Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.283
Filtrar
1.
Cell ; 186(18): 3921-3944.e25, 2023 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-37582357

RESUMEN

Cancer driver events refer to key genetic aberrations that drive oncogenesis; however, their exact molecular mechanisms remain insufficiently understood. Here, our multi-omics pan-cancer analysis uncovers insights into the impacts of cancer drivers by identifying their significant cis-effects and distal trans-effects quantified at the RNA, protein, and phosphoprotein levels. Salient observations include the association of point mutations and copy-number alterations with the rewiring of protein interaction networks, and notably, most cancer genes converge toward similar molecular states denoted by sequence-based kinase activity profiles. A correlation between predicted neoantigen burden and measured T cell infiltration suggests potential vulnerabilities for immunotherapies. Patterns of cancer hallmarks vary by polygenic protein abundance ranging from uniform to heterogeneous. Overall, our work demonstrates the value of comprehensive proteogenomics in understanding the functional states of oncogenic drivers and their links to cancer development, surpassing the limitations of studying individual cancer types.


Asunto(s)
Neoplasias , Proteogenómica , Humanos , Neoplasias/genética , Oncogenes , Transformación Celular Neoplásica/genética , Variaciones en el Número de Copia de ADN
2.
Cell ; 182(1): 200-225.e35, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32649874

RESUMEN

To explore the biology of lung adenocarcinoma (LUAD) and identify new therapeutic opportunities, we performed comprehensive proteogenomic characterization of 110 tumors and 101 matched normal adjacent tissues (NATs) incorporating genomics, epigenomics, deep-scale proteomics, phosphoproteomics, and acetylproteomics. Multi-omics clustering revealed four subgroups defined by key driver mutations, country, and gender. Proteomic and phosphoproteomic data illuminated biology downstream of copy number aberrations, somatic mutations, and fusions and identified therapeutic vulnerabilities associated with driver events involving KRAS, EGFR, and ALK. Immune subtyping revealed a complex landscape, reinforced the association of STK11 with immune-cold behavior, and underscored a potential immunosuppressive role of neutrophil degranulation. Smoking-associated LUADs showed correlation with other environmental exposure signatures and a field effect in NATs. Matched NATs allowed identification of differentially expressed proteins with potential diagnostic and therapeutic utility. This proteogenomics dataset represents a unique public resource for researchers and clinicians seeking to better understand and treat lung adenocarcinomas.


Asunto(s)
Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Proteogenómica , Adenocarcinoma del Pulmón/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Carcinogénesis/genética , Carcinogénesis/patología , Variaciones en el Número de Copia de ADN/genética , Metilación de ADN/genética , Femenino , Humanos , Neoplasias Pulmonares/inmunología , Masculino , Persona de Mediana Edad , Mutación/genética , Proteínas de Fusión Oncogénica , Fenotipo , Fosfoproteínas/metabolismo , Proteoma/metabolismo
3.
Cell ; 173(2): 321-337.e10, 2018 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-29625050

RESUMEN

Genetic alterations in signaling pathways that control cell-cycle progression, apoptosis, and cell growth are common hallmarks of cancer, but the extent, mechanisms, and co-occurrence of alterations in these pathways differ between individual tumors and tumor types. Using mutations, copy-number changes, mRNA expression, gene fusions and DNA methylation in 9,125 tumors profiled by The Cancer Genome Atlas (TCGA), we analyzed the mechanisms and patterns of somatic alterations in ten canonical pathways: cell cycle, Hippo, Myc, Notch, Nrf2, PI-3-Kinase/Akt, RTK-RAS, TGFß signaling, p53 and ß-catenin/Wnt. We charted the detailed landscape of pathway alterations in 33 cancer types, stratified into 64 subtypes, and identified patterns of co-occurrence and mutual exclusivity. Eighty-nine percent of tumors had at least one driver alteration in these pathways, and 57% percent of tumors had at least one alteration potentially targetable by currently available drugs. Thirty percent of tumors had multiple targetable alterations, indicating opportunities for combination therapy.


Asunto(s)
Bases de Datos Genéticas , Neoplasias/patología , Transducción de Señal/genética , Genes Relacionados con las Neoplasias , Humanos , Neoplasias/genética , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Wnt/genética , Proteínas Wnt/metabolismo
4.
Cell ; 173(2): 371-385.e18, 2018 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-29625053

RESUMEN

Identifying molecular cancer drivers is critical for precision oncology. Multiple advanced algorithms to identify drivers now exist, but systematic attempts to combine and optimize them on large datasets are few. We report a PanCancer and PanSoftware analysis spanning 9,423 tumor exomes (comprising all 33 of The Cancer Genome Atlas projects) and using 26 computational tools to catalog driver genes and mutations. We identify 299 driver genes with implications regarding their anatomical sites and cancer/cell types. Sequence- and structure-based analyses identified >3,400 putative missense driver mutations supported by multiple lines of evidence. Experimental validation confirmed 60%-85% of predicted mutations as likely drivers. We found that >300 MSI tumors are associated with high PD-1/PD-L1, and 57% of tumors analyzed harbor putative clinically actionable events. Our study represents the most comprehensive discovery of cancer genes and mutations to date and will serve as a blueprint for future biological and clinical endeavors.


Asunto(s)
Neoplasias/patología , Algoritmos , Antígeno B7-H1/genética , Biología Computacional , Bases de Datos Genéticas , Entropía , Humanos , Inestabilidad de Microsatélites , Mutación , Neoplasias/genética , Neoplasias/inmunología , Análisis de Componente Principal , Receptor de Muerte Celular Programada 1/genética
5.
Annu Rev Neurosci ; 47(1): 41-61, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38382543

RESUMEN

To perform computations with the efficiency necessary for animal survival, neocortical microcircuits must be capable of reconfiguring in response to experience, while carefully regulating excitatory and inhibitory connectivity to maintain stable function. This dynamic fine-tuning is accomplished through a rich array of cellular homeostatic plasticity mechanisms that stabilize important cellular and network features such as firing rates, information flow, and sensory tuning properties. Further, these functional network properties can be stabilized by different forms of homeostatic plasticity, including mechanisms that target excitatory or inhibitory synapses, or that regulate intrinsic neuronal excitability. Here we discuss which aspects of neocortical circuit function are under homeostatic control, how this homeostasis is realized on the cellular and molecular levels, and the pathological consequences when circuit homeostasis is impaired. A remaining challenge is to elucidate how these diverse homeostatic mechanisms cooperate within complex circuits to enable them to be both flexible and stable.


Asunto(s)
Encéfalo , Homeostasis , Red Nerviosa , Plasticidad Neuronal , Homeostasis/fisiología , Animales , Humanos , Plasticidad Neuronal/fisiología , Red Nerviosa/fisiología , Encéfalo/fisiología , Neuronas/fisiología , Sinapsis/fisiología , Neocórtex/fisiología
6.
Cell ; 161(6): 1425-36, 2015 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-26004067

RESUMEN

Global DNA demethylation in humans is a fundamental process that occurs in pre-implantation embryos and reversion to naive ground state pluripotent stem cells (PSCs). However, the extent of DNA methylation reprogramming in human germline cells is unknown. Here, we performed whole-genome bisulfite sequencing (WGBS) and RNA-sequencing (RNA-seq) of human prenatal germline cells from 53 to 137 days of development. We discovered that the transcriptome and methylome of human germline is distinct from both human PSCs and the inner cell mass (ICM) of human blastocysts. Using this resource to monitor the outcome of global DNA demethylation with reversion of primed PSCs to the naive ground state, we uncovered hotspots of ultralow methylation at transposons that are protected from demethylation in the germline and ICM. Taken together, the human germline serves as a valuable in vivo tool for monitoring the epigenome of cells that have emerged from a global DNA demethylation event.


Asunto(s)
Blastocisto/metabolismo , Metilación de ADN , Embrión de Mamíferos/metabolismo , Células Germinativas/metabolismo , Masa Celular Interna del Blastocisto , Células Madre Embrionarias/metabolismo , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino
7.
Nature ; 623(7986): 432-441, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37914932

RESUMEN

Chromatin accessibility is essential in regulating gene expression and cellular identity, and alterations in accessibility have been implicated in driving cancer initiation, progression and metastasis1-4. Although the genetic contributions to oncogenic transitions have been investigated, epigenetic drivers remain less understood. Here we constructed a pan-cancer epigenetic and transcriptomic atlas using single-nucleus chromatin accessibility data (using single-nucleus assay for transposase-accessible chromatin) from 225 samples and matched single-cell or single-nucleus RNA-sequencing expression data from 206 samples. With over 1 million cells from each platform analysed through the enrichment of accessible chromatin regions, transcription factor motifs and regulons, we identified epigenetic drivers associated with cancer transitions. Some epigenetic drivers appeared in multiple cancers (for example, regulatory regions of ABCC1 and VEGFA; GATA6 and FOX-family motifs), whereas others were cancer specific (for example, regulatory regions of FGF19, ASAP2 and EN1, and the PBX3 motif). Among epigenetically altered pathways, TP53, hypoxia and TNF signalling were linked to cancer initiation, whereas oestrogen response, epithelial-mesenchymal transition and apical junction were tied to metastatic transition. Furthermore, we revealed a marked correlation between enhancer accessibility and gene expression and uncovered cooperation between epigenetic and genetic drivers. This atlas provides a foundation for further investigation of epigenetic dynamics in cancer transitions.


Asunto(s)
Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Neoplasias , Humanos , Hipoxia de la Célula , Núcleo Celular , Cromatina/genética , Cromatina/metabolismo , Elementos de Facilitación Genéticos/genética , Epigénesis Genética/genética , Transición Epitelial-Mesenquimal , Estrógenos/metabolismo , Perfilación de la Expresión Génica , Proteínas Activadoras de GTPasa/metabolismo , Metástasis de la Neoplasia , Neoplasias/clasificación , Neoplasias/genética , Neoplasias/patología , Secuencias Reguladoras de Ácidos Nucleicos/genética , Análisis de la Célula Individual , Factores de Transcripción/metabolismo
8.
Nature ; 617(7960): 312-324, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37165242

RESUMEN

Here the Human Pangenome Reference Consortium presents a first draft of the human pangenome reference. The pangenome contains 47 phased, diploid assemblies from a cohort of genetically diverse individuals1. These assemblies cover more than 99% of the expected sequence in each genome and are more than 99% accurate at the structural and base pair levels. Based on alignments of the assemblies, we generate a draft pangenome that captures known variants and haplotypes and reveals new alleles at structurally complex loci. We also add 119 million base pairs of euchromatic polymorphic sequences and 1,115 gene duplications relative to the existing reference GRCh38. Roughly 90 million of the additional base pairs are derived from structural variation. Using our draft pangenome to analyse short-read data reduced small variant discovery errors by 34% and increased the number of structural variants detected per haplotype by 104% compared with GRCh38-based workflows, which enabled the typing of the vast majority of structural variant alleles per sample.


Asunto(s)
Genoma Humano , Genómica , Humanos , Diploidia , Genoma Humano/genética , Haplotipos/genética , Análisis de Secuencia de ADN , Genómica/normas , Estándares de Referencia , Estudios de Cohortes , Alelos , Variación Genética
10.
Nature ; 595(7866): 227-232, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34234334

RESUMEN

Motivated by far-reaching applications ranging from quantum simulations of complex processes in physics and chemistry to quantum information processing1, a broad effort is currently underway to build large-scale programmable quantum systems. Such systems provide insights into strongly correlated quantum matter2-6, while at the same time enabling new methods for computation7-10 and metrology11. Here we demonstrate a programmable quantum simulator based on deterministically prepared two-dimensional arrays of neutral atoms, featuring strong interactions controlled by coherent atomic excitation into Rydberg states12. Using this approach, we realize a quantum spin model with tunable interactions for system sizes ranging from 64 to 256 qubits. We benchmark the system by characterizing high-fidelity antiferromagnetically ordered states and demonstrating quantum critical dynamics consistent with an Ising quantum phase transition in (2 + 1) dimensions13. We then create and study several new quantum phases that arise from the interplay between interactions and coherent laser excitation14, experimentally map the phase diagram and investigate the role of quantum fluctuations. Offering a new lens into the study of complex quantum matter, these observations pave the way for investigations of exotic quantum phases, non-equilibrium entanglement dynamics and hardware-efficient realization of quantum algorithms.

11.
Blood ; 144(6): 657-671, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-38635773

RESUMEN

ABSTRACT: Pseudouridine is the most prevalent RNA modification, and its aberrant function is implicated in various human diseases. However, the specific impact of pseudouridylation on hematopoiesis remains poorly understood. Here, we investigated the role of transfer RNA (tRNA) pseudouridylation in erythropoiesis and its association with mitochondrial myopathy, lactic acidosis, and sideroblastic anemia syndrome (MLASA) pathogenesis. By using patient-specific induced pluripotent stem cells (iPSCs) carrying a genetic pseudouridine synthase 1 (PUS1) mutation and a corresponding mutant mouse model, we demonstrated impaired erythropoiesis in MLASA-iPSCs and anemia in the MLASA mouse model. Both MLASA-iPSCs and mouse erythroblasts exhibited compromised mitochondrial function and impaired protein synthesis. Mechanistically, we revealed that PUS1 deficiency resulted in reduced mitochondrial tRNA levels because of pseudouridylation loss, leading to aberrant mitochondrial translation. Screening of mitochondrial supplements aimed at enhancing respiration or heme synthesis showed limited effect in promoting erythroid differentiation. Interestingly, the mammalian target of rapamycin (mTOR) inhibitor rapamycin facilitated erythroid differentiation in MLASA-iPSCs by suppressing mTOR signaling and protein synthesis, and consistent results were observed in the MLASA mouse model. Importantly, rapamycin treatment partially ameliorated anemia phenotypes in a patient with MLASA. Our findings provide novel insights into the crucial role of mitochondrial tRNA pseudouridylation in governing erythropoiesis and present potential therapeutic strategies for patients with anemia facing challenges related to protein translation.


Asunto(s)
Eritropoyesis , Células Madre Pluripotentes Inducidas , Mitocondrias , ARN de Transferencia , Animales , Ratones , Humanos , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Mitocondrias/metabolismo , Mitocondrias/patología , Células Madre Pluripotentes Inducidas/metabolismo , Seudouridina/metabolismo , Anemia Sideroblástica/genética , Anemia Sideroblástica/metabolismo , Anemia Sideroblástica/patología , ARN Mitocondrial/genética , ARN Mitocondrial/metabolismo , Hidroliasas/metabolismo , Hidroliasas/genética , Síndrome MELAS/genética , Síndrome MELAS/patología , Síndrome MELAS/metabolismo , Modelos Animales de Enfermedad
12.
Nature ; 588(7838): 403-407, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33328669

RESUMEN

Simple models of interacting spins have an important role in physics. They capture the properties of many magnetic materials, but also extend to other systems, such as bosons and fermions in a lattice, gauge theories, high-temperature superconductors, quantum spin liquids, and systems with exotic particles such as anyons and Majorana fermions1,2. To study and compare these models, a versatile platform is needed. Realizing such systems has been a long-standing goal in the field of ultracold atoms. So far, spin transport has only been studied in systems with isotropic spin-spin interactions3-12. Here we realize the Heisenberg model describing spins on a lattice, with fully adjustable anisotropy of the nearest-neighbour spin-spin couplings (called the XXZ model). In this model we study spin transport far from equilibrium after quantum quenches from imprinted spin-helix patterns. When spins are coupled only along two of three possible orientations (the XX model), we find ballistic behaviour of spin dynamics, whereas for isotropic interactions (the XXX model), we find diffusive behaviour. More generally, for positive anisotropies, the dynamics ranges from anomalous superdiffusion to subdiffusion, whereas for negative anisotropies, we observe a crossover in the time domain from ballistic to diffusive transport. This behaviour is in contrast with expectations from the linear-response regime and raises new questions in understanding quantum many-body dynamics far away from equilibrium.

13.
Proc Natl Acad Sci U S A ; 120(20): e2302407120, 2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-37155859

RESUMEN

Clarifying the reaction pathways at the solid-water interface and in bulk water solution is of great significance for the design of heterogeneous catalysts for selective oxidation of organic pollutants. However, achieving this goal is daunting because of the intricate interfacial reactions at the catalyst surface. Herein, we unravel the origin of the organic oxidation reactions with metal oxide catalysts, revealing that the radical-based advanced oxidation processes (AOPs) prevail in bulk water but not on the solid catalyst surfaces. We show that such differing reaction pathways widely exist in various chemical oxidation (e.g., high-valent Mn3+ and MnOX) and Fenton and Fenton-like catalytic oxidation (e.g., Fe2+ and FeOCl catalyzing H2O2, Co2+ and Co3O4 catalyzing persulfate) systems. Compared with the radical-based degradation and polymerization pathways of one-electron indirect AOP in homogeneous reactions, the heterogeneous catalysts provide unique surface properties to trigger surface-dependent coupling and polymerization pathways of a two-electron direct oxidative transfer process. These findings provide a fundamental understanding of catalytic organic oxidation processes at the solid-water interface, which could guide the design of heterogeneous nanocatalysts.

14.
Proc Natl Acad Sci U S A ; 120(15): e2220608120, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-37018199

RESUMEN

A precise modulation of heterogeneous catalysts in structural and surface properties promises the development of more sustainable advanced oxidation water purification technologies. However, while catalysts with superior decontamination activity and selectivity are already achievable, maintaining a long-term service life of such materials remains challenging. Here, we propose a crystallinity engineering strategy to break the activity-stability tradeoff of metal oxides in Fenton-like catalysis. The amorphous/crystalline cobalt-manganese spinel oxide (A/C-CoMnOx) provided highly active, hydroxyl group-rich surface, with moderate peroxymonosulfate (PMS)-binding affinity and charge transfer energy and strong pollutant adsorption, to trigger concerted radical and nonradical reactions for efficient pollutant mineralization, thereby alleviating the catalyst passivation by oxidation intermediate accumulation. Meanwhile, the surface-confined reactions, benefited from the enhanced adsorption of pollutants at A/C interface, rendered the A/C-CoMnOx/PMS system ultrahigh PMS utilization efficiency (82.2%) and unprecedented decontamination activity (rate constant of 1.48 min-1) surpassing almost all the state-of-the-art heterogeneous Fenton-like catalysts. The superior cyclic stability and environmental robustness of the system for real water treatment was also demonstrated. Our work unveils a critical role of material crystallinity in modulating the Fenton-like catalytic activity and pathways of metal oxides, which fundamentally improves our understanding of the structure-activity-selectivity relationships of heterogeneous catalysts and may inspire material design for more sustainable water purification application and beyond.

15.
J Neurosci ; 44(17)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38453467

RESUMEN

Pain perception arises from the integration of prior expectations with sensory information. Although recent work has demonstrated that treatment expectancy effects (e.g., placebo hypoalgesia) can be explained by a Bayesian integration framework incorporating the precision level of expectations and sensory inputs, the key factor modulating this integration in stimulus expectancy-induced pain modulation remains unclear. In a stimulus expectancy paradigm combining emotion regulation in healthy male and female adults, we found that participants' voluntary reduction in anticipatory anxiety and pleasantness monotonically reduced the magnitude of pain modulation by negative and positive expectations, respectively, indicating a role of emotion. For both types of expectations, Bayesian model comparisons confirmed that an integration model using the respective emotion of expectations and sensory inputs explained stimulus expectancy effects on pain better than using their respective precision. For negative expectations, the role of anxiety is further supported by our fMRI findings that (1) functional coupling within anxiety-processing brain regions (amygdala and anterior cingulate) reflected the integration of expectations with sensory inputs and (2) anxiety appeared to impair the updating of expectations via suppressed prediction error signals in the anterior cingulate, thus perpetuating negative expectancy effects. Regarding positive expectations, their integration with sensory inputs relied on the functional coupling within brain structures processing positive emotion and inhibiting threat responding (medial orbitofrontal cortex and hippocampus). In summary, different from treatment expectancy, pain modulation by stimulus expectancy emanates from emotion-modulated integration of beliefs with sensory evidence and inadequate belief updating.


Asunto(s)
Anticipación Psicológica , Ansiedad , Imagen por Resonancia Magnética , Humanos , Masculino , Femenino , Ansiedad/psicología , Ansiedad/fisiopatología , Adulto , Anticipación Psicológica/fisiología , Adulto Joven , Percepción del Dolor/fisiología , Dolor/psicología , Dolor/fisiopatología , Teorema de Bayes , Emociones/fisiología , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Encéfalo/fisiología , Placer/fisiología , Mapeo Encefálico
16.
J Virol ; : e0104824, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39212384

RESUMEN

Pseudorabies virus (PRV) utilizes multiple strategies to inhibit type I interferon (IFN-I) production and signaling to achieve innate immune evasion. Among several other functions, mitochondria serve as a crucial immune hub in the initiation of innate antiviral responses. It is currently unknown whether PRV inhibits innate immune responses by manipulating mitochondria. In this study, we found that PRV infection damages mitochondrial structure and function, as shown by mitochondrial membrane potential depolarization, reduction in mitochondrial numbers, and an imbalance in mitochondrial dynamics. In addition, PRV infection triggered PINK1-Parkin-mediated mitophagy to eliminate the impaired mitochondria, which resulted in a suppression of IFN-I production, thereby promoting viral replication. Furthermore, we found that mitophagy resulted in the degradation of the mitochondrial antiviral signaling protein, which is located on the mitochondrial outer membrane. In conclusion, the data of the current study indicate that PRV-induced mitophagy represents a previously uncharacterized PRV evasion mechanism of the IFN-I response, thereby promoting virus replication.IMPORTANCEPseudorabies virus (PRV), a pathogen that induces different disease symptoms and is often fatal in domestic animals and wildlife, has caused great economic losses to the swine industry. Since 2011, different PRV variant strains have emerged in Asia, against which current commercial vaccines may not always provide optimal protection in pigs. In addition, there are indications that some of these PRV variant strains may sporadically infect people. In the current study, we found that PRV infection causes mitochondria injury. This is associated with the induction of mitophagy to eliminate the damaged mitochondria, which results in suppressed antiviral interferon production and signaling. Hence, our study reveals a novel mechanism that is used by PRV to antagonize the antiviral host immune response, providing a theoretical basis that may contribute to the research toward and development of new vaccines and antiviral drugs.

17.
Acc Chem Res ; 57(5): 776-794, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38381559

RESUMEN

ConspectusThe development of catalytic activation modes provides a reliable and effective platform for designing new enantioselective reactions and preparing chiral molecules with diverse structures. Chiral aldehyde catalysis is an attractive concept in asymmetric catalysis, which utilizes a chiral aldehyde catalyst to promote the asymmetric hydroamination of allylic amines, the asymmetric α-functionalization of primary amines, or the asymmetric transamination of α-keto esters. Typically, the chiral aldehyde-catalyzed asymmetric α-functionalization of primary amines provides an efficient and straightforward method for the synthesis of α-functionalized chiral amines, which does not require any additional protection or deprotection manipulations of the amine group. However, achieving catalytic stereoselective transformations with high efficiency and enantioselectivity by this strategy has remained an intractable challenge.This Account summarizes our endeavors in the development and application of chiral aldehyde catalysis. Using a chiral aldehyde as a catalyst, we reported the catalytic asymmetric α-C alkylation of 2-aminomalonate with 3-indolylmethanol in 2014, which represents the first chiral aldehyde-catalyzed asymmetric α-functionalization of an activated primary amine. Subsequently, several axially chiral aldehyde catalysts were continuously prepared by using chiral BINOL as the starting material, and their applications in asymmetric synthesis were explored. On the one hand, they were used as organocatalysts to realize the various transformations of α-amino acid esters, such as asymmetric 1,4-addition toward conjugated enones/α,ß-unsaturated diesters and cyclic 1-azadienes as well as asymmetric α-arylation/allylation and benzylation with corresponding halohydrocarbons. Notably, taking advantage of the difference in the distribution of catalytic sites between two chiral aldehyde catalysts, we disclosed chiral aldehyde-catalyzed diastereodivergent 1,6-conjugated addition and Mannich reactions. On the other hand, the potential for the cooperative catalysis of a chiral aldehyde with a transition metal has also been demonstrated. Enabled by the combination of a chiral aldehyde, a palladium complex, and a Lewis acid, the enantioselective α-allylation of amino acid esters with allyl alcohol esters was established. Moreover, the ternary catalytic system has been successfully used for the α-functionalization of amino acid esters with 1,3-dienes, allenes, allenylic alcohol esters, 1,3-disubstituted allyl alcohol esters, and arylmethanol esters as well as the asymmetric cascade Heck-alkylation reaction. The combination of a chiral aldehyde and nickel complex allows for the asymmetric α-propargylation of amino acid esters with propargylic alcohol esters and provides excellent enantioselectivities. These transformations provide a large library of optically active amines and amino acids. With those chiral amino acid esters as key building blocks, the synthesis or formal synthesis of multiple natural products and biologically significant unnatural molecules was accomplished. This includes the stereodivergent synthesis of natural pyrrolizidine alkaloid NP25302 and the formal synthesis of natural product (S)-hypoestestatin 1 and manzacidin C, clinical candidate compound (+)-AG-041R, and somatostatin mimetics. It is fully anticipated that chiral aldehyde catalysis will soon witness rapid expansion both in the development of novel asymmetric transformations and in innovative applications for constructing optically active nitrogen-containing molecules with significant values.

18.
FASEB J ; 38(17): e70041, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39250170

RESUMEN

Pro-inflammatory cytokines in muscle play a pivotal role in physiological responses and in the pathophysiology of inflammatory disease and muscle atrophy. Lactobacillus delbrueckii (LD), as a kind of probiotics, has inhibitory effects on pro-inflammatory cytokines associated with various inflammatory diseases. This study was conducted to explore the effect of dietary LD on the lipopolysaccharide (LPS)-induced muscle inflammation and atrophy in piglets and to elucidate the underlying mechanism. A total of 36 weaned piglets (Duroc × Landrace × Large Yorkshire) were allotted into three groups with six replicates (pens) of two piglets: (1) Nonchallenged control; (2) LPS-challenged (LPS); (3) 0.2% LD diet and LPS-challenged (LD+LPS). On d 29, the piglets were injected intraperitoneally with LPS or sterilized saline, respectively. All piglets were slaughtered at 4 h after LPS or saline injection, the blood and muscle samples were collected for further analysis. Our results showed that dietary supplementation of LD significantly attenuated LPS-induced production of pro-inflammatory cytokines IL-6 and TNF-α in both serum and muscle of the piglets. Concomitantly, pretreating the piglets with LD also clearly inhibited LPS-induced nuclear translocation of NF-κB p65 subunits in the muscle, which correlated with the anti-inflammatory effects of LD on the muscle of piglets. Meanwhile, LPS-induced muscle atrophy, indicated by a higher expression of muscle atrophy F-box, muscle RING finger protein (MuRF1), forkhead box O 1, and autophagy-related protein 5 (ATG5) at the transcriptional level, whereas pretreatment with LD led to inhibition of these upregulations, particularly genes for MuRF1 and ATG5. Moreover, LPS-induced mRNA expression of endoplasmic reticulum stress markers, such as eukaryotic translational initiation factor 2α (eIF-2α) was suppressed by pretreatment with LD, which was accompanied by a decrease in the protein expression levels of IRE1α and GRP78. Additionally, LD significantly prevented muscle cell apoptotic death induced by LPS. Taken together, our data indicate that the anti-inflammatory effect of LD supply on muscle atrophy of piglets could be likely regulated by inhibiting the secretion of pro-inflammatory cytokines through the inactivation of the ER stress/NF-κB singling pathway, along with the reduction in protein degradation.


Asunto(s)
Estrés del Retículo Endoplásmico , Lactobacillus delbrueckii , Lipopolisacáridos , Atrofia Muscular , Animales , Lipopolisacáridos/toxicidad , Porcinos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Atrofia Muscular/inducido químicamente , Atrofia Muscular/metabolismo , Atrofia Muscular/prevención & control , Atrofia Muscular/patología , Destete , Proteolisis , Probióticos/farmacología , Inflamación/metabolismo , Miositis/inducido químicamente , Miositis/metabolismo , Miositis/patología , Citocinas/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Músculo Esquelético/efectos de los fármacos
19.
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
20.
Nucleic Acids Res ; 51(5): e29, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36631981

RESUMEN

Alternative splicing is an important source of heterogeneity underlying gene expression between individual cells but remains an understudied area due to the paucity of computational tools to analyze splicing dynamics at single-cell resolution. Here, we present MARVEL, a comprehensive R package for single-cell splicing analysis applicable to RNA sequencing generated from the plate- and droplet-based methods. We performed extensive benchmarking of MARVEL against available tools and demonstrated its utility by analyzing multiple publicly available datasets in diverse cell types, including in disease. MARVEL enables systematic and integrated splicing and gene expression analysis of single cells to characterize the splicing landscape and reveal biological insights.


Asunto(s)
Empalme Alternativo , Programas Informáticos , Biología Computacional , Empalme del ARN , Análisis de Secuencia de ARN , Análisis de la Célula Individual
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA