Biology subjects

Dong, Y.

Publications and source records attributed to Dong, Y..

At least 199 records · Page 11Linked to original sources

bioRxiv2022

Targeting Epsins to Inhibit FGF Signaling while Potentiating TGF-β Signaling Constrains Endothelial-to-Mesenchymal-Transition in Atherosclerosis

BACKGROUNDEpsin endocytic adaptor proteins are implicated in the progression of atherosclerosis; however, the underlying molecular mechanisms have not yet been fully defined. In this study, we determined how epsins enhance endothelial-to-mesenchymal transition (EndoMT) in atherosclerosis and assessed the efficacy of a therapeutic peptide in a preclinical model of this disease. METHODSUsing single cell RNA sequencing (scRNA-seq), combined with molecular, cellular, and biochemical analyses, we investigated the role of epsins in stimulating EndoMT using knock-out mouse models. The therapeutic efficacy of a synthetic peptide targeting atherosclerotic plaques was then assessed in Apoe-/- mice. RESULTSScRNA-seq and lineage tracing revealed that epsins 1 and 2 promote EndoMT, and the loss of endothelial epsins inhibits EndoMT marker expression as well as transforming growth factor-beta signaling in vitro and in atherosclerotic mice, which is associated with smaller lesions in Apoe-/- mouse model. Mechanistically, the loss of endothelial cell epsins results in increased fibroblast growth factor receptor-1 (FGFR1) expression that inhibits TGF-{beta} signaling and EndoMT. Epsins directly bind ubiquitinated FGFR1 through their ubiquitin-interacting motif (UIM), which results in endocytosis and degradation of this receptor complex. Consequently, administration of a synthetic UIM-containing peptide API significantly attenuates EndoMT and progression of atherosclerosis. CONCLUSIONSWe conclude that epsins potentiate EndoMT during atherogenesis by increasing TGF-{beta} signaling through FGFR1 internalization and degradation. Inhibition of EndoMT by reducing epsin-FGFR1 interaction with a therapeutic peptide may represent a novel treatment strategy for atherosclerosis.

cell biology↗

bioRxiv2022

Targeting Epsins by nanotherapy regulates lipid metabolism and promotes 1 ABCG1-mediated cholesterol efflux to fortify atheroma regression

BACKGROUNDExcess cholesterol accumulation in lesional macrophages elicits complex responses in atherosclerosis. Epsins, a family of endocytic adaptors, fuel the progression of atherosclerosis; however, the underlying mechanism and therapeutic potential of targeting Epsins remains unknown. In this study, we determined the role of Epsins in macrophage-mediated metabolic regulation. We then developed an innovative method to therapeutically-target macrophage Epsins with specially-designed S2P-conjugated lipid nanoparticles (NPs), which encapsulate small interfering RNAs to suppress Epsins. METHODSWe used single cell RNA sequencing (scRNA-seq) with our newly developed algorithm MEBOCOST to study cell-cell communications mediated by metabolites from sender cells and sensor proteins on receiver cells. Biomedical, cellular and molecular approaches were utilized to investigate the role of macrophage Epsins in regulating lipid metabolism and transport. We performed this study using myeloid-specific Epsin double knockout (LysM-DKO) mice and mice with a genetic reduction of ABCG1 (LysM-DKO-ABCG1fl/+). The NPs targeting lesional macrophages were developed to encapsulate interfering RNAs to treat atherosclerosis. RESULTSWe revealed that Epsins regulate lipid metabolism and transport in atherosclerotic macrophages. Inhibiting Epsins by nanotherapy halts inflammation and accelerates atheroma resolution. Harnessing lesional macrophage-specific NP delivery of Epsin siRNAs, we showed that silencing of macrophage Epsins markedly diminished atherosclerotic plaque size and promoted plaque regression. Mechanistically, we demonstrated that Epsins bound to CD36 to facilitate lipid uptake by enhancing CD36 endocytosis and recycling. Conversely, Epsins promoted ABCG1 degradation via lysosomes and hampered ABCG1-mediated cholesterol efflux and reverse cholesterol transport. In a LysM-DKO-ABCG1fl/+ mouse model, enhanced cholesterol efflux and reverse transport due to Epsin deficiency was suppressed by the reduction of ABCG1. CONCLUSIONSOur findings suggest that targeting Epsins in lesional macrophages may offer therapeutic benefits for advanced atherosclerosis by reducing CD36-mediated lipid uptake and increasing ABCG1-mediated cholesterol efflux. Novelty and SignificanceO_ST_ABSWHAT IS KNOWN?C_ST_ABSO_LIEpsin endocytic adaptor proteins are upregulated in human and mouse atherosclerotic lesions C_LIO_LILesional macrophages internalize lipids primarily through scavenger receptor-mediated endocytosis such as CD36 and SR-A C_LIO_LIMacrophage-mediated cholesterol efflux and reverse cholesterol transport is crucial to atheroma resolution C_LI WHAT NEW INFORMATION DOES THIS ARTICLE CONTRIBUTE?O_LIScRNA-seq combined with the newly-developed algorithm MEBOCOST reveals that Epsins are involved in macrophage-mediated lipid metabolic regulation C_LIO_LIMacrophage epsins promote lipid uptake by targeting CD36 endocytosis and membrane recycling via the Epsin ENTH domain C_LIO_LIEpsins bind ubiquitinated ABCG1--resulting in the endocytosis and lysosomal degradation of this cholesterol transporter, which reduces cholesterol efflux. C_LIO_LIMacrophage-specific, nanoparticle-mediated RNAi delivery exhibits a therapeutic benefit for the treatment of atherosclerosis C_LIO_LIAtherosclerotic plaque regression using this nanoparticle delivery platform represents a clinically-relevant approach for the treatment of advance atherosclerosis C_LI BRIEF SUMMARYDespite the development of new cholesterol-lowering therapies, including the recently approved PCSK9 small interfering RNA (siRNA) antagonists, patients still face a tremendous risk of developing major acute cardiovascular events resulting from chronic inflammation in the plaque. We employed a novel nanomedicine platform containing a stabilin-2 targeting peptide (S2P) to deliver Epsin-specific siRNAs to lesional macrophages. We discovered that inhibition of these adaptor proteins in lesional macrophages significantly diminished plaque size and necrotic core area, increased fibrous cap thickness, and promoted plaque regression.

cell biology↗

bioRxiv2022

Vast human gut virus diversity uncovered by combined short- and long-read sequencing

Current metagenome-assembled human phage catalogs contained mostly fragmented genomes. Here, we developed a vigorous phage detection method involving phage enrichment and long-read sequencing and applied to 135 fecal samples. With ~10 times more efficient in obtaining complete genomes (~34%) than the Gut Virome Database, we identified the first megabasephage (~1.03Mb), and revealed the hidden diversity of the gut phageome including dozens of phages more prevalent than the crAssphages and Gubaphages.

bioinformatics↗

bioRxiv2022

Dendritic cell Piezo1 integrating mechanical stiffness and inflammatory signals directs the differentiation of TH1 and Treg cells in cancer

Dendritic cells (DCs) play an important role in anti-tumor immunity by inducing T cell differentiation. Herein, we found that the mechanical sensor Piezo1 expressed by DCs integrates innate inflammatory stimuli and stiffness signals and directs the reciprocal differentiation of TH1 and regulatory T (Treg) cells in cancer. Genetic deletion of Piezo1 in DCs inhibited the generation of TH1 cells while driving the development of Treg cells in promoting cancer growth. Mechanistically, Piezo1-deficient DCs regulated the secretion of the polarizing cytokines TGF{beta}1 and IL-12, leading to increased TGF{beta}R2-p-Smad3 activity and decreased IL-12R{beta}2-p-STAT4 activity while inducing the reciprocal differentiation of Treg and TH1 cells. In addition, Piezo1 integrated the SIRT1-hypoxia-inducible factor-1 alpha (HIF1)-dependent metabolic pathway and calcium-calcineurin-NFAT signaling pathway to orchestrate reciprocal TH1 and Treg lineage commitment through DC-derived IL-12 and TGF{beta}1. Our studies provide critical insight for understanding the role of the DC-based mechanical regulation of immunopathology in directing T cell lineage commitment in tumor microenvironments.

immunology↗

bioRxiv2022

Rational evolution of a recombinant DNA polymerase for efficient incorporation of unnatural nucleotides by dual-site boosting

Machine learning modelling assisting function-oriented enzyme engineering is normally built on predefined protein sequence space. However, efficient defining the determinant amino acid positions upon which the combinatorial mutation library is constructed is still a challenge in protein science. Herein, we present a comprehensive investigation of modifying a recombinant DNA polymerase for efficient incorporating one unnatural nucleotide, including the identification of key sites/regions, machine learning-assisted mutants screening, and the underlying mechanism of kinetics boosting. By using hundreds of training points and only dozens of testing samples, we found that one highly engineered enzymes catalytic efficiency can be further improved by one order of magnitude by specific mutation on two sites, 485I and 451L. Compared to the position 485 which is known to dominate local conformation of B-family DNA polymerases, 451 is a split-new active site discovered by our approach. A novel allosteric regulation mechanism is underlying the apparent synergy of 485I and 451L on the kinetics boosting. As a result, a "half-closed" conformation of the binding pocket and a cooperative binding of both primer and template DNA strands on the protein accelerated the processes of substrates incorporation, molecular recognition, and releasing of incorrect nucleotides. These findings have implications in guiding the function-tuning of DNA polymerases for a broad range of biotechnological applications.

biochemistry↗

bioRxiv2022

Saliva metabolome alterations after acute stress

Major stress has systemic effects on the body that can have adverse consequences for physical and mental health. However, the molecular basis of these damaging effects remains incompletely understood. Here we use a longitudinal approach to characterise the acute systemic impact of major psychological stress in a pig model. We perform untargeted metabolomics on non-invasively-obtained saliva samples from pigs before and 24-hours after transfer to the novel physical and social environment of a slaughterhouse. The main molecular changes occurring include decreases in amino acids, B-vitamins, and amino acid-derived metabolites synthesized in B-vitamin-dependent reactions, as well as yet-unidentified metabolite features. Decreased levels of several of the identified metabolites are implicated in the pathology of human psychological disorders and neurodegenerative disease, suggesting a possible neuroprotective function. Our results provide a fingerprint of the acute effect of psychological stress on the metabolome and suggest candidate biomarkers with potential roles in stress-related disorders. One Sentence SummaryIdentification of metabolites decreased under acute psychological stress may lead to future discoveries for the prevention and treatment of stress-related disorders.

molecular biology↗

bioRxiv2022

Widespread transposon co-option in the Caenorhabditis germline regulatory network

The movement of selfish DNA elements can lead to widespread genomic alterations with potential to create novel functions. Here we show that transposon expansions in Caenorhabditis nematodes led to extensive rewiring of germline transcriptional regulation. We find that about one third of C. elegans germline-specific promoters have been co-opted from two related Miniature Inverted Repeat Transposable Elements (MITEs), CERP2 and CELE2. The promoters are regulated by HIM-17, a THAP domain-containing transcription factor related to a transposase. Expansion of CERP2 occurred prior to radiation of the Caenorhabditis genus, as did fixation of mutations in HIM-17 through positive selection, whereas CELE2 expanded only in C. elegans. Through comparative analyses in C. briggsae, we find evolutionary conservation of most CERP2 co-opted promoters, but a substantial fraction of events are species specific. Our work reveals the emergence of a novel transcriptional network driven by TE co-option with a major impact on regulatory evolution.

genomics↗

bioRxiv2022

Conserved Untranslated Regions of Multipartite Viruses: Natural Markers of Novel Viral Genomic Components and Tags of Viral Evolution

Viruses with split genomes are categorized as being either segmented or multipartite according to whether their genomic segments occur in single or different virions. Some complexity will exist, in that inherited "core" vital segments viruses may renew the others once host and environmental alterations keep driving viral evolution. Despite this uncertainty, empirical observations have been made across the split genomes in the untranslated regions (UTRs) on the short or long stretches of conserved or identical sequences. In this study, we describe a methodology that combines RNA and small RNA sequencing, conventional BLASTx, and iterative BLASTn of UTRs to detect viral genomic components even if they encode orphan genes (ORFans). Within the phylum Kitrinoviricota, novel putative multipartite viruses and viral genomic components were annotated using data obtained from our sampling or publicly available sources. The novel viruses, as extensions or intermediate nodes, enriched the information of the evolutionary networks. Furthermore, the diversity of novel genomic components emphasized the evolutionary roles of reassortment and recombination, as well as genetic deletion, strongly supporting the genomic complexity. These data also suggest insufficient knowledge of these genomic components for categorizing some extant viral taxa. The relative conservation of UTRs at the genome level may explain the relationships between monopartite and multipartite viruses and how the multipartite viruses can have a life strategy involving multiple host cells. Author summaryThe current workflows for virus identification are largely based on high-throughput sequencing and coupled protein sequence homology-dependent analysis methods and tools. However, for viruses with split genomes, the identification of genomic components whose deduced protein sequences are not homologous to known sequences is inadequate. Furthermore, many plant-infecting multipartite viruses contain conserved UTRs across their genomic components. Based on this, we propose a practical method of UTR-backed iterative BLASTn (UTR-iBLASTn) to explore the components with ORFans and study virus evolution using the UTRs as signals. These shed light on viral "dark matter"--unknown/omitted genomic components of segmented/multipartite viruses from different kingdoms and hosts, and the origins of these components.

microbiology↗

bioRxiv2022

Hantaan virus replication is promoted via AKT activated mitochondria OXPHOS

Oxidative phosphorylation (OXPHOS) is a vital pathway provides ATP for intracellular activities. Here, we found that Hantaan virus (HTNV) exploited mitochondria OXPHOS to assist its replication in host cells and Protein Kinase B/AKT played a major function in this process. Inhibiting AKT activation by BEZ treatment can inhibit HTNV replication and prevent the increase of OXPHOS level caused by HTNV infection. We also found that HTNV infection can promote AKT translocation to mitochondria, where AKT phosphorylates Polynucleotide phosphorylase (PNPT). Taken together, our research demonstrates that HTNV replication exploits OXPHOS in host cells and it increases OXPHOS function by AKT-PNPT interaction in mitochondria. IMPORTANCEVirus depends on metabolic pathways in host cells to favor its replication. This is a vital process which needs complicated host-virus interaction and targeting this process is a new strategy for antiviral drug development. Hantaan virus (HTNV) is the major pathogen which causes Hemorrhagic Fever with Renal Syndrome (HFRS) in China. However, there are neither effective therapeutic drugs nor FDA-licensed vaccine against HFRS, a deeper understanding of HTNV infection characteristics is of great significance for global public health and safety. This research means to elucidate the major metabolic pathway exploited by HTNV during its replication in host cells and its underlying molecular mechanism, which can enrich our understanding about HTNV biological characteristics and pathogenesis, also provide a new view on anti-HTNV drug development.

pathology↗

bioRxiv2021

The Long Noncoding RNA FEDORA is a Cell-Type- and Sex-Specific Regulator of Depression

Women suffer from depression at twice the rate of men, but the underlying molecular mechanisms are poorly understood. Here, we identify dramatic baseline sex differences in expression of long noncoding RNAs (lncRNAs) in human postmortem brain tissue that are profoundly lost in depression. One such lncRNA, RP11-298D21.1 (which we termed FEDORA), is enriched in oligodendrocytes and neurons and upregulated in several cortical regions of depressed females but not males. We found that virally-expressing FEDORA selectively either in neurons or in oligodendrocytes of prefrontal cortex promoted depression-like behavioral abnormalities in female mice only, changes associated with cell-type-specific regulation of synaptic properties, myelin thickness, and gene expression. We also found that blood FEDORA levels have diagnostic significance for depressed women. These findings demonstrate the important role played by lncRNAs, and FEDORA in particular, in shaping the sex-specific landscape of the brain and contributing to sex differences in depression.

neuroscience↗

bioRxiv2021

The endophilin curvature-sensitive motif requires electrostatic guidance to recycle synaptic vesicles in vivo

Curvature-sensing mechanisms assist proteins in executing particular actions on various membrane organelles. Here, we investigated the functional specificity of curvature-sensing amphipathic motifs through the study of endophilin, an endocytic protein for synaptic vesicle recycling. We generated chimeric endophilin proteins by replacing the endophilin amphipathic motif H0 with other curvature-sensing amphipathic motifs. We found that the role of amphipathic motifs cannot simply be extrapolated from the identity of their parental proteins. For example, the amphipathic motif of the nuclear pore complex protein NUP133 functionally replaced the synaptic role of endophilin H0. Interestingly, non-functional endophilin chimeras had similar defects - producing fewer synaptic vesicles but more endosomes - indicating that the curvature-sensing motifs in these chimeras have a common deficiency at reforming synaptic vesicles. Finally, we converted non-functional endophilin chimeras into functional proteins by changing the cationic property of amphipathic motifs, setting a precedent for reprogramming the functional specificity of curvature-sensing motifs in vivo.

cell biology↗

bioRxiv2021

Lung-selective Cas13d-based nanotherapy inhibits lethal SARS-CoV-2 infection by targeting host protease Ctsl

The COVID-19 pandemic persists as a global health crisis for which curative treatment has been elusive. Development of effective and safe anti-SARS-CoV-2 therapies remains an urgent need. SARS-CoV-2 entry into cells requires specific host proteases including TMPRSS2 and Cathepsin L (Ctsl)1-3, but there has been no reported success in inhibiting host proteases for treatment of SARS-CoV-2 pathogenesis in vivo. Here we have developed a lung Ctsl mRNA-targeted, CRISPR/Cas13d-based nanoparticle therapy to curb fatal SARS-CoV-2 infection in a mouse model. We show that this nanotherapy can decrease lung Ctsl expression in normal mice efficiently, specifically, and safely. Importantly, this lung-selective Ctsl-targeted nanotherapy significantly extended the survival of lethally SARS-CoV-2 infected mice by decreasing lung virus burden, reducing expression of pro-inflammatory cytokines/chemokines, and diminishing the severity of pulmonary interstitial inflammation. Additional in vitro analyses demonstrated that Cas13d-mediated Ctsl knockdown inhibited infection mediated by the spike protein of SARS-CoV-1, SARS-CoV-2, and more importantly, the authentic SARS-CoV-2 B.1.617.2 Delta variant, regardless of TMPRSS2 expression status. Our results demonstrate the efficacy and safety of a lung-selective, Ctsl-targeted nanotherapy against infection by SARS-CoV-2 and likely other emerging coronaviruses, forming a basis for investigation of this approach in clinical trials.

microbiology↗

bioRxiv2021

Beneficial Effects of Celastrol on Immune Balance by Modulating Gut Microbiota in Dextran Sodium Sulfate-Induced Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease caused by multi-factors including colonic inflammation and microbiota dysbiosis. Previous studies have indicated that Celastrol (CSR) has strong anti-inflammatory and immune-inhibitory effects. Here, we investigated the effects of CSR on colonic inflammation and the mucosal immunity in an experimental colitis model, and addressed the mechanism by which CSR preforms the protective effect. We characterized the therapeutic effects and the potential mechanism of CSR in treating UC using histological staining, intestinal permeability assay, cytokine assay, flow cytometry, fecal microbiota transplantation (FMT), 16S rRNA sequencing, untargeted metabolomics, and cell differentiation approaches. CSR administration significantly ameliorated DSS-induced colitis, as evidenced by the recovery of body weight and colon length, decreased disease activity index (DAI) score, as well as decreased intestinal permeability. CSR down-regulated the secretion of proinflammatory cytokines, upregulated the anti-inflammatory mediators, and improved the balances of Treg/Th1 and Treg/Th17 to maintain colonic immune homeostasis. However, the protective effects of CSR disappeared when the antibiotic cocktail was applied to deplete the gut microbiota, and the gut microbiota-mediated effect was confirmed by FMT. Furthermore, CSR treatment increased the gut microbiota diversity and composition, and raised the metabolic productions of pyruvate and adenosine, which probably involve in gut microbiota mediated protective effect. In conclusion, CSR ameliorates colonic inflammation in a gut microbiota-dependent manner. The underlying protective mechanism is associated with the rectified Treg/Th1 and Treg/Th17 balance, and increased pyruvate and adenosine production. The study provided the solid evidence that CSR might be a promising therapeutic drug for UC.

microbiology↗

bioRxiv2021

pcnaDeep: A Fast and Robust Single-Cell Tracking Method Using Deep-Learning Mediated Cell Cycle Profiling

MotivationComputational methods that track single-cells and quantify fluorescent biosensors in time-lapse microscopy images have revolutionised our approach in studying the molecular control of cellular decisions. One barrier that limits the adoption of single-cell analysis in biomedical research is the lack of efficient methods to robustly track single-cells over cell division events. ResultsHere, we developed an application that automatically tracks and assigns mother-daughter relationships of single-cells. By incorporating cell cycle information from a well-established fluorescent cell cycle reporter, we associate mitosis relationships enabling high fidelity long-term single-cell tracking. This was achieved by integrating a deep-learning based fluorescent PCNA signal instance segmentation module with a cell tracking and cell cycle resolving pipeline. The application offers a user-friendly interface and extensible APIs for customized cell cycle analysis and manual correction for various imaging configurations. Availability and ImplementationpcnaDeep is an open-source Python application under the Apache 2.0 licence. The source code, documentation and tutorials are available at https://github.com/chan-labsite/PCNAdeep. Supplementary InformationSupplementary data are available online.

bioinformatics↗

bioRxiv2021

Peroxide antimalarial drugs target redox homeostasis in Plasmodium falciparum infected red blood cells

Plasmodium falciparum causes the most lethal form of malaria. Peroxide antimalarials based on artemisinin underpin the frontline treatments for malaria, but artemisinin resistance is rapidly spreading. Synthetic peroxide antimalarials, known as ozonides, are in clinical development and offer a potential alternative. Here, we used chemoproteomics to investigate the protein alkylation targets of artemisinin and ozonide probes, including an analogue of the ozonide clinical candidate, artefenomel. We greatly expanded the list of protein targets for peroxide antimalarials and identified significant enrichment of redox-related proteins for both artemisinins and ozonides. Disrupted redox homeostasis was confirmed by dynamic live imaging of the glutathione redox potential using a genetically encoded redox-sensitive fluorescence-based biosensor. Targeted LC-MS-based thiol metabolomics also confirmed changes in cellular thiol levels. This work shows that peroxide antimalarials disproportionately alkylate proteins involved in redox homeostasis and that disrupted redox processes are involved in the mechanism of action of these important antimalarials. ImportanceThe frontline treatments for malaria are combination therapies based on the peroxide antimalarial, artemisinin. Concerningly, artemisinin resistance has emerged in malaria-endemic regions, and now poses a major threat to malaria treatment and eradication efforts. New medicines are urgently required to replace the artemisinins, and some of the most advanced candidates are the fully synthetic peroxide antimalarials, OZ277 (arterolane) and OZ439 (artefenomel). The mechanism of action of peroxide antimalarials involves the reductive activation of the peroxide bond by intra-parasitic haem, but there is no consensus regarding the specific protein targets of the resulting radical species for artemisinins and/or the ozonides. This study provides a comprehensive and unbiased chemoproteomic profile of over 400 target proteins, and confirms the specific impact of peroxide antimalarials on redox metabolism. The key role of redox targets is particularly relevant considering that the mechanism of artemisinin resistance appears to involve modulation of peroxide activation and redox homeostasis.

pharmacology and toxicology↗

bioRxiv2021

NEURON-SPECIFIC CHROMOSOMAL MEGADOMAIN ORGANIZATION IS ADAPTIVE TO RECENT RETROTRANSPOSON EXPANSIONS

Here, we mapped cell-type specific chromatin domain organization in adult mouse cerebral cortex and report strong enrichment of Endogenous Retrovirus 2 (ERV2) repeat sequences in the neuron-specific heterochromatic B2NeuN+ megabase-scaling subcompartment. Comparative chromosomal conformation mapping in Mus spretus and Mus musculus revealed neuron-specific reconfigurations tracking recent ERV2 retrotransposon expansions in the murine germline, with significantly higher B2 megadomain contact frequencies at sites with ongoing ERV2 insertions in Mus musculus. Ablation of the retrotransposon silencer Kmt1e/Setdb1 triggered B2 megadomain disintegration and rewiring with open chromatin domains enriched for cellular stress response genes, along with severe neuroinflammation and proviral assembly of ERV2/Intracisternal-A-Particles (IAPs) infiltrating dendrites and spines. We conclude that neuronal megadomain architectures include evolutionarily adaptive heterochromatic organization which, upon perturbation, unleashes ERV proviruses with strong tropism within mature neurons.

neuroscience↗

bioRxiv2021

A vimentin-targeting oral compound with host-directed antiviral and anti-inflammatory actions addresses multiple features of COVID-19 and related diseases

Damage in COVID-19 results from both the SARS-CoV-2 virus and its triggered overreactive host immune responses. Therapeutic agents that focus solely on reducing viral load or hyperinflammation fail to provide satisfying outcomes in all cases. Although viral and cellular factors have been extensively profiled to identify potential anti-COVID targets, new drugs with significant efficacy remain to be developed. Here, we report the potent preclinical efficacy of ALD-R491, a vimentin-targeting small molecule compound, in treating COVID-19 through its host-directed antiviral and anti-inflammatory actions. We found that by altering the physical properties of vimentin filaments, ALD-491 affected general cellular processes as well as specific cellular functions relevant to SARS-CoV-2 infection. Specifically, ALD-R491 reduced endocytosis, endosomal trafficking, and exosomal release, thus impeding the entry and egress of the virus; increased the microcidal capacity of macrophages, thus facilitating the pathogen clearance; and enhanced the activity of regulatory T cells, therefore suppressing the overreactive immune responses. In cultured cells, ALD-R491 potently inhibited the SARS-CoV-2 spike protein and human ACE2-mediated pseudoviral infection. In aged mice with ongoing, productive SARS-CoV-2 infection, ALD-R491 reduced disease symptoms as well as lung damage. In rats, ALD-R491 also reduced bleomycin-induced lung injury and fibrosis. Our results indicate a unique mechanism and significant therapeutic potential for ALD-R491 against COVID-19. We anticipate that ALD-R491, an oral, fast-acting, and non-toxic agent targeting the cellular protein with multipart actions, will be convenient, safe, and broadly effective, regardless of viral mutations, for patients with early- or late-stage disease, post-COVID complications and other related diseases. IMPORTANCEWith the Delta variant currently fueling a resurgence of new infections in the fully-vaccinated population, developing an effective therapeutic drug is especially critical and urgent in fighting COVID-19. In contrast to the many efforts to repurpose existing drugs or address only one aspect of COVID-19, we are developing a novel agent with first-in-class mechanism-of-actions that address both the viral infection and the overactive immune system in the pathogenesis of the disease. Unlike virus-directed therapeutics that may lose efficacy due to viral mutations and immunosuppressants that require ideal timing to be effective, this agent, with its unique host-directed antiviral and anti-inflammatory actions, can work against all variants of the virus, be effective during all stages of the disease, and even resolve post-disease damage and complications. A further development of the compound will provide an important tool in the fight against COVID-19, its complications, as well as future outbreaks of new viruses.

pharmacology and toxicology↗

bioRxiv2021

Transcriptome Profiles of Anopheles gambiae Harboring Natural Low-Level Plasmodium Infection Reveal Adaptive Advantages for the Mosquito

Anopheline mosquitoes are the sole vectors for the Plasmodium pathogens responsible for malaria, which is among the oldest and most devastating of human diseases. The continuing global impact of malaria reflects the evolutionary success of a complex vector-pathogen relationship that accordingly has been the long-term focus of both debate and study. An open question in the biology of malaria transmission is the impact of naturally occurring low-level Plasmodium infections of the vector on the mosquitos health and longevity as well as critical behaviors such as host- preference/seeking. To begin to answer this, we have completed a comparative RNAseq-based transcriptome profile study examining the effect of biologically salient, salivary gland transmission- stage Plasmodium infection on the molecular physiology of Anopheles gambiae s.s. head, sensory appendage, and salivary glands. When compared with their uninfected counterparts, Plasmodium infected mosquitoes exhibit increased transcript abundance of genes associated with olfactory acuity as well as a range of synergistic processes that align with increased fitness based on both anti-aging and reproductive advantages. Taken together, these data argue against the long-held paradigm that malaria infection is pathogenic for anophelines and, instead, suggests there are biological and evolutionary advantages for the mosquito that drive the preservation of its high vectorial capacity.

molecular biology↗