Circulating extracellular vesicles during pregnancy in women with type 1 diabetes: a secondary analysis of the CONCEPTT trial

A review of CONCEPTT study findings including subanalyses in pregnant women using continuous glucose monitoring with type 1 diabetes and their offspring

The main objective of this article is to provide a comprehensive review of continuous glucose monitor (CGM) use in pregnant women with type 1 diabetes (T1D) from the CONCEPTT study including subanalyses. Literature search was accessed through MEDLINE (1966-September 2023) using the key terms: CONCEPTT, pregnancy, women, T1D, and CGM with limitations set to distinguish human subjects written in English. A total of 17 publications including one main clinical trial and 15 subanalyses have been published to date regarding the use of CGM in pregnant women with T1D which were conducted by a research group identified as the CONCEPTT Collaborative Group. While advances in maternal care have resulted in safer pregnancy for both the mother and child, women with preexisting T1D and pregnancy still experience higher rates of complications both in the short and long term. The use of CGM in pregnancy has not been studied extensively until more recently. The CONCEPTT clinical trial was a landmark study that involved several subanalyses. The main trial proved that CGM use in T1D pregnancy resulted in less hyperglycemia in the third trimester, reduced large for gestational age (LGA, >90th percentile), reduced neonatal intensive care unit admissions lasting longer than 24 h, and reduced neonatal hypoglycemia. Although subanalyses showed a variety of results including 'inconclusive' due to lack of prespecification, it is believed that CGM in T1D during pregnancy is to be recommended and used for overall improved outcomes.

Impact of acute moderate-intensity aerobic exercise on circulating extracellular vesicles in pregnant and non-pregnant women

Exercise improves cardiovascular and metabolic health in pregnancy and may represent a non-pharmacological approach to improving pregnancy outcomes. Extracellular vesicles (EVs) are emerging biomarkers of endothelial dysfunction and offer the potential for evaluating vascular health non-invasively during pregnancy. The purpose of this study was to investigate changes in circulating EV levels after an acute bout of moderate-intensity aerobic exercise in healthy pregnant and non-pregnant women. We studied plasma samples from pregnant (N = 13, 13-28 weeks) and non-pregnant (N = 17) women. A pre-exercise blood sample was obtained followed by a 30 min bout of moderate-intensity treadmill-based exercise. Immediately following the exercise, a post-exercise blood draw was collected. Large EVs were isolated from plasma by differential centrifugation and characterized by Western blot and electron microscopy. We quantified circulating EVs by nanoscale flow cytometry. Endothelial EVs were identified as VE-Cadherin+, platelet EVs as CD41+, and leukocyte EVs as CD45+ events. Acute exercise was associated with a significant reduction in levels of circulating endothelial EVs in the non-pregnant group (p = 0.0232) but not in the pregnant group (p = 0.2734). A greater proportion of non-pregnant women (13/17, 76.47%) exhibited a reduction in endothelial EVs compared with their pregnant counterparts (4/13, 30.76%, p < 0.05). We also observed a positive association between measures of fitness (average speed) and baseline levels of platelet (r = 0.5816, p = 0.0159) and total EVs (r = 0.5325, p = 0.0296) in the non-pregnant group but not in pregnant individuals. Collectively, our study highlights that after a matched acute exercise, changes to circulating EV levels differ depending on pregnancy status.

Extracellular Vesicles as an Index for Endothelial Injury and Cardiac Dysfunction in a Rodent Model of GDM

Gestational diabetes mellitus (GDM) increases risk of adverse pregnancy outcomes and maternal cardiovascular complications. It is widely believed that maternal endothelial dysfunction is a critical determinant of these risks, however, connections to maternal cardiac dysfunction and mechanisms of pathogenesis are unclear. Circulating extracellular vesicles (EVs) are emerging biomarkers that may provide insights into the pathogenesis of GDM. We examined the impact of GDM on maternal cardiac and vascular health in a rat model of diet-induced obesity-associated GDM. We observed a >3-fold increase in circulating levels of endothelial EVs (p < 0.01) and von Willebrand factor (p < 0.001) in GDM rats. A significant increase in mitochondrial DNA (mtDNA) within circulating extracellular vesicles was also observed suggesting possible mitochondrial dysfunction in the vasculature. This was supported by nicotinamide adenine dinucleotide deficiency in aortas of GDM mice. GDM was also associated with cardiac remodeling (increased LV mass) and a marked impairment in maternal diastolic function (increased isovolumetric relaxation time [IVRT], p < 0.01). Finally, we observed a strong positive correlation between endothelial EV levels and IVRT (r = 0.57, p < 0.05). In summary, we observed maternal vascular and cardiac dysfunction in rodent GDM accompanied by increased circulating endothelial EVs and EV-associated mitochondrial DNA. Our study highlights a novel method for assessment of vascular injury in GDM and highlights vascular mitochondrial injury as a possible therapeutic target.

The implications of exosomes in pregnancy: emerging as new diagnostic markers and therapeutics targets

Extracellular vehicles (EVs) are a heterogeneous group of cell and membranous particles originating from different cell compartments. EVs participate in many essential physiological functions and mediate fetal-maternal communications. Exosomes are the smallest unit of EVs, which are delivered to the extracellular space. Exosomes can be released by the umbilical cord, placenta, amniotic fluid, and amniotic membranes and are involved in angiogenesis, endothelial cell migration, and embryo implantation. Also, various diseases such as gestational hypertension, gestational diabetes mellitus (GDM), preterm birth, and fetal growth restriction can be related to the content of placental exosomes during pregnancy. Due to exosomes' ability to transport signaling molecules and their effect on sperm function, they can also play a role in male and female infertility. In the new insight, exosomal miRNA can diagnose and treat infertilities disorders. In this review, we focused on the functions of exosomes during pregnancy.

Extracellular vesicles in gestational diabetes mellitus: A scoping review

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy worldwide. Despite extensive study, the molecular mechanisms leading to GDM and associated perinatal complications are not well understood. The condition is also associated with an increased risk of future cardiometabolic disease in both mothers and their offspring. Thus, there is a pressing need for the development of effective screening tools and to identify novel molecular mechanisms responsible for the short and long-term risks associated with GDM. In this regard, extracellular vesicles (EVs) offer promise as novel biomarkers of GDM-mediated changes to both mother and fetus. The purpose of this scoping review is to provide an overview of studies examining EVs in the context of GDM. EMBASE and Ovid Medline were searched for articles published from inception to December 2020. We update current knowledge in this area and identify key knowledge gaps with recommendations for future research.