Biology subjects

Wen, Y.

Publications and source records attributed to Wen, Y..

At least 91 records · Page 5Linked to original sources

bioRxiv2021

A penalized linear mixed model with generalized method of moments for complex phenotype prediction

Linear mixed models have long been the method of choice for risk prediction analysis on high-dimensional genomic data. However, it remains computationally challenging to simultaneously model a large amount of genetic variants that can be noise or have predictive effects of complex forms. In this work, we have developed a penalized linear mixed model with generalized method of moments (pLMMGMM) estimators for prediction analysis. pLM-MGMM is built within the linear mixed model framework, where random effects are used to model the joint predictive effects from all genetic variants within a region. Fundamentally different from existing methods that usually focus on linear relationships and use empirical criteria for feature screening, pLMMGMM can jointly consider a large number of genetic regions and efficiently select those harboring variants with both linear and non-linear predictive effects. Through theoretical investigations, we have shown that our method has the selection consistency, estimation consistency and asymptotic normality. Through extensive simulations and the analysis of PET-imaging outcomes, we have demonstrated that pLMMGMM outperformed existing models and it can accurately detect regions that harbor risk factors with various forms of predictive effects.

bioinformatics↗

bioRxiv2021

A sensitive and specific genetically encodable biosensor for potassium ions

Potassium ions (K+) play a critical role as an essential electrolyte in all biological systems. Here we report the crystal structure-guided optimization and directed evolution of an improved genetically encoded fluorescent K+ biosensor, GINKO2. GINKO2 is highly sensitive and specific for K+ and enables in vivo detection of K+ dynamics in multiple species.

bioengineering↗

bioRxiv2021

Profiling tumor immune microenvironment of non-small cell lung cancer using multiplex immunofluorescence

PurposeWe attempt to profile the tumor immune microenvironment (TIME) of non-small cell lung cancer (NSCLC) by multiplex immunofluorescence (MIF). Experimental DesignMIF test was performed on 681 NSCLC cases in our center between 2009 and 2011. The number, density, proportion and correlation of 26 types of immune cells in tumor nest and tumor stroma were evaluated. An unsupervised consensus clustering approach was utilized to identify robust clusters of patients. Immune-related risk score (IRRS) was constructed for prognosis prediction for disease-free survival (DFS). ResultsThe landscape of TIME was illustrated, revealing some close interactions particularly between intrastromal neutrophils and intratumoral regulatory T cells (Treg) (r2 = 0.439, P < 0.001), intrastromal CD4+CD38+ T cells and intrastromal CD20-positive B cells (r2 = 0.539, P < 0.001), and intratumoral CD8-positive T cells and intratumoral M2 macrophages expressing PD-L1 (r2 = 0.339, P < 0.001). Three immune subtypes correlated with distinct immune characteristics and clinical outcomes were identified. The immune-activated subtype had the longest DFS and demonstrated the highest infiltration of CD4-positive T cells and CD20-positive B cells. The immune-defected subtype had the highest levels of cancer stem cells and macrophages. The immune-exempted subtype had the highest levels of neutrophils and Treg. The IRRS based on six robust prognostic biomarkers showed potential ability for risk stratification (high vs. median vs. low) and prediction of five-year DFS rates (43.1% vs. 37.9% vs. 23.2%, P<0.001). ConclusionsOur study profiled the intricate and intrinsic structure of TIME in NSCLC, which showed potency in subtyping and prognostication. Translational RelevanceSignificant unmet need exists in understanding the tumor immune microenvironment (TIME) of non-small cell lung cancer (NSCLC) and its correlation with prognosis. In this retrospective cohort study (n = 681), we profiled the immune landscape of NSCLC in situ and identified a novel stratification of TIME by three immune subtypes: immune-activated, immune-exempted, and immune-defected using multiplex immunofluorescence for testing 26 kinds of immune cells. Each of the immune subtypes was correlated with distinct composition, spatial distribution, and functional orientation of immune cells, and accordingly indicating significantly different disease-free survival (DFS). Close interactions were observed for several kinds of immune cells, including neutrophils and regulatory T cells, CD4+CD38+ T cells and CD20-positive B cells, and CD8-positive T cells and M2 macrophages. We also developed the immune-related risk score (IRRS) with different immune characteristics based on six robust immune biomarkers in TIME and evaluated its role in risk stratification and prognosis prediction of DFS. This study might bring potential clinical implementations for the design of novel immunotherapies and the optimization of combined strategies.

cancer biology↗

bioRxiv2021

Genetic characteristics of human papillomavirus type 16, 18, 52 and 58 in southern China

Persistent infections of high-risk human papillomaviruses (HPVs) are the leading cause of cervical cancers. We collected cervical exfoliated cell samples from females in Changsha city, Hunan Province and obtained 358 viral genomes of four major HPV types, including HPV 16 (n=82), 18 (n=35), 52 (n=121) and 58 (n=100). The lineage/sublineage distribution of the four HPVs confirmed previous epidemiological reports, with the predominant prevailing sublineage as A4 (50%), A1 (37%) and A3 (13%) for HPV16, A1 (83%) for HPV18, B2 (86%) for HPV52 and A1 (65%), A3 (19%) and A2 (12%) for HPV58. We also identified two potentially novel HPV18 sublineages, i.e. A6 and A7. Virus mutation analysis further revealed the presence of HPV16 and HPV58 strains associated with potentially high oncogenicity. These findings expanded our knowledge on the HPV genetic diversity in China, providing valuable evidence to facilitate HPV DNA screening, vaccine effectiveness evaluation and control strategy development.

genomics↗

bioRxiv2021

Chitinase 3-like-1 Contributes to Acetaminophen-induced Liver Injury by Promoting Hepatic Platelet Recruitment

Hepatic platelet accumulation contributes to acetaminophen (APAP)-induced liver injury (AILI). However, little is known about the molecular pathways involved in platelet recruitment to the liver and whether targeting such pathways could attenuate AILI. The present study unveiled a critical role of chitinase 3-like-1 (Chi3l1) in hepatic platelet recruitment during AILI. Increased Chi3l1 and platelets in the liver were observed in patients and mice overdosed with APAP. Compared to wild-type (WT) mice, Chi3l1-/- mice developed attenuated AILI with markedly reduced hepatic platelet accumulation. Mechanistic studies revealed that Chi3l1 signaled through CD44 on macrophages to induce podoplanin expression, which mediated platelet recruitment through C-type lectin-like receptor 2. Moreover, APAP treatment of CD44-/- mice resulted in much lower numbers of hepatic platelets and liver injury than WT mice, a phenotype similar to that in Chi3l1-/- mice. Recombinant Chi3l1 could restore hepatic platelet accumulation and AILI in Chi3l1-/- mice, but not in CD44-/- mice. Importantly, we generated anti-Chi3l1 monoclonal antibodies and demonstrated that they could effectively inhibit hepatic platelet accumulation and AILI. Overall, we uncovered the Chi3l1/CD44 axis as a critical pathway mediating APAP-induced hepatic platelet recruitment and tissue injury. We demonstrated the feasibility and potential of targeting Chi3l1 to treat AILI.

pharmacology and toxicology↗

bioRxiv2021

A genetically encoded fluorescent biosensor for extracellular L-lactate

To enable investigations of the emerging roles of cell-to-cell shuttling of L-lactate, we have developed an intensiometric green fluorescent genetically encoded biosensor for extracellular L-lactate. We demonstrate that this biosensor, designated eLACCO1.1, enables minimally invasive cellular resolution imaging of extracellular L-lactate in cultured mammalian cells and brain tissue.

molecular biology↗

bioRxiv2021

Task-specific elevation of motor learning by conjunctive transcranial direct current stimulation

The optimal protocol for neuromodulation by transcranial direct current stimulation (tDCS) remains unclear. Using rotarod paradigm, we found that mouse motor learning was enhanced by anodal tDCS (3.2 mA/cm2) during but not before or after task performance. Dual-task experiments showed that motor learning enhancement was specific to the task accompanied by concurrent anodal tDCS. Studies using stroke model mice induced by middle cerebral artery occlusion (MCAO) showed that concurrent anodal tDCS restored motor learning capability in a task-specific manner. Transcranial in vivo calcium imaging further showed that anodal and cathodal tDCS elevated and suppressed neuronal activity in the primary motor cortex (M1), respectively. Anodal tDCS specifically promoted the activity of task-related M1 neurons during task performance, suggesting that elevated Hebbian synaptic potentiation in task-activated circuits accounts for motor learning enhancement. Thus, application of tDCS concurrent with the targeted behavioral dysfunction could represent a more effective approach for treating brain disorders.

neuroscience↗

bioRxiv2020

Genetic and Epigenetic Regulation of Skeletal Muscle Ribosome Biogenesis with Exercise

Ribosomes are the macromolecular engines of protein synthesis. Skeletal muscle ribosome biogenesis is stimulated by exercise, but the contribution of ribosomal DNA (rDNA) copy number and methylation to exercise-induced rDNA transcription is unclear. To investigate the genetic and epigenetic regulation of ribosome biogenesis with exercise, a time course of skeletal muscle biopsies was obtained from 30 participants (18 men and 12 women; 31 {+/-}8 yrs, 25 {+/-}4 kg/m2) at rest and 30 min, 3h, 8h, and 24h after acute endurance (n=10, 45 min cycling, 70% VO2max) or resistance exercise (n=10, 4 x 7 x 2 exercises); 10 control participants underwent biopsies without exercise. rDNA transcription and dosage were assessed using qPCR and whole genome sequencing. rDNA promoter methylation was investigated using massARRAY EpiTYPER, and global rDNA CpG methylation was assessed using reduced-representation bisulfite sequencing. Ribosome biogenesis and MYC transcription were associated with resistance but not endurance exercise, indicating preferential up-regulation during hypertrophic processes. With resistance exercise, ribosome biogenesis was associated with rDNA gene dosage as well as epigenetic changes in enhancer and non-canonical MYC-associated areas in rDNA, but not the promoter. A mouse model of in vivo metabolic RNA labeling and genetic myonuclear fluorescent labeling validated the effects of an acute hypertrophic stimulus on ribosome biogenesis and Myc transcription, and corroborated rDNA enhancer and Myc-associated methylation alterations specifically in myonuclei. This study provides the first information on skeletal muscle genetic and rDNA gene-wide epigenetic regulation of ribosome biogenesis in response to exercise, revealing novel roles for rDNA dosage and CpG methylation. GRAPHICAL ABSTRACT O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

cell biology↗

bioRxiv2020

Improved Photocleavable Proteins with Faster and More Efficient Dissociation

The photocleavable protein (PhoCl) is a green-to-red photoconvertible fluorescent protein that, when illuminated with violet light, undergoes main chain cleavage followed by spontaneous dissociation of the resulting fragments. The first generation PhoCl (PhoCl1) exhibited a relative slow rate of dissociation, potentially limiting its utilities for optogenetic control of cell physiology. In this work, we report the X-ray crystal structures of the PhoCl1 green state, red state, and cleaved empty barrel. Using structure-guided engineering and directed evolution, we have developed PhoCl2c with higher contrast ratio and PhoCl2f with faster dissociation. We characterized the performance of these new variants as purified proteins and expressed in cultured cells. Our results demonstrate that PhoCl2 variants exhibit faster and more efficient dissociation, which should enable improved optogenetic manipulations of protein localization and protein-protein interactions in living cells.

synthetic biology↗

bioRxiv2020

Retinal glial cells under hypoxia possibly function in mammalian myopia by responding to mechanical stimuli, affecting hormone metabolism and peptide secretion

PurposeChanges in the retina and the choroid blood vessels are regularly observed in myopia. The aim of this study is to test if the retinal glial cells, which directly contact blood vessels, play a role in mammalian myopia. MethodWe adapted the common form-deprivation myopia mouse model and used the retina slice and whole-mount immunofluorescence technique to evaluate changes in the morphology, and distribution of retinal glial cells. We then searched the Gene Expression Omnibus database for series on myopia and retinal glial cells (astrocytes and Muller cells). Using review articles and the National Center for Biotechnology Information gene database, we obtained clusters of myopia-related gene lists. By searching SwissTargetPrediction, we collected information on atropine target proteins. We then used online tools to find the Gene Ontology analysis enriched clusters, pathways, and proteins that provide correlative evidence. ResultGlial fibrillary acidic protein fluorescence was observed in mice eyes that were covered and deprived of light for five days compared to uncovered eyes, and the cell morphology became more star-like. From in silico experiments, we identified several pathways and proteins that were common to both myopia and retinal glial cells in hypoxic conditions. The common pathways in human astrocytes represented response to mechanical stimuli, peptide secretion, skeletal system development, and monosaccharide binding. In mouse Muller cells, the pathways represented membrane raft and extracellular structure organisation. The proteins common to myopia and hypoxic glial cells were highly relevant to atropine target proteins. ConclusionRetinal astrocytes and Muller cells under hypoxic conditions contribute to the development of myopia, and may be a valid target for atropine.

bioinformatics↗

bioRxiv2020

Assembly of higher-order SMN oligomers is essential for metazoan viability and requires an exposed structural motif present in the YG zipper dimer

Protein oligomerization is one mechanism by which homogenous solutions can separate into distinct liquid phases, enabling assembly of membraneless organelles. Survival Motor Neuron (SMN) is the eponymous component of a large macromolecular complex that chaperones biogenesis of eukaryotic ribonucleoproteins, and localizes to distinct membraneless organelles in both the nucleus and cytoplasm. SMN forms the oligomeric core of this complex, and missense mutations within its YG box domain are known to cause Spinal Muscular Atrophy (SMA). The SMN YG box utilizes a variation of the glycine zipper motif to form dimers, but the mechanism of higher-order oligomerization remains unknown. Here, we use a combination of molecular genetic, bioinformatic, biophysical, and computational approaches to show that formation of higher-order SMN oligomers depends on a set of YG box residues that are not involved in dimerization. Mutation of key residues within this new structural motif restricts assembly of SMN to dimers and causes locomotor dysfunction and viability defects in animal models.

biochemistry↗

bioRxiv2020

High-resolution architecture of human epiphysis formation

Human limb skeletal system consists of both bone and cartilage which originated from fetal cartilage. However, the roadmap of chondrocyte divergent differentiation to bone and articular cartilage has yet to be established. Epiphysis possesses articular cartilage, growth plate and the secondary ossification center (SOC), making it an ideal model to uncover the trajectory of chondrocyte divergent differentiation. Here, we mapped differentiation trajectory of human chondrocyte during postnatal finger epiphysis development by using single-cell RNA sequencing. Our results uncovered that chondroprogenitors have two differentiation pathways to hypertrophic chondrocytes during ossification, and one pathway to articular chondrocytes for formation of cartilages. Interestingly, we found that, as an addition to the known typical endochondral ossification path from resting, proliferative to hypertrophic chondrocytes, there was a bypass by which chondroprogenitors differentiate into hypertrophic chondrocytes without proliferative stage. Furthermore, our results revealed two new chondrocyte subpopulations (bypass chondrocytes as it appeared in the ossification bypass, and ID1+ chondroblasts in articular chondrocyte path) during postnatal epiphysis development in addition to six well-known subpopulations. Overall, our study provides a comprehensive roadmap of chondrocyte differentiation in human epiphysis thereby expanding the knowledge of bone and articular cartilage, which could be utilized to design biotherapeutics for bone and articular cartilage regeneration.

developmental biology↗

bioRxiv2020

The role of cation diffusion facilitator CDF-1 in lipid metabolism in Caenorhabditis elegans

Zinc is one of the most important trace elements that plays a vital role in many biological processes, and aberrant zinc metabolism has been implicated in lipid-related metabolic diseases. Previously, we showed that zinc antagonizes iron to regulate sterol regulatory element-binding proteins and stearoyl-CoA desaturase (SREBP-SCD) pathway in lipid metabolism in model organism Caenorhabditis elegans. Here, we further identified another cation diffusion facilitator CDF-1 in addition to SUR-7 in response to zinc to regulate lipid metabolism. Inactivation of SBP-1, the only homolog of SREBPs, leads to increased zinc level but decreased lipid accumulation reversely. However, either cdf-1(n2527) or sur-7(tm6523) mutation could successfully restore the altered fatty acid profile, fat content and zinc level of sbp-1(ep79) mutant. Furthermore, we found that CDF-1/SUR-7 may function bypass SBP-1 to directly affect the conversion activity of SCD in the biosynthesis of unsaturated fatty acids and lipid accumulation. Collectively, these results consistently support the link between zinc homeostasis and lipid metabolism via SREBP-SCD axis by cation diffusion facilitators CDF-1 and SUR-7.

zoology↗

bioRxiv2020

Ceftazidime Is a Potential Drug to Inhibit SARS-CoV-2 Infection In Vitro by Blocking Spike Protein-ACE2 Interaction

Coronavirus Disease 2019 (COVID-19) spreads globally as a sever pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Cell entry of SARS-CoV-2 mainly depends on binding of the viral spike (S) proteins to angiotensin converting enzyme 2 (ACE2) on host cells. Therefore, repurposing of known drugs to inhibit S protein-ACE2 interaction could be a quick way to develop effective therapy for COVID-19. Using a high-throughput screening system to investigate the interaction between spike receptor binding domain (S-RBD) and ACE2 extracellular domain, we screened 3581 FDA-approved drugs and natural small molecules and identified ceftazidime as a potent compound to inhibit S-RBD-ACE2 interaction by binding to S-RBD. In addition to significantly inhibit S-RBD binding to HPAEpiC cells, ceftazidime efficiently prevented SARS-CoV-2 pseudovirus to infect ACE2-expressing 293T cells. The inhibitory concentration (IC50) was 113.2 M, which is far below the blood concentration (over 300 M) of ceftazidime in patients when clinically treated with recommended dose. Notably, ceftazidime is a drug clinically used for the treatment of pneumonia with minimal side effects compared with other antiviral drugs. Thus, ceftazidime has both anti-bacterial and anti-SARS-CoV-2 effects, which should be the first-line antibiotics used for the clinical treatment of COVID-19.

immunology↗

bioRxiv2020

Transcriptional Profiling Reveals the Transcription Factor Networks Regulating the Survival of Striatal Neurons

The striatum is structurally highly diverse, and its organ functionality critically depends on normal embryonic development. Although several studies have been conducted on the gene functional changes that occur during striatal development, a system-wide analysis of the underlying molecular changes is lacking. Here, we present a comprehensive transcriptome profile that allowed us to explore the trajectory of striatal development and identify the correlation between the striatal development and Huntingtons disease (HD). Furthermore, we applied an integrative transcriptomic profiling approach based on machine learning to systematically map a global landscape of 277 transcription factor (TF) networks. Most of these TF networks are linked to biological processes, and some unannotated genes provide information about the corresponding mechanisms. For example, we found that the Meis2 and Six3 were crucial for the survival of striatal neurons, which was verified using conditional knockout (CKO) mice. Finally, we used RNA-Seq to speculate their downstream targets.

neuroscience↗

bioRxiv2020

High performance intensiometric direct- and inverse-response genetically encoded biosensors for citrate

Motivated by the growing recognition of citrate as a central metabolite in a variety of biological processes associated with healthy and diseased cellular states, we have developed a series of high-performance genetically encoded citrate biosensors suitable for imaging of citrate concentrations in mammalian cells. The design of these biosensors was guided by structural studies of the citrate-responsive sensor histidine kinase, and took advantage of the same conformational changes proposed to propagate from the binding domain to the catalytic domain. Following extensive engineering based on a combination of structure guided mutagenesis and directed evolution, we produced an inverse-response biosensor ({Delta}F/Fmin ~ 18) designated Citroff1 and a direct-response biosensor ({Delta}F/Fmin ~ 9) designated Citron1. We report the x-ray crystal structure of Citron1 and demonstrate the utility of both biosensors for qualitative and quantitative imaging of steady-state and pharmacologically-perturbed citrate concentrations in live cells.

molecular biology↗

bioRxiv2020

Public broadly neutralizing antibodies against hepatitis B virus in individuals with elite serologic activity

SUMMARYAlthough there is no effective cure for chronic hepatitis B virus (HBV) infection, antibodies are protective and constitute clinical correlates of recovery from infection. To examine the human neutralizing antibody response to HBV in elite neutralizers we screened 144 individuals. The top individuals produced shared clones of broadly neutralizing antibodies (bNAbs) that targeted 3 non-overlapping epitopes on the HBV S antigen (HBsAg). Single bNAbs protected humanized mice against infection, but selected for resistance mutations in mice with established infection. In contrast, infection was controlled by a combination of bNAbs targeting non-overlapping epitopes with complementary sensitivity to mutations that commonly emerge during human infection. The co-crystal structure of one of the bNAbs with a peptide epitope containing residues frequently mutated in human immune escape variants revealed a loop anchored by oppositely charged residues. The structure provides a molecular explanation for why immunotherapy for HBV infection may require combinations of complementary bNAbs.

immunology↗

bioRxiv2019

Selective activation of estrogen receptors α and β: Implications for depressive-like phenotypes in female mice exposed to chronic unpredictable stress

The estrogen receptor (ER) mechanisms by which 17{beta}-estradiol influences depressive-like behaviour have primarily been investigated acutely and not within an animal model of depression. Therefore, the current study aimed to dissect the contribution of ER and ER{beta} to the effects of 17{beta}-estradiol under non-stress and chronic stress conditions. Ovariectomized (OVX) or sham-operated mice were treated chronically (47 days) with 17{beta}-estradiol (E2), the ER{beta} agonist diarylpropionitrile (DPN), the ER agonist propylpyrazole-triol (PPT), or vehicle. On day 15 of treatment, mice from each group were assigned to Chronic Unpredictable Stress (CUS; 28 days) or non-CUS conditions. Mice were assessed for anxiety- and depressive-like behaviour and hypothalamic-pituitary-adrenal (HPA) axis function. Cytokine and chemokine levels, and postsynaptic density protein 95 were measured in the hippocampus and frontal cortex, and adult hippocampal neurogenesis was assessed. Overall, the effects of CUS were more robust that those of estrogenic treatments, as seen by increased immobility in the tail suspension test (TST), reduced PSD-95 expression, reduced neurogenesis in the ventral hippocampus, and HPA axis negative feedback dysregulation. However, we also observe CUS-dependent and -independent effects of ovarian status and estrogenic treatments. The effects of CUS on PSD-95 expression, the cytokine milieu, and in TST were largely driven by PPT and DPN, indicating that these treatments were not protective. Independent of CUS, estradiol increased neurogenesis in the dorsal hippocampus, blunted the corticosterone response to an acute stressor, but increased anxiety-like behaviour. These findings provide insights into the complexities of estrogen signaling in modulating depressive-like phenotypes under non-stress and chronic stress conditions.

neuroscience↗