scholarly journals Development of a mouse model of ascending infection and preterm birth

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260370
Author(s):  
Nicholas R. Spencer ◽  
Enkhtuya Radnaa ◽  
Tuvshintugs Baljinnyam ◽  
Talar Kechichian ◽  
Ourlad Alzeus G. Tantengco ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Mouse Model ◽  
Amniotic Fluid ◽  
Imaging System ◽  
Ex Vivo ◽  
Post Inoculation ◽  
Dependent Manner ◽  
Microbial Invasion ◽  
Ascending Infection ◽  
Risk Pregnancy

Background Microbial invasion of the intraamniotic cavity and intraamniotic inflammation are factors associated with spontaneous preterm birth. Understanding the route and kinetics of infection, sites of colonization, and mechanisms of host inflammatory response is critical to reducing preterm birth risk. Objectives This study developed an animal model of ascending infection and preterm birth with live bacteria (E. coli) in pregnant CD-1 mice with the goal of better understanding the process of microbial invasion of the intraamniotic cavity and intraamniotic inflammation. Study design Multiple experiments were conducted in this study. To determine the dose of E. coli required to induce preterm birth, CD-1 mice were injected vaginally with four different doses of E. coli (103, 106, 1010, or 1011 colony forming units [CFU]) in 40 μL of nutrient broth or broth alone (control) on an embryonic day (E)15. Preterm birth (defined as delivery before E18.5) was monitored using live video. E. coli ascent kinetics were measured by staining the E. coli with lipophilic tracer DiD for visualization through intact tissue with an in vivo imaging system (IVIS) after inoculation. The E. coli were also directly visualized in reproductive tissues by staining the bacteria with carboxyfluorescein succinimidyl ester (CFSE) prior to administration and via immunohistochemistry (IHC) by staining tissues with anti-E. coli antibody. Each pup’s amniotic fluid was cultured separately to determine the extent of microbial invasion of the intraamniotic cavity at different time points. Intraamniotic inflammation resulting from E. coli invasion was assessed with IHC for inflammatory markers (TLR-4, P-NF-κB) and neutrophil marker (Ly-6G) for chorioamnionitis at 6- and 24-h post-inoculation. Results Vaginally administered E. coli resulted in preterm birth in a dose-dependent manner with higher doses causing earlier births. In ex vivo imaging and IHC detected uterine horns proximal to the cervix had increased E. coli compared to the distal uterine horns. E. coli were detected in the uterus, fetal membranes (FM), and placenta in a time-dependent manner with 6 hr having increased intensity of E. coli positive signals in pups near the cervix and in all pups at 24 hr. Similarly, E. coli grew from the cultures of amniotic fluid collected nearest to the cervix, but not from the more distal samples at 6 hr post-inoculation. At 24 hr, all amniotic fluid cultures regardless of distance from the cervix, were positive for E. coli. TLR-4 and P-NF-κB signals were more intense in the tissues where E. coli was present (placenta, FM and uterus), displaying a similar trend toward increased signal in proximal gestational sacs compared to distal at 6 hr. Ly-6G+ cells, used to confirm chorioamnionitis, were increased at 24 hr compared to 6 hr post-inoculation and control. Conclusion We report the development of mouse model of ascending infection and the associated inflammation of preterm birth. Clinically, these models can help to understand mechanisms of infection associated preterm birth, determine targets for intervention, or identify potential biomarkers that can predict a high-risk pregnancy status early in pregnancy.

scholarly journals A hemolytic pigment of Group B Streptococcus allows bacterial penetration of human placenta

2013 ◽  
Vol 210 (6) ◽  
pp. 1265-1281 ◽  
Author(s):  
Christopher Whidbey ◽  
Maria Isabel Harrell ◽  
Kellie Burnside ◽  
Lisa Ngo ◽  
Alexis K. Becraft ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Amniotic Fluid ◽  
Preterm Labor ◽  
Group B Streptococcus ◽  
Dependent Manner ◽  
Microbial Infection ◽  
Amniotic Cavity ◽  
Protein Toxin ◽  
Ascending Infection ◽  
Group B

Microbial infection of the amniotic fluid is a significant cause of fetal injury, preterm birth, and newborn infections. Group B Streptococcus (GBS) is an important human bacterial pathogen associated with preterm birth, fetal injury, and neonatal mortality. Although GBS has been isolated from amniotic fluid of women in preterm labor, mechanisms of in utero infection remain unknown. Previous studies indicated that GBS are unable to invade human amniotic epithelial cells (hAECs), which represent the last barrier to the amniotic cavity and fetus. We show that GBS invades hAECs and strains lacking the hemolysin repressor CovR/S accelerate amniotic barrier failure and penetrate chorioamniotic membranes in a hemolysin-dependent manner. Clinical GBS isolates obtained from women in preterm labor are hyperhemolytic and some are associated with covR/S mutations. We demonstrate for the first time that hemolytic and cytolytic activity of GBS is due to the ornithine rhamnolipid pigment and not due to a pore-forming protein toxin. Our studies emphasize the importance of the hemolytic GBS pigment in ascending infection and fetal injury.

scholarly journals Cervical epithelial damage promotes Ureaplasma parvum ascending infection, intrauterine inflammation and preterm birth induction in mice

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ioannis Pavlidis ◽  
Owen B. Spiller ◽  
Gabriella Sammut Demarco ◽  
Heather MacPherson ◽  
Sarah E. M. Howie ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Mouse Model ◽  
Bacterial Load ◽  
Preterm Births ◽  
Intrauterine Infection ◽  
Cervical Injury ◽  
Epithelial Damage ◽  
Ureaplasma Parvum ◽  
Non Invasive ◽  
Ascending Infection

AbstractAround 40% of preterm births are attributed to ascending intrauterine infection, and Ureaplasma parvum (UP) is commonly isolated in these cases. Here we present a mouse model of ascending UP infection that resembles human disease, using vaginal inoculation combined with mild cervical injury induced by a common spermicide (Nonoxynol-9, as a surrogate for any mechanism of cervical epithelial damage). We measure bacterial load in a non-invasive manner using a luciferase-expressing UP strain, and post-mortem by qPCR and bacterial titration. Cervical exposure to Nonoxynol-9, 24 h pre-inoculation, facilitates intrauterine UP infection, upregulates pro-inflammatory cytokines, and increases preterm birth rates from 13 to 28%. Our results highlight the crucial role of the cervical epithelium as a barrier against ascending infection. In addition, we expect the mouse model will facilitate further research on the potential links between UP infection and preterm birth.

scholarly journals Cervical gene delivery of the antimicrobial peptide, Human β-defensin (HBD)-3, in a mouse model of ascending infection-related preterm birth

2019 ◽  
Author(s):  
Natalie Suff ◽  
Rajvinder Karda ◽  
Juan Antinao Diaz ◽  
Joanne Ng ◽  
Julien Baruteau ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Uterine Cavity ◽  
Preterm Births ◽  
Premature Delivery ◽  
Cervical Canal ◽  
Adeno Associated Virus ◽  
Cellular Events ◽  
Microbial Invasion ◽  
Ascending Infection ◽  
Pregnant Mice

AbstractApproximately 40% of preterm births are preceded by microbial invasion of the intrauterine space: ascent from the vagina is the most common pathway. Within the cervical canal, antimicrobial peptides and proteins (AMPs) help to constitute a barrier which prevents ascending infection. We investigated whether expression of the AMP, human β-defensin-3 (HBD3), in the cervical mucosa prevented bacterial ascent from the vagina into the uterine cavity of pregnant mice. An adeno-associated virus vector containing both the HBD3 gene and GFP transgene (AAV8 HBD3.GFP) or control (AAV8 GFP), was administered intravaginally into E13.5 pregnant mice. Ascending infection was induced at E16.5 using bioluminescent E.coli (E.coli K1 A192PP-lux2). Bioluminescence imaging showed bacterial ascent into the uterine cavity, cellular events that led to premature delivery and a reduction in pups born alive, compared with uninfected controls. In addition, a significant reduction in uterine bioluminescence in the AAV8 HBD3.GFP-treated mice was observed 24 hours post-E.coli infection, compared to AAV8 GFP treated mice, signifying reduced bacterial ascent in AAV8 HBD3.GFP-treated mice. There was also an increase in the number of living pups in AAV HBD3.GFP-treated mice. We propose that HBD3 may be considered a possible candidate for augmenting cervical innate immunity to prevent ascending infection-related preterm birth.

scholarly journals Imbalance of Amniotic Fluid Activin-A and Follistatin in Intraamniotic Infection, Inflammation, and Preterm Birth

2016 ◽  
Vol 101 (7) ◽  
pp. 2785-2793 ◽  
Author(s):  
John T. Hardy ◽  
Irina A. Buhimschi ◽  
Megan E. McCarthy ◽  
Guomao Zhao ◽  
Christine A. Laky ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Inflammatory Response ◽  
Amniotic Fluid ◽  
Prostaglandin F2α ◽  
Normal Pregnancy ◽  
Activin A ◽  
Lps Challenge ◽  
Microbial Invasion ◽  
Effector Pathways ◽  
The Impact

Context: Microbial invasion of the amniotic fluid (AF) cavity stimulates an inflammatory response that involves activin-A, a pleiotropic mediator member of the TGFβ superfamily involved in connective tissue remodeling. The role of AF follistatin, a natural inhibitor of activin-A, in inflammation-induced preterm birth (PTB), has yet to be determined. Objective: The objective of the study was to investigate the relationships between AF activin-A and follistatin in physiological gestation and in pregnancies complicated by PTB and to evaluate a possible role played by the activin-A-follistatin balance in processes leading to PTB and preterm premature rupture of membranes (PPROM). Study Design: The AF levels of total activin-A and follistatin were immunoassayed in 168 women with a normal pregnancy outcome or PTB with and without intraamniotic inflammation or PPROM. The impact of the activin-A-follistatin imbalance on PTB terminal effector pathways (prostaglandins [prostaglandin E2, prostaglandin F2α] and matrix metalloproteinases [MMP-1, MMP-2, MMP-3, and MMP-9]) was investigated in an amniochorion explant system challenged with lipopolysaccharide (LPS) to mimic inflammation. Results: AF follistatin and the activin-A to follistatin ratio varied with gestational age, both decreasing toward term (P < .001). Activin-A was up-regulated in AF infection (>2-fold elevation in activin-A to follistatin ratio) correlating directly with severity of inflammation (both P < .001). Activin-A increased prostaglandins, MMP-1, and MMP-9 released by amniochorion (P < .05) to LPS-equivalent levels. Follistatin effectively blunted the prostaglandin response to activin-A and LPS and that of MMPs after activin-A but not after LPS challenge. Conclusion: Activin-A and follistatin are part of the complex inflammatory response of the gestational sac to infection and modulate effector pathways leading to PTB. The activin-A to follistatin ratio may play a role in determining the clinical phenotype of PTB as preterm labor or PPROM.

scholarly journals QuantitativeIn VivoDetection ofChlamydia muridarumAssociated Inflammation in a Mouse Model Using Optical Imaging

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Manishkumar Patel ◽  
Shu-An Lin ◽  
Melissa A. Boddicker ◽  
Christopher DeMaula ◽  
Brett Connolly ◽  
...  
Keyword(s):  
Mouse Model ◽  
Optical Imaging ◽  
Imaging System ◽  
Ex Vivo ◽  
Statistical Significance ◽  
Transmitted Disease ◽  
Chlamydia Infection ◽  
Imaging Biomarker ◽  
Chlamydia Muridarum

Chlamydia trachomatisis a bacterial sexually transmitted disease with over 1.3 million cases reported to the CDC in 2010. While Chlamydia infection is easily treated with antibiotics, up to 70% of infections are asymptomatic and go untreated. The current mouse model relies on invasive upper genital tract gross pathology readouts at ~60–80 days postinfection. High throughput optical imaging through the use of biomarkers has been successfully used to quickly evaluate several disease processes. Here we evaluate Neutrophil Elastase 680 (Elastase680) for its ability to measureChlamydia muridarumassociated inflammation in live mice using fluorescence molecular tomography (FMT) andIn VivoImaging System (IVIS). Optical imaging was able to distinguish with statistical significance between vaccinated and nonvaccinated mice as well as mock-challenged and challenged mice 2 weeks after challenge which was 9 weeks sooner than typical gross pathological assessment. Immunohistochemistry confirmed the presence of neutrophils and correlated well with bothin vivoandex vivoimaging. In this report we demonstrate that Elastase680 can be used as a molecular imaging biomarker for inflammation associated with chlamydial infection in a mouse model and that these biomarkers can significantly decrease the time for pathology evaluation and thus increase the rate of therapeutics discovery.

Ex vivo cytokine production by cells in mid-trimester amniotic fluid predict subsequent spontaneous preterm birth (SPTB)

2006 ◽  
Vol 195 (6) ◽  
pp. S7
Author(s):  
Ann Marie Bongiovanni ◽  
Devrim Sezen ◽  
Claudel Jean-Pierre ◽  
Iara Linhares ◽  
Daniel Skupski ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Amniotic Fluid ◽  
Cytokine Production ◽  
Ex Vivo ◽  
Spontaneous Preterm Birth

scholarly journals Potential Peripartum Markers of Infectious-Inflammatory Complications in Spontaneous Preterm Birth

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Vojtech Tambor ◽  
Marie Vajrychova ◽  
Marian Kacerovsky ◽  
Marek Link ◽  
Petra Domasinska ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Amniotic Fluid ◽  
Neonatal Morbidity ◽  
Diagnostic Tools ◽  
Spontaneous Preterm Birth ◽  
Amniotic Cavity ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Microbial Invasion ◽  
Infection And Inflammation ◽  
Exploratory Data

Spontaneous preterm birth significantly contributes to the overall neonatal morbidity associated with preterm deliveries. Nearly 50% of cases are associated with microbial invasion of the amniotic cavity followed by an inflammatory response. Robust diagnostic tools for neonates jeopardized by infection and inflammation may thus decrease the overall neonatal morbidity substantially. Amniotic fluid retrieved during labor retains fetal and pregnancy-related protein fingerprint and its sampling does not place any unwanted stress on women. Using exploratory and targeted methods we analyzed proteomes of amniotic fluid sampled at the end of spontaneous preterm labor prior to delivery from women with and without infection and inflammation. Exploratory data indicated several amniotic fluid proteins to be associated with infectious-inflammatory complications in spontaneous preterm birth. LC-SRM analysis subsequently verified statistically significant changes in lipocalin-1 (P=0.047and AUC = 0.67,P=0.046), glycodelin (P=0.013and AUC = 0.73,P=0.013), and nicotinamide phosphoribosyltransferase (P=0.018and AUC = 0.71,P=0.01).

Repurposing N,N-Dimethylacetamide (DMA), a Pharmaceutical Excipient, as a Prototype Novel Anti-inflammatory Agent for the Prevention and/or Treatment of Preterm Birth

2018 ◽  
Vol 24 (9) ◽  
pp. 989-992 ◽  
Author(s):  
Samir Gorasiya ◽  
Juliet Mushi ◽  
Ryan Pekson ◽  
Sabesan Yoganathan ◽  
Sandra E. Reznik
Keyword(s):  
Preterm Birth ◽  
Ex Vivo ◽  
The United States ◽  
Occurrence Rate ◽  
Pharmaceutical Excipient ◽  
Ongoing Work ◽  
Exciting Line ◽  
Pregnant Mice

Background: Preterm birth (PTB), or birth that occurs before 37 weeks of gestation, accounts for the majority of perinatal morbidity and mortality. As of 2016, PTB has an occurrence rate of 9.6% in the United States and accounts for up to 18 percent of births worldwide. Inflammation has been identified as the most common cause of PTB, but effective pharmacotherapy has yet to be developed to prevent inflammation driven PTB. Our group has discovered that N,N-dimethylacetamide (DMA), a readily available solvent commonly used as a pharmaceutical excipient, rescues lipopolysaccharide (LPS)-induced timed pregnant mice from PTB. Methods: We have used in vivo, ex vivo and in vitro approaches to investigate this compound further. Results: Interestingly, we found that DMA suppresses cytokine secretion by inhibiting nuclear factor-kappa B (NF-κB). In ongoing work in this exciting line of investigation, we are currently investigating structural analogs of DMA, some of them novel, to optimize this approach focused on the inflammation associated with PTB. Conclusion: Successful development of pharmacotherapy for the prevention of PTB rests upon the pursuit of multiple strategies to solve this important clinical challenge.

Ethanol Extract of Achillea fragrantissima Enhances Angiogenesis through Stimulation of VEGF Production

2020 ◽  
Vol 21 ◽  
Author(s):  
Hana M. Hammad ◽  
Amer Imraish ◽  
Maysa Al-Hussaini ◽  
Malek Zihlif ◽  
Amani A. Harb ◽  
...  
Keyword(s):  
Wound Healing ◽  
Rural Communities ◽  
Ex Vivo ◽  
Ethanol Extract ◽  
Aortic Ring ◽  
Treated Group ◽  
Control Group ◽  
Dependent Manner ◽  
Achillea Fragrantissima

Objective: Achillea fragrantissima L. (Asteraceae) is a traditionally used medicinal herb in the rural communities of Jordan. Methods: The present study evaluated the efficacy of the ethanol extract of this species on angiogenesis in both, ex vivo using rat aortic ring assay and in vivo using rat excision wound model. Results: In concentrations of 50 and 100 µg/ml, the ethanol extract showed angiogenic stimulatory effect and significantly increased length of capillary protrusions around aorta rings of about 60% in comparison to those of untreated aorta rings. In MCF-7 cells, the ethanol extract of A. fragrantissima stimulates the production of VEGF in a dose-dependent manner. 1% and 5% of ethanol extract of A. fragrantissima containing vaseline based ointment was applied on rat excision wounds for six days and was found to be effective in wound healing and maturation of the scar. Both preparations resulted in better wound healing when compared to the untreated control group and vaseline-treated group. This effect was comparable to that induced by MEBO, the positive control. Conclusion: The results indicate that A. fragrantissima has a pro-angiogenic effect, which may act through the VEGF signaling pathway.

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