutic outcome. In fact degenerative phenomena are supported by a complex biochemical cascade which unbalances the extracellular matrix homeostasis, closely regulated by chondrocytes. In the first stage an intense inflammatory reaction is triggered: pro-catabolic cytokines such as IL-1ß and TNF-α triggering matrix metalloproteases and aggrecanase (ADAMT-4 and 5), responsible for the early loss of ultrastructural components, such as type II collagen and aggrecan. In addition nitric oxide and reactive oxygen species modulate the physiopathology of the condral matrix inducing apoptosis of chondrocytes through a mitochondria-dependent pathway. In addition, "Lonely Death": chondrocytes, are confined within a dense, avascular extracellular matrix capsule, and can trigger a genetically induced apoptosis and necrosis. The degenerative process starts from a central point and then spreads in a centrifugal manner in depth and in adjacent areas, eventually covering the whole joint; chondropenia represents a journey from the first clinically detectable time-point until it can be characterized as frank osteoarthritis. Currently, there are no instruments sensitive enough which allow a timely diagnosis of chondropenia. Innovative magnetic resonance imaging techniques, such as T2 mapping, can be effective and a sensitive diagnostic instrument for quantifying cartilage volume and proteoglycan content. However, avant-garde biophysical techniques, such as mechanical indenters, ultrasound and biochemical markers (uCTX-II), are rational and scientific tools applicable to the clinical and therapeutic management of early degenerative cartilage disease. The objective of this review on chondropenia is to present a state of the art and innovative concepts.

Immunohistological localization of BMP-2, BMP-7, and their receptors in knee joints with focal cartilage lesions.

INTRODUCTION: Although it is well known that BMP-2 and BMP-7 play significant roles in cartilage metabolism, data about intra-articular expression and localization of these proteins and their receptors in humans are rare. METHODS: Biopsies of synovia and debrided cartilage were taken in patients undergoing autologous chondrocyte implantation. Expression of BMP-2, BMP-7, and their receptors BMPR-1A, BMPR-1B and BMPR-2 were semiquantitatively evaluated by immunohistological staining. RESULTS: BMP-7 was equally highly expressed in all cartilage and synovial biopsies. Increased levels of BMPR-1A, but not of BMPR-1B, and BMPR-2, were found in all synovial and 47% of all cartilage samples (P = 0.002). BMP-2 was positively scored in 47% of all cartilage and 40% of all synovial specimens. Defect size, KOSS, Henderson or Kellgren-Lawrence score did not statistically significant correlate with the expression of the analyzed proteins or Mankin and Pritzker scores. Duration of symptoms and localization of lesions were associated with KOSS (P < 0.02), but there was no influence of these parameters on protein expression. CONCLUSIONS: BMP-2, BMP-7, and BMPR-1A were expressed in cartilage and synovia of knees with focal cartilage lesions. Although defect localization and duration of symptoms decisively influence KOSS, there was no associated alteration of protein expression observed.

Eicosapentaenoic acid and docosahexaenoic acid reduce interleukin-1ß-mediated cartilage degradation.

INTRODUCTION: In inflammatory joint disease, such as osteoarthritis (OA), there is an increased level of proinflammatory cytokines, such as interleukin (IL)-1ß. These cytokines stimulate the production of matrix metalloproteinases (MMPs), which leads to the degradation of the cartilage extracellular matrix and the loss of key structural components such as sulphated glycosaminoglycan (sGAG) and collagen II. The aim of this study was to examine the therapeutic potential of n-3 polyunsaturated fatty acids (PUFAs) in an in vitro model of cartilage inflammation. METHODS: Two specific n-3 compounds were tested, namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), each at 0.1, 1 and 10 µM. Full thickness bovine cartilage explants, 5 mm in diameter, were cultured for 5 days with or without IL-1ß and in the presence or absence of each n-3 compound. The media were replaced every 24 hours and assayed for sGAG content using the 1,9-dimethylmethylene blue (DMB) method. Chondrocyte viability was determined at the end of the culture period using fluorescence microscopy to visualise cells labelled with calcein AM and ethidium homodimer. RESULTS: Treatment with IL-1ß (10 ng.ml⁻¹) produced a large increase in sGAG release compared to untreated controls, but with no effect on cell viability, which was maintained above 80% for all treatments. In the absence of IL-1ß, both n-3 compounds induced a mild catabolic response with increased loss of sGAG, particularly at 10 µM. By contrast, in the presence of IL-1ß, both EPA and DHA at 0.1 and 1 µM significantly reduced IL-1ß-mediated sGAG loss. The efficacy of the EPA treatment was maintained at approximately 75% throughout the 5-day period. However, at the same concentrations, the efficacy of DHA, although initially greater, reduced to approximately half that of EPA after 5 days. For both EPA and DHA, the highest dose of 10 µM was less effective. CONCLUSIONS: The results support the hypothesis that n-3 compounds are anti-inflammatory through competitive inhibition of the arachidonic acid oxidation pathway. The efficacy of these compounds is likely to be even greater at more physiological levels of IL-1ß. Thus we suggest that n-3 PUFAs, particularly EPA, have exciting therapeutic potential for preventing cartilage degradation associated with chronic inflammatory joint disease.

ARG098, a novel anti-human Fas antibody, suppresses synovial hyperplasia and prevents cartilage destruction in a severe combined immunodeficient-HuRAg mouse model.

BACKGROUND: The anti-human Fas/APO-1/CD95 (Fas) mouse/human chimeric monoclonal IgM antibody ARG098 (ARG098) targets the human Fas molecule. The cytotoxic effects of ARG098 on cells isolated from RA patients, on normal cells in vitro, and on RA synovial tissue and cartilage in vivo using implanted rheumatoid tissues in an SCID mouse model (SCID-HuRAg) were investigated to examine the potential of ARG098 as a therapy for RA. METHODS: ARG098 binding to each cell was analyzed by cytometry. The effects of ARG098 on several cells were assessed by a cell viability assay in vitro. Effects on the RA synovium, lymphocytes, and cartilage were assessed in vivo using the SCID-HuRAg mouse model. RESULTS: ARG098 bound to cell surface Fas molecules, and induced apoptosis in Fas-expressing RA synoviocytes and infiltrating lymphocytes in the RA synovium in a dose-dependent manner. However, ARG098 did not affect the cell viability of peripheral blood mononuclear cells of RA patients or normal chondrocytes. ARG098 also induced apoptosis in RA synoviocytes and infiltrating lymphocytes in the RA synovium in vivo. The destruction of cartilage due to synovial invasion was inhibited by ARG098 injection in the modified SCID-HuRAg mouse model. CONCLUSIONS: ARG098 treatment suppressed RA synovial hyperplasia through the induction of apoptosis and prevented cartilage destruction in vivo. These results suggest that ARG098 might become a new therapy for RA.

Role of the cholinergic nervous system in rheumatoid arthritis: aggravation of arthritis in nicotinic acetylcholine receptor α7 subunit gene knockout mice.

BACKGROUND: The alpha7 subunit of nicotinic acetylcholine receptors (alpha7nAChR) can negatively regulate the synthesis and release of proinflammatory cytokines by macrophages and fibroblast-like synoviocytes in vitro. In addition, stimulation of the alpha7nAChR can reduce the severity of arthritis in murine collagen-induced arthritis (CIA). OBJECTIVE: To provide more insight into the role of the alpha7nAChR in the pathogenesis of arthritis by investigating the effect of the absence of alpha7nAChR in CIA in alpha7-deficient (alpha7nAChR(-/-)) compared with wild-type (WT) mice. METHODS: CIA was induced in alpha7nAChR(-/-) and WT littermate mice at day 0 by immunisation with chicken collagen type II (cCII) followed by a booster injection with cCII on day 20. Mice were killed on day 44 or day 63 and arthritis activity as well as radiological and histological damage were scored. The effects on the immune response were evaluated by measurement of antigen-specific antibodies and cytokines, and evaluation of the effects on antigen-specific stimulated spleen cells. RESULTS: In alpha7nAChR(-/-) mice a significant increase in the incidence and severity of arthritis as well as increased synovial inflammation and joint destruction were seen. Exacerbation of CIA was associated with elevated systemic proinflammatory cytokines and enhanced T-helper cell 1 (Th1)-cytokine and tumour necrosis factor alpha production by spleen cells. Moreover, a specific decrease in the collagen-specific 'Th1-associated' IgG2a response was seen, whereas IgG1 titres were unaffected. CONCLUSIONS: The results presented here indicate that immune cell function in a model of rheumatoid arthritis is regulated by the cholinergic system and, at least in part, mediated by the alpha7nAChR.

Cartilage-hair hypoplasia: molecular basis and heterogeneity of the immunological phenotype.

PURPOSE OF REVIEW: To report on the expanding clinical and immunological spectrum associated with ribonuclease mitochondrial RNA-processing mutations and to review the cellular and molecular mechanisms involved in the pathophysiology of cartilage-hair hypoplasia (CHH) and related disorders in humans. RECENT FINDINGS: Different types of mutations are associated with skeletal or extraskeletal manifestations of CHH, respectively. In particular, severe immunodeficiency is mostly associated with mutations that alter cyclin B2 mRNA cleavage and thus are likely to reflect disturbances in cell cycle control. The first cases of ribonuclease mitochondrial RNA-processing mutations with severe immunodeficiency, but no skeletal abnormalities, have been identified. SUMMARY: Abnormalities of ribosome biogenesis have been shown to cause distinct bone marrow failure syndromes, including CHH. However, the specific role of ribosomal and extraribosomal defects in the pathophysiology of the various phenotypic features of CHH remains undefined. Development of suitable animal models is needed to address this important issue.

Variability of clinical and laboratory features among patients with ribonuclease mitochondrial RNA processing endoribonuclease gene mutations.

BACKGROUND: Cartilage hair hypoplasia is an autosomal recessive type of metaphyseal chondrodysplasia, caused by mutations in the ribonuclease mitochondrial RNA processing (RMRP) gene. Typical features of cartilage hair hypoplasia include short stature, a predisposition to malignancy, and a variable degree of impairment of cellular immunity. OBJECTIVE: We sought to describe the heterogeneity of clinical and immunologic phenotype in 12 consecutive patients with RMRP mutations who were referred to 2 different institutions for immunologic evaluation. METHODS: We have retrospectively analyzed the clinical and laboratory features in 12 patients with molecular defects in the RMRP gene. T-cell repertoire was investigated by quantitating Vbeta families' expression and analyzing their diversity. T-cell receptor excision circle analysis was used to study thymic output. RESULTS: All 12 patients had significant immune abnormalities, leading to severe immune deficiency in 9. CD8 lymphocytopenia was identified as a novel phenotype associated with RMRP mutations. Significant, even intrafamilial, phenotypic heterogeneity was observed. In 3 cases, severe immunodeficiency was the only phenotypic manifestation associated with RMRP mutations, a novel finding. Mutations leading to significant immune defects were most often located in the promoter, and the first case of a compound heterozygote for 2 such mutations is reported. CONCLUSION: This report broadens the spectrum of phenotypes associated with RMRP mutations and suggests that mutations in this gene should be considered when evaluating patients with combined immune deficiency, regardless of the presence of other manifestations.

[Traditional techniques and experimental therapeutic approach for the restore of degenerate cartilages]. / Tecniche tradizionali e approcci terapeutici sperimentali per la rigenerazione di lesioni cartilaginee.

Cartilage is unable to repair itself. The actual treatments for cartilage lesions primarily cover up symptoms only and this had led to develop alternative means to restore degenerated cartilage, above all by using cell therapy. The therapeutic approaches initially focused on the implantation of autologous chondrocytes, but this technique proved unsatisfactory. The discovery that several adult human tissues contain mesenchymal stem cells (MSCs) capable of differentiating into chondrocytes raised the possibility of using MSCs to repair cartilages. In the present study we investigated whether mesenchymal stem cells from adipose tissue (hADAS) are able to differentiate into cartilage cells. We isolated cells from lipoaspirates, characterized them detecting specific surface markers by FACS analysis and immunofluorescence. We differentiate hADAS towards condrogenic line in a culture media supplemented with some specific factors and in a specific condition called pellet culture. The isolation of hADAS cells is reproducible and characterized by an high reproductivity, non dependent from the donor age. The expression of surface markers suits with the literature data. The cells differentiated towards chondrogenic line in pellet culture show a different morphology from the undifferentiated cells. The potential application of MSC therapy provides new hope for the development of innovative treatments for the repair of cartilage lesions and disorders.