Biology subjects

Zhao, T.

Publications and source records attributed to Zhao, T..

At least 91 records · Page 5Linked to original sources

bioRxiv2023

Discovering paracrine regulators of cellular composition from spatial transcriptomics data using SPER

A defining characteristic of biological tissue is its cell type composition. Many pathologies and chronic diseases are associated with perturbations from the homeostatic composition, and these transformations can lead to aberrant or deleterious tissue function. Spatial transcriptomics enables the concurrent measurement of gene expression and cell type composition, providing an opportunity to identify transcripts that co-vary with and potentially influence nearby cell composition. However, no method yet exists to systematically identify such intercellular regulatory factors. Here, we develop Spatial Paired Expression Ratio (SPER), a computational approach to evaluate the spatial dependence between transcript abundance and cell type proportions in spatial transcriptomics. We demonstrate the ability of SPER to accurately detect paracrine drivers of cellular abundance using simulated data. Using publicly available spatial transcriptomics data from mouse brain and human lung, we show that genes identified by SPER show statistical enrichment for both extracellular secretion and participation in known receptor-ligand interactions, supporting their potential role as compositional regulators. Taken together, SPER represents a general approach to discover paracrine drivers of cellular compositional changes from spatial transcriptomics.

systems biology↗

bioRxiv2023

Precise Alterations in Hippocampal Neural Deterioration and Neural Correlates of Visual Short-Term Memory in Individuals with Amnestic Mild Cognitive Impairment

PurposeAtrophy of the hippocampus is an early biomarker of Alzheimers disease (AD) and a main contributor to the patients mnemonic degeneration. While previous research has mostly focused on how hippocampal atrophy impaired long-term memory performance, its relation to short-term memory impairment, which was also found among patients with AD, remains largely uninvestigated. Filling this gap, the current study examined how atrophy in the hippocampus and its subfields may have influenced visual short-term memory (VSTM) in patients with amnestic mild cognitive impairment (aMCI), a common precursor of AD. MethodsFifty-eight aMCI patients and 69 healthy controls (HC) matched in age were included in the current study. VSTM was assessed using an adapted change detection task with a memory load of 2 or 4 items. Hippocampal subfields were automatically segmented in T1-weighted image using FreeSurfer and were manually inspected for errors. Volumes of the subfields were extracted and compared between aMCI and HC subjects using ANCOVA with age, gender and education as covariates. Furthermore, we also examined the partial correlation between VSTM performances and hippocampal subfield volumes with age, gender and education as covariates. ResultsCompared to HC subjects, aMCI subjects had lower response accuracy (ACC) and lower memory capacity under both load conditions and had longer reaction time (RT) in the 2-load condition. Left hippocampus volume was significantly smaller in aMCI and was positively correlated with ACC and capacity in HC but not in aMCI. Among the hippocampal subfields, left hippocampal tail, left molecular layer, left dentate gyrus (DG), left CA4, bilateral subiculum, bilateral presubiculum, bilateral fimbria, were significantly smaller while right hippocampal fissure was significantly widened in aMCI compared to HC. Volumes of the left subiculum, left molecular layer, left DG and left CA4 were positively correlated with ACC and capacity in HC but not in aMCI. Bilateral fimbria volume was negatively correlated with RT under the 2-load condition in HC but not in aMCI. ConclusionThe results of this study suggested that hippocampal deterioration, especially in subfields related to information input and output (e.g. molecular layer, DG, subiculum), may have contributed to VSTM impairment in aMCI by disrupting hippocampal-cortical communications. This finding adds to increasing evidence of hippocampal engagement in short-term memory processes and points to VSTM impairment as a potential neuropsychological indicator for MCI and AD.

neuroscience↗

bioRxiv2023

SACNet: A Multiscale Diffeomorphic Convolutional Registration Network with Prior Neuroanatomical Constraints for Flexible Susceptibility Artifact Correction in Echo Planar Imaging

Susceptibility artifacts (SAs), inevitable in brain diffusion MR (dMRI) scans acquired using single-shot echo planar imaging (EPI), severely compromise the accurate detection of human brain structure. Existing SA correction (SAC) methods offer inadequate correction quality and limited applicability across diverse datasets with varied acquisition protocols. To address these challenges, we proposed SACNet, a SAC framework based on unsupervised registration convolutional networks, featuring: i) a novel diffeomorphism regularization function to avoid unnatural SAC warps, modified from a potential well function; ii) an integration with prior neuroanatomical constraints and coarse-to-fine processing strategy to enables multi-scale geometric and intensity recoveries in severe distorted areas; iii) a unified registration framework that incorporates multiple phase-encoding (PE) EPI images and structural images, ensuring compatibility with both single- and inverse-PE protocols, with or without field maps. Utilizing simulated dMRI images and over 2000 brain scans from neonatal, child, adult and traveling participants, our method consistently demonstrates state-of-the-art correction performance. Notably, SACNet effectively reduces SAs-related multicenter effects compared to existing methods. We have developed user-friendly tools using containerization techniques, hope to facilitate SAC correction quality across extensive neuroimaging studies.

neuroscience↗

bioRxiv2023

Functional connectome through the human life span

The lifespan growth of the functional connectome remains unknown. Here, we assemble task-free functional and structural magnetic resonance imaging data from 33,250 individuals aged 32 postmenstrual weeks to 80 years from 132 global sites. We report critical inflection points in the nonlinear growth curves of the global mean and variance of the connectome, peaking in the late fourth and late third decades of life, respectively. After constructing a fine-grained, lifespan-wide suite of system-level brain atlases, we show distinct maturation timelines for functional segregation within different systems. Lifespan growth of regional connectivity is organized along a primary-to-association cortical axis. These connectome-based normative models reveal substantial individual heterogeneities in functional brain networks in patients with autism spectrum disorder, major depressive disorder, and Alzheimers disease. These findings elucidate the lifespan evolution of the functional connectome and can serve as a normative reference for quantifying individual variation in development, aging, and neuropsychiatric disorders.

neuroscience↗

bioRxiv2023

SARS-CoV-2 Omicron infection augments the magnitude and durability of systemic and mucosal immunity in triple-dose CoronaVac recipients

BackgroundThe inactivated whole-virion vaccine, CoronaVac, is one of the most widely used coronavirus disease 2019 (COVID-19) vaccines worldwide. There is a paucity of data indicating the durability of the immune response and the impact of immune imprinting induced by CoronaVac upon Omicron breakthrough infection. MethodsIn this prospective cohort study, 41 recipients of triple-dose CoronaVac and 14 unvaccinated individuals were recruited. We comprehensively profiled adaptive immune parameters in both groups, including spike-specific immunoglobulin (Ig) G and IgA titers, neutralizing activity, B cells, follicular helper T (Tfh) cells, CD4+ and CD8+ T cells, and their memory subpopulations at 12 months after the third booster dose and at 4 weeks and 20 weeks after Omicron BA.5 infection. ResultsTwelve months after the third CoronaVac vaccination, spike-specific antibody and cellular responses were detectable in most vaccinated individuals. BA.5 infection significantly augmented the magnitude, cross-reactivity and durability of serum neutralization activities, Fc-mediated phagocytosis, and nasal spike-specific IgA responses, memory B cells, activated Tfh cells memory CD4+ T cells, and memory CD8+ T cells for both the ancestral strain and Omicron subvariants, compared to unvaccinated individuals. Notably, the increase in BA.5-specific immunity after breakthrough infection was consistently higher than for the ancestral strain, suggesting no evidence of immune imprinting. Immune landscape analyses showed vaccinated individuals have better synchronization of multiple immune components than unvaccinated individuals upon heterologous SARS-CoV-2 infection. ConclusionOur data provides detailed insight into the protective role of inactivated COVID-19 vaccine in shaping humoral and cellular immune responses to heterologous Omicron infection. Trial registrationClinicalTrials.gov NCT05680896 FundingThis study was supported by the National Natural Science Foundation of China (92269118, 92269205), Nanjing Important Science & Technology Specific Projects (2021-11005), Scientific Research Project of Jiangsu Health Commission (M2022013), Clinical Trials from the Affiliated Drum Tower Hospital, Medical School of Nanjing University (2021-LCYJ-PY-9), and Jiangsu graduate practice innovation project (JX22013929).

immunology↗

bioRxiv2023

Nifuroxazide enhances radiotherapy efficacy against hepatocellular carcinoma by upregulating PD-L1 degradation via the ubiquitin-proteasome pathway

Radiation therapy is a primary treatment for hepatocellular carcinoma (HCC), but its effectiveness can be diminished by various factors. The over-expression of PD-L1 has been identified as a critical reason for radiotherapy resistance. Previous studies have demonstrated that nifuroxazide exerts antitumor activity by damaging the Stat3 pathway, but its efficacy against PD-L1 has remained unclear. In this study, we investigated whether nifuroxazide could enhance the efficacy of radiotherapy in HCC by reducing PD-L1 expression. Our results showed that nifuroxazide significantly increased the sensitivity of tumor cells to radiation therapy by inhibiting cell proliferation and migration while increasing apoptosis in vitro. Additionally, nifuroxazide attenuated the up-regulation of PD-L1 expression induced by irradiation, which may be associated with increased degradation of PD-L1 through the ubiquitination-proteasome pathway. Furthermore, nifuroxazide greatly enhanced the efficacy of radiation therapy in H22-bearing mice by inhibiting tumor growth, improving survival, boosting the activation of T lymphocytes, and decelerating the ratios of Treg cells in spleens. Importantly, nifuroxazide limited the increased expression of PD-L1 in tumor tissues induced by radiation therapy. This study confirms, for the first time, that nifuroxazide can augment PD-L1 degradation to improve the efficacy of radiation therapy in HCC-bearing mice.

immunology↗

bioRxiv2023

Herpes zoster mRNA vaccine induces superior vaccine immunity over licensed vaccine in mice and rhesus macaques

Herpes zoster remains an important global health issue and mainly occurs in aged and immunocompromised individuals with an early exposure history to Varicella Zoster Virus (VZV). Although the licensed vaccine Shingrix has a remarkably high efficacy, undesired reactogenicity and increasing global demand causing vaccine shortage urged the development of improved or novel VZV vaccines. In this study, we developed a novel VZV mRNA vaccine candidate (named as ZOSAL) containing sequence-optimized mRNAs encoding full-length glycoprotein E encapsulated in an ionizable lipid nanoparticle. In mice and rhesus macaques, ZOSAL demonstrated superior immunogenicity and safety in multiple aspects over Shingrix, especially in the induction of strong T cell immunity. Transcriptomic analysis revealed that both ZOSAL and Shingrix could robustly activate innate immune compartments, especially Type-I IFN signaling and antigen processing/presentation. Multivariate correlation analysis further identified several early factors of innate compartments that can predict the magnitude of T cell responses, which further increased our understanding of the mode of action of two different VZV vaccine modalities. Collectively, our data demonstrated the superiority of VZV mRNA vaccine over licensed subunit vaccine. The mRNA platform therefore holds prospects for further investigations in next-generation VZV vaccine development.

immunology↗

bioRxiv2023

Sub-nucleolar trafficking of Hendra virus matrix protein is regulated by ubiquitination and oligomerisation

Hendra virus (HeV) is a highly pathogenic member of the Henipavirus genus (order Mononegavirales), the replication cycle of which occurs primarily in the cytoplasm. The HeV matrix protein (HeV M) plays critical roles in viral assembly and budding at the plasma membrane, but also undergoes nuclear/nucleolar trafficking, to accumulate in nucleoli early in infection and, later, localise predominantly at the plasma membrane. Previously we found that HeV M protein targets specific sub-nucleolar compartments (corresponding to the FC-DFC (fibrillar centre (FC)/dense fibrillar component (DFC)) where it interacts with the nucleolar protein Treacle and modulates rRNA biogenesis by subverting the host nucleolar DNA damage response, indicating the importance of specific sub-nucleolar trafficking to infection. However, the mechanisms underlying targeting and movement between sub-nucleolar compartments by viral or cellular proteins remain poorly defined. Here, we assessed the molecular regulation of HeV M protein nucleolar/sub-nucleolar trafficking, finding that in infected cells and in cells expressing HeV M protein alone, M protein localizes into Treacle-enriched FC-DFC at early time points, and that FC-DFC localization is subsequently lost due to relocalization into the surrounding granular component (GC) of the nucleolus. Analysis using mutated M proteins and pharmacological modulation of ubiquitination indicate that this dynamic localization is regulated by ubiquitination and oligomerisation, with ubiquitination required for retention of HeV M in Treacle-enriched sub-nucleolar compartments, and oligomerisation required for egress. To our knowledge, this study provides the first direct insights into the dynamics and mechanisms of viral protein trafficking between sub-nucleolar compartments, important to the interplay between HeV M protein and host cell factors during infection. AUTHOR SUMMARYHenipaviruses, including Hendra (HeV) and Nipah viruses, cause deadly diseases in humans and livestock and are considered priority diseases by the World Health Organization due to their epidemic potential and lack of effective treatments. Understanding how these viruses interact with host cells is essential for developing new therapeutics. Our study examines the matrix (M) protein of henipaviruses and its interaction with the nucleolus, a cell structure that mediates ribosome production, and is a common target for various viruses, although their functions are largely unresolved. Previously, we showed that the HeV M protein targets a sub-nucleolar structure, called the FC-DFC, to modulate ribosome biogenesis. Here, we report that the M proteins movement between sub-nucleolar compartments is controlled by two processes: ubiquitination, which causes accumulation of the protein in the FC-DFC, and oligomerization, which is associated with exit. Similar mechanisms are also observed in other henipaviruses. Our findings reveal mechanisms regulating the hijacking of host cell functions by henipaviruses and suggest new potential targets for antiviral therapies. This study is the first to investigate how viral proteins move within the nucleolus, offering new insights into interactions that may be significant to multiple viruses.

microbiology↗

bioRxiv2023

Development of connectome dynamics at birth predicts neurocognitive outcomes at age 2

The functional connectome of the human brain comprises time-varying network structure that facilitates efficient inter-module communication and support flexible cognitive functions. However, little is known about how the connectome dynamics of the brain emerges and develops at very early stages of human life and whether this dynamics is predictive of neurocognitive outcomes later in life. Here, we employed resting-state functional MRI data from 39 infants (31 to 42 postmenstrual weeks) and a multilayer network model to characterize the development of connectome dynamics during the third trimester and its critical role in predicting future neurocognitive outcomes at 2 years of age. We observed that the modular architecture of baby functional connectomes spontaneously reconfigures over time, with lower network module switching across time primarily in the primary regions and higher module switching mainly in the association areas. With development, the dynamic switching between the brain modules was significantly decreased, primarily located in the lateral precentral gyrus, medial temporal lobe, and subcortical areas. The clustering analysis further revealed that the primary areas displayed a higher developmental rate than the higher-order systems. Using the support vector regression approach, we found that brain connectome dynamics at birth significantly predicted cognitive and language performance at 2 years of age. Our findings highlight the emergence and spatially inhomogeneous maturation of the neonate connectome dynamics, laying a critical neural foundation for the development of cognitive and language skills later in life.

neuroscience↗

bioRxiv2023

Optogenetic strategies for optimizing the performance of biosensors of membrane phospholipids in live cells

High-performance biosensors play a crucial role in elucidating the intricate spatiotemporal regulatory roles and dynamics of membrane lipids. However, enhancing their sensitivity and substrate-detecting capabilities remains a significant challenge. Here, we presented optogenetic-based strategies to optimize phospholipid biosensors. These strategies involved pre-sequestering unbound probes in the cell nucleus to minimize background signals in the cytoplasm. These stored probes could be released from the nucleus in response to blue light according to experimental requirements. Furthermore, we employed optically-controlled phase separation to generate punctate probes that amplified signals and facilitated the visualization of phospholipids in cells. These improved phospholipid biosensors hold great potential for enhancing our understanding of the spatiotemporal dynamics and regulatory roles of membrane lipids in live cells and this methodological insights might be valuable for developing other high-performance biosensors.

cell biology↗

bioRxiv2023

Unbiased phosphoproteomics analysis unveils modulation of insulin signaling by extramitotic CDK1 kinase activity in human myotubes

Sensitivity and plasticity of insulin signaling and glucose uptake in skeletal muscle depends on determinants such as genetic variation and obesity. We collected muscle biopsies and isolated myoblasts from a multi-ethnic cohort of lean South Asians (N=10), lean Chinese (N=10), and obese Chinese (N=10), and analysed the proteome and phosphoproteome dynamics in terminally differentiated myotubes after a low-dose insulin stimulation (10nM at 0, 5, 30 min). The myotubes initially responded with increased abundance and phosphorylation level changes along the PI3K/AKT/mTOR axis, decreased abundance of translation initiation factors, and increased phosphorylation levels on proteins involved in mRNA processing at 5 min. After the acute response, protein abundance returned to baseline at 30 min, while phosphorylation changes persisted in proteins including AKT, RPS6 and AS160 (TBC1D4). A joint kinase-substrate statistical analysis revealed that protein abundance changes of AKT, PAK1 and CDK1 showed concordant phosphorylation changes in their respective substrates upon insulin stimulation. We also observed increased phosphorylation of some substrates uniquely in each group, particularly the substrates of CDKs showing stronger changes in South Asians than in Chinese. Pharmacological inhibition and siRNA knockdown of CDK1, a non-myogenic kinase, in terminally differentiated myotubes reduced glucose uptake and desensitized several phosphorylation-mediated signaling on protein translation initiation factors, IRS1, and AS160. Our data suggest that basal extramitotic activity of CDK1 is required for PI3K/AKT/mTORC1 signaling cascade and glucose uptake in insulin-stimulated myotubes. The data also provide a rich resource for studying the role of other kinases in the mechanism of insulin resistance in human myotubes.

physiology↗

bioRxiv2023

Integration of eQTL and Machine Learning Methods to Dissect Causal Genes with Pleiotropic effects in Genetic Regulation Networks of Seed Cotton Yield

Expression quantitative trait loci (eQTL) provide a powerful means of investigating the biological basis of genome-wide association study (GWAS) results and exploring complex traits or phenotypes. In addition to identifying the causal gene in cis, eQTL analysis also reveals a large number of trans-regulated genes located on different chromosomes, which form a gene regulatory network (GRN) that complements the GWAS locus. However, the dissection of a GRN and the crosstalk underlying multiple agronomical traits, along with prioritizing important genes in eQTL-derived GRNs, remains a major challenge. In this study, we generated 558 transcriptional profiles of lint-bearing ovules at one day post-anthesis (DPA) from a selective core cotton germplasm, from which we identified 12,207 eQTLs. By integrating with a GWAS catalog, we found that 66 out of 187 (35.29%) known phenotypic GWAS loci are colocalized with 1,090 eQTLs, forming 38 major functional GRNs predominantly (30 out of 38) associated with seed size-related phenotypes. Of the eGenes, 34 were shared between at least two functional GRNs, exhibiting pleiotropic effects, such as NF-YB3, GRDP1, and IDD7. Narrow-sense heritability analysis showed that the heritability increased with combining the eQTLs with GRNs compared to those with previous yield trait GWAS loci. The extreme gradient boosting (XGBoost) machine learning approach was then applied to predict seed cotton yield phenotypes based on gene expression. Top-ranking eGenes (NF-YB3, FLA2, and GRDP1) derived by XGBoost with pleiotropic effects on yield traits were validated, along with their potential roles by correlation analysis, domestication selection analysis, and transgenic plants. This study provides insights into the mining of GRNs in relation to the pleiotropy of phenotype. The combination of eQTL and machine learning approaches is efficient in improving the genetic dissection of agricultural traits.

genetics↗

bioRxiv2023

A Connectome of the Male Drosophila Ventral Nerve Cord

Animal behavior is principally expressed through neural control of muscles. Therefore understanding how the brain controls behavior requires mapping neuronal circuits all the way to motor neurons. We have previously established technology to collect large-volume electron microscopy data sets of neural tissue and fully reconstruct the morphology of the neurons and their chemical synaptic connections throughout the volume. Using these tools we generated a dense wiring diagram, or connectome, for a large portion of the Drosophila central brain. However, in most animals, including the fly, the majority of motor neurons are located outside the brain in a neural center closer to the body, i.e. the mammalian spinal cord or insect ventral nerve cord (VNC). In this paper, we extend our effort to map full neural circuits for behavior by generating a connectome of the VNC of a male fly.

neuroscience↗

bioRxiv2023

Origin and early divergence of tandem duplicated sorbitol transporter genes in Rosaceae

Sorbitol is a critical photosynthate and storage substance in the Rosaceae family. Sorbitol transporters (SOTs) play a vital role in facilitating sorbitol allocation from source to sink organs and sugar accumulation in sink organs. Despite observing gene duplications in the SOT gene family, the origin and evolutionary process of these duplications are unclear, due to the complicated interplay of whole genome duplications and tandem duplications. Here, we investigated the synteny relationships of all detected Polyol/Monosaccharide Transporter (PLT) genes in 61 angiosperm genomes and SOT genes in major representative Rosaceae genomes. Combining phylogenetic analysis, we elucidated the lineage-specific expansion and syntenic conservation of PLTs and SOTs across different plant lineages. We found that Rosaceae SOTs, as PLT family members, originated from a pair of PLT tandem duplicating genes belonging to Class III-A. Additionally, lineage-specific and synergistic duplications in Amygdaloideae had contributed to the expansion of SOTs in Rosaceae plants. Overall, our findings provide insights into the genomic origins, duplication, and divergence of SOT gene family members, which are fundamental for further functional characterizations of each member.

genomics↗

bioRxiv2023

Arabidopsis NF-YCs interact with CRY2 and PIF4/5 to repress blue light-mediated hypocotyl growth

Plants can not move automatically, thus they have to perceive the changing environment (light, temperate and so on) by developing the adapted phenotypes. Light-induced hypocotyl length is an ideal phenotype for studying how plants response to light. So far, many signaling components in light-induced hypocotyl growth have been reported. Here, we focused on identifying transcription factors (TFs) involved in blue light-induced hypocotyl growth by constructing Arabidopsis TFs overexpressing lines and screening blue light-induced hypocotyl length. Finally, we found that three NF-YC proteins, NF-YC7, NF-YC5 and NF-YC8 (NF-YCs as short name), develop longer hypocotyls than the wild type under blue light. While deficient mutants, nf-yc5nf-yc7 and nf-yc7nf-yc8, fail to promote the hypocotyl elongation under blue light. NF-YCs physically interacted with CRY2 and PIF4/5, while the NF-YCs-PIF4/5 interactions were repressed by CRY2. Moreover, overexpression of CRY2 or deficiency of PIF4/5 repressed the hypocotyl elongation induced by NF-YC7 under blue light. Further investigation revealed that NF-YC7 increased the blue light-induced CRY2 degradation and regulated the activities of PIF4/5. Taking together, this study provided a new insight into that NF-YCs function as CRY2-and PIF4/5-interacting proteins and modulate their stabilization to repress the blue light-mediated hypocotyl growth. Author SummaryLight is an essential environmental factor for plants growth and development. Plants response to light signaling by displaying short hypocotyls, green leaves, and so on. The mechanisms of light responding to light have aroused extensive attention. In this study, we clarified that NF-YC family members NF-YC5/7/8 interact with CRY2, PIF4/5 and modulate their stabilization to repress the blue light-mediated hypocotyl growth. It was the first time for reporting NF-Y family members function as CRY2-and PIF4/5-interacting proteins. Therefore, this study provides a novel understanding how plants adapt to light.

genetics↗

bioRxiv2023

Resolving the developmental mechanisms of coagulation abnormalities characteristic of SARS-CoV2 based on single-cell transcriptome analysis

The COVID-19 outbreak caused by the SARS-CoV-2 virus has developed into a global health emergency. In addition to causing respiratory symptoms following SARS-CoV-2 infection, COVID-19-associated coagulopathy (CAC) is the main cause of death in patients with severe COVID-19. In this study, we performed single-cell sequencing analysis of the right ventricular free wall tissue from healthy donors, patients who died in the hypercoagulable phase of CAC, and patients in the fibrinolytic phase of CAC. Among these, we collected 61,187 cells, which were enriched in 24 immune cell subsets and 13 cardiac-resident cell subsets. We found that in response to SARS-CoV-2 infection, CD9highCCR2highmonocyte-derived mo promoted hyperactivation of the immune system and initiated the extrinsic coagulation pathway by activating CXCR-GNB/G-PI3K-AKT. This sequence of events is the main process contributing the development of coagulation disorders subsequent to SARS-CoV-2 infection. In the characteristic coagulation disorder caused by SARS-CoV-2, excessive immune activation is accompanied by an increase in cellular iron content, which in turn promotes oxidative stress and intensifies intercellular competition. This induces cells to alter their metabolic environment, resulting in an increase in sugar uptake, such as that via the glycosaminoglycan synthesis pathway, in CAC coagulation disorders. In addition, high levels of reactive oxygen species generated in response elevated iron levels promote the activation of unsaturated fatty acid metabolic pathways in endothelial cell subgroups, including vascular endothelial cells. This in turn promotes the excessive production of the toxic peroxidation by-product malondialdehyde, which exacerbates both the damage caused to endothelial cells and coagulation disorders.

microbiology↗

bioRxiv2023

Microbiome-enabled genomic selection improves prediction accuracy for nitrogen-related traits in maize

Root-associated microbiomes in the rhizosphere (rhizobiomes) are increasingly known to play an important role in nutrient acquisition, stress tolerance, and disease resistance of plants. However, it remains largely unclear to what extent these rhizobiomes contribute to trait variation for different genotypes and if their inclusion in the genomic selection (GS) protocol can enhance prediction accuracy. To address these questions, we developed a microbiome-enabled GS (MEGS) method that incorporated host SNPs and ASVs (amplicon sequence variants) from plant rhizobiomes in a maize diversity panel under high and low nitrogen (N) field conditions. Our cross-validation results showed that the MEGS model significantly outperformed the conventional GS model for nearly all time-series traits related to plant growth and N responses, with an average relative improvement of 3.7%. The improvement was more pronounced under low N conditions (8.4% -- 40.2% of relative improvement), consistent with the view that some beneficial microbes can enhance N nutrient uptake, particularly in low N fields. However, our study could not definitively rule out the possibility that the observed improvement is partially due to the ASVs being influenced by microenvironments. Using a high-dimensional mediation analysis method, our study has also identified microbial mediators that establish a link between plant genotype and phenotype. Some of the detected mediator microbes were previously reported to promote plant growth. The enhanced prediction accuracy of the MEGS models, demonstrated in a single environment, serves as a proof-of-concept for the potential application of microbiome-enabled plant breeding for sustainable agriculture.

genetics↗

bioRxiv2023

Imaging Microglia Surveillance during Sleep-wake Cycles in Freely Behaving Mice

Microglia surveillance manifests itself as dynamic changes in cell morphology and functional remodeling. Whether and how microglia surveillance is coupled to brain state switches during natural sleep-wake cycles remain unclear. To address this question, we used miniature two-photon microscopy (mTPM) to acquire time-lapse high-resolution microglia images of the somatosensory cortex, along with EEG/EMG recordings and behavioral video, in freely-behaving mice. We uncovered fast and robust brain state-dependent changes in microglia surveillance, occurring in parallel with sleep dynamics and early-onset phagocytic microglial contraction during sleep deprivation stress. We also detected local norepinephrine fluctuation occurring in a sleep state-dependent manner. We showed that the locus coeruleus-norepinephrine system, which is crucial to sleep homeostasis, is required for both sleep state-dependent and stress-induced microglial responses and {beta}2-adrenergic receptor signaling plays a significant role in this process. These results provide direct evidence that microglial surveillance is exquisitely tuned to signals and stressors that regulate sleep dynamics and homeostasis so as to adjust its varied roles to complement those of neurons in the brain. In vivo imaging with mTPM in freely behaving animals, as demonstrated here, opens a new avenue for future investigation of microglia dynamics and sleep biology in freely behaving animals.

neuroscience↗