Biology subjects

Zhang, R.

Publications and source records attributed to Zhang, R..

At least 289 records · Page 16Linked to original sources

bioRxiv2024

YAP promotes chromosomal instability by transcriptionally activating AJUBA through its super enhancer in breast cancer

Chromosomal instability (CIN) has been proven to be a fundamental property of cancer and a key underlying mechanism of tumorigenesis and progression. Still, relatively few studies have revealed the mechanism of this process. In this research, we identified the core Hippo component, YAP, played a crucial role in CIN formation in breast cancer. Using public ChIP-seq data and bioinformatic analysis, we found YAP could transcriptionally induce spindle assembly checkpoint, AJUBA, via TEAD, then activate AJUBA-AURKA signaling. Abolish AJUBA-AURKA axis could reverse YAP-induced CIN formation and aberrant mitosis. Mechanically, YAP/TEAD complex could accumulate to the super enhancer region of AJUBA, thus significantly induced its expression, and subsequently promoted AURKA auto-phosphorylating. These findings revealed a novel cross-talk between Hippo and AJUBA-AURKA signaling, and provided a new insight in CIN formation in breast cancer.

cancer biology↗

bioRxiv2024

Mechanism Study on the Effect of Kidney Tonifying and Liver Soothing Methods on Mouse Oocyte Quality by Regulating OSFs and Smads Pathways

Objective: To observe the effects of kidney tonifying and liver soothing methods on the secretion of factor BMP-6, related receptors ALK-2/6, and downstream Smads pathway Smad1/5/844 in oocytes, and to explore the targeted mechanisms of their effects on mouse oocyte quality; Method: Healthy female mice aged 6-7 weeks were randomly divided into 6 groups, namely high and low dose kidney tonifying groups; High - and low-dose liver soothing groups; Control group and normal group. The high-dose and low-dose groups of tonifying the kidney were given oral solution of tonifying the kidney and regulating the meridian at 5.4g/ml and 2.7g/ml, respectively. The high-dose and low-dose groups of soothing the liver were given suspension of Xiaoyao Pill at 0.6g/ml and 0.3g/ml, respectively. The control group and normal group were given distilled water by gavage. Immunohistochemistry and Western blot were used to detect the expression of BMP-6, ALK-2/6, and Smad1/5/8/4 proteins in oocytes, while PCR was used to detect the mRNA expression of these indicators in oocytes; Result: Both methods can increase the expression of BMP-6 in oocytes of mice in the treatment group, activate ALK-2/6, and phosphorylate Smad1/5/8 to bind with Smad4, initiating signal transduction; The high-dose group of kidney tonifying is superior to other groups in regulating BMP-6, ALK-2/6, and Smad1/5/4. Conclusion: Kidney tonifying and liver soothing methods can regulate BMP-6 and its Smads pathway through different mechanisms to improve mouse oocyte quality.

synthetic biology↗

bioRxiv2024

PackDock: a Diffusion Based Side Chain Packing Model for Flexible Protein-Ligand Docking

Structure-based drug design (SBDD) relies on accurate knowledge of protein structure and ligand-binding conformations. However, most of the static conformations obtained by advanced methods such as structural biology and de novo protein folding algorithms often dont meet the needs for drug design. We introduce PackDock, a flexible docking method that combines "conformation selection" and "induced fit" mechanisms in a two-stage docking pipeline. The core module of this method is PackPocket, which uses a diffusion model to explore the side-chain conformation space in ligand binding pockets, both with or without a ligand. We evaluate our method using several tests that reflect real-world application scenarios. (1) Side-chain packing and Re-docking experiments validate the ability of PackDock to predict accurate side-chain conformations and ligand conformations. (2) Cross-docking experiments with apo and non-homologous ligand-induced holo structures align with real docking scenarios, demonstrating PackDocks practical value. (3) Docking experiments with hypothetical models show that PackPocket can potentially conduct SBDD starting from protein sequence information only. Additionally, we found that PackDock can identify key amino acid conformation changes, which may provide insights for lead compound optimization. We demonstrate PackDock can accurately predict the complex conformations in various application scenarios, by combining the conformation selection theory and the induced fit theory, and by using the ability of PackPocket to accurately predict the side chain conformations in the pocket region. We believe this method can improve the usability of existing structures, providing a new perspective for the SBDD community.

bioinformatics↗

bioRxiv2024

A multi-institutional study to investigate the sparing effect after whole brain electron FLASH in mice: Reproducibility and temporal evolution of functional, electrophysiological, and neurogenic endpoints

PurposeUltra-high dose-rate radiotherapy (FLASH) has been shown to mitigate normal tissue toxicities associated with conventional dose rate radiotherapy (CONV) without compromising tumor killing in preclinical models. A prominent challenge in preclinical radiation research, including FLASH, is validating both the physical dosimetry and the biological effects across multiple institutions. MethodsWe previously demonstrated dosimetric reproducibility of two different electron FLASH devices at separate institutions using standardized phantoms and dosimeters. In this study, we compared the outcome of FLASH and CONV 10 Gy whole brain irradiation on female adult mice at both institutions to evaluate the reproducibility and temporal evolution of multiple endpoints. ResultsFLASH sparing of behavioral performance on novel object recognition (4 months post-irradiation) and electrophysiologic long-term potentiation (LTP, 5-months post-irradiation) was reproduced between institutions. Interestingly, differences between FLASH and CONV on the endpoints of hippocampal neurogenesis (Sox2, doublecortin), neuroinflammation (microglial activation), and electrophysiology (LTP) at late times were not observed at early times. ConclusionsIn summary, we demonstrated reproducible FLASH sparing effects between two beams and two institutions with validated dosimetry. FLASH sparing effects on the endpoints evaluated manifested at late but not early time points.

cancer biology↗

bioRxiv2024

Synthetic integrin antibodies discovered by yeast display reveal αV subunit pairing preferences with β subunits

Eight of the 24 integrin heterodimers bind to the tripeptide Arg-Gly-Asp (RGD) motif in their extracellular ligands, and play essential roles in cell adhesion, migration, and homeostasis. Despite similarity in recognizing the RGD motif and some redundancy, these integrins can selectively recognize RGD-containing ligands including fibronectin, vitronectin, fibrinogen, nephronectin and the prodomain of the transforming growth factors to fulfill specific functions in cellular processes. Subtype-specific antibodies against RGD-binding integrins are desirable for investigating their specific functions. In this study, we discovered 11 antibodies that exhibit high specificity and affinity towards integrins V{beta}3, V{beta}5, V{beta}6, V{beta}8, and 5{beta}1 from a synthetic yeast-displayed Fab library. Of these, 6 are function-blocking antibodies containing an R(G/L/T) D motif in their CDR3 sequences. We report antibody binding specificity, kinetics, and binding affinity for purified integrin ectodomains as well as intact integrins on the cell surface. We further employed these antibodies to reveal binding preferences of the V subunit for its 5 {beta}-subunit partners: {beta}6={beta}8>{beta}3>{beta}1={beta}5.

cell biology↗

bioRxiv2024

Integrative Omics Uncovers Low Tumorous Magnesium Content as A Driver Factor of Colorectal Cancer

Magnesium (Mg) deficiency is associated with increased risk and malignancy of colorectal cancer (CRC), yet the underlying mechanisms remain elusive. Here we used genomic, proteomic, and phosphoproteomic data to elucidate the impact of Mg deficiency on CRC. Genomic analysis identified 160 genes with higher mutation frequencies in Low-Mg tumors, including key driver genes such as KMT2C and ERBB3. Unexpectedly, initiation driver genes of CRC, such as TP53 and APC, displayed higher mutation frequencies in High-Mg tumors. Additionally, proteomics and phosphoproteomics indicated that low tumorous Mg content may activate epithelial-mesenchymal transition (EMT) by modulating inflammation or remodeling the phosphoproteome of cancer cells. Notably, we observed a negative correlation between the phosphorylation of DBN1 at S142 (DBN1S142p) and Mg content. A mutation in S142 to D (DBN1S142D) mimicking DBN1S142p upregulated MMP2 and enhanced cell migration, while treatment with MgCl2 reduced DBN1S142p, thereby reversing this phenotype. Mechanistically, Mg2+ attenuated the DBN1-ACTN4 interaction by decreasing DBN1S142p, which, in turn, enhanced the binding of ACTN4 to F-actin and promoted F-actin polymerization, ultimately reducing MMP2 expression. These findings shed new light on the crucial role of Mg deficiency in CRC progression and suggest that Mg supplementation may offer a promising preventive and therapeutic strategy for CRC.

cancer biology↗

bioRxiv2024

Rim4 is a Meiotic Thermal Sensor and Drives Biogenesis of Stress Granules

Rim4 is a meiosis-specific RNA-binding protein (RBP) that sequesters mRNAs to suppress their translation. Previous work has defined the Rim4 C-terminal low-complexity domain (LCD) as sequences that form self-propagating amyloid-like aggregates. Here, we uncovered a dynamic and reversible form of Rim4 self-assembly primarily triggered by heat during meiosis, proportionally from 30{degrees}C to 42{degrees}C. The formed thermal Rim4 condensates in cell promptly stimulates stress granule (SG) assembly, recruiting SG-resident proteins, such as Pab1 and Pbp1, and strikingly, decreases the required temperature for meiotic SG formation ([~]33{degrees}C) by [~]9{degrees}C as compared to mitosis ([~]42{degrees}C). This sensitization of meiotic SG formation to heat effectively prevents meiosis progression and sporulation under harmful thermal turbulence. Meanwhile, the Rim4-positive meiotic SGs protect Rim4 and Rim4-sequestered mRNAs from autophagy to allow a rapid recovery from stalled meiosis upon the stress relief. Mechanistically, we found that the yeast 14-3-3 proteins (Bmh1 and Bmh2) and nucleic acids brake initiation of heat-induced Rim4 self-assembly, and Hsp104 facilitates the restoration of intracellular Rim4 distribution during the recovery.

cell biology↗

bioRxiv2024

Morphological deficits of glial cells in a transgenic mouse model for developmental stuttering

Vocal production involves intricate neural coordination across various brain regions. Stuttering, a common speech disorder, has genetic underpinnings, including mutations in lysosomal-targeting pathway genes. Using a Gnptab-mutant mouse model linked to stuttering, we examined neuron and glial cell morphology in vocal production circuits. Our findings revealed altered astrocyte and microglia processes in these circuits in Gnptab-mutant mice, while control regions remained unaffected. Our results shed light on the potential role of glial cells in stuttering pathophysiology and highlight their relevance in modulating vocal production behaviors.

cell biology↗

bioRxiv2024

HortGenome Search Engine, a universal genomic search engine for horticultural crops

Horticultural crops comprising fruit, vegetable, ornamental, beverage, medicinal and aromatic plants play essential roles in food security and human health, as well as landscaping. With the advances of sequencing technologies, genomes for hundreds of horticultural crops have been deciphered in recent years, providing a basis for understanding gene functions and regulatory networks and for the improvement of horticultural crops. However, these valuable genomic data are scattered in warehouses with various complex searching and displaying strategies, which increases learning and usage costs and makes comparative and functional genomic analyses across different horticultural crops very challenging. To this end, we have developed a lightweight universal search engine, HortGenome Search Engine (HSE; http://hort.moilab.net), which allows querying genes, functional annotations, protein domains, homologs, and other gene-related functional information of more than 400 horticultural crops. In addition, four commonly used tools, including BLAST, Batch Query, Enrichment analysis, and Synteny Viewer, have been developed for efficient mining and analysis of these genomic data.

bioinformatics↗

bioRxiv2024

G-quadruplexes as pivotal components of cis-regulatory elements in the human genome

Cis-regulatory elements have the ability to precisely regulate gene expression in cells, and G-quadruplexes (G4s), as non-canonical secondary structures, may potentially play a role in this regulation. However, a lack of systematic studies exists to uncover the connection between these two elements. Here, we comprehensively characterized the associations between G4s and human candidate cis-regulatory elements (cCREs) inferred from the Encyclopedia of DNA Elements (ENCODE) data. Our findings demonstrate that G4s are prominently enriched in most types of cCREs, particularly in elements with promoter-like signatures (PLS). Furthermore, we observed that the co-occurrence of CTCF signals with H3K4me3 or H3K27ac signals significantly strengthens the association between cCREs and G4s. This association becomes more pronounced when examining cell type-specific cCREs and G4s. Interestingly, compared to cCREs, genetic variants occurring in G4s, especially within their G-runs, often exhibit higher regulatory potential and deleterious effects. Runs of several consecutive guanines (G-runs) in the vicinity of transcriptional start sites tend to be more constrained in mammalian evolution than cCREss G-runs. Besides, the presence of G4s, is often linked to a more favorable local chromatin environment for the activation and execution of regulatory functions of cCREs, potentially attributable to the formation of G4 secondary structures. Finally, we discovered that G4-associated cCREs exhibit widespread activation in a variety of cancers. Altogether, our study suggests that G4s are integral components of human cis-regulatory elements, and the G4 primary sequences are associated with the localization of the cCREs, while the G4 structures are linked to the activation of the cCREs. Therefore, we propose to define G4s as pivotal regulatory elements in the human genome.

genomics↗

bioRxiv2023

Profiling cellular heterogeneity and fructose transporter expression in the rat nephron by integrating single-cell and microdissected tubule segment transcriptomes

Single-cell RNA sequencing (scRNAseq) is a crucial tool in kidney research. These technologies cluster cells according to transcriptome similarity, irrespective of the anatomical location and ordering within the nephron. Thus, a cluster transcriptome may obscure heterogeneity of the cell population within a nephron segment. Elevated dietary fructose leads to salt-sensitive hypertension, in part by fructose reabsorption in the proximal tubule (PT). However, organization of the four known fructose transporters in apical PTs (SGLT4, SGLT5, GLUT5 and NaGLT1) remains poorly understood. We hypothesized that cells within each subsegment of the proximal tubule exhibit complex, heterogenous fructose transporter expression patterns. To test this hypothesis we analyzed rat and kidney transcriptomes and proteomes from publicly available scRNAseq and tubule microdissection databases. We found that microdissected PT-S1 segments consist of 81{+/-}12% cells with scRNAseq-derived transcriptional characteristics of S1, whereas PT-S2 express a mixture of 18{+/-}9% S1, 58{+/-}8% S2, and 19{+/-}5% S3 transcripts, and PT-S3 consists of 75{+/-}9% S3 transcripts. The expression of all four fructose transporters was detectable in all three PT segments, but key fructose transporters SGLT5 and GLUT5 progressively increased from S1 to S3, and both were significantly upregulated in S3 vs. S1/S2 (Slc5a10: 1.9 log2FC, p<1x10-299; Scl2a5: 1.4 log2FC, p<4x10-105). A similar distribution was found in human kidneys. These data suggest that S3 is the primary site of fructose reabsorption in both humans and rats. Finally, because of the multiple scRNAseq transcriptional phenotypes found in each segment our findings also imply that anatomic labels applied to scRNAseq clusters may be misleading.

physiology↗

bioRxiv2023

HURP facilitates spindle assembly by stabilizing microtubules and working synergistically with TPX2

In large vertebrate spindles, the majority of microtubules are formed via branching microtubule nucleation, whereby microtubules nucleate along the side of pre-existing microtubules. Hepatoma up-regulated protein (HURP) is a microtubule-associated protein that has been implicated in spindle assembly, but its mode of action is yet to be defined. In this study, we show that HURP is necessary for RanGTP-induced branching microtubule nucleation in Xenopus egg extract. Specifically, HURP stabilizes the microtubule lattice to promote microtubule formation from {gamma}- TuRC. This function is shifted to promote branching microtubule nucleation in the presence of TPX2, another branching-promoting factor, as HURPs localization to microtubules is enhanced by TPX2 condensation. Lastly, we provide a structure of HURP on the microtubule lattice, revealing how HURP binding stabilizes the microtubule lattice. We propose a model in which HURP stabilizes microtubules during their formation, and TPX2 preferentially enriches HURP to microtubules to promote branching microtubule nucleation and thus spindle assembly.

molecular biology↗

bioRxiv2023

SurfDock is a Surface-Informed Diffusion Generative Model for Reliable and Accurate Protein-ligand Complex Prediction

In the field of structure-based drug design, accurately predicting the binding conformation of ligands to proteins is a long-standing objective. Despite recent advances in deep learning yielding various methods for predicting protein-ligand complex structures, these AI-driven approaches frequently fall short of traditional docking methods in practice and often yield structures that lack physical and chemical plausibility. To overcome these limitations, we present SurfDock, an advanced geometric diffusion network, distinguished by its ability to integrate multiple protein representations including protein sequence, three-dimensional structural graphs, and surface-level details into its equivariant architecture. SurfDock employs a generative diffusion model on a non-Euclidean manifold, enabling precise optimization of molecular translations, rotations, and torsions for reliable binding poses generation. Complemented by a mixture density network for scoring using the same comprehensive representation, SurfDock achieves significantly improved docking success rates over all existing methods, excelling in both accuracy and adherence to physical constraints. Equipped with post-docking energy minimization as an optional feature, the plausibility of generated poses is further enhanced. Importantly, SurfDock demonstrates excellent generalizability to unseen proteins and extensibility to virtual screening tasks with state-of-the-art performance. We consider it a transformative contribution that could serve as an invaluable asset in structure-based drug design.

bioinformatics↗

bioRxiv2023

ATAT: Automated Tissue Alignment and Traversal in Spatial Transcriptomics with Self-Supervised Learning

Spatial transcriptomics (ST) has enhanced RNA analysis in tissue biopsies, but interpreting these data is challenging without expert input. We present Automated Tissue Alignment and Traversal (ATAT), a novel computational framework designed to enhance ST analysis in the context of multiple and complex tissue architectures and morphologies, such as those found in biopsies of the gastrointestinal tract. ATAT utilizes self-supervised contrastive learning on hematoxylin and eosin (H&E) stained images to automate the alignment and traversal of ST data. This approach addresses a critical gap in current ST analysis methodologies, which rely heavily on manual annotation and pathologist expertise to delineate regions of interest for accurate gene expression modeling. Our framework not only streamlines the alignment of multiple ST samples, but also demonstrates robustness in modeling gene expression transitions across specific regions. Additionally, we highlight the ability of ATAT to traverse complex tissue topologies in real-world cases from various individuals and conditions. Our method successfully elucidates differences in immune infiltration patterns across the intestinal wall, enabling the modeling of transcriptional changes across histological layers. We show that ATAT achieves comparable performance to the state-of-the-art method, while alleviating the burden of manual annotation and enabling alignment of tissue samples with complex morphologies. AvailabilityATAT is available at: https://github.com/StevenSong/tissue-alignment

bioinformatics↗

bioRxiv2023

Toward Best Practice in Identifying Subtle Differential Expression with RNA-seq: A Real-World Multi-Center Benchmarking Study Using Quartet and MAQC Reference Materials

Translating RNA-seq into clinical diagnostics requires ensuring the reliability of detecting clinically relevant subtle differential expressions, such as those between different disease subtypes or stages. Moreover, cross-laboratory reproducibility and consistency under diverse experimental and bioinformatics workflows urgently need to be addressed. As part of the Quartet project, we presented a comprehensive RNA-seq benchmarking study utilizing Quartet and MAQC RNA reference samples spiked with ERCC controls in 45 independent laboratories, each employing their in-house RNA-seq workflows. We assessed the data quality, accuracy and reproducibility of gene expression and differential gene expression and compared over 40 experimental processes and 140 combined differential analysis pipelines based on multiple ground truths. Here we show that real-world RNA-seq exhibited greater inter-laboratory variations when detecting subtle differential expressions between Quartet samples. Experimental factors including mRNA enrichment methods and strandedness, and each bioinformatics step, particularly normalization, emerged as primary sources of variations in gene expression and have a more pronounced impact on the subtle differential expression measurement. We underscored the pivotal role of experimental execution over the choice of experimental protocols, the importance of strategies for filtering low-expression genes, and optimal gene annotation and analysis tools. In summary, this study provided best practice recommendations for the development, optimization, and quality control of RNA-seq for clinical diagnostic purposes.

genomics↗

bioRxiv2023

SAN: mitigating spatial covariance heterogeneity in cortical thickness data collected from multiple scanners or sites

In neuroimaging studies, combining data collected from multiple study sites or scanners is becoming common to increase the reproducibility of scientific discoveries. At the same time, unwanted variations arise by using different scanners (inter-scanner biases), which need to be corrected before downstream analyses to facilitate replicable research and prevent spurious findings. While statistical harmonization methods such as ComBat have become popular in mitigating inter-scanner biases in neuroimaging, recent methodological advances have shown that harmonizing heterogeneous covariances results in higher data quality. In vertex-level cortical thickness data, heterogeneity in spatial autocorrelation is a critical factor that affects covariance heterogeneity. Our work proposes a new statistical harmonization method called SAN (Spatial Autocorrelation Normalization) that preserves homogeneous covariance vertex-level cortical thickness data across different scanners. We use an explicit Gaussian process to characterize scanner-invariant and scanner-specific variations to reconstruct spatially homogeneous data across scanners. SAN is computationally feasible, and it easily allows the integration of existing harmonization methods. We demonstrate the utility of the proposed method using cortical thickness data from the Social Processes Initiative in the Neurobiology of the Schizophrenia(s) (SPINS) study. SAN is publicly available as an R package.

neuroscience↗

bioRxiv2023

Spatially resolved molecular and cellular atlas of the mouse brain

A comprehensive atlas of genes, cell types, and their spatial distribution across a whole mammalian brain is fundamental for understanding function of the brain. Here, using snRNA-seq and Stereo-seq techniques, we generated a mouse brain atlas with spatial information for 308 cell clusters with single-cell resolution involving over 6 million cells as well as for 29,655 genes. We have identified new astrocyte clusters, and demonstrated that distinct cell clusters exhibit preference for cortical subregions. In addition, we identified 155 genes exhibiting regional specificity in the brainstem, and 513 long non-coding RNA exhibited regional specificity in the adult brain. Parcellation of brain regions based on spatial transcriptomic information showed large overlap with that by traditional method. Furthermore, we have uncovered 411 transcription factor regulons with spatiotemporal specificity during development. Thus, our study has discovered genes and regulon with spatiotemporal specificity, and provided a high-resolution spatial transcriptomic atlas of the mouse brain.

neuroscience↗

bioRxiv2023

Effects of greening-induced warming and cooling on tree phenology in temperate and boreal forests

Tree phenology, periodic biological events in trees, is highly sensitive to climate change. It has been reported that forest greening can influence the local climate by altering the seasonal surface energy budget. However, tree phenological responses to forest greening remains poorly understood at large spatial scales. Combining remote-sensing derived phenological and leaf area indices since 2001, herein we show that forest greening led to earlier spring (-1.05 {+/-} 0.17 d) and autumn phenology (-1.95 {+/-} 0.14 d) in temperate and boreal forests. Our results show that forest greening in winter and spring decreased surface albedo and thus resulted in biophysical warming that caused earlier spring leaf phenology. In contrast, forest greening in summer and autumn triggered biophysical cooling by enhancing evapotranspiration, which led to earlier autumn leaf phenology. These findings suggest that forest greening could significantly alter tree phenology through seasonal biophysical impacts. Therefore, it is essential to incorporate these complicated biophysical impacts of greening into tree phenology models to accurately predict future shifts in tree phenology under future climate change.

ecology↗