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Biology subjects

He, S.

Publications and source records attributed to He, S..

At least 109 records · Page 6Linked to original sources

Squidiff: Predicting cellular development and responses to perturbations using a diffusion model

Single-cell sequencing has revolutionized our understanding of cellular heterogeneity and responses to environmental stimuli. However, mapping transcriptomic changes across diverse cell types in response to various stimuli and elucidating underlying disease mechanisms remains challenging. Studies involving physical stimuli, such as radiotherapy, or chemical stimuli, like drug testing, demand labor-intensive experimentation, hindering mechanistic insight and drug discovery. Here we present Squidiff, a diffusion model-based generative framework that predicts transcriptomic changes across diverse cell types in response to environmental changes. We demonstrate Squidiffs robustness across cell differentiation, gene perturbation, and drug response prediction. Through continuous denoising and semantic feature integration, Squidiff learns transient cell states and predicts high-resolution transcriptomic landscapes over time and conditions. Furthermore, we applied Squidiff to model blood vessel organoid development and cellular responses to neutron irradiation and growth factors. Our results demonstrate that Squidiff enables in silico screening of molecular landscapes, facilitating rapid hypothesis generation and providing valuable insights for precision medicine.

bioinformatics↗

Sulfatide deficiency-induced astrogliosis and myelin lipid dyshomeostasis are independent of Trem2-mediated microglial activation

Disrupted lipid homeostasis and neuroinflammation often co-exist in neurodegenerative disorders including Alzheimers disease (AD). However, the intrinsic connection and causal relationship between these deficits remain elusive. Our previous studies show that the loss of sulfatide (ST), a class of myelin-enriched lipids, causes AD-like neuroinflammatory responses, cognitive impairment, bladder enlargement, as well as lipid dyshomeostasis. To better understand the relationship between neuroinflammation and lipid disruption induced by ST deficiency, we established a ST-deficient mouse model with constitutive Trem2 knockout and studied the impact of Trem2 in regulating ST deficiency-induced microglia-mediated neuroinflammation, astrocyte activation and lipid disruption. Our study demonstrates that Trem2 regulates ST deficiency-induced microglia-mediated neuroinflammatory pathways and astrogliosis at the transcriptomic level, but not astrocyte activation at the protein level, suggesting that Trem2 is indispensable for ST deficiency-induced microglia-mediated neuroinflammation but not astrogliosis. Meanwhile, ST loss-induced lipidome disruption and free water retention were consistently observed in the absence of Trem2. Collectively, these results emphasize the essential role of Trem2 in mediating lipid loss-associated microglia-mediated neuroinflammation, but not both astrogliosis and myelin lipid disruption. Moreover, we demonstrated that attenuating neuroinflammation has a limited impact on brain ST loss-induced lipidome alteration or AD-like peripheral disorders. Our findings suggest that preserving lipidome and astrocyte balance may be crucial in decelerating the progression of AD.

neuroscience↗

Differential destinations, dynamics, and functions of high- and low-order features in the feedback signal during object processing

Brain is a hierarchical information processing system, in which the feedback signals from high-level to low-level regions are critical. The feedback signals may convey complex high-order features (e.g., category, identity) and simple low-order features (e.g., orientation, spatial frequency) to sensory cortex to interact with the feedforward information, but how these types of feedback information are represented and how they differ in facilitating visual processing is unclear. The current study used the peripheral object discrimination task, 7T fMRI, and MEG to isolate feedback from feedforward signals in human early visual cortex. The results showed that feedback signals conveyed both low-order features natively encoded in early visual cortex and high-order features generated in high-level regions, but with different spatial and temporal properties. The high-order feedback information targeted both superficial and deep layers, whereas the low-order feedback information reached only deep layers in V1. In addition, MEG results revealed that the feedback information from occipito-temporal to early visual cortex emerged around 200 ms after stimulus onset, and only the representational strength of high-order feedback information was significantly correlated with behavioral performance. These results indicate that the complex and simple components of feedback information play different roles in predictive processing mechanisms to facilitate sensory processing.

neuroscience↗

Disruption of the Novel Nested Gene Aff3ir Mediates Disturbed Flow-Induced Atherosclerosis in Mice

Disturbed shear stress-induced endothelial atherogenic responses are pivotal in the initiation and progression of atherosclerosis, contributing to the uneven distribution of atherosclerotic lesions. This study investigates the role of Aff3ir-ORF2, a novel nested gene variant, in disturbed flow-induced endothelial cell activation and atherosclerosis. We demonstrate that disturbed shear stress significantly reduces Aff3ir-ORF2 expression in athero-prone regions. Using three distinct mouse models with manipulated AFF3ir-ORF2 expression, we demonstrate that AFF3ir-ORF2 exerts potent anti-inflammatory and anti-atherosclerotic effects in ApoE-/- mice. RNA sequencing revealed that interferon regulatory factor 5 (IRF5), a key regulator of inflammatory processes, mediates inflammatory responses associated with AFF3ir-ORF2 deficiency. AFF3ir-ORF2 interacts with IRF5, promoting its retention in the cytoplasm, thereby inhibiting the IRF5-dependent inflammatory pathways. Notably, IRF5 knockdown in AFF3ir-ORF2 deficient mice almost completely rescues the aggravated atherosclerotic phenotype. Moreover, endothelial-specific AFF3ir-ORF2 supplementation using the CRISPR/Cas9 system significantly ameliorated endothelial activation and atherosclerosis. These findings elucidate a novel role for AFF3ir-ORF2 in mitigating endothelial inflammation and atherosclerosis by acting as an inhibitor of IRF5, highlighting its potential as a valuable therapeutic approach for treating atherosclerosis.

cell biology↗

An evolutionarily conserved Hox-Gbx segmentation code in the rice coral Montipora capitata

Segmentation of the gastric cavity is a synapomorphic trait of cnidarians of the class Anthozoa (corals and sea anemones), with different clades forming distinct numbers of segments. In the starlet sea anemone Nematostella vectensis, for example, eight bilaterally positioned gastric segments are generated by the action of a group of Hox-Gbx genes in the developing larval endo-mesoderm. Still, given the range of segment numbers observed in different anthozoans, it remains unclear whether this Hox-Gbx module is evolutionarily conserved and how it might be deployed to generate different numbers of segments. Here, we systematically interrogate the role of Hox-Gbx genes during development of the rice coral Montipora capitata. We first characterize the temporal sequence of segmentation in M. capitata juveniles and then combine transcriptomic profiling and in situ hybridization to identify three conserved homeobox-containing genes, McAnthox8, McAnthox6a.1 and McGbx, which are collectively expressed in the developing endo-mesoderm prior to and during segment formation. The expression boundaries of these genes prefigure the positions of the first six segment boundaries, similar to their Nematostella homologs. Further, we show that chemical inhibition of BMP activity at the planula stage abolishes the expression of Hox-Gbx genes, leading to the formation of an unsegmented gastric cavity. These findings demonstrate the existence of a functionally conserved Hox-Gbx module in evolutionarily divergent anthozoan species, suggesting that the last common ancestor of all anthozoans likely utilized a similar genetic toolkit to axially pattern the endo-mesoderm into metameric subunits.

evolutionary biology↗

BrainUnit: Integrating Physical Units into High-Performance AI-Driven Scientific Computing

Artificial intelligence (AI) is revolutionizing scientific research across various disciplines. The foundation of scientific research lies in rigorous scientific computing based on standardized physical units. However, current mainstream high-performance numerical computing libraries for AI generally lack native support for physical units, significantly impeding the integration of AI methodologies into scientific research. To fill this gap, we introduce BrainUnit, a unit system designed to seamlessly integrate physical units into AI libraries, with a focus on compatibility with JAX. BrainUnit offers a comprehensive library of over 2000 physical units and more than 300 unit-aware mathematical functions. It is fully compatible with JAX transformations, allowing for automatic differentiation, just-in-time compilation, vectorization, and parallelization while maintaining unit consistency. We demonstrate BrainUnits efficacy through several use cases in brain dynamics modeling, including detailed biophysical neuron simulations, multiscale brain network modeling, neuronal activity fitting, and cognitive task training. Our results show that BrainUnit enhances the accuracy, reliability, and interpretability of scientific computations across scales, from ion channels to whole-brain networks, without impacting performance. By bridging the gap between abstract computational frameworks and physical units, BrainUnit represents a crucial step towards more robust and physically grounded AI-driven scientific computing.

neuroscience↗

HBIcloud: An Integrative Multi-Omics Analysis Platform

As biological datasets have grown exponentially in size and complexity, there has been an increasing need for integrative tools that can handle diverse data types and facilitate comprehensive analyses. Traditional methods often require significant computational expertise, creating barriers for many researchers. HBIcloud is a comprehensive online platform designed to facilitate multi-omics data analysis by integrating a wide array of tools across genomics, transcriptomics, proteomics, metabolomics, phenomics, and multi-omics integration. Developed to address the growing complexity and volume of biological data, HBIcloud provides researchers with a powerful and user-friendly resource for conducting sophisticated analyses without the need for extensive programming skills. With a total of 94 tools, the platform offers standardized workflows, extensive parameter options, and rich documentation, catering to the diverse needs of the scientific community. The research behind HBIcloud aimed to create a centralized, user-friendly platform that simplifies the analytical process, enabling researchers to focus on scientific discovery rather than technical challenges. By integrating a wide array of tools and offering extensive support and documentation, HBIcloud addresses the critical need for standardized, reproducible workflows in multi-omics research. This paper presents a detailed overview of HBIcloud, highlighting its development background, key features, and its significant contribution to advancing multi-omics research. Furthermore, we discuss the future prospects of HBIcloud, including planned enhancements and its potential for high citation impact within the scientific community. By providing a robust and versatile platform, HBIcloud aims to accelerate discovery and innovation in the field of multi-omics, fostering collaborative research and expanding the boundaries of biological understanding. The official website of HBIcloud is https://bioinformatics.hainanu.edu.cn/HBIcloud/.

bioinformatics↗

Organoid Modeling and Single-Cell Profiling Uncover the Migration Mechanism of Smooth Muscle Cells in Moyamoya Disease

Moyamoya disease (MMD) is a chronic cerebrovascular disorder characterized by progressive occlusion of the intracranial arteries, resulting in severe ischemic or hemorrhagic stroke. The main characteristic of the affected vessels in MMD is arterial intimal thickening. However, there are no in vitro or in vivo models that can mimic its vascular characteristics. Moreover, the mechanisms underlying the intimal thickening remain unexplained. Here, we generated vascular organoids by differentiating human induced pluripotent stem cell derived from the peripheral blood of MMD patients, thereby creating an organoid model reflecting both the genetic background and characteristics of the affected vessels. Through single-cell sequencing, we found the increased vascular smooth muscle cell (VSMC) proportion and its functional abnormalities in MMD organoids. Proteomics and RNA sequencing identified abnormal TUBA4A and TUBB4B overexpression in both the organoids and patient serum. The following in vitro experiments demonstrated that TUBA4A and TUBB4B promote the contractile-to-synthetic phenotypic switching, migration and proliferation in VSMC. Further experiments identified the GJA1-mediated PI3K/AKT/KLF4 pathway as a key regulating pathway of these phenotypic changes in VSMCs. Our findings demonstrate that the abnormal expression of TUBA4A and TUBB4B in VSMC might be a significant contributor to the intimal thickening in the affected vessels of MMD.

cell biology↗

The Impact of Brain-Derived Neurotrophic Factor rs6265 (Val66Met) Polymorphism on Therapeutic Electrical Stimulation for Peripheral Nerve Regeneration: A Preclinical Study of Therapy-Genotype Interactions

The Impact of Brain-Derived Neurotrophic Factor rs6265 (Val66Met) Polymorphism on Therapeutic Electrical Stimulation for Peripheral Nerve Regeneration: A Preclinical Study of Therapy-Genotype Interactions IntroductionPeripheral nerve injuries (PNIs) significantly impact patient quality of life. Therapeutic electrical stimulation (TES) shows promise in enhancing nerve regeneration, but outcomes vary widely. This study investigates the impact of the rs6265 single nucleotide polymorphism (SNP) on TES efficacy in a preclinical rat model and human stem cell-derived motor neurons. MethodsWild-type (WT) and rs6265 variant rats underwent sciatic nerve transection and received either TES or sham treatment. Muscle reinnervation was assessed through compound muscle action potentials and muscle fiber cross-sectional area. Isogenic human iPSC-derived motor neurons were used to study activity-dependent BDNF secretion. ResultsTES improved muscle reinnervation and fiber size in WT but not rs6265 allele carriers. rs6265 allele carriers exhibited impaired activity-dependent BDNF secretion in vitro. DiscussionThe rs6265 polymorphism influences TES efficacy, highlighting the need for personalized approaches in PNI treatment. These findings suggest that genetic screening could optimize therapeutic outcomes. Clinical RelevanceUnderstanding genetic factors affecting TES response can enhance treatment strategies for PNI, potentially improving patient recovery and reducing outcome variability.

neuroscience↗

GageTracker: a tool for dating gene age by micro- and macro-synteny with high speed and accuracy

With the advent of the Earth Genome Project, an increasing number of species' genomes presents exciting opportunities for exploring genetic and phenotypic diversity in organisms. Determining the origin time of genes facilitates the elucidation of crucial genetic mechanisms underlying significant biological evolutionary questions such as the transition from aquatic to terrestrial life, the emergence of mammals, the origin of humans, as well as the development of species- or lineage-specific traits. However, accurately determining the origin time of these genes in species separated by long evolutionary distances remains a major challenge in bioinformatics as these genes often undergo significant changes in their genome sequences, making it difficult to trace them back to their origin. Here, we proposed a new approach for dating gene age based on the micro- and macro-synteny algorithms. This approach employs the parallel computation of orthologous genome alignments across multiple species. Our method was integrated into the GageTracker (Gene Age Tracker) software, providing a fast and accurate way to trace gene age with minimal user input, available at https://github.com/RiversDong/GageTracker. Benchmarked against the simMammals dataset (Alignathon), GageTracker achieved the same high-quality genome alignments as the optimized LastZ aligner, but improved operation speed by 1.4-7 times. In a separate analysis of 12 Drosophila genomes, GageTracker efficiently assessed the ages of 23,720 genes (including ~13,965 protein-coding genes) in just ~22 hours with default parameters. When comparing with the GenTree database (recognized as the most comprehensive and accurate tool for evaluating gene age), GageTracker achieved an impressive ~94.4% accuracy and ~99% macro consistency in assessing the age of protein-coding genes. Moreover, for the ~5.6% conflicting genes, GageTracker displayed slightly higher support rates than GenTree, as evidenced by data from OrthoDB, FlyBase, and Ensembl ortholog databases. Notably, younger genes identified by GageTracker exhibited a preferential expression pattern in the testis, further reinforcing the reliability of GageTracker in accurately tracing gene age.

bioinformatics↗

Evoked resonant neural activity outperforms spectral markers in decoding sleep from the subthalamic nucleus

BackgroundDeep brain stimulation is a treatment for advanced Parkinsons disease and currently tuned to target motor symptoms during daytime. Parkinsons disease is associated with multiple nocturnal symptoms such as akinesia, insomnia and sleep fragmentation which may require adjustments of stimulation during sleep for best treatment outcome. ObjectivesThere is a need for a robust biomarker to guide stimulation titration across sleep stages. This study aimed to investigate whether evoked resonant neural activity (ERNA) is modulated during sleep. MethodsWe recorded local field potentials from the subthalamic nucleus of four Parkinsons patients with externalised electrodes while applying single stimulation pulses to investigate the effect of sleep on ERNA. ResultsWe found that ERNA features change with wakefulness and sleep stages, and are correlated with canonical frequency bands and heart rate. We further evaluated the performance of machine learning models in classifying non-REM sleep versus wakefulness and found that ERNA amplitude outperforms all spectral markers. ConclusionsGiven the heterogeneity of spectral features during sleep, their susceptibility to movement artefacts and superior classification accuracy of models using ERNA features, this study paves the way for ERNA as a marker for automatic stimulation titration during sleep and improved patient care.

neuroscience↗

Cryo-EM structure and evolutionary history of the conjugation surface exclusion protein TraT

Conjugation plays a major role in dissemination of antimicrobial resistance genes. Following transfer of IncF-like plasmids, recipients become refractory to a second wave of conjugation with the same plasmid via entry (TraS) and surface (TraT) exclusion mechanisms. Here, we show that TraT from the pKpQIL and F plasmids (TraTpKpQIL and TraTF) exhibits plasmid surface exclusion specificity. The cryo-EM structures of TraTpKpQIL and TraTF revealed that they oligomerise into decameric champagne bottle cork-like structures, which are anchored to the outer membrane via a diacylglycerol modified -helical barrel domain. Unexpectedly, we identified chromosomal TraT homologues from multiple Gram-negative phyla which formed numerous deep-branching lineages in a phylogenetic tree of TraT sequences. Plasmid-associated TraT sequences largely cluster into two separate lineages that have more recently evolved, incorporating TraT from Enterobacterales IncF and Legionellaceae F-like plasmids. These findings suggest that different plasmid backbones have acquired and co-opted TraT on independent occasions.

microbiology↗

2'-O-Methyl-guanosine 3-base RNA fragments mediate essential natural TLR7/8 antagonism

Recognition of RNA fragments by Toll-like receptors (TLR) 7 and 8 is a key contributor to the initiation of a protective innate immune response against pathogens. A long-standing enigma is how degradation products of host RNAs, generated by the daily phagocytic clearance of billions of apoptotic cells, fail to activate TLR7 and TLR8 signalling1. Here, we report that select 2-O-methyl (2-Ome) guanosine RNA fragments as short as 3 bases, including those derived from host-RNAs, are potent TLR7 and TLR8 antagonists that reduce TLR7 sensing in vivo. Mechanistically, antagonistic fragments are directed towards a distinct binding site on these proteins by 5-end 2-Ome guanosine. Our results indicate that host-RNAs evade detection by TLR7/8 due to a pool of abundant host ribosomal 2-Ome-modified RNA fragments that naturally antagonize TLR7 and TLR8 sensing to avoid auto-immunity. Crucially, rare TLR7 and TLR8 mutations located at this antagonistic site decrease the inhibitory activity of 2-Ome guanosine RNA fragments and lead to auto-immunity in patients. Our findings also establish that select chemically synthesised 3-base oligonucleotides can harness the protective anti-inflammatory activity of this natural immune checkpoint for therapeutic targeting of TLR7-driven diseases. One Sentence SummaryShort 2-O-Methyl RNA fragments are natural TLR7/8 antagonists

immunology↗

Longevity or Well-being? A Dual-Dimension Structure of Neuroticism

The development of personality traits is often viewed as evolutionarily adaptive. Current neuroticism research, however, predominantly highlights its negative health impacts, neglecting its potential evolutionary advantages. We propose that neuroticisms inter-individual variability can be structured into two distinct geometric dimensions. One, named the Emotional Reactivity-Instability/Distress Spectrum (ERIS), correlates strongly with longevity and is associated with chronic diseases and risk-averse lifestyle. This dimension is underpinned by evolutionarily conserved subcortical brain regions and genes. The other, resembling the overall neuroticism score, is primarily linked to mental and stress-related disorders, as well as life satisfaction. It involves higher-order emotional brain regions and is genetically enriched in human-accelerated regions. Collectively, these dimensions represent a dual-strategy personality framework that optimizes survival and well-being, with the former being evolutionarily conservative and the latter potentially a unique human adaptation.

neuroscience↗

Many erroneous noncoding transcripts in cancer cells can highly specifically regulate cancer-related genes and pathways

Transcription and splicing errors in cancer cells generate erroneous transcripts. Since erroneous transcripts are degraded by the nonsense-mediated mRNA decay (NMD) pathway, whether they are junk or could be functional has been overlooked and understudied. We addressed this question by first performing a pan-cancer analysis and identified substantial erroneous noncoding transcripts (ENT) in cancers. Given that RNA/DNA binding domains (DBD) were predicted in ENTs, we deleted predicted DBDs in multiple ENTs in multiple cell lines, with RNA-sequencing and cell experiments before and after DBD deletion. DBD deletion caused significantly changed expression of ENTs target genes (whose promoter regions contain ENTs DNA binding sites, DBS) and changed cell migration and proliferation ability, indicating that many ENTs can transcriptionally regulate genes. Tightly coupled data analysis and experiments reveal that ENTs functions are highly cancer- and cellular-context specific, making ENTs a new class of safe and specific targets for noncoding RNA-based cancer therapeutics.

genomics↗

Beyond Static Models: The Dynamic Interplay of Facial Emotions and Attentional Scope

The interplay between emotion and attention has long been intensely scrutinized, with competing theories proposing divergent mechanisms. Building on our previous work, here we present evidence that refines these perspectives, revealing a nuanced, temporally dynamic relationship between emotional stimuli and attentional focus. Using a modified Flanker task with facial emotion cues, we demonstrate that the effects of emotional stimuli on attention evolve over time, contrary to traditional fixed-effect assumptions. Our results show distinct temporal patterns: Neutral faces elicited typical flanker effects initially, but only interference persisted later. Early-stage happy faces amplified flanker facilitation but not interference, while threat faces augmented flanker interference but not facilitation. In the late stage, flanker facilitation disappeared across all emotion conditions, and interference patterns converged, mirroring the neutral face condition. These findings indicate emotions influence on attention is more complex and dynamic than previously recognized, potentially reflecting learning or habituation processes. We propose a new framework for understanding emotion-attention interactions that transcends traditional dichotomies of attention focus and approach-avoidance, offering a more nuanced perspective on this critical cognitive interface.

neuroscience↗

Optimizing single-cell RNA sequencing methods for human colon biopsies: droplet-based vs. picowell-based platforms

Background & AimsSingle-cell RNA sequencing (scRNA) has empowered many insights into gastrointestinal microenvironments. However, profiling human biopsies using droplet-based scRNA (D-scRNA) is challenging since it requires immediate processing to minimize epithelial cell damage. In contrast, picowell-based (P-scRNA) platforms permit short-term frozen storage before sequencing. We compared P- and D-scRNA platforms on cells derived from human colon biopsies. MethodsEndoscopic rectosigmoid mucosal biopsies were obtained from two adults and conducted D-scRNA (10X Chromium) and P-scRNA (Honeycomb HIVE) in parallel using an individuals pool of single cells (> 10,000 cells/participant). Three experiments were performed to evaluate 1) P-scRNA with cells under specific storage conditions (immediately processed [fresh], vs. frozen at -20C vs. -80C [2 weeks]); 2) fresh P-scRNA versus fresh D-scRNA; and 3) P-scRNA stored at -80C with fresh D-scRNA. ResultsSignificant recovery of loaded cells was achieved for fresh (80.9%) and -80C (48.5%) P-scRNA and D-scRNA (76.6%), but not -20C P-scRNA (3.7%). However, D-scRNA captures more typeable cells among recovered cells (71.5% vs. 15.8% Fresh and 18.4% -80C P-scRNA), and these cells exhibit higher gene coverage at the expense of higher mitochondrial read fractions across most cell types. Cells profiled using D-scRNA demonstrated more consistent gene expression profiles among the same cell type than those profiled using P-scRNA. Significant intra-cell-type differences were observed in profiled gene classes across platforms. ConclusionsOur results highlight non-overlapping advantages of P-scRNA and D-scRNA and underscore the need for innovation to enable high-fidelity capture of colonic epithelial cells. The platform-specific variation highlights the challenges of maintaining rigor and reproducibility across studies that use different platforms.

genomics↗

Human birth tissue products as a regenerative medicine to inhibit post-surgical pain through multi-modal action

Pain after surgery causes significant suffering. Opioid analgesics cause severe side effects and accidental death. Therefore, there is an urgent need to develop non-opioid therapies for managing post-surgical pain. Local application of Clarix Flo (FLO), a human amniotic membrane (AM) product, attenuated established post-surgical pain hypersensitivity without exhibiting known side effects of opioid use in mice. This effect was achieved through direct inhibition of nociceptive dorsal root ganglion (DRG) neurons via CD44-dependent pathways. We further purified the major matrix component, the heavy chain-hyaluronic acid/pentraxin 3 (HC-HA/PTX3) from human AM that has greater purity and water solubility than FLO. HC-HA/PTX3 replicated FLO-induced neuronal and pain inhibition. Mechanistically, HC-HA/PTX3 induced cytoskeleton rearrangements to inhibit sodium current and high-voltage activated calcium current on nociceptive neurons, suggesting it is a key bioactive component mediating pain relief. Collectively, our findings highlight the potential of naturally derived biologics from human birth tissues as an effective non-opioid treatment for post-surgical pain. Moreover, we unravel the underlying mechanisms of pain inhibition induced by FLO and HC-HA/PTX3.

neuroscience↗