Human Sclera Maintains Common Characteristics with Cartilage throughout Evolution

BACKGROUND: The sclera maintains and protects the eye ball, which receives visual inputs. Although the sclera does not contribute significantly to visual perception, scleral diseases such as refractory scleritis, scleral perforation and pathological myopia are considered incurable or difficult to cure. The aim of this study is to identify characteristics of the human sclera as one of the connective tissues derived from the neural crest and mesoderm. METHODOLOGY/PRINCIPAL FINDINGS: We have demonstrated microarray data of cultured human infant scleral cells. Hierarchical clustering was performed to group scleral cells and other mesenchymal cells into subcategories. Hierarchical clustering analysis showed similarity between scleral cells and auricular cartilage-derived cells. Cultured micromasses of scleral cells exposed to TGF-betas and BMP2 produced an abundant matrix. The expression of cartilage-associated genes, such as Indian hedge hog, type X collagen, and MMP13, was up-regulated within 3 weeks in vitro. These results suggest that human 'sclera'-derived cells can be considered chondrocytes when cultured ex vivo. CONCLUSIONS/SIGNIFICANCE: Our present study shows a chondrogenic potential of human sclera. Interestingly, the sclera of certain vertebrates, such as birds and fish, is composed of hyaline cartilage. Although the human sclera is not a cartilaginous tissue, the human sclera maintains chondrogenic potential throughout evolution. In addition, our findings directly explain an enigma that the sclera and the joint cartilage are common targets of inflammatory cells in rheumatic arthritis. The present global gene expression database will contribute to the clarification of the pathogenesis of developmental diseases such as high myopia

Principles of cartilage tissue engineering in TMJ reconstruction

Diseases and defects of the temporomandibular joint (TMJ), compromising the cartilaginous layer of the condyle, impose a significant treatment challenge. Different regeneration approaches, especially surgical interventions at the TMJ's cartilage surface, are established treatment methods in maxillofacial surgery but fail to induce a regeneration ad integrum. Cartilage tissue engineering, in contrast, is a newly introduced treatment option in cartilage reconstruction strategies aimed to heal cartilaginous defects. Because cartilage has a limited capacity for intrinsic repair, and even minor lesions or injuries may lead to progressive damage, biological oriented approaches have gained special interest in cartilage therapy. Cell based cartilage regeneration is suggested to improve cartilage repair or reconstruction therapies. Autologous cell implantation, for example, is the first step as a clinically used cell based regeneration option. More advanced or complex therapeutical options (extracorporeal cartilage engineering, genetic engineering, both under evaluation in pre-clinical investigations) have not reached the level of clinical trials but may be approached in the near future. In order to understand cartilage tissue engineering as a new treatment option, an overview of the biological, engineering, and clinical challenges as well as the inherent constraints of the different treatment modalities are given in this paper

β1-Integrin is up-regulated via Rac1-dependent reactive oxygen species as part of the hypertrophic cardiomyocyte response

beta(1)-Integrin mediates cardiomyocyte growth and survival and its proper regulation is essential for the structural and functional integrity of the heart. beta(1)-Integrin expression is enhanced in hypertrophy, but the mechanism and significance of its up-regulation are unknown. Because reactive oxygen species (ROS) are important mediators of myocardial remodeling we examined their role in regulated beta(1)-integrin expression. Hypertrophy was induced in neonatal cardiomyocytes by endothelin-1 (ET-1), which activated the regulatory NADPH oxidase subunit Rac1, evoked ROS, and enhanced fetal gene expression and cardiomyocyte size. ET-1 also enhanced cell adhesion and FAK phosphorylation and inhibited oxidative stress-induced cardiomyocyte apoptosis. Further, ET-1 increased beta(1)-integrin mRNA and protein expression via Rac1-ROS-dependent MEK/ERK and EGF receptor-PI3K/Akt activation as shown by adenoviral dominant-negative Rac1 or overexpression of copper/zinc-superoxide dismutase. The relevance of regulated beta(1)-integrin expression was examined in cardiomyocytes, in which targeting siRNA impeded the ET-1-induced beta(1)-integrin up-regulation. In these cells, ET-1-induced cell adhesion, FAK phosphorylation, and hypertrophic response were significantly blunted, whereas its antiapoptotic effect was predominantly unchanged, suggesting at least partial dissociation of prohypertrophic and prosurvival signaling elicited by ET-1. In conclusion, beta(1)-integrin up-regulation in response to ET-1 is mediated via Rac1-ROS-dependent activation of prohypertrophic pathways and is mandatory for ET-1-induced FAK activation, cell adhesion, and hypertrophic response

NOX2-derived reactive oxygen species are crucial for CD29-induced pro-survival signalling in cardiomyocytes

AIMS: The highly expressed cell adhesion receptor CD29 (beta(1)-integrin) is essential for cardiomyocyte growth and survival, and its loss of function causes severe heart disease. However, CD29-induced signalling in cardiomyocytes is ill defined and may involve reactive oxygen species (ROS). A decisive source of cardiac ROS is the abundant NADPH oxidase (NOX) isoform NOX2. Because understanding of NOX-derived ROS in the heart is still poor, we sought to test the role of ROS and NOX in CD29-induced survival signalling in cardiomyocytes. METHODS AND RESULTS: In neonatal rat ventricular myocytes, CD29 activation induced intracellular ROS formation (oxidative burst) as assessed by flow cytometry using the redox-sensitive fluorescent dye dichlorodihydrofluorescein diacetate. This burst was inhibited by apocynin and diphenylene iodonium. Further, activation of CD29 enhanced NOX activity (lucigenin-enhanced chemiluminescence) and activated the MEK/ERK and PI3K/Akt survival pathways. CD29 also induced phosphorylation of the inhibitory Ser9 on the pro-apoptotic kinase glycogen synthase kinase-3beta in a PI3K/Akt- and MEK-dependent manner, and improved cardiomyocyte viability under conditions of oxidative stress. The ROS scavenger MnTMPyP or adenoviral co-overexpression of the antioxidant enzymes superoxide dismutase and catalase inhibited CD29-induced pro-survival signalling. Further, CD29-induced protective pathways were lost in mouse cardiomyocytes deficient for NOX2 or functional p47(phox), a regulatory subunit of NOX. CONCLUSION: p47(phox)-dependent, NOX2-derived ROS are mandatory for CD29-induced pro-survival signalling in cardiomyocytes. These findings go in line with a growing body of evidence suggesting that ROS can be beneficial to the cell and support a crucial role for NOX2-derived ROS in cell survival in the heart

EULAR evidence-based recommendations for diagnosis of hand osteoarthritis: report of a task force of ESCISIT

Objectives: to develop evidence-based recommendations for the diagnosis of hand osteoarthritis (OA). Methods: the multidisciplinary guideline development group, representing 15 European countries, generated 10 key propositions regarding diagnosis using a Delphi consensus approach. For each recommendation, research evidence was searched for systematically. Whenever possible, the sensitivity, specificity and likelihood ratio (LR) were calculated; relative risk and odds ratios were estimated for risk factors for hand OA. Quality of evidence was categorised using the European League Against Rheumatism (EULAR) hierarchy, and strength of recommendation was assessed by the EULAR visual analogue scale. Results: diagnostic topics included clinical manifestations, radiographic features, subgroups, differential diagnosis, laboratory tests, risk factors and comorbidities. The sensitivity, specificity and LR varied between tests depending upon the cut-off level, gold standard and controls. Overall, no single test could be used to define hand OA on its own (LR <10) but a composite of the tests greatly increased the chance of the diagnosis. The probability of a subject having hand OA was 20% when Heberden nodes alone were present, but this increased to 88% when in addition the subject was over 40 years old, had a family history of nodes and had joint space narrowing in any finger joint. Conclusion: ten key recommendations for diagnosis of hand OA were developed using research evidence and expert consensus. Diagnosis of hand OA should be based on assessment of a composite of features

EULAR evidence based recommendations for the diagnosis of hand osteoarthritis -report of a task force of the EULAR Standing Committee for International ClinicalStudies Including Therapeutics (ESCISIT).

OBJECTIVES: To develop evidence-based recommendations for the diagnosis of hand osteoarthritis (OA). METHODS: The multidisciplinary guideline development group, representing 15 European countries, generated 10 key propositions regarding diagnosis using a Delphi consensus approach. For each recommendation, research evidence was searched for systematically. Whenever possible, the sensitivity, specificity and likelihood ratio (LR) were calculated; relative risk and odds ratios were estimated for risk factors for hand OA. Quality of evidence was categorised using the European League Against Rheumatism (EULAR) hierarchy, and strength of recommendation was assessed by the EULAR visual analogue scale. RESULTS: Diagnostic topics included clinical manifestations, radiographic features, subgroups, differential diagnosis, laboratory tests, risk factors and comorbidities. The sensitivity, specificity and LR varied between tests depending upon the cut-off level, gold standard and controls. Overall, no single test could be used to define hand OA on its own (LR <10) but a composite of the tests greatly increased the chance of the diagnosis. The probability of a subject having hand OA was 20% when Heberden nodes alone were present, but this increased to 88% when in addition the subject was over 40 years old, had a family history of nodes and had joint space narrowing in any finger joint. CONCLUSION: Ten key recommendations for diagnosis of hand OA were developed using research evidence and expert consensus. Diagnosis of hand OA should be based on assessment of a composite of features