RESUMO
Interleukin-33 (IL-33), an epithelial cell-derived cytokine that responds rapidly to environmental insult, has a critical role in initiating airway inflammatory diseases. However, the molecular mechanism underlying IL-33 secretion following allergen exposure is not clear. Here, we found that two cell events were fundamental for IL-33 secretion after exposure to allergens. First, stress granule assembly activated by allergens licensed the nuclear-cytoplasmic transport of IL-33, but not the secretion of IL-33. Second, a neo-form murine amino-terminal p40 fragment gasdermin D (Gsdmd), whose generation was independent of inflammatory caspase-1 and caspase-11, dominated cytosolic secretion of IL-33 by forming pores in the cell membrane. Either the blockade of stress granule assembly or the abolishment of p40 production through amino acid mutation of residues 309-313 (ELRQQ) could efficiently prevent the release of IL-33 in murine epithelial cells. Our findings indicated that targeting stress granule disassembly and Gsdmd fragmentation could reduce IL-33-dependent allergic airway inflammation.
Assuntos
Alérgenos , Interleucina-33 , Proteínas de Ligação a Fosfato/metabolismo , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Animais , Caspase 1/metabolismo , Inflamação , Interleucina-1beta/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Peptídeo Hidrolases/metabolismo , Grânulos de EstresseRESUMO
Despite intensive efforts to discover highly effective treatments to eradicate tuberculosis (TB), it remains as a major threat to global human health. For this reason, new TB drugs directed toward new targets are highly coveted. MmpLs (Mycobacterial membrane proteins Large), which play crucial roles in transporting lipids, polymers and immunomodulators and which also extrude therapeutic drugs, are among the most important therapeutic drug targets to emerge in recent times. Here, crystal structures of mycobacterial MmpL3 alone and in complex with four TB drug candidates, including SQ109 (in Phase 2b-3 clinical trials), are reported. MmpL3 consists of a periplasmic pore domain and a twelve-helix transmembrane domain. Two Asp-Tyr pairs centrally located in this domain appear to be key facilitators of proton-translocation. SQ109, AU1235, ICA38, and rimonabant bind inside the transmembrane region and disrupt these Asp-Tyr pairs. This structural data will greatly advance the development of MmpL3 inhibitors as new TB drugs.
Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/ultraestrutura , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Membrana Transportadoras/ultraestrutura , Adamantano/análogos & derivados , Adamantano/metabolismo , Antituberculosos/química , Transporte Biológico , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Etilenodiaminas/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/ultraestrutura , Compostos de Fenilureia/metabolismo , Rimonabanto/metabolismo , Tuberculose/microbiologiaRESUMO
Alternative lengthening of telomeres (ALT), a telomerase-independent process maintaining telomeres, is mediated by break-induced replication (BIR). RAD52 promotes ALT by facilitating D-loop formation, but ALT also occurs through a RAD52-independent BIR pathway. Here, we show that the telomere non-coding RNA TERRA forms dynamic telomeric R-loops and contributes to ALT activity in RAD52 knockout cells. TERRA forms R-loops in vitro and at telomeres in a RAD51AP1-dependent manner. The formation of R-loops by TERRA increases G-quadruplexes (G4s) at telomeres. G4 stabilization enhances ALT even when TERRA is depleted, suggesting that G4s act downstream of R-loops to promote BIR. In vitro, the telomeric R-loops assembled by TERRA and RAD51AP1 generate G4s, which persist after R-loop resolution and allow formation of telomeric D-loops without RAD52. Thus, the dynamic telomeric R-loops formed by TERRA and RAD51AP1 enable the RAD52-independent ALT pathway, and G4s orchestrate an R- to D-loop switch at telomeres to stimulate BIR.
Assuntos
RNA Longo não Codificante , Telomerase , Homeostase do Telômero , Telômero/genética , Telômero/metabolismo , Telomerase/genética , Telomerase/metabolismo , Estruturas R-Loop/genética , Reparo do DNARESUMO
GLS1 orchestrates glutaminolysis and promotes cell proliferation when glutamine is abundant by regenerating TCA cycle intermediates and supporting redox homeostasis. CB-839, an inhibitor of GLS1, is currently under clinical investigation for a variety of cancer types. Here, we show that GLS1 facilitates apoptosis when glutamine is deprived. Mechanistically, the absence of exogenous glutamine sufficiently reduces glutamate levels to convert dimeric GLS1 to a self-assembled, extremely low-Km filamentous polymer. GLS1 filaments possess an enhanced catalytic activity, which further depletes intracellular glutamine. Functionally, filamentous GLS1-dependent glutamine scarcity leads to inadequate synthesis of asparagine and mitogenome-encoded proteins, resulting in ROS-induced apoptosis that can be rescued by asparagine supplementation. Physiologically, we observed GLS1 filaments in solid tumors and validated the tumor-suppressive role of constitutively active, filamentous GLS1 mutants K320A and S482C in xenograft models. Our results change our understanding of GLS1 in cancer metabolism and suggest the therapeutic potential of promoting GLS1 filament formation.
Assuntos
Glutaminase , Glutamina , Apoptose , Asparagina/genética , Glutaminase/genética , Glutaminase/metabolismo , Glutamina/metabolismo , Humanos , Espécies Reativas de OxigênioRESUMO
Antiferromagnetic spintronics1-16 is a rapidly growing field in condensed-matter physics and information technology with potential applications for high-density and ultrafast information devices. However, the practical application of these devices has been largely limited by small electrical outputs at room temperature. Here we describe a room-temperature exchange-bias effect between a collinear antiferromagnet, MnPt, and a non-collinear antiferromagnet, Mn3Pt, which together are similar to a ferromagnet-antiferromagnet exchange-bias system. We use this exotic effect to build all-antiferromagnetic tunnel junctions with large nonvolatile room-temperature magnetoresistance values that reach a maximum of about 100%. Atomistic spin dynamics simulations reveal that uncompensated localized spins at the interface of MnPt produce the exchange bias. First-principles calculations indicate that the remarkable tunnelling magnetoresistance originates from the spin polarization of Mn3Pt in the momentum space. All-antiferromagnetic tunnel junction devices, with nearly vanishing stray fields and strongly enhanced spin dynamics up to the terahertz level, could be important for next-generation highly integrated and ultrafast memory devices7,9,16.
RESUMO
Chiral amines are commonly used in the pharmaceutical and agrochemical industries1. The strong demand for unnatural chiral amines has driven the development of catalytic asymmetric methods1,2. Although the N-alkylation of aliphatic amines with alkyl halides has been widely adopted for over 100 years, catalyst poisoning and unfettered reactivity have been preventing the development of a catalyst-controlled enantioselective version3-5. Here we report the use of chiral tridentate anionic ligands to enable the copper-catalysed chemoselective and enantioconvergent N-alkylation of aliphatic amines with α-carbonyl alkyl chlorides. This method can directly convert feedstock chemicals, including ammonia and pharmaceutically relevant amines, into unnatural chiral α-amino amides under mild and robust conditions. Excellent enantioselectivity and functional-group tolerance were observed. The power of the method is demonstrated in a number of complex settings, including late-stage functionalization and in the expedited synthesis of diverse amine drug molecules. The current method indicates that multidentate anionic ligands are a general solution for overcoming transition-metal-catalyst poisoning.
Assuntos
Alquilação , Aminas , Catálise , Cobre , Amidas/química , Aminas/química , Cobre/química , Ligantes , Preparações Farmacêuticas/químicaRESUMO
Alternative lengthening of telomeres (ALT) is mediated by break-induced replication (BIR), but how BIR is regulated at telomeres is poorly understood. Here, we show that telomeric BIR is a self-perpetuating process. By tethering PML-IV to telomeres, we induced telomere clustering in ALT-associated PML bodies (APBs) and a POLD3-dependent ATR response at telomeres, showing that BIR generates replication stress. Ablation of BLM helicase activity in APBs abolishes telomere synthesis but causes multiple chromosome bridges between telomeres, revealing a function of BLM in processing inter-telomere BIR intermediates. Interestingly, the accumulation of BLM in APBs requires its own helicase activity and POLD3, suggesting that BIR triggers a feedforward loop to further recruit BLM. Enhancing BIR induces PIAS4-mediated TRF2 SUMOylation, and PIAS4 loss deprives APBs of repair proteins and compromises ALT telomere synthesis. Thus, a BLM-driven and PIAS4-mediated feedforward loop operates in APBs to perpetuate BIR, providing a critical mechanism to extend ALT telomeres.
Assuntos
Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Retroalimentação Fisiológica , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas Inibidoras de STAT Ativados/genética , RNA Helicases/genética , Homeostase do Telômero , Telômero/química , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , DNA Polimerase III/genética , DNA Polimerase III/metabolismo , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/antagonistas & inibidores , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/antagonistas & inibidores , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas Inibidoras de STAT Ativados/antagonistas & inibidores , Proteínas Inibidoras de STAT Ativados/metabolismo , RNA Helicases/antagonistas & inibidores , RNA Helicases/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteína Rad52 de Recombinação e Reparo de DNA/genética , Proteína Rad52 de Recombinação e Reparo de DNA/metabolismo , RecQ Helicases/genética , RecQ Helicases/metabolismo , Transdução de Sinais , Sumoilação , Telômero/metabolismo , Proteína 2 de Ligação a Repetições Teloméricas/genéticaRESUMO
Deregulation of oncogenic signals in cancer triggers replication stress. Immediate early genes (IEGs) are rapidly and transiently expressed following stressful signals, contributing to an integrated response. Here, we find that the orphan nuclear receptor NR4A1 localizes across the gene body and 3' UTR of IEGs, where it inhibits transcriptional elongation by RNA Pol II, generating R-loops and accessible chromatin domains. Acute replication stress causes immediate dissociation of NR4A1 and a burst of transcriptionally poised IEG expression. Ectopic expression of NR4A1 enhances tumorigenesis by breast cancer cells, while its deletion leads to massive chromosomal instability and proliferative failure, driven by deregulated expression of its IEG target, FOS. Approximately half of breast and other primary cancers exhibit accessible chromatin domains at IEG gene bodies, consistent with this stress-regulatory pathway. Cancers that have retained this mechanism in adapting to oncogenic replication stress may be dependent on NR4A1 for their proliferation.
Assuntos
Neoplasias da Mama/metabolismo , Proliferação de Células , Proteínas Imediatamente Precoces/metabolismo , Mitose , Células Neoplásicas Circulantes/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Regiões 3' não Traduzidas , Animais , Antineoplásicos/farmacologia , Sítios de Ligação , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Montagem e Desmontagem da Cromatina , Feminino , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica , Células HEK293 , Humanos , Proteínas Imediatamente Precoces/genética , Indóis/farmacologia , Células MCF-7 , Camundongos Endogâmicos NOD , Camundongos SCID , Mitose/efeitos dos fármacos , Células Neoplásicas Circulantes/efeitos dos fármacos , Células Neoplásicas Circulantes/patologia , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/antagonistas & inibidores , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Fenilacetatos/farmacologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Estruturas R-Loop , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Transdução de Sinais , Elongação da Transcrição Genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
R loops arising during transcription induce genomic instability, but how cells respond to the R loop-associated genomic stress is still poorly understood. Here, we show that cells harboring high levels of R loops rely on the ATR kinase for survival. In response to aberrant R loop accumulation, the ataxia telangiectasia and Rad3-related (ATR)-Chk1 pathway is activated by R loop-induced reversed replication forks. In contrast to the activation of ATR by replication inhibitors, R loop-induced ATR activation requires the MUS81 endonuclease. ATR protects the genome from R loops by suppressing transcription-replication collisions, promoting replication fork recovery, and enforcing a G2/M cell-cycle arrest. Furthermore, ATR prevents excessive cleavage of reversed forks by MUS81, revealing a MUS81-triggered and ATR-mediated feedback loop that fine-tunes MUS81 activity at replication forks. These results suggest that ATR is a key sensor and suppressor of R loop-induced genomic instability, uncovering a signaling circuitry that safeguards the genome against R loops.
Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Ligação a DNA/metabolismo , Endonucleases/metabolismo , Estruturas R-Loop/genética , Proteínas Mutadas de Ataxia Telangiectasia/fisiologia , Proteínas de Ciclo Celular/metabolismo , Quinase 1 do Ponto de Checagem/genética , Dano ao DNA , Reparo do DNA , Replicação do DNA/genética , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Instabilidade Genômica/fisiologia , Células HeLa , Humanos , Fosforilação , Proteínas Quinases/metabolismo , Transdução de SinaisRESUMO
Homologous recombination (HR) repairs DNA double-strand breaks (DSBs) in the S and G2 phases of the cell cycle1-3. Several HR proteins are preferentially recruited to DSBs at transcriptionally active loci4-10, but how transcription promotes HR is poorly understood. Here we develop an assay to assess the effect of local transcription on HR. Using this assay, we find that transcription stimulates HR to a substantial extent. Tethering RNA transcripts to the vicinity of DSBs recapitulates the effects of local transcription, which suggests that transcription enhances HR through RNA transcripts. Tethered RNA transcripts stimulate HR in a sequence- and orientation-dependent manner, indicating that they function by forming DNA-RNA hybrids. In contrast to most HR proteins, RAD51-associated protein 1 (RAD51AP1) only promotes HR when local transcription is active. RAD51AP1 drives the formation of R-loops in vitro and is required for tethered RNAs to stimulate HR in cells. Notably, RAD51AP1 is necessary for the DSB-induced formation of DNA-RNA hybrids in donor DNA, linking R-loops to D-loops. In vitro, RAD51AP1-generated R-loops enhance the RAD51-mediated formation of D-loops locally and give rise to intermediates that we term 'DR-loops', which contain both DNA-DNA and DNA-RNA hybrids and favour RAD51 function. Thus, at DSBs in transcribed regions, RAD51AP1 promotes the invasion of RNA transcripts into donor DNA, and stimulates HR through the formation of DR-loops.
Assuntos
DNA/genética , DNA/metabolismo , Recombinação Homóloga/genética , Estruturas R-Loop/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Gênica , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem Celular , DNA/química , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Genes/genética , Genes Reporter/genética , Proteínas de Fluorescência Verde/genética , Humanos , Técnicas In Vitro , RNA Mensageiro/química , Proteínas de Ligação a RNA/metabolismo , Rad51 Recombinase/metabolismoRESUMO
The photoinduced all-trans to 13-cis isomerization of the retinal Schiff base represents the ultrafast first step in the reaction cycle of bacteriorhodopsin (BR). Extensive experimental and theoretical work has addressed excited-state dynamics and isomerization via a conical intersection with the ground state. In conflicting molecular pictures, the excited state potential energy surface has been modeled as a pure S[Formula: see text] state that intersects with the ground state, or in a 3-state picture involving the S[Formula: see text] and S[Formula: see text] states. Here, the photoexcited system passes two crossing regions to return to the ground state. The electric dipole moment of the Schiff base in the S[Formula: see text] and S[Formula: see text] state differs strongly and, thus, its measurement allows for assessing the character of the excited-state potential. We apply the method of ultrafast terahertz (THz) Stark spectroscopy to measure electric dipole changes of wild-type BR and a BR D85T mutant upon electronic excitation. A fully reversible transient broadening and spectral shift of electronic absorption is induced by a picosecond THz field of several megavolts/cm and mapped by a 120-fs optical probe pulse. For both BR variants, we derive a moderate electric dipole change of 5 [Formula: see text] 1 Debye, which is markedly smaller than predicted for a neat S[Formula: see text]-character of the excited state. In contrast, S[Formula: see text]-admixture and temporal averaging of excited-state dynamics over the probe pulse duration gives a dipole change in line with experiment. Our results support a picture of electronic and nuclear dynamics governed by the interaction of S[Formula: see text] and S[Formula: see text] states in a 3-state model.
Assuntos
Bacteriorodopsinas , Retinaldeído , Bacteriorodopsinas/química , Bacteriorodopsinas/metabolismo , Retinaldeído/química , Retinaldeído/metabolismo , Espectroscopia Terahertz/métodos , Bases de Schiff/química , Halobacterium salinarum/metabolismo , Halobacterium salinarum/química , IsomerismoRESUMO
Acute myeloid leukemia (AML) is an aging-related and heterogeneous hematopoietic malignancy. In this study, a total of 1,474 newly diagnosed AML patients with RNA sequencing data were enrolled, and targeted or whole exome sequencing data were obtained in 94% cases. The correlation of aging-related factors including age and clonal hematopoiesis (CH), gender, and genomic/transcriptomic profiles (gene fusions, genetic mutations, and gene expression networks or pathways) was systematically analyzed. Overall, AML patients aged 60 y and older showed an apparently dismal prognosis. Alongside age, the frequency of gene fusions defined in the World Health Organization classification decreased, while the positive rate of gene mutations, especially CH-related ones, increased. Additionally, the number of genetic mutations was higher in gene fusion-negative (GF-) patients than those with GF. Based on the status of CH- and myelodysplastic syndromes (MDS)-related mutations, three mutant subgroups were identified among the GF- AML cohort, namely, CH-AML, CH-MDS-AML, and other GF- AML. Notably, CH-MDS-AML demonstrated a predominance of elderly and male cases, cytopenia, and significantly adverse clinical outcomes. Besides, gene expression networks including HOXA/B, platelet factors, and inflammatory responses were most striking features associated with aging and poor prognosis in AML. Our work has thus unraveled the intricate regulatory circuitry of interactions among different age, gender, and molecular groups of AML.
Assuntos
Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Idoso , Humanos , Masculino , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Envelhecimento/genética , Mutação , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , PrognósticoRESUMO
Numerous DNA repair and signaling proteins function at DNA damage sites to protect the genome. Here, we show that fusion of the promiscuous biotin ligase BirAR118G with RAD18 leads to localized protein biotinylation at DNA damage sites, allowing identification of ZPET (zinc finger protein proximal to RAD eighteen)/ZNF280C as a potential DNA damage response (DDR) protein. ZPET binds ssDNA and localizes to DNA double-strand breaks (DSBs) and stalled replication forks. In vitro, ZPET inhibits MRE11 binding to ssDNA. In cells, ZPET delays MRE11 binding to chromatin after DSB formation and slows DNA end resection through binding ssDNA. ZPET hinders resection independently of 53BP1 and HELB. Cells lacking ZPET displayed enhanced homologous recombination (HR), accelerated replication forks under stress, and increased resistance to DSBs and PARP inhibition. These results not only reveal ZPET as an HR repressor but also suggest that localized protein biotinylation at DNA damage sites is a useful strategy to identify DDR proteins.
Assuntos
Biotinilação/métodos , Dano ao DNA , Reparo do DNA/genética , Proteínas de Ligação a DNA/metabolismo , Recombinação Homóloga/genética , Fatores de Transcrição/metabolismo , Carbono-Nitrogênio Ligases/genética , Linhagem Celular , Quebras de DNA de Cadeia Dupla , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Escherichia coli/genética , Técnicas de Silenciamento de Genes , Humanos , Proteína Homóloga a MRE11/metabolismo , Ligação Proteica , Transporte Proteico/genética , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Dynamic metabolism is exhibited by early mammalian embryos to support changing cell fates during development. It is widely acknowledged that metabolic pathways not only satisfy cellular energetic demands, but also play pivotal roles in the process of cell signalling, gene regulation, cell proliferation and differentiation. Recently, various new technological advances have been made in metabolomics and computational analysis, deepening our understanding of the crucial role of dynamic metabolism during early mammalian embryogenesis. In this Review, we summarize recent studies on oocyte and embryo metabolism and its regulation, with a particular focus on its association with key developmental events such as fertilization, zygote genome activation and cell fate determination. In addition, we discuss the mechanisms of certain metabolites that, in addition to serving as energy sources, contribute to epigenetic modifications.
Assuntos
Embrião de Mamíferos , Epigênese Genética , Animais , Diferenciação Celular , Proliferação de Células , Desenvolvimento Embrionário/genética , MamíferosRESUMO
ABSTRACT: Chronic active Epstein-Barr virus (EBV) disease (CAEBV) is a lethal syndrome because of persistent EBV infection. When diagnosed as CAEBV, EBV infection was observed in multiple hematopoietic lineages, but the etiology of CAEBV is still elusive. Bone marrow and peripheral cells derived from 5 patients with CAEBV, 1 patient with EBV-associated hemophagocytic lymphohistiocytosis, and 2 healthy controls were analyzed. Multiple assays were applied to identify and characterize EBV-infected cells, including quantitative polymerase chain reaction, PrimeFlow, and single-cell RNA-sequencing (scRNA-seq). Based on scRNA-seq data, alterations in gene expression of particular cell types were analyzed between patients with CAEBV and controls, and between infected and uninfected cells. One patient with CAEBV was treated with allogeneic hematopoietic stem cell transplantation (HSCT), and the samples derived from this patient were analyzed again 6 months after HSCT. EBV infected the full spectrum of the hematopoietic system including both lymphoid and myeloid lineages, as well as the hematopoietic stem cells (HSCs) of the patients with CAEBV. EBV-infected HSCs exhibited a higher differentiation rate toward downstream lineages, and the EBV infection had an impact on both the innate and adaptive immunity, resulting in inflammatory symptoms. EBV-infected cells were thoroughly removed from the hematopoietic system after HSCT. Taken together, multiple lines of evidence presented in this study suggest that CAEBV disease originates from the infected HSCs, which might potentially lead to innovative therapy strategies for CAEBV.
Assuntos
Infecções por Vírus Epstein-Barr , Linfo-Histiocitose Hemofagocítica , Humanos , Herpesvirus Humano 4/genética , Doença Crônica , Linfo-Histiocitose Hemofagocítica/complicações , Células-Tronco HematopoéticasRESUMO
Cryptotaenia japonica, a traditional medicinal and edible vegetable crops, is well-known for its attractive flavors and health care functions. As a member of the Apiaceae family, the evolutionary trajectory and biological properties of C. japonica are not clearly understood. Here, we first reported a high-quality genome of C. japonica with a total length of 427 Mb and N50 length 50.76 Mb, was anchored into 10 chromosomes, which confirmed by chromosome (cytogenetic) analysis. Comparative genomic analysis revealed C. japonica exhibited low genetic redundancy, contained a higher percentage of single-cope gene families. The homoeologous blocks, Ks, and collinearity were analyzed among Apiaceae species contributed to the evidence that C. japonica lacked recent species-specific WGD. Through comparative genomic and transcriptomic analyses of Apiaceae species, we revealed the genetic basis of the production of anthocyanins. Several structural genes encoding enzymes and transcription factor genes of the anthocyanin biosynthesis pathway in different species were also identified. The CjANSa, CjDFRb, and CjF3H gene might be the target of Cjaponica_2.2062 (bHLH) and Cjaponica_1.3743 (MYB). Our findings provided a high-quality reference genome of C. japonica and offered new insights into Apiaceae evolution and biology.
Assuntos
Antocianinas , Apiaceae , Genoma de Planta , Genômica , Antocianinas/biossíntese , Antocianinas/genética , Antocianinas/metabolismo , Genoma de Planta/genética , Apiaceae/genética , Apiaceae/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Cromossomos de Plantas/genéticaRESUMO
BACKGROUND AND AIMS: RAD51 recombinase (RAD51) is a highly conserved DNA repair protein and is indispensable for embryonic viability. As a result, the role of RAD51 in liver development and function is unknown. Our aim was to characterize the function of RAD51 in postnatal liver development. APPROACH AND RESULTS: RAD51 is highly expressed during liver development and during regeneration following hepatectomy and hepatic injury, and is also elevated in chronic liver diseases. We generated a hepatocyte-specific Rad51 deletion mouse model using Alb -Cre ( Rad51 -conditional knockout (CKO)) and Adeno-associated virus 8-thyroxine-binding globulin-cyclization recombination enzyme to evaluate the function of RAD51 in liver development and regeneration. The phenotype in Rad51 -CKO mice is dependent on CRE dosage, with Rad51fl/fl ; Alb -Cre +/+ manifesting a more severe phenotype than the Rad51fl/fl ; Alb -Cre +/- mice. RAD51 deletion in postnatal hepatocytes results in aborted mitosis and early onset of pathological polyploidization that is associated with oxidative stress and cellular senescence. Remarkable liver fibrosis occurs spontaneously as early as in 3-month-old Rad51fl/fl ; Alb -Cre +/+ mice. While liver regeneration is compromised in Rad51 -CKO mice, they are more tolerant of carbon tetrachloride-induced hepatic injury and resistant to diethylnitrosamine/carbon tetrachloride-induced HCC. A chronic inflammatory microenvironment created by the senescent hepatocytes appears to activate ductular reaction the transdifferentiation of cholangiocytes to hepatocytes. The newly derived RAD51 functional immature hepatocytes proliferate vigorously, acquire increased malignancy, and eventually give rise to HCC. CONCLUSIONS: Our results demonstrate a novel function of RAD51 in liver development, homeostasis, and tumorigenesis. The Rad51 -CKO mice represent a unique genetic model for premature liver senescence, fibrosis, and hepatocellular carcinogenesis.
RESUMO
The bone marrow microenvironment (BMM) can regulate leukemia stem cells (LSCs) via secreted factors. Increasing evidence suggests that dissecting the mechanisms by which the BMM maintains LSCs may lead to the development of effective therapies for the eradication of leukemia. Inhibitor of DNA binding 1 (ID1), a key transcriptional regulator in LSCs, previously identified by us, controls cytokine production in the BMM, but the role of ID1 in acute myeloid leukemia (AML) BMM remains obscure. Here, we report that ID1 is highly expressed in the BMM of patients with AML, especially in BM mesenchymal stem cells, and that the high expression of ID1 in the AML BMM is induced by BMP6, secreted from AML cells. Knocking out ID1 in mesenchymal cells significantly suppresses the proliferation of cocultured AML cells. Loss of Id1 in the BMM results in impaired AML progression in AML mouse models. Mechanistically, we found that Id1 deficiency significantly reduces SP1 protein levels in mesenchymal cells cocultured with AML cells. Using ID1-interactome analysis, we found that ID1 interacts with RNF4, an E3 ubiquitin ligase, and causes a decrease in SP1 ubiquitination. Disrupting the ID1-RNF4 interaction via truncation in mesenchymal cells significantly reduces SP1 protein levels and delays AML cell proliferation. We identify that the target of Sp1, Angptl7, is the primary differentially expression protein factor in Id1-deficient BM supernatant fluid to regulate AML progression in mice. Our study highlights the critical role of ID1 in the AML BMM and aids the development of therapeutic strategies for AML.
Assuntos
Proteína 7 Semelhante a Angiopoietina , Proteína 1 Inibidora de Diferenciação , Leucemia Mieloide Aguda , Animais , Camundongos , Proteína 7 Semelhante a Angiopoietina/genética , Proteína 7 Semelhante a Angiopoietina/metabolismo , Medula Óssea/metabolismo , Modelos Animais de Doenças , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Microambiente Tumoral , Humanos , Proteína 1 Inibidora de Diferenciação/metabolismoRESUMO
The adenopituitary secretes follicle-stimulating hormone (FSH), which plays a crucial role in regulating the growth, development, and reproductive functions of organisms. Investigating the process of FSH synthesis and secretion can offer valuable insights into potential areas of focus for reproductive research. Epidermal growth factor (EGF) is a significant paracrine/autocrine factor within the body, and studies have demonstrated its ability to stimulate FSH secretion in animals. However, the precise mechanisms that regulate this action are still poorly understood. In this research, in vivo and in vitro experiments showed that the activation of epidermal growth factor receptor (EGFR) by EGF induces the upregulation of miR-27b-3p and that miR-27b-3p targets and inhibits Foxo1 mRNA expression, resulting in increased FSH synthesis and secretion. In summary, this study elucidates the precise molecular mechanism through which EGF governs the synthesis and secretion of FSH via the EGFR/miR-27b-3p/FOXO1 pathway.
Assuntos
Fator de Crescimento Epidérmico , MicroRNAs , Animais , Ratos , Transporte Biológico , Receptores ErbB/genética , Hormônio Foliculoestimulante , MicroRNAs/genéticaRESUMO
The involvement of γδT cells, Th17 cells, and CD4+CD25+ regulatory T cells (Tregs) is crucial in the progression of pulmonary fibrosis (PF), particularly in maintaining immune tolerance and homeostasis. However, the dynamics of these cells in relation to PF progression, especially under pharmacological interventions, remains poorly understood. This study aims to unravel the interplay between the dynamic changes of these cells and the effect of pharmacological agents in a mouse model of PF induced by intratracheal instillation of bleomycin. We analyzed changes in lung histology, lung index, hydroxyproline levels, and the proportions of γδT cells, Th17 cells, and Tregs on the 3rd, 14th, and 28th days following treatment with Neferine, Isoliensinine, Pirfenidone, and Prednisolone. Our results demonstrate that these drugs can partially or dynamically reverse weight loss, decrease lung index and hydroxyproline levels, and ameliorate lung histopathological damage. Additionally, they significantly modulated the abnormal changes in γδT, Th17, and Treg cell proportions. Notably, on day 3, the proportion of γδT cells increased in the Neferine and Prednisolone groups but decreased in the Isoliensinine and Pirfenidone groups, while the proportion of Th17 cells decreased across all treated groups. On day 14, the Neferine group showed an increase in all three cell types, whereas the Pirfenidone group exhibited a decrease. In the Isoliensinine group, γδT and Th17 cells increased, and in the Prednisolone group, only Tregs increased. By day 28, an increase in Th17 cell proportion was observed in all treatment groups, with a decrease in γδT cells noted in the Neferine group. These shifts in cell proportions are consistent with the pathogenesis changes induced by these anti-PF drugs, suggesting a correlation between cellular dynamics and pharmacological interventions in PF progression. Our findings imply potential strategies for assessing the efficacy and timing of anti-PF treatments based on these cellular changes.