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Biology subjects

Huang, H.-C.

Publications and source records attributed to Huang, H.-C..

At least 19 recordsLinked to original sources

Identification of gene kinetics patterns improves RNA velocity and cell fate prediction using JuloVelo

Single-cell RNA velocity has transformed our capacity to predict future cell states from sequencing snapshots, but existing methods rely on constant or binary kinetic assumptions that fail to capture the heterogeneous splicing dynamics of cellular differentiation. Here we present JuloVelo, a deep learning framework that demonstrates that identifying gene kinetics patterns to initialize neural network training dramatically improves RNA velocity model performance. By pre-determining whether each gene follows a Circle, Complete induction, or Complete repression pattern across cellular differentiation, JuloVelo initializes training with pattern-matched, pre-trained network weights, effectively guiding the cell-specific kinetics optimization away from biologically implausible parameter regimes. Additionally, JuloVelo demonstrates that multiome datasets can also be processed and modeled by utilizing promoter chromatin accessibility to guide kinetics pre-determination, and integrates an in silico perturbation framework to simulate transcription factor modulation on cell fate. Validated across eight datasets spanning erythrogenesis, neurogenesis, and endocrinogenesis, JuloVelo consistently outperformed constant-rate and cell-specific models, resolving the entire five-lineage differentiation program in hippocampal neurogenesis. Multiome processing improved both intrinsic and extrinsic velocity stability, and JuloVelo reduced computational execution time by approximately 70% compared to cellDancer. JuloVelo is available as an open-source package at https://github.com/jhlabtw/JuloVelo.jl.

bioinformatics↗

Monocyte-Mimetic Nanoparticle Delivery of Verteporfin Promotes Plaque-Stabilizing Remodeling in Atherosclerosis

Background: Despite advances in lipid-lowering and anti-inflammatory therapies, pharmacological strategies that act directly within established atherosclerotic lesions to suppress plaque progression remain limited. We recently developed a monocyte-mimetic nanoparticle (MoNP) platform that selectively targets inflamed endothelium and delivers Verteporfin (VP), termed MoNP-VP, to suppress YAP/TAZ-associated endothelial activation and plaque development. Here, we extend this biomimetic nanotherapy by defining the pharmacological effects of MoNP-VP within atherosclerotic vessels and evaluating its therapeutic efficacy in pre-existing plaques under distinct lipid burden. Methods: MoNP-VP were formulated by encapsulating VP in polymeric cores followed by cloaking with mouse monocyte membranes. Partial ligation was performed in ApoE-deficient mice, and single-cell RNA sequencing was used to define pharmacodynamic responses in carotid lesions. Proprotein convertase subtilisin/kexin type 9 (PCSK9) gain-of-function was induced in wild-type mice to generate pre-existing aortic lesions, followed by continued high-fat-diet or switching to chow to evaluate MoNP-VP efficacy under persistent hyperlipidemia and lipid-lowering conditions. Results: Single-cell analysis revealed that MoNP-VP remodeled the plaque microenvironment in carotid arteries, selectively reducing foamy macrophage populations while enriching vascular stromal populations associated with fibrotic remodeling. In mice with pre-existing aortic plaques, MoNP-VP suppressed lesion progression and reduced macrophage content under persistent hyperlipidemia. Following diet-induced lipid lowering, MoNP-VP further reduced macrophage accumulation despite no significant change in plaque size. Across both settings, MoNP-VP increased fibroblast-like cell populations and collagen deposition accompanied by activation of TGF{beta} signaling, features consistent with a more stable plaque. Importantly, repeated MoNP-VP administration was well tolerated and elicited no overt systemic toxicity. Conclusion: These findings bridge mechanistic insight and therapeutic efficacy in pre-established plaques by demonstrating that MoNP-VP remodels the inflammatory plaque microenvironment and promotes lesion stabilization, supporting its translational potential as a precision nanotherapy for atherosclerosis.

molecular biology↗

Norepinephrine Induces Proliferation and Migration of Human Pulmonary Artery Smooth Muscle Cells via Endothelin 1

Background: Pulmonary arterial hypertension (PAH) is a serious disease with poor prognosis, especially in infants or preterm babies and there is still no optimal treatment for this disease. Noradrenalin (NE) is a vasoactive mediator which is released by sympathetic ganglion. According to previous studies, NE/1-adrenoreceptors is not only in regulating normal physiologic responses, but also in the pathogenesis of PAH. However, the mechanisms of NE in PAH are not fully understood. Methods: Human PASMC (PASMC) was used in this study. Cell viability assay and Wound healing assay were used to evaluate the proliferation and migration of PASMC. Immunoprecipitation and western blots analysis were used to investigate the mechanisms which involved in NE-induced PASMC proliferation. Results: We investigated that NE could induce human PASMC proliferation and migration. Furthermore, we first find that endothelin 1 (ET-1) signaling pathway plays an important role in NE-induced PASMC proliferation. ET1 is a critical molecular which is known for regulating cell growth and migration. We investigated that NE could increase NE-1 secretion, further enhancing ET-1 bind to its receptors. For further clarifying the downstream signals in NE/ET-1 induced PASMC proliferation, we detected the phosphorylation and expression levels of ERK and JNK. Conclusions: By combining the results from ours and previous studies, we believed that JNK/c-jun pathway may play an important role in NE-induced PASMC proliferation. Key Words: Noradrenaline; Pulmonary Arterial Hypertension; Pulmonary Artery Smooth Muscle Cells; Endothelin-1; JNK/c-Jun Signaling.

molecular biology↗

Integrated microbiome and metabolomic profiling reveals alterations across the adenoma-colorectal cancer sequence

The incidence of colorectal cancer (CRC) has been increasing in Taiwan and is associated with multiple risk factors, including aging, obesity, and dietary habits. Increasing evidence suggests that gut microbiota dysbiosis contributes to CRC development. This study aimed to characterize microbial and metabolic alterations across premalignant and malignant colorectal lesions and to identify potential microbiome-associated biomarkers. Individuals undergoing colonoscopy for screening or surveillance at Taipei Veterans General Hospital were enrolled. Gut microbial composition was analyzed using full-length 16S rRNA gene sequencing to achieve high-resolution taxonomic profiling. Predicted functional pathways were inferred from microbial communities, and targeted metabolomic profiling was performed to evaluate microbial metabolic outputs. A total of 122 individuals were included, comprising 62 healthy controls, 15 adenoma cases, and 45 CRC cases. Progressive shifts in microbial composition and predicted functional pathways were observed along the adenoma-carcinoma sequence. Several bacterial taxa, including Phocaeicola dorei, Anaerotignum faecicola, Negativibacillus massiliensis, and Dysosmobacter segnis, were enriched in CRC. At the functional level, CRC samples showed enrichment of pathways associated with energy metabolism and bacterial stress responses. Metabolomic analysis further revealed increased levels of tauro-ursocholanic acid in CRC samples, whereas short-chain fatty acids (SCFAs) were reduced compared with controls. Integrative analysis combining full-length 16S sequencing, functional pathway prediction, and metabolomic profiling revealed coordinated microbial and metabolic alterations across the adenoma-carcinoma sequence. These findings provide insight into microbiome-associated processes in colorectal tumorigenesis and suggest potential microbial and metabolic biomarkers for CRC. ImportanceColorectal cancer (CRC) develops through a adenoma-carcinoma sequence, yet the microbial and metabolic alterations accompanying this progression remain incompletely understood. In this study, we integrated full-length 16S rRNA gene sequencing with metabolomic profiling to characterize taxonomic, functional, and metabolic changes across healthy controls, adenoma, and CRC. Our results reveal synchronized shifts in specific microbial taxa, predicted metabolic pathways, and fecal metabolites along the adenoma-carcinoma sequence. Several bacterial species, including Phocaeicola dorei, Anaerotignum faecicola, and Dysosmobacter segnis, increased in CRC, whereas short-chain fatty acids decreased progressively from controls to adenoma and CRC. Functional pathway analysis further indicated alterations in microbial fermentation, amino acid metabolism, and energy-related pathways. Together, these findings highlight the potential role of microbiome-associated metabolic changes in colorectal tumorigenesis and suggest candidate microbial and metabolic markers that may aid in understanding disease development and improving risk stratification.

microbiology↗

scDock: Streamlining drug discovery targeting cell-cell communication via scRNA-seq analy-sis and molecular docking

SummaryIdentifying drugs that target intercellular communication networks represents a promising therapeutic strategy, yet linking single-cell RNA sequencing (scRNA-seq) analysis to structure-based drug screening remains technically challenging and requires substantial bioinformatics expertise. We present scDock, an integrated and user-friendly pipeline that seamlessly connects scRNA-seq data processing, cell-cell communication inference, and molecular docking-based drug discovery. Through a single configuration file, users can execute the complete workflow, from raw scRNA-seq data to ranked drug candidates, without programming skills. scDock automates the identification of disease-relevant ligand-receptor interactions from scRNA-seq data and perfoms structure-based virtual screening against these communication targets using Protein Data Bank (PDB) or AlphaFold-predicted protein structures. The pipeline generates comprehensive outputs at each stage, enabling users to explore intercellular signaling alterations and discover therapeutic compounds targeting specific cell-cell communications. scDock addresses a critical gap by providing an accessible end-to-end solution for communication-targeted drug discovery from single-cell data. Availability and ImplementationscDock is freely available at https://github.com/Andrewneteye4343/scDock. It is implemented in R, Python, shell scripts, and supports Linux systems, including Ubuntu and Debian.

bioinformatics↗

Airway microbiome-host transcriptome networks link microbial dysbiosis to survival outcomes and therapeutic opportunities in severe COVID-19

The lower respiratory tract microbiome may critically influence outcomes in severe COVID-19, yet remains understudied. We analyzed bronchoalveolar lavage fluid from 86 severe patients requiring mechanical ventilation, stratified into two groups. We identified 213 bacteria with differential abundance, 11 bacteria associated with differentially expressed genes, and 39 of them were associated with patient survival. The more serious group exhibited reduced microbial network complexity, suggesting ecosystem disruption. To explore therapeutic potential, we employed our previously published model and predicted that compounds like palbociclib, XMD-1499, RS-17053, and RS-504393 may shift host gene expression favoring beneficial microbial signatures. These results highlight an important link between microbial dysbiosis and COVID-19 severity, offering promising directions for microbiome-informed therapeutic strategies. Our findings underscore the importance of the lung microbiome in modulating host responses and clinical outcomes, and suggest that modulating microbial-host interactions may serve as a novel adjunctive approach in the treatment of severe COVID-19. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=101 SRC="FIGDIR/small/661228v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@2fc879org.highwire.dtl.DTLVardef@1128d5dorg.highwire.dtl.DTLVardef@fef0eaorg.highwire.dtl.DTLVardef@17aa499_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Hepatic Arterial Flow-Induced Portal Tract Fibrosis in Portal Hypertension: The Role of VCAM-1 and Osteopontin-Expressing Macrophages

BackgroundThe liver undergoes significant hemodynamic changes during surgery, transplantation, or cirrhosis with portal hypertension(PH). The hepatic artery buffer response(HABR), which compensates for reduced portal venous flow by increasing hepatic artery(HA) flow, is hypothesized to induce pathological portal tract remodeling. This study investigates the molecular mechanisms underlying this process. MethodsPH was induced in Sprague-Dawley rats via partial portal vein ligation(PPVL). Structural evaluation(microCT), immune cell profiling, hemodynamic measurements, and transcriptomic analysis in macrophages(M{phi}) from sham or PPVL rats were conducted. ResultsMicroCT revealed decreased portal vein flow and increased HA flow correlated with portal pressure(r=0.799, p<0.01). A 2-fold increase in portal tract fibrosis(p<0.001) was observed with increased -SMA+ myofibroblasts in PPVL rats. CD68+ M{phi} peaked at 10 days post-PPVL, and their depletion significantly reduced fibrosis(p<0.001), indicating critical roles of M{phi} in portal tract remodeling. VCAM-1 was elevated in HA endothelium and portal fibroblasts (PFs); VCAM-1 neutralization reduced collagen accumulation(p<0.05), CD68+ M{phi}(46.3%, p<0.01), and CD3+ T cells(18%, p<0.05). M{phi}-conditioned medium increased VCAM-1 in PFs(8-fold, p<0.001) and enhanced PF migration, while VCAM-1 knockdown reduced this effect (p<0.01). Single-cell RNA sequencing data(GSE171904) and RNA-FISH revealed increased interactions between osteopontin (Spp1)+ M{phi} and PFs, with Spp1+ M{phi} driving fibrosis. Spp1 knockdown in M{phi} co-culture reduced PF fibrogenic markers, while recombinant Spp1 upregulated Col1a1, Fn1, and Acta2 expression in PFs. ConclusionIncreased VCAM-1 in arterial endothelial cells and PFs facilitates the recruitment of Spp1+ M{phi}, which drive HA flow-mediated vascular remodeling and portal tract fibrosis. These findings highlight arterial flow-induced fibrosis as a key mechanism in PH, potentially contributing to disease progression and decompensation. SynopsisLiver hemodynamic changes in portal hypertension drive extracellular matrix accumulation and portal tract remodeling via Spp1+ macrophages. This study highlights how altered blood flow induces fibrosis, and its potential role in decompensation, and identifies therapeutic targets for advanced liver disease.

pathology↗

Liver Lymphatic Dysfunction as a Driver of Fibrosis and Cirrhosis Progression

The liver lymphatic system plays a critical role in maintaining interstitial fluid balance and immune regulation. Efficient lymphatic drainage is essential for liver homeostasis, but its role in liver disease progression remains poorly understood. In cirrhosis, lymphangiogenesis initially compensates for increased lymph production, but impaired lymphatic drainage in advanced stages may lead to complications such as ascites and portal hypertension. This study aimed to evaluate how liver lymphatic dysfunction affects disease progression and to assess therapeutic strategies. Using a surgical model to block liver lymphatic outflow, we found that impaired drainage accelerates liver injury, fibrosis, and immune cell infiltration, even in healthy livers. Mechanistically, enhanced TGF-{beta} signaling in liver lymphatic endothelial cells (LyECs) contributed to reduced lymphatic vessel (LV) density and function in late-stage decompensated cirrhosis. This dysfunction was linked to the progression from compensated to decompensated cirrhosis, particularly in patients with primary sclerosing cholangitis (PSC). Conversely, liver-specific overexpression of VEGF-C via AAV8 improved lymphatic drainage, restored LV density, reduced fibrosis, mitigated liver injury, and alleviated portal hypertension in cirrhotic rats. These findings establish impaired liver lymphatic function as a pivotal driver of cirrhosis progression and identify VEGF-C as a promising therapeutic target to prevent decompensation.

pathology↗

Centella asiatica Tissue Culture-Derived Extracellular Vesicles: A Multifaceted Approach to Skincare Applications

BackgroundCentella asiatica has long been used as a medicinal herb in traditional Asian medicine. Its wound healing, skin improvement, and neuroprotective properties have been widely studied. Extracellular vesicles (EVs) are secreted by cells and contain bioactive components with therapeutic properties. ObjectivesThis study aims to characterize EVs isolated from C. asiatica tissue culture and investigate their therapeutic properties using in vitro assays and a UVB-induced damage mouse model. MethodsEVs were isolated from C. asiatica tissue culture and characterized by nanoparticle tracking analysis (NTA) and scanning electron microscopy (SEM). Cytotoxicity, anti-oxidation, anti-melanin, and anti-inflammation of the EVs were evaluated by MTT assay, tyrosinase assay and RT-qPCR in chemical or in vitro assays. A UVB-induced photodamage mouse model was established to assess the anti-inflammation effect of EVs in vivo. Gels with or without EVs were applied to the damaged site and skin appearance was observed daily and skin histopathology was analyzed on day 7 by H&E and immunohistochemical staining. ResultsC. asiatica EVs were found to contain high levels of polyphenols and mitigate hydrogen peroxide-induced intracellular ROS. The EVs were further able to reduce intracellular melanin content and tyrosinase activity, and exhibited anti-inflammatory effects by downregulating the expression of pro-inflammatory genes COX2 as well as nitric oxide production. In mice with UVB-induced skin damage, daily application of C. asiatica EV gel reduced skin epidermis thickness and inflammation compared to UVB-only or blank gel at seven days after UV irradiation. ConclusionsThe beneficial effects of C. asiatica EVs on skin quality warrant further studies as promising agents in skin care applications.

pharmacology and toxicology↗

Influenza A Virus H7 nanobody recognizes a conserved immunodominant epitope on hemagglutinin head and confers heterosubtypic protection

Influenza remains a persistent global health challenge, largely due to the virus continuous antigenic drift and shift, which impede the development of a universal vaccine. To address this, the identification of broadly neutralizing antibodies and their epitopes is crucial. Nanobodies, with their unique characteristics and binding capacity, offer a promising avenue to identify such epitopes. Here, we isolated and purified a hemagglutinin (HA)-specific nanobody that recognizes an H7 subtype of influenza A virus. Notably, the nanobody, named E10, exhibited broad-spectrum binding, cross-group neutralization and in vivo protection across various influenza A subtypes. Through phage display and in vitro characterization, we demonstrated that E10 specifically targets an epitope on HA head. This epitope is part of the conserved lateral patch of HA head and proved to be highly immunodominant upon H7 infection. Importantly, immunization with a peptide including the E10 epitope elicited cross-reactive antibodies and mediated partial protection from lethal viral challenge. Our data highlight the potential of E10 and its associated epitope as a candidate for future influenza prevention strategies.

microbiology↗

Nuclear RNAi Modulates Influenza A Virus Infectivity By Downregulating Type-I Interferon Response

The role of Argonaute (AGO) proteins and the RNA interference (RNAi) machinery in mammalian antiviral response has been debated. Therefore, we set out to investigate how mammalian RNAi impacts influenza A virus (IAV) infection. We reveal that IAV infection triggers nuclear accumulation of AGO2, which is directly facilitated by p53 activation. Mechanistically, we show that IAV induces nuclear AGO2 targeting of TRIM71, a proposed AGO2 E3 ligase, and type-I interferon-pathway genes for silencing. Accordingly, Tp53-/- mice do not accumulate nuclear AGO2 and demonstrate decreased susceptibility to IAV infection. Hence, the RNAi machinery is highjacked by the virus to evade the immune system and support viral replication. Furthermore, the FDA approved drug arsenic trioxide, which prevents p53 tetramerization and nuclear translocation, increases interferon response and decreases viral replication in vitro and in a mouse model in vivo. Our data indicates that targeting the AGO2:p53-mediated silencing of innate immunity may offer a promising strategy to mitigate viral infections.

biochemistry↗

Identification of NanoLuciferase Substrates Transported by Human ABCB1 and ABCG2 and their Zebrafish Homologs at the Blood-Brain Barrier

ATP-binding cassette (ABC) transporters expressed at the blood-brain barrier (BBB) impede delivery of therapeutic agents to the brain, including agents to treat neurodegenerative diseases and primary and metastatic brain cancers. Two transporters, P-glycoprotein (P-gp, ABCB1) and ABCG2, are highly expressed at the BBB and are responsible for the efflux of numerous clinically useful chemotherapeutic agents, including irinotecan, paclitaxel, and doxorubicin. Based on a previous mouse model, we have generated transgenic zebrafish in which expression of NanoLuciferase (NanoLuc) is controlled by the promoter of glial fibrillary acidic protein, leading to expression in zebrafish glia. To identify agents that disrupt the BBB, including inhibitors of ABCB1 and ABCG2, we identified NanoLuc substrates that are also transported by P-gp, ABCG2, and their zebrafish homologs. These substrates will elevate the amount of bioluminescent light produced in the transgenic zebrafish with BBB disruption. We transfected HEK293 cells with NanoLuc and either human ABCB1, ABCG2, or their zebrafish homologs Abcb4 or Abcg2a, respectively, and expressed at the zebrafish BBB. We evaluated the luminescence of ten NanoLuc substrates, then screened the eight brightest to determine which are most efficiently effluxed by the ABC transporters. We identified one substrate efficiently pumped out by ABCB1, two by Abcb4, six by ABCG2, and four by Abcg2a. These data will aid in the development of a transgenic zebrafish model of the BBB to identify novel BBB disruptors and should prove useful in the development of other animal models that use NanoLuc as a reporter. Significance StatementThe ATP-Binding Cassette (ABC) transporters ABCB1 and ABCG2 at the blood-brain barrier (BBB) hinder pharmacological treatment of brain-related diseases. Consequently, there is a need for tools to identify BBB disruptors. We conducted a screen of ten NanoLuciferase substrates, identifying the brightest and those that were transported by human and zebrafish ABC transporters at the BBB. This work supports and complements our development of a transgenic zebrafish model, in which NanoLuciferase is expressed within glial cells, enabling detection of BBB disruption.

pharmacology and toxicology↗

Loss of Lamin A leads to the nuclear translocation of AGO2 and compromised RNA interference

In mammals, RNA interference (RNAi) was historically studied as a cytoplasmic event; however, in the last decade, a growing number of reports convincingly show the nuclear localization of the Argonaute (AGO) proteins. Nevertheless, the extent of nuclear RNAi and its implication in biological mechanisms remain to be elucidated. We found that reduced Lamin A levels significantly induce nuclear influx of AGO2 in SHSY5Y neuroblastoma and A375 melanoma cancer cell lines, which normally have no nuclear AGO2. Lamin A KO manifested a more pronounced effect in SHSY5Y cells compared to A375 cells, evident by changes in cell morphology, increased cell proliferation, and oncogenic miRNA expression. Furthermore, in SHSY5Y cells, AGO fPAR-CLIP in Lamin A KO cells revealed significantly reduced activity of RNAi. Further exploration of the nuclear AGO interactome by mass spectrometry indicated that AGO2 is in complex with FAM120A, an RNA-binding protein and known interactor of AGO2. By performing FAM120A fPAR-CLIP, we discovered that FAM120A co-binds AGO targets and that this competition reduces the activity of RNAi. Therefore, loss of Lamin A triggers nuclear AGO2 translocation, RNAi impairment, and selective upregulation of oncogenic miRNAs, facilitating cancer cell proliferation.

biochemistry↗

Lesion-specific suppression of YAP/TAZ by biomimetic nanodrug ameliorates atherosclerosis development

Atherosclerosis, characterized by the buildup of lipid-rich plaque on the vessel wall, is the primary cause of myocardial infarction and ischemic stroke. Recent studies have demonstrated that dysregulation of yes-associated protein 1 (YAP) and transcriptional coactivator with PDZ-binding domain (TAZ) contributes to plaque development, making YAP/TAZ potential therapeutic targets. However, systemic modulation of YAP/TAZ expression or activities risks serious off-target effects, limiting clinical applicability. To address the challenge, this study develops monocyte membrane-coated nanoparticles (MoNP) as a drug delivery vehicle targeting activated endothelium lining the plaque surface and utilizes MoNP to deliver verteporfin (VP), a potent YAP/TAZ inhibitor, for lesion-specific treatment of atherosclerosis. The results reveal that MoNP significantly enhance payload delivery to inflamed endothelial cells (EC) while avoiding phagocytic cells, and preferentially accumulate in atherosclerotic regions. MoNP-mediated delivery of VP substantially reduces YAP/TAZ expression, suppressing inflammatory gene expression and macrophage infiltration in cultured EC and mouse arteries exposed to atherogenic stimuli. Importantly, this lesion-targeted VP nanodrug effectively decreases plaque development in mice without causing noticeable histopathological changes in major organs. Collectively, these findings demonstrate a plaque-targeted and pathway-specific biomimetic nanodrug, potentially leading to safer and more effective treatments for atherosclerosis.

bioengineering↗

Identifying key residues in intrinsically disordered regions of proteins using machine learning

Conserved residues in protein homolog sequence alignments are structurally or functionally important. For intrinsically disordered proteins (IDPs) or proteins with intrinsically disordered regions (IDRs), however, alignment often fails because they lack a steric structure to constrain evolution. Although sequences vary, the physicochemical features of IDRs may be preserved in maintaining function. Therefore, a method to retrieve common IDR features may help identify functionally important residues. We applied un-supervised contrastive learning to train a model with self-attention neuronal networks on human IDR orthologs. During training, parameters were optimized to match sequences in ortholog pairs but not in other IDRs. The trained model successfully identifies previously reported critical residues from experimental studies, especially those with an overall pattern (e.g. multiple aromatic residues or charged blocks) rather than short motifs. This predictive model can therefore be used to identify potentially important residues in other proteins. Availability and implementationThe training scripts are available on GitHub (https://github.com/allmwh/IFF). The training datasets have been deposited in an Open Science Framework repository (https://osf.io/jk29b). The trained model can be run from the Jupyter Notebook in the GitHub repository using Binder (mybinder.org). The only required input is the primary sequence.

bioinformatics↗

Membrane Protein Modification Modulates Big and Small Extracellular Vesicle Biodistribution and Tumorigenic Potential in Breast Cancers In Vivo

Extracellular vesicles (EVs) are released by cells to mediate intercellular communication under pathological and physiological conditions. While small EVs (sEVs; <100-200 nm, exosomes) are intensely investigated, the properties and functions of medium and large EVs (big EVs [bEVs]; >200 nm, microvesicles) are less well explored. Here, we identify bEVs and sEVs as distinct EV populations, and determine that bEVs are released in a greater bEV:sEV ratio in the aggressive human triple-negative breast cancer (TNBC) subtype. PalmGRET, bioluminescence resonance energy transfer (BRET)-based EV reporter, reveals dose- dependent EV biodistribution at non-lethal and physiological EV dosages, as compared to lipophilic fluorescent dyes. Remarkably, the bEVs and sEVs exhibit unique biodistribution profiles, et individually promote in vivo tumor growth in a syngeneic immunocompetent TNBC breast tumor murine model. The bEVs and sEVs share mass spectrometry (MS)- identified tumor progression-associated EV surface membrane proteins (tpEVSurfMEMs), which include SLC29A1, CD9 and CD44. tpEVSurfMEM depletion attenuates EV lung organotropism, alters biodistribution, and reduces protumorigenic potential. This study identifies distinct in vivo property and function of bEVs and sEVs in breast cancer, which suggest the significant role of bEVs in diseases, diagnostic and therapeutic applications.

cancer biology↗

Control of neuronal terminal differentiation through cell context-dependent CFI-1/ARID3 functions

ARID3 transcription factors are expressed in the nervous system, but their functions and mechanisms of action are largely unknown. Here, we generated in vivo a genome-wide binding map for CFI-1, the sole C. elegans ARID3 ortholog. We identified 6,396 protein-coding genes as putative direct targets of CFI-1, most of which (77%) are expressed in post-mitotic neurons and encode terminal differentiation markers (e.g., neurotransmitter receptors, ion channels, neuropeptides). To gain mechanistic insights, we focused on two neuron types. In sensory neurons (IL2 class), CFI-1 exerts a dual role: it acts directly to activate, and indirectly to repress, distinct terminal differentiation genes. In motor neurons, however, CFI-1 acts directly as a repressor, continuously antagonizing three transcriptional activators (UNC-3/Ebf, LIN-39/Hox4-5, MAB-5/Hox6-8). By focusing on a glutamate receptor gene (glr-4/GRIK1), we found CFI-1 exerts its repressive activity through proximal binding to the glr-4 locus. Further, the core DNA binding domain of CFI-1 is partially required for glr-4 repression in motor neurons. Altogether, this study uncovers cell context-dependent mechanisms through which a single ARID3 protein controls the terminal differentiation of distinct neuron types.

developmental biology↗

The NLRP1 and CARD8 inflammasomes detect reductive stress

The danger signals that activate the NLRP1 and CARD8 inflammasomes have not been fully established. We recently discovered that cytosolic peptide accumulation activates these inflammasomes. In addition, we found that the oxidized form of TRX1 binds to and represses NLRP1, suggesting that NLRP1 also detects a lack of reactive oxygen species, or reductive stress. However, no agents that induce reductive stress were known to test this premise. Here, we identify and characterize several radical-trapping antioxidants, including JSH-23, that induce reductive stress. We show that these compounds accelerate the proteasome-mediated degradation of the repressive N-terminal fragments of NLRP1 and CARD8, releasing the inflammasome-forming C-terminal fragments from autoinhibition. Moreover, we found that reductive stress and peptide accumulation together trigger much more intense inflammasome activation than either signal alone. Overall, this work validates chemical probes that induce reductive stress, and establishes reductive stress alongside peptide accumulation as the key inflammasome-activating danger signals.

immunology↗