Prenatal stress changes the glycoprotein M6a gene expression and induces epigenetic changes in rat offspring brain

MONTELEONE, MC.; ADROVER, E; PALLARÉS, ME; ANTONELLI, MC; FRASCH, AC; BROCCO, MA.

Miami

Congreso; Miami 2014 Winter Symposium; 2014

Elsevier and University of Miami

Introduction: Prenatal stress (PS) exerts strong impact on fetal brain development and on adult offspring brain functions. Previous work demonstrated that chronic stress alters the expression of M6a mRNA, a neuronal glycoprotein involved in filopodium extension. In this work, we analyzed the effect of PS on gpm6a expression and the epigenetic mechanisms involved. Methods: Pregnant Wistar rats received restraint stress during the last week of gestation and male offspring were sacrificed on postnatal days 28 and 60. Hippocampus and prefrontal cortex samples were analyzed for gene expression (qPCR for mRNAs and microRNAs), methylation status (bisulfite conversion) and protein levels (Western blot and immunocytochemistry). Hippocampal neurons in culture were used to analyze microRNA overexpression and histone desacetylase inhibitors effects on M6a levels and neuron morphology. Results: Prenatal stress induced changes in gpm6a levels in both tissues ages analyzed, indicating a persistent effect. Variations in the methylation pattern at three specific CpGs were found in hippocampus, but not in PFC samples from PS offspring. microRNAs predicted to target gpm6a were identified in silico and qPCR measurements showed that PS significantly modified the expression of microRNA-133b in both tissues. Overexpression of this microRNA in neuronal cultures showed a reduction in gmp6a mRNA and protein level. Moreover filopodium density was also reduced, suggesting that M6a function was affected. Treatment of neurons with apicidin, a class I histone deacetylase inhibitor, significantly increased M6a levels indicating that HDAC2 or 3 could be involved in gpm6a regulation.