Association between ADAM metallopeptidase domain 33 gene polymorphism and risk of childhood asthma: a meta-analysis

This study aimed to investigate the association between ADAM metallopeptidase domain 33 (ADAM33) gene polymorphisms and the risk of childhood asthma. The relevant studies about the relationship between ADAM33 gene polymorphisms and childhood asthma were searched from electronic databases and the deadline of retrieval was May 2016. The single nucleotide polymorphisms (SNPs) of ADAM33 (rs511898, rs2280092, rs3918396, rs528557, rs2853209, rs44707, rs2280091 and rs2280089) were analyzed based on several models including the allele, codominant, recessive and dominant models. The results showed that the ADAM33 rs2280091 polymorphism in all four genetic models was associated with an increased risk of childhood asthma. Positive associations were also found between the polymorphisms rs2280090, rs2787094, rs44707 and rs528557 and childhood asthma in some genetic models. This meta-analysis suggested that ADAM33 polymorphisms rs2280091, rs2280090, rs2787094, rs44707 and rs528557 were significantly associated with a high risk of childhood asthma.

Polimorfismos de nucleótidos simples V4 y T1 del gen ADAM33 en pacientes venezolanos con asma o enfermedad pulmonar obstructiva crónica / Single nucleotide polymorphisms V4 and T1 of the ADAM33 gene in Venezuelan patients with asthma or chronic obstructive pulmonary disease

ADAM33 es una metaloproteinasa de la matriz extracelular involucrada en la remodelación tisular y, por ello, en el asma y la enfermedad pulmonar obstructiva crónica (EPOC). Se han reportado varios polimorfismos del gen de ADAM33 asociados a la actividad enzimática. Los polimorfismos más estudiados son el V4, citosina por una guanina en la región 3’ UTR, y el T1, adenina por una guanina en el exón 19 del gen. El objetivo del presente trabajo fue determinar la posible asociación de los polimorfismos de nucleótido simple de ADAM33, V4 y T1, con la presencia de asma o EPOC en pacientes venezolanos. Los polimorfismos V4 y T1 fueron analizados en 303 individuos (103 asmáticos, 100 EPOC, y 100 controles) mediante PCR-RFLP (reacción en cadena de la polimerasa y análisis de polimorfismos por longitud de fragmentos de restricción enzimática). La frecuencia genotípica del polimorfismo V4 fue significativamente mayor (p<0,05) en ambos grupos de pacientes, asmáticos y EPOC, con respecto al control. No se encontraron diferencias significativas (P=0,4) en el polimorfismo T1. Sin embargo, se evidenció una diferencia significativa (p<0,05) cuando los haplotipos y diplotipos de ADAM33 V4/T1 se compararon entre los tres grupos. Se concluye que el polimorfismo ADAM33 V4 está asociado con la presencia de asma o EPOC en pacientes venezolanos.

ADAM33 is a metalloproteinase important in the extracellular matrix for tissue remodeling, and, consequently, in asthma and chronic obstructive pulmonary disease (COPD). Several polymorphisms of the ADAM33 gene have been associated with enzyme activity. One of the most studied polymorphisms is V4, cytosine for guanine in the 3’UTR region, and T1, adenine for guanine in the exon 19 of the gen. The aim of this study was to ascertain the possible association among single polymorphisms of ADAM33, V4 and T1, in Venezuelan patients with asthma or COPD. The polymorphisms V4 and T1 were analyzed in 303 individuals (103 asthmatic, 100 COPD and 100 controls) by PCR-RFLP (polymerase chain reaction and restriction fragment length polymorphisms). There was a significant difference (P<0.05) in the frequency of ADAM33 V4 polymorphism in both, asthmatic and COPD patients groups, as compared to controls. No significant differences (P=0.4) were found for T1 polymorphism. However, there were significant differences (P<0.05) when haplotypes and diplotypes of ADAM33 V4/T1 were compared in all three groups. It can be concluded that the polymorphism V4 of ADAM33 is associated with asthma or COPD in Venezuelan patients.

Parotid Incidentaloma Identified by Positron Emission/Computed Tomography: When to Consider Diagnoses Other than Warthin Tumor

Introduction Parotid gland incidentalomas (PGIs) are unexpected hypermetabolic foci in the parotid region that can be found when scanning with whole-body positron emission/computed tomography (PET/CT). These deposits are most commonly due to benign lesions such as Warthin tumor. Objective The aim of this study was to determine the prevalence of PGIs identified in PET/CT scans and to assess the role of smoking in their etiology. Methods We retrospectively reviewed all PET/CT scans performed at our center in search of PGIs and identified smoking status and standardized uptake value (SUVmax) in each case. We also analyzed the database of parotidectomies performed in our department in the previous 10 years and focused on the pathologic diagnosis and the presence or absence of smoking in each case. Results Sixteen cases of PGIs were found in 4,250 PET/CT scans, accounting for 0.4% . The average SUVmax was 6.5 (range 2.8 to 16). Cytology was performed in five patients; it was benign in four cases and inconclusive in one case. Thirteen patients had a history of smoking. Of the parotidectomies performed in our center with a diagnosis of Warthin tumor, we identified a history of smoking in 93.8% of those patients. Conclusions The prevalence of PGIs on PET/CT was similar to that reported by other authors. Warthin tumor is frequently diagnosed among PGIs on PET/CT, and it has a strong relationship with smoking. We suggest that a diagnosis other than Warthin tumor should be considered for PGIs in nonsmokers. .

Screening for frailty in older adults using a self-reported instrument / Rastreamento de fragilidade em idosos por instrumento autorreferido

OBJECTIVE To validate a screening instrument using self-reported assessment of frailty syndrome in older adults. METHODS This cross-sectional study used data from the Saúde, Bem-estar e Envelhecimento study conducted in Sao Paulo, SP, Southeastern Brazil. The sample consisted of 433 older adult individuals (≥ 75 years) assessed in 2009. The self-reported instrument can be applied to older adults or their proxy respondents and consists of dichotomous questions directly related to each component of the frailty phenotype, which is considered the gold standard model: unintentional weight loss, fatigue, low physical activity, decreased physical strength, and decreased walking speed. The same classification proposed in the phenotype was utilized: not frail (no component identified); pre-frail (presence of one or two components), and frail (presence of three or more components). Because this is a screening instrument, “process of frailty” was included as a category (pre-frail and frail). Cronbach’s α was used in psychometric analysis to evaluate the reliability and validity of the criterion, the sensitivity, the specificity, as well as positive and negative predictive values. Factor analysis was used to assess the suitability of the proposed number of components. RESULTS Decreased walking speed and decreased physical strength showed good internal consistency (α = 0.77 and 0.72, respectively); however, low physical activity was less satisfactory (α = 0.63). The sensitivity and specificity for identifying pre-frail individuals were 89.7% and 24.3%, respectively, while those for identifying frail individuals were 63.2% and 71.6%, respectively. In addition, 89.7% of the individuals from both the evaluations were identified in the “process of frailty” category. CONCLUSIONS The self-reported assessment of frailty can identify the syndrome among older adults and can be used as a screening tool. Its ...

OBJETIVO Validar instrumento de rastreamento por avaliação autorreferida da síndrome de fragilidade entre idosos. MÉTODOS Estudo transversal com dados do estudo Saúde, Bem-estar e Envelhecimento, realizado em São Paulo, SP. A amostra probabilística foi constituída por 433 idosos (idade ≥ 75 anos) avaliados em 2009. O instrumento autorreferido utilizado pode ser aplicado a idosos ou proxi-informantes e foi composto por questões dicotômicas relacionadas diretamente a cada componente do fenótipo de fragilidade considerado padrão-ouro: perda de peso não intencional, fadiga, baixa atividade física, redução de força e de velocidade de marcha. Manteve-se a classificação proposta no fenótipo: não frágil (nenhum componente identificado); pré-frágil (presença de um ou dois componentes) e frágil (presença de três ou mais componentes). Por tratar-se de instrumento de rastreamento, incluiu-se a categoria processo de fragilização (pré-frágil e frágil). Utilizou-se o coeficiente α de Cronbach na análise psicométrica para avaliar confiabilidade e validade de critério, sensibilidade, especificidade e valores preditivos positivo e negativo. Para verificar a adequação do número de componentes propostos, utilizou-se a análise fatorial. RESULTADOS Os componentes “redução de velocidade de caminhada” e “redução de força” apresentaram boa consistência interna (α = 0,77 e α = 0,72, respectivamente) e a “baixa atividade física” (α = 0,63) foi um pouco menos satisfatória. A sensibilidade e a especificidade para identificação dos pré-frágeis foram de 89,7% e 24,3% e dos frágeis, 63,2% e 71,6%, respectivamente. A categoria “processo de fragilização” identificou, igualmente, 89,7% das pessoas em ambas as avaliações. CONCLUSÕES O instrumento de avaliação de fragilidade autorreferida é capaz de identificar a síndrome entre as pessoas idosas, podendo ser utilizado como instrumento de rastreamento, ...

Alteraciones de la hemostasia en el síndrome drepanocítico / Hemostasis alterations in sickle cell syndrome

El síndrome drepanocítico (SD) comprende un grupo de anemias hemolíticas hereditarias de tipo multisistémico asociadas a la hemoglobina S. Los pacientes que padecen este síndrome tienen un mayor riesgo, en comparación con individuos sanos, de presentar accidentes cerebrovasculares, hipertensión pulmonar, necrosis avascular de articulaciones, síndrome torácico agudo y complicaciones durante el embarazo, asociados a un estado de hipercoagulabilidad inducido por alteraciones en los diferentes componentes de la hemostasia, que incluyen la activación del endotelio y de los sistemas plaquetario, de la coagulación y de la fibrinólisis. Esta revisión resume las alteraciones en la hemostasia reportadas en los pacientes con SD, en los cuales se ha demostrado: mayor interacción de células endoteliales con leucocitos, hematíes y plaquetas; aumento de la expresión de proteínas de adhesión, como el factor von Willebrand y sus multímeros de alto peso molecular; aumento de la adhesión y la agregación plaquetaria y de la expresión de proteínas en sus membranas. En el sistema de coagulación se ha detectado aumento en la expresión del factor tisular (FT) en micropartículas derivadas de diferentes células, aumento de marcadores de activación de este sistema, entre estos los fragmentos 1.2 de la protrombina y los complejos trombina-antitrombina y una disminución de las proteínas C y S que actúan como anti-coagulantes. Adicionalmente, se han encontrado aumentados los marcadores de activación del sistema fibrinolítico como los dímeros D y los complejos plasmina/antiplasmina. Todas estas manifestaciones favorecen la aparición de complicaciones trombóticas, implicadas en el deterioro de la calidad de vida de los pacientes. Se recomienda implementar en el diagnóstico y seguimiento de esta enfermedad, la determinación de variables del sistema hemostático, con el fin de identificar alteraciones en etapas tempranas y aplicar terapias que puedan prevenir complicaciones trombóticas.

Sickle cell syndrome (SCS) includes a group of congenital hemolytic anemias associated to the presence of hemoglobin S, which is characterized by acute pain episodes and progressive damage of different organs. Some patients with sickle cell syndrome have shown, when compared with healthy individuals, an increased risk of presenting stroke, pulmonary hypertension, avascular necrosis of joints, acute chest syndrome and pregnancy complications, associated to a hypercoagulable state induced by alterations in different components of hemostasis, such as changes that include activation of the endothelium, platelet activity, coagulation and fibrinolytic systems. This paper compiles hemostasis disorders, associated with thrombotic manifestations, reported until now in sickle cell syndrom. These patients have an increase in activation markers of the coagulation system, such as prothrombin fragment 1.2, thrombin-antithrombin complex, etc., depletion of natural anticoagulant proteins, abnormal activation of the fibrinolytic system and increased tissue factor expression. Similarly, abnormal expression of glycoproteins and increased adhesion and platelet aggregation have been reported. All these alterations produce a hypercoagulable state, which induces, among other things, the appearance of thrombotic complications. In view of the importance of controlling the different complications that can occur in patients with sickle cell syndrome, we recommend the implementation, in diagnosis and monitoring studies, of the evaluation of the different components of the hemostatic system, identifying alterations at an early stage and applying effective treatments to prevent thrombotic complications.

Genetic polymorphisms and asthma: findings from a case - control study in the Madeira island population

BACKGROUND: Asthma is a complex disease influenced by multiple genetic and environmental factors. While Madeira has the highest prevalence of asthma in Portugal (14.6%), the effect of both genetic and environmental factors in this population has never been assessed. We categorized 98 asthma patients according to the Global Initiative for Asthma (GINA) guidelines, established their sensitization profile, and measured their forced expiratory volume in 1second (FEV1) and forced vital capacity (FVC) indexes. Selected single nucleotide polymorphisms (SNPs) were analysed as potential markers for asthma susceptibility and severity in the interleukin 4 (IL4), interleukin 13 (IL13), beta-2-adrenergic receptor (ADRB2), a disintegrin and metalloprotease 33 (ADAM33), gasdermin-like (GSDML) and the signal transducer and activator of transcription 6 (STAT6) genes comparatively to a population reference set. RESULTS: Although mites are the major source of allergic sensitization, no significant difference was found amongst asthma severity categories. IL4-590*CT/TT and IL4-RP2*253183/183183 were found to predict the risk (2-fold) and severity (3 to 4-fold) of asthma and were associated with a lower FEV1 index. ADRB2-c.16*AG is a risk factor (3.5-fold), while genotype GSDML-236*TT was protective (4-fold) for moderate-severe asthma. ADAM33-V4*C was associated to asthma and mild asthma by the transmission disequilibrium test (TDT). Finally, ADAM33-V4*CC and STAT6-21*TT were associated with higher sensitization (mean wheal size ≥10mm) to house dust (1.4-fold) and storage mite (7.8-fold). CONCLUSION: In Madeira, IL4-590C/T, IL4-RP2 253/183, GSDML-236C/T and ADAM33-V4C/G SNPs are important risk factors for asthma susceptibility and severity, with implications for asthma healthcare management.

Differential expression and localization of ADAM10 and ADAM17 during rat spermatogenesis suggest a role in germ cell differentiation

BACKGROUND: Extracellular metolloproteases have been implied in different process such as cell death, differentiation and migration. Membrane-bound metalloproteases of the ADAM family shed the extracellular domain of many cytokines and receptor controlling auto and para/juxtacrine cell signaling in different tissues. ADAM17 and ADAM10 are two members of this family surface metalloproteases involved in germ cell apoptosis during the first wave of spermatogenesis in the rat, but they have other signaling functions in somatic tissues. RESULTS: In an attempt to further study these two enzymes, we describe the presence and localization in adult male rats. Results showed that both enzymes are detected in germ and Sertoli cells during all the stages of spermatogenesis. Interestingly their protein levels and cell surface localization in adult rats were stage-specific, suggesting activation of these enzymes at particular events of rat spermatogenesis. CONCLUSIONS: Therefore, these results show that ADAM10 and ADAM17 protein levels and subcellular (cell surface) localization are regulated during rat spermatogenesis.

Plasmatic ADAMTS-13 metalloprotease and von Willebrand factor in children with cyanotic congenital heart disease

Changes in plasma von Willebrand factor concentration (VWF:Ag) and ADAMTS-13 activity (the metalloprotease that cleaves VWF physiologically) have been reported in several cardiovascular disorders with prognostic implications. We therefore determined the level of these proteins in the plasma of children with cyanotic congenital heart disease (CCHD) undergoing surgical treatment. Forty-eight children were enrolled (age 0.83 to 7.58 years). Measurements were performed at baseline and 48 h after surgery. ELISA, collagen-binding assays and Western blotting were used to estimate antigenic and biological activities, and proteolysis of VWF multimers. Preoperatively, VWF:Ag and ADAMTS-13 activity were decreased (65 and 71% of normal levels considered as 113 (105-129) U/dL and 91 ± 24% respectively, P < 0.003) and correlated (r = 0.39, P = 0.0064). High molecular weight VWF multimers were not related, suggesting an interaction of VWF with cell membranes, followed by proteolytic cleavage. A low preoperative ADAMTS-13 activity, a longer activated partial thromboplastin time and the need for cardiopulmonary bypass correlated with postoperative bleeding (P < 0.05). Postoperatively, ADAMTS-13 activity increased but less extensively than VWF:Ag (respectively, 2.23 and 2.83 times baseline, P < 0.0001), resulting in an increased VWF:Ag/ADAMTS-13 activity ratio (1.20 to 1.54, respectively, pre- and postoperative median values, P = 0.0029). ADAMTS-13 consumption was further confirmed by decreased ADAMTS-13 antigenic concentration (0.91 ± 0.30 to 0.70 ± 0.25 µg/mL, P < 0.0001) and persistent proteolysis of VWF multimers. We conclude that, in pediatric CCHD, changes in circulating ADAMTS-13 suggest enzyme consumption, associated with abnormal structure and function of VWF.

Decreased plasma ADAMTS-13 activity as a predictor of postoperative bleeding in cyanotic congenital heart disease

OBJECTIVE: To analyze the preoperative plasma antigenic concentration and activity of von Willebrand factor and its main cleaving protease ADAMTS-13 in pediatric patients with cyanotic congenital heart disease undergoing surgical treatment and investigate possible correlations with postoperative bleeding. METHODS: Plasma antigenic concentrations (von Willebrand factor:Ag and ADAMTS-13:Ag) were measured using enzyme-linked immunoassays. Collagen-binding assays were developed to measure biological activities (von Willebrand factor:collagen binding and ADAMTS-13 activity). The multimeric structure of von Willebrand factor was analyzed using Western immunoblotting. Demographic, diagnostic, and general and specific laboratory data and surgery-related variables were subjected to univariate, bivariate, and multivariate analysis for the prediction of postoperative bleeding. RESULTS: Forty-eight patients were enrolled, with ages ranging from 9 months to 7.6 years (median 2.5 years). The plasma concentrations of von Willebrand factor:Ag and ADAMTS-13:Ag were decreased by 65 and 82%, respectively, in the patients compared with the controls (p<0.001). An increased density of low-molecular-weight fractions of von Willebrand factor, which are suggestive of proteolytic degradation (p = 0.0081), was associated with decreased ADAMTS-13 activity, which was likely due to ADAMTS-13 consumption (71% of controls, p = 0.0029) and decreased von Willebrand factor:collagen binding (76% of controls, p = 0.0004). Significant postoperative bleeding occurred in 13 patients. The preoperative ADAMTS-13 activity of <64.6% (mean level for the group), preoperative activated partial thromboplastin time, and the need for cardiopulmonary bypass were characterized as independent risk factors for postoperative bleeding, with respective hazard ratios of 22.35 (95% CI 1.69 to 294.79), 1.096 (95% CI 1.016 to 1.183), and 37.43 (95% ...

Análise de expressão do gene ADAM23 em tumores do sistema nervoso central (SNC) e estudo de sua função em gliomas e em melanomas / Analysis of ADAM23 gene expression in tumors of the central nervous system (CNS) and study of its function in melanoma and glioma

O gene ADAM23 está epigeneticamente silenciado em tumores de mama de estágios mais avançados e o seu silenciamento nesses tumores confere ao paciente um maior risco de desenvolvimento de metástases e um pior prognóstico. O silenciamento do gene ADAM23 na linhagem tumoral de mama MDA-MB-435 reduz a capacidade proliferativa e aumenta a capacidade migratória e invasiva das células em modelo tridimensional de cultura. No entanto, paradoxalmente, o silenciamento do gene ADAM23 nessa linhagem reduz a capacidade tumorigênica e metastática das células em ensaios in vivo utilizando animais imunodeficientes. Ensaios subsequentes utilizando misturas de células positivas e negativas para a expressão de ADAM23 revelaram que as células negativas estimulam a proliferação, migração e invasão das células positivas e que a heterogeneidade tumoral em relação à expressão de ADAM23 é importante para a disseminação e colonização metastática. Este trabalho teve como objetivo validar a associação entre o silenciamento do gene ADAM23 em tumores primários e a progressão tumoral, e também encontrar um modelo celular alternativo para a realização de ensaios funcionais que comprovassem o papel do gene ADAM23 na proliferação, migração, e invasão celular, bem como a existência de interação celular entre células ADAM23 positivas e negativas. A análise da expressão do gene ADAM23 em amostras de gliomas de diferentes estágios através de PCR em Tempo Real revelou que a expressão desse gene diminui ao longo da progressão tumoral e está bastante reduzida em tumores de grau avançado. Porém, ao contrário do observado em tumores de mama, o silenciamento do gene ADAM23 em gliomas não é causado por hipermetilação de sua região promotora nem por mutações em sua região codificante, ou perda de heterozigose. Infelizmente, não foi possível selecionar clones derivados da linhagem celular de glioblastoma U87MG com silenciamento estável do gene ADAM23 para a realização de ensaios funcionais. Aparentemente, o silenciamento de ADAM23 nessa linhagem resulta na parada do ciclo celular na fase G0/G1, impedindo a seleção de clones com silenciamento estável do gene. O mesmo fenômeno não foi observado na linhagem de melanoma SKmel-37, permitindo a seleção de clones com silenciamento estável de ADAM23 e a realização de ensaios funcionais. Curvas de proliferação em monocamada e ensaios de incorporação de MTT em modelo tridimensional in vitro demonstraram que o silencimento de ADAM23 na linhagem SKmel-37 diminui sua taxa de proliferação em 20-50%. Ensaios de citometria de fluxo demonstraram que o silenciamento de ADAM23 interfere na expressão das integrinas αvß3 e αvß5 na membrana celular, resultando em diminuição de 50% na afinidade aos ligantes de matriz e aumento significativo na capacidade de migração e invasão no colágeno. Ensaios in vitro e in vivo utilizando misturas de células SKmel-37 ADAM23 positivas e negativas também confirmaram a existência de interação entre os dois subtipos celulares. Ensaios in vitro de migração e invasão no colágeno revelaram que células ADAM23 negativas induzem a migração e a invasão de células positivas e, em ensaios de tumorigienese in vivo, observamos que os tumores formados a partir da injeção de uma mistura de células positivas e negativas apresentam crescimento semelhante ao dos tumores formados a partir da injeção de células ADAM23 positivas

The ADAM23 gene is epigenetically silenced in breast tumors of more advanced stages and its silencing in these tumors gives the patient a greater risk of developing metastasis and a worse prognosis. The ADAM23 gene silencing in the MDA-MB-435 breast tumor cell line reduces the proliferative capacity and increases migratory and invasive abilities of cells in three-dimensional culture models. Yet, paradoxically, the ADAM23 gene silencing in this line reduces tumorigenic and metastatic abilities of cells in in vivo assays using immunodeficient animals. Subsequent tests using ADAM23 positive and negative cells mixtures revealed that negative cells stimulate proliferation, migration and invasion of positive cells and the heterogeneity of ADAM23 expression in tumors is important for the spreading and metastatic colonization. This study aimed to validate the association between ADAM23 gene silencing in primary tumors and tumor progression as well as find an alternative cellular model for performing functional tests to prove the role of the ADAM23 gene in proliferation, migration and cell invasion, and to prove the existence of cell interaction between ADAM23 positive and negative cells. The analysis of ADAM23 gene expression in samples from different stages of gliomas by RT-PCR revealed that the expression of this gene decreases over tumor progression and is greatly reduced in tumors of advanced degree. However, unlike that observed in breast tumors, the ADAM23 gene silencing in gliomas is not caused by hypermethylation of its promoter region or by mutations in its coding region, or by loss of heterozygosity. Unfortunately, it was not possible to select clones derived from the U87MG glioblastoma cell line with stable silencing of the gene ADAM23 for the functional testing. Apparently, the silencing of ADAM23 in this cell line results in cell cycle arrest in G0/G1 phase, preventing the selection of clones with stable gene silencing. The same phenomenon was not observed in SKmel-37 melanoma cell line, allowing selection of clones with stable silencing of ADAM23 and functional testing. Monolayer proliferation curves and in vitro MTT incorporation assays in three-dimensional models showed that ADAM23 silencing in the SKmel-37 cell line reduces their rate of proliferation by 20-50%. Flow cytometry assays demonstrated that ADAM23 silencing interferes with the expression of αvß3 and αvß5 integrins in the cell membrane, resulting in a 50% decrease in binding afinity to the matrix and a significant increase in migratory and invasive abilities on collagen. In vitro and in vivo assays using ADAM23 positive and negative SKmel-37 cell mixtures also confirmed the existence of interaction between the two cell subsets. In vitro invasion and migration on collagen assays revealed that ADAM23 negative cells induce migration and invasion of positive cells. Furthermore, in in vivo tumorigenic tests we found that tumors formed from injection of a mixture of positive and negative cells exhibit growth similar to the tumors formed after injection of ADAM23 positive cells

Caracterização funcional das isoformas de splicing do gene ADAM23 / Functional characterization of ADAM23 gene splicing isoforms

A ADAM23 é uma glicoproteína transmembrana pertencente à família ADAM (A Disintegrin and Metalloprotease) que apresenta a estrutura protéica típica dos membros desta família, mas não possui atividade de metaloprotease. O gene ADAM23 apresenta três isoformas de splicing, α, ß e γ, que codificam proteínas com porções C-terminais distintas. As isoformas α e ß codificam proteínas com domínios transmembranas diferentes, enquanto γ provavelmente consiste em uma isoforma secretada ou citoplasmática de ADAM23. Foi demonstrado que o gene ADAM23 está epigeneticamente silenciado em tumores de mama de estágios mais avançados e que seu silenciamento está associado a um maior risco de desenvolvimento de metástases e a um pior prognóstico. Recentemente, foi descrito que a proteína ADAM23 interage diretamente com a integrina αVß3 na linhagem tumoral de mama MDA-MB-435, sendo capaz de modular seu estado conformacional, controlando sua ativação. Utilizando RNAi, observou-se que o silenciamento completo do gene ADAM23 (i.e., as três isoformas) aumenta os níveis de αVß3 em conformação ativa na superfície das células MDA-MB-435, promovendo um incremento de sua capacidade migratória e adesiva. No presente trabalho, avaliamos por reações de amplificação em tempo real o perfil de expressão das três isoformas de splicing do gene ADAM23 em cinco tecidos normais (mama, cólon, cérebro, próstata e pâncreas) e em doze linhagens tumorais derivadas destes tecidos. Observamos diferenças nos níveis de expressão das isoformas em todas as amostras avaliadas, tanto dentro de uma determinada amostra, como quando comparamos tecidos normais entre si ou com linhagens tumorais. A isoforma γ é a mais expressa em todos os tecidos normais (exceto em cérebro) e em todas as linhagens tumorais. Em tecido normal de mama e de próstata e nas doze linhagens tumorais, ADAM23α é a segunda isoforma mais expressa, sendo ß a menos expressa. Constatamos também que a fração representada por cada isoforma, em relação à expressão total do gene ADAM23, está alterada nas linhagens tumorais, em comparação aos tecidos normais correspondentes. Com o intuito de elucidar a função das isoformas de ADAM23 separadamente, utilizamos shRNAs (short hairpin RNAs) para reduzir a expressão de cada isoforma de modo individual e específico na linhagem tumoral MDA-MB-435, e avaliamos seu efeito na proliferação, na morfologia, na adesão e no espraiamento celular. Verificamos que a redução da expressão da isoforma γ aumentou significativamente a taxa de proliferação das células MDA-MB-435 cultivadas em modelo tridimensional. Demonstramos também que ADAM23γ participa da regulação da morfologia e da capacidade de espraiamento das células MDA-MB-435 em condições padrão de cultivo (i.e., meio de cultura completo e placas não-sensibilizadas com substratos) e em componentes específicos da matriz extracelular, como fibronectina, colágeno I e matrigel. A isoforma α também está envolvida no controle da morfologia e do espraiamento da linhagem MDA-MB-435, porém, de modo distinto da isoforma γ. Já ADAM23ß não interfere na morfologia das células MDA-MB-435 e tem efeito marginal no espraiamento celular apenas em condições padrão de cultivo. Em conjunto, nossos resultados demonstram que as isoformas de ADAM23 são diferencialmente expressas em tecidos normais e tumorais, e exercem funções biológicas distintas

ADAM23 is a transmembrane glycoprotein that belongs to the ADAM (A Disintegrin and Metalloprotease) family of proteins and exhibits the typical protein structure of the family members, but it doesn't have metalloprotease activity. The ADAM23 gene has three splicing isoforms, α, ß and γ, that code for proteins with different C-terminal regions. Isoforms α and ß code for proteins with different transmembrane domains, while γ probably constitute a secreted or cytoplasmatic isoform of ADAM23. It has been demonstrated that the ADAM23 gene is epigenetically silenced in advanced stage breast tumors and that its silencing is associated with a higher risk of developing metastases and with a worse prognosis. Recently, it was described that ADAM23 protein interacts directly with αVß3 integrin in the breast tumor cell line MDA-MB-435, modulating its conformational state and controlling its activation. Using RNAi, it was observed that the complete silencing of ADAM23 gene (the three isoforms) raises the levels of αVß3 in its active conformation in the surface of MDA-MB-435 cells, promoting an increase in its migratory and adhesive capacity. In the present work, we evaluated by real time PCR the expression pattern of the three splicing isoforms of ADAM23 gene in five normal tissues (breast, colon, brain, prostate and pancreas) and in twelve tumor cell lines derived from these tissues. We observed differences in the expression levels of the three isoforms in all samples, either within a specific sample or comparing normal tissues among them or with tumor cell lines. Isoform γ has the highest expression in all normal tissues (except for brain) and in all tumor cell lines evaluated. In breast and prostate normal tissues and in all tumor cell lines, ADAM23α is the second most expressed isoform, while ß is the less expressed. We also noticed that the ratio represented by each isoform, relative to the total expression of ADAM23 gene, is altered in the tumor cell lines, compared to the corresponding normal tissues. With the aim to elucidate the function of ADAM23 isoforms separately, we used shRNAs (short hairpin RNAs) to reduce the expression of each isoform specifically in the MDA-MB-435 tumor cell line, and studied its effects in proliferation, morphology, adhesion and cell spreading. We observed that the reduced expression of isoform γ significantly increased the proliferation rate of MDA-MB-435 cells cultivated in tridimensional system. Also, we demonstrated that ADAM23γ participates in the regulation of cell morphology and spreading of MDA-MB-435 cells, both in standard culture conditions (cell culture media with fetal serum and in plates not sensitized with substrates) and in specific components of extracellular matrix, such as fibronectin, collagen type I and matrigel. Isoform α is also involved in the control of morphology and spreading of MDA-MB-435 cell line, although in a distinct manner from isoform γ. ADAM23ß doesn't interfere in the morphology of MDA-MB-435 cells and plays a discrete role in cell spreading only under standard culture conditions. Together, our results demonstrate that ADAM23 isoforms are differently expressed in normal and tumoral tissue, and play distinct biological roles

Púrpura trombótico trombocitopénico: revisión de la literatura a partir de 18 casos / Thrombotic thrombocytopenic purpura: experience in 18 cases and literature review

Background: Thrombotic thrombocytopenic purpura (TTP) is characterized by anemia, thrombocytopenia, neurological and renal involvement of variable severity and it has a dismal prognosis. Platelet-derived von Willebrand Factor-cleaving metalloprotease ADAMTS-13 activity may orient the diagnosis, but normal levels do not discard it. The most effective therapy thus known is plasmapheresis. Aim: To report the experience in 18 patients with TTP. Material and methods: Retrospective assessment of 11 patients and prospective assessment of seven subjects with TTP, aged 15 to 81 years. Results: All presented with anemia, thrombocytopenia and LDH elevation. Sixteen had neurological symptoms, five had fever, four had macroscopic urinary excretion of pigments, four had petechiae, and two had nosebleeds. Haptoglobin was low in 10 of 11 patients in whom it was measured. ADAMTS-13 had low activity in 15 of 17 patients (in 11, the inhibitor was found). Seventeen patients were treated with plasmapheresis and nine received steroids also. Seven patients died due to shock with respiratory involvement or múltiple organic failure. Conclusions: TTP has heterogeneous modes of presentation. If the diagnosis is strongly suspected, plasmapheresis can be started without laboratory confirmation. An ADAMTS-13 activity below 6 percent is almost exclusive of TTP .

Associação dos polimorfismos dos genes TGF-beta1, CD14, IL-4, IL-4R e ADAM33 com a gravidade da asma em crianças e adolescentes / Association of TGF-beta1, CD14, IL-4, IL-4R and ADAM33 gene polymorphisms with asthma severity in children and adolescents

OBJETIVO: Verificar, em uma amostra de pacientes com asma atópica persistente leve, moderada e grave, a associação entre os polimorfismos dos genes fator de crescimento transformante-beta1 (TGF-beta1) (C-509T e T869C), CD14 (C-159T), IL-4 (C-590T), IL-4R (ILe50Val) e ADAM33 (S_2) com a gravidade da asma. MÉTODOS: Realizou-se um estudo clínico laboratorial prospectivo em pacientes com asma atópica persistente, comparados a um grupo controle no Hospital Universitário da Universidade Estadual de Campinas nos anos de 2006 e 2007. A análise do polimorfismo T869C do gene TGF-beta1 foi realizada pela técnica de reação em cadeia da polimerase (PCR) + sistema de amplificação refratária de mutação (ARMS). Os outros polimorfismos, C-509T do gene TGF-beta1, C-159T do gene CD14, C-590T da IL-4, ILe50Val da IL-4Ra e S2 do gene ADAM33, foram detectados por PCR e enzima de restrição. RESULTADOS: Foram incluídos 88 pacientes com asma atópica persistente (27 leves, 23 moderados e 38 graves) e 202 indivíduos saudáveis, doadores de sangue. Em relação ao polimorfismo T869C (TGF-beta1), observou-se uma associação entre o genótipo CC e os pacientes com asma grave. Nenhuma associação foi encontrada com os polimorfismos C-509T (TGF-beta1), C-590T (IL4) e S_2 (ADAM33). Quando se comparou a distribuição da freqüência genotípica do polimorfismo C-159T (CD14) na asma grave com o grupo controle, foi observado um resultado significativo com o genótipo TT. Houve associação significativa do genótipo Val/Val (IL-4R) com a asma leve. CONCLUSÃO: Nossos resultados indicam que os polimorfismos T869C (TGF-beta1), C-159T (CD14) e Val/Val (IL-4R) podem estar envolvidos na modulação da gravidade da asma.

OBJECTIVE: To verify the association of transforming growth factor-beta1 (TGF-beta1) (C-509T and T869C), CD14 (C-159T), IL-4 (C-590T), IL-4R (ILe50Val) and ADAM33 (S_2) gene polymorphisms with asthma severity in a sample of patients with mild, moderate and severe persistent atopic asthma. METHODS: A clinical, laboratory, prospective study was performed in patients with persistent atopic asthma, compared to a control group at Hospital Universitário da Universidade Estadual de Campinas between 2006 and 2007. Analysis of the TGF-beta1 T869C gene polymorphism was performed using the technique polymerase chain reaction (PCR) + amplification refractory mutation system (ARMS). TGF-beta1 C-509T, CD14 C-159T, IL-4 C-590T, IL-4Ra ILe50Val, and ADAM33 S2 gene polymorphisms were detected by PCR and restriction enzyme. RESULTS: This study included 88 patients with persistent atopic asthma (27 mild, 23 moderate and 38 severe) and 202 healthy blood donors. As to T869C polymorphism (TGF-beta1), there was an association between the CC genotype and patients with severe asthma. There was no association in polymorphisms C-509T (TGF-beta1), C-590T (IL-4) and S_2 (ADAM33). When distribution of C-159T polymorphism genotype frequency (CD14) in severe asthma was compared with the control group, there was a significant result with the TT genotype. There was significant association of the Val/Val genotype (IL-4R) with mild asthma. CONCLUSION: Our results indicate that T869C (TGF-beta1), C-159T (CD14) and Val/Val (IL-4R) polymorphisms might be involved in modulation of asthma severity.

Sindrome uremico hemolitico: ubicación nosologica actual / Hemolytic uremic syndrome (HUS): an up-dated nosological classification

An up-date of the causes and pathogenesis of the HUS is reported. After more than 40 years of research we are able to define the infectious agents and the toxin involved. The mechanisms and the molecules involved in the non-diarrheal (atypical) entities producing HUS have also been characterized. This new situation allows us to develop a diagnostic algorithm that enables us to better define preventive and therapeutic measures, based on more rational evidence.

Visión clínica de la ADAMTS13 / Clinical vision of the ADAMTS13

La disfunción ADAMTS13 ha sido implicada en la patogénesis de la púrpura trombocitopénica trombótica (PTT). Este desorden ocurre con mayor frecuencia en mujeres y, en el 13 por ciento de ellas, se asocia al embarazo. Sin embargo, hay poca información sobre el comportamiento de la proteasa en embarazo normal. Estudiamos el factor de de von Willebrand y la actividad ADAMTS13 en mujeres sanas no embarazadas, embarazadas y puerperio. Se incluyeron a cincuenta y cinco mujeres no embarazadas, donantes normales del banco de sangre, que no tomaban píldoras anticonceptivas, como controles. Se incluyeron 270 embarazadas y puérperas normales. La actividad ADAMTS13 disminuyó progresivamente a partir del período de 12-16 semanas hasta el final del puerperio temprano (media el 52 por ciento, rango 22-89, p < 0,0001), con un aumento leve posterior. Los niveles fueron levemente menores en nulíparas que en mujeres con paridad previa (65 por ciento vs 83 por ciento, p = 0,0003), y primíparas que en multiparas entre 6-11 semanas hasta 17-23 semanas del embarazo (69 por ciento vs. 80 por ciento, p = 0,005). Aunque en todas las mujeres los níveles de proteasa fueron iguales en los diferentes grupos sanguíneos, las mujeres no embarazadas del grupo sanguíneo O demostraron una media mayor de actividad de ADAMTS13 que el no-O (78 por ciento vs 69 por ciento, p = 0,064). Nuestros resultados sugieren que los cambios de actividad de ADAMTS13, durante el embarazo y puerperio, podrían hacer que el final del embarazo fuera un período más vulnerable para el desarrollo de microangiopatía trombótica.

Eficacia de la asociación rituximab-vindesina en el tratamiento de un caso de púrpura trombótico-trombopénico (PTT) adquirido idiopático refractario / Successful treatment of idiopathic acquired refractory thrombotic thrombocytopenic purpura with an association of rituximab - vindesine. Report of one case

We report a 23 years old female who presented a second episode of thrombotic thrombocytopenic purpura (TTP). She was treated with fresh frozen plasma infusions and 14 plasma exchange (PE) sessions without response. Therefore a second-line therapy was started, associating a weekly cycle administration of vindesine (Vds) 2 mg/m2 and rituximab (R) 375 mg/m2. Five cycles of this association plus one cycle of R exclusively, were administered. After the third course, biological signs of improvement were observed and complete normalization of blood cell counts and other specific parameters was seen after 8 weeks. From the beginning of her second relapse we detected a severe deficit (<5%) in von Willebrand-cleaving factor (ADAMTS13) associated to the presence of ADAMTS13 inhibitors. The combined treatment induced an improvement in ADAMTS13 values without detectable inhibitors. After 21 months of follow-up the patient was well, without signs of relapse but ADAMTS13 values were still under normal, which may be an unfavorable prognostic factor. PE is the treatment of choice for acquired idiopathic TTP, but for refractory cases or TTP cases with severe ADAMTS13 values/high inhibitor titers, PE associated to an immunosuppressive treatment should be considered.

Caracterização do padrão de expressão e metilação dos genes ADAM 12 e 33 em tumores de mama e sua correlação com dados clínico-patológicos / Characterization of the expression pattern and methylation status of the ADAMs 12 and 33 genes in breast tumors and the correlation with clinical pathological data

As proteínas que fazem parte da Família ADAM são glicoproteínas transmembrânicas formadas por multidomínios... Para melhor entender o papel dos diferentes membros da família ADAM na tumorigenese, este trabalho avaliou o padrão de expressão dos genes ADAM 8, 10, 12, 15, 17, 19, 22, 23 e 33 em tecido normal e linhagens tumorais de mama. Após a análises computacionais, verificou-se a presença de ilhas de CpG na região promotora destes genes sugerindo que a metilação poderia estar envolvida na regulação da expressão desses genes. A análise do padrão de expressão destes genes através de RT-PCR revelou uma redução significativa nos níveis de expressão dos genes ADAM 12 e 33 nas linhagens tumorais em relação ao tecido normal. Utilizando a metodologia de tratamento com bissulfito de sódio seguido de sequenciamento, foi possível verificar a existência de uma correlação direta para a maioria das linhagens tumorais analisadas entre a diminuição dos níveis de expressão dos genes ADAM12 e 33 e a presença de metilação na região promotora desses genes... A correlação entre o padrão de metilação e os dados clínico-patológicos das pacientes revelou uma associação estatisticamente significativa entre a presença de metilação na região promotora das ADAM12 e 33 com o estádio do tumor. Também foi observada uma associação positiva entre a metilação no gene ADAM 12, o tamanho do tumor e o status do linfonodo. No entanto, a hipermetilação da região promotora destes genes não mostrou estar estatisticamente correlacionada com a sobrevida global e com a sobrevida livre de doença...(AU)

The ADAMs (A Desintegrin And Metalloprotease domain) comprise a family of multidomain membrane-anchored cell surface proteins with a common structural organization. They are unique among cell surface proteins in possessing both a desintegrin domain, with adhesion properties, and a metalloprotease domain, with a protease activity. Members of this family play am important role in shedding of cell surface proteins (adhesion molecules, cytokines, growth factors and their receptors) and in process of cell-cell and cell-matrix interactions. The availability of growth factors and their receptors as well as the cell-cell and cell-matrix interactions are important in the process of cell proliferation, adhesion and migration. These processes are crucial in progression of tumor and metastasis. As a further contribution to investigate the role of ADAM family members in the tumorigenesis process, we have evaluated the expression pattern of the ADAMs 8, 10, 12, 15, 17, 19, 22 and 33. After a computational analysis using the CpG plot program, these members were shown to have a characteristic CpG island in their promoter region, suggesting that the regulation of these ADAMs could be controlled by methylation. Analysis of the expression pattern by RT-PCR, followed by Southern blot and densitometry showed a significant reduction of the ADAMs 12 and 33 in the breast cell lines relative to the normal tissue. By bisulfite treatment followed by DNA sequencing it was possible to verify a direct correlation between downregulation of the ADAMs 12 and 33 in the cell lines and the hypermethylation of the promoter regions of these genes in almost all cell lines analysed. Expression of these two genes was also activated through treatment of two different cell lines with the demetilating agent 5´-aza-2´-deoxicytidine. This fact confirmed the involvement of methylation in regulation of the expression of the ADAMs 12 and 33. As further contribution to elucidate the role of ADAMs 12 and 33 in breast tumorigenesis, we evaluated the methylation status of the corresponding promoter region of these genes by bissulfite treatment followed by Methylation Specific PCR (MSP) in 108 breast ductal invasive primary tumors. We have detected ADAM12 promoter hypermethylation in 49.1% of the cases and ADAM33 promoter hypermethylation in 55.6% of the cases. The statistical analyses of the methylation pattern of the promoter regions of the ADAMs 12 and 33 and the clinical-pathological data of the patients revealed a significant association between both promoter regions hypermetylation with tumor stage (p=0.005 and p=0.017 respectively). We also observed a significant association between the hypermethylation of ADAM12 promoter region with tumor size (p=0.028) and number of positive lymph nodes (p=0.038). However, the hypermethylation of the both promoter regions were not significantly associated with overall and disease-free survival (AU)

Identificação de regiões diferencialmente metiladas em câncer de mama através da técnica AP-PCR sensível à metilação (MSAP-PCR) / Identification of differentially methylated regions in breast tumors by methylation sensitive AP-PCR (MSAP-PCR)

A estabilidade do genoma e o perfil normal de expressão gênica são mantidos por um padrão fixo e pré-determinado de metilação do DNA. Esse padrão pode, no entanto, ser alterado nas células tumorais e contribuir na tumorigênese. Neste trabalho, nós utilizamos a técnica de AP-PCR sensível à metilação (MSAP-PCR) com o objetivo de identificar regiões diferencialmente metiladas em tumores de mama. Através desta metodologia, fomos capazes de identificar duas regiões diferencialmente metiladas. O primeiro fragmento de DNA isolado foi mapeado no cromossomo 2q33-34, nas proximidades do gene ADAM23... O tratamento das linhagens celulares MCF-7 e SKBR-3 com o agente desmetilante 5?-aza-2?-deoxycytidina levou a uma reexpressão do gene ADAM23 e a um decréscimo significativo nos níveis de metilação. Uma maior porcentagem de metilação foi verificada em tumores de mama com um estádio mais avançado e a presença de metilação parece estar associada com a presença de linfonodos axilares comprometidos e de metástases, assim como, com a ocorrência de recidivas da doença... Nossos resultados sugerem que a diminuição nos níveis de metilação da região SATR1 é um evento comum em tumores de mama, o qual pode facilitar a ocorrência de rearranjos cromossômicos e contribuir no processo de progressão tumoral. Nossos dados também reforçam a importância da hipometilação global do genoma na tumorigênese e devem ser considerados no desenvolvimento de novos protocolos de tratamento contra o câncer que utilizam agentes desmetilantes...(AU)

Genome stability and normal gene expression are maintained by a fixed and predetermined DNA methylation pattern. However, this pattern may be altered in tumor cells, contributing to tumorigenesis. In this work, we used the Methylation Sensitive Arbitrarilly Primed - PCR (MSAP-PCR) in arder to identify differentially methylated regions in breast tumors. Using this methodology, we were able to identify two differentially methylated regions. The first isolated DNA fragment was mapped to chromosome 2q33-34, in the proximity of the ADAM23 gene. The members of the ADAM family are cell surface proteins, which present two characteristic domains: the desintegrin domain and the metalloprotease doma in. The ADAM23 protein presents an inactive metalloprotease domain and it is thought to be involved exclusively in cell-cell adhesion. We verified that the promoter region of the ADAM23 gene is hypermethyllated in 66,7°/o of the tumor celllines and in 51,4- 69,2°/o of the analyzed primary breast tumors. The presence of methylation is strongly associated with reductions in both mRNA and protein expression, suggesting that the silencing of ADAM23 gene may be related to alterations in cell adhesion properties and to tumor progression. A threshold of 40-60°/o of methylated dinucleotides within the promoter region is necessary for the complete silencing of the gene. Treatment of MCF-7 and SKBR-3 cell lines with 5'-Aza 2'-deoxycytidine led to a reactivation of ADAM23 gene expression and a marked decrease in the methylation levei. A higher percentage of methylation was observed in breast tumors in advanced stages and the presence of methylation seems to be associated with the presence of positive axillary lymph nades and metastases as well as with disease recurrence. In ali, these results suggest that the methylation of the AM23 gene may be used as a molecular marker in breast tumors.The second DNA fragment isolated was mapped to chromosome 5 and presented a high similarity with a satellite sequence named SA TR 1. Satellite sequences correspond to blocks of tandemly repeated sequences usually located in regions of pericentromeric and/or telomeric heterochromatin. The loss of methylation in satellite sequences is frequently found in tumors and has been associated with an increased frequency of DNA rearrangements and chromosome instability. The loss of methylation in the STAR1 sequence was observed in 63°/o of the breast tumor cell !ines and in 63-87°/o of primary breast tumors. Patients with a ecrease in the leveis of methylation in the SA TR 1 region presented a shorter disease-free survival in relation to patients with normal leveis of methylation (log-rank, p=0.1963). Our results suggest that a decrease in the leveis of methylation in the SATR1 region is common in breast tumors and may facilitate the occurrence of chromosome rearrangements and contribute to tumor progression. Our results also reinforce the importance of global genome hypomethylation in tumorigenesis and must be considered in the development of new treatment protocols, which use demethylating agents in the treatment of cancer (AU)