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Here, we describe an approach to correct the genetic defect in fragile X syndrome (FXS) via recruitment of endogenous repair mechanisms. A leading cause of autism spectrum disorders, FXS results from epigenetic silencing of FMR1 due to a congenital trinucleotide (CGG) repeat expansion. By investigating conditions favorable to FMR1 reactivation, we find MEK and BRAF inhibitors that induce a strong repeat contraction and full FMR1 reactivation in cellular models. We trace the mechanism to DNA demethylation and site-specific R-loops, which are necessary and sufficient for repeat contraction. A positive feedback cycle comprising demethylation, de novo FMR1 transcription, and R-loop formation results in the recruitment of endogenous DNA repair mechanisms that then drive excision of the long CGG repeat. Repeat contraction is specific to FMR1 and restores the production of FMRP protein. Our study therefore identifies a potential method of treating FXS in the future.
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Síndrome del Cromosoma X Frágil , Expansión de Repetición de Trinucleótido , Humanos , Estructuras R-Loop , Metilación de ADN , Síndrome del Cromosoma X Frágil/genética , Epigénesis Genética , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/metabolismoRESUMEN
The efficacy of T cell-based immunotherapies is limited by immunosuppressive pressures in the tumor microenvironment. Here we show a predominant role for the interaction between BTLA on effector T cells and HVEM (TNFRSF14) on immunosuppressive tumor microenvironment cells, namely regulatory T cells. High BTLA expression in chimeric antigen receptor (CAR) T cells correlated with poor clinical response to treatment. Therefore, we deleted BTLA in CAR T cells and show improved tumor control and persistence in models of lymphoma and solid malignancies. Mechanistically, BTLA inhibits CAR T cells via recruitment of tyrosine phosphatases SHP-1 and SHP-2, upon trans engagement with HVEM. BTLA knockout thus promotes CAR signaling and subsequently enhances effector function. Overall, these data indicate that the BTLA-HVEM axis is a crucial immune checkpoint in CAR T cell immunotherapy and warrants the use of strategies to overcome this barrier.
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Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos , Receptores Inmunológicos , Miembro 14 de Receptores del Factor de Necrosis Tumoral , Microambiente Tumoral , Animales , Humanos , Inmunoterapia Adoptiva/métodos , Miembro 14 de Receptores del Factor de Necrosis Tumoral/metabolismo , Miembro 14 de Receptores del Factor de Necrosis Tumoral/inmunología , Miembro 14 de Receptores del Factor de Necrosis Tumoral/genética , Ratones , Microambiente Tumoral/inmunología , Receptores Quiméricos de Antígenos/inmunología , Receptores Quiméricos de Antígenos/metabolismo , Receptores Quiméricos de Antígenos/genética , Receptores Inmunológicos/metabolismo , Receptores Inmunológicos/genética , Linfocitos T Reguladores/inmunología , Transducción de Señal , Línea Celular Tumoral , Neoplasias/inmunología , Neoplasias/terapia , Ratones NoqueadosRESUMEN
How Polycomb repressive complex 2 (PRC2) is regulated by RNA remains an unsolved problem. Although PRC2 binds G-tracts with the potential to form RNA G-quadruplexes (rG4s), whether rG4s fold extensively in vivo and whether PRC2 binds folded or unfolded rG4 are unknown. Using the X-inactivation model in mouse embryonic stem cells, here we identify multiple folded rG4s in Xist RNA and demonstrate that PRC2 preferentially binds folded rG4s. High-affinity rG4 binding inhibits PRC2's histone methyltransferase activity, and stabilizing rG4 in vivo antagonizes H3 at lysine 27 (H3K27me3) enrichment on the inactive X chromosome. Surprisingly, mutagenizing the rG4 does not affect PRC2 recruitment but promotes its release and catalytic activation on chromatin. H3K27me3 marks are misplaced, however, and gene silencing is compromised. Xist-PRC2 complexes become entrapped in the S1 chromosome compartment, precluding the required translocation into the S2 compartment. Thus, Xist rG4 folding controls PRC2 activity, H3K27me3 enrichment, and the stepwise regulation of chromosome-wide gene silencing.
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G-Cuádruplex , Histonas , Complejo Represivo Polycomb 2 , ARN Largo no Codificante , Inactivación del Cromosoma X , Animales , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Ratones , Complejo Represivo Polycomb 2/metabolismo , Complejo Represivo Polycomb 2/genética , Histonas/metabolismo , Histonas/genética , Células Madre Embrionarias de Ratones/metabolismo , Cromatina/metabolismo , Cromatina/genética , Cromosoma X/genética , Cromosoma X/metabolismo , Silenciador del Gen , Pliegue del ARN , Unión ProteicaRESUMEN
Individuals can exhibit differences in metabolism that are caused by the interplay of genetic background, nutritional input, microbiota and other environmental factors1-4. It is difficult to connect differences in metabolism to genomic variation and derive underlying molecular mechanisms in humans, owing to differences in diet and lifestyle, among others. Here we use the nematode Caenorhabditis elegans as a model to study inter-individual variation in metabolism. By comparing three wild strains and the commonly used N2 laboratory strain, we find differences in the abundances of both known metabolites and those that have not to our knowledge been previously described. The latter metabolites include conjugates between 3-hydroxypropionate (3HP) and several amino acids (3HP-AAs), which are much higher in abundance in one of the wild strains. 3HP is an intermediate in the propionate shunt pathway, which is activated when flux through the canonical, vitamin-B12-dependent propionate breakdown pathway is perturbed5. We show that increased accumulation of 3HP-AAs is caused by genetic variation in HPHD-1, for which 3HP is a substrate. Our results suggest that the production of 3HP-AAs represents a 'shunt-within-a-shunt' pathway to accommodate a reduction-of-function allele in hphd-1. This study provides a step towards the development of metabolic network models that capture individual-specific differences of metabolism and more closely represent the diversity that is found in entire species.
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Caenorhabditis elegans , Redes y Vías Metabólicas , Animales , Humanos , Oxidorreductasas de Alcohol/genética , Oxidorreductasas de Alcohol/metabolismo , Aminoácidos/metabolismo , Caenorhabditis elegans/clasificación , Caenorhabditis elegans/enzimología , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Ácido Láctico/análogos & derivados , Ácido Láctico/metabolismo , Redes y Vías Metabólicas/genética , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Modelos Animales , Propionatos/metabolismo , Vitamina B 12/metabolismoRESUMEN
Posttranslational modifications regulate the properties and abundance of synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors that mediate fast excitatory synaptic transmission and synaptic plasticity in the central nervous system. During long-term depression (LTD), protein tyrosine phosphatases (PTPs) dephosphorylate tyrosine residues in the C-terminal tail of AMPA receptor GluA2 subunit, which is essential for GluA2 endocytosis and group I metabotropic glutamate receptor (mGluR)-dependent LTD. However, as a selective downstream effector of mGluRs, the mGluR-dependent PTP responsible for GluA2 tyrosine dephosphorylation remains elusive at Schaffer collateral (SC)-CA1 synapses. In the present study, we find that mGluR5 stimulation activates Src homology 2 (SH2) domain-containing phosphatase 2 (SHP2) by increasing phospho-Y542 levels in SHP2. Under steady-state conditions, SHP2 plays a protective role in stabilizing phospho-Y869 of GluA2 by directly interacting with GluA2 phosphorylated at Y869, without affecting GluA2 phospho-Y876 levels. Upon mGluR5 stimulation, SHP2 dephosphorylates GluA2 at Y869 and Y876, resulting in GluA2 endocytosis and mGluR-LTD. Our results establish SHP2 as a downstream effector of mGluR5 and indicate a dual action of SHP2 in regulating GluA2 tyrosine phosphorylation and function. Given the implications of mGluR5 and SHP2 in synaptic pathophysiology, we propose SHP2 as a promising therapeutic target for neurodevelopmental and autism spectrum disorders.
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Endocitosis , Depresión Sináptica a Largo Plazo , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Receptores AMPA , Receptores de Glutamato Metabotrópico , Receptores AMPA/metabolismo , Animales , Fosforilación , Endocitosis/fisiología , Depresión Sináptica a Largo Plazo/fisiología , Receptores de Glutamato Metabotrópico/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , Ratas , Tirosina/metabolismo , Receptor del Glutamato Metabotropico 5/metabolismo , Sinapsis/metabolismo , Ratones , Humanos , Neuronas/metabolismoRESUMEN
Many of the biological functions performed by RNA are mediated by RNA-binding proteins (RBPs), and understanding the molecular basis of these interactions is fundamental to biology. Here, we present massively parallel RNA assay combined with immunoprecipitation (MPRNA-IP) for in vivo high-throughput dissection of RNA-protein interactions and describe statistical models for identifying RNA domains and parsing the structural contributions of RNA. By using custom pools of tens of thousands of RNA sequences containing systematically designed truncations and mutations, MPRNA-IP is able to identify RNA domains, sequences, and secondary structures necessary and sufficient for protein binding in a single experiment. We show that this approach is successful for multiple RNAs of interest, including the long noncoding RNA NORAD, bacteriophage MS2 RNA, and human telomerase RNA, and we use it to interrogate the hitherto unknown sequence or structural RNA-binding preferences of the DNA-looping factor CTCF. By integrating systematic mutation analysis with crosslinking immunoprecipitation, MPRNA-IP provides a novel high-throughput way to elucidate RNA-based mechanisms behind RNA-protein interactions in vivo.
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Proteínas de Unión al ARN , ARN , Humanos , Sitios de Unión , Factor de Unión a CCCTC/metabolismo , Factor de Unión a CCCTC/genética , Inmunoprecipitación , Levivirus/genética , Levivirus/metabolismo , Mutación , Conformación de Ácido Nucleico , Unión Proteica , ARN/metabolismo , ARN/química , ARN/genética , ARN Largo no Codificante/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/química , ARN Viral/metabolismo , ARN Viral/química , ARN Viral/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/química , Telomerasa/metabolismo , Telomerasa/genética , Modelos EstadísticosRESUMEN
BACKGROUND: Stopping aspirin within 1 month after implantation of a drug-eluting stent for ticagrelor monotherapy has not been exclusively evaluated for patients with acute coronary syndrome. The aim of this study was to investigate whether ticagrelor monotherapy after <1 month of dual antiplatelet therapy (DAPT) is noninferior to 12 months of ticagrelor-based DAPT for adverse cardiovascular and bleeding events in patients with acute coronary syndrome. METHODS: In this randomized, open-label, noninferiority trial, 2850 patients with acute coronary syndrome who underwent drug-eluting stent implantation at 24 centers in South Korea were randomly assigned (1:1) to receive either ticagrelor monotherapy (90 mg twice daily) after <1 month of DAPT (n=1426) or 12 months of ticagrelor-based DAPT (n=1424) between April 24, 2019, and May 31, 2022. The primary end point was the net clinical benefit as a composite of all-cause death, myocardial infarction, definite or probable stent thrombosis, stroke, and major bleeding at 1 year after the index procedure in the intention-to-treat population. Key secondary end points were the individual components of the primary end point. RESULTS: Among 2850 patients who were randomized (mean age, 61 years; 40% ST-segment-elevation myocardial infarction), 2823 (99.0%) completed the trial. Aspirin was discontinued at a median of 16 days (interquartile range, 12-25 days) in the group receiving ticagrelor monotherapy after <1 month of DAPT. The primary end point occurred in 40 patients (2.8%) in the group receiving ticagrelor monotherapy after <1-month DAPT, and in 73 patients (5.2%) in the ticagrelor-based 12-month DAPT group (hazard ratio, 0.54 [95% CI, 0.37-0.80]; P<0.001 for noninferiority; P=0.002 for superiority). This finding was consistent in the per-protocol population as a sensitivity analysis. The occurrence of major bleeding was significantly lower in the ticagrelor monotherapy after <1-month DAPT group compared with the 12-month DAPT group (1.2% versus 3.4%; hazard ratio, 0.35 [95% CI, 0.20-0.61]; P<0.001). CONCLUSIONS: This study provides evidence that stopping aspirin within 1 month for ticagrelor monotherapy is both noninferior and superior to 12-month DAPT for the 1-year composite outcome of death, myocardial infarction, stent thrombosis, stroke, and major bleeding, primarily because of a significant reduction in major bleeding, among patients with acute coronary syndrome receiving drug-eluting stent implantation. Low event rates, which may suggest enrollment of relatively non-high-risk patients, should be considered in interpreting the trial. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03797651.
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Síndrome Coronario Agudo , Stents Liberadores de Fármacos , Infarto del Miocardio , Intervención Coronaria Percutánea , Accidente Cerebrovascular , Trombosis , Humanos , Persona de Mediana Edad , Aspirina/uso terapéutico , Ticagrelor/efectos adversos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Síndrome Coronario Agudo/tratamiento farmacológico , Síndrome Coronario Agudo/cirugía , Stents Liberadores de Fármacos/efectos adversos , Quimioterapia Combinada , Hemorragia/etiología , Infarto del Miocardio/tratamiento farmacológico , Accidente Cerebrovascular/etiología , Trombosis/etiología , Intervención Coronaria Percutánea/efectos adversos , Intervención Coronaria Percutánea/métodos , Resultado del TratamientoRESUMEN
BACKGROUND AND AIMS: Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses a broad and continuous spectrum of liver diseases ranging from fatty liver to steatohepatitis. The intricate interactions of genetic, epigenetic, and environmental factors in the development and progression of MASLD remain elusive. Here, we aimed to achieve an integrative understanding of the genomic and transcriptomic alterations throughout the progression of MASLD. APPROACH AND RESULTS: RNA-Seq profiling (n = 146) and whole-exome sequencing (n = 132) of MASLD liver tissue samples identified 3 transcriptomic subtypes (G1-G3) of MASLD, which were characterized by stepwise pathological and molecular progression of the disease. Macrophage-driven inflammatory activities were identified as a key feature for differentiating these subtypes. This subtype-discriminating macrophage interplay was significantly associated with both the expression and genetic variation of the dsDNA sensor IFI16 (rs6940, A>T, T779S), establishing it as a fundamental molecular factor in MASLD progression. The in vitro dsDNA-IFI16 binding experiments and structural modeling revealed that the IFI16 variant exhibited increased stability and stronger dsDNA binding affinity compared to the wild-type. Further downstream investigation suggested that the IFI16 variant exacerbated DNA sensing-mediated inflammatory signals through mitochondrial dysfunction-related signaling of the IFI16-PYCARD-CASP1 pathway. CONCLUSIONS: This study unveils a comprehensive understanding of MASLD progression through transcriptomic classification, highlighting the crucial roles of IFI16 variants. Targeting the IFI16-PYCARD-CASP1 pathway may pave the way for the development of novel diagnostics and therapeutics for MASLD.
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Metagenomic studies show that diverse resident viruses inhabit the healthy gut; however, little is known about the role of these viruses in the maintenance of gut homeostasis. We found that mice treated with antiviral cocktail displayed more severe dextran sulfate sodium (DSS)-induced colitis compared with untreated mice. DSS-induced colitis was associated with altered enteric viral abundance and composition. When wild-type mice were reconstituted with Toll-like receptor 3 (TLR3) or TLR7 agonists or inactivated rotavirus, colitis symptoms were significantly ameliorated. Mice deficient in both TLR3 and TLR7 were more susceptible to DSS-induced experimental colitis. In humans, combined TLR3 and TLR7 genetic variations significantly influenced the severity of ulcerative colitis. Plasmacytoid dendritic cells isolated from inflamed mouse colon produced interferon-ß in a TLR3 and TLR7-dependent manner. These results imply that recognition of resident viruses by TLR3 and TLR7 is required for protective immunity during gut inflammation.
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Colitis/inmunología , Tracto Gastrointestinal/virología , Interferón beta/inmunología , Glicoproteínas de Membrana/inmunología , Rotavirus/inmunología , Receptor Toll-Like 3/inmunología , Receptor Toll-Like 7/inmunología , Animales , Antivirales/farmacología , Colitis/inducido químicamente , Células Dendríticas/inmunología , Sulfato de Dextran , Microbioma Gastrointestinal , Tracto Gastrointestinal/inmunología , Humanos , Inflamación/inmunología , Interferón beta/biosíntesis , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , ARN Ribosómico 16S/genética , Receptor Toll-Like 3/genética , Receptor Toll-Like 7/genéticaRESUMEN
The selenium-binding protein 1 (SELENBP1) has been reported to be up-regulated in the prefrontal cortex (PFC) of schizophrenia patients in postmortem reports. However, no causative link between SELENBP1 and schizophrenia has yet been established. Here, we provide evidence linking the upregulation of SELENBP1 in the PFC of mice with the negative symptoms of schizophrenia. We verified the levels of SELENBP1 transcripts in postmortem PFC brain tissues from patients with schizophrenia and matched healthy controls. We also generated transgenic mice expressing human SELENBP1 (hSELENBP1 Tg) and examined their neuropathological features, intrinsic firing properties of PFC 2/3-layer pyramidal neurons, and frontal cortex (FC) electroencephalographic (EEG) responses to auditory stimuli. Schizophrenia-like behaviors in hSELENBP1 Tg mice and mice expressing Selenbp1 in the FC were assessed. SELENBP1 transcript levels were higher in the brains of patients with schizophrenia than in those of matched healthy controls. The hSELENBP1 Tg mice displayed negative endophenotype behaviors, including heterotopias- and ectopias-like anatomical deformities in upper-layer cortical neurons and social withdrawal, deficits in nesting, and anhedonia-like behavior. Additionally, hSELENBP1 Tg mice exhibited reduced excitabilities of PFC 2/3-layer pyramidal neurons and abnormalities in EEG biomarkers observed in schizophrenia. Furthermore, mice overexpressing Selenbp1 in FC showed deficits in sociability. These results suggest that upregulation of SELENBP1 in the PFC causes asociality, a negative symptom of schizophrenia.
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Esquizofrenia , Humanos , Animales , Ratones , Esquizofrenia/genética , Esquizofrenia/metabolismo , Corteza Prefrontal/metabolismo , Células Piramidales/metabolismo , Encéfalo/metabolismo , Ratones Transgénicos , Proteínas de Unión al Selenio/genética , Proteínas de Unión al Selenio/metabolismoRESUMEN
BACKGROUND AND AIMS: In patients with acute coronary syndrome (ACS), dual antiplatelet therapy (DAPT) with aspirin and a potent P2Y12 inhibitor is recommended for 12 months after drug-eluting stent (DES) implantation. Monotherapy with a potent P2Y12 inhibitor after short-term DAPT is an attractive option to better balance the risks of ischaemia and bleeding. Therefore, this study evaluated the efficacy and safety of ticagrelor monotherapy after short-term DAPT, especially in patients with ACS. METHODS: Electronic databases were searched from inception to 11 November 2023, and for the primary analysis, individual patient data were pooled from the relevant randomized clinical trials comparing ticagrelor monotherapy after short-term (≤3 months) DAPT with ticagrelor-based 12-month DAPT, exclusively in ACS patients undergoing DES implantation. The co-primary endpoints were ischaemic endpoint (composite of all-cause death, myocardial infarction, or stroke) and bleeding endpoint [Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding] at 1 year. RESULTS: Individual patient data from two randomized clinical trials including 5906 ACS patients were analysed. At 1 year, the primary ischaemic endpoint did not differ between the ticagrelor monotherapy and ticagrelor-based DAPT groups [1.9% vs. 2.5%; adjusted hazard ratio (HR) 0.79; 95% confidence interval (CI) 0.56-1.13; P = .194]. The incidence of the primary bleeding endpoint was lower in the ticagrelor monotherapy group (2.4% vs. 4.5%; adjusted HR 0.54; 95% CI 0.40-0.72; P < .001). The results were consistent in a secondary aggregate data meta-analysis including the ACS subgroup of additional randomized clinical trials which enrolled patients with ACS as well as chronic coronary syndrome. CONCLUSIONS: In ACS patients undergoing DES implantation, ticagrelor monotherapy after short-term DAPT was associated with less major bleeding without a concomitant increase in ischaemic events compared with ticagrelor-based 12-month DAPT. STUDY REGISTRATION: PROSPERO (ID: CRD42023476470).
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BACKGROUND AND AIMS: Drug-coated balloons (DCBs) have demonstrated favourable outcomes following endovascular therapy for femoropopliteal artery (FPA) disease. However, uncertainty remains whether the use of intravascular ultrasound (IVUS) can improve the outcomes of DCBs. METHODS: This prospective, multicentre, randomized trial, conducted at seven centres in South Korea, compared the outcomes of IVUS-guided vs. angiography-guided angioplasty for treating FPA disease with DCBs. Patients were assigned to receive IVUS-guided (n = 119) or angiography-guided (n = 118) angioplasty using DCBs. The primary endpoint was 12-month primary patency. RESULTS: Between May 2016 and August 2022, 237 patients were enrolled and 204 (86.0%) completed the trial (median follow-up; 363 days). The IVUS guidance group showed significantly higher primary patency [83.8% vs. 70.1%; cumulative difference 19.6% (95% confidence interval 6.8 to 32.3); P = .01] and increased freedom from clinically driven target lesion revascularization [92.4% vs. 83.0%; difference 11.6% (95% confidence interval 3.1 to 20.1); P = .02], sustained clinical improvement (89.1% vs. 76.3%, P = .01), and haemodynamic improvement (82.4% vs. 66.9%, P = .01) at 12 months compared with the angiography guidance group. The IVUS group utilized larger balloon diameters and pressures for pre-dilation, more frequent post-dilation, and higher pressures for post-dilation, resulting in a greater post-procedural minimum lumen diameter (3.90 ± 0.59 vs. 3.71 ± 0.73 mm, P = .03). CONCLUSIONS: Intravascular ultrasound guidance significantly improved the outcomes of DCBs for FPA disease in terms of primary patency, freedom from clinically driven target lesion revascularization, and sustained clinical and haemodynamic improvement at 12 months. These benefits may be attributed to IVUS-guided optimization of the lesion before and after DCB treatment.
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Angioplastia de Balón , Arteria Femoral , Enfermedad Arterial Periférica , Arteria Poplítea , Ultrasonografía Intervencional , Grado de Desobstrucción Vascular , Humanos , Ultrasonografía Intervencional/métodos , Masculino , Angioplastia de Balón/métodos , Arteria Femoral/diagnóstico por imagen , Femenino , Arteria Poplítea/diagnóstico por imagen , Enfermedad Arterial Periférica/terapia , Enfermedad Arterial Periférica/diagnóstico por imagen , Estudios Prospectivos , Anciano , Persona de Mediana Edad , Materiales Biocompatibles Revestidos , Resultado del Tratamiento , AngiografíaRESUMEN
BACKGROUND: Cell wall integrity (CWI) is crucial for fungal growth, pathogenesis, and adaptation to extracellular environments. Calcofluor white (CFW) is a cell wall perturbant that inhibits fungal growth, yet little is known about how phytopathogenic fungi respond to the CFW-induced stress. RESULTS: In this study, we unveiled a significant discovery that CFW triggered the translocation of the transcription factor CgCrzA from the cytoplasm to the nucleus in Colletotrichum gloeosporioides. This translocation was regulated by an interacting protein, CgMkk1, a mitogen-activated protein kinase involved in the CWI pathway. Further analysis revealed that CgMkk1 facilitated nuclear translocation by phosphorylating CgCrzA at the Ser280 residue. Using chromatin immunoprecipitation sequencing, we identified two downstream targets of CgCrzA, namely CgCHS5 and CgCHS6, which are critical for growth, cell wall integrity, and pathogenicity as chitin synthase genes. CONCLUSIONS: These findings provide a novel insight into the regulatory mechanism of CgMkk1-CgCrzA-CgChs5/6, which enables response of the cell wall inhibitor CFW and facilitates infectious growth for C. gloeosporioides.
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Colletotrichum , Proteínas Fúngicas , Factores de Transcripción , Virulencia/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Colletotrichum/genética , Colletotrichum/patogenicidad , Pared Celular/metabolismo , Regulación Fúngica de la Expresión Génica , FosforilaciónRESUMEN
Subcutaneous and inhaled insulins are associated with needle phobia, lipohypertrophy, lipodystrophy, and cough in diabetes treatment. Oral nanoinsulin has been developed, reaping the physiologic benefits of peroral administration. This review profiles intestinal receptors exploitable in targeted delivery of oral nanoinsulin. Intestinal receptor targeting improves oral insulin bioavailability and sustains blood glucose-lowering response. Nonetheless, these studies are conducted in small animal models with no optimization of insulin dose, targeting ligand type and content, and physicochemical and molecular biologic characteristics of nanoparticles against the in vivo/clinical diabetes responses as a function of the intestinal receptor population characteristics with diabetes progression. The interactive effects between nanoinsulin and antidiabetic drugs on intestinal receptors, including their up-/downregulation, are uncertain. Sweet taste receptors upregulate SGLT-1, and both have an undefined role as new intestinal targets of nanoinsulin. Receptor targeting of oral nanoinsulin represents a viable approach that is relatively green, requiring an in-depth development of the relationship between receptors and their pathophysiological profiles with physicochemical attributes of the oral nanoinsulin. SIGNIFICANCE STATEMENT: Intestinal receptor targeting of oral nanoinsulin improves its bioavailability with sustained blood glucose-lowering response. Exploring new intestinal receptor and tailoring the design of oral nanoinsulin to the pathophysiological state of diabetic patients is imperative to raise the insulin performance to a comparable level as the injection products.
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Diabetes Mellitus , Insulina , Nanopartículas , Animales , Glucemia , Diabetes Mellitus/tratamiento farmacológico , Glucosa/uso terapéutico , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Insulina/química , Insulina/uso terapéutico , Insulina Regular Humana/uso terapéutico , Nanopartículas/químicaRESUMEN
Recovery from COVID-19 depends on the ability of the host to effectively neutralize virions and infected cells, a process largely driven by antibody-mediated immunity. However, with the newly emerging variants that evade Spike-targeting antibodies, re-infections and breakthrough infections are increasingly common. A full characterization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mechanisms counteracting antibody-mediated immunity is therefore needed. Here, we report that ORF8 is a virally encoded SARS-CoV-2 factor that controls cellular Spike antigen levels. We show that ORF8 limits the availability of mature Spike by inhibiting host protein synthesis and retaining Spike at the endoplasmic reticulum, reducing cell-surface Spike levels and recognition by anti-SARS-CoV-2 antibodies. In conditions of limited Spike availability, we found ORF8 restricts Spike incorporation during viral assembly, reducing Spike levels in virions. Cell entry of these virions then leaves fewer Spike molecules at the cell surface, limiting antibody recognition of infected cells. Based on these findings, we propose that SARS-CoV-2 variants may adopt an ORF8-dependent strategy that facilitates immune evasion of infected cells for extended viral production.
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COVID-19 , Regulación Viral de la Expresión Génica , Evasión Inmune , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , Anticuerpos Antivirales , COVID-19/inmunología , COVID-19/virología , Evasión Inmune/genética , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Regulación Viral de la Expresión Génica/genética , Células A549 , Células HEK293 , Retículo Endoplásmico/virología , Interacciones Microbiota-Huesped/genética , Interacciones Microbiota-Huesped/inmunologíaRESUMEN
In photosynthesis, four electrons and four protons taken from water in photosystem II (PSII) are used to reduce NAD(P)+ to produce NAD(P)H in photosystem I (PSI), which is the most important reductant to reduce CO2. Despite extensive efforts to mimic photosynthesis, artificial photosynthesis to produce NAD(P)H using water electron and proton sources has yet to be achieved. Herein, we report the photocatalytic reduction of NAD(P)+ to NAD(P)H and its analogues in a molecular model of PSI, which is combined with water oxidation in a molecular model of PSII. Photoirradiation of a toluene/trifluoroethanol (TFE)/borate buffer aqueous solution of hydroquinone derivatives (X-QH2), 9-mesityl-10-methylacridinium ion, cobaloxime, and NAD(P)+ (PSI model) resulted in the quantitative and regioselective formation of NAD(P)H and p-benzoquinone derivatives (X-Q). X-Q was reduced to X-QH2, accompanied by the oxidation of water to dioxygen under the photoirradiation of a toluene/TFE/borate buffer aqueous solution of [(N4Py)FeII]2+ (PSII model). The PSI and PSII models were combined using two glass membranes and two liquid membranes to produce NAD(P)H using water as an electron and proton source with the turnover number (TON) of 54. To the best of our knowledge, this is the first time to achieve the stoichiometry of photosynthesis, photocatalytic reduction of NAD(P)+ by water to produce NAD(P)H and O2.
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Direct air capture (DAC) shows considerable promise for the effective removal of CO2; however, materials applicable to DAC are lacking. Among metal-organic framework (MOF) adsorbents, diamine-Mg2(dobpdc) (dobpdc4- = 4,4-dioxidobiphenyl-3,3'-dicarboxylate) effectively removes low-pressure CO2, but the synthesis of the organic ligand requires high temperature, high pressure, and a toxic solvent. Besides, it is necessary to isolate the ligand for utilization in the synthesis of the framework. In this study, we synthesized a new variant of extended MOF-74-type frameworks, M2(hob) (M = Mg2+, Co2+, Ni2+, and Zn2+; hob4- = 5,5'-(hydrazine-1,2-diylidenebis(methanylylidene))bis(2-oxidobenzoate)), constructed from an azine-bonded organic ligand obtained through a facile condensation reaction at room temperature. Functionalization of Mg2(hob) with N-methylethylenediamine, N-ethylethylenediamine, and N,N'-dimethylethylenediamine (mmen) enables strong interactions with low-pressure CO2, resulting in top-tier adsorption capacities of 2.60, 2.49, and 2.91 mmol g-1 at 400 ppm of CO2, respectively. Under humid conditions, the CO2 capacity was higher than under dry conditions due to the presence of water molecules that aid in the formation of bicarbonate species. A composite material combining mmen-Mg2(hob) and polyvinylidene fluoride, a hydrophobic polymer, retained its excellent adsorption performance even after 7 days of exposure to 40% relative humidity. In addition, the one-pot synthesis of Mg2(hob) from a mixture of the corresponding monomers is achieved without separate ligand synthesis steps; thus, this framework is suitable for facile large-scale production. This work underscores that the newly synthesized Mg2(hob) and its composites demonstrate significant potential for DAC applications.
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We report the macrocyclic ring size-electronic structure-electrophilic reactivity correlation of mononuclear nonheme iron(III)-peroxo complexes bearing N-tetramethylated cyclam analogues (n-TMC), [FeIII(O2)(12-TMC)]+ (1), [FeIII(O2)(13-TMC)]+ (2), and [FeIII(O2)(14-TMC)]+ (3), as a model study of Rieske oxygenases. The Fe(III)-peroxo complexes show the same δ and pseudo-σ bonds between iron and the peroxo ligand. However, the strength of these interactions varies depending on the ring size of the n-TMC ligands; the overall Fe-O bond strength and the strength of the Fe-O2 δ bond increase gradually as the ring size of the n-TMC ligands becomes smaller, such as from 14-TMC to 13-TMC to 12-TMC. MCD spectroscopy plays a key role in assigning the characteristic low-energy δ â δ* LMCT band, which provides direct insight into the strength of the Fe-O2 δ bond and which, in turn, is correlated with the superoxo character of the iron-peroxo group. In oxidation reactions, reactivities of 1-3 toward hydrocarbon C-H bond activation are compared, revealing the reactivity order of 1 > 2 > 3; the [FeIII(O2)(n-TMC)]+ complex with a smaller n-TMC ring size, 12-TMC, is much more reactive than that with a larger n-TMC ring size, 14-TMC. DFT analysis shows that the Fe(III)-peroxo complex is not reactive toward C-H bonds, but it is the end-on Fe(II)-superoxo valence tautomer that is responsible for the observed reactivity. The hydrogen atom abstraction (HAA) reactivity of these intermediates is correlated with the overall donicity of the n-TMC ligand, which modulates the energy of the singly occupied π* superoxo frontier orbital that serves as the electron acceptor in the HAA reaction. The implications of these results for the mechanism of Rieske oxygenases are further discussed.
Asunto(s)
Ciclamas , Hierro , Hierro/química , Oxigenasas , Ligandos , Biomimética , Oxígeno/química , Hidrógeno , Compuestos FérricosRESUMEN
The reaction of Li[(TAML)CoIII]·3H2O (TAML = tetraamido macrocyclic tetraanionic ligand) with iodosylbenzene at 253 K in acetone in the presence of redox-innocent metal ions (Sc(OTf)3 and Y(OTf)3) or triflic acid affords a blue species 1, which is converted reversibly to a green species 2 upon cooling to 193 K. The electronic structures of 1 and 2 have been determined by combining advanced spectroscopic techniques (X-band electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR), X-ray absorption spectroscopy/extended X-ray absorption fine structure (XAS/EXAFS), and magnetic circular dichroism (MCD)) with ab initio theoretical studies. Complex 1 is best represented as an S = 1/2 [(Sol)(TAMLâ¢+)CoIII---OH(LA)]- species (LA = Lewis/Brønsted acid and Sol = solvent), where an S = 1 Co(III) center is antiferromagnetically coupled to S = 1/2 TAMLâ¢+, which represents a one-electron oxidized TAML ligand. In contrast, complex 2, also with an S = 1/2 ground state, is found to be multiconfigurational with contributions of both the resonance forms [(H-TAML)CoIVâO(LA)]- and [(H-TAMLâ¢+)CoIIIâO(LA)]-; H-TAML and H-TAMLâ¢+ represent the protonated forms of TAML and TAMLâ¢+ ligands, respectively. Thus, the interconversion of 1 and 2 is associated with a LA-associated tautomerization event, whereby H+ shifts from the terminal -OH group to TAMLâ¢+ with the concomitant formation of a terminal cobalt-oxo species possessing both singlet (SCo = 0) Co(III) and doublet (SCo = 1/2) Co(IV) characters. The reactivities of 1 and 2 at different temperatures have been investigated in oxygen atom transfer (OAT) and hydrogen atom transfer (HAT) reactions to compare the activation enthalpies and entropies of 1 and 2.
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Background Clinical decision making and drug development for fibrostenosing Crohn disease is constrained by a lack of imaging definitions, scoring conventions, and validated end points. Purpose To assess the reliability of MR enterography features to describe Crohn disease strictures and determine correlation with stricture severity. Materials and Methods A retrospective study of patients with symptomatic terminal ileal Crohn disease strictures who underwent MR enterography at tertiary care centers (Cleveland Clinic: September 2013 to November 2020; Mayo Clinic: February 2008 to March 2019) was conducted by using convenience sampling. In the development phase, blinded and trained radiologists independently evaluated 26 MR enterography features from baseline and follow-up examinations performed more than 6 months apart, with no bowel resection performed between examinations. Follow-up examinations closest to 12 months after baseline were selected. Reliability was assessed using the intraclass correlation coefficient (ICC). In the validation phase, after five features were redefined, reliability was re-estimated in an independent convenience sample using baseline examinations. Multivariable linear regression analysis identified features with at least moderate interrater reliability (ICC ≥0.41) that were independently associated with stricture severity. Results Ninety-nine (mean age, 40 years ± 14 [SD]; 50 male) patients were included in the development group and 51 (mean age, 45 years ± 16 [SD]; 35 female) patients were included in the validation group. In the development group, nine features had at least moderate interrater reliability. One additional feature demonstrated moderate reliability in the validation group. Stricture length (ICC = 0.85 [95% CI: 0.75, 0.91] and 0.91 [95% CI: 0.75, 0.96] in development and validation phase, respectively) and maximal associated small bowel dilation (ICC = 0.74 [95% CI: 0.63, 0.80] and 0.73 [95% CI: 0.58, 0.87] in development and validation group, respectively) had the highest interrater reliability. Stricture length, maximal stricture wall thickness, and maximal associated small bowel dilation were independently (regression coefficients, 0.09-3.97; P < .001) associated with stricture severity. Conclusion MR enterography definitions and scoring conventions for reliably assessing features of Crohn disease strictures were developed and validated, and feature correlation with stricture severity was determined. © RSNA, 2024 Supplemental material is available for this article. See also the article by Rieder and Ma et al in this issue. See also the editorial by Galgano and Summerlin in this issue.