Project description:The ovary is the first organ to age in the human body, affecting both fertility and overall health in women1-8. However, the biological mechanisms underlying human ovarian ageing remain poorly understood. Here we performed single-cell multi-omics analysis of young and reproductively aged human ovaries to understand the molecular and cellular basis of ovarian ageing in humans. Our analysis reveals coordinated changes in transcriptomic output and chromatin accessibility across cell types during ageing, including elevated mTOR and MAPK signaling, decreased activity of the oxidative phosphorylation and DNA damage repair pathways, and an increased signature of cellular senescence. By constructing cell type-specific regulatory networks, we uncover enhanced activity of the transcription factor CEBPD across cell types in the aged ovary, with a corresponding significant loss of activity of most cell identity-associated transcription factors. Moreover, by performing integrative analyses of our single-nuclei multi-omics data with common genetic variants associated with age at natural menopause (ANM) from genome-wide association studies, we demonstrate a global impact of functional variants on changes in gene regulatory networks across ovarian cell types. Finally, we nominate about a dozen of functional non-coding variants, their target genes and cell types and regulatory mechanisms that underlie genetic association with ANM. This work provides a comprehensive multimodal landscape of human ovarian ageing and mechanistic insights into inherited variation of ANM.
Project description:Reproductive longevity is critical for fertility and impacts healthy ageing in women, yet insights into the underlying biological mechanisms and treatments to preserve it are limited. Here, we identify 290 genetic determinants of ovarian ageing, assessed using normal variation in age at natural menopause (ANM) in ~200,000 women of European ancestry. These common alleles influence clinical extremes of ANM; women in the top 1% of genetic susceptibility have an equivalent risk of premature ovarian insufficiency to those carrying monogenic FMR1 premutations. Identified loci implicate a broad range of DNA damage response (DDR) processes and include loss-of-function variants in key DDR genes. Integration with experimental models demonstrates that these DDR processes act across the life-course to shape the ovarian reserve and its rate of depletion. Furthermore, we demonstrate that experimental manipulation of DDR pathways highlighted by human genetics increase fertility and extend reproductive life in mice. Causal inference analyses using the identified genetic variants indicates that extending reproductive life in women improves bone health and reduces risk of type 2 diabetes, but increases risks of hormone-sensitive cancers. These findings provide insight into the mechanisms governing ovarian ageing, when they act across the life-course, and how they might be targeted by therapeutic approaches to extend fertility and prevent disease.
Project description:To study the evolutionary dynamics of regulatory DNA, we mapped >1.3 million deoxyribonuclease I–hypersensitive sites (DHSs) in 45 mouse cell and tissue types, and systematically compared these with human DHS maps from orthologous compartments. We found that the mouse and human genomes have undergone extensive cis-regulatory rewiring that combines branch-specific evolutionary innovation and loss with widespread repurposing of conserved DHSs to alternative cell fates, and that this process is mediated by turnover of transcription factor (TF) recognition elements. Despite pervasive evolutionary remodeling of the location and content of individual cis-regulatory regions, within orthologous mouse and human cell types the global fraction of regulatory DNA bases encoding recognition sites for each TF has been strictly conserved. Our findings provide new insights into the evolutionary forces shaping mammalian regulatory DNA landscapes.
Project description:The control of cell identity is orchestrated by transcriptional and chromatin regulators in the context of specific chromosome structures. With the recent isolation of human naive embryonic stem cells (ESCs) representative of the ground state of pluripotency, it is possible to deduce this regulatory landscape in one of the earliest stages of human development. Here we generate cohesin ChIA-PET chromatin interaction data in naive and primed human ESCs and use it to reconstruct and compare the 3D regulatory landscapes of these two stages of early human development. The results reveal shared and stage-specific regulatory landscapes of topological domains and their subdomains, which consist of CTCF-CTCF/cohesin loops and enhancer-promoter/cohesin loops. The enhancer-promoter loop data reveal that genes with key roles in pluripotency are nearly always regulated by one or more super-enhancers, and show that these genes tend to occur in insulated neighborhoods. Our results reveal the key features of the 3D regulatory landscape of early human cells that form the foundation for embryonic development. ChIA_PET data against SMC1 from naive and primed human embroynic stem cells.
Project description:The control of cell identity is orchestrated by transcriptional and chromatin regulators in the context of specific chromosome structures. With the recent isolation of human naive embryonic stem cells (ESCs) representative of the ground state of pluripotency, it is possible to deduce this regulatory landscape in one of the earliest stages of human development. Here we generate cohesin ChIA-PET chromatin interaction data in naive and primed human ESCs and use it to reconstruct and compare the 3D regulatory landscapes of these two stages of early human development. The results reveal shared and stage-specific regulatory landscapes of topological domains and their subdomains, which consist of CTCF-CTCF/cohesin loops and enhancer-promoter/cohesin loops. The enhancer-promoter loop data reveal that genes with key roles in pluripotency are nearly always regulated by one or more super-enhancers, and show that these genes tend to occur in insulated neighborhoods. Our results reveal the key features of the 3D regulatory landscape of early human cells that form the foundation for embryonic development. ChIP-seq data from naive and primed human embroynic stem cells.
Project description:The control of cell identity is orchestrated by transcriptional and chromatin regulators in the context of specific chromosome structures. With the recent isolation of human naive embryonic stem cells (ESCs) representative of the ground state of pluripotency, it is possible to deduce this regulatory landscape in one of the earliest stages of human development. Here we generate cohesin ChIA-PET chromatin interaction data in naive and primed human ESCs and use it to reconstruct and compare the 3D regulatory landscapes of these two stages of early human development. The results reveal shared and stage-specific regulatory landscapes of topological domains and their subdomains, which consist of CTCF-CTCF/cohesin loops and enhancer-promoter/cohesin loops. The enhancer-promoter loop data reveal that genes with key roles in pluripotency are nearly always regulated by one or more super-enhancers, and show that these genes tend to occur in insulated neighborhoods. Our results reveal the key features of the 3D regulatory landscape of early human cells that form the foundation for embryonic development. Polyadenylated RNA-seq from naive and primed human embroynic stem cells.
Project description:Understanding the regulatory landscape of the human genome is a central question in complex trait genetics. Most single nucleotide polymorphisms (SNPs) associated with cancer risk lie in non protein-coding regions, implicating regulatory DNA elements as functional targets of susceptibility variants. Here, we describe genome-wide annotation of regions of open chromatin and histone modification in fallopian tube and ovarian surface epithelial cells (FTSECs, OSECs), the debated cellular origins of high-grade serous ovarian cancers (HGSOCs), and in endometriosis epithelial cells (EECs), the likely precursor of clear cell ovarian carcinomas (CCOCs). The regulatory architecture of these cell types was compared to normal human mammary epithelial cells (HMECs) and LNCaP prostate cancer cells. We observed similar positional patterns of global enhancer signatures across the three different ovarian cancer precursor cell types, and evidence of tissues specific regulatory signatures to non-gynecological cell types. We found significant enrichment for risk-associated SNPs intersecting regulatory biofeatures at 17 known HGSOC susceptibility loci in FTSECs (P=3.8x10-30) OSECs (P=2.4x10-23) and HMECs (P=6.7x10-15) but not for EECs (P=0.45) or LNCaP cells (P=0.88). Hierarchical clustering of risk SNPs conditioned on the six different cell types indicates FTSECs and OSECs are highly related (96% of samples using multi-scale bootstrapping) indicating both cell types may be precursors of HGSOC. These data represent the first description of regulatory catalogues of normal precursor cells for different ovarian cancer subtypes, and provide unique insights into the tissue specific regulatory variation with respect to the likely functional targets germline genetic susceptibility variants for ovarian cancer FAIRE-Seq and ChIP-Seq of 2 different histone modifications in 5 cell types.
Project description:Transcriptional profiling of human control and Néstor-Guillermo Progeria Syndrome (NGPS) fibroblasts and induced pluripotent stem cells (iPSCs). Somatic cell reprogramming involves rejuvenation of adult cells and relies on the ability to erase age-associated molecular marks. Accordingly, reprogramming efficiency declines with ageing, and age-associated features such as genetic instability, cell senescence or telomere shortening negatively affect this process. However, the regulatory mechanisms that constitute age-associated barriers for cell reprogramming remain largely unknown. Here, by using cells from patients with premature ageing, we demonstrate that NF-κB activation is a critical barrier for the generation of induced pluripotent stem cells (iPSCs) in ageing. We show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs generation of iPSCs by eliciting reprogramming repressors DOT1L and YY1, reinforcing cell senescence signals and down-regulating pluripotency genes. We also show that genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) and Hutchinson-Gilford Progeria Syndrome (HGPS) patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo ameliorates the accelerated ageing phenotype and extends lifespan in a progeroid animal model. Collectively, our results provide evidence for a novel role of NF-κB in the control of cell fate transitions and reinforce the interest of studying age-associated molecular impairments to implement cell reprogramming methodologies, and to identify new targets of rejuvenation strategies. Control and NGPS fibroblasts were reprogrammed. RNA was extracted and transcriptional profiling was obtained with GeneChip Human Exon 1.0 ST Arrays.
Project description:Although it is well established that the ovarian reserve diminishes with increasing age, and that a woman’s age is correlated to lower oocyte quality, the interplay of a diminished reserve and age on oocyte developmental competence is not clear. After maturation, oocytes are mostly transcriptionally quiescent, and developmental competence prior to embryonic genome activation (EGA) relies on maternal RNA and proteins. Age and ovarian reserve both affects oocyte developmental competence, however, their relative importance in this process are difficult to tease out, as ageing is accompanied by a decrease in ovarian reserve. Oocytes store large quantities of RNA, including several noncoding transcripts (ncRNAs) involved in early development transcription and translation modulation. Despite the central role of ncRNAs in maternal to zygote transition, no characterization of the ncRNA transcriptome in human oocytes has been reported. This study aims at identifying how the human oocyte transcriptome changes across reproductive ages and ovarian reserve levels, with the goal of identifying candidate markers of developmental competence, and to assess the independent relevance of age and ovarian reserve in the changes of the transcriptome