bioRxiv Science⌕ Search

Biology subjects

Niu, R.

Publications and source records attributed to Niu, R..

11 recordsLinked to original sources

Gaming Addiction Transmission: Interpersonal Neural Pathways Revealed by HYPER-NESS

Gaming addiction may be contagious through social interaction. In team competitive video games, individuals of varying addiction levels are often paired. This raises the question of whether, and through what mechanisms, one individuals addiction level is affected by other players. Methodologically, addressing this question requires understanding both what happens between brains and within individual brains during a gaming session. To this end, we used HYPER-NESS (Hyper Brain Network Estimation via Source Separation), a novel analytical framework to decompose and weight the distinct contributions of inter-brain and intra-brain processes to social brain networks. We applied this framework to a hyperscanning fNIRS dataset where dyads were scanned while playing a video game together against experimenters. We found that inter-brain and intra-brain contributions to the social brain networks were differentially associated with changes in game reward and social reward sensitivity, depending on the addiction level of ones partner. Granger causality analysis of both social and individual brain networks revealed influences from the high-addiction partner to low-addiction partner. Furthermore, significant cross-frequency coupling was found selectively between low-addiction players, supporting the idea that this form of inter-brain interactions underpins the joint processing of task-relevant rewards. To our knowledge, these findings provide the first neural-level account for the hypothesis that gaming addiction propagates though dyadic social interaction.

neuroscience↗

Dual regulation of the receptor-like kinase BIR1 involves site-directed transcript cleavage and 5-leader-mediated translational control

In Arabidopsis, receptor-like kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE 1 (BAK1)-INTERACTING RECEPTOR-LIKE KINASE 1 (BIR1) is a negative regulator of plant immunity and cell death. BIR1 was earlier described as a target of epigenetic and post-transcriptional silencing. Degradome analysis mapped predominant mRNA cleavage sites at the 5-untranslated leader region (site A) and the protein-coding sequence (sites B and C). Here, we identified another cleavage site (D) within the BIR1 coding region and investigated the contribution of site-directed mRNA cleavage to BIR1 regulation. Mutations at B, C, and D sites enhanced mRNA stability by impairing transcript cleavage, resulting in increased BIR1 mRNA and protein accumulation. This regulation is disrupted in RNA silencing mutants, supporting a model of cis-directed small interfering RNA (siRNA)-mediated degradation. Cleavage events are highly localized, occurring at a limited number of sites that involve only a few siRNAs. Furthermore, our data reveal a repressive role for the 5-leader in regulating BIR1 translation, potentially mediated by upstream open reading frames (uORFs) and a long non-coding RNA (lncRNA) derived from the natural antisense At4g39838 locus. This lncRNA is complementary to a TCA-rich repeat region encompassing cleavage site A, which may serve as a putative binding site. Together, these findings reveal a multilayered regulatory mechanism that integrates sRNA-mediated cleavage with translational control, with broader implications for the fine-tuning of stress-responsive gene expression during infection.

plant biology↗

LoFT-TCR: A LoRA-based Fine-tuning Framework for TCR-Antigen Binding Prediction

T cells recognize and eliminate diseased cells by binding their T cell receptors (TCRs) to short endogenous peptides (antigens) presented on the cell surface. Such interactions are central to adaptive immunity, yet current experimental approaches to identify TCR-antigen binding pairs remain labor-intensive and constrained by limited reagents. Here, we propose LoFT-TCR, a low-rank adaptation (LoRA)-based fine-tuning framework designed for TCR-antigen binding prediction. To capture precise and informative sequence representations, we first fine-tuned the protein large language model ESM-2 on antigen-specific TCR datasets using LoRA. Subsequently, we constructed a heterogeneous interaction graph where nodes encode sequence features and edges indicate interaction relationships. By leveraging a graph learning framework, LoFT-TCR effectively integrates sequence and topological information to enhance prediction capability. Systematic experiments validated that fine-tuning ESM-2 significantly enhanced the models capability to extract discriminative sequence representations, which are critical for accurate TCR specificity prediction. Moreover, LoFT-TCR consistently achieved superior performance compared to state-of-the-art methods on both TCR-antigen binding prediction and TCR specificity discrimination tasks. Experimental results demonstrate that LoFT-TCR achieves substantial improvements in predictive accuracy and holds potential for advancing personalized T cell-based immunotherapy.

immunology↗

RNA helicase Ddx21 safeguards fetal HSPC expansion by recruiting Kdm5a to epigenetically sustain ribosomal and hematopoietic gene transcription

Fetal hematopoietic stem and progenitor cells (HSPCs) require active ribosome biogenesis to sustain their rapid proliferation, yet how non-structural ribosomal factors regulate this process remains unclear. Here, we identify the RNA helicase Ddx21 as a critical determinant of fetal hematopoiesis through its epigenetic role in maintaining active ribosomal transcription. Conditional knockout of Ddx21 in murine fetal hematopoietic cells resulted in severe anemia, fetal liver hypoplasia, and depletion of HSPCs, accompanied by erythroid maturation arrest. Mechanistically, Ddx21 deficiency disrupted ribosomal and hematopoietic gene expressions, impaired translational capacity, and activated p53 pathway, triggering cell cycle arrest and apoptosis. While p53 inhibition partially rescued proliferation defects, it failed to restore rRNA transcription, pointing to p53-independent mechanisms. Multi-omics profiling revealed that Ddx21 interacts with the histone demethylase Kdm5a, co-occupying active promoters marked by H3K4me3. Loss of Ddx21 diminished H3K4me3 levels at ribosomal DNA (rDNA) and hematopoietic genes such as cKit and Gata1, downregulating their transcription. Strikingly, Kdm5a inhibition restored rRNA expression and protein translation in Ddx21-deficient cells, and combined inhibition of Kdm5a and p53 cooperatively rescued HSPC function. These findings demonstrate a paradigm wherein Ddx21 couples ribosome biogenesis to epigenetic regulation by sequestering Kdm5a at active chromatin, thereby preserving transcriptional output essential for fetal hematopoietic expansion.

cell biology↗

TridentTCR: Predicting T Cell Receptor Specificity for Antigens and Autoimmune-Related Targets via a Topology-Aware Graph and Large Language Model

T cells recognize and eliminate diseased cells by binding their T cell receptors (TCRs) to short endogenous peptides presented on the cell surface, commonly referred to as antigens. Accurate prediction of antigen-TCR specificity is essential for advancing T cell-based immunotherapies while minimizing autoimmune toxicity. However, current computational methods struggle to generalize across diverse TCR repertoires and reliably differentiate therapeutic antigens from autoimmune-related antigens (arAgs). Here, we introduce TridentTCR, a computational framework integrating a pretrained large language model (LLM) for high-fidelity sequence embedding with a topology-aware graph neural network to capture structural insights from the antigen-TCR interaction network. TridentTCR significantly advances TCR specificity prediction by enabling robust trinary classification, distinguishing TCR interactions involving general antigens, arAgs, and non-binding. Additionally, TridentTCR outperforms existing state-of-the-art models in binary classification (binding vs. non-binding). Validation on independent clinical datasets demonstrated strong generalization capability for unseen TCRs and antigens. In a disease-specific context, TridentTCR identifies notable cross-reactivity between ZnT8186-194-specific TCRs and a mimotope from Bacteroides stercoris, suggesting that T cell cross-reactivity may contribute to the initiation of type 1 diabetes. Furthermore, we introduced a quantitative metric, antigenic immune response entropy (AIRE), which leverages TridentTCR predictions alongside clonotype frequencies and repertoire diversity to precisely quantify antigen-specific immune responses from single-cell profiling data. Collectively, TridentTCR provides an interpretable and clinically relevant tool, enabling improved understanding of TCR specificity, cross-reactivity, and off-target autoimmune risks in clinical immunotherapy.

immunology↗

Targeted degradation of endogenous condensation-prone proteins improves crop performance

Effective methods, such as CRISPR and RNA interference, exist for modulating gene expression at DNA and RNA levels, but approaches for directly modifying endogenous proteins remain lacking in plants. Here, we develop a targeted condensation-prone-protein degradation (TCD) strategy to eliminate endogenous proteins, particularly those prone to condensation. We identify an E3 ligase, E3TCD1, that degrades itself but selectively targets other proteins when fused to them. In rice, transgenic E3TCD1 fusions with Teosinte branched 1 and Early flowering 3 (OsELF3) modulate tiller numbers and flowering times, respectively. The TCD system is also controllable. Using the ProTBF1-uORFsTBF1 expression control cassette, we can conditionally degrade the negative defense regulator OsELF3 upon pathogen invasion, enhancing rice resistance without interfering with rice flowering time. This method, unlike animal-targeting strategies, does not rely on small molecules, antibodies, or genetic knock-ins, showing promise as a gene therapeutic avenue for optimizing crop performance and potentially addressing human diseases.

plant biology↗

Nothing but lies: improving the validity of neural predictors of deception

Deception is a universal human behavior. Yet longstanding skepticism about the validity of measures used to understand the biological mechanisms underlying deceptive behavior has relegated such studies to the scientific periphery. Here we address these fundamental questions by applying novel machine learning methods and functional neuroimaging to signaling games capturing motivated deception in human participants. First, we develop an approach to test for the presence of confounding processes and thereby validate past skepticism by showing that much of the predictive power of neural predictors trained on deception data comes from confounding processes. Second, we show that the presence of confounding signals need not be fatal, and we improve the validity of our neural predictor via a novel machine learning procedure that identifies and removes these confounding signals. Together, these findings point to a scientific approach for studying a neglected class of behavior, with important methodological and societal implications.

neuroscience↗

Social buffering switches fear to safety encoding by oxytocin recruitment of central amygdala "buffer neurons"

The presence of a companion can reduce fear, but the precise neural mechanisms underlying this social buffering of fear (SBF) are incompletely known. We studied SBF encoding in the amygdala of rats that were fear-conditioned (FC) to auditory conditioned stimuli (CS). Pharmacological, opto,- and/or chemogenetic interventions showed that oxytocin (OT) signaling from hypothalamus-to-central amygdala (CeA) projections was required for acute fear reduction in the presence, and SBF retention 24h later in the absence of the companion. Single-unit recordings with optetrodes revealed fear-encoding CeA neurons (characterized by increased CS responses after FC) were inhibited by SBF and blue light (BL) stimulation of OTergic projections. Other CeA neurons developed CS responses only after SBF that persisted during SBF retention. Their baseline activity was enhanced by BL and exposure to the companion. SBF thus switches the CS from encoding "fear" to "safety" by OT-mediated recruitment of a distinct group of CeA "buffer neurons".

neuroscience↗

Lower shear stress exacerbates atherosclerosis by inducing the generation of neutrophil extracellular traps via Piezo1-mediated mechanosensation

BACKGROUNDAtherosclerosis is a chronic lipid-driven inflammatory disease, largely influenced by hemodynamics. Neutrophil extracellular traps (NETs)-mediated inflammation plays an important role in atherosclerosis. However, little is known about the mechanism of the generation of NETs under different shear stress and subsequent damage to endothelial cells. We sought to identify a novel mechanical signal provokes NETs generation and to investigate its potential role in atherosclerosis. METHODSApoE-/- mice were fed with high-fat diet (HFD) to induce atherosclerosis. The model of lower shear stress (LSS) with a partial ligation of the left carotid artery was established to assess the role of LSS in NETs generation and atherosclerotic lesions development. Furthermore, the underlying mechanism of LSS promoting NETs generation and injuring endothelial cells was deciphered in neutrophil-like human promyelocytic leukemia (HL-60) cells in parallel-plate flow chamber. RESULTSWe found that LSS correlated spatially with both NETs and atherosclerosis, while inhibition of NETosis could significantly reduce plaque formation in ApoE-/- mice. In vitro, LSS could promote NETs generation directly through down-regulation of Piezo1, a mechanosensitive ion channel. downexpression of Piezol could activate neutrophils and promote NETosis in static. Conversely, Yoda1-evoked activation of Piezo1 attenuated LSS-induced NETosis. Mechanistically, the downexpression of Piezo1 resulted in decreased Ca2+ influx and increased histone deacetylase 2 (HDAC2), which increase reactive oxygen species levels, then led to NETosis. LSS-induced NETs generation promoted the apoptosis and adherence of endothelial cells. CONCLUSIONSLSS directly promotes NETosis through piezo1-HDAC2 axis in atherosclerosis progression. This study uncovers the essential role of Piezo1-mediated mechanical signaling in NETs generation and plaque formation, which provides a promising therapeutic strategy for atherosclerosis. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/small/529165v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@583911org.highwire.dtl.DTLVardef@aa3e2org.highwire.dtl.DTLVardef@8d83e5org.highwire.dtl.DTLVardef@ce55a0_HPS_FORMAT_FIGEXP M_FIG C_FIG Proposed mechanism for lower shear stress LSS exacerbating atherosclerosis. LSS stimuli decrease Piezo1 expression in the neutrophils, resulting in decreased intracellular Ca2+ concentration, as well as the higher expression level of HDAC2, which could activate oxidative stress and promote intracellular reactive oxygen species formation, and ultimately lead to NETs generation. NETs could aggravate endothelial cells injury and exasperate atherosclerosis. Highlights{blacksquare} Lower shear stress (LSS) promotes Neutrophil extracellular traps (NETs) formation, which is critical for lipid deposits and plaque formation in Atherosclerosis. {blacksquare}Atherosclerotic plaque formation was significantly reduced in the aorta of high fat diet fed ApoE-/- mice intraperitoneal injected with NETs inhibitor, GSK484, especially in the lower shear stress regions. {blacksquare}Piezo1 is a key molecule in the process of neutrophils sense lower shear stress. {blacksquare}lower shear stress inhibits the activation of Piezo1 and promotes NETosis through piezo1-HDAC2 axis. {blacksquare}LSS-induced NETs promote the apoptosis and adhesion of endothelial cells.

cell biology↗

Dendritic cell CX3CR1 and macrophages F4/80 play a central role in between gut micro biome and inflammation in Arsenic induced mice

Microbiota plays a crucial role to protect the intestine contrary to the harmful foreign microorganisms and organize the immune system via numerous mechanisms, which include either direct or indirect environmental factors. The underlying mechanism arsenic (As) influenced immune system and regulates inflammation by altering gut microbiome in ileum remains unclear. However, chronic exposure to arsenic (at doses of 0.15 mg or 1.5 mg or 15 mg As2O3/ L in drinking water) significantly increased mRNA and protein levels of F4/80 and CX3CR1, concurrently, the increased levels of mRNA and protein IFN{gamma}, TNF, IL-18 and decreased levels of IL-10 were found in both 3 and 6 months exposure periods. High-throughput sequencing analysis revealed that gut microbiota at phylum; family and taxonomical levels were showed the abundance of gut microbiota. Evidentially, the ultra-structure of intestinal villi, microbes engulfed and immune cell migration were showed by the transmission electron microscopy. Chronic exposure to As influenced the inflammation by changing immune system and altered gut microbiota. In this study we conclude that chronic exposure to As breakdown the normal gut microbial community and increase the pathogenicity, the resultant risk pathogen direct contact with intestinal immune system and regulate the inflammation.

molecular biology↗

uORFlight: a vehicle towards uORF-mediated translational regulation mechanisms in eukaryotes

Upstream open reading frames (uORFs) are prevalent in eukaryotic mRNAs. They act as a translational control element for precisely tuning the expression of the downstream major open reading frame (mORF) with essential cellular functionalities. uORF variation has been clearly associated with several human diseases. In contrast, natural uORF variants in plants have not ever been identified or linked with any phenotypic changes. The paucity of such evidence encouraged us to generate this database-uORFlight (http://uorflight.whu.edu.cn). It facilitates the exploration of uORF variation among different splicing models of Arabidopsis and rice genes. Most importantly, users can evaluate uORF frequency among different accessions at the population scale and find out the causal single nucleotide polymorphism (SNP) or insertion/deletion (INDEL) which can be associated with phenotypic variation through database mining or simple experiments. Such information will help to make hypotheses of uORF function in plant development or adaption to changing environments on the basis of the cognate mORF function. This database also curates plant uORF relevant literature into distinct groups. To be broadly interesting, our database expands uORF annotation into more species of fungi (Botrytis cinerea), plant (Brassica napus, Glycine max, Gossypium raimondii, Medicago truncatula, Solanum lycopersicum, Solanum tuberosum, Triticum aestivum and Zea mays), metazoan (Caenorhabditis elegans and Drosophila melanogaster) and vertebrate (Homo sapiens, Mus musculus and Danio rerio). Therefore, uORFlight will light up the runway toward how uORF genetic variation determines phenotypic diversity and advance our understanding of translational control mechanisms.

genomics↗