Avaliação dos glicosaminoglicanos do tecido periuretral de pacientes com e sem prolapso genital / Evaluation of glycosaminoglycans of periurethral tissue in patients with and without pelvic organ prolapse

OBJETIVOS: Caracterizar e quantificar os subtipos de glicosaminoglicanos sulfatados (GAGs) existentes no tecido peri-uretral de pacientes com e sem prolapso genital. METODOS: Foram incluídas 35 pacientes que se submeteram a cirurgia vaginal para correção de distopias genitais e/ou incontinência urinária de esforço ou por outra condição benigna. As pacientes foram avaliadas por anamnese padronizada, exame físico e urodinâmico e agrupadas segundo a existência do prolapso genital. Durante o procedimento cirúrgico, amostras de aproximadamente 1,0 x 1,0 cm do tecido periuretral foram retiradas para avaliação. Os GAGs foram extraídos do tecido por proteólise e precipitação por ácido tricloroacético e caracterizados por eletroforese em gel de agarose. A quantificação foi feita por meio de densitometria a 525 nm do gel corado com azul de toluidina. Compararam-se os dados pela análise de variância (ANOVA). RESULTADOS: Nos grupos estudados, houve maior predomínio de dermatam sulfato (DS), em torno de 85 por cento do total de GAGs, seguido do condroitim sulfato (CS) e do heparam sulfato (HS). Observou-se aumento significativo dos GAGs totais, do DS e do HS em mulheres com prolapso genital. Não se observou diferença significante com relação ao CS. CONCLUSÃO: Este estudo demonstrou diferenças na matriz extracelular do tecido periuretral com aumento de GAGs totais, DS e HS nas mulheres com prolapso genital.

OBJECTIVE: To characterize and quantify periurethral tissue sulphated glycosaminoglycans (GAGs) in women with and without pelvic organ prolapse. STUDY DESIGN: Periurethral tissue was obtained from 35 women who underwent surgery for pelvic organ prolapse, for stress urinary incontinence, or for other gynecological benign conditions. Patients were submitted to a clinical history, physical and urodynamic examination and were divided in two groups according to genital prolapse. The standard biopsy with 1.0 x 1.0 cm was taken from periurethral tissue during surgery and assessed by biochemical methods. The GAGs were obtained by proteolysis and precipitated by trichloroacetic acid. The relative concentration of sulfated GAGs was determined by densitometry of toluidine blue stained gel using a spectrophotometer with a 525 nm wavelength. Data were compared using analysis of variance (ANOVA). RESULTS: In the two groups dermatan sulphate (DS) was the predominant glycosaminoglycan (85 percent), followed by chondroitin sulphate (CS) and heparan sulphate (HS). Women with pelvic organ prolapse had significantly more total GAGs, DS and HS. Differences in CS were not observed. CONCLUSIONS: This study showed altered biochemical characteristics in the extracellular matrix of periurethral tissue and also accumulation of GAGs, DS and CS, in women with pelvic organ prolapse.

The specificity of interactions between proteins and sulfated polysaccharides

Os polissacarídeos sulfatados são capazes de se ligar às proteínas com diferentes níveis de especificidade. São macromoléculas altamente ácidas que podem se ligar de forma inespecífica a qualquer domínio básico da superfície de uma proteína em soluções com baixa força iônica, contudo tais interações não parecem ser fisiologicamente significativas. Por outro lado, foram identificados vários sistemas nos quais componentes estruturais muito específicos dos polissacarídeos sulfatados conferem alta afinidade para algumas proteínas. O exemplo mais conhecido é o pentassacarídeo da heparina com alta afinidade pela antitrombina. Outros exemplos podem ser observados no estudo de invertebrados marinhos, tais como a importância da estrutura fina do dermatam sulfato para sua interação com o cofator II da heparina e o envolvimento defucanas sulfatadas encontradas no gel que envolve osóvulos dos ouriços-do-mar na espécie especificidade da fertilização. Um terceiro exemplo de interação específica é aquele descrito para o glicosaminoglicano heparam sulfato encontrado na superfície celular. Neste caso, o padrão de sulfatação pode determinar diferentes afinidades do carboidrato por citoquinas, fatores de crescimento e outras proteínas encontradas na superfície celular e na matriz extracelular. Estas interações complexas entre proteínas e carboidratos são capazes de influenciar a difusão das proteínas através dos tecidos, assim como modelar a resposta celular a estas moléculas.

Galactosaminoglycans from normal myometrium and leiomyoma

In many tumors, the amount of chondroitin sulfate in the extracellular matrix has been shown to be elevated when compared to the corresponding normal tissue. Nevertheless, the degree of chondroitin sulfate increase varies widely. In order to investigate a possible correlation between the amount of chondroitin sulfate and tumor size, several individual specimens of human leiomyoma, a benign uterine tumor, were analyzed. The glycosaminoglycans from eight tumors were extracted and compared with those from the respective adjacent normal myometrium. The main glycosaminoglycan found in normal myometrium was dermatan sulfate, with small amounts of chondroitin sulfate and heparan sulfate. In leiomyoma, both dermatan sulfate and chondroitin sulfate were detected and the total amounts of the two galactosaminoglycans was increased in all tumors when compared to normal tissue. In contrast, the heparan sulfate concentration decreased in the tumor. To assess the disaccharide composition of galactosaminoglycans, these compounds were incubated with bacterial chondroitinases AC and ABC. The amounts of L-iduronic acid-containing disaccharides remained constant, whereas the concentration of D-glucuronic acid-containing disaccharides increased from 2 to 10 times in the tumor, indicating that D-glucuronic acid-containing disaccharides are responsible for the elevation in galactosaminoglycan concentration. This increase is positively correlated with tumor size

Proteoglycans and glycosaminoglycans synthesized by the hepatic granulomas isolated from schistosome-infected mice and by a granuloma-derived connective tissue cell line

1. This paper summarizes our studies on proteglycans and glycosaminoglycans in the hepatic fibrosis occurring in schistosomiasis. 2. We have compared proteglycans and glycosaminoglycans isolated from schistosomal fibrotic granulomas with those obtained from the cellular and extracellular compartments of a murine cell line derived from schistosome-induced granulomas, primary cell line "GR". 3. Our results have shown some biochemical and structural similarities between proteglycans and glycosaminoglycans extracted from granulomas and those synthesized and secreted by GR cells, suggesting that cells may be the major cell population involved in synthesis and accumulation of these molecules in the schistosomal periovular granulomas in liver. Furthermore, we have shown that GR cells can function as an extramedullary myelopoietic stroma that mediates a long-term myeloid proliferation through an autocrine mechanism where the interaction between myelopoietic growth factors and cell-surface heparan sulfate proteoglycans was characterized