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1.
Cell ; 185(10): 1793-1805.e17, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35483372

RESUMO

The lack of tools to observe drug-target interactions at cellular resolution in intact tissue has been a major barrier to understanding in vivo drug actions. Here, we develop clearing-assisted tissue click chemistry (CATCH) to optically image covalent drug targets in intact mammalian tissues. CATCH permits specific and robust in situ fluorescence imaging of target-bound drug molecules at subcellular resolution and enables the identification of target cell types. Using well-established inhibitors of endocannabinoid hydrolases and monoamine oxidases, direct or competitive CATCH not only reveals distinct anatomical distributions and predominant cell targets of different drug compounds in the mouse brain but also uncovers unexpected differences in drug engagement across and within brain regions, reflecting rare cell types, as well as dose-dependent target shifts across tissue, cellular, and subcellular compartments that are not accessible by conventional methods. CATCH represents a valuable platform for visualizing in vivo interactions of small molecules in tissue.


Assuntos
Química Click , Imagem Óptica , Animais , Encéfalo , Sistemas de Liberação de Medicamentos , Mamíferos , Camundongos , Imagem Óptica/métodos
2.
Nat Immunol ; 22(7): 829-838, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33963333

RESUMO

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.


Assuntos
COVID-19/imunologia , Proteínas do Envelope de Coronavírus/metabolismo , Síndrome da Liberação de Citocina/imunologia , SARS-CoV-2/imunologia , Receptor 2 Toll-Like/metabolismo , Animais , COVID-19/complicações , COVID-19/diagnóstico , COVID-19/virologia , Chlorocebus aethiops , Síndrome da Liberação de Citocina/diagnóstico , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Humanos , Imunidade Inata/efeitos dos fármacos , Leucócitos Mononucleares , Macrófagos , Masculino , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Cultura Primária de Células , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Índice de Gravidade de Doença , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/antagonistas & inibidores , Receptor 2 Toll-Like/genética , Células Vero , Tratamento Farmacológico da COVID-19
3.
Nature ; 621(7977): 138-145, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37587337

RESUMO

Maintaining body temperature is calorically expensive for endothermic animals1. Mammals eat more in the cold to compensate for energy expenditure2, but the neural mechanism underlying this coupling is not well understood. Through behavioural and metabolic analyses, we found that mice dynamically switch between energy-conservation and food-seeking states in the cold, the latter of which are primarily driven by energy expenditure rather than the sensation of cold. To identify the neural mechanisms underlying cold-induced food seeking, we used whole-brain c-Fos mapping and found that the xiphoid (Xi), a small nucleus in the midline thalamus, was selectively activated by prolonged cold associated with elevated energy expenditure but not with acute cold exposure. In vivo calcium imaging showed that Xi activity correlates with food-seeking episodes under cold conditions. Using activity-dependent viral strategies, we found that optogenetic and chemogenetic stimulation of cold-activated Xi neurons selectively recapitulated food seeking under cold conditions whereas their inhibition suppressed it. Mechanistically, Xi encodes a context-dependent valence switch that promotes food-seeking behaviours under cold but not warm conditions. Furthermore, these behaviours are mediated by a Xi-to-nucleus accumbens projection. Our results establish Xi as a key region in the control of cold-induced feeding, which is an important mechanism in the maintenance of energy homeostasis in endothermic animals.


Assuntos
Temperatura Corporal , Temperatura Baixa , Comportamento Alimentar , Tálamo , Animais , Camundongos , Temperatura Corporal/fisiologia , Mapeamento Encefálico , Cálcio/metabolismo , Comportamento Alimentar/fisiologia , Metabolismo Energético/fisiologia , Tálamo/anatomia & histologia , Tálamo/citologia , Tálamo/fisiologia , Optogenética , Neurônios/metabolismo , Núcleo Accumbens/citologia , Núcleo Accumbens/fisiologia , Homeostase/fisiologia , Termogênese/fisiologia
4.
Cell ; 153(5): 1012-24, 2013 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-23706739

RESUMO

Histone acetylation plays critical roles in chromatin remodeling, DNA repair, and epigenetic regulation of gene expression, but the underlying mechanisms are unclear. Proteasomes usually catalyze ATP- and polyubiquitin-dependent proteolysis. Here, we show that the proteasomes containing the activator PA200 catalyze the polyubiquitin-independent degradation of histones. Most proteasomes in mammalian testes ("spermatoproteasomes") contain a spermatid/sperm-specific α subunit α4 s/PSMA8 and/or the catalytic ß subunits of immunoproteasomes in addition to PA200. Deletion of PA200 in mice abolishes acetylation-dependent degradation of somatic core histones during DNA double-strand breaks and delays core histone disappearance in elongated spermatids. Purified PA200 greatly promotes ATP-independent proteasomal degradation of the acetylated core histones, but not polyubiquitinated proteins. Furthermore, acetylation on histones is required for their binding to the bromodomain-like regions in PA200 and its yeast ortholog, Blm10. Thus, PA200/Blm10 specifically targets the core histones for acetylation-mediated degradation by proteasomes, providing mechanisms by which acetylation regulates histone degradation, DNA repair, and spermatogenesis.


Assuntos
Reparo do DNA , Histonas/metabolismo , Proteínas Nucleares/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Espermatogênese , Testículo/metabolismo , Acetilação , Sequência de Aminoácidos , Animais , Quebras de DNA de Cadeia Dupla , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Proteínas Nucleares/química , Estrutura Terciária de Proteína , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência
5.
Nature ; 609(7927): 569-574, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36045288

RESUMO

Adipose tissues communicate with the central nervous system to maintain whole-body energy homeostasis. The mainstream view is that circulating hormones secreted by the fat convey the metabolic state to the brain, which integrates peripheral information and regulates adipocyte function through noradrenergic sympathetic output1. Moreover, somatosensory neurons of the dorsal root ganglia innervate adipose tissue2. However, the lack of genetic tools to selectively target these neurons has limited understanding of their physiological importance. Here we developed viral, genetic and imaging strategies to manipulate sensory nerves in an organ-specific manner in mice. This enabled us to visualize the entire axonal projection of dorsal root ganglia from the soma to subcutaneous adipocytes, establishing the anatomical underpinnings of adipose sensory innervation. Functionally, selective sensory ablation in adipose tissue enhanced the lipogenic and thermogenetic transcriptional programs, resulting in an enlarged fat pad, enrichment of beige adipocytes and elevated body temperature under thermoneutral conditions. The sensory-ablation-induced phenotypes required intact sympathetic function. We postulate that beige-fat-innervating sensory neurons modulate adipocyte function by acting as a brake on the sympathetic system. These results reveal an important role of the innervation by dorsal root ganglia of adipose tissues, and could enable future studies to examine the role of sensory innervation of disparate interoceptive systems.


Assuntos
Tecido Adiposo , Células Receptoras Sensoriais , Tecido Adiposo/inervação , Tecido Adiposo/metabolismo , Tecido Adiposo Bege/inervação , Tecido Adiposo Bege/metabolismo , Animais , Axônios , Metabolismo Energético , Gânglios Espinais/fisiologia , Homeostase , Hormônios/metabolismo , Camundongos , Especificidade de Órgãos , Células Receptoras Sensoriais/fisiologia , Gordura Subcutânea/inervação , Gordura Subcutânea/metabolismo , Sistema Nervoso Simpático/citologia , Sistema Nervoso Simpático/fisiologia , Termogênese/genética
6.
Nature ; 609(7928): 785-792, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35922005

RESUMO

Highly pathogenic coronaviruses, including severe acute respiratory syndrome coronavirus 2 (refs. 1,2) (SARS-CoV-2), Middle East respiratory syndrome coronavirus3 (MERS-CoV) and SARS-CoV-1 (ref. 4), vary in their transmissibility and pathogenicity. However, infection by all three viruses results in substantial apoptosis in cell culture5-7 and in patient tissues8-10, suggesting a potential link between apoptosis and pathogenesis of coronaviruses. Here we show that caspase-6, a cysteine-aspartic protease of the apoptosis cascade, serves as an important host factor for efficient coronavirus replication. We demonstrate that caspase-6 cleaves coronavirus nucleocapsid proteins, generating fragments that serve as interferon antagonists, thus facilitating virus replication. Inhibition of caspase-6 substantially attenuates lung pathology and body weight loss in golden Syrian hamsters infected with SARS-CoV-2 and improves the survival of mice expressing human DPP4 that are infected with mouse-adapted MERS-CoV. Our study reveals how coronaviruses exploit a component of the host apoptosis cascade to facilitate virus replication.


Assuntos
Ácido Aspártico , Caspase 6 , Infecções por Coronavirus , Coronavirus , Cisteína , Interações Hospedeiro-Patógeno , Replicação Viral , Animais , Apoptose , Ácido Aspártico/metabolismo , Caspase 6/metabolismo , Coronavirus/crescimento & desenvolvimento , Coronavirus/patogenicidade , Infecções por Coronavirus/enzimologia , Infecções por Coronavirus/virologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Cricetinae , Cisteína/metabolismo , Dipeptidil Peptidase 4/genética , Dipeptidil Peptidase 4/metabolismo , Humanos , Interferons/antagonistas & inibidores , Interferons/imunologia , Pulmão/patologia , Mesocricetus , Camundongos , Coronavírus da Síndrome Respiratória do Oriente Médio , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , SARS-CoV-2 , Taxa de Sobrevida , Redução de Peso
7.
Proc Natl Acad Sci U S A ; 121(5): e2316834121, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38252823

RESUMO

CRISPR-Cas-based genome editing is widely used in bacteria at scales ranging from construction of individual mutants to massively parallel libraries. This procedure relies on guide RNA-directed cleavage of the genome followed by repair with a template that introduces a desired mutation along with synonymous "immunizing" mutations to prevent re-cleavage of the genome after editing. Because the immunizing mutations do not change the protein sequence, they are often assumed to be neutral. However, synonymous mutations can change mRNA structures in ways that alter levels of the encoded proteins. We have tested the assumption that immunizing mutations are neutral by constructing a library of over 50,000 edits that consist of only synonymous mutations in Escherichia coli. Thousands of edits had substantial effects on fitness during growth of E. coli on acetate, a poor carbon source that is toxic at high concentrations. The percentage of high-impact edits varied considerably between genes and at different positions within genes. We reconstructed clones with high-impact edits and found that 69% indeed had significant effects on growth in acetate. Interestingly, fewer edits affected fitness during growth in glucose, a preferred carbon source, suggesting that changes in protein expression caused by synonymous mutations may be most important when an organism encounters challenging conditions. Finally, we showed that synonymous edits can have widespread effects; a synonymous edit at the 5' end of ptsI altered expression of hundreds of genes. Our results suggest that the synonymous immunizing edits introduced during CRISPR-Cas-based genome editing should not be assumed to be innocuous.


Assuntos
Escherichia coli , RNA Guia de Sistemas CRISPR-Cas , Escherichia coli/genética , Biblioteca Gênica , Carbono , Acetatos
8.
Plant Cell ; 35(10): 3641-3661, 2023 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-37453082

RESUMO

DNA-dependent RNA polymerases (Pols) transfer the genetic information stored in genomic DNA to RNA in all organisms. In eukaryotes, the typical products of nuclear Pol I, Pol II, and Pol III are ribosomal RNAs, mRNAs, and transfer RNAs, respectively. Intriguingly, plants possess two additional Pols, Pol IV and Pol V, which produce small RNAs and long noncoding RNAs, respectively, mainly for silencing transposable elements. The five plant Pols share some subunits, but their distinct functions stem from unique subunits that interact with specific regulatory factors in their transcription cycles. Here, we summarize recent advances in our understanding of plant nucleus-localized Pols, including their evolution, function, structures, and transcription cycles.


Assuntos
RNA Polimerases Dirigidas por DNA , Plantas , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Plantas/genética , Plantas/metabolismo , RNA Polimerase II/genética , DNA , Metilação de DNA
9.
Nat Chem Biol ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831037

RESUMO

Enediyne natural products are renowned for their potent cytotoxicities but the biosynthesis of their defining 1,5-diyne-3-ene core moiety remains largely enigmatic. Since the discovery of the enediyne polyketide synthase cassette in 2002, genome sequencing has revealed thousands of distinct enediyne biosynthetic gene clusters, each harboring the conserved enediyne polyketide synthase cassette. Here we report that (1) the products of this cassette are an iodoheptaene, a diiodotetrayne and two pentaynes; (2) the diiodotetrayne represents a common biosynthetic intermediate for all known enediynes; and (3) cryptic iodination can be exploited to increase enediyne titers. These findings establish a unified biosynthetic pathway for the enediynes, set the stage to further advance enediyne core biosynthesis and enable fundamental breakthroughs in chemistry, enzymology and translational applications of enediyne natural products.

10.
Nat Chem Biol ; 20(2): 243-250, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37945897

RESUMO

The anthraquinone-fused enediynes (AFEs) combine an anthraquinone moiety and a ten-membered enediyne core capable of generating a cytotoxic diradical species. AFE cyclization is triggered by opening the F-ring epoxide, which is also the site of the most structural diversity. Previous studies of tiancimycin A, a heavily modified AFE, have revealed a cryptic aldehyde blocking installation of the epoxide, and no unassigned oxidases could be predicted within the tnm biosynthetic gene cluster. Here we identify two consecutively acting cofactorless oxygenases derived from methyltransferase and α/ß-hydrolase protein folds, TnmJ and TnmK2, respectively, that are responsible for F-ring tailoring in tiancimycin biosynthesis by comparative genomics. Further biochemical and structural characterizations reveal that the electron-rich AFE anthraquinone moiety assists in catalyzing deformylation, epoxidation and oxidative ring cleavage without exogenous cofactors. These enzymes therefore fill important knowledge gaps for the biosynthesis of this class of molecules and the underappreciated family of cofactorless oxygenases.


Assuntos
Antineoplásicos , Oxigenases , Antraquinonas/química , Antraquinonas/metabolismo , Enedi-Inos/química , Enedi-Inos/metabolismo , Compostos de Epóxi
11.
Proc Natl Acad Sci U S A ; 120(9): e2220468120, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36802426

RESUMO

The enediynes are structurally characterized by a 1,5-diyne-3-ene motif within a 9- or 10-membered enediyne core. The anthraquinone-fused enediynes (AFEs) are a subclass of 10-membered enediynes that contain an anthraquinone moiety fused to the enediyne core as exemplified by dynemicins and tiancimycins. A conserved iterative type I polyketide synthase (PKSE) is known to initiate the biosynthesis of all enediyne cores, and evidence has recently been reported to suggest that the anthraquinone moiety also originates from the PKSE product. However, the identity of the PKSE product that is converted to the enediyne core or anthraquinone moiety has not been established. Here, we report the utilization of recombinant E. coli coexpressing various combinations of genes that encode a PKSE and a thioesterase (TE) from either 9- or 10-membered enediyne biosynthetic gene clusters to chemically complement ΔPKSE mutant strains of the producers of dynemicins and tiancimycins. Additionally, 13C-labeling experiments were performed to track the fate of the PKSE/TE product in the ΔPKSE mutants. These studies reveal that 1,3,5,7,9,11,13-pentadecaheptaene is the nascent, discrete product of the PKSE/TE that is converted to the enediyne core. Furthermore, a second molecule of 1,3,5,7,9,11,13-pentadecaheptaene is demonstrated to serve as the precursor of the anthraquinone moiety. The results establish a unified biosynthetic paradigm for AFEs, solidify an unprecedented biosynthetic logic for aromatic polyketides, and have implications for the biosynthesis of not only AFEs but all enediynes.


Assuntos
Produtos Biológicos , Escherichia coli , Escherichia coli/genética , Antraquinonas/química , Policetídeo Sintases/genética , Policetídeo Sintases/química , Enedi-Inos/química , Antibióticos Antineoplásicos
12.
Proc Natl Acad Sci U S A ; 120(39): e2306288120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37729198

RESUMO

Nonsmall cell lung cancer (NSCLC) is highly malignant with limited treatment options, platinum-based chemotherapy is a standard treatment for NSCLC with resistance commonly seen. NSCLC cells exploit enhanced antioxidant defense system to counteract excessive reactive oxygen species (ROS), which contributes largely to tumor progression and resistance to chemotherapy, yet the mechanisms are not fully understood. Recent studies have suggested the involvement of histones in tumor progression and cellular antioxidant response; however, whether a major histone variant H1.2 (H1C) plays roles in the development of NSCLC remains unclear. Herein, we demonstrated that H1.2 was increasingly expressed in NSCLC tumors, and its expression was correlated with worse survival. When crossing the H1c knockout allele with a mouse NSCLC model (KrasLSL-G12D/+), H1.2 deletion suppressed NSCLC progression and enhanced oxidative stress and significantly decreased the levels of key antioxidant glutathione (GSH) and GCLC, the catalytic subunit of rate-limiting enzyme for GSH synthesis. Moreover, high H1.2 was correlated with the IC50 of multiple chemotherapeutic drugs and with worse prognosis in NSCLC patients receiving chemotherapy; H1.2-deficient NSCLC cells presented reduced survival and increased ROS levels upon cisplatin treatment, while ROS scavenger eliminated the survival inhibition. Mechanistically, H1.2 interacted with NRF2, a master regulator of antioxidative response; H1.2 enhanced the nuclear level and stability of NRF2 and, thus, promoted NRF2 binding to GCLC promoter and the consequent transcription; while NRF2 also transcriptionally up-regulated H1.2. Collectively, these results uncovered a tumor-driving role of H1.2 in NSCLC and indicate an "H1.2-NRF2" antioxidant feedforward cycle that promotes tumor progression and chemoresistance.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Animais , Camundongos , Humanos , Histonas/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Antioxidantes , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Glutationa , Modelos Animais de Doenças
13.
Plant J ; 118(6): 1872-1888, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38481350

RESUMO

As a plant-specific transcription factor, lateral organ boundaries domain (LBD) protein was reported to regulate plant growth and stress response, but the functional research of subfamily II genes is limited. SlMYC2, a master regulator of Jasmonic acid response, has been found to exhibit high expression levels in fruit and has been implicated in the regulation of fruit ripening and resistance to Botrytis. However, its role in fruit expansion remains unknown. In this study, we present evidence that a subfamily II member of LBD, namely SlLBD40, collaborates with SlMYC2 in the regulation of fruit expansion. Overexpression of SlLBD40 significantly promoted fruit growth by promoting mesocarp cell expansion, while knockout of SlLBD40 showed the opposite result. Similarly, SlMYC2 knockout resulted in a significant decrease in cell expansion within the fruit. Genetic analysis indicated that SlLBD40-mediated cell expansion depends on the expression of SlMYC2. SlLBD40 bound to the promoter of SlEXPA5, an expansin gene, but did not activate its expression directly. While, the co-expression of SlMYC2 and SlLBD40 significantly stimulated the activation of SlEXPA5, leading to an increase in fruit size. SlLBD40 interacted with SlMYC2 and enhanced the stability and abundance of SlMYC2. Furthermore, SlMYC2 directly targeted and activated the expression of SlLBD40, which is essential for SlLBD40-mediated fruit expansion. In summary, our research elucidates the role of the interaction between SlLBD40 and SlMYC2 in promoting cell expansion in tomato fruits, thus providing novel insights into the molecular genetics underlying fruit growth.


Assuntos
Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Solanum lycopersicum , Fatores de Transcrição , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética
14.
PLoS Pathog ; 19(3): e1011238, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36961862

RESUMO

A major threat to rice production is the disease epidemics caused by insect-borne viruses that emerge and re-emerge with undefined origins. It is well known that some human viruses have zoonotic origins from wild animals. However, it remains unknown whether native plants host uncharacterized endemic viruses with spillover potential to rice (Oryza sativa) as emerging pathogens. Here, we discovered rice tiller inhibition virus (RTIV), a novel RNA virus species, from colonies of Asian wild rice (O. rufipogon) in a genetic reserve by metagenomic sequencing. We identified the specific aphid vector that is able to transmit RTIV and found that RTIV would cause low-tillering disease in rice cultivar after transmission. We further demonstrated that an infectious molecular clone of RTIV initiated systemic infection and causes low-tillering disease in an elite rice variety after Agrobacterium-mediated inoculation or stable plant transformation, and RTIV can also be transmitted from transgenic rice plant through its aphid vector to cause disease. Finally, global transcriptome analysis indicated that RTIV may disturb defense and tillering pathway to cause low tillering disease in rice cultivar. Thus, our results show that new rice viral pathogens can emerge from native habitats, and RTIV, a rare aphid-transmitted rice viral pathogen from native wild rice, can threaten the production of rice cultivar after spillover.


Assuntos
Afídeos , Oryza , Vírus , Animais , Humanos , Oryza/genética , Afídeos/genética , Perfilação da Expressão Gênica , Plantas Geneticamente Modificadas/genética , Vírus/genética , Doenças das Plantas
15.
Plant Physiol ; 194(4): 2149-2164, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37992039

RESUMO

Transgenes are often spontaneously silenced, which hinders the application of genetic modifications to crop breeding. While gene silencing has been extensively studied in Arabidopsis (Arabidopsis thaliana), the molecular mechanism of transgene silencing remains elusive in crop plants. We used rice (Oryza sativa) plants silenced for a 35S::OsGA2ox1 (Gibberellin 2-oxidase 1) transgene to isolate five elements mountain (fem) mutants showing restoration of transgene expression. In this study, we isolated multiple fem2 mutants defective in a homolog of Required to Maintain Repression 1 (RMR1) of maize (Zea mays) and CLASSY (CLSY) of Arabidopsis. In addition to failing to maintain transgene silencing, as occurs in fem3, in which mutation occurs in NUCLEAR RNA POLYMERASE E1 (OsNRPE1), the fem2 mutant failed to establish transgene silencing of 35S::OsGA2ox1. Mutation in FEM2 eliminated all RNA POLYMERASE IV (Pol-IV)-FEM1/OsRDR2 (RNA-DEPENDENT RNA POLYMERASE 2)-dependent small interfering RNAs (siRNAs), reduced DNA methylation on genome-wide scale in rice seedlings, caused pleiotropic developmental defects, and increased disease resistance. Simultaneous mutation in 2 FEM2 homologous genes, FEM2-Like 1 (FEL1) and FEL2, however, did not affect DNA methylation and rice development and disease resistance. The predominant expression of FEM2 over FEL1 and FEL2 in various tissues was likely caused by epigenetic states. Overexpression of FEL1 but not FEL2 partially rescued hypomethylation of fem2, indicating that FEL1 maintains the cryptic function. In summary, FEM2 is essential for establishing and maintaining gene silencing; moreover, FEM2 is solely required for Pol IV-FEM1 siRNA biosynthesis and de novo DNA methylation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Oryza , Oryza/genética , Oryza/metabolismo , Arabidopsis/genética , Cromatina/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Resistência à Doença/genética , Melhoramento Vegetal , Metilação de DNA/genética , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas de Arabidopsis/metabolismo , Plantas/metabolismo , Genômica , Mutação/genética
16.
EMBO Rep ; 24(6): e56128, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37042626

RESUMO

Surgery-induced renal ischemia and reperfusion (I/R) injury and nephrotoxic drugs like cisplatin can cause acute kidney injury (AKI), for which there is no effective therapy. Lipid accumulation is evident following AKI in renal tubules although the mechanisms and pathological effects are unclear. Here, we report that Ehmt2-encoded histone methyltransferase G9a is upregulated in patients and mouse kidneys after AKI. Renal tubular specific knockout of G9a (Ehmt2Ksp ) or pharmacological inhibition of G9a alleviates lipid accumulation associated with AKI. Mechanistically, G9a suppresses transcription of the lipolytic enzyme Ces1; moreover, G9a and farnesoid X receptor (FXR) competitively bind to the same promoter regions of Ces1. Ces1 is consistently observed to be downregulated in the kidney of AKI patients. Pharmacological inhibition of Ces1 increases lipid accumulation, exacerbates renal I/R-injury and eliminates the beneficial effects on AKI observed in Ehmt2Ksp mice. Furthermore, lipid-lowering atorvastatin and an FXR agonist alleviate AKI by activating Ces1 and reducing renal lipid accumulation. Together, our results reveal a G9a/FXR-Ces1 axis that affects the AKI outcome via regulating renal lipid accumulation.


Assuntos
Injúria Renal Aguda , Túbulos Renais , Camundongos , Animais , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Injúria Renal Aguda/genética , Injúria Renal Aguda/induzido quimicamente , Lipídeos , Rim/patologia , Camundongos Endogâmicos C57BL
17.
Mol Cell ; 68(3): 591-604.e5, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29100056

RESUMO

The Hippo pathway is crucial in organ size control and tissue homeostasis, with deregulation leading to cancer. An extracellular nutrition signal, such as glucose, regulates the Hippo pathway activation. However, the mechanisms are still not clear. Here, we found that the Hippo pathway is directly regulated by the hexosamine biosynthesis pathway (HBP) in response to metabolic nutrients. Mechanistically, the core component of Hippo pathway (YAP) is O-GlcNAcylated by O-GlcNAc transferase (OGT) at serine 109. YAP O-GlcNAcylation disrupts its interaction with upstream kinase LATS1, prevents its phosphorylation, and activates its transcriptional activity. And this activation is not dependent on AMPK. We also identified OGT as a YAP-regulated gene that forms a feedback loop. Finally, we confirmed that glucose-induced YAP O-GlcNAcylation and activation promoted tumorigenesis. Together, our data establish a molecular mechanism and functional significance of the HBP in directly linking extracellular glucose signal to the Hippo-YAP pathway and tumorigenesis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Transformação Celular Neoplásica/metabolismo , Glucose/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Neoplasias/enzimologia , Fosfoproteínas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Regulação Neoplásica da Expressão Gênica , Glicosilação , Células HEK293 , Células HeLa , Humanos , Camundongos Nus , Neoplasias/genética , Neoplasias/patologia , Fosfoproteínas/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Serina , Transdução de Sinais , Fatores de Tempo , Fatores de Transcrição , Transcrição Gênica , Ativação Transcricional , Proteínas de Sinalização YAP
18.
Drug Resist Updat ; 74: 101082, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38569225

RESUMO

Molecular targeted drugs and chimeric antigen receptor (CAR) T cell therapy represent specific biological treatments that have significantly improved the efficacy of treating hematologic malignancies. However, they face challenges such as drug resistance and recurrence after treatment. Combining molecular targeted drugs and CAR-T cells could regulate immunity, improve tumor microenvironment (TME), promote cell apoptosis, and enhance sensitivity to tumor cell killing. This approach might provide a dual coordinated attack on cancer cells, effectively eliminating minimal residual disease and overcoming therapy resistance. Moreover, molecular targeted drugs can directly or indirectly enhance the anti-tumor effect of CAR-T cells by inducing tumor target antigen expression, reversing CAR-T cell exhaustion, and reducing CAR-T cell associated toxic side effects. Therefore, combining molecular targeted drugs with CAR-T cells is a promising and novel tactic for treating hematologic malignancies. In this review article, we focus on analyzing the mechanism of therapy resistance and its reversal of CAR-T cell therapy resistance, as well as the synergistic mechanism, safety, and future challenges in CAR-T cell therapy in combination with molecular targeted drugs. We aim to explore the benefits of this combination therapy for patients with hematologic malignancies and provide a rationale for subsequent clinical studies.


Assuntos
Neoplasias Hematológicas , Imunoterapia Adotiva , Terapia de Alvo Molecular , Microambiente Tumoral , Humanos , Neoplasias Hematológicas/terapia , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/tratamento farmacológico , Imunoterapia Adotiva/métodos , Imunoterapia Adotiva/tendências , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Terapia de Alvo Molecular/métodos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Terapia Combinada/métodos , Receptores de Antígenos Quiméricos/imunologia , Antineoplásicos/uso terapêutico , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Animais
19.
Drug Resist Updat ; 73: 101062, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38330827

RESUMO

Multidrug resistance protein 7 (MRP7), also known as ATP-binding cassette (ABC) transporter subfamily C10 (ABCC10), is an ABC transporter that was first identified in 2001. ABCC10/MRP7 is a 171 kDa protein located on the basolateral membrane of cells. ABCC10/MRP7 consists of three transmembrane domains and two nucleotide binding domains. It mediates multidrug resistance of tumor cells to a variety of anticancer drugs by increasing drug efflux and results in reducing intracellular drug accumulation. The transport substrates of ABCC10/MRP7 include antineoplastic drugs such as taxanes, vinca alkaloids, and epothilone B, as well as endobiotics such as leukotriene C4 (LTC4) and estradiol 17 ß-D-glucuronide. A variety of ABCC10/MRP7 inhibitors, including cepharanthine, imatinib, erlotinib, tariquidar, and sildenafil, can reverse ABCC10/MRP7-mediated MDR. Additionally, the presence or absence of ABCC10/MRP7 is also closely related to renal tubular dysfunction, obesity, and other diseases. In this review, we discuss: 1) Structure and functions of ABCC10/MRP7; 2) Known substrates and inhibitors of ABCC10/MRP7 and their potential therapeutic applications in cancer; and 3) Role of ABCC10/MRP7 in non-cancerous diseases.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Resistência a Múltiplos Medicamentos/genética , Mesilato de Imatinib/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/genética
20.
Nano Lett ; 24(3): 1001-1008, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38198561

RESUMO

We report a zero-dimensional (0D) lead-free chiral perovskite (S-/R-MBA)4Bi2I10 with a high degree of circularly polarized light (CPL) emission. Our 0D lead-free chiral perovskite exhibits an average degree of circular polarization (DOCP) of 19.8% at 78 K under linearly polarized laser excitation, and the maximum DOCP can reach 25.8%, which is 40 times higher than the highest DOCP of 0.5% in all reported lead-free chiral perovskites to the best of our knowledge. The high DOCP of (S-/R-MBA)4Bi2I10 is attributed to the free exciton emission with a Huang-Rhys factor of 2.8. In contrast, all the lead-free chiral perovskites in prior reports are dominant by self-trapped exciton in which the spin relaxation reduces DOCP dramatically. Moreover, we realize the manipulation of the valley degree of freedom of monolayer WSe2 by using the spin injection of the 0D chiral lead-free perovskites. Our results provide a new perspective to develop lead-free chiral perovskite devices for CPL light source, spintronics, and valleytronics.

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