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Geng, S.

Publications and source records attributed to Geng, S..

At least 19 recordsLinked to original sources

Cellular context shapes the transcriptomic impact of somatic variants

Somatic SNVs are commonly prioritized by recurrence or sequence annotation, leaving the molecular consequences of private variants unresolved. We developed PrismSNV and Ligo-Seq, a single-cell full-length transcriptome sequencing platform, to quantify transcriptomic displacement associated with within-cell SNV-state toggling. Across 26 samples from three cancer types, more than 60% of candidate SNVs showed significant cell-type-specific displacement with over 30% variation in magnitude. Sequence-based deleteriousness was poorly aligned with cellular displacement, and fewer than 3% of top-displacement SNVs across six tumor types were catalogued in ClinVar. Displacement was strongest in transcriptionally plastic, less differentiated states. Analysis of 655,349 CD4+ T-cell transcriptomes further showed that SNV-gene associations changed in magnitude and sometimes direction during activation. Lack of recurrence or clinical annotation does not imply transcriptomic inertness; variant impact is shaped by cellular context rather than sequence alone, establishing the variant-cell pair as a critical unit for interpreting somatic variation.

genetics↗

PTMExplorer: A Multi-Dimensional Integrative Visualization Platform for Protein Post-Translational Modification Function and Structure

Deciphering the functions of post-translational modifications (PTMs) is a critical bridge connecting large-scale modification proteomics data to mechanistic studies. However, most existing tools for visualizing PTM omics data are limited to site catalogs or single-dimensional feature displays. They lack the capability to simultaneously map user-derived differential modification sites onto multi-dimensional contexts, including protein three-dimensional (3D) structure, evolutionary conservation, functional sites, and disease associations. This limitation makes it difficult for researchers to rapidly assess the biological importance of candidate sites from among a vast number of differentially modified sites. Here, we present PTMExplorer, an interactive platform for the multi-dimensional visualization of protein PTMs. PTMExplorer comprises three core modules: PTM Inspector, built upon ProtVista, provides a multi-track, sequence-feature integrated view incorporating intrinsically disordered region (IDR) prediction (via flDPnn), surface accessibility calculation (via FreeSASA), and UniProt functional annotations; PTM 3D Locator, leveraging the Nightingale/Mol* engine, anchors modification sites onto AlphaFold/Protein Data Bank (PDB) 3D structures through residue mapping via PDBe-SIFTS; and PTM Overview, utilizing the R circlize package, presents a panoramic polar circos plot illustrating modification distribution and inter-group differential regulation. Additionally, three major disease-associated modification databases (PTMD, qPTM, and PhosCancer) are integrated as PTM-Disease Nexus, enabling co-localization comparison between user-defined differential sites and reported disease-related sites. PTMExplorer currently supports eight model organisms, accepts user-uploaded differential analysis results, and provides multi-dimensional annotations and various visualization options (https://www.bioladder.cn/PTMExplorer/). Using a multi-omics dataset from hepatocellular carcinoma (18 patients, 9 modification types) as a case study, we demonstrate the practical utility of PTMExplorer in screening potential biomarkers, revealing multi-modification coordination mechanisms, and distinguishing between absolute and relative quantification patterns.

bioinformatics↗

IGF2BP3 amplifies antiviral innate immunity with implications for autoimmune diseases

The insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is a known N6-methyladenosine (m6A) reader, but its role in antiviral innate immunity is unknown. Here, we identify IGF2BP3 as a critical positive regulator of antiviral responses. Viral infection and interferon (IFN) stimulation upregulate IGF2BP3, establishing a feedforward loop that potentiates virus-induced activation of the TBK1-IRF3 and NF-{kappa}B pathways, thereby amplifying type I interferon (IFN-I) production, and restricting viral replication in human and murine cells and in vivo. Mechanistically, IGF2BP3 directly binds and stabilizes MAVS and TBK1 mRNAs and promotes their translation by facilitating recruitment to the eIF4F/PABP-associated initiation complex. Upon infection, IGF2BP3 relocalizes to antiviral stress granules (avSGs), where it scaffolds the RIG-I-G3BP1 complex to enhance viral RNA sensing. Notably, IGF2BP3 is aberrantly upregulated in patients with systemic lupus erythematosus (SLE) and in Trex1 knockout (KO) mice, and pharmacological inhibition by curcumol suppresses IFN-I-driven pathology and improves survival. Collectively, our findings establish IGF2BP3 as a central feedforward circuit that couples viral RNA sensing to the control of RNA stability and translation of key signaling molecules, and reveals its potential as a therapeutic target in interferon-associated autoimmune diseases. Significance StatementAntiviral immunity demands rapid and coordinated gene expression, yet how RNA-binding proteins link viral recognition to downstream signaling is poorly understood. We reveal that the m6A reader IGF2BP3 acts as a central amplifier of antiviral innate immunity. Induced by both viruses and interferons, IGF2BP3 enhances viral RNA sensing, stabilizes key signaling transcripts, and boosts their translation, creating a self-reinforcing feedforward circuit that strengthens interferon responses. Beyond host defense, IGF2BP3 is aberrantly elevated in interferon-driven autoimmunity, and its pharmacological inhibition reduce disease pathology in vivo. Our findings uncover a previously unrecognized mechanism that integrates RNA metabolism, stress-granule signaling, and translational control to regulate innate immunity, offering new therapeutic perspectives for both infectious and autoimmune disease.

immunology↗

The gut microbiota metabolite Urolithin A mitigates JAK signaling to suppress cytokine-mediated autoimmune diseases

Aberrant activation of type I interferon (IFN-I) is closely related to the development of autoimmune diseases. The metabolic regulation of cytokine signaling is essential for immune homeostasis. In this study, we characterized Urolithin A(UA), a natural gut-derived metabolite, as an inhibitor of Janus kinase (JAK) signaling. UA was found to broadly dampen JAK phosphorylation and the downstream signaling induced by cytokines such as type I interferons (IFN-I), type II interferons (IFN-II), and interleukin-6 (IL-6). UA can directly bind to JAK1 JH1 domain and treatment with UA attenuated autoimmune pathogenesis in Trex1-KO mice, IMQ-induced SLE and psoriasis models. Our findings unveil that UA is an anti-inflammatory metabolite that promotes immune homeostasis and could be used to treat inflammatory and autoimmune diseases.

immunology↗

Decoding Continuous Character-based Language from Non-invasive Brain Recordings

Deciphering natural language from brain activity through non-invasive devices remains a formidable challenge. Previous non-invasive decoders either require multiple experiments with identical stimuli to pinpoint cortical regions and enhance signal-to-noise ratios in brain activity, or they are limited to discerning basic linguistic elements such as letters and words. We propose a novel approach to decoding continuous language from single-trial non-invasive fMRI recordings, in which a three-dimensional convolutional network augmented with information bottleneck is developed to automatically identify responsive voxels to stimuli, and a character-based decoder is designed for the semantic reconstruction of continuous language characterized by inherent character structures. The resulting decoder can produce intelligible textual sequences that faithfully capture the meaning of perceived speech both within and across subjects, while existing decoders exhibit significantly inferior performance in cross-subject contexts. The ability to decode continuous language from single trials across subjects demonstrates the promising applications of non-invasive language brain-computer interfaces in both healthcare and neuroscience.

neuroscience↗

An arms race under RIG-I loss: 5'ppp-RNA and its alternative recognition receptor MDA5

The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape lifes evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5ppp-RNA virus in a lower vertebrate fish, M. miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and G. gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.

immunology↗

Mapping the shared and unique structural asymmetry abnormalities of young children with autism and developmental delay/intellectual disability with normative models and their multimodal cascade

To understand the neural mechanism of autism spectrum disorder (ASD) concurrent with developmental delay/intellectual disability (DD/ID), it is essential to comprehensively take genetic, brain, and behavioural measurements as a whole and focus on subjects at early age. However, such research is still lacking. Here, using the sMRI data of 1030 children under 8 years old, we employed developmental normative models to explore the atypical development of gray matter volume (GMV) asymmetry in individuals with ASD without DD/ID, ASD with DD/ID and DD/ID, and their associations with neurophysiological measures and transcription profiles. By computing the individual deviations from typical controls, we observed an ASD-specific abnormal GMV laterality pattern that was more rightwards in the inferior parietal cortex and precentral cortex and noted abnormal within-group heterogeneity in the temporal pole. Specifically, ASD with DD/ID children exhibited more regional abnormalities; ASD without DD/ID children showed higher within-group variability; while children with DD/ID showed no significant abnormalities. However, there were no significant differences among the three groups. The GMV laterality of ASD without DD/ID children was associated with ASD symptoms, whereas that of ASD with DD/ID children was associated with both ASD symptoms and verbal IQ. Last, the GMV laterality of the ASD with DD/ID, ASD without DD/ID, and DD/ID groups was associated with shared and unique gene expression profiles, but the associations of the latter two groups with intellectual genes showed opposite effects. Our findings illustrated the atypical development of regional structural lateralization in autistic children, which is associated with upstream genes and downstream behavioural performance. The differences and similarity between ASD and DD/ID additionally improve our standing to the neural mechanism of neurodevelopmental disorders comorbidity.

neuroscience↗

Dynamics of Brain Lateralization and Genetic Underpinnings during Chinese Natural Speech Processing: Preferential Occurrence of Logic-Related Patterns in Males and Emotion-Related Patterns in Females

Though language is considered unique to humans with left dominant lateralization in the brain, the dynamic nature of the interplay between hemispheres during language processing remains largely unknown. Here, we investigated whole-brain functional dynamic lateralization patterns during Chinese language processing and potential sex disparities using functional MRI data of 20 subjects listening to narrative stories in a 7T MRI scanner. Our findings revealed two distinct dynamic lateralization states, with regions of the language system consistently showing the left lateralization but reversed lateralization for other regions. These two states, characterized by higher-level functioning regions exhibiting left- or right-lateralization, corresponded to the processing of rational and emotional contents, respectively. We observed pronounced inclinations towards the former state in males and the latter state in females, especially during the processing of rational contents. Finally, genetic analyses revealed that the sex differences in lateralization states were potentially influenced by sex hormones.

neuroscience↗

Abnormal white matter development during early childhood in autism and developmental disability

The abnormal maturation of white matter microstructure in autism spectrum disorder (ASD) compared with typical developing (TD) and developmental delay/intellectual disorder (DD/ID) during early childhood and their associations with clinical implications remain unclear. Here, we characterized spatial and temporal patterns of white matter development in 364 children (including ASD, DD/ID and TD) under 8 years old using neurite orientation dispersion and density imaging. Using neurite density index (NDI), we consistently detected three white matter clusters across all the groups through clustering analysis, indicating the conserved spatial layout in atypical development. Further, three developmental stages with successively lower growth rates were identified in ASD, similar to those in TD but delayed overall. Meanwhile, DD/ID children showed the slowest growth rates and lacked staging features. Finally, for ASD children, the NDI was correlated with cognitive impairments at the fast developmental stage but associated with social deficits during the moderate-to-slow stage.

neuroscience↗

Monocytes reprogrammed by 4-PBA potently contribute to the resolution of inflammation and atherosclerosis

BackgroundChronic inflammation initiated by inflammatory monocytes underlies the pathogenesis of atherosclerosis. However, approaches that can effectively resolve chronic low-grade inflammation targeting monocytes are not readily available. The small chemical compound 4-phenylbutyric acid (4-PBA) exhibits broad anti-inflammatory effects in reducing atherosclerosis. Selective delivery of 4-PBA reprogrammed monocytes may hold novel potential in providing targeted and precision therapeutics for the treatment of atherosclerosis. MethodsSystems analyses integrating single-cell RNA-sequencing and complementary immunological approaches characterized key resolving characteristics as well as defining markers of reprogrammed monocytes trained by 4-PBA. Molecular mechanisms responsible for monocyte reprogramming was assessed by integrated biochemical and genetic approaches. The inter-cellular propagation of homeostasis resolution was evaluated by co-culture assays with donor monocytes trained by 4-PBA and recipient naive monocytes. The in vivo effects of monocyte resolution and atherosclerosis prevention by 4-PBA were assessed with the high fat diet-fed ApoE-/- mouse model with i.p. 4-PBA administration. Furthermore, the selective efficacy of 4-PBA trained monocytes were examined by i.v. transfusion of ex vivo trained monocytes by 4-PBA into recipient high fat diet-fed ApoE-/- mice. ResultsIn this study, we found that monocytes can be potently reprogrammed by 4-PBA into an immune-resolving state characterized by reduced adhesion and enhanced expression of anti-inflammatory mediator CD24. Mechanistically, 4-PBA reduced the expression of ICAM-1 via reducing peroxisome stress and attenuating SYK-mTOR signaling. Concurrently, 4-PBA enhanced the expression of resolving mediator CD24 through promoting PPAR{gamma} neddylation mediated by TOLLIP. 4-PBA trained monocytes can effectively propagate anti-inflammation activity to neighboring monocytes through CD24. Our data further demonstrated that 4-PBA trained monocytes effectively reduce atherosclerosis pathogenesis when administered in vivo. ConclusionOur study describes a robust and effective approach to generate resolving monocytes, characterizes novel mechanisms for targeted monocyte reprogramming, and offers a precision-therapeutics for atherosclerosis based on delivering reprogrammed resolving monocytes.

immunology↗

Sustained store-operated calcium entry utilizes activated chromatin state leads to instability in iTregs

Thymus-originated tTregs and in vitro induced iTregs are subsets of regulatory T cells. While they share the capacity of immune suppression, their stabilities are different, with iTregs losing their phenotype upon stimulation or under inflammatory milieu. Epigenetic differences, particularly methylation state of Foxp3 CNS2 region, provide an explanation for this shift. Whether additional regulations, including cellular signaling, could directly lead phenotypical instability requires further analysis. Here we show that upon TCR triggering, store-operated calcium entry (SOCE) and NFAT nuclear translocation are blunted in tTregs, yet fully operational in iTregs, similar to Tconvs. On the other hand, tTregs show minimal changes in their chromatin accessibility upon activation, in contrast to iTregs that demonstrate an activated chromatin state with highly accessible T cell activation and inflammation related genes. Assisted by several cofactors, NFAT driven by strong SOCE signaling in iTregs preferentially binds to primed opened T helper (TH) genes, resulting in their activation normally observed only in Tconv activation, ultimately leads to instability. Conversely, suppression of SOCE in iTregs can partially rescue their phenotype. Thus our study adds two new layer, cellular signaling and chromatin accessibility, of understanding in Treg stability, and may provide a path for better clinical applications of Treg cell therapy.

immunology↗

Design principles of Cdr2 node patterns in fission yeast cells

Pattern forming networks have diverse roles in cell biology. Rod-shaped fission yeast cells use pattern formation to control the localization of mitotic signaling proteins and the cytokinetic ring. During interphase, the kinase Cdr2 forms membrane-bound multiprotein complexes termed nodes, which are positioned in the cell middle due in part to the node inhibitor Pom1 enriched at cell tips. Node positioning is important for timely cell cycle progression and positioning of the cytokinetic ring. Here, we combined experimental and modeling approaches to investigate pattern formation by the Pom1-Cdr2 system. We found that Cdr2 nodes accumulate near the nucleus, and Cdr2 undergoes nucleocytoplasmic shuttling when cortical anchoring is reduced. We generated particle-based simulations based on tip inhibition, nuclear positioning, and cortical anchoring. We tested model predictions by investigating Pom1-Cdr2 localization patterns after perturbing each positioning mechanism, including in both anucleate and multinucleated cells. Experiments show that tip inhibition and cortical anchoring alone are sufficient for the assembly and positioning of nodes in the absence of the nucleus, but that the nucleus and Pom1 facilitate the formation of unexpected node patterns in multinucleated cells. These findings have implications for spatial control of cytokinesis by nodes and for spatial patterning in other biological systems.

cell biology↗

A conserved RWP-RK transcription factor VSR1 controls gametic differentiation in volvocine algae

Volvocine green algae are a model for understanding the evolution of mating types and sexes. They are facultatively sexual, with gametic differentiation occurring in response to nitrogen starvation (-N) in most genera, and to sex inducer hormone (SI) in Volvox. The conserved RWP RK family transcription factor (TF) MID is encoded by the minus mating type (MT) locus or male sex-determining region (SDR) of heterothallic volvocine species and dominantly determines minus or male gametic differentiation. However, the factor(s) responsible for establishing the default plus or female differentiation programs have remained elusive. We performed a phylo transcriptomic screen for autosomal RWP-RK TFs induced during gametogenesis in unicellular isogamous Chlamydomonas reinhardtii (Chlamydomonas) and in multicellular oogamous Volvox carteri (Volvox) and identified a single conserved ortho-group we named Volvocine Sex Regulator 1 (VSR1). Chlamydomonas vsr1 mutants of either mating type failed to mate and could not induce expression of key mating-type-specific genes. Similarly, Volvox vsr1 mutants in either sex could initiate sexual embryogenesis, but the presumptive eggs or androgonidia (sperm packet precursors) were infertile and unable to express key sex-specific genes. Yeast two-hybrid assays identified a conserved domain in VSR1 capable of self-interaction or interaction with the conserved N terminal domain of MID. In vivo co-immunoprecipitation experiments demonstrated association of VSR1 and MID in both Chlamydomonas and Volvox. These data support a new model for volvocine sexual differentiation where VSR1 homodimers activate expression of plus/female gamete-specific-genes, but when MID is present MID-VSR1 heterodimers are preferentially formed and activate minus/male gamete-specific-genes. Significance StatementSex and recombination are conserved features of eukaryotic life cycles, but sex determination mechanisms are diverse, and are poorly understood in most major taxa. Our study identified a long-sought regulator of sexual differentiation in volvocine green algae--the RWP-RK family transcription factor (TF) VSR1-- leading to the first complete paradigm for mating type or sex determination in this lineage. Our results support a model where gametically expressed VSR1 homodimerizes and activates plus/female specific genes. When the dominant sex-linked minus/male RWP-RK family TF MID is present MID-VSR1 heterodimers are preferentially formed and activate minus/male genes. The widespread association of RWP-RK TFs with gamete differentiation in the green lineage suggests that a similar paradigm may operate throughout the plant kingdom.

genetics↗

FoxP3-mediated blockage of ryanodine receptor 2 is the molecular basis for the contact-based suppression by regulatory T cells

The suppression mechanism of regulatory T cells is an intensely investigated topic. As our focus has shifted towards a model centered on indirect inhibition of dendritic cells, a universally applicable effector mechanism controlled by FoxP3 expression has not been found. Here, we report that FoxP3 blocks the transcription of ER Ca2+-release channel ryanodine receptor 2. Reduced RyR2 shuts down basal Ca2+ oscillation in Tregs, which reduces m-Calpain activities that is needed for T cells to disengage from DCs, suggesting a persistent blockage of DC antigen presentation. RyR2 deficiency renders the CD4+ T cell pool to become immune suppressive, and behave in the same manner as FoxP3+ Tregs in viral infection, asthma, hypersensitivity, colitis and tumor development. In the absence of FoxP3, RyR2-deficient CD4+ T cells rescue the systemic autoimmunity associated with Scurfy mice. Therefore, FoxP3-mediated Ca2+ signaling inhibition may be a central effector mechanism of Treg immune suppression. One Sentence SummaryCalcium channel RyR2 dictates Treg adhesion-based suppression

immunology↗

Divergence and convergence of cortical encoding during word reading in bilinguals

Word reading includes a series of cognitive processes that convert low-level visual characteristics to neural representations. However, the consistency of the neural mechanisms for processing these cognitive components across different writing systems in bilinguals remains inconclusive. Here, we explored this question by employing representational similarity analysis with a semantic access task involving Chinese words, English words and Chinese pinyin. Distinct anatomical distribution patterns were detected for each type of brain representation across ideographic and alphabetic languages, resulting in 100% classification accuracy. Meanwhile, convergent cognitive components processing was found in the core language-related regions in left hemisphere, including the inferior frontal gyrus, temporal pole, superior and middle temporal gyrus, precentral gyrus and supplementary motor areas. Broadly, our findings indicated that the neural basis for word recognition of different writing systems in bilinguals was divergent in anatomical locations of neural representations for specialized processing but convergent in cognitive domains, which supported and enriched the assimilation-accommodation hypothesis. TeaserCortical encoding linguistic processing across languages was support by parallel interdigitated distributed networks but convergent in cognitive domains.

neuroscience↗

Low frequency somatic copy number alterations in normal human lymphocytes revealed by large scale single-cell whole genome profiling

Genomic-scale somatic copy number alterations in healthy humans are difficult to investigate because of low occurrence rates and the structural variations stochastic natures. Using a Tn5-transposase assisted single-cell whole genome sequencing method, we sequenced over 20,000 single lymphocytes from 16 individuals. Then, with the scale increased to a few thousand single cells per individual, we found that about 7.5% of the cells had large-size copy number alterations. Trisomy 21 was the most prevalent aneuploid event among all autosomal copy number alterations, while monosomy X occurred most frequently in over-30-year-old females. In the monosomy X single cells from individuals with phased genomes and identified X-inactivation ratios in bulk, the inactive X Chromosomes were lost more often than were the active ones.

genomics↗

Inhibition of BET family proteins suppresses African swine fever virus infection

African swine fever (ASF), an acute, severe, highly contagious disease caused by African swine fever virus (ASFV) infection in domestic pigs and boars, has a mortality rate of up to 100%. Because effective vaccines and treatments for ASF are lacking, effective control of the spread of ASF remains a great challenge for the pig industry. Host epigenetic regulation is essential for the viral gene transcription. Bromodomain and extraterminal (BET) family proteins, including BRD2, BRD3, BRD4, and BRDT, are epigenetic "readers" critical for gene transcription regulation. Among these proteins, BRD4 recognizes acetylated histones via its two bromodomains (BD1 and BD2) and recruits transcription factors, thereby playing a pivotal role in transcriptional regulation and chromatin remodeling during viral infection. However, how BET/BRD4 regulates ASFV replication and gene transcription is unknown. Here, we randomly selected 12 representative BET family inhibitors and compared their effects on ASFV infection in pigs primary alveolar macrophages (PAMs). They were found to inhibit viral infection by interfering with the different stages of viral life cycle (attachment, internalization, desencapsidation and formation of viral factories). The four most effective inhibitors (ARV-825, ZL0580, I-BET-762 and PLX51107) were selected for further antiviral activity analysis. These BET/BRD4 inhibitors dose-dependently decreased the ASFV titer, viral RNA transcription and protein production in PAMs. Collectively,our study reported novel activity of BET/BRD4 inhibitors in inducing suppression of ASFV infection, providing insights into role of BET/BRD4 in epigenetic regulation of ASFV and potential new strategies for ASF prevention and control. IMPORTANCESince the continuing spread of the ASFV in the world, and lack of commercial vaccines, the development of improved control strategies including antiviral drugs are urgently needed. BRD4 is an important epigenetic factor and has been commonly used for drug development for tumor treatment. Furthermore, the latest research showed that BET/BRD4 inhibition could suppress replication of virus. In this study, we first showed the inhibitory effect of agents targeting BET/BRD4 on ASFV infection with no significant host cytotoxicity. Then, we found 4 BET/BRD4 inhibitors which can inhibit ASFV replication, RNA transcription and protein synthesis. Finally, we analyzed 4 inhibitors biological effect on BRD4 according to the structure of BRD4, and docking analysis of BET-762, PLX51107, ARV-825 and ZL0580 binding to BD1 and BD2 domains of BRD4 was performed. Our findings support the hypothesis that BET/BRD4 can be considered as attractive host targets in antiviral drug discovery against ASFV.

molecular biology↗

Epigenomic and transcriptomic differences between low-grade and acute inflammation in LPS-induced murine immune cells

Chronic, low-grade inflammation has a widespread and significant impact on health, especially in Western society. While inflammation is beneficial for the removal of microbes, low-grade inflammation never resolves and can cause or worsen other diseases. The process by which low-grade inflammation occurs remains poorly understood. Here we exposed murine bone-marrow derived monocytes to chronic lipopolysaccharide (LPS) stimulation at low dose or high dose, as well as a PBS control. The cells were profiled for genome-wide H3K27ac modification and gene expression. The gene expression of TRAM-deficient and IRAK-M-deficient monocytes with LPS exposure was also analyzed. We discover that low-grade inflammation preferentially utilizes the TRAM/TRIF-dependent pathway of TLR4 signaling, and induces the expression of interferon response genes. In contrast, acute inflammation uniquely upregulates metabolic and proliferative pathways that also appear to be TRAM-dependent. The extensive differences in the epigenomic landscape between low-dose and high-dose conditions suggest the importance of epigenetic regulations in driving differential responses. Our data provide potential targets for future mechanistic or therapeutic studies.

immunology↗