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Biology subjects

Zhang, S.

Publications and source records attributed to Zhang, S..

At least 199 records · Page 11Linked to original sources

Tunable Chemical and Optical Control of ER-Plasma Membrane Contact Site Geometry and Dynamics with High-Fidelity Visualization

Endoplasmic reticulum-plasma membrane (ER-PM) contact sites are essential signaling hubs that regulate lipid transport, calcium homeostasis, and spatially organized signal transduction. Emerging evidence indicates that not only the presence but also the dynamics, stability, and geometry of ER-PM contacts critically shape cellular functions; however, tools that enable simultaneous high-fidelity visualization and reversible, quantitative control of these contacts in living cells remain limited. Here, we introduce a modular toolkit for inducible ER-PM contact-site reconstitution based on complementary chemical and optical dimerization strategies. We develop a nontoxic and reversible abscisic acid (ABA)-inducible system using the plant-derived ABIcs/PYLcs pair, and a rapidly reversible optogenetic system based on the iLID/SspB module, both of which allow robust visualization and dose-dependent control over contact-site formation kinetics, increasing contact-site density and total area fraction per cell without altering the size of individual contacts. In contrast, systematic variation of rigid -helical linker length or inducible tether abundance selectively tunes the lateral growth, stability, and lifetime of individual contact sites, without changing their density. By combining these two orthogonal strategies, we achieve independent control of both individual contact-site size and overall contact-site density, providing complementary mechanisms to adjust total contact area per cell. This versatile platform enables quantitative dissection of ER-PM contact site structure-function relationships and offers broad utility in studies of lipid exchange, calcium signaling, membrane repair, metabolic regulation, and disease-relevant dysregulation.

bioengineering↗

RLBWT-Based LCP Computation in Compressed Space for Terabase-Scale Pangenome Analysis

Lossless full text indexes are utilized in a myriad of applications in bioinformatics. The continuously decreasing cost of generating biological data has resulted in the need to build full text indexes on biological datasets of increasing size. Many compressed full text indexes have been developed to address this problem. In particular, run-length Burrows-Wheeler transform (RLBWT) based compressed full text indexes have seen wide development and adoption. However, the construction of these RLBWT-based compressed full text indexes is still computationally expensive, sometimes prohibitively so, even for current dataset sizes. Therefore, we present algorithms for the construction of RLBWT-based compressed full text indexes and their supporting data structures in compressed space. The algorithms have a space complexity of O(r) words and run in O(n) time for repetitive datasets, where r is the number of runs in the BWT, n is the length of the text, and repetitive datasets implies the average run length is at least log n. We provide the first algorithm to compute LCP-related information for repetitive datasets in optimal time and O(r) space, greatly reducing memory requirements. The key idea behind this algorithm is the utilization of r samples of the inverse suffix array at regular intervals. For example, on the Human Pangenome Reference Consortium Release 2 dataset, this reduces peak memory from 2,135 GiB to 170 GiB (12.6x reduction) compared to the previous best method (pfp-thresholds). AvailabilityThe implementation is available at https://github.com/ucfcbb/TeraTools. Supplementary InformationSupplementary Material is available online at bioRxiv.

bioinformatics↗

A Modularized Stretchable Microneedle Array for Minimally Invasive and Efficient Drug Delivery

A novel Modularized Stretchable Microneedle Array (MSMA) is developed for minimally invasive and efficient drug delivery. By applying a modular design, the MSMA can be highly customized, offering versatility for different therapeutic applications. Its high stretchability allows for simultaneous stretching of both the microneedle and the skin, enhancing the penetration rate. Evaluations using tissue-mimicking materials and porcine skin demonstrated significant improvements in penetration efficiency and reduced residual strain. The MSMA achieved penetration rates of up to 89% on porcine skin under a minimum push-down distance of 2 mm. Moreover, the MSMAs ability to stretch and release in synchronization with the skin significantly reduces residual strain. This innovative platform promises reduced pain and discomfort, representing a substantial advancement in transdermal drug delivery technology.

bioengineering↗

AI-Based Methods for Cryptic Pocket Detection Are Fast and Qualitative Compared to Quantitatively Predictive Simulations

Identifying and understanding cryptic pockets remains a compelling goal in drug discovery, as they can offer new avenues for targeting proteins that are otherwise challenging to modulate. While artificial intelligence (AI) methods for structure prediction have been revolutionary, they have not learned enough physics to characterize the rest of a proteins conformational ensemble, such as structures with cryptic pockets. This limitation has motivated the development of new AI-based methods for characterizing ensembles, or properties thereof, such as AlphaFlow, BioEmu, PocketMiner, and CryptoBank. Here, we benchmark how well these models and physics-based molecular dynamics (MD) simulations can recapitulate the thermodynamics of known cryptic pockets in Ebola VP35 and TEM {beta}-lactamase. These two pockets were chosen because the probability that they are open and the impact of point mutations have been well characterized experimentally. Multiple methods are remarkably successful at predicting whether a mutation will increase or decrease the probability of cryptic pocket opening. However, none can reliably predict the absolute probability of pocket opening. MD is very close for the two wild-type proteins but all the methods struggle for pockets with small probabilities of opening experimentally (e.g. less than 1%). BioEmu and PocketMiner capture some trends between variants with experimental populations over 1% but have systematic errors and poorer performance for rare pockets (e.g. <1% open experimentally). These results highlight the promise of AI- and simulation-based strategies for cryptic pocket characterization while pointing to the need for further improvements to achieve robust predictors.

biophysics↗

Joint Segmental Duplication Co-option Drives Human-specific Transcriptional Readthrough and Expression Fine-tuning of NPEPPS-TBC1D3

Segmental duplication (SD) is a major driver of functional changes in evolution and disease. Many genes embedded within SDs, such as NPEPPS and TBC1D3, display substantial copy number variation (CNV) across individuals. Yet, the precise identification of the functional copies and their transcriptional outputs remains largely unstudied. Focusing on NPEPPS and TBC1D3, we illustrate human-specific expression fine-tuning mechanisms associated with readthrough transcripts. We identified a human-specific NPEPPS-TBC1D3 digenic genomic structure that originated from a joint SD pair and became fixed across populations. Experiments demonstrate that this structure generates NPEPPS-TBC1D3 readthrough transcripts, which are the predominant isoforms of TBC1D3 expression in various cell types, fine-tuning its protein level. Furthermore, a human-specific hypomethylation signal within an upstream CpG island of NPEPPS precisely pinpoints the expressed TBC1D3 paralog. Moreover, we reveal transcriptional readthrough events are [~]3-fold enriched for joint-SD-associated transcriptional readthrough (JSDTR) and identify 109 JSDTR gene pairs, including neurodevelopmentally important pairs and clinically interesting SERF1A/B-SMN1/2. Taken together, our findings comprehensively describe an example of how a joint SD event shaped evolution and suggest that JSDTR is a broad mechanism for the emergence of new functions.

genetics↗

Identification and inhibition of the Cyclin D Rb-docking interface that drives cell division

The animal cell division cycle is initiated by the cyclin-dependent kinases CDK4 and CDK6 in complex with D-type cyclins. Cyclin D-CDK4/6 complex formation is promoted by the assembly factors p21 and p27, which bind both subunits. p27 binds the hydrophobic patch on cyclin D that is similar to the patch used by other cell cycle cyclins to dock their substrates. This raised the question as to how cyclin D could find its substrates if its hydrophobic patch were already occupied? Here, we show that D-type cyclins use their A2 helix to dock the retinoblastoma protein Rb, a key substrate regulating cell cycle progression. The specific interface of cyclin Ds A2 helix is unique among cyclins and its mutation slows proliferation. Taken together, our work identifies a cyclin D-substrate docking mechanism that can be targeted by novel cancer therapeutics.

biochemistry↗

Synthetic Data to Explore Transcriptional Regulation of Differentially Expressed Genes in Ovarian Cancer

In major diseases like cancer, many genes are dysregulated. While differential expression (DE) analyses help identify these genes, they do not reveal the transcriptional regulatory landscape between control and disease states. Here, we developed a process-driven model based on generalized stochastic transcriptional regulation (TR) to study DE genes in ovarian cancer. We generated over 39,000 synthetic gene expression profiles based on RNA-seq dataset of 11 samples (5 control FTE and 6 ovarian cancer), and fitted the model parameters to real data achieving between 82% and 99% transcriptome-wide similarity through various data analytics. Through the model we investigated the top 100 DE genes transcriptional regulation. Notably, GSTA3, SNTN, DNAI2 and KIF19, which have been associated with cancer, possess significantly larger transcriptional quantal and RNA degradation rates, leading to their greater variability in cancer. This mechanistic understanding could potentially guide gene-targeted interventions for cancer or other diseases in the future.

systems biology↗

A Bear-Specific Coding Exon in TMEM41B Is Associated with Cold Adaptation

AbstractBears exhibit an unusual form of hibernation in which core body temperature remains relatively high despite profound suppression of whole-body metabolism. How such a warm yet hypometabolic state is achieved remains poorly understood. Here, through integrative analysis of 238 RNA-seq datasets spanning seven species, we identify transmembrane protein 41B (TMEM41B) as an evolutionarily conserved factor associated with thermogenic capacity. Loss of Tmem41b in mice and Drosophila results in severe cold intolerance, whereas its overexpression enhances thermogenic performance, supporting a conserved role in heat production. Comparative genomic analyses reveal a bear-specific 51-amino acid N-terminal extension in TMEM41B, arising from a 5' untranslated region mutation that converts a premature stop codon into coding sequence. Interactome profiling indicates that this bear-specific isoform differs from the canonical TMEM41B in its protein interaction landscape, including reduced association with components of mitochondria-associated endoplasmic reticulum membranes such as voltage-dependent anion-selective channel protein 1 (VDAC1). Consistent with this altered interaction profile, the extended isoform is associated with reduced mitochondrial oxidative activity. Functional analyses further suggest that the 51- amino acid extension modulates multiple cellular programs, including suppression of oxidative phosphorylation and myogenic differentiation alongside activation of osteogenic pathways, collectively biasing cells toward a hypometabolic state. Notably, expression of the polar bear TMEM41B isoform in mice induces a torpor-like phenotype under fasting conditions. Together, these findings identify TMEM41B as a conserved regulator of thermogenic capacity and suggest that evolutionary modification of its N terminus may contribute to metabolic suppression and energy conservation during bear hibernation.

evolutionary biology↗

The overall and sequence-specific degradation of soil extracellular 16S rRNA genes across China: rates and influential factors

While extracellular DNA persistence substantially influences soil microbiome investigations, its degradation kinetics remain poorly quantified. Here, we developed a primer-labeled DNA approach coupled with microcosm incubation to determine the overall and sequence-specific degradation rates of extracellular DNA amplicon fragments across China. We observed substantial variations in the overall degradation rates of extracellular 16S rRNA gene amplicon fragments among the study sites, with degradation rate constants ranging from 0.05 to 0.16 day-1. The overall degradation rate constants showed significant correlations with soil moisture content, prokaryotic abundance, prokaryotic community profiles, and mean annual precipitation (MAP). The significant influences of moisture content on the overall degradation rates were further verified by a moisture gradient microcosm experiment. The sequence-specific degradation rate constant profiles were additionally correlated with pH, nitrogen content, and mean annual temperature (MAT). Furthermore, propidium monoazide (PMA)-based exclusion of extracellular DNA signals significantly altered soil prokaryotic abundance, richness, and prokaryotic community profiles, and the pool sizes of sequence-specific extracellular 16S rRNA gene amplicon fragments were significantly correlated with their respective degradation rates. This study developed a methodology for determining the overall and sequence-specific degradation rates of extracellular DNA amplicon fragments, highlighting the profound influences of extracellular DNA on soil microbial research and informing the optimization of environmental DNA technologies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=116 SRC="FIGDIR/small/699460v2_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@b1b3e2org.highwire.dtl.DTLVardef@98f334org.highwire.dtl.DTLVardef@1870650org.highwire.dtl.DTLVardef@1af7105_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗

Templating and confining calcium phosphate mineralization within designed protein assemblies

Bone formation involves the deposition of ordered hydroxyapatite (HAp) on collagen fibrils, but the underlying molecular mechanisms remain largely unresolved, limiting the design of protein-apatite hybrid materials. Here we show that computationally designed de novo proteins can template and confine HAp mineralization. We design C3-symmetric oligomers with inner surfaces chemically complementary to the HAp {010} facet, and assemble these through additional interfaces into D3 oligomers, one-dimensional nanotubes, and two-dimensional arrays. Electron microscopy revealed templated mineralization and confinement at each hierarchical level, with mineral shape guided by the underlying protein architecture. Conversion of an initially formed amorphous phase to HAp is driven by the designed protein-mineral interface. Our results establish a framework for programmable protein-guided mineralization, providing a foundation for next-generation hybrid materials.

biochemistry↗

Antiviral drug synergy and mutational signatures in different epithelial cell models of RSV and hPIV infection

Despite the huge global health burden presented by respiratory viruses, effective broad-spectrum antiviral therapeutic options remain limited. Here we evaluated the antiviral activity of four RNA-dependent RNA polymerase (RdRp) inhibitors, remdesivir, ribavirin, favipiravir, and molnupiravir, against respiratory syncytial virus (RSV) and human parainfluenza (hPIV) using monotherapy or dual-drug combinations with epithelial cell lines and primary human airway culture models. Remdesivir showed the greatest potency across both viruses, while ribavirin and favipiravir also demonstrated inhibition. Molnupiravir was active against RSVA but not hPIV3. Several dual-drug combinations, including remdesivir-favipiravir, remdesivir-molnupiravir and favipiravir-molnupiravir, produced marked synergy against RSVA, and more limited synergy for hPIV3. Antiviral efficacy was validated in primary airway epithelial cultures, where effective concentrations preserved epithelial integrity and attenuated viral disruption of ciliary function. Across both viruses, increasing antiviral exposure was associated with dose-dependent signature mutagenesis. Importantly, antivirals induced significantly higher RSVA mutation burden in the primary airway model. These findings highlight the therapeutic potential of RdRp inhibitor combinations for RSVA and hPIV3, provide mechanistic insight through antiviral-related mutational signatures and demonstrate advantages of the primary human airway culture model for development of effective multi-drug regimens and broad-spectrum antiviral preparedness. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=106 SRC="FIGDIR/small/699296v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1eb00dforg.highwire.dtl.DTLVardef@186358forg.highwire.dtl.DTLVardef@265181org.highwire.dtl.DTLVardef@1b10d0e_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Development of Integrin α5β1-targeted PET/NIR imaging probes for glioblastoma intraoperative navigation and intracavity targeted radionuclide therapy

Incomplete extent of tumor resection is the major factor of glioblastoma recurrence, leading to its poor prognosis. Developing therapies that enable the minimal tumor cell remnant during surgical resection is a major challenge to combat this aggressive cancer. This study develops a glioblastoma integrin 5{beta}1-selective peptide binder through series strategy screening and labeling it with 68Ga, indocyanine green (ICG), or 177Lu for efficacious multimodal treatment. This strategy combines positron emission tomography (PET) imaging for preoperative diagnosis, intraoperative NIR-II fluorescence-guided surgery for maximal tumor resection, and followed by intracavity targeted radionuclide therapy for elimination of residual tumor cells. We identified GR, with five arginine mutation, exhibiting superior integrin 5{beta}1 binding affinity and brain penetration. [68Ga]GR demonstrated substantial tumor uptake and prolonged retention time in both mouse models and tissues from glioblastoma patients. The guidance of ICG-GR achieved accurately intraoperative tumor imaging and maximal tumor resection in orthotopic mouse glioblastoma models. Notably, combining intracavity administration of [177Lu]GR following ICG-GR guiding resection markedly inhibited tumor growth and reduced possibility of tumor recurrence compared with surgery alone (unguided or ICG-GR-guided) or unguided surgery followed by [177Lu]GR. Therefore, we have reported the integrin 5{beta}1-targeted radionuclide and optical agents for maximal elimination of tumor cells during surgical resection in glioblastoma patients. HIGHLIGHTSO_LIGR is a glioblastoma-specific peptide with both favorable binding affinity superior brain penetration. C_LIO_LIICG-GR is a glioblastoma-targeted NIR probe enabling maximal surgical resection. C_LIO_LIICG-GR-guided surgery with [177Lu]GR-based adjuvant therapy allows robust elimination of tumor cells. C_LI

cancer biology↗

Platelet C5aR1 Aggravates Myocardial Infarction through Platelet-Neutrophil Interactions and CXCL4-Dependent NET Release

Platelet activation is a central driver of myocardial infarction. The complement anaphylatoxin C5a is abundantly generated during myocardial infarction, and its receptor C5aR1 is highly expressed on platelets. However, the functional role of platelet C5aR1 in myocardial infarction (MI) remains unknown. Here, we show that platelet&[ndash]expressed C5aR1 critically amplifies thromboinflammatory cardiac injury by promoting platelet&[ndash]mediated neutrophil activation after MI. Platelet&[ndash]specific C5aR1 deletion reduced infarct size, fibrosis, and adverse remodeling while enhancing neovascularization and preserving cardiac function. Mechanistically, cell&[ndash]specific C5aR1 deletion markedly reduced myocardial platelet&[ndash]neutrophil accumulation and neutrophil extracellular trap (NET) formation, while circulating platelet&[ndash]neutrophil complexes were increased. Ex vivo, C5a&[ndash]stimulated platelets robustly induced NET release from neutrophils in a platelet C5aR1&[ndash] and CXCL4&[ndash]dependent manner, whereas platelets lacking C5aR1 failed to trigger NET formation. Pharmacological C5aR1 inhibition with PMX205 phenocopied the genetic platelet&[ndash]specific deletion, resulting in comparable cardioprotection. Together, these findings identify platelet C5aR1 as a druggable target of platelet&[ndash]neutrophil&[ndash]NET signaling that exacerbates myocardial injury and limits reparative healing after MI, highlighting platelet C5aR1 as a potential therapeutic approach to restrain thromboinflammation.

immunology↗

Ac-FAPI-04 Promotes Anti-tumor Immunity via IL-27 Activation and Tnfaip3 Inhibition

BackgroundAccumulating evidence substantiates the capacity of targeted radionuclide therapy (TRT) to potentiate tumor immunotherapy responses. However, combining TRT and immunotherapies exhibits substantial varying efficacy, underscoring the importance of investigating mechanisms through which TRT remodels the tumor microenvironment (TME). Despite recent advancements, the specific signaling molecules mediated by TRT that regulate the functions of cytotoxic T lymphocytes (CTLs) remain unclear. MethodsGiven the demonstrated potential of -radionuclides targeting the fibroblast activation protein (FAP) in TRT, this study employed [225Ac]Ac-FAPI-04 to investigate the mechanisms of TRT-induced TME remodeling. The cytotoxic effects were first evaluated in the B16F10 cell line, followed by an assessment of its in vivo therapeutic efficacy in tumor-bearing mice. RNA-sequencing analysis was utilized to elucidate underlying signaling pathways involving immune responses. Results[225Ac]Ac-FAPI-04 significantly induced DNA double-strand breaks, further elevated ROS levels, and apoptosis in tumor cells. Transcriptomic profiling revealed that [225Ac]Ac-FAPI-04 activates the IL-27/JAK-STAT pathway to amplify interferon-mediated responses, indicating IL-27 serves as a critical regulatory signal for CTLs during TRT. A concomitant observation was the downregulation of Tnfaip3 following [225Ac]Ac-FAPI-04 treatment. Tnfaip3 is implicated in modulating CTLs behavior and intratumoral infiltration, while its downregulation was associated with the upregulation of cytotoxic effector molecules, as confirmed in this study. ConclusionThis study identifies a TRT-induced pattern of synergistic signaling mediated by IL-27 and Tnfaip3, which collectively enhances CTL recruitment and potentiates their cytotoxic function. These findings provide a detailed mechanistic rationale for strategies aimed at augmenting the therapeutic efficacy of TRT and immunotherapy combinations.

molecular biology↗

Unlocking Ultrasensitive Phosphoproteomics of Nanoscale Samples: A Rapid IMAC Enrichment Platform Using Ti-PAN Tip

Protein phosphorylation is a critical mechanism in cellular signal transduction, playing essential roles in various cellular processes. However, significant challenges of their low abundance, high dynamic range, and complexity are especially prominent for accurate phosphoproteome analysis in nanoscale samples, such as oocytes, where misregulation of phosphorylation can lead to infertility. In this study, we developed a novel phosphopeptide enrichment tip (Ti-PAN) using highly hydrophilic textile PAN fibers, enabling rapid in-situ one-tip IMAC enrichment in just 8 minutes. This approach not only minimizes sample loss but also enhances analytical sensitivity and is easily adaptable to automation for high-throughput applications, demonstrating excellent recovery (>94%) and outstanding selectivity for phosphopeptides with remarkable resistance to interference up to 1:5000. By integrating it with a compatible sample preparation workflow based on n-dodecyl {beta}-D-maltoside (DDM) lysis with the high-sensitivity MS data acquisition method of turboDDA, comprehensive mapping of phosphosites in microsamples was achieved, including those from the ERK interactome, mouse brain slices, and oocytes. Using this approach, we identified 2,139 to 11,296 phosphosites across 645 to 2,168 phosphoproteins from samples ranging from 100 to 100,000 cells. Furthermore, we successfully applied this strategy to analyze the phosphoproteome of mouse oocytes at different developmental stages, using as few as 5 oocytes per sample. This led to the identification of 2,709 phosphosites on 701 phosphoproteins, revealing several key kinases involved in meiotic resumption and oocyte maturation, including STK4 (serine/threonine kinase 4) and DYRK3 (dual specificity tyrosine phosphorylation-regulated kinase 3). To our knowledge, this represents the deepest coverage of phosphoproteomes from such minimal oocyte material reported to date, offering valuable mechanistic insights into developmental controls during oocyte maturation. This Ti-PAN-based method provides a robust, versatile, and automatable platform for large-scale, highly sensitive phosphopeptide enrichment, substantially advancing phosphoproteomic studies in complex biological systems.

biochemistry↗

All-in-one Single-Cell Proteomic Analysis of Protein Alterations in Human Oocytes Undergoing in Vitro Aging

Study questionWhat specific proteomic changes and molecular markers associated with in vitro aging occur in human oocytes? Summary answerSingle-cell proteomic analysis revealed the protein dynamics during the in vitro aging of oocytes. Subsequent functional analysis highlighted key biological processes affected in aged oocytes and identified several genes as candidate key factors for oocyte and early embryo quality. What is known alreadyOvulated oocytes undergo a time-dependent degradation process if fertilization does not occur within a specific window. This aging process leads to morphological, molecular, and epigenetic changes that can compromise oocyte quality and subsequent embryo development. In previous studies, transcriptome sequencing in humans and mice has revealed serial changes in aging oocytes including oxidative stress, mitochondrial dysfunction, DNA damage, and alterations in cell cycle regulation. These changes can lead to apoptosis, chromosomal abnormalities, and epigenetic modifications, all of which negatively affect oocyte quality. However, research regarding protein level changes and regulatory mechanisms in human oocytes during in vitro aging remains unclear. Study design, size, durationUtilizing "All-in-one" single-cell proteomics, we investigated the protein expression levels in human oocytes at the germinal vesicle (GV) stage and metaphase II (M II) stage following 24 hours of in-vitro aging. We analyzed four groups of oocytes: fresh GV (n=8), in vitro-aged GV (n=9), fresh M II (n=11), and in vitro-aged M II (n=11). This approach allowed for a detailed comparison of proteomic changes associated with in vitro aging in oocytes at different developmental stages. Participants/materials, setting, methodsOocytes at GV and MII stage were collected for "All-in-one" single-cell quantitative proteomic respectively. Differentially expressed genes were analyzed using the R package DESeq2 or DEP (filtered with q-value[&le;]0.05 and Foldchange[&ge;]1.5). EGSEA package was used to perform pathway analysis. Main results and the role of chanceThe proteomic analysis of fresh and in vitro-aged human GV and MII oocytes identified 3,268 proteins. In GV oocytes, compared to fresh samples, 73 proteins were upregulated and 90 were downregulated. Gene Ontology (GO) enrichment analyses revealed these DEPs were involved in key biological processes such as lysosome organization, spindle assembly and oxidative stress response. Gene Set Enrichment Analysis (GSEA) revealed a significant down regulation of genes associated with protein translation initiation and methylation pathways, while those in the apoptosis mitochondrial changes were upregulated. In MII oocytes, 63 proteins were upregulated and 69 were downregulated. GO analysis highlighted their involvement in cytoplasmic translation, ribosome biogenesis and oocyte development. GSEA showed that aged MII oocytes exhibited a downregulation of gene sets in protein translation but an upregulation in membrane fusion pathways compared to fresh oocytes. Furthermore, we identified proteins with consistent expression trends across both GV and MII stages, including MRFAP1 and MT2A, as candidate biomarkers for human oocyte aging in vitro. Limitations, reasons for cautionSingle cell proteomic techniques may not fully capture the dynamic range of proteins present within oocytes, leading to potential underrepresentation of low-abundance proteins that could play crucial roles. Furthermore, the heterogeneity within oocytes introduces variability that can obscure the identification of consistent proteomic signatures associated with oocyte quality or aging. Wider implications of the findingsThese findings not only provide an understanding of the protein changes underlying the in vitro aging of human oocytes but also offer potential biomarkers and intervention targets for future research and clinical applications in assisted reproductive technologies. Study funding/Competing interest(s)This project received funding from the National Natural Science Foundation of China (NO.82471693, 22574175); the Natural Science Foundation of Hunan Province (NO. 2024JJ4100), the Hunan Provincial Grant for Innovative Province Construction (2019SK4012), the Hundred Youth Talents Program of Hunan Province (to S.Z.), the Major Scientific Program of CITIC Group (No. 2023ZXKYB34100) and Scientific Research Foundation of Reproductive and Genetic Hospital of CITIC-XIANGYA (YNXM-202313, YNXM-202319, YNXM-202211). The authors have no conflicts of interest to declare.

developmental biology↗

Gene networks associated with early endosperm proliferation and basal endosperm layer differentiation in maize

Endosperm is a primary source of food and feed globally. Early developmental events including proliferation and cell differentiation in this dedicated seed sink structure are expected be responsive to the availability of photoassimilates and in turn to affect seed size and quality. However, the gene regulatory programs underlying early development of cereal endosperm remain largely unknown. We profiled the maize (Zea mays) endosperm transcriptome during the first four days after pollination using laser-capture microdissection and identified multiple temporal co-expression modules including a subset activated upon fertilization. Our analysis of the associated cis-regulatory elements and co-expressed transcription factor (TF) families enabled us to construct a gene network regulating basal endosperm transfer layer (BETL) differentiation through MYB-related (MYBR) transcription factors and a network of E2F TFs for early endosperm proliferation. We found a significant association of the BETL network with kernel size variation and a contribution of the Glucose-target-of-rapamycin (TOR)-dependent processes to the E2F-mediated regulation of endosperm proliferation. Using the available data, we propose early proliferative development and transfer cell differentiation in endosperm are coordinated via sugar-sensing inputs to ultimately control seed size. Our analysis can guide the development of strategies for improvement of seed composition and yield.

plant biology↗

Multi-task spatial omics analytics for high-precision modeling of tissue architecture with STAX

The rapid advancement of spatial omics technology has revolutionized biomedical research, unveiling unprecedented insights into the molecular and cellular architecture of biological systems. Despite this progress, a critical limitation arises from the widespread use of disparate analytical tools within a single workflow, leading to inconsistencies caused by heterogeneous preprocessing pipelines and extensive method-specific hyperparameter tuning. To this end, we aim to unify diverse analytical tasks within a multi-task learning platform, STAX, for diverse spatial omics types. STAX excels across numerous critical applications, including spatial domain identification, spatial slice integration, cohort-level spatial analysis, spatial spot completion, cell-gene co-embedding, expression profile denoising, and 3D spatial multi-slice simulation. Extensive evaluations demonstrate that STAX consistently delivers superior performance, robustness, and biologically meaningful interpretations, establishing it as an indispensable tool for spatial omics research. In short, STAX effectively addresses multiple analytical challenges in spatial omics, empowering researchers with a unified platform to accelerate biomedical discoveries and deepen understanding of complex biological systems.

bioinformatics↗