Maternal and fetal roles in bacterially induced preterm labor in the mouse.
Am J Obstet Gynecol
; 214(3): 386.e1-9, 2016 Mar.
Article
em En
| MEDLINE
| ID: mdl-26478101
ABSTRACT
BACKGROUND:
The relative roles of the mother and fetus in signaling for labor remain poorly understood.OBJECTIVE:
We previously demonstrated using gene knockout (KO) mice that Escherichia coli-induced preterm delivery is completely dependent on MyD88, a toll-like receptor adaptor protein. Here we leveraged this finding to conduct a genetic experiment testing whether the mother, the fetus, or both signal for parturition in bacterially induced labor. STUDYDESIGN:
Six different maternal/fetal genotype combinations for MyD88 were studied wild-type (WT) dams carrying one of the following (1) WT or (2) MyD88 heterozygous (het) fetuses (generated by mating WT females with WT or MyD88-knockout [KO] males, respectively); (3) WT dams carrying MyD88-KO fetuses (generated by replacing the ovaries of WT females with MyD88-KO ovaries, followed by mating with MyD88-KO males); a similar strategy was used to generate MyD88-KO dams carrying (4) MyD88-KO, (5) MyD88 het, or (6) WT fetuses. On day 14.5 of gestation, mice received intrauterine injections of either 1 × 10(9) killed E coli or sterile medium. Delivery of ≥ 1 fetus within 48 hours was considered preterm. A separate group of similarly treated pregnant mice was euthanized 5 hours after surgery for gene expression and tissue analysis.RESULTS:
E coli-induced preterm delivery is dependent on maternal and not fetal genotype > 95% of WT and < 5% of MyD88-KO dams deliver prematurely, regardless of fetal genotype (P = .0001). In contrast, fetal survival in utero is influenced by fetal genotype in MyD88-KO dams, in which premature birth rarely occurs, only 81% of WT and 86% of MyD88-heterozygous fetuses were alive 48 hours after surgery compared with 100% of MyD88-KO fetuses (P < .01). Messenger ribonucleic acids for the inflammatory mediators interleukin-1ß, tumor necrosis factor, interleukin-6, and cyclooxygenase-2 were elevated in uterine tissues only in WT mothers treated with E coli and were low or undetectable in the uteri of KO mothers or in animals treated with saline. Serum progesterone levels were lower in KO mothers with WT ovaries than in WT mothers with KO ovaries, but bacterial exposure did not have an impact on these levels.CONCLUSION:
In the murine E coli-induced labor model, preterm delivery and uterine expression of inflammatory mediators is determined by the mother and not the fetus and is not attributable to a decline in serum progesterone.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Complicações Infecciosas na Gravidez
/
RNA Mensageiro
/
Infecções por Escherichia coli
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Fator 88 de Diferenciação Mieloide
/
Trabalho de Parto Prematuro
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Pregnancy
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article