CHRONIC DISEASE RISK AND GENETIC RISK FACTORS IN FETAL ALCOHOL SPECTRUM DISORDER Fetal alcohol spectrum disorders (FASDs) are chronic, debilitating conditions that affect approximately 2 - 5% of infants born in the United States. FASD patients present with physical and psychological abnormalities, including craniofacial defects, growth deficiency, and mental retardation. Many of the developmental impacts of fetal alcohol exposure are appreciated during early life stages. However, the lifelong risk for chronic disease in adults with FASD is largely uncharacterized. Additionally, many of the genetic risk factors for FASDs have yet to be identified. Detailed knowledge about the genes contributing to FASD risk, and the long-term outcome of developmental exposure will enable the development of focused preventive approaches. This proposal aims to expose chronic disease risk in FASD and identify a novel genetic risk factor using the zebrafish model.
In Specific Aim 1, we will identify whether the risk for obesity and diabetes is elevated in fetal alcohol exposed zebrafish populations, and determine the metabolic changes contributing to this increased risk. We recently showed that fetal alcohol exposed males are more susceptible to diet-induced gains in body mass index (BMI) in adulthood than control siblings, demonstrating that fetal alcohol exposure may alter disease risk in a gender-stratified manner. We will perform an 8-week high cholesterol/ high fat diet challenge and determine whether fetal alcohol exposed fish are at greater risk than controls for developing features of metabolic syndrome, including increased adiposity, heightened area of fat deposition with BMI gains, and altered blood glucose homeostasis. We will also perform polar hepatic metabolomics to determine the metabolic pathways underlying altered disease risk in FASD populations.
In Specific Aim 2, we will evaluate the role of a novel gene, liver receptor homologue -1 (lrh-1), in alcohol metabolism and FASD pathogenesis. We have recently demonstrated that lrh-1 is alcohol-responsive, highly expressed in the liver, and significantly elevated following ethanol exposure. Further, treatment with Lrh-1 chemical antagonist significantly heightens the incidence of alcohol-induced kidney development defects in embryos. We hypothesize that Lrh-1 activity protects against alcohol-induced developmental defects. First, we will use qRT- PCR to determine how alcohol exposure affects lrh-1 expression in larvae and the adult liver. Next, we will determine how Lrh-1 regulates alcohol metabolism in embryos and adult females by performing qPCR for metabolic genes and evaluating tissue concentrations of ethanol following exposure. Using a published lrh-1 mutant, we will determine whether Lrh-1 knockdown heightens or reduces risk for developmental abnormality, including craniofacial defect, kidney development defect, and alcohol-induced growth restriction. In sum, our studies will definitively demonstrate susceptibility of fetal alcohol exposed adults to environmental and metabolic stress. They will also determine whether a novel gene (lrh-1) contributes to FASD pathogenesis. Our findings may aid in the identification of protein and pathway targets relevant for the treatment of FASD.
CHRONIC DISEASE RISK AND GENETIC RISK FACTORS IN FETAL ALCOHOL SPECTRUM DISORDER Fetal alcohol spectrum disorders (FASDs) are chronic, debilitating conditions that affect up to 5% of infants born in the United States. This proposal will explore the impact of fetal alcohol exposure on chronic disease risk, such as obesity and diabetes, and evaluate the role of liver receptor homologue - 1 (lrh-1) in FASD pathogenesis. An increased understanding of chronic disease disposition and the genetic risk factors for FASD will enable early intervention in at risk populations and pinpoint relevant pathways to target with therapeutics.