scholarly journals Integrative multi-omics analyses reveal multi-modal FOXG1 functions acting on epigenetic processes and in concert with NEUROD1 to regulate synaptogenesis in the mouse hippocampus

2021 ◽  
Author(s):  
Ipek Akol ◽  
Stefanie Heidrich ◽  
Darren O'hAilin ◽  
Christine Hacker ◽  
Alejandro Villarreal ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Hippocampal Neurons ◽  
Network Activity ◽  
Neuronal Maturation ◽  
Omics Data ◽  
Data Set ◽  
Genome Wide ◽  
A Genome ◽  
Primary Hippocampal Neurons ◽  
Mouse Hippocampus

Background: FOXG1 has important functions for neuronal differentiation and balances excitatory/inhibitory network activity. Mutations in the human FOXG1 gene cause a rare neurodevelopmental disorder, FOXG1-syndrome, which manifests differing phenotypes, including severe cognitive dysfunction, microencephaly, social withdrawal, and communication and memory deficits. Changes at the molecular level underlying these functional abnormalities upon FOXG1 haploinsufficiency are largely unexplored, in human patients as well as in animals modelling the debilitating disease. Methods: We present multi-omics data and explore comprehensively how FOXG1 impacts neuronal maturation at the chromatin level in the adult mouse hippocampus. We used RNA-, ATAC- and ChIP-sequencing of primary hippocampal neurons and co-immunoprecipitation to explore various levels of epigenetic changes and transcription factor networks acting to alter neuronal differentiation upon reduction of FOXG1. Results: We provide the first comprehensive multi-omics data set exploring FOXG1 presence at the chromatin and identifying the consequences of reduced FOXG1 expression in primary hippocampal neurons. Analyzing the multi-omics data, our study reveals that FOXG1 uses various different ways to regulate transcription at the chromatin level. On a genome-wide level, FOXG1 (i) both represses and activates transcription, (ii) binds mainly to enhancer regions, and (iii) bidirectionally alters the epigenetic landscape in regard to levels of H3K27ac, H3K4me3, and chromatin accessibility. Genes affected by the chromatin alterations upon FOXG1 reduction impact synaptogenesis and axonogenesis. This finding emphasizes the importance of FOXG1 to integrate and coordinate transcription of genes necessary for proper neuronal function by acting on a genome-wide level. Interestingly, FOXG1 acts through histone deacetylases (HDACs) and inhibition of HDACs partly rescued transcriptional alterations observed upon FOXG1 reduction. On a more detailed level of analysis, we show that FOXG1 (iv) operates synergistically with NEUROD1. Interestingly, we could not detect a clear hierarchy of these two key transcription factors, but instead provide first evidence that they act in highly concerted and orchestrated manner to control neuronal differentiation. Conclusions: This integrative and multi-omics view of changes upon FOXG1 reduction reveals an unprecedented multimodality ofFOXG1 functions converging on neuronal maturation, fueling novel therapeutic options based on epigenetic drugs to alleviate, at least in part, neuronal dysfunctions.

scholarly journals Eyes of Africa: The Genetics of Blindness: Study Design and Methodology

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Olusola Olawoye ◽  
Chimdi Chuka-Okosa ◽  
Onoja Akpa ◽  
Tony Realini ◽  
Michael Hauser ◽  
...  
Keyword(s):  
Genome Wide Association Study ◽  
Case Control Study ◽  
African Ancestry ◽  
Collaborative Study ◽  
Data Set ◽  
Human Heredity ◽  
Genome Wide ◽  
A Genome ◽  
Multiplex Families ◽  
Control Study

Abstract Background This report describes the design and methodology of the “Eyes of Africa: The Genetics of Blindness,” a collaborative study funded through the Human Heredity and Health in Africa (H3Africa) program of the National Institute of Health. Methods This is a case control study that is collecting a large well phenotyped data set among glaucoma patients and controls for a genome wide association study. (GWAS). Multiplex families segregating Mendelian forms of early-onset glaucoma will also be collected for exome sequencing. Discussion A total of 4500 cases/controls have been recruited into the study at the end of the 3rd funded year of the study. All these participants have been appropriately phenotyped and blood samples have been received from these participants. Recent GWAS of POAG in African individuals demonstrated genome-wide significant association with the APBB2 locus which is an association that is unique to individuals of African ancestry. This study will add to the existing knowledge and understanding of POAG in the African population.

scholarly journals Stable DNMT3L overexpression in SH-SY5Y neurons recreates a facet of the genome-wide Down syndrome DNA methylation signature

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Benjamin I. Laufer ◽  
J. Antonio Gomez ◽  
Julia M. Jianu ◽  
Janine M. LaSalle
Keyword(s):  
Dna Methylation ◽  
Down Syndrome ◽  
Neuronal Differentiation ◽  
Molecular Mechanisms ◽  
Cpg Island ◽  
Differential Methylation ◽  
Chromosome 21 ◽  
Pairwise Comparisons ◽  
Genome Wide ◽  
A Genome

Abstract Background Down syndrome (DS) is characterized by a genome-wide profile of differential DNA methylation that is skewed towards hypermethylation in most tissues, including brain, and includes pan-tissue differential methylation. The molecular mechanisms involve the overexpression of genes related to DNA methylation on chromosome 21. Here, we stably overexpressed the chromosome 21 gene DNA methyltransferase 3L (DNMT3L) in the human SH-SY5Y neuroblastoma cell line and assayed DNA methylation at over 26 million CpGs by whole genome bisulfite sequencing (WGBS) at three different developmental phases (undifferentiated, differentiating, and differentiated). Results DNMT3L overexpression resulted in global CpG and CpG island hypermethylation as well as thousands of differentially methylated regions (DMRs). The DNMT3L DMRs were skewed towards hypermethylation and mapped to genes involved in neurodevelopment, cellular signaling, and gene regulation. Consensus DNMT3L DMRs showed that cell lines clustered by genotype and then differentiation phase, demonstrating sets of common genes affected across neuronal differentiation. The hypermethylated DNMT3L DMRs from all pairwise comparisons were enriched for regions of bivalent chromatin marked by H3K4me3 as well as differentially methylated sites from previous DS studies of diverse tissues. In contrast, the hypomethylated DNMT3L DMRs from all pairwise comparisons displayed a tissue-specific profile enriched for regions of heterochromatin marked by H3K9me3 during embryonic development. Conclusions Taken together, these results support a mechanism whereby regions of bivalent chromatin that lose H3K4me3 during neuronal differentiation are targeted by excess DNMT3L and become hypermethylated. Overall, these findings demonstrate that DNMT3L overexpression during neurodevelopment recreates a facet of the genome-wide DS DNA methylation signature by targeting known genes and gene clusters that display pan-tissue differential methylation in DS.

scholarly journals A genome-wide scan for a simulated data set using two newly developed methods

1999 ◽  
Vol 17 (S1) ◽  
pp. S621-S626
Author(s):  
Li Hsu ◽  
Corinne Aragaki ◽  
Filemon Quiaoit ◽  
Xiangjing Wang ◽  
Xiubin Xu ◽  
...  
Keyword(s):  
Simulated Data ◽  
Data Set ◽  
Genome Wide ◽  
A Genome ◽  
Genome Wide Scan

scholarly journals A Clustering Approach for Motif Discovery in ChIP-Seq Dataset

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 802
Author(s):  
Chun-xiao Sun ◽  
Yu Yang ◽  
Hua Wang ◽  
Wen-hu Wang
Keyword(s):  
Dna Sequences ◽  
Motif Discovery ◽  
Simulated Data ◽  
Data Set ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale ◽  
Clustering Approach ◽  
Ap Clustering ◽  
Generation Sequencing

Chromatin immunoprecipitation combined with next-generation sequencing (ChIP-Seq) technology has enabled the identification of transcription factor binding sites (TFBSs) on a genome-wide scale. To effectively and efficiently discover TFBSs in the thousand or more DNA sequences generated by a ChIP-Seq data set, we propose a new algorithm named AP-ChIP. First, we set two thresholds based on probabilistic analysis to construct and further filter the cluster subsets. Then, we use Affinity Propagation (AP) clustering on the candidate cluster subsets to find the potential motifs. Experimental results on simulated data show that the AP-ChIP algorithm is able to make an almost accurate prediction of TFBSs in a reasonable time. Also, the validity of the AP-ChIP algorithm is tested on a real ChIP-Seq data set.

Genome-Wide Analysis of EKLF Occupancy in Erythroid Chromatin Reveals 5′, 3′ and Intragenic Binding Sites in EKLF Target Genes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 283-283
Author(s):  
Andre M. Pilon ◽  
Elliott H. Margulies ◽  
Hatice Ozel Abaan ◽  
Amy Werner- Allen ◽  
Tim M. Townes ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Binding Sites ◽  
Erythroid Cells ◽  
Data Set ◽  
Erythroid Progenitor ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
A Genome

Abstract Erythroid Kruppel-Like Factor (EKLF; KLF1) is the founding member of the Kruppel family of transcription factors, with 3 C2H2 zinc-fingers that bind a 9-base consensus sequence (NCNCNCCCN). The functions of EKLF, first identified as an activator of the beta-globin locus, include gene activation and chromatin remodeling. Our knowledge of genes regulated by EKLF is limited, as EKLF-deficient mice die by embryonic day 15 (E15), due to a severe anemia. Analysis of E13.5 wild type and EKLF-deficient fetal liver (FL) erythroid cells revealed that EKLF-deficient cells fail to complete terminal erythroid maturation (Pilon et al. submitted). Coupling chromatin immunoprecipitation and ultra high-throughput massively parallel sequencing (ChIP-seq) is increasingly being used for mapping protein-DNA interactions in vivo on a genome-wide scale. ChIP-seq allows a simultaneous analysis of transcription factor binding in every region of the genome, defining an “interactome”. To elucidate direct EKLF-dependent effects on erythropoiesis, we have combined ChIP-seq with expression array (“transcriptome”) analyses. We feel that integration of ChIP-seq and microarray data can provide us detailed knowledge of the role of EKLF in erythropoiesis. Chromatin was isolated from E13.5 FL cells of mice whose endogenous EKLF gene was replaced with a fully functional HA-tagged EKLF gene. ChIP was performed using a highly specific high affinity anti-HA antibody. A library of EKLF-bound FL chromatin enriched by anti-HA IP was created and subjected to fluorescent in situ sequencing on a Solexa 1G platform, providing 36-base signatures that were mapped to unique sites in the mouse genome, defining the EKLF “interactome.” The frequency with which a given signature appears provides a measurable peak of enrichment. We performed three biological/technical replicates and analyzed each data set individually as well as the combined data. To validate ChIP-seq results, we examined the locus of a known EKLF target gene, a-hemoglobin stabilizing protein (AHSP). Peaks corresponded to previously identified DNase hypersensitive sites, regions of histone hyperacetylation, and sites of promoter-occupancy determined by ChIP-PCR. A genome wide analysis, focusing on the regions with the highest EKLF occupancy revealed a set of 531 locations where high levels EKLF binding occurs. Of these sites, 119 (22%) are located 10 kb or more from the nearest gene and are classified as intergenic EKLF binding sites. Another 78 sites (14.6%) are within 10 kb of an annotated RefSeq gene. A plurality of the binding sites, 222 (42%), are within RefSeq coordinates and are classified as intragenic EKLF binding sites. Microarray profiling of mRNA from sorted, matched populations of dE13.5 WT and EKLF-deficient FL erythroid progenitor cells showed dysregulation of >3000 genes (p<0.05). Ingenuity Pathways Analysis (IPA) of the >3000 dysregulated mRNAs indicated significant alteration of a cell cycle-control network, centered about the transcription factor, E2f2. We confirmed significantly decreased E2f2 mRNA and protein levels by real-time PCR and Western blot, respectively; demonstrated that EKLF-deficient FL cells accumulate in G0/G1 by cell cycle analysis; and verified EKLF-binding to motifs within the E2f2 promoter by ChIP-PCR and analysis of the ChIP Seq data. We hypothesized that only a subset of the 3000 dysregulated genes would be direct EKLF targets. We limited the ChIP-seq library to display the top 5% most frequently represented fragments across the genome, and applied this criterion to the network of dysregulated mRNAs in the IPA cell cycle network. ChIP-seq identified peaks of EKLF association with 60% of the loci in this pathway. However, consistent with the role of EKLF as a transcriptional activator, 95% of the occupied genomic loci corresponded to mRNAs whose expression in EKLF-deficient FL cells was significantly decreased (p<0.05). The majority (59%) of these EKLF-bound sites were located at intragenic sites (i.e., introns), while a minority (15% and 26%) were found adjacent to the genes or in intergenic regions. We have shown that both the AHSP and E2f2 loci require EKLF to cause the locus to become activated and sensitive to DNase I digestion in erythroid cells. Based on the increased frequency of intragenic EKLF-binding sites, particularly in genes of the cell cycle network, we propose that the occupancy of intragenic sites by EKLF may facilitate chromatin modification.

scholarly journals NRP/B, a Novel Nuclear Matrix Protein, Associates With p110RB and Is Involved in Neuronal Differentiation

1998 ◽  
Vol 141 (3) ◽  
pp. 553-566 ◽  
Author(s):  
Tae-Aug Kim ◽  
Jinkyu Lim ◽  
Setsuo Ota ◽  
Sandhya Raja ◽  
Rick Rogers ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Nuclear Matrix ◽  
Hippocampal Neurons ◽  
Matrix Protein ◽  
Neuroblastoma Cells ◽  
Adult Brain ◽  
Nuclear Matrix Protein ◽  
Neuronal Process ◽  
Process Formation ◽  
Primary Hippocampal Neurons

The nuclear matrix is defined as the insoluble framework of the nucleus and has been implicated in the regulation of gene expression, the cell cycle, and nuclear structural integrity via linkage to intermediate filaments of the cytoskeleton. We have discovered a novel nuclear matrix protein, NRP/B (nuclear restricted protein/brain), which contains two major structural elements: a BTB domain–like structure in the predicted NH2 terminus, and a “kelch motif” in the predicted COOH-terminal domain. NRP/B mRNA (5.5 kb) is predominantly expressed in human fetal and adult brain with minor expression in kidney and pancreas. During mouse embryogenesis, NRP/B mRNA expression is upregulated in the nervous system. The NRP/B protein is expressed in rat primary hippocampal neurons, but not in primary astrocytes. NRP/B expression was upregulated during the differentiation of murine Neuro 2A and human SH-SY5Y neuroblastoma cells. Overexpression of NRP/B in these cells augmented neuronal process formation. Treatment with antisense NRP/B oligodeoxynucleotides inhibited the neurite development of rat primary hippocampal neurons as well as the neuronal process formation during neuronal differentiation of PC-12 cells. Since the hypophosphorylated form of retinoblastoma protein (p110RB) is found to be associated with the nuclear matrix and overexpression of p110RB induces neuronal differentiation, we investigated whether NRP/B is associated with p110RB. Both in vivo and in vitro experiments demonstrate that NRP/B can be phosphorylated and can bind to the functionally active hypophosphorylated form of the p110RB during neuronal differentiation of SH-SY5Y neuroblastoma cells induced by retinoic acid. Our studies indicate that NRP/B is a novel nuclear matrix protein, specifically expressed in primary neurons, that interacts with p110RB and participates in the regulation of neuronal process formation.

scholarly journals A Bayesian Gene-Based Genome-Wide Association Study Analysis of Osteosarcoma Trio Data Using a Hierarchically Structured Prior

2018 ◽  
Vol 17 ◽  
pp. 117693511877510 ◽  
Author(s):  
Yi Yang ◽  
Saonli Basu ◽  
Lisa Mirabello ◽  
Logan Spector ◽  
Lin Zhang
Keyword(s):  
Risk Factors ◽  
Association Study ◽  
Genome Wide Association Study ◽  
Bone Cancer ◽  
Genome Wide Association ◽  
Ratio Test ◽  
Data Set ◽  
Estrogen Receptor Signaling ◽  
Genome Wide ◽  
A Genome

Osteosarcoma is considered to be the most common primary malignant bone cancer among children and young adults. Previous studies suggest growth spurts and height to be risk factors for osteosarcoma. However, studies on the genetic cause are still limited given the rare occurrence of the disease. In this study, we investigated in a family trio data set that is composed of 209 patients and their unaffected parents and conducted a genome-wide association study (GWAS) to identify genetic risk factors for osteosarcoma. We performed a Bayesian gene-based GWAS based on the single-nucleotide polymorphism (SNP)-level summary statistics obtained from a likelihood ratio test of the trio data, which uses a hierarchically structured prior that incorporates the SNP-gene hierarchical structure. The Bayesian approach has higher power than SNP-level GWAS analysis due to the reduced number of tests and is robust by accounting for the correlations between SNPs so that it borrows information across SNPs within a gene. We identified 217 genes that achieved genome-wide significance. Ingenuity pathway analysis of the gene set indicated that osteosarcoma is potentially related to TP53, estrogen receptor signaling, xenobiotic metabolism signaling, and RANK signaling in osteoclasts.

scholarly journals Five genetic variants explain over 70% of hair coat pheomelanin intensity variation in purebred and mixed breed domestic dogs

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250579
Author(s):  
Andrea J. Slavney ◽  
Takeshi Kawakami ◽  
Meghan K. Jensen ◽  
Thomas C. Nelson ◽  
Aaron J. Sams ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Full Range ◽  
Intensity Variation ◽  
Domestic Dogs ◽  
Validation Dataset ◽  
Data Set ◽  
Genome Wide ◽  
A Genome ◽  
Mixed Breed ◽  
Wide Range

In mammals, the pigment molecule pheomelanin confers red and yellow color to hair, and the intensity of this coloration is caused by variation in the amount of pheomelanin. Domestic dogs exhibit a wide range of pheomelanin intensity, ranging from the white coat of the Samoyed to the deep red coat of the Irish Setter. While several genetic variants have been associated with specific coat intensity phenotypes in certain dog breeds, they do not explain the majority of phenotypic variation across breeds. In order to gain further insight into the extent of multigenicity and epistatic interactions underlying coat pheomelanin intensity in dogs, we leveraged a large dataset obtained via a direct-to-consumer canine genetic testing service. This consisted of genome-wide single nucleotide polymorphism (SNP) genotype data and owner-provided photos for 3,057 pheomelanic mixed breed and purebred dogs from 63 breeds and varieties spanning the full range of canine coat pheomelanin intensity. We first performed a genome-wide association study (GWAS) on 2,149 of these dogs to search for additional genetic variants that underlie intensity variation. GWAS identified five loci significantly associated with intensity, of which two (CFA15 29.8 Mb and CFA20 55.8 Mb) replicate previous findings and three (CFA2 74.7 Mb, CFA18 12.9 Mb, CFA21 10.9 Mb) have not previously been reported. In order to assess the combined predictive power of these loci across dog breeds, we used our GWAS data set to fit a linear model, which explained over 70% of variation in coat pheomelanin intensity in an independent validation dataset of 908 dogs. These results introduce three novel pheomelanin intensity loci, and further demonstrate the multigenic nature of coat pheomelanin intensity determination in domestic dogs.

scholarly journals miR-106b-responsive gene landscape identifies regulation of Kruppel-like factor family

2016 ◽  
Author(s):  
Cody J. Wehrkamp ◽  
Sathish Kumar Natarajan ◽  
Ashley M. Mohr ◽  
Mary Anne Phillippi ◽  
Justin L. Mott
Keyword(s):  
Protein Level ◽  
Mrna Level ◽  
Tumor Biology ◽  
Rna Seq ◽  
Data Set ◽  
Genome Wide ◽  
A Genome ◽  
Mrna Analysis ◽  
Novel Targets ◽  
Microrna Dysregulation

MicroRNA dysregulation is a common feature of cancer and due to the promiscuity of microRNA binding this can result in a wide array of genes whose expression is altered. miR-106b is an oncomiR overexpressed in cholangiocarcinoma and its upregulation in this and other cancers often leads to repression of anti-tumorigenic targets. The goal of this study was to identify the miR-106b-regulated gene landscape in cholangiocarcinoma cells using a genome-wide, unbiased mRNA analysis. Through RNA-Seq we found 112 mRNAs significantly repressed by miR-106b. The majority of these genes contain the specific miR-106b seed-binding site. We have validated 11 genes from this set at the mRNA level and demonstrated regulation by miR-106b of five proteins. Combined analysis of our miR-106b-regulated mRNA data set plus published reports indicate that miR-106b binding is anchored by G:C pairing in and near the seed. Novel targets Kruppel-like factor 2 (KLF2) and KLF6 were verified both at the mRNA and at the protein level. Further investigation showed regulation of four other KLF family members by miR-106b. We have discovered coordinated repression of several members of the KLF family by miR-106b that may play a role in cholangiocarcinoma tumor biology.

Sign in / Sign up

Export Citation Format

Share Document