Biology subjects

Zeng, Y.

Publications and source records attributed to Zeng, Y..

At least 19 recordsLinked to original sources

bioRxiv2026

Interpreting Short Tandem Repeat Variations with Plant Genomic Foundation Models in Olive

Short tandem repeats (STRs) are highly mutable, multiallelic variants with distinctive mutation dynamics and have been associated with phenotypic variation across diverse species. However, genome-wide STR variation remains poorly characterized in olive, and the large number of naturally occurring alleles creates a challenge for variant interpretation. Genomic language models offer a potential way to assess how STR length changes alter learned sequence representations, but their responses to natural multiallelic STR series have not been systematically evaluated. Here, we identified 117,119 polymorphic STRs across 212 Iranian and Mediterranean olive accessions. STRs recovered the major SNP-defined ancestry axes while resolving additional geographically structured subcomponents. We then quantified STR-induced embedding perturbation using three plant genomic language models: AgroNT, PlantCAD2, and GPN. Across all three models, embedding distance generally increased with repeat-length difference from the reference allele, and 7,417 loci were embedding-sensitive in all three models. These signals were robust to fixed-length input construction and exceeded those of matched nonrepetitive indels at most tested loci. Integration with oil-composition associations prioritized four exploratory loci supported by all three models. Overall, we provide a genome-wide olive STR resource and show that plant genomic language models capture reproducible responses to natural STR length variation. Combining cross-model embedding evidence with phenotype association provides a potential framework for prioritizing candidate STRs for further investigation.

bioinformatics↗

bioRxiv2026

A microbiota-driven neuroepithelial feed-forward circuit drives gastroesophageal junction tumorigenesis

The gastroesophageal junction (GEJ) is continuously exposed to refluxed bile acids and microbial perturbations, yet how these environmental cues are converted into persistent oncogenic signaling is unknown. Here we show that bile acid remodeling enriches the oral commensal Prevotella melaninogenica at the GEJ, where bacterial succinate activates both vagal sensory neurons and SUCNR1-expressing tuft cells. Activated tuft cells release 15-deoxy-12,14-prostaglandin J2 (15-d-PGJ2), which sensitizes sensory neurons and sustains nerve remodeling, while neuronal CGRP drives expansion and tuft-cell differentiation of neuro-responsive epithelial progenitors through RAMP1. This self-reinforcing microbiota-neuron-epithelium circuit promotes dysplastic progression, and its genetic or pharmacological disruption, including with the approved CGRP antagonist rimegepant, suppresses tumor development, revealing an interceptable mechanism linking environmental dysbiosis to cancer initiation through neural circuits.

cancer biology↗

bioRxiv2026

Traveling brain waves support flexible storage of human working memory

Human working memory enables us to temporarily store and flexibly utilize information. It is thought that there are two distinct neural mechanisms by which information is retained in working memory: persistent firing of working memory-relevant neurons, or short-term synaptic plasticity in the absence of ongoing neuronal firing. However, both these mechanisms can lead to strong neural interference when working memory contents are updated with novel information. As an alternative, here we propose that information can be flexibly held in working memory in the form of traveling waves - spatiotemporal patterns of neural activity that propagate across brain tissue. In an artificial neural network, we simulated wave propagation by passing transient neural firing patterns representative of single-item information across different network layers. In comparison to sustained neural firing, we demonstrate that these transient traveling waves result in minimal synaptic plasticity, thereby facilitating working memory updating without significant neural interference. We then identified such traveling waves in intracranial recordings from the human temporal lobe. Traveling waves started precisely when information was being encoded and persisted uniformly throughout maintenance and recall, aligning with the activation pattern seen in the artificial neural network. In trials where participants committed memory errors, no such continuous traveling wave activity in the temporal lobe was observed. Our data from artificial neural networks and human intracranial brain recordings converge to indicate that neural traveling waves support information processing in working memory while minimizing interference during updating. This reported mechanism, together with the classical working memory models, serves as a mutually complementary, multi-mechanistic framework for working memory storage.

neuroscience↗

bioRxiv2026

Brain state shapes the polarity of pulsed infrared neural stimulation responses in individual cortical neurons

Pulsed infrared neural stimulation (INS, 1875nm the peak of energy absorption by water) is a non-viral method developed to activate single submillimeter sites in the brain. When used in ultrahigh-field fMRI, it reveals functionally specific brain-wide columnar networks comprising synaptically activated nodes. INS is non-damaging and effective for use in the human cortex and is useful for neural and behavioral neuromodulation in primates. To investigate how physiological state influences its cellular effects, we performed in vivo two-photon calcium imaging with GCaMP6s in mice and tracked identified cortical neurons in awake vs anesthetized states. Across the tested radiant exposures, INS-evoked responses differed markedly between states: under anesthesia, stimulation produced predominantly positive-going calcium responses, whereas during wakefulness the same identified neurons exhibited negative-going responses. Pharmacological manipulation of this baseline level by GABAergic signaling shifted response polarity in opposite directions: picrotoxin under anesthesia produced awake-like negative responses, whereas muscimol during wakefulness produced anesthetized-like positive responses. Trial-by-trial analyses further showed that the relationship between pre-stimulus baseline level and INS-evoked response depended on physiological state. Because INS relies on transient tissue heating, we also developed an in situ EGFP-based calibration approach to estimate temperature-related fluorescence changes. These fluoro-thermal contributions were modest at lower radiant exposures and became increasingly important at higher exposures, particularly near the fiber pathway. The low-intensity results are consistent with, but do not establish, a state-dependent feed-forward inhibitory framework. Together, these findings show that the neuronal response to focal INS is shaped by ongoing brain state and provide a practical framework for separating state-dependent calcium responses from temperature-related fluorescence effects, making INS a potentially versatile tool for neuroscience and clinical applications.

neuroscience↗

bioRxiv2026

Transcriptome analysis reveals CCND2 promotes myogenic differentiation of pig skeletal muscle

ABSTRACT Objective: Skeletal muscle growth rate differs substantially among diverse pig breeds. In the present study, RNA-seq was performed to identify differentially expressed genes (DEGs) across pig breeds with distinct growth rates. CCND2 showed obvious differential expression among pig breeds. Although CCND2 is essential for cell cycle control, its biological function in skeletal muscle differentiation has rarely been reported. This work aims to identify DEGs in pig breeds with different growth rates and explore CCND2 role in porcine skeletal muscle development. Methods: RNA-seq was performed to identify differentially expressed genes (DEGs) across pig breeds with distinct growth rates. Weighted gene co-expression network analysis (WGCNA) was used to identify gene modules potentially associated with skeletal muscle growth and development. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was performed to validate the role of CCND2 in skeletal muscle differentiation. Results We identified 5,416, 4,846, and 2,777 DEGs in the Duroc pig (DU) vs. Jiangquan black pig (JQ), DU vs. Laiwu pigs (LW), and JQ vs. LW comparison groups, respectively. WGCNA identified two gene modules (lightgreen and darkmagenta) potentially associated with skeletal muscle growth and development. CCND2 exhibited differential expression in comparisons between DU vs JQ and DU vs LW, with higher expression observed in Duroc pigs. qRT-PCR analysis revealed that overexpression of CCND2 at day 6 (D6) of cell differentiation significantly increased the expression levels of CCND2 gene and markers of myogenic differentiation (p < 0.05). Conversely, knockdown of CCND2 significantly decreased the expression levels of CCND2 gene and myogenic differentiation markers (p < 0.05). Conclusions This study identified breed-specific DEGs and key gene modules in porcine skeletal muscle and verified that CCND2 promotes myogenic differentiation. These findings provide a genetic theoretical basis for further investigations into skeletal muscle growth and development. Keywords pig, skeletal muscle, transcriptome, WGCNA, CCND2

genomics↗

bioRxiv2026

Accurate and scalable decontamination of imaging-based spatial transcriptomics via optimal transport

Imaging-based spatial transcriptomics enables molecule-resolved profiling of gene expression and tissue organization in situ. However, segmentation errors, transcript spillover and three-dimensional cell overlap can introduce misassigned transcripts into cell-level expression profiles, compromising biological interpretation and obscuring genuine signals. Existing methods either remove suspect expression at the cost of signal loss or lack a biologically grounded criterion for transcript assignment. Here we present CellDot, an optimal-transport framework that determines the fate of each transcript by retaining it in its host cell, reassigning it to a plausible neighboring cell or removing it as background. By integrating reference-guided expression compatibility with spatial information and data-adaptive constraints, CellDot enables accurate and traceable molecule-level correction while preserving biologically meaningful variation. In evaluations across multiple human tumor datasets, CellDot exhibited superior performance compared to existing decontamination methods, successfully restoring spatial expression patterns that matched independent cross-platform measurements. Moreover, it significantly enhanced the recovery of cellular states, intercellular communication, and spatial niche programs. Our experiments using real data demonstrated CellDot's scalability and established it as the only method applicable to a whole-transcriptome Atera dataset, underscoring its distinct advantages in the field of spatial transcriptomics.

bioinformatics↗

bioRxiv2026

Configural and featural processing, and their role in the face network

Object recognition can rely on the detection of individual features, as well as the spatial configuration of features, which is especially prominent in the identification of faces. We previously showed that canonical 'face effects' (e.g., inversion, part-whole) can be elicited by non-face stimuli that are identified strictly by configuration, but not in stimuli that are identified by features. Here we asked 1) whether there exist distinct neural bases that support domain-general configural vs. featural processing; and 2) how domain-specific face-areas may respond and interact with these processors. We trained adults to recognize these configural and featural stimuli, and then used fMRI to observe neural responses associated with each type of processing. Configural stimuli drove responses in superior parietal, superior frontal, and lateral occipitotemporal cortices, while featural stimuli primarily elicited responses in the ventral fusiform gyrus. Next, we identified face-areas with a separate fMRI localizer; the Occipital Face Area (previously linked to the identification of face parts) was selectively activated during recognition of featural stimuli, while the Fusiform Face Area was ambivalent, preferring neither configural nor featural stimuli. The posterior Superior Temporal Sulcus face-area, typically involved in the moveable aspects of faces (e.g. facial expressions), selectively responded to configural stimuli over featural stimuli. Finally, we observed that the functional connectivity of these face-areas to configural or featural regions mirrored this functional pattern. These domain-general processors and their differential connectivity with the face network may offer a mechanism by which face-areas use this information to accomplish their distinct roles in face perception.

neuroscience↗

bioRxiv2026

CellART: a unified framework for extracting single-cell information from high-resolution spatial transcriptomics

Understanding how different cell types assemble into tissues and organs, as well as how they interact to transmit and receive biological signals, is essential for advancing biomedical and biological research. Recent advancements in spatial transcriptomics (ST) technologies have opened new avenues for investigating biological systems by achieving subcellular spatial resolution. Since cells are the fundamental units of life, extracting single-cell information from high-resolution ST data is crucial. However, existing ST platforms often capture sparse transcript counts per spot or measure only a limited number of genes, complicating the extraction of comprehensive single-cell information. In this study, we introduce CellART, a unified framework designed to extract single-cell information across diverse high-resolution ST platforms, including VisiumHD, Xenium, MERFISH, and Stereo-seq. By leveraging multimodal data, such as staining images, spatial transcriptomics data, and single-cell RNA sequencing references, CellART simultaneously performs cell segmentation and cell type annotation through a seamless integration of deep learning and probabilistic modeling. We demonstrate the efficiency, generalizability, and robustness of CellART across various high-resolution spatial transcriptomics platforms, capable of processing datasets containing millions of spots. Comprehensive experiments validate the biological relevance and accuracy of the recovered cellular information within spatial configurations. Notably, we highlight the utility of CellART in breast and colorectal cancer datasets, showcasing its ability to fully leverage high-resolution ST data. By enhancing cellular resolution, CellART facilitates the identification of transient cancer cell states and immune cell subtypes. Furthermore, CellART enables investigations into cancer-immune cell communication, uncovering both established interactions and novel ligand-receptor pairs. The outputs of CellART are compatible with widely used community tools, facilitating a variety of downstream analyses.

bioinformatics↗

bioRxiv2026

Spatially-restricted metabolic delivery of auxin for selective adventitious root induction

Auxin impacts on nearly every aspect of plant growth and development. Its exogenous application therefore results in pleiotropic growth responses. Exploiting this activity for plant propagation requires avoiding or minimizing such off-target effects and is generally achieved as a trade-off between toxicity and organogenetic efficacity. We recently identified the compound HYSPARIN (HYS) with potent, and uniquely selective adventitious root inductive activity. Unlike other root-inducing compounds, HYS preferentially activates auxin responses in the shoot via an unknown mechanism. Here, we show that HYS acts as a shoot-specific proauxin. Rather than acting through auxin homeostasis, we found that HYS is hydrolysed in planta independently of ILR1/ILL amidohydrolases to release the synthetic auxin MCPA. Structure-activity relationship analysis confirmed a strong dependence on its MCPA moiety for activating auxin responses, and identified its promoiety as a determinant of shoot-specificity and activity. Selective application of MCPA also potently induces AR is consistent with a model in which HYS metabolism produces a spatially restricted, AR inductive auxin signal. The activation mechanism of HYS thus provides a conceptual framework for tissue-specific metabolic delivery of auxin and may enable the programmable delivery of other xenobiotics in plants.

plant biology↗

bioRxiv2026

Exploratory profiling of defense system signatures in Klebsiella pneumoniae clonal populations

Bacterial defense systems against bacteriophages are critical for bacterial genome stability and fitness, yet their distribution and epidemiological relevance in Klebsiella pneumoniae remain unexplored. We aimed to characterize defense system signatures across major K. pneumoniae clonal lineages and evaluate their utility as genomic signatures for tracking clonal dissemination. Here, we analyzed 6,346 genomes to characterize population structure, defense system signatures, and their coevolution with resistance determinants and plasmid backbones. PopPUNK clustering resolved 146 lineages that stratified into major clonal lineages (G-ST-KL combinations) with distinct resistance and virulence profiles. DefenseFinder and PADLOC identified 320 distinct defense systems, revealing that each clonal lineage harbors a unique defensotype characterized by systematic module replacement rather than stochastic gene loss. Co-occurrence networks further showed that these systems are organized into lineage-specific functional modules, with contrasting architectures even among lineages sharing the same sequence type. Integration of defense, resistance, and plasmid data uncovered strong lineage-specific associations, whereby broad-host-range plasmid backbones acquired distinct defense-resistance payloads in different clonal backgrounds. Geographic and host-niche analyses demonstrated that defense system distribution reflects clonal lineage expansion rather than independent geographic selection, and analysis of 689 Chinese genomes confirmed vertical inheritance of lineage-specific signatures along transmission chains. Collectively, defense systems in K. pneumoniae are organized into lineage-specific defensotypes shaped by synergistic modules and clonal evolutionary dynamics. Defense system profiling provides an additional layer of epidemiological resolution beyond conventional typing and offers practical utility for genomic surveillance, particularly in resource-limited settings where PCR-based detection of conserved systems could serve as a rapid proxy for identifying high-risk K. pneumoniae clones.

bioinformatics↗

bioRxiv2026

Sensory neurons encode long-term inflammatory memory that promotes gastric regeneration and tumorigenesis

Inflammatory memory has emerged as a fundamental principle by which prior injury shapes future tissue responses, yet whether sensory neurons participate in long-term tissue memory remains unknown. Here, we show that vagal sensory neurons acquire a durable, experience-dependent state following gastric injury or Helicobacter pylori infection, leading to enhanced regeneration, metaplasia, and tumor progression upon re-injury. This neuronal program is stable, functionally transferable, and sufficient to drive epithelial responses in vivo. Mechanistically, injury-activated ILC2s establish sensory neuronal memory through IL-13-dependent epigenetic remodeling, inducing SMYD4-mediated H3K4 trimethylation and promoting CGRP-dependent activation of gastric epithelial cells. Together, our findings support a model in which tissue memory is not restricted to epithelial or immune compartments but emerges through coordinated long-term adaptations across multiple cellular systems. Within this framework, sensory neurons provide a persistent substrate for recall responses, linking prior inflammatory experience to sustained epithelial plasticity and cancer susceptibility. HIGHLIGHTSO_LISensory neurons function as a durable compartment of tissue memory. C_LIO_LICGRP-RAMP1 signaling couples neuronal memory to gastric stem cells. C_LIO_LIILC2-derived IL-13 establishes sensory neuronal memory programs. C_LIO_LISMYD4-mediated H3K4me3 stabilizes long-term neuronal memory. C_LIO_LINeuronal memory promotes gastric regeneration and tumor susceptibility. C_LI

cancer biology↗

bioRxiv2026

Liver-to-Atria Inflammatory Axis Driving Arrhythmia

BackgroundMetabolic dysfunction-associated steatohepatitis (MASH) is emerging as a risk factor of cardiometabolic diseases, including the atrial fibrillation (AF) - the most common sustained arrhythmia. Given that the liver is a major source of inflammatory mediators, lipids, and hepatokines under metabolic stress, we hypothesized that hepatocyte-derived factors in MASH may accelerate atrial remodeling and arrhythmogenesis. MethodsAnalysis of the Atherosclerosis Risk in Communities (ARIC) visit 5 cohort was performed to determine the association between the FIB-4 index - a classic indicator of liver fibrosis, and AF risk, with multivariable adjustment for common comorbidities. A murine model of MASH was induced using the GAN (Gubra-Amylin NASH) diet. Programmed intracardiac stimulation and echocardiography were performed to assess AF susceptibility and cardiac function. Calcium imaging, histology, flow cytometry, plasma proteomics, and single-nucleus RNA sequencing (snRNA-seq) analyses were employed to elucidate the role of recruited inflammatory macrophages via hepatocyte-derived osteopontin (OPN) in MASH-induced atrial remodeling. ResultsAnalysis of the ARIC cohort confirmed a higher cumulative incidence of AF and an elevated adjusted hazard ratio (HR) in patients with intermediate and high FIB-4 indices compared to individuals with low FIB-4 scores. MASH mice exhibited increased susceptibility to pacing-induced AF, accompanied by enhanced proarrhythmic calcium release events, atrial enlargement, and fibrosis, independent of ventricular dysfunction. Proteomics and snRNA-seq revealed that the hepatocyte-secreted OPN under MASH conditions promoted the differentiation and recruitment of TGFBR1+ inflammatory macrophages to the atria, leading to gasdermin D (GSDMD) activation - an effector of inflammasome signaling and consequent proarrhythmic atrial remodeling. Activation of the monocyte-derived pro-inflammatory TGFBR1+ macrophages was dependent on the OPN receptor CD44. Furthermore, the MASH-induced atrial fibroinflammatory milieu and enhanced AF susceptibility were mitigated through several strategies, including hepatocyte-specific Spp1 (encoding OPN) deletion, neutralization of circulating OPN, ablation of CD44 or GSDMD. ConclusionsThese findings establish a pathogenic role of the hepatokine osteopontin in driving activation and recruitment of TGFBR1+ inflammatory macrophages into the atria, leading to proarrhythmic atrial remodeling under MASH. Osteopontin-targeted therapy or GSDMD inhibition prevents AF, indicating a novel therapeutic strategy for liver disease-related atrial arrhythmogenesis. Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIIn the ARIC cohort, metabolic dysfunction-associated steatohepatitis (MASH) is associated with increased risk of atrial fibrillation (AF) after adjusting for common comorbidities. Elevated levels of circulating osteopontin (encoded by SPP1) predict an increased risk of AF in patients with MASH-induced liver fibrosis. C_LIO_LIMASH enhances hepatocyte secretion of osteopontin, leading to expansion of myeloid cells and recruitment of inflammatory macrophages into atria. This liver-to-atrial inflammatory circuit promotes the development of a substrate conducive to AF, which can be attenuated by hepatocyte-specific Spp1 deletion or neutralizing anti-anti-osteopontin antibody treatment to eliminate the mediator, or ablation of inflammasome effector gasdermin D to correct the atrial response. C_LI What are the clinical implications?O_LIOsteopontin may serve as a biomarker for AF in MASH cohorts. C_LIO_LIAnti-osteopontin therapy through neutralizing antibodies may serve as a novel therapeutic strategy for liver disease-related atrial arrhythmia. C_LI

systems biology↗

bioRxiv2026

Generation of High-Affinity Anti-GIPR Antagonist Antibodies with Sustained and Non-rebound Weight Loss in DIO Mice by AlfaBodY

The glucose-dependent insulinotropic polypeptide receptor (GIPR) is an attractive therapeutic target for metabolic disorders, with GIPR antagonism emerging as a promising strategy for obesity and type 2 diabetes. However, developing functional antibodies against GPCRs remains challenging due to their complex architecture and conformational dynamics. Here, we employed AlfaBodY, an iterative active learning platform integrating structural and sequence information, to in silico design human anti-GIPR antibodies. Through four rounds of optimization, we generated antibodies with high binding affinities. Lead candidates AB106-131 (KD 1.2 nM) and AB106-156 (KD 1.7 nM) exhibited 7 to 10-fold higher affinity than 2G10 (KD 12 nM) while maintaining comparable antagonistic activity in a cAMP reporter assay (IC50 4[~]5 nM). In diet-induced obese mice, AB106-156 alone induced weight loss comparable to that of semaglutide ([~] -15%), while preserving lean mass and achieving sustained weight control after treatment withdrawal. Co-administration with the GLP-1 receptor agonist semaglutide produced synergistic weight reduction (-25.4%) and markedly attenuated the fat-mass rebound observed with semaglutide alone. Our results demonstrate that AI-driven design can generate potent anti-GIPR antibodies with favourable in vivo efficacy, supporting further development of GIPR antagonist for obesity and related metabolic disorders. The AlfaBodY platform enables faster development of more efficacious biologic drugs.

pharmacology and toxicology↗

bioRxiv2026

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↗

bioRxiv2026

DNA demethylation suppresses a state of enhanced cellular pluripotency and regeneration competence in Arabidopsis.

The plant kingdom exhibits a wide range of phenotypic variation in capacity to regenerate tissues and organs, from whole-plant vegetative propagation via cuttings, to recalcitrance even under optimized tissue culture. Currently, the molecular pathways underpinning this phenotypic variation are poorly understood. Here, we report that Arabidopsis mutants of the DNA demethylase pathway exhibit dramatically enhanced regeneration and the ability to propagate whole plants from cuttings without the use of exogenous hormones. Vegetatively propagated plants possess a shared regeneration signature of de novo DNA methylation gains at the transcription start sites of many genes, including approximately 30 genes involved in cellular pluripotency and tissue regeneration. These methylation changes can be inherited through sexual reproduction and are associated with exacerbated transcriptomic changes. We propose that loss of the DNA demethylase pathway unlocks a path on the epigenetic landscape towards increased pluripotency and regeneration without the application of exogenous hormones.

plant biology↗

bioRxiv2026

Granulin loss and TMEM106B risk converge on lysosomal C-terminal fragment pathology in frontotemporal dementia

Frontotemporal dementia (FTD) is the second most common cause of dementia after Alzheimer disease. Mutations in GRN, which encodes progranulin, are a major cause of FTD. Common genetic variants in the TMEM106B gene modify risk of FTD and the effect is especially strong in GRN mutation carriers. Intriguingly, in GRN mutation carriers, being homozygous for the protective TMEM106B haplotype seems to confer near lifetime protection against FTD. Despite the strong genetic link between GRN and TMEM106B, how these two genes interact mechanistically has remained unresolved. Recent studies have revealed that a C-terminal fragment of TMEM106B forms amyloid fibrils and accumulates in the brains of older individuals and patients with neurodegenerative disorders, including FTD. How the production of this fragment connects to granulin deficiency is also unknown. Using lysosome immunoprecipitation, we show that granulin deficiency drives the accumulation of the TMEM106B C-terminal fragment within lysosomes in Grn-knockout mice and GRN-null human iPSC-derived neurons. Recombinant progranulin supplementation reduced TMEM106B C-terminal fragment accumulation. Isogenic neurons carrying the TMEM106B risk allele displayed allele-dose-dependent fragment accumulation that was reversible by progranulin. Structural and genetic analyses demonstrated that TMEM106B dimerization stabilizes the protein and limits C-terminal fragment formation. These findings define a lysosomal pathway linking granulin deficiency to TMEM106B C-terminal fragment accumulation and explain how protective TMEM106B alleles can confer resistance to FTD, even for GRN mutation carriers. One Sentence SummaryGranulin deficiency drives lysosomal accumulation of an amyloidogenic TMEM106B C-terminal fragment, revealing a molecular mechanism that explains how TMEM106B alleles can confer risk or protection from frontotemporal dementia.

genetics↗

bioRxiv2026

Functional impact of PCSK9 variants on LDL uptake in a knockout hepatic model

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a central regulator of low-density lipoprotein (LDL) cholesterol metabolism, yet the functional consequences of many clinically observed PCSK9 variants remain unknown. To establish a rigorous system for quantitative variant assessment, we generated a PCSK9 knockout (KO) HepG2 cell line through CRISPR/Cas9-mediated deletion of exons 2-8, effectively removing both the prodomain and catalytic regions required for PCSK9 function. This null background enabled systematic functional mapping of wild-type (WT) PCSK9 and multiple clinically relevant variants representing well-characterized, recurrent, and previously understudied alleles. Functional assays revealed pronounced heterogeneity among variant activities. The classical gain-of-function (GOF) variants D374Y and R496W exhibited robust suppression of LDL uptake, whereas A443T--an infrequently reported and previously uncharacterized variant--demonstrated a loss-of-function (LOF)-like phenotype with significantly enhanced LDL uptake. Additional poorly characterized variants, including V4I, R104C/V114A, and R496W/N425S, displayed minimal functional profiles, providing novel mechanistic insights. Surface LDL receptor (LDLR) levels generally correlated with LDL uptake but revealed unique patterns for specific variants. This KO-based rescue system provides a high-resolution framework for mechanistic classification of both established and poorly characterized PCSK9 variants, bridging the gap between genetic discovery and functional interpretation while supporting precision lipid-lowering strategies.

biochemistry↗

bioRxiv2026

Behavioral, Physiological, and Transcriptional Mechanisms of Memory in a Synthetic Living Construct

Synthetic living constructs, which lack the long histories of selection in ecological contexts that shape behaviors of conventional organisms, offer an important complement to traditional studies of learning. Could novel biobots exhibit sensing and memory of experiences? Here, we investigated the effects of chemical stimuli on basal Xenobots - autonomously motile entities derived from Xenopus embryonic ectodermal explants (with no additional sculpting or bioengineering). We quantified and characterized the coordinated ciliary activity that generates fluid flow fields guiding the trajectory of Xenobot motion. We also show distinct and specific changes in Xenobot behavior after brief exposure to Xenopus embryonic cell extract and to ATP. These two experiences produced distinct, long-term, stimulus-specific memories, detectable through both transcriptional and physiological signatures. Exposure to specific environmental stimuli induced alterations in the spatiotemporal patterns of calcium signaling across Xenobots. Together, these data lay a foundation for characterizing the capabilities of synthetic cellular collectives to sense and discriminate among stimuli, as well as store functional information in a non-neural context. Understanding behavioral competencies in novel, non-neural systems have broad implications across evolutionary biology, behavioral science, bioengineering, and bio/hybrid robotics.

synthetic biology↗