Maternal mediators of fetal growth restriction linked to prenatal alcohol exposure

Project Summary/Abstract Prenatal Alcohol Exposure (PAE) is a common cause of fetal growth restriction (FGR), which is a known risk factor for brain disability. Our previous studies identified extracellular maternal miRNAs as a causal link between PAE and FGR. These studies in pregnant women in Ukraine, resulted in discovery of 11 miRNAs (HEamiRNAs) that were elevated in plasma of heavy alcohol- exposed mothers who subsequently delivered growth-restricted, alcohol-affected infants (HEa), but not in exposed mothers who delivered infants that were apparently unaffected (HEua), or unexposed (UE) mothers. Maternal HEamiRNAs collectively explained 24-31% of the variance in infant height, weight and head circumference at birth, and in rodents, non-human primates, and in human trophoblast cell lines, explained PAE inhibition of placental trophoblast epithelial- mesenchymal transition (EMT) and FGR. Studies in this proposal, test an innovative hypothesis that two candidate cytokines, also identified in the Ukraine cohort, and extracellular miRNAs, control fetal growth in response to PAE, and that these may be manipulated to overcome FGR. In Aim 1, we test the hypothesis that two PAE-sensitive cytokines, C-reactive protein and sFlt1, control HEamiRNA transfer between maternal circulation and trophoblasts, as a means to inhibit the growth of chorionic villi, leading to FGR. Aim 2 is based on initial studies that showed 3 HEamiRNAs, which were elevated in both preeclampsia and FGR, promoted EMT gene expression in trophoblasts. We plan to test the hypotheses that cytokines, and sub-groups of birth outcome- defined HEamiRNAs may be manipulated to overcome FGR. Studies in Aims 1 and 2 will use cell culture and mouse models, with ultrasound imaging and transcriptomic studies, to assess the role of cytokines and HEamiRNAs in PAE-mediated inhibition of placental and fetal growth. In Aim 3, we will assess associations between HEamiRNAs, and other conditions linked to defects in placental development and function (preeclampsia, pre-term birth, spontaneous abortion, FGR), in samples from pregnant women recruited in the San Diego region with and without evidence of placental dysfunction, including PAE. We will additionally investigate the distribution HEamiRNAs in lipoprotein particles (LPPs) and extracellular vesicles (EVs) to determine whether pregnancy and/or placental dysfunction is associated with re-distribution of HEamiRNAs among extracellular compartments, possibly influencing their endocrine function and target tissue distribution. The proposed studies, led by qualified investigators with complementary skills, meet a significant need for mechanism-centered diagnoses and intervention for pregnancy complications due to PAE and other etiologies.