Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.614
Filter
Add more filters

Publication year range
1.
Cell ; 184(1): 149-168.e17, 2021 01 07.
Article in English | MEDLINE | ID: mdl-33278357

ABSTRACT

COVID-19 is characterized by excessive production of pro-inflammatory cytokines and acute lung damage associated with patient mortality. While multiple inflammatory cytokines are produced by innate immune cells during SARS-CoV-2 infection, we found that only the combination of TNF-α and IFN-γ induced inflammatory cell death characterized by inflammatory cell death, PANoptosis. Mechanistically, TNF-α and IFN-γ co-treatment activated the JAK/STAT1/IRF1 axis, inducing nitric oxide production and driving caspase-8/FADD-mediated PANoptosis. TNF-α and IFN-γ caused a lethal cytokine shock in mice that mirrors the tissue damage and inflammation of COVID-19, and inhibiting PANoptosis protected mice from this pathology and death. Furthermore, treating with neutralizing antibodies against TNF-α and IFN-γ protected mice from mortality during SARS-CoV-2 infection, sepsis, hemophagocytic lymphohistiocytosis, and cytokine shock. Collectively, our findings suggest that blocking the cytokine-mediated inflammatory cell death signaling pathway identified here may benefit patients with COVID-19 or other infectious and autoinflammatory diseases by limiting tissue damage/inflammation.


Subject(s)
COVID-19/immunology , COVID-19/pathology , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/pathology , Interferon-gamma/immunology , Tumor Necrosis Factor-alpha/immunology , Animals , Antibodies, Neutralizing/administration & dosage , Cell Death , Disease Models, Animal , Female , Human Umbilical Vein Endothelial Cells , Humans , Inflammation/immunology , Inflammation/pathology , Lymphohistiocytosis, Hemophagocytic/chemically induced , Male , Mice , Mice, Transgenic , THP-1 Cells
2.
Cell ; 181(3): 674-687.e13, 2020 04 30.
Article in English | MEDLINE | ID: mdl-32298652

ABSTRACT

Caspases regulate cell death, immune responses, and homeostasis. Caspase-6 is categorized as an executioner caspase but shows key differences from the other executioners. Overall, little is known about the functions of caspase-6 in biological processes apart from apoptosis. Here, we show that caspase-6 mediates innate immunity and inflammasome activation. Furthermore, we demonstrate that caspase-6 promotes the activation of programmed cell death pathways including pyroptosis, apoptosis, and necroptosis (PANoptosis) and plays an essential role in host defense against influenza A virus (IAV) infection. In addition, caspase-6 promoted the differentiation of alternatively activated macrophages (AAMs). Caspase-6 facilitated the RIP homotypic interaction motif (RHIM)-dependent binding of RIPK3 to ZBP1 via its interaction with RIPK3. Altogether, our findings reveal a vital role for caspase-6 in facilitating ZBP1-mediated inflammasome activation, cell death, and host defense during IAV infection, opening additional avenues for treatment of infectious and autoinflammatory diseases and cancer.


Subject(s)
Caspase 6/immunology , Caspase 6/metabolism , Inflammasomes/immunology , Animals , Apoptosis/immunology , Cell Death/immunology , Immunity, Innate , Inflammasomes/metabolism , Inflammasomes/physiology , Inflammation/immunology , Inflammation/metabolism , Inflammation/pathology , Macrophages/immunology , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Necroptosis/immunology , Protein Binding , Pyroptosis/immunology , RNA-Binding Proteins/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism
3.
Nat Immunol ; 22(7): 829-838, 2021 07.
Article in English | MEDLINE | ID: mdl-33963333

ABSTRACT

The innate immune response is critical for recognizing and controlling infections through the release of cytokines and chemokines. However, severe pathology during some infections, including SARS-CoV-2, is driven by hyperactive cytokine release, or a cytokine storm. The innate sensors that activate production of proinflammatory cytokines and chemokines during COVID-19 remain poorly characterized. In the present study, we show that both TLR2 and MYD88 expression were associated with COVID-19 disease severity. Mechanistically, TLR2 and Myd88 were required for ß-coronavirus-induced inflammatory responses, and TLR2-dependent signaling induced the production of proinflammatory cytokines during coronavirus infection independent of viral entry. TLR2 sensed the SARS-CoV-2 envelope protein as its ligand. In addition, blocking TLR2 signaling in vivo provided protection against the pathogenesis of SARS-CoV-2 infection. Overall, our study provides a critical understanding of the molecular mechanism of ß-coronavirus sensing and inflammatory cytokine production, which opens new avenues for therapeutic strategies to counteract the ongoing COVID-19 pandemic.


Subject(s)
COVID-19/immunology , Coronavirus Envelope Proteins/metabolism , Cytokine Release Syndrome/immunology , SARS-CoV-2/immunology , Toll-Like Receptor 2/metabolism , Animals , COVID-19/complications , COVID-19/diagnosis , COVID-19/virology , Chlorocebus aethiops , Cytokine Release Syndrome/diagnosis , Cytokines/metabolism , Disease Models, Animal , Female , Gene Expression Profiling , Humans , Immunity, Innate/drug effects , Leukocytes, Mononuclear , Macrophages , Male , Mice , Mice, Knockout , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Primary Cell Culture , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Severity of Illness Index , Signal Transduction/drug effects , Signal Transduction/genetics , Signal Transduction/immunology , Toll-Like Receptor 2/antagonists & inhibitors , Toll-Like Receptor 2/genetics , Vero Cells , COVID-19 Drug Treatment
4.
Cell ; 161(4): 919-32, 2015 May 07.
Article in English | MEDLINE | ID: mdl-25957690

ABSTRACT

Aging has been associated with a progressive decline of proteostasis, but how this process affects proteome composition remains largely unexplored. Here, we profiled more than 5,000 proteins along the lifespan of the nematode C. elegans. We find that one-third of proteins change in abundance at least 2-fold during aging, resulting in a severe proteome imbalance. These changes are reduced in the long-lived daf-2 mutant but are enhanced in the short-lived daf-16 mutant. While ribosomal proteins decline and lose normal stoichiometry, proteasome complexes increase. Proteome imbalance is accompanied by widespread protein aggregation, with abundant proteins that exceed solubility contributing most to aggregate load. Notably, the properties by which proteins are selected for aggregation differ in the daf-2 mutant, and an increased formation of aggregates associated with small heat-shock proteins is observed. We suggest that sequestering proteins into chaperone-enriched aggregates is a protective strategy to slow proteostasis decline during nematode aging.


Subject(s)
Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans/growth & development , Caenorhabditis elegans/metabolism , Proteome/metabolism , Aging , Animals , Caenorhabditis elegans Proteins/genetics , Mutation , Protein Aggregates
5.
Development ; 151(20)2024 Oct 15.
Article in English | MEDLINE | ID: mdl-38512707

ABSTRACT

In many animals and flowering plants, sex determination occurs in the diploid phase of the life cycle with XX/XY or ZW/ZZ sex chromosomes. However, in early diverging plants and most macroalgae, sex is determined by female (U) or male (V) sex chromosomes in a haploid phase called the gametophyte. Once the U and V chromosomes unite at fertilization to produce a diploid sporophyte, sex determination no longer occurs, raising key questions about the fate of the U and V sex chromosomes in the sporophyte phase. Here, we investigate genetic and molecular interactions of the UV sex chromosomes in both the haploid and diploid phases of the brown alga Ectocarpus. We reveal extensive developmental regulation of sex chromosome genes across its life cycle and implicate the TALE-HD transcription factor OUROBOROS in suppressing sex determination in the diploid phase. Small RNAs may also play a role in the repression of a female sex-linked gene, and transition to the diploid sporophyte coincides with major reconfiguration of histone H3K79me2, suggesting a more intricate role for this histone mark in Ectocarpus development than previously appreciated.


Subject(s)
Life Cycle Stages , Phaeophyceae , Animals , Phaeophyceae/genetics , Transcription Factors/genetics , Sex Chromosomes/genetics , Haploidy
7.
Mol Cell ; 73(1): 7-21.e7, 2019 01 03.
Article in English | MEDLINE | ID: mdl-30472188

ABSTRACT

The transcriptional regulators YAP and TAZ play important roles in development, physiology, and tumorigenesis and are negatively controlled by the Hippo pathway. It is yet unknown why the YAP/ TAZ proteins are frequently activated in human malignancies in which the Hippo pathway is still active. Here, by a gain-of-function cancer metastasis screen, we discovered OTUB2 as a cancer stemness and metastasis-promoting factor that deubiquitinates and activates YAP/TAZ. We found OTUB2 to be poly-SUMOylated on lysine 233, and this SUMOylation enables it to bind YAP/TAZ. We also identified a yet-unknown SUMO-interacting motif (SIM) in YAP and TAZ required for their association with SUMOylated OTUB2. Importantly, EGF and oncogenic KRAS induce OTUB2 poly-SUMOylation and thereby activate YAP/TAZ. Our results establish OTUB2 as an essential modulator of YAP/TAZ and also reveal a novel mechanism via which YAP/TAZ activity is induced by oncogenic KRAS.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Breast Neoplasms/enzymology , Cell Movement , Intracellular Signaling Peptides and Proteins/metabolism , Neoplastic Stem Cells/enzymology , Phosphoproteins/metabolism , Thiolester Hydrolases/metabolism , Adaptor Proteins, Signal Transducing/genetics , Animals , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Differentiation , Cell Line, Tumor , Cell Movement/drug effects , Epidermal Growth Factor/pharmacology , ErbB Receptors/agonists , ErbB Receptors/metabolism , Female , HEK293 Cells , Humans , Intracellular Signaling Peptides and Proteins/genetics , Lysine , Mice, Inbred BALB C , Mice, Nude , Mutation , Neoplasm Metastasis , Neoplastic Stem Cells/pathology , Phenotype , Phosphoproteins/genetics , Proteasome Endopeptidase Complex/metabolism , Protein Binding , Protein Interaction Domains and Motifs , Proteolysis , Proto-Oncogene Proteins p21(ras)/genetics , Signal Transduction , Sumoylation , Thiolester Hydrolases/genetics , Time Factors , Trans-Activators , Transcription Factors , Transcriptional Coactivator with PDZ-Binding Motif Proteins , YAP-Signaling Proteins
8.
EMBO J ; 41(16): e108791, 2022 08 16.
Article in English | MEDLINE | ID: mdl-35811497

ABSTRACT

TGF-ß signaling is a key player in tumor progression and immune evasion, and is associated with poor response to cancer immunotherapies. Here, we identified ubiquitin-specific peptidase 8 (USP8) as a metastasis enhancer and a highly active deubiquitinase in aggressive breast tumors. USP8 acts both as a cancer stemness-promoting factor and an activator of the TGF-ß/SMAD signaling pathway. USP8 directly deubiquitinates and stabilizes the type II TGF-ß receptor TßRII, leading to its increased expression in the plasma membrane and in tumor-derived extracellular vesicles (TEVs). Increased USP8 activity was observed in patients resistant to neoadjuvant chemotherapies. USP8 promotes TGF-ß/SMAD-induced epithelial-mesenchymal transition (EMT), invasion, and metastasis in tumor cells. USP8 expression also enables TßRII+ circulating extracellular vesicles (crEVs) to induce T cell exhaustion and chemoimmunotherapy resistance. Pharmacological inhibition of USP8 antagonizes TGF-ß/SMAD signaling, and reduces TßRII stability and the number of TßRII+ crEVs to prevent CD8+ T cell exhaustion and to reactivate anti-tumor immunity. Our findings not only reveal a novel mechanism whereby USP8 regulates the cancer microenvironment but also demonstrate the therapeutic advantages of engineering USP8 inhibitors to simultaneously suppress metastasis and improve the efficacy of cancer immunotherapy.


Subject(s)
Extracellular Vesicles , Neoplasms , Receptor, Transforming Growth Factor-beta Type II/metabolism , Ubiquitin Thiolesterase , CD8-Positive T-Lymphocytes/metabolism , Endopeptidases/metabolism , Endosomal Sorting Complexes Required for Transport , Extracellular Vesicles/metabolism , Humans , Neoplasms/genetics , Neoplasms/metabolism , Protein Serine-Threonine Kinases/genetics , Receptor, Transforming Growth Factor-beta Type II/genetics , Receptors, Transforming Growth Factor beta/genetics , Receptors, Transforming Growth Factor beta/metabolism , Signal Transduction , Transforming Growth Factor beta/metabolism , Tumor Microenvironment , Ubiquitin Thiolesterase/metabolism
9.
Development ; 150(4)2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36786333

ABSTRACT

The first mitotic division of the initial cell is a key event in all multicellular organisms and is associated with the establishment of major developmental axes and cell fates. The brown alga Ectocarpus has a haploid-diploid life cycle that involves the development of two multicellular generations: the sporophyte and the gametophyte. Each generation deploys a distinct developmental programme autonomously from an initial cell, the first cell division of which sets up the future body pattern. Here, we show that mutations in the BASELESS (BAS) gene result in multiple cellular defects during the first cell division and subsequent failure to produce basal structures during both generations. BAS encodes a type B″ regulatory subunit of protein phosphatase 2A (PP2A), and transcriptomic analysis identified potential effector genes that may be involved in determining basal cell fate. The bas mutant phenotype is very similar to that observed in distag (dis) mutants, which lack a functional Tubulin-binding co-factor Cd1 (TBCCd1) protein, indicating that TBCCd1 and PP2A are two essential components of the cellular machinery that regulates the first cell division and mediates basal cell fate determination.


Subject(s)
Phaeophyceae , Protein Phosphatase 2 , Protein Phosphatase 2/genetics , Protein Phosphatase 2/metabolism , Mutation/genetics , Gene Expression Profiling , Protein Processing, Post-Translational , Phaeophyceae/genetics , Phaeophyceae/metabolism
10.
Nucleic Acids Res ; 52(D1): D285-D292, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-37897340

ABSTRACT

Chromatin accessibility profiles at single cell resolution can reveal cell type-specific regulatory programs, help dissect highly specialized cell functions and trace cell origin and evolution. Accurate cell type assignment is critical for effectively gaining biological and pathological insights, but is difficult in scATAC-seq. Hence, by extensively reviewing the literature, we designed scATAC-Ref (https://bio.liclab.net/scATAC-Ref/), a manually curated scATAC-seq database aimed at providing a comprehensive, high-quality source of chromatin accessibility profiles with known cell labels across broad cell types. Currently, scATAC-Ref comprises 1 694 372 cells with known cell labels, across various biological conditions, >400 cell/tissue types and five species. We used uniform system environment and software parameters to perform comprehensive downstream analysis on these chromatin accessibility profiles with known labels, including gene activity score, TF enrichment score, differential chromatin accessibility regions, pathway/GO term enrichment analysis and co-accessibility interactions. The scATAC-Ref also provided a user-friendly interface to query, browse and visualize cell types of interest, thereby providing a valuable resource for exploring epigenetic regulation in different tissues and cell types.


Subject(s)
Chromatin Immunoprecipitation Sequencing , Chromatin , Databases, Genetic , Single-Cell Analysis , Chromatin/genetics , Epigenesis, Genetic , Humans , Animals
11.
Proc Natl Acad Sci U S A ; 120(51): e2303713120, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38091291

ABSTRACT

The mitochondrial permeability transition pore (mPTP) is a channel in the inner mitochondrial membrane whose sustained opening in response to elevated mitochondrial matrix Ca2+ concentrations triggers necrotic cell death. The molecular identity of mPTP is unknown. One proposed candidate is the mitochondrial ATP synthase, whose canonical function is to generate most ATP in multicellular organisms. Here, we present mitochondrial, cellular, and in vivo evidence that, rather than serving as mPTP, the mitochondrial ATP synthase inhibits this pore. Our studies confirm previous work showing persistence of mPTP in HAP1 cell lines lacking an assembled mitochondrial ATP synthase. Unexpectedly, however, we observe that Ca2+-induced pore opening is markedly sensitized by loss of the mitochondrial ATP synthase. Further, mPTP opening in cells lacking the mitochondrial ATP synthase is desensitized by pharmacological inhibition and genetic depletion of the mitochondrial cis-trans prolyl isomerase cyclophilin D as in wild-type cells, indicating that cyclophilin D can modulate mPTP through substrates other than subunits in the assembled mitochondrial ATP synthase. Mitoplast patch clamping studies showed that mPTP channel conductance was unaffected by loss of the mitochondrial ATP synthase but still blocked by cyclophilin D inhibition. Cardiac mitochondria from mice whose heart muscle cells we engineered deficient in the mitochondrial ATP synthase also demonstrate sensitization of Ca2+-induced mPTP opening and desensitization by cyclophilin D inhibition. Further, these mice exhibit strikingly larger myocardial infarctions when challenged with ischemia/reperfusion in vivo. We conclude that the mitochondrial ATP synthase does not function as mPTP and instead negatively regulates this pore.


Subject(s)
Mitochondrial Permeability Transition Pore , Mitochondrial Proton-Translocating ATPases , Mice , Animals , Mitochondrial Proton-Translocating ATPases/genetics , Mitochondrial Proton-Translocating ATPases/metabolism , Mitochondrial Permeability Transition Pore/metabolism , Mitochondrial Membrane Transport Proteins/metabolism , Cyclophilins/genetics , Cyclophilins/metabolism , Peptidyl-Prolyl Isomerase F , Mitochondria, Heart/genetics , Mitochondria, Heart/metabolism , Calcium/metabolism
12.
J Pathol ; 263(3): 372-385, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38721894

ABSTRACT

Small cell cervical carcinoma (SCCC) is the most common neuroendocrine tumor in the female genital tract, with an unfavorable prognosis and lacking an evidence-based therapeutic approach. Until now, the distinct subtypes and immune characteristics of SCCC combined with genome and transcriptome have not been described. We performed genomic (n = 18), HPV integration (n = 18), and transcriptomic sequencing (n = 19) of SCCC samples. We assessed differences in immune characteristics between SCCC and conventional cervical cancer, and other small cell neuroendocrine carcinomas, through bioinformatics analysis and immunohistochemical assays. We stratified SCCC patients through non-negative matrix factorization and described the characteristics of these distinct types. We further validated it using multiplex immunofluorescence (n = 77) and investigated its clinical prognostic effect. We confirmed a high frequency of PIK3CA and TP53 alterations and HPV18 integrations in SCCC. SCCC and other small cell carcinoma had similar expression signatures and immune cell infiltration patterns. Comparing patients with SCCC to those with conventional cervical cancer, the former presented immune excluded or 'desert' infiltration. The number of CD8+ cells in the invasion margin of SCCC patients predicted favorable clinical outcomes. We identified three transcriptome subtypes: an inflamed phenotype with high-level expression of genes related to the MHC-II complex (CD74) and IFN-α/ß (SCCC-I), and two neuroendocrine subtypes with high-level expression of ASCL1 or NEUROD1, respectively. Combined with multiple technologies, we found that the neuroendocrine groups had more TP53 mutations and SCCC-I had more PIK3CA mutations. Multiplex immunofluorescence validated these subtypes and SCCC-I was an independent prognostic factor of overall survival. These results provide insights into SCCC tumor heterogeneity and potential therapies. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Subject(s)
Carcinoma, Neuroendocrine , Tumor Microenvironment , Uterine Cervical Neoplasms , Humans , Female , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/immunology , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/virology , Tumor Microenvironment/immunology , Tumor Microenvironment/genetics , Carcinoma, Neuroendocrine/genetics , Carcinoma, Neuroendocrine/immunology , Carcinoma, Neuroendocrine/pathology , Carcinoma, Neuroendocrine/mortality , Carcinoma, Small Cell/genetics , Carcinoma, Small Cell/immunology , Carcinoma, Small Cell/pathology , Middle Aged , Biomarkers, Tumor/genetics , Adult , Mutation , Transcriptome , Class I Phosphatidylinositol 3-Kinases/genetics , Prognosis , Gene Expression Profiling/methods , Aged , Multiomics
13.
Nucleic Acids Res ; 51(9): e50, 2023 05 22.
Article in English | MEDLINE | ID: mdl-36938898

ABSTRACT

Genetic screening based on the clustered regularly interspaced palindromic repeat (CRISPR) system has been indicated to be a powerful tool for identifying regulatory genes or cis-elements. However, when applying CRISPR screens to pinpoint functional elements at particular loci, a large number of guide RNA (gRNA) spacers may be required to achieve saturated coverage. Here, we present a controlled template-dependent elongation (CTDE) method relying on reversible terminators to synthesize gRNA libraries with genomic regions of interest. By applying this approach to H3K4me3 chromatin immunoprecipitation (ChIP)-derived DNA of mammalian cells, mega-sized gRNA libraries were synthesized in a tissue-specific manner, with which we conducted screening experiments to annotate essential sites for cell proliferation. Additionally, we confirmed that an essential site within the intron of LINC00339 regulates its own mRNA and that LINC00339 is a novel regulator of the cell cycle that maintains HepG2 proliferation. The CTDE method has the potential to be automated with high efficiency at low cost, and will be widely used to identify functional elements in mammalian genomes.


Subject(s)
Gene Library , Genome , Histones , Mammals , RNA, Guide, CRISPR-Cas Systems , Animals , Humans , Cell Proliferation , Chromatin Immunoprecipitation , Clustered Regularly Interspaced Short Palindromic Repeats , CRISPR-Cas Systems , DNA/genetics , Genome/genetics , Genomics , Hep G2 Cells , Histones/genetics , Mammals/genetics , Organ Specificity , Cell Cycle/genetics , Automation
14.
Nucleic Acids Res ; 51(W1): W520-W527, 2023 07 05.
Article in English | MEDLINE | ID: mdl-37194711

ABSTRACT

Super-enhancers (SEs) play an essential regulatory role in various biological processes and diseases through their specific interaction with transcription factors (TFs). Here, we present the release of SEanalysis 2.0 (http://licpathway.net/SEanalysis), an updated version of the SEanalysis web server for the comprehensive analyses of transcriptional regulatory networks formed by SEs, pathways, TFs, and genes. The current version added mouse SEs and further expanded the scale of human SEs, documenting 1 167 518 human SEs from 1739 samples and 550 226 mouse SEs from 931 samples. The SE-related samples in SEanalysis 2.0 were more than five times that in version 1.0, which significantly improved the ability of original SE-related network analyses ('pathway downstream analysis', 'upstream regulatory analysis' and 'genomic region annotation') for understanding context-specific gene regulation. Furthermore, we designed two novel analysis models, 'TF regulatory analysis' and 'Sample comparative analysis' for supporting more comprehensive analyses of SE regulatory networks driven by TFs. Further, the risk SNPs were annotated to the SE regions to provide potential SE-related disease/trait information. Hence, we believe that SEanalysis 2.0 has significantly expanded the data and analytical capabilities of SEs, which helps researchers in an in-depth understanding of the regulatory mechanisms of SEs.


Subject(s)
Enhancer Elements, Genetic , Gene Regulatory Networks , Software , Transcription Factors , Animals , Humans , Mice , Gene Expression Regulation , Genomics , Transcription Factors/genetics , Transcription Factors/metabolism
15.
Mol Biol Evol ; 40(6)2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37140022

ABSTRACT

The spontaneous mutation rate µ is a crucial parameter to understand evolution and biodiversity. Mutation rates are highly variable across species, suggesting that µ is susceptible to selection and drift and that species life cycle and life history may impact its evolution. In particular, asexual reproduction and haploid selection are expected to affect the mutation rate, but very little empirical data are available to test this expectation. Here, we sequence 30 genomes of a parent-offspring pedigree in the model brown alga Ectocarpus sp.7, and 137 genomes of an interspecific cross of the closely related brown alga Scytosiphon to have access to the spontaneous mutation rate of representative organisms of a complex multicellular eukaryotic lineage outside animals and plants, and to evaluate the potential impact of life cycle on the mutation rate. Brown algae alternate between a haploid and a diploid stage, both multicellular and free living, and utilize both sexual and asexual reproduction. They are, therefore, excellent models to empirically test expectations of the effect of asexual reproduction and haploid selection on mutation rate evolution. We estimate that Ectocarpus has a base substitution rate of µbs = 4.07 × 10-10 per site per generation, whereas the Scytosiphon interspecific cross had µbs = 1.22 × 10-9. Overall, our estimations suggest that these brown algae, despite being multicellular complex eukaryotes, have unusually low mutation rates. In Ectocarpus, effective population size (Ne) could not entirely explain the low µbs. We propose that the haploid-diploid life cycle, combined with extensive asexual reproduction, may be additional key drivers of the mutation rate in these organisms.


Subject(s)
Diploidy , Phaeophyceae , Animals , Haploidy , Mutation Rate , Eukaryota , Life Cycle Stages/genetics , Plants , Phaeophyceae/genetics
16.
Lancet ; 402(10412): 1541-1551, 2023 10 28.
Article in English | MEDLINE | ID: mdl-37738999

ABSTRACT

BACKGROUND: Spesolimab is an anti-interleukin-36 receptor monoclonal antibody approved to treat generalised pustular psoriasis (GPP) flares. We aimed to assess the efficacy and safety of spesolimab for GPP flare prevention. METHODS: This multicentre, randomised, placebo-controlled, phase 2b trial was done at 60 hospitals and clinics in 20 countries. Eligible study participants were aged between 12 and 75 years with a documented history of GPP as per the European Rare and Severe Psoriasis Expert Network criteria, with a history of at least two past GPP flares, and a GPP Physician Global Assessment (GPPGA) score of 0 or 1 at screening and random assignment. Patients were randomly assigned (1:1:1:1) to receive subcutaneous placebo, subcutaneous low-dose spesolimab (300 mg loading dose followed by 150 mg every 12 weeks), subcutaneous medium-dose spesolimab (600 mg loading dose followed by 300 mg every 12 weeks), or subcutaneous high-dose spesolimab (600 mg loading dose followed by 300 mg every 4 weeks) over 48 weeks. The primary objective was to demonstrate a non-flat dose-response curve on the primary endpoint, time to first GPP flare. FINDINGS: From June 8, 2020, to Nov 23, 2022, 157 patients were screened, of whom 123 were randomly assigned. 92 were assigned to receive spesolimab (30 high dose, 31 medium dose, and 31 low dose) and 31 to placebo. All patients were either Asian (79 [64%] of 123) or White (44 [36%]). Patient groups were similar in sex distribution (76 [62%] female and 47 [38%] male), age (mean 40·4 years, SD 15·8), and GPP Physician Global Assessment score. A non-flat dose-response relationship was established on the primary endpoint. By week 48, 35 patients had GPP flares; seven (23%) of 31 patients in the low-dose spesolimab group, nine (29%) of 31 patients in the medium-dose spesolimab group, three (10%) of 30 patients in the high-dose spesolimab group, and 16 (52%) of 31 patients in the placebo group. High-dose spesolimab was significantly superior versus placebo on the primary outcome of time to GPP flare (hazard ratio [HR]=0·16, 95% CI 0·05-0·54; p=0·0005) endpoint. HRs were 0·35 (95% CI 0·14-0·86, nominal p=0·0057) in the low-dose spesolimab group and 0·47 (0·21-1·06, p=0·027) in the medium-dose spesolimab group. We established a non-flat dose-response relationship for spesolimab compared with placebo, with statistically significant p values for each predefined model (linear p=0·0022, emax1 p=0·0024, emax2 p=0·0023, and exponential p=0·0034). Infection rates were similar across treatment arms; there were no deaths and no hypersensitivity reactions leading to discontinuation. INTERPRETATION: High-dose spesolimab was superior to placebo in GPP flare prevention, significantly reducing the risk of a GPP flare and flare occurrence over 48 weeks. Given the chronic nature of GPP, a treatment for flare prevention is a significant shift in the clinical approach, and could ultimately lead to improvements in patient morbidity and quality of life. FUNDING: Boehringer Ingelheim.


Subject(s)
Psoriasis , Quality of Life , Humans , Male , Female , Child , Adolescent , Young Adult , Adult , Middle Aged , Aged , Treatment Outcome , Antibodies, Monoclonal, Humanized , Chronic Disease , Acute Disease , Psoriasis/drug therapy , Double-Blind Method
17.
N Engl J Med ; 385(26): 2431-2440, 2021 12 23.
Article in English | MEDLINE | ID: mdl-34936739

ABSTRACT

BACKGROUND: Generalized pustular psoriasis (GPP) is a rare, life-threatening, inflammatory skin disease characterized by widespread eruption of sterile pustules. Interleukin-36 signaling is involved in the pathogenesis of this disorder. Spesolimab, a humanized anti-interleukin-36 receptor monoclonal antibody, is being studied for the treatment of GPP flares. METHODS: In a phase 2 trial, we randomly assigned patients with a GPP flare in a 2:1 ratio to receive a single 900-mg intravenous dose of spesolimab or placebo. Patients in both groups could receive an open-label dose of spesolimab on day 8, an open-label dose of spesolimab as a rescue medication after day 8, or both and were followed to week 12. The primary end point was a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) pustulation subscore of 0 (range, 0 [no visible pustules] to 4 [severe pustulation]) at the end of week 1. The key secondary end point was a GPPGA total score of 0 or 1 (clear or almost clear skin) at the end of week 1; scores range from 0 to 4, with higher scores indicating greater disease severity. RESULTS: A total of 53 patients were enrolled: 35 were assigned to receive spesolimab and 18 to receive placebo. At baseline, 46% of the patients in the spesolimab group and 39% of those in the placebo group had a GPPGA pustulation subscore of 3, and 37% and 33%, respectively, had a pustulation subscore of 4. At the end of week 1, a total of 19 of 35 patients (54%) in the spesolimab group had a pustulation subscore of 0, as compared with 1 of 18 patients (6%) in the placebo group (difference, 49 percentage points; 95% confidence interval [CI], 21 to 67; P<0.001). A total of 15 of 35 patients (43%) had a GPPGA total score of 0 or 1, as compared with 2 of 18 patients (11%) in the placebo group (difference, 32 percentage points; 95% CI, 2 to 53; P = 0.02). Drug reactions were reported in 2 patients who received spesolimab, in 1 of them concurrently with a drug-induced hepatic injury. Among patients assigned to the spesolimab group, infections occurred in 6 of 35 (17%) through the first week; among patients who received spesolimab at any time in the trial, infections had occurred in 24 of 51 (47%) at week 12. Antidrug antibodies were detected in 23 of 50 patients (46%) who received at least one dose of spesolimab. CONCLUSIONS: In a phase 2 randomized trial involving patients with GPP, the interleukin-36 receptor inhibitor spesolimab resulted in a higher incidence of lesion clearance at 1 week than placebo but was associated with infections and systemic drug reactions. Longer and larger trials are warranted to determine the effect and risks of spesolimab in patients with pustular psoriasis. (Funded by Boehringer Ingelheim; Effisayil 1 ClinicalTrials.gov number, NCT03782792.).


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Psoriasis/drug therapy , Receptors, Interleukin/antagonists & inhibitors , Adult , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Double-Blind Method , Female , Humans , Injections, Intravenous , Male , Middle Aged , Placebos/adverse effects , Placebos/therapeutic use , Severity of Illness Index , Symptom Flare Up
18.
Small ; 20(3): e2305265, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37699753

ABSTRACT

Nanosilicon (nano-Si) anode is subjected to significant stress concentration, which is caused by extrusion deformation of expanded Si nanoparticles with uneven distribution. The low-strength binder and adhesive interface are unable to withstand the stress, resulting in exfoliation and impeding the use of nano-Si anodes. This work aims to mitigate stress in a Si anode with flexible copper (Cu) skeletons that are metallurgically bonded to uniformly distributed Si nanoparticles. It is worth noting that the proposed porous Si-Cu anode exhibits improved high-load cycling performance and promising potential in the full cell, with an energy density of 463 Wh kg-1 at 0.5 C and retention of 81% after 500 cycles at 2 C. Chemo-mechanical simulation and in (ex) situ observation demonstrate that expansion stress is reduced and more evenly distributed in the anode due to uniform distribution of Si nanoparticles, flexible Cu skeletons, and adequate pores. More importantly, the stress is primarily distributed in the flexible Cu skeletons and bonding interface, preventing anode exfoliation, and ensuring efficient lithium ion/electron transference. This work sheds light on the structure construction of an alloy-type anode.

19.
Small ; 20(26): e2308527, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38221686

ABSTRACT

Flexible hydroelectric generators (HEGs) are promising self-powered devices that spontaneously derive electrical power from moisture. However, achieving the desired compatibility between a continuous operating voltage and superior current density remains a significant challenge. Herein, a textile-based van der Waals heterostructure is rationally designed between conductive 1T phase tungsten disulfide@carbonized silk (1T-WS2@CSilk) and carbon black@cotton (CB@Cotton) fabrics with an asymmetric distribution of oxygen-containing functional groups, which enhances the proton concentration gradients toward high-performance wearable HEGs. The vertically staggered 1T-WS2 nanosheet arrays on the CSilk fabric provide abundant hydrophilic nanochannels for rapid carrier transport. Furthermore, the moisture-induced primary battery formed between the active aluminum (Al) electrode and the conductive textiles introduces the desired electric field to facilitate charge separation and compensate for the decreased streaming potential. These devices exhibit a power density of 21.6 µW cm-2, an open-circuit voltage (Voc) of 0.65 V sustained for over 10 000 s, and a current density of 0.17 mA cm-2. This performance makes them capable of supplying power to commercial electronics and human respiratory monitoring. This study presents a promising strategy for the refined design of wearable electronics.

20.
J Viral Hepat ; 31(5): 255-265, 2024 May.
Article in English | MEDLINE | ID: mdl-38332479

ABSTRACT

There are estimated 300 million people afflicted with chronic hepatitis B (CHB) worldwide. The risk of liver cirrhosis and hepatocellular carcinoma (HCC) increases considerably with chronic hepatitis B infection. While current therapeutics are effective in controlling hepatitis B virus (HBV) infection and disease progression, a cure for HBV infection remains unattainable due to an intranuclear replicative intermediate known as covalently closed circular DNA (cccDNA). It has recently been shown that serum HBV RNA is a non-invasive biomarker that reflects cccDNA transcriptional activity. This review provides a comprehensive overview and the latest updates on the molecular characteristics and clinical significance of serum HBV RNA, such as species of serum HBV RNA, forms of serum HBV RNA carriers and predictive value for relapses in CHB patients after nucleos(t)ide analogues (NAs) discontinuation and development of liver fibrosis and HCC. Furthermore, we summarize standardized assays for testing serum HBV RNA, the dynamic changes of serum HBV RNA levels in treatment-naïve CHB patients and those under NAs therapy, as well as the host and viral influencing factors of serum HBV RNA levels. Finally, we discuss the future perspectives in studies of serum HBV RNA.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis B, Chronic , Liver Neoplasms , Humans , Hepatitis B virus/genetics , Carcinoma, Hepatocellular/drug therapy , RNA , Antiviral Agents/therapeutic use , Liver Neoplasms/drug therapy , Neoplasm Recurrence, Local , Liver Cirrhosis/drug therapy , DNA, Circular , DNA, Viral
SELECTION OF CITATIONS
SEARCH DETAIL