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1.
Nat Commun ; 14(1): 6601, 2023 10 19.
Article in English | MEDLINE | ID: mdl-37857610

ABSTRACT

Immunogenomic loci remain poorly understood because of their genetic complexity and size. Here, we report the de novo assembly of a cattle genome and provide a detailed annotation of the immunogenomic loci. The assembled genome contains 143 contigs (N50 ~ 74.0 Mb). In contrast to the current reference genome (ARS-UCD1.2), 156 gaps are closed and 467 scaffolds are located in our assembly. Importantly, the immunogenomic regions, including three immunoglobulin (IG) loci, four T-cell receptor (TR) loci, and the major histocompatibility complex (MHC) locus, are seamlessly assembled and precisely annotated. With the characterization of 258 IG genes and 657 TR genes distributed across seven genomic loci, we present a detailed depiction of immune gene diversity in cattle. Moreover, the MHC gene structures are integrally revealed with properly phased haplotypes. Together, our work describes a more complete cattle genome, and provides a comprehensive view of its complex immune-genome.


Subject(s)
Genome , Genomics , Cattle , Animals , Genome/genetics , Major Histocompatibility Complex/genetics , Immunoglobulins , Genes, Immunoglobulin
2.
Science ; 380(6648): 972-979, 2023 06 02.
Article in English | MEDLINE | ID: mdl-37262147

ABSTRACT

The suprachiasmatic nucleus (SCN) drives circadian clock coherence through intercellular coupling, which is resistant to environmental perturbations. We report that primary cilia are required for intercellular coupling among SCN neurons to maintain the robustness of the internal clock in mice. Cilia in neuromedin S-producing (NMS) neurons exhibit pronounced circadian rhythmicity in abundance and length. Genetic ablation of ciliogenesis in NMS neurons enabled a rapid phase shift of the internal clock under jet-lag conditions. The circadian rhythms of individual neurons in cilia-deficient SCN slices lost their coherence after external perturbations. Rhythmic cilia changes drive oscillations of Sonic Hedgehog (Shh) signaling and clock gene expression. Inactivation of Shh signaling in NMS neurons phenocopied the effects of cilia ablation. Thus, cilia-Shh signaling in the SCN aids intercellular coupling.


Subject(s)
Cilia , Circadian Clocks , Circadian Rhythm , Hedgehog Proteins , Suprachiasmatic Nucleus Neurons , Animals , Mice , Cilia/metabolism , Cilia/physiology , Circadian Clocks/genetics , Circadian Rhythm/physiology , Hedgehog Proteins/genetics , Hedgehog Proteins/metabolism , Suprachiasmatic Nucleus Neurons/physiology , Signal Transduction , Gene Expression Regulation , Mice, Transgenic
3.
Biochem Biophys Res Commun ; 673: 73-80, 2023 09 17.
Article in English | MEDLINE | ID: mdl-37364388

ABSTRACT

Recognition of intracellular nucleic acids is a vital step for host to mount prompt immune responses against microbial pathogens. However, inappropriate response to self-nucleic acids leads to sustained type I interferon (IFN) production, which is implicated in the development of several autoimmune diseases, such as Aicardi-Goutières syndrome (AGS). Therefore, effective confinement of intracellular nucleic acid-induced IFN expression is a potential strategy for the treatment of such autoimmune diseases. In this study, we found that rosmarinic acid (RA), a natural compound isolated from rosemary, inhibits intracellular nucleic acid-stimulated IFN expression. Mechanistic investigation revealed that RA binds to both G3BP1 and cGAS, and impairs cGAS activation through disrupting the binding of DNA with cGAS. More importantly, we showed that RA could effectively attenuate the expression of IFN-stimulated genes (ISGs) in the well-established cell models for AGS. Thus, our study provides a promising compound for the treatment of autoimmune responses induced by aberrant nucleic acid-sensing.


Subject(s)
Autoimmune Diseases , Interferon Type I , Nucleic Acids , Humans , Interferon Type I/metabolism , Autoimmunity , DNA Helicases/metabolism , RNA Helicases/metabolism , Poly-ADP-Ribose Binding Proteins , RNA Recognition Motif Proteins , Autoimmune Diseases/genetics , Nucleotidyltransferases/metabolism , Rosmarinic Acid
4.
Cell Stem Cell ; 29(11): 1531-1546.e7, 2022 Nov 03.
Article in English | MEDLINE | ID: mdl-36265493

ABSTRACT

The communication between glioblastoma stem cells (GSCs) and the surrounding microenvironment is a prominent feature accounting for the aggressive biology of glioblastoma multiforme (GBM). However, the mechanisms by which GSCs proactively drive interactions with microenvironment is not well understood. In this study, we interrogated metabolites that are preferentially secreted from GSCs and found that GSCs produce and secrete histamine to shape a pro-angiogenic tumor microenvironment. This histamine-producing ability is attributed to H3K4me3 modification-activated histidine decarboxylase (HDC) transcription via MYC. Notably, HDC is highly expressed in GBM, which is associated with poor survival of these patients. GSC-secreted histamine activates endothelial cells by triggering a histamine H1 receptor (H1R)-Ca2+-NF-κB axis, thereby promoting angiogenesis and GBM progression. Importantly, pharmacological blockage of H1R using antihistamines impedes the growth of GBM xenografts in mice. Our findings establish that GSC-specific metabolite secretion remodels the tumor microenvironment and highlight histamine targeting as a potential strategy for GBM therapy.


Subject(s)
Brain Neoplasms , Glioblastoma , Humans , Mice , Animals , Glioblastoma/pathology , Histamine/metabolism , Tumor Microenvironment , Brain Neoplasms/pathology , Endothelial Cells/metabolism , Neoplastic Stem Cells/pathology , Cell Line, Tumor
5.
Mitochondrial DNA B Resour ; 7(4): 694-695, 2022.
Article in English | MEDLINE | ID: mdl-35493711

ABSTRACT

Uncaria macrophylla (Rubiaceae) is a medicinal vine plant of the Rubiaceae family that was distributed in East Asia and Southeast Asia. The first complete chloroplast genome of Uncaria macrophylla was sequenced and assembled in this study. The genome is 155,138 bp in length and contained 129 encoded genes in total, including 79 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The phylogenomic analysis showed that U. macrophylla was closely related to Uncaria rhynchophylla according to the current sampling extent.

6.
EMBO Rep ; 23(1): e53166, 2022 01 05.
Article in English | MEDLINE | ID: mdl-34779554

ABSTRACT

Cyclic GMP-AMP synthase (cGAS) functions as a key sensor for microbial invasion and cellular damage by detecting emerging cytosolic DNA. Here, we report that GTPase-activating protein-(SH3 domain)-binding protein 1 (G3BP1) primes cGAS for its prompt activation by engaging cGAS in a primary liquid-phase condensation state. Using high-resolution microscopy, we show that in resting cells, cGAS exhibits particle-like morphological characteristics, which are markedly weakened when G3BP1 is deleted. Upon DNA challenge, the pre-condensed cGAS undergoes liquid-liquid phase separation (LLPS) more efficiently. Importantly, G3BP1 deficiency or its inhibition dramatically diminishes DNA-induced LLPS and the subsequent activation of cGAS. Interestingly, RNA, previously reported to form condensates with cGAS, does not activate cGAS. Accordingly, we find that DNA - but not RNA - treatment leads to the dissociation of G3BP1 from cGAS. Taken together, our study shows that the primary condensation state of cGAS is critical for its rapid response to DNA.


Subject(s)
DNA Helicases , Nucleotidyltransferases , Poly-ADP-Ribose Binding Proteins , RNA Helicases , RNA Recognition Motif Proteins , DNA/metabolism , DNA Helicases/genetics , DNA Helicases/metabolism , Nucleotidyltransferases/metabolism , Poly-ADP-Ribose Binding Proteins/genetics , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/genetics , RNA Helicases/metabolism , RNA Recognition Motif Proteins/genetics , RNA Recognition Motif Proteins/metabolism , Stress Granules
7.
Surg Radiol Anat ; 43(10): 1703-1709, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34232369

ABSTRACT

PURPOSE: Vascularized pedicled bone-grafting from the cuboid to the talus provides low donor site morbidity and satisfactory outcomes in patients with early-stage talar avascular necrosis. We investigated the anatomy of the rotational vascularized pedicled bone graft from the cuboid. METHODS: 15 embalmed cadaver specimens were perfused with red latex via the popliteal artery. The lateral malleolus was dissected. The course of the lateral tarsal artery and the vascular territory in the cuboid supplied by the lateral tarsal artery were observed. Vessel diameters were measured. RESULTS: The course of the lateral tarsal artery to the cuboid was consistent, and a vascularized pedicle of the lateral tarsal artery was present in all specimens. Mean diameter of the lateral tarsal artery was 1.40 ± 0.12 mm (range 1.67-1.25). Mean length of the vascularized pedicle was 67.15 ± 3.18 mm (range 62.43-74.36). The pedicle bone graft was long enough to reach the bony border of both the lateral and medial malleolus. CONCLUSION: A vascularized pedicled cuboid bone graft based on the lateral tarsal artery has clinical utility for early-stage talar avascular necrosis.


Subject(s)
Bone Transplantation/methods , Osteonecrosis/surgery , Tarsal Bones/anatomy & histology , Tarsal Bones/blood supply , Arteries , Cadaver , Humans , Talus/anatomy & histology , Talus/blood supply , Talus/surgery , Tarsal Bones/surgery
8.
J Immunol ; 206(10): 2453-2467, 2021 05 15.
Article in English | MEDLINE | ID: mdl-33941659

ABSTRACT

The detection of intracellular nucleic acids is a fundamental mechanism of host defense against infections. The dysregulated nucleic acid sensing, however, is a major cause for a number of autoimmune diseases. In this study, we report that GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is critical for both intracellular DNA- and RNA-induced immune responses. We found that in both human and mouse cells, the deletion of G3BP1 led to the dampened cGAS activation by DNA and the insufficient binding of RNA by RIG-I. We further found that resveratrol (RSVL), a natural compound found in grape skin, suppressed both intracellular DNA- and RNA-induced type I IFN production through inhibiting G3BP1. Importantly, using experimental mouse models for Aicardi-Goutières syndrome, an autoimmune disorder found in humans, we demonstrated that RSVL effectively alleviated intracellular nucleic acid-stimulated autoimmune responses. Thus, our study demonstrated a broader role of G3BP1 in sensing different kinds of intracellular nucleic acids and presented RSVL as a potential treatment for autoimmune conditions caused by dysregulated nucleic acid sensing.


Subject(s)
Autoimmunity/genetics , DNA Helicases/deficiency , DNA Helicases/metabolism , Intracellular Space/metabolism , Nucleic Acids/metabolism , Poly-ADP-Ribose Binding Proteins/deficiency , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/deficiency , RNA Helicases/metabolism , RNA Recognition Motif Proteins/deficiency , RNA Recognition Motif Proteins/metabolism , Signal Transduction/genetics , A549 Cells , Animals , Autoimmunity/drug effects , Cell Survival/drug effects , DNA Helicases/antagonists & inhibitors , DNA Helicases/genetics , Fibroblasts/metabolism , Gene Knockout Techniques , HEK293 Cells , Humans , Intracellular Space/immunology , Macrophages/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Poly-ADP-Ribose Binding Proteins/antagonists & inhibitors , Poly-ADP-Ribose Binding Proteins/genetics , RNA Helicases/antagonists & inhibitors , RNA Helicases/genetics , RNA Recognition Motif Proteins/antagonists & inhibitors , RNA Recognition Motif Proteins/genetics , Resveratrol/administration & dosage , Signal Transduction/immunology , Transfection
9.
Nat Commun ; 12(1): 2114, 2021 04 09.
Article in English | MEDLINE | ID: mdl-33837182

ABSTRACT

Lack of detailed knowledge of SARS-CoV-2 infection has been hampering the development of treatments for coronavirus disease 2019 (COVID-19). Here, we report that RNA triggers the liquid-liquid phase separation (LLPS) of the SARS-CoV-2 nucleocapsid protein, N. By analyzing all 29 proteins of SARS-CoV-2, we find that only N is predicted as an LLPS protein. We further confirm the LLPS of N during SARS-CoV-2 infection. Among the 100,849 genome variants of SARS-CoV-2 in the GISAID database, we identify that ~37% (36,941) of the genomes contain a specific trio-nucleotide polymorphism (GGG-to-AAC) in the coding sequence of N, which leads to the amino acid substitutions, R203K/G204R. Interestingly, NR203K/G204R exhibits a higher propensity to undergo LLPS and a greater effect on IFN inhibition. By screening the chemicals known to interfere with N-RNA binding in other viruses, we find that (-)-gallocatechin gallate (GCG), a polyphenol from green tea, disrupts the LLPS of N and inhibits SARS-CoV-2 replication. Thus, our study reveals that targeting N-RNA condensation with GCG could be a potential treatment for COVID-19.


Subject(s)
Amino Acid Substitution/drug effects , COVID-19/prevention & control , Catechin/analogs & derivatives , Nucleocapsid Proteins/genetics , SARS-CoV-2/drug effects , Virus Replication/drug effects , COVID-19/virology , Catechin/pharmacology , Genome, Viral/genetics , Humans , Liquid-Liquid Extraction , Nucleocapsid Proteins/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism , SARS-CoV-2/genetics , Virus Replication/genetics
10.
Fitoterapia ; 151: 104860, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33582265

ABSTRACT

Glycyrrhizic acid, the main active ingredient of licorice, has good antibacterial, anti-tumor, anti-viral, anti-inflammatory, and immunostimulatory activities. However, the content of glycyrrhizic acid fluctuates greatly in different licorice cultivars, and production depends on plant sources, which greatly limits its development and applications. Therefore, increasing glycyrrhizic acid content has become a research priority. In recent years, regulation of the glycyrrhizic acid biosynthesis pathway has been analyzed, the downstream synthesis pathway in licorice has been fully investigated, some key genes have been cloned, polymorphisms have been studied, and the content of glycyrrhizic acid was shown to be regulated by environmental stimuli. This work has provided a basis for studying the regulation mechanism of the glycyrrhizic acid synthesis pathway. This review summarizes and discusses relevant research to provide a current understanding of the glycyrrhizic acid synthesis pathway and its regulation in licorice.


Subject(s)
Glycyrrhiza/metabolism , Glycyrrhizic Acid/metabolism , Biosynthetic Pathways , Environment
11.
J Cell Biol ; 220(2)2021 02 01.
Article in English | MEDLINE | ID: mdl-33475699

ABSTRACT

Primary cilia protrude from the cell surface and have diverse roles during development and disease, which depends on the precise timing and control of cilia assembly and disassembly. Inactivation of assembly often causes cilia defects and underlies ciliopathy, while diseases caused by dysfunction in disassembly remain largely unknown. Here, we demonstrate that CEP55 functions as a cilia disassembly regulator to participate in ciliopathy. Cep55-/- mice display clinical manifestations of Meckel-Gruber syndrome, including perinatal death, polycystic kidneys, and abnormalities in the CNS. Interestingly, Cep55-/- mice exhibit an abnormal elongation of cilia on these tissues. Mechanistically, CEP55 promotes cilia disassembly by interacting with and stabilizing Aurora A kinase, which is achieved through facilitating the chaperonin CCT complex to Aurora A. In addition, CEP55 mutation in Meckel-Gruber syndrome causes the failure of cilia disassembly. Thus, our study establishes a cilia disassembly role for CEP55 in vivo, coupling defects in cilia disassembly to ciliopathy and further suggesting that proper cilia dynamics are critical for mammalian development.


Subject(s)
Aurora Kinase A/metabolism , Cell Cycle Proteins/metabolism , Cilia/metabolism , Animals , Cell Cycle Checkpoints , Cell Cycle Proteins/deficiency , Cells, Cultured , Centrosome/metabolism , Centrosome/ultrastructure , Chaperonin Containing TCP-1/metabolism , Cilia/ultrastructure , Ciliary Motility Disorders/pathology , Encephalocele/pathology , Enzyme Stability , Gene Targeting , HEK293 Cells , Humans , Mice , Mitosis , Phenotype , Polycystic Kidney Diseases/pathology , Protein Binding , Retinitis Pigmentosa/pathology , Smoothened Receptor/metabolism
12.
Nat Commun ; 12(1): 662, 2021 01 28.
Article in English | MEDLINE | ID: mdl-33510165

ABSTRACT

Dynamic assembly and disassembly of primary cilia controls embryonic development and tissue homeostasis. Dysregulation of ciliogenesis causes human developmental diseases termed ciliopathies. Cell-intrinsic regulatory mechanisms of cilia disassembly have been well-studied. The extracellular cues controlling cilia disassembly remain elusive, however. Here, we show that lysophosphatidic acid (LPA), a multifunctional bioactive phospholipid, acts as a physiological extracellular factor to initiate cilia disassembly and promote neurogenesis. Through systematic analysis of serum components, we identify a small molecular-LPA as the major driver of cilia disassembly. Genetic inactivation and pharmacological inhibition of LPA receptor 1 (LPAR1) abrogate cilia disassembly triggered by serum. The LPA-LPAR-G-protein pathway promotes the transcription and phosphorylation of cilia disassembly factors-Aurora A, through activating the transcription coactivators YAP/TAZ and calcium/CaM pathway, respectively. Deletion of Lpar1 in mice causes abnormally elongated cilia and decreased proliferation in neural progenitor cells, thereby resulting in defective neurogenesis. Collectively, our findings establish LPA as a physiological initiator of cilia disassembly and suggest targeting the metabolism of LPA and the LPA pathway as potential therapies for diseases with dysfunctional ciliogenesis.


Subject(s)
Cilia/drug effects , Lysophospholipids/pharmacology , Neurogenesis/drug effects , Retinal Pigment Epithelium/drug effects , Signal Transduction , Animals , Cell Line , Cell Proliferation/drug effects , Cell Proliferation/genetics , Cilia/genetics , Cilia/metabolism , HEK293 Cells , Heterotrimeric GTP-Binding Proteins/metabolism , Humans , Lysophospholipids/metabolism , Mice, Inbred C57BL , Mice, Knockout , Neural Stem Cells/cytology , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , Neurogenesis/genetics , Protein Binding , RNA Interference , Receptors, Lysophosphatidic Acid/genetics , Receptors, Lysophosphatidic Acid/metabolism , Retinal Pigment Epithelium/cytology , Retinal Pigment Epithelium/metabolism
13.
J Cell Biol ; 218(12): 4030-4041, 2019 12 02.
Article in English | MEDLINE | ID: mdl-31619485

ABSTRACT

The primary cilium is a sensory organelle that protrudes from the cell surface. Primary cilia undergo dynamic transitions between assembly and disassembly to exert their function in cell signaling. In this study, we identify the small GTPase Rab7 as a novel regulator of cilia disassembly. Depletion of Rab7 potently induced spontaneous ciliogenesis in proliferating cells and promoted cilia elongation during quiescence. Moreover, Rab7 performs an essential role in cilia disassembly; knockdown of Rab7 blocked serum-induced ciliary resorption, and active Rab7 was required for this process. Further, we demonstrate that Rab7 depletion significantly suppresses cilia tip excision, referred to as cilia ectocytosis, which has been identified as required for cilia disassembly. Mechanically, the failure of F-actin polymerization at the site of excision of cilia tips caused suppression of cilia ectocytosis on Rab7 depletion. Overall, our results suggest a novel function for Rab7 in regulating cilia ectocytosis and cilia disassembly via control of intraciliary F-actin polymerization.


Subject(s)
Actin Cytoskeleton/metabolism , Cilia/metabolism , Signal Transduction , rab GTP-Binding Proteins/metabolism , Actins/metabolism , Cell Division , Cell Line , Cell Proliferation , GTP Phosphohydrolases/metabolism , HEK293 Cells , Humans , Maltose-Binding Proteins/metabolism , Polymers/metabolism , RNA, Small Interfering/metabolism , rab7 GTP-Binding Proteins
14.
Cell Rep ; 28(9): 2386-2396.e5, 2019 08 27.
Article in English | MEDLINE | ID: mdl-31461653

ABSTRACT

It is known that lethal viruses profoundly manipulate host metabolism, but how the metabolism alternation affects the immediate host antiviral immunity remains elusive. Here, we report that the O-GlcNAcylation of mitochondrial antiviral-signaling protein (MAVS), a key mediator of interferon signaling, is a critical regulation to activate the host innate immunity against RNA viruses. We show that O-GlcNAcylation depletion in myeloid cells renders the host more susceptible to virus infection both in vitro and in vivo. Mechanistically, we demonstrate that MAVS O-GlcNAcylation is required for virus-induced MAVS K63-linked ubiquitination, thereby facilitating IRF3 activation and IFNß production. We further demonstrate that D-glucosamine, a commonly used dietary supplement, effectively protects mice against a range of lethal RNA viruses, including human influenza virus. Our study highlights a critical role of O-GlcNAcylation in regulating host antiviral immunity and validates D-glucosamine as a potential therapeutic for virus infections.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Immunity, Innate , Orthomyxoviridae Infections/immunology , Protein Processing, Post-Translational , Acetylation , Adaptor Proteins, Signal Transducing/genetics , Animals , Chlorocebus aethiops , Female , Glucosamine/metabolism , HEK293 Cells , HeLa Cells , Humans , Interferon-beta/genetics , Interferon-beta/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Inbred ICR , Myeloid Cells/metabolism , Myeloid Cells/virology , Signal Transduction , Vero Cells
15.
Chem Commun (Camb) ; 55(63): 9343-9346, 2019 Aug 14.
Article in English | MEDLINE | ID: mdl-31313763

ABSTRACT

A hierarchical trimetallic coordination polymer film was prepared using a spray-assisted interface synthetic strategy and in situ deposited onto Ni foam (denoted as Co0.5Ni0.3Fe0.2BDC-HCPF/Ni foam). The as-prepared material exhibits a 3D network hierarchical structure with 1D interconnected nanofibers and can be directly used as an efficient OER electrocatalyst.

16.
Medicine (Baltimore) ; 98(26): e16194, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31261559

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) is increasingly prevalent in chronic kidney disease (CKD) patients. The efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) in AF and CKD patients remains unknown. This systematic review and meta-analysis will mainly assess net clinical benefit (NCB) property of NOACs versus warfarin in patients with AF and CKD by a pooled-analysis. METHODS: We will search Medline, Embase, Cochrane Library, and Clinical Trials.gov Website comprehensively for eligible randomized controlled trials that report the efficacy and safety outcomes according to renal function of NOACs. Relative risks and their 95% confidence intervals will be calculated using fixed- and random-effects models. Subgroup, sensitivity, and regression analyses will be performed to evaluate intertrial heterogeneity and bias of the results. NCB that balance stroke/systemic embolism (SSE) and major bleeding will be calculated using Singer's method. RESULTS: This systemic review and meta-analysis will evaluate the NCB of NOACs versus warfarin via SSE, major bleeding and all-cause death in patients with CKD. CONCLUSIONS: This study will provide new evidence for clinical profile of NOACs on SSE, major bleeding, all-cause death, and NCB in CKD patients. PROSPERO REGISTRATION NUMBER: CRD42019116940.


Subject(s)
Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Meta-Analysis as Topic , Renal Insufficiency, Chronic/drug therapy , Systematic Reviews as Topic , Administration, Oral , Anticoagulants/adverse effects , Anticoagulants/pharmacology , Atrial Fibrillation/complications , Humans , Renal Insufficiency, Chronic/complications , Research Design , Warfarin/adverse effects , Warfarin/therapeutic use
17.
Nat Cell Biol ; 21(4): 476-486, 2019 04.
Article in English | MEDLINE | ID: mdl-30858581

ABSTRACT

The capacity of cells to alter bioenergetics in response to the demands of various biological processes is essential for normal physiology. The coordination of energy sensing and production with highly energy-demanding cellular processes, such as cell division, is poorly understood. Here, we show that a cell cycle-dependent mitochondrial Ca2+ transient connects energy sensing to mitochondrial activity for mitotic progression. The mitochondrial Ca2+ uniporter (MCU) mediates a rapid mitochondrial Ca2+ transient during mitosis. Inhibition of mitochondrial Ca2+ transients via MCU depletion causes spindle checkpoint-dependent mitotic delay. Cellular ATP levels drop during early mitosis, and the mitochondrial Ca2+ transients boost mitochondrial respiration to restore energy homeostasis. This is achieved through mitosis-specific MCU phosphorylation and activation by the mitochondrial translocation of energy sensor AMP-activated protein kinase (AMPK). Our results establish a critical role for AMPK- and MCU-dependent mitochondrial Ca2+ signalling in mitosis and reveal a mechanism of mitochondrial metabolic adaptation to acute cellular energy stress.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Calcium Channels/physiology , Calcium/metabolism , Mitochondria/metabolism , Mitosis , Adenosine Triphosphate/biosynthesis , Animals , Calcium Channels/genetics , Cell Line , Cells, Cultured , HeLa Cells , Humans , Mice, Inbred C57BL , Microtubules/metabolism , Mitochondria/enzymology
18.
Ann Bot ; 123(7): 1179-1189, 2019 07 08.
Article in English | MEDLINE | ID: mdl-30916314

ABSTRACT

BACKGROUND AND AIMS: Differences in local abundance and ploidy level are predicted to impact the direction of introgression between species. Here, we tested these hypotheses on populations of Betula albosinensis (red birch) and Betula platyphylla (white birch) which were thought to differ in ploidy level, the former being tetraploid and the latter diploid. METHODS: We sampled 391 birch individuals from nine localities in China, and classified them into species based on leaf morphology. Twelve nuclear microsatellite markers were genotyped in each sample, and analysed using principal coordinates analysis and STRUCTURE software. We compared the effects of two different methods of scoring polyploid genotypes on population genetic analyses. We analysed the effect of ploidy, local species abundance and latitude on levels of introgression between the species. KEY RESULTS: Leaf morphology divided our samples into red and white birch, but genetic analyses unexpectedly revealed two groups within red birch, one of which was tetraploid, as expected, but the other of which appeared to have diploid microsatellite genotypes. Five individuals were identified as early-generation hybrids or backcrosses between white birch and red birch and five were identified between red birch and 'diploid' red birch. Cline analysis showed that levels of admixture were not significantly correlated with latitude. Estimated genetic differentiation among species was not significantly different between determined tetraploid and undetermined tetraploid genotypes. CONCLUSIONS: Limited hybridization and gene flow have occurred between red birch and white birch. Relative species abundance and ploidy level do not impact the direction of introgression between them, as genetic admixture is roughly symmetrical. We unexpectedly found populations of apparently diploid red birch and this taxon may be a progenitor of allotetraploid red birch populations. Incomplete lineage sorting may explain patterns of genetic admixture between apparently diploid and allotetraploid red birch.


Subject(s)
Betula , Hybridization, Genetic , China , Diploidy , Microsatellite Repeats
19.
Cell ; 176(6): 1447-1460.e14, 2019 03 07.
Article in English | MEDLINE | ID: mdl-30799039

ABSTRACT

The presence of DNA in the cytoplasm is normally a sign of microbial infections and is quickly detected by cyclic GMP-AMP synthase (cGAS) to elicit anti-infection immune responses. However, chronic activation of cGAS by self-DNA leads to severe autoimmune diseases for which no effective treatment is available yet. Here we report that acetylation inhibits cGAS activation and that the enforced acetylation of cGAS by aspirin robustly suppresses self-DNA-induced autoimmunity. We find that cGAS acetylation on either Lys384, Lys394, or Lys414 contributes to keeping cGAS inactive. cGAS is deacetylated in response to DNA challenges. Importantly, we show that aspirin can directly acetylate cGAS and efficiently inhibit cGAS-mediated immune responses. Finally, we demonstrate that aspirin can effectively suppress self-DNA-induced autoimmunity in Aicardi-Goutières syndrome (AGS) patient cells and in an AGS mouse model. Thus, our study reveals that acetylation contributes to cGAS activity regulation and provides a potential therapy for treating DNA-mediated autoimmune diseases.


Subject(s)
DNA/immunology , Nucleotidyltransferases/metabolism , Self Tolerance/immunology , Acetylation , Amino Acid Sequence , Animals , Aspirin/pharmacology , Autoimmune Diseases/genetics , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , Autoimmune Diseases of the Nervous System/genetics , Autoimmune Diseases of the Nervous System/immunology , Autoimmune Diseases of the Nervous System/metabolism , Autoimmunity , Cell Line , DNA/genetics , DNA/metabolism , Disease Models, Animal , Exodeoxyribonucleases/metabolism , HEK293 Cells , HeLa Cells , Humans , Mice , Mice, Inbred C57BL , Models, Molecular , Mutation , Nervous System Malformations/genetics , Nervous System Malformations/immunology , Nervous System Malformations/metabolism , Nucleotidyltransferases/antagonists & inhibitors , Nucleotidyltransferases/chemistry , Nucleotidyltransferases/genetics , THP-1 Cells
20.
Nat Immunol ; 20(1): 18-28, 2019 01.
Article in English | MEDLINE | ID: mdl-30510222

ABSTRACT

Cyclic GMP-AMP synthase (cGAS) is a key sensor responsible for cytosolic DNA detection. Here we report that GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is critical for DNA sensing and efficient activation of cGAS. G3BP1 enhanced DNA binding of cGAS by promoting the formation of large cGAS complexes. G3BP1 deficiency led to inefficient DNA binding by cGAS and inhibited cGAS-dependent interferon (IFN) production. The G3BP1 inhibitor epigallocatechin gallate (EGCG) disrupted existing G3BP1-cGAS complexes and inhibited DNA-triggered cGAS activation, thereby blocking DNA-induced IFN production both in vivo and in vitro. EGCG administration blunted self DNA-induced autoinflammatory responses in an Aicardi-Goutières syndrome (AGS) mouse model and reduced IFN-stimulated gene expression in cells from a patient with AGS. Thus, our study reveals that G3BP1 physically interacts with and primes cGAS for efficient activation. Furthermore, EGCG-mediated inhibition of G3BP1 provides a potential treatment for cGAS-related autoimmune diseases.


Subject(s)
Autoimmune Diseases of the Nervous System/metabolism , DNA Helicases/metabolism , Multiprotein Complexes/metabolism , Nervous System Malformations/metabolism , Nucleotidyltransferases/metabolism , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/metabolism , RNA Recognition Motif Proteins/metabolism , Animals , Autoantigens/immunology , Autoantigens/metabolism , Autoimmune Diseases of the Nervous System/drug therapy , Autoimmune Diseases of the Nervous System/genetics , Catechin/analogs & derivatives , Catechin/therapeutic use , Clustered Regularly Interspaced Short Palindromic Repeats , Cytosol/immunology , Cytosol/metabolism , DNA/immunology , DNA/metabolism , DNA Helicases/antagonists & inhibitors , DNA Helicases/genetics , Disease Models, Animal , Exodeoxyribonucleases/genetics , HEK293 Cells , HeLa Cells , Humans , Interferons/metabolism , Mice , Mice, Knockout , Nervous System Malformations/drug therapy , Nervous System Malformations/genetics , Neuroprotective Agents/therapeutic use , Phosphoproteins/genetics , Poly-ADP-Ribose Binding Proteins/antagonists & inhibitors , Poly-ADP-Ribose Binding Proteins/genetics , Protein Binding , RNA Helicases/antagonists & inhibitors , RNA Helicases/genetics , RNA Recognition Motif Proteins/antagonists & inhibitors , RNA Recognition Motif Proteins/genetics
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