Knockdown of the psychosis susceptibility gene ZNF804A alters expression of genes involved in cell adhesion

Abstract

Genome-wide association studies have convincingly implicated several novel genes in susceptibility to schizophrenia and bipolar disorder. The first genome-wide significant association with the broad phenotype of psychosis was with a polymorphism in the ZNF804A gene. However, the biological function(s) of ZNF804A have, to date, been entirely unknown. In this study, we manipulated the expression of ZNF804A in neural progenitor cells derived from human cortical neuroepithelium and assessed its effects on the cellular transcriptome. Gene ontology analysis of differentially expressed genes indicated a significant effect of ZNF804A knockdown on the expression of genes involved in cell adhesion, suggesting a role for ZNF804A in processes such as neural migration, neurite outgrowth and synapse formation. Several highly significant gene expression changes were confirmed in repeat cell culture experiments. Most consistent gene expression changes were seen for C2ORF80, a gene of as-yet-unknown function, and STMN3, a gene involved in neurite outgrowth and axonal and dendritic branching. These data, generated in a hypothesis-free manner, provide a basis for more targeted investigations of ZNF804A function.

Recent Advances in the Genetics of Schizophrenia

“…Beyond the group enrichments and network analyses described above, many studies have begun to link variants to specific genes as eQTLs and experimentally follow them up to understand the biological consequences of these variants. Examples include signals near ZNF804A [103, 104], TCF4 [105], and CACNA1C [106, 107]. The most detailed and well publicized such study has been that of Sekar et al [108] in the HLA region.…”

Further Evidence for the Impact of a Genome-Wide-Supported Psychosis Risk Variant in ZNF804A on the Theory of Mind Network

“…In line with this, Hill and Bray (2012) found evidence that the risk SNP exerts effects on ZNF804A allelic expression at a fetal stage of brain development. Furthermore, first results suggest a role in the regulation of expression of other genes associated with schizophrenia (Girgenti et al, 2012) as well as genes involved in cell adhesion (Hill et al, 2011).…”

Knockdown of the schizophrenia susceptibility gene TCF4 alters gene expression and proliferation of progenitor cells from the developing human neocortex

“…19 Although we performed our experiments while these cells were in a proliferative state with growth factors (but not 4-OHT) present, our previous work using the same cell line under similar conditions has shown that gene perturbations do not necessarily affect the expression of cell cycle genes. Thus, our knockdown of the schizophrenia susceptibility gene ZNF804A was found to result in gene expression changes that were enriched for the GO term "cell adhesion," 20 while manipu lation of miR-137 caused gene expression changes that were most significantly enriched for the GO term "neuronal differentiation." 26 Although the gene expression changes we observed following TCF4 knockdown were highly enriched for involvement in the cell cycle, differentially expressed genes shared by the 2 TCF4 siRNA conditions (Table 1 and Appendix 1, Table S2) include many related to various other functions in both the developing and mature brain.…”

“…19 Cells were cultured on laminin-coated T75 flasks using a modified DMEM:F12 media, as described previously. 20 For the RNA interference experiments, 4-OHT was excluded from the media so that proliferation was not artificially stimulated through c-Myc overexpression.…”

“…The microarray data from all samples were used to select an appropriate internal control gene for these assays, as performed previously. 20,26 ATP5B was hereby chosen as a suitable internal control because it had the smallest coefficient of variation across samples, it had no significant differences between siRNA conditions, the probe mapped to a single genomic site and it was possible to design primers targeting the same exon as the probe. All primer sequences are shown in Appendix 1, Table S1, available at jpn.ca.…”