No abstract

Prenatal alcohol exposure can cause developmental abnormalities (fetal alcohol spectrum disorders; FASD), including small eyes, face and brain, and neurobehavioral deficits. These cannot be detected early in pregnancy with available imaging techniques. Early diagnosis could facilitate development of therapeutic interventions. Banked human fetal brains and eyes at 9–22 weeks’ gestation were paired with maternal blood samples, analyzed for morphometry, protein, and RNA expression, and apoptotic signaling. Alcohol (EtOH)-exposed (maternal self-report) fetuses were compared with unexposed controls matched for fetal age, sex, and maternal race. Fetal brain-derived exosomes (FB-E) were isolated from maternal blood and analyzed for protein, RNA, and apoptotic markers. EtOH use by mothers, assessed by self-report, was associated with reduced fetal eye diameter, brain size, and markers of synaptogenesis. Brain caspase-3 activity was increased. The reduction in eye and brain sizes were highly correlated with amount of EtOH intake and caspase-3 activity. Levels of several biomarkers in FB-E, most strikingly myelin basic protein (MBP; r > 0.9), correlated highly with morphological abnormalities. Reduction in FB-E MBP levels was highly correlated with EtOH exposure (p < 1.0 × 10−10). Although the morphological features of FAS appear long before they can be detected by live imaging, FB-E in the mother’s blood may contain markers, particularly MBP, that predict FASD.

Objective: We have developed novel methods for isolating fetal central nervous system (CNS)-derived extracellular vesicles (FCEs) from maternal plasma as a noninvasive platform for testing aspects of fetal neurodevelopment in early pregnancy.We investigate the hypothesis that levels of defined sets of functional proteins in FCEs can be used to detect abnormalities in fetal neuronal and glial proliferation, differentiation, and survival.Method: Maternal plasma was obtained between 10 and 19 weeks from women with current heavy EtOH exposure and matched controls. FCE levels of synaptophysin, synaptotagmin, synaptopodin, and neurogranin were quantified normalized to the exosome marker CD81. Quantitative RT-PCR was performed with specific primers for miR-9.Results: FCE cargo protein levels of synaptophysin, synaptotagmin, synaptopodin, and neurogranin were all significantly reduced in pregnancies exposed to current heavy EtOH use (P < .001 for all). Both synaptophysin and neurogranin appeared to be particularly discriminatory with no overlap between exposed and control subjects.Up to tenfold inhibition (90%) in MicroRNA-9 was observed in FCEs from EtOH exposed fetuses compared with controls. Conclusion:Our results suggest that FCEs purified from maternal plasma may be a powerful tool to assess abnormal proliferation and differentiation of CNS stem cells as early as the late first trimester.