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2.
Cell ; 161(2): 291-306, 2015 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-25860611

RESUMEN

Cholesterol is dynamically transported among organelles, which is essential for multiple cellular functions. However, the mechanism underlying intracellular cholesterol transport has remained largely unknown. We established an amphotericin B-based assay enabling a genome-wide shRNA screen for delayed LDL-cholesterol transport and identified 341 hits with particular enrichment of peroxisome genes, suggesting a previously unappreciated pathway for cholesterol transport. We show dynamic membrane contacts between peroxisome and lysosome, which are mediated by lysosomal Synaptotagmin VII binding to the lipid PI(4,5)P2 on peroxisomal membrane. LDL-cholesterol enhances such contacts, and cholesterol is transported from lysosome to peroxisome. Disruption of critical peroxisome genes leads to cholesterol accumulation in lysosome. Together, these findings reveal an unexpected role of peroxisome in intracellular cholesterol transport. We further demonstrate massive cholesterol accumulation in human patient cells and mouse model of peroxisomal disorders, suggesting a contribution of abnormal cholesterol accumulation to these diseases.


Asunto(s)
Colesterol/metabolismo , Lisosomas/metabolismo , Peroxisomas/metabolismo , ARN Interferente Pequeño/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Adrenoleucodistrofia/metabolismo , Anfotericina B/farmacología , Animales , Transporte Biológico , Estudio de Asociación del Genoma Completo , Humanos , Ratones , Trastorno Peroxisomal/metabolismo , Trastorno Peroxisomal/patología , Fosfatidilinositol 4,5-Difosfato/metabolismo , Sinaptotagminas/metabolismo , Pez Cebra
3.
Nature ; 588(7838): 479-484, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33177714

RESUMEN

Cholesterol is an essential lipid and its synthesis is nutritionally and energetically costly1,2. In mammals, cholesterol biosynthesis increases after feeding and is inhibited under fasting conditions3. However, the regulatory mechanisms of cholesterol biosynthesis at the fasting-feeding transition remain poorly understood. Here we show that the deubiquitylase ubiquitin-specific peptidase 20 (USP20) stabilizes HMG-CoA reductase (HMGCR), the rate-limiting enzyme in the cholesterol biosynthetic pathway, in the feeding state. The post-prandial increase in insulin and glucose concentration stimulates mTORC1 to phosphorylate USP20 at S132 and S134; USP20 is recruited to the HMGCR complex and antagonizes its degradation. The feeding-induced stabilization of HMGCR is abolished in mice with liver-specific Usp20 deletion and in USP20(S132A/S134A) knock-in mice. Genetic deletion or pharmacological inhibition of USP20 markedly decreases diet-induced body weight gain, reduces lipid levels in the serum and liver, improves insulin sensitivity and increases energy expenditure. These metabolic changes are reversed by expression of the constitutively stable HMGCR(K248R). This study reveals an unexpected regulatory axis from mTORC1 to HMGCR via USP20 phosphorylation and suggests that inhibitors of USP20 could be used to lower cholesterol levels to treat metabolic diseases including hyperlipidaemia, liver steatosis, obesity and diabetes.


Asunto(s)
Colesterol/biosíntesis , Ingestión de Alimentos/fisiología , Hidroximetilglutaril-CoA Reductasas/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ubiquitina Tiolesterasa/metabolismo , Animales , Línea Celular , Glucosa/metabolismo , Humanos , Insulina/metabolismo , Hígado/metabolismo , Masculino , Enfermedades Metabólicas/genética , Enfermedades Metabólicas/metabolismo , Metabolismo/genética , Ratones , Ratones Endogámicos C57BL , Fosforilación , Fosfoserina/metabolismo , Ubiquitina Tiolesterasa/antagonistas & inhibidores , Ubiquitina Tiolesterasa/química , Ubiquitina Tiolesterasa/deficiencia , Ubiquitinación , Aumento de Peso
4.
Mol Cell ; 66(1): 154-162.e10, 2017 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-28344083

RESUMEN

Hedgehog (Hh) has been known as the only cholesterol-modified morphogen playing pivotal roles in development and tumorigenesis. A major unsolved question is how Hh signaling regulates the activity of Smoothened (SMO). Here, we performed an unbiased biochemical screen and identified that SMO was covalently modified by cholesterol on the Asp95 (D95) residue through an ester bond. This modification was inhibited by Patched-1 (Ptch1) but enhanced by Hh. The SMO(D95N) mutation, which could not be cholesterol modified, was refractory to Hh-stimulated ciliary localization and failed to activate downstream signaling. Furthermore, homozygous SmoD99N/D99N (the equivalent residue in mouse) knockin mice were embryonic lethal with severe cardiac defects, phenocopying the Smo-/- mice. Together, the results of our study suggest that Hh signaling transduces to SMO through modulating its cholesterylation and provides a therapeutic opportunity to treat Hh-pathway-related cancers by targeting SMO cholesterylation.


Asunto(s)
Colesterol/metabolismo , Proteínas Hedgehog/metabolismo , Transducción de Señal , Receptor Smoothened/metabolismo , Animales , Células CHO , Cilios/metabolismo , Cricetulus , Regulación del Desarrollo de la Expresión Génica , Predisposición Genética a la Enfermedad , Células HEK293 , Cardiopatías Congénitas/genética , Cardiopatías Congénitas/metabolismo , Proteínas Hedgehog/genética , Humanos , Ratones , Ratones Transgénicos , Mutación , Células 3T3 NIH , Receptor Patched-1/genética , Receptor Patched-1/metabolismo , Fenotipo , Procesamiento Proteico-Postraduccional , Interferencia de ARN , Receptor Smoothened/genética , Transfección
5.
Nucleic Acids Res ; 51(10): 5228-5241, 2023 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-37070178

RESUMEN

Conversely to canonical splicing, back-splicing connects the upstream 3' splice site (SS) with a downstream 5'SS and generates exonic circular RNAs (circRNAs) that are widely identified and have regulatory functions in eukaryotic gene expression. However, sex-specific back-splicing in Drosophila has not been investigated and its regulation remains unclear. Here, we performed multiple RNA analyses of a variety sex-specific Drosophila samples and identified over ten thousand circular RNAs, in which hundreds are sex-differentially and -specifically back-spliced. Intriguingly, we found that expression of SXL, an RNA-binding protein encoded by Sex-lethal (Sxl), the master Drosophila sex-determination gene that is only spliced into functional proteins in females, promoted back-splicing of many female-differential circRNAs in the male S2 cells, whereas expression of a SXL mutant (SXLRRM) did not promote those events. Using a monoclonal antibody, we further obtained the transcriptome-wide RNA-binding sites of SXL through PAR-CLIP. After splicing assay of mini-genes with mutations in the SXL-binding sites, we revealed that SXL-binding on flanking exons and introns of pre-mRNAs facilitates back-splicing, whereas SXL-binding on the circRNA exons inhibits back-splicing. This study provides strong evidence that SXL has a regulatory role in back-splicing to generate sex-specific and -differential circRNAs, as well as in the initiation of sex-determination cascade through canonical forward-splicing.


Asunto(s)
Proteínas de Drosophila , ARN Circular , Proteínas de Unión al ARN , Animales , Femenino , Masculino , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , ARN/genética , ARN/metabolismo , Empalme del ARN/genética , ARN Circular/metabolismo , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo
6.
J Biol Chem ; 299(4): 103073, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36858198

RESUMEN

Polycomb repressive complex 2 (PRC2) suppresses gene transcription by methylating lysine 27 of histone H3 (H3K27) and plays critical roles in embryonic development. Among the core PRC2 subunits, EZH2 is the catalytic subunit and EED allosterically activates EZH2 upon binding trimethylated H3K27 (H3K27me3). Activating mutations on Y641, A677, and A687 within the enzymatic SET (Su(Var)3 to 9, Enhancer-of-zeste, and Trithorax) domain of EZH2 have been associated with enhanced H3K27me3 and tumorigenicity of many cancers including B-cell lymphoma and melanoma. To tackle the critical residues outside the EZH2 SET domain, we examined EZH2 mutations in lymphoma from cancer genome databases and identified a novel gain-of-function mutation W113C, which increases H3K27me3 in vitro and in vivo and promotes CDKN2A silencing to a similar level as EZH2 Y641F. Different from other gain-of-function mutations, this mutation is located in the SET-activation loop at the EZH2 N terminus, which stabilizes the SET domain and facilitates substrate binding. This may explain how the W113C mutation increases PRC2 activity. Tazemetostat is a Food and Drug Administration-approved EZH2-binding inhibitor for follicular lymphoma treatment. Intriguingly, the W113C mutation leads to tazemetostat resistance in both H3K27 methylation and tumor proliferation. Another class of allosteric PRC2 inhibitor binding EED overcomes the resistance, effectively decreases H3K27me3, and blocks tumor proliferation in cells expressing EZH2 W113C. As this mutation is originally identified from lymphoma samples, our results demonstrated its activating characteristic and the deleterious consequence, provide insights on PRC2 regulation, and support the continued exploration of treatment optimization for lymphoma patients.


Asunto(s)
Resistencia a Antineoplásicos , Mutación con Ganancia de Función , Linfoma de Células B , Humanos , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Histonas/metabolismo , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/genética , Mutación , Complejo Represivo Polycomb 2/genética
7.
Mol Genet Genomics ; 299(1): 71, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39031208

RESUMEN

BACKGROUND: DNA methylation is an important epigenetic modification that plays a crucial role in the development and progression of various tumors. However, the association between methylation­driven genes and diagnosis, prognosis, and immune characteristics of head and neck squamous cell carcinoma (HNSCC) remains unclear. METHODS: We obtained transcriptome, methylation, and clinical data from HNSCC patients in TCGA database, and used MethylMix algorithm to identify methylation-driven genes. A methylation driven gene-related risk model was constructed using Lasso regression analysis, and validated using data from GEO database. Immune infiltration and immune function analysis of the expression profiles were conducted using ssGSEA. Differences in immune checkpoint-related genes were analyzed, and the efficacy of immunotherapy was evaluated using TCIA database. Finally, a series of cell functional experiments were conducted to validate the results. RESULTS: Five methylation-driven genes were identified and utilized to construct a prognostic risk model. Based on the median risk score, all patients were categorized into high-risk and low-risk groups. The K-M analysis revealed that patients in the high-risk group have a worse prognosis. Additionally, the risk model demonstrated better prognostic predictive value as indicated by ROC analysis. GSEA enrichment analysis indicated that gene sets in the high and low-risk groups were primarily enriched in pathways associated with tumor immunity and metabolism. Our subsequent investigations showed that high-risk patients exhibited more immunosuppressive phenotypes, while low-risk patients were more likely to respond positively to immunotherapy. CONCLUSION: These findings of our research have the potential to improve patient stratification, guide treatment decisions, and advance the development of personalized therapies for HNSCC.


Asunto(s)
Metilación de ADN , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello , Carcinoma de Células Escamosas de Cabeza y Cuello , Transcriptoma , Humanos , Metilación de ADN/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/inmunología , Pronóstico , Transcriptoma/genética , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/inmunología , Neoplasias de Cabeza y Cuello/diagnóstico , Biomarcadores de Tumor/genética , Masculino , Femenino , Inmunoterapia , Perfilación de la Expresión Génica , Epigénesis Genética , Bases de Datos Genéticas
8.
Radiology ; 310(2): e231710, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38319165

RESUMEN

Background Preoperative recognition of irreversible bowel necrosis is important, as it provides valuable guidance for surgical strategy selection but also may inform perioperative risk assessment and communication. Few studies have focused on the association between CT signs and bowel necrosis. Purpose To assess the diagnostic accuracy of CT signs to predict bowel necrosis in patients with closed-loop small bowel obstruction (CL-SBO). Materials and Methods This retrospective single-center study included patients who were surgically confirmed to have CL-SBO caused by adhesion or internal hernia between January 2016 and May 2022. Necrosis was determined based on surgical exploration and postoperative pathologic examination. Two radiologists independently reviewed CT signs by both subjective visual assessment and objective measurement. Disagreements were resolved in consensus with a third gastrointestinal radiologist. Univariable and multivariable analyses were used to assess the association between CT signs and bowel necrosis, and Cohen κ was used to assess interobserver agreement. Sensitivity and specificity were calculated for each CT sign. Results This study included 145 patients: 61 (42.1%) in the necrotic group (median age, 62 years [IQR, 51-71.5 years]; 37 [60.7%] women) and 84 (57.9%) in the nonnecrotic group (median age, 61.5 years [IQR, 51-68.8 years]; 51 [60.7%] women). Univariable analysis and multivariable analysis showed that increased attenuation of intestinal contents and increased attenuation of intestinal wall were independent predictors for bowel necrosis (odds ratio = 45.3 and 15.1; P = .001 and P < .001, respectively). Increased attenuation of intestinal contents and increased attenuation of intestinal wall had similar sensitivity (64% and 67%, respectively) and specificity (99% and 92%, respectively) for predicting bowel necrosis. However, interobserver agreement was better for assessing the contents than the wall (κ = 0.84 and 0.59, respectively). Conclusion Increased attenuation of intestinal contents was a highly specific CT sign with good reproducibility to predict bowel necrosis in CL-SBO. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Taourel and Zins in this issue.


Asunto(s)
Contenido Digestivo , Obstrucción Intestinal , Humanos , Femenino , Persona de Mediana Edad , Masculino , Reproducibilidad de los Resultados , Estudios Retrospectivos , Obstrucción Intestinal/diagnóstico por imagen , Obstrucción Intestinal/cirugía , Necrosis/diagnóstico por imagen , Tomografía Computarizada por Rayos X
9.
Small ; : e2401532, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38699945

RESUMEN

Borocarbonitride (BCN) catalysts, boasting multiple redox sites, have shown considerable potential in alkane oxidative dehydrogenation (ODH) to olefin molecules. However, their catalytic efficiency still lags behind that of leading commercial catalysts, primarily due to the limited reactivity of oxygen functional groups. In this study, a groundbreaking hybrid catalyst is developed, featuring BCN nanotubes (BCNNTs) encapsulated with manganese (Mn) clusters, crafted through a meticulous supramolecular self-assembly and postcalcination strategy. This novel catalyst demonstrates a remarkable enhancement in activity, achieving 30% conversion and ≈100% selectivity toward styrene in ethylbenzene ODH reactions. Notably, its performance surpasses both pure BCNNTs and those hosting Mn nanoparticles. Structural and kinetic analyses unveil a robust interaction between BCNNTs and the Mn component, substantially boosting the catalytic activity of BCNNTs. Furthermore, density functional theory (DFT) calculations elucidate that BCNNTs encapsulated with Mn clusters not only stabilize key intermediates (─B─O─O─B─) but also enhance the nucleophilicity of active sites through electron transfer from the Mn cluster to the BCNNTs. This electron transfer mechanism effectively lowers the energy barrier for ─C─H cleavage, resulting in a 13% improvement in catalytic activity compared to pure BCNNTs.

10.
Small ; : e2401283, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38924314

RESUMEN

Fibrillated cellulose-based nanocomposites can improve energy efficiency of building envelopes, especially windows, but efficiently engineering them with a flexible ability of lighting and thermal management remains highly challenging. Herein, a scalable interfacial engineering strategy is developed to fabricate haze-tunable thermal barrier films tailored with phosphorylated cellulose nanofibrils (PCNFs). Clear films with an extremely low haze of 1.6% (glass-scale) are obtained by heat-assisted surface void packing without hydrophobization of nanocellulose. PCNF gel cakes serve here as templates for surface roughening, thereby resulting in a high haze (73.8%), and the roughened films can block heat transfer by increasing solar reflection in addition to a reduced thermal conduction. Additionally, obtained films can tune distribution of light from visible to near-infrared spectral range, enabling uniform colored lighting and inhibiting localized heating. Furthermore, an integrated simulation of lighting and cooling energy consumption in the case of office buildings shows that the film can reduce the total energy use by 19.2-38.1% under reduced lighting levels. Such a scalable and versatile engineering strategy provides an opportunity to endow nanocellulose-reinforced materials with tunable optical and thermal functionalities, moving their practical applications in green buildings forward.

11.
Small ; 20(11): e2305688, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37922529

RESUMEN

Developing a facile strategy for constructing oriented mixed matrix membranes (MMMs) with uniformly dispersed and high-loading metal-organic frameworks (MOFs) is a crucial scientific challenge in probing the enhanced capability and potential applications of MOF-polymer MMMs. Herein, a novel synchronous synthetic method for constructing oriented CuBDC/poly(m-phenylenediamine) (CuBDC/PmPD) MMM with uniform MOF dispersion at high loading at the air-solution interface via the dual function of metal ions is reported. The resulting MMM exhibits excellent separation performance in ion sieving and seawater desalination due to the structural integrity of the proposed membrane and the highly interconnected channels created through the oriented distribution of MOF in a polymer matrix. Such a cutting-edge approach may provide promising insights into the development of advanced MMMs with optimized structure and superior performances.

12.
Chembiochem ; : e202400370, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38923146

RESUMEN

Amino acids are not only the building blocks of proteins but also lead to the development of novel nanomaterials with unique properties. Herein, we proposed a simple strategy to produce gold nanoparticles (Au NPs) with peroxidase-like (POD-like) activities by using a series of amino acids as reducing agents, named Au NPs@M (M represents different amino acids). The Au NPs@His was identified as the nanozyme with the most potent catalytic performance, which was used in combination with smartphones to achieve rapid detection of hydrogen peroxide with a detection limit of 0.966 µM. It also enables rapid detection of glucose with a detection limit of 2.904 µM, highlighting the significant contribution of Au NPs@His in expediting the detection of critical biomolecules. This work not only provides a convenient and highly efficient method to identify glucose but also shows the potential of histidine as a reducing agent in constructing Au nanomaterials exerting enzyme-like catalysis.

13.
Chemistry ; : e202401909, 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-38972837

RESUMEN

Modulating the assembly pathway is an indispensable strategy for optimizing the performance of optical materials. However, implementing this strategy is nontrivial for metal nanocluster building blocks, due to the limited functional modification of nanoclusters and complexity of their emission mechanism. In this report, we demonstrate that a gold nanocluster modified by 4,6-diamino-2-pyrimidinethiol (DPT-AuNCs) self-assembles into two distinct aggregation structures in methanol (MeOH)/water mixed solvent, thus exhibiting pathway complexity. Kinetic studies show that DPT-AuNCs firstly assembles into non-luminescent nanofibers (kinetically controlled), which further transforms into strongly luminescent microflowers (thermodynamicallycontrolled). In-depth analysis of the assembly mechanism reveals that the transformation of aggregation structures involves the disassembly of nanofibers and a subsequent nucleation-growth process. Temperature-dependent photoluminescence (PL) spectroscopy and infrared (IR) measurements reveal that inter-cluster hydrogen bonding bridged by solvent molecules and C-H···π interaction are the key factors for emission enhancement. The photoluminescent property of DPT-AuNCs can be controlled by varying the cosolvent in water, enabling DPT-AuNCs to distinguish different kind of alcohols, particularly the isomerism n-propanol (NPA) and isopropanol (IPA). Additionally, he addition of seeds effectively regulate the assembly kinetics of DPT-AuNCs. This study advances our understanding of assembly pathways and improves the luminescent performance of nanoclusters (NCs).

14.
Anal Biochem ; 689: 115494, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38403258

RESUMEN

Invasive Aspergillosis is a high-risk illness with a high death rate in immunocompromised people due to a lack of early detection and timely treatment. Based on immunology study, we achieved an efficient production of anti-galactomannan antibody by Chinese hamster ovary (CHO) cells and applied it to time-resolved fluoroimmunoassay for Aspergillus galactomannan detection. We first introduced dual promoter expression vector into CHO host cells, and then applied a two-step screening strategy to screen the stable cell line by methionine sulfoximine pressurization. After amplification and fermentation, antibody yield reached 4500 mg/L. Then we conjugated the antibodies with fluorescent microspheres to establish a double antibody sandwich time-resolved fluoroimmunoassay, which was compared with the commercial Platelia™ Aspergillus Ag by clinical serum samples. The preformed assay could obtain the results in less than 25 min, with a limit of detection for galactomannan of approximately 1 ng/mL. Clinical results of the two methods showed that the overall percent agreement was 97.7% (95% CI: 96.6%-98.4%) and Cohen's kappa coefficient was 0.94. Overall, the assay is highly consistent with commercial detection, providing a more sensitive and effective method for the rapid diagnosis of invasive aspergillosis.


Asunto(s)
Aspergilosis , Aspergillus , Galactosa/análogos & derivados , Animales , Cricetinae , Humanos , Células CHO , Cricetulus , Aspergilosis/diagnóstico , Mananos , Fluoroinmunoensayo , Anticuerpos Monoclonales
15.
Inorg Chem ; 63(31): 14354-14365, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39056108

RESUMEN

A series of analogous chain selenite chlorides Ba2M(SeO3)2Cl2 (M = Cu 1, Ni 2, Co 3, Mn 4) and Pb2Cu(SeO3)2Cl2 5 with tunable spin S from S = 1/2 to S = 5/2 have been hydrothermally synthesized and characterized. These analogues crystallized in the orthorhombic Pnnm space group (monoclinic P21/n space group for 5) all containing M2+-SeO3-M2+ spin chains, which are further separated by the Ba2+ ions (Pb2+ for 5). The magnetic susceptibility results of 1, 2, and 5 show broad maxima around 80.0, 18.9, and 78.0 K, respectively, indicating good one-dimensional (1D) magnetism. Meanwhile, no long-range order (LRO) is observed down to 2 K for both 1 and 5, while the isostructural compounds 2, 3, and 4 exhibit LRO at 3.4 K, 10.8 K, and 5.7 K, respectively, which are further confirmed by the heat capacity and electron spin resonance results, as well as the observed spin-flop transitions in the M-H curves measured at 2 K below TN. The magnetizations of 1-5 at 7 T are still far from saturation. In addition, thermal stability and FT-IR and UV-vis-NIR spectroscopy of 1-5 are reported.

16.
Inorg Chem ; 63(21): 9511-9519, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38135507

RESUMEN

Lanthanide complexes with judiciously designed ligands have been extensively studied for their potential applications as single-molecule magnets. With the influence of ligands on their magnetic properties generally established, recent research has unearthed certain effects inherent to site differentiation due to the different types and varying numbers of substituents on the same ligand platform. Using two new sandwich-type Er(III) complexes with cyclooctatetraenyl (COT) ligands featuring two differently positioned trimethylsilyl (TMS) substituents, namely, [Li(DME)Er(COT1,5-TMS2)2]n (Er1) and [Na(DME)3][Er(COT1,3-TMS2)2] (Er2) [COT1,3-TMS2 and COT1,5-TMS2 donate 1,3- and 1,5-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; DME = 1,2-dimethoxyethane], and with reference to previously reported [Li(DME)3][Er(COT1,4-TMS2)2] (A) and [K(DME)2][Er(COT1,4-TMS2)2] (B), any possible substituent position effects have been explored for the first time. The rearrangement of the TMS substituents from the starting COT1,4-TMS2 to COT1,3-TMS2 and COT1,5-TMS2, by way of formal migration of the TMS group, was thermally induced in the case of Er1, while for the formation of Er2, the use of Na+ in the placement of its Li+ and K+ congeners is essential. Both Er1 and Er2 display single-molecule magnetic behaviors with energy barriers of 170(3) and 172(6) K, respectively. Magnetic hysteresis loops, butterfly-shaped for Er1 and wide open for Er2, were observed up to 12 K for Er1 and 13 K for Er2. Studies of magnetic dynamics reveal the different pathways for relaxation of magnetization below 10 K, mainly by the Raman process for Er1 and by quantum tunneling of magnetization for Er2, leading to the order of magnitude difference in magnetic relaxation times and sharply different magnetic hysteresis loops.

17.
Fish Shellfish Immunol ; 152: 109784, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39067495

RESUMEN

Exocyst, a protein complex, plays a crucial role in various cellular functions, including cell polarization, migration, invasion, cytokinesis, and autophagy. Sec3, known as Exoc1, is a key subunit of the Exocyst complex and can be involved in cell survival and apoptosis. In this study, two subtypes of Sec3 were isolated from Epinephelus coioides, an important marine fish in China. The role of E. coioides Sec3 was explored during Singapore grouper iridovirus (SGIV) infection, an important pathogen of marine fish which could induce 90 % mortality. E. coioides Sec3 sequences showed a high similarity with that from other species, indicating the presence of a conserved Sec3 superfamily domain. E. coioides Sec3 mRNA could be detected in all examined tissues, albeit at varying expression levels. SGIV infection could upregulate E. coioides Sec3 mRNA. Upregulated Sec3 significantly promoted SGIV-induced CPE, and the expressions of viral key genes. E. coioides Sec3 could inhibit the activation of NF-κB and AP-1, as well as SGIV-induced cell apoptosis. The results illustrated that E. coioides Sec3 promotes SGIV infection by regulating the innate immune response.


Asunto(s)
Lubina , Infecciones por Virus ADN , Enfermedades de los Peces , Proteínas de Peces , Inmunidad Innata , Filogenia , Ranavirus , Animales , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/virología , Infecciones por Virus ADN/inmunología , Infecciones por Virus ADN/veterinaria , Inmunidad Innata/genética , Lubina/inmunología , Ranavirus/fisiología , Proteínas de Peces/genética , Proteínas de Peces/inmunología , Proteínas de Peces/química , Regulación de la Expresión Génica/inmunología , Alineación de Secuencia/veterinaria , Secuencia de Aminoácidos , Perfilación de la Expresión Génica/veterinaria
18.
Fish Shellfish Immunol ; 145: 109313, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38128678

RESUMEN

The dual-specificity phosphatase (DUSP) family plays key roles in the maintenance of cellular homeostasis and apoptosis etc. In this study, the DUSP member DUSP1 of Epinephelus coioides was characterized: the length was 2371 bp including 281 bp 5' UTR, 911 bp 3' UTR, and a 1125 bp open reading frame encoding 374 amino acids. E. coioides DUSP1 has two conserved domains, a ROHD and DSPc along with a p38 MAPK phosphorylation site, localized at Ser308. E. coioides DUSP1 mRNA can be detected in all of the tissues examined, and the subcellular localization showed that DUSP1 was mainly distributed in the nucleus. Singapore grouper iridovirus (SGIV) infection could induce the differential expression of E. coioides DUSP1. Overexpression of DUSP1 could inhibit SGIV-induced cytopathic effect (CPE), the expressions of SGIV key genes, and the viral titers. Overexpression of DUSP1 could also regulate SGIV-induced apoptosis, and the expression of apoptosis-related factor caspase 3. The results would be helpful to further study the role of DUSP1 in viral infection.


Asunto(s)
Lubina , Infecciones por Virus ADN , Enfermedades de los Peces , Iridovirus , Ranavirus , Animales , Lubina/genética , Iridovirus/fisiología , Singapur , Clonación Molecular , Apoptosis , Fosfatasas de Especificidad Dual/genética , Proteínas de Peces/genética , Filogenia
19.
Bioorg Chem ; 143: 107060, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38154389

RESUMEN

Phytochemical investigation on the aerial parts of Gnetum parvifolium led to the isolation of 15 new and eight known structurally diverse stilbenes. The isolated compounds comprised (E)- or (Z)-stilbene (1-6, 15-20), dihydrostilbene (21), phenylbenzofuran (7, 8, 22), benzylated stilbene (9-11), benzylated stilbene dimer (12), and nitrogen-containing stilbene (13a, 13b, 14) types. The structures of the new compounds (1-12, 13a, 13b, 14) were established through spectroscopic analyses and experimental and calculated ECD data. Compound 12 is the first stilbene dimer connected through a benzyl group. In the anti-neuroinflammatory activity assay, compounds 4, 5, 9-11, 13b, and 16-21 displayed significant inhibitory effects against LPS-induced NO release in BV-2 microglial cells, with IC50 values of 0.35-16.1 µM. Compound 10 had the most potent activity (IC50 = 0.35 µM), and the further research indicated that it could decrease the mRNA levels of iNOS, IL-1ß, IL-6, and TNF-α in a dose-dependent manner.


Asunto(s)
Gnetum , Estilbenos , Estructura Molecular , Gnetum/química , Estilbenos/farmacología , Estilbenos/química
20.
Lipids Health Dis ; 23(1): 231, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39080710

RESUMEN

BACKGROUND: Diabetes mellitus is generally accompanied by dyslipidaemia, but inconsistent relationships between lipid profiles and diabetes are noted. Moreover, genetic variations in insertion/deletion (I/D) polymorphisms at angiotensin-converting enzyme gene (ACE) and T/C polymorphisms in the angiotensin type 1 receptor gene (AGTR1) are related to diabetes and lipid levels, but the associations are controversial. Thus, the current research aimed to explore the effects of ACE I/D, AGTR1 rs5182 and diabetes mellitus on serum lipid profiles in 385 Chinese participants with an average age of 75.01 years. METHODS: The ACE I/D variant was identified using the polymerase chain reaction (PCR) method, whereas the AGTR1 rs5182 polymorphism was identified using the PCR-based restriction fragment length polymorphism (PCR-RFLP) method and verified with DNA sequencing. Total cholesterol (TC), triglyceride (TG), apolipoprotein A (ApoA), apolipoprotein B (ApoB), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were measured using routine methods, and the lipid ratios were calculated. RESULTS: ACE I/D, but not AGTR1 rs5182, was a predictor of TG/HDL-C for the whole study population. Both ACE I/D and AGTR1 rs5182 were predictors of HDL-C and LDL-C levels in females but not in males. Moreover, in females, diabetes mellitus and ACE I/D were identified as predictors of TG and TG/HDL-C, whereas AGTR1 rs5182 and diabetes mellitus were predictors of TG/HDL-C. Moreover, diabetes mellitus and the combination of ACE I/D and AGTR1 rs5182 variations were predictors of TG and TG/HDL-C exclusively in females. CONCLUSIONS: The results demonstrated the potential for gender-dependent interactions of ACE I/D, AGTR1 rs5182, and diabetes on lipid profiles. These findings may serve as an additional explanation for the inconsistent changes of blood lipids in individuals with diabetes mellitus, thereby offering a novel perspective for the clinical management of blood lipid levels in diabetic patients.


Asunto(s)
Peptidil-Dipeptidasa A , Receptor de Angiotensina Tipo 1 , Humanos , Masculino , Femenino , Anciano , Receptor de Angiotensina Tipo 1/genética , Peptidil-Dipeptidasa A/genética , Peptidil-Dipeptidasa A/sangre , Polimorfismo de Nucleótido Simple , Lípidos/sangre , Lípidos/genética , Pueblo Asiatico/genética , Triglicéridos/sangre , Anciano de 80 o más Años , HDL-Colesterol/sangre , HDL-Colesterol/genética , Diabetes Mellitus/genética , Diabetes Mellitus/sangre , Mutación INDEL , LDL-Colesterol/sangre , LDL-Colesterol/genética , Estudios de Asociación Genética , China/epidemiología , Predisposición Genética a la Enfermedad , Pueblos del Este de Asia
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