The matrix metalloproteases and endothelin-1 in infection-associated preterm birth

High preterm birth at Cipto Mangunkusumo Hospital as a national referral hospital in Indonesia

Background: Preterm birth is the leading direct that causes neonatal death. Indonesia was listed as one of the countries with the greatest number of preterm birth in 2010. This study aims to identify the prevalence and the potential risk factors of preterm birth among women underwent delivery in Cipto Mangunkusumo Hospital, an Indonesian national reference hospital.Methods: This retrospective cohort study involved 2,612 women who delivered between January and December 2013. Any clinical data which related to the potential risk factors and outcomes were recorded. The data were managed using chi-square for bivariate analysis and t-test or Mann-Whitney for numerical data followed by multiple logistic regression for multivariate analysis in SPSS version 20.0.Results: Preterm birth affected 1,020 of 2,616 pregnancies (38.5%). Non-booked patients increased nearly twice risk for preterm delivery (OR 1.89, 95% CI 1.37–2.61). While women with singleton pregnancy (OR 0.17, 95% CI 0.12–0.25), head presentation (OR 0.75, 95% CI 0.63–0.89), and regular ANC (OR 0.67, 95% CI 0.54–0.84) had lower risk for preterm birth. Apgar score, birthweight, and mode of delivery were significantly different between the pre-term group and the full-term group.Conclusion: Prevalence of preterm birth in Cipto Mangunkusumo Hospital was approximately 2.5 times higher compared to the national number. Several factors reducing preterm birth rate include singleton pregnancy, head presentation, and regular ANC.

Blood metal levels and third trimester maternal plasma matrix metalloproteinases (MMPs)

While it is known that in utero exposure to environmental toxicants, namely heavy metals, can adversely affect the neonate, there remains a significant paucity of information on maternal biological changes specific to metal exposures during pregnancy. This study aims at identifying associations between maternal metal exposures and matrix metalloproteinases (MMPs) that are known to be engaged in pregnancy process. Third trimester maternal plasma (n = 1533) from a pregnancy cohort (Maternal-Infant Research on Environmental Chemicals Study, MIREC) were analyzed for MMP-1,-2,-7,-9 and -10 by affinity-based multiplex protein array analyses. Maternal metal concentrations (mercury, cadmium, lead, arsenic and manganese) in 1st and 3rd trimesters exhibited strong correlations (p < 0.05). Multivariate regression models were used to estimate odds ratio (OR) for the association between metal concentrations in quartiles and high (90%) and low (10%) maternal MMP levels. Significant (p < 0.05) metal exposure-related effects were observed with the different MMP isoform responses. MMP profiles were specific to the trimester at which the maternal blood metals were analyzed. Our findings suggest that the profiles of these MMP isoforms vary with the type of metal exposure, blood metal concentrations and the trimester at which metal levels were determined. These new findings on maternal metal-MMP relationships can guide future explorations on toxicity mechanisms relevant to metal exposure-mediated adverse birth outcomes.

Is there a role for probiotics in the prevention of preterm birth?

Preterm birth (PTB) continues to be a global health challenge. An over-production of inflammatory cytokines and chemokines, as well as an altered maternal vaginal microbiome has been implicated in the pathogenesis of inflammation/infection-associated PTB. Lactobacillus represents the dominant species in the vagina of most healthy pregnant women. The depletion of Lactobacillus in women with bacterial vaginosis (BV) has been associated with an increased risk of PTB. It remains unknown at what point an aberrant vaginal microbiome composition specifically induces the cascade leading to PTB. The ability of oral or vaginal lactobacilli probiotics to reduce BV occurrence and/or dampen inflammation is being considered as a means to prevent PTB. Certain anti-inflammatory properties of lactobacilli suggest potential mechanisms. To date, clinical studies have not been powered with sufficiently high rates of PTB, but overall, there is merit in examining this promising area of clinical science.

The clinical significance of a positive Amnisure test in women with preterm labor and intact membranes

OBJECTIVE

This study was conducted to examine the frequency and clinical significance of a positive Amnisure test in patients with preterm labor and intact membranes by sterile speculum exam.

STUDY DESIGN

A retrospective cohort study was performed including 90 patients with preterm labor and intact membranes who underwent Amnisure tests prior to amniocentesis (< 72 h); most patients (n=64) also underwent fetal fibronectin (fFN) tests. Amniotic fluid (AF) was cultured for aerobic/anaerobic bacteria and genital mycoplasmas and assayed for matrix metalloproteinase-8.

RESULTS

(1) the prevalence of a positive Amnisure test was 19% (17/90); (2) patients with a positive Amnisure test had significantly higher rates of adverse pregnancy and neonatal outcomes (e.g., impending preterm delivery, intra-amniotic infection/inflammation, and neonatal morbidity) than those with a negative Amnisure test; (3) a positive test was associated with significantly increased risk of intra-amniotic infection and/or inflammation, delivery within 7, 14, or 28 days and spontaneous preterm birth (< 35 weeks) among patients with a negative fFN test.

CONCLUSIONS

A positive Amnisure test in patients with preterm labor and intact membranes is a risk factor for adverse pregnancy outcome, particularly in patients with a negative fFN test. A positive Amnisure test in patients without symptoms or signs of ROM should not be taken as an indicator that membranes have ruptured.

Prevention of inflammation-associated preterm birth by knockdown of the endothelin-1-matrix metalloproteinase-1 pathway

Premature delivery occurs in 12% of all births, accounts for nearly half of neonatal morbidity and is increasing in frequency. Current therapeutic approaches to preterm delivery are ineffective and present serious risks to both the mother and fetus. Although there are multiple factors that contribute to the etiology of preterm birth, the single most common cause is infection. Recently, using cDNA microarray analysis of human placental tissue, we demonstrated that human placental matrix metalloproteinase-1 (MMP-1) is upregulated during labor. In a separate line of investigation, we have shown that blockade of endothelin-1 (ET-1) action through the use of an endothelin-converting enzyme-1 (ECE-1) inhibitor, an established commercially available endothelin receptor antagonist or a novel quinolone-derived endothelin receptor antagonist synthesized by our group also prevents preterm labor and delivery in a mouse model. We have now shown that induction of preterm labor with lipopolysaccharide in our mouse model is associated with increased levels of MMP-1. Furthermore, we showed that silencing the ECE-1/ET-1 pathway by using ECE-1 RNA interference prevents both the onset of preterm labor and upregulation of MMP-1. The data indicate that ET-1 and MMP-1 act in the same molecular pathway in preterm labor.