1PLoS ONE 2013 -1 8: e73169
PMID24058414
TitleKnockdown of human TCF4 affects multiple signaling pathways involved in cell survival, epithelial to mesenchymal transition and neuronal differentiation.
AbstractHaploinsufficiency of TCF4 causes Pitt-Hopkins syndrome (PTHS): a severe form of mental retardation with phenotypic similarities to Angelman, Mowat-Wilson and Rett syndromes. Genome-wide association studies have also found that common variants in TCF4 are associated with an increased risk of schizophrenia. Although TCF4 is transcription factor, little is known about TCF4-regulated processes in the brain. In this study we used genome-wide expression profiling to determine the effects of acute TCF4 knockdown on gene expression in SH-SY5Y neuroblastoma cells. We identified 1204 gene expression changes (494 upregulated, 710 downregulated) in TCF4 knockdown cells. Pathway and enrichment analysis on the differentially expressed genes in TCF4-knockdown cells identified an over-representation of genes involved in TGF-? signaling, epithelial to mesenchymal transition (EMT) and apoptosis. Among the most significantly differentially expressed genes were the EMT regulators, SNAI2 and DEC1 and the proneural genes, NEUROG2 and ASCL1. Altered expression of several mental retardation genes such as UBE3A (Angelman Syndrome), ZEB2 (Mowat-Wilson Syndrome) and MEF2C was also found in TCF4-depleted cells. These data suggest that TCF4 regulates a number of convergent signaling pathways involved in cell differentiation and survival in addition to a subset of clinically important mental retardation genes.
SCZ Keywordsschizophrenia
2Asian J Psychiatr 2013 Feb 6: 56-9
PMID23380319
TitleEvolutionary genetic analyses of MEF2C gene: implications for learning and memory in Homo sapiens.
AbstractMEF2C facilitates context-dependent fear conditioning (CFC) which is a salient aspect of hippocampus-dependent learning and memory. CFC might have played a crucial role in human evolution because of its advantageous influence on survival of species. In this study, we analyzed 23 orthologous mammalian gene sequences of MEF2C gene to examine the evidence for positive selection on this gene in Homo sapiens using Phylogenetic Analysis by Maximum Likelihood (PAML) and HyPhy software. Both PAML Bayes Empirical Bayes (BEB) and HyPhy Fixed Effects Likelihood (FEL) analyses supported significant positive selection on 4 codon sites in H. sapiens. Also, haplotter analysis revealed significant ongoing positive selection on this gene in Central European population. The study findings suggest that adaptive selective pressure on this gene might have influenced human evolution. Further research on this gene might unravel the potential role of this gene in learning and memory as well as its pathogenetic effect in certain hippocampal disorders with evolutionary basis like schizophrenia.
SCZ Keywordsschizophrenia
3Schizophr. Res. 2016 Apr -1: -1
PMID27061659
TitleSpecific gene expression patterns of 108 schizophrenia-associated loci in cortex.
AbstractThe latest genome-wide association study of schizophrenia identified 108 distinct genomic loci that contribute to schizophrenia. Brain development and function depend on the precise regulation of gene expression. The expression of many genes is differentially regulated across brain regions and developmental time points. We investigated the specific gene expression patterns arising from the 108 schizophrenia-associated loci using multiple publicly available databases and multiple regional brain datasets from developing and adult post-mortem human brains. The temporal-spatial expression analysis revealed that the genes in these loci were intensively enriched in the cortex during several developmental stages. These cortex-specific genes were particularly expressed in the fetal brain and adult neocortex.
SCZ Keywordsschizophrenia