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1.
Cell ; 187(18): 5081-5101.e19, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-38996528

ABSTRACT

In developing brains, axons exhibit remarkable precision in selecting synaptic partners among many non-partner cells. Evolutionarily conserved teneurins are transmembrane proteins that instruct synaptic partner matching. However, how intracellular signaling pathways execute teneurins' functions is unclear. Here, we use in situ proximity labeling to obtain the intracellular interactome of a teneurin (Ten-m) in the Drosophila brain. Genetic interaction studies using quantitative partner matching assays in both olfactory receptor neurons (ORNs) and projection neurons (PNs) reveal a common pathway: Ten-m binds to and negatively regulates a RhoGAP, thus activating the Rac1 small GTPases to promote synaptic partner matching. Developmental analyses with single-axon resolution identify the cellular mechanism of synaptic partner matching: Ten-m signaling promotes local F-actin levels and stabilizes ORN axon branches that contact partner PN dendrites. Combining spatial proteomics and high-resolution phenotypic analyses, this study advanced our understanding of both cellular and molecular mechanisms of synaptic partner matching.


Subject(s)
Axons , Drosophila Proteins , Drosophila melanogaster , Nerve Tissue Proteins , Olfactory Receptor Neurons , Signal Transduction , Synapses , Animals , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Nerve Tissue Proteins/metabolism , Olfactory Receptor Neurons/metabolism , Axons/metabolism , Synapses/metabolism , Actins/metabolism , GTPase-Activating Proteins/metabolism , Brain/metabolism , Dendrites/metabolism , rac1 GTP-Binding Protein/metabolism , Tenascin , rac GTP-Binding Proteins
2.
Cell ; 184(16): 4137-4153.e14, 2021 08 05.
Article in English | MEDLINE | ID: mdl-34256014

ABSTRACT

Diet modulates the gut microbiome, which in turn can impact the immune system. Here, we determined how two microbiota-targeted dietary interventions, plant-based fiber and fermented foods, influence the human microbiome and immune system in healthy adults. Using a 17-week randomized, prospective study (n = 18/arm) combined with -omics measurements of microbiome and host, including extensive immune profiling, we found diet-specific effects. The high-fiber diet increased microbiome-encoded glycan-degrading carbohydrate active enzymes (CAZymes) despite stable microbial community diversity. Although cytokine response score (primary outcome) was unchanged, three distinct immunological trajectories in high-fiber consumers corresponded to baseline microbiota diversity. Alternatively, the high-fermented-food diet steadily increased microbiota diversity and decreased inflammatory markers. The data highlight how coupling dietary interventions to deep and longitudinal immune and microbiome profiling can provide individualized and population-wide insight. Fermented foods may be valuable in countering the decreased microbiome diversity and increased inflammation pervasive in industrialized society.


Subject(s)
Diet , Gastrointestinal Microbiome , Immunity , Biodiversity , Dietary Fiber/pharmacology , Feeding Behavior , Female , Fermented Foods , Gastrointestinal Microbiome/drug effects , Humans , Inflammation/pathology , Male , Middle Aged , Signal Transduction/drug effects
3.
Cell ; 180(2): 373-386.e15, 2020 01 23.
Article in English | MEDLINE | ID: mdl-31955847

ABSTRACT

Molecular interactions at the cellular interface mediate organized assembly of single cells into tissues and, thus, govern the development and physiology of multicellular organisms. Here, we developed a cell-type-specific, spatiotemporally resolved approach to profile cell-surface proteomes in intact tissues. Quantitative profiling of cell-surface proteomes of Drosophila olfactory projection neurons (PNs) in pupae and adults revealed global downregulation of wiring molecules and upregulation of synaptic molecules in the transition from developing to mature PNs. A proteome-instructed in vivo screen identified 20 cell-surface molecules regulating neural circuit assembly, many of which belong to evolutionarily conserved protein families not previously linked to neural development. Genetic analysis further revealed that the lipoprotein receptor LRP1 cell-autonomously controls PN dendrite targeting, contributing to the formation of a precise olfactory map. These findings highlight the power of temporally resolved in situ cell-surface proteomic profiling in discovering regulators of brain wiring.


Subject(s)
Olfactory Pathways/metabolism , Olfactory Receptor Neurons/metabolism , Proteomics/methods , Animals , Axons/metabolism , Brain/metabolism , Dendrites/metabolism , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Gene Expression Profiling/methods , Gene Expression Regulation, Developmental/genetics , Membrane Proteins/metabolism , Neurogenesis/physiology , Olfactory Nerve/metabolism , Olfactory Pathways/cytology , Olfactory Pathways/physiology , Receptors, Lipoprotein/metabolism , Smell/physiology
4.
Cell ; 182(6): 1460-1473.e17, 2020 09 17.
Article in English | MEDLINE | ID: mdl-32916129

ABSTRACT

The gut microbiome has been implicated in multiple human chronic gastrointestinal (GI) disorders. Determining its mechanistic role in disease has been difficult due to apparent disconnects between animal and human studies and lack of an integrated multi-omics view of disease-specific physiological changes. We integrated longitudinal multi-omics data from the gut microbiome, metabolome, host epigenome, and transcriptome in the context of irritable bowel syndrome (IBS) host physiology. We identified IBS subtype-specific and symptom-related variation in microbial composition and function. A subset of identified changes in microbial metabolites correspond to host physiological mechanisms that are relevant to IBS. By integrating multiple data layers, we identified purine metabolism as a novel host-microbial metabolic pathway in IBS with translational potential. Our study highlights the importance of longitudinal sampling and integrating complementary multi-omics data to identify functional mechanisms that can serve as therapeutic targets in a comprehensive treatment strategy for chronic GI diseases. VIDEO ABSTRACT.


Subject(s)
Gastrointestinal Microbiome/genetics , Gene Expression Regulation/genetics , Irritable Bowel Syndrome/metabolism , Metabolome , Purines/metabolism , Transcriptome/genetics , Animals , Bile Acids and Salts/metabolism , Biopsy , Butyrates/metabolism , Chromatography, Liquid , Cross-Sectional Studies , Epigenomics , Feces/microbiology , Female , Gastrointestinal Microbiome/physiology , Gene Expression Regulation/physiology , Host Microbial Interactions/genetics , Humans , Hypoxanthine/metabolism , Irritable Bowel Syndrome/genetics , Irritable Bowel Syndrome/microbiology , Longitudinal Studies , Male , Metabolome/physiology , Mice , Observational Studies as Topic , Prospective Studies , Software , Tandem Mass Spectrometry , Transcriptome/physiology
5.
Cell ; 178(2): 473-490.e26, 2019 07 11.
Article in English | MEDLINE | ID: mdl-31230715

ABSTRACT

We introduce APEX-seq, a method for RNA sequencing based on direct proximity labeling of RNA using the peroxidase enzyme APEX2. APEX-seq in nine distinct subcellular locales produced a nanometer-resolution spatial map of the human transcriptome as a resource, revealing extensive patterns of localization for diverse RNA classes and transcript isoforms. We uncover a radial organization of the nuclear transcriptome, which is gated at the inner surface of the nuclear pore for cytoplasmic export of processed transcripts. We identify two distinct pathways of messenger RNA localization to mitochondria, each associated with specific sets of transcripts for building complementary macromolecular machines within the organelle. APEX-seq should be widely applicable to many systems, enabling comprehensive investigations of the spatial transcriptome.


Subject(s)
DNA-(Apurinic or Apyrimidinic Site) Lyase/metabolism , Endonucleases/metabolism , Multifunctional Enzymes/metabolism , RNA/metabolism , Sequence Analysis, RNA/methods , Fluorescent Dyes/chemistry , HEK293 Cells , Humans , Microscopy, Fluorescence , Mitochondria/genetics , RNA/chemistry , RNA, Messenger/chemistry , RNA, Messenger/metabolism , Transcriptome
7.
Nature ; 620(7975): 904-910, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37558880

ABSTRACT

Arrestins have pivotal roles in regulating G protein-coupled receptor (GPCR) signalling by desensitizing G protein activation and mediating receptor internalization1,2. It has been proposed that the arrestin binds to the receptor in two different conformations, 'tail' and 'core', which were suggested to govern distinct processes of receptor signalling and trafficking3,4. However, little structural information is available for the tail engagement of the arrestins. Here we report two structures of the glucagon receptor (GCGR) bound to ß-arrestin 1 (ßarr1) in glucagon-bound and ligand-free states. These structures reveal a receptor tail-engaged binding mode of ßarr1 with many unique features, to our knowledge, not previously observed. Helix VIII, instead of the receptor core, has a major role in accommodating ßarr1 by forming extensive interactions with the central crest of ßarr1. The tail-binding pose is further defined by a close proximity between the ßarr1 C-edge and the receptor helical bundle, and stabilized by a phosphoinositide derivative that bridges ßarr1 with helices I and VIII of GCGR. Lacking any contact with the arrestin, the receptor core is in an inactive state and loosely binds to glucagon. Further functional studies suggest that the tail conformation of GCGR-ßarr governs ßarr recruitment at the plasma membrane and endocytosis of GCGR, and provides a molecular basis for the receptor forming a super-complex simultaneously with G protein and ßarr to promote sustained signalling within endosomes. These findings extend our knowledge about the arrestin-mediated modulation of GPCR functionalities.


Subject(s)
Receptors, Glucagon , beta-Arrestin 1 , beta-Arrestin 1/chemistry , beta-Arrestin 1/metabolism , Cell Membrane/metabolism , Endocytosis , Endosomes/metabolism , Glucagon/metabolism , Heterotrimeric GTP-Binding Proteins/metabolism , Ligands , Phosphatidylinositols/metabolism , Receptors, Glucagon/chemistry , Receptors, Glucagon/metabolism , Protein Binding
8.
Nature ; 604(7907): 779-785, 2022 04.
Article in English | MEDLINE | ID: mdl-35418679

ABSTRACT

Adhesion G protein-coupled receptors (aGPCRs) are essential for a variety of physiological processes such as immune responses, organ development, cellular communication, proliferation and homeostasis1-7. An intrinsic manner of activation that involves a tethered agonist in the N-terminal region of the receptor has been proposed for the aGPCRs8,9, but its molecular mechanism remains elusive. Here we report the G protein-bound structures of ADGRD1 and ADGRF1, which exhibit many unique features with regard to the tethered agonism. The stalk region that proceeds the first transmembrane helix acts as the tethered agonist by forming extensive interactions with the transmembrane domain; these interactions are mostly conserved in ADGRD1 and ADGRF1, suggesting that a common stalk-transmembrane domain interaction pattern is shared by members of the aGPCR family. A similar stalk binding mode is observed in the structure of autoproteolysis-deficient ADGRF1, supporting a cleavage-independent manner of receptor activation. The stalk-induced activation is facilitated by a cascade of inter-helix interaction cores that are conserved in positions but show sequence variability in these two aGPCRs. Furthermore, the intracellular region of ADGRF1 contains a specific lipid-binding site, which proves to be functionally important and may serve as the recognition site for the previously discovered endogenous ADGRF1 ligand synaptamide. These findings highlight the diversity and complexity of the signal transduction mechanisms of the aGPCRs.


Subject(s)
Receptors, G-Protein-Coupled , Signal Transduction , Humans , Ligands , Oncogene Proteins/agonists , Oncogene Proteins/metabolism , Protein Binding , Protein Domains , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/metabolism
9.
N Engl J Med ; 391(9): 821-831, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39231344

ABSTRACT

BACKGROUND: In June 2019, a patient presented with persistent fever and multiple organ dysfunction after a tick bite at a wetland park in Inner Mongolia. Next-generation sequencing in this patient revealed an infection with a previously unknown orthonairovirus, which we designated Wetland virus (WELV). METHODS: We conducted active hospital-based surveillance to determine the prevalence of WELV infection among febrile patients with a history of tick bites. Epidemiologic investigation was performed. The virus was isolated, and its infectivity and pathogenicity were investigated in animal models. RESULTS: WELV is a member of the orthonairovirus genus in the Nairoviridae family and is most closely related to the tickborne Hazara orthonairovirus genogroup. Acute WELV infection was identified in 17 patients from Inner Mongolia, Heilongjiang, Jilin, and Liaoning, China, by means of reverse-transcriptase-polymerase-chain-reaction assay. These patients presented with nonspecific symptoms, including fever, dizziness, headache, malaise, myalgia, arthritis, and back pain and less frequently with petechiae and localized lymphadenopathy. One patient had neurologic symptoms. Common laboratory findings were leukopenia, thrombocytopenia, and elevated d-dimer and lactate dehydrogenase levels. Serologic assessment of convalescent-stage samples obtained from 8 patients showed WELV-specific antibody titers that were 4 times as high as those in acute-phase samples. WELV RNA was detected in five tick species and in sheep, horses, pigs, and Transbaikal zokors (Myospalax psilurus) sampled in northeastern China. The virus that was isolated from the index patient and ticks showed cytopathic effects in human umbilical-vein endothelial cells. Intraperitoneal injection of the virus resulted in lethal infections in BALB/c, C57BL/6, and Kunming mice. The Haemaphysalis concinna tick is a possible vector that can transovarially transmit WELV. CONCLUSIONS: A newly discovered orthonairovirus was identified and shown to be associated with human febrile illnesses in northeastern China. (Funded by the National Natural Science Foundation of China and the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences.).


Subject(s)
Fever , Nairovirus , Tick Bites , Adult , Aged , Animals , Female , Humans , Male , Mice , Middle Aged , Young Adult , Antibodies, Viral/blood , China/epidemiology , Fever/diagnosis , Fever/epidemiology , Fever/virology , Nairovirus/genetics , Nairovirus/isolation & purification , Nairovirus/pathogenicity , Phylogeny , Tick Bites/complications , Tick Bites/virology , Prevalence , Disease Models, Animal , Sheep , Horses , Swine , Infant , Child, Preschool , Child , Adolescent , Aged, 80 and over
10.
Nature ; 595(7867): 415-420, 2021 07.
Article in English | MEDLINE | ID: mdl-34262212

ABSTRACT

Gut microorganisms modulate host phenotypes and are associated with numerous health effects in humans, ranging from host responses to cancer immunotherapy to metabolic disease and obesity. However, difficulty in accurate and high-throughput functional analysis of human gut microorganisms has hindered efforts to define mechanistic connections between individual microbial strains and host phenotypes. One key way in which the gut microbiome influences host physiology is through the production of small molecules1-3, yet progress in elucidating this chemical interplay has been hindered by limited tools calibrated to detect the products of anaerobic biochemistry in the gut. Here we construct a microbiome-focused, integrated mass-spectrometry pipeline to accelerate the identification of microbiota-dependent metabolites in diverse sample types. We report the metabolic profiles of 178 gut microorganism strains using our library of 833 metabolites. Using this metabolomics resource, we establish deviations in the relationships between phylogeny and metabolism, use machine learning to discover a previously undescribed type of metabolism in Bacteroides, and reveal candidate biochemical pathways using comparative genomics. Microbiota-dependent metabolites can be detected in diverse biological fluids from gnotobiotic and conventionally colonized mice and traced back to the corresponding metabolomic profiles of cultured bacteria. Collectively, our microbiome-focused metabolomics pipeline and interactive metabolomics profile explorer are a powerful tool for characterizing microorganisms and interactions between microorganisms and their host.


Subject(s)
Bacteria/metabolism , Gastrointestinal Microbiome , Metabolome , Metabolomics/methods , Animals , Bacteria/classification , Bacteria/genetics , Bacteroides/genetics , Bacteroides/metabolism , Genes, Bacterial/genetics , Genomics , Host Microbial Interactions , Humans , Male , Mice , Nitrogen/metabolism , Phenotype , Phylogeny
11.
Nature ; 594(7864): 589-593, 2021 06.
Article in English | MEDLINE | ID: mdl-34135509

ABSTRACT

The metabotropic glutamate receptors (mGlus) are involved in the modulation of synaptic transmission and neuronal excitability in the central nervous system1. These receptors probably exist as both homo- and heterodimers that have unique pharmacological and functional properties2-4. Here we report four cryo-electron microscopy structures of the human mGlu subtypes mGlu2 and mGlu7, including inactive mGlu2 and mGlu7 homodimers; mGlu2 homodimer bound to an agonist and a positive allosteric modulator; and inactive mGlu2-mGlu7 heterodimer. We observed a subtype-dependent dimerization mode for these mGlus, as a unique dimer interface that is mediated by helix IV (and that is important for limiting receptor activity) exists only in the inactive mGlu2 structure. The structures provide molecular details of the inter- and intra-subunit conformational changes that are required for receptor activation, which distinguish class C G-protein-coupled receptors from those in classes A and B. Furthermore, our structure and functional studies of the mGlu2-mGlu7 heterodimer suggest that the mGlu7 subunit has a dominant role in controlling dimeric association and G-protein activation in the heterodimer. These insights into mGlu homo- and heterodimers highlight the complex landscape of mGlu dimerization and activation.


Subject(s)
Receptors, Metabotropic Glutamate/chemistry , Cryoelectron Microscopy , Humans , Protein Multimerization , Protein Structure, Tertiary
12.
Nature ; 594(7864): 583-588, 2021 06.
Article in English | MEDLINE | ID: mdl-34135510

ABSTRACT

The metabotropic glutamate receptors (mGlus) have key roles in modulating cell excitability and synaptic transmission in response to glutamate (the main excitatory neurotransmitter in the central nervous system)1. It has previously been suggested that only one receptor subunit within an mGlu homodimer is responsible for coupling to G protein during receptor activation2. However, the molecular mechanism that underlies the asymmetric signalling of mGlus remains unknown. Here we report two cryo-electron microscopy structures of human mGlu2 and mGlu4 bound to heterotrimeric Gi protein. The structures reveal a G-protein-binding site formed by three intracellular loops and helices III and IV that is distinct from the corresponding binding site in all of the other G-protein-coupled receptor (GPCR) structures. Furthermore, we observed an asymmetric dimer interface of the transmembrane domain of the receptor in the two mGlu-Gi structures. We confirmed that the asymmetric dimerization is crucial for receptor activation, which was supported by functional data; this dimerization may provide a molecular basis for the asymmetric signal transduction of mGlus. These findings offer insights into receptor signalling of class C GPCRs.


Subject(s)
GTP-Binding Proteins/chemistry , Receptors, Metabotropic Glutamate/chemistry , Binding Sites , Cryoelectron Microscopy , Humans , Protein Multimerization , Protein Structure, Tertiary , Signal Transduction
13.
Proc Natl Acad Sci U S A ; 119(36): e2205420119, 2022 09 06.
Article in English | MEDLINE | ID: mdl-36037383

ABSTRACT

Although human sperm is morphologically mature in the epididymis, it cannot fertilize eggs before capacitation. Cholesterol efflux from the sperm plasma membrane is a key molecular event essential for cytoplasmic alkalinization and hyperactivation, but the underlying mechanism remains unclear. The human voltage-gated proton (hHv1) channel functions as an acid extruder to regulate intracellular pHs of many cell types, including sperm. Aside from voltage and pH, Hv channels are also regulated by distinct ligands, such as Zn2+ and albumin. In the present work, we identified cholesterol as an inhibitory ligand of the hHv1 channel and further investigated the underlying mechanism using the single-molecule fluorescence resonance energy transfer (smFRET) approach. Our results indicated that cholesterol inhibits the hHv1 channel by stabilizing the voltage-sensing S4 segment at resting conformations, a similar mechanism also utilized by Zn2+. Our results suggested that the S4 segment is the central gating machinery in the hHv1 channel, on which voltage and distinct ligands are converged to regulate channel function. Identification of membrane cholesterol as an inhibitory ligand provides a mechanism by which the hHv1 channel regulates fertilization by linking the cholesterol efflux with cytoplasmic alkalinization, a change that triggers calcium influx through the CatSper channel. These events finally lead to hyperactivation, a remarkable change in the mobility pattern indicating fertilization competence of human sperm.


Subject(s)
Cholesterol , Ion Channel Gating , Cholesterol/metabolism , Humans , Ion Channel Gating/physiology , Ion Channels/metabolism , Ligands , Male , Semen/metabolism
14.
J Biol Chem ; 299(7): 104918, 2023 07.
Article in English | MEDLINE | ID: mdl-37315791

ABSTRACT

Unlike other members of the voltage-gated ion channel superfamily, voltage-gated proton (Hv) channels are solely composed of voltage sensor domains without separate ion-conducting pores. Due to their unique dependence on both voltage and transmembrane pH gradients, Hv channels normally open to mediate proton efflux. Multiple cellular ligands were also found to regulate the function of Hv channels, including Zn2+, cholesterol, polyunsaturated arachidonic acid, and albumin. Our previous work showed that Zn2+ and cholesterol inhibit the human voltage-gated proton channel (hHv1) by stabilizing its S4 segment at resting state conformations. Released from phospholipids by phospholipase A2 in cells upon infection or injury, arachidonic acid regulates the function of many ion channels, including hHv1. In the present work, we examined the effects of arachidonic acid on purified hHv1 channels using liposome flux assays and revealed underlying structural mechanisms using single-molecule FRET. Our data indicated that arachidonic acid strongly activates hHv1 channels by promoting transitions of the S4 segment toward opening or "preopening" conformations. Moreover, we found that arachidonic acid even activates hHv1 channels inhibited by Zn2+ and cholesterol, providing a biophysical mechanism to activate hHv1 channels in nonexcitable cells upon infection or injury.


Subject(s)
Arachidonic Acid , Cholesterol , Ion Channel Gating , Ion Channels , Protons , Zinc , Humans , Albumins/pharmacology , Arachidonic Acid/pharmacology , Cholesterol/pharmacology , Fluorescence Resonance Energy Transfer , Ion Channel Gating/drug effects , Ion Channels/agonists , Ion Channels/antagonists & inhibitors , Ion Channels/chemistry , Ion Channels/metabolism , Liposomes/metabolism , Phospholipases A2/metabolism , Single Molecule Imaging , Zinc/pharmacology , Hydrogen-Ion Concentration
15.
J Biol Chem ; 299(3): 102967, 2023 03.
Article in English | MEDLINE | ID: mdl-36736429

ABSTRACT

High-resolution structures of voltage-gated sodium channels (Nav) were first obtained from a prokaryotic ortholog NavAb, which provided important mechanistic insights into Na+ selectivity and voltage gating. Unlike eukaryotic Navs, the NavAb channel is formed by four identical subunits, but its ion selectivity and pharmacological profiles are very similar to eukaryotic Navs. Recently, the structures of the NavAb voltage sensor at resting and activated states were obtained by cryo-EM, but its intermediate states and transition dynamics remain unclear. In the present work, we used liposome flux assays to show that purified NavAb proteins were functional to conduct both H+ and Na+ and were blocked by the local anesthetic lidocaine. Additionally, we examined the real-time conformational dynamics of the NavAb voltage sensor using single-molecule FRET. Our single-molecule FRET measurements on the tandem NavAb channel labeled with Cy3/5 FRET fluorophore pair revealed spontaneous transitions of the NavAb S4 segment among three conformational states, which fitted well with the kinetic model developed for the S4 segment of the human voltage-gated proton channel hHv1. Interestingly, even under strong activating voltage, the NavAb S4 segment seems to adopt a conformational distribution similar to that of the hHv1 S4 segment at a deep resting state. The conformational behaviors of the NavAb voltage sensor under different voltages need to be further examined to understand the mechanisms of voltage sensing and gating in the canonical voltage-gated ion channel superfamily.


Subject(s)
Bacterial Proteins , Ion Channel Gating , Voltage-Gated Sodium Channels , Protein Conformation , Voltage-Gated Sodium Channels/metabolism , Bacteria , Bacterial Proteins/metabolism
16.
Avian Pathol ; 53(4): 229-241, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38323582

ABSTRACT

Marek's disease (MD) is a neoplastic disease that significantly affects the poultry industry. Long non-coding RNAs (lncRNAs) are crucial regulatory factors in various biological processes, including tumourigenesis. However, the involvement of novel lncRNAs in the course of MD virus (MDV) infection is still underexplored. Here, we present the first comprehensive characterization of differentially expressed lncRNAs in chicken spleen at different stages of MDV infection. A series of differentially expressed lncRNAs was identified at each stage of MDV infection through screening. Notably, our investigation revealed a novel lncRNA, lncRNA 803, which exhibited significant differential expression at different stages of MDV infection and was likely to be associated with the p53 pathway. Further analyses demonstrated that the overexpression of lncRNA 803 positively regulated the expression of p53 and TP53BP1 in DF-1 cells, leading to the inhibition of apoptosis. This is the first study to focus on the lncRNA expression profiles in chicken spleens during MDV pathogenesis. Our findings highlight the potential role of the p53-related novel lncRNA 803 in MD pathogenesis and provide valuable insights for decoding the molecular mechanism of MD pathogenesis involving non-coding RNA.RESEARCH HIGHLIGHTS Differentially expressed lncRNAs in spleens of chickens infected with Marek's disease virus at different stages were identified for the first time.The effects of novel lncRNA 803 on p53 pathway and apoptosis of DF-1 cells were reported for the first time.


Subject(s)
Apoptosis , Chickens , Marek Disease , Poultry Diseases , RNA, Long Noncoding , Spleen , Tumor Suppressor Protein p53 , Animals , RNA, Long Noncoding/genetics , Marek Disease/virology , Marek Disease/genetics , Chickens/virology , Spleen/virology , Spleen/pathology , Poultry Diseases/virology , Poultry Diseases/genetics , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Cell Line , Herpesvirus 2, Gallid/genetics , Herpesvirus 2, Gallid/physiology
17.
Nature ; 556(7702): 520-524, 2018 04.
Article in English | MEDLINE | ID: mdl-29670288

ABSTRACT

Neuropeptide Y (NPY) receptors belong to the G-protein-coupled receptor superfamily and have important roles in food intake, anxiety and cancer biology 1,2 . The NPY-Y receptor system has emerged as one of the most complex networks with three peptide ligands (NPY, peptide YY and pancreatic polypeptide) binding to four receptors in most mammals, namely the Y1, Y2, Y4 and Y5 receptors, with different affinity and selectivity 3 . NPY is the most powerful stimulant of food intake and this effect is primarily mediated by the Y1 receptor (Y1R) 4 . A number of peptides and small-molecule compounds have been characterized as Y1R antagonists and have shown clinical potential in the treatment of obesity 4 , tumour 1 and bone loss 5 . However, their clinical usage has been hampered by low potency and selectivity, poor brain penetration ability or lack of oral bioavailability 6 . Here we report crystal structures of the human Y1R bound to the two selective antagonists UR-MK299 and BMS-193885 at 2.7 and 3.0 Å resolution, respectively. The structures combined with mutagenesis studies reveal the binding modes of Y1R to several structurally diverse antagonists and the determinants of ligand selectivity. The Y1R structure and molecular docking of the endogenous agonist NPY, together with nuclear magnetic resonance, photo-crosslinking and functional studies, provide insights into the binding behaviour of the agonist and for the first time, to our knowledge, determine the interaction of its N terminus with the receptor. These insights into Y1R can enable structure-based drug discovery that targets NPY receptors.


Subject(s)
Arginine/analogs & derivatives , Dihydropyridines/chemistry , Dihydropyridines/metabolism , Diphenylacetic Acids/chemistry , Diphenylacetic Acids/metabolism , Neuropeptide Y/metabolism , Phenylurea Compounds/chemistry , Phenylurea Compounds/metabolism , Receptors, Neuropeptide Y/antagonists & inhibitors , Receptors, Neuropeptide Y/chemistry , Arginine/chemistry , Arginine/metabolism , Arginine/pharmacology , Binding Sites , Crystallography, X-Ray , Dihydropyridines/pharmacology , Diphenylacetic Acids/pharmacology , Humans , Inositol Phosphates/metabolism , Ligands , Molecular Docking Simulation , Mutant Proteins/chemistry , Mutant Proteins/metabolism , Mutation , Neuropeptide Y/chemistry , Neuropeptide Y/pharmacology , Nuclear Magnetic Resonance, Biomolecular , Phenylurea Compounds/pharmacology , Protein Binding , Receptors, Neuropeptide Y/agonists , Receptors, Neuropeptide Y/metabolism , Structure-Activity Relationship , Substrate Specificity
18.
Article in English | MEDLINE | ID: mdl-39210826

ABSTRACT

The subcellular localization of RNA is critical to a variety of physiological and pathological processes. Dissecting the spatiotemporal regulation of the transcriptome is key to understanding cell function and fate. However, it remains challenging to effectively enrich and catalogue RNAs from various subcellular structures using traditional approaches. In recent years, proximity labeling has emerged as an alternative strategy for efficient isolation and purification of RNA from these intricate subcellular compartments. This review focuses on examining RNA-related proximity labeling tools and exploring their application in elucidating the spatiotemporal regulation of RNA at the subcellular level.

19.
Food Microbiol ; 120: 104482, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38431313

ABSTRACT

Hafnia paralvei, a Gram-negative foodborne pathogen, is found ubiquitously in various aquatic animals and seafoods, which can form biofilm as a dominant virulence factor that contributes to its pathogenesis. However, the biofilm formation mechanism of H. paralvei and its effect on food spoilage has not been fully characterized. Here we show that biofilm formation, is regulated by c-di-GMP which mediated by bcsB, can increase the spoilage ability of H. paralvei. We found that GTP was added exogenously to enhance the synthesis of c-di-GMP, which further promoted biofilm formation. The gene dgcC, one of 11 genes encoding GGDEF domain-containing proteins in H. paralvei, was significantly upregulated with GTP as substrate. The upregulation of dgcC contributes to a significant increase of c-di-GMP and the formation of biofilm. In addition, the overexpression of dgcC induced upregulation of bcsB, a reported effector protein encoding gene, which was further demonstrated that overexpression of bcsB can encourage the synthesis of bacterial cellulose and biofilm formation. The effect of biofilm formation induced by c-di-GMP on spoilage of Yellow River carp (Cyprinus carpio) was evaluated by sensory evaluation, the total viable count, and the total volatile basic nitrogen, which showed that biofilm formation can significantly increase the spoilage ability of H. paralvei on C. carpio. Our findings provide the regulation of c-di-GMP on expression of bcsB, that can contribute to biofilm formation and spoilage ability of H. paralvei, which is favor to understanding the pathogenesis of Hafnia paralvei and its role in food spoilage.


Subject(s)
Bacterial Proteins , Carps , Cyclic GMP/analogs & derivatives , Hafnia , Animals , Bacterial Proteins/metabolism , Gene Expression Regulation, Bacterial , Gene Expression , Seafood , Biofilms , Guanosine Triphosphate
20.
Ecotoxicol Environ Saf ; 281: 116615, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38905933

ABSTRACT

BACKGROUND: Paraquat (PQ) is a widely used herbicide that poisons human by accident or intentional ingestion. PQ poisoning causes systemic inflammatory response syndrome (SIRS) resulting in acute lung injury (ALI) with an extremely high mortality rate. Blood trematode Schistosoma japonicum-produced cystatin (Sj-Cys) is a strong immunomodulatory protein that has been experimentally used to treat inflammation related diseases. In this study, Sj-Cys recombinant protein (rSj-Cys) was used to treat PQ-induced lung injury and the immunological mechanism underlying the therapeutic effect was investigated. METHODS: PQ-induced acute lung injury mouse model was established by intraperitoneally injection of 20 mg/kg of paraquat. The poisoned mice were treated with rSj-Cys and the survival rate was observed up to 7 days compared with the group without treatment. The pathological changes of PQ-induced lung injury were observed by examining the histochemical sections of affected lung tissue and the wet to dry ratio of lung as a parameter for inflammation and edema. The levels of the inflammation related cytokines IL-6 and TNF-α and regulatory cytokines IL-10 and TGF-ß were measured in sera and in affected lung tissue using ELISA and their mRNA levels in lung tissue using RT-PCR. The macrophages expressing iNOS were determined as M1 and those expressing Arg-1 as M2 macrophages. The effect of rSj-Cys on the transformation of inflammatory M1 to regulatory M2 macrophages was measured in affected lung tissue in vivo (EKISA and RT-PCR) and in MH-S cell line in vitro (flow cytometry). The expression levels of TLR2 and MyD88 in affected lung tissue were also measured to determine their role in the therapy of rSj-Cys on PQ-induced lung injury. RESULT: We identified that treatment with rSj-Cys significantly improved the survival rate of mice with PQ-induced lung injury from 30 % (untreated) to 80 %, reduced the pathological damage of poisoning lung tissue, associated with significantly reduced levels of proinflammatory cytokines (IL-6 from 1490 to 590 pg/ml, TNF-α from 260 to 150 pg/ml) and increased regulatory cytokines (IL-10 from360 to 550 pg/ml, and TGF-ß from 220 to 410 pg/ml) in both sera (proteins) and affected lung tissue (proteins and mRNAs). The polarization of macrophages from M1to M2 type was found to be involved in the therapeutic effect of rSj-Cys on the PQ-induced acute lung injury, possibly through inhibiting TLR2/MyD88 signaling pathway. CONCLUSIONS: Our study demonstrated the therapeutic effect of rSj-Cys on PQ poisoning caused acute lung injury by inducing M2 macrophage polarization through inhibiting TLR2/MyD88 signaling pathway. The finding in this study provides an alternative approach for the treatment of PQ poisoning and other inflammatory diseases.


Subject(s)
Acute Lung Injury , Cystatins , Paraquat , Schistosoma japonicum , Animals , Paraquat/toxicity , Acute Lung Injury/chemically induced , Acute Lung Injury/pathology , Acute Lung Injury/drug therapy , Mice , Herbicides/toxicity , Macrophages/drug effects , Lung/pathology , Lung/drug effects , Male , Cytokines/metabolism , Disease Models, Animal
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