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1.
Aliment Pharmacol Ther ; 55(12): 1512-1523, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35538396

RESUMO

BACKGROUND: Conventional healthcare models struggle to engage those at risk of hepatitis C virus (HCV) infection. This international study evaluated point-of-care (PoC) HCV RNA diagnostic outreach and direct-acting antiviral (DAA) treatment for individuals receiving opioid agonist therapy (OAT) in community pharmacies. AIMS: We assessed the effectiveness of a roving nurse-led pathway offering PoC HCV RNA testing to OAT clients in community pharmacies relative to conventional care. METHODS: Pharmacies in Scotland, Wales, and Australia were randomised to provide PoC HCV RNA testing or conventional referral. Pharmacists directed OAT clients to on-site nurses (intervention) or local clinics (control). Infected participants were treated with DAAs, alongside OAT. Primary outcome was the number of participants with sustained virologic response at 12 weeks (SVR) and analysed using mixed effects logistic regression in the intention-to-treat (ITT) population. RESULTS: Forty pharmacies were randomised. The ITT population contained 1410 OAT clients. In the conventional arm (n = 648), 62 (10%) agreed to testing, 17 (27%) were tested, 6 (35%) were positive and 5 (83%) initiated treatment. In the intervention arm (n = 762), 148 (19%) agreed to testing, 144 (97%) were tested, 23 (16%) were positive and 22 (96%) initiated treatment. SVR was obtained by 2 (40%; conventional) and 18 (82%; intervention). Intervention arm participants had higher odds of testing, OR 16.95 (7.07-40.64, p < 0.001); treatment, OR 4.29 (1.43-12.92, p = 0.010); and SVR, OR 8.64 (1.82-40.91, p = 0.007). CONCLUSIONS: Nurse-led PoC diagnosis in pharmacies made HCV care more accessible for OAT clients relative to conventional care. However, strategies to improve testing uptake are required. TRIAL REGISTRATION: NCT03935906.


Assuntos
Hepatite C Crônica , Hepatite C , Farmácias , Abuso de Substâncias por Via Intravenosa , Analgésicos Opioides/uso terapêutico , Antivirais/uso terapêutico , Hepacivirus , Hepatite C/tratamento farmacológico , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/tratamento farmacológico , Humanos , RNA/uso terapêutico , Abuso de Substâncias por Via Intravenosa/tratamento farmacológico , Abuso de Substâncias por Via Intravenosa/epidemiologia
2.
J Med Econ ; 23(12): 1640-1652, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33107769

RESUMO

AIMS: Respiratory syncytial virus (RSV) is a common cause of respiratory infection in infants and severe infection can result in hospitalization. The passive immunization, palivizumab, is used as prophylaxis against RSV, however, use in the UK is restricted to populations at high risk of hospitalization. This study assesses the cost-effectiveness (CE) of palivizumab in premature infants with and without risk factors for hospitalization (congenital heart disease [CHD], bronchopulmonary dysplasia [BPD]). METHODS: A decision tree model, based on earlier CE analyses, was updated using data derived from targeted literature reviews and advice gained from a Round Table meeting. All costs were updated to 2019 prices. One-way and probabilistic sensitivity analyses were performed to assess the degree of uncertainty surrounding the results. RESULTS: Palivizumab is dominant (i.e. clinically superior and cost saving) when used in premature infants born ≤35 weeks gestational age (wGA) without CHD or BPD and aged <6 months at the start of the RSV season, infants aged <24 months with CHD and infants aged <24 months requiring treatment for BPD within the last 6 months. LIMITATIONS: One-way sensitivity analysis suggests that these results are highly sensitive to the efficacy of prophylaxis, number of doses, impact of long-term respiratory sequalae, rate of hospitalization and mortality due to RSV. A conservative approach has been taken toward long-term respiratory sequalae due to uncertainty around epidemiology and etiology and a lack of recent cost and utility data. CONCLUSIONS: Palivizumab prophylaxis is cost-effective in preventing severe RSV infection requiring hospital admission in a wider population than currently recommended in UK guidelines. Prophylaxis in premature infants born <29 wGA, 29-32 wGA and 33-35 wGA without CHD or BPD aged <6 months at the start of the RSV season is not funded under current guidance, however, prophylaxis has been demonstrated to be cost-effective in this analysis.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sinciciais Respiratórios , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Antivirais/uso terapêutico , Análise Custo-Benefício , Hospitalização , Humanos , Lactente , Recém-Nascido , Palivizumab/uso terapêutico , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Reino Unido
3.
J Transl Med ; 16(1): 214, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-30064459

RESUMO

BACKGROUND: A relationship between rheumatoid arthritis (RA) and periodontitis has been suggested from findings that individuals with RA are prone to have advanced periodontitis and vice versa. In search of possible common pathogenetic features of these two diseases, we investigated the presence of citrullinated proteins and expression of endogenous peptidylarginine deiminases (PAD2 and PAD4), in periodontal tissue of individuals with periodontitis and healthy controls, in relation to the periodontal pathogens Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), producing leukotoxin as virulence factor. These two oral bacteria have been suggested to be linked to anti-citrullinated protein antibodies in patients with RA. METHODS: Gingival tissue biopsies were obtained from 15 patients with periodontitis and 15 individuals without periodontal disease. Presence of CD3-positive lymphocytes, citrullinated proteins, PAD2, PAD4, P. gingivalis as well as A. actinomycetemcomitans and Mannheimia haemolytica produced leukotoxins were analysed by immunohistochemistry, followed by triple-blind semi-quantitative analysis. Mann-Whitney and Fisher's exact tests were used to analyse differences between groups. PADI2 and PADI4 mRNA levels were assessed by RT-qPCR and analysed using Wilcoxon signed rank test. RESULTS: Increased staining of citrullinated proteins was observed in gingival connective tissue from subjects with periodontitis (80%, 12/15) compared to healthy gingival tissue (27%, 4/15), whereas no differences were observed in gingival epithelium. There was also an increased staining of the citrullinating enzymes PAD2 and PAD4 in gingival connective tissue of patients with periodontitis whereas similar levels of PAD2 and PAD4 were observed in the gingival epithelium of the two groups. Similarly, the mRNA levels of PADI2 and PADI4 were also increased in the gingival tissue of patients with periodontitis compared to healthy controls. Furthermore, presence of P. gingivalis and leukotoxins was comparable in both epithelium and connective tissue, from the different investigated individuals with and without periodontitis, and there were no correlations between the presence of periodontal pathogens and the expression of citrullinated proteins or PAD enzymes. CONCLUSION: Chronic gingival inflammation is associated with increased local citrullination and PAD2 and PAD4 expression in periodontitis. The increased citrullination and PAD2 and PAD4 expression in periodontitis were, however, independent of the presence of periodontal pathogen P. gingivalis and A. actinomycetemcomitans leukotoxin.


Assuntos
Aggregatibacter actinomycetemcomitans/fisiologia , Citrulinação , Gengiva/enzimologia , Gengiva/microbiologia , Periodontite/enzimologia , Periodontite/microbiologia , Porphyromonas gingivalis/fisiologia , Desiminases de Arginina em Proteínas/metabolismo , Adulto , Artrite Reumatoide/microbiologia , Artrite Reumatoide/patologia , Exotoxinas/metabolismo , Gengiva/patologia , Humanos , Inflamação/patologia , Linfócitos/patologia , Pessoa de Meia-Idade , Periodontite/genética , Periodontite/patologia , Desiminases de Arginina em Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
4.
J Biomed Graph Comput ; 3(4)2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24294351

RESUMO

BACKGROUND: Hand osteoarthritis (HOA) is typified by pain and reduced function. We hypothesised that people with HOA have enhanced sensitivity and activation of peripheral nociceptors in the hand, thereby potentiating chronic pain. In our study we aimed to assess if central sensitisation mediates pain perception in osteoarthritis of the hand. METHODS: Participants with proximal and distal interphalangeal joint (PIP/DIP) HOA and non-OA controls were recruited. Clinical pain scores using the visual analogue scale (VAS) were recorded before and after performing a painful hand task. Central pain processing was evaluated with functional brain neuroimaging (fMRI) using a finger flexion-extension (FFE) task performed over 3 minutes. Data was analysed with FMRIB software (www.fmrib.ox.ac.uk/fsl). Group mean activation of functional MRI signal between hand osteoarthritis and control non-arthritic participants was compared. RESULTS: Our group of hand OA participants reported high pain levels compared with non-arthritic controls as demonstrated by the mean VAS in hand OA participants of 59.31± 8.19 mm compared to 4.00 ± 1.89 mm in controls (p < 0.0001), despite all participants reporting analgesic use. Functional MRI analysis showed increased activation in the thalamus, cingulate, frontal and somatosensory cortex in the hand OA group but not in controls (thresholded at p < 0.05). Regions of activation were mapped to Brodmann areas 3, 4, 6, 9, 13, 22, 24 and 44. Activated regions found in our study are recognised higher brain pain processing centres implicated in central sensitisation. CONCLUSIONS: People with hand osteoarthritis demonstrated features of central sensitisation that was evident after a finger flexion-extension task using functional MRI. Functional MRI is a useful biomarker in detecting pain in hand osteoarthritis and could be used in future hand osteoarthritis pain studies to evaluate pain modulation strategies.

5.
Int J Rheumatol ; 2012: 703138, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23209475

RESUMO

Hand osteoarthritis (HOA) is a prevalent condition for which treatments are based on analgesia and physical therapies. Our primary objective was to evaluate pain perception in participants with HOA by assessing the characteristics of nodal involvement, pain threshold in each hand joint, and radiological severity. We hypothesised that inflammation in hand osteoarthritis joints enhances sensitivity and firing of peripheral nociceptors, thereby causing chronic pain. Participants with proximal and distal interphalangeal (PIP and DIP) joint HOA and non-OA controls were recruited. Clinical parameters of joint involvement were measured including clinical nodes, VAS (visual analogue score) for pain (0-100 mm scale), HAQ (health assessment questionnaire), and Kellgren-Lawrence scores for radiological severity and pain threshold measurement were performed. The mean VAS in HOA participants was 59.3 mm ± 8.19 compared with 4.0 mm ± 1.89 in the control group (P < 0.0001). Quantitative sensory testing (QST) demonstrated lower pain thresholds in DIP/PIP joints and other subgroups in the OA group including the thumb, metacarpophalangeal (MCPs), joints, and wrists (P < 0.008) but not in controls (P = 0.348). Our data demonstrate that HOA subjects are sensitised to pain due to increased firing of peripheral nociceptors. Future work to evaluate mechanisms of peripheral sensitisation warrants further investigation.

6.
Rheumatol Int ; 32(9): 2809-17, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21874326

RESUMO

Cartilage destruction is a hallmark of osteoarthritis (OA) and is characterized by increased protease activity resulting in the degradation of critical extracellular matrix (ECM) proteins essential for maintaining cartilage integrity. Tenascin-C (TN-C) is an ECM glycoprotein, and its expression is upregulated in OA cartilage. We aimed to investigate the presence of TN-C fragments in arthritic cartilage and establish whether they promote cartilage degradation. Expression of TN-C and its fragments was evaluated in cartilage from subjects undergoing joint replacement surgery for OA and RA compared with normal subjects by western blotting. The localization of TN-C in arthritic cartilage was also established by immunohistochemistry. Recombinant TN-C fragments were then tested to evaluate which regions of TN-C are responsible for cartilage-degrading activity in an ex vivo cartilage explant assay measuring glycosaminoglycan (GAG) release, aggrecanase and matrix metalloproteinase (MMP) activity. We found that specific TN-C fragments are highly upregulated in arthritic cartilage. Recombinant TN-C fragments containing the same regions as those identified from OA cartilage mediate cartilage degradation by the induction of aggrecanase activity. TN-C fragments mapping to the EGF-L and FN type III domains 3-8 of TN-C had the highest levels of aggrecan-degrading ability that was not observed either with full-length TN-C or with other domains of TN-C. TN-C fragments represent a novel mechanism for cartilage degradation in arthritis and may present new therapeutic targets for the inhibition of cartilage degradation.


Assuntos
Cartilagem Articular/metabolismo , Osteoartrite/metabolismo , Fragmentos de Peptídeos/metabolismo , Tenascina/metabolismo , Regulação para Cima , Animais , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/patologia , Endopeptidases/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Metaloproteinases da Matriz/metabolismo , Modelos Animais , Osteoartrite/patologia , Fragmentos de Peptídeos/farmacologia , Suínos , Tenascina/farmacologia
7.
Proteomics Clin Appl ; 4(5): 511-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-21137068

RESUMO

PURPOSE: Citrullination is a post-translational modification of arginine residues to citrulline catalyzed by peptidyl arginine deiminases. Induced expression of citrullinated proteins are frequently detected in various inflammatory states including arthritis; however, direct detection of citrullination in arthritic samples has not been successfully performed in the past. EXPERIMENTAL DESIGN: Citrullination of human fibrinogen, a candidate autoantigen in arthritis, was studied. Accurate identification of citrullinated fibrinogen peptides from rheumatoid arthritis synovial tissue specimens was performed using accurate mass and retention time analysis. RESULTS: A peptide with the sequence ESSSHHPGIAEFPSRGK corresponding to amino acids 559-575 of fibrinogen α-chain was identified to be citrullinated with an occupancy rate between 1.4 and 2.5%. Citrullination of the peptide KREEAPSLRPAPPPISGGGYRARPAK corresponding to amino acids 52-77 of the fibrinogen ß-chain was identified with an occupancy rate of 1.2%. CONCLUSIONS AND CLINICAL RELEVANCE: We report a proof of principle study for the identification of citrullinated proteins and within them, identification of citrullination sites and quantification of their occupancies in synovial tissue from rheumatoid arthritis patients using high-resolution MS. Detailed studies on which molecules are citrullinated in arthritis can provide information about their role in immune regulation and serve as novel biomarkers and potentially even as therapeutic targets.


Assuntos
Artrite Reumatoide/metabolismo , Citrulina/metabolismo , Fibrinogênio/metabolismo , Membrana Sinovial/metabolismo , Idoso , Sequência de Aminoácidos , Feminino , Fibrinogênio/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Processamento de Proteína Pós-Traducional , Espectrometria de Massas por Ionização por Electrospray/métodos
8.
Arthritis Rheum ; 62(1): 44-52, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20039432

RESUMO

OBJECTIVE: High titers of specific anti-citrullinated protein antibodies (ACPAs) are frequently present in the serum of rheumatoid arthritis (RA) patients, but their presence in synovial fluid is less well characterized. The purpose of this study was to compare the levels of antibody to 4 well-defined citrullinated candidate RA autoantigens in serum and synovial fluid and to determine whether antibodies to one citrullinated antigen are dominant over another. Furthermore, we studied their relationships with mutated citrullinated vimentin (MCV), a newly identified RA-specific serum assay, and the classic cyclic citrullinated peptide (CCP) in the synovial fluid of well-defined HLA-DR groups. METHODS: Paired serum and synovial fluid samples from 290 RA patients and serum samples from 100 age- and sex-matched healthy controls were analyzed for the presence of anti-MCV and anti-CCP antibodies and for reactivity to citrullinated fibrinogen, alpha-enolase, type II collagen, and vimentin. A total of 219 of the 290 patients were genotyped for the HLA-DR shared epitope alleles. RESULTS: Significantly higher proportions of antibodies against all RA-associated citrullinated antigens were found in synovial fluid as compared with serum. This was also true for the MCV and CCP responses but not for non-RA-associated anti-tetanus toxoid antibodies. As expected, we found a high correlation between citrullinated vimentin and MCV responses. All synovial fluid ACPAs were predominantly associated with HLA-DRB1*04 alleles and were confined to the CCP+/MCV+ subset of patients. CONCLUSION: MCV and CCP positivity represent a similar subset of RA patients, whereas ACPAs with different fine specificities fall into subgroups of anti-CCP+/anti-MCV+ patients. The levels of all specific ACPAs were elevated in synovial fluid, suggesting that there is local antibody production and/or retention of ACPAs at the site of inflammation governed by RA-predisposing genes.


Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Citrulina/imunologia , Peptídeos Cíclicos/imunologia , Líquido Sinovial/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Reumatoide/genética , Autoantígenos/imunologia , Biomarcadores Tumorais/imunologia , Citrulina/química , Colágeno Tipo II/imunologia , Proteínas de Ligação a DNA/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Fibrinogênio/química , Fibrinogênio/imunologia , Genótipo , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Fosfopiruvato Hidratase/imunologia , Proteínas Supressoras de Tumor/imunologia , Vimentina/química , Vimentina/genética , Vimentina/imunologia , Adulto Jovem
9.
Curr Opin Rheumatol ; 20(3): 300-5, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18388522

RESUMO

PURPOSE OF REVIEW: The purpose of this review is to describe how the current knowledge of antibodies to citrullinated protein antigens in rheumatoid arthritis and related conditions emerged; to discuss the diagnostic and prognostic value associated with antibodies to citrullinated protein antigens as a biomarker; and most importantly for this review, to discuss the potential pathogenetic significance of these antibodies. RECENT FINDINGS: Antibodies to citrullinated protein antigens have evolved from being mainly a diagnostic marker, to being recognized as something that can help us understand fundamental etiologic and pathogenetic features of rheumatoid arthritis. Fundamental in this context is the finding that rheumatoid arthritis can be divided into two distinct subsets by means of presence or absence of antibodies to citrullinated protein antigens. Thus, several genetic as well as environmental risk factors differ between these two variants of rheumatoid arthritis. From analysis of these genetic and environmental risk factors, new testable hypotheses have been produced concerning triggering of antibodies to citrullinated protein antigens, and potential pathogenicity of antibodies to citrullinated protein antigens and accompanying immune reactions. SUMMARY: The implications of the findings are that antibodies to citrullinated protein antigens can be used for early and precise diagnosis of a subset of rheumatoid arthritis with worse prognosis than other polyarthritides, and that a new basis is formed for etiologic and pathogenetic studies of antibodies to citrullinated protein antigens-positive rheumatoid arthritis.


Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/imunologia , Peptídeos Cíclicos/imunologia , Artrite Reumatoide/fisiopatologia , Autoanticorpos/sangue , Biomarcadores/sangue , Humanos , Inflamação/imunologia
10.
Methods Mol Med ; 136: 349-59, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17983159

RESUMO

Two-dimensional electrophoresis (2DE) is a powerful method for separation of complex mixtures of proteins. The standard procedure is not, however, well suited to analysis of articular cartilage, which contains high concentrations of proteoglycans, the polyanionic glycosaminoglycan chains of which interfere with isoelectric focusing. We have developed a method for selective removal of proteoglycans by precipitation with cetylpyridinium chloride, after which the residual cartilage proteins are amenable to conventional 2DE analysis. Using this method, reproducible 2D-patterns can be obtained from proteins secreted by articular cartilage. The separated proteins may then be visualized by metabolic radiolabeling and silver staining, digested in gel with trypsin, and identified by tandem mass spectrometry.


Assuntos
Cartilagem Articular/química , Cartilagem Articular/metabolismo , Eletroforese em Gel Bidimensional/métodos , Proteínas/análise , Proteoma/análise , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Cartilagem Articular/citologia , Condrócitos/citologia , Condrócitos/fisiologia , Meios de Cultivo Condicionados/química , Humanos , Osteoartrite/metabolismo , Osteoartrite/patologia , Proteoglicanas/química , Técnicas de Cultura de Tecidos
11.
Arthritis Rheum ; 56(11): 3715-25, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17968943

RESUMO

OBJECTIVE: Proteomic analysis has previously shown that activin A, a member of the transforming growth factor beta family, is produced by human articular cartilage. This study was undertaken to investigate whether activin A affects cartilage matrix catabolism and how its production is regulated. METHODS: The effect of exogenous activin A on interleukin-1-induced aggrecanase-generated neoepitope production was assessed by Western blotting, using medium from human cartilage explants. Levels of activin A production were determined by enzyme-linked immunosorbent assay. For genes of interest, messenger RNA (mRNA) induction in cartilage explants or primary chondrocyte monolayers was assessed by reverse transcriptase-polymerase chain reaction. Activin A activity in cartilage explant medium was measured by incubating it with human dermal fibroblasts and determining the increase in phospho-Smad2 by Western blotting. RESULTS: Activin A (1-10 ng/ml) suppressed aggrecanase-mediated cleavage of aggrecan in human articular cartilage. Activin A mRNA and protein secretion were induced by dissection and culture of human or porcine articular cartilage. This activin A was biologically active. Its production was due to an active cellular process and was enhanced in osteoarthritic (OA) tissue. Activin A production on dissection was reduced by 80% by the fibroblast growth factor (FGF) receptor inhibitor PD173074 and by 70% by the IKK inhibitor BMS345541. CONCLUSION: Activin A is potentially an anticatabolic molecule in articular cartilage. Its expression is induced by wounding in an FGF-2- and NF-kappaB-dependent manner. OA cartilage produced more activin A than did normal cartilage in vitro.


Assuntos
Ativinas/metabolismo , Cartilagem Articular/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , NF-kappa B/metabolismo , Osteoartrite do Joelho/metabolismo , Ativinas/farmacologia , Agrecanas/metabolismo , Animais , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/patologia , Citocinas/metabolismo , Citocinas/farmacologia , Endopeptidases/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Imidazóis/farmacologia , Osteoartrite do Joelho/patologia , Pirimidinas/farmacologia , Quinoxalinas/farmacologia , Proteína Smad2/metabolismo , Sus scrofa
12.
Arthritis Rheum ; 50(8): 2539-46, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15334468

RESUMO

OBJECTIVE: To investigate the effect of explantation and fine cutting of articular cartilage upon intracellular inflammatory signaling pathways and expression of interleukin-1 (IL-1). METHODS: Cartilage from porcine metacarpophalangeal joints was cultured in serum-free medium. Tissue extracts were examined for ERK activation by phosphorylated-Western blotting, for JNK and p38 MAPK activity by kinase assay, and for IkappaBalpha. IL-1alpha and IL-1beta messenger RNA (mRNA) was measured by reverse transcriptase-polymerase chain reaction. IL-1 activity was measured by the induction of serum amyloid A protein in cultured chondrocytes. RESULTS: All 3 MAPKs (p38, JNK, and ERK) were rapidly activated upon dissection and explantation of the cartilage. IL-1alpha and IL-1beta mRNA was also induced: the speed and magnitude of induction were increased if the explants had been finely cut. IL-1 activity that could be inhibited by IL-1 receptor antagonist or antibodies to IL-1alpha was found in extracts of explants cultured for 20 hours or lysates of cells isolated from them. This activity was likely due to intracellular proIL-1alpha that was not secreted. ProIL-1beta would not be detected because it is biologically inactive. The mechanism of inflammatory signaling pathway activation underlying the induction of IL-1 is unknown. CONCLUSION: Explantation and cutting of articular cartilage activates intracellular inflammatory signaling pathways and induces expression of mRNA for IL-1alpha and IL-1beta. Biologically active IL-1alpha protein was detectable in cartilage lysates and was probably intracellular proIL-1alpha. We were unable to show that IL-1 was secreted by chondrocytes.


Assuntos
Cartilagem Articular/fisiologia , Interleucina-1/análise , Proteínas Quinases JNK Ativadas por Mitógeno , Animais , Condrócitos/metabolismo , Técnicas de Cultura , Interleucina-1/genética , MAP Quinase Quinase 4 , Quinases de Proteína Quinase Ativadas por Mitógeno/análise , Proteínas Quinases Ativadas por Mitógeno/análise , RNA Mensageiro/análise , Transdução de Sinais/fisiologia , Suínos , Proteínas Quinases p38 Ativadas por Mitógeno
13.
J Biol Chem ; 279(42): 43514-21, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15292256

RESUMO

We show that proteomic analysis can be applied to study cartilage pathophysiology. Proteins secreted by articular cartilage were analyzed by two-dimensional SDS-PAGE and mass spectrometry. Cartilage explants were cultured in medium containing [35S]methionine/cysteine to radiolabel newly synthesized proteins. To resolve the cartilage proteins by two-dimensional electrophoresis, it was necessary to remove the proteoglycan aggrecan by precipitation with cetylpyridinium chloride. 50-100 radiolabeled protein spots were detected on two-dimensional gels of human cartilage cultures. Of 170 silver-stained proteins identified, 19 were radiolabeled, representing newly synthesized gene products. Most of these were known cartilage constituents. Several nonradiolabeled cartilage proteins were also detected. The secreted protein pattern of explants from 12 osteoarthritic joints (knee, hip, and shoulder) and 14 nonosteoarthritic adult joints were compared. The synthesis of type II collagen was strongly up-regulated in osteoarthritic cartilage. Normal adult cartilage synthesized little or no type II collagen in contrast to infant and juvenile cartilage. Potential regulatory molecules novel to cartilage were identified; pro-inhibin betaA and processed inhibin betaA (which dimerizes to activin A) were produced by all the osteoarthritic samples and half of the normals. Connective tissue growth factor and cytokine-like protein C17 (previously only identified as an mRNA) were also found. Activin induced the tissue inhibitor for metalloproteinases-1 in human chondrocytes. Its expression was induced in isolated chondrocytes by growth factors or interleukin-1. We conclude that type II collagen synthesis in articular cartilage is down-regulated at skeletal maturity and reactivated in osteoarthritis in attempted repair and that activin A may be an anabolic factor in cartilage.


Assuntos
Ativinas/genética , Cartilagem Articular/metabolismo , Condrócitos/fisiologia , Colágeno Tipo II/biossíntese , Subunidades beta de Inibinas/genética , Osteoartrite/metabolismo , Proteoma , Animais , Modelos Animais de Doenças , Glicosaminoglicanos/análise , Humanos , Técnicas de Cultura de Órgãos , Valores de Referência , Suínos , Inibidor Tecidual de Metaloproteinase-1/metabolismo
14.
Arthritis Rheum ; 50(2): 526-33, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14872495

RESUMO

OBJECTIVE: To determine whether the basic fibroblast growth factor (bFGF) mediates signal transduction in articular cartilage in response to mechanical loading. METHODS: Articular cartilage from porcine metacarpophalangeal or knee joints was cyclically loaded (62.5-250N) for 2 minutes in the absence or presence of a bFGF receptor inhibitor, SB 402451 (250 nM). Activation of the extracellularly regulated kinase MAP kinase ERK was measured by Western blot analysis. Changes in protein synthesis were assessed by measuring the incorporation of (35)S-Met/Cys into proteins secreted by cartilage explants or by isolated chondrocytes. RESULTS: Rapid activation of the ERK MAP kinase occurred when articular cartilage was loaded. This was dependent upon release of the bFGF because it was restricted by the FGF receptor inhibitor. Loaded explants were shown to release bFGF. Loading or bFGF stimulation of explants induced synthesis and secretion of tissue inhibitor of metalloproteinases 1 (TIMP-1), which was inhibited by SB 402451. CONCLUSION: Cyclical loading of articular cartilage causes bFGF-dependent activation of ERK and synthesis of TIMP-1.


Assuntos
Cartilagem Articular/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/fisiologia , Joelho de Quadrúpedes/metabolismo , Animais , Western Blotting , Cartilagem Articular/citologia , Cartilagem Articular/efeitos dos fármacos , Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Técnicas In Vitro , Proteínas Quinases Ativadas por Mitógeno/biossíntese , Pirimidinas/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Joelho de Quadrúpedes/citologia , Joelho de Quadrúpedes/efeitos dos fármacos , Estresse Mecânico , Suínos , Inibidor Tecidual de Metaloproteinase-1/biossíntese , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Suporte de Carga
15.
Proc Natl Acad Sci U S A ; 99(12): 8259-64, 2002 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-12034879

RESUMO

The extracellularly regulated kinase (ERK), one of the three types of mitogen-activated kinases, was rapidly activated after cutting porcine articular cartilage either when maintained as explants or in situ. Cutting released a soluble ERK-activating factor from the cartilage, which was purified and identified by MS as basic fibroblast growth factor (bFGF). Experiments with neutralizing Abs to bFGF and an FGFR1 tyrosine kinase inhibitor showed that this growth factor was the major ERK-activating factor released after injury. Treating cartilage with the heparin-degrading enzyme heparitinase also caused release of bFGF, suggesting the presence of an extracellular store that is sequestered in the matrix and released upon damage. Basic FGF induced the synthesis of a number of chondrocyte proteins including matrix metalloproteinases 1 and 3, tissue inhibitor of metalloproteinases-1, and glycoprotein 38, which were identified by MS. The strong induction of matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 suggests that bFGF could have a role in remodeling damaged tissue.


Assuntos
Cartilagem Articular/lesões , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Fator 2 de Crescimento de Fibroblastos/farmacologia , Animais , Cartilagem Articular/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/efeitos dos fármacos , Técnicas de Cultura/métodos , Ativação Enzimática , Regulação da Expressão Gênica/efeitos dos fármacos , Articulações , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Proteoglicanas/biossíntese , Proteínas Recombinantes/farmacologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Estresse Mecânico , Suínos
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