Biology subjects

Guo, Z.

Publications and source records attributed to Guo, Z..

At least 163 records · Page 9Linked to original sources

bioRxiv2023

Video-rate Mid-infrared Photothermal Imaging by Single Pulse Photothermal Detection per Pixel

By optically sensing the mid-infrared absorption induced photothermal effect, midinfrared photothermal (MIP) microscope enables super-resolution IR imaging and scrutinizing of biological systems in an aqueous environment. However, the speed of current lock-in based sample-scanning MIP system is limited to 1.0 millisecond or longer per pixel, which is insufficient for capturing dynamics inside living systems. Here, we report a single pulse laserscanning MIP microscope that dramatically increases the imaging speed by three orders of magnitude. We harness a lock-in free demodulation scheme which uses high-speed digitization to resolve single IR pulse induced contrast at nanosecond time scale. To realize single pulse photothermal detection at each pixel, we employ two sets of galvo mirrors for synchronized scanning of mid-infrared and probe beams to achieve an imaging line rate over 2 kHz. With video-rate imaging capability, we observed two types of distinct dynamics of lipids in living cells. Furthermore, by hyperspectral imaging, we chemically dissected a single cell wall at nanometer scale. Finally, with a uniform field of view over 200 by 200 m2 and 2 Hz frame rate, we mapped fat storage in free-moving C. elegans and live embryos.

bioengineering↗

bioRxiv2023

A scalable, GMP-compatible, autologous organotypic cell therapy for Dystrophic Epidermolysis Bullosa

BackgroundGene editing in induced pluripotent stem (iPS) cells has been hailed to enable new cell therapies for various monogenetic diseases including dystrophic epidermolysis bullosa (DEB). However, manufacturing, efficacy and safety roadblocks have limited the development of genetically corrected, autologous iPS cell-based therapies. MethodsWe developed Dystrophic Epidermolysis Bullosa Cell Therapy (DEBCT), a new generation GMP-compatible (cGMP), reproducible, and scalable platform to produce autologous clinical-grade iPS cell-derived organotypic induced skin composite (iSC) grafts to treat incurable wounds of patients lacking type VII collagen (C7). DEBCT uses a combined high-efficiency reprogramming and CRISPR-based genetic correction single step to generate genome scar- free, COL7A1 corrected clonal iPS cells from primary patient fibroblasts. Validated iPS cells are converted into epidermal, dermal and melanocyte progenitors with a novel 2D organoid differentiation protocol, followed by CD49f enrichment and expansion to minimize maturation heterogeneity. iSC product characterization by single cell transcriptomics was followed by mouse xenografting for disease correcting activity at 1 month and toxicology analysis at 1-6 months. Culture-acquired mutations, potential CRISPR-off targets, and cancer-driver variants were evaluated by targeted and whole genome sequencing. FindingsiPS cell-derived iSC grafts were reproducibly generated from four recessive DEB patients with different pathogenic mutations. Organotypic iSC grafts onto immune-compromised mice developed into stable stratified skin with functional C7 restoration. Single cell transcriptomic characterization of iSCs revealed prominent holoclone stem cell signatures in keratinocytes and the recently described Gibbin-dependent signature in dermal fibroblasts. The latter correlated with enhanced graftability. Multiple orthogonal sequencing and subsequent computational approaches identified random and non-oncogenic mutations introduced by the manufacturing process. Toxicology revealed no detectable tumors after 3-6 months in DEBCT- treated mice. InterpretationDEBCT successfully overcomes previous roadblocks and represents a robust, scalable, and safe cGMP manufacturing platform for production of a CRISPR-corrected autologous organotypic skin graft to heal DEB patient wounds.

bioengineering↗

bioRxiv2023

ADAM10 mediates macroglial cell fate decisions in the developing brain

ADAMs (a disintegrin and metalloproteinase) are transmembrane proteins with cell adhesion and protease activities that contain disintegrin and metalloproteinase domains. ADAM10, a member of the ADAM family, is widely expressed in the brain. There are >40 substrates reported for ADAM10, including Notch, Delta-like ligand-1 (Dll1), and N-cadherin. To date, however, its function in the brain has been largely unknown. We used genetic manipulation to delete Adam10 specifically from glial progenitors in developing brains and observed that conditional knockout mice showed locomotor abnormalities. They all died within 4 months with apparent defects in the cerebellum. By comprehensively analyzing data from bulk RNA sequencing, single-cell RNA sequencing, and staining of the cerebellum, we found that ADAM10 promoted astrocyte generation under physiological conditions. Upon the removal of Adam10 in glial progenitors, the production of oligodendrocytes vastly increased, whereas the generation of astrocytes was substantially inhibited. Our results showed that ADAM10 plays a critical role in macroglial cell fate decisions during brain development.

neuroscience↗

bioRxiv2023

Probabilistic cell/domain-type assignment of spatial transcriptomics data with SpatialAnno

In the analysis of both single-cell RNA sequencing (scRNA-seq) and spatially resolved transcriptomics (SRT) data, classifying cells/spots into cell/domain types is an essential analytic step for many secondary analyses. Most of the existing annotation methods have been developed for scRNA-seq datasets without any consideration of spatial information. Here, we present SpatialAnno, an efficient and accurate annotation method for spatial transcriptomics datasets, with the capability to effectively leverage a large number of non-marker genes as well as "qualitative" information about marker genes without using a reference dataset. Uniquely, SpatialAnno estimates low-dimensional embeddings for a large number of non-marker genes via a factor model while promoting spatial smoothness among neighboring spots via a Potts model. Using both simulated and four real spatial transcriptomics datasets from the 10x Visium, ST, Slide-seqV1/2, and seqFISH platforms, we showcase the methods improved spatial annotation accuracy, including its robustness to the inclusion of marker genes for irrelevant cell/domain types and to various degrees of marker gene misspecification. SpatialAnno is computationally scalable and applicable to SRT datasets from different platforms. Furthermore, the estimated embeddings for cellular biological effects facilitate many downstream analyses.

bioinformatics↗

bioRxiv2023

CAM5, WRKY53, and TGA5 regulate defense gene expression mediated by the volatile organic compound ethyl vinyl ketone

Plants produce ethyl vinyl ketone (evk) in response to biotic stress, but the evks identification and downstream defense response remain unclear. In this paper, it is predicted by docking for the first time that evk can be recognized by RBOH protein and assist the electron transfer of RBOHD/RBOHF by binding to its FAD or NADPH binding site. Here, we show that evk treatment increased H2O2 and intracellular calcium concentrations in Arabidopsis thaliana mesophyll cells, as observed by confocal laser scanning microscopy and non-invasive micro-test technology, and that H2O2 signaling functioned upstream of Ca2+ signaling. Yeast two-hybrid, firefly luciferase complementation imaging, and in vitro pull-down assays demonstrated that the ACA8 (AUTOINHIBITED Ca2+-ATPASE, ISOFORM 8)-CML8 (CALMODULIN-LIKE 8) interaction promoted Ca2+ efflux to return Ca2+ levels to the resting state. Evk treatment led to the antagonism of salicylic acid (SA) and jasmonic acid (JA). CALMODULIN 5 (CAM5) positively regulates WRKY53 expression, and CAM5 and WRKY53 positively regulate SA-related gene expression. These proteins physically interact and form a complex that is unlocked by Ca2+ to release WRKY53. An electrophoretic mobility shift assay and dual-luciferase reporter assay demonstrated that WRKY53 and TGA5 cooperate to enhance the expression of the defense gene PATHOGENESIS-REALTED 1 (PR1) and that WRKY53 enhances the binding of TGA5 to the PR1 promoter. This paper proposes a framework that evk, as a RES substance, can achieve plants REScue through complete defense response.

plant biology↗

bioRxiv2023

Androgen aggravates aortic aneurysms via suppressing PD-1 in mice

Androgen has long been recognized for its pivotal role in the sexual dimorphism of cardiovascular diseases, including aortic aneurysms, a devastating vascular disease with a higher prevalence and mortality rate in men than women. However, the molecular mechanism by which androgen mediates aortic aneurysms is largely unknown. Here, we report that male but not female mice develop aortic aneurysms in response to aldosterone and high salt (Aldo-salt). We demonstrate that both androgen and androgen receptors (AR) are crucial for the sexually dimorphic response to Aldo-salt. We identify T cells expressing programmed cell death protein 1 (PD-1), an immune checkpoint molecule important in immunity and cancer immunotherapy, as a key link between androgen and aortic aneurysms. We show that intraperitoneal injection of anti-PD-1 antibody reinstates Aldo-salt-induced aortic aneurysms in orchiectomized mice. Mechanistically, we demonstrate that AR binds to the PD-1 promoter to suppress its expression in the spleen. Hence, our study reveals an important but unexplored mechanism by which androgen contributes to aortic aneurysms by suppressing PD-1 expression in T cells. Our study also suggests that cancer patients predisposed to the risk factors of aortic aneurysms may be advised to screen for aortic aneurysms during immune checkpoint therapy. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/525073v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@2e8406org.highwire.dtl.DTLVardef@1dde495org.highwire.dtl.DTLVardef@c9f42eorg.highwire.dtl.DTLVardef@be2799_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗

bioRxiv2023

Unlocking de novo antibody design with generative artificial intelligence

Generative AI has the potential to redefine the process of therapeutic antibody discovery. In this report, we describe and validate deep generative models for the de novo design of antibodies against human epidermal growth factor receptor (HER2) without additional optimization. The models enabled an efficient workflow that combined in silico design methods with high-throughput experimental techniques to rapidly identify binders from a library of [~]106 heavy chain complementarity-determining region (HCDR) variants. We demonstrated that the workflow achieves binding rates of 10.6% for HCDR3 and 1.8% for HCDR123 designs and is statistically superior to baselines. We further characterized 421 diverse binders using surface plasmon resonance (SPR), finding 71 with low nanomolar affinity similar to the therapeutic anti-HER2 antibody trastuzumab. A selected subset of 11 diverse high-affinity binders were functionally equivalent or superior to trastuzumab, with most demonstrating suitable developability features. We designed one binder with [~]3x higher cell-based potency compared to trastuzumab and another with improved cross-species reactivity1. Our generative AI approach unlocks an accelerated path to designing therapeutic antibodies against diverse targets.

synthetic biology↗

bioRxiv2022

AGO2a but not AGO2b mediates antiviral defense against the infection of wildtype Cucumber mosaic virus in tomato

Evolutionarily conserved antiviral RNA interference (RNAi) mediates a primary antiviral innate immunity preventing the infection of broad spectrum viruses in plants. However, the detailed mechanism in plants is still largely unknown, especially in important agricultural crops including tomato. On the other aspect, varieties of pathogenic viruses evolve to possess Viral Suppressor of RNA silencing (VSR) to suppress antiviral RNAi in host. Due to the prevalence of VSR, it is still skeptical that antiviral RNAi truly functions to prevent the invasion of natural wildtype viruses in plants and animals. In the research, it is for the first time we applied CRISPR-Cas9 to generate ago2a, ago2b or ago2ab mutants for two differentiated Solanum lycopersicum AGO2, one key effector in antiviral RNAi. We found that AGO2a but not AGO2b was significantly induced to inhibit the propagation of not only VSR-deficient Cucumber mosaic virus (CMV) but also wildtype CMV-Fny in tomato, however, both AGO2a and AGO2b did not regulate disease induction after the infection of either virus. Our findings firstly reveal a prominent role of AGO2a in antiviral RNAi innate immunity in tomato and demonstrate that antiviral RNAi evolves to defend the infection of natural wildtype CMV-Fny in tomato, however AGO2a-mediated antiviral RNAi does not play major roles in promoting tolerance of tomato plants to CMV infection for maintaining health.

immunology↗

bioRxiv2022

eccDNA Atlas: a comprehensive resource of eccDNA catalog

Extrachromosomal circular DNA (eccDNA) represents a large category of nonmitochondrial and nonplasmid circular extrachromosomal DNA playing an indispensable role in various aspects such as tumorigenesis, immune responses, liquid biopsy, etc. However, characteristic and functions of eccDNA are fragmented, hiding behind abundant literatures and massive whole-genome sequencing (WGS) data, which have not been sufficiently used for identification of eccDNAs. Therefore, establishing an integrated repository portal is essential for identifying and analyzing eccDNAs. Here, we developed eccDNA Atlas (http://lcbb.swjtu.edu.cn/eccDNAatlas), a user-friendly database of eccDNAs that aims to provide a high-quality and integrated resource for browsing, searching and analyzing eccDNAs from multiple species. eccDNA Atlas currently containing 630,434 eccDNAs and 7,774 ecDNAs manually curated from literatures and 1,105 ecDNAs predicted by AmpliconArchitect based on WGS data involved in 66 diseases, 57 tissue and 319 cell lines. The content of each eccDNA entry included multiple aspects such as sequence, disease, function, characteristic, validation strategies, etc. Furthermore, abundant annotations and analyzing utilities were provided to explore existed eccDNAs in eccDNA Atlas or user-defined eccDNAs including oncogenes, typical enhancers, super enhancers, gene expression, survival, and genome visualization. Based on these resources, eccDNA Atlas will significantly improve our understanding of eccDNAs and serve as an important catalyst for future research of eccDNAs.

bioinformatics↗

bioRxiv2022

Discovery of aphid-transmitted Rice tiller inhibition virus from native plants through metagenomic sequencing

A major threat to rice production is the disease epidemics caused by insect-borne viruses that emerge and re-emerge with undefined origins. It is well known that some human viruses have zoonotic origins from wild animals. However, it remains unknown whether native plants host new endemic viruses with spillover potential to rice (Oryza sativa) as emerging pathogens. Here, we discovered rice tiller inhibition virus (RTIV), a novel RNA virus species, from colonies of Asian wild rice (O. rufipogon) in a genetic reserve by metagenomic sequencing. We identified the specific aphid vector to transmit RTIV and found RTIV would cause low-tillering disease in rice cultivar after transmission. We further demonstrated that an infectious molecular clone of RTIV initiated systemic infection and causes low-tillering disease in an elite rice variety after Agrobacterium-mediated inoculation or stable plant transformation, and RTIV can also be transmitted from transgenic rice plant through its aphid vector to cause disease. Finally, global transcriptome analysis indicated that RTIV may disturb defense and tillering pathway to cause low tillering disease in rice cultivar. Thus, our results show that new rice viral pathogens can emerge from native habitats, and RTIV, a rare aphid-transmitted rice viral pathogen from native wild rice, can threaten the production of rice cultivar after spillover.

pathology↗

bioRxiv2022

Global terrestrial nitrogen uptake and nitrogen use efficiency

Plant biomass production (BP), nitrogen uptake (Nup) and their ratio, nitrogen use efficiency (NUE), must be quantified to understand how nitrogen (N) cycling constrains terrestrial carbon (C) uptake. But the controls of key plant processes determining Nup and NUE, including BP, C and N allocation, tissue C:N ratios and N resorption efficiency (NRE), remain poorly known. We compiled measurements from 804 forest and grassland sites and derived regression models for each of these processes with growth temperature, vapour pressure deficit, stand age, soil C:N ratio, fAPAR (remotely sensed fraction of photosynthetically active radiation absorbed by green vegetation) and growing-season average daily incident photosynthetic photon flux density (gPPFD) (effectively the seasonal concentration of light availability, which increases polewards) as predictors. An empirical model for leaf N was based on optimal photosynthetic capacity (a function of gPPFD and climate) and observed leaf mass-per-area. The models were used to produce global maps of Nup and NUE. Global BP was estimated as 72 Pg C/yr; Nup as 950 Tg N/yr; and NUE as 76 gC/gN. Forest BP was found to increase with growth temperature and fAPAR and to decrease with stand age, soil C:N ratio and gPPFD. Forest NUE is controlled primarily by climate through its effect on C allocation - especially to leaves, being richer in N than other tissues. NUE is greater in colder climates, where N is less readily available, because belowground allocation is increased. NUE is also greater in drier climates because leaf allocation is reduced. NRE is enhanced (further promoting NUE) in both cold and dry climates. These findings can provide observationally based benchmarks for model representations of C-N cycle coupling. State-of-the-art vegetation models in the TRENDY ensemble showed variable performance against these benchmarks, and models including coupled C-N cycling produced relatively poor simulations of Nup and NUE.

ecology↗

bioRxiv2022

Field dependent deep learning enables high-throughput whole-cell 3D super-resolution imaging

Single-molecule localization microscopy (SMLM) in a typical wide-field setup has been widely used for investigating sub-cellular structures with super resolution. However, field-dependent aberrations restrict the field of view (FOV) to only few tens of micrometers. Here, we present a deep learning method for precise localization of spatially variant point emitters (FD-DeepLoc) over a large FOV covering the full chip of a modern sCMOS camera. Using a graphic processing unit (GPU) based vectorial PSF fitter, we can fast and accurately model the spatially variant point spread function (PSF) of a high numerical aperture (NA) objective in the entire FOV. Combined with deformable mirror based optimal PSF engineering, we demonstrate high-accuracy 3D SMLM over a volume of ~180 x 180 x 5 m3, allowing us to image mitochondria and nuclear pore complex in the entire cells in a single imaging cycle without hardware scanning - a 100-fold increase in throughput compared to the state-of-the-art.

biophysics↗

bioRxiv2022

Neuraminidase activity modulates cellular co-infection during influenza A virus multicycle growth

Infection of individual cells by multiple virions plays critical roles in the replication and spread of many viruses, but mechanisms that control cellular co-infection during multi-cycle viral growth remain unclear. Here, we investigate virus-intrinsic factors that control cellular co-infection by influenza A virus (IAV). Using quantitative fluorescence to track the spread of virions from single infected cells, we identify the IAV surface protein neuraminidase (NA) as a key determinant of cellular co-infection. We map this effect to NAs ability to deplete viral receptors from both infected and neighboring uninfected cells. In cases where viral infectious potential is low, genetic or pharmacological inhibition of NA increases the local spread of infection by increasing the viral load received by neighboring cells. These results identify virus-intrinsic factors that contribute to cellular multiplicity of infection, and suggest that optimal levels of NA activity depend on the infectious potential of the virus in question.

microbiology↗

bioRxiv2022

Molecular mechanism of substrate recognition by folate transporter SLC19A1

Folate (vitamin B9) is the coenzyme involved in one-carbon transfer biochemical reactions essential for cell survival and proliferation, with its inadequacy causing developmental defects or severe diseases. Notably, mammalian cells lack the ability to de novo synthesize folate but instead rely on its intake from extracellular sources via specific transporters or receptors, among which SLC19A1 is the ubiquitously expressed one in tissues. However, the mechanism of substrate recognition by SLC19A1 has been unclear. Here we report the cryo-EM structures of human SLC19A1 and its complex with 5-methyltetrahydrofolate at 3.5-3.6 [A] resolution and elucidate the critical residues for substrate recognition. In particular, we reveal that two variant residues among SLC19 subfamily members would designate the specificity for folate. Moreover, we identify intracellular thiamine pyrophosphate as the favorite coupled substrate for folate transport by SLC19A1. Together, this work has established the molecular basis of substrate recognition by this central folate transporter.

biochemistry↗

bioRxiv2022

Chemoenzymatic Measurement of Cell-surface Glycan in Single-cell Multiomics: LacNAc as an Example

Despite the rich information of a cells physiological state encoded in the dynamic changes of cell-surface glycans, methods of capturing glycosylation states at the single-cell level are quite limited. Here we report a chemoenzymatic single-cell N-acetyllactosamine (LacNAc) detection method via tagging the LacNAc with a specific DNA barcode. Compared to the lectin-based glycan detection, the chemoenzymatic labeling does not change the transcriptional status of immune cells and is more compatible with scRNA-seq. Integrated analysis of LacNAc and transcriptome of T cells at a single-cell level reveals that the quantity of cell-surface LacNAc is significantly upregulated in activated CD8+ T cells but maintained at the basal level in quiescent CD8+ T cells (i.e., naive and central memory T cells). Further analysis confirms that the LacNAc level is positively correlated to the glycolytic activity of CD8+ T cells at all statues. Taken together, our study demonstrates the feasibility of chemoenzymatic detection of cell-surface glycan in single-cell RNA sequencing-based multiomics with information of TCR sequence and cell-surface epitopes (i.e., scTCR and CITE-seq) and offers a new way to characterize the biological role of glycan in diversified physiological states.

immunology↗

bioRxiv2022

Identification and functional prediction of sugar beet circRNAs involved in drought responses

Drought is one of the most common abiotic constraints on the quality and productivity of crops on a global scale. Despite the rapidly updating information on circRNAs (circular RNAs), their roles in the anti-drought regulation of sugar beet are least understood. As a newly recognized class of non-coding RNAs, circRNAs exert crucial effects on miRNA (microRNA) functionality, as well as on transcriptional regulation. To clarify the mechanism of how circRNAs of sugar beet respond to drought stress, deep sequencing was employed to characterize these circRNAs in a genome-wide manner under drought treatment. Our results identify a total of 17 differentially expressed circRNAs. As revealed by the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology outcomes, circRNAs were found capable and involved in drought-responsive events. Utilizing the target genes exhibiting direct/indirect associations with drought resistance, we established a circRNA-miRNA-mRNA meshwork based on the circRNAs that were expressed differentially. The probable sponge functions of novel_circ_0000442 and novel_circ_0000443 were exerted by targeting ath-miR157d. This helped regulate the expression of relevant target genes, including BVRB_1 g004570, BVRB_1 g005450, and BVRB_1 g005790, that were involved in drought response. Apart from offering novel understandings of anti-drought mechanisms, our findings lay a basis for probing deeper into the intricate regulatory networks of sugar beet genes.

plant biology↗

bioRxiv2022

Integrated single-cell multiomic analysis of HIV latency reversal reveals novel regulators of viral reactivation.

Despite the success of antiretroviral therapy, HIV cannot be cured because of a reservoir of latently infected cells that evades therapy. To understand the mechanisms of HIV latency, we employed an integrated single-cell RNA-seq/ATAC-seq approach to simultaneously profile the transcriptomic and epigenomic characteristics of ~4000 latently infected cells after reactivation using three different latency-reversing agents (LRAs). Differentially expressed genes and differentially accessible motifs were used to examine transcriptional pathways and transcription factor (TF) activities across the cell population. We identify cellular transcripts and TFs whose expression/activity was correlated with viral reactivation and demonstrate that a machine learning model trained on these data was 68% accurate at predicting viral reactivation. Finally, we validate the role of a new candidate HIV-regulating factor, GATA3, in the viral response to prostratin stimulation. These data demonstrate the power of integrated multimodal single-cell analysis to uncover novel relationships between host cell factors and HIV latency.

microbiology↗

bioRxiv2022

The fitness landscape of the mobilized colistin resistance gene mcr-1

The emergence and global discovery of the mobilized colistin resistance gene, mcr-1, limits the clinical effectiveness of colistin as last-resort antibiotic against multiple-drug resistant bacteria. Although MCR-1 exhibits low levels of colistin resistance in E. coli, it is currently unknown whether mcr-1 may potentially evolve a high level of colistin resistance in the future. Here, we generated mcr-1 mutant library that included 27,965 variants, covering 94.44% of the single-nucleotide mutations. We quantified the relative growth of these variant strains under colistin exposure. Notably, most mutations in the catalytic domain, but not in the transmembrane domain, reduce colistin resistance. The structural basis for the mutational effects revealed that the transmembrane domain may contribute to MCR-1 evolution. Altogether, our data shed light on the prediction of MCR-1 evolution, which could be useful for designing novel treatment strategies.

evolutionary biology↗