Construction of a gene-phenotypic association network of cell adhesion molecule-1-mediated sleep deprivation-induced anxiety-like behaviors with systems genetics
OBJECTIVE To explore the possible molecular mechanism through which amygdala cell adhesion molecule-1(CADM1)is involved in acute sleep deprivation-induced anxiety.METHODS Sixteen 8-week-old C57BL/6J mice were randomly divided into the control group and para-chlorophe-nylalanine(PCPA)-induced acute sleep deprivation experimental group.The PCPA mice were intraperi-toneally injected with PCPA suspension(at a dose of 300 mg∙kg-1)between 8∶00 and 9∶00 am for 2 consecutive days while the control mice were injected with the same dose of normal saline.The sleep latency and sleep duration of mice were detected via the righting reflex test.Anxiety-like behaviors were detected by the open field test and elevated plus maze test.The expression level of CADM1 in the mouse amygdala was detected by Western Blot and Immunofluorescence staining.The GeneNet-work database was used to analyze the association between Cadm1 genes and other genes in the mouse amygdala.The key candidate regulatory genes were screened,and the Cadm1-anxiety behavior phenotype network was constructed.The mRNA expression levels of the key candidate regulatory genes were analyzed via qPCR analysis.RESULTS Compared with the control mice,the sleep latency of PCPA mice was significantly prolonged(P<0.01)while the sleep duration was significantly shortened(P<0.01).The activity time and distance of PCPA mice in the open field center were significantly shorter than those of the control group(P<0.05).The elevated plus maze experiment showed that the percentage of the number of times PCPA mice entered the open arm and the percentage of residence time in the open arm were significantly lower than those of the control group(P<0.05).Western Blot and immuno-fluorescence staining showed that the expression of CADM1 protein in the amygdala from PCPA mice was down-regulated compared with the control mice(P<0.05).Based on gene-behavioral association network analysis,Cadm1 was significantly associated with 25 anxiety-like behavior-related genes.The enrichment analysis of Cadm1 co-expression genes showed that Cadm1 was associated with γ-amino-butyric acid GABAergic synaptic pathway(P=4.31e-09),and that the key genes were huntingtin associ-ated protein 1(Hap1)(r=0.705,P=1.09e-08)、inositol 1,4,5-triphosphate receptor type 1(Itpr1)(r=-0.751,P=3.34e-10)、gamma-aminobutyric acid type A receptor subunit delta(Gabrd)(r=-0.836,P=3.93e-14)、γ-aminobutyric acid A receptor β1 subunit gene(Gabrb1)(r=0.732,P=1.50e-09)and adrenoceptor alpha 2A(Adra2a)(r=0.759,P=1.73e-10).The results of qPCR analysis showed that the mRNA levels of Hap1(P<0.05)、Gabrb1 and Adra2a were significantly up-regulated(P<0.01)while those of Itpr1 and Gabrd were significantly down-regulated(P<0.01).CONCLUSION Acute sleep deprivation leads to down-regulation of Cadm1 expression in the amygdala,and induces anxiety-like behaviors by affecting the expression of GABAergic synaptic signaling pathways Hap1,Gabrb1,Adra2a,Itpr1 and Gabrd.