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Biology subjects

Han, L.

Publications and source records attributed to Han, L..

At least 19 recordsLinked to original sources

Impaired loading following denervation elicits dynamic, differential growth trajectories of musculoskeletal tissues

Physical forces dictate the function and maintenance of adult musculoskeletal tissues. Yet, the impact of biophysical cues on the growth and maturation of these tissues, especially dense connective tissues, remains unclear. Here, we investigated the effects of neonatal mechanical loading on early postnatal growth of the musculoskeletal tissues of the lower limb, with particular focus on the Achilles tendon. We performed sciatic nerve resection (SNR) on one-day-old mice to denervate the hamstrings and distal hindlimb muscles. Sciatic Nerve Resection resulted in severe and sustained alterations in gait, accompanied by an altered transcriptional landscape in distal musculoskeletal tissues, with marked reductions in bone and tendon growth and smaller, fibrotic hindlimb musculature. Sciatic nerve resection impaired cumulative growth in the Achilles tendon, shifting cell proliferation and matrix-driven growth trajectories and altering mechanotransduction gene programs toward inflammation and matrix catabolism with age. This work highlights the essential role of mechanical loading in driving mechanosignaling and postnatal growth trajectories in musculoskeletal tissues of the developing limb, with implications for overall musculoskeletal health in adulthood.

bioengineering↗

Multi-resolution humanness scoring of antibodies via a region-isolated language model

Antibodies recognized as foreign can elicit anti-drug antibodies that compromise efficacy and safety, making humanness scoring, estimating how human-like a sequence appears, an early, repeated step in antibody development. Widely used scores reduce a variable domain to a single framework-dominated number, leaving the complementarity-determining regions (CDRs) grafted during humanization, diversified by generative models weakly supervised and rarely audited. Here we introduce IgScope, a 23-million-parameter antibody language model trained from scratch that scores humanness at chain, IMGT-region, and residue resolution; a region-isolated attention module confines attention to within-region pairs, and chimeric-sequence training supplies region-level supervision. On 2.38 million held-out chains, masking all framework tokens leaves CDR accuracy unchanged, and back-mutated murine residues in human frameworks are detected at 93.4% accuracy. At chain level, IgScope matches the strongest published correlation with clinical anti-drug-antibody incidence (r = 0.567, n = 217) and outperforms a same-protocol recomputation. Region-level scoring exposes what chain-level scoring conceals: antibodies designed de novo by four generative models pass whole-chain humanness (0.966-0.988), while their CDRs score far below natural (P < 1e-30) in every chain class. Quality control turns the same resolution to the mirror-image question: in humanized-mouse platforms, whose domains are human by design, IgScope scores the domain as human and, in HUGO-Nano chimeric VHHs, isolates only the FR2 signal of four camelid hallmark residues deliberately retained to stabilize the VHH. IgScope gives antibody humanization a verified foundation and generative design an audit.

bioinformatics↗

Establishing toxicologically relevant primary alveolar macrophage models to enable a realistic assessment of nanomaterials safety

Alveolar macrophages (AMs) are key sentinels of the distal lung, maintaining surfactant homeostasis and clearing inhaled particles through continuous surveillance and phagocytosis. Mechanistic studies of particle-cell interactions, important to assess the respiratory safety or toxicity of particles, however, are limited by the lack of suitable in vitro models that preserve the core features of resident AMs. Here, we benchmarked six murine AM models, including short-term cultured primary AMs (AMs 3 h, AMs 24 h), primary AMs maintained with GM-CSF, TGF-{beta}, and the PPAR-{gamma} agonist rosiglitazone (AMs GTR), bone marrow-derived AM-like cells (BM-AMs), the immortalized AM cell line MH-S, and the non-transformed fetal liver-derived AM-like cell line MPI, against in vivo AMs based on surface phenotype, transcriptomic identity, and their responses to three carbon-based nanomaterials (CBNs). Both cell lines showed limited AM identity, characterized by low CD11c and SiglecF but high CD11b surface expression. In contrast, AMs GTR and BM-AMs more closely preserved resident AM-like surface marker profiles. Transcriptomic features, although differing for alterations in metabolism-related pathways, particularly oxidative phosphorylation, revealed most in vivo-like for the primary AM models. Functional, toxicological assessment using soot-like carbon nanoparticles (CNP), double-walled carbon nanotubes (DWCNT) and multi-walled carbon nanotubes (MWCNT) demonstrated strong model-dependent responses. Consistent with MWCNT-induced reduction in AM numbers observed in vivo, AMs GTR and BM-AMs exhibited the strongest in vitro responses, including cytotoxicity and inflammatory cytokine release. MH-S cells in contrast stood out for their cytotoxic sensitivity supporting their use for high throughput cytotoxicity tests. Overall, these findings identify AMs GTR and BM-AMs as the closest models for studying AMs biology and AM-intrinsic responses to poorly soluble nanoparticles like CBNs, and with regard to availability of higher cell numbers, BM-AMs might provide a scalable platform for mechanistic and higher-throughput nanotoxicology studies.

pharmacology and toxicology↗

PIEZO1 mediates mechanosensing and myofibroblastic activation of synovial fibroblasts in post-traumatic osteoarthritis

Fibrosis and inflammation of the synovium are common pathological features of joint diseases. In osteoarthritis (OA), extensive evidence supports that synovial pathology drives symptoms and disease progression, yet the mechanisms underpinning pathological synovial remodeling, including fibrosis, remain unclear. Here, we identify the mechanosensitive ion channel PIEZO1 as a critical regulator of myofibroblast-like activation of synovial fibroblasts (SFs) in post-traumatic osteoarthritis (PTOA). Using multi-omic assessments in human and murine synovium, a murine model of joint injury, histopathology, and functional in vitro phenotyping, we demonstrate that joint injury triggers expansion of myofibroblast-like SFs concurrent with fibrotic remodeling and mechanical stiffening of the synovium. Myofibroblastic commitment of synovial progenitors was associated with activation of the YAP1 regulon, and PIEZO1 agonism drove nuclear accumulation of YAP1 in SFs. PIEZO1 was enriched in synovia of injured joints, and in cultured SFs pharmacologic PIEZO1 activation promoted SMA enrichment and increased matrix contraction, which were both ablated by YAP1 inhibition. PIEZO1 silencing abrogated TGF-{beta}-induced contractility and markedly altered the transcriptomic response to mechanical loading in vitro, including ECM production and neuroinflammatory programs. In vivo, acute intra-articular pharmacologic PIEZO1 activation induced a pro-fibrotic, pro-inflammatory, and anti-adipogenic transcriptomic program in synovium. Collectively, these findings establish PIEZO1 as a key mediator of the pathogenic activation of SFs and identify aberrant mechanosensing as a mechanism underlying synovial fibrosis in PTOA.

cell biology↗

The ammonia-senescence ratchet drives an adaptation-senescence-ammonioptosis transition in liver cancer

Senescence suppresses tumor proliferation while exposing survival dependencies, motivating separate, sequential steps of senescence induction and senescent-cell clearance. Whether senescence-sustaining metabolism can instead be overdriven to trigger cell-autonomous death remains unknown. Senescent cells generate ammonia through glutaminolysis to buffer intracellular acidification, yet extracellular ammonia can impair anti-tumor immunity, leaving unexplored whether ammonia can instead drive tumor-cell-intrinsic death. Here, we reverse this logic and identify a self-reinforcing ammonia-senescence ratchet in which ammonia accumulation promotes senescence, whereas senescence reciprocally enhances ammoniagenesis, progressively driving tumor cells from metabolic adaptation through senescence to ammonioptosis. Reducing intracellular ammonia suppressed senescence and cell death, whereas ammonia repletion restored lethality. We engineered acid-responsive H3B-120@CoGd-LDH (HBCG) to preferentially amplify tumor-cell ammonia by reinforcing senescence and ammoniagenesis, restricting ammonia disposal and weakening lysosomal buffering. HBCG limited extracellular ammonia accumulation and CD8+ T-cell exposure in co-cultures, induced ammonioptosis in patient-derived liver-cancer organoids and suppressed tumor growth in immunocompetent mice. This work reveals that adaptation, senescence and ammonioptosis can be connected through escalating intracellular ammonia stress, providing a mechanistic framework for understanding stress-driven tumor-cell fate transitions.

bioengineering↗

Molecular signatures of genetically defined jugular nociceptors and their responses to allergic airway inflammation

Abstract Rationale: Vagal sensory neurons are molecularly and functionally diverse, and they play critical roles in visceral sensation and homeostasis. The vagal system is anatomically divided into jugular and nodose ganglia, which exhibit distinct peripheral innervation patterns and physiological functions. Although recent transcriptomic studies have characterized nodose neuronal subtypes in detail, the molecular profiles of jugular sensory neurons remain poorly defined. Objectives: To define the molecular profiles of genetically identified jugular sensory neurons and determine the transcriptional responses of jugular and nodose airway afferents to allergic airway inflammation. Methods: We performed deep transcriptomic profiling of two genetically defined jugular nociceptor populations, MrgprC11 and MrgprD neurons, and compared them with airway-innervating P2ry1 nodose neurons and Phox2b nodose neurons. We further examined transcriptional changes of MrgprC11 and P2ry1 neurons following OVA-induced allergic airway inflammation. Measurements and Main Results: Transcriptomic analyses revealed distinct molecular signatures of jugular nociceptive neurons and identified subtype-specific genes across diverse functional categories. Following OVA challenge, MrgprC11 and P2ry1 neurons exhibited strikingly divergent transcriptional responses. More than 400 genes that were differentially expressed in both neuronal populations were regulated in opposite directions. GO enrichment analysis suggested that MrgprC11 jugular neurons adopted a metabolically restrained state with reduced translation and bioenergetic activities, whereas P2ry1 nodose neurons exhibited metabolically active state with enhanced translation and bioenergetic activities. Conclusions: These findings provide new insight into vagal sensory neuron diversity and reveal distinct transcriptional adaptations of jugular and nodose airway afferents during allergic inflammation.

neuroscience↗

SWELL1 channel-mediated D-2HG export promotes immune evasion and metabolic fitness in IDH-mutant gliomas

Isocitrate dehydrogenase (IDH) is the most frequently mutated metabolic enzyme in human cancers. Mutant IDH produces the oncometabolite D-2-hydroxyglutarate (D-2HG), which promotes tumorigenesis in part through epigenetic alterations. Beyond its cell-autonomous effects, tumor-derived D-2HG acts as a potent immunosuppressant that establishes an immune-cold tumor microenvironment. However, the mechanism by which D-2HG is released from tumors remains largely unknown. Here, we identify the SWELL1 (LRRC8A)/LRRC8C-containing volume-regulated anion channel (VRAC) as a principal pathway for D-2HG efflux from IDH-mutant cells. Genetic deletion of SWELL1, the essential VRAC subunit, markedly reduces D-2HG release and reverses associated immunosuppression in an orthotopic mouse model of IDH-mutant glioma. Strikingly, loss of VRAC causes intracellular accumulation of D-2HG, which paradoxically limits tumor cell proliferation by driving epigenetic remodeling and mitochondrial metabolic stress. Pharmacological inhibition of VRAC with dicumarol suppresses IDH-mutant glioma growth, enhances intratumoral T cell activation, synergizes with immune checkpoint blockade, and prolongs survival in tumor-bearing mice. In human IDH-mutant lower-grade gliomas, elevated LRRC8C expression correlates with DNA hypermethylation and an immunosuppressive tumor microenvironment (TME), and predicts poor overall survival. Together, these findings establish VRAC-mediated D-2HG export as a central mechanism regulating both immune evasion and tumor cell fitness, uncovering new therapeutic opportunities across IDH-mutant cancers.

cancer biology↗

Site-specific processing of phosphoethanolamine cellulose by the BcsZ cellulase reveals stochastic biofilm cellulose modification

Cellulose is a common component of bacterial biofilms where it interacts with other biopolymers to form a 3-dimensional matrix enclosing the bacteria. Synthesized and secreted by the synthase-dependent biosynthesis pathway common to many bacterial exopolysaccharides, its surface exposure depends on the presence of the periplasmic cellulase BcsZ. During export across the periplasm, E. coli and other Enterobacteriaceae modify cellulose with lipid-derived phosphoethanolamine (pEtN). How BcsZ hydrolyzes pEtN-cellulose in the periplasm is unknown and so is the native distribution pattern of pEtN on cellulose. Here, we used carbohydrate synthesis, X-ray crystallography, native mass spectrometry, and super-resolution MINFLUX nanoscopy to delineate the role of BcsZ during cellulose biosynthesis. Crystal structures of BcsZ bound to chemically synthesized pEtN cello-oligosaccharides identify how the enzyme recognizes pEtN-modified glucosyl units. Comparing mono and double substituted cellohexaoses, we identify varying binding poses that are determined by two pEtN coordination sites within the BcsZ catalytic pocket. Combined, our structural analyses reveal an ideal BcsZ cellohexaose ligand containing two pEtN modified units separated by an unmodified cellotriosyl unit. The enzyme binds and hydrolyzes this compound with substantially increased affinity and efficiency. Further, BcsZ digestion of native pEtN cellulose combined with native mass spectrometry analyses reveals the stochastic distribution of pEtN on biofilm cellulose. Additionally, MINFLUX co-localization of BcsZ with other components of the biosynthetic complex demonstrates the random distribution of BcsZ across the periplasm. Our data suggest BcsZ functions independently of the biosynthetic complex to clear mislocalized pEtN cellulose from the periplasm.

biophysics↗

BCIJelly: An integrated ecosystem for brain-computer interface research

Brain-computer interface (BCI) research relies on multistage computational pipelines, but progress has been slowed by fragmented data formats, heterogeneous decoder implementations and hardware-specific deployment toolchains. Here, we introduce BCIJelly, a unified ecosystem that standardizes 18 BCI datasets into AI-ready inputs and integrates 15 benchmark decoders, 80 reusable modules, automated architecture search (AAS) and hardware-aware neuromorphic deployment. Our AAS constructs task-specific decoders without manual design and extends into a large language model (LLM)-driven closed-loop mode supporting single-task, multitask and cross-species decoder design. A single-command pipeline compiles trained decoders for neuromorphic hardware, reducing power consumption by 30 to 50 times while preserving decoding performance. An interactive visualization software enables code-free exploration of neural recordings and decoding outputs. BCIJelly is validated across five BCI paradigms (motor, visual, speech, emotion and auditory) in humans, macaques and mice, providing an extensible ecosystem connecting data standardization, decoder development, systematic evaluation and hardware-aware deployment for BCI research.

neuroscience↗

A Practice on Antibody Hydrophobic Interaction Chromatography Retention Time Prediction using Pre-Trained Large Language Model Fine-Tuning

Hydrophobicity is a critical property associated with the risk of non-specific binding, and it is commonly assessed using hydrophobic interaction chromatography retention time. Several computational approaches have been developed to predict antibody developability based on pre-trained language models. Such models can be fine-tuned with limited labeled antibody sequences and, in principle, do not require structural information, which is often challenging to obtain. Nevertheless, few studies have achieved strong performance in hydrophobicity prediction without incorporating structural features. Here, we present a case study of fine-tuning the pre-trained model IgBert to predict antibody hydrophobicity. Using Herceptin as a reference, we performed hydrophobic interaction chromatography retention time experiments and generated Herceptin-adjusted datasets. The fine-tuned model achieved a best R2 of 0.916, underscoring the critical role of rigorous data quality control. We also synthesized and validated 20 commercially available antibody sequences, and the results showed that the predicted hydrophobic properties were correctly reflected. Our findings provide practical guidance and highlight considerations for future applications of fine-tuned pre-trained language models in antibody hydrophobicity prediction.

bioinformatics↗

Decorin-mediated Extracellular Matrix Stabilization Maintains Cartilage Integrity During Aging

Aging is a primary risk factor for osteoarthritis (OA), yet the mechanisms that preserve extracellular matrix integrity in long-lived connective tissues remain poorly defined. The function of articular cartilage depends on maintaining extracellular matrix integrity over a lifetime of mechanical use. Here we identify failure of matrix stabilization as an initiating mechanism of age-associated OA. Cartilage-specific deletion of decorin in mature mice disrupted the superficial collagen II fibrillar network, reduced aggrecan retention, and impaired poroelastic fluid pressurization by 9 months of age, preceding substantial transcriptional changes in resident chondrocytes. With advancing age, these matrix defects culminated in cartilage erosion, fibrotic remodeling, and spontaneous OA by 18 months. Mechanistically, decorin attenuated force-induced collagen II fibril realignment and reinforced the superficial fibrillar network, preserving matrix architecture under sustained physiological loading. These findings establish decorin-mediated extracellular matrix stabilization as a critical determinant of cartilage longevity and support a matrix-first model of age-associated degeneration.

biophysics↗

Deep nanoparticle protein corona plasma proteomics resolves a stage-specific peripheral signature of Alzheimer's disease

Structured AbstractO_ST_ABSINTRODUCTIONC_ST_ABSAlzheimers disease (AD) progresses over decades, yet plasma biomarkers that resolve disease stage rather than simply detect disease remain scarce. This distinction is clinically consequential because effective AD intervention depends on identifying patients before disease biology has progressed beyond a therapeutically responsive stage. METHODSWe used small-molecule-modulated protein corona proteomics to profile plasma from 90 individuals in the Australian Imaging, Biomarker and Lifestyle cohort, stratified by Centiloid (CL) A{beta}-amyloid burden (30 amyloid- negative, CL < 15; 30 moderate-to-high, CL 26 to 100; 30 very high, CL > 100). We quantified 3,176 proteins and applied differential abundance and actual causality analyses to identify stage-specific and candidate causal proteins. RESULTSDifferential protein abundance was exclusively captured during the moderate-to-high AD transition, revealing a discrete proteomic "switch." The switch was marked by accumulation of the autophagy receptor CALCOCO1, together with coordinated depletion of the S100A8/S100A9 calprotectin complex and core erythroid-cytoskeletal network structural markers (e.g., SPTA1, SPTB, ANK1). Adhesion G protein-coupled receptor G6 (ADGRG6) showed a significant moderate positive monotonic association with absolute CL burden, providing a proportional molecular anchor for cumulative disease burden. Actual causality analysis identified COL6A2, FOXRED2, P3H1, PRR4, and GOLGA5 as candidate upstream drivers linking matrix remodeling, Golgi trafficking, and collagen processing to AD progression. DISCUSSIONThese findings suggest a candidate blood-accessible framework for staging AD by active disease biology, which, if replicated in independent cohorts, may have implications for therapeutic selection and mechanism-guided clinical trials. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/740710v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1ead718org.highwire.dtl.DTLVardef@cfa523org.highwire.dtl.DTLVardef@62a367org.highwire.dtl.DTLVardef@1d5c9a5_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

A Promoter Competition Hub Orchestrates Runx1 Alternative Promoter Usage during Skeletal Muscle Stem Cell Activation

Alternative promoter (AP) usage profoundly expands transcriptomic and proteomic diversity, yet the regulatory principles governing promoter choice remain poorly understood. Here, using the dual-promoter Runx1 locus as a paradigm in skeletal muscle stem cells (MuSCs), we uncover a promoter competition hub that orchestrates AP selection during MuSC fate transition from activation to proliferation. We find antagonistic expression dynamics between the two Runx1 promoters, with the primary promoter (PP) active in the early activating stage and the secondary promoter (SP) induced later in proliferation. Combinatorial genetic perturbations in vitro and in vivo establish the non-redundant roles of PP- and SP-derived isoforms in MuSC lineage progression. Mechanistically, we find that PP and SP engage in reciprocal competition in a multi-connected enhancer-promoter (E-P) loop hub. Further dissection identifies a cohort of key enhancers that dynamically interact with PP/SP to orchestrate the competition. Moreover, we establish the transcription factor USF1 as a key factor driving the dynamic E-P interactions and PP/SP competition. Beyond Runx1, high-resolution Micro-C reveals promoter competition as a general mechanism regulating a subset of AP choices in MuSC activation/proliferation. Collectively, our study uncovers a dynamic promoter competition hub that governs AP selection in MuSC lineage progression, offering fundamental insights into how 3D genome architecture coordinates precise, stage-specific gene expression programs during cell fate transitions.

genetics↗

Phase-tuned interfacial condensates drive transcellular access

Nanocondensates occupy mesoscopic scale in both spatial scale and thermodynamic state, and the mesoscopic scale is central to structure-function conversion in living systems. However, how the dual mesoscopic properties of nanocondensates support biological function remains unclear because their small size and rapid dynamics hinder direct observation in living cells. Here we construct nanocondensates in situ at the cell-membrane interface and observe them permeating membranes within seconds, diffusing freely, exiting cells within minutes, re-entering neighbouring cells and traversing multilayered barriers. We report the first observation of this phenomenon and term it nanocondensate tunnelling. We find that nanocondensates cross membranes without membrane enclosure, preserving their wetting characteristics after passage. Theoretical and ultrastructural analyses support a transient-pore model linking this behaviour. We exploit nanocondensate tunnelling to transport small molecules, siRNA and antibodies across cellular barriers, and small molecules and siRNA across a multilayered corneal barrier, demonstrating its functional capacity for intercellular transfer. Our results suggest that nanocondensate tunnelling represents a previously undescribed mode of intercellular transfer. Nanocondensate tunnelling provides a physical basis for biologics delivery and a testable framework for investigating unresolved biological phenomena such as viral permeation.

bioengineering↗

Deciphering AMP deaminase-2 structure, activators and regulators underpinning cellular function in human fructose and nucleotide metabolism

AMP deaminase (AMPD) plays an integral role in fructose metabolism via its regulation by ATP, GTP and phosphate (Pi). The fructose catabolic pathway consumes ATP, producing ADP, which is further metabolized to AMP, triggering a cascade of reactions initiated by AMPD. This degradative pathway results in the final product uric acid, which is associated with metabolic acidosis, mitochondrial dysfunction, and gout. Understanding the regulation of the human liver AMPD isozyme (hAMPD2-2) under physiological conditions and under fructose consumption conditions will enable the design of targeted therapeutics to block the accumulation of uric acid. We report the first successful expression and purification from Escherichia coli of both the full-length and catalytic domains of hAMPD2-2. Steady-state kinetics confirmed allosteric activation by ATP of both the full-length and catalytic domains of hAMPD2-2 at physiological ATP concentrations (2-5 mM), suggesting that the allosteric ATP-binding site is located in the catalytic domain. Competitive inhibition by GTP of the ATP-activated enzyme, with Ki values of 74 and 101 M for the full-length and catalytic domains, respectively, was also consistent with this regulatory model. Pi, previously described in yeast AMPD as a competitive inhibitor, was shown to play a more nuanced role, that of enhancing inhibition of hAMPD2-2 when the enzyme is complexed to GTP, via competition at the ATP allosteric site. Pi binding thus further inhibits the pathway under normal physiological conditions, limiting production of cellular uric acid unless and until Pi and GTP levels are low.

biochemistry↗

Single-cell spatial transcriptomics and snRNA-seq decoding the organizational principles of functional modules in the mouse amygdala

The amygdala is a functionally heterogeneous nuclear complex comprising multiple subnuclei that orchestrate diverse behaviors, making it essential for survival and reproduction. However, the precise neural mechanisms underlying these heterogeneous functions remain elusive, primarily due to limited knowledge of the amygdalas cellular heterogeneity, developmental origins, spatial organization, and gene expression profiles. Here, we integrate single-cell-resolution spatial transcriptomics with precise anatomical dissection and single-nucleus RNA sequencing to systematically map the subnuclear enrichment patterns of amygdalar cell types. We further demonstrate that developmental origin determines subnuclear positioning and propose a novel functional modular architecture based on cellular composition and gene expression signatures. Furthermore, we reveal that the central amygdala (CEA) exhibits developmental heterogeneity, with Isl1+ neurons in its medial subdivision (CEAm) predominantly originating from hypothalamic progenitors. Our findings establish a spatially resolved cellular and molecular framework for investigating amygdalar functions at cellular type resolution and understanding amygdala-related neuropsychiatric disorders.

neuroscience↗

Atherosclerotic plaque iron accumulation characterizes a distinct phase of intra-plaque hemorrhage and is associated with inflammation and remodeling

Intraplaque haemorrhage (IPH) is a hallmark of advanced atherosclerosis and a major risk factor for ischemic stroke and myocardial infarction. Current IPH classification focusses on extravascular erythrocyte presence as a proxy of acute bleeding, where iron detection generally indicates older haemorrhages. While often used interchangeably, a comprehensive analysis of transcriptional and metabolic context and impact of iron and erythrocyte deposition on the plaque is still lacking. Here, we investigate iron as a late-stage IPH hallmark in human atherosclerotic plaques. We analysed erythrocyte-rich, iron-rich, and non-IPH regions in human carotid endarterectomy plaques by re-analysing a published transcriptomic dataset of 43 patient samples. In addition, we performed histological and immune phenotyping to define plaque traits associated with iron versus erythrocyte accumulation. Finally, we performed spatial metabolic profiling to functionally define iron-rich regions. Although iron and erythrocyte deposits frequently co-localised, both co-related with different histological traits. While iron- and erythrocyte-rich regions shared transcriptomic features of advanced plaques compared with non-IPH regions, direct comparison showed differences in gene expression profiles. Iron deposition was associated with increased myeloid cell accumulation and a unique spatial metabolic signature distinct from erythrocyte-rich and non-IPH regions. While sharing many characteristics with IPH plaques, the molecular, cellular and metabolic landscape of iron-rich regions is marked by features of plaque remodelling and repair. This makes iron deposition a unique hallmark of late-stage IPH, extending the current erythrocyte-based definition of IPH.

pathology↗

Combination of engineered cell type-specific promoters and a high-efficiency AAV capsid restores hearing in adult DFNB1 mice model with demonstrated safety in nonhuman primate

A major challenge in gene therapy for GJB2-related hearing loss (DFNB1)--the most common form of hereditary deafness--is achieving efficient and precise connexin 26 delivery. Herein, we engineered two cell type-specific promoters (GJB2-1 and WFS1-2274) and developed an AAV capsid, AAV-MAS012, with enhanced transduction efficiency in mature cochlear cells. Our AAV-mediated gene therapy systems restored hearing of low-to-mid-frequencies in newborn Gjb2 cKO mice to wild-type levels and maintained for 45 weeks. Additionally, our therapeutic systems restored low-to-mid-frequencies hearing function to wild-type levels in adult Gjb2 cKO mice. A humanized version of the therapy, AAV-MAS012-WFS1-2274-hGJB2, rescued hearing function in two distinct Gjb2-deficient mouse models, and demonstrated a favorable safety profile in nonhuman primates. This study represents the first successful hearing restoration in adult Gjb2-deficient mice. The significant therapeutic efficacy of the humanized gene therapy system shows great potential for clinical translation in DFNB1 patients.

genetics↗