Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 811
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Cell ; 186(21): 4662-4675.e12, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37734372

RESUMEN

Bats, rodents, and shrews are the most important animal sources of human infectious diseases. However, the evolution and transmission of viruses among them remain largely unexplored. Through the meta-transcriptomic sequencing of internal organ and fecal samples from 2,443 wild bats, rodents, and shrews sampled from four Chinese habitats, we identified 669 viruses, including 534 novel viruses, thereby greatly expanding the mammalian virome. Our analysis revealed high levels of phylogenetic diversity, identified cross-species virus transmission events, elucidated virus origins, and identified cases of invertebrate viruses in mammalian hosts. Host order and sample size were the most important factors impacting virome composition and patterns of virus spillover. Shrews harbored a high richness of viruses, including many invertebrate-associated viruses with multi-organ distributions, whereas rodents carried viruses with a greater capacity for host jumping. These data highlight the remarkable diversity of mammalian viruses in local habitats and their ability to emerge in new hosts.

2.
Cell ; 182(1): 226-244.e17, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32649875

RESUMEN

Lung cancer in East Asia is characterized by a high percentage of never-smokers, early onset and predominant EGFR mutations. To illuminate the molecular phenotype of this demographically distinct disease, we performed a deep comprehensive proteogenomic study on a prospectively collected cohort in Taiwan, representing early stage, predominantly female, non-smoking lung adenocarcinoma. Integrated genomic, proteomic, and phosphoproteomic analysis delineated the demographically distinct molecular attributes and hallmarks of tumor progression. Mutational signature analysis revealed age- and gender-related mutagenesis mechanisms, characterized by high prevalence of APOBEC mutational signature in younger females and over-representation of environmental carcinogen-like mutational signatures in older females. A proteomics-informed classification distinguished the clinical characteristics of early stage patients with EGFR mutations. Furthermore, integrated protein network analysis revealed the cellular remodeling underpinning clinical trajectories and nominated candidate biomarkers for patient stratification and therapeutic intervention. This multi-omic molecular architecture may help develop strategies for management of early stage never-smoker lung adenocarcinoma.


Asunto(s)
Progresión de la Enfermedad , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Proteogenómica , Fumar/genética , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/patología , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinógenos/toxicidad , Estudios de Cohortes , Citosina Desaminasa/metabolismo , Asia Oriental , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Genoma Humano , Humanos , Metaloproteinasas de la Matriz/metabolismo , Mutación/genética , Análisis de Componente Principal
3.
Nature ; 631(8020): 459-466, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38776963

RESUMEN

Bitter taste receptors, particularly TAS2R14, play central roles in discerning a wide array of bitter substances, ranging from dietary components to pharmaceutical agents1,2. TAS2R14 is also widely expressed in extragustatory tissues, suggesting its extra roles in diverse physiological processes and potential therapeutic applications3. Here we present cryogenic electron microscopy structures of TAS2R14 in complex with aristolochic acid, flufenamic acid and compound 28.1, coupling with different G-protein subtypes. Uniquely, a cholesterol molecule is observed occupying what is typically an orthosteric site in class A G-protein-coupled receptors. The three potent agonists bind, individually, to the intracellular pockets, suggesting a distinct activation mechanism for this receptor. Comprehensive structural analysis, combined with mutagenesis and molecular dynamic simulation studies, elucidate the broad-spectrum ligand recognition and activation of the receptor by means of intricate multiple ligand-binding sites. Our study also uncovers the specific coupling modes of TAS2R14 with gustducin and Gi1 proteins. These findings should be instrumental in advancing knowledge of bitter taste perception and its broader implications in sensory biology and drug discovery.


Asunto(s)
Ácidos Aristolóquicos , Colesterol , Ácido Flufenámico , Receptores Acoplados a Proteínas G , Gusto , Humanos , Ácidos Aristolóquicos/metabolismo , Ácidos Aristolóquicos/química , Ácidos Aristolóquicos/farmacología , Sitios de Unión/efectos de los fármacos , Colesterol/química , Colesterol/metabolismo , Colesterol/farmacología , Microscopía por Crioelectrón , Ácido Flufenámico/química , Ácido Flufenámico/metabolismo , Ácido Flufenámico/farmacología , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/química , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Ligandos , Modelos Moleculares , Simulación de Dinámica Molecular , Mutación , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/ultraestructura , Gusto/efectos de los fármacos , Gusto/fisiología , Transducina/química , Transducina/metabolismo
4.
Nature ; 580(7803): E7, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32296181

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

5.
Nature ; 579(7798): 265-269, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32015508

RESUMEN

Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health1-3. Despite intense research efforts, how, when and where new diseases appear are still a source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to the Central Hospital of Wuhan on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing4 of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here 'WH-Human 1' coronavirus (and has also been referred to as '2019-nCoV'). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China5. This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans.


Asunto(s)
Betacoronavirus/clasificación , Enfermedades Transmisibles Emergentes/complicaciones , Enfermedades Transmisibles Emergentes/virología , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/virología , Neumonía Viral/complicaciones , Neumonía Viral/virología , Síndrome Respiratorio Agudo Grave/etiología , Síndrome Respiratorio Agudo Grave/virología , Adulto , Betacoronavirus/genética , COVID-19 , China , Enfermedades Transmisibles Emergentes/diagnóstico por imagen , Enfermedades Transmisibles Emergentes/patología , Infecciones por Coronavirus/diagnóstico por imagen , Infecciones por Coronavirus/patología , Genoma Viral/genética , Humanos , Pulmón/diagnóstico por imagen , Masculino , Filogenia , Neumonía Viral/diagnóstico por imagen , Neumonía Viral/patología , ARN Viral/genética , Recombinación Genética/genética , SARS-CoV-2 , Síndrome Respiratorio Agudo Grave/diagnóstico por imagen , Síndrome Respiratorio Agudo Grave/patología , Tomografía Computarizada por Rayos X , Secuenciación Completa del Genoma
6.
EMBO Rep ; 24(3): e55286, 2023 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-36652307

RESUMEN

An increasing amount of evidence emphasizes the role of metabolic reprogramming in immune cells to fight infections. However, little is known about the regulation of metabolite transporters that facilitate and support metabolic demands. In this study, we found that the expression of equilibrative nucleoside transporter 3 (ENT3, encoded by solute carrier family 29 member 3, Slc29a3) is part of the innate immune response, which is rapidly upregulated upon pathogen invasion. The transcription of Slc29a3 is directly regulated by type I interferon-induced signaling, demonstrating that this metabolite transporter is an interferon-stimulated gene (ISG). Suprisingly, we unveil that several viruses, including SARS-CoV-2, require ENT3 to facilitate their entry into the cytoplasm. The removal or suppression of Slc29a3 expression is sufficient to significantly decrease viral replication in vitro and in vivo. Our study reveals that ENT3 is a pro-viral ISG co-opted by some viruses to gain a survival advantage.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Interferones/metabolismo , Proteínas de Transporte de Membrana/genética , Inmunidad Innata , Genoma Viral , Proteínas de Transporte de Nucleósidos/genética , Proteínas de Transporte de Nucleósidos/metabolismo
7.
Mol Biol Evol ; 40(8)2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37494294

RESUMEN

The roles of DNA methylation in invertebrates are poorly characterized, and critical data are missing for the phylum Annelida. We fill this knowledge gap by conducting the first genome-wide survey of DNA methylation in the deep-sea polychaetes dominant in deep-sea vents and seeps: Paraescarpia echinospica, Ridgeia piscesae, and Paralvinella palmiformis. DNA methylation calls were inferred from Oxford Nanopore sequencing after assembling high-quality genomes of these animals. The genomes of these worms encode all the key enzymes of the DNA methylation metabolism and possess a mosaic methylome similar to that of other invertebrates. Transcriptomic data of these polychaetes support the hypotheses that gene body methylation strengthens the expression of housekeeping genes and that promoter methylation acts as a silencing mechanism but not the hypothesis that DNA methylation suppresses the activity of transposable elements. The conserved epigenetic profiles of genes responsible for maintaining homeostasis under extreme hydrostatic pressure suggest DNA methylation plays an important adaptive role in these worms.


Asunto(s)
Anélidos , Poliquetos , Animales , Epigenoma , Poliquetos/genética , Poliquetos/metabolismo , Perfilación de la Expresión Génica , Genoma , Metilación de ADN
8.
Mol Ecol ; 33(1): e17200, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37985390

RESUMEN

Information on genetic divergence and migration patterns of vent- and seep-endemic macrobenthos can help delimit biogeographical provinces and provide scientific guidelines for deep-sea conservation under the growing threats of anthropogenic disturbances. Nevertheless, related studies are still scarce, impeding the informed conservation of these hotspots of deep-sea biodiversity. To bridge this knowledge gap, we conducted a population connectivity study on the galatheoid squat lobster Shinkaia crosnieri - a deep-sea foundation species widely distributed in vent and seep ecosystems in the Northwest Pacific. With the application of an interdisciplinary methodology involving population genomics and oceanographic approaches, we unveiled two semi-isolated lineages of S. crosnieri with limited and asymmetrical gene flow potentially shaped by the geographic settings, habitat types, and ocean currents - one comprising vent populations in the Okinawa Trough, with those inhabiting the southern trough area likely serving as the source; the other being the Jiaolong (JR) seep population in the South China Sea. The latter might have recently experienced a pronounced demographic contraction and exhibited genetic introgression from the Okinawa Trough lineage, potentially mediated by the intrusion of the North Pacific Intermediate Water. We then compared the biogeographic patterns between S. crosnieri and two other representative and co-occurring vent- and seep-endemic species using published data. Based on their biogeographical subdivisions and source-sink dynamics, we highlighted the southern Okinawa Trough vents and the JR seep warrant imperative conservation efforts to sustain the deep-sea biodiversity in the Northwest Pacific.


Asunto(s)
Ecosistema , Respiraderos Hidrotermales , Filogenia , Biodiversidad , Flujo Genético , China
9.
BMC Cancer ; 24(1): 967, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39112947

RESUMEN

BACKGROUND: This study aimed to evaluate the effectiveness and safety of recombinant human endostatin (Rh-endostatin) plus programmed cell death 1 (PD-1) inhibitors and chemotherapy as first-line treatment for advanced or metastatic non-small cell lung cancer (NSCLC) in a real-world setting. METHODS: This was a retrospective study on patients with EGFR/ALK-negative, advanced or metastatic NSCLC. Patients received Rh-endostatin plus PD-1 inhibitors and chemotherapy every three weeks for 4 to 6 cycles. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. RESULTS: A total of 68 patients were included in this retrospective analysis. As of data cutoff (December 13, 2022), the median follow-up of 21.4 months (interquartile range [IQR], 8.3-44.4 months). The median PFS and OS was 22.0 (95% confidence interval [CI]: 16.6-27.4) and 31.0 months (95% CI: 23.4-not evaluable [NE]), respectively. The ORR was 72.06% (95% CI: 59.85-82.27%), and DCR was 95.59% (95% CI: 87.64-99.08%). Patients with stage IIIB/IIIC NSCLC had significantly longer median PFS (23.4 vs. 13.2 months), longer median OS (not reached vs. 18.0 months), and higher ORR (89.2% vs. 51.6%) than those with stage IV NSCLC (all p ≤ 0.001). The ORR was higher in patients with high PD-L1 expression (tumor proportion score [TPS] ≥ 50%) than in those with low PD-L1 expression or positive PD-L1 expression (75% vs. 50%, p = 0.025). All patients experienced treatment-related adverse events (TRAEs), and ≥ grade 3 TRAEs occurred in 16 (23.53%) patients. CONCLUSIONS: Rh-endostatin combined with PD-1 inhibitors plus chemotherapy as first-line treatment yielded favorable effectiveness with a manageable profile in patients with advanced or metastatic NSCLC, representing a promising treatment modality.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma de Pulmón de Células no Pequeñas , Endostatinas , Neoplasias Pulmonares , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Endostatinas/administración & dosificación , Endostatinas/efectos adversos , Endostatinas/uso terapéutico , Receptores ErbB/antagonistas & inhibidores , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/metabolismo , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Supervivencia sin Progresión , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Estudios Retrospectivos , Resultado del Tratamiento
10.
Brain Behav Immun ; 120: 413-429, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38925413

RESUMEN

Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by involuntary movements, cognitive deficits, and psychiatric symptoms. Currently, there is no cure, and only limited treatments are available to manage the symptoms and to slow down the disease's progression. The molecular and cellular mechanisms of HD's pathogenesis are complex, involving immune cell activation, altered protein turnover, and disturbance in brain energy homeostasis. Microglia have been known to play a dual role in HD, contributing to neurodegeneration through inflammation but also enacting neuroprotective effects by clearing mHTT aggregates. However, little is known about the contribution of microglial metabolism to HD progression. This study explores the impact of a microglial metabolite transporter, equilibrative nucleoside transporter 3 (ENT3), in HD. Known as a lysosomal membrane transporter protein, ENT3 is highly enriched in microglia, with its expression correlated with HD severity. Using the R6/2 ENT3-/- mouse model, we found that the deletion of ENT3 increases microglia numbers yet worsens HD progression, leading to mHTT accumulation, cell death, and disturbed energy metabolism. These results suggest that the delicate balance between microglial metabolism and function is crucial for maintaining brain homeostasis and that ENT3 has a protective role in ameliorating neurodegenerative processes.


Asunto(s)
Modelos Animales de Enfermedad , Progresión de la Enfermedad , Enfermedad de Huntington , Microglía , Proteínas de Transporte de Nucleósidos , Animales , Humanos , Masculino , Ratones , Encéfalo/metabolismo , Proteína Huntingtina/metabolismo , Proteína Huntingtina/genética , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Microglía/metabolismo , Proteínas de Transporte de Nucleósidos/metabolismo , Proteínas de Transporte de Nucleósidos/genética
11.
Epilepsy Behav ; 153: 109668, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38394791

RESUMEN

BACKGROUND: Driving is an important part of the daily life for most adults, and restrictions on driving can significantly affect the quality of life for people with epilepsy. This study aimed to investigate the current driving status of patients at an epilepsy clinic in China. METHOD: Study participants were administered a survey by a questionnaire including the demographic and clinical characteristics of seizure, driving-related questions and attitudes to driving. RESULTS: A total of 101 patients responded the survey. Among 33(32.7%) who hold the driving license, 20 (60.6%) still drive, 3 had seizures while driving, and the rate of traffic accidents was 0. There was no significant difference in seizure frequency and type of medication between patients with and without the driving license, but compliance with medication was significantly better for those who held the driving license. CONCLUSIONS: One-third of people with epilepsy hold the driving license and good drug compliance is a favorable factor for driving. Standardizing different levels of restriction on driving for people with epilepsy is urgently needed.


Asunto(s)
Conducción de Automóvil , Epilepsia , Adulto , Humanos , Calidad de Vida , Epilepsia/complicaciones , Epilepsia/epidemiología , Epilepsia/tratamiento farmacológico , Convulsiones , Accidentes de Tránsito , China/epidemiología , Encuestas y Cuestionarios
12.
J Nat Prod ; 87(4): 876-883, 2024 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-38377956

RESUMEN

Cytochrome P450-modified bacterial terpenoids remain in a vast chemical space to be explored. In the present study, we conducted global genome mining of 223,829 bacterial genomes and identified 2892 bacterial terpenoid biosynthetic gene clusters (BGCs) with cytochrome P450 genes. Among these, we selected 562 with multiple P450 enzymes, which were further clustered as 355 gene cluster families by sequence similarity analysis. We then chose lev, a BGC from Streptomyces levis MCCC1A01616, for heterologous expression and discovered four new α-amorphene-type sesquiterpenoids, levinoids A-D (1-4). The structures and absolute configurations of these four new compounds were determined by employing extensive NMR analysis, NMR chemical shift calculations with DP4+, and ECD calculations. Furthermore, levinoid C (3) exhibited a moderate level of neuroprotective activity (EC50 = 21 µM) in the glutamate-induced excitotoxicity cell model. Our findings highlight the untapped chemical diversity of P450-modified bacterial terpenoids, opening new avenues for further exploration and discovery.


Asunto(s)
Sistema Enzimático del Citocromo P-450 , Sesquiterpenos , Streptomyces , Sesquiterpenos/química , Sesquiterpenos/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Streptomyces/química , Streptomyces/genética , Estructura Molecular , Genoma Bacteriano , Familia de Multigenes , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/química
13.
Surg Endosc ; 38(2): 640-647, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38012439

RESUMEN

BACKGROUND: Lymph node status is an important factor in determining preoperative treatment strategies for stage T1b-T2 esophageal cancer (EC). Thus, the aim of this study was to investigate the risk factors for lymph node metastasis (LNM) in T1b-T2 EC and to establish and validate a risk-scoring model to guide the selection of optimal treatment options. METHODS: Patients who underwent upfront surgery for pT1b-T2 EC between January 2016 and December 2022 were analyzed. On the basis of the independent risk factors determined by multivariate logistic regression analysis, a risk-scoring model for the prediction of LNM was constructed and then validated. The area under the receiver operating characteristic curve (AUC) was used to assess the discriminant ability of the model. RESULTS: The incidence of LNM was 33.5% (214/638) in our cohort, 33.4% (169/506) in the primary cohort and 34.1% (45/132) in the validation cohort. Multivariate analysis confirmed that primary site, tumor grade, tumor size, depth, and lymphovascular invasion were independent risk factors for LNM (all P < 0.05), and patients were grouped based on these factors. A 7-point risk-scoring model based on these variables had good predictive accuracy in both the primary cohort (AUC, 0.749; 95% confidence interval 0.709-0.786) and the validation cohort (AUC, 0.738; 95% confidence interval 0.655-0.811). CONCLUSION: A novel risk-scoring model for lymph node metastasis was established to guide the optimal treatment of patients with T1b-T2 EC.


Asunto(s)
Neoplasias Esofágicas , Humanos , Metástasis Linfática/patología , Estudios Retrospectivos , Factores de Riesgo , Neoplasias Esofágicas/cirugía , Neoplasias Esofágicas/patología , Escisión del Ganglio Linfático , Ganglios Linfáticos/cirugía , Ganglios Linfáticos/patología
14.
Eur Arch Otorhinolaryngol ; 281(5): 2645-2653, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38498191

RESUMEN

PURPOSE: Locally-advanced oropharynx (LA-OPSCC) and hypopharynx/larynx (LA-HPLSCC) cancers may be treated with surgical or non-surgical modalities. While survival outcomes are comparable, patterns of disease recurrence are not well established. METHODS: Retrospective review of 98 consecutive patients with LA-OPSCC or LA-HPLSCC treated by either surgery plus adjuvant therapy (S-POAT, n = 48) or chemoradiation (CRT, n = 50). RESULTS: CRT-treated patients had higher recurrence risk (42% vs 14.6%, p = 0.003). This was significant only among LA-OPSCC (p = 0.002) but not LA-HPLSCC patients (p = 0.159). Median time to recurrence in LA-OPSCC was 16.8 vs 11.6 months, and 16.6 vs 15.1 months in LA-HPLSCC, comparing surgically treated and CRT cohorts. Surgically-treated p16-negative LA-OPSCC experienced improved locoregional control than CRT-treated patients (100% vs 12.5%, p = 0.045) and 3-year RFS (83.0% vs 33.3%, p < 0.001). CONCLUSION: Locoregional control and RFS benefit was observed in surgically treated p16 negative LA-OPSCC patients. Locoregional recurrence is the main reason of treatment failure in LA-HNSCC, occurring commonly within the first 2 years post-treatment, regardless of treatment option.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias Orofaríngeas , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Recurrencia Local de Neoplasia/terapia , Quimioradioterapia , Neoplasias de Cabeza y Cuello/terapia , Estudios Retrospectivos , Neoplasias Orofaríngeas/cirugía
15.
Angew Chem Int Ed Engl ; : e202414295, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39216012

RESUMEN

A concise synthetic strategy utilizing a Zr-catalyst for the construction of cyctetryptomycin A and B is herein reported. Cyctetryptomycin A and B are recently isolated, complex tetrameric natural products for which total synthesis has not been previously reported. This study presents a practical approach for the construction of two consecutive quaternary carbon centers via a Zr-catalyst. Furthermore, the first total synthesis of cyctetryptomycin A and B was achieved by this Zr-catalyzed radical coupling. The radical dimerization reaction mediated by the Zr-catalyst required dppe as an indispensable additive. Through both experimental and theoretical investigations into the mechanism of this Zr-catalyzed reaction, the specific role of dppe was elucidated. In addition, the synthetic approach was extended to enable the practical synthesis of other dimeric natural products, including tetratryptomycin A, dibrevianamide F, and ditryptophenaline. Finally, the synthetic mechanism of cyctetryptomycin A and B, through the oxidative macrocyclization of tetratryptomycin A by CttpC, was newly elucidated by both experimental and docking simulations.

16.
Biochem Biophys Res Commun ; 671: 327-334, 2023 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-37327704

RESUMEN

The serotonin receptor 5-HT6R is an important G-protein-coupled receptor (GPCR) that involved in essential functions within the central and peripheral nervous systems and is linked to various psychiatric disorders. Selective activation of 5-HT6R promotes neural stem cell regeneration activity. As a 5-HT6R selective agonist, 2-(5 chloro-2-methyl-1H-indol-3-yl)-N, N-dimethylethanolamine (ST1936) has been widely used to investigate the functions of the 5-HT6R. The molecular mechanism of how ST1936 is recognized by 5-HT6R and how it effectively couples with Gs remain unclear. Here, we reconstituted the ST1936-5-HT6R-Gs complex in vitro and solved its cryo-electron microscopy structure at 3.1 Å resolution. Further structural analysis and mutational studies facilitated us to identify the residues of the Y3107.43 and "toggle switch" W2816.48 of the 5-HT6R contributed to the higher efficacy of ST1936 compared with 5-HT. By uncovering the structural foundation of how 5-HT6R specifically recognizes agonists and elucidating the molecular process of G protein activation, our discoveries offer valuable insights and pave the way for the development of promising 5-HT6R agonists.


Asunto(s)
Receptores de Serotonina , Serotonina , Humanos , Microscopía por Crioelectrón , Receptores de Serotonina/metabolismo , Indoles
17.
Mol Ecol ; 32(18): 5071-5088, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37584177

RESUMEN

Acquisition of new genes often results in the emergence of novel functions and is a key step in lineage-specific adaptation. As a group of sessile crustaceans, barnacles establish permanent attachment through initial cement secretion at the larval phase followed by continuous cement secretion in juveniles and adults. However, the origins and evolution of barnacle larval and adult cement proteins remain poorly understood. By performing microdissection of larval cement glands, transcriptome and shotgun proteomics and immunohistochemistry validation, we identified 30 larval and 27 adult cement proteins of the epibiotic turtle barnacle Chelonibia testudinaria, of which the majority are stage- and barnacle-specific. While only two proteins, SIPC and CP100K, were expressed in both larvae and adults, detection of protease inhibitors and the cross-linking enzyme lysyl oxidase paralogs in larvae and adult cement. Other barnacle-specific cement proteins such as CP100k and CP52k likely share a common origin dating back at least to the divergence of Rhizocephala and Thoracica. Different CP52k paralogues could be detected in larval and adult cement, suggesting stage-specific cement proteins may arise from duplication followed by changes in expression timing of the duplicates. Interestingly, the biochemical properties of larval- and adult-specific CP52k paralogues exhibited remarkable differences. We conclude that barnacle larval and adult cement systems evolved independently, and both emerged from co-option of existing genes and de novo formation, duplication and functional divergence of lineage-specific cement protein genes. Our findings provide important insights into the evolutionary mechanisms of bioadhesives in sessile marine invertebrates.


Asunto(s)
Thoracica , Animales , Thoracica/genética , Thoracica/metabolismo , Proteínas/genética , Larva/genética , Larva/metabolismo , Transcriptoma/genética
18.
Mol Ecol ; 32(24): 6796-6808, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37888909

RESUMEN

The dissolution of anthropogenic carbon dioxide (CO2 ) in seawater has altered its carbonate chemistry in the process of ocean acidification (OA). OA affects the viability of marine species. In particular, calcifying organisms and their early planktonic larval stages are considered vulnerable. These organisms often utilize energy reserves for metabolism rather than growth and calcification as supported by bulk RNA-sequencing (RNA-seq) experiments. Yet, transcriptomic profiling of a bulk sample reflects the average gene expression of the population, neglecting the variations between individuals, which forms the basis for natural selection. Here, we used single-embryo RNA-seq on larval sea urchin Heliocidaris crassispina, which is a commercially and ecologically valuable species in East Asia, to document gene expression changes to OA at an individual and family level. Three paternal half-sibs groups were fertilized and exposed to 3 pH conditions (ambient pH 8.0, 7.7 and 7.4) for 12 h prior to sequencing and oxygen consumption assay. The resulting transcriptomic profile of all embryos can be distinguished into four clusters, with differences in gene expressions that govern biomineralization, cell differentiation and patterning, as well as metabolism. While these responses were influenced by pH conditions, the male identities also had an effect. Specifically, a regression model and goodness of fit tests indicated a significant interaction between sire and pH on the probability of embryo membership in different clusters of gene expression. The single-embryo RNA-seq approach is promising in climate stressor research because not only does it highlight potential impacts before phenotypic changes were observed, but it also highlights variations between individuals and lineages, thus enabling a better determination of evolutionary potential.


Asunto(s)
Erizos de Mar , Agua de Mar , Humanos , Animales , Masculino , Agua de Mar/química , Concentración de Iones de Hidrógeno , Erizos de Mar/genética , Perfilación de la Expresión Génica , Larva/fisiología , Transcriptoma/genética , Dióxido de Carbono/química , Océanos y Mares
19.
Mol Ecol ; 32(5): 1098-1116, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36528869

RESUMEN

Thermal priming of reef corals can enhance their heat tolerance; however, the legacy effects of heat stress during parental brooding on larval resilience remain understudied. This study investigated whether preconditioning adult coral Pocillopora damicornis to high temperatures (29°C and 32°C) could better prepare their larvae for heat stress. Results showed that heat-acclimated adults brooded larvae with reduced symbiont density and shifted thermal performance curves. Reciprocal transplant experiments demonstrated higher bleaching resistance and better photosynthetic and autotrophic performance in heat-exposed larvae from acclimated adults compared to unacclimated adults. RNA-seq revealed strong cellular stress responses in larvae from heat-acclimated adults that could have been effective in rescuing host cells from stress, as evidenced by the widespread upregulation of genes involved in cell cycle and mitosis. For symbionts, a molecular coordination between light harvesting, photoprotection and carbon fixation was detected in larvae from heat-acclimated adults, which may help optimize photosynthetic activity and yield under high temperature. Furthermore, heat acclimation led to opposing regulations of symbiont catabolic and anabolic pathways and favoured nutrient translocation to the host and thus a functional symbiosis. Notwithstanding, the improved heat tolerance was paralleled by reduced light-enhanced dark respiration, indicating metabolic depression for energy saving. Our findings suggest that adult heat acclimation can rapidly shift thermal tolerance of brooded coral larvae and provide integrated physiological and molecular evidence for this adaptive plasticity, which could increase climate resilience. However, the metabolic depression may be maladaptive for long-term organismal performance, highlighting the importance of curbing carbon emissions to better protect corals.


Asunto(s)
Antozoos , Termotolerancia , Animales , Antozoos/genética , Arrecifes de Coral , Larva , Termotolerancia/genética , Aclimatación , Simbiosis
20.
Opt Express ; 31(4): 6156-6169, 2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36823879

RESUMEN

Exceptional points (EPs) of non-Hermitian systems are gaining more and more attention due to their important applications in unidirectional transmitters, sensors, etc. However, theoretical studies on EPs of reflection, transmission, and absorption spectra are less available. In this paper, in the dark-bright mode-coupled plasmonic systems, the variations of EPs of reflection, transmission, and absorption spectra are numerically investigated using temporal coupled-mode theory, and an assumption is given using the representation transformation theory. The intermediate representation (IR) is firstly proposed and related to the reflection spectrum, while the normal representation (NR) is associated with the absorption spectrum. In the region far from EPs, the IR (or NR) describes the reflection (or absorption) spectrum well. Near EPs, modified formulas similar to the representation transformation theory are given. In order to verify the correctness of the assumption, two metasurfaces are designed. And the simulation results are in good agreement with the assumption and it is found in the near-infrared and visible-light band that the absorption loss of the dark mode is linearly related to the EPs of reflection, transmission, and absorption spectra, while the radiation loss of the bright mode is only linearly related to the EPs of the absorption spectrum. These laws can help to manipulate the splitting of spectral lines for reflection, transmission, and absorption by adjusting the radiation loss and absorption loss of bright mode, the absorption loss of dark mode, and the coupling coefficients between two resonant modes. This research provides a guiding scheme for the design of micro and nano photonics devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA