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Biology subjects

Mei, X.

Publications and source records attributed to Mei, X..

At least 19 recordsLinked to original sources

Non-enzymatic RNA Glycation is a Metabolic Sensor of Cellular Stress

Non-enzymatic RNA modifications expand the epitranscriptome, encoding a rapid and chemistry-driven response to cellular stress. While methylglyoxal, a reactive glycolytic byproduct of metabolic stress, has been shown to modify proteins and DNA, its impact on RNA has remained unexplored. Here, we identify mRNA as a dynamic substrate of MGO, whose modification is actively regulated by DJ-1 and the glyoxalase detoxification system. We show that mRNA glycation impairs translation and engages both the integrated stress response and the ribotoxic stress pathway, culminating in compromised pancreatic {beta}-cell function and reduced insulin secretion. Notably, this phenotype is alleviated by the frontline antihyperglycemic agent metformin. Together, our findings position mRNA as a direct sensor of metabolic stress and establish RNA glycation as a mechanistic link between glycolytic imbalance, translational stress and disease.

molecular biology↗

Dynamic shifts in brain criticality support cognitive processing

Systems operating near their critical point, or close to a transition between order and disorder, have computational advantages. In the case of neural networks, proximity to criticality is proposed to support optimal brain function. However, different cognitive processes rely on disparate computational demands. Using large-scale electrophysiological recordings in behaving rodents, we examined how critical dynamics in the hippocampus are regulated during learning and sleep-dependent memory consolidation. We found that operating near criticality enables learning by facilitating hippocampal coordination with input regions and maximizing flexibility of neural representations. In contrast, the hippocampal network shifts toward a more ordered, subcritical regime during sleep memory replay, and recovers its proximity to criticality through cholecystokinin interneurons-mediated inhibition. Overall, our findings provide a biophysical substrate for understanding how critical dynamics in neuronal networks can support a variety of brain functions. Importantly, our results suggest that optimal learning systems, whether biological or artificial, may require a dynamic regulation between flexible and rigid states, and can offer biophysical constraints to guide the design of Large Language Models (LLM) tuned to criticality.

neuroscience↗

The Herbicide Glyphosate Promotes Hypertension via Gut Microbiota-Mediated Mechanisms

Glyphosate, the active ingredient in herbicide Roundup, is the most widely used environmental contaminant that has been extensively studied for its potential carcinogenic effects. In the US alone, a staggering 81% of the US population [≥]6 years of age is exposed to glyphosate. Notably, this coincides with the alarming rise in the incidence of hypertension, the single largest risk factor for global mortality through cardiovascular diseases. Here we asked if there is a link between glyphosate exposure and hypertension, the premise being that glyphosate targets the shikimate pathway present in gut microbiota coupled with more recent knowledge that gut microbiota causally regulate blood pressure. We hypothesized that glyphosate elevates hypertension through microbiota-mediated mechanisms and document a highly concerning detrimental effect of glyphosate by demonstrating a causal link between oral glyphosate exposure and significant elevation in blood pressure. Gut microbiota was identified as the central mediator of this effect. Mechanistically, glyphosate-mediated elevation in blood pressure was through disruption of both gut-liver and gut-vascular homeostasis via FXR-signaling and accumulation of the microbial metabolite shikimic acid, respectively. Together, these findings underscore the need to reconsider the unabated use of this herbicide, which adversely affects a cardinal sign of health.

physiology↗

Dynamic alterations of DNA methylation and transcriptome in adaptation to and recovery from the space environment

Space exploration presents tremendous health challenges. Here, we report time series of multi-omic and phenotypic profiles of seventeen astronauts from six China Manned Space missions with continuous spaceflight durations ranging from 13 to 180 days. We revealed a key role of DNA methylation regulation in reshaping gene expression patterns to adapt to the space environment. Long-duration spaceflight showed more alterations in epigenetic modifications correlated with alternative splicing and protein acetylation. During recovery, an "overrange rebound" phenomenon was observed, furthermore, a mathematical model was established to describe this implying important phenomenon. Moreover, we revealed the correlations between molecular alterations and phenotypic changes such as coagulation activation and bone intensity loss. Additionally, we performed ground-based simulation experiments to estimate the impacts of individual stressors in the space environment on DNA methylation. In summary, our study highlights the importance and complexity of epigenetic regulation in adaptation to and recovery from the space environment.

genomics↗

Goal-directed hippocampal theta sweeps during memory-guided navigation

During navigation, animals continually sample their surrounding space and plan routes to distant goals. The brain mechanisms underlying these behaviors and how they coordinate to support memory-guided navigation in open environments are not understood. Using large-scale recordings in rats, we found two distinct types of place cell sequences within theta cycles that encoded trajectories sweeping beyond the animals location: stereotypic left-right alternating sweeps and learning-dependent goal-directed sweeps. Goal-directed sweeps predicted upcoming trajectories to remembered goal locations, were coordinated with prefrontal cortex activity and preferentially replayed during sharp-wave ripples. We further describe a circuit mechanism in which a subpopulation of CA1 cells encodes egocentric goal direction, combined with reduced feedback inhibition, to generate goal-directed theta sweeps. These results indicate a flexible mechanism to support different behavioral demands during navigation.

neuroscience↗

Inulin reduces Ralstonia invasion by promoting cooperation between Lysinibacillus sphaericus and Pseudoarthrobacter spp.

In field production, beneficial microbial agents are typically applied along with key resources that beneficial microbes prefer to utilize. This practice aims to help the beneficial microbes colonize the field and exert their disease resistance functions. However, the mechanisms by which these key resources influence the colonization and disease resistance effects of beneficial microbes remain unknown. In this study, we found that inulin can enhance the growth capacity of Lysinibacillus sphaericus HR92 and its ability to inhibit Ralstonia solanacearum. Further investigation revealed that inulin can enhance strain HR92s flagellar assembly, bacterial chemotaxis, fatty acid metabolism, and siderophore synthesis capabilities, ultimately improving strain HR92s effectiveness in controlling bacterial wilt. Moreover, adding inulin to the soil can enrich Pseudarthrobacter strains. This genus enhances the expression of genes involved in the synthesis of the antibacterial substance HR92, and competes for nutrients with Ralstonia solanacearum, thereby further inhibiting the occurrence of bacterial wilt disease. Additionally, the combination of inulin and Pseudarthrobacter strains upregulates the valine and leucine pathway genes in strain HR92. These genes play a crucial role in the synthesis of surfactin and the antimicrobial VOC 3-methyl-1-butanol. We have demonstrated that the addition of key resources not only enhances the control efficacy of beneficial bacteria against soil-borne diseases but also enriches the "helpers" of beneficial bacteria in soil. ImportanceRalstonia solanacearum is a plant pathogen that can cause bacterial wilt in several important crops. Given the limitations of beneficial bacterial inoculation, we propose a strategy to enhance the biocontrol efficacy of beneficial microorganisms by utilizing key resources. In this study, we demonstrate that key resources inulin can improve the biological control effects of beneficial bacteria, thereby maintaining plant health. Furthermore, we found that increasing the concentration of inulin altered the diversity of the rhizosphere microbiota and specifically enriched the abundance of Pseudarthrobacter, which compete with pathogens for nutrients on one hand and, on the other hand, synergize with inulin to enhance the biocontrol efficacy of the beneficial bacterium HR92. Together, our study reveals that key resources can enhance the biocontrol efficacy of beneficial bacteria and enrich potential beneficial bacteria in resident microbial communities, further reducing tomato diseases.

microbiology↗

Spatiotemporal changes in soil properties predict plant health at continental scale

Abiotic and biotic soil properties are strong predictors of plant yield globally1-5, but they become unreliable over large areas when plant health is threatened by pathogen6-8. Here we present a novel approach to predict plant health based on spatiotemporal changes in soil chemical and biological properties. We first demonstrate that plant health and soil properties consistently respond to environmental change (organic fertilization) regardless of the soil type or geographical origin. Second, we experimentally show that trackable shifts in soil properties reliably explain soil suppressiveness to the Ralstonia solanacearum bacterial pathogen and that a scalable spatiotemporal model predicts plant health with 84% accuracy across multiple climatic zones and cropping systems. Our results suggest that this tight coupling between soil properties and plant health could facilitate the development of agricultural practices aimed at sustainably improving crop yields while safeguarding crop health.

ecology↗

The ketone body β-Hydroxybutyrate mediated epigenetic chromatin β-hydroxybutyrylation protects kidneys

Starvation, intermittent fasting and exercise, all of which are recommended lifestyle modifiers share a common metabolic signature, ketogenesis to generate the ketone bodies, predominantly {beta}-hydroxybutyrate. {beta}-hydroxybutyrate exerts beneficial effects across various contexts, preventing or mitigating disease. We hypothesized that these dynamic health benefits of {beta}-hydroxybutyrate might stem from its ability to regulate genome architecture through chromatin remodeling via histone {beta}-hydroxybutyrylation, thereby influencing the transcriptome. Focusing on the kidney, which is an end organ protected by {beta}-hydroxybutyrate, we examined histone {beta}-hydroxybutyrylation-mediated chromatin remodeling. Notably, regions of the genome associated with lipid catabolism were predominantly in an open chromatin configuration, leading to active transcription and translation. Significant {beta}-hydroxybutyrylation was observed in the kidneys and the most highly upregulated gene actively transcribed and translated was 3-hydroxy-3-methyglutaryl CoA Synthase 2 (Hmgcs2), a gene responsible for the biosynthesis of {beta}-hydroxybutyrate in mitochondria. In contrast, regions with more compact chromatin structures were enriched with genes related to immune function such as protein tyrosine phosphatase receptor type C (Ptprc) and lymphocyte cytosolic protein 1 (Lcp1), which exhibited reduced transcription and translation. These results reveal that renal epigenetic histone {beta}-hydroxybutyrylation is a novel mechanism by which transcriptional regulation of both energy metabolism and immune function occur concomitantly to protect kidneys and lower hypertension. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/628574v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@f16cdorg.highwire.dtl.DTLVardef@a22427org.highwire.dtl.DTLVardef@f3a6d3org.highwire.dtl.DTLVardef@4d705d_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO C_FIG

physiology↗

Substrate utilization and cross-feeding synergistically determine microbiome resistance to pathogen invasion

Understanding how microbiomes resist pathogen invasion remains a key challenge in natural ecosystems. Here, we combined genome-scale metabolic models with synthetic community experiments to unravel the mechanisms driving pathogen suppression. We developed curated genome-scale models for each strain, incorporating 48 common resource utilization profiles to fully capture their metabolic capacities. Trophic interactions inferred from models accurately predicted pathogen invasion outcomes, achieving an F1 score of 96% across 620 invasion tests involving diverse microbial communities and nutrient environments. Importantly, considering both substrate and metabolite features provided a more holistic understanding of pathogen suppression. In particular, cross-feeding metabolites within the native community emerged as crucial yet often overlooked predictors of community resistance, disproportionally favoring native species over invaders. This study lays the foundation for designing disease-resistant microbiomes, with broad implications for mitigating pathogen exposure in diverse environments.

ecology↗

TvAP65 in Trichomonas vaginalis Promotes HPV Infection by Interacting with Host Molecules

Cervical cancer induced by human papillomavirus (HPV) infection poses a serious threat to womens health. Studies have shown that Trichomonas vaginalis (T. vaginalis), which is widely prevalent globally, can facilitate HPV infection. However, the underlying mechanism remains unclear. This study found that T. vaginalis significantly enhanced HPV infection in HaCaT cells and mouse vaginas through in vivo and in vitro experiments, and promoted the expression of HPV membrane receptor molecules CD151 and HSPG2. The HPV infection rate and CD151/HSPG2 expression levels were significantly decreased after reducing the expression of T. vaginalis adhesion protein 65 (TvAP65). In contrast, both HPV infection rates and CD151/HSPG2 expression were significantly increased in HaCaT cells over-expressing TvAP65. When both TvAP65 in T. vaginalis and CD151/HSPG2 in HaCaT cells were knocked down simultaneously, the infection rate of HPV in HaCaT cells was further reduced. These results suggest that TvAP65 promotes HPV infection by up-regulating the expression of CD151 and HSPG2. Furthermore, this study knocked down the 12 interacting molecules of TvAP65 in HaCaT cells one by one, and found that the HPV infection rate was significantly reduced after T. vaginalis infected HaCaT cells with low expression of FTH1, SPCS1, ATP5MC3, ITGB7, PMEPA1 or REEP5. Among them, SPCS1 played the most significant role. Simultaneous knockdown of TvAP65 and SPCS1 further significantly down-regulated the infection rate of HPV in HaCaT cells. Moreover, this molecule also down-regulated the promoting effect of T. vaginalis on HSPG2/CD151 expression. These results imply that SPCS1 plays an important role in T. vaginalis promoting HSPG2/CD151 expression and HPV infection. This study not only further proved that T. vaginalis can promote HPV infection but also explores the molecular mechanism by which TvAP65, through its interaction with SPCS1, up-regulates the expression of HSPG2 and CD151, thereby facilitating HPV infection. This provides a theoretical basis for clarifying the mechanism of co-infection between T. vaginalis and HPV.

microbiology↗

On-Demand Expansion Fluorescence and Photoacoustic Microscopy (ExFLPAM)

Expansion microscopy (ExM) is a promising technology that enables nanoscale imaging on conventional optical microscopes by physically magnifying the specimens. Here, we report the development of a strategy that enables i) on-demand labeling of subcellular organelles in live cells for ExM through transfection of fluorescent proteins that are well-retained during the expansion procedure; and ii) non-fluorescent chromogenic color-development towards efficient bright-field and photoacoustic imaging in both planar and volumetric formats, which is applicable to both cultured cells and biological tissues. Compared to the conventional ExM methods, our strategy provides an expanded toolkit, which we term as expansion fluorescence and photoacoustic microscopy (ExFLPAM), by allowing on-demand fluorescent protein labeling of cultured cells, as well as non-fluorescent absorption contrast-imaging of biological samples.

bioengineering↗

Single-cell sequencing for the molecular identity involved in zinc therapy for spinal cord injury

Spinal cord injury (SCI) is a severe traumatic neurological condition often caused by car accidents, violent impacts, or unintentional falls and can have devastating consequences for the patient. SCI include primary and secondary injuries. Followed by primary injury, and secondary injuries including inflammatory responses and oxidative stress, which exacerbate the disease process of SCI. Therefore, the treatment of SCI, especially the suppression of secondary injuries, is a major focus of attention in the field of neuroscience. In previous studies, we have demonstrated that zinc therapy can exert neuroprotective effects in mice after acute SCI, including reducing the inflammatory response in the central nervous system, decreasing the neuronal apoptosis and downregulating oxidative stress at the region of injury. However, little is known about how zinc therapy systematically alleviates SCI. Here, we have systematically analysed and mapped the single-cell atlas of the spinal cord in mice with SCI treated by zinc therapy, which provides a systematic analysis of the transcriptome of individual cells in the spinal cord. Among the results, we found that zinc therapy-induced alterations in the IL-17 inflammatory pathway and produced immune heterogeneity in microglia which are the inherent immune cells in the central nervous system. By cell subpopulations clustering analysis, we defined seven microglia subpopulations in zinc-therapy spinal cord tissue and identified the presence of novel VEGFA+ microglia. This finding presents that the microglia subpopulations affected by zinc therapy may have the potential to promote angiogenesis, which is a potential mechanism for the treatment of SCI. In conclusion, this study maps/reveals the transcriptomic of zinc therapy for the treatment of acute SCI with unprecedented resolution and provides a molecular basis for the clinical application.

genomics↗

CURLYLEAF is a key modulator of apoplast water status in Arabidopsis leaf

The apoplast of plant leaf, the intercellular space between mesophyll cells, is normally largely filled with air with a minimal amount of water in it, which is essential for key physiological processes such as gas exchange to occur. Interestingly, phytopathogens exploit virulence factors to induce a water-rich environment, known as "water soaking", in the apoplast of the infected leaf tissue to promote disease. We propose that plants evolved a "water soaking" pathway, which normally keeps a "minimized and balanced" water level in the leaf apoplast for plant growth but is disturbed by microbial pathogens to facilitate infection. Investigation of the "water soaking" pathway and leaf water control mechanisms is a fundamental, yet previously-overlooked, aspect of plant physiology. To identify key components in the "water soaking" pathway, we performed a genetic screen to isolate Arabidopsis severe water soaking (sws) mutants that show leaf water over-accumulation under high air humidity, a condition required for visible water soaking. Here we report the sws1 mutant, which displays rapid water soaking upon high humidity treatment due to a loss-of-function mutation in CURLY LEAF (CLF), encoding a histone methyl-transferase in the POLYCOMB REPRESSIVE COMPLEX 2 (PRC2). We found that the sws1 (clf) mutant exhibits an enhanced abscisic acid (ABA) level and stomatal closure, which are indispensable for its water soaking phenotype and mediated by CLFs direct regulation of a group of ABA-associated NAC transcription factors, NAC019/055/072. Interestingly, the clf mutant showed a weakened immunity, which likely also contributes to the water soaking phenotype. In addition, the clf plant supports a significantly higher level of Pseudomonas syringae pathogen-induced water soaking and bacterial multiplication, in an ABA pathway and NAC019/055/072-dependent manner. Collectively, our study probes into a fundamental question in plant biology and demonstrates CLF as a key modulator of leaf water status via epigenetic regulation of ABA pathway and stomatal movement.

plant biology↗

Organs-on-a-Chip Database (OOCDB): A Comprehensive, Systematic and Real-time Organs-on-a-chip Database

Organs-on-a-Chip is a microfluidic microphysiological system that uses microfluidic technology to make high-resolution and real-time imaging analysis on the structure and function of living human cells at the level of tissue and organ in vitro. Compared with the traditional two-dimensional cell culture model and animal model, organs-on-a-chip technology can simulate the pathological and toxicological interactions between different organs or tissues more closely and reflect the collaborative response of multiple organs to drugs. Although lots of organs-on-a-chip-related literature have been published, none of current databases have achieved all the following functionalities yet: searching, downloading and analyzing data and results from literature of organs-on-a-chip. To address this need, we established a database named organs-on-a-chip database (OOCDB), as a platform to integrate information related to organs-on-a-chip from various sources: literature, patents, microarray and transcriptome sequencing raw data, many open access data of organs-on-a-chip and organoids, as well as the data generated in our lab. OOCDB comprises dozens of sub databases and analysis tools and each sub database contains a number of data related to organs-on-a-chip, aiming to provide a comprehensive, systematic and convenient search engine for researchers. In addition, it provides functions such as mathematical modeling, three-dimensional model and citation map to meet the needs of researchers and to promote the development of organs-on-a-chip. The organs-on-a-chip database can be visited at http://www.organchip.cn.

bioinformatics↗

Engineering ecologically complementary rhizosphere probiotics using consortia of specialized bacterial mutants

While bacterial diversity is beneficial for the functioning of rhizosphere microbiomes, multi-species bioinoculants often fail to promote plant growth. One potential reason for this is that competition between inoculated consortia members create conflicts for their survival and functioning. To circumvent this, we used transposon mutagenesis to increase the functional diversity within Bacillus amyloliquefaciens bacterial species and tested if we could improve plant growth-promotion by assembling consortia of closely related but functionally specialized mutants. While most insertion mutations were harmful, some improved strains plant growth-promotion traits without increasing antagonism between them. Crucially, plant growth-promotion could be improved by applying these specialist mutants as consortia, leading to clear positive relationships between consortia richness, plant root colonization and protection from bacterial wilt disease. Together, our results suggest that increasing intra-species diversity could be an effective way to increase probiotic consortia multifunctionality, leading to more stable plant growth-promotion throughout growth cycle via insurance effects.

ecology↗

SPE-51, a sperm secreted protein with an Immunoglobulin-like domain, is required for sperm-egg fusion in C. elegans

Despite the importance of fertilization, the molecular basis of sperm-egg interaction is not well understood. In a forward genetics screen for fertility mutants in Caenorhabditis elegans we identified spe-51. Mutant worms make sperm that are unable to fertilize the oocyte but otherwise normal by all available measurements. The spe-51 gene encodes a secreted protein that includes an immunoglobulin (Ig)-like domain and a hydrophobic sequence of amino acids. The SPE-51 protein acts cell-autonomously and localizes to the surface of the spermatozoa. This is the first example of a secreted protein required for the interactions between the sperm and egg with genetic validation for a specific function in fertilization. Our analyses of these genes begin to build a paradigm for sperm-secreted or reproductive tract-secreted proteins that coat the sperm surface and influence their survival, motility, and/or the ability to fertilize the egg.

developmental biology↗

The EGF-motif containing protein SPE-36 is a secreted protein required for sperm function at fertilization in C. elegans

The growing number of genes specifically required for fertilization suggests that there is a significant amount of molecular complexity at the sperm-egg interface. Thus, we have adopted a model of a "fertilization synapse" where specialized zones of interaction and multi-protein complexes mediate gamete interaction and fusion. The fertilization synapse is likely to be composed of both trans and cis protein-protein interactions at the surface of each gamete. Mutations in the Caenorhabditis elegans spe-36 gene result in a sperm-specific fertility defect. Surprisingly, spe-36 encodes a secreted EGF-motif containing protein that functions cell autonomously. Despite the fact that morphology and migratory behavior of spe-36 sperm are indistinguishable from wild-type sperm, spe-36 sperm make close contact with oocytes but fail to fertilize them. The genetic requirement for a secreted sperm-derived protein for fertilization is novel and represents a paradigm-shifting discovery in the molecular understanding of fertilization.

developmental biology↗

Interleukin-22 mediated renal metabolic reprogramming via PFKFB3 to treat kidney injury

Kidney damage initiates the deteriorating metabolic states in tubule cells that lead to the development of end-stage renal disease (ESTD). Interleukin 22 (IL-22) is an effective therapeutic antidote for kidney injury via promoting kidney recovery, but little is known about the underlying molecular mechanisms. Here we first provide evidence that IL-22 attenuates kidney injury via metabolic reprogramming of renal tubular epithelial cells (TECs). Specifically, our data suggest that IL-22 regulates mitochondrial function and glycolysis in damaged TECs. Further observations indicate that IL-22 alleviates the accumulation of mitochondrial reactive oxygen species (ROS) and dysfunctional mitochondria via the induction of AMPK/AKT signaling and PFBFK3 activities. In mice, amelioration of kidney injury and necrosis and improvement of kidney functions via regulation of these metabolism relevant signaling and mitochondrial fitness of recombinant IL-22 are certificated in cisplatin induced kidney damage and diabetic nephropathy (DN) animal models. Taken together, our findings unravel new mechanistic insights into protective effects of IL-22 on kidney and highlight the therapeutic opportunities of IL-22 and the involved metabolic regulators in various kidney diseases.

pharmacology and toxicology↗