Project 2: Prenatal Alcohol Exposure (PAE) and Fetal Alcohol Spectrum Disorder (FASD)

Project Summary The objective of the proposed research is to target molecular pathways involved in alcohol-induced limb/fin defects to identify novel mechanisms with a role in FASD with the long-term goals of informing clinical practice, and ultimately reducing the incidence and severity of Fetal Alcohol Spectrum Disorders (FASD). This objective will be met by applying two innovative and complementary approaches that use cell, zebrafish and mouse models to (i) genetically knockout and identify genes that rescue or exacerbate the effects of ethanol exposure, and (ii) high throughput screening of focused chemical libraries to identify compounds that modulate the effects of ethanol exposure. Our approach utilizes genetically modified zebrafish and mice, and the developing fin and limb respectively, as readily examined target tissues whose molecular signaling pathways and vulnerability to ethanol teratogenesis are well documented. This research proposal is founded on 1) strong evidence that craniofacial abnormalities and limb defects have been observed in those identified with FASD, 2) recognition that disruption of sonic hedgehog (Shh) signaling, a major morphogenic pathway regulating embryonic development as a significant consequence of prenatal ethanol exposure (PAE), 3) that genetically reduced Shh signaling results in increased vulnerability to ethanol-induced birth defects, and 4) the availability of differentially expressed gene sets from our previous study on the effects of PAE on mouse limb development. The hypothesis to be tested is that the identification of novel genes and compounds that can rescue morphological and behavioral deficits elicited by PAE will reveal fundamental and novel insights into the mechanism of ethanol-induced birth defects. This hypothesis will be tested with experiments that employ well- established cell line, zebrafish, and mouse FASD models and will address the following Specific Aims: Aim 1 will use these in vivo and in vitro models to assess gene-environment interactions, particularly the candidate genes whose expression was shown to be altered in ethanol-exposed mouse limb buds by our previous ethanol RNA Seq study. Aim 2 is to utilize high-throughput screening technologies in vitro and in vivo to identify small molecule modulators that rescue or exacerbate the effects of PAE. Small molecule compounds that rescue or exacerbate ethanol-induced fin defects in zebrafish embryos and limbs defects in mice will be identified. The proposed studies will be conducted by NCCU faculty and trainees under the mentorship of UNC’s Bowles Center for Alcohol Studies researchers. In addition to expanding our understanding of ethanol’s teratogenic mechanism of action as well as providing clues regarding genetic sensitivities and interventions for FASD and potentially novel pathways with a role in FASD, this research project will foster state of the art research and will provide the foundation for important FASD studies to be addressed in future grant applications/research.