Biology subjects

Meng, F.

Publications and source records attributed to Meng, F..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Generation of cloned sheep lacking galactose-α1,3-galactose and Nglycolylneuraminic acid antigens

Livestock have long been regarded as a potential source of donor organs to alleviate the global organ shortage for transplantation. Sheep have a similar physiology and anatomy to humans, providing the standard model for demonstrating biocompatibility and performance of biological heart valves to obtain regulatory approval for their use in transplantation. Like most mammals, sheep cells contain two well-characterized carbohydrate epitopes, galactose-1,3-galactose (-Gal) and N-glycolylneuraminic acid (Neu5Gc), which are absent in humans. Formation of these xenoantigens is catalysed by two enzymes, namely (1,3) galactosyltransferase (GGTA1) and CMP-Neu5Gc hydroxylase (CMAH), respectively. Towards generating new sheep models, we used Cas9-mediated genome editing in both male and female ovine fetal fibroblasts to knockout (KO) both alleles of CMAH and GGTA1. Selected double KO (DKO) fibroblast strains were used for somatic cell transfer cloning to produce blastocysts that were transferred into gestational surrogate ewes. Following transfer of 128 male and 40 female cloned blastocysts, 6 male and 8 female lambs were born, however, none of the males survived. Molecular analyses of cells from the five surviving ewes confirmed their compound heterozygous state, resulting in a functional DKO phenotype and subsequent immune rejection of embryonic tissues during natural breeding with wild-type rams. This new DKO sheep model better mimics the human immune status, offering greater physiological relevance for preclinical testing of biological heart valves, alleviation of red meat allergy syndrome due to the presence of dietary xenoantigens, and an alternative source of donor organs that may be culturally more widely accepted than pigs.

cell biology↗

bioRxiv2025

Multi-omics analysis reveals genetic regulatory mechanismsof muscle traits in wild and domesticated Bactrian camels

Bactrian camels, large domesticated animals adapted to extreme environments, have evolved under natural and artificial selection to suit their living conditions and meet human needs. In arid and semi-arid regions, they provide valuable resources through economically important traits such as meat, milk, and wool production, contributing significantly to both economy and ecology. However, research on gene function, adaptive evolution, and molecular mechanisms underlying complex traits in Bactrian camels remains limited, constraining the full utilization of their breeding potential and conservation efforts.To address this gap, we performed whole-genome resequencing (WGS) on 35 domesticated Bactrian camels from the Chinese Sunite local population and integrated this data with publicly available WGS data from 112 Asian Bactrian camels. Our comprehensive analysis revealed significant genetic differences and genomic features between wild and domesticated Bactrian camels. We further integrated 27 epigenomic (ATAC-seq) and transcriptomic (RNA-seq) datasets from eight biologically important tissues of four Bactrian camels, along with skeletal muscle scRNA-seq and scATAC data. This allowed us to identify tissue-specific genes, regulatory elements, and genes under positive selection.Our integrated analysis identified target genes and their upstream regulatory elements, including potential regulatory transcription factors, with a focus on positively selected regions in Bactrian camel muscle tissue. We constructed regulatory pathways from key SNPs to regulatory elements to genes, and for the first time, identified regulatory elements in major tissues of the Bactrian camel genome. Our results also summarized the single-cell transcriptional landscape of Bactrian camel skeletal muscle, revealing cellular heterogeneity and genetic expression patterns across two developmental stages.This comprehensive regulatory element map provides a valuable resource for genetic and genomic studies in Bactrian camels. It reveals key regulatory networks, important genes, and regulatory elements influencing muscle development, as well as potentially significant functional variants affecting meat production traits. These findings will provide crucial data support for future genetic improvement and breeding efforts in Bactrian camels.

genetics↗

bioRxiv2025

Quantifying spatiotemporal decoupling of GDGT-temperature relationships in a deep alpine lake

Glycerol dialkyl glycerol tetraethers (GDGTs), membrane lipids produced by archaea and some bacteria, are widely used in paleoclimate reconstructions due to their empirical relationship with temperature. However, their application in lakes is complicated by uncertainties in source attribution and environmental controls on their distribution. To address these constraints, we analyzed both branched and isoprenoid GDGTs (brGDGTs and isoGDGTs) in settling particles collected over 19 months using sediment traps at four depths (10, 15, 25 and 35 m) in Lake Lugu, a deep, stratified alpine lake in southwestern China. GDGT fluxes showed synchronous spatiotemporal variations across depths, with higher values during winter mixing than summer stratification, suggesting in situ production enhanced by nutrient upwelling during lake overturn. Correlations between GDGT distributions and high-resolution water temperature profiles revealed strong temperature sensitivity in isoGDGTs, particularly the Ring Index (RI), with peak correlations linked to mean temperatures [~]20 days prior to trap recovery, indicating a clear temporal lag in GDGT-temperature relationship. Moreover, stronger correlations with temperatures at overlying depths, implying vertical transport of isoGDGTs and a dominant autochthonous origin from the upper water column. In contrast, brGDGTs displayed weak or non-significant temperature dependence, likely reflecting distinct microbial sources or other controlling factors. These findings underscore the utility of isoGDGT-based proxies, particularly RI, while highlighting the importance of accounting for spatiotemporal offsets in GDGTs production when reconstructing paleotemperatures in deep, stratified lakes.

ecology↗

bioRxiv2025

Cities as evolutionary incubators for the global spread of the Spotted Lanternfly

Habitat destruction and invasive species pose two of the greatest global threats to biodiversity. These factors do not operate in isolation, and nowhere is their interaction more apparent than in urban environments. Urban organisms rapidly evolve under novel ecological circumstances where they also encounter anthropogenic opportunities for range expansion. Here, we examine the role of urbanization in the invasive success of an emerging global pest, the Spotted Lanternfly, during colonization and expansion. We demonstrate that the invasive population in the United States has undergone three sequential bottlenecks, resulting in significantly reduced genetic diversity and elevated inbreeding. The success of this invasive population may be in part attributable to adaptation in the native range prior to the invasion: we detect divergence between urban and rural lanternflies in Shanghai, China, (the invasion origin) in genes related to stress response, metabolism, and detoxification pathways. Additionally, we detect genomic signatures of selection in the invasive population suggesting adaptive refinement as the invasion progresses. This study provides evidence of adaptive evolution in response to urbanization despite substantial loss of genetic diversity, and implicates adaptive responses to pesticide application, dietary shifts, and climate in the invasive success of the Spotted Lanternfly.

evolutionary biology↗

bioRxiv2025

SMART: An Integrated Platform Revolutionizing Cryo-Electron Microscopy Workflow from Data Acquisition to Atomic Modeling

Recent advancements in cryo-electron microscopy (cryo-EM) have revolutionized structural biology, yet persistent workflow fragmentation between data acquisition, reconstruction, and modeling limits its full potential. This paper presents SMART, the first fully integrated cryo-EM platform unifying three critical AI-driven modules: DataSmart (automated data collection), CryoSmart (3D reconstruction), and ModelSmart (end-to-end atomic modeling). The platform embeds more than 10 distinct AI algorithms across its workflow, achieving unprecedented automation levels. These advancements not only lower the expertise barrier for cryo-EM adoption but also establish a new paradigm for AI-empowered structural biology, with broad implications for high-throughput drug discovery. This protocol provides a comprehensive delineation of the operational procedures for the SMART platform. As an example, this protocol enabled the determination of the 2.1 [A] resolution structure of TRPML1, a Ca2+-permeable, nonselective, six-transmembrane tetrameric cation channel found in late endosomes and lysosomes (LELs) of mammalian cells. This integrated workflow enables users, including those with minimal cryo-EM experience, to efficiently complete the entire pipeline from data collection to atomic model building.

bioinformatics↗

bioRxiv2025

Lactate metabolism antagonizes antiviral innate immunity bypromoting VDAC1-lactylation-mediated mtDNA release

Foot-and-mouth disease (FMD) is an acute, highly contagious disease caused by the foot-and-mouth disease virus (FMDV). Due to its zoonotic nature, this disease not only significantly impacts livestock productivity but also poses a serious threat to human health. FMDV exhibits distinct host specificity, mainly infecting cloven-hoofed animals such as cattle, sheep, pigs, and deer, while perissodactyl animals like horses and donkeys show natural resistance. Elucidating the interspecies differences in response to FMDV infection is essential for understanding the pathogenesis of the virus. In this study, we report that FMDV infection in horse epithelial cells induces the production of lactate, which modulates the function of VDAC1 protein through lactylation, facilitating the release of mtDNA from mitochondria into the cytoplasm. This process activates the cGAS-STING signaling pathway, which stimulates interferon-{beta} expression and suppresses FMDV replication. Our findings provide new insights into the mechanism behind horse resistance to FMDV and lay a theoretical foundation for further research concerning the differential pathogenesis of FMDV infection across species.

cell biology↗

bioRxiv2025

Discover the Maze-like Pathway for Glabridin Biosynthesis

Tailoring enzymes diversify plant metabolite scaffolds through complex, context-dependent modifications, generating maze-like biosynthetic networks that complicate metabolic pathway reconstruction. Here, we systematically deconstructed and reconstructed the biosynthetic network of glabridin, a valuable skin-whitening isoflavone from Glycyrrhiza. By integrating metabolic pathway mining with genome and 183 transcriptomes, we identified four functional routes among sixteen theoretical possibilities and uncovered a previously uncharacterized, ladder-like multi-route tailoring network. Reconstruction of such architecture in yeast revealed metabolic redundancy and interconnectivity confer unexpected robustness, enabling higher production efficiencies compared to a single-route design. Further modular engineering enabled the de novo biosynthesis of glabridin in yeast. Our work establishes a framework for reconstructing metabolic mazes and demonstrates that multi-route architectures can be harnessed to enhance the robustness and productivity of cell factories.

synthetic biology↗

bioRxiv2025

China Autism Brain Imaging Consortium: Charting Brain Growth in Chinese Children with Autism

Autism Spectrum Disorder (ASD) is a lifelong neurodevelopmental condition characterized by atypical brain growth. While advances in neuroimaging and openly sharing large-sample datasets such as the Autism Brain Imaging Data Exchange (ABIDE) have improved understanding of ASD, most studies focus on adolescents and adults, with early brain development-critical for diagnosis and intervention-remaining underexplored. Existing research predominantly involves Western samples, offering limited insight and generalizability into non-Caucasian populations. We introduce the China Autism Brain Imaging Consortium (CABIC) (https://php.bdnilab.com/resources/), a grassroots effort by researchers across the country to aggregate previously collected multi-site structural MRI datasets and phenotypic information from 1,451 autistic children and 1,119 typically developing children, covering an age range from early childhood to school age (1.0 - 12.92 years). Here, we present this resource and depict brain growth charts to push forward a more comprehensive understanding of the brain development in Chinese autism children. We constructed brain growth charts that reveal a developmental shift in autistic children, transitioning from early overgrowth to delayed maturation. Regional analyses identified distinct atypical trajectories across specific brain regions. Individual deviation scores quantified inter-subject variability, characterizing the heterogeneity of brain development in ASD. Comparative analyses between CABIC and ABIDE highlighted differences potentially attributable to ethnicity and culture, advancing our understanding of cross-population neurodevelopmental diversity. CABIC MRI datasets will be shared publicly to foster investigation of the potential neural mechanisms underlying ASD in non-Western populations and support efforts toward precision medicine for autistic individuals across diverse backgrounds.

neuroscience↗

bioRxiv2025

Identification of Antituberculars with Favorable Potency and Pharmacokinetics through Structure-Based and Ligand-Based Modeling

Drug discovery is inherently challenged by a multiple criteria decision making problem. The arduous path from hit discovery through lead optimization and preclinical candidate selection necessitates the evolution of a plethora of molecular properties. In this study, we focus on the hit discovery phase while beginning to address multiple criteria critical to the development of novel therapeutics to treat Mycobacterium tuberculosis infection. We develop a hybrid structure- and ligand-based pipeline for nominating diverse inhibitors targeting the {beta}-ketoacyl synthase KasA by employing a Bayesian optimization-guided docking method and an ensemble model for compound nominations based on machine learning models for in vitro antibacterial efficacy, as characterized by minimum inhibitory concentration (MIC), and mouse pharmacokinetic (PK) plasma exposure. The application of our pipeline to the Enamine HTS library of 2.1M molecules resulted in the selection of 93 compounds, the experimental validation of which revealed exceptional PK (41%) and MIC (19%) success rates. Twelve compounds meet hit-like criteria in terms of MIC and PK profile and represent promising seeds for future drug discovery programs.

microbiology↗

bioRxiv2024

Enalapril mitigates aging by targeting antioxidative genes via phosphorylated Smad1/5/9

Aging increases the risk of a myriad of chronic diseases, which are expensive and difficult to treat owing to their various risk factors. Repurposing existing medications has accelerated the development of therapies aimed at slowing aging. In this study, we revealed that enalapril, a drug widely prescribed for hypertension, can improve both cellular senescence and individual health. Mechanistically, phosphorylated Smad1/5/9 act as pivotal mediators of the anti-senescence properties of enalapril. It stimulates downstream genes involved in cell cycle regulation and antioxidative defense, facilitating cell proliferation and diminishing the production of reactive oxygen species (ROS), thus increasing the antioxidative ability of enalapril. At the organismal level, enalapril has been shown to bolster the physiological performance of various organs; it notably enhances memory capacity and renal function and relieves lipid accumulation. Our work highlights the potential of enalapril to augment antioxidant defenses and combat the effects of aging, thereby indicating its promise as a treatment strategy for aging-associated diseases and its use for healthy aging.

cell biology↗

bioRxiv2024

Foxn3 is part of a transcriptional network that regulates cilia genes in the developing mouse retina

Analysis of retinas from mice with a targeted disruption of the gene encoding the forkhead transcription factor Foxn3 revealed additional displaced amacrine interneurons and retinal astrocytes in the inner plexiform and ganglion cell layers, as well as ectopic primary cilia on bipolar and amacrine interneurons. Foxn3 is a transcriptional repressor and numerous genes linked to cilia structure or assembly were upregulated in embryonic retinas without Foxn3, including Foxj1, a forkhead transcription factor required for motile cilia. CUTCRUN analysis revealed that many of the upregulated retinal genes were bound by the Foxn3 and Rfx3 proteins. A short hydrophobic motif (LXXLXWL) shared by the Foxj1, Foxn4, and Foxn3 proteins was found to be required for association with the Rfx3 protein and for transcriptional repression by Foxn3, as well as for full transcriptional activation by Foxn4 with Rfx3. AlphaFold 3 predicts an interaction between the shared hydrophobic motif and the Rfx3 dimerization domain. Mutations in Rfx3 at the predicted interaction site disrupted association of Rfx3 with Foxn3 or Foxn4. These results reveal a new layer of transcriptional regulation of genes required for cilia, with Foxn3 functioning as a repressor of cilia genes and limiting primary cilia formation in the developing retina.

developmental biology↗

bioRxiv2024

Data-Driven Image Analysis to Determine Antibody-Induced Dissociation of Cell-Cell Adhesion and Antibody Pathogenicity in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is a blistering autoimmune disease that affects the skin and mucous membranes. The precise mechanisms by which PV antibodies induce a complete loss of cohesion of keratinocytes are not fully understood. But it is accepted that the process starts with antibody binding to desmosomal targets which leads to its disassembly and subsequent structural changes to cell-cell adhesions. In vitro immunofluorescence imaging of desmosome molecules has been used to characterize this initial phase, often qualitatively. However, there remains an untapped potential of image analysis in providing us more in-depth knowledge regarding ultrastructural changes after antibody binding. Currently, there is no such effort to establish a quantitative framework from immunofluorescence images in PV pathology. We take on this effort here in a comprehensive study to examine the effects of antibodies on key adhesion molecules and the cytoskeletal network, aiming to establish a correlation of ultrastructural changes in cell-cell adhesion with antibody pathogenicity. Specifically, we introduced a data-driven approach to quantitatively evaluate perturbations in adhesion molecules, including desmoglein 3, E-cadherin, as well as the cytoskeleton, following antibody treatment. We identify distinct immunofluorescence imaging signatures that mark the impact of antibody binding on the remodeling of the adhesion molecules and introduce a pathogenicity score to compare the relative effects of different antibodies. From this analysis, we showed that the biophysical response of keratinocytes to distinct PV associated antibodies is highly specific, allowing for accurate prediction of their pathogenicity. For instance, the high pathogenicity scores of the PVIgG and AK23 antibodies show strong agreement with their reported PV pathology. Our data-driven approach offers a more detailed framework for the action of autoantibodies in pemphigus and has the potential to pave the way for the development of effective novel diagnostic methods and therapeutic strategies. SIGNIFICANCEPemphigus vulgaris (PV) presents a critical unmet medical challenge due to its autoimmune-induced disruption of skin cell adhesion. Our study presents a data-driven approach to quantitatively analyze changes in adhesion molecules and the cytoskeleton upon exposure to various PV antibodies. By introducing a pathogenicity score, we pinpoint the specific impacts of different antibodies on various proteins, build association among these antibodies, and reveal the contribution of previously overlooked non-desmosomal antibodies, broadening the understanding of PV pathology. Although centered on PV, our method offers a versatile framework applicable for evaluating the effects of other antibodies and drugs, paving the way for new diagnostic tools for personalized medicine.

biophysics↗

bioRxiv2024

Engineered yeast multicellularity via synthetic cell-cell adhesion and direct-contact signalling

Coordination of behaviour in multicellular systems is one the main ways that nature increases the complexity of biological function in organisms and communities. While Saccharomyces cerevisiae yeast is used extensively in research and biotechnology, it is a unicellular organism capable of only limited multicellular states. Here we expand the possibilities for engineering multicellular behaviours in yeast by developing modular toolkits for two key mechanisms seen in multicellularity, contact-dependent signalling and specific cell-to-cell adhesion. MARS (Mating-peptide Anchored Response System) is a toolkit based on surface-displayed fungal mating peptides and G protein-coupled receptor (GPCR) signalling which can mimic juxtacrine signalling between yeasts. SATURN (Saccharomyces Adhesion Toolkit for multicellUlar patteRNing) surface displays adhesion-proteins pairs on yeasts and facilitates the creation of cell aggregation patterns. Together they can be used to create multicellular logic circuits, equivalent to developmental programs that lead to cell differentiation based on the local population. Using MARS and SATURN, we further developed JUPITER (JUxtacrine sensor for Protein-protein InTERaction), a genetic sensor for assaying protein-protein interactions in culture, demonstrating this as a tool to select for high affinity binders among a population of mutated nanobodies. Collectively, MARS, SATURN, and JUPITER present valuable tools that facilitate the engineering of complex multicellularity with yeast and expand the scope of its biotechnological applications.

synthetic biology↗

bioRxiv2024

Impact of genome assemblies, genotyping methods, variant types, ploidy levels and population structures on genomic prediction in switchgrass

Genomic prediction, the use of genetic information for predicting traits, has accelerated the breeding processes and provided mechanistic insights into the genetic bases of complex traits. While substantial efforts have been devoted to optimize genomic prediction, there remain areas that need to be further explored, including the impact of genome assemblies, genotyping approaches, variant types, allelic complexities, polyploidy levels, and population structures. Here, we assess the impact of these factors on the prediction of 20 complex traits in switchgrass (Panicum virgatum L.), a perennial biofuel feedstock. We found that short read-based genome assembly perform comparably to or even better than long read-based assembly in trait prediction; exome capture-based models have higher prediction accuracy than genotyping-by-sequencing-based models for 13 traits; bi-allelic insertion/deletions are as useful as bi-allelic single nucleotide polymorphisms in trait prediction, whereas multi-allelic variants outperform bi-allelic ones for 15 traits. Models built for tetraploids have higher prediction accuracy than those for octoploids for most traits. Traits of individuals with higher within-population genetic distances tend to have higher prediction accuracy. Finally, integrating different types of variants can improve the prediction accuracy. By exploring these factors, anthesis date prediction models built using multi-allelic insertion/deletions derived from exome capture led to the largest number of orthologs of benchmark flowering time genes compared to other models. Our study provides insights into the factors influencing genomic prediction outcomes that inform best practices for future studies and for improving agronomic traits in switchgrass and other species through selective breeding.

plant biology↗

bioRxiv2024

Bola-amphiphilic dendrimer empowers imatinib to target metastatic ovarian cancer stem cells via beta-catenin-HRP2 signaling axis

Ovarian cancer is the leading cause of death among all gynecological malignancies, and drug resistance renders the current chemotherapy agents ineffective for patients with advanced metastatic tumors. We report an effective treatment strategy for targeting metastatic ovarian cancer involving a nanoformulation (Bola/IM) - bola-amphiphilic dendrimer (Bola)-encapsulated imatinib (IM) - to target the critical mediator of ovarian cancer stem cells (CSCs) CD117 (c-Kit). Bola/IM offered significantly more effective targeting of CSCs compared to IM alone, through a novel and tumor-specific {beta}-catenin/HRP2 axis, allowing potent inhibition of cancer cell survival, stemness and metastasis in metastatic and drug-resistant ovarian cancer cells. Promising results were also obtained in clinically relevant patient-derived ascites and organoids, alongside high tumor-oriented accumulation and favorable pharmacokinetic properties in mouse models. Furthermore, Bola/IM displayed synergistic anticancer activity when combined with the first-line chemotherapeutic drug cisplatin in patient-derived xenograft mouse models, without any adverse effects. Our findings support the use of Bola/IM as a nanoformulation to empower IM, providing targeted and potent treatment of metastatic ovarian cancer. Our study thus represents a significant advancement towards addressing the unmet medical need for improved therapies targeting this challenging disease.

cancer biology↗

bioRxiv2024

Desmosomal Cadherin Tension Loss in Pemphigus Vulgaris Mediated by the Inhibition of Active RhoA at Cell-Cell Adhesions

Binding of autoantibodies to keratinocyte surface antigens, primarily desmoglein 3 (Dsg3) of the desmosomal complex, leads to the dissociation of cell-cell adhesion in the blistering disorder pemphigus vulgaris (PV). After the initial disassembly of desmosomes, cell-cell adhesions actively remodel in association with the cytoskeleton and focal adhesions. Growing evidence highlights the role of adhesion mechanics and mechanotransduction at cell-cell adhesions in this remodeling process, as their active participation may direct autoimmune pathogenicity. However, a large part of the biophysical transformations after antibody binding remains underexplored. Specifically, it is unclear how tension in desmosomes and cell-cell adhesions changes in response to antibodies, and how the altered tensional states translate to cellular responses. Here, we showed a tension loss at Dsg3 using fluorescence resonance energy transfer (FRET)-based tension sensors, a tension loss at the entire cell-cell adhesion, and a potentially compensatory increase in junctional traction force at cell-extracellular matrix adhesions after PV antibody binding. Further, our data indicate that this tension loss is mediated by the inhibition of RhoA at cell-cell contacts, and the extent of RhoA inhibition may be crucial in determining the severity of pathogenicity among different PV antibodies. More importantly, this tension loss can be partially restored by altering actomyosin based cell contractility. Collectively, these findings provide previously unattainable details in our understanding of the mechanisms that govern cell-cell interactions under physiological and autoimmune conditions, which may open the window to entirely new therapeutics aimed at restoring physiological balance to tension dynamics that regulates the maintenance of cell-cell adhesion.

biophysics↗

bioRxiv2024

NPRL2 gene therapy induces effective antitumor immunity in KRAS/STK11 mutant anti-PD1 resistant metastatic non-small cell lung cancer (NSCLC) in a humanized mouse model

NPRL2/TUSC4 is a tumor suppressor gene whose expression is reduced in many cancers including NSCLC. Restoration of NPRL2 expression in cancer cells induces DNA damage which leads to cell cycle arrest and apoptosis. We investigated the antitumor immune responses to NPRL2 gene therapy in aPD1R/ KRAS/STK11mt NSCLC in a humanized mouse model. Humanized mice were generated by transplanting fresh human cord blood derived CD34 stem cells into sub-lethally irradiated NSG mice. Lung metastases were developed from KRAS/STK11mt/aPD1R A549 cells in humanized mice and treated with NPRL2 gene-loaded cationic lipid nanoparticles (DOTAP-NPRL2) with or without pembrolizumab (aPD1). NPRL2 treatment reduced lung metastases significantly, whereas pembrolizumab was ineffective. The antitumor effect was greater in humanized than non-humanized mice suggesting that an immune response contributed to antitumor activity. NPRL2 combined with pembrolizumab was not synergistic in the KRAS/STK11mt/aPD1R tumors but was synergistic in the KRASwt/aPD1S H1299 tumors. Consistent with the A549 humanized mouse model, NPRL2 showed a significantly strong antitumor effect on KRASmt/aPD1R LLC2 syngeneic tumors, whereas aPD1 was ineffective. The antitumor effect of NPRL2 was correlated with increased infiltration of human cytotoxic immune cells and Ag-presenting HLA-DR+ DC, CD11c DC, and downregulation of myeloid and regulatory T cells in the TME. The antitumor effect of NPRL2 was significantly abolished upon in-vivo depletion of CD8 T, macrophages, and CD4 T cells. However, the antitumor effect remained unaffected upon in-vivo depletion of NK cells. A distinct pattern of gene expression profile was found in lung met after NPRL2 treatment in humanized mice. The expression of genes associated with T cell functions, including IFN{gamma}, CD8b, CD7, TNFSF18, ITGA1, GATA3, and TBX21 was significantly increased, whereas the expression of genes associated with negative regulation of T cell functions, including FOXP3, TGFB1, TGFB2, and IL-10RA were strongly inhibited upon NPRL2 treatment. NPRL2 downregulated the expression of T cell co-inhibitory molecules, including CTLA4, ICOS, LAG3, PDCD1, CD274, IDO1, PDCD1LG2, CD47, and KLRB1. Tumors established from NPRL2 stably expressing cells in humanized mice exhibited significantly slower growth compared to controls. TME analysis showed an increased presence of human CD45+, CD3+ T, CD8+ T cells, and HLA-DR+ dendritic cells and a decreased percentage of Treg, CD3+PD1+T cells, MDSC, and CD163+ TAM in NPRL2-expressing tumors. In-vitro, NPRL2 stably expressing cells showed a substantial increase in colony formation inhibition and heightened sensitivity to carboplatin in colony formation, apoptosis, and PARP cleavage assays. Stable expression of NPRL2 resulted in the downregulation of MAPK and AKT-mTOR growth signaling through inhibition of pAKT, pmTOR, pPRAS40, p4E-BP1, and pS6 expression. Taken together, these data suggest that NPRL2 gene therapy induces antitumor activity on KRAS/STK11mt/aPD1R tumors through DC-mediated antigen presentation and cytotoxic immune cell activation.

cancer biology↗

bioRxiv2024

Mitochondrial fission surveillance is coupled to Caenorhabditis elegans DNA and chromosome segregation integrity

Mitochondrial fission and fusion are tightly regulated to specify mitochondrial abundance, localization, and arrangement during cell division as well as in the diverse differentiated cell types and physiological states. However, the regulatory pathways for such mitochondrial dynamics are less explored than the mitochondrial fission and fusion components. Here we report a large-scale screen for genes that regulate mitochondrial fission. Mitochondrial fission defects cause a characteristic asymmetric fluorescent pattern in embryos carrying mitochondrial stress reporter genes. Using this asymmetric activation, we performed RNAi screens that identified 3 kinase genes from a [~]500-kinase library and another 11 genes from 3,300 random genes that function in mitochondrial fission. Many of these identified genes play roles in chromosome segregation. We find that chromosome missegregation and genome instability lead to dysregulation of mitochondrial fission in a manner independent of Drp-1. ATL-1, the C. elegans ATR orthologue, plays a protective role in alleviating the mitochondrial fission defect caused by chromosome missegregation. This establishes a screening paradigm for identifying mitochondrial fission regulators which reveals the role of ATR in surveilling mitochondrial fission to mitigate dysregulation caused by improper chromosome segregation.

cell biology↗