Search bioRxiv⌕ Search

Biology subjects

Huang, S.

Publications and source records attributed to Huang, S..

At least 19 recordsLinked to original sources

CST-Polα/primase, backed up by Rif1, protects telomeric ss-dsDNA junctions from damage recognition and resection

The yeast Cdc13-Stn1-Ten1 (CST) complex is critical for telomere length regulation and telomere protection. Recent studies further implicate Pol/primase (PP) as an essential partner of CST in executing these functions, but the mechanistic bases remain poorly understood. Using the pathogenic yeast Nakaseomyces glabratus, a model amenable to mechanistic dissection of CST-PP, we analyzed the protection mechanisms of CST-PP by combining mutations that disrupt individual subunits or complex assembly with mutations in DNA damage response (DDR) and DNA repair factors. The complete loss of Cdc13 - which eliminates the CST-PP assembly - results in telomere damage recognition involving Rad9, Rad24 and Mec3, as well as aberrant resection mediated by Exo1 and Sgs1. In contrast, disrupting the interaction between CST and PP leads to proliferation defects triggered primarily by Exo1, implying a more selective protection function for PP. The involvement of the DDR clamp loader and clamp together with Exo1 points to ss-dsDNA junctions with recessed 5' ends as a crucial lesion in the absence of Cdc13. Further analysis implicates RNase H1 and H2 in promoting DNA damage, possibly by exposing such junctions. Based on similarities between Cdc13 and POT1, a telomere protein previously implicated in junctional protection, we modeled Cdc13 binding to a ss-dsDNA junction and showed that point mutations at the proposed interaction site impaired telomere protection and altered the distribution of the telomere C-strand 5' ends in vivo. We further demonstrate that Rif1, another telomere protein with junctional binding activity, supports the protection function of CST-PP. Together, our findings illuminate the molecular basis of telomere DNA damage and of CST-PP mediated telomere protection.

molecular biology↗

Pyruvate partitioning defines an immunosuppressive metabolic niche in colorectal cancer

Purpose. Colorectal cancer (CRC) reprograms glucose metabolism, diverting pyruvate from mitochondrial oxidation toward lactate export. How this partitioning decision is organized across cell types and tissue space, and how it relates to immune programmes, remains unresolved. Methods. We defined a Pyruvate Partitioning Index (PPI) as the difference between an oxidative arm (MPC1, MPC2, PDHA1, PDHB, DLAT, DLD, PDHX) and an export arm (LDHA, LDHB, SLC16A1, SLC16A3, SLC16A7), and computed it across TCGA COADREAD (n = 592), GSE39582 (n = 579), two single-cell atlases (370,115 and 63,689 cells), 13 Visium sections and an exploratory urothelial immunotherapy cohort (IMvigor210, n = 298). Results. PPI was lowest in microsatellite-unstable (MSI) tumours (Mann-Whitney p = 3.8 x 10^-9) and inversely associated with overall survival (log-rank p = 1.2 x 10^-4). Epithelial cells were the most oxidative compartment (median +0.058) and myeloid cells the most export-prone (-0.171; Kruskal p [~] 0), reproduced independently; MMRd epithelium was intrinsically export-shifted (-0.012 vs +0.076 vs +0.192 for MMRd, MMRp and normal). Spatially, PPI was non-random (Moran's I significant in 12/13 sections), with low-PPI spots enriched for SPP1+ macrophages, myofibroblasts and plasma cells, but not CD8+ T-cell factors. Low-PPI tumours showed coordinated increases in immune-checkpoint, myeloid and Treg programmes (checkpoint rho = -0.262), and network perturbation identified LDHA as the hub. Conclusions. Pyruvate partitioning is cellularly and spatially organized in CRC and defines a myeloid-stromal immunosuppressive niche. Because MSI tumours (the best CRC immunotherapy responders) had the lowest PPI, the PPI-response relationship appears cancer-type specific and requires validation in CRC cohorts.

cancer biology↗

Stimulus overlap confounds generalization in EEG foundation-model benchmarks

Neural decoding benchmarks commonly evaluate generalization across participants while reusing the same experimental stimuli in training and test sets. This design cannot distinguish transfer to new stimuli from recognition of familiar material, a distinction that is increasingly important for electroencephalography (EEG) foundation models, pretrained models designed to learn reusable neural representations. Here we introduce a training-matched audit that varies stimulus overlap while holding test trials, training participants and stimulus counts fixed. Across ten tasks from seven EEG emotion datasets, stimulus overlap increased differential-entropy decoding accuracy in every task and accounted for 77% of above-chance seen-stimulus performance on FACED-9. Across representations, overlap-dependent gains tracked stimulus identifiability; for CBraMod and LaBraM, advantages over input-matched handcrafted features were concentrated on familiar stimuli. Architecture-matched random controls nevertheless showed transferable benefits of pretraining on unseen stimuli. These results separate participant generalization from stimulus generalization and provide a framework for evaluating both in neural decoding benchmarks.

neuroscience↗

CHORUS: A proteome-scale atlas of membrane interaction interfaces constructed using cross-protein language model embeddings from sequences alone

Membrane proteins drive vital cellular signaling and bioenergetics yet resolving their physical interaction interfaces remains hindered by the paucity of experimental complexes and the breakdown of sequence alignments across hydrophobic bilayers. Here, we present CHORUS, a sequence-only deep-learning framework that decodes interaction sites across membrane proteins without requiring 3D structures, multiple sequence alignments (MSAs), or predefined partner identities. By systematically synthesizing complementary latent representations across diverse protein language model (pLM) families and functional layer depths, CHORUS outperforms 18 established sequence- and structure-based methods across 4,655 homology-isolated test contexts (average precision: 0.643), demonstrating amplified predictive capacity within the lipid-embedded core (0.746). We show that CHORUS delineates quaternary contact boundaries across megadalton respiratory supercomplexes directly from sequences alone (0.984). We deliver the CHORUS Atlas (https://chorus.atlas.sunnylab.org), providing precomputed, residue-resolved interaction landscapes for 80,619 reviewed transmembrane proteins spanning 4,918 species and 33.7 million residues to empower interactome-scale discovery and allosteric therapeutic design.

bioinformatics↗

scPRIME-seq uncovers synchronized multimodal molecular collapse facilitated by pre-neoplastic epigenetic burden in prostate cancer

Tumorigenesis involves alterations across the genome, epigenome and transcriptome, yet how these layers interact to drive malignant transformation remains unclear, largely due to the lack of scalable multimodal single-cell approaches. Here, we developed scPRIME-seq, a high-throughput platform for simultaneous single-cell profiling of transcriptome, genome and DNA methylome, and applied it to 436,908 cells from 29 prostate cancers and 15 benign tissues. This multimodal atlas resolved dynamic changes across 30 cell types and a unified tumorigenic trajectory. Integrated analysis revealed a cell-state transition tipping point, where the onset of aneuploidy is temporally coupled with global methylomic alterations and transcriptomic rewiring. Early focal epigenetic alterations, including TMEM106A promoter hypermethylation and the emergence of hypomethylated domains, were present in founder aneuploid clones and benign tissues, indicating a pre-neoplastic origin of epigenetic burden. These pre-neoplastic alterations coincide with transcriptomic changes that affect epithelial interactions with stromal and immune compartments, promoting a putative tumor-permissive microenvironment. scPRIME-seq provides a high-throughput multimodal framework for identifying conserved, cell-intrinsic molecular programs underlying tumorigenesis.

cancer biology↗

In situ identification of pre-hematopoietic stem cells and their niche

Definitive hematopoietic stem cells (HSCs) emerge predominantly along the ventral surface of the dorsal aorta in the embryonic aorta-gonad-mesonephros (AGM) region, yet the spatial organization of the niche underlying this developmental asymmetry remains poorly understood. Defining the native niche of pre-HSCs has also been hindered by their rarity, transient nature and lack of a single definitive marker for their identification in situ. Here, we integrated single-cell and spatial transcriptomics to construct a spatiotemporal atlas of the niche in the AGM. Neural cells and chondrogenic mesenchyme predominated dorsally, whereas N-cadherin mesenchymal stromal cells (N-cad+ MSCs) formed a ventral layer between the aortic endothelium and mesonephric cells. BMP and SHH signaling showed overall dorsal enrichment, whereas WNT, NOTCH and KIT signaling were enriched ventrally, with these cellular and signaling patterns dynamically remodeled across HSC ontogeny. Imaging-based spatial transcriptomics validated the findings and further enabled the identification of individual pre-HSCs in situ and revealed a multicellular niche comprising endothelial cells, N-cad+ MSCs, intra-aortic hematopoietic cluster cells and macrophages. TGF{beta} and NOTCH signals were primarily supplied locally, whereas major sources of BMP and WNT were more distant. Functional perturbation identified niche-derived CD200 as an immune-regulatory signal promoting HSC development, validating a spatially predicted niche interaction. Together, our findings link tissue-scale spatial organization with the local multicellular niche supporting the preferential development of HSCs along the ventral aorta.

developmental biology↗

Simultaneous multi-area recordings in macaque frontoparietal cortex during a manual object-interaction task

Dexterous hand control is essential for daily activities and a top restoration priority for people with tetraplegia, yet neurophysiological datasets suitable for studying and decoding naturalistic hand behavior remain scarce. Most available recordings constrain movements to a small number of degrees of freedom or cover only a single stereotypical grasp-and-hold structure. Moreover, previous brain-computer interface (BCI) studies have largely relied on signals from a single cortical area, even though dexterous hand control is distributed across an interconnected frontoparietal network. To address these limitations, we designed a paradigm that elicits rich hand movements across 40 distinct hand-object interaction conditions. We recorded simultaneous frontoparietal activity with hand kinematics from a rhesus macaque performing them. Neural activity was recorded from the primary motor cortex, anterior intraparietal area, and ventral premotor cortex using microelectrode arrays spanning 1,920 channels, while a multi-camera markerless motion-capture system acquired video from which kinematics were extracted offline. The dataset comprises data from 20 sessions, including processed neural features, synchronized 3D coordinates of hand and elbow keypoints, and trial-level metadata including task conditions and event timing. We further provide technical validation, including a neural decoding benchmark with multiple algorithms for continuous keypoint coordination reconstruction. We found that cross-day and cross-task decoding performance varied among algorithms. Variation in channel availability leads to different performance degradation curves in different algorithms. This task-rich dataset offers a valuable resource for investigating the neural mechanisms of dexterous hand control and for advancing the performance of motor BCIs.

neuroscience↗

Unraveling APA dynamics during quiescence transitions reveals Pabp modulation of sod2 expression via APA to regulate cellular quiescence

Quiescence is a reversible proliferation arrest enabling cells to adapt to environmental changes, yet the post-transcriptional mechanisms governing its transitions remain poorly understood. Here, we map genome-wide alternative polyadenylation (APA) dynamics across 15 time points of quiescence transitions in fission yeast using 3'-end RNA sequencing. We reveal that APA undergoes extensive remodeling: driving global 3'UTR lengthening during early quiescence entry, 3' UTR shortening upon quiescence establishment, and progressive reversal to proliferative-state lengths during quiescence exit. Integrating 3' UTR dynamics with differential expression analysis, we identify candidate genes potentially regulated through APA-mediated 3' UTR mechanisms. We demonstrate that sod2, encoding mitochondrial superoxide dismutase, autoregulates its mRNA and protein levels via APA-dependent 3' UTR changes. Disrupting proximal APA site of sod2 in a mitophagy-deficient (atg43{Delta}) background exacerbates quiescence maintenance defects and mitochondrial dysfunction. We further identify Pabp as an upstream regulator of sod2 APA. This study establishes the temporal APA remodeling during quiescence transitions and reveals a Pabp-APA-sod2 regulatory axis governing post-transcriptional control of cellular quiescence.

cell biology↗

An accumbal cholinergic ISR-HCN2 axis sustains maladaptive cue motivation

Environmental cues associated with rewarding outcomes can exert persistent control over behavior long after the reward is absent, yet the cellular adaptations that stabilize such maladaptive motivation remain unclear. Here we identify nucleus accumbens cholinergic interneurons (CINs) as causal regulators of persistent cue-driven seeking. Self-administration of addictive drugs or high-fat reward, but not sucrose, selectively increased CIN pacemaker firing. Cocaine-paired cues evoked rapid acetylcholine release in the nucleus accumbens core, and bidirectional manipulation of CINs suppressed or enhanced cue-induced cocaine seeking. Mechanistically, cocaine experience engaged the integrated stress response (ISR) in CINs, increased HCN2 expression and Ih, and stabilized a hyperexcitable state. CIN-specific ISR suppression or HCN2 knockdown reduced cocaine seeking, whereas HCN2 overexpression enhanced it. Local HCN blockade and systemic treatment with the clinically approved HCN blocker ivabradine reduced cue-driven seeking across addictive-drug and high-fat-reward paradigms while sparing sucrose seeking. These findings identify an ISR-HCN2-dependent cholinergic mechanism that stabilizes maladaptive cue-driven motivation and nominate HCN-dependent excitability as a tractable target for therapeutic intervention.

neuroscience↗

A therapeutic vulnerability linking MNK1/2 inhibition and G1/S cyclin-dependent kinase blockade in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a clinically challenging disease with limited therapeutic options. MAP kinase-interacting kinases 1 and 2 (MNK1/2)-mediated phosphorylation of eukaryotic initiation factor 4E (eIF4E) promotes oncogenic translation and represents a potential therapeutic target. We previously showed that loss of eIF4E phosphorylation suppresses metastasis but not primary tumor growth. Here, an shRNA screen surveying druggable genes unveiled cyclin-dependent kinase 4 (CDK4) as a genetic vulnerability to MNK1/2 inhibition in MDA-MB-231 TNBC cells. Although CDK4/6 inhibitors are approved for hormone receptor (HR)-positive, HER2-negative breast cancer, they are not approved for TNBC. We demonstrate that MNK1/2 inhibition synergizes with CDK4/6 blockade suppresses TNBC cell growth, a synergy also observed in another independent TNBC cell line (SUM159) using a broader G1/S CDK (CDK2/4/6) inhibitor. Integrated RNA sequencing and ribosome profiling revealed combination-specific changes in translation associated with mitotic checkpoint control and DNA repair. Our findings document MNK1/2 inhibition as a strategy to sensitize TNBC to G1/S CDK inhibition and provide a new avenue for therapeutic combination.

cancer biology↗

zAcademy: an open-source programmable conditioning arena reveals sex- and genotype-dependent avoidance learning in adult zebrafish

Zebrafish are widely used to study learning and memory. Here, we describe zAcademy, a programmable conditioning arena released in full as open hardware and open software. zAcademy combines a 3D-printed dual-chamber arena, bottom-mounted LED matrices that generate visual patterns under software control, graphite rod electrodes gated by an Arduino-controlled relay, an overhead infrared camera, and a position-based analysis workflow. In one 180-min session, adult zebrafish were classically conditioned to associate a checkerboard light pattern beneath the arena (conditioned stimulus, CS) with a mild shock (unconditioned stimulus, US). Conditioned avoidance was assessed in six unreinforced CS-alone probes: one immediately after training to test learning, the remaining five at 30-min intervals to test memory. Spatial preference was quantified as a performance index (PI; occupancy of the dark zone). Wild-type fish shifted toward the dark zone immediately after training, whereas shank3 KO fish did not. The wild-type response was carried primarily by females rather than males. In addition, among initial responders, females sustained elevated PI at more later probes. zAcademy provides an inexpensive, fully documented, and readily modified platform for comparing experience-dependent behavioral change across genotypes and sexes.

animal behavior and cognition↗

A conserved transcriptional axis links cortical organization, developmental timing and autism-associated perturbations

Much of our mechanistic understanding of cortical development and neurodevelopmental disorders comes from studies in mice, yet translating these insights to humans rests on a fundamental assumption: that the cortex is organized according to conserved principles across species. Here, by independently decomposing human and mouse cortical transcriptomes, we test this assumption and identify a shared organizational axis extending from limbic anterior ventral (AV) to primary sensory posterior dorsal (PD) cortex. This axis aligns with conserved variation in cell-type composition, thalamocortical connectivity, myelination and excitation-inhibition balance. Its spatial topology emerges by mid-gestation and is progressively refined while remaining stable in orientation across subsequent development. What varies systematically along the axis is developmental timing: AV-enriched genes preferentially retained earlier cortical-construction features and progressively decline after birth, whereas PD-enriched genes preferentially reflected later maturation processes and progressively increased, with developmental rates graded along the axis. Across genetically distinct autism mouse models, developmental dysregulation converged on this axis, following a shared pattern that generally intensified toward the PD pole. The same axis also organized genotype-specific patterns of cortical volume alteration, while human autism risk genes showed corresponding enrichment along this transcriptional coordinate. Overall, we identify a conserved transcriptional axis that links cortical architecture to developmental timing and organizes the heterogeneous cortical effects of autism-associated mutations.

neuroscience↗

A patient-centric therapeutic paradigm uncouples prostate cancer suppression from systemic metabolic collapse

The clinical benefits of cancer therapies are often compromised by the tolerable adverse effects that impair systemic organismal health and may evolve into latent life threats. Here, we identified profound abiraterone-induced but androgen-independent metabolic perturbations in prostate cancer patients and developed Lifehug-9892 to balance tumor therapy with systemic metabolic homeostasis. By integrating population cohorts with high-resolution metabolomics, we demonstrate that abiraterone induces profound systemic lipidomic dysregulation, characterized by the massive, pathological accumulation of desmosterol. Abiraterone inhibits but stabilizes DHCR24, leading to a metabolic trap in patients showing elevated levels of both desmosterol and cholesterol. Desmosterol accumulation is highly lipotoxic, potently triggering endothelial cell senescence and necrosis, macrophage foam cell formation, murine atherosclerosis, and hepatic senescence. To mechanistically uncouple and therapeutically rescue this systemic metabolic collapse, Lifehug-9892 was rationally designed to selectively retain on-target CYP17A1 inhibition while completely sparing DHCR24 function. Lifehug-9892 maintains potent tumor-suppressive activity while fully preserving the desmosterol-cholesterol metabolic axis and preventing systemic cardiovascular and hepatic damage. Our study uncovers a critical mechanistic link between drug-induced metabolic dysregulation and organismal health in cancer patients, providing a biochemical framework for developing patient-centric targeted therapies that preserve host homeostasis.

cancer biology↗

Diverse Intestinal Injuries Drive Heterogeneous Transcriptional Responses and Limited Reactivation of Developmental Gene Programs in Human Enteroids

The murine intestine reactivates developmental gene programs following various forms of damage in vivo and in vitro; however, injury response mechanisms used by the human intestine remain unclear. Using adult human small intestinal epithelium-only organoids ("enteroids"), we characterized the early response to eight injury conditions and injury-associated signaling pathways (P53, PGE2, YAP, TGFB) to interrogate whether human developmental genes were activated. P53 activation and decreased proliferation were common features across treatments. Most (7/8) injuries did not activate human development genes. Butyrate is a notable exception given it inhibited P53 and promoted a human developmental transcriptional signature. We observe that P53 induces a human adult gene signature while TGFB and YAP promote a developmental signature. Together our data characterizes various transcriptional responses to injury, supports injury-associated signaling pathways as regulators of human adult and developmental genes, and highlights how our data can be mined to predict injury-specific interventions for epithelial protection.

cell biology↗

Parasitic Vectors in Aquaculture: Neobenedenia girellae and Leeches as Potential Transmission Agents for Trypanosoma carassii spectrum and Pathogenic bacteria

Parasitic infections pose multifaceted threats to farmed fish, extending beyond direct pathogenicity to facilitate infections of bacteria, viruses, and microparasites. This synergistic interaction often leads to co-infections that significantly exacerbate disease outbreaks and mortality, presenting a severe challenge to aquaculture sustainability. Recently, a novel trypanosomiasis caused by the Trypanosoma carassii spectrum has emerged in cage-cultured Larimichthys crocea along the southeast coast of China, resulting in widespread prevalence and high mortality rates. Although this pathogen is hypothesized to originate from freshwater fish, its transmission route in marine environments has remained elusive. In this study, we investigated potential vectors and intermediate hosts of T. carassii spectrum, including leeches and monogenean in natural marine settings, and simulated transmission pathways using an established laboratory model involving T. carassii spectrum, Micropterus salmoides and the leech Poecilobdella manillensis. First, our field surveys in the coast of Ningde, Fujian Province, revealed a nearly 100% co-infection rate of T. carassii spectrum and the monogenean Neobenedenia girellae in diseased juvenile L. crocea. PCR analysis detected T. carassii spectrum traces in some N. girellae specimens, and subsequent experiments confirmed that N. girellae ingests the trypanosome while feeding on host blood. Furthermore, bacterial co-pathogens, such as Vibrio harveyi, were also detected within N. girellae. We also document two fatal leech infestations: Zeylanicobdella arugamensis in hybrid groupers (Epinephelus moara [female] X Epinephelus lanceolatus [male]) in Zhangpu, and Limnotrachelobdella okae in E. lanceolatus and E. fuscoguttatus in Raoping. These leeches tested negative for trypanosomes but carried pathogenic bacteria that co-infected the host fish; nonetheless, they are established vectors for trypanosome transmission. In a laboratory cohabitation model simulating T. carassii spectrum transmission, infected M. salmoides were housed with healthy conspecifics under three conditions: Group A (with the leech P. manillensis), Group B (no leeches), and Group C (no leeches, with physical separation between infected and healthy fish). After 14 days, blood smear microscopy and PCR analysis revealed infection rates in healthy fish of 58.33% in Group A, 40.00% in Group B, and 0% in Group C. Conclusively, T. carassii spectrum can be transmitted via leeches (with higher efficiency) and may also spread through direct contact under high-density aquaculture conditions, whereas N. girellae may act as an incidental vector, further research is warranted to clarify transmission dynamics in natural marine ecosystems. Additionally, our findings highlight the role of ectoparasites, including N. girellae and leeches, as potential reservoirs and vectors for bacterial pathogens of fish. In high-density intensive aquaculture, this vectorial capacity transforms parasites from primary pathogens into key drivers of polymicrobial disease outbreaks.

zoology↗

Potato Agent: AI-Driven Data and Knowledge Exploration on an Agent-Ready Potato Multi-Omics Platform

Potato is an important non-cereal food crop worldwide. However, the limited number of functionally validated genes remains a major bottleneck to favorable allele stacking and genome design breeding in potato. Rapid advances in AI agents offer a promising means to support crop breeding by translating natural-language questions into coordinated data analysis and knowledge retrieval. Their reliable use for potato breeding, however, is constrained by fragmented multi-omics resources that lack consistent curation and machine-accessible interfaces. Here, we constructed an agent-ready potato multi-omics database integrating genomic resources from 150 potato accessions, 259 bulk RNA-seq samples, and 14 spatial transcriptomic datasets into a pangenome, a tissue expression atlas, co-expression networks, and spatial expression maps accessible through open APIs. We developed 39 potato-specific Agent Skills for reproducible bioinformatics analysis and comprehensive data and knowledge exploration, enabling natural-language questions to be translated into standardized data-retrieval and analysis tasks. By integrating direct evidence from potato studies, functions of homologous genes in Arabidopsis, rice, and maize, and tissue expression patterns, we generated genome-wide functional predictions for 37,658 genes in the DM reference genome. We further developed Potato Agent as a multi-user, browser-based platform with isolated workspaces and online result preview, reducing the technical burden of agent deployment and providing direct access to integrated data, knowledge, and workflows. Case studies demonstrated its capabilities in reproducible bioinformatics analysis, agent-assisted identification of a tuber development regulator, scientific data visualization, and haplotype-aware promoter analysis and sgRNA design. Together, the agent-ready database and Potato Agent provide an integrated infrastructure for functional gene discovery and hybrid breeding in potato.

plant biology↗

ACKR1-expressing venous endothelial cells establish a pro-fibrotic niche in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by excessive extracellular matrix deposition and irreversible architectural distortion of the lung. Fibrotic remodeling is driven by dynamic interactions among endothelial, fibroblast, epithelial and immune cells. Although pulmonary endothelial cells (ECs) are increasingly recognized as important contributors to IPF pathogenesis, the molecular and cellular events underlying endothelial dysfunction remains poorly understood. Using integrative multi-omics analyses of human IPF lungs combined with functional in vitro assays, we identify ACKR1-expressing venous endothelial cells (ACKR1+ VECs) as critical regulators of a pathogenic niche that promotes lung fibrosis. Single-cell RNA sequencing and spatial transcriptomics analyses reveal that ACKR1+ VECs exhibit a distinct pro-fibrotic and pro-inflammatory transcriptional program enriched for hypoxia responses, extracellular matrix remodeling, and immune cell recruitment. In both mouse and human fibrotic lungs, ACKR1+ VECs localize adjacent to fibroblastic foci and are surrounded by pro-fibrotic CD68+/CCR5+/SPP1+ macrophages-monocytes, suggesting a spatial organized cellular crosstalk supporting fibrotic remodeling. Consistent with these findings, in vitro co-culture assays using ACKR1+ VECs isolated from IPF lungs demonstrate that these cells drive myeloid recruitment and fibroblast activation through ACKR1 dependent mechanisms. Silencing of ACKR1 in IPF-derived VECs suppressed inflammatory and fibrotic transcriptional programs, and pharmacological inhibition of ACKR1 attenuated stromal and immune remodeling and reduced bleomycin-induced lung fibrosis in vivo. Together, these findings identify ACKR1+ VECs as key orchestrators of fibrosis progression and establish ACKR1 and the pathogenic vasculature as promising therapeutic targets for IPF. Clinical RelevanceIdiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with limited treatment options. We identify ACKR1-expressing venous endothelial cells as key drivers of inflammatory and fibrotic remodeling and show that pharmacologic inhibition of ACKR1 attenuates experimental lung fibrosis. These findings establish endothelial ACKR1 as a promising therapeutic target and highlight the pulmonary vasculature as a novel avenue for disease-modifying therapies in IPF.

molecular biology↗

Comprehensive Mapping of SGCA Variant Effects Reveals Domain-Specific Constraints Relevant to Sarcoglycanopathies

Pathogenic variants in SGCA, encoding -sarcoglycan, cause an autosomal recessive limb-girdle muscular dystrophy, LGMDR3/2D, yet clinical interpretation of SGCA variants remains challenging due to the high prevalence of rare missense variants. -sarcoglycan is an essential component of the sarcoglycan complex at the muscle cell membrane, and pathogenic variants frequently impair its membrane localization. Here, we systematically assess the effects of all possible single-nucleotide variants across the SGCA coding sequence using a saturation mutagenesis-based experimental assay that quantifies -sarcoglycan surface expression. We generate a comprehensive functional atlas that distinguishes tolerated and damaging variants, aligning with independent genetic and clinical evidence, and reveals domain-specific properties of the cytoplasmic region, in which C-terminal truncating variants retain membrane localization, suggesting possible pathogenic mechanisms beyond impaired trafficking. This work provides a scalable functional framework to support genetic diagnosis and variant interpretation in sarcoglycanopathies. Graphical AbstractSchematic overview of saturation mutagenesis-based functional mapping of SGCA. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=187 SRC="FIGDIR/small/740214v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@19be841org.highwire.dtl.DTLVardef@ad2e49org.highwire.dtl.DTLVardef@1b9cb61org.highwire.dtl.DTLVardef@d77317_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗