RESUMEN
To identify host genes differentially expressed during Salmonella enterica serotype Typhimurium infection, an RNA differential display was made with total RNA extracted from ileal loops that were infected with Salmonella Typhimurium 2.5 h after infection. Down-regulated cDNA was identified in bovine Peyer's patches after infection that was highly homologous to a human plasma membrane calcium-transporting ATPase (PMCA). Differential expression of PMCA, evaluated by Northern analysis, was found to have more than a 4.6-fold decrease in expression of mRNA (size, approximately 5.1 kb). PMCA mRNA was detected by in situ hybridization exclusively within epithelial cells in the Peyer's patches. cDNA (4.4 kb) was amplified by rapid amplification of cDNA ends, cloned, and sequenced and showed a high homology to hPMCA. Bovine PMCA is down-regulated in epithelial cells of Peyer's patches after infection with Salmonella Typhimurium and, subsequently, may influence cellular calcium levels that contribute to the inflammatory processes in the pathogenesis of diarrhea.
Asunto(s)
ATPasas Transportadoras de Calcio/biosíntesis , Enfermedades de los Bovinos/enzimología , Ganglios Linfáticos Agregados/microbiología , Salmonelosis Animal/enzimología , Salmonella typhimurium/crecimiento & desarrollo , Animales , Northern Blotting/veterinaria , ATPasas Transportadoras de Calcio/genética , ATPasas Transportadoras de Calcio/metabolismo , Proteínas de Transporte de Catión , Bovinos , Enfermedades de los Bovinos/metabolismo , Enfermedades de los Bovinos/microbiología , ADN Complementario/química , ADN Complementario/genética , Regulación hacia Abajo , Regulación Bacteriana de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Masculino , Ganglios Linfáticos Agregados/patología , ATPasas Transportadoras de Calcio de la Membrana Plasmática , ARN Bacteriano/química , ARN Bacteriano/genética , Salmonelosis Animal/microbiología , Salmonelosis Animal/patología , Salmonella typhimurium/genéticaRESUMEN
The study was made on 59 chinchilla rabbits. S. typhimurium 1847 live culture was introduced into the lumen of an isolated loop of the thin intestine. The activity of adenylate cyclase (AC), guanylate cyclase (GC), the levels of cyclic adenosine 3,5-monophosphate (cAMP), cyclic guanosine 3,5-monophosphate (cGMP), the activity of cAMP- and cGMP-phosphodiesterases were determined in the mucous membrane of the ligated part of the intestine. Considerable fluid accumulation in the loop, activation of AC and cGMP-phosphodiesterase, a rise in the level of cAMP and a drop in the level of cGMP in the mucosa of the ligated part of the intestine were registered. In one group of the animals phosphadene and in the other group unitiol were introduced into the infected intestinal loop; as a result, a decrease in the accumulation of fluid in the loop, on the average, by 40% and a tendency to an increase in the level of cAMP and a drop in the level of cGMP in the mucous membrane of the ligated part of the intestine were observed. Changes in the level of cGMP play, seemingly, a more important role in the development of diarrhea in salmonellosis.