Zoe Iliodromiti

Intrauterine inflammation and preterm delivery

Spontaneous preterm delivery, prematurity, and low birth weight due to prematurity account for a great part of neonatal morbidity and mortality. Specifically, chronic amniotic fluid inflammation may cause preterm labor, with the involvement of different mediators that produce diverse aspects of the inflammatory response. Although bacteria are considered to be the main trigger for intrauterine infection/inflammation, viral infections also appear to be involved. Recently, molecular genetic techniques have helped us better understand the underlying pathophysiologic processes. This is especially important because epidemiological and experimental studies indicate that intrauterine infection and inflammation constitute a risk factor for adverse neurological outcome in preterm infants. Chronic subclinical chorioamnionitis associated with preterm birth can also modify lung development. Although no current clinical strategy is aimed at adapting the maternofetal inflammatory response, immunomodulators may serve as a future intervention in preterm embryos.

Impact of Maternal Diabetes on Epigenetic Modifications Leading to Diseases in the Offspring

Gestational diabetes, occurring during the hyperglycemic period of pregnancy in maternal life, is a pathologic state that increases the incidence of complications in both mother and fetus. Offspring thus exposed to an adverse fetal and early postnatal environment may manifest increased susceptibility to a number of chronic diseases later in life. Compelling evidence for the role of epigenetic transmission in these complications has come from comparison of siblings born before and after the development of maternal diabetes, exposure to this intrauterine diabetic environment being shown to cause alterations in fetal growth patterns which predispose these infants to developing overweight and obesity later in life. Diabetes of the offspring is also mainly the consequence of exposure to the diabetic intrauterine environment, in addition to genetic susceptibility. Since obesity and diabetes are known to increase the risk of cardiovascular disease, cardiovascular sequelae in the offspring of diabetic mothers are virtually inevitable. Research data also suggest that exposure to a diabetic intrauterine environment during pregnancy is associated with an increase in dyslipidemia, subclinical vascular inflammation, and endothelial dysfunction processes in the offspring, all of which are linked with development of cardiovascular disease later in life. The main underlying mechanisms involve persistent hyperglycemia hyperinsulinemia and leptin resistance.

Previous Gestational Diabetes Mellitus and Markers of Cardiovascular Risk

The prevalence of gestational diabetes mellitus (GDM) in the developed world has increased at an alarming rate over the last few decades. GDM has been shown to be associated with postpartum diabetes, insulin resistance, hypertension, and dyslipidemia. A history of previous GDM (pGDM), associated or not with any of these metabolic abnormalities, can increase the risk of developing not only type 2 diabetes mellitus but also cardiovascular disease (CVD) independent of a diagnosis of type 2 diabetes later in life. In this paper we discuss the relationship among inflammatory markers, metabolic abnormalities, and vascular dysfunction in women with pGDM. We also review the current knowledge on metabolic modifications occurring in normal pregnancy and the link between alterations of a normal metabolic state with the long-term maternal complications that may result in increased CVD risk. Our review of studies on pGDM prompts us to recommend that these women be considered a population at risk for later CVD events, which however could be avoided via the use of specially designed follow-up programs in the future.

Placental growth factor (PlGF): a key to optimizing fetal growth

Abstract The needs of the uterus and the fetus for the provision of nutrients and oxygen, supplied by the blood flow, are understandably extremely high, with the circulatory system playing the most important role in this action. Abnormal vascular growth and transformation that create a high vessel resistance network have been associated with various pregnancy pathologies, including miscarriage, small for gestational age (SGA) fetuses with or without preeclampsia and intrauterine growth restriction (IUGR). Placental growth factor (PlGF) has a major role in vasculogenesis and angiogenesis in human placenta. Low concentrations of PlGF and high concentrations of its inhibitor-soluble Fms-like tyrosine kinase-1 (sFlt-1) are linked with impaired angiogenesis and placental development, leading to the above pregnancy complications. The activity of vascular endothelial growth factor (VEGF), which is the most potent of all angiogenic mediators, is partly modulated by PlGF. Although the mechanisms via which PlGF exerts its various effects are still under investigation, we herein discuss the known actions exerted by this major mediator together with its results on fetal growth.

The oxytocin-oxytocin receptor system and its antagonists as tocolytic agents.

Oxytocin, a hormone involved in numerous physiologic processes, plays a central role in the mechanisms of parturition and lactation. It acts through its receptor, which belongs to the G-protein-coupled receptor superfamily, while Gq/phospholipase C (PLC)/inositol 1,4,5-triphosphate (InsP3) is the main pathway via which it exerts its action in the myometrium. Changes in receptor levels, receptor desensitization, and locally produced oxytocin are factors that influence the effect of oxytocin on uterine contractility in labor. Activation of oxytocin receptor causes myometrial contractions by increasing intracellular Ca+2 and production of prostaglandins. Since oxytocin induces contractions, the inhibition of its action has been a target in the management of preterm labor. Atosiban is today the only oxytocin receptor antagonist that is available as a tocolytic. However, the quest for oxytocin receptor antagonists with a better pharmacological profile has led to the synthesis of peptide and nonpeptide molecules such as barusiban, retosiban, L-368,899, and SSR-126768A. Many of these oxytocin receptor antagonists are used only as pharmacological tools, while others have tocolytic action. In this paper, we summarize the action of oxytocin and its receptor and we present an overview of the clinical and experimental data of oxytocin antagonists and their tocolytic action.

Role of Adipokines and Other Inflammatory Mediators in Gestational Diabetes Mellitus and Previous Gestational Diabetes Mellitus

Previous Gestational Diabetes Mellitus (pGDM) is a common condition and has been associated with future development of Type 2 Diabetes Mellitus (T2DM) and Metabolic Syndrome (MS) in women affected. The pathogenesis and risk factors implicated in the development of these conditions later in the lives of women with pGDM are not as yet fully understood. Research has recently focused on a group of substances produced mainly by adipose tissue called adipokines, this group including, among others, adiponectin, leptin, Retinol-Binding Protein-4 (RBP-4), and resistin. These substances as well as other inflammatory mediators (CRP, IL-6, PAI-1, TNF-α) seem to play an important role in glucose tolerance and insulin sensitivity dysregulation in women with pGDM. We summarize the data available on the role of these molecules.

Possible Early Prediction of Preterm Birth by Determination of Novel Proinflammatory Factors in Midtrimester Amniotic Fluid

Abstract:  Interferon‐γ‐inducible T cell‐α chemoattractant (ITAC) is a chemokine, directing activated T lymphocytes toward sites of inflammation. ADAM‐8 (A disintegrin and metalloprotease‐8) is a glycoprotein expressed in cells promoting inflammation. Elastase, a protease targeting at the degradation of intra‐ or extracellular proteins, is inhibited by secretory leukocyte proteinase inhibitor (SLPI), which protects against microbial invasion. Adhesion molecules (soluble intercellular adhesion molecule—sICAM‐1 and soluble vascular cell adhesion molecule—sVCAM‐1) serve as markers of inflammation or tissue damage. We hypothesized that elevated midtrimester amniotic fluid concentrations of above substances, and decreased levels of SLPI could possibly be useful predictors of asymptomatic intra‐amniotic inflammation and/or infection, eventually resulting in preterm labor and delivery. The study involved 312 women undergoing midtrimester amniocentesis. Thirteen cases, progressing to preterm delivery (<37 weeks), were matched with 21 controls (delivering >37 weeks) for age, parity, and gestational age at amniocentesis. Amniotic fluid levels of the above substances were measured by enzyme‐linked immunosorbent assay (ELISA). Only amniotic fluid ITAC and ADAM‐8 levels were significantly higher (P= 0.005 and P < 0.02, respectively) in women delivering at <37 weeks than at >37 weeks. SLPI concentrations significantly increased in women going into labor without ruptured membranes irrespective of pre‐ or term delivery (P < 0.007, P < 0.001, respectively) and correlated with elastase (r= 0.508, P < 0.002). In conclusion, elevated midtrimester amniotic fluid levels of ITAC and ADAM‐8 could predict occult infections/inflammations, possibly resulting in preterm birth.

The major circadian pacemaker ARNT-like protein-1 (BMAL1) is associated with susceptibility to gestational diabetes mellitus

AIMS Recently a relationship between circadian clock function and the risk for type 2 diabetes (T2D) has been shown. BMAL1 is a key component of the mammalian molecular clock. Two SNPs in the BMAL1 gene have been identified to confer T2D susceptibility. In the present study we investigated for the first time the association between the BMAL1 gene and the risk for GDM, in a Greek population. METHODS We studied 185 women with GDM and 161 non-diabetic controls for BMAL1 polymorphisms. For BMAL1 mRNA expression, peripheral leukocytes were harvested from 20 GDM and 20 control women, harboring different genotypes for the tested polymorphisms, using real-time quantitative PCR. RESULTS The minor allele (A) of the BMAL1 rs7950226 (G>A) polymorphism was found to be significantly associated with an increased risk of GDM (P=0.025). Analysis of the second BMAL1 rs11022775 (T>C) polymorphism, showed that the C-allele frequency was strongly increased in women with GDM (P=4.455e-06). The CC genotype was also significantly overrepresented in GDM vs. controls (P=0.00001). Additionally, the rs7950226G/rs11022775C and rs7950226A/rs11022775C haplotypes were also found to be associated with increased susceptibility to GDM. Furthermore, the expression levels of BMAL1 mRNA were significantly lower in GDM patients than in controls. CONCLUSION These data suggest that the impairment of the BMAL1 clock gene expression is closely associated with GDM susceptibility.

Osteoprotegerin as a Marker of Atherosclerosis in Diabetic Patients

Atherosclerosis is the principal cause of cardiovascular disease (CVD) and has many risk factors, among which is diabetes. Osteoprotegerin (OPG) is a soluble glycoprotein, involved in bone metabolism. OPG is also found in other tissues, and studies have shown that it is expressed in vascular smooth muscle cells. OPG has been implicated in various inflammations and also has been linked to diabetes mellitus. Increased serum OPG levels were found in patients with diabetes and poor glycemic control. Furthermore, prepubertal children with type 1 diabetes have significantly increased OPG levels. Receptor activator of nuclear factor kappa-B ligand (RANKL) is not found in the vasculature in normal conditions, but may appear in calcifying areas. OPG and RANKL are important regulators of mineral metabolism in both bone and vascular tissues. Few data are available on the relationship between plasma OPG/RANKL levels and endothelial dysfunction as assessed using noninvasive methods like ultrasound indexes, neither in the general population nor, more specifically, in diabetic patients. The aim of our review study was to investigate, based on the existing data, these interrelationships in order to identify a means of predicting, via noninvasive methods, later development of endothelial dysfunction and vascular complications in diabetic patients.

Mediators of chronic inflammation in polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is an endocrine disorder affecting 5–10% of reproductive-age women. Hyperandrogenemia, which characterizes the syndrome, stimulates the maturation of adipocytes and favors central obesity. The linking hub between obesity and other metabolic manifestations of the syndrome seems to be chronic low-grade inflammation. We discuss the most reliable current data regarding the role of inflammatory mediators in PCOS, with particular focus on the genetic mechanisms implicated. C-reactive protein levels are 96% higher in PCOS patients than in healthy controls. Patients with the -308A polymorphism of the tumor necrosis factor-α gene have elevated androgens in comparison with carriers of the -308G. Interleukin 18 (IL-18) is elevated in lean patients, with a further rise in the presence of obesity and insulin resistance. Polymorphisms of the IL-1a, IL-1b and IL-6 genes have also been associated with PCOS. Plasminogen activator inhibitor-1 levels are positively associated with the syndrome, and carriers of the 4G allele of the 4G/5G polymorphism are at risk of developing PCOS. Other mediators discussed include adhesion molecules, osteoprotegerin, asymmetric dimethylarginine, homocysteine and advanced glycation end-products. The elucidation of the pathogenetic mechanisms implicated in PCOS and their connection with low-grade inflammation may in the future offer the opportunity for the formulation of novel therapeutic strategies and individualized therapy for these patients.