Transcriptome profiling in engrailed-2 mutant mice reveals common molecular pathways associated with autism spectrum disorders

Abstract

BackgroundTranscriptome analysis has been used in autism spectrum disorder (ASD) to unravel common pathogenic pathways based on the assumption that distinct rare genetic variants or epigenetic modifications affect common biological pathways. To unravel recurrent ASD-related neuropathological mechanisms, we took advantage of the En2 -/- mouse model and performed transcriptome profiling on cerebellar and hippocampal adult tissues.MethodsCerebellar and hippocampal tissue samples from three En2 -/- and wild type (WT) littermate mice were assessed for differential gene expression using microarray hybridization followed by RankProd analysis. To identify functional categories overrepresented in the differentially expressed genes, we used integrated gene-network analysis, gene ontology enrichment and mouse phenotype ontology analysis. Furthermore, we performed direct enrichment analysis of ASD-associated genes from the SFARI repository in our differentially expressed genes.ResultsGiven the limited number of animals used in the study, we used permissive criteria and identified 842 differentially expressed genes in En2 -/- cerebellum and 862 in the En2 -/- hippocampus. Our functional analysis revealed that the molecular signature of En2 -/- cerebellum and hippocampus shares convergent pathological pathways with ASD, including abnormal synaptic transmission, altered developmental processes and increased immune response. Furthermore, when directly compared to the repository of the SFARI database, our differentially expressed genes in the hippocampus showed enrichment of ASD-associated genes significantly higher than previously reported. qPCR was performed for representative genes to confirm relative transcript levels compared to those detected in microarrays.ConclusionsDespite the limited number of animals used in the study, our bioinformatic analysis indicates the En2 -/- mouse is a valuable tool for investigating molecular alterations related to ASD.

Neurobiological bases of autism–epilepsy comorbidity: a focus on excitation/inhibition imbalance

“…More interestingly, transcriptome analysis of embryonic (E12.5) telencephalon from ARX mutant mice revealed, among deregulated genes, a significant enrichment (12%) of genes implicated in ASD and epilepsy (Mattiske et al ., ). Similarly, we recently showed significant enrichment of ASD and epilepsy genes among differentially expressed genes in the adult hippocampus of En2 knockout ( En2 −/− ) mice (Sgadò et al ., ; Provenzano et al ., ). Moreover, genes involved in pre‐ and postsynaptic GABAergic transmission were significantly enriched among downregulated genes in the En2 −/− adult hippocampus (Provenzano et al ., ).…”

An Evo-Devo Approach to Thyroid Hormones in Cerebral and Cerebellar Cortical Development: Etiological Implications for Autism

“…Other models include the repetitive behavior observed in C58/J, C57BL/6J, and Grin1 knockdown mice (360). The homeobox-containing transcription factor engrailed-2 (En2) is involved in patterning and neuronal differentiation; Sgadò et al (361, 362) showed that adult En2 −/− mice exhibit reduced brain interneuron expression of GABAergic marker mRNAs, and reduction in parvalbumin, somatostatin, and neuropeptide Y in the cerebellum and cerebral cortex (including hippocampus). The genetically inbred BTBR T + Itpr3 tf/J mouse model of ASD exhibits social impairment and stereotypic behavior suggestive of mTOR overactivation (363).…”

Genes Biomarkers in Autism: Brain Development and Function

“…Human Engrailed-2 (En2) gene is localized to 7q36, an autism susceptibility locus. This genes were introduced on mouse since 2005[10, [16][17][18][19][20]. However, it is also found in human brain study [21].…”