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Menche, J.

Publications and source records attributed to Menche, J..

At least 19 recordsLinked to original sources

reComBat-seq: Regularized negative binomial regression for batch-effect correction in underdetermined transcriptomics datasets

MotivationBatch effect correction is essential for the integration of large-scale transcriptomics datasets such as single-cell RNA-seq or multi-study bulk RNA-seq datasets for reducing technical noise that may mask biological signal. Existing correction methods, either do not produce count data output which is crucial for state-of-the-art downstream analyses such as differential expression analysis or fail to converge in underdetermined study designs. ResultsWe present reComBat-seq, a method that extends the Negative Binomial regression framework of ComBat-seq by incorporating Elastic Net regularization. This approach resolves problems with rank-deficient design matrices while also preserving the integer nature of count data. Benchmarking on simulated and real datasets such as single-cell RNA-seq data demonstrates that reComBat-seq successfully removes batch effects in complex study designs while maintaining compatibility with downstream differential expression tools. Availability and ImplementationreComBat-seq source code can be found at https://github.com/menchelab/reComBat-seq. All code to reproduce the presented analyses can be found at https://github.com/menchelab/reComBatseq_Studies. Data produced in this study is available at https://doi.org/10.5281/zenodo.19736515. Used single-cell RNA-seq data can be found at https://doi.org/10.5281/zenodo.14234956. Supplementary InformationProofs and volcano plots of differential expression analysis

bioinformatics↗

RAStoERK: a reference interaction atlas for insights into signaling and disease

The RAS/RAF/MEK/ERK pathway has been extensively studied for its roles in physiology and disease, yet a systems-level view of its interplay with the broader cellular context is lacking, limiting insight into paralog-specific roles, mutation-driven rewiring, and cross-pathway integration. To address this, we simultaneously mapped the interactomes of all pathway components and their activating and inactivating mutations, identifying 2,500 high-confidence interactors, 88% of which previously unreported, and generating a high-confidence, comprehensive reference map of the pathway in resting and activated states. The pathway behaves like a "molecular organism" that connects to other signaling complexes, operates from distinct subcellular sites, and integrates into networks relevant to physiology and disease. Dataset exploration uncovered paralog- and mutation-specific interaction signatures and pathway-level crosstalk, including previously unknown connections to mRNA metabolism and WNT signaling. The interactomes available at RAStoERK.univie.ac.at provide a foundational community resource for unbiased discovery, targeted mechanistic studies, and potential therapeutic exploration. HighlightsO_LIHigh-resolution interactome map of the RAS to ERK pathway in resting and active states C_LIO_LIState-dependent pathway-level interactions with signaling and functional modules C_LIO_LIMutation-driven interactome rewiring and integration into pathophysiological networks C_LIO_LIA resource to discover pathway crosstalk, disease links, and actionable interventions C_LI

molecular biology↗

Inferring and Evaluating Network Medicine-Based Disease Modules with Nextflow

Most human diseases result from complex molecular interactions of genes and proteins. Various network-based computational methods characterize these mechanisms by expanding seed genes into disease-associated subnetworks, or disease modules. Evaluating these diverse methods is tedious due to unique installation and data preparation requirements. Moreover, the underlying algorithmic strategies differ, making it difficult to determine which of the created modules are most useful or biologically plausible. To address this challenge, we developed an all-in-one Nextflow pipeline that enables automated and reproducible analyses. It handles installation, input preparation, execution, and systematic evaluation of six widely used module detection tools, considering module topology, functional coherence, robustness, and the capacity to recover seeds. In addition, it annotates the resulting disease modules with biological context information, prioritizes potential drug candidates, and generates visualizations and a comprehensive summary report. To showcase the value of our pipeline and offer guidance to potential users, we performed a comprehensive evaluation across 50 different disease-network combinations, revealing substantial variability among the derived disease modules. We show that this variability is driven by differences in modeling approach, input network, and seed composition. While most methods are robust to minor perturbations, they struggle to recover omitted seeds, and none consistently outperforms others, underscoring the need for careful method selection. Our work enables the research community to systematically compare approaches for disease module discovery, promoting reproducible network medicine research. Integrated into the nf-core project (https://nf-co.re/diseasemodulediscovery), it is intended as an extendable, long-term resource for tracking progress in the field.

bioinformatics↗

tRNA thiolation defects disrupt cellular proteostasis and tissue homeostasis in mammals

Sulfur modification of tRNA wobble uridines is an evolutionarily conserved mechanism that ensures efficient protein synthesis. In humans, loss of this anticodon modification due to mutations in CTU2 (cytosolic thiouridylase 2) causes DREAM-PL syndrome, a severe congenital disorder often leading to early postnatal death. However, the mechanisms by which loss of tRNA thiolation drives pathology remain unclear. Here, we show that loss of CTU2 triggers significant cellular proteostasis defects in patient cells and model cell lines. Structural and biochemical analyses reveal that the pathogenic CTU2L63P mutation destabilizes the CTU1/CTU2 complex and abolishes tRNA binding and thiolation. Acute loss of CTU2 caused codon-specific ribosome pausing at A-ending codons decoded by thiolated tRNAs, and decreased ribosome occupancy of A-rich transcripts in a dosage-dependent manner. Codon-biased mRNAs transcribed from genes critical for ciliogenesis are predicted to be most affected, linking their reduced translation to DREAM-PL etiology in humans. Surprisingly, Ctu2L63P mice display severe thiolation defects, but develop normally, are viable and fertile. Our findings highlight the importance of functional tRNA thiolation for organismal health in humans and identify species-specific vulnerabilities during embryonic development in mammals.

cell biology↗

A multilayer network approach elucidates time- and tissue-specific developmental and aging processes

Understanding the dynamic interplay of proteins across different life stages and tissues is essential for deciphering the molecular mechanisms underpinning development, aging, and disease. Here, we present a comprehensive network-based framework that constructs and integrates 119 time- and tissue-specific protein-protein interaction (PPI) networks derived from transcriptomic data, offering insights into proteomic dynamics across the human lifespan. Based on this, we observed three distinct protein groups: (i) common-core proteins, expressed universally across all tissues and time points; (ii) time-/tissue-specific proteins, selectively expressed within specific temporal or spatial contexts; and (iii) time-/tissue-unique proteins, whose expression is restricted to specific points in space and time. Our analysis shows a clear gradient of network centrality, transitioning from the highly connected common-core proteins to more specialized time-/tissue-specific and unique proteins, mirroring a progressive shift in functional specificity. Further, we characterized the distinct molecular signatures of intrauterine to extrauterine life, delineating two key protein networks: the embryonic development network (EDev) and the environmental aging network (EAgi). Their network characterization and comparison highlighted specific communities within the EDev network enriched for developmental diseases, and specific EAgi communities involved in aging. This network classification allowed us to rank candidate anti-aging drugs and their molecular targets, laying the foundation for a systematic, data-driven, network-based investigation of development and aging, providing a roadmap for future research aimed at mitigating age-related diseases and promoting longevity.

systems biology↗

Functional profiling reveals a non-enzymatic role of NUDT5 in repressing purine de novo synthesis

Folate metabolism is intricately linked to purine de novo synthesis through the incorporation of folate-derived one-carbon units into the purine scaffold. Here, we investigate the chemical and genetic dependencies caused by mutations in the folate enzyme MTHFD1 and discover a key role for Nudix hydrolase 5 (NUDT5) in regulating purine de novo synthesis. Through genetic knockout and development of a selective chemical NUDT5 degrader, we uncover an unprecedented scaffolding role rather than NUDT5 enzymatic activity is responsible for this phenotype. We find that NUDT5 interacts with the rate-limiting enzyme of purine de novo synthesis, PPAT, to repress the pathway in response to elevated purine levels. Our findings establish NUDT5 as an important regulator of purine de novo synthesis and elucidate its role in mediating sensitivities to 6-thioguanine in cancer treatment and to adenosine in MTHFD1 deficiency.

molecular biology↗

Linking Transcriptional and Cellular Responses of Human and Murine Pneumococcal Pneumonia

Community-acquired pneumonia (CAP), often caused by Streptococcus pneumoniae, poses a significant global health challenge, especially among high-risk populations. This study investigates the temporal dynamics of pulmonary gene expression during S. pneumoniae-induced pneumonia using a murine model to elucidate host-pathogen interactions and identify potential biomarkers of disease severity. Using bulk RNA sequencing, we analyzed lung tissues at early (1h, 8h) and acute infection (2d, 3d), as well as post-resolution (30d) time-points. At 2 days post-infection, differentially expressed genes (DEGs) revealed heightened innate immune responses, including chemokine and interferon signaling pathways. By 30 days post-infection, gene expression profiles and histological changes normalized, reflecting resolution of inflammation. Stratifying mice into recovered, sick, and moribund phenotypes during the acute infection phase highlighted significant transcriptional distinctions, including upregulated pro-inflammatory genes and Schlafen family members. Arginase 1 emerged as a predictive marker of disease severity, with elevated expression detectable as early as 8 hours post-infection. Comparative analyses revealed significant overlap between transcriptional responses in our model and those from a Gram-negative Acinetobacter baumannii pneumonia model, implicating conserved pathways, such as IL-17 and Toll-like receptor signaling. Additionally, murine DEGs correlated with human plasma proteins associated with severe CAP, including CCL8 and CD14, suggesting translational relevance. This study underscores phase-specific transcriptional reprogramming during pneumococcal pneumonia and identifies potential biomarkers and therapeutic targets for improving outcomes in severe CAP cases.

microbiology↗

Dissecting DNA-mismatch-repair-driven mutational processes in human cells

Mismatch repair (MMR) is an essential DNA repair pathway that preserves genome stability by correcting replication errors and other DNA lesions. MMR deficiency (MMRd) leads to increased mutation rates and microsatellite instability, and contributes to tumorigenesis in multiple cancer types, yet the full spectrum of mutational patterns caused by MMRd remains incompletely defined. Here, using CRISPR-Cas9 knockouts in human isogenic cell lines, we systematically profile mutations arising in MMR-deficient cells. We observe a marked increase in mutation burden and the appearance of established MMRd-associated mutational signatures. Unexpectedly, we also detect signatures SBS57 and DBS14 and connect them to germline single-nucleotide polymorphisms that co-occur with MMR-driven indels. In addition, we provide experimental genomic evidence supporting a role of MMR in preventing mutations underlying the widespread SBS1 signature, and we link MMR deficiency to the indel signature ID12, which currently lacks a known aetiology. Finally, comparing in vitro MMRd profiles from rapidly dividing cells without exogenous mutagen exposure to in vivo tumour genomes that reflect lifelong mutation accumulation reveals pronounced differences in signature composition, underscoring the context dependence of MMR-linked mutagenesis. Together, our results broaden the known mutational footprint of MMR deficiency and illuminate previously uncharacterised mechanisms relevant to cancer development.

genetics↗

Multimodal learning of transcriptomes and text enables interactive single-cell RNA-seq data exploration with natural-language chats

Single-cell RNA-seq characterizes biological samples at unprecedented scale and detail, but data interpretation remains challenging. Here we introduce CellWhisperer, a multimodal machine learning model and software that connects transcriptomes and text for interactive single-cell RNA-seq data analysis. CellWhisperer enables the chat-based interrogation of transcriptome data in English language. To train our model, we created an AI-curated dataset with over a million pairs of RNA-seq profiles and matched textual annotations across a broad range of human biology, and we established a multimodal embedding of matched transcriptomes and text using contrastive learning. Our model enables free-text search and annotation of transcriptome datasets by cell types, states, and other properties in a zero-shot manner and without the need for reference datasets. Moreover, Cell-Whisperer answers questions about cells and genes in natural-language chats, using a biologically fluent large language model that we fine-tuned to analyze bulk and single-cell transcriptome data across various biological applications. We integrated CellWhisperer with the widely used CELLxGENE browser, allowing users to in-teractively explore RNA-seq data through an integrated graphical and chat interface. Our method demonstrates a new way of working with transcriptome data, leveraging the power of natural language for single-cell data analysis and establishing an important building block for future AI-based bioinformatics research assistants.

bioinformatics↗

Multiple ubiquitin ligases protect human genome integrity by targeting cancer-associated APOBEC3 deaminases for degradation.

HighlightsO_LIRNA-free APOBEC3 (A3) can enter the nucleus, leading to genomic mutations. C_LIO_LIThree E3 ligases specifically bind the RNA-binding domain of nuclear A3s. C_LIO_LICancer-associated A3B and A3H-I are thereby targeted for proteasomal degradation. C_LIO_LIThese E3 ligases thus act as genome guardians by limiting A3-mediated mutagenesis. C_LI APOBEC family members play crucial roles in antiviral restriction. However, certain APOBEC3 (A3) proteins drive harmful hypermutation in humans, contributing to cancer. The cancer-associated A3 proteins are capable of transiting from the cytosol to the nucleus, where they can cause genome mutations. Here, we uncover a specific set of cellular pathways that protect genomic DNA from the major cancer-associated A3 proteins. Through genetic and proteomic screening we identify UBR4, UBR5, and HUWE1 as key ubiquitin E3 ligases marking cancer-associated A3B and A3H-I for degradation, thereby limiting A3-driven hypermutation. Mechanistically, UBR5 and HUWE1 recognize unoccupied A3 RNA-binding domains, thus promoting proteasomal degradation of APOBEC3 protein that is not engaged in its antiviral cellular function. Depletion or mutation of the E3 ligases in cells and human cancer samples increases A3-driven genome mutagenesis. Our findings reveal that UBR4, UBR5, and HUWE1 are crucial factors in a ubiquitination cascade that maintains human genome stability.

cell biology↗

Spermidine/spermine N1-acetyltransferase controls tissue-specific regulatory T cell function in chronic inflammation

Regulatory T cells (Tregs) are a critical immune component guarding against excessive inflammatory responses. During chronic inflammation, Tregs fail to control effector T cell responses. The causes of Treg dysfunction in these diseases are poorly characterized and therapies are aimed at blocking aberrant effector responses rather than rescuing Treg function. Here we utilized single-cell RNA sequencing data from patients suffering from chronic skin and colon inflammation to uncover SAT1, the gene encoding spermidine/spermine N1-acetyltransferase (SSAT), as a novel marker and driver of skin-specific Treg dysfunction during TH17-mediated inflammation. Tregs expressing SAT1 exhibit a tissue-specific inflammation signature and show a proinflammatory effector-like profile. In CRISPRa on healthy human skin-derived Tregs increased expression of SAT1 leads to a loss of suppressive function and a switch to a TH17-like phenotype. This phenotype is induced by co-receptor expression on keratinocytes exposed to a TH17 microenvironment. Finally, the potential therapeutic impact of targeting SSAT was demonstrated in a mouse model of skin inflammation by inhibiting SSAT pharmacologically, which rescued Treg number and function in the skin and systemically. Together, these data show that SAT1 expression has severe functional consequences on Tregs and provides a novel target to treat chronic inflammatory skin disease.

immunology↗

Large neutral amino acid levels tune perinatal neuronal excitability and survival

Surprisingly little is known about the critical metabolic changes that neural cells have to undergo during development and how even mild, temporary shifts in this program can influence brain circuitries and behavior. Inspired by the discovery that mutations in SLC7A5, a transporter of metabolically-relevant large neutral amino acids, lead to a form of autism spectrum disorder, we employed metabolomic profiling to study the metabolic states of the cerebral cortex across different stages of life. We found that the cerebral cortex undergoes significant metabolic remodeling throughout development, with certain groups of metabolites showing stage-specific changes. But what are the consequences of interfering with this metabolic program? By manipulating Slc7a5 expression in neural cells, we found that the metabolism of large neutral amino acids and lipids in the cerebral cortex are highly interconnected. Deletion of Slc7a5 in neurons perturbs specifically the postnatal metabolic state leading to a shift in lipid metabolism and a stage- and cell-type-specific alteration in neuronal activity patterns, resulting in a long-term cortical circuit dysfunction.

neuroscience↗

Assessment of community efforts to advance computational prediction of protein-protein interactions

Comprehensive insights from the human protein-protein interaction (PPI) network, known as the human interactome, can provide important insights into the molecular mechanisms of complex biological processes and diseases. Despite the remarkable experimental efforts undertaken to date to determine the structure of the human interactome, many PPIs remain unmapped. Computational approaches, especially network-based methods, can facilitate the identification of new PPIs. Many such approaches have been proposed. However, a systematic evaluation of existing network-based methods in predicting PPIs is still lacking. Here, we report community efforts initiated by the International Network Medicine Consortium to benchmark the ability of 24 representative network-based methods to predict PPIs across five different interactomes, including a synthetic interactome generated by the duplication-mutation-complementation model, and the interactomes of four different organisms: A. thaliana, C. elegans, S. cerevisiae, and H. sapiens. We selected the top-seven methods through a computational validation on the human interactome. We next experimentally validated their top-500 predicted PPIs (in total 3,276 predicted PPIs) using the yeast two-hybrid assay, finding 1,177 new human PPIs (involving 633 proteins). Our results indicate that task-tailored similarity-based methods, which leverage the underlying network characteristics of PPIs, show superior performance over other general link prediction methods. Through experimental validation, we confirmed that the top-ranking methods show promising performance externally. For example, from the top 500 PPIs predicted by an advanced similarity-base method [MPS(B&T)], 430 were successfully tested by Y2H with 376 testing positive, yielding a precision of 87.4%. These results establish advanced similarity-based methods as powerful tools for the prediction of human PPIs.

systems biology↗

BioProfiling.jl: Profiling biological perturbations with high-content imaging in single cells and heterogeneous populations

MotivationHigh-content imaging screens provide a cost-effective and scalable way to assess cell states across diverse experimental conditions. The analysis of the acquired microscopy images involves assembling and curating morphological measurements of individual cells into morphological profiles suitable for testing biological hypotheses. Despite being a critical step, there is currently no standard approach to morphological profiling and no solution is available for the high-performance Julia programming language. ResultsHere, we introduce BioProfiling.jl, an efficient end-to-end solution for compiling and filtering informative morphological profiles in Julia. The package contains all the necessary data structures to curate morphological measurements and helper functions to transform, normalize and visualize profiles. Robust statistical distances and permutation tests enable quantification of the significance of the observed changes despite the high fraction of outliers inherent to high-content screens. This package also simplifies visual artifact diagnostics, thus streamlining a bottleneck of morphological analyses. We showcase the features of the package by analyzing a chemical imaging screen, in which the morphological profiles prove to be informative about the compounds mechanisms of action and can be conveniently integrated with the network localization of molecular targets. AvailabilityThe Julia package is available on GitHub: https://github.com/menchelab/BioProfiling.jl We also provide Jupyter notebooks reproducing our analyses: https://github.com/menchelab/BioProfilingNotebooks Contactjoerg.menche@univie.ac.at

bioinformatics↗

A systematic genetic interaction map of human solute carriers assigns a role to SLC25A51/MCART1 in mitochondrial NAD uptake

Solute Carriers (SLCs) represent the largest family of human transporter proteins, consisting of more than 400 members1,2. Despite the importance of these proteins in determining metabolic states and adaptation to environmental changes, a large proportion of them is still orphan and lacks associated substrates1,3,4. Here we describe a systematic mapping of genetic interactions among SLCs in human cells. Network-based identification of correlated genetic interaction profile neighborhoods resulted in initial functional assignments to dozens of previously uncharacterized SLCs. Focused validation identified SLC25A51/MCART1 as the SLC enabling mitochondrial import of NAD(H). This functional interaction map of the human transportome offers a route for systematic integration of transporter function with metabolism and provides a blueprint for elucidation of the dark genome by biochemical and functional categories.

cell biology↗

Morphological profiling of human T and NK lymphocytes identifies actin-mediated control of the immunological synapse

The detection and neutralization of infected cells and tumors by cytotoxic lymphocytes is a vital immune defense mechanism. The immunological synapse orchestrates the target recognition process and the subsequent cytotoxic activity. Here, we present an integrated experimental and computational strategy to systematically characterize the morphological properties of the immunological synapse of human cytotoxic lymphocytes. Our approach combines high-content imaging with an unbiased, data-driven identification of high-resolution morphological profiles. Such profiling discriminates with high accuracy immunological synapse perturbations induced by an array of actin drugs in both model cell lines and primary lymphocytes. It reveals inter-individual heterogeneity in lymphocyte morphological traits. Furthermore, it uncovers immunological synapse alterations in functionally defective CD8+ T cells from immunodeficient patients carrying ARPC1B mutations. Our study thus provides a foundation for the application of morphological profiling as a powerful and scalable approach to monitor lymphocyte activation status in experimental and disease settings.

immunology↗

Network Analysis Of Inflammatory Bowel Disease Reveals PTPN2 As New Monogenic Cause Of Intestinal Inflammation

BACKGROUND & AIMSGenome-wide association studies (GWAS) have uncovered multiple loci associated with inflammatory bowel disease (IBD), yet delineating functional consequences is complex. We used a network-based approach to uncover traits common to monogenic and polygenic forms of IBD in order to reconstruct disease relevant pathways and prioritize causal genes.\n\nMETHODSWe have used an iterative random walk with restart to explore network neighborhood around the core monogenic IBD cluster and disease-module cohesion to identify functionally relevant GWAS genes. Whole exome sequencing was used to screen a cohort of monogenic IBD for germline mutations in top GWAS genes. One mutation was identified and validated by a combination of biochemical approaches.\n\nRESULTSMonogenic IBD genes clustered siginificantly on the molecular networks and had central roles in network topology. Iterative random walk from these genes allowed to rank the GWAS genes, among which 14 had high disease-module cohesion and were selected as putative causal genes. As a proof of concept, a germline loss of function mutation was identified in PTPN2, one of the top candidates, as a novel genetic etiology of early-onset intestinal autoimmunity. The mutation abolished the catalytic activity of the enzyme, resulting in haploinsufficiency and hyper-activation of the JAK/STAT pathway in lymphocytes.\n\nCONCLUSIONSOur network-based approach bridges the gap between large-scale network medicine prediction and single-gene defects and underscores the crucial need of fine tuning the JAK/STAT pathway to preserve intestinal immune homeostasis. Our data provide genetic-based rationale for using drugs targeting the JAK/STAT pathway in IBD.

immunology↗

Ifnar1 signaling breaks the hepatic urea cycle to regulate adaptive immunity

Infections induce complex host responses linked to antiviral defense, inflammation and tissue damage and repair. These processes are increasingly understood to involve systemic metabolic reprogramming. We hypothesized that the liver as a central metabolic hub may orchestrate many of these changes during infection. Thus, we investigated the systemic interplay between inflammation and metabolism in a mouse model of chronic viral infection and hepatitis. Here we show that virus-induced type I interferon (IFN-I) modulates wide-spread metabolic alterations of the liver in a hepatocyte-intrinsic Ifnar1-dependent way. Specifically, IFN-I repressed the transcription of numerous genes with metabolic function including Otc and Ass1, which encode enzymes of the urea cycle. This led to decreased arginine and increased ornithine concentrations in the circulation, resulting in suppressed virus-specific CD8 T cell responses and ameliorated liver pathology. These findings establish IFN-I-induced modulation of hepatic metabolism and the urea cycle as an endogenous mechanism of immunoregulation.

immunology↗