Biology subjects

Zhang, C.

Publications and source records attributed to Zhang, C..

At least 325 records · Page 18Linked to original sources

bioRxiv2024

PepMSND: Integrating Multi-level Feature Engineering and Comprehensive Databases to Enhance in vivo/in vitro Peptide Blood Stability Prediction

Deep learning technology has revolutionized the field of peptides, but key questions such as how to predict the blood stability of peptides remain. While such a task can be accomplished by experiments, it requires much time and cost. Here, to address this challenge, we collect extensive experimental data on peptide stability in blood from public databases and literature and construct a database of peptide blood stability that includes 635 samples. Based on this database, we develop a novel model called PepMSND, integrating KAN, Transformer, GAT and SE(3)-Transformer to make multi-level feature engineering to make peptide stability prediction. Our model can achieve the ACC of 0.8672 and the AUC of 0.9118 on average and outperforms the baseline models. This work can facilitate the development of novel peptides with strong stability, which is crucial for their therapeutic use in clinical applications.

bioinformatics↗

bioRxiv2024

Temperature-sensitive cortical condensation modulates mechano-response at Tricellular Junctions

A general mechanism to maintain epithelial integrity during cell movements is to couple adhesion strength with mechanical force. Mechanosensitive proteins are recruited to adhesion sites to reinforce cell-cell or cell-matrix linkage in response to elevated tension. However, subcellular mechanisms for highly dynamic protein transport into and out of tension-bearing structures remain elusive. Furthermore, it is still unknown whether mechanosensitivity can be modulated by physiological signals in vivo. Here we revealed a direct "edge-to-vertex" route of Canoe/Afadin transport to tricellular junctions under tension, which relies on an obligatory binding partner Mbt/PAK. Without Mbt/PAK, Canoe/Afadin becomes insensitive to cytoskeletal tension and forms "tactoid-shaped" condensates directly at bicellular junctions. Remarkably, a temporary increase in temperature within the physiological range dissolves these condensates, allowing Canoe/Afadin to regain mechanosensitivity and enrichment at tricellular junctions. Functionally, the localization of Mbt/PAK at cell junctions oscillates during synchronous cell division within embryonic mitotic domains, enabling dynamic adjustments of Canoe/Afadin mechanosensitivity to preserve epithelial integrity in rapidly dividing tissues. Collectively, our findings suggest a physiological process in which the state of protein condensation, regulated by biochemical inputs, can supersede mechanical signals to modulate adhesion strength during cell division.

cell biology↗

bioRxiv2024

NCPepFold: Accurate Prediction of Non-canonical Cyclic Peptide Structures via Cyclization Optimization with Multigranular Representation

Artificial intelligence-based peptide structure prediction methods have revolutionized biomolecular science. However, restricting predictions to peptides composed solely of 20 natural amino acids significantly limits their practical application, as such peptides often demonstrate poor stability under physiological conditions. Here, we present NCPepFold, a computational approach that can utilize a specific cyclic position matrix to directly predict the structure of cyclic peptides with non-canonical amino acids. By integrating multi-granularity information at the residue- and atomic-level, along with fine-tuning techniques, NCPepFold significantly improves prediction accuracy, with the average peptide RMSD for cyclic peptides being 1.640 [A]. In summary, this is a novel deep learning model designed specifically for cyclic peptides with non-canonical amino acids without length restrictions, offering great potential for peptide drug design and advancing biomedical research.

bioinformatics↗

bioRxiv2024

Harnessing the FBXW7 somatic mutant R465C for targeted protein degradation

Targeted protein degradation (TPD) is a pharmacological strategy that eliminates specific proteins from cells by harnessing cellular proteolytic degradation machinery. In proteasome-dependent TPD, expanding the repertoire of E3 ligases compatible with this approach could enhance the applicability of this strategy across various biological contexts. In this study, we discovered that a somatic mutant of FBXW7, R465C, can be exploited by heterobifunctional compounds for targeted protein degradation. This work demonstrates the potential of utilizing mutant E3 ligases that occur exclusively in diseased cells for TPD applications.

biochemistry↗

bioRxiv2024

Cycledesigner Leveraging RFdiffusion and HighFold to Design Cyclic Peptide Binders for Specific Targets

Cyclic peptides are potentially therapeutic in clinical applications, due to their great stability and activity. Yet, designing and identifying potential cyclic peptide binders targeting specific targets remains a formidable challenge, entailing significant time and resources. In this study, we modified the powerful RFdiffusion model to allow the cyclic peptide structure identification and integrated it with ProteinMPNN and HighFold to design binders for specific targets. This innovative approach, termed cycledesigner, was followed by a series of scoring functions that efficiently screen. With the combination of effective cyclic peptide design and screening, our study aims to further broaden the scope of cyclic peptide binder design.

bioinformatics↗

bioRxiv2024

Enalapril mitigates aging by targeting antioxidative genes via phosphorylated Smad1/5/9

Aging increases the risk of a myriad of chronic diseases, which are expensive and difficult to treat owing to their various risk factors. Repurposing existing medications has accelerated the development of therapies aimed at slowing aging. In this study, we revealed that enalapril, a drug widely prescribed for hypertension, can improve both cellular senescence and individual health. Mechanistically, phosphorylated Smad1/5/9 act as pivotal mediators of the anti-senescence properties of enalapril. It stimulates downstream genes involved in cell cycle regulation and antioxidative defense, facilitating cell proliferation and diminishing the production of reactive oxygen species (ROS), thus increasing the antioxidative ability of enalapril. At the organismal level, enalapril has been shown to bolster the physiological performance of various organs; it notably enhances memory capacity and renal function and relieves lipid accumulation. Our work highlights the potential of enalapril to augment antioxidant defenses and combat the effects of aging, thereby indicating its promise as a treatment strategy for aging-associated diseases and its use for healthy aging.

cell biology↗

bioRxiv2024

Genome Organization with CUT and Tag (GO-CaT) identifies substructure and maturation of lamina-associated domains in neurons of the developing human brain

Approximately 30-40% of the human genome is anchored to the nuclear lamina (NL) through variably sized (10 kb-10 Mb) lamina-associated domains (LADs), which can be classified into two subtypes (T1 and T2) based on their level of lamina-association. The dynamics of LAD substructure in cells that remain postmitotic for long periods of time are poorly understood. Here, we developed Genome Organization with CUT and Tag (GO-CaT) to determine the T1- and T2-LAD substructure of postmitotic excitatory neurons isolated from the prenatal and adult human cortex. While T1-LADs exhibited epigenomic features characteristic of stable, cell type-invariant LADs including strong transcriptional repression, in prenatal neurons, T2-LADs were enriched for promoter-enhancer DNA interactions, intermediate levels of gene expression, and genetic risk associated with neurodevelopmental and cognitive disorders. In adult cortical neurons, T1-LADs were expanded in size and genomic coverage, incorporating the majority of the prenatal T2-LADs, sequestering genes involved in neurodevelopment. In contrast, the minority of prenatal T2-LADs that relocated to inter-LAD regions in adult neurons were enriched for processes related to synaptic function. Overall, these data provide evidence that LADs "mature" in postmitotic neurons, remodeling from a genomic architecture that is more permissive for the dynamics of transcription of development to one that is more restricted and focused on the decades-long transcriptional needs of adult brain neurons.

genomics↗

bioRxiv2024

Bwa, an ortholog of alkaline ceramidase-ACER2, promotes intestinal stem cell proliferation through pro-inflammatory cytokine signaling in Drosophila melanogaster

Sphingolipids, including ceramides, are an important component of high-fat diets. These molecules can regulate fatty acid oxidation and intestinal stem cell proliferation, predisposing the gut to tumorigenesis. However, the molecular mechanisms involved in ceramide metabolism-mediated intestinal stem cell (ISC) proliferation and tumorigenesis are poorly understood. To understand how changes in sphingolipid metabolite flux affect intestinal stem cells, we manipulated the activities of each of the enzymes of the ceramide synthetic pathway using cell type-specific over-expression or depletion of the corresponding mRNAs in each intestinal cell type of the Drosophila midgut. We documented cell-autonomous and non-cell-autonomous effects, including alterations in cell size, number, differentiation, and proliferation. In our screen, the altered expression of several ceramide metabolism enzymes led to changes in ISC proliferation, cell sizes, and overall cellularity. Among other genes, over-expression of ceramidase homolog, Brain washing (bwa) in gut enteroblasts (EB) increased EB cell size and caused a non-cell-autonomous, 7-8-fold increase in ISC proliferation. Our analysis confirmed previous reports that bwa does not have ceramidase activity, and lipidomic studies indicated that bwa increases the saturation status of sphingolipids, free fatty acids, and other lipids. The pro-proliferative effects of bwa could be counter-acted by depleting a serine palmitoyltransferase, Lace, or a sphingosine acyltransferase, Schlank, which are needed for ceramide synthesis, or by co-expressing a ceramide desaturase enzyme, ifc, indicating that increased saturated ceramides were causal for ISC proliferation and the disruption of gut homeostasis. Accumulating saturated sphingolipids and fatty acids induced inflammatory signaling in the gut, and activated ISC proliferation through the pro-inflammatory cytokines, Upd3 and Upd2. We propose that saturated sphingolipids promote ISC proliferation through pro-inflammatory pathways.

cell biology↗

bioRxiv2024

Evaluation of Brain Age as a Specific Marker of Brain Health

Brain age is widely regarded as a powerful marker of general brain health. Brain age models are typically trained on large datasets to predict chronological age, which may offer advantages in predicting specific health outcomes, much like the success of finetuning large language models for specific applications. However, it is also well-accepted that machine learning models trained to directly predict specific outcomes (i.e., direct models) often outperform those trained on surrogate objectives. Therefore, despite their much larger training data, it is unclear whether brain age models outperform direct models in predicting specific brain health outcomes. Here, we compare large-scale brain age models (pretrained on 53,542 participants) and direct models for predicting specific health outcomes related to Alzheimers Disease (AD) dementia. Using anatomical T1 scans from three continents (N = 1,848), we find that summarizing brain age with a single scalar (i.e., brain age gap) led to poor prediction performance. Using higher-dimensional intermediate representations of brain age models led to better prediction, but was still worse than direct models without finetuning. Using intermediate representations of finetuned brain age models was necessary to achieve similar performance as direct models. Overall, our results do not discount brain age as a useful marker of general brain health, but suggest that using chronological age as a pretraining target might be suboptimal for predicting specific health outcomes.

neuroscience↗

bioRxiv2024

Development and validation of novel proliferation-related gene signature for MSS colorectal cancer prognosis

Colorectal cancer (CRC) is classified into microsatellite instability (MSI) and microsatellite stabilized (MSS) based on the differences in DNA repair mechanisms. In recent years, many studies have proved that some emerging therapeutic approaches have good therapeutic effects on MSI as a subtype but are ineffective for MSS as a subtype. This paper aims to start with the molecular mechanism of MSS and try to find the characteristic target genes of MSS as a subtype. We used bioinformatics techniques and machine learning to find GTF2IRD1. The gene GTF2IRD1 is highly expressed in MSS-type CRC but is stable in MSI. Subsequently, we verified its expression and function with relevant experiments. We demonstrated that GTF2IRD1 can promote the proliferation of MSS-type colorectal cancer and correlate with the poor prognosis of MSS-type colorectal cancer patients, which may provide a potential target gene for the clinical treatment of MSS-type colorectal cancer.

cancer biology↗

bioRxiv2024

scCompass: An integrated cross-species scRNA-seq database for AI-ready

Emerging single-cell sequencing technology has generated large amounts of data, allowing analysis of cellular dynamics and gene regulation at the single-cell resolution. Advances in artificial intelligence enhance life sciences research by delivering critical insights and optimizing data analysis processes. However, inconsistent data processing quality and standards remain to be a major challenge. Here we propose scCompass, which provides a data quality solution to build a large-scale, cross-species and model-friendly single-cell data collection. By applying standardized data pre-processing, scCompass integrates and curates transcriptomic data from 13 species and nearly 105 million single cells. Using this extensive dataset, we are able to archieve stable expression genes (SEGs) and organ-specific expression genes (OSGs) in human and mouse. We provide different scalable datasets that can be easily adapted for AI model training and the pretrained checkpoints with state-of-the-art (SOTA) single-cell foundataion models. In summary, the AI-readiness of scCompass, which combined with user-friendly data sharing, visualization and online analysis, greatly simplifies data access and exploitation for researchers in single cell biology(http://www.bdbe.cn/kun).

bioinformatics↗

bioRxiv2024

Rate of de novo mutations in the three-spined stickleback

Being a fundamentally important genetic parameter and evolutionary force, estimates of germline mutation rates have many uses in evolutionary biology. However, accurate estimates of de novo mutation (DNM) rates are still relatively scarce even for extensively studied evolutionary biology models. We estimated DNM rates for the three-spined stickleback (Gasterosteus aculeatus), the supermodel of ecology and evolutionary biology. Using a large number of family trios sequenced to depth of 45x coverage, we identified 115 unique mutations genome wide and estimated the DNM rate at {micro} = 5.05 x 10-9/bp/gen without any detectable sex bias. The localised DNM rate was found to be positively correlated with recombination rate supporting the notion that recombination is a mutagenic process. Comparison of {micro} and genomic characteristics to those of the related nine-spined stickleback (Pungitius pungitius) revealed a high degree of similarity suggesting that despite 17.5 million years of independent evolution, the mutational processes in the two species appear to have been conserved.

evolutionary biology↗

bioRxiv2024

The transcription factor GABPA is a master regulator of naive pluripotency

The establishment of naive pluripotency is a continuous process starting with the generation of inner cell mass (ICM) which then differentiating into epiblast (EPI). Recent studies have revealed key transcription factors (TFs) for ICM formation, but which TFs initiate EPI specification remains unknown. Here, using a targeted rapid protein degradation system, we show that GABPA is not only a regulator of major ZGA, but also a master EPI specifier required for naive pluripotency establishment by regulating 47% of EPI genes during E3.5 to E4.5 transition. Chromatin binding dynamics analysis suggests that GABPA controls EPI formation at least partly by binding to the ICM gene promoters occupied by the pluripotency regulators TFAP2C and SOX2 at E3.5 to establish naive pluripotency at E4.5. Our study not only uncovers GABPA as a master pluripotency regulator, but also supports the notion that mammalian pluripotency establishment requires a dynamic and stepwise multi-TFs regulatory network.

developmental biology↗

bioRxiv2024

Reducing functionally defective HSCs alleviates aging-related phenotypes in old mice

Aging is a process accompanied by functional decline in tissues and organs with great social and medical consequences. Developing effective anti-aging strategies is of great significance. In this study, we demonstrated that transplantation of young hematopoietic stem cells (HSCs) into old mice can mitigate aging phenotypes, underscoring the crucial role of HSCs in the aging process. Through comprehensive molecular and functional analyses, we identified a subset of HSCs in aged mice that exhibit "younger" molecular profiles and functions, marked by low levels of CD150 expression. Mechanistically, CD150low HSCs from old mice can effectively differentiate into downstream lineage cells but not their CD150high counterparts. Notably, transplantation of old CD150low HSCs attenuates aging phenotypes and prolongs lifespan of elderly mice compared to those transplanted with unselected or CD150high HSCs. Importantly, reducing the dysfunctional CD150high HSCs can alleviate aging phenotypes in old recipient mice. Thus, our study demonstrates the presence of "younger" HSCs in old mice, and aging-associated functional decline can be mitigated by reducing dysfunctional HSCs.

cell biology↗

bioRxiv2024

SARS-CoV-2 JN.1 reveals attenuated pathogenicity and airborne transmission

JN.1 is a subvariant of SARS-CoV-2 Omicron BA.2.86 lineage that was predominant worldwide in early 2024, of which the in vivo characteristics are largely unknown. Our results demonstrated that the replication of JN.1 was more efficient than that of the parental BA.2 in Vero cells, which demonstrated low dependence on TMPRSS2. Compared to Omicron variants BA.2 and XBB EG.5.1, JN.1 replicated less efficiently in hACE2 mouse lungs of which the intranasal infection was not lethal to hACE2 mice and led to weaker immune dysregulation. On a more sensitive, aged hACE2 hamster model, JN.1 led to a lower mortality rate and no weight loss, corresponding well with the low preference in lower airways. Lower amounts of viruses in nasal washes and exhaled aerosols were detected in JN.1 infected wildtype hamsters than EG.5.1, and consistently, JN.1 also exhibited largely reduced airborne transmission. Moreover, the poor transmission was also clearly demonstrated even by using hamsters expressing hACE2 receptors in the whole airway. Thus both pathogenicity and airborne transmission of JN.1 were demonstrated to be largely attenuated. ImportanceCurrently, SARS-CoV-2 JN.1 and its subvariants have fully replaced the previous dominant XBB lineage around the world. Although the strong immune evasion of JN.1 has been distinctly revealed, its in vivo pathogenicity and airborne transmission remained unclear. By using multiple Omicron-sensitive rodent models, our findings demonstrated that the pathogenicity of JN.1 was largely attenuated. The weak airborne transmission of JN.1 in wildtype and hACE2 hamsters was consistent with the reported relative lower transmissibility in human, and the using of airway-expressing hACE2 hamsters ulteriorly eliminates the potential bias in viral transmission studies induced by receptor divergence between animal models and human. These findings uncover the in vivo virological characteristics of SARS-CoV-2 novel lineage, providing insights for communicable disease control.

microbiology↗

bioRxiv2024

Astrocytic modulation of population encoding in mouse visual cortex via GABA transporter 3 revealed by multiplexed CRISPR/Cas9 gene editing

Astrocytes, which are increasingly recognized as pivotal constituents of brain circuits governing a wide range of functions, express GABA transporter 3 (Gat3), an astrocyte-specific GABA transporter responsible for maintenance of extra-synaptic GABA levels. Here, we examined the functional role of Gat3 in astrocyte-mediated modulation of neuronal activity and information encoding. First, we developed a multiplexed CRISPR construct applicable for effective genetic ablation of Gat3 in the visual cortex of adult mice. Using in vivo two-photon calcium imaging of visual cortex neurons in Gat3 knockout mice, we observed changes in spontaneous and visually driven single neuronal response properties such as response magnitudes and trial-to-trial variability. Gat3 knockout exerted a pronounced influence on population-level neuronal activity, altering the response dynamics of neuronal populations and impairing their ability to accurately represent stimulus information. These findings demonstrate that Gat3 in astrocytes profoundly shapes the sensory information encoding capacity of neurons and networks within the visual cortex.

neuroscience↗

bioRxiv2024

TIA1 Mediates Divergent Inflammatory Responses to Tauopathy in Microglia and Macrophages

The RNA binding protein TIA1 is known to regulate stress responses. Here we show that TIA1 plays a much broader role in inflammatory cells, being required for the microglial sensome. We crossed TIA1 cKO mice (using a CX3CR1 driven cre element) to PS19 MAPT P301S tauopathy mice. The peripheral macrophages of TIA1 cKO mice exhibited a hyper-inflammatory phenotype with increased cytokine signaling, as expected. Surprisingly, the brains of these mice showed striking reductions in inflammation, including decreases in microglial inflammatory cytokines (TNF and IL-1{beta}) and sensome markers (CLEC7A, TREM2, ITGAX); these reductions were accompanied by corresponding decreases in tau pathology. Analysis of the brain TIA1 protein interactome identified brain selective TIA1 protein mediated pathways, including strong interactions with the microglial protein C1q, which directs pruning of dystrophic neurons. These results uncover a previously unknown regulatory role for TIA1 in microglial activation in the context of neurodegenerative disease and highlights the divergent regulation of two mononuclear phagocytic lineages: microglia and macrophages.

neuroscience↗

bioRxiv2024

Evolution and functioning of an X-A balance sex determination system in hops

Chromosomal sex determining systems with male heterogamety include actively male-determining-Y and X-A balance systems, both of which are found in animals and plants. The sex-determining genes have been identified in several active-Y plant systems, but the evolution and functioning of X-A balance systems remains mysterious. To study this, we sequenced and compared the genomes of two hop species. The evolution of the hop X-A balance system involved an ancient recombination suppression event across a large X chromosome region shared by both species. In one species, an autosome fused to this ancestral sex chromosome, and recombination was subsequently suppressed again. The two evolutionary strata created in this neo-X have degenerated to different degrees, and evolved correspondingly different dosage compensation levels that correlate with histone modification patterns. Finally, we identified an X-specific ETR1-like ethylene receptor in the ancestral X region. Its dosage may affect sex determination, as part of the counting mechanism of this X-A balance system. One sentence summaryBased on whole genome sequences of the cultivated hop, Humulus lupulus, and its wild relative H. japonicus, we describe the evolution of sex chromosomal regions, three of which that evolved region-specific dosage compensation, and identify a candidate gene involved in their X-A balance sex determining system.

evolutionary biology↗