Biology subjects

Zhang, H.

Publications and source records attributed to Zhang, H..

At least 91 records · Page 5Linked to original sources

bioRxiv2026

Expanding genetic code to generate human brain organoids with both vasculature and microglia

Brain organoids offer an invaluable model system for studying human brain development and disease. However, the establishment of high-fidelity brain organoids with multiple cell lineages including vasculature and immune cells remains a huge challenge. Here, we present a new strategy to generate human cerebral organoids with vasculature and microglia-like cells using genetic code expansion technology (GCE-T) via site-specific protein engineering. The strategy integrates orthogonal genetic translation machinery in hPSCs via PiggyBac transposon system, enabling temporally control of ETV2 expression and endothelial differentiation in hPSC-derived cerebral organoids. The vascularized human cerebral organoids (vhCOs) exhibit coordinated development of multiple cell lineages and blood-brain barrier (BBB) features. Moreover, vhCOs form perfusable vascular network after transplanted in the immune-deficient mice. Single-nucleus RNA sequencing reveals enhanced neurovascular interactions, multi-brain-regional identities, diverse neuronal subtypes and specialized endothelial subclusters in vhCOs, closely resembling human fetal brain. Strikingly, we identify enriched microglia-like cells comprising three distinct subtypes in vhCOs, which contribute to microglia-vascular interactions and synergistically modulate vascular development. Upon Zika virus (ZIKV) infection, vhCOs show neurovascular dysfunction and impaired microglia development, offering new insights into viral-induced neurodevelopmental disorders. This study offers a unique platform for producing more valuable brain organoids with vasculature and immune components, opening a new avenue to advance organoid research and applications.

bioengineering↗

bioRxiv2026

Bone Mechanosensing Dictates Hematopoietic Stem Cell Fate and Immune Homeostasis

The vertebrate water-to-land transition was accompanied by a six-fold increase in gravitational force, followed by the migration of hematopoietic stem cells (HSCs) from kidney or liver to the bone marrow, and the acquisition of enhanced immune functions to cope with novel environmental pressures. Bone senses mechanical loading and provides a microenvironment for HSC development, yet whether bone mechanosensation affects immune cell development and immune homeostasis remains unclear. Here, we unveil bone as a mechanosensory organ that translates mechanical force into hematopoietic instructions. Mechanical loading of bone directs HSCs toward lymphoid lineages in mice and non-human primates, whereas unloading favors myeloid commitment. This process requires osteocyte mechanosensor Piezo1, which induces loading-responsive bone-derived factors such as IL1R2, SERPINC1 and INMT, thereby restraining inflammatory signaling and guiding HSC differentiation. Osteocyte Piezo1 deficiency recapitulates the hematopoietic and immune alterations observed during unloading. Functionally, this pathway enhances acute infection resistance and suppresses immunosenescence in mice and in aged long-tailed macaques. Notably, skeletal mechanoregulation of immune homeostasis is conserved across vertebrate species. Our research defines the mechano-bone-immune axis (mechano-osteoimmunology), offering a novel evolutionary perspective on the interconnected development of the skeletal and immune systems and presenting a promising non-pharmacological target to address immune dysfunction.

immunology↗

bioRxiv2026

Environment-dependent landscapes of coding variant impacts on coproporphyrinogen oxidase

Hereditary coproporphyria (HCP) -- caused by variants in coproporphyrinogen oxidase (CPOX) -- can be diagnosed via genome sequencing. However, 74% of clinically-reported CPOX missense variants are classified as variants of uncertain significance (VUS) due to lack of evidence. CPOX variant classification is further complicated by environment-dependence: For example, the CPOX variant p.Asn272His (c.814A>C) is classified as benign yet has been associated with HCP-like symptoms in the context of mercury exposure. Here we measured the functional impact of nearly all possible CPOX amino acid substitutions in both the presence and absence of mercury. The resulting CPOX variant effect maps reflect known protein structure and mutational tolerance patterns while also offering new sequence-structure-function insights. Scores from this atlas not only distinguish pathogenic from benign variants but also identify mercury-dependent variant impacts, thus informing our clinical, structural, and functional understanding of CPOX deficiency and illustrating the value of systematic context-dependent multiplexed assays of genetic variant effects.

molecular biology↗

bioRxiv2026

A Glutamine antagonist-modulated tumor microenvironment unleashes enzalutamides immunotherapeutic effects

Androgen receptor (AR) antagonists, such as enzalutamide, suppress prostate cancer (PCa) cells to achieve temporary therapeutic effects. In addition to tumor cell-autonomous suppressive function, AR antagonists can also potentially exert anti-tumor effects via mitigating cytotoxic T cells exhaustion. However, strategies for effectively harnessing enzalutamides immunotherapeutic effects remain elusive. In studying a recently described glutamine antagonist prodrug (DRP-104) in PCa models, we found that despite the initial response, tumors ultimately became resistant. Intriguingly, compared to the untreated (DRP-104 treatment-naive) tumors, the resistant tumors became highly susceptible to enzalutamide in vivo. Additionally, treating tumors with DRP-104 and enzalutamide simultaneously also yielded superior therapeutic efficacy. We demonstrated that DRP-104 therapy promoted the infiltration of CD8+ T cells as well as regulatory T cells (Treg) in responsive tumors, and the tumor-infiltrating Treg were mostly depleted upon enzalutamide treatments. Mechanistically, we showed that Treg differentiation from mouse CD4+ T cells was attenuated by enzalutamide. We further demonstrated that Treg induction was accompanied by the interaction between AR and aryl hydrocarbon receptor (AhR), the nuclear receptor indispensable for Treg differentiation, in the nuclei of CD4+ T cells, and this interaction was diminished by enzalutamide. In further support of AR signaling in Treg biogenesis, analysis of available gene expression datasets found that AR expression was elevated in Treg when compared to CD4+ T cells in human peripheral blood mononuclear cells (PBMCs). In addition, it was positively correlated with Treg module scores in several human cancer types. Finally, using an anti-GPC3 (Glypican 3) vaccination model, we demonstrated that CD4+ T cells subjected to Treg induction in the presence of enzalutamide were less effective in protecting GPC3-expressing tumor cells from CD8+ T cells cytotoxic killing. Collectively, these results suggest that AR promotes Treg s differentiation and/or immunosuppressive functions, and nominate enzalutamide as a Treg-mitigating agent for potentiating immunotherapies. Our results also demonstrate that an otherwise unintended, Treg-promoting property of DRP-104 can be leveraged to unleash the immune-regulatory function of enzalutamide for the treatment of PCa.

cancer biology↗

bioRxiv2026

Effect of CSFV on Differential Genes of Histone Lactylation at H3K18 in the PI3K-AKT Signaling Pathway

Classical swine fever (CSF) is a highly contagious disease caused by Classical swine fever virus (CSFV), posing a serious threat to the global swine industry. This study aimed to investigate the effect of CSFV on differential genes of histone lactylation at the H3K18 site in the PI3K-AKT signaling pathway. The site with the most significant change in histone lactylation antibody level was screened by Western blot. Omics analysis was performed using CUT&Tag technology to identify differential genes in the PI3K-AKT pathway between the CSFV-infected group and the mock group, followed by validation using RT-qPCR. Functional analysis of significantly differential proteins was conducted, and the protein expression level of THBS4 was detected by Western blot. The results showed that after CSFV infection of 3D4/21 cells, the H3K18la site exhibited the most significant difference in antibody level. A total of 8,859 differential genes at the H3K18la site were identified by CUT&Tag analysis, including 6,349 up-regulated genes and 2,510 down-regulated genes. Further focusing on the PI3K-AKT signaling pathway, 10 differential genes were identified, comprising 6 up-regulated genes and 4 down-regulated genes. Compared with the control group, the mRNA expression levels of CD19, LAMA1, PDGFRA, BDNF, ANGPT4, and THBS4 were up-regulated in the CSFV-infected group, while FOXO3 and NRTN were down-regulated. Western blot results showed that the protein expression level of THBS4 increased after CSFV infection. These findings lay an important foundation for understanding the molecular mechanisms regulating viral replication and immune evasion, and have significant scientific implications and potential application value.

microbiology↗

bioRxiv2026

Dozens of genetic variants sustain adaptation to urban spatial heterogeneity in Arabidopsis thaliana

Urbanization creates mosaics of microhabitats that sustain diverse plant communities and offer untapped opportunities to understand contemporary ecological and evolutionary processes. Using a city-wide colonization experiment in Cologne (Germany), we identified the environmental factors limiting establishment and persistence of the ruderal species Arabidopsis thaliana and the genetic variants enabling adaptation. We show that standing genetic variation is essential for realizing the species urban niche, enabling rapid adaptation to fine-scale gradients in disturbance, vegetation, and soil conditions. Despite originating from only two parental genotypes, populations evolved substantial adaptive differentiation within three generations, revealing a highly polygenic basis of local adaptation. More broadly, our approach establishes cities as powerful open-air laboratories for uncovering and fostering ecological and evolutionary processes that generate and sustain biodiversity in human-dominated landscapes.

evolutionary biology↗

bioRxiv2026

CWF19L2 couples pre-mRNA alternative splicing with the maternal-to-zygotic transition to safeguard female fertility

The maternal-to-zygotic transition (MZT) requires precise spatiotemporal execution of pre-mRNA alternative splicing (AS), yet the core splicing machinery driving this developmental reprogramming remains incompletely understood. Here, we identify the CWF19-like protein 2 (CWF19L2) as an indispensable pre-mRNA AS regulator that safeguards against oocyte and early embryo competence defects (OECD). While murine germline-specific depletion of Cwf19l2 spares morphological folliculogenesis, oocyte maturation, or fertilization, it induces complete female sterility characterized by profound developmental arrest at the 2-cell stage. Mechanistically, maternal deficiency of CWF19L2 localized to nuclear speckles disrupts transcription-splicing-translation coupling, collapsing AS homeostasis during maternal reserves and zygotic genome activation. We further demonstrate that CWF19L2 orchestrates the pre-mRNA splicing network through directly binding to target transcripts and indirectly modulating via interacting with the core spliceosomal factor PRPF8. Importantly, exogenous Cwf19l2 mRNA partially rescues the embryonic arrest. Together, our findings establish CWF19L2 as an indispensable AS engine during the MZT, providing a mechanistic foundation for OECD and a novel molecular etiology for female infertility.

Cell Biology↗

bioRxiv2026

Extending the least-cost theory of stomatal regulation to include soil moisture stress

O_LITerrestrial biosphere models commonly use empirical scaling factors to represent soil moisture constraints on carbon and water fluxes, but these lack mechanistic grounding and produce inconsistent estimates of soil moisture limitations on primary production and transpiration across models. C_LIO_LIHere we extended the least-cost hypothesis for optimal stomatal conductance to account for soil moisture limitations by allowing soil water availability to modulate the carbon cost of water transport, drawing on the observed temperature dependence of stem respiration, and derived a simple empirical approximation to the theory using global {delta}13C and eddy covariance data. C_LIO_LIThe empirical analysis shows moderated thermal acclimation of stem respiration and a weak increase in water transport costs with aridity, supporting the interpretation that the decline in light-use efficiency (LUE) under arid conditions is primarily attributable to non-stomatal limitations. C_LIO_LIValidation against an independent global dataset of sapflow-derived canopy conductance and transpiration shows that the revised scheme significantly improves the predictive power of the least-cost hypothesis, offering a more mechanistically coherent alternative to existing soil moisture parameterisations. C_LI

Plant Biology↗

bioRxiv2026

CellTosg2Sequence: A Unified Text-Omics-Signaling-Graph Large Language Model for Single-Cell Analysis

In single-cell (sc)-based scientific discovery, text-formatted biomedical prior knowledge and signaling graphs are essential for annotating and interpreting numeric sc-omics data and for generating novel testable hypotheses. A major limitation of existing single-cell large language models (scLLMs) is that they rely on numeric expression data with gene names as the only textual signal, while comprehensive biomedical priors -- cellular localization, gene function, disease associations, and signaling interaction patterns -- remain absent from the model input. We introduce CellTosg2Sequence, a textual-prior- and signaling-graph-augmented cell-omics-sentence language model. A lightweight heterogeneous graph encoder maps a curated 62,507-node biomedical knowledge graph (KG) into compact virtual tokens that are prepended to each cell sentence, allowing the language model to condition on biological structure with minimal sequence-length overhead. We train CellTosg2Sequence with a three-stage objective: Stage I anchors the KG channel under autoregressive language-model pretraining, leveraging Qwen2.5-32Bs own language reasoning for rapid KG alignment; Stage II aligns labels via supervised fine-tuning with KG-anchored InfoNCE; Stage III applies Group Relative Policy Optimization (GRPO) with an ontology-hierarchy reward, enabling free-generation cell-type prediction that generalizes beyond the closed training vocabulary. Across multiple benchmarks and ablation experiments, CellTosg2Sequence outperforms strong baselines. All results are achieved with lightweight LoRA training and a single unified checkpoint. Data ethicsThis work uses publicly available single-cell datasets from the Human Cell Atlas (https://www.humancellatlas.org) and the Tahoe-100M consortium. All HCA constituent studies were collected under appropriate donor consent and institutional oversight as described in their original publications; we perform computational re-analysis only and introduce no new human subjects data. HCA data access follows the HCA Data Portal terms of use. No new patient data are collected in this study; no additional IRB approval is required for this secondary computational analysis.

bioinformatics↗

bioRxiv2026

A human intracranial map of consciousness returning from anesthesia

How consciousness arises from the brain remains a central yet unsolved question. Although substantial effort has been devoted to characterizing the neural correlates of conscious perception during wakefulness, how consciousness re-emerges from unconscious states remains poorly understood. Here, we took advantage of the rare opportunity to record human intracranial local field potentials from propofol-induced general anesthesia through the transition to behavioral engagement and subsequent full wakefulness, capturing both the stable states of unconsciousness and consciousness and the reconstituting neural dynamics that bridge them. Anesthesia cannot be defined by any single electrophysiological signature; rather, it is an organized low-frequency regime characterized by a constellation of coordinated neural phenomena, including aperiodic slow waves, alpha/beta periodicity, global alpha synchronization, and slow-wave-alpha/beta phase-amplitude coupling. Following anesthetic cessation, this regime progressively dissolved as neural excitability and dynamical complexity climbed. The appearance of conscious behavior coincided with a fast and dramatic transformation in high-gamma activity, from stochastic and unpredictable bursts to structured responses that were distributed, task-selective, and event-locked. These findings suggest that the recovery of consciousness is a multiscale reorganization in which distinct neural underpinnings rise and fall. Together, this work charts an electrophysiological map of how conscious cognition is extinguished, reconfigured, and restored in the human brain.

neuroscience↗

bioRxiv2026

Orthogonal Acoustic Control of Gene Expression Using a Synthetic T7RNAP Rapa-Inducible Dimerization System

Precise spatiotemporal regulation of engineered microbes remains a critical bottleneck in synthetic biology. While ultrasound is extensively utilized for imaging and drug delivery, its translation into bacterial chassis is hindered by the lack of stringent biochemical triggers. Here, we present a rationally designed, ultrasound-responsive hybrid molecular switch based on a strict acoustic-biochemical "AND-gate". We engineered a highly sensitive split-T7 RNA polymerase system, which the dimerization and subsequent gene transcription can only be triggered in the presence of both ultrasound and a PEG-modified rapamycin. By systematically optimizing the acoustic parameters, we deployed this spatiotemporal switch to dynamically regulate a microbial consortium. With lysisE suicide protein as the output module, we achieved precise and programmable tuning of bacterial population in a co-culture system. This acoustic gating strategy may provide a robust and versatile toolkit for complex microbiome engineering and dynamic biomanufacturing. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=158 SRC="FIGDIR/small/733485v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@6d229corg.highwire.dtl.DTLVardef@fb5d1eorg.highwire.dtl.DTLVardef@9e905dorg.highwire.dtl.DTLVardef@17e3a1_HPS_FORMAT_FIGEXP M_FIG Graphic Abstract C_FIG

Synthetic Biology↗

bioRxiv2026

A missense mutation in FBXL3 links circadian regulation to out-of-season estrus in sheep

Seasonal breeding is a remarkable adaptive trait, but it constrains efficient production in the sheep industry. Recent studies have shown that seasonal breeding is associated with endogenous circannual rhythms, which are regulated in part by the circadian clock system. FBXL3, a pivotal component of the SCF (SKP1 - CUL1 - F-box) E3 ubiquitin ligase complex, is a known determinant of the mammalian circadian period. In this study, we identified a missense mutation, T183M, in FBXL3 through selective sweep analysis. The allele frequency of this mutation differed significantly between sheep breeds exhibiting year-round estrus and those showing seasonal breeding patterns. The association between the T183M mutation and seasonal breeding was further validated using an ovariectomized, estradiol-implanted sheep model. We then generated mice carrying the homologous T183M mutation and found that they exhibited significantly lengthened circadian periods, accompanied by reduced CRY1 expression and increased CLOCK expression. Co-immunoprecipitation assays confirmed that the mutation reduced the interaction between FBXL3 and CRY1. These findings demonstrate an evolutionarily conserved role of FBXL3 in the circadian clock system. We propose that the T183M mutation disrupts day-length recognition, thereby influencing seasonal estrus in sheep. Author summarySeasonal breeding limits sheep productivity and is regulated by circadian rhythms, yet the key genetic determinants remain poorly understood. Here, we identified an FBXL3 T183M missense mutation whose allele frequency differed markedly between year-round-estrous and seasonally breeding sheep, and validated its association with seasonal reproduction in a sheep population. Functional analyses in mutant mice showed that this variant lengthened the circadian period, disrupted the expression of core clock genes, and weakened the interaction between FBXL3 and CRY1. These findings suggest that the FBXL3 T183M variant impairs day-length perception, thereby modulating seasonal estrus in sheep. Our study reveals a conserved circadian mechanism underlying seasonal breeding and highlights FBXL3 T183M as a promising genetic target for improving reproductive performance in sheep.

genetics↗

bioRxiv2026

Antigen Stimulation Reactivates HIV-1 Proviruses Despite Integration in Repressive Chromatin

Intact HIV-1 proviruses become progressively enriched in transcriptionally repressive genomic regions during long-term antiretroviral therapy (ART) and in elite controllers, raising questions about their capacity for reactivation in vivo. We used an antigen-restricted quantitative viral outgrowth assay (ag qVOA) to test whether cognate antigen stimulation can reverse latency of proviruses integrated within repressive chromatin. Using cells from two people with HIV (PWH) on ART, one on long-term treatment and one an elite controller, we show that antigen-specific stimulation induces viral outgrowth from intact proviruses integrated into a pericentromeric transition region and a zinc finger gene, respectively. These findings demonstrate that antigen recognition can overcome epigenetic constraints to reactivate proviruses with low inducibility and suggest that proviruses in so-called "deeper latency" may contribute to residual viremia and viral rebound following treatment interruption.

immunology↗

bioRxiv2026

A multi-agent system for spine MRI report generation from multi-sequence imaging

Spinal pathology is a leading cause of pain and disability worldwide. Spine magnetic resonance imaging (MRI) is central to clinical evaluation, yet its interpretation remains complex and time-consuming, requiring integration of information across multiple imaging sequences and anatomical regions. Despite recent advances in automated MRI analysis, effectively combining multi-sequence data while preserving sequence-specific diagnostic information remains an open challenge. Here we present SpineAgent, a multi-agent framework for spine MRI report generation built upon a multi-sequence foundation model trained on routine clinical data from 32,047 patients and 453,683 MRI series, comprising a total of 13,441,191 MRI slices. To accommodate diverse modalities of sequences, we first pre-train two DINOv3-based encoders separately on T1- and T2-weighted sequences. We then introduce a continual training strategy that learns a synthesizer to embed images of other sequences using the T1 and T2 encoders, producing patient-level embedding that integrates various signals across MRI sequences. Using these embeddings, SpineAgent achieves state-of-the-art performance, with mean 10.8% AUROC improvement across 17 spinal condition-prediction tasks compared to the best competing method, and demonstrates strong generalizability under cross-manufacturer and cross-cohort evaluation. Beyond classification, SpineAgent enables pathology localization by identifying findings-relevant slices and segmenting pathological regions. It also supports multimodal image-report retrieval, providing a solid foundation for scalable and explainable MRI report generation. We further integrate these validated capabilities of SpineAgent into 37 specialized agents for condition diagnosis, pathological-region localization, and clinically-similar-cases retrieval. Finally, we incorporate their outputs as structured tokens within a Medical Report Agent trained end-to-end for report generation. Through both automated metrics and expert evaluation by five radiologists, SpineAgent achieves leading performance in spine MRI report generation. Together, SpineAgent introduces a continual training approach for multi-sequence spine MRI understanding. By decomposing report generation into clinically grounded subtasks addressed by specialized agents, the SpineAgent framework enables accurate, interpretable and generalizable spine MRI reporting across diverse imaging sequences and anatomical regions.

bioinformatics↗

bioRxiv2026

BCMA/CD19 dual-targeting with FasTCAR: AZD0120 demonstrates potent preclinical efficacy in multiple myeloma

Chimeric antigen receptor (CAR)-T cell therapy has improved outcomes for patients with multiple myeloma (MM), but its broader use is restricted by manufacturing complexities and treatment-related toxicities. AZD0120 is a dual-targeting B-cell maturation antigen (BCMA)/CD19 CAR-T cell therapy manufactured via the rapid FasTCAR process. We developed a dual-targeting "loop" CAR that incorporates a novel humanized anti-BCMA single-chain variable fragment (scFv), clone SG, and an FMC63-derived anti-CD19 scFv. This AZD0120 CAR preserved functional binding to both antigens and conferred robust in vitro and in vivo cytotoxicity while maintaining single-antigen reactivity. Conventional manufacture of CAR-T cells with the AZD0120 CAR (AZD0120C) yielded cells with minimal tonic signaling, limited responsiveness to soluble BCMA, and preservation of naive/stem cell memory-enriched phenotypes, yet robust cytokine production upon BCMA+ target engagement. AZD0120C demonstrated cytotoxicity comparable to benchmark BCMA CAR-Ts across MM lines in vitro and showed strong in vivo expansion and tumor control in xenograft models. FasTCAR manufacturing - designed to shorten vein-to-vein timelines and enrich less-differentiated phenotypes - further enhanced in vivo performance: AZD0120 consistently achieved superior tumor control and greater CAR-T expansion vs AZD0120C across disseminated MM.1S, NALM-6, and JeKo-1 models, with superior efficacy observed at lower cell doses. Collectively, these data support clinical evaluation of AZD0120 as a differentiated BCMA/CD19 CAR-T cell therapy with the potential to improve disease control and patient access in MM. Key PointsO_LIAZD0120 is a dual-targeting CAR-T that displays a favorable anti-myeloma functional profile and co-targets a source of potential relapse C_LIO_LIThe FasTCAR process yields TN/SCM-rich CAR-T populations, promotes in vivo expansion and achieves potent tumor control in xenograft models C_LI

cancer biology↗

bioRxiv2026

Visualization of the architecture of flexible chromatin and the binding of chromatin regulators

Chromatin organization plays a central role in regulating genome accessibility and gene expression in eukaryotic cells. However, the inherent flexibility and structural heterogeneity of chromatin pose significant challenges for its structure determination. Here, we use a Nuc-back strategy with cryo-electron tomography (cryo-ET) and subtomogram averaging methods to visualize chromatin at the nucleosome level by averaging nucleosome at moderate-to-high resolution, classifying the fundamental unit of chromatin, i.e., nucleosome, into distinct classes, and linking different nucleosome structures to chromatin architecture. We reveal that nucleosome heterogeneity is a key factor in chromatin flexibility which disrupts interactions between nucleosomes. In addition, this strategy allows for the localization and visualization of chromatin regulators and their structure on chromatin. These results provide a foundation for future research in 3D genome and epigenetic process visualization. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=82 SRC="FIGDIR/small/730377v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@1b003c8org.highwire.dtl.DTLVardef@c86543org.highwire.dtl.DTLVardef@7033f5org.highwire.dtl.DTLVardef@635485_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2026

Associations Between Plasma Lipoprotein(a) Levels and Circulating Monocyte Subsets Differ across Populations

BackgroundLipoprotein(a) [Lp(a)] is a causal risk factor for cardiovascular disease (CVD), with plasma concentrations higher in Black individuals than in White individuals. Published findings support a model in which high Lp(a), in part through oxidized phospholipid (oxPL)-mediated signaling, promotes a pro-inflammatory monocyte phenotype that may contribute to arterial wall inflammation and the development of CVD. Here, we examined the relationship between Lp(a) concentrations and isoform size and the distribution of circulating monocyte populations in Black and White individuals using single-cell RNA sequencing (scRNA-seq) data. MethodsUsing standardized assays, we measured plasma Lp(a) levels, isoform size, inflammatory markers, and oxidized phospholipids in stored plasma samples from our previously published cohort of 128 participants. After excluding smokers and individuals with type II diabetes, a total of 34 participants (20 Black participants, 14 White participants) were included in analyses. Participants were further stratified by plasma Lp(a) levels into normal Lp(a) [median 12.6 nmol/L, with 15 individuals (8 Black participants) and high Lp(a) (median 159 nmol/L, with 19 individuals (12 Black partcipants)]. Multivariable linear regression was used to assess the association between plasma Lp(a) levels, Lp(a)-oxPL, and the proportion of monocyte subsets. Across all participants, scRNA-seq data identified six classical monocyte subsets, one non-classical monocyte subset, one MHCIIhi monocyte subset, and one interferon (IFN)-responsive monocyte subset. ResultsThe distribution of monocyte subsets was similar in individuals with normal versus high Lp(a) levels. Despite the small study cohort, self resported race modified the assocation between plasma Lp(a) levels and the proportion of non-classical monocytes (P = 0.032), which was inversely associated in White participants (P = 0.028), but not in Black partcipatns (P = 0.470). OxPL bound to APO(a) showed a positive correlation with plasma Lp(a) levels (R2 = 0.84; P = 3.3x10-14), and non-classical monocytes (PWhites = 0.027; PBlacks = 0.275; PInteraction = 0.014). Race also modified the association between plasma Lp(a) levels and the proportion of classical 2 monocytes (P = 0.027). ConclusionsThese results underscore the importance of self reported race when analysing studies on Lp(a), monocytes and, cardiovascular related monocyte immune functions.

immunology↗

bioRxiv2026

Heterochromatin organization and liquid-liquid phase separation: it is not about if but about when

Heterochromatin is a membraneless compartment within the cell nucleus. In recent years, a controversy arose on whether heterochromatin organization is driven by liquid-liquid phase separation or not. While many heterochromatin proteins were shown to undergo liquid-liquid phase separation in vitro, other studies reported that this does not happen in cells. Here, we tested the ability of heterochromatin proteins to generate heterochromatin barrier compartments in cells. We found that, while several proteins (H1.0, H1.4, HP1alpha, HP1beta, Mbd1, Mbd2 and MeCP2) form barrier compartments in mouse and/or human cells this differs between cell types. In addition, not all compartments in the same cell form barriers. We established and experimentally validated a model that predicted the ability to form barrier compartments is dependent on the protein accumulation in heterochromatin followed by the competition between compartments for the nucleoplasm pool of the protein and resulted in larger size for the barrier compartments. These findings resolve the existing controversy and rationalize how in cells heterochromatin compartments form and compete to establish dynamic barriers to the entry and exit of its components. HighlightsHeterochromatin barrier formation differs between proteins, cell lines and heterochromatin compartments within the cell. Barrier formation depends on heterochromatin anchors, including ligands and other scaffolds. Barrier compartments are defined by their larger size and higher protein enrichment. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=83 SRC="FIGDIR/small/729812v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@a63021org.highwire.dtl.DTLVardef@a20362org.highwire.dtl.DTLVardef@8c2390org.highwire.dtl.DTLVardef@72dde3_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗