Differential CpG methylation at Nnat in the early establishment of beta cell heterogeneity
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ABSTRACT:
PROVIDER: PRJNA1049900 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR27139387_1.fastq.gz | Fastqsanger.gz | |||
| SRR27139387_2.fastq.gz | Fastqsanger.gz | |||
| SRR27139388_1.fastq.gz | Fastqsanger.gz | |||
| SRR27139388_2.fastq.gz | Fastqsanger.gz | |||
| SRR27139389_1.fastq.gz | Fastqsanger.gz |
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Project description:Aims/hypothesis: Beta cells within the pancreatic islet represent a heterogenous population wherein individual sub-groups of cells make distinct contributions to the overall control of insulin secretion. These include a subpopulation of highly-connected ‘hub’ cells, important for the propagation of intercellular Ca2+ waves. Functional subpopulations have also been demonstrated in human beta cells, with an altered subtype distribution apparent in type 2 diabetes. At present, the molecular mechanisms through which beta cell hierarchy is established are poorly understood. Changes at the level of the epigenome provide one such possibility which we explore here by focussing on the imprinted gene neuronatin (Nnat), which is required for normal insulin synthesis and secretion. Methods: Single cell RNA-seq datasets were examined using Seurat 4.0 and ClusterProfiler running under R. Transgenic mice expressing eGFP under the control of the Nnat enhancer/promoter regions were generated for fluorescence-activated cell (FAC) sorting of beta cells and downstream analysis of CpG methylation by bisulphite and RNA sequencing, respectively. Animals deleted for the de novo methyltransferase, DNMT3A from the pancreatic progenitor stage were used to explore control of promoter methylation. Proteomics was performed using affinity purification mass spectrometry and Ca2+ dynamics explored by rapid confocal imaging of Cal-520 and Cal-590. Insulin secretion was measured using Homogeneous Time Resolved Fluorescence Imaging. Results: Nnat mRNA was differentially expressed in a discrete beta cell population in a developmental stage- and DNA methylation (DNMT3A)-dependent manner. Thus, pseudo-time analysis of embryonic data sets demonstrated the early establishment of Nnat-positive and negative subpopulations during embryogenesis. NNAT expression is also restricted to a subset of beta cells across the human islet that is maintained throughout adult life. NNAT+ beta cells also displayed a discrete transcriptome at adult stages, representing a sub-population specialised for insulin production, reminiscent of recently-described “bHI” cells and were diminished in db/db mice. ‘Hub’ cells were less abundant in the NNAT+ population, consistent with epigenetic control of this functional specialization. Conclusions/interpretation: These findings demonstrate that differential DNA methylation at Nnat represents a novel means through which beta cell heterogeneity is established during development. We therefore hypothesise that changes in methylation at this locus may thus contribute to a loss of beta cell hierarchy and connectivity, potentially contributing to defective insulin secretion in some forms of diabetes.
2024-03-25 | GSE249659 | GEO
Project description:Beta cells within the pancreatic islet represent a heterogenous population wherein individual sub-groups of cells make distinct contributions to the overall control of insulin secretion. These include a subpopulation of highly-connected ‘hub’ cells, important for the propagation of intercellular Ca2+ waves. Functional subpopulations have also been demonstrated in human beta cells, with an altered subtype distribution apparent in type 2 diabetes. At present, the molecular mechanisms through which beta cell hierarchy is established are poorly understood. Changes at the level of the epigenome provide one such possibility which we explore here by focussing on the imprinted gene neuronatin(Nnat), which is required for normal insulin synthesis and secretion.
2024-03-22 | PXD048465 | Pride
Project description:Aims/hypothesisBeta cells within the pancreatic islet represent a heterogenous population wherein individual sub-groups of cells make distinct contributions to the overall control of insulin secretion. These include a subpopulation of highly-connected 'hub' cells, important for the propagation of intercellular Ca2+ waves. Functional subpopulations have also been demonstrated in human beta cells, with an altered subtype distribution apparent in type 2 diabetes. At present, the molecular mechanisms through which beta cell hierarchy is established are poorly understood. Changes at the level of the epigenome provide one such possibility which we explore here by focussing on the imprinted gene neuronatin (Nnat), which is required for normal insulin synthesis and secretion.MethodsSingle cell RNA-seq datasets were examined using Seurat 4.0 and ClusterProfiler running under R. Transgenic mice expressing eGFP under the control of the Nnat enhancer/promoter regions were generated for fluorescence-activated cell (FAC) sorting of beta cells and downstream analysis of CpG methylation by bisulphite and RNA sequencing, respectively. Animals deleted for the de novo methyltransferase, DNMT3A from the pancreatic progenitor stage were used to explore control of promoter methylation. Proteomics was performed using affinity purification mass spectrometry and Ca2+ dynamics explored by rapid confocal imaging of Cal-520 and Cal-590. Insulin secretion was measured using Homogeneous Time Resolved Fluorescence Imaging.ResultsNnat mRNA was differentially expressed in a discrete beta cell population in a developmental stage- and DNA methylation (DNMT3A)-dependent manner. Thus, pseudo-time analysis of embryonic data sets demonstrated the early establishment of Nnat-positive and negative subpopulations during embryogenesis. NNAT expression is also restricted to a subset of beta cells across the human islet that is maintained throughout adult life. NNAT+ beta cells also displayed a discrete transcriptome at adult stages, representing a sub-population specialised for insulin production, reminiscent of recently-described "βHI" cells and were diminished in db/db mice. 'Hub' cells were less abundant in the NNAT+ population, consistent with epigenetic control of this functional specialization.Conclusions/interpretationThese findings demonstrate that differential DNA methylation at Nnat represents a novel means through which beta cell heterogeneity is established during development. We therefore hypothesise that changes in methylation at this locus may thus contribute to a loss of beta cell hierarchy and connectivity, potentially contributing to defective insulin secretion in some forms of diabetes.
| S-EPMC10705251 | biostudies-literature
Project description:Neuronatin (Nnat) has previously been reported to be part of a network of imprinted genes. Disruption of neuronatin results in an unusual phenotype of a bimodal body weight.In order to understand at the molecular level how the Nnat deficiency could contribute to the hypervariable phenotypes seen, we performed RNA sequencing from laser-capture micro dissected paraventricular nucleus (PVN) and arcuate nucleus (ARC) and compared the transcriptome between Nnat+/-p mice and their Nnat+/+ littermates in different feeding conditions. We performed an analysis of three subgroups: Nnat+/+ (all non-obese), Nnat+/-p non-obese, and Nnat+/-p obese mice and combined two approaches to identify differences in hypothalamic gene expression between subgroups
2021-09-03 | GSE171155 | GEO
Project description:Cytosine (C) modifications within CpG dyads are central regulatory elements of mammalian genomes. In addition to 5-methylcytosine (mC), genomes can also contain high levels of 5-hydroxymethylcytosine (hmC) that is read differently by nuclear proteins than mC. However, hmC can co-exist with C and mC in different combinations in the two strands of CpG dyads, and it is poorly understood, how these combinatorial marks differ in their protein interactomes and regulatory functions. To identify nuclear binding proteins, we employed DNA promoter probes with differentially modified CpG dyads in pulldown experiments. The datasets comprise three biological replicates of HEK293T nuclear proteins binding to a VEGFA promoter sequence with differentially modified CpG dyads. Each biological replicate contains five technical replicates per modified CpG dyad, resulting in a total of 15 replicates for C/C, mC/mC and hmC/mC, and 10 replicates for hmC/C and hmC/hmC.
2024-08-15 | MSV000095609 | MassIVE
Project description:Epigenetic regulation is essential for the normal development of human cerebral cortex, and its disruptions would lead to diverse neurodevelopmental disorders. The epigenetic co-repressor CDYL exhibits widespread expression across various cell clusters within the human embryonic cortex, yet its roles in this intricate process have remained elusive. Here, we show that CDYL is critical for cortical neurogenesis, and CDYL deficiency led to an augmentation in the generation of GABAergic neurons instead of cortical progenitors and neurons in the cortical organoid model. Combining analysis of bulk RNA-seq and ChIP seq, we identified NNAT as a significant CDYL target by H3K27me3 modification, crucial for the fate determination of neural stem cells within human cortical organoids, distinctly diverging from the murine cortex at a similar developmental stage. Collectively, our study sheds light on the critical function of CDYL in the maintenance of cortical neural stem cell fate commitment during human corticogenesis through the inhibition of NNAT expression.
2023-11-13 | GSE247086 | GEO
Project description:Epigenetic regulation is essential for the normal development of human cerebral cortex, and its disruptions would lead to diverse neurodevelopmental disorders. The epigenetic co-repressor CDYL exhibits widespread expression across various cell clusters within the human embryonic cortex, yet its roles in this intricate process have remained elusive. Here, we show that CDYL is critical for cortical neurogenesis, and CDYL deficiency led to an augmentation in the generation of GABAergic neurons instead of cortical progenitors and neurons in the cortical organoid model. Combining analysis of bulk RNA-seq and ChIP seq, we identified NNAT as a significant CDYL target by H3K27me3 modification, crucial for the fate determination of neural stem cells within human cortical organoids, distinctly diverging from the murine cortex at a similar developmental stage. Collectively, our study sheds light on the critical function of CDYL in the maintenance of cortical neural stem cell fate commitment during human corticogenesis through the inhibition of NNAT expression.
2023-11-13 | GSE247084 | GEO
Project description:TET protein-catalyzed 5mC oxidation not only creates novel DNA modifications such as 5hmC, but also initiates active or passive DNA demethylation. However, the TETsâ function in crosstalk with specific histone modifications is largely elusive. Here, we show that TET2-mediated DNA demethylation plays a primary role in the de novo establishment and maintenance of H3K4me3/H3K27me3 bivalent domain underlying the methylated DNA CpG islands (CGIs). Overexpression of wild type (WT) but not catalytic inactive mutant (Mut) TET2 in TET-low-expressing cells results in increase of 5hmC level and accompanying DNA demethylation at a subset of CGIs. Importantly, this is sufficient to create de novo bivalent domains at these loci. Genome-wide analysis reveals that these de novo synthesized bivalent domains are largely associated with a subset of key developmental gene promoters, which are often located within CpG islands that are previously hyper-methylated and silenced. On the other hand, depletion of Tet1 and Tet2 in mouse ES cells results in an apparent loss of H3K27me3 at bivalent domains, which are located within CGIs and associated with a particular set of key developmental gene promoters. Collectively, these data suggest that TET proteins have a primary role in charge of regulating the crosstalk between two key epigenetic mechanisms, DNA methylation and histone methylation (H3K4me3 and H3K27me3), particularly at a subset of CpG islands associated with developmental genes. We examined H3K4me3,H3K27me3,5mC and 5hmC in 293T and mES cell types,using Illumina Hiseq2500.
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Project description:CpG island reconfiguration for the establishment and synchronization of polycomb functions upon exit from naive pluripotency
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Project description:TET protein-catalyzed 5mC oxidation not only creates novel DNA modifications such as 5hmC, but also initiates active or passive DNA demethylation. However, the TETs’ function in crosstalk with specific histone modifications is largely elusive. Here, we show that TET2-mediated DNA demethylation plays a primary role in the de novo establishment and maintenance of H3K4me3/H3K27me3 bivalent domain underlying the methylated DNA CpG islands (CGIs). Overexpression of wild type (WT) but not catalytic inactive mutant (Mut) TET2 in TET-low-expressing cells results in increase of 5hmC level and accompanying DNA demethylation at a subset of CGIs. Importantly, this is sufficient to create de novo bivalent domains at these loci. Genome-wide analysis reveals that these de novo synthesized bivalent domains are largely associated with a subset of key developmental gene promoters, which are often located within CpG islands that are previously hyper-methylated and silenced. On the other hand, depletion of Tet1 and Tet2 in mouse ES cells results in an apparent loss of H3K27me3 at bivalent domains, which are located within CGIs and associated with a particular set of key developmental gene promoters. Collectively, these data suggest that TET proteins have a primary role in charge of regulating the crosstalk between two key epigenetic mechanisms, DNA methylation and histone methylation (H3K4me3 and H3K27me3), particularly at a subset of CpG islands associated with developmental genes.
2016-07-25 | GSE72481 | GEO