Reis Karina Pires, Heimfarth Luana, Pierozan Paula, Ferreira Fernanda, Loureiro Samanta Oliveira, Fernandes Carolina Gonçalves, Carvalho Rônan Vivian, Pessoa-Pureur Regina
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS, Brazil.
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS, Brazil.
Alcohol. 2015 Nov;49(7):665-74. doi: 10.1016/j.alcohol.2015.06.005. Epub 2015 Aug 6.
Ethanol exposure to offspring during pregnancy and lactation leads to developmental disorders, including central nervous system dysfunction. In the present work, we have studied the effect of chronic ethanol exposure during pregnancy and lactation on the phosphorylating system associated with the astrocytic and neuronal intermediate filament (IF) proteins: glial fibrillary acidic protein (GFAP), and neurofilament (NF) subunits of low, medium, and high molecular weight (NFL, NFM, and NFH, respectively) in 9- and 21-day-old pups. Female rats were fed with 20% ethanol in their drinking water during pregnancy and lactation. The homeostasis of the IF phosphorylation was not altered in the cerebral cortex, cerebellum, or hippocampus of 9-day-old pups. However, GFAP, NFL, and NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. PKA had been activated in the hippocampus, and Ser55 in the N-terminal region of NFL was hyperphosphorylated. In addition, JNK/MAPK was activated and KSP repeats in the C-terminal region of NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. Decreased NFH immunocontent but an unaltered total NFH/phosphoNFH ratio suggested altered stoichiometry of NFs in the hippocampus of ethanol-exposed 21-day-old pups. In contrast to the high susceptibility of hippocampal cytoskeleton in developing rats, the homeostasis of the cytoskeleton of ethanol-fed adult females was not altered. Disruption of the cytoskeletal homeostasis in neural cells supports the view that regions of the brain are differentially vulnerable to alcohol insult during pregnancy and lactation, suggesting that modulation of JNK/MAPK and PKA signaling cascades target the hippocampal cytoskeleton in a window of vulnerability in 21-day-old pups. Our findings are relevant, since disruption of the cytoskeleton in immature hippocampus could contribute to later hippocampal damage associated with ethanol toxicity.
孕期和哺乳期子代暴露于乙醇会导致发育障碍，包括中枢神经系统功能障碍。在本研究中，我们研究了孕期和哺乳期慢性乙醇暴露对与星形胶质细胞和神经元中间丝（IF）蛋白相关的磷酸化系统的影响，这些蛋白包括胶质纤维酸性蛋白（GFAP）以及低、中、高分子量的神经丝（NF）亚基（分别为NFL、NFM和NFH），研究对象为9日龄和21日龄的幼崽。雌性大鼠在孕期和哺乳期饮用含20%乙醇的水。9日龄幼崽的大脑皮层、小脑或海马中IF磷酸化的稳态未发生改变。然而，21日龄幼崽海马中的GFAP、NFL和NFM发生了过度磷酸化。PKA在海马中被激活，NFL N端区域的Ser55发生了过度磷酸化。此外，JNK/MAPK被激活，21日龄幼崽海马中NFM C端区域的KSP重复序列发生了过度磷酸化。NFH免疫含量降低，但总NFH/磷酸化NFH比值未改变，这表明乙醇暴露的21日龄幼崽海马中NF的化学计量发生了改变。与发育中大鼠海马细胞骨架的高易感性相反，乙醇喂养的成年雌性大鼠的细胞骨架稳态未发生改变。神经细胞中细胞骨架稳态的破坏支持了这样一种观点，即大脑区域在孕期和哺乳期对酒精损伤的易感性存在差异，这表明JNK/MAPK和PKA信号级联的调节在21日龄幼崽的易损期靶向海马细胞骨架。我们的发现具有重要意义，因为未成熟海马中细胞骨架的破坏可能导致后期与乙醇毒性相关的海马损伤。
