Biology subjects

Xu, H.

Publications and source records attributed to Xu, H..

At least 397 records · Page 22Linked to original sources

bioRxiv2020

A conserved ubiquitin- and ESCRT-dependent pathway to regulate human lysosomal membrane proteins

The lysosome is an essential organelle to recycle cellular materials and maintain nutrient homeostasis, but the mechanism to down-regulate lysosomal membrane proteins is poorly understood. In this study, we developed a cycloheximide chase assay to measure the half-lives of ~30 human lysosomal membrane proteins, and identified RNF152 as a short-lived protein. The degradation of RNF152 depends on ubiquitin and the endosomal sorting complexes required for transport (ESCRT) machinery. Ubiquitinated RNF152 is sorted and internalized by the ESCRT machinery into the lysosomal lumen for degradation. Strikingly, when expressed in budding yeast, human RNF152 is also degraded by the vacuole (yeast lysosome) in an ESCRT-dependent manner. Thus, our study uncovered a conserved mechanism to down-regulate lysosome membrane proteins.

cell biology↗

bioRxiv2020

GSAP regulates mitochondrial function through the Mitochondria-associated ER membrane in the pathogenesis of Alzheimer's disease

Biochemical, pathogenic and human genetic data confirm that GSAP ({gamma}-secretase activating protein), a selective {gamma}-secretase modulatory protein, plays important roles in Alzheimers disease (AD) and Down syndrome. However, the molecular mechanism(s) underlying GSAP-dependent pathogenesis remains largely elusive. Here, through unbiased proteomics and single-nuclei RNA-seq, we identified that GSAP regulates multiple biological pathways, including protein phosphorylation, trafficking, lipid metabolism, and mitochondrial function. We demonstrated that GSAP physically interacts with Fe65:APP complex to regulate APP trafficking/partitioning. GSAP is enriched in the mitochondria-associated membrane (MAM) and regulates lipid homeostasis through the amyloidogenic processing of APP. GSAP deletion generates a lipid environment unfavorable for AD pathogenesis, leading to improved mitochondrial function and the rescue of cognitive deficits in an AD mouse model. Finally, we identified a novel GSAP single-nucleotide polymorphism that regulates its brain transcript level and is associated with an increased AD risk. Together, our findings indicate that GSAP impairs mitochondrial function through its MAM localization, and lowering GSAP expression reduces pathological effects associated with AD.

neuroscience↗

bioRxiv2020

Large-scale single-cell analysis reveals critical immune characteristics of COVID-19 patients

Dysfunctional immune response in the COVID-19 patients is a recurrent theme impacting symptoms and mortality, yet the detailed understanding of pertinent immune cells is not complete. We applied single-cell RNA sequencing to 284 samples from 205 COVID-19 patients and controls to create a comprehensive immune landscape. Lymphopenia and active T and B cell responses were found to coexist and associated with age, sex and their interactions with COVID-19. Diverse epithelial and immune cell types were observed to be virus-positive and showed dramatic transcriptomic changes. Elevation of ANXA1 and S100A9 in virus-positive squamous epithelial cells may enable the initiation of neutrophil and macrophage responses via the ANXA1-FPR1 and S100A8/9-TLR4 axes. Systemic upregulation of S100A8/A9, mainly by megakaryocytes and monocytes in the peripheral blood, may contribute to the cytokine storms frequently observed in severe patients. Our data provide a rich resource for understanding the pathogenesis and designing effective therapeutic strategies for COVID-19. HIGHLIGHTSO_LILarge-scale scRNA-seq analysis depicts the immune landscape of COVID-19 C_LIO_LILymphopenia and active T and B cell responses coexist and are shaped by age and sex C_LIO_LISARS-CoV-2 infects diverse epithelial and immune cells, inducing distinct responses C_LIO_LICytokine storms with systemic S100A8/A9 are associated with COVID-19 severity C_LI

genomics↗

bioRxiv2020

SARS-CoV-2 viroporin triggers the NLRP3 inflammatory pathway

Cytokine storm resulting from a heightened inflammatory response is a prominent feature of severe COVID-19 disease. This inflammatory response results from assembly/activation of a cell-intrinsic defense platform known as the inflammasome. We report that the SARS-CoV-2 viroporin encoded by ORF3a activates the NLRP3 inflammasome, the most promiscuous of known inflammasomes. ORF3a triggers IL-1{beta} expression via NF{kappa}B, thus priming the inflammasome while also activating it via ASC-dependent and -independent modes. ORF3a-mediated inflammasome activation requires efflux of potassium ions and oligomerization between NEK7 and NLRP3. With the selective NLRP3 inhibitor MCC950 able to block ORF3a-mediated inflammasome activation and key ORF3a residues needed for virus release and inflammasome activation conserved in SARS-CoV-2 isolates across continents, ORF3a and NLRP3 present prime targets for intervention. SummaryDevelopment of anti-SARS-CoV-2 therapies is aimed predominantly at blocking infection or halting virus replication. Yet, the inflammatory response is a significant contributor towards disease, especially in those severely affected. In a pared-down system, we investigate the influence of ORF3a, an essential SARS-CoV-2 protein, on the inflammatory machinery and find that it activates NLRP3, the most prominent inflammasome by causing potassium loss across the cell membrane. We also define key amino acid residues on ORF3a needed to activate the inflammatory response, and likely to facilitate virus release, and find that they are conserved in virus isolates across continents. These findings reveal ORF3a and NLRP3 to be attractive targets for therapy.

microbiology↗

bioRxiv2020

Roles of Signaling Compounds and WRKY31 in the Defense of Pinus massoniana L. Against Dendrolimus punctatus

Dendrolimus punctatus is an important pest affecting Masson pine (Pinus massoniana L.) forests and can cause serious economic and ecological losses. WRKY transcription factors play important roles in coping with various environmental stresses. In particular, recent studies have shown that WRKY transcription factors play an important role in plant responses against herbivorous insects. However, the mechanisms underlying the actions of these genes in the defense responses of P. massoniana L. are still unclear. Our previous study provided evidence that WRKY may play an important role in the insect resistance of P. massoniana L. In this study, application of semiochemicals such as exogenous hormones and Ca2+ by spraying increased the concentrations of endogenous hormones, terpenoid synthases, and volatile substances in P. massoniana L. and effectively improved its resistance to D. punctatus. After analyzing the WRKY family of P. massoniana L., the PmWRKY31 gene was selected and studied. Yeast two-hybrid assays showed that the LP8 gene interacted with PmWRKY31. Fluorescence-based quantitative polymerase chain reaction showed that after treatment with exogenous hormones and Ca2+, the expression levels of the PmWRKY31 gene, hormonal signal-related genes, and terpene biosynthetic pathway-related genes were significantly increased, whereas the expression of the LP8 gene was decreased. Therefore, the PmWRKY31 and LP8 genes affected downstream gene expression by positively and negatively regulating the hormone signaling pathways, respectively. This result provides theoretical support for the involvement of WRKY transcription factors in the insect resistance of P. massoniana L. through their regulation of hormone signaling.

plant biology↗

bioRxiv2020

The mouse cortico-basal ganglia-thalamic network

The cortico-basal ganglia-thalamic loop is one of the fundamental network motifs in the brain. Revealing its structural and functional organization is critical to understanding cognition, sensorimotor behavior, and the natural history of many neurological and neuropsychiatric diseases. Classically, the basal ganglia is conceptualized to contain three primary information output channels: motor, limbic, and associative. However, given the roughly 65 cortical areas and two dozen thalamic nuclei that feed into the dorsal striatum, a three-channel view is overly simplistic for explaining the myriad functions of the basal ganglia. Recent works from our lab and others have subdivided the dorsal striatum into numerous functional domains based on convergent and divergent inputs from the cortex and thalamus. To complete this work, we generated a comprehensive data pool of [~]700 injections placed across the striatum, external globus pallidus (GPe), substantia nigra pars reticulata (SNr), thalamic nuclei, and cortex. We identify 14 domains of SNr, 36 in the GPe, and 6 in the parafascicular and ventromedial thalamic nuclei. Subsequently, we identify 6 parallel cortico-basal ganglia-thalamic subnetworks that sequentially transduce specific subsets of cortical information with complex patterns of convergence and divergence through every elemental node of the entire cortico-basal ganglia loop. These experiments reveal multiple important novel features of the cortico-basal ganglia network motif. The prototypical sub-network structure is characterized by a highly interconnected nature, with cortical information processing through one or more striatal nodes, which send a convergent output to the SNr and a more parallelized output to the GPe; the GPe output then converges with the SNr. A domain of the thalamus receives the nigral output, and is interconnected with both the striatal domains and the cortical areas that filter into its nigral input source. This study provides conceptual advancement of our understanding of the structural and functional organization of the classic cortico-basal ganglia network.

neuroscience↗

bioRxiv2020

Hydroxychloroquine increased psychiatric-like behaviors and disrupted the expression of related genes in the mouse brain

Hydroxychloroquine (HCQ), which has been proposed as a therapeutic or prophylactic drug for SARS-COV-2, has been administered to thousands of individuals with varying efficacy; however, our understanding of its adverse effects is insufficient. It was reported that HCQ induced psychiatric symptoms in a few patients with autoimmune diseases, but it is still uncertain whether HCQ poses a risk to mental health. Therefore, in this study, we treated healthy mice with two different doses of HCQ that are comparable to clinically administered doses for 7 days. Psychiatric-like behaviors and the expression of related molecules in the brain were evaluated at two time points, i.e., 24 h and 10 days after drug administration. We found that HCQ increased anxiety behavior at both 24 h and 10 days and enhanced depressive behavior at 24 h. Furthermore, HCQ decreased the mRNA expression of interleukin-1beta and corticotropin-releasing hormone (Crh) in the hippocampus and decreased the mRNA expression of brain-derived neurotrophic factor (Bdnf) in both the hippocampus and amygdala. Most of these behavioral and molecular changes were sustained beyond 10 days after drug administration, and some of them were dose-dependent. Although this animal study does not prove that HCQ has a similar effect in humans, it indicates that HCQ poses a significant risk to mental health and suggests that further clinical investigation is essential. According to our data, we recommend that HCQ be carefully used as a prophylactic drug in people who are susceptible to mental disorders.

animal behavior and cognition↗

bioRxiv2020

Prevailing role of mucosal immunoglobulions and B cells in teleost skin immune responses to bacterial infection

The skin of vertebrates is the outermost organ of the body and serves as the first line of defense against external aggressions. In contrast to mammalian skin, that of teleost fish lacks keratinization and has evolved to operate as a mucosal surface containing a skin-associated lymphoid tissue (SALT). Thus far, IgT representing the prevalent immunoglobulin (Ig) in SALT have only been reported upon infection with a parasite. However, very little is known about the types of B cells and Igs responding to bacterial infection in the teleost skin mucosa, as well as the inductive or effector role of the SALT in such responses. To address these questions, here we analyzed the immune response of trout skin upon infection with one of the most widespread fish skin bacterial pathogens, Flavobacterium columnare. This pathogen induced strong skin innate immune and inflammatory responses at the initial phases of infection. More critically, we found that the skin mucus of fish having survived the infection contained significant IgT-but not IgM- or IgD-specific titers against the bacteria. Moreover, we demonstrate the local proliferation and production of IgT+ B-cells and specific IgT titers respectively within the SALT upon bacterial infection. Thus, our findings represent the first demonstration that IgT is the main Ig isotype induced by the skin mucosa upon bacterial infection, and that because of the large surface of the skin, its SALT probably represents a prominent IgT inductive site in fish.

immunology↗

bioRxiv2020

A non-canonical EZH2 function sensitizes solid tumors to genotoxic stress

Drugs that block the activity of the methyltransferase EZH2 are in clinical development for the treatment of non-Hodgkin lymphomas harboring gain-of-function EZH2 mutations that enhance its polycomb repressive function. In contrast, in castration-resistant prostate cancer (CRPC) we have previously reported that EZH2 plays a non-canonical role as a transcriptional activator. In this setting, we now show that EZH2 inhibitors can also block the non-canonical activity of EZH2 and inhibit the growth of CRPC cells. Gene expression and epigenomic profiling of cells treated with EZH2 inhibitors demonstrated that rather than de-repressing tumor suppressor genes silenced by PRC2, EZH2 inhibitors downregulate a set of DNA repair genes that are directly regulated by EZH2. In addition, genome-wide CRISPR/Cas9-mediated loss-of-function screens in the presence of EZH2 inhibitors identified these DNA repair genes to underlie the growth-inhibitory function of these compounds. Interrogation of public data from diverse solid tumor types expressing wild-type EZH2 showed that expression of DNA damage repair genes is significantly correlated with cellular sensitivity to EZH2 inhibitors. Consistent with these findings, treatment of CRPC cells with EZH2 inhibitors dramatically enhanced their sensitivity to genotoxic stress. These studies reveal a previously unappreciated mechanism of action of EZH2 inhibitors and provide a mechanistic basis for potential new combination cancer therapies.

cancer biology↗

bioRxiv2020

Human cells contain myriad excised linear intron RNAs with potential functions in gene regulation and utility as disease biomarkers

Previous Thermostable Group II Intron Reverse Transcriptase sequencing (TGIRT-seq) found that human plasma contains short ([≤]300 nt) structured full-length excised linear intron RNAs (FLEXIs) with potential utility as blood-based biomarkers. Here, TGIRT-seq identified >9,000 different FLEXIs in human cells, including relatively abundant FLEXIs with cell-type-specific expression patterns. Analysis of published CLIP-seq datasets identified 126 RNA-binding proteins (RBPs) that bind different FLEXIs, including 53 RBPs that bind [≥]30 FLEXIs. These RBPs included splicing factors, transcription factors, a chromatin remodeling protein, cellular growth regulators, and proteins with cytoplasmic functions. Analysis of published datasets identified subsets of these RBPs that bind at FLEXI splice sites and impact alternative splicing or FLEXI host gene mRNA levels. Hierarchical clustering identified 6 subsets of RBPs whose binding sites were co-enriched in different subsets of FLEXIs: AGO1-4 and DICER, including but not limited to annotated agotrons and mirtron pre-miRNAs; DKC1, NOLC1, SMNDC1, and AATF (Apoptosis Antagonizing Transcription Factor), including but not limited to FLEXIs encoding snoRNAs; two sets of alternative splicing factors; and two sets that included RBPs with cytoplasmic functions (e.g., LARP4, PABPC4, METAP2, and ZNF622) together with nuclear regulatory proteins. The subsets of host genes encoding FLEXIs that bind these RBPs were enriched with non-FLEXI other short and long introns that bind the same RBPs, and TGIRT-seq of nuclear and cytoplasmic fractions from 4 cell lines showed cytoplasmic enrichment of FLEXIs with binding sites for RBPs that function in the cytoplasm. Collectively, our findings suggest that different subsets of RBPs bind FLEXIs and other introns to coordinately regulate the expression of functionally related host genes and then co-localize with stably bound FLEXIs to different intracellular locations. The cell-type specific expression of relatively abundant FLEXIs suggests utility as cellular as well as blood-based RNA biomarkers.

genomics↗

bioRxiv2020

Resetting of 24-nt siRNA landscape is initiated in the unicellular zygote in rice

BackgroundThe zygote, a totipotent stem cell, constitutes a critical stage of the life cycle of sexually reproducing organisms. It is produced by the fusion of two differentiated cells -- the egg and sperm, which in plants have radically different siRNA transcriptomes from each other and from multicellular embryos. Due to technical challenges, the epigenetic changes that accompany the zygotic transition are poorly understood. ResultsHere, we characterized the small RNA transcriptome of rice zygotes. We found widespread redistribution of 24-nt siRNAs relative to gametes, including absence of sperm signature siRNAs, reduction at egg signature siRNA loci, and upregulation at seedling signature siRNA loci. Loci with reduced siRNAs in zygote relative to egg were gene-distal and heterochromatic, while loci with increased siRNAs relative to egg had a similar genomic distribution to canonical siRNA loci. Although both egg and zygote siRNA loci had higher mCHH level in wildtype than in drm2 embryo, zygote but not egg siRNA loci were associated with hypermethylation in mature embryo. A small fraction of siRNA loci (~1%) called siren loci accounted for 60% of all siRNAs within zygote siRNA loci, that likely arose from maternal carryover as they had similarly abundant siRNAs in egg; these siren loci were not associated with embryo hypermethylation. ConclusionsTaken together, our results indicate re-distribution of siRNAs in rice zygotes towards the canonical vegetative profile, that are consistent with the initiation of resetting of the gametic epigenome before the first embryonic division.

plant biology↗

bioRxiv2020

Maladaptive myelination promotes epileptogenesis in absence epilepsy

Neuronal activity can influence the generation of new oligodendrocytes (oligodendrogenesis) and myelination. In health, this is an adaptive process that can increase synchrony within distributed neuronal networks and contribute to cognitive function. We hypothesized that in seizure disorders, aberrant neuronal activity may promote maladaptive myelination that contributes to pathogenesis. Absence epilepsy is a disease defined by increasingly frequent behavioral arrest seizures over time, thought to be due to thalamocortical network hypersynchrony. We tested the hypothesis that activity-dependent myelination resulting from absence seizures promotes epileptogenesis. Using two distinct models of absence epilepsy, Wag/Rij rats and Scn8a+/mut mice, we found increased oligodendrogenesis and myelination specifically within the absence seizure network. These changes are evident only after seizure onset in both models and are prevented with pharmacological inhibition of seizures. Genetic blockade of activity-dependent myelination during epileptogenesis markedly decreased seizure frequency in the Scn8a+/mut mouse model of absence epilepsy. Taken together, these findings indicate that activity-dependent myelination driven by absence seizures contributes to seizure kindling during epileptogenesis.

neuroscience↗

bioRxiv2020

Abnormal energy metabolism can alter foraging behavior in termites in different social contexts

Foraging behavior, as an energy-consuming behavior, is very important for collective survival in termites. How energy metabolism related to glucose decomposition and ATP production influences foraging behavior in termites is still unclear. Here, we analyzed the change in energy metabolism in the whole organism and brain after silencing the key metabolic gene isocitrate dehydrogenase (IDH) and then investigated its impact on foraging behavior in the subterranean termite Odontotermes formosanus in different social contexts. The IDH gene exhibited higher expression in the abdomen and head of O. formosanus. The knockdown of IDH resulted in metabolic disorders in the whole organism, including the impairment of the NAD+-IDH reaction and decreased ATP levels and glucose accumulation. The dsIDH-injected workers showed significantly reduced walking activity but increased foraging success. Interestingly, IDH downregulation altered brain energy metabolism, resulting in a decline in ATP levels and an increase in IDH activity. Additionally, the social context obviously affected brain energy metabolism and, thus, altered foraging behavior in O. formosanus. We found that the presence of predator ants increased the negative influence on the foraging behavior of dsIDH-injected workers, including a decrease in foraging success. However, an increase in the number of nestmate soldiers could provide social buffering to relieve the adverse effect of predator ants on worker foraging behavior. Our orthogonal experiments further verified that the role of the IDH gene as an inherent factor was dominant in manipulating termite foraging behavior compared with external social contexts, suggesting that energy metabolism, especially brain energy metabolism, plays a crucial role in regulating termite foraging behavior. Author summaryForaging behavior plays a key role in collective survival in social insects, as found in termites. Worker termites are responsible for foraging duty and exhibit large foraging areas and long foraging distances, so they need to consume much energy during foraging. It is well established that energy can influence insect behaviors. However, how energy metabolism affects foraging behavior in termites remains unknown. Here, we found that the downregulation of the conserved metabolic gene IDH impaired whole-organism and the brain energy metabolism and further altered foraging behavior, resulting in decreased walking activity but increased foraging success in the termite O. formosanus, which is an important insect pest damaging embankments and trees in China. Additionally, the social context affected brain energy metabolism and obviously changed foraging behavior in O. formosanus, causing a decline in foraging success in the absence of nestmate soldiers and the presence of predator ants. However, the increasing number of nestmate soldiers strengthened social buffering to relieve the negative effect of predator ants on worker foraging behavior. Our findings provide new insights into the underlying molecular mechanism involved in modulating the sophisticated foraging strategy of termites in different social contexts from the perspective of energy metabolism.

animal behavior and cognition↗

bioRxiv2020

Distinct roles of two RDL GABA-receptors in fipronil action in the diamondback moth (Plutella xylostella)

The phenylpyrazole insecticide, fipronil, blocks insect RDL {gamma}-aminobutyric acid (GABA) receptors, thereby impairs inhibitory neurotransmission. Some insect species, such as the diamondback moth (Plutella xylostella), possess more than one Rdl gene. The involvement of multiple Rdls in fipronil toxicity and resistance remain largely unknown. In this study, we investigated the roles of two Rdl genes, PxRdl1 and PxRdl2, from P. xylostella in the action of fipronil. Expressed in Xenopus oocytes, PxRDL2 receptors were 40-times less sensitive to fipronil than PxRDL1. PxRDL2 receptors were also less sensitive to GABA compared to PxRDL1. Knockout of the fipronil-sensitive PxRdl1 gene reduced the potency of fipronil by 10 fold, whereas knockout of the fipronil-resistant PxRdl2 gene enhanced the potency of fipronil by 4.4 fold. Furthermore, in two fipronil-resistant diamondback moth field populations, the expression of PxRdl2 was elevated by 3.7-fold and 4.1-fold, respectively compared to a susceptible strain, whereas the expression of PxRdl1 was comparable among the resistant and susceptible strains. Collectively, our results indicate antagonistic effects of PxRDL1 and PxRDL2 on the fipronil action in vivo and suggest enhanced expression of fipronil-resistant PxRdl2 potentially a new mechanism of fipronil resistance in insects.

molecular biology↗

bioRxiv2020

An improved Nicotiana benthamiana strain for aphid and whitefly research

Nicotiana benthamiana is used extensively as a platform for transient gene expression and as a model system for studying plant-virus interactions. However, many tobacco-feeding generalist herbivores, including Myzus persicae (green peach aphid), Bemisia tabaci (whitefly), Macrosiphum euphorbiae (potato aphid), Heliothis virescens (tobacco budworm), Trichoplusia ni (cabbage looper), and Helicoverpa zea (corn earworm), grow poorly on N. benthamiana, limiting its utility for research on plant-insect interactions. Using CRISPR/Cas9, we generated knockout mutations in two N. benthamiana acylsugar acyltransferases, ASAT1 and ASAT2, which contribute to the biosynthesis of insect-deterrent acylsucroses. Whereas asat1 mutations reduced the abundance of two predominant acylsucroses, asat2 mutations caused almost complete depletion of foliar acylsucroses. The tested hemipteran and lepidopteran species survived, gained weight, and/or reproduced significantly better on asat2 mutant plants than on wildtype N. benthamiana. Furthermore, both asat1 and asat2 mutations reduced the water content and increased the temperature of leaves, indicating that foliar acylsucroses can protect against desiccation. Two experiments demonstrated the utility of the N. benthamiana asat2 mutant line for insect bioassays. Transmission of turnip mosaic virus by M. persicae was significantly improved by an asat2 mutation. Tobacco rattle virus constructs were used for virus-induced gene silencing of acetylcholinesterase, squalene synthase, toll-like receptor 7, and tubulin-specific chaperon D genes in B. tabaci, an experiment that would have been difficult with wild-type N. benthamiana due to high insect mortality. Additionally, the absence of acylsugars in asat2 mutant lines will simplify transient expression assays for the functional analysis of acylsugar biosynthesis genes from other Solanaceae.

plant biology↗

bioRxiv2020

Non-canonical, potassium-driven cerebrospinal fluid clearance

Cerebrospinal fluid (CSF) provides vital support for the brain. Abnormal CSF accumulation is deleterious for perinatal neurodevelopment, but how CSF leaves the brain during this critical period is unknown. We found in mice a postnatal neurodevelopmental transition phase featuring precipitous CSF K+ clearance, accompanied by water, through the choroid plexus (ChP). The period corresponds to a human fetal stage when canonical CSF clearance pathways have yet to form and congenital hydrocephalus begins to manifest. Unbiased ChP metabolic and ribosomal profiling highlighted this transition phase with increased ATP yield and activated energy-dependent K+ transporters, in particular the Na+-K+-Cl- and water cotransporter NKCC1. ChP-targeted NKCC1 overexpression enhanced K+-driven CSF clearance and enabled more permissive cerebral hydrodynamics. Moreover, ventriculomegaly in an obstructive hydrocephalus model was improved by ChP-targeted NKCC1 overexpression. Collectively, we identified K+-driven CSF clearance through ChP during a transient but critical neurodevelopmental phase, with translational value for pathologic conditions.

neuroscience↗

bioRxiv2020

Combination of ipratropium bromide and salbutamol in children and adolescents with asthma: a meta-analysis

BackgroundA combination of ipratropium bromide (IB) and salbutamol is commonly used to treat asthma in children and adolescents; however, there has been a lack of consistency in its usage in clinical practice. ObjectiveTo evaluate the efficacy and safety of IB + salbutamol in the treatment of asthma in children and adolescents. MethodsThe MEDLINE, Embase, and Cochrane Library as well as other Chinese biomedical databases (including China Biological Medicine Database, Chinese National Knowledge Infrastructure, Chongqing VIP, and Wanfang Chinese language bibliographic database) were systematically searched from the date of database inception to 02/09/2019 for randomized controlled trials in children and adolescents ([≤]18 years) with asthma who received IB + salbutamol or salbutamol alone. The primary outcomes included hospital admission and adverse events. A random effects model with a 95% confidence interval (CI) was used. Subgroup analysis was performed according to age, severity of asthma, and co-interventions with other asthma controllers. This study was registered with PROSPERO. ResultsOf the 637 studies that were identified, 55 met the inclusion criteria and involved 6396 participants. IB + salbutamol significantly reduced the risk of hospital admission compared with salbutamol alone (risk ratio [RR] 0.79; 95% CI 0.66-0.95; p = 0.01; I2 = 40%). Subgroup analysis only showed significant difference in the risk of hospital admission in participants with severe asthma exacerbation (RR 0.71; 95% CI 0.60-0.85; p = 0.0001; I2 = 0%) and moderate-to-severe exacerbation (RR 0.69; 95% CI 0.50-0.96; p = 0.03; I2 = 3%). There were no significant differences in the risk of adverse events between IB + salbutamol group and salbutamol alone group (RR 1.77; 95% CI 0.63-4.98). ConclusionIB + salbutamol may be more effective than salbutamol alone for the treatment of asthma in children and adolescents, especially in those with severe and moderate to severe asthma exacerbation. Future prospective research on these subgroup population are needed.

pharmacology and toxicology↗

bioRxiv2020

Automated and accurate segmentation of leaf venation networks via deep learning

O_LILeaf vein network geometry can predict levels of resource transport, defence, and mechanical support that operate at different spatial scales. However, it is challenging to quantify network architecture across scales, due to the difficulties both in segmenting networks from images, and in extracting multi-scale statistics from subsequent network graph representations. C_LIO_LIHere we develop deep learning algorithms using convolutional neural networks (CNNs) to automatically segment leaf vein networks. Thirty-eight CNNs were trained on subsets of manually-defined ground-truth regions from >700 leaves representing 50 southeast Asian plant families. Ensembles of 6 independently trained CNNs were used to segment networks from larger leaf regions (~100 mm2). Segmented networks were analysed using hierarchical loop decomposition to extract a range of statistics describing scale transitions in vein and areole geometry. C_LIO_LIThe CNN approach gave a precision-recall harmonic mean of 94.5% {+/-} 6%, outperforming other current network extraction methods, and accurately described the widths, angles, and connectivity of veins. Multi-scale statistics then enabled identification of previously-undescribed variation in network architecture across species. C_LIO_LIWe provide a LeafVeinCNN software package to enable multi-scale quantification of leaf vein networks, facilitating comparison across species and exploration of the functional significance of different leaf vein architectures. C_LI

plant biology↗