Biology subjects

Chang, Z.

Publications and source records attributed to Chang, Z..

At least 19 recordsLinked to original sources

bioRxiv2026

Host brain infection induces RNAi epimutation in Mucor circinelloides and enhances blood-brain barrier invasion

Mucorales fungi cause mucormycosis, a rapidly progressive invasive fungal disease with high mortality, particularly in immunocompromised patients and in severe disseminated infections. Central nervous system involvement is among the most devastating manifestations of mucormycosis, yet the mechanisms that enable Mucorales to adapt to the brain environment remain poorly understood. In Mucor species, RNA interference (RNAi) can generate reversible heritable epimutations that silence specific genes without altering DNA sequence, providing a transient and reversible mechanism for antifungal drug resistance. Here, we show that host brain infection induces RNAi-dependent silencing of endogenous fungal loci that promote central nervous system adaptation. Small RNA sequencing of Mucor circinelloides recovered from infected mouse organs identified seven brain epimutation loci, named bepA to bepG, that accumulated small RNAs preferentially after brain infection. Among these, bepA encodes a conserved mitogen-activated protein kinase (MAPK)-like serine/threonine kinase related to cell wall integrity signaling. Deletion of the bepA gene confers resistance to the calcineurin inhibitors FK506 and cyclosporin A, allowing hyphal growth under conditions that impair calcineurin-dependent morphogenesis. BepA modulates FK506-induced MAPK signaling and controls a transcriptional program enriched in cell-wall remodeling genes. To model fungal central nervous system entry by a filamentous fungal pathogen, we established a human blood-brain barrier transwell platform that quantifies Mucor migration across brain endothelial monolayers. This model revealed that bepA mutation enhances fungal migration across brain endothelial monolayers without detectable changes in electrical barrier resistance. These findings identify brain-induced RNAi epimutation as a mechanism of organ-specific fungal adaptation and reveal reversible silencing of a MAPK-like kinase as a route to enhanced central nervous system invasion.

genetics↗

bioRxiv2026

Development of Deep-Learning Models that Predict Quantitative Protein-Ligand Interac-tions in Glycobiology as a part of a Capstone Course

Glycans coat the surface of all cells, and every glycan is recognised by specific glycan-binding proteins (GBPs). There are no general tools that can accurately estimate the binding strength between glycan and GBP from the amino acid sequence of the GBP and the molecular structure of the glycan, represented as SMILES string. We describe models for predicting such binding strengths developed as a part of a Capstone Course at the University of Alberta. The models are trained on a dataset that combines BindingDB, a published database of small-molecule protein interactions, and data from glycan arrays measured by Consortium of Functional Glycomics (CFG). In this hybrid dataset of protein-ligand interactions the ligands are both glycans from CFG and small molecules from BindingDB; similarly, proteins include GBP and proteins from BindingDB. Three models are presented (i) ProMax which fuses ESM-2, MolFormer, and MolCLR features; (ii) APEX which constrains learning to a predetermined form, a physical model of binding; (iii) UltraMax adds inter-atomic distances for the ligands. To address the datasets severe long-tail distribution, the models employ tail-aware losses for rare high-binding instances. Trained and evaluated on approximately one million protein-ligand pairs using hold-out splits for unseen molecules, the three models provide a unified framework for quantitative glycan-protein binding prediction. We observed that learning glycan-protein binding is harder than the similar task of learning small-molecule-protein interactions. Simple mirror-inversion tests led us to postulate that insufficient use of chiral features is an important source of difficulty in learning these interactions.

bioinformatics↗

bioRxiv2025

A gut-brain axis for aversive interoception drives innate and anticipatory emesis in Drosophila.

Signals from the gut are increasingly recognized as modulators of brain function and behavior. However, the pathways through which the gut conveys adverse or unpleasant information to the brain are still not well understood. In this study, we identify an aversive gut-brain axis in Drosophila melanogaster that detects toxin-induced gut damage and triggers both innate and learned anticipatory emesis (vomiting). After toxin ingestion, reactive oxygen species are produced by midgut enterocytes and detected by the transient receptor potential channel TrpA1 on nearby enteroendocrine cells. This sensing stimulates the release of neuropeptides from enteroendocrine cells, likely representing the gastric malaise flies experience after eating. We show that these neuropeptides act on specific serotonergic and dopaminergic neurons in the brain. These neurons interact with each other and signal to the downstream memory-related mushroom bodies to promote emesis. This circuit not only drives an immediate emetic response but also represents a malaise-driven aversive signal. The signal manifests as the persistent activity of dopaminergic neurons, which reinforces aversive valence to odor cues in the mushroom bodies. Thus, the flies learn that a specific odor predicts the presence of a toxin in food and exhibit anticipatory emesis upon re-exposure to the same odor. Taken together, we have identified an interoceptive signaling pathway that may be conserved for detecting harmful gut conditions and for remembering how to avoid them. Our work offers a mechanistic framework for studying aversive gut-brain communication involved in feeding, metabolism, depression, brain injury, and neurodegenerative diseases.

neuroscience↗

bioRxiv2025

Inter-individual variability of neurotransmitter receptor and transporter density in the human brain

Neurotransmitter receptors guide the propagation of signals between brain regions. Mapping receptor distributions in the brain is therefore necessary for understanding how neurotransmitter systems mediate the link between brain structure and function. Normative receptor density can be estimated using group averages from Positron Emission Tomography (PET) imaging. However, the generalizability and reliability of group-average receptor maps depends on the inter-individual variability of receptor density, which is currently unknown. Here we collect group standard deviation brain maps of PET-estimated protein abundance for 12 different neurotransmitter receptors and transporters across 7 neurotransmitter systems, including dopamine, serotonin, acetylcholine, glutamate, GABA, cannabinoid, and opioid. We illustrate how cortical and subcortical inter-individual variability of receptor and transporter density varies across brain regions and across neurotransmitter systems. We complement inter-individual variability with inter-regional variability, and show that receptors that vary more across brain regions than across individuals also demonstrate greater out-of-sample spatial consistency. Altogether, this work quantifies how receptor systems vary in healthy individuals, and provides a means of assessing the generalizability of PET-derived receptor density quantification.

neuroscience↗

bioRxiv2025

Tumor Cells Enriched for Interferon and Inflammatory Programs Pre-Exist in High Grade Serous Ovarian Cancer and are Proportionately Significantly Increased Post Chemotherapy

Drug-tolerant, high-grade serous ovarian cancer (HGSOC) cells that persist after first-line chemotherapy and subsequently relapse often retain sensitivity to secondary treatment, suggesting a therapeutic window before stable chemoresistance emerges. We performed single-cell RNA sequencing (scRNA-seq) on seven matched pairs of tumors, collected pre- and post-chemotherapy, to define vulnerabilities in these reversibly-resistant cells. Treatment induced a marked enrichment of tumor and stromal cell populations expressing correlated interferon (IFN) and inflammatory (IFM) gene signatures, with a concurrent depletion of proliferation-related and MYC-associated states in the tumor cells. Cross-cohort single cell sequencing analysis of >130 treatment-naive tumors revealed heterogeneity in the abundance of IFN/IFM-expressing cells. Multiplex immunofluorescence imaging of IFN-stimulated gene (ISG) products confirmed the presence of spatially clustered ISG-positive tumor cells in all cases, as well as in serous tubal intraepithelial carcinomas (STIC lesions), the presumptive HGSOC precursors. ISG expression correlated strongly with ORF1P, a protein encoded by the endogenous retrotransposon LINE1. These data suggest that early oncogenic events drive LINE1 derepression and innate immune activation, establishing an IFN-rich transcriptional state that persists in tumor subpopulations and is strongly enhanced by chemotherapy.

cancer biology↗

bioRxiv2024

Positive impact of Type-A and -C response regulator genes on growth and panicle architecture in rice

Cytokinin signal transduction occurs through a "two-component system." Type-A and -C response regulators (RRs) are groups of proteins of similar structures constituting significant components of cytokinin signal transduction. In rice, 13 (Type-A) and two (Type-C) RRs have been identified to date; however, their functions remain partially known. In this study, we examined the expression patterns of Type-A and Type-C RRs in rice using RNA-Seq and confirmed their functions by constructing mutants of the 15 genes with CRISPR/Cas9. Almost all Type-A RRs played positive roles in the development of secondary branches and secondary spikelets, particularly RR2 and RR4. Notably, rr1 rr2 and rr8 rr12 rr13 higher-order mutants displayed small panicle sizes and decreased plant height. Additionally, both Type-C RRs played positive roles in regulating heading date. RNA-seq revealed several genes with significantly altered expression in the rr2 and rr4 mutants, with almost half of the differentially expressed genes (DEGs) overlapping between the two mutants. Many of the DEGs were associated with the cytokinin and abscisic acid pathways. Our findings provide new insights into the functions of Type-A and -C RRs in rice growth and may serve as a foundation for future studies focusing on cytokinin signaling.

plant biology↗

bioRxiv2024

Co-transcriptional RNA processing boosts zygotic gene activation

Transcription decodes protein-coding genes and interprets regulatory information embedded in the genome by generating RNA. In eukaryotes, gene transcription is coupled with RNA processing via the carboxyl terminal domain (CTD) of RNA polymerase (Pol) II, which enhances messenger RNA (mRNA) production. We propose that co-transcriptional RNA processing is essential for zygotic gene activation (ZGA), transitioning the transcription program from noncoding to protein-coding after fertilization. Truncating the CTD in mouse cells disrupts this coupling, halting global mRNA synthesis and increasing noncoding RNA (ncRNA) levels through enhanced intergenic transcription and RNA stabilization. CTD truncation also triggers epigenetic reprogramming and nuclear reorganization towards totipotency, resembling early cleavage embryos. Mechanistically, the CTD restrains nonproductive polymerase activity in noncoding sequences, while at protein-coding genes requiring RNA processing, it promotes elongation by facilitating polymerase promoter-proximal pausing, transcription directionality, and velocity. Longer CTD lengths enhance gene activity, likely evolving to accommodate the increasing noncoding sequences in mammalian genomes.

developmental biology↗

bioRxiv2024

NOK promotes tumorigenesis through coordinating epidermal growth factor receptor to boost the downstream signaling in breast cancer

BACKGROUNDEpidermal growth factor receptor (EGFR) forms a homodimer or heterodimer with other ErbB receptor family members to activate different downstream cytoplasmic signaling proteins during tumorigenesis. METHODSAdenovirus and lentivirus were used to overexpress or deplete NOK and/or EGFR to evaluate the phosphorylation of EGFR, the interaction of NOK-EGFR and their role in cell proliferation and metastasis. RESULTSEGFR heterodimerizes with NOK (also known as STYK1), a novel tyrosine kinase with a transmembrane domain, to promote tumorigenesis and metastasis of breast cancer cells. We found that NOK directly interacted with EGFR and formed a heterodimer complex. Depletion of NOK impaired, but over-expression of NOK increased, the phosphorylation of EGFR. NOK enhanced EGF signaling activation, in particular, the phosphorylation of STAT3, STAT5 and Erk1/2 via its juxtamembrane (JM) domain in promoting the proliferation and migration of breast cancer cells. Overexpression of NOK and EGFR synergistically induced the tumorigenesis of NIH-3T3 normal cells. We finally demonstrated that co-expression of NOK and EGFR correlated with tumor malignant stages in breast cancer patients. CONCLUSIONSOur findings uncover a mechanism by which NOK coordinates EGFR to enhance EGF signaling during tumorigenesis and metastasis and propose a potential strategy for targeting NOK-EGFR in breast cancer treatment. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/608018v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@17b0078org.highwire.dtl.DTLVardef@5bfe6forg.highwire.dtl.DTLVardef@19d3d15org.highwire.dtl.DTLVardef@155fc4_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIEGFR heterodimerizes with NOK/STYK1, a novel tyrosine kinase with a transmembrane domain, in a manner of cross interaction via their juxtamembrane (JM) domains and kinase domains. C_LIO_LINOK enhances EGF signaling activation, in particular, the phosphorylation of STAT3, STAT5 and Erk1/2 via its JM domain. C_LIO_LINOK and EGFR synergistically promote proliferation and migration of breast cancer cells and induce tumorigenesis of normal cells. C_LIO_LICo-expression of NOK and EGFR correlates with tumor malignant stages in breast cancer patients. C_LI

cell biology↗

bioRxiv2024

VirID: Beyond Virus Discovery - An Integrated Platform for Comprehensive RNA Virus Characterization

RNA viruses exhibit vast phylogenetic diversity and can significantly impact public health and agriculture. However, current bioinformatics tools for viral discovery from metagenomic data frequently generate false positive virus results, overestimate viral diversity, and misclassify virus sequences. Additionally, current tools often fail to determine virus-host associations, which hampers investigation of the potential threat posed by a newly detected virus. To address these issues we developed VirID, a software tool specifically designed for the discovery and characterization of RNA viruses from metagenomic data. The basis of VirID is a comprehensive RNA-dependent RNA polymerase (RdRP) database to enhance a workflow that includes RNA virus discovery, phylogenetic analysis, and phylogeny-based virus characterization. Benchmark tests on a simulated data set demonstrated that VirID had high accuracy in profiling viruses and estimating viral richness. In evaluations with real-world samples, VirID was able to identity RNA viruses of all type, but also provided accurate estimations of viral genetic diversity and virus classification, as well as comprehensive insights into virus associations with humans, animals, and plants. VirID therefore offers a robust tool for virus discovery and serves as a valuable resource in basic virological studies, pathogen surveillance, and early warning systems for infectious disease outbreaks.

bioinformatics↗

bioRxiv2024

Cytochrome P450 Enzyme Design by Constraining Catalytic Pocket in Diffusion model

Although cytochrome P450 enzymes are the most versatile biocatalysts in nature, there is insufficient comprehension of the molecular mechanism underlying their functional innovation process. Here, by combining ancestral sequence reconstruction, reverse mutation assay and structure analysis, we identified five founder residues in the catalytic pocket of flavone 6-hydroxylase (F6H) and proposed a "three-point fixation" model to elucidate the functional innovation mechanisms of P450s in nature. According to this design principle of catalytic pocket, we further developed a de novo diffusion model (P450Diffusion) to generate artificial P450s. Ultimately, among the 17 non-natural P450s we generated, ten designs exhibited significant F6H activity and six exhibited a 1.3- to 3.5-fold increase in catalytic capacity compared to the natural CYP706X1. This work not only explores the design principle of catalytic pockets of P450s, but also provides an insight into the artificial design of P450 enzymes with desired functions.

molecular biology↗

bioRxiv2023

Single-cell and spatial multiomic inference of gene regulatory networks using SCRIPro

The accurate reconstruction of gene regulation networks (GRNs) from sparse and noisy single-cell or spatial multi-omics data remains a challenge. Here, we present SCRIPro, a comprehensive computational framework that robustly infers GRNs for both single-cell and spatial multi-omics data. SCRIPro first addresses sample sparseness by a density clustering approach. SCRIPro assesses transcriptional regulator (TR) importance through chromatin reconstruction and in silico deletion, referencing 1,292 human and 994 mouse TRs. It combines TR-target importance scores with expression levels for precise GRN reconstruction. Finally, we benchmarked SCRIPro on diverse datasets, it outperforms existing motif-based methods and accurately reconstructs cell type-specific, stage-specific, and region-specific GRNs.

bioinformatics↗

bioRxiv2023

Inhibitory subpopulations in preBötzinger Complex play distinct roles in modulating inspiratory rhythm and pattern

Inhibitory neurons embedded within mammalian neural circuits shape breathing, walking, chewing, and other rhythmic motor behaviors. At the core of the neural circuit controlling breathing is the preBotzinger Complex (preBotC), a nucleus in the ventrolateral medulla necessary for generation of inspiratory rhythm. In the preBotC, a recurrently connected network of glutamatergic Dbx1-derived (Dbx1+) neurons generates rhythmic inspiratory drive. Functionally and anatomically intercalated among preBotC Dbx1+ neurons are GABAergic (GAD1/2+) and glycinergic (GlyT2+) neurons, whose roles in breathing remain unclear. To elucidate the inhibitory microcircuits within preBotC, we first characterized the spatial distribution of molecularly-defined preBotC inhibitory subpopulations in double reporter mice expressing either the red fluorescent protein tdTomato or EGFP in GlyT2+, GAD1+, or GAD2+ neurons. We found that, in neonatal mice, the majority of preBotC inhibitory neurons expressed a combination of GlyT2 and GAD2 while a much smaller subpopulation also expressed GAD1. To determine the functional role of these subpopulations, we used holographic photostimulation, a patterned illumination technique with high spatiotemporal resolution, in rhythmically active medullary slices from neonatal Dbx1tdTomato;GlyT2EGFP and Dbx1tdTomato;GAD1EGFP double reporter mice. Stimulation of 4 or 8 preBotC GlyT2+ neurons during endogenous rhythm prolonged the interburst interval in a phase-dependent manner and increased the latency to burst initiation when bursts were evoked by stimulation of Dbx1+ neurons. In contrast, stimulation of 4 or 8 preBotC GAD1+ neurons did not affect interburst interval or latency to burst initiation. Instead, photoactivation of GAD1+ neurons during the inspiratory burst prolonged endogenous and evoked burst duration and decreased evoked burst amplitude. We conclude that the majority of preBotC inhibitory neurons express both GlyT2 and GAD2 and modulate breathing rhythm by delaying burst initiation while a smaller GAD1+ subpopulation shapes inspiratory patterning by altering burst duration and amplitude.

neuroscience↗

bioRxiv2021

Oxidative phosphorylation safeguards pluripotency via UDP-N-acetylglucosamine

The roles of mitochondrial respiration in pluripotency remain largely unknown. We show here that mouse ESC mitochondria possess superior respiration capacity compared to somatic cell mitochondria, and oxidative phosphorylation (OXPHOS) generates the majority of cellular ATP in ESCs. Inhibition of OXPHOS results in extensive pluripotency and metabolic gene expression reprogram, leading to disruption of self-renewal and pluripotency. Metabolomics profiling identifies UDP-N-acetylglucosamine (UDP-GlcNAc) as one of the most significantly decreased metabolites in response to OXPHOS inhibition. The loss of ESC identity induced by OXPHOS inhibition can be ameliorated by directly adding GlcNAc both in vitro and in vivo. This work demonstrates that mitochondrial respiration, but not glycolysis, produces the majority of ATP in ESCs, and uncovers a novel mechanism whereby mitochondrial respiration is coupled with the hexosamine biosynthesis pathway to generate UDP-GlcNAc for ESC identity maintenance. SIGNIFICANCEOxidative phosphorylation (OXPHOS) and glycolysis are the two major pathways for generating ATP in mammalian cells. It is widely assumed that somatic cells utilize OXPHOS, whereas embryonic stem cells (ESCs) utilize glycolysis with low mitochondrial respiration rates even under aerobic conditions. However, the relative contribution of OXPHOS and glycolysis to ATP generation in ESCs, and the role of mitochondrial respiration in regulating ESC identity, have remained unclear. In this study, Cao et al demonstrate that mouse ESC mitochondria have a significantly higher respiration capacity than somatic cell mitochondria. Oxidative phosphorylation produces the majority of cellular ATP in mESCs and is coupled with the hexosamine biosynthesis pathway to generate UDP-GlcNAc for pluripotency maintenance. These findings define the function and mechanism of OXPHOS in regulating pluripotency, and challenge the traditional concept that mESCs rely on glycolysis over OXPHOS for their major supply of energy. HIGHLIGHTSO_LIESC mitochondria have a significantly higher respiration capability than somatic cell mitochondria C_LIO_LIOXPHOS, but not glycolysis, produces the majority of cellular ATP in ESCs C_LIO_LIOXPHOS inhibition induces a decrease in O-GlcNAcylation and the expression of pluripotency genes in blastocysts that can be partially rescued by adding GlcNAc C_LIO_LIOXPHOS is coupled with the hexosamine biosynthesis pathway for UDP-GlcNAc biosynthesis to maintain ESC identity C_LI

cell biology↗

bioRxiv2021

Cytokinin oxidase/dehydrogenase family genes play important roles in the growth and development of rice

Cytokinins play key roles in plant growth and development; hence, cytokinin biosynthesis and degradation have been extensively studied. Cytokinin oxidase/dehydrogenases (CKXs) are a group of enzymes that regulate oxidative cleavage to maintain cytokinin homeostasis. In rice, 11 OsCKX genes have been identified to date; however, most of their functions remain unknown. Here, we comprehensively analyzed the expression patterns and functions of OsCKX genes. Using CRISPR/Cas9 technology, we constructed mutants of all OsCKX genes to determine the functions of OsCKXs in rice development. The results revealed that the single osckx and higher-order osckx4 osckx9 mutant lines showed functional overlap and subfunctionalization. Notably, the osckx1 osckx2 and osckx4 osckx9 double mutants displayed contrasting phenotypic changes in tiller number and panicle size compared to the wild type. Moreover, we identified several genes with significantly altered expression in osckx4 and osckx9 single and double mutant plants. Many differentially expressed genes were found to be associated with auxin and cytokinin pathways. Additionally, the cytokinins in osckx4 osckx9 mutants were increased compared to the wild type. Overall, our findings provide new insights into the functions of OsCKX genes in rice growth and may be used as a foundation for future studies aimed at improving rice yield. Key words: Cytokinin, expression pattern, OsCKX, panicle, phenotype, rice, tiller HighlightThe osckx4 osckx9 double mutant had a significantly greater number of tillers, whereas the osckx1 osckx2 double mutant showed the opposite phenotypic change, compared to the wild type

plant biology↗

bioRxiv2021

Single-trial-based Temporal Principal Component Analysis on Extracting Event-related Potentials of Interest for an Individual Subject

Temporal principal component analysis (t-PCA) has been widely used to extract event-related potentials (ERPs) at the group level of multiple subjects ERP data. The t-PCA is, however, poorly employed to isolate ERPs from single-trial data of an individual subject. Additionally, the effects of varied trial numbers on the yields of t-PCA have not been systematically examined. To fill both gaps, in an emotional experiment (22 subjects), we use t-PCA and Promax rotation to extract interesting P2/N2 from single-trial data of each subject with consecutive increasingly trial numbers (from 10 to 42) and all trials, respectively. Besides, time-domain analysis and other two group t-PCA strategies (trial-averaged and single-trial) are also employed to isolate ERPs of interest from all subjects. The results indicate that the proposed technique produces the internal consistent measure of N2 from few trials (i.e., 19) as from all trials compared with the other three approaches (more than 30 trials). As for P2, all approaches yield internal-subject consistent effect after approximately 33 trials are included in the average, but Cronbachs alpha values for the proposed technique are higher than the other two group PCA strategies over varied trials. Combined, the yields provide evidence that the proposed approach may efficiently temporally filter the data to extract more reliable and stable ERPs for an individual subject.

neuroscience↗

bioRxiv2021

Brazil Nut Effect Drives Pattern Formation in Early Mammalian Embryos

The formation of three-dimensional ordered spatial patterns, which is essential for embryonic development, tissue regeneration, and cancer metastasis, is mainly guided by the chemical concentration gradient of morphogens. However, since no chemical concentration gradient has been observed in the early embryonic development (pre-implantation) of mammals, the pattern formation mechanism has been unsolved for a long time. During the second cell fate decision of mouse embryos, the inner cell mass (ICM) segregates into topographically regionalized epiblast (EPI) and primitive endoderm (PrE) layers. Here, we report that the segregation process of PrE/EPI precursors coincides with an emerged periodic expansion-contraction vibration of the blastocyst cavity, which induces phase transition in the ICM compartment to a higher fluidity state and generates directional tissue flows. By experiments and modeling, we demonstrate that the spatial segregation of PrE and EPI precursors is mediated by a "Brazil nut effect"-like viscous segregation mechanism in which PrE precursors with low affinity gradually migrate to the surface of ICM along with the tissue flow, while EPI precursors with high affinity remains inside ICM under cavity vibration. Artificially manipulation of the frequency and amplitude of cavity vibration could control the process of spatial separation as well as lineage specification of PrE/EPI. Furthermore, disruption of the cavity vibration in the initial stage after segregation could reverse the ICM cells back to a mixed state. Therefore, this study reveals a fundamental mechanism that guarantees the robustness of cell segregation and pattern formation without specific morphogens in early mammalian embryos. Our model also emphasizes a conserved function of cavity structure that widely exists in organisms as an energy reservoir and converter between different forms, such as chemical and mechanical energy.

developmental biology↗

bioRxiv2020

Xingnaojing injection can regulate dysbacteriosis and increase the concentration of short chain fatty acids in the feces after stroke in mice

BackgroundXingnaojing injection (XNJ) is extracted from the Chinese ancient prescription "An-Gong-Niu-Huang Pill", is widely used for stroke in China. We mainly observe the effect of XNJ (Xingnaojing) injection on the gut microbiota in stroke model mice. MethodsForty-two 7-to 8-week-old male C57 mice weighing 22-24 g were chosen for the experiment. There were 6 mice in each group; the 7 groups were the normal group (NG), the MCAO group (CG), the MCAO+XNJ group (EG), the sham surgery group (SG), the sham germ-free normal group (SGFNG), the sham germ-free+MCAO group (SGFCG), and the sham germ-free+MCAO+XNJ group (SGFEG). Two days before modeling, we abdominally administered Xingnaojing (6 mg/kg) the SGFEG and EG groups. The processing time of sustained XNJ was 5 days. Three days after modeling, 1 ~ 2 mouse feces were collected, and after a MiSeq PE library was constructed, an Illumina MiSeq PE 300 platform was used for high-throughput sequencing. After cleaning the sequencing data, the microbiome and microbiomeseq packages were used for analysis using R software (version 3.6.2). ResultsAlpha diversity analysis revealed that the diversity was not different between the CG and EG. The Simpson index was different between the SGFCG and SGFEG. XNJ increased the levels of Sutterellaceae and decreased the level of Deferribacteres and Morganella. LEfSe analysis showed that SGFCG mice were also enriched with Morganella. XNJ increased the concentrations of the SCFAs PA (propionate), VA (valerate), IBA (isobutyrate), and IVA (isovalerate) in the feces of the SGFEG group. BA (butyrate) had greater positive correlation with gut bacteria than other acids in the SGFCG, and XNJ changed this trend. KEGG analysis showed that peptidoglycan biosynthesis was most different between the CG and EG. ConclusionIschemic stroke (IS) causes dysbiosis of some specific bacteria in the gut microbiota in MCAO mice. Xingnaojing ameliorated this condition by increasing the levels of Sutterellaceae and decreasing the level of Deferribacteres and Morganella. These results are in accordance with other research on Chinese medicines for IS that affect the gut microbiota. Enrichment analysis of SCFAs revealed that XNJ improved the levels of SCFAs through an energy metabolism-related pathway.

bioinformatics↗

bioRxiv2020

Momilactone B inhibits Arabidopsis growth and development via disruption of ABA and auxin signaling

In competition for limited resources, many plants release allelochemicals to inhibit the growth of neighboring plants. Momilactone B (MB) is a major allelochemical produced by rice (Oryza sativa), however its mode of action is currently unknown. We used Arabidopsis (Arabidopsis thaliana) as a model system to evaluate potential mechanisms underlying the inhibitory effects of MB on seed germination, seedling establishment and root growth through the use of confocal microscopy and the examination of transcriptional responses in MB-treated seedlings. In response to MB treatment, transcript levels for genes encoding several key ABA biosynthetic enzymes and signaling components, including the transcription factor ABA-INSENSITIVE 4 (ABI4), were dramatically increased. Additionally, ABA insensitive 4 (abi4) mutant seedlings exhibited reduced susceptibility to exogenously-provided MB. Although the transcript levels of DELLA genes, which negatively regulate GA signaling, were significantly increased upon MB exposure, exogenous GA application did not reverse the inhibitory effects of MB on Arabidopsis germination and seedling development. Moreover, a reduction in seedling root meristematic activity, associated with reduced expression of auxin biosynthetic genes and efflux transporters, and apparent lowered auxin content, was observed in MB-treated root tips. Exogenous auxin applications partially rescued the inhibitory effects of MB observed in root growth. Our results indicate that MB suppresses Arabidopsis seed germination and root growth primarily via disruption of ABA and auxin signaling. These findings underscore the crucial roles played by phytohormones in mediating responses to allelochemical exposure. One-sentence summaryMomilactone B, the key allelochemical of rice, inhibits Arabidopsis growth and development via disruption of ABA and auxin signaling, suggesting the crucial roles of phytohormones in plant allelopathy

plant biology↗