RNA-seq analysis of amygdala tissue in social isolation rearing models of schizophrenia / 中华神经医学杂志

ABSTRACT

Objective:To investigate the gene transcription level changes in the amygdala of social isolation rearing models of schizophrenia to determine the pathogenic genes and their related pathways of schizophrenia.Methods:A total of 29 3-week-old SPF C57BL/6J male mice were randomly divided into control group ( n=16) and model group ( n=13); 4 mice were raised in each transparent mouse cage in the control group, and 1 mouse was raised in each transparent mouse cage in the model group; mice in each cage could see their surrounding mice but could not touch each other. Mice in both groups were fed for 4 weeks and then subjected to open field experiment, pre-pulse inhibition experiment and new object recognition experiment within one week. After the experiment, mice were sacrificed by spinal dislocation, and the amygdala was taken for transcriptome sequencing. The topGO software was used for gene ontology (GO) functional enrichment analysis of differentially expressed genes (DEGs), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed using KEGG database. Results:(1) Animal experiment compared with the control group, the model group had significantly increased movement distance in the open field experiment ([1 239.20±106.35] m vs. [1 845.53±143.65] m, t=3.464, P=0.002), significantly decreased activity time in the central region 5 min before experiment ([13.15±1.41] s vs. [8.47±1.19]) s, t=2.464, P=0.020). Compared with the control group, the model group had significantly lower percentage of deficient prepulse inhibition (PPI) of 78 dB ([22.28±1.53] % vs. [14.59±2.75] %, t=2.629, P=0.013), and deficient PPI of 88 dB ([32.83±3.39] % vs. [18.44±3.07] %, t=3.081, P=0.005). Compared with the control group, the model group had significantly decreased ratio of time exploring new objects/time exploring former objects ([80.5±2.2]% vs. [71.0±3.6]%, t=2.356, P=0.026). (2) Bioinformatics analysis: a total of 96 DEGs were found, of which 42 were with up-regulated expressions ( Th, Crlf1, etc.), and 54 were with down-regulated expressions ( Prkcd, etc.). Th and Crlf1 were positively correlated ( r=0.940, P=0.018). GO enrichment results suggested that DEGs were enriched in projection function of plasma membrane boundary cells, neuronal differentiation, and cell apoptosis. KEGG enrichment results suggested that DEGs were enriched in WNT signaling pathway, apoptosis pathway and tyrosine metabolism pathway. Protein network interaction analysis suggested that Wnt6, Tcf712, Pitx2, Tcf7 and Cd4 were key proteins. Conclusion:DEGs such as Th, Prkcd, Lrrc74b, Fadd, Wnt6, Ror2, Notum, and Tcf7l2, and their related signaling pathways may be related to schizophrenia in the amygdala of social isolation rearing mice.