Ethanol inhibited apoptosis-related RNA binding protein, Napor-3 gene expression in the prenatal rat brain
Nibedita Naha, Hae Young Lee, Mohammad Imran Naser, Tae Ju Park, Sung Hoon Kim, Myeong Ok Kim
Med Sci Monit 2009; 15(1): BR6-12
Cell death and differentiations are the critical processes in developing fetal brain, where ethanol induces lots of changes in gene expression patterns of fetal nervous system leading to fetal alcohol syndrome (FAS). The objective of the present study was to observe whether maternal ethanol exposure can alter gene expression pattern in mother and in fetus during mid and late prenatal stage.
Material and Method: 10% ethanol was orally applied to female Spraque-Dawley rats and fetuses were sacrificed on gestational day (GD) 19.5 and 21.5. Total mRNA was isolated for differential-display PCR (DD-PCR) and sequence was analyzed to find out the homologous gene(s) using GenBank database of the BLAST program. Finally, the gene expression pattern in different maternal and fetal brain areas of the control and the ethanol treated groups were studied by RNase protection assay (RPA) and in situ hybridization.
Results: Out of several differentially expressed genes, apoptosis-related RNA binding protein (RBP), 'Napor-3' mRNA expression was significantly inhibited by ethanol in fetal rat fore-, mid- and hind- brain, and adult rat cortex and hippocampus when compared with the untreated control. The cDNA analysis was further supported our result (accession: AF090697, 95% sequence homology).
Conclusions: The age and area dependent suppression of apoptosis-related RBP, Napor-3 gene expression in proliferating fetal brain by maternal ethanol suggesting high susceptibility towards ethanol intake at the time of neuronal cell development and proliferation. Further, ethanol also affects maternal brain tissues that may be one of the reasons for ethanol-induce irreversible damage of the developing brain. The present study for the first time provides the evidence that Napor-3 suppression by ethanol during mid and late stage fetal brain converts natural physiological event apoptosis into pathological process, which may be useful as a novel therapeutic approach towards FAS-associated developmental brain damage as a consequence of maternal drinking behavior.
Keywords: Rats, RNA-Binding Proteins - metabolism, Sequence Analysis, DNA, Rats, Sprague-Dawley, Nerve Tissue Proteins - metabolism, Molecular Sequence Data, Maternal Exposure - adverse effects, Male, In Situ Hybridization, Gene Expression Regulation, Developmental - drug effects, Female, Ethanol - toxicity, DNA, Complementary - genetics, Brain - metabolism, Base Sequence, Apoptosis - drug effects, Animals, Analysis of Variance