Insight
is our reward

Publications in Health Sciences by NOMIS researchers

INTRODUCTION: While there may be microbial contributions to Alzheimer’s disease (AD), findings have been inconclusive. We recently reported an AD-associated CD83(+)microglia subtype associated with increased immunoglobulinG4(IgG4) in the transverse colon (TC).

METHODS: We used immunohistochemistry (IHC), IgG4 repertoire profiling, and brain organoid experiments to explore this association.

RESULTS: CD83(+) microglia in the superior frontal gyrus (SFG) are associated with elevated IgG4 and human cytomegalovirus (HCMV) in the TC, anti-HCMV IgG4 in cerebrospinal fluid, and both HCMV and IgG4 in the SFG and vagal nerve. This association was replicated in an independent AD cohort. HCMV-infected cerebral organoids showed accelerated AD pathophysiological features (Aβ42 and pTau-212) and neuronal death.

DISCUSSION: Findings indicate complex, cross-tissue interactions between HCMV and the adaptive immune response associated with CD83(+)microglia in persons with AD. This may indicate an opportunity for antiviral therapy in persons with AD and biomarker evidence of HCMV, IgG4, or CD83(+)microglia.

Research field(s)
Genetics & Heredity, Neurology & Neurosurgery, Biology

NOMIS Researcher(s)

Published in

November 15, 2024

Microbial communities are shaped by cell-cell interactions. Although archaea are often found in associations with other microorganisms, the mechanisms structuring these communities are poorly understood. Here, we report on the structure and function of haloarchaeal contractile injection systems (CISs). Using a combination of functional assays and time-lapse imaging, we show that Halogeometricum borinquense exhibits antagonism toward Haloferax volcanii by inducing cell lysis and inhibiting proliferation. This antagonism is contact-dependent and requires a functional CIS, which is encoded by a gene cluster that is associated with toxin-immunity pairs. Cryo–focused ion beam milling and imaging by cryo–electron tomography revealed that these CISs are bound to the cytoplasmic membrane, resembling the bacterial type six secretion systems (T6SSs). We show that related T6SS gene clusters are conserved and expressed in other haloarchaeal strains, which exhibit antagonistic behavior. Our data provide a mechanistic framework for understanding how archaea may shape microbial communities and affect the food webs they inhabit.

Research field(s)
Microbiology

NOMIS Researcher(s)

October 31, 2024

There is growing concern about the impact of declining political trust on democracies. Psychological research has introduced the concept of epistemic (mis)trust as a stable disposition acquired through development, which may influence our sociopolitical engagement. Given trust’s prominence in current politics, we examined the relationship between epistemic trust and people’s choices of (un)trustworthy political leaders. In two representative samples in the UK and US (N = 1096), we tested whether epistemic trust predicts political leader choices through three political dimensions: dogmatism, political trust, and ideology. Although epistemic trust did not directly predict choices of political leaders, it predicted dogmatism and political ideology, which in turn predicted choices of political leaders. A network analysis revealed that epistemic trust and political dimensions only interact through their common connection with dogmatism. These findings suggest that cognitive and affective development may underlie an individual’s political ideology and associated beliefs.

Research field(s)
Political Science & Public Administration, Psychology & Cognitive Sciences

NOMIS Researcher(s)

Published in

October 18, 2024

Ixotrophy is a contact-dependent predatory strategy of filamentous bacteria in aquatic environments for which the molecular mechanism remains unknown. We show that predator-prey contact can be established by gliding motility or extracellular assemblages we call “grappling hooks.” Cryo–electron microscopy identified the grappling hooks as heptamers of a type IX secretion system substrate. After close predator-prey contact is established, cryo–electron tomography and functional assays showed that puncturing by a type VI secretion system mediated killing. Single-cell analyses with stable isotope–labeled prey revealed that prey components are taken up by the attacker. Depending on nutrient availability, insertion sequence elements toggle the activity of ixotrophy. A marine metagenomic time series shows coupled dynamics of ixotrophic bacteria and prey. We found that the mechanism of ixotrophy involves multiple cellular machineries, is conserved, and may shape microbial populations in the environment.

Research field(s)
Microbiology, Microbiology

The Food Socioscope project aims to understand the systemic transition towards greater sustainability in the food sector. It has two main components: a participatory data collection with a community directory, and a comprehensive research effort. The first component builds a community of practitioners from various sectors (e.g., companies, NGOs, public authorities) who manage initiatives promoting food sustainability. This community, facilitated by the Food Socioscope Netboard, fosters knowledge exchange by publishing key characteristics of these initiatives online. The second component collects qualitative data through in-depth field interviews, site visits and videos with practitioners, following a rigorously tested protocol. This in-depth data, capturing activities from micro to macro levels, feeds into the research project to improve understanding of systemic change in food sustainability. The research spans the entire food supply chain and examines the supporting infrastructure and organizational setups. By analysing 600 initiatives, worldwide, within their broader contexts, the project aims to identify mechanisms of transition, including barriers and success factors. To collect, process and analyse its vast amount of qualitative data, in multiple languages, the project uses novel protocols, AI models, network analysis, and other quantitative methods. This paper presents the project and preliminary findings regarding regulation, the asymmetry of social contracts and the practitioners’ motivations.

Research field(s)
Sociology, Social Psychology

NOMIS Researcher(s)

Published in

October 14, 2024

Human-specific (HS) genes have been implicated in brain evolution, but their impact on human neuron development and diseases remains unclear. Here, we study SRGAP2B/C, two HS gene duplications of the ancestral synaptic gene SRGAP2A, in human cortical pyramidal neurons (CPNs) xenotransplanted in the mouse cortex. Downregulation of SRGAP2B/C in human CPNs led to strongly accelerated synaptic development, indicating their requirement for the neoteny that distinguishes human synaptogenesis. SRGAP2B/C genes promoted neoteny by reducing the synaptic levels of SRGAP2A,thereby increasing the postsynaptic accumulation of the SYNGAP1 protein, encoded by a major intellectual disability/autism spectrum disorder (ID/ASD) gene. Combinatorial loss-of-function experiments in vivo revealed that the tempo of synaptogenesis is set by the reciprocal antagonism between SRGAP2A and SYNGAP1, which in human CPNs is tipped toward neoteny by SRGAP2B/C. Thus, HS genes can modify the phenotypic expression of genetic mutations leading to ID/ASD through the regulation of human synaptic neoteny.

Research field(s)
Genetics & Heredity

NOMIS Researcher(s)

October 1, 2024

Animal speciation often involves novel behavioral features that rely on nervous system evolution. Human-specific brain features have been proposed to underlie specialized cognitive functions and to be linked, at least in part, to the evolution of synapses, neurons, and circuits of the cerebral cortex. Here, we review recent results showing that, while the human cortex is composed of a repertoire of cells that appears to be largely similar to the one found in other mammals, human cortical neurons do display specialized features at many levels, from gene expression to intrinsic physiological properties. The molecular mechanisms underlying human species-specific neuronal features remain largely unknown but implicate hominid-specific gene duplicates that encode novel molecular modifiers of neuronal function. The identification of human-specific genetic modifiers of neuronal function brings novel insights on brain evolution and function and, could also provide new insights on human species-specific vulnerabilities to brain disorders.

Research field(s)
Genetics & Heredity, Evolutionary Biology

NOMIS Researcher(s)

Published in

September 1, 2024
The digitisation of health care is offering the promise of transforming the management of paediatric sepsis, which is a major source of morbidity and mortality in children worldwide. Digital technology is already making an impact in paediatric sepsis, but is almost exclusively benefiting patients in high-resource health-care settings. However, digital tools can be highly scalable and cost-effective, and—with the right planning—have the potential to reduce global health disparities. Novel digital solutions, from wearable devices and mobile apps, to electronic health record-embedded decision support tools, have an unprecedented opportunity to transform paediatric sepsis research and care. In this Series paper, we describe the current state of digital solutions in paediatric sepsis around the world, the advances in digital technology that are enabling the development of novel applications, and the potential effect of advances in artificial intelligence in paediatric sepsis research and clinical care.

Research field(s)
Pediatrics

NOMIS Researcher(s)

Published in

September 1, 2024

Sepsis is a major contributor to poor child health outcomes around the world. The high morbidity, mortality, and societal cost associated with paediatric sepsis render it a global health priority, as summarised in Paper 1 of this Series. Sepsis is characterised by a dysregulated host response to infection that manifests as organ failure, and children are uniquely susceptible to sepsis, as discussed in Paper 2. The focus of this third Series paper is quality improvement in paediatric sepsis. The 2017 WHO resolution on sepsis outlined key aims to reduce the burden of sepsis. As of 2024, only a small number of countries have implemented systematic, paediatric-focused quality improvement programmes to raise sepsis awareness, enhance recognition of sepsis, promote timely treatment, and provide long-term support for paediatric sepsis survivors. We examine programme successes and systematic barriers to quality improvement targeting paediatric sepsis. We highlight the need for programme design to consider the entire patient journey, starting with prevention, caregiver awareness, recognition at home, education of the health-care workforce, development of health-care systems, and establishment of long-term family and survivor support extending beyond the intensive care unit. Building on lessons learnt from existing quality improvement programmes, we outline implementation strategies and measures to enable benchmarking. Ultimately, quality improvement on a global scale can only be accelerated through a global learning platform focusing on paediatric sepsis.

This is the third 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

NOMIS Researcher(s)

Published in

September 1, 2024

Sepsis disproportionally affects children across all health-care settings and is one of the leading causes of morbidity and mortality in neonatal and paediatric age groups. As shown in the first paper in this Series, the age-specific incidence of sepsis is highest during the first years of life, before approaching adult incidence rates during adolescence. In the second paper in this Series, we focus on the unique susceptibility of paediatric patients to sepsis and how the underlying dysregulated host response relates to developmental aspects of children’s immune system, genetic, perinatal, and environmental factors, and comorbidities and socioeconomic determinants of health, which often differ between children and adults. State-of-the-art clinical management of paediatric sepsis is organised around three treatment pillars—diagnosis, early resuscitation, and titration of advanced care—and we examine available treatment guidelines and the limitations of their supporting evidence. Serious evidence gaps remain in key areas of paediatric sepsis care, especially surrounding recognition, common interventions, and survivor support, and to this end we offer a research roadmap for the next decade that could accelerate targeted diagnostics and personalised use of immunomodulation. However, improving outcomes for children with sepsis relies fundamentally on systematic quality improvement in both recognition and treatment, which is the theme of the third paper in this Series. Digital health, as shown in the fourth and final paper of this Series, holds promising potential in breaking down the barriers that hinder progress in paediatric sepsis care and, ultimately, global child health.

This is the second 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

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

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

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

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

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

NOMIS Researcher(s)

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

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

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

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