Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros

Bases de datos
Tipo de estudio
Tipo del documento
Asunto de la revista
País de afiliación
Intervalo de año de publicación
1.
Am J Pathol ; 184(10): 2768-78, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25216938

RESUMEN

Necrotizing enterocolitis (NEC) affects up to 10% of premature infants, has a mortality of 30%, and can leave surviving patients with significant morbidity. Neuregulin-4 (NRG4) is an ErbB4-specific ligand that promotes epithelial cell survival. Thus, this pathway could be protective in diseases such as NEC, in which epithelial cell death is a major pathologic feature. We sought to determine whether NRG4-ErbB4 signaling is protective in experimental NEC. NRG4 was used i) in the newborn rat formula feeding/hypoxia model; ii) in a recently developed model in which 14- to 16-day-old mice are injected with dithizone to induce Paneth cell loss, followed by Klebsiella pneumoniae infection to induce intestinal injury; and iii) in bacterially infected IEC-6 cells in vitro. NRG4 reduced NEC incidence and severity in the formula feed/hypoxia rat model. It also reduced Paneth cell ablation-induced NEC and prevented dithizone-induced Paneth cell loss in mice. In vitro, cultured ErbB4(-/-) ileal epithelial enteroids had reduced Paneth cell markers and were highly sensitive to inflammatory cytokines. Furthermore, NRG4 blocked, through a Src-dependent pathway, Cronobacter muytjensii-induced IEC-6 cell apoptosis. The potential clinical relevance of these findings was demonstrated by the observation that NRG4 and its receptor ErbB4 are present in human breast milk and developing human intestine, respectively. Thus, NRG4-ErbB4 signaling may be a novel pathway for therapeutic intervention or prevention in NEC.


Asunto(s)
Enterocolitis Necrotizante/prevención & control , Leche Humana/química , Neurregulinas/metabolismo , Receptor ErbB-4/metabolismo , Transducción de Señal , Animales , Animales Recién Nacidos , Citocinas/metabolismo , Modelos Animales de Enfermedad , Enterocolitis Necrotizante/metabolismo , Células Epiteliales/metabolismo , Femenino , Humanos , Íleon/metabolismo , Intestinos/patología , Ratones , Células de Paneth/metabolismo , Ratas , Ratas Sprague-Dawley
2.
PLoS One ; 14(11): e0216762, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31675374

RESUMEN

Enterococcus faecalis is a ubiquitous intestinal symbiont and common early colonizer of the neonatal gut. Although colonization with E. faecalis has been previously associated with decreased pathology of necrotizing enterocolitis (NEC), these bacteria have been also implicated as opportunistic pathogens. Here we characterized 21 strains of E. faecalis, naturally occurring in 4-day-old rats, for potentially pathogenic properties and ability to colonize the neonatal gut. The strains differed in hemolysis, gelatin liquefaction, antibiotic resistance, biofilm formation, and ability to activate the pro-inflammatory transcription factor NF-κB in cultured enterocytes. Only 3 strains, BB70, 224, and BB24 appreciably colonized the neonatal intestine on day 4 after artificial introduction with the first feeding. The best colonizer, strain BB70, effectively displaced E. faecalis of maternal origin. Whereas BB70 and BB24 significantly increased NEC pathology, strain 224 significantly protected from NEC. Our results show that different strains of E. faecalis may be pathogenic or protective in experimental NEC.


Asunto(s)
Enterococcus faecalis/patogenicidad , Enterocolitis Necrotizante/microbiología , Animales , Animales Recién Nacidos , Modelos Animales de Enfermedad , Enterococcus faecalis/clasificación , Enterococcus faecalis/genética , Enterocolitis Necrotizante/patología , Enterocolitis Necrotizante/prevención & control , Enterocitos/microbiología , Enterocitos/patología , Femenino , Variación Genética , Humanos , Recién Nacido , Intestinos/microbiología , Intestinos/patología , Fenotipo , Embarazo , Probióticos/uso terapéutico , Ratas , Ratas Sprague-Dawley , Especificidad de la Especie , Virulencia
3.
PLoS One ; 13(6): e0196710, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29933378

RESUMEN

The use of lactobacilli in prevention of necrotizing enterocolitis (NEC) is hampered by insufficient knowledge about optimal species/strains and effects on intestinal bacterial populations. We therefore sought to identify lactobacilli naturally occurring in postnatal rats and examine their ability to colonize the neonatal intestine and protect from NEC. L. murinus, L. acidophilus, and L. johnsonii were found in 42, 20, and 1 out of 51 4-day old rats, respectively. Higher proportion of L. murinus in microbiota correlated with lower NEC scores. Inoculation with each of the three species during first feeding significantly augmented intestinal populations of lactobacilli four days later, indicating successful colonization. L. murinus, but not L. acidophilus or L. johnsonii, significantly protected against NEC. Thus, lactobacilli protect rats from NEC in a species- or strain-specific manner. Our results may help rationalizing probiotic therapy in NEC.


Asunto(s)
Enterocolitis Necrotizante/prevención & control , Microbioma Gastrointestinal , Intestinos/microbiología , Lactobacillus , Probióticos , Animales , Animales Recién Nacidos , Enterocolitis Necrotizante/microbiología , Enterocolitis Necrotizante/patología , Intestinos/patología , Ratas , Ratas Sprague-Dawley
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA