Data/hora: 10/06/2024 17:57:21

Provedor de dados: | 56
País: | Brazil
Título: | The Shiga toxin 2 B subunit inhibits net fluid absorption in human colon and elicits fluid accumulation in rat colon loops
Autores: | Creydt,V. Pistone; Miyakawa,M. Fernandez; Martín,F.; Zotta,E.; Silberstein,C.; Ibarra,C.
Data: | 2004-06-01
Ano: | 2004
Palavras-chave: | Hemolytic-uremic syndrome; Diarrhea; Shiga toxin 2; B subunit; Water transport.
Resumo: | Shiga toxin (Stx)-producing Escherichia coli (STEC) colonizes the large intestine causing a spectrum of disorders, including watery diarrhea, bloody diarrhea (hemorrhagic colitis), and hemolytic-uremic syndrome. It is estimated that hemolytic-uremic syndrome is the most common cause of acute renal failure in infants in Argentina. Stx is a multimeric toxin composed of one A subunit and five B subunits. In this study we demonstrate that the Stx2 B subunit inhibits the water absorption (Jw) across the human and rat colonic mucosa without altering the electrical parameters measured as transepithelial potential difference and short circuit current. The time-course Jw inhibition by 400 ng/ml purified Stx2 B subunit was similar to that obtained using 12 ng/ml Stx2 holotoxin suggesting that both, A and B subunits of Stx2 contributed to inhibit the Jw. Moreover, non-hemorrhagic fluid accumulation was observed in rat colon loops after 16 h of treatment with 3 and 30 ng/ml Stx2 B subunit. These changes indicate that Stx2 B subunit induces fluid accumulation independently of A subunit activity by altering the usual balance of intestinal absorption and secretion toward net secretion. In conclusion, our results suggest that the Stx2 B subunit, which is non-toxic for Vero cells, may contribute to the watery diarrhea observed in STEC infection. Further studies will be necessary to determine whether the toxicity of Stx2 B subunit may have pathogenic consequences when it is used as a component in an acellular STEC vaccine or as a vector in cancer vaccines.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000600004
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2004000600004
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.37 n.6 2004
Fonte: | info:eu-repo/semantics/openAccess