Differential cellular distribution of tonicity-induced expression of transcription factor TonEBP in the rat brain following prolonged systemic hypertonicity.

摘要: In a previous work performed on cerebral cortex and hippocampus we reported that tonicity-responsive enhancer binding protein (TonEBP), originally identified as transactivator of osmoprotective genes involved in osmoadaptation renal cells, was induced neurons only, but to varying levels, following acute systemic hypertonicity. Whether or not this cellular specificity reflected unique ability differential time course among brain cells for tonicity-induction TonEBP investigated throughout the study by subjecting animals prolonged normal rats, immunolabeling TonEBP-mRNA situ hybridization labeling showed widespread, uneven parallel distribution. expressed primarily cell nuclei neurons, where it heterogeneously distributed nucleoplasmic granular pool. rats subjected hypertonicity, increased only. The tonicity-induced expression given group rather uniform varied greatly neuronal groups positively correlated with average size nuclei, determined quantitative analysis digitized images. detailed distribution is brain. very minor proportion non-neuronal subset astrocytes possibly oligodendrocytes, faint nuclear immunolabeling, which however did increase hypertonic animals. Ependymocytes, capillary endothelial microglial no labeling, even Altogether our data indicate albeit extent, are only able use TonEBP-mediated processes adaptation hyperosmotic unbalance.