Comparison of gene expression profiles between wild-type and Kdm7a mutan embryos
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ABSTRACT: Temporal and spatial colinear expression of Hox genes determines the specification of positional identities of the embryo. Post-translational modifications of histones contribute to transcriptional regulation, and are required for proper control of biological processes, including differentiation and development. Lysine demethylase 7A (Kdm7a) demethylates lysine 9 di-methylation of histone H3 (H3K9me2) and participates in transcriptional activation of developmental genes. However, the role of Kdm7a during mouse embryonic development remains to be elucidated. Here, we show that Kdm7a-/- mice exhibit anterior homeotic transformation of the axial skeleton (i.e. an increase in the number of presacral elements). Importantly, posterior Hox genes (caudally from Hox9) are specifically down-regulated in Kdm7a-/- embryos, which correlate with increased levels of H3K9me2. Taken together, these data suggest that Kdm7a is able to control transcription of posterior Hox genes, likely through its demethylating activity, and thereby regulating anterior-posterior development in mice.
Project description:Temporal and spatial colinear expression of Hox genes determines the specification of positional identities of the embryo. Post-translational modifications of histones contribute to transcriptional regulation, and are required for proper control of biological processes, including differentiation and development. Lysine demethylase 7A (Kdm7a) demethylates lysine 9 di-methylation of histone H3 (H3K9me2) and participates in transcriptional activation of developmental genes. However, the role of Kdm7a during mouse embryonic development remains to be elucidated. Here, we show that Kdm7a-/- mice exhibit anterior homeotic transformation of the axial skeleton (i.e. an increase in the number of presacral elements). Importantly, posterior Hox genes (caudally from Hox9) are specifically down-regulated in Kdm7a-/- embryos, which correlate with increased levels of H3K9me2. Taken together, these data suggest that Kdm7a is able to control transcription of posterior Hox genes, likely through its demethylating activity, and thereby regulating anterior-posterior development in mice.
Project description:Lysine demethylase 7A (KDM7A) catalyzes the removal of dimethylation from histone H3 lysine 9 and lysine 27, both of which are associated with transcription repression. Previous study indicated that Kdm7a mRNA in the medial prefrontal cortex (mPFC) increased after drug exposure, yet its role in drug-related behaviors is largely unknown. In a morphine-conditioned place preference (CPP) paradigm, our findings revealed a specific increase of Kdm7a expression in the mPFC seven days after drug withdrawal. Subsequently, our results demonstrated that knockdown of Kdm7a in the mPFC did not affect the acquisition of morphine-induced CPP, but it attenuated memory consolidation. To further explore Kdm7a-mediated transcriptomic changes, we employed Nanopore direct RNA sequencing. Transcriptome profiling unveiled several gene expression alterations impacted by KDM7A, which were enriched in relevant neural function categories. Notably, we identified and validated fascin actin-bundling protein 1 (Fscn1) as a downstream molecular target. Knockdown of Fscn1 had a similar impact on CPP to Kdm7a, along with a corresponding decrease in dendritic spine density in the mPFC. Additionally, ChIP analysis demonstrated that silencing Kdm7a in N2a cells resulted in decreased enrichment of H3K9me2 and H3K27me2 at the Fscn1 promoter region, suggesting that Kdm7a may act as a crucial regulator of transcriptional responses to morphine-related reward memory via Fscn1.
Project description:Lysine 9 di-methylation and lysine 27 tri-methylation of histone H3 (H3K9me2 and H3K27me3) are mostly linked to gene repression. However, functions of repressive histone methylation dynamics during inflammatory responses remain poorly understood. Here, we show that lysine demethylase 7A (KDM7A) and 6A (UTX) are rapidly transported to nuclear factor kappa-B (NF-κB) related elements in human endothelial cells in response to tumor necrosis factor (TNF)-α. KDM7A and UTX demethylate H3K9me2 and H3K27me3, respectively, and cooperatively activate NF-κB dependent inflammatory genes. Furthermore, using both in situ Hi-C and other 3C based technology, loops between super enhancers (SEs) are newly formed following TNF-α-stimuli at NF-κB-dependent inflammatory loci where KDM7A- and UTX-recruitment coincide. Collectively, these findings suggest that erasing of repressive histone marks by KDM7A and UTX within NF-κB-related elements might functionally associate with formation of SE-SE three-dimensional interactions and could be a cue signal during inflammatory responses in human endothelial cells.
Project description:Hox genes impart segment identity to body structures along the anterior-posterior axis and are crucial for the proper development of all organisms. Multiple regulatory elements, best defined in Drosophila melanogaster, ensure that Hox expression patterns follow the spatial and temporal colinearity reflected in their tight genomic organization. However, the precise mechanisms that regulate colinear patterns of Hox gene expression remain unclear, especially in higher vertebrates where it is not fully determined how the distinct activation domains of the tightly clustered Hox genes are defined independent of each other. Here, we report the identification of a large number of novel cis-elements at mammalian Hox clusters that can help in regulating their precise expression pattern.
Project description:There are multiple post-translational modifications on amino acid residues at the N-terminus of histones that affect the structure of chromatin and alter the transcription of genes, thereby regulating a variety of biological processes. Lysine demethylase 7A (KDM7A) mainly removes histone modifications such as H3K9me1/2 and H3K27me1/2. Current research on KDM7A has focused on tumors, metabolism and development, while research on the function of the mammalian nervous system is still lacking. The functions and mechanisms of KDM7A in the regulation of neuronal cell differentiation and cell activity in the nervous system were investigated. Our study found that KDM7A regulates H3K9me2 and H3K27me2 but also affects other inhibitory or active histones, such as H3K9me3 and H3K27ac, thereby disturbing the transcription of some immediate early genes (IEGs) and consequently affecting the differentiation and activity of neuronal cells. IEGs are important for neuron cell proliferation, differentiation, formation of dendrites and neural circuit-related proteins, which are involved in maintaining the normal function of the nervous system. Imbalances in IEG expression have been found in some neurological disorders, such as depression and schizophrenia. Moreover, the changes in various histone modifications in neurodegenerative diseases and brain injury have recently received increasing attention. Therefore, our study provides a basis for revealing the epigenetic regulatory mechanisms of neurological disorders.
Project description:Hox genes impart segment identity to body structures along the anterior-posterior axis and are crucial for the proper development of all organisms. Multiple regulatory elements, best defined in Drosophila melanogaster, ensure that Hox expression patterns follow the spatial and temporal colinearity reflected in their tight genomic organization. However, the precise mechanisms that regulate colinear patterns of Hox gene expression remain unclear, especially in higher vertebrates where it is not fully determined how the distinct activation domains of the tightly clustered Hox genes are defined independent of each other. Here, we report the identification of a large number of novel cis-elements at mammalian Hox clusters that can help in regulating their precise expression pattern. Agilent two-color ChIP-on-Chip experiment, Organism: Mus musculus ,Genotypic Technology designed Custom Mouse 1 million ChIP-on-chip Array (AMADID-0245671)
Project description:Lysine demethylase KDM7A removes histone modifications H3K9me1/2 and H3K27me1/2. KDM7A plays critical roles in gene expression and contribute to biological processes including tumorigenesis, metabolism, and embryonic development. However, the functions of KDM7A in mammalian nervous system are still poorly explored. In this study, functional roles of KDM7A are comprehensively investigated in neuronal cells by applying CUT&Tag-seq, RNA-seq and mice models. Knockdown of Kdm7a in N2A cells result in the alteration of histone modifications near transcription start sites (TSSs) and the expression changes of a large number of genes. In particular, the expression of immediate early genes (IEGs), a series of genes maintaining the function of the nervous system and associating with neurological disorders, are significantly decreased upon Kdm7a knockdown. Furthermore, in vivo knockdown of Kdm7a in dentate gyrus (DG) neuron of mice hippocampus, via Adeno-associated virus (AAV)-based stereotaxic microinjection, led to a significant decrease of the expression of c-Fos, a marker of neuron activity. Behavior assays in mice further revealed that Kdm7a knockdown in hippocampus repress neuron activity, which leading to impairment of emotion and memory. Collectively, the study reveals that KDM7A affects neuron functions by regulating IEGs, which may provide new clues for understanding epigenetic mechanisms in neurological disorders.
Project description:We demonstrate that conditional ablation of the homeobox transcription factor Cdx2 from early endoderm results in the replacement of the posterior intestinal epithelium with keratinocytes, a dramatic cell fate conversion caused by ectopic activation of the foregut/esophageal differentiation program. This anterior homeotic transformation is first evident in the early embryonic Cdx2-deficient gut as expression of several key foregut endoderm regulators was shifted caudally. While the intestinal transcriptome was severely affected, Cdx2-deficiency only transiently modified selected posterior Hox genes and the primary enteric Hox code was maintained. Further, we demonstrate that Cdx2-directed intestinal cell fate adoption plays an important role in the establishment of normal epithelial-mesenchymal interactions, as multiple signaling pathways involved in this process were severely affected. We conclude that Cdx2 controls important aspects of intestinal identity and development, and that this function is largely independent of the enteric Hox code. Gene ablation was achieved by creating a Cdx2 loxP/loxP mouse which was then crossed with a Foxa3-CRE mouse to yield Cdx2 loxP/loxP Foxa3-CRE mice.
Project description:KDM7A Divergent Transcript (KDM7A-DT) is a stress-induced lncRNAs. In our previous studies, KDM7A-DT showed the most robust cellular phenotype alteration and a significant TP53-dependency upon oxidative and oncogenic stress induction. To investigate the functional roles of KDM7A-DT, we first performed overexpression experiments using fibroblasts. We found that MRC5 cells overexpressing KDM7A-DT escaped cell cycle proliferation and long-term survival ability and were associated with a distinct stress-related morphology (enlarged and flattened cells) compared to cells expressing just the vehicle control. To examine the effects of KDM7A-DT overexpression on the transcriptome, we performed a differential expression gene (DEG) analysis comparing a group of four independent biological replicates of MRC5 overexpressing KDM7A-DT to a group of samples from control cells.
Project description:Lysine 9 di-methylation and lysine 27 tri-methylation of histone H3 (H3K9me2 and H3K27me3) are mostly linked to gene repression. However, functions of repressive histone methylation dynamics during inflammatory responses remain poorly understood. Here, we show that lysine demethylase 7A (KDM7A) and 6A (UTX) are rapidly transported to nuclear factor kappa-B (NF-κB) related elements in human endothelial cells in response to tumor necrosis factor (TNF)-α. KDM7A and UTX demethylate H3K9me2 and H3K27me3, respectively, and cooperatively activate NF-κB dependent inflammatory genes. Furthermore, using both in situ Hi-C and other 3C based technology, loops between super enhancers (SEs) are newly formed following TNF-α-stimuli at NF-κB-dependent inflammatory loci where KDM7A- and UTX-recruitment coincide. Collectively, these findings suggest that erasing of repressive histone marks by KDM7A and UTX within NF-κB-related elements might functionally associate with formation of SE-SE three-dimensional interactions and could be a cue signal during inflammatory responses in human endothelial cells.