Screening the expression characteristics of several miRNAs in G93A‐SOD1 G93A‐SOD1 transgenic mouse: altered expression of miRNA‐124 is associated with astrocyte differentiation by targeting Sox2 and Sox9

摘要

Abstract Micro RNA s (mi RNA s) are suspected to be a contributing factor in amyotrophic lateral sclerosis ( ALS ). Here, we assess the altered expression of mi RNA s and the effects of miR‐124 in astrocytic differentiation in neural stem cells of ALS transgenic mice. Differentially expressed mi RNA ‐positive cells (including miR‐124, miR‐181a, miR‐22, miR‐26b, miR‐34a, miR‐146a, miR‐219, miR‐21, miR‐200a, and miR‐320) were detected by in?situ hybridization and qRT ‐ PCR in the spinal cord and the brainstem. Our results demonstrated that miR‐124 was down‐regulated in the spinal cord and brainstem. In vitro , miR‐124 was down‐regulated in neural stem cells and up‐regulated in differentiated neural stem cells in G93A‐ superoxide dismutase 1 ( SOD 1 ) mice compared with WT mice by qRT ‐ PCR . Meanwhile, Sox2 and Sox9 protein levels showed converse change with miR‐124 in?vivo and vitro . After over‐expression or knockdown of miR‐124 in motor neuron‐like hybrid ( NSC 34) cells of mouse, Sox2 and Sox9 proteins were noticeably down‐regulated or up‐regulated, whereas Sox2 and Sox9 mRNA s remained virtually unchanged. Moreover, immunofluorescence results indicated that the number of double‐positive cells of Sox2/glial fibrillary acidic protein (GFAP) and Sox9/glial fibrillary acidic protein (GFAP) was higher in G93A‐ SOD 1 mice compared with WT mice. We also found that many Sox2‐ and Sox9‐positive cells were nestin positive in G93A‐ SOD 1 mice, but not in WT mice. Furthermore, differentiated neural stem cells from G93A‐ SOD 1 mice generated a greater proportion of astrocytes and lower proportion of neurons than those from WT mice. MiR‐124 may play an important role in astrocytic differentiation by targeting Sox2 and Sox9 in ALS transgenic mice. Cover Image for this issue: doi: 10.1111/jnc.14171 .