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Publications in Health Sciences by NOMIS researchers

The burden and contemporary epidemiology of sepsis in children

NOMIS Researcher(s)

Published in

September 1, 2024

Sepsis is a dysregulated host response to infection that leads to life-threatening organ dysfunction. Half of the 50 million people affected by sepsis globally every year are neonates and children younger than 19 years. This burden on the paediatric population translates into a disproportionate impact on global child health in terms of years of life lost, morbidity, and lost opportunities for children to reach their developmental potential. This Series on paediatric sepsis presents the current state of diagnosis and treatment of sepsis in children, and maps the challenges in alleviating the burden on children, their families, and society. Drawing on diverse experience and multidisciplinary expertise, we offer a roadmap to improving outcomes for children with sepsis. This first paper of the Series is a narrative review of the burden of paediatric sepsis from low-income to high-income settings. Advances towards improved operationalisation of paediatric sepsis across all age groups have facilitated more standardised assessment of the Global Burden of Disease estimates of the impact of sepsis on child health, and these estimates are expected to gain further precision with the roll out of the new Phoenix criteria for sepsis. Sepsis remains one of the leading causes of childhood morbidity and mortality, with immense direct and indirect societal costs. Although substantial regional differences persist in relation to incidence, microbiological epidemiology, and outcomes, these cannot be explained by differences in income level alone. Recent insights into post-discharge sequelae after paediatric sepsis, ranging from late mortality and persistent neurodevelopmental impairment to reduced health-related quality of life, show how common post-sepsis syndrome is in children. Targeting sepsis as a key contributor to poor health outcomes in children is therefore an essential component of efforts to meet the Sustainable Development Goals.

This is the first in a Series of four papers on paediatric sepsis (Paper 4 appears in The Lancet Digital Health). All papers in the Series are available at thelancet.com/series/paediatric-sepsis

Research field(s)
Pediatrics

DOI
10.1016/S2352-4642(24)00140-8

Docking a flexible basket onto the core of the nuclear pore complex

NOMIS Researcher(s)

Published in

August 13, 2024

The nuclear basket attaches to the nucleoplasmic side of the nuclear pore complex (NPC), coupling transcription to mRNA quality control and export. The basket expands the functional repertoire of a subset of NPCs in Saccharomyces cerevisiae by drawing a unique RNA/protein interactome. Yet, how the basket docks onto the NPC core remains unknown. By integrating AlphaFold-based interaction screens, electron microscopy and membrane-templated reconstitution, we uncovered a membrane-anchored tripartite junction between basket and NPC core. The basket subunit Nup60 harbours three adjacent short linear motifs, which connect Mlp1, a parallel homodimer consisting of coiled-coil segments interrupted by flexible hinges, and the Nup85 subunit of the Y-complex. We reconstituted the Y-complex•Nup60•Mlp1 assembly on a synthetic membrane and validated the protein interfaces in vivo. Here we explain how a short linear motif-based protein junction can substantially reshape NPC structure and function, advancing our understanding of compositional and conformational NPC heterogeneity.

Research field(s)
Biochemistry & Molecular Biology, Biology

DOI
10.1038/s41556-024-01484-x

Removal of TREX1 activity enhances CRISPR–Cas9-mediated homologous recombination

NOMIS Researcher(s)

Published in

August 12, 2024

CRISPR–Cas9-mediated homology-directed repair (HDR) can introduce desired mutations at targeted genomic sites, but achieving high efficiencies is a major hurdle in many cell types, including cells deficient in DNA repair activity. In this study, we used genome-wide screening in Fanconi anemia patient lymphoblastic cell lines to uncover suppressors of CRISPR–Cas9-mediated HDR. We found that a single exonuclease, TREX1, reduces HDR efficiency when the repair template is a single-stranded or linearized double-stranded DNA. TREX1 expression serves as a biomarker for CRISPR–Cas9-mediated HDR in that the high TREX1 expression present in many different cell types (such as U2OS, Jurkat, MDA-MB-231 and primary T cells as well as hematopoietic stem and progenitor cells) predicts poor HDR. Here we demonstrate rescue of HDR efficiency (ranging from two-fold to eight-fold improvement) either by TREX1 knockout or by the use of single-stranded DNA templates chemically protected from TREX1 activity. Our data explain why some cell types are easier to edit than others and indicate routes for increasing CRISPR–Cas9-mediated HDR in TREX1-expressing contexts.

Research field(s)
Biochemistry & Molecular Biology, Genetics & Heredity

DOI
10.1038/s41587-024-02356-3

CCAR1 promotes DNA repair via alternative splicing

NOMIS Researcher(s)

Published in

July 25, 2024

DNA repair is directly performed by hundreds of core factors and indirectly regulated by thousands of others. We massively expanded a CRISPR inhibition and Cas9-editing screening system to discover factors indirectly modulating homology-directed repair (HDR) in the context of ∼18,000 individual gene knockdowns. We focused on CCAR1, a poorly understood gene that we found the depletion of reduced both HDR and interstrand crosslink repair, phenocopying the loss of the Fanconi anemia pathway. CCAR1 loss abrogated FANCA protein without substantial reduction in the level of its mRNA or that of other FA genes. We instead found that CCAR1 prevents inclusion of a poison exon in FANCA. Transcriptomic analysis revealed that the CCAR1 splicing modulatory activity is not limited to FANCA, and it instead regulates widespread changes in alternative splicing that would damage coding sequences in mouse and human cells. CCAR1 therefore has an unanticipated function as a splicing fidelity factor.

Research field(s)
Genetics & Heredity, Biomedical Research

DOI
10.1016/j.molcel.2024.06.011

Deep 3D histology powered by tissue clearing, omics and AI

NOMIS Researcher(s)

Published in

July 12, 2024

To comprehensively understand tissue and organism physiology and pathophysiology, it is essential to create complete three-dimensional (3D) cellular maps. These maps require structural data, such as the 3D configuration and positioning of tissues and cells, and molecular data on the constitution of each cell, spanning from the DNA sequence to protein expression. While single-cell transcriptomics is illuminating the cellular and molecular diversity across species and tissues, the 3D spatial context of these molecular data is often overlooked. Here, I discuss emerging 3D tissue histology techniques that add the missing third spatial dimension to biomedical research. Through innovations in tissue-clearing chemistry, labeling and volumetric imaging that enhance 3D reconstructions and their synergy with molecular techniques, these technologies will provide detailed blueprints of entire organs or organisms at the cellular level. Machine learning, especially deep learning, will be essential for extracting meaningful insights from the vast data. Further development of integrated structural, molecular and computational methods will unlock the full potential of next-generation 3D histology.

Research field(s)
Biochemistry & Molecular Biology, Chemistry

DOI
10.1038/s41592-024-02327-1

Single cell transcriptomes and multiscale networks from persons with and without Alzheimer’s disease

NOMIS Researcher(s)

Published in

July 10, 2024

The emergence of single nucleus RNA sequencing (snRNA-seq) offers to revolutionize the study of Alzheimer’s disease (AD). Integration with complementary multiomics data such as genetics, proteomics and clinical data provides powerful opportunities to link cell subpopulations and molecular networks with a broader disease-relevant context. We report snRNA-seq profiles from superior frontal gyrus samples from 101 well characterized subjects from the Banner Brain and Body Donation Program in combination with whole genome sequences. We report findings that link common AD risk variants with CR1 expression in oligodendrocytes as well as alterations in hematological parameters. We observed an AD-associated CD83(+) microglial subtype with unique molecular networks and which is associated with immunoglobulin IgG4 production in the transverse colon. Our major observations were replicated in two additional, independent snRNA-seq data sets. These findings illustrate the power of multi-tissue molecular profiling to contextualize snRNA-seq brain transcriptomics and reveal disease biology.

Research field(s)
Genetics & Heredity, Biology

DOI
10.1038/s41467-024-49790-0

FilamentID reveals the composition and function of metabolic enzyme polymers during gametogenesis

NOMIS Researcher(s)

Published in

June 20, 2024

Gamete formation and subsequent offspring development often involve extended phases of suspended cellular development or even dormancy. How cells adapt to recover and resume growth remains poorly understood. Here, we visualized budding yeast cells undergoing meiosis by cryo-electron tomography (cryoET) and discovered elaborate filamentous assemblies decorating the nucleus, cytoplasm, and mitochondria. To determine filament composition, we developed a “filament identification” (FilamentID) workflow that combines multiscale cryoET/cryo-electron microscopy (cryoEM) analyses of partially lysed cells or organelles. FilamentID identified the mitochondrial filaments as being composed of the conserved aldehyde dehydrogenase Ald4ALDH2 and the nucleoplasmic/cytoplasmic filaments as consisting of acetyl-coenzyme A (CoA) synthetase Acs1ACSS2. Structural characterization further revealed the mechanism underlying polymerization and enabled us to genetically perturb filament formation. Acs1 polymerization facilitates the recovery of chronologically aged spores and, more generally, the cell cycle re-entry of starved cells. FilamentID is broadly applicable to characterize filaments of unknown identity in diverse cellular contexts.

Research field(s)
Microbiology, Biology

DOI
10.1016/j.cell.2024.04.026

APOE3 Christchurch Heterozygosity and Autosomal Dominant Alzheimer’s Disease

NOMIS Researcher(s)

Published in

June 19, 2024

Variants in APOE and PSEN1 (encoding apolipoprotein E and presenilin 1, respectively) alter the risk of Alzheimer’s disease. We previously reported a delay of cognitive impairment in a person with autosomal dominant Alzheimer’s disease caused by the PSEN1E280A variant who also had two copies of the apolipoprotein E3 Christchurch variant (APOE3Ch). Heterozygosity for the APOE3Ch variant may influence the age at which the onset of cognitive impairment occurs. We assessed this hypothesis in a population in which the PSEN1E280A variant is prevalent.

Research field(s)
Health Sciences, Genetics & Heredity, Clinical Medicine

DOI
10.1056/NEJMoa2308583

Geometry-driven migration efficiency of autonomous epithelial cell clusters

NOMIS Researcher(s)

Published in

June 19, 2024

The directed migration of epithelial cell collectives through coordinated movements plays a crucial role in various physiological processes and is increasingly understood at the level of large confluent monolayers. However, numerous processes rely on the migration of small groups of polarized epithelial clusters in complex environments, and their responses to external geometries remain poorly understood. To address this, we cultivate primary epithelial keratocyte tissues on adhesive microstripes to create autonomous epithelial clusters with well-defined geometries. We show that their migration efficiency is strongly influenced by the contact geometry and the orientation of cell–cell contacts with respect to the direction of migration. A combination of velocity and polarity alignment with contact regulation of locomotion in an active matter model captures quantitatively the experimental data. Furthermore, we predict that this combination of rules enables efficient navigation in complex geometries, which we confirm experimentally. Altogether, our findings provide a conceptual framework for extracting the interaction rules of active systems from their interaction with physical boundaries, as well as design principles for collective navigation in complex microenvironments.

Research field(s)
Biophysics

DOI
10.1038/s41567-024-02532-x

Evolution of diapause in the African turquoise killifish by remodeling the ancient gene regulatory landscape

NOMIS Researcher(s)

Published in

May 28, 2024

Suspended animation states allow organisms to survive extreme environments. The African turquoise killifish has evolved diapause as a form of suspended development to survive a complete drought. However, the mechanisms underlying the evolution of extreme survival states are unknown. To understand diapause evolution, we performed integrative multi-omics (gene expression, chromatin accessibility, and lipidomics) in the embryos of multiple killifish species. We find that diapause evolved by a recent remodeling of regulatory elements at very ancient gene duplicates (paralogs) present in all vertebrates. CRISPR-Cas9-based perturbations identify the transcription factors REST/NRSF and FOXOs as critical for the diapause gene expression program, including genes involved in lipid metabolism. Indeed, diapause shows a distinct lipid profile, with an increase in triglycerides with very-long-chain fatty acids. Our work suggests a mechanism for the evolution of complex adaptations and offers strategies to promote long-term survival by activating suspended animation programs in other species.

Research field(s)
Molecular Biology, Biochemistry & Molecular Biology, Developmental Biology, Genetics & Heredity

DOI
10.1016/j.cell.2024.04.048

Lifelong persistence of nuclear RNAs in the mouse brain

NOMIS Researcher(s)

Published in

April 4, 2024

Genomic DNA that resides in the nuclei of mammalian neurons can be as old as the organism itself. The life span of nuclear RNAs, which are critical for proper chromatin architecture and transcription regulation, has not been determined in adult tissues. In this work, we identified and characterized nuclear RNAs that do not turn over for at least 2 years in a subset of postnatally born cells in the mouse brain. These long-lived RNAs were stably retained in nuclei in a neural cell type–specific manner and were required for the maintenance of heterochromatin. Thus, the life span of neural cells may depend on both the molecular longevity of DNA for the storage of genetic information and also the extreme stability of RNA for the functional organization of chromatin.

Research field(s)
Genetics & Heredity, Biology

DOI
10.1126/science.adf3481

The Economics of Child Mental Health: Introducing the Causes and Consequences of Child Mental Health Special Issue

NOMIS Researcher(s)

Published in

April 1, 2024

This special issue of the Journal of Human Resources showcases an emerging literature on the economics of child mental health. Until recently, the severe stigma associated with mental health issues meant that few people felt comfortable talking about them or realized how very prevalent they are (Bharadwaj, Pai, and Suziedelyte 2017). Arguably, this changed with the COVID-19 pandemic, which precipitated widespread discussions of a child and youth mental health crisis (United States Public Health Service, Office of the Surgeon General 2021).

Research field(s)
Economics, Psychology & Cognitive Sciences

DOI
10.3368/jhr.2023SI-intro-child-mental-health

G-quadruplexes control hepatitis B virus replication by promoting cccDNA transcription and phase separation in hepatocytes

NOMIS Researcher(s)

Published in

March 21, 2024

Phase separation regulates fundamental processes in gene expression and is mediated by the local concentration of proteins and nucleic acids, as well as nucleic acid secondary structures such as G-quadruplexes (G4s). These structures play fundamental roles in both host gene expression and in viral replication due to their peculiar localisation in regulatory sequences. Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is an episomal minichromosome whose persistence is at the basis of chronic infection. Identifying the mechanisms controlling its transcriptional activity is indispensable to develop new therapeutic strategies against chronic hepatitis B. The aim of this study was to determine whether G4s are formed in cccDNA and regulate viral replication. Combining biochemistry and functional studies, we demonstrate that cccDNA indeed contains ten G4s structures. Furthermore, mutations disrupting two G4s located in the enhancer I HBV regulatory region altered cccDNA transcription and viral replication. Finally, we showed for the first time that cccDNA undergoes phase separation in a G4-dependent manner to promote its transcription in infected hepatocytes. Altogether, our data give new insight in the transcriptional regulation of the HBV minichromosome that might pave the way for the identification of novel targets to destabilize or silence cccDNA.

Research field(s)
Biochemistry & Molecular Biology, Biophysics, Virology

DOI
10.1093/nar/gkad1200

A common cis-regulatory variant impacts normal-range and disease-associated human facial shape through regulation of PKDCC during chondrogenesis

NOMIS Researcher(s)

Published in

March 14, 2024

Genome-wide association studies (GWAS) identified thousands of genetic variants linked to phenotypic traits and disease risk. However, mechanistic understanding of how GWAS variants influence complex morphological traits and can, in certain cases, simultaneously confer normal-range phenotypic variation and disease predisposition, is still largely lacking. Here, we focus on rs6740960, a single nucleotide polymorphism (SNP) at the 2p21 locus, which in GWAS studies has been associated both with normal-range variation in jaw shape and with an increased risk of non-syndromic orofacial clefting. Using in vitro derived embryonic cell types relevant for human facial morphogenesis, we show that this SNP resides in an enhancer that regulates chondrocytic expression of PKDCC – a gene encoding a tyrosine kinase involved in chondrogenesis and skeletal development. In agreement, we demonstrate that the rs6740960 SNP is sufficient to confer chondrocyte-specific differences in PKDCC expression. By deploying dense landmark morphometric analysis of skull elements in mice, we show that changes in Pkdcc dosage are associated with quantitative changes in the maxilla, mandible, and palatine bone shape that are concordant with the facial phenotypes and disease predisposition seen in humans. We further demonstrate that the frequency of the rs6740960 variant strongly deviated among different human populations, and that the activity of its cognate enhancer diverged in hominids. Our study provides a mechanistic explanation of how a common SNP can mediate normal-range and disease-associated morphological variation, with implications for the evolution of human facial features.

Research field(s)
Developmental Biology, Genetics & Heredity, Evolutionary Biology

DOI
10.7554/eLife.82564

Uncovering the potential of evaluative conditioning in shaping attitudes toward sustainable product packaging

NOMIS Researcher(s)

Published in

March 14, 2024

Introduction: The necessity to promote pro-environmental behavior change in individuals and society is increasingly evident. This study aimed to investigate the effect of evaluative conditioning on consumers’ perception of product packaging.

Methods: We first produced two stimulus sets: one including images of supermarket products with different packaging and the other containing affective images of healthy nature (positive) and climate change impact (negative). These images were then paired in an evaluative conditioning experiment where respondents were informed about the impact of product packaging.

Results: We found an effect of conditioning depending on the initial sustainability perception that participants had toward product packaging. Pairing products for which participants were uncertain about their sustainability with negative or positive affective images had a significant effect on the sustainable associations of the consumers in a negative or positive direction, respectively. However, the impact of conditioning on products that clearly had (un)sustainable packaging was not that strong.

Discussion: These results provide new tools and evidence to further investigate the power of evaluative conditioning in pro-environmental attitude and behavior change.

Research field(s)
Psychology & Cognitive Sciences

DOI
10.3389/fpsyg.2024.1284422

Massively parallel disruption of enhancers active in human neural stem cells

NOMIS Researcher(s)

Published in

February 27, 2024

Changes in gene regulation have been linked to the expansion of the human cerebral cortex and to neurodevelopmental disorders, potentially by altering neural progenitor proliferation. However, the effects of genetic variation within regulatory elements on neural progenitors remain obscure. We use sgRNA-Cas9 screens in human neural stem cells (hNSCs) to disrupt 10,674 genes and 26,385 conserved regions in 2,227 enhancers active in the developing human cortex and determine effects on proliferation. Genes with proliferation phenotypes are associated with neurodevelopmental disorders and show biased expression in specific fetal human brain neural progenitor populations. Although enhancer disruptions overall have weaker effects than gene disruptions, we identify enhancer disruptions that severely alter hNSC self-renewal. Disruptions in human accelerated regions, implicated in human brain evolution, also alter proliferation. Integrating proliferation phenotypes with chromatin interactions reveals regulatory relationships between enhancers and their target genes contributing to neurogenesis and potentially to human cortical evolution.

Research field(s)
Developmental Biology, Genetics & Heredity

DOI
10.1016/j.celrep.2024.113693

Publish or perish: Simulating the impact of publication policies on science

NOMIS Researcher(s)

Published in

February 26, 2024

Science can be viewed as a collective, epistemic endeavor. However, a variety of factors- such as the publish-or-perish culture, institutional incentives, and publishers who favor novel and positive findings- may challenge the ability of science to accurately aggregate information about the world. Evidence of the shortcomings in the current structure of science can be seen in the replication crisis that faces psychology and other disciplines. We analyze scientific publishing through the lens of cultural evolution, framing the scientific process as a multi-generational interplay between scientists and publishers in a multi-armed bandit setting. We examine the dynamics of this model through simulations, exploring the effect that different publication policies have on the accuracy of the published scientific record. Our findings highlight the need for replications and caution against behaviors that prioritize factors uncorrelated with result accuracy.

Research field(s)
Psychology & Cognitive Sciences, Psychology & Cognitive Sciences

Targeting nuclear receptor corepressors for reversible male contraception

NOMIS Researcher(s)

Published in

February 20, 2024

Despite numerous female contraceptive options, nearly half of all pregnancies are unintended. Family planning choices for men are currently limited to unreliable condoms and invasive vasectomies with questionable reversibility. Here, we report the development of an oral contraceptive approach based on transcriptional disruption of cyclical gene expression patterns during spermatogenesis. Spermatogenesis involves a continuous series of self-renewal and differentiation programs of spermatogonial stem cells (SSCs) that is regulated by retinoic acid (RA)–dependent activation of receptors (RARs), which control target gene expression through association with corepressor proteins. We have found that the interaction between RAR and the corepressor silencing mediator of retinoid and thyroid hormone receptors (SMRT) is essential for spermatogenesis. In a genetically engineered mouse model that negates SMRT-RAR binding (SMRTmRID mice), the synchronized, cyclic expression of RAR-dependent genes along the seminiferous tubules is disrupted. Notably, the presence of an RA-resistant SSC population that survives RAR de-repression suggests that the infertility attributed to the loss of SMRT-mediated repression is reversible. Supporting this notion, we show that inhibiting the action of the SMRT complex with chronic, low-dose oral administration of a histone deacetylase inhibitor reversibly blocks spermatogenesis and fertility without affecting libido. This demonstration validates pharmacologic targeting of the SMRT repressor complex for non-hormonal male contraception.

Research field(s)
Clinical Medicine

DOI
10.1073/pnas.2320129121

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