Biology subjects

Lin, Y.

Publications and source records attributed to Lin, Y..

At least 181 records · Page 10Linked to original sources

bioRxiv2024

BCAS2 promotes primitive hematopoiesis by sequestering β-catenin within the nucleus

Breast carcinoma amplified sequence 2 (BCAS2), a core component of the hPrP19 complex, plays crucial roles in various physiological and pathological processes. However, whether BCAS2 has functions other than being a key RNA-splicing regulator within the nucleus remains unknown. Here, we show that BCAS2 is essential for primitive hematopoiesis in zebrafish and mouse embryos. The activation of Wnt/{beta}-catenin signal, which is required for hematopoietic progenitor differentiation, is significantly decreased upon depletion of bcas2 in zebrafish embryos and mouse embryonic fibroblasts (MEFs). Interestingly, BCAS2 deficiency has no obvious impact on the splicing efficiency of {beta}-catenin pre-mRNA, while significantly attenuating {beta}-catenin nuclear accumulation. Moreover, we find that BCAS2 directly binds to {beta}-catenin via its coiled-coil domains, thereby sequestering {beta}-catenin within the nucleus. Thus, our results uncover a previously unknown function of BCAS2 in promoting Wnt signaling by enhancing {beta}-catenin nuclear retention during primitive hematopoiesis.

developmental biology↗

bioRxiv2024

Temporal dynamics analysis reveals that concurrent working memory load eliminates the Stroop effect through disrupting stimulus-response mapping

Concurrent verbal working memory task can eliminate the color-word Stroop effect. Previous research, based on specific and limited resources, suggested that the disappearance of the conflict effect was due to the memory information preempting the resources for distractors. However, it remains unclear which particular stage of Stroop conflict processing is influenced by working memory loads. In this study, electroencephalography (EEG) recordings with event-related potential (ERP) analyses, time-frequency analyses, multivariate pattern analyses (MVPA), and representational similarity analyses (RSA) were applied to provide an in-depth investigation of the aforementioned issue. Subjects were required to complete the single task (the classical manual color-word Stroop task) and the dual task (the Sternberg working memory task combined with the Stroop task), respectively. Behaviorally, the results indicated that the Stroop effect was eliminated in the dual-task condition. The EEG results showed that the concurrent working memory task did not modulate the P1, N450, and alpha bands. However, it modulated the sustained potential (SP), late theta (740-820 ms), and beta (920-1040 ms) power, showing no difference between congruent and incongruent trials in the dual-task condition but significant difference in the single-task condition. Importantly, the RSA results revealed that the neural activation pattern of the late theta was similar to the response interaction pattern. Together, these findings implied that concurrent working memory task eliminated the Stroop effect through disrupting stimulus-response mapping.

neuroscience↗

bioRxiv2024

Targeting fatty acid synthase suppresses tumor development in NF2/CDKN2A-deficient malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an uncommon yet deadly cancer linked to asbestos exposure. The lack of effective early diagnosis and treatment leads to reduced life expectancy among patients with MPM. This study is aimed to identify a novel molecular target inhibitor to develop more effective therapeutics for MPM. Our drug screening assay showed that the fatty acid synthase (FASN) inhibitor cerulenin demonstrates strong and selective anti-proliferative properties against NF2/CDKN2A(p16)-deficient MPM cells, surpassing the effects of cisplatin or pemetrexed. FASN protein is frequently detected in NF2/p16-deficient MPM tumor-derived tissues (15/15, 100%), but rarely in NF2/p16-intact MPM tumors (8/25, 32%). Notably, cerulenin administration successfully reduced the growth of NF2/p16-deficient MPM tumors in xenografted mice. Cerulenin inhibits mitochondrial fission by targeting dynamin-related protein 1 (DRP1) in NF2/p16-deficient cells. Moreover, the disruption of the FASN gene leads to increased ubiquitination of DRP1. These findings suggest that FASN might play a role in the tumorigenesis of MPM cells through the regulation of mitochondrial dynamics. This research offers a novel perspective on the potential development of precision medicine for MPM.

cancer biology↗

bioRxiv2024

Spatial Transcriptomics and Single-Nucleus Multi-omics Analysis Revealing the Impact of High Maternal Folic Acid Supplementation on Offspring Brain Development

Folate, an essential vitamin B9, is crucial for diverse biological processes including neurogenesis. Folic acid (FA) supplementation during pregnancy is a standard practice for preventing neural tube defects (NTDs). However, concerns are growing over the potential risks of excessive maternal FA intake. Here, we employed mouse model and spatial transcriptomics and single-nucleus multi-omics approaches to investigate the impact of high maternal FA supplementation during the periconceptional period on offspring brain development. Maternal high FA supplementation affected gene pathways linked to neurogenesis and neuronal axon myelination across multiple brain regions, as well as gene expression alterations related to learning and memory in thalamic and ventricular regions. Single-nucleus multi-omics analysis revealed that maturing excitatory neurons in the dentate gyrus (DG) are particularly vulnerable to high maternal FA intake, leading to aberrant gene expressions and chromatin accessibility in pathways governing ribosomal biogenesis critical for synaptic formation. Our findings provide new insights into specific brain regions, cell types, gene expressions and pathways that can be affected by maternal high FA supplementation.

neuroscience↗

bioRxiv2024

FLASH proton reirradiation, with or without hypofractionation, mitigates chronic toxicity in the normal murine intestine, skin, and bone.

Background and purposeThe normal tissue sparing afforded by FLASH radiotherapy (RT) is being intensely investigated for potential clinical translation. Here, we studied the effects of FLASH proton RT (F-PRT) in the reirradiation setting, with or without hypofractionation. Chronic toxicities in three murine models of normal tissue toxicity including the intestine, skin, and bone were investigated. Materials and methodsIn studies of the intestine, single-dose irradiation was performed with 12 Gy of Standard proton RT (S-PRT), followed by a second dose of 12 Gy of F-PRT or S-PRT. Additionally, a hypofractionation scheme was applied in the reirradiation setting (3 x 6.4 Gy of F-PRT or S-PRT, given every 48 hrs). In studies of skin/bone of the murine leg, 15 Gy of S-PRT was followed by hypofractionated reirradiation with F-PRT or S-PRT (3 x 11 Gy). ResultsCompared to reirradiation with S-PRT, F-PRT reduced intestinal fibrosis and collagen deposition in the reirradiation setting and significantly increased survival rate, demonstrating its protective effects on intestinal tissues. In previously irradiated leg tissues, reirradiation with hypofractionated F-PRT created transient dermatitis that fully resolved in contrast to reirradiation with hypofractionated S-PRT. Lymphedema was also alleviated after a second course of radiation with F-PRT, along with significant reductions in the accumulation of fibrous connective tissue in the skin compared to mice reirradiated with S-PRT. The delivery of a second course of fractionated S-PRT induced tibial fractures in 83.3% of the mice, whereas only 20% of mice reirradiated with F-PRT presented with fractures. ConclusionThese studies provide the first evidence of the sparing effects of F-PRT, in the setting of hypofractionated reirradiation. The results support FLASH as highly relevant to the reirradiation regimen where it exhibits significant potential to minimize chronic complications for patients undergoing RT.

cell biology↗

bioRxiv2024

Genomic evolution reshapes cell type diversification in the amniote brain

Over 320 million years of evolution, amniotes have developed complex brains and cognition through largely unexplored genetic and gene expression mechanisms. We created a comprehensive single-cell atlas of over 1.3 million cells from the telencephalon and cerebellum of turtles, zebra finches, pigeons, mice, and macaques, employing single-cell resolution spatial transcriptomics to validate gene expression patterns across species. Our study revealed significant species-specific variations in cell types, highlighting their conservation and diversification in evolution. We found pronounced differences in telencephalon excitatory neurons (EX) and cerebellar cell types between birds and mammals. Birds predominantly express SLC17A6 in EX, whereas mammals expressed SLC17A7 in neocortex and SLC17A6 elsewhere, possibly due to loss of SLC17A7 function loss in birds. Additionally, we identified a novel bird-specific Purkinje cell subtype (SVIL+), implicating the LSD11/KDM1A pathway in learning and circadian rhythms, and related numerous positively selected genes in birds, suggesting an evolutionary optimization of cerebellar functions for ecological and behavioral adaptation. Our findings elucidate the complex interplay between genetic evolution and environmental adaptation, underscoring the role of genetic diversification in the development of specialized cell types across amniotes.

evolutionary biology↗

bioRxiv2024

Maternal total sleep deprivation causes oxidative stress and mitochondrial dysfunction in oocytes associated with fertility decline in mice

Previous studies have shown sleep deprivation has an impact on several aspects of health and disease. Sleep deprivation suppresses melatonin production and excessive HPA activation in women, which may reduce the chances of fertility. However, little is known about how and by what relevant mechanisms it affects female fertility. In this study, female mice underwent 72 hours of total sleep deprivation (TSD) caused by rotating wheel or 2 different controls: a stationary wheel, or forced movement at night. Even though, there was no evident anomaly of natural ovulation, the TSD female mice showed impaired early embryo development . Overall levels of estrogen and FSH were lower throughout the estrus cycle (especially in proestrus). RNA Sequencing (RNA-Seq) was used to discover differentially expressed genes (DEGs) that might be involved in oocyte quality after TSD. A total of 42 genes showed significant differential expression in GV oocytes after TSD. These included genes such as Usmg5, Atp5k, Ccnd2 and Tpm3, which were enriched in gene ontology terms of mitochondrial protein complex, oxidoreductase activity, cell division, cell cycle G1/S phase transition, as well as others. The increased concentrations of reactive oxygen species (ROS) in germinal vesicle (GV) and metaphase II (MII) oocytes from TSD mice were observed, which might be induced by impaired mitochondrial function caused by TSD. The GV oocytes displayed increased mitochondrial DNA (mtDNA) copy number and a significant transient increase in inner mitochondrial membrane potential ({bigtriangleup}{psi}m) from the TSD mice probably due to compensatory effect. In contrast, MII oocytes in the TSD group showed a decrease in the mtDNA copy number and a lower {bigtriangleup} {psi}m compared with the controls. Furthermore, abnormal distribution of mitochondria in the GV and MII oocytes was also observed in TSD mice, suggesting mitochondrial dysfunction. In addition, abnormal spindle and abnormal arrangement of chromosomes in MII oocytes were markedly increased in the TSD mice compared with the control mice. In conclusion, our results suggest that TSD significantly alters the oocyte transcriptome, contributing to oxidative stress and disrupted mitochondrial function, which then resulted in oocyte defects and impaired early embryo development in female mice.

developmental biology↗

bioRxiv2024

Preeclampsia-specific immune cell network in placenta revealed by Cytometry by time of flight and single-cell RNA-seq

Preeclampsia (PE), a major cause of maternal and perinatal mortality with highly heterogeneous causes and symptoms, is usually complicated by gestational diabetes mellitus (GDM). However, a comprehensive understanding of the immune microenvironment in the placenta of PE and the differences between PE and GDM is still lacking. In this study, Cytometry by time of flight (CyTOF) indicated that the frequencies of memory-like Th17 cells (CD45RA-CCR7+IL-17A+CD4+), memory-like CD8+ T cells (CD38+CXCR3-CCR7+Helios-CD127-CD8+) and pro-inflam Macs (CD206-CD163-CD38midCD107alowCD86midHLA-DRmidCD14+) were increased, while the frequencies of anti-inflam Macs (CD206+CD163-CD86midCD33+HLA-DR+CD14+) and granulocyte myeloid-derived suppressor cells (gMDSCs, CD11b+CD15hiHLA-DRlow) were decreased in the placenta of PE compared with that of NP, but not in that of GDM or GDM&PE. The pro-inflam Macs were positively correlated with memory-like Th17 cells and memory-like CD8+ T cells but negatively correlated with gMDSCs. Single-cell RNA sequencing revealed that transferring the F4/80+CD206- pro-inflam Macs with a Folr2+Ccl7+Ccl8+C1qa+C1qb+C1qc+ phenotype from the uterus of PE mice to normal pregnant mice induced the production of memory-like IL-17a+Rora+Il1r1+TNF+Cxcr6+S100a4+CD44+ Th17 cells via IGF1-IGF1R, which contributed to the development and recurrence of PE. Pro-inflam Macs also induced the production of memory-like CD8+ T cells but inhibited the production of Ly6g+S100a8+S100a9+Retnlg+Wfdc21+ gMDSCs at the maternal-fetal interface, leading to PE-like symptoms in mice. In conclusion, this study revealed the PE-specific immune cell network, which was regulated by pro-inflam Macs, providing new ideas about the pathogenesis of PE.

immunology↗

bioRxiv2024

Clearing truncated tau protein restores neuronal function and prevents microglia activation in tauopathy mice

Tau protein truncated at aspartate 421 (Asp421) is a characteristic feature of Alzheimers disease (AD) and other tauopathies. It is likely to have a role in their pathogenesis by promoting tau aggregation. Here, using two tauopathy mouse models, we show that a monoclonal antibody against Asp421, 5G2, led to a) a 59-74% clearance of insoluble tau protein in the brains of JNPL3 tauopathy mice following a thirteen-week treatment period, b) a 46% decrease of tau levels in brain interstitial fluid immediately following a single dose of 5G2 as examined by brain microdialysis in awake JNPL3 mice, c) improved neuronal function and d) reduced microglial activation as determined by two-photon imaging in awake PS19 tauopathy mice, where we also found tau accumulation earlier than signs of microglial activation. For mechanistic insight using culture models, 5G2 prevented toxicity of AD brain-derived pathological tau protein, cleared intracellular tau, and prevented microgliosis. We also knocked down the intracellular Fc receptor and ubiquitin E3 ligase, TRIM21, and found a reduction in cellular retention of tau antibodies, which appeared to reduce the acute efficacy (24 h) of tau antibodies but not their longer-term efficacy (5 days). Overall, these findings strongly support the feasibility of targeting Asp421 truncated tau protein to treat tauopathies, indicate that tau-associated abnormalities of neuronal activity precede microglial activation and that antibody-mediated tau clearance via the TRIM21 pathway is mostly transient.

neuroscience↗

bioRxiv2024

Immunopipe: A comprehensive and flexible scRNA-seq and scTCR-seq data analysis pipeline

Single-cell sequencing technologies provide us with information at the level of individual cells. The combination of single-cell RNA-seq and single-cell TCR-seq profiling enables the exploration of cell heterogeneity and T-cell receptor repertoires simultaneously. The integration of both types of data can play a crucial role in enhancing our understanding of T-cell-mediated immunity and, in turn, facilitate the advancement of immunotherapy. Here, we present immunopipe, a comprehensive and flexible pipeline to perform integrated analysis of scRNA-seq and scTCR-seq data. In addition to the command line tool, we provide a user-friendly web interface for pipeline configuration and execution monitoring, benefiting researchers without extensive programming experience. With its comprehensive functionality and ease of use, immunopipe empowers researchers to uncover valuable insights from scRNA-seq and scTCR-seq data, ultimately advancing the understanding of immune responses and immunotherapy development.

bioinformatics↗

bioRxiv2024

Fast adaptive super-resolution lattice light-sheet microscopy for rapid, long-term, near-isotropic subcellular imaging

Lattice light-sheet microscopy (LLSM) provides a crucial observation window into intra- and inter-cellular physiology of living specimens with high speed and low phototoxicity, however, at the diffraction-limited resolution or anisotropic super-resolution with structured illumination. Here we present the meta-learning-empowered reflective lattice light-sheet virtual structured illumination microscopy (Meta-rLLS-VSIM), which instantly upgrades LLSM to a near-isotropic super resolution of [~]120-nm laterally and [~]160-nm axially, more than twofold improvement in each dimension, without any modification of the optical system or sacrifice of other imaging metrics. Moreover, to alleviate the tremendous demands on training data and time necessitated by existing deep-learning (DL) methods, we devised an adaptive online training approach by synergizing the front-end imaging system and back-end meta-learning framework, which reduced the total time for data acquisition and model training down to tens of seconds. With this method, a new model can be well-trained with tenfold less data and three orders of magnitude less time than current standard supervised learning. We demonstrate the versatile functionalities of Meta-rLLS-VSIM by imaging a variety of bioprocesses with ultrahigh spatiotemporal resolution for long duration of hundreds of multi-color volumes, characterizing the dynamic regulation of contractile ring filaments during mitosis and the growth of pollen tubes, and delineating the nanoscale distributions, dispersion, and interaction pattern of multiple organelles in embryos and eukaryotic cells.

biophysics↗

bioRxiv2024

Neuronal hypofunction and network dysfunction in a mouse model at an early stage of tauopathy

We previously reported altered neuronal Ca2+ dynamics in the motor cortex of 12-month-old JNPL3 tauopathy mice during quiet wakefulness or forced running, with a tau antibody treatment significantly restoring the neuronal Ca2+ activity profile and decreasing pathological tau in these mice 1. Whether neuronal functional deficits occur at an early stage of tauopathy and if tau antibody treatment is effective in younger tauopathy mice needed further investigation. In addition, neuronal network activity and neuronal firing patterns have not been well studied in behaving tauopathy models. In this study, we first performed in vivo two-photon Ca2+ imaging in JNPL3 mice in their early stage of tauopathy at 6 months of age, compared to 12 month old mice and age-matched wild-type controls to evaluate neuronal functional deficits. At the animal level, frequency of neuronal Ca2+ transients decreased only in 6 month old tauopathy mice compared to controls, and only when animals were running on a treadmill. The amplitude of neuronal transients decreased in tauopathy mice compared to controls under resting and running conditions in both age groups. Total neuronal activity decreased only in 6 month old tauopathy mice compared to controls under resting and running conditions. Within either tauopathy or wild-type group, only total activity decreased in older wild-type animals. The tauopathy mice at different ages did not differ in neuronal Ca2+ transient frequency, amplitude or total activity. In summary, neuronal function did significantly attenuate at an early age in tauopathy mice compared to controls but interestingly did not deteriorate between 6 and 12 months of age. A more detailed populational analysis of the pattern of Ca2+ activity at the neuronal level in the 6 month old cohort confirmed neuronal hypoactivity in layer 2/3 of primary motor cortex, compared to wild-type controls, when animals were either resting or running on a treadmill. Despite reduced activity, neuronal Ca2+ profiles exhibited enhanced synchrony and dysregulated responses to running stimulus. Further ex vivo electrophysiological recordings revealed reduction of spontaneous excitatory synaptic transmission onto and in pyramidal neurons and enhanced excitability of inhibitory neurons in motor cortex, which were likely responsible for altered neuronal network activity in this region. Lastly, tau antibody treatment reduced pathological tau and gliosis partially restored the neuronal Ca2+ activity deficits but failed to rescue altered network changes. Taken together, substantial neuronal and network dysfunction occurred in the early stage of tauopathy that was partially alleviated with acute tau antibody treatment, which highlights the importance of functional assessment when evaluating the therapeutic potential of tau antibodies. HighlightsO_LILayer 2/3 motor cortical neurons exhibited hypofunction in awake and behaving mice at the early stage of tauopathy. C_LIO_LIAltered neuronal network activity disrupted local circuitry engagement in tauopathy mice during treadmill running. C_LIO_LILayer 2/3 motor cortical neurons in tauopathy mice exhibited enhanced neuronal excitability and altered excitatory synaptic transmissions. C_LIO_LIAcute tau antibody treatment reduced pathological tau and gliosis, and partially restored neuronal hypofunction profiles but not network dysfunction. C_LI

neuroscience↗

bioRxiv2024

A comprehensive collection of pain and addiction targets and compounds library for high throughput screening and AI-driven drug discovery

As part of the NIH Helping to End Addiction Long-term (HEAL) Initiative, the National Center for Advancing Translational Sciences (NCATS) is dedicated to the development of new pharmacological tools and investigational drugs for managing and treating pain, as well as the prevention and treatment of opioid misuse and addiction. In line with these objectives, we created a comprehensive, annotated small molecule library including drugs, probes, and tool compounds that act on published pain and addiction-relevant targets. Nearly 3,000 small molecules associated with approximately 200 known and hypothesized HEAL targets have been assembled, curated, and annotated in one collection. Physical samples of the library compounds have been acquired and plated in 1536-well format, enabling rapid and efficient high throughput screen (HTS) against a wide range of assays. The creation of the HEAL Targets and Compounds Library, coupled with an integrated computational platform for AI-driven machine learning (ML), structural modeling, and virtual screening (VS), provides a valuable source for strategic drug repurposing, innovative profiling, and hypothesis testing of novel targets related to pain and opioid use disorder (OUD). The library is available to investigators for screening pain and OUD-relevant phenotypes.

bioinformatics↗

bioRxiv2024

Deciphering the Immune Subtypes and Signature Genes: A Novel Approach Towards Diagnosing and Prognosticating Severe Asthma through Interpretable Machine Learning.

Asthma, a pervasive pulmonary disorder, affects countless individuals globally. Characterized by chronic inflammation of the bronchial passages, its symptoms include cough, wheezing, dyspnea, and chest tightness. While many manage their symptoms through pharmaceutical interventions and self-care, a significant subset grapples with severe asthma, posing therapeutic challenges. This study delves into the intricate etiology of asthma, emphasizing the pivotal roles of immune cells such as T cells, eosinophils, and mast cells in its pathogenesis. The recent emergence of monoclonal antibodies, including Mepolizumab, Reslizumab, and Benralizumab, offers therapeutic promise, yet their efficacy varies due to the heterogeneous nature of asthma. Recognizing the potential of personalized medicine, this research underscores the need for a comprehensive understanding of asthmas immunological diversity. We employ ssGSEA and LASSO algorithms to identify differentially expressed immune cells and utilize machine learning techniques, including XGBoost and Random Forest, to predict severe asthma outcomes and identify key genes associated with immune cells. Using a murine asthma model and an online database, we aim to elucidate distinct immune-centric asthma subtypes. This study seeks to provide novel insights into the diagnosis and classification of severe asthma through a transcriptomic lens.

bioinformatics↗

bioRxiv2024

SwinCell: a transformer-based framework for dense 3D cellular segmentation

Segmentation of three-dimensional (3D) cellular images is fundamental for studying and understanding cell structure and function. However, 3D cellular segmentation is challenging, particularly for dense cells and tissues. This challenge arises mainly from the complex contextual information within 3D images, anisotropic properties, and the sensitivity to internal cellular structures, which often lead to miss-segmentation. In this work, we introduce SwinCell, a 3D transformer-based framework that leverages Swin-transformer for flow prediction and effectively distinguishes individual cell instances in 3D. We demonstrate the broad utility of the SwinCell in the segmentation of nuclei, colon tissue cells, and dense cultured cells. SwinCell strikes a balance between maintaining detailed local feature recognition and understanding broader contextual information. Tested extensively with both public and in-house 3D cell imaging datasets, SwinCell shows superior performance in segmenting dense cells in 3D, making it a powerful 3D segmentation tool for cellular analysis that could expedite research in cell biology and tissue engineering.

cell biology↗

bioRxiv2024

Hour-long, kilohertz sampling rate 3D single-virus tracking in live cells enabled by StayGold fluorescent protein fusions

The viral infection process covers a large range of spatiotemporal scales. Tracking the viral infection process with fluorescent labels over long durations while maintaining a fast sampling rate requires bright and highly photostable labels. StayGold is a recently identified green fluorescent protein that has a greater photostability and higher signal intensity under identical illumination conditions as compared to existing fluorescence protein variants. Here, StayGold protein fusions were used to generate virus-like particles (StayGold-VLPs) to achieve hour-long 3D single-virus tracking (SVT) with one thousand localizations per second (kHz sampling rate) in live cells. The expanded photon budget from StayGold protein fusions prolonged the tracking duration, facilitating a comprehensive study of viral trafficking dynamics with high temporal resolution over long timescales. The development of StayGold-VLPs presents a simple and general VLP labeling strategy for better performance in SVT, enabling exponentially more information to be collected from single trajectories and allowing for the future possibility of observing the whole life cycle of a single virus. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=103 SRC="FIGDIR/small/585070v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@96584corg.highwire.dtl.DTLVardef@7f1e4corg.highwire.dtl.DTLVardef@19e38ddorg.highwire.dtl.DTLVardef@a75aed_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

bioRxiv2024

Single-Domain Antibody-Based Protein Degrader for Synucleinopathies

Synucleinopathies are a group of neurodegenerative diseases characterized by the accumulation of -synuclein (-syn) in the brain, leading to motor and neuropsychiatric symptoms. Currently, there are no known cures for synucleinopathies, and treatments mainly focus on symptom management. In this study, we developed a single-domain antibody (sdAb)-based protein degrader with features designed to enhance proteasomal degradation of -syn. This sdAb derivative targets both -syn and Cereblon (CRBN), a substrate-receptor for the E3-ubiquitin ligase CRL4CRBN, and thereby induces -syn ubiquitination and proteasomal degradation. Our results indicate that this therapeutic candidate enhances proteasomal degradation of -syn, in addition to the endogenous lysosomal degradation machinery. By promoting proteasomal degradation of -syn, we improved clearance of -syn in primary culture and mouse models of synucleinopathy. These findings indicate that our sdAb-based protein degrader is a promising therapeutic candidate for synucleinopathies. Considering that only a small percentage of antibodies enter the brain, more potent sdAbs with greater brain entry than whole antibodies could enhance clinical benefits of antibody-based therapies.

neuroscience↗

bioRxiv2024

Resting natural killer cells promote the progress of colon cancer liver metastasis by elevating tumor-derived sSCF

PurposeThe abundance and biological contribution of Natural killer (NK) cells in cancer are controversial. Here, we aim to uncover clinical relevance and cellular roles of NK cells in colon cancer liver metastasis (CCLM) MethodsWe integrated single-cell RNA sequencing, spatial transcriptomics, and bulk RNA-sequencing datasets to investigate NK cells biological properties and functions in the microenvironment of primary and liver metastatic tumors. Results were validated through an in vitro co-culture experiment based on bioinformatics analysis. ResultsWe used single-cell RNA sequencing and spatial transcriptomics to map the immune cellular landscape of colon cancer and well-matched liver metastatic cancer. We discovered that GZMK+ resting NK cells increased significantly in tumor tissues and were enriched in the tumor regions of both diseases. After combining bulk RNA and clinical data, we observed that these NK cell subsets contributed to a worse prognosis. Meanwhile, KIR2DL4+ activated NK cells exhibited the opposite position and relevance. Pseudotime cell trajectory analysis revealed the evolution of activated to resting NK cells. In vitro experiments further confirmed that tumor-cell-co-cultured NK cells exhibited a decidual-like status, as evidenced by remarkable increasing CD9 expression. Functional experiments finally revealed that NK cells exhibited tumor-activating characteristics by promoting the dissociation of SCF (stem cell factor) on the tumor cells membrane depending on cell-to-cell interaction, as the supernatant of the co-culture system enhanced tumor progression. ConclusionTogether, our findings revealed a population of protumorigenic NK cells that may be exploited for novel therapeutic strategies to improve therapeutic outcomes for patients with CCLM.

immunology↗