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Differentiation of a Human Neural Stem Cell Line on Three Dimensional Cultures, Analysis of MicroRNA and Putative Target Genes
Published on: April 12, 2015
MicroRNAs contribute to postnatal development of laminar differences and neuronal subtypes in the rat medial
Lene C Olsen1, Kally C O'Reilly2, Nina B Liabakk1
1Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Abstract:
The medial entorhinal cortex (MEC) is important in spatial navigation and memory formation and its layers have distinct neuronal subtypes, connectivity, spatial properties, and disease susceptibility. As little is known about the molecular basis for the development of these laminar differences, we analyzed microRNA (miRNA) and messenger RNA (mRNA) expression differences between rat MEC layer II and layers III-VI during postnatal development. We identified layer and age-specific regulation of gene expression by miRNAs, which included processes related to neuron specialization and locomotor behavior. Further analyses by retrograde labeling and expression profiling of layer II stellate neurons and in situ hybridization revealed that the miRNA most up-regulated in layer II, miR-143, was enriched in stellate neurons, whereas the miRNA most up-regulated in deep layers, miR-219-5p, was expressed in ependymal cells, oligodendrocytes and glia. Bioinformatics analyses of predicted mRNA targets with negatively correlated expression patterns to miR-143 found that miR-143 likely regulates the Lmo4 gene, which is known to influence hippocampal-based spatial learning.
Insights
This study reveals microRNA (miRNA) and messenger RNA (mRNA) expression differences in the rat medial entorhinal cortex (MEC) layers during development. Specific miRNAs like miR-143 and miR-219-5p are linked to neuron specialization and spatial learning.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- The medial entorhinal cortex (MEC) is crucial for spatial navigation and memory.
- Distinct neuronal subtypes, connectivity, and spatial properties exist across MEC layers.
- The molecular mechanisms underlying these laminar differences during development are poorly understood.
Purpose of the Study:
- To investigate microRNA (miRNA) and messenger RNA (mRNA) expression differences between rat MEC layer II and deep layers (III-VI) during postnatal development.
- To identify layer- and age-specific gene regulation by miRNAs.
- To explore the functional implications of identified miRNA-mRNA interactions in neuronal specialization and behavior.
Main Methods:
- Analysis of miRNA and mRNA expression profiles in rat MEC layers II and III-VI during postnatal development.
- Retrograde labeling and expression profiling of layer II stellate neurons.
- In situ hybridization to determine miRNA localization.
- Bioinformatics analysis of predicted mRNA targets for miRNAs.
Main Results:
- Identified layer- and age-specific regulation of gene expression by miRNAs.
- Discovered that miR-143 is enriched in layer II stellate neurons, while miR-219-5p is found in deep layer glial cells.
- Bioinformatics analysis suggests miR-143 regulates the Lmo4 gene, impacting spatial learning.
Conclusions:
- miRNAs play a significant role in establishing laminar differences within the MEC.
- Specific miRNAs, such as miR-143, are implicated in the specialization of layer II stellate neurons and influence spatial learning via targets like Lmo4.
- These findings provide insights into the molecular basis of MEC development and function.
