Biology subjects

Liu, L.

Publications and source records attributed to Liu, L..

At least 235 records · Page 13Linked to original sources

bioRxiv2025

Longitudinal single-cell analysis reveals RUNX1T1 as an early driver in treatment-induced neuroendocrine transdifferentiation

Treatment-induced neuroendocrine prostate cancer (t-NEPC) is a lethal form of advanced prostate cancer that can emerge from adenocarcinoma under androgen receptor pathway inhibition, but the tumor-cell states and regulators underlying this transition remain incompletely defined. Here, we analyzed longitudinal single-cell RNA sequencing data from the LTL331/331R patient-derived xenograft model across seven disease stages, comprising 32,269 tumor-cell transcriptomes from treatment-naive adenocarcinoma, post-castration regression, and relapsed NEPC. We identified an AR-low/NE-low intermediate state that emerged after castration and before overt relapse, as well as two transcriptionally distinct terminal NEPC states marked by ASCL1high/FOXA2low and ASCL1low/FOXA2high programs. RUNX1T1 was induced in the intermediate state and remained elevated across both terminal states. RUNX1T1 enhanced NE-associated features and cell viability during enzalutamide treatment in adenocarcinoma cells, whereas its knockdown in NCI-H660 cells reduced NE-associated transcriptional programs, proliferation, and survival and shifted the transcriptome toward an intermediate-like state. Chromatin interactome analysis and co-immunoprecipitation linked RUNX1T1 to G9A/LASP1-containing chromatin repressor complexes. These findings define a temporal framework for treatment-induced NEPC progression and identify RUNX1T1 as an early-induced and sustained regulator of NE lineage transition and maintenance of established NEPC.

cancer biology↗

bioRxiv2025

NUSAP1 regulates mitotic processes via KIF2C interaction and AURKA phosphorylation in primary microcephaly

Primary microcephaly (PM) is a neurodevelopmental disorder characterized by a significantly smaller head than normal. Despite the identification of several genes associated with PM subtypes, the etiology remains unclear in a significant proportion of patients. Here, we reported two de novo nonsense mutations in the NUSAP1 gene identified in two independent PM families: c.1209 C>G (p.Tyr403*) and c.1213C>T (p.Gln405*). Nusap1-edited mouse models, designed to mimic Human NUSAP1 mutations, replicated the microcephaly phenotype, characterized by a small brain and thinner cerebral cortex. We demonstrated that Nusap1 was specifically expressed in neural stem/progenitor cells (NSPCs), and the number of NSPCs was significantly reduced in Nusap1-edited mice. In vitro experiments revealed that NUSAP1 mutations disrupted mitotic metaphase chromosome alignment, increased polyploidy, induced cell cycle arrest, and promoted apoptosis. Co-IP confirmed direct interactions between NUSAP1 and KIF2C, and showed that truncating mutations impaired their binding. Furthermore, NUSAP1 rescued the cell cycle arrest and increased apoptosis caused by KIF2C overexpression in NUSAP1 KO HEK293T cells, whereas the mutant truncated protein failed to exert such a rescue effect. We also uncovered an interaction between NUSAP1 and Aurora kinase A (AURKA). Intriguingly, subsequent experiments revealed that AURKA-mediated phosphorylation of NUSAP1 modulates its binding affinity to KIF2C. In conclusion, our findings established NUSAP1 as a novel pathogenic gene for PM. We proposed a model in which AURKA-mediated phosphorylation of NUSAP1 regulates its interaction with KIF2C, balancing spindle microtubule stability and depolymerization to ensure proper sister chromatid segregation. Disruptions in this pathway impair NSPCs mitosis, thereby affecting neocortical development.

genetics↗

bioRxiv2025

FASN Inactivation-induced Progranulin (GRN) Expression Promotes Lysosome-dependent Cell Death to Suppress Leukemogenesis

Cancer cells rely on lipogenesis in addition to exogenous lipid uptake, and fatty acid synthase (FASN) is aberrantly overexpressed in myeloid leukemia. However, the precise role of FASN in leukemogenesis in vivo remains elusive. Here, we demonstrated that FASN is essential for leukemogenesis. Ablation of FASN impeded leukemic cell growth, survival, clonogenicity in vitro, and the leukemic burden in vivo. Conditional knockout of FASN barely affected hematopoiesis but significantly attenuated the leukemic progression of MLL-AF9 transplants. By screening a library of platensimycin derivatives, we identified compound MS-C19 as a potent FASN inhibitor. Pharmacological targeting of FASN by MS-C19 suppressed leukemic cell growth and clonogenicity in clinical AML blasts. Mechanistically, both MS-C19 treatment and FASN deficiency triggered the activation of lysosomal and inflammatory gene expression. Loss of FASN led to lysosomal membrane permeabilization and subsequent lysosome-associated cell death, but not lysosome biogenesis. We further identified that GRN, a lysosomal and neuroinflammatory gene, was potently transcribed by TFEB upon FASN loss. Depletion of GRN significantly reversed the inhibitory effects caused by FASN knockdown. Our work demonstrates that FASN is a therapeutic target for myeloid leukemia, and inactivation of FASN by the lead compound MS-C19 provides an alternative approach for leukemic intervention. Key PointsO_LIGenetic ablation of FASN induces apoptosis, impedes leukemia cell growth, and improves the survival of leukemic xenografts. C_LIO_LITargeting FASN by the compound MS-C19, a derivative of the natural microbe antibiotic platensimycin, reduces the cell survival of leukemic cell lines, the clinical leukemic blasts, and MLL-AF9 transformed murine leukemic cells. C_LIO_LIFASN inhibition induces lysosome-dependent cell death that relies on Progranulin (GRN) expression. C_LI

cancer biology↗

bioRxiv2025

Synaptic Toxicity of OGA Inhibitors and the Failure of Ceperognastat

O-GlcNAcase inhibitors (OGAi) have been proposed as therapeutics for Alzheimers disease due to their ability to increase O-GlcNAcylation of tau and reduce its aggregation. However, the recent failure of ceperognastat in a Phase II trial--marked by accelerated cognitive decline in the treatment arm--has raised concerns about the safety of this therapeutic class. Here, we evaluated the acute synaptic effects of three structurally distinct OGAi (ceperognastat, ASN90, and MK8719) in mouse hippocampal slices. Electrophysiological recordings revealed that all three compounds impaired both short- and long-term synaptic plasticity, as evidenced by reduced paired-pulse facilitation/depression and suppressed long-term potentiation. Immunohistochemistry showed altered synaptic protein levels, with increased PSD-95 and reduced Synaptophysin 1 in neurons, alongside a biphasic shift in Tau phosphorylation. These findings indicate that OGAi produce rapid and convergent synaptotoxic effects across pre- and postsynaptic compartments, likely reflecting a class-wide mechanism. We argue that electrophysiological screening should be standard in CNS drug development and caution against targeting essential synaptic processes in chronic neurodegenerative conditions.

pharmacology and toxicology↗

bioRxiv2025

Cellular and Regional Vulnerability Shapes the Molecular Landscape of Psychosis in Alzheimers Disease

Approximately 40 percent of Alzheimers disease patients develop psychosis (AD+P), yet the molecular and cellular basis of these symptoms remains poorly understood. Here we profiled single-nucleus transcriptomes and epigenomes from 48 postmortem Alzheimers brains stratified by psychiatric diagnosis. Across cell types, AD+P was distinguished by transcriptional programs in upper-layer cortical pyramidal neurons consistent with re-engagement of developmental and structural plasticity pathways. These neurons exhibited greater loss in AD+P cortex, indicating that such programs emerge in a context of heightened vulnerability. Integrating these findings with functional perturbation screens in stem-cell-derived brain organoids, we found that activation of these programs alters cortico-cortical network connectivity and can exacerbate network dysfunction. Our data suggest that compensatory neuronal plasticity, shaped by glial inflammatory responses, may paradoxically contribute to circuit instability and selective vulnerability underlying neuropsychiatric symptoms in dementia. HighlightsO_LICell-type- and brain-region-specific transcriptional changes in AD with psychosis (AD+P) C_LIO_LIUpper-layer pyramidal dysfunction and metabolic vulnerability marks the pathophysiology of AD+P C_LIO_LICircuit wiring programs are evoked in AD+P as maladaptive compensatory responses C_LIO_LIAD+P-associated IL-6 signaling impairs neuronal network function in brain organoids C_LI

neuroscience↗

bioRxiv2025

Locus Coeruleus to Medial Prefrontal Cortex Noradrenergic Neural Circuit Modulates States of Consciousness during Sevoflurane Anesthesia in Mice

How exactly does general anesthesia achieve its effects? It is so widely used in surgeries and medical treatments to enhance comfort for nearly one hundred years, yet its precise mechanisms underlying the loss and recovery of consciousness still remain unclear. Utilizing a variety of research methods-pharmacological, optogenetic, chemogenetic, fiber photometry, and gene knockdown approaches-our study has shed light on the significant modulatory function of locus coeruleus noradrenergic neurons during the transition from sevoflurane anesthesia to awakening. Furthermore, the activation of the LC-mPFC circuit has been found to have a substantial arousal effect, with 1-AR playing a crucial role in this process. Additionally, GABAA-R has been identified as the key binding site for sevoflurane within the locus coeruleus. These findings collectively offer novel insights into the neural network mechanisms underlying general anesthesia, advancing our understanding of this complex medical phenomenon.

neuroscience↗

bioRxiv2025

CRISPR-On-Beads: A Simple and Sensitive Approach for Bacterial DNA Detection

CRISPR/Cas12a, recognized for its high efficiency and specificity in nucleic acid recognition, has found extensive applications in infectious disease sensing. Nonetheless, a significant challenge persists in devising a simple method for the rapid, convenient, and accurate visualization of detection results. In this study, we demonstrate an innovative and simple CRISPR-on-beads assay for visual detection of methicillin-resistant Staphylococcus aureus (MRSA). This approach combines isothermal target amplification, CRISPR/LbCas12a-mediated cleavage, and magnetic bead-based probe binding for signal amplification, enabling rapid and convenient identification of bacterial DNA. Our results show that this detection method exhibits both high sensitivity and specificity, with a detection limit as low as 30 CFU/L. This newly developed biosensing approach can easily be integrated with a portable fluorescence microscope for medical diagnostics in resource-limited settings.

bioengineering↗

bioRxiv2025

Low level of viral intra-host diversity is associated with severe SFTS disease

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus that can cause severe clinical symptoms and high fatality. However, the dynamics of SFTSV intra-host diversity during infection and its association with disease severity remain unexplored. Here, we characterized SFTSV iSNVs in longitudinal clinical samples from patients with distinct clinical outcomes. Our analyses revealed that SFTSV intra-host diversity was associated with disease severity and showed distinct patterns in severe and mild cases. Severe cases exhibited paradoxically lower SFTSV intra-host diversity despite higher viral loads, likely driven by reduced selection pressure. Notably, iSNVs linked to viral replication emerged in severe cases, while iSNVs associated with immunity invasion arose in mild cases. Machine learning models showed that intra-host diversity can contribute to classification of SFTS by severity. Our findings, through the lens of within-host viral populations, highlight variations in viral-host interactions during SFTSV infection and provide potential biomarkers for predicting SFTS severity.

pathology↗

bioRxiv2025

Differing drivers of range-wide genetic diversity across previously glaciated Northern hemisphere landscapes

O_LIThe latitudinal gradient (LG) hypothesis predicts a poleward decrease of genetic diversity. Similarly, the central-marginal hypothesis (CMH) predicts higher genetic diversity in range centres than margins. We examined these patterns in Europe (EU), North America (NA) and East Asia (EA), which experienced contrasting patterns of landscape fragmentation. C_LIO_LIWe compiled genetic variation data for 445 plant species and 8,530 populations. We calculated ecological metrics comprising distance to the range margin and native climatic niche margin, distance to refugia, latitude and altitude. We applied Bayesian inference to evaluate the relationships between genetic variation and ecological metrics. C_LIO_LIWe found universal support for the CMH, with populations at the centres of species ranges and/or native climatic niches exhibiting higher genetic diversity than those at the margins and stronger patterns in woody versus herbaceous plants. Evidence for a LG in diversity was less consistent with latitude: negatively correlated with genetic diversity in EU, positively correlated in EA, and no correlation in NA. C_LIO_LIOur analysis supports the view that the LG is largely driven by latitudinal trends in glaciation, particularly in EU, but highlights that glaciation patterns and their resulting impacts on landscape genetic diversity were more heterogeneous in NA and EA. C_LI

evolutionary biology↗

bioRxiv2025

TransAgent: Dynamizing Transcriptional Regulation Analysis via Multi-omics-Aware AI Agent

Transcriptional regulation research, as a core area of life sciences, faces challenges such as scattered multi-omics data, complex joint analysis, and difficulties in integrating data processing tools. To address these issues, we propose TransAgent, an agent software specifically designed for transcriptional regulation analysis. Through innovative designs such as multi-mode operation (planning/execution/automatic), dynamic memory management, rapid MCP tool expansion (integrating over 30 tools), integration of transcriptional regulation annotation data (over 20 data sources including epigenomics and gene expression profiles), and cloud Docker computing, TransAgent significantly improves analysis efficiency. We have successfully applied TransAgent to various transcriptional regulation analysis scenarios such as re-construction of super-enhancer regulatory circuit in esophageal squamous cell carcinoma and identification of key regulators in cardiomyocyte differentiation, demonstrating analytical robustness and uncovering biological insights. TransAgent automates the entire process from raw data processing to advanced analysis, such as joint prediction of multi-omics data, transforming traditionally time-consuming and labor-intensive tasks into a conversation-driven approach. This provides a new paradigm for transcriptional regulation research, centered around large models as the core driver of scalable agent application analysis.

bioinformatics↗

bioRxiv2025

Dimethyl fumarate reprograms cervical cancer cells to enhance antitumor immunity by activating mtDNA-cGAS-STING pathway

BackgroundCervical cancer (CC) remains a significant global health challenge for women, especially in advanced stages where effective treatments are limited. Current immunotherapies, including PD-1/PD-L1 blockades and adoptive T cell therapies, show limited response rates and durability. Dimethyl fumarate (DMF), an FDA-approved drug for autoimmune diseases, has demonstrated that it might exhibit direct antitumor activity in several cancers. However, its influence on anti-tumor immunity and its function in CC remain poorly understood. This study aims to investigate the therapeutic potential of DMF in CC models and elucidate its underlying mechanisms of action. MethodsCC cell lines and mouse models were treated with DMF. Transcriptional level changes in cervical cancer cells following DMF treatment were analyzed by RNA-seq. Mitochondrial DNA (mtDNA) release, and cGAS-STING activation were assessed via qPCR, immunofluorescence, immunoblotting and ELISA. CD8+ T cell recruitment was analyzed by flow cytometry. Combinatorial therapies (DMF + anti-PD-1/TILs) were tested in syngeneic or patient-derived xenografts (PDX) models. ResultsDMF treatment induces mitochondrial dysfunction in tumor cells, resulting in the release of mtDNA into the cytosol. The cytosolic mtDNA activates the cGAS-STING-TBK1 pathway and type I interferon response, leading to the secretion of CCL5 and CXCL10, thereby enhancing CD8 T cell infiltration. Additionally, DMF exhibits synergistic effect with PD-1 blockade in murine CC model, and can enhance the therapeutic efficacy of adoptively transferred T cells toward CC patient-derived xenografts model. ConclusionThis work elucidated that DMF reprograms CC cells to activate the mtDNA-cGAS-STING pathway, fostering a chemokine-rich microenvironment that recruits CD8+ T cells. Its synergy with PD-1 blockade or TIL therapy underscores its potential as an immunomodulatory adjuvant. These findings suggest that DMF holds promise as a novel immunotherapeutic strategy for improving clinical outcomes in CC.

immunology↗

bioRxiv2025

Unique Gluing Effect of ASXL1 K351 Monoubiquitination Stimulates PR-DUB-Mediated Nucleosomal H2AK119Ub Deubiquitination

Protein ubiquitination plays a critical role in regulating fundamental biological processes through both proteolytic and nonproteolytic mechanisms. While classically known for its role in targeting proteins for degradation, ubiquitination can also modulate enzymatic activity. However, all of the known mechanisms of such modulation involve spatially constrained mechanisms that take place near the enzyme-substrate interfaces. Here, we report an unprecedented regulatory paradigm mediated by ubiquitination that is located distal to the enzyme-substrate interface but can still activate the polycomb repressive deubiquitinase (PR-DUB) complex. Using cryo-electron microscopy, molecular dynamics (MD) simulations, hydrogen-deuterium exchange mass spectrometry (HDX-MS), and kinetics assays, we determined that the ASXL1 K351 monoubiquitination promotes PR-DUB-mediated nucleosomal H2AK119Ub deubiquitination by stabilizing the catalytic pocket of PR-DUB, causing significant increase in maximal catalytic velocity (Vmax) but almost no change in the substrate binding affinity (Km). Structural analysis revealed that the ubiquitin moiety at ASXL1 K351 bridges the BAP1 and ASXL1 subunits, acting as an intramolecular "glue" that constrains the conformational dynamics of these subunits without altering the nucleosome binding interface. Further MD and HDX-MS results demonstrated the monoubiquitination of ASXL1 K351 enables PR-DUB to effectively maintain a spatial arrangement of the catalytic conformation that closely aligns with substrate cleavage. This study expands our understanding of the mechanisms of ubiquitin function to include intramolecular fastening with a molecular gluing effect and provides a deeper mechanistic understanding of PR-DUB activation in nucleosomal H2AK119Ub removal.

biochemistry↗

bioRxiv2025

CES1 DEFICIENCY IS ASSOCIATED WITH METABOLIC REPROGRAMING AND ENDOTHELIAL DYSFUNCTION IN PULMONARY ARTERIAL HYPERTENSION

BackgroundPulmonary arterial hypertension (PAH) is a progressive disease characterized by pulmonary microvascular loss and obliterative remodeling, driven by metabolic reprogramming, oxidative stress, and endothelial dysfunction. While BMPR2 mutations contribute to metabolic shifts in pulmonary microvascular endothelial cells (PMVECs), their low penetrance suggests additional genetic modifiers play a role. A genetic screen of PAH PMVECs identified carboxylesterase 1 (CES1)--an endoplasmic reticulum (ER) enzyme involved in lipid metabolism and detoxification--as a candidate regulator of endothelial metabolism and angiogenesis. We hypothesize that CES1 loss promotes endothelial dysfunction via metabolic reprogramming, lipotoxicity, and oxidative stress. MethodsPAH and healthy PMVECs and lung tissues were obtained from transplant donors and commercial sources. CES1 expression was modulated in PMVECs using siRNA knockdown and plasmid overexpression. Mitochondrial and ER function were assessed via confocal microscopy and proteomics. CES1 heterozygous knockout (HET KO) and endothelial-specific knockout (ECKO) mice were exposed to normoxia or hypoxia, with lung tissues analyzed by single-cell RNA sequencing (scRNA-seq) and histopathology. ResultsCES1 expression was significantly reduced in PAH PMVECs and vascular lesions. CES1-deficient PMVECs exhibited increased apoptosis, reactive oxygen species (ROS) production, mitochondrial fragmentation, ER stress, and impaired angiogenesis. Confocal imaging and metabolic studies revealed lipid droplet accumulation, reduced fatty acid oxidation, and a glycolytic shift-- phenotypes reversed by CES1 restoration. Mechanistically, CES1 transcription was induced by BMPR2 via NRF2 activation, a key regulator of redox and metabolic homeostasis. In vivo, CES1-deficient mice developed severe pulmonary hypertension (PH) under hypoxia, with extensive vascular remodeling, right ventricular dysfunction, and dysregulated angiogenesis and lipid metabolism pathways, as confirmed by lung scRNA-seq. ConclusionsCES1 is essential for pulmonary endothelial homeostasis and serves as a critical modifier of BMPR2 signaling. Given the limited efficacy of current PAH therapies in reversing endothelial dysfunction and small-vessel loss, restoring CES1 expression represents a promising therapeutic strategy.

biochemistry↗

bioRxiv2025

ZMS-6659, a selective Polθ helicase inhibitor, demonstrates anti-tumor activity as monotherapy and synergy effect with PARP inhibitors and topoisomerase inhibitors

The repair of DNA double strand break (DSB) is crucial for genome stability. Homologous recombination (HR) is a high-fidelity, error-free DSB repair pathway, and its dysfunction leads to genome instability and can result in tumorigenesis. In HR deficient contexts, microhomology-mediated end joining (MMEJ), dependent on DNA polymerase theta (Pol{theta}), is up-regulated to serve as a backup pathway for DSB repair. Several studies have proved that Pol{theta} inhibition causes synthetic lethality with HR deficiency, and Pol{theta} emerges as a potential DNA damage repair (DDR) target for the treatment of HR deficient tumors both as single agent or in combination with PARP inhibitors (PARPi). In addition, evidences show that the blockage of Pol{theta} can enhance the sensitivity to DNA damage agents. Herein, we characterized ZMS-6659, a highly potent small-molecule Pol{theta} inhibitor targeting the helicase domain. ZMS-6659 induces synthetic lethality in HR deficient models, elicits synergistic effects with even low dose of PARPi and delays PARPi resistance without additional hematotoxicity. Besides, ZMS-6659 also enhance the sensitivity to topoisomerase inhibitors in HR proficient cell lines. These findings support the clinical exploration of ZMS-6659 in combination with PARPi in HR deficient tumors, and suggest a potential application expansion beyond HR deficiency.

cancer biology↗

bioRxiv2025

Widespread discordance between mRNA expression, protein abundance and de novo lipogenesis activity in hepatocytes during the fed-starvation transition

The mammalian liver plays a critical role in maintaining metabolic homeostasis during fasting and feeding. Liver function is further shaped by sex dimorphism and zonation of hepatocytes. To explore how these factors interact, we performed deep RNA-sequencing and label-free proteomics on periportal and pericentral hepatocytes isolated from male and female mice under fed and starved conditions. We developed a classification system to assess protein-mRNA relationship and found that gene products (mRNA or protein) for most zonation markers showed strong concordance between mRNA and protein. Although classical growth hormone regulated sex-biased gene products also exhibited concordance, [~]60% of sex-biased gene products showed protein-level enrichment without corresponding mRNA differences. In contrast, transition between feeding and starvation triggered widespread changes in mRNA expression without significantly affecting protein levels. In particular, key lipogenic mRNAs (e.g. Acly, Acaca, and Fasn) were dramatically induced by feeding, but their corresponding proteins (ACLY, ACC1, and FAS) showed little to no change even as functional de novo lipogenic activity increased [~]28-fold in the fed state. To facilitate further exploration of these findings, we developed Discorda (https://shinoda-lab.shinyapps.io/discorda/), a web database for interactive analysis. Our findings reinforce the principle that mRNA changes do not reliably predict corresponding protein levels (and vice versa), particularly in the context of sex and acute metabolic regulation of hepatocytes, and that de novo lipogenesis activity can be completely uncoupled from changes in protein expression.

bioinformatics↗

bioRxiv2025

TUCL-Seq for miRNA single molecule sequencing

MicroRNAs (miRNAs) are pivotal regulatory molecules in gene expression, and their precise quantification is essential for elucidating their roles in diverse biological processes. This research paper introduces a pioneering workflow for the single molecule sequencing (SMS) of miRNA, integrating advanced miRNA sample preparation with SMS sequencing. Central to our approach is TUCL-Seq, which is an automated, on-chip miRNA library preparation method designed to streamline the sequencing process. This innovative approach incorporates the addition of sequencing adaptor to RNA samples in solution, and converts it to cDNA on a sequencing flow cell for sequencing. Coupled with single molecule sequencing instrument and base-call software, our workflow significantly reduces sample-to-result time, and decreases the need for manual interventions compared to traditional SMS and next-generation sequencing methods. We demonstrate the efficacy of TUCL-Seq by accurately quantifying synthetic miRNA samples with a 24-hour workflow, showcasing its potential for high-throughput miRNA profiling. Our findings highlight the promise of this integrated workflow for advancing miRNA research and applications in diagnostics and therapeutics.

biochemistry↗

bioRxiv2025

YPEL controls synapse development through p62-Nrf2 antioxidant pathway in Drosophila neuromuscular junction

The Yippee-like (YPEL) genes are highly conserved among all eukaryotic species, yet the molecular and cellular pathways that YPEL regulate are poorly understood. Human and animal studies suggest that YPEL is involved in nervous system functions. Here we report that YPEL is necessary for synapse development in neuromuscular junction and motor functions in Drosophila. YPEL interacts with the Drosophila p62, Refractory to sigma P, which forms cytoplasmic proteinaceous bodies for selective autophagy and signaling. YPEL overexpression decreased p62 bodies, while increased p62 bodies were observed in YPEL mutant neurons. Suppressing p62 bodies by reducing p62 gene dosage significantly alleviated both synaptic and locomotion defects in YPEL mutants, suggesting that YPEL acts through p62 for synapse development. On the other hand, suppressing p62 bodies via autophagy did not restore synapse development in YPEL mutants. Interestingly, reduced levels of reactive oxygen species were found in YPEL mutants, which is consistent with the role of p62 in promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway. Overexpressing Drosophila Nrf2, Cap n collar (Cnc), phenocopied the synaptic and locomotion deficits in YPEL mutants. Importantly, both synaptic and locomotion defects were completely rescued by knocking down Cnc in YPEL mutant motor neurons. Taken together, our study demonstrates that YPEL negatively controls p62 - Nrf2 antioxidant pathway for neuromuscular synapse development and locomotion.

neuroscience↗

bioRxiv2025

Super-Resolution Diffusivity Mapping Reveals Spatial Correlations Between Lateral Mobility and Structural Heterogeneities on Cellular Membranes

Cellular membranes orchestrate critical processes such as molecular transport and signal transduction, both regulated by the lateral mobility of lipids and proteins. However, resolving nanoscale diffusional heterogeneities and elucidating their underlying mechanisms remains a formidable challenge due to the membranes intricate architecture and compositional diversity. Here, we present point-cloud single-molecule diffusivity mapping (pc-SMdM), a cutting-edge super-resolution technique that offers a point-cloud data format with enhanced spatial resolution for diffusivity mapping. Using pc-SMdM, we visualize nanoscale diffusion slowdown clusters with [~]50 nm in diameter on plasma membranes. These clusters are predominantly governed by cholesterol content, alongside contributions from membrane protein assemblies and topographical features. Leveraging two-color pc-SMdM, we concurrently imaged multiple lipids and membrane probes, revealing distinct "fingerprint" diffusivity maps shaped by their interactions within lipid bilayers. Our findings position pc-SMdM as a transformative tool for spatially resolving molecular interactions and membrane dynamics in live cells, offering new insights into the underlying mechanisms that govern membrane mobility at the nanoscale.

biophysics↗