Transcriptome analysis of Shank3-overexpressing mice reveals unique molecular changes in the hypothalamus

Chunmei Jin,Yeunkum Lee,Yinhua Zhang,Yoonhee Kim,Hyojin Kang,Kihoon Han,Shinhyun Kim

doi:10.1186/s13041-018-0413-4

Abstract

Various mutations in the SH3 and multiple ankyrin repeat domains 3 (SHANK3) gene are associated with neurodevelopmental and neuropsychiatric disorders. Thus far, synaptic abnormalities in multiple brain regions, including the hippocampus, prefrontal cortex, striatum, and ventral tegmental area, have been investigated in several lines of Shank3 mutant mice. However, although some reports have shown loss and gain of body weight in Shank3 knock-out and overexpressing transgenic (TG) mice, respectively, the potential functions of Shank3 in the hypothalamus, a brain region critically involved in energy intake and expenditure, are unknown. Hence, we first characterized endogenous Shank3 mRNA and protein expression in the hypothalamus of adult wild-type mice. Thereafter, we performed transcriptome analysis (RNA-sequencing) in the hypothalamus of adult Shank3 TG mice which mildly overexpress Shank3 proteins. By comparing the 174 differentially expressed genes in the hypothalamus with those previously reported in the striatum and medial prefrontal cortex (mPFC) of Shank3 TG mice, we found that 159 were hypothalamus-specific while only 15 were also observed in either the striatum or mPFC. Furthermore, gene set enrichment analysis of the RNA-sequencing analysis revealed that ribosome-related genes were enriched especially in the up-regulated genes of Shank3 TG hypothalamus, which is in contrast to the results of the Shank3 TG striatum and mPFC analyses, where ribosome-related genes were enriched in the down-regulated genes. Beyond revealing endogenous Shank3 mRNA and protein expression in the hypothalamus, our results suggest unique molecular changes in the hypothalamus of Shank3 TG mice compared with those in the striatum and mPFC.

Highlights

Deletions, duplications, and point mutations in the SH3 and multiple ankyrin repeat domains 3 (SHANK3) gene, encoding excitatory postsynaptic core scaffolding proteins, are causally associated with numerous neurodevelopmental and neuropsychiatric disorders
The complete lists of the RNA-seq analysis and Differentially expressed genes (DEGs) are provided in Additional file 2: Tables 1 and 2. d The Venn diagram shows the numbers of common DEGs among the hypothalamus, striatum, medial prefrontal cortex of Shank3 TG mice
The complete lists of the gene set enrichment analysis (GSEA) are provided in Additional file 2: Table 3. g The enrichment plot of RNA-seq analysis of Shank3 TG hypothalamus of the Kyoto Encyclopedia of Genes and Genomes (KEGG) ribosome gene set. h The diagram shows opposite directional normalized enrichment scores (NESs) of the GSEA on KEGG ribosome gene set for the Shank3 TG hypothalamus compared with striatum and medial prefrontal cortex (mPFC)

Summary

Introduction

Duplications, and point mutations in the SH3 and multiple ankyrin repeat domains 3 (SHANK3) gene, encoding excitatory postsynaptic core scaffolding proteins, are causally associated with numerous neurodevelopmental and neuropsychiatric disorders. A qRT-PCR results showing relative expression levels of Shank3 mRNA in various brain regions of adult wild-type (WT) mice. G The enrichment plot of RNA-seq analysis of Shank3 TG hypothalamus of the KEGG ribosome gene set.

Objectives

Results

Conclusion