Biology subjects

Min, C.

Publications and source records attributed to Min, C..

17 recordsLinked to original sources

bioRxiv2026

Reprogramming CAR-T cell function through synthetic cytokine receptors suppresses metastatic progression of TNBC

Patient T cells modified with chimeric antigen receptors (CARs) have shown remarkable therapeutic success in previously incurable cancers. However, despite its success in hematological malignancies, CAR-T therapy has shown only modest efficacy in solid tumors. The medical field has focused on developing new molecular designs that enhance CAR-T persistence, prevent exhaustion in the tumor microenvironment (TME), and increase the specificity of the CAR-T cell to various tumor antigens. However, much less effort has been placed on enhancing CAR-T cells' invasion into and migration through the stromal matrix of the TME, where they can elicit tumor-directed cytotoxicity. Here, we engineered CAR-T cells with synthetic cytokine receptors targeting inflammatory cytokines produced by the cells themselves, which increase their speed through collagen I matrices. We show that this enhanced motility is driven by increased CAR-T cell translocation through confined microchannels via cellular deformation, together with elevated migratory speeds in proximity to neighboring cells, suggesting improved responsiveness to local cues. These migration-enhanced CAR-T cells significantly reduce both primary tumor size and distant organ metastasis in triple-negative breast cancer (TNBC) mouse models compared to standard CAR-T cells. These results support molecular design strategies that exploit mechanisms to improve cellular therapies for metastatic solid tumors.

bioengineering↗

bioRxiv2026

Intravital single-cell behavior profiling reveals disrupted germinal center B cell motility and interactions by EZH2 gain-of-function mutation

Germinal center (GC) B-cells give rise to the majority of non-Hodgkin lymphomas, underscoring the need to pinpoint critical processes that initiate and drive lymphomagenesis. Lymphoma driver mutations can alter GC B cell functions and B cell fate decisions. Here, we studied how EZH2 oncogenic mutation in GC B cells alters cellular motility and interactions with T follicular helper (Tfh) cells and follicular dendritic cells (FDCs) to determine B cell fate. By combining intravital imaging, single-cell behavior analyses, and RNA sequencing, we uncover how lymphoma-associated EZH2 mutations reprogram the behaviors of GC B cells in vivo. We found that EZH2 mutations increased single-cell motility speeds and morphological plasticity of GC B cells, redirecting migration toward the FDC-rich light zone subregions rather than to the dark zone. Although mutant EZH2 GC B cells exhibited normal engagement quality with FDCs, they showed shorter interaction times and reduced surface engagement with Tfh cells. Notably, EZH2 mutant B cells required prior contact with FDC before engaging with Tfh cells, thus impairing DZ recycling. This motility phenotype scaled with local mutant clone abundance, suggesting a behavioral strategy underlying how mutant cells outcompete WT cells. Lastly, we developed scMOTIPh, a computational framework that integrates single-cell behavioral features with transcriptomic profiles. Applying scMOTIPh to mutant GC B cells within the FDC-rich zone revealed enhanced ATP production, metabolic and antigen-presentation programs, and suppression of cell-death pathways, which is consistent with a tendency for malignant transformation and survival fitness. These findings provide an in vivo, single-cell view of how an epigenetic lesion rewires the local microenvironment by modulating single-cell behaviors within native GCs, revealing a dynamic mechanism for early lymphomagenesis.

immunology↗

bioRxiv2026

Senescent cell networks link matrix remodeling and vascular dysfunction in human fibroids

Uterine fibroids (leiomyomas) are highly prevalent benign tumors defined by excessive extracellular matrix (ECM) deposition, altered vascular structure, and progressive tissue stiffening, yet the cellular programs that coordinate these features remain poorly understood. Cellular senescence has been implicated in fibroid biology, but whether senescence represents a uniform state or distinct, functionally specialized cell identities within fibroids is unknown. Here, we identify the distinct heterogeneous populations of senescent cells ("senotypes") present in human fibroids and characterize their role in shaping the fibroid microenvironment. Using single-cell RNA sequencing (scRNA-seq) integrated with a senescence gene signature and protein-level validation, we identify senescent cells (SnC) distributed across fibroblast, mural, and endothelial compartments, each exhibiting distinct transcriptional programs. SnC endothelial cells (ECs) are enriched in fibroids relative to matched myometrium and activate TEAD4-associated mechanosensing, angiogenic, and immune signaling pathways, despite being associated with impaired vessel maturation in situ. In parallel, SnC fibroblast and mural populations in fibroids upregulated SRF-associated cytoskeletal and ECM programs, accompanied by increased COL6A3 expression and collagen VI deposition, consistent with tissue stiffening. Ligand-receptor and spatial analyses reveal that these SnC populations function as interconnected signaling hubs, coordinating immune cell recruitment and stromal remodeling. Importantly, analysis of human fibroids treated with collagenase demonstrated a reduction in both ECM density and SnC burden, supporting a reinforcing relationship between matrix mechanics and senescence. Together, these findings establish senescence in fibroids as a heterogeneous, mechanically reinforced, and network-driven process that links vascular dysfunction, immune signaling, and fibrosis, highlighting distinct SnC states as potential translational targets for non-surgical therapies.

cell biology↗

bioRxiv2026

Neutrophil migration in the lung is altered by alveolar collapse and stretch

RationaleHeterogeneous alveolar collapse is prevalent in inflammatory lung conditions such as chronic obstructive pulmonary disease, acute respiratory distress syndrome, and pneumonia. Although neutrophil-released proteases contribute to the tissue remodeling that leads to alveolar collapse, how this altered mechanical environment in turn affects neutrophil migration remains largely unexplored. ObjectivesIn this study, we investigate how alveolar collapse and stretch influence neutrophil migration and identify the mechanical and biochemical factors that govern regional migration differences. MethodsWe developed a novel precision-cut lung slice platform that generates collapsed vs non-collapsed regions within the same slice. Neutrophils in both regions were longitudinally imaged for up to 5 hours to quantify motility behavior. Migration mechanisms were probed using migration-related inhibitors, collagenase, and cigarette smoke extract. A crystal ribcage system, which preserves intact alveolar shape and the air-liquid interface, was also used to assess the effects of ventilation on neutrophil migration. ResultsNeutrophil migration was faster in the collapsed region compared to not-collapsed regions. This regional difference was eliminated by Rho-associated protein kinase (ROCK) inhibition, which selectively increased migration speed in the non-collapsed region. The regional difference persisted with the addition of collagenase and cigarette smoke extract, both of which significantly increased the migration speed in both regions. In the crystal ribcage, the preserved air-liquid interface and ventilation together enhanced neutrophil migration compared with a collapsed lung. ConclusionsAlveolar collapse and stretch facilitate neutrophil migration, indicating the role of localized tissue remodeling in driving neutrophil activity and further disease progression.

bioengineering↗

bioRxiv2026

Monocytes are biological sensors of aging and frailty in humans

Among older adults, frailty is clinically identifiable and characterized by increased vulnerability to adverse health outcomes. Although various tools exist to identify frailty, diagnosis often depends on late-stage clinical symptoms, which typically limit proactive intervention options. We considered whether aging and frailty information may be encoded in the single-cell behaviors and dynamic responses of primary human monocytes. Combining high-content imaging, single-cell behavior profiling, and machine learning, we demonstrated unique age- and frailty-dependent monocyte behaviors at baseline and following exposure to inflammatory stressors. Using these single-cell behaviors, we developed a deep learning neural network model called scTRAIT. scTRAIT accurately predicts the frailty status of older donors, including the capability to track and forecast longitudinal changes in frailty status. Collectively, these findings demonstrate that aging and frailty information are robustly encoded within single-cell behaviors, establishing monocytes as significant biological sensors of aging and frailty in humans. TeaserSingle-cell monocyte responses enable robust prediction of aging and frailty in humans

bioengineering↗

bioRxiv2026

Acute priming using elevated fluid viscosity recovers young-like single-cellsurveillance behaviors in aged human T cells

Aging is a complex biological process, often characterized by increased vulnerability to disease, infection, and death. This increased vulnerability is mechanistically linked to a progressive and functional decline of the immune system. In humans, aged lymphocytes lose their capacity to effectively surveil within diverse microenvironments, decreasing their capability for clearing infections and maintaining physiological homeostasis. However, specific mechanisms by which aged lymphocytes, specifically T cells, lose this capacity to surveil remain unclear. We profiled three core characteristics of T cell surveillance at single-cell resolution, specifically migration, deformability, and sensing. While aged T cells retained their capacity for spontaneous migration, they exhibited impaired cellular deformability and deficiencies in sensing local signaling cues. To modulate this surveillance defect, we performed mechanical reprogramming using elevated fluid viscosity. Results showed that acute priming of aged T cells with elevated fluid viscosity recovered a transient young-like surveillance phenotype, which was mechanistically linked to membrane tension, cortical F-actin, and Arp3 expression. These findings reveal a key source of surveillance defects in aged T cells and provide an effective mechanical approach to tuning their single-cell behaviors. TeaserRecovery of young-like surveillance phenotypes in aging human T cells via viscosity priming

bioengineering↗

bioRxiv2025

Data-driven simulations elucidate how lymphocyte motility behaviors drive cell-cell interactions within germinal centers

Lymphocytes rely on cell motility to surveil immune microenvironments and engage in contact-mediated interactions with other cells as part of the adaptive immune response. Within the germinal center (GC) light zone, germinal center B-cells (GCBs) and T-follicular helper cells (Tfhs) engage in cell-cell interactions that enable antibody affinity maturation. The number and duration of GCB-Tfh interactions correlate with the success of the germinal center in effectively generating antibodies that can bind and neutralize antigens. Prior studies have shown that GCBs and Tfhs exploit distinct motility patterns to surveil the GC light zone and engage in these cell-cell interactions. However, the quantitative relationship between lymphocyte motility parameters (such as speed and tortuosity) and GCB-Tfh interactions has not been systematically explored. Here, we analyzed single-cell trajectories of GCBs and Tfhs from two-photon intravital microscopy videos of GCs within mouse popliteal lymph nodes. We found that these cells exhibit seven distinct motility behaviors, each with characteristic speeds and tortuosities. GCBs tended to move in slow and tortuous paths, while Tfhs adopted faster and more directed trajectories. We then developed a three-dimensional agent-based model (ABM) to simulate these experimentally-observed GCB and Tfh motility behaviors and predict their impact on GCB-Tfh interactions. Using the ABM, we found that the baseline motility behaviors of GCBs and Tfhs allow GCBs to maximize interactions with distinct Tfhs in a confined space.

systems biology↗

bioRxiv2025

Exploring the mechanism of kaji-ichigoside F1 on bacterial pneumonia based on the network pharmacology and transcriptome

ObjectiveTo explore the anti-inflammatory mechanism of kaji-ichigoside F1 against bacterial pneumonia based on transcriptomics and network pharmacology. MethodNetwork pharmacological was used to analyse the potential target genes of kaji-ichigoside F1 action on bacterial pneumonia; molecular docking was used to analyse the docking binding energy of kaji-ichigoside F1 with key target genes; RAW264.7 macrophages were treated with klebsiella pneumoniae fluid and given kaji-ichigoside F1 intervention, the expression of inflammatory factors IL-1{beta}, IL-6, TNF- and IL-10 were dectected by qRT-PCR; transcriptomic analysis was performed to obtain differentially expressed genes, and relevant signaling pathways. ResultNetwork pharmacological analysis showed that the five the key target genes for kaji-ichigoside F1-bacterial pneumonia interaction were were TLR4, NFKB1, STAT3, IL1B, and JUN; molecular docking results of kaji-ichigoside F1 with key target genes showed the docking binding energy ranging from -5.9 to -8.4 kcal/mol; kaji-ichigoside F1 can reduce the klebsiella pneumoniae induced inflammatory response of macrophages, manifested with reducing the mRNA expression of pro-inflammatory factors IL-1{beta}, IL-6 and TNF-, and increase the mRNA expression of anti-inflammatory factor IL-10; transcriptomics analysis showed that the signaling pathways involved were mainly the TLR signaling pathway and NFKB signaling pathway. ConclusionThis study showed that kaji-ichigoside F1 alleviates bacterial pneumonia by targeting TLR and NFKB signaling pathways, rebalancing macrophage polarization with suppressing pro-inflammatory cytokines and increasing anti-inflammatory cytokines, highlighting kaji-ichigoside F1 as a novel agent for combating bacterial infections. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=144 SRC="FIGDIR/small/649383v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@7c96eorg.highwire.dtl.DTLVardef@13977a6org.highwire.dtl.DTLVardef@1de6214org.highwire.dtl.DTLVardef@f91c50_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2025

Tumor suppressor collateral damage screens reveal mRNA homeostasis protein HBS1L as a novel vulnerability in ch9p21 driven FOCAD deleted cancer

Chromosomal deletion of tumor suppressor genes often occurs in an imprecise manner, leading to co-deletion of neighboring genes. This collateral damage can create novel dependencies specific to the co-deleted context. One notable example is the dependency on PRMT5 activity in tumors with MTAP deletion, which co-occurs with CDKN2A/B loss, leading to the development of MTA-cooperative PRMT5 inhibitors. To identify additional collateral damage context/target pairs for chromosome 9p and other common loci of chromosomal deletions, we conducted a combinatorial CRISPR screen knocking out frequently co-deleted genes in combination with a focused target library. We identified the gene encoding the ribosome rescue factor PELO as synthetic lethal with loss of gene encoding the SKI complex interacting protein FOCAD, which is frequently co-deleted alongside MTAP and CDKN2A/B on chromosome 9p. A genome-wide screen in FOCAD isogenic cells further identified the ribosome rescue GTPase and PELO binding partner HBS1L as the top synthetic lethal target for FOCAD loss. Analysis of publicly available data and genetic manipulation of HBS1L using orthogonal modalities validated this interaction. HBS1L dependency in FOCAD-deleted cells was rescued by FOCAD re-expression, and FOCAD intact cells could be rendered HBS1L-dependent by FOCAD knockout, demonstrating the context specificity of this interaction. Mechanistically, HBS1L loss led to translational arrest and activated the unfolded protein response in FOCAD-deleted cells. In vivo, HBS1L deletion eliminated growth of FOCAD-deleted tumors. Here we propose a model where the FOCAD/SKI complex and HBS1L/PELO work together to resolve aberrant mRNA-induced ribosomal stalling, making the HBS1L/PELO complex an intriguing novel target for treating FOCAD-deleted tumors.

cancer biology↗

bioRxiv2024

Thalamic integration of basal ganglia and cerebellar circuits during motor learning

The ability to control movement and learn new motor skills is one of the fundamental functions of the brain. The basal ganglia (BG) and the cerebellum (CB) are two key brain regions involved in controlling movement, and neuronal plasticity within these two regions is crucial for acquiring new motor skills. However, how these regions interact to produce a cohesive unified motor output remains elusive. Here, we discovered that a subset of neurons in the motor thalamus receive converging synaptic inputs from both BG and CB. By performing multi-site fiber photometry in mice learning motor tasks, we found that motor thalamus neurons integrate BG and CB signals and show distinct movement-related activity. Lastly, we found a critical role of these thalamic neurons and their BG and CB inputs in motor learning and control. These results identify the thalamic convergence of BG and CB and its crucial role in integrating movement signals. HighlightsO_LIIndividual neurons in motor thalamus receive converging synaptic input from SNr and DCN projections. C_LIO_LIThalamic neurons with SNr and DCN input are concentrated at the border between VM and VAL thalamic nuclei. C_LIO_LIThalamic neurons functionally integrate SNr and DCN activity and adapt with motor learning. C_LIO_LIThalamic neurons and their inputs from SNr and DCN are critical for learning and executing motor tasks. C_LI

neuroscience↗

bioRxiv2024

Molecular tension authenticates apoptotic cells being phagocytosed.

Profound cytoskeletal reorganization and plasma membrane deformation in phagocytes is indispensable for phagocytosis of massive apoptotic cells, but whether these dynamics accompany a mechanical signal modulating signaling during efferocytosis remains largely unexplored. Here, we report that tension between phosphatidylserine (PS) and PS receptors (PSR) generated at the phagocytic synapse serves as a signal to determine whether PS-exposing cells should be phagocytosed. Mechanistically, increased membrane tension of phagocytes via Rac1-dependent actin polymerization and membrane stiffness of apoptotic cells caused tension between PS and PSRs, leading to phosphoinositide 3-kinase recruitment to PSRs, which resulted in Rac1 inactivation and myosin II phosphorylation required for phagocytic cup closure. Our observations imply that tension between PS and PSRs acts as a mechanical fail-safe to prevent removal of all PS-exposing cells for the integrity of efferocytosis. One-Sentence SummaryTension between phosphatidylserine and its receptors acts as a final decision-maker determining phagocytosis of apoptotic cells.

cell biology↗

bioRxiv2024

Single-cell morphology encodes functional subtypes of senescence in aging human dermal fibroblasts

Cellular senescence is an established driver of aging, exhibiting context-dependent phenotypes across multiple biological length-scales. Despite its mechanistic importance, profiling senescence within cell populations is challenging. This is in part due to the limitations of current biomarkers to robustly identify senescent cells across biological settings, and the heterogeneous, non-binary phenotypes exhibited by senescent cells. Using a panel of primary dermal fibroblasts, we combined live single-cell imaging, machine learning, multiple senescence induction conditions, and multiple protein-based senescence biomarkers to show the emergence of functional subtypes of senescence. Leveraging single-cell morphologies, we defined eleven distinct morphology clusters, with the abundance of cells in each cluster being dependent on the mode of senescence induction, the time post-induction, and the age of the donor. Of these eleven clusters, we identified three bona-fide senescence subtypes (C7, C10, C11), with C10 showing the strongest age-dependence across a cohort of fifty aging individuals. To determine the functional significance of these senescence subtypes, we profiled their responses to senotherapies, specifically focusing on Dasatinib + Quercetin (D+Q). Results indicated subtype-dependent responses, with senescent cells in C7 being most responsive to D+Q. Altogether, we provide a robust single-cell framework to identify and classify functional senescence subtypes with applications for next-generation senotherapy screens, and the potential to explain heterogeneous senescence phenotypes across biological settings based on the presence and abundance of distinct senescence subtypes.

bioengineering↗

bioRxiv2024

Construction of Animal Models Based on Exploring Pathological Features and Mechanisms of Different Locations in the Progression of DVT-APTE-CTEPD/CTEPH

BackgroundChronic thromboembolic pulmonary disease (CTEPD) and chronic thromboembolic pulmonary hypertension (CTEPH) are sequelae of acute pulmonary embolism (APE) and severely affect patients health and quality of life. The treatment of these conditions is challenging, and their underlying mechanisms remain unclear. The main reason for this is the lack of an animal model that can fully simulate the entire chain of DVT-APTE-CTEPD/CTEPH progression. The objective of this study is to construct an ideal animal model that simulates the major pathological changes of DVT-APTE-CTEPD/CTEPH and can be used for mechanistic exploration. We aim to compare the advantages and disadvantages of different modeling approaches and provide an experimental basis for investigating the mechanisms of pulmonary embolism chronicization at different stages of evolution. Methods and MaterialsWe first evaluated the pathological changes in the pulmonary arterial intima stripping tissue of CTEPH patients. Animal models were established by multiple injections of thrombus columns through the internal jugular vein to simulate distal remodeling of the pulmonary artery. To simulate significant remodeling and fibrosis in the middle and distal segments of the pulmonary artery, thrombus columns were injected along with splenectomy. A CTEPD model with intimal fibrosis remodeling was successfully established by selectively injecting large thromboemboli into the pulmonary artery sites in large animals (dogs). A rat model with pathological manifestations of intimal fibrosis remodeling in the proximal end of the pulmonary artery was constructed using large thrombi combined with nitric oxide synthase inhibitors. An animal model of DVT was established using the inferior vena cava ligation method. ResultsAccording to the different pathological features and mechanisms observed in the progression of human DVT-APTE-CTEPD/CTEPH, we constructed animal models that conform to these pathological manifestations and mechanisms, each with its own advantages. Furthermore, the different methods used to construct animal models can be integrated and applied together. ConclusionAnimal models constructed using different modeling methods can effectively simulate the pathological and physiological manifestations of the corresponding stages of chronic pulmonary embolism. Researchers can select the aforementioned models according to their specific research purposes, directions, and requirements.

zoology↗

bioRxiv2024

AI-driven Classification of Cancer-Associated Fibroblasts Using Morphodynamic and Motile Features

The heterogeneous natures of cancer-associated fibroblasts (CAFs) play critical roles in cancer progression, with some promoting tumor growth while others inhibit it. To utilize CAFs as a target for cancer treatment, issues with subtypes of CAFs must be resolved such that specific pro-tumorigenic subtypes can be suppressed or reprogrammed into anti-tumorigenic ones. Currently, single-cell RNA sequencing (scRNA-Seq) is a prevalent strategy for classifying CAFs, primarily based on their biomolecular features. Alternatively, this study proposes assessing CAFs on a larger biophysical scale, focusing on cell morphological and motile features. Since these features are downstream effectors of differential gene expression combinations, they can serve as holistic descriptors for CAFs, offering a complementary strategy for classifying CAF subtypes. Here, we propose an artificial intelligence (AI) classification framework to comprehensively characterize CAF subtypes using morphodynamic and motile features. This framework extracts these features from label-free live-cell imaging data of CAFs employing advanced deep learning and machine learning algorithms. The results of this study highlight the ability of morphodynamic and motile features to complement biomolecular features in accurately reflecting CAF subtype characteristics. In essence, our AI-based classification framework not only provides valuable insights into CAF biology but also introduces a novel approach for comprehensively describing and targeting heterogeneous CAF subtypes based on biophysical features.

cancer biology↗

bioRxiv2020

Potent SARS-CoV-2 neutralizing antibodies selected from a human antibody library constructed decades ago

Combinatorial antibody libraries not only effectively reduce antibody discovery to a numbers game, but enable documentation of the history of antibody responses in an individual. The SARS-CoV-2 pandemic has prompted a wider application of this technology to meet the public health challenge of pandemic threats in the modern era. Herein, we used a combinatorial human antibody library constructed 20 years before the COVID-19 pandemic to discover three highly potent antibodies that selectively bind SARS-CoV-2 spike protein and neutralize authentic SARS-CoV-2 virus. Compared to neutralizing antibodies from COVID-19 patients with generally low somatic hypermutation (SHM), these antibodies contain over 13-22 SHMs, many of which are involved in specific interactions in crystal structures with SARS-CoV-2 spike RBD. The identification of these somatically mutated antibodies in a pre-pandemic library raises intriguing questions about the origin and evolution of human immune responses to SARS-CoV-2.

microbiology↗

bioRxiv2019

SEMA3F-deficient colorectal cancer cells promote lymphangiogenesis: fatty acid metabolism replace glycolysis for energy supply during lymphatic endothelial cells proliferation in tumor hypoxia microenvironment

lymphangiogenesis as a process is colorectal cancer first metastasis via lymphatic vessels to proximal lymph nodes. The fuel metabolism in mitochondrial and support proliferation of lymphatic endothelial cells (LECs) remain elusive during lymphangiogenesis in tumor hypoxic microenvironment. Recent studies report that loss of SEMA3F critically contributes to lymphangiogenesis of the CRCs. Here, we silenced SEMA3F expression of CRCs and co-culture with hLECs, the tubulogenesis capacity and hLECs migration were escalated in the hypoxia, the hLECs mainly relied on fatty acid metabolism not aerobic glycolysis during lymphangiogenesis. SEMA3F-deficient CRCs up-regulated PMAKP expression and phosphorylation of hLECs, and activated its peroxisome proliferator-activated receptor (PPARs) and Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1a) facilitated their switched toward fatty acids (FA) catabolism. Furthermore, we observed that activation of the PGCI-PPAR lipid oxidation signaling pathway in hLECs was caused by the secretion of interleukin-6 by tumor cells.Taken together, this study indicates that CRCs with SEMA3F expression depletion significantly promotes lymphangiogenesis in hypoxia and faciliates the secretion of IL-6 in tumor cell, and activates mitochondria fatty acids oxidation (FAO) reaction in the hLECs by PGCI-PPAR signaling pathways to support its growth.

cell biology↗

bioRxiv2019

Disease-associated mutations hyperactivate KIF1A motility and anterograde axonal transport of synaptic vesicle precursors

KIF1A is a kinesin-family motor involved in the axonal transport of synaptic vesicle precursors (SVPs) along microtubules. In humans, more than ten point mutations in KIF1A are associated with the motor neuron disease, hereditary spastic paraplegia (SPG). However, not all of these mutations appear to inhibit the motility of the KIF1A motor, and thus, a clear molecular explanation for how KIF1A mutations lead to neuropathy is not available. In this study, we established in vitro motility assays with purified full-length human KIF1A and found that KIF1A mutations associated with the pure form of spastic paraplegia hyperactivate motility of the KIF1A motor. Introduction of the corresponding mutations into Caenorhabditis elegans KIF1A homologue unc-104 revealed abnormal accumulation of SVPs at the tips of axons and increased anterograde axonal transport of SVPs. Our data reveal that hyper-activation of kinesin motor activity, rather than its loss-of-function, is a novel cause of motor neuron disease in humans.\n\nSignificance StatementAnterograde axonal transport supplies organelles and protein complexes throughout axonal processes to support neuronal morphology and function. It has been observed that reduced anterograde axonal transport is associated with neuronal diseases. In contrast, here we show that particular disease-associated mutations in KIF1A, an anterograde axonal motor for synaptic vesicle precursors, induce hyperactivation of KIF1A motor activity and increased axonal transport of synaptic vesicle precursors. Our results advance the knowledge of the regulation of motor proteins and axonal transport and cell biology of motor neuron diseases.

cell biology↗