Project name: Homo sapiens

Description: We report here the expression profile of microRNAs in human neuronal differentiation in the neuroblastoma cell line SH-SY5Y. Six microRNAs were significantly upregulated during differentiation induced by all-trans¬-retinoic acid and brain-derived neurotrophic factor. We demonstrated that ectopic expression of either miR-124a or miR-125b increases the percentage of differentiated SH-SY5Y cells with neurite outgrowth. Subsequently, we focused our functional analysis on miR-125b and demonstrated the important role of this miRNA in both spontaneous and induced differentiation of SH-SH5Y cells, based on neurite outgrowth and neuronal marker expression. In human neural progenitor ReNcell VM cells, miR-125b is also upregulated during differentiation and miR-125b ectopic expression significantly promotes neurite outgrowth. To identify the targets of miR-125b regulation, we profiled the global changes in gene expression following miR-125b ectopic expression in SH-SY5Y cells. miR-125b represses 164 genes that contain the seed match sequence of the microRNA and/or predicted to be direct targets of miR-125b by conventional methods. Pathway analysis suggests that a subset of miR-125b-repressed targets antagonize neuronal genes in several neurogenic pathways, thereby mediating the positive effect of miR-125b on neuronal differentiation. We have further validated the binding of miR-125b to the microRNA response elements of ten selected targets. Together, we report here for the first time the important role of miR-125b in human neuronal differentiation.Keywords: mir125-OE/mir-scrambled control comparison & mir125-KD/mir-scrambled control comparsionOverall design: In this study we sought to understand the role of miRNAs in differentiation of human neural cells using simple in vitro models, human neuroblastoma SH-SY5Y cells and human neural progenitor ReNcell VM cells. When sequentially treated with all-trans-retinoic acid (RA) and brain-derived neurotrophic factor (BDNF), SH-SY5Y cells give rise to fully differentiated neuron-like cells (8). These differentiated SH-SY5Y cells are withdrawn from the cell cycle, express various neuronal markers, and exhibit carbachol-evoked noradrenaline release (8). Moreover, as no glial cell is derived by this process, it is a robust and homogenous model system for investigating neuronal differentiation (8). Using microarrays and Northern blots, we identified a group of miRNAs that are significantly upregulated in differentiated SH-SY5Y cells. We further showed that one of these miRNAs, miR-125b, significantly enhances differentiation and neuronal morphogenesis of SH-SY5Y cells. In addition, this miRNA also promotes neurite outgrowth in human neural progenitor ReNcell VM cells.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Medical

Release date: 2009-02-12

Last updated: 2009-02-10