Fetal regional brain protein signature in FASD rat model

Abstract

Fetal alcohol spectrum disorders (FASD) describe neurodevelopmental deficits in children exposed to alcohol in utero. We hypothesized that gestational alcohol significantly alters fetal brain regional protein signature. Pregnant rats were binge-treated with alcohol or pair-fed and nutritionally-controlled. Mass spectrometry identified 1806, 2077, and 1456 quantifiable proteins in the fetal hippocampus, cortex, and cerebellum, respectively. A stronger effect of alcohol exposure on the hippocampal proteome was noted: over 600 hippocampal proteins were significantly (P < .05) altered, including annexin A2, nucleobindin-1, and glypican-4, regulators of cellular growth and developmental morphogenesis. In the cerebellum, cadherin-13, reticulocalbin-2, and ankyrin-2 (axonal growth regulators) were significantly (P < .05) altered; altered cortical proteins were involved in autophagy (endophilin-B1, synaptotagmin-1). Ingenuity analysis identified proteins involved in protein homeostasis, oxidative stress, mitochondrial dysfunction, and mTOR as major pathways in the cortex and hippocampus significantly (P < .05) affected by alcohol. Thus, neurodevelopmental protein changes may directly relate to FASD neuropathology.

Chronic Binge Alcohol Exposure During Pregnancy Alters mTOR System in Rat Fetal Hippocampus

“…Since a sex effect was not observed for mTOR (e.g., P‐mTOR, sex effect, p = 0.4116; total mTOR, sex effect, p = 0.4481) utilizing two‐way ANOVA with Bonferroni’s multiple comparisons test, the 2 columns were collapsed. This finding is supported by our previous study, where a sex effect was not observed for hippocampal mTOR signaling utilizing mass spectrometry‐based proteomic approaches following chronic binge alcohol exposure (Davis‐Anderson et al, 2018). Immunoblotting data for the expression levels of different proteins were analyzed utilizing two‐tailed Student’s t ‐tests between PF‐Cont and Alcohol groups.…”

“…Alcohol exposure during hippocampal development has been shown to alter hippocampal synaptic plasticity (Medina, 2011; Bhattacharya et al, 2015; Fontaine et al, 2016; Sutherland et al, 1997), synaptic activity (Kajimoto et al, 2016; Krawczyk et al, 2016), cellular morphology (Berman and Hannigan, 2000; Ramos et al, 2002), gene expression, and DNA methylation (Chater‐Diehl et al, 2016; Chen et al, 2013). We have previously reported that gestational chronic binge alcohol exposure alters hippocampal amino acid concentrations and proteomic profile (Davis‐Anderson et al, 2018; Lunde‐Young et al, 2018), and from this work, we have identified hippocampal mammalian target of rapamycin (mTOR) pathways as distinctly vulnerable to dysregulation following gestational alcohol exposure (Davis‐Anderson et al, 2018).…”

“…Animals were assigned to either a pair‐fed control (PF‐Cont) group ( n = 5 dams) or a binge alcohol treatment (Alcohol) group ( n = 5 dams) on gestational day (GD) 4. Alcohol group animals were acclimatized via a once‐daily orogastric gavage of 4.5 g/kg (22.5% wt/v) ethanol [peak blood alcohol concentration (BAC), 216 mg/dl] from GD 5–10, and progressed to 6.0 g/kg (28.5% wt/v) ethanol (peak BAC, 289 mg/dl) from GD 11–21 (Davis‐Anderson et al, 2018; Subramanian et al, 2014). The exposure paradigm utilized in this study is modeled after alcohol consumption patterns in pregnant women and is commonly utilized to study FASD phenotypes in animal models (Caetano et al, 2006; Church and Gerkin, 1988; Cudd et al, 2002; Thomas et al, 2010; Thomas et al, 2008).…”

Hippocampal transcriptome reveals novel targets of FASD pathogenesis

“…Our model of FASD has previously shown distinct dysregulation of amino acid homeostasis and the protein signature in the fetal hippocampus (Davis‐Anderson et al, ). The purpose of the study was to discern the alterations of fetal hippocampal gene expression and their associated pathways in response to maternal alcohol exposure.…”

“…Rats were assigned to a pair‐fed control (PF) group ( n = 6 dams) or an alcohol (ALC) treatment group ( n = 6 dams) on GD 4. The ALC‐treated animals acclimatized via a once daily orogastric gavage of a 4.5 g/kg (22.5% wt/v, peak BAC, 216 mg/dl) alcohol dose from GDs 5–10, and progressed to a 6 g/kg dose (28.5% wt/v, peak BAC, 289 mg/dl) (Davis‐Anderson et al, ) from GDs 11–20. The PF animals were isocalorically matched to the ALCs by daily dosing with a gavage of maltose dextrin to account for calories derived from alcohol.…”