Biology subjects

Kuo, C.-C.

Publications and source records attributed to Kuo, C.-C..

At least 19 recordsLinked to original sources

bioRxiv2026

Aberrant DNA methylation is co-regulated across the genome in leukemia and other types of cancer

Epigenetic dysregulation is a defining feature of cancer, but it remains poorly understood how this is coordinated across the genome. In this study we focusd on DNA methylation (DNAm) in acute myeloid leukemia (AML). Despite highly heterogeneous and largely patient-specific patterns, we identified co-regulated clusters of CpGs that could be assembled into reproducible epigenetic networks. Multilinear regression models accurately predicted the patient-specific DNAm deviations, even for CpGs located on different chromosomes. The alterations were mirrored on homologous chromosomes and there was no clear association with epigenetic driver mutations. Furthermore, we found very similar co-regulation patterns in acute lymphoblastic leukemia (ALL); with AML-derived models successfully predicting the ALL-associated DNAm changes. Notably, the top 1000 AML-associated CpGs showed also pronounced aberrations in DNAm levels across 46 other cancer types, whereas this was hardly observed across multiple non-malignant cell types. Co-regulation analysis realed very similar patterns in non-malignant blood and pan-cancer analysis, albeit the DNAm levels remained overall consistent in the controls. Collectively, our findings demonstrate that the complex, patient-specific DNAm landscapes observed in leukemia are not random. Instead, they are orchestrated within expanded epigenetic networks, which also exist in non-maligant cells, highlighting a higher-order regulatory layer in cancer epigenomics.

cancer biology↗

bioRxiv2025

SMAD2 sets divergent thresholds for TGF-β-induced SMAD1/5 signaling and IgE-mediated pro-inflammatory activation of mast cells

ObjectiveTGF-{beta}/SMAD signaling controls mast cell (MC) development and exerts anti-inflammatory functions, while antigen (Ag)-triggered Fc{varepsilon}RI/MAPK activation commands pro-inflammatory processes. SMAD2 is a signaling hub integrating both, TGF-{beta}/ALK5-mediated SMAD2 C-terminal-and ERK-mediated SMAD2 linker-phosphorylation. Here, we analyzed the role of SMAD2 in TGF-{beta}-and Ag-stimulated signaling, and their cross-talk which regulate MC responses. MethodsThe CRISPR-Cas method was used to disable SMAD2 expression in the PMC-306 cell line. The transcriptome of the corresponding cells was analyzed by NGS in homeostatic and stimulated conditions. Activation of signaling intermediates, target gene responses and effector function were analyzed by qPCR, Western blot and ELISAs. The causal association of SMAD2 with the found effects was proven by re-introduction of a tagged SMAD2 in knock out cells. ResultsThe absence of SMAD2 led to increased proliferation and survival, and decreased transcription of target genes like Smad7 and Jun in steady state and upon TGF-{beta} treatment. Intriguingly, SMAD2 was found to regulate TGF-{beta}-mediated SMAD1/5 activation, resulting in augmented expression of Id3 in SMAD2-deficient MCs. Unexpectedly, we found that SMAD2 is indispensable for Ag-triggered production of pro-inflammatory cytokines, such as IL-6 and TNF. Re-introducing SMAD2 restores these events with varying sensitivity depending on the receptor system triggered. ConclusionsOur findings highlight a previously unrecognized role of SMAD2 as a decisive hub in TGF-{beta}-ALK5-SMAD1/5 and Ag-Fc{varepsilon}RI-MAPK signaling, suggesting that pharmacological modulation of SMAD2 activity could be leveraged as regulator of both suppressive and inflammatory MC functions.

immunology↗

bioRxiv2025

Improving Recombinant Antibody Production Using FcBAR: An In Situ Approach to Detect and Amplify Protein-Protein Interactions

Recombinant proteins, in particular monoclonal antibodies and related molecules, have become dominant therapeutics. As they are produced in mammalian cells, they require the concerted function of hundreds of host cell proteins in the protein secretion pathway. However, the comprehensive set of host cell machinery involved remains unclear. Thus, it is often unknown why some recombinant proteins fail to express well. Here we present and deploy an approach called Fc-targeting Biotinylation by Antibody Recognition (FcBAR), which allows for the in situ detection of protein-protein interactions for any recombinant protein with Fc domain. Briefly, cells are permeabilized and incubated with an anti-Fc antibody, conjugated with horseradish peroxidase. All proteins interacting with Fc-bearing proteins are then biotinylated, pulled down and identified via mass spectrometry. We applied this method on a panel of rituximab-producing CHO-S clones with a range of productivity levels. Through analysis of FcBAR protein-protein interactions and RNA-Seq, we identified protein interactions positively correlated with rituximab secretion, and tested 7 of these targets. We found overexpression of AGPAT4, EPHX1, and NSDHL significantly increased rituximab production. Thus, FcBAR provides an unbiased approach to measure PPIs supporting recombinant antibody production in situ, and can guide efforts to boost production of biotherapeutics and biosimilars by addressing production bottlenecks.

systems biology↗

bioRxiv2025

Maternal separation disrupts noradrenergic control of adult coping behaviors

Early life stress (ELS) in humans and preclinical rodent models profoundly impacts the brain and correlates with negative affective behaviors in adulthood. The locus coeruleus (LC), a stress-responsive brainstem nucleus that supplies most of the brain with norepinephrine (NE), is known to modulate negative affect. Here we used repeated maternal separation stress (MSS) to investigate the impact of ELS on the LC and stress-related behaviors in adulthood. Using ex vivo cell-attached electrophysiology, we recorded spontaneous LC firing across the lifespan from early development, pre-adolescence, adolescence, through adulthood. MSS significantly increased LC firing during early development and adulthood compared to No MSS mice. We next examined potential changes in the expression of genes linked to LC function. MSS decreased mRNA levels for both the alpha-2A adrenergic receptor and dopamine beta-hydroxylase, the enzyme necessary for NE synthesis. At the behavioral level, MSS increased locomotion in approach-avoidance exploratory assays and increased immobility in the forced swim test. Forced swim increased LC cFos expression, a marker for neuronal excitation, in both No MSS and MSS mice. However, MSS mice had significantly less cFos than No MSS controls. We then sought to reverse this MSS-induced increase in immobility by inhibiting the LC during the forced swim test. In No MSS mice, LC inhibition increased immobility time, however, LC inhibition did not affect MSS immobility. Together, this study demonstrates that MSS dysregulates LC-NE activity across the lifespan and disrupts the role of the LC in regulating coping strategies during stressful events.

neuroscience↗

bioRxiv2024

A reconstruction of the mammalian secretory pathway identifies mechanisms regulating antibody production

The secretory pathway processes >30% of mammalian proteins, orchestrating their synthesis, modification, trafficking, and quality control. However, its complexity-- spanning multiple organelles and dependent on coordinated protein interactions--limits our ability to decipher how protein secretion is controlled in biomedical and biotechnological applications. To advance such research, we present secRecon--a comprehensive reconstruction of the mammalian secretory pathway, comprising 1,127 manually curated genes organized within an ontology of 77 secretory process terms, annotated with functional roles, subcellular localization, protein interactions, and complex composition. Using secRecon to integrate multi-omics data, we identified distinct secretory topologies in antibody-producing plasma cells compared to CHO cells. Genes within proteostasis, translocation, and N-glycosylation are deficient in CHO cells, highlighting them as potential engineering targets to boost secretion capacity. Applying secRecon to single-cell transcriptomics and SEC-seq data, we uncovered secretory pathway signatures underlying secretion diversity among IgG-secreting plasma cells. Different transcriptomic clusters had unique secretory phenotypes characterized by variations in the unfolded protein response (UPR), endoplasmic reticulum-associated degradation (ERAD), and vesicle trafficking pathways. Additionally, we discovered specific secretory machinery genes as new markers for plasma cell differentiation. These findings demonstrate secRecon can identify mechanisms regulating protein secretion and guide diverse studies in biomedical research and biotechnology. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=73 SRC="FIGDIR/small/623668v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@f9f865org.highwire.dtl.DTLVardef@122db7forg.highwire.dtl.DTLVardef@1788a1aorg.highwire.dtl.DTLVardef@b2b2bd_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

bioRxiv2024

Microtubule plus-end dynamics are tightly coupled to the turnover of the MOR1 polymerase

MOR1/XMAP215/Dis1/Stu2 family proteins function as polymerases that promote microtubule assembly through tubulin-interacting N-terminal tumor-overexpressed gene (TOG) domains. It remains unclear how the polymerase activity of these proteins is coordinated with their movement along the growing microtubule lattice. Previously, it was found that a L174F mutation in the N-terminal TOG domain of the 217 kDa Arabidopsis thaliana MICROTUBULE ORGANIZATION 1 (MOR1) protein impaired microtubule growth and shrinkage rates in a temperature-dependent manner. In this study, we used a homologous recombination strategy to generate stable transgenic lines expressing full-length MOR1 and mutant mor1-1L174F proteins tagged with the yellow fluorescent protein YPet. When expressed in mor1 mutant backgrounds, MOR1-3xYPet showed strong association with both the growing and shrinking microtubule plus ends, consistent with its involvement in both polymerization and depolymerization. By contrast, when expressed in a wild-type background, MOR1-3xYPet was redistributed along the microtubule lattice, microtubule growth rates were reduced, and plant growth was stunted. By quantifying fluorescence recovery after photobleaching, we confirmed that MOR1 has greater affinity for the plus end than the lattice. Exploiting the FRAP technique further, we identified a positive and linear correlation between microtubule polymerization rates and MOR1 turnover at the microtubule plus end. When microtubule growth rates were reduced in the mor1-1-YPet line by shifting the temperature from 21 to 30{degrees}C and for MOR1-3xYPet under taxol treatments, MOR1s turnover was delayed. In contrast, microtubule growth rates and MOR1 turnover were hastened at 30{degrees}C or after CRISPR/Cas9-mediated knock out of the CLASP protein. These findings support a new model whereby MOR1 has finite processivity on the microtubule, catalyzing a limited fixed number of tubulin additions before dissociation. HIGHLIGHTSMOR1 has high affinity for both growing and shrinking microtubule plus ends, consistent with a function in both polymerization and depolymerization events. MOR1 has greater affinity for microtubule plus ends than the lattice, and lattice binding associated with overexpression is detrimental to plant growth. MOR1 transiently associates with the microtubule plus end, the duration of which is tightly coupled with its polymerase activity.

cell biology↗

bioRxiv2024

Monosynaptic ventral tegmental area glutamate projections to the locus coeruleus enhance aversive processing

Distinct excitatory synaptic inputs to the locus coeruleus (LC) modulate behavioral flexibility. Here we identify a novel monosynaptic glutamatergic input to the LC from the ventral tegmental area (VTA). We show robust VTA axonal projections provide direct glutamatergic transmission to LC. Despite weak synaptic summation, optogenetic activation of these axons enhances LC tonic firing and facilitates real-time and conditioned aversive behaviors. We hypothesized this projection may modulate synaptic integration with other excitatory inputs. We then used coincident VTA-LC photostimulation with local electrical stimulation and observed enhanced LC burst induction. To determine whether this integration also occurs in vivo, we took an analogous approach measuring reward-seeking behavior during unpredictable probabilistic punishment. Here, glutamatergic VTA-LC photostimulation during a concurrent noxious stimulus did not delay reward-seeking behavior, but increased probability of task failure. Together, we identified a novel VTA-LC glutamatergic projection that drives concurrent synaptic summation during salient stimuli to promote behavioral avoidance.

neuroscience↗

bioRxiv2024

DNMT1-Mediated Regulation of Inhibitory Interneuron Migration Impacts Cortical Architecture and Function

The fine-tuned establishment of neuronal circuits during the formation of the cerebral cortex is pivotal for its functionality. Developmental abnormalities affecting the composition of cortical circuits, which consist of excitatory neurons and inhibitory cortical interneurons (cINs), are linked to a spectrum of neuropsychiatric disorders. Excitatory neurons originate in cortical proliferative zones, while inhibitory interneurons migrate from discrete domains of the basal telencephalon into the cortex. This migration is intricately governed by intrinsic genetic programs and extrinsic cues. Our current study reveals the role of the DNA methyltransferase 1 (DNMT1) in regulating the expression of key genes implicated in mouse cIN development and in guiding the migration of somatostatin (SST)-expressing interneurons at postmitotic level within the developing cortex. Dnmt1 deletion causes SST+ cINs to exit prematurely from the superficial migratory stream. In addition to the perturbed migration pattern and altered gene expression signatures, Dnmt1-deficient SST+ cINs had a discernible non-cell autonomous effect on cortical progenitors, which culminated in nuanced alterations of layer thicknesses in the adult cortex. Our study uncovers that DNMT1 governs the migration of SST+ cINs and through this, their instructive role in sculpting the intricate cortical layer architecture by signaling to cortical progenitors, with pronounced effects on neuronal network function.

neuroscience↗

bioRxiv2024

Neural circuit-selective, multiplexed pharmacological targeting of prefrontal cortex-projecting locus coeruleus neurons drives antinociception

Selective manipulation of neural circuits using optogenetics and chemogenetics holds great translational potential but requires genetic access to neurons. Here, we demonstrate a general framework for identifying genetic tool-independent, pharmacological strategies for neural circuit-selective modulation. We developed an economically accessible calcium imaging-based approach for large-scale pharmacological scans of endogenous receptor-mediated neural activity. As a testbed for this approach, we used the mouse locus coeruleus due to the combination of its widespread, modular efferent neural circuitry and its wide variety of endogenously expressed GPCRs. Using machine learning-based action potential deconvolution and retrograde tracing, we identified an agonist cocktail that selectively inhibits medial prefrontal cortex-projecting locus coeruleus neurons. In vivo, this cocktail produces synergistic antinociception, consistent with selective pharmacological blunting of this neural circuit. This framework has broad utility for selective targeting of other neural circuits under different physiological and pathological states, facilitating non-genetic translational applications arising from cell type-selective discoveries.

neuroscience↗

bioRxiv2024

Stabilization of AMPK/PFKL/RPIA in the Glycolytic Bodies Transduces IL6/STAT3 Signal in Hepatocarcinogenesis

Metabolic reprogramming is a pivotal characteristic of cancer, yet the intricate interplay between glycolysis and the pentose phosphate pathway (PPP) remains elusive. This study unveils the pivotal role of 6-phosphofructokinase liver type (PFKL) in glycolysis and ribose 5-phosphate isomerase A (RPIA) in PPP, orchestrating liver tumorigenesis. PFKL, the rate-limiting enzyme in glycolysis, stabilizes RPIA by impeding ubiquitination/proteasome activity. The pro-inflammatory and tumor cytokine interleukin 6 activates pSTAT3 which binds to the promoter region and activates AMPK and PFKL transcription. Furthermore, pAMPK stabilizes PFKL protein by preventing proteasome degradation in hepatoma cells. Inhibiting PFKL, AMPK, and STAT3 genetically or pharmacologically can reduce glycolysis, ATP production, resulting in reduction of hepatoma cell proliferation and migration. Intriguingly, the PFKL, AMPK, RPIA, and PKM2 are co-localized in the Glycolytic body (G-body) which starts forming at chronic hepatitis, dramatically increases during active hepatitis, and the size of G-bodies becomes bigger from cirrhosis to hepatocellular carcinoma. Furthermore, using Bimolecular fluorescence complementation (BiFC) assay, we demonstrated that PFKL and RPIA direct interacts. Targeting AMPK or STAT3 significantly reduced tumor formation and lipid accumulation in zebrafish models, suggesting the STAT3/AMPK/PFKL axis as a potential therapeutic avenue for liver cancer treatment.

cancer biology↗

bioRxiv2023

Endogenous opioids gate the locus coeruleus pain generator

The locus coeruleus (LC) plays a paradoxical role in chronic pain. Although largely known as a potent source of endogenous analgesia, increasing evidence suggests injury can transform the LC into a chronic pain generator. We sought to clarify the role of this system in pain. Here, we show optogenetic inhibition of LC activity is acutely antinociceptive. Following long-term spared nerve injury, the same LC inhibition is analgesic - further supporting its pain generator function. To identify inhibitory substrates that may naturally serve this function, we turned to endogenous LC mu opioid receptors (LC-MOR). These receptors provide powerful LC inhibition and exogenous activation of LC-MOR is antinociceptive. We therefore hypothesized that endogenous LC-MOR-mediated inhibition is critical to how the LC modulates pain. Using cell type-selective conditional knockout and rescue of LC-MOR receptor signaling, we show these receptors bidirectionally regulate thermal and mechanical hyperalgesia - providing a functional gate on the LC pain generator.

neuroscience↗

bioRxiv2023

Inferring secretory and metabolic pathway activity from omic data with secCellFie

Understanding protein secretion has considerable importance in the biotechnology industry and important implications in a broad range of normal and pathological conditions including development, immunology, and tissue function. While great progress has been made in studying individual proteins in the secretory pathway, measuring and quantifying mechanistic changes in the pathways activity remains challenging due to the complexity of the biomolecular systems involved. Systems biology has begun to address this issue with the development of algorithmic tools for analyzing biological pathways; however most of these tools remain accessible only to experts in systems biology with extensive computational experience. Here, we expand upon the user-friendly CellFie tool which quantifies metabolic activity from omic data to include secretory pathway functions, allowing any scientist to infer protein secretion capabilities from omic data. We demonstrate how the secretory expansion of CellFie (secCellFie) can be used to predict metabolic and secretory functions across diverse immune cells, hepatokine secretion in a cell model of NAFLD, and antibody production in Chinese Hamster Ovary cells.

systems biology↗

bioRxiv2023

Neural extracellular matrix regulates visual sensory motor integration

Visual processing depends on sensitive and balanced synaptic neurotransmission. Extracellular matrix proteins in the environment of cells are key modulators in synaptogenesis and synaptic plasticity. In the present study, we provide evidence that the combined loss of the four extracellular matrix components brevican, neurocan, tenascin-C and tenascin-R in quadruple knockout mice leads to severe retinal dysfunction and diminished visual motion processing in vivo. Remarkably, impaired visual motion processing was accompanied by a developmental loss of cholinergic direction-selective starburst amacrine cells. Additionally, we noted imbalance of inhibitory and excitatory synaptic signaling in the quadruple knockout retina. Collectively, the study offers novel insights into the functional importance of four key extracellular matrix proteins for retinal function, visual motion processing and synaptic integrity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=73 SRC="FIGDIR/small/537074v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@eec571org.highwire.dtl.DTLVardef@1e4b282org.highwire.dtl.DTLVardef@18398a7org.highwire.dtl.DTLVardef@9b113b_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefIn their study, Reinhard et al. show that the combined loss of the extracellular matrix components brevican, neurocan, tenascin-C and tenascin-R in quadruple knockout mice leads to retinal dysfunction, diminished visual motion processing, developmental loss of cholinergic direction-selective starburst amacrine cells and imbalance of inhibitory and excitatory synaptic integrity. HighlightsO_LICombined loss of the four extracellular matrix molecules brevican, neurocan, tenascin-C and tenascin-R causes retinal dysfunction C_LIO_LIImpaired visual motion processing in quadruple, tenascin-C and tenascin-R knockout mice C_LIO_LILoss of cholinergic direction-selective starburst amacrine cells in the quadruple knockout retina C_LIO_LIThe matrisome influences inhibitory and excitatory synaptic balance C_LI

neuroscience↗

bioRxiv2023

An electrochemical approach for rapid, sensitive, and selective detection of dynorphin

The endogenous opioid peptide systems are critical for analgesia, reward processing, and affect, but research on their release dynamics and function has been challenging. Here, we have developed microimmunoelectrodes (MIEs) for the electrochemical detection of opioid peptides using square-wave voltammetry. Briefly, a voltage is applied to the electrode to cause oxidation of the tyrosine residue on the opioid peptide of interest, which is detected as current. To provide selectivity to these voltammetric measurements, the carbon fiber surface of the MIE is coated with an antiserum selective to the opioid peptide of interest. To test the sensitivity of the MIEs, electrodes are immersed in solutions containing different concentrations of opioid peptides, and peak oxidative current is measured. We show that dynorphin antiserum-coated electrodes are sensitive to increasing concentrations of dynorphin in the attomolar range. To confirm selectivity, we also measured the oxidative current from exposure to tyrosine and other opioid peptides in solution. Our data show that dynorphin antiserum-coated MIEs are sensitive and selective for dynorphin with little to no oxidative current observed in met-enkephalin and tyrosine solutions. Additionally, we demonstrate the utility of these MIEs in an in vitro brain slice preparation using bath application of dynorphin as well as optogenetic activation of dynorphin release. Future work aims to use MIEs in vivo for real-time, rapid detection of endogenous opioid peptide release in awake, behaving animals.

neuroscience↗

bioRxiv2023

RGT: a toolbox for the integrative analysis of high throughput regulatory genomics data

BackgroundMassive amounts of data are produced by combining next-generation sequencing (NGS) with complex biochemistry techniques to characterize regulatory genomics profiles, such as protein-DNA interaction and chromatin accessibility. Interpretation of such high-throughput data typically requires different computation methods. However, existing tools are usually developed for a specific task, which makes it challenging to analyze the data in an integrative manner. ResultsWe here describe the Regulatory Genomics Toolbox (RGT), a computational library for the integrative analysis of regulatory genomics data. RGT provides different functionalities to handle genomic signals and regions. Based on that, we developed several tools to perform distinct downstream analyses, including the prediction of transcription factor binding sites using ATAC-seq data, identification of differential peaks from ChIP-seq data, and detection of triple helix mediated RNA and DNA interactions, visualization, and finding an association between distinct regulatory factors. ConclusionWe present here RGT; a framework to facilitate the customization of computational methods to analyze genomic data for specific regulatory genomics problems. RGT is a comprehensive and flexible Python package for analyzing high throughput regulatory genomics data and is available at: https://github.com/CostaLab/reg-gen. The documentation is available at: https://reg-gen.readthedocs.io

bioinformatics↗

bioRxiv2022

Deciphering the determinants of recombinant protein yield across the human secretome

Mammalian cells are critical hosts for the production of most therapeutic proteins and many proteins for biomedical research. While cell line engineering and bioprocess optimization have yielded high protein titers of some recombinant proteins, many proteins remain difficult to express. Here, we decipher the factors influencing yields in Chinese hamster ovary (CHO) cells as they produce 2165 different proteins from the human secretome. We demonstrate that variation within our panel of proteins cannot be explained by transgene mRNA abundance. Analyzing the expression of the 2165 human proteins with machine learning, we find that protein features account for only 15% of the variability in recombinant protein yield. Meanwhile, transcriptomic signatures account for 75% of the variability across 95 representative samples. In particular, we observe divergent signatures regarding ER stress and metabolism among the panel of cultures expressing different recombinant proteins. Thus, our study unravels the factors underlying the variation on recombinant protein production in CHO and highlights transcriptomics signatures that could guide the rational design of CHO cell systems tailored to specific proteins.

systems biology↗

bioRxiv2022

A lncRNA identifies IRF8 enhancer element in negative feedback control of dendritic cell differentiation

Transcription factors play a determining role in lineage commitment and cell differentiation. Interferon regulatory factor 8 (IRF8), a hematopoietic transcription factor, is prominently upregulated in dendritic cells (DC) by autoactivation and controls DC differentiation and function. However, it is unclear how IRF8 autoactivation is controlled and eventually limited. Here we identified a novel long non-coding RNA transcribed from the +32 kb enhancer downstream of IRF8 transcription start site and expressed specifically in plasmacytoid DC (pDC), referred to as lncIRF8. A sequence element of the lncIRF8 promoter, but not lncIRF8 itself, is crucial for pDC and classical DC type 1 (cDC1) differentiation. In DC development IRF8 autoactivation is first initiated by flanking enhancers and then second controlled by feedback inhibition through the lncIRF8 promoter element in the +32 kb enhancer. Our work reveals a previously unrecognized negative feedback loop of IRF8 that orchestrates its own expression and thereby controls DC differentiation.

cell biology↗

bioRxiv2022

Induction of senescence upon loss of the Ash2l core subunit of H3K4 methyltransferase complexes

Gene expression is controlled in part by post-translational modifications of core histones. Methylation of lysine 4 of histone H3 (H3K4), associated with open chromatin and gene transcription, is catalyzed by type 2 lysine methyltransferase complexes that require WDR5, RBBP5, ASH2L and DPY30 as core subunits. Ash2l is essential during embryogenesis and for maintaining adult tissues. To expand on the mechanistic understanding of Ash2l, we generated mouse embryo fibroblasts (MEFs) with conditional Ash2l alleles. Upon loss of Ash2l, methylation of H3K4 and gene expression were downregulated, which correlated with inhibition of proliferation and cell cycle progression. Moreover, we observed induction of senescence concomitant with a set of downregulated signature genes but independent of SASP. Many of the signature genes are FoxM1 responsive. Indeed, exogenous FOXM1 was sufficient to delay senescence. Thus, although the loss of Ash2l in MEFs has broad and complex consequences, a distinct set of downregulated genes promotes senescence.

cell biology↗