Sex-Specific Whole-Transcriptome Analysis in the Cerebral Cortex of FAE Offspring

Abstract

Fetal alcohol spectrum disorders (FASDs) are associated with systemic inflammation and neurodevelopmental abnormalities. Several candidate genes were found to be associated with fetal alcohol exposure (FAE)-associated behaviors, but a sex-specific complete transcriptomic analysis was not performed at the adult stage. Recent studies have shown that they are regulated at the developmental stage. However, the sex-specific role of RNA in FAE offspring brain development and function has not been studied yet. Here, we carried out the first systematic RNA profiling by utilizing a high-throughput transcriptomic (RNA-seq) approach in response to FAE in the brain cortex of male and female offspring at adulthood (P60). Our RNA-seq data analysis suggests that the changes in RNA expression in response to FAE are marked sex-specific. We show that the genes Muc3a, Pttg1, Rec8, Clcnka, Capn11, and pnp2 exhibit significantly higher expression in the male offspring than in the female offspring at P60. FAE female mouse brain sequencing data also show an increased expression of Eno1, Tpm3, and Pcdhb2 compared to male offspring. We performed a pathway analysis using a commercial software package (Ingenuity Pathway Analysis). We found that the sex-specific top regulator genes (Rictor, Gaba, Fmri, Mlxipl) are highly associated with eIF2 (translation initiation), synaptogenesis (the formation of synapses between neurons in the nervous system), sirtuin (metabolic regulation), and estrogen receptor (involved in obesity, aging, and cancer) signaling. Taken together, our transcriptomic results demonstrate that FAE differentially alters RNA expression in the adult brain in a sex-specific manner.

Prenatal alcohol exposure alters expression of genes involved in cell adhesion, immune response, and toxin metabolism in adolescent rat hippocampus

“…First, we elected to evaluate gene expression in the hippocampus only, while acknowledging that gene expression, and its changes following PAE are likely to be region dependent. However, changes in gene expression of protocadherins following developmental exposure have been observed in mouse cortex [ 19 ], human buccal samples [ 23 , 55 ], and zebrafish embryo [ 56 ], suggesting that this may be a reliable consequence of prenatal alcohol exposure. Another important factor to consider is the timing of alcohol exposure.…”

“…Interestingly, far fewer genes were altered in female alcohol-exposed offspring relative to male alcohol-exposed offspring (37 vs. 271, respectively). Genes identified were associated with neurological disorders and the protocadherin family of proteins [ 19 ]. Finally, in a study comparing the effects of PAE (35% ethanol-derived calories GD 11–12) on gene expression in the olfactory bulb of adolescent (postnatal day (P) 40) and adult (P90) rats, fewer changes were evident in adolescents.…”

“…Taken together, it is clear that PAE causes long-lasting alterations in gene expression, but these effects vary by brain region. Furthermore, some studies have evaluated sex differences [ 19 , 28 ], whereas others have utilized only male rats [ 29 ] or collapsed across sex [ 30 ]. We conducted an exploratory study to examine whether PAE resulted in changes in gene expression in the adolescent male and female hippocampus using RNA sequencing.…”

“…Using transcriptomics and high-throughput genetic screening techniques, researchers have demonstrated that PAE significantly alters gene expression in humans and in animal models. For the most part, studies have shown that PAE results in a significant down-regulation of gene expression [17][18][19][20]. In a study evaluating DNA methylation following PAE, buccal samples were obtained from newborns and evaluated for differentially methylated regions, with few such regions identified [21].…”

Peripheral blood transcriptomic profiling indicates molecular mechanisms commonly regulated by binge-drinking and placebo-effects

“…Because of complexity in specimen collection and prohibitive cost of TWA, gene expression analyses in response to alcohol use/misuse in living humans are often conducted with selective genes based on research hypotheses 11,12 . Apart from the published animal or in vitro studies [13][14][15] , a recent study by Marvomatis et al utilized genetic data from a large population-based GWAS to impute transcriptomic associations with alcohol consumption patterns, leveraging cis-acting genetic variants 16 . A large-scale study such as this has the advantage of mitigating some of the variability in gene expression amongst individuals.…”