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1.
J Neurol ; 269(3): 1618-1630, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34351472

RESUMO

BACKGROUND: To describe the national Danish N-methyl-D-aspartate receptor encephalitis (NMDARE) cohort. METHODS: All NMDAR immunoglobulin G (IgG) positive cases in Denmark from 2009 to 2019 were included. Medical information was assessed retrospectively for clinical phenotype, workup, treatment and outcome. RESULTS: Seventy-seven patients were NMDAR IgG positive in serum/CSF. Fifty-five fulfilled the criteria of NMDARE, 18 did not and 4 had missing data. Incidence was 0.17/100,000 persons per year in 2018, and incidence rates increased since 2009. Of the 55 NMDARE patients (median age 27; 60% female), 9 had post-herpes simplex (HSE) NMDARE and 7 had a tumor (four teratomas). MRI was normal in 51% of patients. Brain FDG PET was performed in 17 patients, and was abnormal in 47% of patients with a normal MRI. First-line therapy was administered to 91%, and 24% required second-line therapy. Maintenance therapy during recovery was given 84% of patients, with no effect on relapse-risk. ICU admission occurred in 29%. Poor outcome (mRS > 2) was reported in 27% and dependent on age and etiology. Patients > 45 years had a poorer outcome (71% vs 8%, p < 0.0001), more frequently post-HSE NMDARE (47% vs 3%, p < 0.0001) and underlying malignancies (18% vs 0%). CONCLUSION: The incidence of NMDARE in Denmark is currently 0.17/100,000 persons per year, and has increased since 2009. NMDARE patients in Denmark display a higher median age, lower female:male ratio, a less frequent tumor association and need for ICU admission. Maintenance therapy did not reduce relapse rate. Poor outcome was seen with higher age, likely related to underlying etiology.


Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato , Adulto , Encefalite Antirreceptor de N-Metil-D-Aspartato/terapia , Estudos de Coortes , Dinamarca/epidemiologia , Feminino , Humanos , Masculino , N-Metilaspartato , Recidiva Local de Neoplasia , Estudos Retrospectivos
2.
Front Immunol ; 12: 719432, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34975832

RESUMO

Background and Objectives: The two most common autoimmune encephalitides (AE), N-methyl-D-Aspartate receptor (NMDAR) and Leucine-rich Glioma-Inactivated 1 (LGI1) encephalitis, have been known for more than a decade. Nevertheless, no well-established biomarkers to guide treatment or estimate prognosis exist. Neurofilament light chain (NfL) has become an unspecific screening marker of axonal damage in CNS diseases, and has proven useful as a diagnostic and disease activity marker in neuroinflammatory diseases. Only limited reports on NfL in AE exist. We investigated NfL levels at diagnosis and follow-up in NMDAR and LGI1-AE patients, and evaluated the utility of CSF-NfL as a biomarker in AE. Methods: Patients were included from the National Danish AE cohort (2009-present) and diagnosed based upon autoantibody positivity and diagnostic consensus criteria. CSF-NfL was analyzed by single molecule array technology. Clinical and diagnostic information was retrospectively evaluated and related to NfL levels at baseline and follow-up. NMDAR-AE patients were subdivided into: idiopathic/teratoma associated or secondary NMDAR-AE (post-viral or concomitant with malignancies/demyelinating disease). Results: A total of 74 CSF samples from 53 AE patients (37 NMDAR and 16 LGI1 positive) were included in the study. Longitudinal CSF-NfL levels was measured in 21 patients. Median follow-up time was 23.8 and 43.9 months for NMDAR and LGI1-AE respectively. Major findings of this study are: i) CSF-NfL levels were higher in LGI1-AE than in idiopathic/teratoma associated NMDAR-AE at diagnosis; ii) CSF-NfL levels in NMDAR-AE patients distinguished idiopathic/teratoma cases from cases with other underlying etiologies (post-viral or malignancies/demyelinating diseases) and iii) Elevated CSF-NfL at diagnosis seems to be associated with worse long-term disease outcomes in both NMDAR and LGI1-AE. Discussion: CSF-NfL measurement may be beneficial as a prognostic biomarker in NMDAR and LGI1-AE, and high CSF-NfL could foster search for underlying etiologies in NMDAR-AE. Further studies on larger cohorts, using standardized methods, are warranted.


Assuntos
Encefalite Límbica/líquido cefalorraquidiano , Proteínas de Neurofilamentos/líquido cefalorraquidiano , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encefalite Antirreceptor de N-Metil-D-Aspartato/líquido cefalorraquidiano , Encefalite Antirreceptor de N-Metil-D-Aspartato/etiologia , Biomarcadores/líquido cefalorraquidiano , Criança , Doenças Desmielinizantes/complicações , Dinamarca , Encefalite por Herpes Simples/líquido cefalorraquidiano , Feminino , Seguimentos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Leucocitose/etiologia , Encefalite Límbica/etiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Síndromes Paraneoplásicas do Sistema Nervoso/líquido cefalorraquidiano , Síndromes Paraneoplásicas do Sistema Nervoso/etiologia , Prognóstico , Teratoma/complicações , Resultado do Tratamento , Adulto Jovem
3.
Eur J Paediatr Neurol ; 23(4): 639-652, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31128894

RESUMO

BACKGROUND: The incidence of pediatric autoimmune encephalitis (AIE) is unknown. Our aim was to assess the incidence of pediatric AIE in Denmark 2011-17. METHODS: In a nationwide population-based setting, we retrieved data on all children tested for AIE before age 18 years. We reviewed medical records in a) children with AIE antibodies (n = 18) to assess whether children fulfilled the AIE consensus criteria, b) children tested negative for AIE antibodies who were registered with an AIE diagnostic code to estimate the incidence of "antibody negative but probable AIE", and c) a reference cohort (n = 596) to determine the positive predictive value of International Classification of Diseases (ICD) codes used for anti-NMDAR encephalitis. RESULTS: 375 children were tested for AIE 2011-17 (median age 11.1 years; 54% girls); 18 children (5%) had AIE antibodies (percentage tested positive): CSF GAD65-IgG (3.1%), plasma NMDAR-IgG (2.8%), CSF NMDAR-IgG (1.8%), plasma GAD65-IgG (1.0%), and plasma CASPR2-IgG (0.4%). Five children fulfilled the criteria for probably/definite anti-NMDAR encephalitis (incidence: 0.07/100,000 person-years; 95% CI = 0.03-0.17), and 4 children with anti-GAD65 associated AIE (incidence = 0.055/100,000 person-years, 95% CI = 0.021-0.15). The incidence of "antibody negative but probable AIE" was 0.055/100,000 person-years (95% CI = 0.021-0.15). The positive predictive value of ICD diagnostic codes used for anti-NMDAR encephalitis was 8%. CONCLUSIONS: We diagnosed only children with anti-NMDAR, anti-GAD65, and "antibody negative but probable AIE". Before examining AIE antibodies, clinical presentation, paraclinical studies (CSF, EEG, and MRI), and incidence of pediatric AIEs should be considered. Updating the ICD to include AIE codes is warranted.


Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato/epidemiologia , Encefalite/epidemiologia , Doença de Hashimoto/epidemiologia , Adolescente , Criança , Estudos de Coortes , Dinamarca/epidemiologia , Feminino , Humanos , Incidência , Masculino
4.
Tumour Biol ; 37(9): 12619-12626, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27440204

RESUMO

The purpose of this study was to develop a novel index for preoperative, non-invasive prediction of complete primary cytoreduction in patients with FIGO stage IIIC-IV epithelial ovarian cancer. Prospectively collected clinical data was registered in the Danish Gynecologic Cancer Database. Blood samples were collected within 14 days of surgery and stored by the Danish CancerBiobank. Serum human epididymis protein 4 (HE4), serum cancer antigen 125 (CA125), age, performance status, and presence/absence of ascites at ultrasonography were evaluated individually and combined to predict complete tumor removal. One hundred fifty patients with advanced epithelial ovarian cancer were treated with primary debulking surgery (PDS). Complete PDS was achieved in 41 cases (27 %). The receiver operating characteristic curves demonstrated an area under the curve of 0.785 for HE4, 0.678 for CA125, and 0.688 for age. The multivariate model (Cancer Ovarii Non-invasive Assessment of Treatment Strategy (CONATS) index), consisting of HE4, age, and performance status, demonstrated an AUC of 0.853. According to the Danish indicator level, macro-radical PDS should be achieved in 60 % of patients admitted to primary surgery (positive predictive value of 60 %), resulting in a negative predictive value of 87.5 %, sensitivity of 68.3 %, specificity of 83.5 %, and cutoff of 0.63 for the CONATS index. Non-invasive prediction of complete PDS is possible with the CONATS index. The CONATS index is meant as a supplement to the standard preoperative evaluation of each patient. Evaluation of the CONATS index combined with radiological and/or laparoscopic findings may improve the assessment of the optimal treatment strategy in patients with advanced epithelial ovarian cancer.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Epiteliais e Glandulares/sangue , Avaliação de Resultados em Cuidados de Saúde/métodos , Neoplasias Ovarianas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Ascite/diagnóstico por imagem , Antígeno Ca-125/sangue , Carcinoma Epitelial do Ovário , Procedimentos Cirúrgicos de Citorredução/métodos , Dinamarca , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Epiteliais e Glandulares/cirurgia , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Valor Preditivo dos Testes , Período Pré-Operatório , Prognóstico , Estudos Prospectivos , Proteínas/análise , Curva ROC , Reprodutibilidade dos Testes , Ultrassonografia/métodos , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos
5.
PLoS One ; 10(9): e0138753, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26402865

RESUMO

OBJECTIVE: In this study, we examined the concentration of serum immunoglobulin free light chains (FLCs) in systemic lupus erythematosus (SLE) patients and investigated its association with various disease parameters in order to evaluate the role of FLCs as a potential biomarker in SLE. Furthermore, FLCs' association with Epstein-Barr virus (EBV) antibodies was examined. METHODS: Using a nephelometric assay, κFLC and λFLC concentrations were quantified in sera from 45 SLE patients and 40 healthy controls. SLE patients with renal insufficiency were excluded in order to preclude high concentrations of serum FLCs due to decreased clearance. RESULTS: Serum FLC concentrations were significantly elevated in SLE patients compared to healthy controls (p<0.0001) also after adjusting for Ig levels (p<0.0001). The concentration of serum FLCs correlated with a global disease activity (SLE disease activity index (SLEDAI)) score of the SLE patients (r = 0.399, p = 0.007). Furthermore, concentrations of FLCs correlated with titers of dsDNA antibodies (r = 0.383, p = 0.009), and FLC levels and SLEDAI scores correlated in the anti-dsDNA-positive SLE patients, but not in anti-dsDNA-negative SLE patients. Total immunoglobulin (IgG and IgA) concentrations correlated with FLC concentrations and elevated FLC levels were additionally shown to associate with the inflammatory marker C-reactive protein and also with complement consumption determined by low C4 in SLE patients. Collectively, results indicated that elevated serum FLCs reflects increased B cell activity in relation to inflammation. SLE patients had an increased seropositivity of EBV-directed antibodies that did not associate with elevated FLC concentrations. An explanation for this could be that serum FLC concentrations reflect the current EBV activity (reactivation) whereas EBV-directed antibodies reflect the extent of previous infection/reactivations. CONCLUSION: SLE patients have elevated concentrations of serum FLCs that correlate with global disease activity scores and especially serologic markers for active disease. These findings are suggestive of circulating FLCs having potential as a new supplementary serologic biomarker in SLE.


Assuntos
Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Herpesvirus Humano 4/imunologia , Cadeias Leves de Imunoglobulina/sangue , Inflamação/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Idoso , Anticorpos Antinucleares/sangue , Autoanticorpos/sangue , Autoanticorpos/imunologia , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Proteínas do Sistema Complemento/imunologia , Feminino , Humanos , Inflamação/imunologia , Lúpus Eritematoso Sistêmico/virologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Eur J Cancer ; 51(11): 1381-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25971532

RESUMO

BACKGROUND: Carbohydrate associated antigen (CA19-9) has been approved by the FDA as a biomarker for monitoring treatment effect in pancreatic cancer. However, the value of serum CA19-9 as a biomarker of response to chemotherapy in bile duct cancer is unclear. The aim of this study was to determine if a decline in CA19-9 (CA19-9 response) during chemotherapy is predictive of survival in patients with inoperable bile duct cancer. METHODS: Consecutive patients with inoperable bile duct cancer treated at a University Hospital were retrospectively included in an investigational cohort (n = 212). Three validation cohorts were established including patients 1) participating in phase I/II trials at a Danish Hospital (n = 71), 2) identified retrospectively in a Canadian cohort (n = 196) and 3) randomized in the ABC-02 trial (n = 410). Patients with a baseline CA19-9 and at least one CA19-9 value measured 10-12 weeks after the start of chemotherapy were included. Multivariate Cox regression analyses were performed. RESULTS: Patients meeting the criteria to be included were 54 in the investigational cohort and 34, 68 and 148 in the three validation sets, respectively. Multivariate analysis included radiological response, performance status, bilirubin, gender, site of cancer, extend of disease, CA19-9 at baseline and age. A hazard ratio (HR) of 0.60 (95%CI: 0.44-0.80, p = 0.0005) for death in CA19-9 responders was reached in the investigational cohort. The predictive value of CA 19-9 response was confirmed in all three validation cohorts. CONCLUSIONS: CA19-9 response is a robust predictor of survival in patients with inoperable bile duct cancer in four independent data sets.


Assuntos
Neoplasias dos Ductos Biliares/sangue , Neoplasias dos Ductos Biliares/tratamento farmacológico , Antígeno CA-19-9/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Análise de Sobrevida
7.
Anticancer Res ; 34(2): 679-82, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24510999

RESUMO

AIM: We aimed to construct and validate a model based on biomarkers to predict complete primary debulking surgery for ovarian cancer patients. PATIENTS AND METHODS: The study consisted of three parts: Part I: Biomarker data obtained from mass spectrometry, baseline data and, surgical outcome were used to construct predictive indices for complete tumour resection; Part II: sera from randomly selected patients from part I were analyzed using enzyme-linked immunosorbent assay (ELISA) to investigate the correlation to mass spectrometry; Part III: the indices from part I were validated in a new cohort of patients. RESULTS: Part I: The area under the receiver operating characteristic curve (AUC) was 0.82 for both indices. Part II: Linear regression analysis gave an R(2) value of 0.52 and 0.63 for transferrin and ß2-microglobulin, respectively. Part III: The AUC of the two indices decreased to 0.64. CONCLUSION: Our validated model based on biomarkers was unable to predict surgical outcome for patients with ovarian cancer.


Assuntos
Biomarcadores Tumorais/análise , Modelos Estatísticos , Neoplasias Ovarianas/química , Biomarcadores Tumorais/metabolismo , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Modelos Lineares , Modelos Logísticos , Espectrometria de Massas , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/cirurgia , Valor Preditivo dos Testes
8.
Acta Obstet Gynecol Scand ; 92(11): 1313-22, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24032654

RESUMO

OBJECTIVE: To evaluate whether human epididymis protein 4 (HE4) and CA125 correlate with known high-risk prognostic factors for endometrial cancer. DESIGN: Prospective multicenter study. SETTING: Three Danish tertiary gynecological oncology centers. POPULATION: A total of 352 patients with endometrial cancer and atypical endometrial hyperplasia consecutively referred between 1 September 2009 and 1 January 2012. METHODS: Preoperative blood samples were obtained from all patients. Biomarker levels were correlated with pathological characteristics of hysterectomy specimens. MAIN OUTCOME MEASURES: FIGO stage, depth of myometrial invasion, cervical involvement, lymph node metastases, and histological type and grade of tumor. RESULTS: We found that both HE4 and CA125 were significantly positively correlated with histological grade (HE4: p = 0.002 and CA125: p = 0.027), lymph node metastases (HE4: p = 0.013 and CA125: p < 0.0001), myometrial invasion (p < 0.0001) and cervical involvement (p < 0.0001). Furthermore, a significant increase was found with increasing FIGO stage for both markers (p < 0.0001). In a combined index including age, the diagnostic value increases. Area under the receiver operating characteristics curves were higher for the index compared with the markers individually for all our endpoints. The calculated plots for the combined index may assist gynecologists in predicting the risk of deep myometrial invasion, cervical involvement and lymph node metastases. The analyses emphasize that the combined markers should be used in the prediction of prognostic factors. CONCLUSION: This study confirmed that the markers are significantly elevated in patients with prognostic high-risk factors and may, therefore, be used as an additional tool in combination with imaging and clinical information when planning the treatment of endometrial cancer patients.


Assuntos
Biomarcadores Tumorais/sangue , Antígeno Ca-125/sangue , Neoplasias do Endométrio/sangue , Miométrio/patologia , Proteínas/análise , Adulto , Idoso , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/cirurgia , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Curva ROC , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos
9.
Gynecol Oncol ; 127(2): 379-83, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22835718

RESUMO

OBJECTIVE: Diagnostic factors are needed to improve the currently used serum CA125 and risk of malignancy index (RMI) in differentiating ovarian cancer (OC) from other pelvic masses, thereby achieving precise and fast referral to a tertiary center and correct selection for further diagnostics. The aim was to evaluate serum Human Epididymis protein 4 (HE4) and the risk of ovarian malignancy algorithm (ROMA) for these purposes. METHODS: Serum from 1218 patients in the prospective ongoing pelvic mass study was collected prior to diagnosis. The HE4 and CA125 data were registered and evaluated separately and combined in ROMA and compared to RMI. RESULTS: 809 benign tumors, 79 borderline ovarian tumors, 252 OC (64 early and 188 late stage), 9 non-epithelial ovarian tumors and 69 non-ovarian cancers were evaluated. Differentiating between OC and benign disease the specificity was 62.2 (CA125), 63.2 (HE4), 76.5 (ROMA) and 81.5 (RMI) at a set sensitivity of 94.4 which corresponds to RMI=200. The areas under the curve (AUC) were 0.854 (CA125), 0.864 (HE4), 0,897 (ROMA) and 0.905 (RMI) for benign vs. early stage OC. For premenopausal benign vs. OC AUC were 0.925 (CA125), 0.905 (HE4), 0.909 (ROMA) and 0.945 (RMI). CONCLUSION: HE4 and ROMA helps differentiating OC from other pelvic masses, even in early stage OC. ROMA performs equally well as the ultrasound depending RMI and might be valuable as a first line biomarker for selecting high risk patients for referral to a tertiary center and further diagnostics. Further improvements of HE4 and ROMA in differentiating pelvic masses are still needed, especially regarding premenopausal women.


Assuntos
Algoritmos , Biomarcadores Tumorais/sangue , Antígeno Ca-125/sangue , Técnicas de Apoio para a Decisão , Proteínas de Membrana/sangue , Neoplasias Epiteliais e Glandulares/diagnóstico , Neoplasias Ovarianas/diagnóstico , Neoplasias Pélvicas/diagnóstico , Proteínas/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Epitelial do Ovário , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Epiteliais e Glandulares/sangue , Neoplasias Ovarianas/sangue , Neoplasias Pélvicas/sangue , Estudos Prospectivos , Medição de Risco , Sensibilidade e Especificidade , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos , Adulto Jovem
10.
Exp Cell Res ; 315(19): 3312-24, 2009 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-19796635

RESUMO

Cell surface integrins are the primary receptors for cell migration on extracellular matrix, and exist in several activation states regulated in part by ectodomain conformation. The alpha9 integrin subunit, which pairs only with beta1, has specific roles in the immune system and may regulate cell migration. Melanoma cells express abundant alpha9beta1 integrin, and its role in cell migration was assessed. Ligands derived from Tenascin-C and ADAM12 supported alpha9beta1 integrin-mediated cell attachment and GTP-Rac dependent migration, but not focal adhesion formation. Manganese ions induced alpha9beta1 integrin- and Rho kinase-dependent focal adhesion and stress fibre formation, suggesting that the activation status of alpha9beta1 integrin was altered. The effect of manganese ions in promoting focal adhesion formation was reproduced by beta1 integrin activating antibody. The alpha9beta1 integrin translocated to focal adhesions, where active beta1 integrin was also detected by conformation-specific antibodies. Focal adhesion assembly was commensurate with reduced cell migration. Endogenous alpha9beta1 integrin-mediated adhesion was sensitive to the PP1 chemical inhibitor and an inhibitor of endosomal vesicle recycling, but not inhibitors of protein kinase C or the small GTPase Rho. Our results demonstrated that although alpha9beta1 integrin can induce and localise to focal adhesions in a high activation state, its intermediate activity state normally supports cell adhesion consistent with migration.


Assuntos
Adesão Celular , Movimento Celular , Integrinas/fisiologia , Melanoma/patologia , Transdução de Sinais , Linhagem Celular Tumoral , Células Cultivadas , Adesões Focais , Humanos , Integrinas/metabolismo , Manganês/farmacologia , Melanócitos/citologia , Subunidades Proteicas
11.
J Biol Chem ; 283(46): 31920-32, 2008 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-18801731

RESUMO

The disintegrin and metalloproteases (ADAMs) are emerging as therapeutic targets in human disease, but specific drug design is hampered by potential redundancy. Unlike other metzincins, ADAM prodomains remain bound to the mature enzyme to regulate activity. Here ADAM12, a protease that promotes tumor progression and chondrocyte proliferation in osteoarthritic cartilage, is shown to possess a prodomain/catalytic domain cationic molecular switch, regulated by exogenous heparan sulfate and heparin but also endogenous cell surface proteoglycans and the polyanion, calcium pentosan polysulfate. Sheddase functions of ADAM12 are regulated by the switch, as are proteolytic functions in placental tissue and sera of pregnant women. Moreover, human heparanase, an enzyme also linked to tumorigenesis, can promote ADAM12 sheddase activity at the cell surface through cleavage of the inhibitory heparan sulfate. These data present a novel concept that might allow targeting of ADAM12 and suggest that other ADAMs may have specific regulatory activity embedded in their prodomain and catalytic domain structures.


Assuntos
Proteínas ADAM/metabolismo , Heparitina Sulfato/metabolismo , Proteínas de Membrana/metabolismo , Proteínas ADAM/genética , Proteína ADAM12 , Animais , Domínio Catalítico , Linhagem Celular , Membrana Celular/metabolismo , Cricetinae , Ativação Enzimática , Glucuronidase/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Proteínas de Membrana/genética , Osteoartrite/enzimologia , Ligação Proteica , Especificidade por Substrato
12.
J Biol Chem ; 281(14): 9418-22, 2006 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-16455653

RESUMO

The ADAMs (a disintegrin and metalloprotease) comprise a family of multidomain proteins with metalloprotease, cell adhesion, and signaling activities. Human ADAM12, which is implicated in diseases such as cancer, is expressed in two splice forms, the transmembrane ADAM12-L and the shorter and soluble ADAM12-S. ADAM12 is synthesized as a zymogen with the prodomain keeping the metalloprotease inactive through a cysteine-switch mechanism. Maturation and activation of the protease involves the cleavage of the prodomain in the trans-Golgi or possibly at the cell surface by a furin-peptidase. The aim of the present study was to determine the fate of the prodomain following furin cleavage. Here we demonstrate that, following cleavage of the human ADAM12-S prodomain in the trans-Golgi by a furin-peptidase, the prodomain remains non-covalently associated with the mature molecule. Accordingly, both the 68-kDa mature form of ADAM12-S and the 25-kDa prodomain could be detected using domain-specific antisera in immunoprecipitation and Western blot analyses of human serum ADAM12 and purified recombinant human ADAM12. Using electron microscopy after negative staining we have furthermore obtained the first visualization of a full-length ADAM molecule, human ADAM12-S, and report that it appears to be a compact clover composed of four globular domains, one of which is the prodomain. Finally, our data demonstrate that the presence of the metalloprotease domain appears to be sufficient for the prodomain to remain associated with the mature ADAM12-S. Thus, we conclude that the prodomain of human ADAM12-S is an integral domain of the mature molecule and as such might have specific biological functions in the extracellular space.


Assuntos
Proteínas ADAM/biossíntese , Proteínas ADAM/metabolismo , Furina/metabolismo , Proteínas de Membrana/biossíntese , Proteínas de Membrana/metabolismo , Proteínas ADAM/química , Proteína ADAM12 , Processamento Alternativo , Western Blotting , Ativação Enzimática , Precursores Enzimáticos , Complexo de Golgi , Humanos , Imunoprecipitação , Proteínas de Membrana/química , Metaloproteases/metabolismo , Microscopia Eletrônica
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