Biology subjects

Wu, B.

Publications and source records attributed to Wu, B..

At least 19 recordsLinked to original sources

bioRxiv2026

In situ loading of biologics on and tissue redirection of circulating extracellular vesicles with an anchoring nanobody

Extracellular vesicles (EVs) are promising nanocarriers of therapeutic macromolecules, but ex vivo production, cargo loading and quality control constrains clinical translation. Here we demonstrate that NEV3, an EV-anchoring nanobody identified by phage display, binds EVs from multiple sources through interactions involving fibronectin and loads diverse proteins onto EVs, resulting in enhanced intracellular delivery and biological activities in vitro and in vivo. Conjugating NEV3 to target proteins hijacks circulating EVs, prolonging circulation and altering tissue distribution in vivo. When fused with an GFP nanobody or protein A, NEV3 enabled simultaneous capture and loading of circulating GFP or immunoglobulin G (IgG) antibodies on endogenous EVs with enhanced intracellular delivery in vitro and redistribution to liver in vivo. Intravenous protein A-NEV3 significantly reduced circulating IgG and anti-dsDNA antibodies in systemic lupus erythematosus mice with improved survival and reduced pathologies. Intravenous anti-transferrin receptor-protein A-NEV3 redirected circulating EVs to muscle and alleviated muscle pathologies in dystrophin-deficient mdx mice. Our study demonstrates that NEV3 enables in situ loading of protein therapeutics and tissue-specific delivery of circulating EVs, providing a modular strategy for loading cargo onto and redirecting circulating EVs in vivo.

bioengineering↗

bioRxiv2026

Inverse covariation between the neocortex and the limbic system is concentrated at deep evolutionary divergences

The macroscale architecture of mammalian brains consists of a broadly conserved set of structures, but the relative sizes of these structures vary substantially across species. Much of this variation follows conserved scaling relationships, but particular systems can expand or contract relative to the rest of the brain, providing targets for adaptive selection. One prominent example is a volumetric tradeoff between the neocortex and the limbic system, in which expansion of one is associated with reduction of the other, a feature apparent when brain structure volumes are examined across living species. However, whether this relationship has operated throughout mammalian evolution or arose during particular periods of diversification is unknown. Using phylogenetic comparative methods, we here show that the tradeoff between the neocortex and the limbic system is concentrated at deep evolutionary divergences separating major mammalian groups. After accounting for shared ancestry and brain size, the tradeoff strengthens progressively among deeper branches of the mammalian phylogeny, extending broadly across limbic structures, with the strongest signal involving olfactory components. Recent divergences show no consistent relationship. Our analyses indicate that the neocortex-limbic tradeoff emerged during the early diversification of mammals, highlighting how present-day variation in brain organization retains signatures of ancient evolutionary transitions.

neuroscience↗

bioRxiv2026

A bipolar disorder-associated ultra-rare AKAP11 protein-truncating variant attenuates stimulus-dependent PKA activation and induces anxiety- and depression-related behaviors in mice

Rare genetic variants associated with psychiatric disorders are thought to have larger individual effect sizes and direct biological roles, offering a unique opportunity for understanding causal relationships between genetic architecture and disease phenotypes. A recent whole-exome sequencing meta-analysis identified an increased burden of ultra-rare protein-truncating variants (PTVs) in AKAP11 in patients with bipolar disorder and schizophrenia. AKAP11 encodes an A-kinase anchoring protein that mediates the association of protein kinase A (PKA) and its substrates. How ultra-rare AKAP11 variants contribute to psychiatric disorder pathogenesis remains unknown. Here, using CRISPR-Cas9 genome editing, we introduced into the mouse Akap11 locus an ultra-rare PTV identified in a human patient with bipolar disorder. This ultra-rare PTV reduced Akap11 mRNA and protein levels without producing stable novel mRNA isoforms, leading to Akap11 haploinsufficiency. Male heterozygous mice exhibited behavioral abnormalities consistent with anxiety- and depression-like phenotypes. Transcriptomic and proteomic profiling of the neocortex revealed molecular changes involving synaptic organization, synaptic signaling, and neurite morphogenesis. Notably, the heterozygous mutant showed selective elevation in type I, but not type II, PKA regulatory subunits, as well as PKA catalytic subunits, in the neocortex. Functionally, these changes were accompanied by reduced phosphorylation of PKA substrates, attenuated stimulus-dependent PKA activity in cortical excitatory neurons, and impaired nascent dendritic development in cortical neurons. Together, our study presents a clinically relevant and genetically precise mouse model that provides mechanistic insight into how ultra-rare PTVs may contribute to psychiatric disorder pathogenesis, and a platform for testing rational therapeutics.

neuroscience↗

bioRxiv2026

LRRC37A is essential for acrosomal ion homeostasis and male fertility

Mammalian spermatozoa face various challenges during their long march to the destination. As a specialized membrane-bound organelle in the sperm head, the acrosome is particularly sensitive to changes in ionic and osmotic conditions, yet how acrosomal ion homeostasis is maintained remains largely unknown. Here, we show that LRRC37A is required for acrosomal ion homeostasis. Loss of Lrrc37a causes complete male infertility, accompanied by pronounced enlargement and deformation of the acrosome in the sperm head. Acrosome biogenesis was not affected by Lrrc37a knockout during the early stages of spermiogenesis, whereas acrosomal enlargement emerged at later stages and became more pronounced in the epididymis. LRRC37A localized to the outer acrosomal region and interacted with the Na/K-ATPase -subunit isoforms ATP1A1 and ATP1A4. Loss of LRRC37A disrupted the spatial distribution of both isoforms and was accompanied by increased Na within the acrosomal region. In addition, pharmacological perturbation of Na/K-ATPase activity or cellular ion homeostasis induced acrosomal swelling. These findings establish an essential role for LRRC37A in acrosomal ion homeostasis, suggesting that its deficiency may be associated with a distinct form of teratozoospermia characterized by acrosomal enlargement.

cell biology↗

bioRxiv2026

Subtyping active-site inhibitor binding mode to Abl kinase using super-resolution nanopore tweezers.

Accurate determination of kinase inhibitor binding modes could provide essential information for understanding resistance mechanisms and accelerating drug discovery. While conventional structural methods such as X-ray crystallography, cryo-EM and NMR provide high-resolution information but are low-throughput and capture largely static snapshots of dynamic protein-ligand interactions Here, we introduce a single-molecule nanopore tweezer platform that functionally subtypes ATP-competitive Abl kinase inhibitors by resolving distinct ionic current signatures of Abl-inhibitor complexes. This approach distinguishes Type I, Type IIA, and Type IIB inhibitors without structural determination. We further show how clinically relevant Abl variants (T315I and E255V) reshape inhibitor engagement and binding modes. By combining baseline probability features with wavelet-based time-frequency descriptors, ensemble machine-learning models achieved 97.5% classification accuracy across seven kinase inhibitor binding modes at sub-angstrom resolution and enabled deconvolution of mixed-inhibitor samples at nanomolar concentrations. These results establish nanopore tweezers as a label-free, super-resolution platform for profiling kinase conformational states and inhibitor binding modes, complementing structural approaches and supporting precision oncology.

biophysics↗

bioRxiv2026

Accumulation of Lipid Droplets in Microglia following Neonatal Brain Hypoxia-Ischemia

BackgroundHypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal mortality and neurodevelopmental impairments. Following brain hypoxia-ischemia (HI), microglia face substantial metabolic stress; and upon phagocytosis, they become overloaded with lipids derived from engulfed dead neurons and myelin debris. It is unclear how microglia respond to and process the lipid cargo, and whether lipid accumulation may affect microglia function following neonatal HI. MethodsThe postnatal day 10 mice were subjected to HI using the Vannucci model. Lipid droplets (LD) were assessed by histology and immunofluorescent staining. Single-nucleus RNA sequencing (snRNA-seq) was performed using brain tissue from HI-injured and sham-operated mice at 72 hours after HI. LD-accumulating microglia (LDAM) were identified by a specific LD marker gene perilipin 2 (Plin2). Differential gene expression was analyzed between Plin2-positive and Plin2-negative microglia after HI. Human HIE brain sections were also examined for LD accumulation. The dynamic changes of PLIN2-expressing microglia and infiltrating monocyte-derived macrophages (MDM) at 24 hours, 72 hours and 7 days after HI were compared using flow cytometry. In addition, mouse BV2 microglia were subjected to oxygen-glucose deprivation (OGD) to study phagocytosis and cytokine expression. ResultsLipid droplets accumulated primarily in microglia after HI in neonatal mice and in human HIE brain. LD were not found in astrocytes or neurons. Plin2-expressing LDAM emerged as new microglia clusters after HI. Compared with microglia without LD, LDAM showed a distinct transcriptional profile with upregulation of genes linked to microglial activation, enhanced cholesterol and lipid processing, and a shift towards phagocytic and pro-inflammatory state. Blocking LD biogenesis reduced elevated phagocytosis and IL-1{beta} expression in BV2 cells following OGD. ConclusionOur study revealed that microglia accumulate lipid droplets as part of their metabolic responses to HI in the neonatal brain. Microglial lipid droplet formation is associated with a pro-inflammatory phenotype at early stage after HI, and increased phagocytosis in vitro. The lipid metabolic changes may regulate microglial function and influence HI outcomes.

neuroscience↗

bioRxiv2026

DPCGS: a computational framework for linking GWAS to single-cell transcriptomics in complex traits and diseases

Complex traits and diseases arise from the interplay between genetic variation and cellular heterogeneity, making it essential to understand how genetic risk manifests at the cellular level. However, connecting genome-wide association studies (GWAS) to specific cell populations remains challenging due to cellular complexity and the prevalence of noncoding variants. Here, we present DPCGS, a computational framework that systematically integrates GWAS summary statistics with single-cell RNA-sequencing (scRNA-seq) data to identify trait-associated cell subpopulations, genes, and regulatory programs. Unlike existing approaches that primarily evaluate pathway enrichment or cell-type-level associations, DPCGS quantifies the enrichment of genetically prioritized genes within individual cells through a statistically calibrated gene-set scoring strategy, enabling high-resolution mapping of genetic risk to cellular states. Benchmarking across simulated and diverse human single-cell datasets demonstrates that DPCGS achieves superior accuracy, sensitivity, and robustness compared with existing methods, including scDRS and scPagwas. Applying DPCGS to Alzheimers disease and asthma reveals disease-associated cellular populations and uncovers potential molecular drivers, including CD74, FOS, and AP-1 family regulatory programs, providing insights into disease-specific immune and cellular mechanisms. By bridging genetic discoveries from GWAS with functional interpretation at single-cell resolution, DPCGS establishes a generalizable framework for dissecting the cellular architecture of complex traits and diseases. This approach enables systematic discovery of disease-relevant cell subpopulations, regulatory networks, and potential therapeutic targets, offering broad applications in human genetics, single-cell biology, and precision medicine.

bioinformatics↗

bioRxiv2026

Recent social loss, not chronic isolation, reshapes sleep in Drosophila

Drosophila melanogaster is widely used to study social experience, yet it remains unclear whether sleep phenotypes attributed to isolation reflect chronic deprivation or the consequences of a recent change in social state. Many fly studies alter social context again at the time of testing, making these possibilities difficult to distinguish. Here, we developed sociSleep, an identity-preserving tracking system that quantifies sleep without inducing social-state transitions. Using this approach, we found that chronic social isolation had little effect on sleep, whereas recent social loss robustly increased sleep. These findings show that recent social experience, rather than chronic isolation alone, is a major modulator of sleep in flies.

animal behavior and cognition↗

bioRxiv2026

Optogenetic decoupling of ODC inhibition and degradation reveals a requirement of polyamine oscillation for cell cycle progression

The dysregulation of polyamine homeostasis is a fundamental hallmark of both cancer and aging. Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, is regulated by the antizyme OAZ1 through a dual mechanism: inhibition of enzymatic activity and induction of proteasomal degradation via a C-terminal degron. In Bachmann-Bupp syndrome (BABS), mutations in this degron lead to ODC accumulation and toxic polyamine levels. However, the functional coupling between ODC inhibition and degradation remains poorly understood, and the current therapeutic intervention with DFMO target enzymatic activity without addressing protein accumulation. Here, we developed an optogenetic yeast model of BABS to decouple ODC inhibition from its degradation. By fusing a light-switchable LOV2-based module to a truncated, degron-less yeast ODC, we created a system where ODC degradation is controlled by light, independent of OAZ1 binding. We demonstrate that the loss of the ODC degron mimics the BABS cellular phenotype, characterized by increased polyamines, elevated ROS, and growth arrest. Crucially, while constant light-induced degradation is insufficient to rescue growth, oscillating ODC degradation at a 40-minute period restores polyamine homeostasis, cell cycle progression, and cellular growth. Our findings demonstrate that the inhibitory and degradation-inducing roles of OAZ1 can be decoupled and highlight the necessity of periodic polyamine oscillation for the cell cycle. Our work would be of great value for understanding the regulation mechanism of the polyamine metabolic network and establishing new targeted therapeutic strategies. Significance statementMutations in ODC degron lead to ODC accumulation and toxic polyamine levels in BABS. While DFMO has provided clinical relief for BABS patients, its utility is limited because it only inhibit ODC activity. We utilized an optogenetic approach in Saccharomyces cerevisiae to bridge this knowledge gap. We successfully decoupled the inhibitory and degradation-inducing functions of the ODC-OAZ1 axis and achieved three significant biological insights. First, we established yeast as a powerful and versatile model for investigating of the molecular mechanisms of BABS. Second, we demonstrated that the inhibitory and degradation-inducing roles of OAZ1 can be decoupled under specific conditions. Third, we revealed that periodic oscillation in polyamine levels is essential for maintaining proper cell cycle progressing.

molecular biology↗

bioRxiv2026

Minimal Data, Maximal Insight (MDMI): A Structure-guided Pipeline for Discovering Functional Alternatives in Peptide-Protein Interfaces

Discovering functional peptides across vast sequence space remains a formidable challenge, particularly when experimental training data is scarce. We present Minimal Data Maximal Insight (MDMI), a two-stage structure-guided computational pipeline that designs functional peptide variants using only a small, annotated dataset. Rather than relying on sequence information alone, MDMI integrates three-dimensional structural features derived from predicted peptide-protein complexes into a machine learning model that captures interface geometry and binding energetics. This structure-aware predictor, paired with a genetic algorithm for sequence exploration, reduced false positives from 70% to close to zero in an all-negative benchmark panel compared with a sequence-only model in computational benchmarking, and produced approximately four-fold more high-confidence in silico binders than state-of-the-art peptide/protein design baselines. Using the split-GFP system as a testbed, where fluorescence provides a direct functional readout of peptide-protein complementation, MDMI identified peptides with up to 38% sequence divergence from wild-type in Stage 1 while retaining measurable activity. In Stage 2, motif-guided recombination of successful Stage 1 variants produced highly divergent yet functional peptides bearing over 50% sequence difference from wild-type, revealing two distinct functional clusters in sequence space. As further validation, a top-performing candidate expressed as a full-length GFP fusion retained a GFP-like emission profile, supporting formation of a fluorescent GFP-like scaffold. These results demonstrate that structure-informed pipelines can uncover remote functional sequence space from minimal data, with broad implications for peptide and therapeutic analog discovery.

synthetic biology↗

bioRxiv2026

Same-section spatial metabolo-transcriptomics using Stereo-meta-seq reveals DHA-driven kidney maturation

A central unresolved question in developmental biology is whether local metabolites merely accompany, or actively instruct, tissue maturation. Addressing this question requires direct spatial coupling of metabolic states with genome-wide transcriptional programs in situ at high spatial resolution, which existing approaches do not readily achieve. Here, we introduce Stereo-meta-seq, a workflow that integrates quantitative MALDI-MSI with Stereo-seq spatial transcriptomics within a single tissue section. A conductive adapter was designed to overcome the electrical incompatibility of non-conductive Stereo-seq chips with vacuum MALDI platforms, improving efficiency of MSI detection that preserves RNA integrity. MALDI laser-ablation marks are retained in downstream Stereo-seq data and serve as intrinsic fiducials for direct co-registration at 10 m or 20 m resolution, enabling fine grained spatial metabolite-transcript integration. Applying Stereo-meta-seq to human kidney development, we uncover selective enrichment of docosahexaenoic acid (DHA) in maturing proximal tubules. Functional studies in human kidney organoids demonstrate that DHA activates PPAR-and HNF4-driven transcriptional programs and promotes proximal tubule maturation in vitro and after transplantation in vivo. These findings identify lipid metabolism as an instructive regulator of human nephrogenesis and establish Stereo-meta-seq as a practical platform for dissecting metabolite-gene coupling and tissue heterogeneity in situ.

Cell Biology↗

bioRxiv2026

Deep learning-guided design of hydrolases for crystalline PET depolymerization

Poly(ethylene terephthalate) (PET), a ubiquitous polyester used in packaging and textiles, persists in the environment due to its high crystallinity and stability, contributing substantially to global plastic pollution. Enzymatic depolymerization by PET hydrolase (PETase) offers a chemically precise and environmentally sustainable route to convert PET into its monomeric building blocks, enabling recycling. However, practical implementation remains hindered by the rigid, crystalline architecture of PET, which restricts enzyme access and necessitates energy-intensive pretreatment to enable efficient depolymerization. In addition, most PETases achieve only partial depolymerization with low terephthalic acid (TPA) yields and accumulate inhibitory intermediates, while limited thermostability and slow surface kinetics further restrict efficiency. To overcome these barriers, we report VenusPETase, an engineered variant of KbPETase designed using PET-Flow, a state-of-the-art computational framework for PETase engineering. Compared with KbPETase, VenusPETase exhibits a 3.4-fold increase in hydrolytic activity, up to a 27-fold improvement after heat treatment of protein, and a 12 {degrees}C enhancement in thermostability. VenusPETase exhibits rapid degradation across a wide crystallinity range (8%-50%) at 50 {degrees}C, effectively spanning the entire spectrum of commercial PET products. Moreover, VenusPETase outperformed nine high-performance PETases under their respective optimal conditions and degraded untreated PET substrates across 8%-50% crystallinity, producing TPA as over 95% of the released products with minimal intermediate accumulation. X-ray crystallography and molecular dynamics simulations suggest that dynamic modulation, elevated surface electrostatic potential enhance the interaction of VenusPETase with crystalline PET, thereby lowering the hydrolytic energy barrier and improving catalytic performance. We also demonstrate that untreated, postconsumer-PET from nine different products can all be degraded by VenusPETase. The recovered monomers can be directly repolymerized into virgin-quality PET, demonstrating a closed-loop enzymatic recycling process. In a 100 L bioreactor, VenusPETase completely depolymerizes post-consumer crystalline PET (28% crystallinity) within 24 h under 50 {degrees}C. These results establish VenusPETase as a robust biocatalyst that enables efficient, closed-loop recycling of crystalline PET under mild conditions.

biochemistry↗

bioRxiv2026

Dual-acting Estrogen Receptor Modulator-Histone Lysine Demethylase Inhibitors

Epigenetic dysfunction and the malfunction of endocrine proteins such as estrogen receptor alpha (ER) are two key mechanisms for the sustenance of breast carcinoma. Agents that target ER signaling malfunctions are standard therapies for ER-dependent breast cancer (BCa) subtypes. Small molecule inhibitors of epigenetic modifiers, histone lysine demethylases (KDMs), have shown promise as therapeutic agents for several BCa subtypes. We demonstrated herein that the integration of ER antagonist (Tamoxifen) and agonist (17-ethinylestradiol) ligands with deferiprone (DFP)-derived KDM inhibitor moiety furnished dual-acting agents Tam-KDMi and EED-KDMi, respectively. These agents showed robust on-target effects and potent BCa cells-selective anti-proliferative activities. The Tam-KDMi are cytotoxic to both ER(+) and ER(-) BCa cells, while the lack of ER-signaling inhibition conferred an enhanced ER(-) cells cytotoxic to the EED-KDMi. Representative lead compounds Tam-KDMi DW-116 and EED-KDMi DW-088 and DW-95 significantly reduce tumor growth in murine xenograft models of ER(-) and ER(+) BCas with TGI as high as 70%. Collectively, our data showed that DW-116, DW-088 and DW-95 have a high potential as leads for the development of new agents for the treatment of BCa subtypes regardless of the tumor ER expression status.

cancer biology↗

bioRxiv2026

Bidirectional regulation between circadian feeding behavior and specialized midgut clocks in Drosophila

Feeding is a fundamental animal behavior. Increasing evidence suggests that the timing of food intake--rather than the amount or quality alone--contributes to maintaining health. Although mistimed eating can reset peripheral clocks and desynchronize them from central pacemakers to affect physiology and metabolism, how peripheral clocks can in turn shape rhythmic feeding behavior is less well understood. Here, we investigated the contribution of peripheral clocks to circadian feeding behavior in Drosophila males. Using high-resolution feeding assays combined with complementary analytical approaches that assess both rhythmicity and time-resolved dynamics, we examined the roles of distinct peripheral cell types in feeding regulation. This study reveals the involvement of midgut enteroendocrine cells (EECs) and enterocytes (ECs) in maintaining the stability and strength of feeding rhythms, whereas the fat body clock modulates baseline levels of food intake. Beyond serving as an output behavior of circadian rhythms, feeding also acts as an effective behavioral Zeitgeber that drives molecular clocks. In the absence of the dominant Zeitgeber--light--midgut oscillations decay during prolonged ad libitum feeding in constant darkness, whereas feeding/fasting cycles enable the autonomous persistence of clock oscillations in EECs but not in ECs. These findings are suggestive of regulatory feedback between midgut EECs and feeding, highlighting how timed feeding or dietary interventions could influence metabolic health via specialized gut cells.

animal behavior and cognition↗

bioRxiv2026

Coupling of ATP and PMF in Escherichia coli is determined by growth conditions

The ATP molecule is the universal energy currency across all living organisms. There are two fundamental pathways of ATP synthesis: substrate-level and oxidative phosphorylation. While substrate-level phosphorylation generates ATP directly, in oxidative phosphorylation, proton motive force (PMF) is required to power ATP synthesis via the F1Fo ATP synthase. Using Escherichia coli, we show that due to simultaneous use of both pathways, the strength of coupling between ATP and PMF strongly depends on growth conditions: coupling is weak when requirements for independent generation of ATP and PMF are met, and becomes essential when not. We determine the conditions, under which PMF-ATP coupling becomes essential and show that PMF is required for bacterial growth irrespective of its ATP synthesis function. We propose that the main role of F1Fo in Escherichia coli, contrary to the canonical view, is not to generate ATP but to provide an auxiliary pathway that allows both, ATP and PMF, to be produced.

microbiology↗

bioRxiv2026

Concordant transcriptional and morphological remodeling revealed by in vivo Perturb-CLEAR

The principle that form follows function has long guided thinking in biology and architecture alike. In the nervous system, however, form does more than reflect function: neuronal morphology actively constrains input patterns, synaptic integration, and circuit wiring. During postnatal neurodevelopment, dendritic architectures are assembled and remodeled through genetically encoded programs and activities, transforming molecular programs into circuit architecture. However, dendritic morphogenesis has been difficult to quantify at scale while systematically testing how genetic variants, including neurodevelopmental disorder (NDD) risk genes, alter these structures in vivo. We developed Perturb-CLEAR, which integrates pooled CRISPR screening and whole-mount imaging to quantify brain-wide cytoarchitecture, and paired it with Perturb-seq to link structural phenotypes to transcriptomic changes. Applying Perturb-CLEAR to the developing mouse cortex revealed morphogenesis trajectories accompanied by transcriptomic dynamics. Moreover, systematic perturbation of NDD risk genes uncovered gene-specific multimodal phenotypes. Adnp perturbation remodels basal dendrites in L4/5 IT (intratelencephalic) neurons but not other dendritic compartments or cell types, alongside consistent transcriptional shifts. Combined morphology and transcriptome analyses link NDD risk genes to concordant multimodal cellular phenotypes in the developing brain, highlighting diverse paths of perturbation effect propagation across modalities.

neuroscience↗

bioRxiv2026

Context-dependent toxicity of human Tau isoforms in a Drosophila tauopathy model

Tauopathies are characterised by progressive deterioration of brain regions due to abnormal accumulation of the microtubule-associated protein tau (MAPT). Alternative splicing of MAPT pre-mRNA results in six tau isoforms, which are classified into two groups depending on the number of microtubule-binding domain repeats (3R vs 4R). Although many tauopathies are 3R or 4R-specific, the relative contributions of individual isoforms to neurotoxicity remain incompletely understood. To systematically characterise differences in tau isoform toxicity, we created a novel set of Drosophila lines expressing equivalent amounts of the six human tau isoforms (hTau) at levels sufficient to induce visible phenotypes. Using a variety of assays including survival, negative geotaxis and tissue-level or cell-type-specific degeneration, we found that hTau isoform toxicity is not uniform across different biological contexts. Despite generally higher toxicity of 4R isoforms compared to 3R, the effects of individual hTau isoforms varied with the temporal window of expression, tissue type, and neuronal identity. Restricting hTau expression to small homogeneous neuronal populations enabled detailed analysis of isoform-specific degeneration. Neurons previously observed to be vulnerable or resilient to hTau toxicity exhibited differences in the onset and progression of degeneration, suggesting that resilience may be an early and transitory state, with most or all neurons eventually succumbing to tau toxicity over time. Notably, these differences in toxicity were not readily explained by variations in hTau abundance and phosphorylation. Together, our findings demonstrate that tau toxicity is highly context-dependent, clearly isoform-specific, and shaped by interactions between tau and its cellular environment.

neuroscience↗

bioRxiv2026

Cardiomyocyte autophagy promotes a pro-regenerative immune response during cardiac regeneration

Adult zebrafish possess a remarkable ability to regenerate their heart following cardiac injury. Over the past decades, our understanding of the diverse cell types involved in zebrafish cardiac regeneration has greatly advanced. However, the mechanisms governing their interaction and how heterocellular crosstalk drives regeneration remain poorly understood. Here, we identify cardiomyocyte autophagy as a key link between the cardiomyocyte injury response and heterocellular crosstalk between cardiomyocytes and macrophages. We find that cardiomyocyte autophagy is downstream of AP-1 transcription factors. Using newly generated genetic tools, we find that cardiomyocyte autophagy is an important regulator of cardiomyocyte protrusion into the fibrotic injured tissue and its disruption leads to defects in scar resolution. Notably, we find that blocking cardiomyocyte autophagy has a marked effect on the transcriptomic signatures in cardiac macrophages, shifting gene expression from phagocytic/pro-inflammatory/pro-reparative towards pro-angiogenic and pro-fibrotic states. Altogether, our results uncover autophagy as a mechanism linking cardiomyocyte injury responses to macrophage phenotype and coordinated tissue remodeling during heart regeneration.

cell biology↗