Kanji Fukuda

Factors related to degradation of articular cartilage in osteoarthritis : A review

OBJECTIVES Osteoarthritis (OA) is a common joint deterioration initiated by multiple factors. To better understand related factors in the development of this disease, we focused on the mechanical stress loaded on articular cartilage. MATERIALS AND METHODS The anterior cruciate ligaments of rabbit knee joints were transected, and expression of protein kinase C (PKC) examined immunohistochemically. The PKC activator 12-o-tetradecanoyl-phorbol-13-acetate (TPA) was then administered intraarticularly. To determine the involvement of gas mediators, a cartilage defect was made on the medical femoral condyle of rabbit knee joints. Hydrostatic pressure was loaded on the cartilage taken from the surrounding defects, and levels of superoxide anion and nitric oxide (NO) were measured. Bovine chondrocytes were subjected to cyclic mechanical stretch using a Flexercell Strain Instrument. Proteoglycan synthesis and PKC activity were measured. Expression of matrix metalloproteinase (MMP)-3 and tissue inhibitor of metalloproteinase (TIMP)-1 in articular cartilages obtained from OA patients were examined using Northern blots. RESULTS Chondrocytes from experimentally induced OA were stained positively with anti-alpha-PKC antibody. Intraarticular administration of TPA prevented the development of OA changes. Cyclic tensile stretch loaded on chondrocytes decreased proteoglycan synthesis and PKC activity. Thus, PKC is involved in the stress-mediated degradation of articular cartilage. Cartilage defects led to degradation of surrounding cartilage and to enhanced superoxide anion and NO synthesis. We also noted increased and decreased expressions of MMP-3 and TIMP-1 mRNA in human OA cartilage, respectively. CONCLUSION PKC, gas mediators (superoxide anion, NO), and proteinases are all involved in OA.

Serum biomarkers as predictors of lung function decline in chronic obstructive pulmonary disease

BACKGROUND Recent studies show that COPD patients exhibit low-grade systemic inflammation, and that plasma fibrinogen and high neutrophil counts are related to faster declines in lung function. We examined correlations between serum biomarkers and the decline of lung function in COPD patients. METHOD Baseline levels of 9 serum biomarkers (TIMP-1, alpha1-antitrypsin, MMP-9, TNF-alpha, TGF-beta, IL-6, IL-8, neutrophil elastase and CRP), fibrinogen and white blood cell counts (WCC) were measured in 96 COPD patients. Lung function was measured at the time of blood sampling and every 3-6 months during the observation period (median 25.0 months). RESULTS Twenty patients were rapid decliners of lung function and 53 patients were non-decliners. Neutrophil counts, serum CRP and MMP-9 were significantly higher in the rapid decliners (p<0.05). The annual change of % predicted FEV(1) was inversely correlated with MMP-9 (r=-0.288; p<0.01) and CRP (r=-0.354; p<0.005) (partial correlation coefficients adjusted for age, sex, cardiovascular disease, smoking history, and baseline % predicted FEV(1)). The remaining biomarkers were not correlated with the annual change of % predicted FEV(1). CONCLUSION Serum CRP and MMP-9 levels were related to FEV(1) decline. These markers are good candidates as predictors for rapid decline of FEV(1) in COPD patients. Additional long-term and larger size studies of COPD patients could help determine the exact roles for these biomarkers.

Hydrogen peroxide induces apoptosis of chondrocytes; involvement of calcium ion and extracellular signal-regulated protein kinase.

Abstract:Objective: Recent observations demonstrated that reactive oxygen species facilitate cartilage degradation. We demonstrated that hydrogen peroxide (H2O2) caused inhibition of proteoglycan synthesis, induction of apoptosis and stimulation of extracellular signal-regulated protein kinase (ERK) of the chondrocytes (Inflamm Res 48: 399-403, 1999). To determine whether activation of ERK is involved in the induction of chondrocyte apoptosis, we examined the signal transduction pathways in this hydrogen peroxide induced apoptosis.¶Design: Bovine articular chondrocytes were cultured. To determine the induction of apoptosis, Annexin V staining and terminal deoxynucleotidyl transferase were used. The activity of caspase-3 was measured using an apopain assay kit. Intracellular Ca2+ imaging was observed after fura2-AM loading.¶Results: Hydrogen peroxide enhanced annexin V positive apoptotic cells and caspase-3 activity, which is an executor of apoptosis. Hydrogen peroxide also enhanced intracellular Ca2+ and preincubation with the intracellular Ca2+ chelator protected chondrocytes against hydrogen peroxide-induced cell apoptosis, indicating that an increase in the cytosolic Ca2+ plays a decisive role in this action. When ERK activity was blocked with geldanamycin and PD098059, increased apoptosis was evident.¶Conclusion: Hydrogen peroxide induces chondrocyte apoptosis via Ca2+ signaling, and ERK is involved in these signal transduction pathways.¶

Hyaluronic acid inhibits interleukin-1-induced superoxide anion in bovine chondrocytes

Abstract.Objective: To examine the effect of hyaluronic acid (HA) on the induction of superoxide anion by IL-1 in chondrocytes. ¶Materials and Methods: Bovine articular chondrocytes were treated with different concentrations of IL-1. A chemiluminescent probe (L-012) was added to the medium and chemiluminescence detection was used to measure superoxide anion. ¶Results: IL-1 caused induction of superoxide anions in a dose-dependent manner. HA (10–100 g/ml) countered superoxide induction caused by 20 ng/ml of IL-1. ¶Conclusion: HA can afford protection against cartilage degradation, probably acting as a free-radical scavenger.

Induction of Mesenchymal Progenitor Cells with Chondrogenic Property from Mouse-Induced Pluripotent Stem Cells

Despite recent cell-engineering advances, treatment and repair of cartilage remains challenging. Although stem cell transplantation therapy using mesenchymal stem cells (MSCs) is considered a prominent strategy, the major problem of limited proliferative capacity of autologous cells has been unsolved. Recently, an induced pluripotent stem (iPS) cell line was suggested as an alternative way to cure various human diseases due to their potential proliferating infinitely while possessing the capacity to form all types of cells. However, the method to induce lineage-restricted differentiation has not been well examined or established. Here, we suggest a simple method to induce mesenchymal progenitors possessing chondrogenic property from mouse iPS cells. The MSC-like cells produced in our study expressed some MSC markers, and could also differentiate to osteoblast and adipocyte. The present study demonstrates the property of iPS cells as an alternative candidate for treatment of articular disorders, and suggests an effective approach for preparing chondrocyte from iPS cells.

Reactive oxygen species depolymerize hyaluronan: involvement of the hydroxyl radical

We have previously demonstrated that reactive oxygen species (ROS) are involved in cartilage degradation. A decrease in the size of hyaluronan (HA), which is the major macromolecule in synovial fluid and is responsible for imparting viscosity to it, is reported in arthritis patients. The purpose of this study is to determine the ROS that depolymerize HA. The luminol derivative, L-012, was used to determine the generation of ROS. To generate hydroxyl radicals, a mixture of hydrogen peroxide (H(2)O(2)) and ferrous ions (Fe(2+)) was added to HA. The antioxidants and the depolymerization of HA were studied in this system. The hydroxyl radical is one of the ROS, causing the depolymerization of HA, which reacts with L-01. These data suggest that hydroxyl radicals play an important role at the site of inflammation.

Concurrent generation of nitric oxide and superoxide inhibits proteoglycan synthesis in bovine articular chondrocytes : involvement of peroxynitrite

OBJECTIVE Nitric oxide (NO), widely assumed to be a mediator of interleukin 1 (IL-1), inhibits proteoglycan synthesis in articular chondrocytes. IL-1 also produces superoxide anion. We hypothesized that the IL-1 inhibited proteoglycan synthesis is the result of peroxynitrite formed by the reaction of NO with superoxide. METHODS Bovine articular chondrocytes were cultured in the presence of SIN-1, which leads to simultaneous generation of both NO and superoxide. Proteoglycan synthesis was measured based on the incorporation of [35S] sulfate, and the presence of peroxynitrite was confirmed using immunohistochemistry. RESULTS SIN-1 inhibited proteoglycan synthesis and superoxide dismutase reversed SIN-1 inhibited proteoglycan synthesis, indicating the simultaneous generation of superoxide is essential to inhibit proteoglycan synthesis. IL-1 induced peroxynitrite in articular chondrocytes and addition of peroxynitrite inhibited proteoglycan synthesis. CONCLUSION The concurrent generation of superoxide anion and NO is required for the action of IL-1 to inhibit proteoglycan synthesis. Peroxynitrite is a candidate for this underlying mechanism.

Cyclic tensile stretch on bovine articular chondrocytes inhibits protein kinase C activity

Osteoarthrosis, a common pathway of joint deterioration, is caused by mechanical stress loaded on articular cartilage. We previously demonstrated the involvement of protein kinase C (PKC) in the development of osteoarthritis in vitro. In this study, we examined the effect of mechanical stress on chondrocyte metabolism and the activity of PKC in vitro. Low frequency and magnitude of cyclic tensile stretch loaded on chondrocytes increased proteoglycan synthesis. However, high frequency and magnitude of stress decreased its synthesis. In this condition, activity of PKC was reduced. These results suggest an involvement of PKC in the stress-mediated inhibition of proteoglycan synthesis.

ZONAL DIFFERENCES IN NITRIC OXIDE SYNTHESIS BY BOVINE CHRONDROCYTES EXPOSED TO INTERLEUKIN-1

To determine the role of nitric oxide (NO) in the inhibition of aggrecan synthesis, we measured levels of NO produced by bovine chondrocytes from different layers of articular cartilage in the presence of interleukin-1 (IL-1). Chondrocytes from the superficial layer showed a large increase in NO synthesis in response to IL-1. Although chondrocytes from the deep layer also produced NO in response to IL-1, the amount was less than that from the superficial layer. Enhanced NO production evoked by IL-1 was accompanied by a significant inhibition of aggrecan synthesis. These data suggest that chondrocytes in both superficial and deep layer of articular cartilage inhibit aggrecan synthesis with IL-1 via NO production. In addition, superficial layer cells respond to lower amounts of IL-1 with respect to NO-production and inhibition of proteoglycan synthesis.

Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ): a patient-based evaluation tool for hip-joint disease. The Subcommittee on Hip Disease Evaluation of the Clinical Outcome Committee of the Japanese Orthopaedic Association

BackgroundThe Japanese Orthopaedic Association Hip Score is widely used in Japan, but this tool is designed to reflect the viewpoint of health-care providers rather than that of patients. In gauging the effect of medical therapies in addition to clinical results, it is necessary to assess quality of life (QOL) from the viewpoint of patients. However, there is no tool evaluating QOL for Japanese patients with hip-joint disease.MethodsWith the aim of more accurately classifying QOL for Japanese patients with hip-joint disease, we prepared a questionnaire with 58 items for the survey derived from 464 opinions obtained from approximately 100 Japanese patients with hip-joint disease and previously devised evaluation criteria. In the survey, we collected information on 501 cases, and 402 were subjected to factor analysis. From this, we formulated three categories—movement, mental, and pain—each comprising 7 items, for a total of 21 items to be used as evaluation criteria for hip-joint function.ResultsThe Cronbach’s α coefficients for the three categories were 0.93, 0.93, and 0.95, respectively, indicating the high reliability of the evaluation criteria. The 21 items included some related to the Asian lifestyle, such as use of a Japanese-style toilet and rising from the floor, which are not included in other evaluation tools.ConclusionsThis self-administered questionnaire may become a useful tool in the evaluation of not only Japanese patients, but also of members of other ethnic groups who engage in deep flexion of the hip joint during daily activities.