RESUMEN
OBJECTIVE: We assessed the efficacy of a maternal multidose azithromycin (AZI) regimen, with and without antiinflammatory agents to delay preterm birth and to mitigate fetal lung injury associated with Ureaplasma parvum intraamniotic infection. STUDY DESIGN: Long-term catheterized rhesus monkeys (n = 16) received intraamniotic inoculation of U parvum (10(7) colony-forming U/mL, serovar 1). After contraction onset, rhesus monkeys received no treatment (n = 6); AZI (12.5 mg/kg, every 12 h, intravenous for 10 days; n = 5); or AZI plus dexamethasone and indomethacin (n = 5). Outcomes included amniotic fluid proinflammatory mediators, U parvum cultures and polymerase chain reaction, AZI pharmacokinetics, and the extent of fetal lung inflammation. RESULTS: Maternal AZI therapy eradicated U parvum intraamniotic infection from the amniotic fluid within 4 days. Placenta and fetal tissues were 90% culture negative at delivery. AZI therapy significantly delayed preterm delivery and prevented advanced fetal lung injury, although residual acute chorioamnionitis persisted. CONCLUSION: Specific maternal antibiotic therapy can eradicate U parvum from the amniotic fluid and key fetal organs, with subsequent prolongation of pregnancy, which provides a therapeutic window of opportunity to effectively reduce the severity of fetal lung injury.
Asunto(s)
Antibacterianos/administración & dosificación , Azitromicina/administración & dosificación , Corioamnionitis/tratamiento farmacológico , Lesión Pulmonar/prevención & control , Nacimiento Prematuro/prevención & control , Infecciones por Ureaplasma/tratamiento farmacológico , Ureaplasma/aislamiento & purificación , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios no Esteroideos/administración & dosificación , Corioamnionitis/microbiología , Dexametasona/administración & dosificación , Quimioterapia Combinada , Femenino , Enfermedades Fetales/prevención & control , Indometacina/administración & dosificación , Macaca mulatta , Reacción en Cadena de la Polimerasa , Embarazo , Resultado del Tratamiento , Ureaplasma/efectos de los fármacos , Infecciones por Ureaplasma/microbiologíaRESUMEN
Causal, cellular, and inflammatory links between choriodecidual infection with group B streptococcus (GBS) and preterm labor were assessed in a nonhuman primate model. Rhesus monkeys received varying doses of a clinical isolate of GBS, type III or saline, via an indwelling catheter placed between the chorion/decidua and myometrium in the lower pole of the uterus. Choriodecidual inoculation of GBS was followed by a graded response in amniotic fluid (AF) leukocytes, proinflammatory cytokines, prostaglandin E(2) and F(2alpha), and uterine activity (P < .05). The magnitude of the inflammatory response in AF was related, in part, to the initial inoculum size and whether AF cultures remained negative or became positive for GBS. Microbial invasion of AF was associated with advanced inflammation and preterm labor. We provide experimental evidence that choriodeciduitis is a transitional stage of intrauterine infection, which may be self-limited, remain dormant, or progress to intraamniotic infection. These data, coupled with clinical observations, suggest that choriodecidual inflammation is an antecedent event in the pathogenesis of premature cervical ripening (functional cervical insufficiency), premature rupture of the fetal membranes, or preterm labor.
Asunto(s)
Corion/patología , Decidua/patología , Inflamación/patología , Miometrio/patología , Trabajo de Parto Prematuro/patología , Líquido Amniótico/metabolismo , Análisis de Varianza , Animales , Células Cultivadas , Corion/metabolismo , Citocinas/metabolismo , Dinoprostona/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Leucocitos/metabolismo , Leucocitos/patología , Macaca mulatta , Miometrio/metabolismo , Trabajo de Parto Prematuro/metabolismo , Embarazo , Infecciones Estreptocócicas/metabolismo , Infecciones Estreptocócicas/patología , Streptococcus agalactiae/metabolismoRESUMEN
The authors assess causal, cellular and inflammatory links between intraamniotic infection with Ureaplasma parvum or Mycoplasma hominis and preterm labor in a nonhuman primate model. Long-term catheterized rhesus monkeys received intraamniotic inoculations of clinical isolates of Ureaplasma parvum serovar 1, M hominis, media control or physiological saline. Genital mycoplasmas were quantified in amniotic fluid (AF) and documented in fetal tissues by culture and PCR. In association with elevated AF colony counts for U parvum or M hominis, there was a sequential upregulation of AF leukocytes, proinflammatory cytokines, prostaglandin E2 and F2a, metalloproteinase-9 and uterine activity ( P< .05). Fetal membranes and lung were uniformly positive for both microorganisms; fetal blood and cerebrospinal fluid cultures and PCR were more often positive for M hominis than U parvum. Histopathologic findings of chorioamnionitis, a systemic fetal inflammatory response and pneumonitis worsen with duration of in utero infection. U parvum or M hominis, as sole pathogens, elicit a robust proinflammatory response which contributes to preterm labor and fetal lung injury.
Asunto(s)
Corioamnionitis/microbiología , Infecciones por Mycoplasma/microbiología , Mycoplasma hominis/crecimiento & desarrollo , Trabajo de Parto Prematuro/microbiología , Neumonía/microbiología , Infecciones por Ureaplasma/microbiología , Ureaplasma/crecimiento & desarrollo , Líquido Amniótico/microbiología , Animales , Femenino , Macaca mulatta , EmbarazoRESUMEN
Intrauterine infection, which occurs in most early preterm births, triggers an immune response culminating in preterm labor. The authors hypothesize that blockade of lipopolysaccharide (LPS)-induced immune responses by a toll-like receptor 4 antagonist (TLR4A) would prevent elevations in amniotic fluid (AF) cytokines, prostaglandins, and uterine contractility. Chronically catheterized rhesus monkeys at 128 to 147 days' gestation received intra-amniotic infusions of either (1) saline (n = 6), (2) LPS (0.15-10 microg; n = 4), or (3) TLR4A pretreatment with LPS (10 microg) 1 hour later (n = 4). AF cytokines, prostaglandins, and uterine contractility were compared using 1-way ANOVA with Bonferroni-adjusted pairwise comparisons. Compared with saline controls, LPS induced significant elevations in AF interleukin-8 (IL-8), tumor necrosis factor (TNF)- alpha, PGE(2), PGF(2)(alpha), and uterine contractility (P < .05). In contrast, TLR4A pretreatment inhibited LPS-induced uterine activity and was associated with significantly lower AF IL-8, TNF-alpha, PGE(2), and PGF(2)( alpha) versus LPS alone (P < .05). Toll-like receptor antagonists, together with antibiotics, may delay or prevent infection-associated preterm birth.
Asunto(s)
Lipopolisacáridos/inmunología , Trabajo de Parto Prematuro/inmunología , Complicaciones Infecciosas del Embarazo/inmunología , Receptor Toll-Like 4/antagonistas & inhibidores , Contracción Uterina/efectos de los fármacos , Líquido Amniótico/microbiología , Animales , Corioamnionitis , Citocinas/inmunología , Modelos Animales de Enfermedad , Escherichia coli , Femenino , Lipopolisacáridos/administración & dosificación , Macaca mulatta , Trabajo de Parto Prematuro/prevención & control , Embarazo , Prostaglandinas/inmunología , Contracción Uterina/inmunología , Enfermedades Uterinas/microbiologíaRESUMEN
OBJECTIVE: The purpose of this study was to determine whether treatment with ampicillin together with dexamethasone and indomethacin delays preterm birth that is induced by intraamniotic group B Streptococcus in a nonhuman primate model. STUDY DESIGN: After contraction onset that was induced by group B Streptococcus (10(6) colony-forming units/mL), chronically instrumented rhesus macaques received either no treatment (controls; n = 6); ampicillin (n = 4); or ampicillin + dexamethasone + indomethacin (n = 5). Outcomes included the interval from contraction onset until delivery and concentrations of amniotic fluid inflammatory mediators. RESULTS: Mean interval from contraction onset until delivery was 33 +/- 8.7 hours in controls, 82 +/- 28.0 hours with ampicillin (P = .18, vs controls), and 213 +/- 50.8 hours with ampicillin + dexamethasone + indomethacin (P = .004, vs controls). Ampicillin eradicated group B Streptococcus; however, uterine activity, amniotic fluid cytokines, prostaglandins, and matrix metalloproteinase-9 remained elevated. Ampicillin + dexamethasone + indomethacin suppressed interleukin-1beta, tumor necrosis factor-alpha, and prostaglandins E2 and F2alpha but did not alter matrix metalloproteinase expression or chorioamnionitis. CONCLUSION: The combination of ampicillin + dexamethasone + indomethacin suppressed inflammation and significantly prolonged gestation.
Asunto(s)
Ampicilina/uso terapéutico , Antibacterianos/uso terapéutico , Corioamnionitis , Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Factores Inmunológicos/uso terapéutico , Indometacina/uso terapéutico , Trabajo de Parto Prematuro/prevención & control , Amnios/microbiología , Líquido Amniótico/química , Líquido Amniótico/microbiología , Animales , Cesárea , Corion/microbiología , Citocinas/análisis , Modelos Animales de Enfermedad , Quimioterapia Combinada , Femenino , Macaca mulatta , Metaloproteinasa 9 de la Matriz/química , EmbarazoRESUMEN
Intra-amniotic infection (IAI) is associated with preterm birth and perinatal mortality. To identify potential biomarkers, we performed a comprehensive survey of the cervical-vaginal fluid (CVF) proteome from a primate IAI model utilizing multidimensional protein identification technology (LC/LC-MS/MS) and MALDI-TOF-MS analyses. Analyses of CVF proteome identified 205 unique proteins and differential expression of 27 proteins in controls and IAI samples. Protein expression signatures and immunodetection of specific biomarkers identified can be employed for noninvasive detection of IAI.
Asunto(s)
Líquido Amniótico/microbiología , Biomarcadores/química , Líquidos Corporales/metabolismo , Cuello del Útero/metabolismo , Infecciones/diagnóstico , Proteómica/métodos , Vagina/metabolismo , Animales , Líquidos Corporales/microbiología , Cuello del Útero/microbiología , Femenino , Regulación de la Expresión Génica , Macaca mulatta , Embarazo , Preñez , Nacimiento Prematuro/prevención & control , Ureaplasma/metabolismo , Vagina/microbiologíaRESUMEN
The human fetal membranes are complex tissues that perform many important functions during gestation. The extracellular matrix provides their strength to withstand the forces directed from the fetus and myometrium. Relaxin is a collagenolytic hormone that causes increased production of the matrix metalloproteinases. Its expression from the decidua is increased in patients with preterm premature rupture of the membranes, and its leucine-rich G receptor 7 is upregulated at preterm. The authors previously showed that relaxin is not involved in the infection-mediated cytokine response, but in the absence of infection, it causes increased secretion of both interleukin -6 and interleukin-8 from the membranes. In this article, the authors propose that relaxin is one of a number of sterile stimuli capable of causing increased proinflammatory cytokines, similar to but less robust than the effects of infection. These probably represent distinct inflammatory pathways involving different intracellular signaling events, which can result in either preterm premature rupture of the membranes or preterm labor. The current challenge is to fully understand these pathways and to clarify their similarities and differences.
Asunto(s)
Membranas Extraembrionarias/metabolismo , Relaxina/metabolismo , Transducción de Señal , Citocinas/metabolismo , Decidua/metabolismo , Matriz Extracelular/metabolismo , Femenino , Rotura Prematura de Membranas Fetales/metabolismo , Humanos , Inflamación/metabolismo , Proteínas de la Membrana/metabolismo , Embarazo , Nacimiento Prematuro/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Péptidos , Resistencia a la TracciónRESUMEN
OBJECTIVES: The purpose of this study was to determine the relative contributions of individual proinflammatory cytokines and chemokines to the triggering of preterm labor. STUDY DESIGN: Eighteen chronically instrumented pregnant rhesus monkeys at 135 +/- 3 days gestation (term = 167 days) received 1 of 5 intraamniotic infusions: (1) interleukin-1beta (IL-1beta) (10 microg; n = 5), (2) tumor necrosis factor-alpha (TNF-alpha) (10-100 microg; n = 5), (3) IL-6 (20 microg twice a day; n = 2), (4) IL-8 (20 microg twice a day; n = 2), and (5) saline control (n = 4). Primary study outcomes were the mean uterine hourly contraction area (mm Hg x s/h) in 24 hours during peak response to cytokine infusion (all groups) and the interval from cytokine infusion until labor onset (IL-1beta, IL-6, and IL-8 groups). Secondary outcomes were quantities of amniotic fluid cytokines and chemokines (IL-1beta, TNF-alpha, IL-6, and IL-8), prostaglandins E2 and F2alpha, leukocytes, and matrix metalloproteinase-9 (MMP-9). Histopathology of fetal lungs and placental membranes was assessed. RESULTS: IL-1beta stimulated the most intense contraction patterns, resulting in preterm labor in all cases. TNF-alpha induced a variable degree of uterine activity among individual animals stimulating either preterm labor (n = 2) or a uterine contraction pattern of moderate intensity (n = 3). Despite prolonged elevations in amniotic fluid levels, neither IL-6 nor IL-8 induced preterm labor or an increase in uterine activity until near term. The mean interval from the initiation of IL-6 and IL-8 infusion to the onset of labor was significantly longer than after IL-1beta (21.9 vs 1.1 days; P < .01), and did not differ from the saline control group (27.6 days; P = NS). Intraamniotic infusion of IL-1beta or TNF-alpha was associated with significant elevations in all tested amniotic fluid cytokines, IL-8, prostaglandins, MMP-9 and leukocytes compared with gestational age-matched saline controls. IL-6 and IL-8 infusions were not associated with increases in IL-1beta or TNF-alpha and only produced a moderate increase in amniotic fluid prostaglandins. All cytokine infusions induced histologic chorioamnionitis and an accumulation of neutrophils in fetal lungs. CONCLUSION: Preterm labor was induced by intraamniotic infusions of IL-1beta and TNF-alpha, but not by IL-6 or IL-8 although inflammatory changes in fetal membranes and lungs were uniformly present. Our results indicate a primary role for IL-1beta and TNF-alpha in the triggering of preterm labor associated with inflammation or infection.
Asunto(s)
Líquido Amniótico , Interleucina-1beta/administración & dosificación , Trabajo de Parto Prematuro/inducido químicamente , Factor de Necrosis Tumoral alfa/administración & dosificación , Líquido Amniótico/citología , Líquido Amniótico/metabolismo , Animales , Corioamnionitis/inducido químicamente , Citocinas/metabolismo , Membranas Extraembrionarias/efectos de los fármacos , Membranas Extraembrionarias/patología , Femenino , Edad Gestacional , Inflamación/inducido químicamente , Inflamación/patología , Inyecciones , Interleucina-1beta/metabolismo , Interleucina-1beta/farmacología , Interleucina-6/administración & dosificación , Interleucina-6/farmacología , Interleucina-8/administración & dosificación , Interleucina-8/metabolismo , Interleucina-8/farmacología , Pulmón/efectos de los fármacos , Pulmón/embriología , Pulmón/patología , Macaca mulatta , Metaloproteinasa 9 de la Matriz/metabolismo , Infiltración Neutrófila , Embarazo , Prostaglandinas/metabolismo , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Contracción Uterina , Útero/efectos de los fármacosRESUMEN
OBJECTIVE: The purpose of this study was to determine whether treatment with the immune modulators dexamethasone or interleukin-10 prevents interleukin-1beta-induced uterine contractions in a nonhuman primate model. STUDY DESIGN: Thirteen chronically instrumented rhesus monkeys at 135 +/- 1 days of gestation (term, 167 days) received one of three interventions: (1) intra-amniotic interleukin-1beta (10 microg) infusion with maternal dexamethasone (1 mg/kg) intravenously every 6 hours for 1 day before interleukin-1beta and for 2 days thereafter (n = 4), (2) intra-amniotic interleukin-1beta infusion with maternal interleukin-10 (25 microg/kg) given intravenously and 100 microg interleukin-10 given intra-amniotically before the interleukin-1beta and continued every 8 hours for 3 days (n = 5), and (3) intra-amniotic interleukin-1beta administered alone (n = 5). Uterine activity was monitored continuously and quantified as the hourly contraction area (millimeters of mercury times seconds per hour) in all groups until delivery. Amniotic fluid was sampled for leukocyte counts and assayed for prostaglandins E(2) and F(2)alpha, cytokines interleukin-1beta, interleukin-6, interleukin-8, tumor necrosis factor-alpha, interleukin-10, and interleukin-1 receptor antagonist by specific assays. Maternal and fetal blood were assayed for cortisol, dehydroepiandrosterone sulfate, and estradiol. RESULTS: Interleukin-1beta infusion in the absence of immune modulators resulted in an increase in uterine activity and amniotic fluid proinflammatory cytokines, prostaglandins, and leukocytes. Dexamethasone and interleukin-10 treatment significantly reduced interleukin-1beta-induced uterine contractility (P <.05) and amniotic fluid prostaglandins (P <.05) but not interleukin-8 or interleukin-1 receptor antagonist. Amniotic fluid interleukin-6 and maternal and fetal cortisol, dehydroepiandrosterone sulfate, and estradiol concentrations were reduced by dexamethasone (P <.05), whereas tumor necrosis factor-alpha levels and leukocyte counts were attenuated by interleukin-10 treatment (P <.05). An inverse relationship was noted between amniotic fluid interleukin-10 concentrations and interleukin-1beta-induced uterine activity (r = -0.74, P <.05). CONCLUSION: Dexamethasone and interleukin-10 exert similar inhibitory effects on interleukin-1beta-induced uterine activity, which appears to be mediated by a decrease in prostaglandin production. Reduced estrogen biosynthesis or suppression of tumor necrosis factor-alpha and leukocyte migration may contribute to the tocolytic actions of dexamethasone and interleukin-10, respectively. Dexamethasone and interleukin-10 are likely to be useful adjuncts in the treatment of preterm labor that is associated with inflammation or infection.
Asunto(s)
Dexametasona/farmacología , Glucocorticoides/farmacología , Interleucina-10/farmacología , Interleucina-1/farmacología , Contracción Uterina/efectos de los fármacos , Líquido Amniótico/química , Líquido Amniótico/citología , Animales , Citocinas/análisis , Dinoprost/análisis , Dinoprostona/análisis , Interacciones Farmacológicas , Femenino , Edad Gestacional , Frecuencia Cardíaca Fetal , Proteína Antagonista del Receptor de Interleucina 1 , Interleucina-6/análisis , Interleucina-8/análisis , Recuento de Leucocitos , Macaca mulatta , Embarazo , Prostaglandinas/análisis , Sialoglicoproteínas/análisis , Factor de Necrosis Tumoral alfa/análisisRESUMEN
OBJECTIVE: The purpose of this study was to examine the roles of intrauterine infection, inflammation, and spontaneous labor on the expression of matrix metalloproteinase-9 in fetal membranes and amniotic fluid of late pregnant rhesus monkeys. STUDY DESIGN: Pregnant rhesus monkeys with timed gestations were chronically catheterized to allow serial sampling of amniotic fluid before and during experimentally induced intrauterine inflammation. Six animals received group B streptococci into the chorionic-decidual space, and 4 animals received intra-amniotic interleukin-1 beta infusions (10 microg). Three additional animals were serially sampled by amniocentesis through late pregnancy until spontaneous term labor. Amniotic fluid samples were examined by zymography for matrix metalloproteinase-9 and -2 and Western immunoblot for matrix metalloproteinase-9 and -2 and tissue inhibitors of metalloproteinase-1 and -2. Fetal membranes were obtained at cesarean delivery during labor (before rupture), formalin fixed, and embedded in paraffin for immunocytochemistry of matrix metalloproteinase-9 and in situ hybridization of matrix metalloproteinase-9 messenger RNA. Tissues from 2 additional animals were collected as age-matched non-labor controls. RESULTS: In amniotic fluid, the 92-kd latent matrix metalloproteinase-9 was detectable in late pregnancy and increased dramatically, followed by the appearance of the 83-kd active form before spontaneous term delivery. Amniotic fluid matrix metalloproteinase-2 levels (both latent and active forms) remained relatively constant throughout pregnancy and in labor. Both bacteria and interleukin-1 beta rapidly increased the signal of latent matrix metalloproteinase-9 without a consistent increase in the active form before the onset of labor. Chorionic-decidual inoculation of group B streptococci was followed by the expression of latent matrix metalloproteinase-9 before the appearance of group B streptococci in amniotic fluid or the onset of labor. Matrix metalloproteinase-2 increased to a new steady-state level or remained unchanged after group B streptococci inoculation or interleukin-1 beta infusion, respectively. Amniotic fluid tissue inhibitors of metalloproteinase-1 declined and tissue inhibitors of metalloproteinase-2 remained unchanged during early group B streptococci infection, after interleukin-1 beta infusion and on the day of spontaneous term labor. However, both tissue inhibitors of metalloproteinase-1 and -2 levels increased after preterm labor that was induced by group B streptococci. Immunocytochemistry localized matrix metalloproteinase-9 protein to amnion and chorion epithelial and mesenchymal cells and decidual stromal cells. Granular matrix metalloproteinase-9 staining was observed in the connective tissue layer of inflamed fetal membranes. In situ hybridization for messenger RNA confirmed the production of matrix metalloproteinase-9 by amnion and chorion. CONCLUSION: Bacterial- and interleukin-1 beta-induced preterm labor and spontaneous term labor are preceded and accompanied by progressive increases in amniotic fluid matrix metalloproteinase-9 (92 kd) in rhesus monkeys. Amniotic fluid matrix metalloproteinase-9 may serve as a clinical marker for the onset of both preterm and term labor.