Biology subjects

Kelsey, G.

Publications and source records attributed to Kelsey, G..

9 recordsLinked to original sources

bioRxiv2026

Epigenomic profiling of cerebrospinal fluid cells identifies immune regulatory alterations and implicates protocadherins in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), where DNA methylation may play a role by connecting genetic and environmental risk factors. We performed whole-genome DNA methylation profiling of cerebrospinal fluid (CSF) cells from relapsing-remitting MS patients and matched controls, identifying 2,710 differentially methylated positions (DMPs) and 4,330 regions (DMRs). These changes were enriched in immune signaling, adhesion and migration processes, and were accompanied by corresponding RNA expression changes. MS-associated methylation changes enriched in the cohesin chromatin regulation pathway mapped to enhancers of T helper 17 (Th17) cells, whereas in other T cell types they were mapping to bivalent enhancers and repressed chromatin. Notably, this pathway comprised multiple Protocadherin (PCDH) genes, typically expressed in neuronal cells, that displayed consistent methylation and expression changes in CSF cells. Expression of shared intracellular domain of PCDH{gamma} cluster proteins was confirmed in peripheral blood T cells by flow cytometry as well as expression of PCDH{gamma} cluster genes in memory CD4+ T cell subsets. Moreover, co-expression analysis suggests a role of PCDH genes in aryl hydrocarbon receptor (AHR) signaling. In summary, DNA methylation changes in CSF resident cells reflect dysregulated T cell activation and migration in MS and suggest a novel role of protocadherin molecules in MS pathogenesis.

immunology↗

bioRxiv2025

An Nlrp5-null mutation leads to attenuated de novo methylation in oocytes, accompanied by a significant reduction in DNMT3L

Nlrp5 encodes a core component of the subcortical maternal complex (SCMC) a cytoplasmic protein structure unique to the mammalian oocyte and cleavage-stage embryo. NLRP5 mutations have been identified in patients presenting with early embryo arrest, recurrent molar pregnancies and imprinting disorders. Correct patterning of DNA methylation over imprinted domains during oogenesis is necessary for faithful imprinting of genes. It was previously shown that oocytes with mutation in the human SCMC gene KHDC3L had globally impaired methylation, indicating that integrity of the SCMC is essential for correct establishment of DNA methylation at imprinted regions. Here, we present a multi-omic analysis of an Nlrp5- null mouse model, which in GV oocytes displays a misregulation of a broad range of maternal proteins, including proteins involved in several key developmental processes. This misregulation likely underlies impaired oocyte developmental competence. Amongst impacted proteins are several epigenetic modifiers, including a substantial reduction in DNMT3L; we show that de novo DNA methylation is attenuated in Nlrp5-null oocytes. This provides evidence for mechanisms leading to downstream misregulation of imprinted genes, which in turn, may result in imprinting syndromes, multi-locus imprinting disturbances (MLID) and hydatidiform moles.

developmental biology↗

bioRxiv2023

A maternal-effect Padi6 variant results in abnormal nuclear localization of DNMT1 and failure of epigenetic reprogramming and zygotic genome activation in mouse embryos

PADI6 belongs to the multi-protein sub-cortical maternal complex (SCMC) that is present specifically in mammalian oocytes and early embryos. Maternal inactivation of SCMC genes generally results in early embryo lethality. In humans, variants in a subset of SCMC genes have been found in the healthy mothers of children affected by genomic imprinting disorders and characterized by multi-locus imprinting disturbances (MLID). However, how the SCMC controls the DNA methylation required to regulate imprinting remains poorly defined. To address this issue, we generated a mouse line carrying a Padi6 missense variant that had been identified in the mother of two sisters affected by Beckwith-Wiedemann syndrome and MLID. We found that if homozygous in female mice this variant resulted in interruption of embryo development at the 2-cell stage. Single-cell DNA methylation and RNA analyses demonstrated genomic hypermethylation, down-regulation of zygotic genome activation (ZGA) genes and up-regulation of maternal decay genes in 2-cell embryos from homozygous females. In addition, immunofluorescence analysis showed abnormal localization of DNMT1 and UHRF1 in mutant oocytes and zygotes. Taken together, this study demonstrates that PADI6 controls the subcellular localization of DNMT1 that is necessary for pre-implantation epigenetic reprogramming and ZGA.

genomics↗

bioRxiv2022

FOXA2 controls the antioxidant response in FH-deficient cells independent of NRF2

Hereditary Leiomyomatosis and renal cell cancer (HLRCC) is a cancer syndrome caused by inactivating germline mutations in fumarate hydratase (FH) and subsequent accumulation of fumarate. Fumarate accumulation leads to the activation of an anti-oxidant response via nuclear translocation of the transcription factor NRF2. The activation of the anti-oxidant response is key for cellular survival in FH-deficient cells, yet the extent to which chromatin remodelling shapes the anti-oxidant response is currently unknown. Here, we explored the global effects of FH loss on the chromatin landscape to identify transcription factor networks involved in the highly remodelled chromatin landscape of FH-deficient cells. We identify FOXA2 as a key transcription factor which directly regulates anti-oxidant response genes and subsequent metabolic rewiring. Moreover, we also find that FOXA2 regulates anti-oxidant genes independent of the canonical anti-oxidant regulator NRF2. The identification of FOXA2 as an anti-oxidant regulator provides new insights into the molecular mechanisms behind cell responses to fumarate accumulation, and potentially provides new avenues for therapeutic intervention for HLRCC.

cancer biology↗

bioRxiv2021

GLP is critical for oogenesis exhibiting a G9A-independent role in transcriptional repression

GLP (EHMT1) is a multifunctional protein, best known for its role as an H3K9me1 and H3K9me2 methyltransferase through its reportedly obligatory dimerization with G9A (EHMT2). Here, we investigate the role of GLP in the oocyte in comparison to G9A using oocyte-specific conditional knockout mouse models (G9a cKO, Glp cKO, G9a-Glp cDKO). Loss of GLP in Glp cKO and G9a-Glp cDKO oocytes re-capitulated meiotic defects observed in the G9a cKO; however, there was a significant impairment in oocyte maturation and developmental competence in Glp cKO and G9a-Glp cDKO oocytes beyond that observed in the G9a cKO. Consequently, loss of GLP in oogenesis results upon fertilisation in mid-gestation embryonic lethality. To assess the molecular functions of GLP and G9A, we applied a multi-omics approach, supported by immunofluorescence, to identify changes in epigenomic, transcriptomic and proteomic signatures in cKO oocytes. H3K9me2 was equally depleted in all cKO oocytes, whereas H3K9me1 was decreased only upon loss of GLP. The transcriptome, DNA methylome and proteome were markedly more affected in G9a-Glp cDKO than G9a cKO oocytes, with transcriptional de-repression associated with increased protein abundance and gains in genic DNA methylation in G9a-Glp cDKO oocytes. Together, our findings suggest that GLP contributes to transcriptional repression in the oocyte, independent of G9A, and is critical for oogenesis and oocyte developmental competence.

developmental biology↗

bioRxiv2021

Loss of SETD1B results in the redistribution of genomic H3K4me3 in the oocyte

Histone 3 lysine 4 trimethylation (H3K4me3) is an epigenetic mark found at gene promoters and CpG islands. H3K4me3 is essential for mammalian development, yet mechanisms underlying its genomic targeting are poorly understood. H3K4me3 methyltransferases SETD1B and MLL2 are essential for oogenesis. We investigated changes in H3K4me3 in Setd1b conditional knockout (cKO) oocytes using ultra-low input ChIP-seq, with comparisons to DNA methylation and gene expression analyses. H3K4me3 was redistributed in Setd1b cKO oocytes showing losses at active gene promoters associated with downregulated gene expression. Remarkably, many regions also gained H3K4me3, in particular those that were DNA hypomethylated, transcriptionally inactive and CpG-rich, which are hallmarks of MLL2 targets. Consequently, loss of SETD1B disrupts the balance between MLL2 and de novo DNA methyltransferases in determining the epigenetic landscape during oogenesis. Our work reveals two distinct, complementary mechanisms of genomic targeting of H3K4me3 in oogenesis, with SETD1B linked to gene expression and MLL2 to CpG content. Graphical AbstractIn oogenesis, SETD1B and CXXC1 target H3K4me3 to actively transcribed gene promoters, while MLL2 targets transcriptionally inactive regions based on underlying CpG composition (upper panel). When SETD1B is ablated, H3K4me3 is lost at a subset of active promoters, resulting in downregulation of transcription (lower panel). Loss of SETD1B alters the activity of MLL2, permitting MLL2 to deposit H3K4me3 at CpG-rich regions, many of which should otherwise be DNA methylated. Thus, it is evident that MLL2 and de novo DNMTs compete for genomic occupancy late in oogenesis, and loss of SETD1B disrupts the balance of these mechanisms. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

developmental biology↗

bioRxiv2019

Single cell multi-omics profiling reveals a hierarchical epigenetic landscape during mammalian germ layer specification

Formation of the three primary germ layers during gastrulation is an essential step in the establishment of the vertebrate body plan. Recent studies employing single cell RNA-sequencing have identified major transcriptional changes associated with germ layer specification. Global epigenetic reprogramming accompanies these changes, but the role of the epigenome in regulating early cell fate choice remains unresolved, and the coordination between different epigenetic layers is unclear. Here we describe the first single cell triple-omics map of chromatin accessibility, DNA methylation and RNA expression during the exit from pluripotency and the onset of gastrulation in mouse embryos. We find dynamic dependencies between the different molecular layers, with evidence for distinct modes of epigenetic regulation. The initial exit from pluripotency coincides with the establishment of a global repressive epigenetic landscape, followed by the emergence of local lineage-specific epigenetic patterns during gastrulation. Notably, cells committed to mesoderm and endoderm undergo widespread coordinated epigenetic rearrangements, driven by loss of methylation in enhancer marks and a concomitant increase of chromatin accessibility. In striking contrast, the epigenetic landscape of ectodermal cells is already established in the early epiblast. Hence, regulatory elements associated with each germ layer are either epigenetically primed or epigenetically remodelled prior to overt cell fate decisions during gastrulation, providing the molecular logic for a hierarchical emergence of the primary germ layers.\n\nHighlightsO_LIFirst map of mouse gastrulation using comprehensive single cell triple-omic analysis.\nC_LIO_LIExit from pluripotency is associated with a global repressive epigenetic landscape, driven by a sharp gain of DNA methylation and a gradual decrease of chromatin accessibility.\nC_LIO_LIDNA methylation and chromatin accessibility changes in enhancers, but not in promoters, are associated with germ layer formation.\nC_LIO_LIMesoderm and endoderm enhancers become open and demethylated upon lineage commitment.\nC_LIO_LIEctoderm enhancers are primed in the early epiblast and protected from the global repressive dynamics, supporting a default model of ectoderm commitment in vivo.\nC_LI

developmental biology↗

bioRxiv2018

Genome-scale oscillations in DNA methylation during exit from pluripotency

Pluripotency is accompanied by the erasure of parental epigenetic memory with naive pluripotent cells exhibiting global DNA hypomethylation both in vitro and in vivo. Exit from pluripotency and priming for differentiation into somatic lineages is associated with genome-wide de novo DNA methylation. We show that during this phase, coexpression of enzymes required for DNA methylation turnover, DNMT3s and TETs, promotes cell-to-cell variability in this epigenetic mark. Using a combination of single-cell sequencing and quantitative biophysical modelling, we show that this variability is associated with coherent, genome-scale, oscillations in DNA methylation with an amplitude dependent on CpG density. Analysis of parallel single-cell transcriptional and epigenetic profiling provides evidence for oscillatory dynamics both in vitro and in vivo. These observations provide fresh insights into the emergence of epigenetic heterogeneity during early embryo development, indicating that dynamic changes in DNA methylation might influence early cell fate decisions.\n\nHighlightsO_LICo-expression of DNMT3s and TETs drive genome-scale oscillations of DNA methylation\nC_LIO_LIOscillation amplitude is greatest at a CpG density characteristic of enhancers\nC_LIO_LICell synchronisation reveals oscillation period and link with primary transcripts\nC_LIO_LIMultiomic single-cell profiling provides evidence for oscillatory dynamics in vivo\nC_LI

genomics↗

bioRxiv2017

Joint Profiling Of Chromatin Accessibility, DNA Methylation And Transcription In Single Cells

Parallel single-cell sequencing protocols represent powerful methods for investigating regulatory relationships, including epigenome-transcriptome interactions. Here, we report a novel single-cell method for parallel chromatin accessibility, DNA methylation and transcriptome profiling. scNMT-seq (single-cell nucleosome, methylation and transcription sequencing) uses a GpC methyltransferase to label open chromatin followed by bisulfite and RNA sequencing. We validate scNMT-seq by applying it to differentiating mouse embryonic stem cells, finding links between all three molecular layers and revealing dynamic coupling between epigenomic layers during differentiation.

genomics↗