Wegener, G. | Search bioRxiv

bioRxiv2018

Elevated P2x7r and P2x4r transcripts levels in the Flinders Sensitive Line Rats, a genetic animal model of depression

P2x7 and P2x4 receptors (P2x7R and P2x4R, respectively) are ligand-gated ion channels activated by adenosine triphosphate (ATP), which have been associated to dysfunctional processes in stress responses linked to depression, such as neurotransmitter release, cognition, sleep, energy, appetite, immune and endocrine dysfunction. Clinical studies indicate that polymorphisms in the P2x7r gene results in increased susceptibility for development of depression. Existing studies have investigated the role of P2x7R and P2x4R in animal models based on stress exposure. Therefore, the present work aimed to investigate the transcript and protein levels of these receptors in a genetic animal model of depression, the Flinders Sensitive Line (FSL) and its control group, the Flinders Resistant Line (FRL) rats. We found that FSL rats have increased transcript levels of P2x7R and P2x4R in frontal cortex (FC), ventral and dorsal hippocampus (vHip and dHip, respectively) compared to FRL rats. There were no alterations in the protein levels in the FC and dHip, but the P2x7R was lower in FSL than in FRL rats in the vHip. The results suggest that increased transcripts levels of P2x7r and P2x4r in the FSL rats may contribute to the stress-susceptibility observed in these animals.

neuroscience↗

bioRxiv2018

The behavioral and neurobiological effects of reduced Brd1 expression in mice are sex-biased and implicate gender dependent dysregulation of nuclear receptor mediated signaling in mental disorders

The schizophrenia and bipolar disorder associated gene, BRD1, encodes a scaffold protein that in complex with epigenetic modifiers regulate gene sets enriched for psychiatric disorder risk. Preclinical evidence from male Brd1+/- mice has previously implicated BRD1 with phenotypes of translational relevance to schizophrenia. Here we describe the phenotype of female Brd1+/- mice and report attenuated dendritic architecture and monoaminergic dysregulation accompanied by sex-specific changes in affective behaviors. In accordance, global gene expression profiling reveals regional dysregulation of gene sets enriched with major depressive disorder and schizophrenia risk in female and male Brd1+/- mice, respectively. Independent of sex, however, differentially expressed genes cluster in common functional pathways associated with psychiatric disorders, including mitochondrial dysfunction and oxidative phosphorylation as well as G-protein coupled-, and nuclear receptor mediated signaling. Accordingly, we provide in vitro evidence that BRD1 modulates the transcriptional drive of a subset of nuclear receptors (e.g. the vitamin D and glucocorticoid receptors). Moreover, we demonstrate enrichment of psychiatric disorder risk in the target genes of nuclear receptors, sex-biased expression of several nuclear receptor genes in the adult brain of Brd1+/- mice, and that sex-biased genes in general are enriched with nuclear receptor genes particularly at the earliest developmental stage of the human brain. Overall, our data suggests that the spatio-temporal interaction between BRD1 and subsets of nuclear receptors in the brain is sex-biased and that hampered BRD1 mediated regulation of target genes governed by certain nuclear receptors may significantly contribute to sex differences in psychopathology.

neuroscience↗