Cells involved in extracellular matrix remodeling after acute myocardial infarction.

OBJECTIVE: Evaluate the effects of VEGF165 gene transfer in the process of remodeling of the extracellular matrix after an acute myocardial infarct. METHODS: Wistar rats were submitted to myocardial infarction, after the ligation of the left descending artery, and the left ventricle ejection fraction was used to classify the infarcts into large and small. The animals were divided into groups of ten, according to the size of infarcted area (large or small), and received or not VEGF165 treatment. Evaluation of different markers was performed using immunohistochemistry and digital quantification. The primary antibodies used in the analysis were anti-fibronectin, anti-vimentin, anti-CD44, anti-E-cadherin, anti-CD24, anti-alpha-1-actin, and anti-PCNA. The results were expressed as mean and standard error, and analyzed by ANOVA, considering statistically significant if p≤0.05. RESULTS: There was a significant increase in the expression of undifferentiated cell markers, such as fibronectin (protein present in the extracellular matrix) and CD44 (glycoprotein present in the endothelial cells). However, there was decreased expression of vimentin and PCNA, indicating a possible decrease in the process of cell proliferation after treatment with VEGF165. Markers of differentiated cells, E-cadherin (adhesion protein between myocardial cells), CD24 (protein present in the blood vessels), and alpha-1-actin (specific myocyte marker), showed higher expression in the groups submitted to gene therapy, compared to non-treated group. The value obtained by the relation between alpha-1-actin and vimentin was approximately three times higher in the groups treated with VEGF165, suggesting greater tissue differentiation. CONCLUSION: The results demonstrated the important role of myocytes in the process of tissue remodeling, confirming that VEGF165 seems to provide a protective effect in the treatment of acute myocardial infarct.

The Profile of Heparanase Expression Distinguishes Differentiated Thyroid Carcinoma from Benign Neoplasms.

INTRODUCTION: The search for a specific marker that could help to distinguish between differentiated thyroid carcinoma and benign lesions remains elusive in clinical practice. Heparanase (HPSE) is an endo-beta-glucoronidase implicated in the process of tumor invasion, and the heparanase-2 (HPSE2) modulates HPSE activity. The aim of this study was to evaluate the role of heparanases in the development and differential diagnosis of follicular pattern thyroid lesions. METHODS: HPSE and HPSE2 expression by qRT-PCR, immunohistochemistry evaluation, western blot analysis and HPSE enzymatic activity were evaluated. RESULTS: The expression of heparanases by qRT-PCR showed an increase of HPSE2 in thyroid carcinoma (P = 0.001). HPSE activity was found to be higher in the malignant neoplasms than in the benign tumors (P<0.0001). On Western blot analysis, HPSE2 isoforms were detected only in malignant tumors. The immunohistochemical assay allowed us to establish a distinct pattern for malignant and benign tumors. Carcinomas showed a typical combination of positive labeling for neoplastic cells and negative immunostaining in colloid, when compared to benign tumors (P<0.0001). The proposed diagnostic test presents sensitivity and negative predictive value of around 100%, showing itself to be an accurate test for distinguishing between malignant and benign lesions. CONCLUSIONS: This study shows, for the first time, a distinct profile of HPSE expression in thyroid carcinoma suggesting its role in carcinogenesis.

Cells involved in extracellular matrix remodeling after acute myocardial infarction / Células envolvidas no remodelamento da matriz extracelular após infarto agudo do miocárdio

Objective Evaluate the effects of VEGF165 gene transfer in the process of remodeling of the extracellular matrix after an acute myocardial infarct. Methods Wistar rats were submitted to myocardial infarction, after the ligation of the left descending artery, and the left ventricle ejection fraction was used to classify the infarcts into large and small. The animals were divided into groups of ten, according to the size of infarcted area (large or small), and received or not VEGF165 treatment. Evaluation of different markers was performed using immunohistochemistry and digital quantification. The primary antibodies used in the analysis were anti-fibronectin, anti-vimentin, anti-CD44, anti-E-cadherin, anti-CD24, anti-alpha-1-actin, and anti-PCNA. The results were expressed as mean and standard error, and analyzed by ANOVA, considering statistically significant if p≤0.05. Results There was a significant increase in the expression of undifferentiated cell markers, such as fibronectin (protein present in the extracellular matrix) and CD44 (glycoprotein present in the endothelial cells). However, there was decreased expression of vimentin and PCNA, indicating a possible decrease in the process of cell proliferation after treatment with VEGF165. Markers of differentiated cells, E-cadherin (adhesion protein between myocardial cells), CD24 (protein present in the blood vessels), and alpha-1-actin (specific myocyte marker), showed higher expression in the groups submitted to gene therapy, compared to non-treated group. The value obtained by the relation between alpha-1-actin and vimentin was approximately three times higher in the groups treated with VEGF165, suggesting greater tissue differentiation. Conclusion The results demonstrated the important role of myocytes in the process of tissue remodeling, confirming that VEGF165 seems to provide a protective effect in the treatment of acute myocardial infarct. .

Objetivo Avaliar os efeitos da transferência gênica do VEGF165 no processo de remodelamento da matriz extracelular após infarto agudo do miocárdio. Métodos Ratos Wistar foram submetidos ao infarto do miocárdio por ligação da artéria coronária descendente esquerda, e a fração de ejeção de ventrículo esquerdo foi utilizada para classificar os infartos em grandes e pequenos. Os animais foram divididos em grupos de dez animais, de acordo com o tamanho do infarto (grande ou pequeno), e receberam ou não tratamento com o VEGF165. A avaliação dos diferentes marcadores foi realizada por imuno-histoquímica e quantificação digital. Os anticorpos primários utilizados foram antifibronectina, antivimentina, anti- CD44, anti-E-caderina, anti-CD24, anti-alfa-1-actina e anti-PCNA. Os resultados foram representados como média e erro padrão, e analisados por ANOVA, sendo considerado estatisticamente significativo se p≤0,05. Resultados Houve aumento significativo da expressão de marcadores de células indiferenciadas, como fibronectina (proteína presente na matriz extracelular) e CD44 (glicoproteína presente nas células endoteliais). Entretanto, houve diminuição da expressão de vimentina e PCNA, indicando possível diminuição do processo de proliferação celular após o tratamento com VEGF165. Os marcadores de células diferenciadas, E-caderina (proteína de adesão entre as células do miocárdio), CD24 (proteína presente nos vasos sanguíneos) e alfa-1-actina (marcador especifico de miócitos) também apresentaram maior expressão nos grupos submetidos à terapia gênica, comparativamente com o grupo não tratado. O valor obtido pela relação entre alfa-1-actina e vimentina foi aproximadamente três vezes maior nos grupos tratados com VEGF165, indicando maior diferenciação tecidual. Conclusão O papel dos miócitos se mostrou importante no processo de remodelamento tecidual, confirmando que o VEGF165 parece conferir um efeito protetor no tratamento do infarto agudo do miocárdio. .