Astrocyte Transcriptome from the Mecp2308-Truncated Mouse Model of Rett Syndrome
Astrocyte Transcriptome from the Mecp2308-Truncated Mouse Model of Rett Syndrome
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DOI：
10.1007/s12017-015-8363-9
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发表时间：
2015-12-01
影响因子：
3.5
通讯作者：
Bienvenu, Thierry
中科院分区：
文献类型：
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作者：
Delepine, Chloe;Nectoux, Juliette;Bienvenu, Thierry
编码转录调节剂甲基cpg结合蛋白2 （MeCP2）的基因突变是导致神经发育障碍Rett综合征的原因，Rett综合征是女性智力残疾最常见的来源之一。最近的研究表明，星形胶质细胞中Mecp2的缺失有助于rett样症状的发生，而Mecp2的修复可以挽救其中的一些缺陷。本研究的目的是通过Affymetrix小鼠2.0芯片比较Mecp2（308/y）小鼠（B6.129S-MeCP2 < tm1Heto >/J）的野生型和突变型星形胶质细胞的基因表达谱。结果经实时定量RT-PCR和Western blot分析证实。利用Ingenuity Pathways进行基因集富集分析，鉴定Mecp2缺失导致的通路。在野生型和突变样本中，共有2152个基因表达有统计学差异，其中编码转录本有1784个。然而，只有257个出现了倍数变化。我们通过对mecp2缺陷小鼠皮质星形胶质细胞独立原代培养的复制研究证实了我们的数据。有趣的是，已知编码分泌蛋白的两个基因，嗜铬粒蛋白B和脂钙蛋白2，显示出明显的失调。这些由mecp2缺陷胶质细胞分泌的蛋白可能对神经元特性（包括树突形态）产生负面的非细胞自主作用。此外，转录谱揭示了Nr2f2表达的改变，这可能解释了星形胶质细胞中Ccl2、Lcn2和Chgb等几个靶基因的下调和上调。揭示Nr2f2参与mecp2缺陷星形细胞可能为更好地理解Rett综合征的病理生理铺平道路，并提供新的治疗前景。
Mutations in the gene encoding the transcriptional modulator methyl-CpG binding protein 2 (MeCP2) are responsible for the neurodevelopmental disorder Rett syndrome which is one of the most frequent sources of intellectual disability in women. Recent studies showed that loss of Mecp2 in astrocytes contributes to Rett-like symptoms and restoration of Mecp2 can rescue some of these defects. The goal of this work is to compare gene expression profiles of wild-type and mutant astrocytes from Mecp2(308/y) mice (B6.129S-MeCP2 < tm1Heto >/J) by using Affymetrix mouse 2.0 microarrays. Results were confirmed by quantitative real-time RT-PCR and by Western blot analysis. Gene set enrichment analysis utilizing Ingenuity Pathways was employed to identify pathways disrupted by Mecp2 deficiency. A total of 2152 genes were statistically differentially expressed between wild-type and mutated samples, including 1784 coding transcripts. However, only 257 showed fold changes > 1.2. We confirmed our data by replicative studies in independent primary cultures of cortical astrocytes from Mecp2-deficient mice. Interestingly, two genes known to encode secreted proteins, chromogranin B and lipocalin-2, showed significant dysregulation. These proteins secreted from Mecp2-deficient glia may exert negative non-cell autonomous effects on neuronal properties, including dendritic morphology. Moreover, transcriptional profiling revealed altered Nr2f2 expression which may explain down- and upregulation of several target genes in astrocytes such as Ccl2, Lcn2 and Chgb. Unraveling Nr2f2 involvement in Mecp2-deficient astrocytes could pave the way for a better understanding of Rett syndrome pathophysiology and offers new therapeutic perspectives.