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1.
Osteoarthritis Cartilage ; 31(8): 1078-1090, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37100374

RESUMO

OBJECTIVE: Yes-associated protein (YAP) has been widely studied as a mechanotransducer in many cell types, but its function in cartilage is controversial. The aim of this study was to identify the effect of YAP phosphorylation and nuclear translocation on the chondrocyte response to stimuli relevant to osteoarthritis (OA). DESIGN: Cultured normal human articular chondrocytes from 81 donors were treated with increased osmolarity media as an in vitro model of mechanical stimulation, fibronectin fragments (FN-f) or IL-1ß as catabolic stimuli, and IGF-1 as an anabolic stimulus. YAP function was assessed with gene knockdown and inhibition by verteporfin. Nuclear translocation of YAP and its transcriptional co-activator TAZ and site-specific YAP phosphorylation were determined by immunoblotting. Immunohistochemistry and immunofluorescence to detect YAP were performed on normal and OA human cartilage with different degrees of damage. RESULTS: Chondrocyte YAP/TAZ nuclear translocation increased under physiological osmolarity (400 mOsm) and IGF-1 stimulation, which was associated with YAP phosphorylation at Ser128. In contrast, catabolic stimulation decreased the levels of nuclear YAP/TAZ through YAP phosphorylation at Ser127. Following YAP inhibition, anabolic gene expression and transcriptional activity decreased. Additionally, YAP knockdown reduced proteoglycan staining and levels of type II collagen. Total YAP immunostaining was greater in OA cartilage, but YAP was sequestered in the cytosol in cartilage areas with more severe damage. CONCLUSIONS: YAP chondrocyte nuclear translocation is regulated by differential phosphorylation in response to anabolic and catabolic stimuli. Decreased nuclear YAP in OA chondrocytes may contribute to reduced anabolic activity and promotion of further cartilage loss.


Assuntos
Cartilagem Articular , Osteoartrite , Proteínas de Sinalização YAP , Humanos , Cartilagem Articular/metabolismo , Células Cultivadas , Condrócitos/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Osteoartrite/metabolismo , Fatores de Transcrição/genética
2.
Osteoarthritis Cartilage ; 29(2): 235-247, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33248223

RESUMO

OBJECTIVE: Fibronectin is a matrix protein that is fragmented during cartilage degradation in osteoarthritis (OA). Treatment of chondrocytes with fibronectin fragments (FN-f) has been used to model OA in vitro, but the system has not been fully characterized. This study sought to define the transcriptional response of chondrocytes to FN-f, and directly compare it to responses traditionally observed in OA. DESIGN: Normal human femoral chondrocytes isolated from tissue donors were treated with either FN-f or PBS (control) for 3, 6, or 18 h. RNA-seq libraries were compared between time-matched FN-f and control samples in order to identify changes in gene expression over time. Differentially expressed genes were compared to a published OA gene set and used for pathway, transcription factor motif, and kinome analysis. RESULTS: FN-f treatment resulted in 3,914 differentially expressed genes over the time course. Genes that are up- or downregulated in OA were significantly up- (P < 0.00001) or downregulated (P < 0.0004) in response to FN-f. Early response genes were involved in proinflammatory pathways, whereas many late response genes were involved in ferroptosis. The promoters of upregulated genes were enriched for NF-κB, AP-1, and IRF motifs. Highly upregulated kinases included CAMK1G, IRAK2, and the uncharacterized kinase DYRK3, while growth factor receptors TGFBR2 and FGFR2 were downregulated. CONCLUSIONS: FN-f treatment of normal human articular chondrocytes recapitulated many key aspects of the OA chondrocyte phenotype. This in vitro model is promising for future OA studies, especially considering its compatibility with genomics and genome-editing techniques.


Assuntos
Cartilagem Articular/citologia , Condrócitos/efeitos dos fármacos , Fibronectinas/farmacologia , Expressão Gênica/efeitos dos fármacos , Osteoartrite/genética , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/efeitos dos fármacos , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/genética , Condrócitos/metabolismo , Fêmur , Expressão Gênica/genética , Humanos , Técnicas In Vitro , Fatores Reguladores de Interferon/efeitos dos fármacos , Fatores Reguladores de Interferon/genética , Quinases Associadas a Receptores de Interleucina-1/efeitos dos fármacos , Quinases Associadas a Receptores de Interleucina-1/genética , NF-kappa B/efeitos dos fármacos , NF-kappa B/genética , Osteoartrite/metabolismo , Fragmentos de Peptídeos/farmacologia , Fenótipo , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/efeitos dos fármacos , Proteínas Tirosina Quinases/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/efeitos dos fármacos , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Receptor do Fator de Crescimento Transformador beta Tipo II/efeitos dos fármacos , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Fator de Transcrição AP-1/efeitos dos fármacos , Fator de Transcrição AP-1/genética
3.
Osteoarthritis Cartilage ; 29(3): 402-412, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33227437

RESUMO

OBJECTIVE: Cellular senescence is a phenotypic state characterized by stable cell-cycle arrest, enhanced lysosomal activity, and the secretion of inflammatory molecules and matrix degrading enzymes. Senescence has been implicated in osteoarthritis (OA) pathophysiology; however, the mechanisms that drive senescence induction in cartilage and other joint tissues are unknown. While numerous physiological signals are capable of initiating senescence, one emerging theme is that damaged cells convert to senescence in response to sustained mitogenic stimulation. The goal of this study was to develop an in vitro articular cartilage explant model to investigate the mechanisms of senescence induction. DESIGN: This study utilized healthy cartilage derived from cadaveric equine stifles and human ankles. Explants were irradiated to initiate DNA damage, and mitogenic stimulation was provided through serum-containing medium and treatment with transforming growth factor ß1 and basic fibroblastic growth factor. Readouts of senescence were a quantitative flow cytometry assay to detect senescence-associated ß galactosidase activity (SA-ß-gal), immunofluorescence for p16 and γH2AX, and qPCR for the expression of inflammatory genes. RESULTS: Human cartilage explants required both irradiation and mitogenic stimulation to induce senescence as compared to baseline control conditions (7.16% vs 2.34% SA-ß-gal high, p = 0.0007). These conditions also resulted in chondrocyte clusters within explants, a persistent DNA damage response, increased p16, and gene expression changes. CONCLUSIONS: Treatment of cartilage explants with mitogenic stimuli in the context of cellular damage reliably induces high levels of SA-ß-gal activity and other senescence markers, which provides a physiologically relevant model system to investigate the mechanisms of senescence induction.


Assuntos
Cartilagem Articular/metabolismo , Senescência Celular/genética , Condrócitos/metabolismo , Animais , Articulação do Tornozelo , Cartilagem Articular/citologia , Cartilagem Articular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Quimiocina CCL2/efeitos dos fármacos , Quimiocina CCL2/genética , Condrócitos/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Dano ao DNA/genética , Fator 2 de Crescimento de Fibroblastos/farmacologia , Expressão Gênica/efeitos dos fármacos , Histonas/efeitos dos fármacos , Histonas/metabolismo , Cavalos , Humanos , Técnicas In Vitro , Inflamação/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Interleucina-6/genética , Metaloproteinase 13 da Matriz/efeitos dos fármacos , Metaloproteinase 13 da Matriz/genética , Mitógenos/farmacologia , Joelho de Quadrúpedes , Fator de Crescimento Transformador beta1/farmacologia , beta-Galactosidase/efeitos dos fármacos , beta-Galactosidase/metabolismo
4.
Osteoarthritis Cartilage ; 27(4): 703-711, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30590195

RESUMO

OBJECTIVE: To compare key intracellular redox-regulated signaling pathways in chondrocytes derived from knee joint femoral cartilage and ankle joint talar cartilage in order to determine if differences exist that might contribute to the lower prevalence of ankle osteoarthritis (OA). METHODS: Femoral and talar chondrocytes were treated with H2O2 generators (menadione or 2-3-dimethoxy-1,4-napthoquinone (DMNQ), fragments of fibronectin (FN-f)) to stimulate MAP kinase signaling (MAPK), or with IGF-1 to stimulate the Akt signaling pathway. Hyperoxidation of the peroxiredoxins, used as a measure of redox status, and phosphorylation of proteins pertinent to MAPK (p38, ERK, JNK, c-Jun) and Akt (Akt, PRAS40) signaling cascades were detected by immunoblotting. RESULTS: Treatment of femoral and talar chondrocytes with menadione, DMNQ or FN-f led to a time dependent increase in extracellular-regulated kinase (ERK) and p38 phosphorylation. DMNQ and FN-f stimulation enhanced phosphorylation of JNK and its downstream substrate, c-Jun. Menadione treatment did not stimulate JNK activity but hyperoxidized the peroxiredoxins and inhibited IGF-1-induced Akt activation. In all experiments, chondrocytes derived from the femur and talar joints displayed comparable MAP kinase responses after treatment with various catabolic stimuli, as well as similar Akt signaling responses after IGF-1 treatment. CONCLUSIONS: MAP kinase and Akt signaling in response to factors that modulate the intracellular redox status were similar in chondrocytes from knee and ankle joints suggesting that redox signaling differences do not explain differences in OA prevalence. Talar chondrocytes, when isolated from their native matrix, can be used to examine redox-regulated cell signaling events relevant to OA in either joint.


Assuntos
Articulação do Tornozelo/metabolismo , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Articulação do Joelho/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Osteoartrite/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Articulação do Tornozelo/patologia , Cartilagem Articular/patologia , Células Cultivadas , Condrócitos/patologia , Feminino , Humanos , Immunoblotting , Articulação do Joelho/patologia , Masculino , Pessoa de Meia-Idade , Osteoartrite/patologia , Oxirredução , Fosforilação , Transdução de Sinais , Doadores de Tecidos
5.
Osteoarthritis Cartilage ; 27(12): 1831-1840, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31536814

RESUMO

OBJECTIVE: Synovium contains multipotent progenitor/stromal cells (MPCs) with potential to participate in cartilage repair. Understanding the identity of these MPCs will allow their therapeutic potential to be fully exploited. Hence this study aimed to identify primary synovial MPCs and characterize them in the context of cartilage regeneration. METHODS: Primary MPC/MPC-subset specific markers in synovium were identified by FACS analysis of uncultured cells. MPC-subsets from human synovium obtained from patients undergoing total knee arthroplasty were FACS sorted, cultured, immunophenotyped and chondrogenically differentiated. The anatomical localization of MPCs in synovium was examined using immunohistochemistry. Finally, the presence of these MPC subsets in healthy synovium obtained from human organ donors was examined. RESULTS: A combination of CD45, CD31, CD73 and CD90 can isolate two distinct MPC-subsets in synovium. These MPC-subsets, freshly isolated from synovium, did not express CD45 or CD31, but expressed CD73. Additionally, a sub-population of CD73+ cells also expressed CD90. CD45-CD31-CD73+CD90- cells were significantly more chondrogenic than CD45-CD31-CD73+CD90+ cells in the presence of TGFß1. Interestingly, reduced chondrogenic ability of CD73+CD90+ cells could be reversed by the addition of BMP2, showing discrete chondrogenic factor requirements by distinct cell-subsets. In addition, these MPCs had distinct anatomical localization; CD73 was expressed both in intimal and sub-intimal region while CD90 was enriched in the sub-intimal region. We further demonstrated that these subsets are also present in healthy synovium. CONCLUSIONS: We provide indications that primary MPCs in synovial intima and sub-intima are phenotypically and functionally distinct with different chondrogenic properties.


Assuntos
Cartilagem Articular/fisiologia , Diferenciação Celular/fisiologia , Condrogênese/fisiologia , Células-Tronco Multipotentes/metabolismo , Osteoartrite do Joelho , Regeneração/fisiologia , 5'-Nucleotidase/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Moléculas de Adesão Celular/metabolismo , Feminino , Citometria de Fluxo , Proteínas Ligadas por GPI/metabolismo , Humanos , Imuno-Histoquímica , Imunofenotipagem , Antígenos Comuns de Leucócito/metabolismo , Masculino , Pessoa de Meia-Idade , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Receptores de Quimiocinas/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Membrana Sinovial/citologia , Antígenos Thy-1/metabolismo
6.
Osteoarthritis Cartilage ; 25(9): 1505-1515, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28587781

RESUMO

OBJECTIVE: Aberrant Wnt signaling may contribute to osteoarthritis (OA) but the Wnt family members involved have not been fully identified. The purpose of this study was to investigate the role of Wnt5a as a potential mediator of cartilage destruction in OA. DESIGN: Immunohistochemistry to detect Wnt5a was performed using normal and OA human articular cartilage. Cultured normal human chondrocytes were treated with fibronectin fragments (FN-f) as a catabolic stimulus or recombinant Wnt5a protein with or without pretreatment using a panel of signaling inhibitors. Expression of Wnt5a, anabolic genes and catabolic genes were determined by quantitative real-time PCR. Production of Wnt5a protein and matrix metalloproteinases (MMPs) as well as activation of signaling proteins were analyzed by immunoblotting. RESULTS: Wnt5a was present in human articular cartilage with OA changes and its expression and secretion were increased in FN-f stimulated chondrocytes. FN-f stimulated Wnt5a production through the c-Jun N-terminal kinase (JNK) and extracellular signal-related kinase (ERK) pathways. Wnt5a reduced aggrecan gene expression after 48 h of treatment. Wnt5a seemed to promote MMP1, -3, and -13 expression as well as MMP1 and MMP13 protein production in normal human chondrocytes. Wnt5a inhibitor peptides did not affect FN-f induced MMP production. Wnt5a activated ß-catenin independent signaling including calmodulin-dependent protein kinase II (CaMKII), JNK, p38, ERK1/2, p65 and Akt. Inhibition of JNK, p38, ERK, PI-3 kinase and CaMKII by specific signaling inhibitors suppressed Wnt5a mediated MMP1 and MMP13 production. CONCLUSIONS: Wnt5a is present in human OA cartilage and can promote chondrocyte catabolic activity through non-canonical Wnt signaling, which suggests a potential role in OA.


Assuntos
Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Metaloproteinases da Matriz/biossíntese , Osteoartrite/metabolismo , Proteína Wnt-5a/fisiologia , Adulto , Idoso , Agrecanas/biossíntese , Agrecanas/genética , Cartilagem Articular/citologia , Cartilagem Articular/efeitos dos fármacos , Células Cultivadas , Condrócitos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Metabolismo/fisiologia , Pessoa de Meia-Idade , Osteoartrite/patologia , Proteínas Recombinantes/farmacologia , Via de Sinalização Wnt/fisiologia , Proteína Wnt-5a/farmacologia , Adulto Jovem
7.
Osteoarthritis Cartilage ; 25(9): 1516-1521, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28545881

RESUMO

INTRODUCTION: Insulin-like growth factor-1 (IGF-1) promotes matrix synthesis and cell survival in cartilage. Chondrocytes from aged and osteoarthritic cartilage have a reduced response to IGF-1. The purpose of this study was to determine the effect of free fatty acids (FFA) present in a high-fat diet on IGF-1 function in cartilage and the role of endoplasmic reticulum (ER) stress. METHODS: C57BL/6 male mice were maintained on either a high-fat (60% kcal from fat) or a low-fat (10% kcal from fat) diet for 4 months. Mice were then sacrificed; femoral head cartilage caps were collected and treated with IGF-1 to measure proteoglycan (PG) synthesis. Cultured human chondrocytes were treated with 500 µM FFA palmitate or oleate, followed by stimulation with (100 ng/ml) IGF-1 overnight to measure CHOP (a protein marker for ER stress) and PG synthesis. Human chondrocytes were pre-treated with palmitate or 1 mM 4-phenyl butyric acid (PBA) or 1 µM C-Jun N terminal Kinase (JNK) inhibitor, and IGF-1 function (PG synthesis and signaling) was measured. RESULTS: Cartilage explants from mice on the high fat-diet showed reduced IGF-1 mediated PG synthesis compared to a low-fat group. Treatment of human chondrocytes with palmitate induced expression of CHOP, activated JNK and inhibited IGF-1 function. PBA, a small molecule chemical chaperone that alleviates ER stress rescued IGF-1 function and a JNK inhibitor rescued IGF-1 signaling. CONCLUSIONS: Palmitate-induced ER stress inhibited IGF-1 function in chondrocytes/cartilage via activating the mitogen-activated protein (MAP) kinase JNK. This is the first study to demonstrate that ER stress is metabolic factor that regulates IGF-1 function in chondrocytes.


Assuntos
Condrócitos/efeitos dos fármacos , Dieta Hiperlipídica , Fator de Crescimento Insulin-Like I/fisiologia , Ácido Palmítico/farmacologia , Animais , Cartilagem Articular/citologia , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Fator de Crescimento Insulin-Like I/antagonistas & inibidores , Fator de Crescimento Insulin-Like I/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Ácido Oleico/farmacologia , Fosforilação/efeitos dos fármacos , Proteoglicanas/biossíntese
8.
Osteoarthritis Cartilage ; 24(6): 1036-46, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26778533

RESUMO

OBJECTIVE: Many cell types lose responsiveness to anabolic factors during inflammation and disease. Osteogenic Protein 1 (OP1/BMP7) was evaluated for the ability to enhance extracellular matrix synthesis in healthy and OA meniscus cells. Mechanisms of cell response to OP1 were explored. DESIGN: Meniscus and cartilage tissues from healthy tissue donors and osteoarthritis (OA) patients undergoing total knee arthroplasties were acquired. Primary cell cultures were stimulated with OP1 and/or inflammatory factors (IL1α, IL1ß, or fibronectin fragments (FnF)) and cellular responses were analyzed by RT-qPCR and immunoblots. Frozen section immunohistochemistry (IHC) was conducted to assess OP1 and receptor proteins in normal and OA meniscus. RESULTS: OP1 treatment of normal meniscus cells resulted in significant, dose-dependent increases in ACAN (aggrecan) and COL2A1, and decreased MMP13 gene transcription, while only ACAN was upregulated (P < 0.01) at the highest dose of OP1 in OA meniscus cells. OP1 induced significantly more ACAN gene transcription in normal meniscus than normal articular cartilage (P = 0.05), and no differences between normal and OA cartilage were detected. Receptor expression and kinetics of canonical signaling activation were similar between normal and OA specimens. Normal meniscus cells treated with inflammatory factors were refractory to OP1 stimulation. Smad1 phosphorylation at an inhibitory site was induced (P = 0.01 for both normal and OA meniscus) by inflammatory cytokine treatment. CONCLUSIONS: The meniscus demonstrates resistance to OP1 stimulation in OA and in the presence of inflammatory mediators. MAPK-mediated Smad1 linker phosphorylation is a possible mediator of the loss of anabolic extracellular matrix production in the inflammatory cytokine affected meniscus.


Assuntos
Osteoartrite , Agrecanas , Proteína Morfogenética Óssea 7 , Cartilagem Articular , Células Cultivadas , Condrócitos , Humanos , Menisco
9.
Knee Surg Sports Traumatol Arthrosc ; 24(6): 1826-35, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27120191

RESUMO

The diagnosis and the prompt treatment of early osteoarthritis (OA) represent vital steps for delaying the onset and progression of fully blown OA, which is the most common form of arthritis, involving more than 10 % of the world's population older than 60 years of age. Nonsurgical treatments such as physiotherapy, anti-inflammatory medications, and other disease-modifying drugs all have modest and short-lasting effect. In this context, the biological approaches have recently gained more and more attention. Growth factors, blood derivatives, such as platelet concentrates, and mesenchymal adult stem cells, either expanded or freshly isolated, are advocated amongst the most promising tool for the treatment of OA, especially in the early phases. Primarily targeted towards focal cartilage defects, these biological agents have indeed recently showed promising results to relieve pain and reduce inflammation in patients with more advanced OA as well, with the final aim to halt the progression of the disease and the need for joint replacement. However, despite of a number of satisfactory in vitro and pre-clinical studies, the evidences are still limited to support their clinical efficacy in OA setting.


Assuntos
Cartilagem Articular , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Transplante de Células-Tronco Mesenquimais/métodos , Osteoartrite do Joelho/terapia , Plasma Rico em Plaquetas , Regeneração , Tecido Adiposo/citologia , Progressão da Doença , Intervenção Médica Precoce , Humanos , Inflamação , Células-Tronco Mesenquimais , Osteoartrite/terapia , Dor
10.
Osteoarthritis Cartilage ; 23(9): 1523-31, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25937027

RESUMO

OBJECTIVE: We determined if the epidermal growth factor receptor ligand HB-EGF is produced in cartilage and if it regulates chondrocyte anabolic or catabolic activity. METHODS: HB-EGF expression was measured by quantitative PCR using RNA isolated from mouse knee joint tissues and from normal and osteoarthritis (OA) human chondrocytes. Immunohistochemistry was performed on normal and OA human cartilage and meniscus sections. Cultured chondrocytes were treated with fibronectin fragments (FN-f) as a catabolic stimulus and osteogenic protein 1 (OP-1) as an anabolic stimulus. Effects of HB-EGF on cell signaling were analyzed by immunoblotting of selected signaling proteins. MMP-13 was measured in conditioned media, proteoglycan synthesis was measured by sulfate incorporation, and matrix gene expression by quantitative PCR. RESULTS: HB-EGF expression was increased in 12-month old mice at 8 weeks after surgery to induce OA and increased amounts of HB-EGF were noted in human articular cartilage from OA knees. FN-f stimulated chondrocyte HB-EGF expression and HB-EGF stimulated chondrocyte MMP-13 production. However, HB-EGF was not required for FN-f stimulation of MMP-13 production. HB-EGF activated the ERK and p38 MAP kinases and stimulated phosphorylation of Smad1 at an inhibitory serine site which was associated with inhibition of OP-1 mediated proteoglycan synthesis and reduced aggrecan (ACAN) but not COL2A1 expression. CONCLUSION: HB-EGF is a new factor identified in OA cartilage that promotes chondrocyte catabolic activity while inhibiting anabolic activity suggesting it could contribute to the catabolic-anabolic imbalance seen in OA cartilage.


Assuntos
Condrócitos/metabolismo , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/biossíntese , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/fisiologia , Osteoartrite/metabolismo , Agrecanas/análise , Animais , Proteína Morfogenética Óssea 7/farmacologia , Cartilagem/metabolismo , Cartilagem Articular/metabolismo , Condrócitos/efeitos dos fármacos , Colágeno Tipo II/análise , Fibronectinas/farmacologia , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/análise , Humanos , Immunoblotting , Imuno-Histoquímica , Técnicas In Vitro , Articulação do Joelho/metabolismo , Metaloproteinase 13 da Matriz/análise , Camundongos , Osteoartrite do Joelho/metabolismo , Fosforilação , Proteoglicanas/biossíntese , Reação em Cadeia da Polimerase em Tempo Real , Transfecção , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
11.
Osteoarthritis Cartilage ; 23(2): 266-74, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25450855

RESUMO

OBJECTIVE: Interleukin-1 is one of the inflammatory cytokines elevated after traumatic joint injury that plays a critical role in mediating cartilage tissue degradation, suppressing matrix biosynthesis, and inducing chondrocyte apoptosis, events associated with progression to post-traumatic osteoarthritis (PTOA). We studied the combined use of insulin-like growth factor-1 (IGF-1) and dexamethasone (Dex) to block these multiple degradative effects of cytokine challenge to articular cartilage. METHODS: Young bovine and adult human articular cartilage explants were treated with IL-1α in the presence or absence of IGF-1, Dex, or their combination. Loss of sulfated glycosaminoglycans (sGAG) and collagen were evaluated by the DMMB and hydroxyproline assays, respectively. Matrix biosynthesis was measured via radiolabel incorporation, chondrocyte gene expression by qRT-PCR, and cell viability by fluorescence staining. RESULTS: In young bovine cartilage, the combination of IGF-1 and Dex significantly inhibited the loss of sGAG and collagen, rescued the suppression of matrix biosynthesis, and inhibited the loss of chondrocyte viability caused by IL-1α treatment. In adult human cartilage, only IGF-1 rescued matrix biosynthesis and only Dex inhibited sGAG loss and improved cell viability. Thus, the combination of IGF-1 + Dex together showed combined beneficial effects in human cartilage. CONCLUSIONS: Our findings suggest that the combination of IGF-1 and Dex has greater beneficial effects than either molecule alone in preventing cytokine-mediated cartilage degradation in adult human and young bovine cartilage. Our results support the use of such a combined approach as a potential treatment relevant to early cartilage degradative changes associated with joint injury.


Assuntos
Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/lesões , Dexametasona/farmacologia , Glucocorticoides/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Osteoartrite/etiologia , Animais , Bovinos , Citocinas/administração & dosagem , Dexametasona/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Fator de Crescimento Insulin-Like I/uso terapêutico , Interleucina-1alfa/administração & dosagem , Osteoartrite/prevenção & controle
12.
Lupus ; 23(9): 881-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24786785

RESUMO

OBJECTIVE: Interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-alpha (IFN-α), and free light chains (FLCs: lambda, kappa) have all been noted to be of importance in systemic lupus erythematosus (SLE). Herein, we quantified and explored the relationship between these inflammatory mediators and disease activity in SLE; and stratified by their current anti-dsDNA antibody status. METHODS: Seventy-seven SLE patients underwent assessment of disease activity using the SLE disease activity index (SLEDAI). Serum FLC (lambda, kappa, and total), IL-6, IL-10, and IFN-α were quantified. Demographics of disease characteristics were determined by chart reviews. Statistical analyses included Mann-Whitney test, chi square, and linear regression analyses. RESULTS: Mean (SD) age of the patients was 44.9 ± 12.7 years; SLEDAI (mean ± SD) was 3.4 ± 4.0. Serum lambda FLC levels had a moderate correlation (r = 0.46 with physician global assessment, 0.44 with SLEDAI) and the strongest correlation with disease activity as compared with other inflammatory mediators including current dsDNA antibody status. After adjusting for prednisone use, the correlation of lambda FLC with PGA (r = 0.48) and SLEDAI (r = 0.52) was better than of current dsDNA antibody status with PGA (r = 0.33) and adjusted SLEDAI (r = 0.24), respectively. IL-10 and IFN-α activity did not correlate with disease activity. Serum FLC and IL-6 levels could differentiate between active and inactive SLE patients. Serum lambda FLC and IL-6 levels differed significantly among patients with and without current dsDNA antibodies. Serum lambda FLC levels accounted for 31% of variance in SLEDAI scores. CONCLUSION: Serum FLC and IL-6 are potentially useful biomarkers of disease activity in SLE. Further studies, with larger study sample and longitudinal design, are indicated.


Assuntos
Anticorpos Antinucleares/sangue , Cadeias kappa de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/sangue , Interferon-alfa/sangue , Interleucina-10/sangue , Interleucina-6/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Osteoarthritis Cartilage ; 21(12): 1933-41, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24007885

RESUMO

OBJECTIVE: Traumatic joint injury can initiate early cartilage degeneration in the presence of elevated inflammatory cytokines (e.g., tumor necrosis factor (TNF)-α and interleukin (IL)-6). The positive/negative effects of post-injury dynamic loading on cartilage degradation and repair in vivo are not well-understood. This study examined the effects of dynamic strain on immature bovine cartilage in vitro challenged with TNF-α + IL-6 and its soluble receptor (sIL-6R) with/without initial mechanical injury. METHODS: Groups of mechanically injured or non-injured explants were cultured in TNF-α + IL-6/sIL-6R for 8 days. Intermittent dynamic compression was applied concurrently at 10%, 20%, or 30% strain amplitude. Outcome measures included sulfated glycosaminoglycan (sGAG) loss (dimethylmethylene blue (DMMB)), aggrecan biosynthesis ((35)S-incorporation), aggrecanase activity (Western blot), chondrocyte viability (fluorescence staining) and apoptosis (nuclear blebbing via light microscopy), and gene expression (qPCR). RESULTS: In bovine explants, cytokine alone and injury-plus-cytokine treatments markedly increased sGAG loss and aggrecanase activity, and induced chondrocyte apoptosis. These effects were abolished by moderate 10% and 20% strains. However, 30% strain amplitude greatly increased apoptosis and had no inhibitory effect on aggrecanase activity. TNF + IL-6/sIL-6R downregulated matrix gene expression and upregulated expression of inflammatory genes, effects that were rescued by moderate dynamic strains but not by 30% strain. CONCLUSIONS: Moderate dynamic compression inhibits the pro-catabolic response of cartilage to mechanical injury and cytokine challenge, but there is a threshold strain amplitude above which loading becomes detrimental to cartilage. Our findings support the concept of appropriate loading for post-injury rehabilitation.


Assuntos
Apoptose/efeitos dos fármacos , Cartilagem Articular/efeitos dos fármacos , Condrócitos/efeitos dos fármacos , Citocinas/farmacologia , Interleucina-6/farmacologia , Estresse Mecânico , Fator de Necrose Tumoral alfa/farmacologia , Agrecanas/efeitos dos fármacos , Agrecanas/genética , Animais , Apoptose/genética , Cartilagem Articular/lesões , Cartilagem Articular/metabolismo , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/metabolismo , Colágeno Tipo II/efeitos dos fármacos , Colágeno Tipo II/genética , Citocinas/genética , Regulação para Baixo , Endopeptidases/efeitos dos fármacos , Endopeptidases/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glicosaminoglicanos/metabolismo , Interleucina-6/genética , Receptores de Interleucina-6/genética
14.
Osteoarthritis Cartilage ; 17(4): 513-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18829350

RESUMO

OBJECTIVE: An age-related decline in chondrocyte production of osteogenic protein-1 (OP-1) (Bone Morphogenetic Protein-7) may contribute to cartilage loss in osteoarthritis. This study was designed to determine if increased methylation of the OP-1 promoter might serve as a mechanism for the age-related decline in OP-1 expression. METHODS: Human articular chondrocytes were isolated from cartilage obtained after death from tissue donors (ages 19-86 years) without a known history of arthritis. DNA was obtained from isolated chondrocytes in primary culture and analyzed for OP-1 promoter methylation by polymerase chain reaction (PCR) after bisulfite treatment. Cultured cells were treated with the DNA methyltransferase inhibitor 5-azacytidine and OP-1 production was measured in the media by enzyme-linked immunosorbent assay (ELISA). RNA was isolated to measure expression of insulin-like growth factor-1 (IGF-1), the IGF-1 receptor (IGF-1R), aggrecan, and OP-1 by real-time PCR. RESULTS: Methylation of the OP-1 promoter was detected in chondrocytes isolated from tissue obtained from older adults and there was a positive correlation between age and OP-1 methylation status (n=22, R(2)=0.277, P=0.014). Inhibition of methylation in cultured cells with 5-azacytidine increased chondrocyte production of OP-1 protein and increased the expression of the IGF-1, the IGF-1R, aggrecan, and OP-1 genes but not GAPDH. CONCLUSION: Age-related methylation of the OP-1 promoter may contribute to a decrease in OP-1 production in cartilage and a decrease in expression of OP-1 responsive genes such as IGF-1, the IGF-1R, and aggrecan.


Assuntos
Envelhecimento/metabolismo , Proteína Morfogenética Óssea 7/genética , Cartilagem Articular/metabolismo , Metilação de DNA/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Agrecanas/biossíntese , Agrecanas/genética , Azacitidina/farmacologia , Proteína Morfogenética Óssea 7/biossíntese , Cartilagem Articular/citologia , Cartilagem Articular/efeitos dos fármacos , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Metilação de DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/genética , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Receptor IGF Tipo 1/biossíntese , Receptor IGF Tipo 1/genética , Adulto Jovem
15.
Osteoarthritis Cartilage ; 17(9): 1244-51, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19332178

RESUMO

OBJECTIVES: To investigate the effect of anti-apoptotic agents on cartilage degradation after a single impact to ankle cartilage. DESIGN: Ten human normal tali were impacted with the impulse of 1 Ns generating peak forces in the range of 600 N using a 4 mm diameter indenter. Eight millimeter cartilage plugs containing the 4 mm diameter impacted core and a 4 mm adjacent ring were removed and cultured with or without P188 surfactant (8 mg/ml), caspase-3 (10 uM), or caspase-9 (2 uM) inhibitors for 48 h. Results were assessed in the superficial and middle-deep layers immediately after injury at day 0 and at 2, 7 and 14 days after injury by live/dead cell and Tunel assays and by histology with Safranin O/fast green staining. RESULTS: A single impact to human articular cartilage ex vivo resulted in cell death, cartilage degeneration, and radial progression of apoptosis to the areas immediately adjacent to the impact. The P188 was more effective in preventing cell death than the inhibitors of caspases. It reduced cell death by more than 2-fold (P<0.05) in the core and by about 30% in the ring in comparison with the impacted untreated control at all time points. P188 also prevented radial expansion of apoptosis in the ring region especially in the first 7 days post-impaction (7.5% Tunel-positive cells vs 46% in the untreated control; P<0.01). Inhibitors of caspase-3 or -9 were effective in reducing cell death in the impacted core only at early time points, but were ineffective in doing so in the ring. Mankin score was significantly improved in the P188 and caspase-3 treated groups. CONCLUSIONS: Early intervention with the P188 and caspase-3 inhibitor may have therapeutic potential in the treatment of cartilage defects immediately after injury.


Assuntos
Traumatismos do Tornozelo/complicações , Articulação do Tornozelo/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Cartilagem Articular/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Traumatismos do Tornozelo/patologia , Articulação do Tornozelo/patologia , Cartilagem Articular/patologia , Morte Celular , Feminino , Humanos , Masculino , Estresse Mecânico , Fatores de Tempo
16.
J Tissue Eng Regen Med ; 11(8): 2373-2387, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-26999523

RESUMO

A principal purpose of tissue engineering is the augmentation, repair or replacement of diseased or injured human tissue. This study was undertaken to determine whether human biopsies as a cell source could be utilized for successful engineering of human phalanges consisting of both bone and cartilage. This paper reports the use of cadaveric human chondrocytes and periosteum as a model for the development of phalanx constructs. Two factors, osteogenic protein-1 [OP-1/bone morphogenetic protein-7 (BMP7)], alone or combined with insulin-like growth factor (IGF-1), were examined for their potential enhancement of chondrocytes and their secreted extracellular matrices. Design of the study included culture of chondrocytes and periosteum on biodegradable polyglycolic acid (PGA) and poly-l-lactic acid (PLLA)-poly-ε-caprolactone (PCL) scaffolds and subsequent implantation in athymic nu/nu (nude) mice for 5, 20, 40 and 60 weeks. Engineered constructs retrieved from mice were characterized with regard to genotype and phenotype as a function of developmental (implantation) time. Assessments included gross observation, X-ray radiography or microcomputed tomography, histology and gene expression. The resulting data showed that human cell-scaffold constructs could be successfully developed over 60 weeks, despite variability in donor age. Cartilage formation of the distal phalanx models enhanced with both OP-1 and IGF-1 yielded more cells and extracellular matrix (collagen and proteoglycans) than control chondrocytes without added factors. Summary data demonstrated that human distal phalanx models utilizing cadaveric chondrocytes and periosteum were successfully fabricated and OP-1 and OP-1/IGF-1 accelerated construct development and mineralization. The results suggest that similar engineering and transplantation of human autologous tissues in patients are clinically feasible. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Condrócitos/metabolismo , Falanges dos Dedos da Mão/metabolismo , Periósteo/metabolismo , Engenharia Tecidual/métodos , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Condrócitos/patologia , Falanges dos Dedos da Mão/patologia , Falanges dos Dedos da Mão/transplante , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Periósteo/patologia
17.
J Histochem Cytochem ; 46(6): 723-9, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9603783

RESUMO

The depletion of the pericellular and territorial matrices in articular cartilage is considered to be one of the earliest events in pathobiology of osteoarthritis (OA). A newly discovered family of proteins with a disintegrin-like and metalloproteinase-like domain (ADAM) may be involved in matrix degradation as well as in cell-cell and cell-matrix interactions. The purpose of this study was to determine by in situ hybridization whether human articular chondrocytes from newborn, normal adult, and OA cartilages express messenger RNA for ADAM-10, one of the members of this family, and by semiquantitative RT-PCR to compare the levels of this expression. The results confirmed the expression of ADAM-10 by human articular chondrocytes and revealed the highest levels of expression in the continuously remodeling cartilage of newborns and the most fibrillated areas of OA cartilage, especially the regions of cell clusters. Importantly, ADAM-10 mRNA expression was evident in tissues with the greatest loss of Safranin O staining from the territorial and interterritorial matrix of the chondrocytes. Messenger RNA was upregulated in OA tissue compared to the age-matched normal cartilage, as detected by RT-PCR. Upregulated levels of ADAM-10 mRNA expression appear to be related to the degree of cartilage damage and/or degradation, which suggests a potential role for at least one member of this new family in the cartilage matrix destruction accompanying OA.


Assuntos
Cartilagem Articular/metabolismo , Proteínas de Membrana/metabolismo , Metaloendopeptidases/metabolismo , Osteoartrite/metabolismo , Proteínas ADAM , Proteína ADAM10 , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Secretases da Proteína Precursora do Amiloide , Células Cultivadas , Pré-Escolar , Corantes , Feminino , Humanos , Hibridização In Situ , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fenazinas , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Transcrição Gênica
18.
J Histochem Cytochem ; 49(9): 1165-76, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11511685

RESUMO

The objective of our study was to determine the tissue distribution and localization of ADAM-10 protein in human and bovine cartilage and the changes it undergoes with cartilage degeneration seen in osteoarthritis (OA) and under the influence of interleukin-1 (IL-1). Human normal and OA articular cartilage and bovine nasal cartilage cultured in the presence of IL-1alpha were processed for histology and immunohistochemistry. ADAM-10 protein was extracted from human cartilage and analyzed by Western blotting using anti-ADAM-10 antibodies. Fluor S Image analyzer and Quantity One software program were applied to quantify the total amount of ADAM-10. ADAM-10 protein was detected in both human and bovine cartilage. The strongest immunostaining was found in the cytoplasm and/or cell membranes of the superficial and upper middle layer of normal adult human cartilage, in the clusters and fibrillated areas of OA cartilage, and in IL-1alpha-stimulated bovine nasal cartilage. The distribution of ADAM-10 protein in bovine nasal cartilage was dependent on the length of exposure to IL-1alpha and corresponded to the areas of proteoglycan depletion. By Western blotting analysis of human cartilage, ADAM-10 was primarily detected in the membrane-enriched fraction and its levels were increased in degenerated and OA cartilage compared to normal cartilage. The results of this study suggest that ADAM-10 might be an important factor associated with cartilage degenerative processes. (J Histochem Cytochem 49:1165-1176, 2001)


Assuntos
Cartilagem Articular/metabolismo , Cartilagem/metabolismo , Interleucina-1/metabolismo , Proteínas de Membrana/metabolismo , Metaloendopeptidases/metabolismo , Mucosa Nasal/metabolismo , Osteoartrite/metabolismo , Proteínas ADAM , Proteína ADAM10 , Adulto , Idoso , Idoso de 80 Anos ou mais , Secretases da Proteína Precursora do Amiloide , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Western Blotting , Cartilagem/ultraestrutura , Cartilagem Articular/ultraestrutura , Bovinos , Membrana Celular/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Proteínas de Membrana/imunologia , Metaloendopeptidases/imunologia , Pessoa de Meia-Idade , Regulação para Cima
19.
J Histochem Cytochem ; 49(10): 1211-20, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11561005

RESUMO

Culture of articular chondrocytes in alginate beads offers several advantages over culture in monolayer; cells retain their phenotype for 8 months or longer. Earlier studies of chondrocytes cultured in alginate concentrated on collagen and proteoglycan synthesis. However, gene expression by in situ hybridization (ISH) has not been investigated. The purposes of the present study on human chondrocytes were (a) to modify the ISH procedure for the alginate beads to examine the mRNA expression of alpha1 (II) procollagen, aggrecan, and two matrix metalloproteinases (MMP-3 and MMP-8) thought to be involved in cartilage matrix degradation, and (b) to compare expression in cultured chondrocytes with that in chondrocytes of intact human cartilage. The modifications made for ISH include the presence of CaCl2 and BaCl2 in the fixation and washing steps and exclusion of cetyl pyridinium chloride. By ISH we show that aggrecan, MMP-3, and MMP-8 are continuously expressed during 8 months of culture. The alpha1 (II) procollagen gene is expressed only during the first 2 months of culture and after 3 months its expression is undetectable, which is consistent with its absence in adult articular cartilage. By Western blotting, Type II collagen protein had been synthesized and deposited in both the cell-associated and further-removed matrix compartments at 7 and 14 days of culture. These data indicate that chondrocytes cultured in alginate beads could be preserved for immunohistochemistry and ISH and that culture of human chondrocytes in alginate beads may serve as a good model for studying cartilage-specific phenotype as well as factors that influence cartilage matrix turnover.


Assuntos
Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Proteínas da Matriz Extracelular , RNA Mensageiro/metabolismo , Adulto , Agrecanas , Western Blotting , Cartilagem Articular/citologia , Cartilagem Articular/crescimento & desenvolvimento , Células Cultivadas , Humanos , Imuno-Histoquímica , Hibridização In Situ , Recém-Nascido , Lectinas Tipo C , Masculino , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 8 da Matriz/genética , Metaloproteinase 8 da Matriz/metabolismo , Pró-Colágeno/genética , Pró-Colágeno/metabolismo , Proteoglicanas/genética , Proteoglicanas/metabolismo
20.
J Histochem Cytochem ; 48(2): 239-50, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10639490

RESUMO

This study demonstrates for the first time that human articular chondrocytes express osteogenic protein-1 (OP-1). OP-1 was originally purified from bone matrix and was shown to induce cartilage and bone formation. Both OP-1 protein and message were present in human normal and osteoarthritic (OA) cartilages. OP-1 mRNA was upregulated in OA cartilage compared with normal adult tissues. However, the level of mature OP-1 protein in the same OA tissues was downregulated, whereas the pro-OP-1 remained high. Moreover, these two forms of OP-1 were localized in an inverted manner. Mature OP-1 was primarily detected in the superficial layer, whereas the pro-form was mostly in the deep layer of cartilage. The presence of pro- and mature OP-1 in extracts of normal and OA cartilages was confirmed by Western blotting. These findings imply that articular chondrocytes continue to express and synthesize OP-1 throughout adulthood. The observed patterns of the distribution of pro- and mature OP-1 also suggest differences in the processing of this molecule by normal and OA chondrocytes and by the cells in the superficial and deep layers. Distinct distribution of OP-1 and its potential activation in deep zones and regions of cloning in OA cartilages may provide clues to the potential involvement of endogenous OP-1 in repair mechanisms. (J Histochem Cytochem 48:239-250, 2000)


Assuntos
Proteínas Morfogenéticas Ósseas/biossíntese , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Fator de Crescimento Transformador beta , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Proteína Morfogenética Óssea 7 , Proteínas Morfogenéticas Ósseas/genética , Criança , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Osteoartrite/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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