Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 7.197
Filter
Add more filters

Publication year range
1.
Cell ; 184(9): 2362-2371.e9, 2021 04 29.
Article in English | MEDLINE | ID: mdl-33735608

ABSTRACT

The 501Y.V2 variants of SARS-CoV-2 containing multiple mutations in spike are now dominant in South Africa and are rapidly spreading to other countries. Here, experiments with 18 pseudotyped viruses showed that the 501Y.V2 variants do not confer increased infectivity in multiple cell types except for murine ACE2-overexpressing cells, where a substantial increase in infectivity was observed. Notably, the susceptibility of the 501Y.V2 variants to 12 of 17 neutralizing monoclonal antibodies was substantially diminished, and the neutralization ability of the sera from convalescent patients and immunized mice was also reduced for these variants. The neutralization resistance was mainly caused by E484K and N501Y mutations in the receptor-binding domain of spike. The enhanced infectivity in murine ACE2-overexpressing cells suggests the possibility of spillover of the 501Y.V2 variants to mice. Moreover, the neutralization resistance we detected for the 501Y.V2 variants suggests the potential for compromised efficacy of monoclonal antibodies and vaccines.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immune Evasion , SARS-CoV-2/pathogenicity , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antigens, Viral/immunology , Cell Line, Tumor , HEK293 Cells , Humans , Mutation/genetics , SARS-CoV-2/genetics
2.
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
3.
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
4.
Nature ; 622(7981): 112-119, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37704727

ABSTRACT

The molecular mechanisms and evolutionary changes accompanying synapse development are still poorly understood1,2. Here we generate a cross-species proteomic map of synapse development in the human, macaque and mouse neocortex. By tracking the changes of more than 1,000 postsynaptic density (PSD) proteins from midgestation to young adulthood, we find that PSD maturation in humans separates into three major phases that are dominated by distinct pathways. Cross-species comparisons reveal that human PSDs mature about two to three times slower than those of other species and contain higher levels of Rho guanine nucleotide exchange factors (RhoGEFs) in the perinatal period. Enhancement of RhoGEF signalling in human neurons delays morphological maturation of dendritic spines and functional maturation of synapses, potentially contributing to the neotenic traits of human brain development. In addition, PSD proteins can be divided into four modules that exert stage- and cell-type-specific functions, possibly explaining their differential associations with cognitive functions and diseases. Our proteomic map of synapse development provides a blueprint for studying the molecular basis and evolutionary changes of synapse maturation.


Subject(s)
Proteomics , Synapses , Adolescent , Animals , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Mice , Young Adult , Cognition/physiology , Dendritic Spines , Gestational Age , Macaca , Neurons/metabolism , Post-Synaptic Density/metabolism , Rho Guanine Nucleotide Exchange Factors/metabolism , Signal Transduction , Species Specificity , Synapses/metabolism , Synapses/physiology
5.
Nature ; 602(7898): 657-663, 2022 02.
Article in English | MEDLINE | ID: mdl-35016194

ABSTRACT

The SARS-CoV-2 B.1.1.529 (Omicron) variant contains 15 mutations of the receptor-binding domain (RBD). How Omicron evades RBD-targeted neutralizing antibodies requires immediate investigation. Here we use high-throughput yeast display screening1,2 to determine the profiles of RBD escaping mutations for 247 human anti-RBD neutralizing antibodies and show that the neutralizing antibodies can be classified by unsupervised clustering into six epitope groups (A-F)-a grouping that is highly concordant with knowledge-based structural classifications3-5. Various single mutations of Omicron can impair neutralizing antibodies of different epitope groups. Specifically, neutralizing antibodies in groups A-D, the epitopes of which overlap with the ACE2-binding motif, are largely escaped by K417N, G446S, E484A and Q493R. Antibodies in group E (for example, S309)6 and group F (for example, CR3022)7, which often exhibit broad sarbecovirus neutralizing activity, are less affected by Omicron, but a subset of neutralizing antibodies are still escaped by G339D, N440K and S371L. Furthermore, Omicron pseudovirus neutralization showed that neutralizing antibodies that sustained single mutations could also be escaped, owing to multiple synergetic mutations on their epitopes. In total, over 85% of the tested neutralizing antibodies were escaped by Omicron. With regard to neutralizing-antibody-based drugs, the neutralization potency of LY-CoV016, LY-CoV555, REGN10933, REGN10987, AZD1061, AZD8895 and BRII-196 was greatly undermined by Omicron, whereas VIR-7831 and DXP-604 still functioned at a reduced efficacy. Together, our data suggest that infection with Omicron would result in considerable humoral immune evasion, and that neutralizing antibodies targeting the sarbecovirus conserved region will remain most effective. Our results inform the development of antibody-based drugs and vaccines against Omicron and future variants.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Immune Evasion/immunology , Neutralization Tests , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/classification , Antibodies, Viral/classification , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/immunology , Cells, Cultured , Convalescence , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Humans , Immune Sera/immunology , Models, Molecular , Mutation , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism
6.
Nature ; 612(7940): 534-539, 2022 12.
Article in English | MEDLINE | ID: mdl-36477528

ABSTRACT

An effective vaccine is needed for the prevention and elimination of malaria. The only immunogens that have been shown to have a protective efficacy of more than 90% against human malaria are Plasmodium falciparum (Pf) sporozoites (PfSPZ) manufactured in mosquitoes (mPfSPZ)1-7. The ability to produce PfSPZ in vitro (iPfSPZ) without mosquitoes would substantially enhance the production of PfSPZ vaccines and mosquito-stage malaria research, but this ability is lacking. Here we report the production of hundreds of millions of iPfSPZ. iPfSPZ invaded human hepatocytes in culture and developed to mature liver-stage schizonts expressing P. falciparum merozoite surface protein 1 (PfMSP1) in numbers comparable to mPfSPZ. When injected into FRGhuHep mice containing humanized livers, iPfSPZ invaded the human hepatocytes and developed to PfMSP1-expressing late liver stage parasites at 45% the quantity of cryopreserved mPfSPZ. Human blood from FRGhuHep mice infected with iPfSPZ produced asexual and sexual erythrocytic-stage parasites in culture, and gametocytes developed to PfSPZ when fed to mosquitoes, completing the P. falciparum life cycle from infectious gametocyte to infectious gametocyte without mosquitoes or primates.


Subject(s)
Plasmodium falciparum , Sporozoites , Animals , Humans , Mice , Culicidae/parasitology , Malaria/parasitology , Malaria/prevention & control , Malaria Vaccines/biosynthesis , Malaria Vaccines/chemistry , Malaria, Falciparum/parasitology , Plasmodium falciparum/growth & development , Sporozoites/growth & development , Sporozoites/pathogenicity , Hepatocytes/parasitology , Liver/parasitology , Merozoite Surface Protein 1 , Erythrocytes/parasitology , In Vitro Techniques
7.
Mol Cell ; 79(4): 689-701.e10, 2020 08 20.
Article in English | MEDLINE | ID: mdl-32610038

ABSTRACT

Meiotic recombination proceeds via binding of RPA, RAD51, and DMC1 to single-stranded DNA (ssDNA) substrates created after formation of programmed DNA double-strand breaks. Here we report high-resolution in vivo maps of RPA and RAD51 in meiosis, mapping their binding locations and lifespans to individual homologous chromosomes using a genetically engineered hybrid mouse. Together with high-resolution microscopy and DMC1 binding maps, we show that DMC1 and RAD51 have distinct spatial localization on ssDNA: DMC1 binds near the break site, and RAD51 binds away from it. We characterize inter-homolog recombination intermediates bound by RPA in vivo, with properties expected for the critical displacement loop (D-loop) intermediates. These data support the hypothesis that DMC1, not RAD51, performs strand exchange in mammalian meiosis. RPA-bound D-loops can be resolved as crossovers or non-crossovers, but crossover-destined D-loops may have longer lifespans. D-loops resemble crossover gene conversions in size, but their extent is similar in both repair pathways.


Subject(s)
Cell Cycle Proteins/metabolism , Homologous Recombination , Meiosis , Phosphate-Binding Proteins/metabolism , Rad51 Recombinase/metabolism , Replication Protein A/metabolism , Animals , Cell Cycle Proteins/genetics , Chromosomes/genetics , Chromosomes/metabolism , Crossing Over, Genetic , DNA, Single-Stranded/metabolism , Genome , Male , Mice, Inbred C57BL , Mice, Inbred DBA , Phosphate-Binding Proteins/genetics , Rad51 Recombinase/genetics , Replication Protein A/genetics , Testis
8.
Nature ; 599(7886): 616-621, 2021 11.
Article in English | MEDLINE | ID: mdl-34759322

ABSTRACT

The origin and early dispersal of speakers of Transeurasian languages-that is, Japanese, Korean, Tungusic, Mongolic and Turkic-is among the most disputed issues of Eurasian population history1-3. A key problem is the relationship between linguistic dispersals, agricultural expansions and population movements4,5. Here we address this question by 'triangulating' genetics, archaeology and linguistics in a unified perspective. We report wide-ranging datasets from these disciplines, including a comprehensive Transeurasian agropastoral and basic vocabulary; an archaeological database of 255 Neolithic-Bronze Age sites from Northeast Asia; and a collection of ancient genomes from Korea, the Ryukyu islands and early cereal farmers in Japan, complementing previously published genomes from East Asia. Challenging the traditional 'pastoralist hypothesis'6-8, we show that the common ancestry and primary dispersals of Transeurasian languages can be traced back to the first farmers moving across Northeast Asia from the Early Neolithic onwards, but that this shared heritage has been masked by extensive cultural interaction since the Bronze Age. As well as marking considerable progress in the three individual disciplines, by combining their converging evidence we show that the early spread of Transeurasian speakers was driven by agriculture.


Subject(s)
Agriculture/history , Archaeology , Genetics, Population , Human Migration/history , Language/history , Linguistics , China , Datasets as Topic , Geographic Mapping , History, Ancient , Humans , Japan , Korea , Mongolia
9.
Proc Natl Acad Sci U S A ; 121(4): e2315401121, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38232280

ABSTRACT

Biomacromolecular folding kinetics involves fast folding events and broad timescales. Current techniques face limitations in either the required time resolution or the observation window. In this study, we developed the TeZla micromixer, integrating Tesla and Zigzag microstructures with a multistage velocity descending strategy. TeZla achieves a significant short mixing dead time (40 µs) and a wide time window covering four orders of magnitude (up to 300 ms). Using this unique micromixer, we explored the folding landscape of c-Myc G4 and its noncanonical-G4 derivatives with different loop lengths or G-vacancy sites. Our findings revealed that c-Myc can bypass folding intermediates and directly adopt a G4 structure in the cation-deficient buffer. Moreover, we found that the loop length and specific G-vacancy site could affect the folding pathway and significantly slow down the folding rates. These results were also cross-validated with real-time NMR and circular dichroism. In conclusion, TeZla represents a versatile tool for studying biomolecular folding kinetics, and our findings may ultimately contribute to the design of drugs targeting G4 structures.


Subject(s)
G-Quadruplexes , Kinetics , Physics
10.
Development ; 150(21)2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37882667

ABSTRACT

A mouse organoid culture model was developed to regenerate articular cartilage by sequential treatment with BMP2 and BMP9 (or GDF2) that parallels induced joint regeneration at digit amputation wounds in vivo. BMP9-induced chondrogenesis was used to identify clonal cell lines for articular chondrocyte and hypertrophic chondrocyte progenitor cells from digit fibroblasts. A protocol that includes cell aggregation enhanced by BMP2 followed by BMP9-induced chondrogenesis resulted in the differentiation of organized layers of articular chondrocytes, similar to the organization of middle and deep zones of articular cartilage in situ, and retained a differentiated phenotype following transplantation. In addition, the differentiation of a non-chondrogenic connective tissue layer containing articular chondrocyte progenitor cells demonstrated that progenitor cell sequestration is coupled with articular cartilage differentiation at a clonal level. The studies identify a dormant endogenous regenerative program for a non-regenerative tissue in which fibroblast-derived progenitor cells can be induced to initiate morphogenetic and differentiative programs that include progenitor cell sequestration. The identification of dormant regenerative programs in non-regenerative tissues such as articular cartilage represents a novel strategy that integrates regeneration biology with regenerative medicine.


Subject(s)
Cartilage, Articular , Animals , Mice , Cartilage, Articular/metabolism , Chondrocytes/metabolism , Stem Cells , Cell Differentiation/genetics , Cell Line , Disease Models, Animal , Chondrogenesis/genetics
11.
Circ Res ; 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38989590

ABSTRACT

BACKGROUND: Macrophage-driven inflammation critically involves in cardiac injury and repair following myocardial infarction (MI). However, the intrinsic mechanisms that halt the immune response of macrophages, which is critical to preserve homeostasis and effective infarct repair, remain to be fully defined. Here, we aimed to determine the ubiquitination-mediated regulatory effects on averting exaggerated inflammatory responses in cardiac macrophages. METHODS: We used transcriptome analysis of mouse cardiac macrophages and bone marrow-derived macrophages to identify the E3 ubiquitin ligase RNF149 (RING finger protein 149) as a modulator of macrophage response to MI. Employing loss-of-function methodologies, bone marrow transplantation approaches, and adenovirus-mediated RNF149 overexpression in macrophages, we elucidated the functional role of RNF149 in MI. We explored the underlying mechanisms through flow cytometry, transcriptome analysis, immunoprecipitation/mass spectrometry analysis, and functional experiments. RNF149 expression was measured in the cardiac tissues of patients with acute MI and healthy controls. RESULTS: RNF149 was highly expressed in murine and human cardiac macrophages at the early phase of MI. Knockout of RNF149, transplantation of Rnf149-/- bone marrow, and bone marrow macrophage-specific RNF149-knockdown markedly exacerbated cardiac dysfunction in murine MI models. Conversely, overexpression of RNF149 in macrophages attenuated the ischemia-induced decline in cardiac contractile function. RNF149 deletion increased infiltration of proinflammatory monocytes/macrophages, accompanied by a hastened decline in reparative subsets, leading to aggravation of myocardial apoptosis and impairment of infarct healing. Our data revealed that RNF149 in infiltrated macrophages restricted inflammation by promoting ubiquitylation-dependent proteasomal degradation of IFNGR1 (interferon gamma receptor 1). Loss of IFNGR1 rescued deleterious effects of RNF149 deficiency on MI. We further demonstrated that STAT1 activation induced Rnf149 transcription, which, in turn, destabilized the IFNGR1 protein to counteract type-II IFN (interferon) signaling, creating a feedback control mechanism to fine-tune macrophage-driven inflammation. CONCLUSIONS: These findings highlight the significance of RNF149 as a molecular brake on macrophage response to MI and uncover a macrophage-intrinsic posttranslational mechanism essential for maintaining immune homeostasis and facilitating cardiac repair following MI.

12.
Nature ; 582(7812): 426-431, 2020 06.
Article in English | MEDLINE | ID: mdl-32461690

ABSTRACT

Sex chromosomes in males of most eutherian mammals share only a small homologous segment, the pseudoautosomal region (PAR), in which the formation of double-strand breaks (DSBs), pairing and crossing over must occur for correct meiotic segregation1,2. How cells ensure that recombination occurs in the PAR is unknown. Here we present a dynamic ultrastructure of the PAR and identify controlling cis- and trans-acting factors that make the PAR the hottest segment for DSB formation in the male mouse genome. Before break formation, multiple DSB-promoting factors hyperaccumulate in the PAR, its chromosome axes elongate and the sister chromatids separate. These processes are linked to heterochromatic mo-2 minisatellite arrays, and require MEI4 and ANKRD31 proteins but not the axis components REC8 or HORMAD1. We propose that the repetitive DNA sequence of the PAR confers unique chromatin and higher-order structures that are crucial for recombination. Chromosome synapsis triggers collapse of the elongated PAR structure and, notably, oocytes can be reprogrammed to exhibit spermatocyte-like levels of DSBs in the PAR simply by delaying or preventing synapsis. Thus, the sexually dimorphic behaviour of the PAR is in part a result of kinetic differences between the sexes in a race between the maturation of the PAR structure, formation of DSBs and completion of pairing and synapsis. Our findings establish a mechanistic paradigm for the recombination of sex chromosomes during meiosis.


Subject(s)
DNA Breaks, Double-Stranded , Meiosis , Pseudoautosomal Regions/genetics , Pseudoautosomal Regions/metabolism , Animals , Cell Cycle Proteins/metabolism , Chromatin Assembly and Disassembly , Chromosome Pairing/genetics , DNA-Binding Proteins , Female , Heterochromatin/genetics , Heterochromatin/metabolism , Heterochromatin/ultrastructure , Kinetics , Male , Meiosis/genetics , Mice , Minisatellite Repeats/genetics , Oocytes/metabolism , Recombination, Genetic/genetics , Sex Characteristics , Sister Chromatid Exchange , Spermatocytes/metabolism , Ubiquitin-Protein Ligases/metabolism
13.
Nature ; 581(7809): 401-405, 2020 05.
Article in English | MEDLINE | ID: mdl-32461649

ABSTRACT

Plasmonics enables the manipulation of light beyond the optical diffraction limit1-4 and may therefore confer advantages in applications such as photonic devices5-7, optical cloaking8,9, biochemical sensing10,11 and super-resolution imaging12,13. However, the essential field-confinement capability of plasmonic devices is always accompanied by a parasitic Ohmic loss, which severely reduces their performance. Therefore, plasmonic materials (those with collective oscillations of electrons) with a lower loss than noble metals have long been sought14-16. Here we present stable sodium-based plasmonic devices with state-of-the-art performance at near-infrared wavelengths. We fabricated high-quality sodium films with electron relaxation times as long as 0.42 picoseconds using a thermo-assisted spin-coating process. A direct-waveguide experiment shows that the propagation length of surface plasmon polaritons supported at the sodium-quartz interface can reach 200 micrometres at near-infrared wavelengths. We further demonstrate a room-temperature sodium-based plasmonic nanolaser with a lasing threshold of 140 kilowatts per square centimetre, lower than values previously reported for plasmonic nanolasers at near-infrared wavelengths. These sodium-based plasmonic devices show stable performance under ambient conditions over a period of several months after packaging with epoxy. These results indicate that the performance of plasmonic devices can be greatly improved beyond that of devices using noble metals, with implications for applications in plasmonics, nanophotonics and metamaterials.

14.
Proc Natl Acad Sci U S A ; 120(47): e2310951120, 2023 Nov 21.
Article in English | MEDLINE | ID: mdl-37976262

ABSTRACT

Meiotic DNA double-strand breaks (DSBs) initiate homologous recombination and are crucial for ensuring proper chromosome segregation. In mice, ANKRD31 recently emerged as a regulator of DSB timing, number, and location, with a particularly important role in targeting DSBs to the pseudoautosomal regions (PARs) of sex chromosomes. ANKRD31 interacts with multiple proteins, including the conserved and essential DSB-promoting factor REC114, so it was hypothesized to be a modular scaffold that "anchors" other proteins together and to meiotic chromosomes. To determine whether and why the REC114 interaction is important for ANKRD31 function, we generated mice with Ankrd31 mutations that either reduced (missense mutation) or eliminated (C-terminal truncation) the ANKRD31-REC114 interaction without diminishing contacts with other known partners. A complete lack of the ANKRD31-REC114 interaction mimicked an Ankrd31 null, with delayed DSB formation and recombination, defects in DSB repair, and altered DSB locations including failure to target DSBs to the PARs. In contrast, when the ANKRD31-REC114 interaction was substantially but not completely disrupted, spermatocytes again showed delayed DSB formation globally, but recombination and repair were hardly affected and DSB locations were similar to control mice. The missense Ankrd31 allele showed a dosage effect, wherein combining it with the null or C-terminal truncation allele resulted in intermediate phenotypes for DSB formation, recombination, and DSB locations. Our results show that ANKRD31 function is critically dependent on its interaction with REC114 and that defects in ANKRD31 activity correlate with the severity of the disruption of the interaction.


Subject(s)
Chromosomes , Homologous Recombination , Animals , Male , Mice , Homologous Recombination/genetics , Meiosis/genetics , Mutation , Spermatogenesis/genetics
15.
EMBO J ; 40(21): e107915, 2021 11 02.
Article in English | MEDLINE | ID: mdl-34585770

ABSTRACT

Synaptic refinement is a critical physiological process that removes excess synapses to establish and maintain functional neuronal circuits. Recent studies have shown that focal exposure of phosphatidylserine (PS) on synapses acts as an "eat me" signal to mediate synaptic pruning. However, the molecular mechanism underlying PS externalization at synapses remains elusive. Here, we find that murine CDC50A, a chaperone of phospholipid flippases, localizes to synapses, and that its expression depends on neuronal activity. Cdc50a knockdown leads to phosphatidylserine exposure at synapses and subsequent erroneous synapse removal by microglia partly via the GPR56 pathway. Taken together, our data support that CDC50A safeguards synapse maintenance by regulating focal phosphatidylserine exposure at synapses.


Subject(s)
Membrane Proteins/genetics , Microglia/drug effects , Neurons/drug effects , Phosphatidylserines/pharmacology , Receptors, G-Protein-Coupled/genetics , Synapses/drug effects , Animals , Gene Expression Regulation , Genes, Reporter , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , Male , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microglia/cytology , Microglia/metabolism , Neuronal Plasticity , Neurons/cytology , Neurons/metabolism , Phosphatidylserines/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Receptors, G-Protein-Coupled/metabolism , Synapses/genetics , Synapses/metabolism , Synaptic Transmission , Synaptosomes/drug effects , Synaptosomes/metabolism , Vesicular Glutamate Transport Protein 2 , Red Fluorescent Protein
16.
Development ; 149(2)2022 01 15.
Article in English | MEDLINE | ID: mdl-35005773

ABSTRACT

Amputation injuries in mammals are typically non-regenerative; however, joint regeneration is stimulated by BMP9 treatment, indicating the presence of latent articular chondrocyte progenitor cells. BMP9 induces a battery of chondrogenic genes in vivo, and a similar response is observed in cultures of amputation wound cells. Extended cultures of BMP9-treated cells results in differentiation of hyaline cartilage, and single cell RNAseq analysis identified wound fibroblasts as BMP9 responsive. This culture model was used to identify a BMP9-responsive adult fibroblast cell line and a culture strategy was developed to engineer hyaline cartilage for engraftment into an acutely damaged joint. Transplanted hyaline cartilage survived engraftment and maintained a hyaline cartilage phenotype, but did not form mature articular cartilage. In addition, individual hypertrophic chondrocytes were identified in some samples, indicating that the acute joint injury site can promote osteogenic progression of engrafted hyaline cartilage. The findings identify fibroblasts as a cell source for engineering articular cartilage and establish a novel experimental strategy that bridges the gap between regeneration biology and regenerative medicine.


Subject(s)
Cell Differentiation , Fibroblasts/cytology , Hyaline Cartilage/cytology , Regeneration , Tissue Engineering/methods , Animals , Cells, Cultured , Chondrocytes/cytology , Chondrocytes/drug effects , Chondrogenesis , Fibroblasts/drug effects , Growth Differentiation Factor 2/pharmacology , Hyaline Cartilage/metabolism , Hyaline Cartilage/physiology , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, SCID
17.
EMBO Rep ; 24(11): e56958, 2023 11 06.
Article in English | MEDLINE | ID: mdl-37721527

ABSTRACT

Impaired branched-chain amino acid (BCAA) catabolism has recently been implicated in the development of mechanical pain, but the underlying molecular mechanisms are unclear. Here, we report that defective BCAA catabolism in dorsal root ganglion (DRG) neurons sensitizes mice to mechanical pain by increasing lactate production and expression of the mechanotransduction channel Piezo2. In high-fat diet-fed obese mice, we observed the downregulation of PP2Cm, a key regulator of the BCAA catabolic pathway, in DRG neurons. Mice with conditional knockout of PP2Cm in DRG neurons exhibit mechanical allodynia under normal or SNI-induced neuropathic injury conditions. Furthermore, the VAS scores in the plasma of patients with peripheral neuropathic pain are positively correlated with BCAA contents. Mechanistically, defective BCAA catabolism in DRG neurons promotes lactate production through glycolysis, which increases H3K18la modification and drives Piezo2 expression. Inhibition of lactate production or Piezo2 silencing attenuates the pain phenotype of knockout mice in response to mechanical stimuli. Therefore, our study demonstrates a causal role of defective BCAA catabolism in mechanical pain by enhancing metabolite-mediated epigenetic regulation.


Subject(s)
Ganglia, Spinal , Mechanotransduction, Cellular , Humans , Mice , Animals , Ganglia, Spinal/metabolism , Epigenesis, Genetic , Amino Acids, Branched-Chain/metabolism , Mice, Knockout , Pain/genetics , Lactates/metabolism
18.
Mol Cell ; 68(1): 185-197.e6, 2017 Oct 05.
Article in English | MEDLINE | ID: mdl-28943315

ABSTRACT

Many infections and stress signals can rapidly activate the NLRP3 inflammasome to elicit robust inflammatory responses. This activation requires a priming step, which is thought to be mainly for upregulating NLRP3 transcription. However, recent studies report that the NLRP3 inflammasome can be activated independently of transcription, suggesting that the priming process has unknown essential regulatory steps. Here, we report that JNK1-mediated NLRP3 phosphorylation at S194 is a critical priming event and is essential for NLRP3 inflammasome activation. We show that NLRP3 inflammasome activation is disrupted in NLRP3-S194A knockin mice. JNK1-mediated NLRP3 S194 phosphorylation is critical for NLRP3 deubiquitination and facilitates its self-association and the subsequent inflammasome assembly. Importantly, we demonstrate that blocking S194 phosphorylation prevents NLRP3 inflammasome activation in cryopyrin-associated periodic syndromes (CAPS). Thus, our study reveals a key priming molecular event that is a prerequisite for NLRP3 inflammasome activation. Inhibiting NLRP3 phosphorylation could be an effective treatment for NLRP3-related diseases.


Subject(s)
Inflammasomes/genetics , Macrophages/immunology , Mitogen-Activated Protein Kinase 8/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Shock, Septic/genetics , Amino Acid Sequence , Animals , Deubiquitinating Enzymes/genetics , Deubiquitinating Enzymes/immunology , Escherichia coli/chemistry , Female , Gene Expression Regulation , HEK293 Cells , Humans , Inflammasomes/immunology , Lipopolysaccharides/pharmacology , Macrophages/pathology , Male , Mice , Mice, Transgenic , Mitogen-Activated Protein Kinase 8/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/deficiency , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Phosphorylation , Sequence Alignment , Sequence Homology, Amino Acid , Shock, Septic/chemically induced , Shock, Septic/mortality , Shock, Septic/pathology , Signal Transduction , Survival Analysis
19.
Drug Resist Updat ; 72: 101019, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37984225

ABSTRACT

This report expands on our previous research, highlighting a unique inverse correlation between MYC expression in tumor cells and immune cells during the development of EGFR-TKI resistance. It is observed that MYC expression and fatty acid oxidation (FAO) metabolism in tissue-resident memory (TRM) CD8 + T cells are significantly impaired. These findings offer new insights into the mechanisms of TKI resistance. Although the study is preliminary, it suggests caution when interpreting the effectiveness of MYC inhibitors in reversing TKI resistance, especially when immune factors are not considered.


Subject(s)
Lung Neoplasms , Humans , Lung Neoplasms/drug therapy , ErbB Receptors/genetics , ErbB Receptors/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Drug Resistance, Neoplasm/genetics , Cell Line, Tumor , Fatty Acids/therapeutic use , Mutation
20.
Drug Resist Updat ; 76: 101112, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38924997

ABSTRACT

AIMS: Despite aggressive treatment, the recurrence of glioma is an inevitable occurrence, leading to unsatisfactory clinical outcomes. A plausible explanation for this phenomenon is the phenotypic alterations that glioma cells undergo aggressive therapies, such as TMZ-therapy. However, the underlying mechanisms behind these changes are not well understood. METHODS: The TMZ chemotherapy resistance model was employed to assess the expression of intercellular adhesion molecule-1 (ICAM1) in both in vitro and in vivo settings. The potential role of ICAM1 in regulating TMZ chemotherapy resistance was investigated through knockout and overexpression techniques. Furthermore, the mechanism underlying ICAM1-mediated TMZ chemotherapy resistance was examined using diverse molecular biological methods, and the lipid raft protein was subsequently isolated to investigate the cellular subcomponents where ICAM1 operates. RESULTS: Acquired TMZ resistant (TMZ-R) glioma models heightened production of intercellular adhesion molecule-1 (ICAM1) in TMZ-R glioma cells. Additionally, we observed a significant suppression of TMZ-R glioma proliferation upon inhibition of ICAM1, which was attributed to the enhanced intracellular accumulation of TMZ. Our findings provide evidence supporting the role of ICAM1, a proinflammatory marker, in promoting the expression of ABCB1 on the cell membrane of TMZ-resistant cells. We have elucidated the mechanistic pathway by which ICAM1 modulates phosphorylated moesin, leading to an increase in ABCB1 expression on the membrane. Furthermore, our research has revealed that the regulation of moesin by ICAM1 was instrumental in facilitating the assembly of ABCB1 exclusively on the lipid raft of the membrane. CONCLUSIONS: Our findings suggest that ICAM1 is an important mediator in TMZ-resistant gliomas and targeting ICAM1 may provide a new strategy for enhancing the efficacy of TMZ therapy against glioma.

SELECTION OF CITATIONS
SEARCH DETAIL