Biology subjects

Xu, L.

Publications and source records attributed to Xu, L..

At least 109 records · Page 6Linked to original sources

bioRxiv2025

Delivery of collagen-encoding mRNA to the skin for cosmetic applications

Collagens, the predominant structural proteins in mammalian, maintain tissue integrity through its unique triple-helical conformation. Traditionally, cosmetic collagens have been administered as hydrolyzed peptides derived from animal sources, which exhibit poor bioavailability and functional efficacy due to limited skin penetration and disrupted tertiary/quaternary structures. To overcome these limitations, we developed a novel system for in vivo collagen expression. This system utilizes the topical application of in vitro synthesized, AI-designed mRNAs encoding types I, III, and XVII collagens to improve human skin condition. Significant upregulation of target collagen expression was observed in dermal fibroblasts, leading to improved skin condition through in situ assembly of collagens in natural conformation.

bioengineering↗

bioRxiv2025

Structural and functional insights into QueC-family protein in QatABCD anti-phage system

QatABCD is a widespread prokaryotic anti-phage defense system comprising four protein components, out of which QatC, a QueC-family protein is the signature component. QueC family proteins are nucleoside biosynthesis enzymes involved in the biosynthesis of queuosine, a 7-deazaguanine derivative. Recently, QueC-family proteins were shown to catalyze a deazaguanylation protein-nucleobase conjugation reaction in type IV CBASS antiphage defense. However, the mechanism of QatABCD, even the function of QatC in this system, remains unknown. Here, we demonstrate that QatBCD forms a complex in which QatD is highly flexible. Crystal structures of the QatBC complex in apo and ATP-bound form support a shared role for QueC-family proteins in targeting protein substrates for N-terminal modification as in type IV CBASS. We show that the QatB N-terminal loop, its binding with QatC and QatC catalytic site are essential for QatABCD defense in vivo, suggesting a modification might occur analogous to CBASS. These findings provide structural and functional insights into QueC-family protein in QatABCD system, suggesting the conserved mechanisms and critical roles of QueC-family in prokaryotic immunity.

biochemistry↗

bioRxiv2025

Engineering a Biomimetic Multiphasic Suture Anchor System for Enhanced Rotator Cuff Enthesis Regeneration

Conventional suture anchor methods in rotator cuff repair often fail to replicate the native tendon-to-bone interface, leading to re-tears due to stress concentrations and poor biological integration at anchor sites. To address these challenges, we engineered a biomimetic multiphasic scaffold system (BMS) that integrates with standard suture anchors and deliver spatially organized structural and biological cues to enhance enthesis regeneration. The BMS comprises three distinct phases: aligned nanofibrous decellularized bovine Achilles tendon extracellular matrix (dECM) with stiff methacrylated hyaluronic acid (MeHA) for tendon regeneration; nonaligned nanofibrous dECM with soft MeHA for fibrocartilage formation; and a porous, citrate-based composite scaffold with bioactive glass for bone integration. In vitro, the BMS facilitated zone-specific tenogenic, fibrochondrogenic, and chondrogenic differentiation. Further, in vivo, it promoted successful integrative healing, forming distinct tendon, fibrocartilage, and bone regions at the repair site. This advanced multiphasic scaffold replicates native tissue properties, offering a promising strategy to improve rotator cuff repair. Its integration with conventional suture anchors provides an innovative design that enhances mechanical fixation and guides enthesis healing to reduce re-tear rates. Broadly, this platform offers a versatile solution for biointegrative repair strategies across complex soft-to-hard tissue interfaces.

bioengineering↗

bioRxiv2025

FcγRI is the key determinant of antibody-mediated Zika virus infection of human placental macrophages

Zika virus (ZIKV) can be vertically transmitted from a pregnant mother to the developing fetus, resulting in microcephaly and/or other congenital malformations. Dengue virus (DENV) cross-reactive antibodies can facilitate ZIKV placental transcytosis and enhance ZIKV infection of placenta macrophage-Hofbauer cells through binding to Fc-{gamma} receptors (Fc{gamma}Rs). To understand the role of individual Fc{gamma}R in antibody-mediated ZIKV placental infection, we generated a comprehensive panel of Fc-variants spanning a wide range of binding affinities to different Fc{gamma}Rs. We found that mutations with increased affinity to Fc{gamma}RI strongly correlated with an increased frequency of infected pro-monocytic U937 and Hofbauer cells. Next, we genetically deleted individual Fc{gamma}R in U937 cells, and found that the knockout of FCGR1A gene completely abolished ZIKV infection. In contrast, the deletion of FCGR2B gene showed no effect on ZIKV infection, and the deletion of FCGR2A gene had only a moderate impact on ZIKV infection. We further observed that Fc{gamma}RI was involved in both increased ZIKV internalization and replication. Collectively, our results establish Fc{gamma}RI as the key Fc receptor responsible for antibody-mediated ZIKV infection in both U937 and primary placental macrophages. These mechanistic findings not only provide insight into the importance of Fc{gamma}RI in ZIKV vertical transmission but also highlight Fc{gamma}RI as a potential therapeutic target, with significant implications for the development of strategies to prevent ZIKV transmission from mother to fetus.

immunology↗

bioRxiv2025

Beyond the Genotype: A Multi-Omic Analysis of APOEe4's Role in Alzheimer's Disease

Alzheimers disease (AD) is characterized by widespread molecular dysregulation, with the APOEe4 allele recognized as its strongest genetic risk factor. However, the mechanisms by which APOEe4 drives distinct molecular changes - whether by exacerbating pathology or triggering compensatory responses - remain incompletely understood. We generated and analyzed proteomic, epigenetic, and genetic data from post-mortem dorsolateral prefrontal cortex samples of a uniquely APOEe4-enriched subset of the Religious Orders Study and Memory and Aging Project (ROSMAP). Specifically, we generated DIA LC-MS proteomic data (n = 302), analyzed previously generated DNA methylation profiles from our group (n = 310), and used published whole-genome sequencing data (n = 254) to compute polygenic risk scores (PRS). In this cohort, 69% (n = 214) were APOEe4 carriers, and 19.6% (n = 42) of them showed no pathological evidence of AD based on NIA-Reagan criteria, enabling identification of APOEe4-related risk and resilience mechanisms. In the absence of AD, APOEe4 carriers exhibited lower levels of 27 proteins, suggesting early synaptic (e.g., VAMP1, SYN3, CASKIN1) and metabolic (e.g., GLUD1, PI4KA) vulnerability. By contrast, APOEe4 carriers with AD displayed marked upregulation of inflammatory and proteostatic proteins (e.g., GNAO1, AHNAK, FGG, HEBP1, APEX1, RAB4A, SLC12A5, LRP1, BAG6) and hypermethylation of cg06329447 in ELAVL4. Network analyses highlighted convergent disruptions in synaptic transmission, metabolism, and proteostasis - key pathways altered in APOEe4-associated AD. Mediation analyses identified GRIPAP1 and GSTK1 as top protein mediators (accounting for [~]26-33% of APOEe4s effect), with VAMP1, CASKIN1, DPP3, SYN3, and FGG each contributing [~]9-15%. ELAVL4 hypermethylation also mediated [~]12% of the APOEe4 effect, linking epigenetic dysregulation to disease risk. To assess whether the identified proteins reflected broader genetic risk for AD or were specific to APOEe4, we calculated PRS both excluding and including the APOE genomic region. While the non-APOE PRS showed no association with identified molecular markers, the APOE-inclusive PRS was significantly associated with eight AD-related proteins in carriers, indicating they are not explained by polygenic risk outside of APOE. Finally, predictive modeling stratified by APOEe4 status revealed that in non-carriers, PRS most effectively classified AD (AUC = 0.73), whereas in carriers, proteomic and epigenetic markers outperformed PRS (AUC up to 0.74). Together, these findings demonstrate that APOEe4 confers AD risk through early synaptic and metabolic disruptions and later-stage inflammatory and epigenetic changes, laying the groundwork for genotype-tailored biomarker development and therapeutic strategies. VISUAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=156 HEIGHT=200 SRC="FIGDIR/small/682426v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@1477a2forg.highwire.dtl.DTLVardef@1a6d173org.highwire.dtl.DTLVardef@1010821org.highwire.dtl.DTLVardef@bcde3a_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗

bioRxiv2025

REST elevation-dependent chromatin remodeling and alternative Grk6 transcript synthesis hyperactivates Cxcr4-Sdf1 signaling in cerebellar granule cell progenitors

RE1 Silencing Transcription Factor (REST) is a repressor of transcriptional initiation of genes involved in neurogenesis. Here, we show that conditional REST elevation in cerebellar granule cell progenitors (CGNPs) of RESTTG mice perturbed foliation, increased cell migration, and sustained C-X-C motif receptor 4 (Cxcr4) signaling, a pathway key to postnatal CGNP migration. Mechanistic studies uncovered a novel role for REST in controlling transcript diversity and exon skipping in CGNPs. Alternative transcript expression was detected in known Cxcr4 signaling regulator, G-protein-coupled receptor kinase-6 (Grk6). Further analysis of Grk6s isoform expression revealed an upregulation of a transcript lacking exon 10a (Grk6-207) in RESTTG CGNPs. Grk6-207 expression in wildtype CGNPs hyperactivated Cxcr4 signaling and increased chemotaxis. Structural modeling of Grk6-207 predicted changes in active site conformation and interactions with Cxcr4 and {beta}-Arrestin-1, supporting impairment of Cxcr4 signaling desensitization. Interestingly, REST elevation promoted increased chromatin accessibility at the exon10a-10b junction and exon 10a exclusion. Integrated multiomic analyses identified the enhancer of zeste (Ezh2) as a potential mediator of alternative transcript generation which demonstrated increased occupancy at the exon10a-10b locus in RESTTG CGNPs. Pharmacological inhibition of Ezh2 downregulated Grk6-207, confirming a role for Ezh2 in Grk6 exon10a exclusion and the increased migration in RESTTG CGNPs. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=67 SRC="FIGDIR/small/682654v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@166db32org.highwire.dtl.DTLVardef@1c0c5e0org.highwire.dtl.DTLVardef@ff2d6borg.highwire.dtl.DTLVardef@fed170_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2025

Molecular mechanism of the key dormancy regulator DosR-dependent transcription activation in Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) is the etiological agent responsible for the worldwide disease Tuberculosis. DosR is recognized as the key dormancy regulator of Mtb due to its global transcriptional regulation in intracellular adaptation and long-term persistence prevailing in latent infection. However, the molecular mechanism regarding DosR-dependent transcription activation remains inadequately defined. Here, we successfully determined the cryo-EM structure of an intact DosR-dependent transcriptional activation complex (DosR-TAC), comprising Mtb RNA polymerase (RNAP), DosR, and the hypoxic promoter DNA. In DosR-TAC, two DosR monomers symmetrically dimerize through their N-terminal receiver domains (DosR_RECs) and the distinct 10 helices of the C-terminal DNA-binding domains (DosR_DBDs). Unlike its inhibitory configuration, the DosR dimer undergoes significant conformational changes within the original linker, isomerizing DosR_REC into a canonical ({beta})5 fold. This extended linker affords the DosR_DBDs and DosRI_REC to contact promoter DNA, while concurrently interacting with the conserved domains of RNAP ({sigma}AR4, CTD, and NTD). Additionally, RT-qPCR and growth curve assays of the wild-type and DosR mutant strains, also unravel the physiological importance of this divergent linker. These findings, together with prior hypotheses regarding DosR, support an allosteric activation-recruitment model for DosR. Altogether, these results highlight the molecular mechanism of DosR-dependent transcription activation critical for dormancy survival of Mtb, and offer potential targets for developing anti-dormancy strategies against persistent tuberculosis.

microbiology↗

bioRxiv2025

Agro-STARR-seq enables in planta genome-wide enhancer discovery and AI-empowerd enhancer design

Comprehensive enhancer screening is essential for dissecting gene regulatory networks. However, methods for such screening remain limited in plants. We present Agro-STARR-seq, an in planta enhancer screening platform using Agrobacterium-mediated delivery of STARR-seq libraries into Nicotiana benthamiana leaves. In the Arabidopsis genome, we identified 14,715 sequences with enhancer activity, of which 91.59% were located outside of open chromatin regions. This largest in planta enhancer dataset to date enabled AI-assisted design of highly active synthetic enhancers. For the large N. benthamiana genome, we pre-processed the genomic DNA with an Assay for Transposase Accessible Chromatin (ATAC) procedure before the Agro-STARR-seq protocol,and found that only one-third of open chromatin exhibited enhancer activity, 76.00% of which showed no canonical H3K27ac histone marks. Footprinting analysis further enables systematic linkage of transcription factor (TF) binding to enhancer function. Overall, Agro-STARR-seq provides a novel platform for dissecting and engineering plant enhancers.

genomics↗

bioRxiv2025

ETV2 mediated differentiation of human pluripotent stem cells results in functional endothelial cells for engineering advanced vascularized microphysiological models

Patient-specific microphysiological models, exemplified by organs-on-a-chip and organoids, have become a valuable tool for broad applications, revolutionizing biomedical research. However, limitations persist, with functional vasculature being a significant challenge. Generating functional human induced pluripotent stem cell (h-iPSC) derived endothelial cells (h-iECs) represent an urgent need. With the discovery of ETV2s determinant role in specifying EC lineages during differentiation, researchers have adopted techniques involving ETV2 overexpression to produce h-iECs more efficiently and consistently. However, the capacity of these cells to form functional vasculatures has not yet been thoroughly investigated. Here, we generated multiple h-iPSC lines with inducible ETV2 expression, and subsequently differentiated them into h-iECs, which were validated functionally and by key endothelial markers and RNA-seq analysis. These cells are capable of self-organizing into stable microvascular networks (MVNs) in a microfluidic chip reproducibly, forming lumenized and functional vessels that mimic the in vivo capillary bed in both morphology and function - a result not achieved using h-iECs differentiated with conventional two-step methods using the same h-iPSC lines. Furthermore, complex microphysiological models featuring perfusable vasculature were also successfully developed using ETV2 activated h-iECs, demonstrated with vascularized tumor and blood-brain barrier (BBB) models. Additionally, by pooling genetically engineered h-iPSCs with inducible ETV2, we effectively employed an orthogonally induced differentiation approach to enhance vascularization of an organoid model. Our methodology opens avenues in precision medicine, leading to personalized microphysiological models with perfusable vasculature for various applications.

bioengineering↗

bioRxiv2025

Access to running wheels decreases social motivation in adult C57BL/6J female mice

Physical activity offers myriad benefits to health and well-being, in humans and other animals as well. In rodents, voluntary wheel running can attenuate the effects of both physical and social stressors on rodent social behavior. Whether wheel running affects rodent social behaviors per se remains less well understood. We conducted the current study to test whether home cage access to running wheels impacts the social behaviors of adult, group-housed C57BL/6J female mice during same-sex interactions with novel females. Group-housed females were either given continuous home cage running wheel access or a standard paper hut starting at weaning, and as adults, social behaviors were measured during interactions with novel females. In two cohorts, we found that 5 weeks of running wheel access during adolescence reduced the time that subject females spent investigating a novel female and also tended to reduce total ultrasonic vocalizations produced during interactions. These effects were not reversed by a 2-week period of running wheel removal but were recapitulated in a different cohort by 2 weeks of running wheel access in adulthood. Unexpectedly, we found that these effects on female social behavior were not due to wheel running per se, because females raised from weaning with immobile running wheels also showed low rates of social behaviors during same-sex interactions in adulthood. Overall, we find that the presence of a running wheel in the home cage has an enduring inhibitory influence on female social behavior during same-sex interactions, a finding that has implications for the design of studies that include same-sex interactions between female mice.

animal behavior and cognition↗

bioRxiv2025

Gliomas phenocopy an inborn error of metabolism to drive neuronal activity and tumor growth

The metabolic hallmarks of high-grade glioma (HGG) are not fully understood. Human brain tissue metabolomics revealed that the creatine synthesis pathway intermediate guanidinoacetate (GAA) accumulated [~]100-fold in HGGs relative to controls, which was caused by imbalanced activities of enzymes in this pathway. Glioma cells secreted GAA rather than using it to produce creatine, implicating an unexpected function. GAA accumulates in GAMT deficiency, an inborn error of metabolism, and elevates neuronal excitability. Neuronal excitability is also increased in glioma and drives tumor growth through neuron-glioma interactions. We hypothesized that glioma-generated GAA excites surrounding neurons. Indeed, GAA induced neuronal hyperactivity by activating GABAA receptors and causing depolarizing GABA currents in glioma-associated neurons with dysregulated chloride homeostasis. Depleting tumoral GAA decreased electrochemical activity, neuron-glioma interactions, and tumor aggressiveness. Our findings unveil a new mechanism linking cancer metabolism with cancer neuroscience and leverage human genetics to nominate GAA synthesis as a target in gliomas.

cancer biology↗

bioRxiv2025

Large-Scale Neural Network Compensation Underlying Camouflaging in Trait Autism and Its Potential Mental Health Costs

Social camouflaging refers to strategies to hide or compensate for social difficulties, often at a significant mental health cost, and is particularly prevalent in autism. The large-scale neural network mechanisms underlying this adaptation remain poorly understood. This study aimed to identify these neural underpinnings and their link to other potential mental health issues. Using a dimensional approach, we recruited 110 healthy young adults who completed self-report questionnaires measuring autistic traits and camouflaging as well as depression and anxiety, and underwent resting-state fMRI scans. Using the 300-node Seitzman atlas encompassing 13 functional networks, we examined the interaction between camouflaging and autistic traits on brain network connectivity. Results showed that among individuals with higher autistic traits, greater camouflaging was associated with hyperconnectivities between the Default Mode (DMN) and Cingulo-Opercular Networks (CON), and within the CON. Crucially, DMN-CON hyperconnectivity mediated the relationship between camouflaging and potential mental health cost (i.e., depression and anxiety scores) but only in individuals with higher autistic traits. These findings reveal a specific neuro-compensatory mechanism underlying autistic camouflaging involving self-referential and executive control systems and provide a neurobiological explanation for its potential mental health burden, highlighting the need for societal changes that reduce the pressure for such adaptations. Lay AbstractSocial camouflaging refers to strategies autistic people often use to hide their social differences to better adapt to everyday social contexts. While it may help in the short term, this constant effort can be mentally exhausting and is often linked to severe anxiety and depression. However, little is known about how different brain networks work together to enable social camouflaging and might contribute to a greater risk of anxiety and depression. In this study, autistic traits were measured in 110 young healthy adults in addition to questionnaire-based measures of social camouflaging, anxiety, and depression. Additionally, brain activity was recorded using magnetic resonance imaging while they were resting and not doing any task. We found that, in people with higher autistic traits, social camouflaging was linked to stronger connections between the brain network involved in thinking about oneself (self-reflection; Default Mode Network) and the one in charge of maintaining goal-directed behavior (action control; Cingulo-Opercular Network), as well as stronger connections within the latter brain network. These stronger connections between the self-reflection network and action control network partly explained why camouflaging may be associated with higher levels of anxiety and depression. In short, autistic camouflaging seems to rely on a cognitively demanding neural compensatory process, which can take a toll on mental health. Understanding this underscores the importance of creating a more accepting society to support the well-being of autistic individuals.

neuroscience↗

bioRxiv2025

Structural and mechanistic insights into bacterial hydrazine biosynthesis

Nitrogen-nitrogen (N-N) bond-containing motifs are prevalent in both clinical drugs and natural products. Bacterial hydrazine synthetases catalyze N-N bond formation by coupling an amino acid and a hydroxylamine via a distinctive O-aminoacyl-hydroxylamine intermediate. Despite its wide occurrence, the structural and mechanistic basis of this process has remained elusive. Here, we report the first crystal structures of the O-aminoacyl-hydroxylamine synthetase component of a bacterial hydrazine synthetase, captured in binary and ternary complexes with substrates and catalytic intermediates. These structures reveal the molecular determinants of substrate recognition and, together with biochemical and computational analyses, establish a detailed mechanistic framework for the hydrazine synthetase family. Leveraging these insights, we expanded hydrazine biosynthesis through the targeted discovery of novel hydrazine synthetases and implemented a chemoenzymatic synthesis strategy. This work provides fundamental insights into hydrazine synthetases and lays the groundwork for their rational engineering as versatile biocatalysts.

microbiology↗

bioRxiv2025

SARS-CoV-2 S protein activates the HIV latent reservoir through the mTOR pathway

During the global COVID-19 pandemic, mRNA vaccines using the S protein as antigen were widely used.Vaccine-induced S proteins can persist in vivo for weeks, triggering low-level immune activation. HIV latent reservoir maintenance is a major challenge for ART therapy, especially when immune pressure is waning. This then raises critical questions for HIV-infected patients: does prolonged exposure to S proteins affect HIV latent reservoir stability? Recent studies have pointed out that S proteins may activate the mTOR signaling pathway, which in turn affects the immune response and metabolic processes of cells. And the mTOR pathway is closely related to the maintenance and activation of HIV latent reservoir. However, how S proteins affect the HIV latent reservoir and the mechanism of activation are unclear. To explore the mechanism of how SARS-CoV-2 S proteins regulate the HIV latent reservoir and to explore whether S proteins regulate the HIV latent reservoir through the mTOR pathway, we constructed an in vitro HIV latent reservoir model for our experiments.To evaluate the potential role of S protein in HIV latent reservoir activation, relevant markers of HIV latent reservoir activation were detected using ELISA, flow cytometry, and RT-qPCR; and the relationship between S protein and mTOR was also detected by WB, CO-IP, and IFC.It was found that S proteins activated the HIV latent reservoir while increasing mTOR expression. It was further observed that mTOR inhibitors significantly inhibited S protein-induced activation of the HIV latent reservoir, and mTOR activators reversed the inhibitory effect of mTOR inhibitors on HIV latent reservoir activation. In summary, we found that S proteins activated the HIV latent reservoir through the mTOR pathway. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=170 SRC="FIGDIR/small/670887v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@f6d87aorg.highwire.dtl.DTLVardef@1fe4cc0org.highwire.dtl.DTLVardef@60eefeorg.highwire.dtl.DTLVardef@1ea9a34_HPS_FORMAT_FIGEXP M_FIG S protein interacts with mTOR and activates the mTOR-p-p70S6K-pS6 pathway, which promotes HIV transcription C_FIG

immunology↗

bioRxiv2025

Mutant IDH silences GSX2 to reprogram neural progenitor cell fate and promote gliomagenesis

Isocitrate dehydrogenase (IDH) mutations arise early in gliomas and are associated with a defined neurodevelopmental cancer cell hierarchy. However, how mutant IDH contributes to this hierarchy and whether this interaction promotes gliomagenesis remain unclear. We captured the dynamics of IDH-mutant glioma initiation in genetically engineered mice through time-resolved, single-cell genomics. Mutant IDH activates and induces lineage switching of neural progenitor cells (NPCs). These actions expand oligodendrocyte precursor cells, the predominant cell-of-origin for these tumors, at the expense of interneurons. Lineage switching is mediated by promoter hypermethylation and silencing of Gsx2, a homeobox gene required for neurogenesis. Critically, Gsx2 ablation recapitulates NPC fate reprogramming by mutant IDH. We provide a new model of neural cell fate control by IDH oncogenes and insights into the developmental origins of glioma.

cancer biology↗

bioRxiv2025

Rapid turnover of sex chromosomes likely drives speciation in Neotropical armored catfish Harttia (Siluriformes, Loricariidae)

Withdrawal StatementThe authors have withdrawn their manuscript because they have decided to incorporate new genomic datasets currently in production to strengthen the analysis of sex-linked markers presented in the current version of the manuscript. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

evolutionary biology↗

bioRxiv2025

Improving polygenic risk prediction performance through integrating electronic health records by phenotype embedding

Large-scale biobanks provide comprehensive electronic health records (EHRs) that capture detailed clinical phenotypes, potentially enhancing disease risk prediction. However, traditional polygenic risk score (PRS) methods rely on simplified phenotype definitions or predefined trait sets, limiting their ability to represent the intricate phenotypic structures embedded within EHRs. To address this gap, we introduce a general framework, EEPRS, that leverages phenotype embeddings derived from EHRs to improve genetic risk prediction using only genome-wide association study (GWAS) summary statistics, enabling accurate, robust and interpretable risk prediction for a wide range of diseases. Employing embedding methods such as Word2Vec and GPT, we conducted EHR embedding-based GWAS and identified a distinct cardiovascular cluster via hierarchical clustering of genetic correlations. Across 41 clinical traits in the UK Biobank, our EEPRS framework consistently outperformed traditional single-trait PRS, particularly within this identified cluster. Validation using PRS-based phenome-wide association studies (PRS-PheWAS) further confirmed robust associations between EHR embedding-based PRS and circulatory system diseases. Furthermore, our data-adaptive method, EEPRS_optimal, employing cross-validation to select the best embedding method, leading to additional improvements in prediction. We further developed MTAG_EEPRS for multi-trait PRS, resulting in averaging 92.48% improvement in R2 for continuous traits and 24.06% in AUC for binary traits compared to single-trait PRS. Overall, EEPRS represents a robust and interpretable framework, enhancing genetic prediction accuracy through integrating EHR embeddings with single-trait and multi-trait PRS.

genetics↗

bioRxiv2025

Escape from X inactivation drives sex differences and female trait variation

X chromosome inactivation (XCI) partially balances gene dosage between sexes, yet many genes are expressed from the inactive X (Xi) to a variable degree. In this study, we investigate whether variation in Xi expression among genes predicts transcriptional and phenotypic consequences of X-linked variation. We find that Xi expression levels are a strong linear predictor of female-male expression differences, suggesting that other compensatory or regulatory mechanisms play a more minor role in sex differences in X-linked gene expression. Among females, we identify traits--including BMI, estradiol, and testosterone levels--for which higher Xi expression correlates with the strength of evidence for either additive or dominance effects on the trait. We hypothesize that an underappreciated mechanism could generate dominance effects of X-linked variants on a trait--specifically when the variant influences skew in X inactivation. The work establishes Xi expression as important for understanding transcriptional sex differences and the physiological variation among females.

genomics↗