Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.206
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 175(1): 277-291.e31, 2018 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-30241608

RESUMO

Human health is dependent upon environmental exposures, yet the diversity and variation in exposures are poorly understood. We developed a sensitive method to monitor personal airborne biological and chemical exposures and followed the personal exposomes of 15 individuals for up to 890 days and over 66 distinct geographical locations. We found that individuals are potentially exposed to thousands of pan-domain species and chemical compounds, including insecticides and carcinogens. Personal biological and chemical exposomes are highly dynamic and vary spatiotemporally, even for individuals located in the same general geographical region. Integrated analysis of biological and chemical exposomes revealed strong location-dependent relationships. Finally, construction of an exposome interaction network demonstrated the presence of distinct yet interconnected human- and environment-centric clouds, comprised of interacting ecosystems such as human, flora, pets, and arthropods. Overall, we demonstrate that human exposomes are diverse, dynamic, spatiotemporally-driven interaction networks with the potential to impact human health.


Assuntos
Exposição Ambiental/análise , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Adulto , Animais , Ecossistema , Doença Ambiental/etiologia , Humanos
3.
EMBO J ; 42(20): e113743, 2023 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-37661833

RESUMO

Mitochondria play essential roles in cancer cell adaptation to hypoxia, but the underlying mechanisms remain elusive. Through mitochondrial proteomic profiling, we here find that the prolyl hydroxylase EglN1 (PHD2) accumulates on mitochondria under hypoxia. EglN1 substrate-binding region in the ß2ß3 loop is responsible for its mitochondrial translocation and contributes to breast tumor growth. Furthermore, we identify AMP-activated protein kinase alpha (AMPKα) as an EglN1 substrate on mitochondria. The EglN1-AMPKα interaction is essential for their mutual mitochondrial translocation. After EglN1 prolyl-hydroxylates AMPKα under normoxia, they rapidly dissociate following prolyl-hydroxylation, leading to their immediate release from mitochondria. In contrast, hypoxia results in constant EglN1-AMPKα interaction and their accumulation on mitochondria, leading to the formation of a Ca2+ /calmodulin-dependent protein kinase 2 (CaMKK2)-EglN1-AMPKα complex to activate AMPKα phosphorylation, ensuring metabolic homeostasis and breast tumor growth. Our findings identify EglN1 as an oxygen-sensitive metabolic checkpoint signaling hypoxic stress to mitochondria through its ß2ß3 loop region, suggesting a potential therapeutic target for breast cancer.


Assuntos
Proteínas Quinases Ativadas por AMP , Neoplasias da Mama , Feminino , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Hipóxia , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Mitocôndrias/metabolismo , Proteômica
4.
Proc Natl Acad Sci U S A ; 121(13): e2316912121, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38502698

RESUMO

Multi-principal element alloys (MPEAs) exhibit outstanding strength attributed to the complex dislocation dynamics as compared to conventional alloys. Here, we develop an atomic-lattice-distortion-dependent discrete dislocation dynamics framework consisted of random field theory and phenomenological dislocation model to investigate the fundamental deformation mechanism underlying massive dislocation motions in body-centered cubic MPEA. Amazingly, the turbulence of dislocation speed is identified in light of strong heterogeneous lattice strain field caused by short-range ordering. Importantly, the vortex from dislocation flow turbulence not only acts as an effective source to initiate dislocation multiplication but also induces the strong local pinning trap to block dislocation movement, thus breaking the strength-ductility trade-off.

5.
Brief Bioinform ; 25(3)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38546324

RESUMO

Enrichment analysis contextualizes biological features in pathways to facilitate a systematic understanding of high-dimensional data and is widely used in biomedical research. The emerging reporter score-based analysis (RSA) method shows more promising sensitivity, as it relies on P-values instead of raw values of features. However, RSA cannot be directly applied to multi-group and longitudinal experimental designs and is often misused due to the lack of a proper tool. Here, we propose the Generalized Reporter Score-based Analysis (GRSA) method for multi-group and longitudinal omics data. A comparison with other popular enrichment analysis methods demonstrated that GRSA had increased sensitivity across multiple benchmark datasets. We applied GRSA to microbiome, transcriptome and metabolome data and discovered new biological insights in omics studies. Finally, we demonstrated the application of GRSA beyond functional enrichment using a taxonomy database. We implemented GRSA in an R package, ReporterScore, integrating with a powerful visualization module and updatable pathway databases, which is available on the Comprehensive R Archive Network (https://cran.r-project.org/web/packages/ReporterScore). We believe that the ReporterScore package will be a valuable asset for broad biomedical research fields.


Assuntos
Pesquisa Biomédica , Microbiota , Benchmarking , Bases de Dados Factuais , Metaboloma
6.
Circ Res ; 134(10): 1330-1347, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38557119

RESUMO

BACKGROUND: Tetraspanin CD151 is highly expressed in endothelia and reinforces cell adhesion, but its role in vascular inflammation remains largely unknown. METHODS: In vitro molecular and cellular biological analyses on genetically modified endothelial cells, in vivo vascular biological analyses on genetically engineered mouse models, and in silico systems biology and bioinformatics analyses on CD151-related events. RESULTS: Endothelial ablation of Cd151 leads to pulmonary and cardiac inflammation, severe sepsis, and perilous COVID-19, and endothelial CD151 becomes downregulated in inflammation. Mechanistically, CD151 restrains endothelial release of proinflammatory molecules for less leukocyte infiltration. At the subcellular level, CD151 determines the integrity of multivesicular bodies/lysosomes and confines the production of exosomes that carry cytokines such as ANGPT2 (angiopoietin-2) and proteases such as cathepsin-D. At the molecular level, CD151 docks VCP (valosin-containing protein)/p97, which controls protein quality via mediating deubiquitination for proteolytic degradation, onto endolysosomes to facilitate VCP/p97 function. At the endolysosome membrane, CD151 links VCP/p97 to (1) IFITM3 (interferon-induced transmembrane protein 3), which regulates multivesicular body functions, to restrain IFITM3-mediated exosomal sorting, and (2) V-ATPase, which dictates endolysosome pH, to support functional assembly of V-ATPase. CONCLUSIONS: Distinct from its canonical function in strengthening cell adhesion at cell surface, CD151 maintains endolysosome function by sustaining VCP/p97-mediated protein unfolding and turnover. By supporting protein quality control and protein degradation, CD151 prevents proteins from (1) buildup in endolysosomes and (2) discharge through exosomes, to limit vascular inflammation. Also, our study conceptualizes that balance between degradation and discharge of proteins in endothelial cells determines vascular information. Thus, the IFITM3/V-ATPase-tetraspanin-VCP/p97 complexes on endolysosome, as a protein quality control and inflammation-inhibitory machinery, could be beneficial for therapeutic intervention against vascular inflammation.


Assuntos
COVID-19 , Endossomos , Lisossomos , Tetraspanina 24 , Animais , Lisossomos/metabolismo , Tetraspanina 24/metabolismo , Tetraspanina 24/genética , Humanos , Camundongos , COVID-19/metabolismo , COVID-19/imunologia , COVID-19/patologia , Endossomos/metabolismo , Camundongos Knockout , Vasculite/metabolismo , Camundongos Endogâmicos C57BL , SARS-CoV-2 , Inflamação/metabolismo , Inflamação/patologia , Sepse/metabolismo
7.
Proc Natl Acad Sci U S A ; 120(23): e2211787120, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37252982

RESUMO

Understanding the local chemical ordering propensity in random solid solutions, and tailoring its strength, can guide the design and discovery of complex, paradigm-shifting multicomponent alloys. First, we present a simple thermodynamic framework, based solely on binary enthalpies of mixing, to select optimal alloying elements to control the nature and extent of chemical ordering in high-entropy alloys (HEAs). Next, we couple high-resolution electron microscopy, atom probe tomography, hybrid Monte-Carlo, special quasirandom structures, and density functional theory calculations to demonstrate how controlled additions of Al and Ti and subsequent annealing drive chemical ordering in nearly random equiatomic face-centered cubic CoFeNi solid solution. We establish that short-range ordered domains, the precursors of long-range ordered precipitates, inform mechanical properties. Specifically, a progressively increasing local order boosts the tensile yield strengths of the parent CoFeNi alloy by a factor of four while also substantially improving ductility, which breaks the so-called strength-ductility paradox. Finally, we validate the generality of our approach by predicting and demonstrating that controlled additions of Al, which has large negative enthalpies of mixing with the constituent elements of another nearly random body-centered cubic refractory NbTaTi HEA, also introduces chemical ordering and enhances mechanical properties.

8.
Genome Res ; 32(6): 1199-1214, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35667843

RESUMO

Conventional environmental health studies have primarily focused on limited environmental stressors at the population level, which lacks the power to dissect the complexity and heterogeneity of individualized environmental exposures. Here, as a pilot case study, we integrated deep-profiled longitudinal personal exposome and internal multi-omics to systematically investigate how the exposome shapes a single individual's phenome. We annotated thousands of chemical and biological components in the personal exposome cloud and found they were significantly correlated with thousands of internal biomolecules, which was further cross-validated using corresponding clinical data. Our results showed that agrochemicals and fungi predominated in the highly diverse and dynamic personal exposome, and the biomolecules and pathways related to the individual's immune system, kidney, and liver were highly associated with the personal external exposome. Overall, this data-driven longitudinal monitoring study shows the potential dynamic interactions between the personal exposome and internal multi-omics, as well as the impact of the exposome on precision health by producing abundant testable hypotheses.


Assuntos
Expossoma , Exposição Ambiental/efeitos adversos , Saúde Ambiental , Monitoramento Ambiental/métodos , Humanos
9.
Exp Cell Res ; 441(1): 114168, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39004201

RESUMO

Intramuscular fat (IMF) content significantly impacts meat quality. influenced by complex interactions between skeletal muscle cells and adipocytes. Adipogenesis plays a pivotal role in IMF formation. Exosomes, extracellular membranous nanovesicles, facilitate intercellular communication by transporting proteins, nucleic acids (DNA and RNA), and other biomolecules into target cells, thereby modulating cellular behaviors. Recent studies have linked exosome-derived microRNAs (miRNAs) and other cargo to adipogenic processes. Various cell types, including skeletal muscle cells, interact with adipocytes via exosome secretion and uptake. Exosomes entering adipocytes regulate adipogenesis by modulating key signaling pathways, thereby influencing the extent and distribution of IMF deposition. This review comprehensively explores the origin, formation, and mechanisms of exosome action, along with current research and their applications in adipogenesis. Emphasis is placed on exosome-mediated regulation of miRNAs, non-coding RNAs (ncRNAs), proteins, lipids, and other biomolecules during adipogenesis. Leveraging exosomal contents for genetic breeding and treating obesity-related disorders is discussed. Insights gathered contribute to advancing understanding and potential therapeutic applications of exosome-regulated adipogenesis mechanisms.


Assuntos
Adipogenia , Exossomos , MicroRNAs , Adipogenia/genética , Exossomos/metabolismo , Exossomos/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Humanos , Animais , Adipócitos/metabolismo
10.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35210359

RESUMO

Deformation-induced martensitic transformation (DIMT) has been used for designing high-performance alloys to prevent structural failure under static loads. Its effectiveness against fatigue, however, is unclear. This limits the application of DIMT for parts that are exposed to variable loads, although such scenarios are the rule and not the exception for structural failure. Here we reveal the dual role of DIMT in fatigue crack growth through in situ observations. Two antagonistic fatigue mechanisms mediated by DIMT are identified, namely, transformation-mediated crack arresting, which prevents crack growth, and transformation-mediated crack coalescence, which promotes crack growth. Both mechanisms are due to the hardness and brittleness of martensite as a transformation product, rather than to the actual transformation process itself. In fatigue crack growth, the prevalence of one mechanism over the other critically depends on the crack size and the mechanical stability of the parent austenite phase. Elucidating the two mechanisms and their interplay allows for the microstructure design and safe use of metastable alloys that experience fatigue loads. The findings also generally reveal how metastable alloy microstructures must be designed for materials to be fatigue-resistant.

11.
Proc Natl Acad Sci U S A ; 119(25): e2200607119, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35696570

RESUMO

Multi-principal element alloys (MPEAs) exhibit outstanding mechanical properties because the core effect of severe atomic lattice distortion is distinctly different from that of traditional alloys. However, at the mesoscopic scale the underlying physics for the abundant dislocation activities responsible for strength-ductility synergy has not been uncovered. While the Eshelby mean-field approaches become insufficient to tackle yielding and plasticity in severely distorted crystalline solids, here we develop a three-dimensional discrete dislocation dynamics simulation approach by taking into account the experimentally measured lattice strain field from a model FeCoCrNiMn MPEA to explore the heterogeneous strain-induced strengthening mechanisms. Our results reveal that the heterogeneous lattice strain causes unusual dislocation behaviors (i.e., multiple kinks/jogs and bidirectional cross slips), resulting in the strengthening mechanisms that underpin the strength-ductility synergy. The outcome of our research sheds important insights into the design of strong yet ductile distorted crystalline solids, such as high-entropy alloys and high-entropy ceramics.

12.
Genomics ; 116(5): 110889, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38901654

RESUMO

Cholangiocarcinoma (CCA) is widely noted for its high degree of malignancy, rapid progression, and limited therapeutic options. This study was carried out on transcriptome data of 417 CCA samples from different anatomical locations. The effects of lipid metabolism related genes and immune related genes as CCA classifiers were compared. Key genes were derived from MVI subtypes and better molecular subtypes. Pathways such as epithelial mesenchymal transition (EMT) and cell cycle were significantly activated in MVI-positive group. CCA patients were classified into three (four) subtypes based on lipid metabolism (immune) related genes, with better prognosis observed in lipid metabolism-C1, immune-C2, and immune-C4. IPTW analysis found that the prognosis of lipid metabolism-C1 was significantly better than that of lipid metabolism-C2 + C3 before and after correction. KRT16 was finally selected as the key gene. And knockdown of KRT16 inhibited proliferation, migration and invasion of CCA cells.


Assuntos
Neoplasias dos Ductos Biliares , Biomarcadores Tumorais , Colangiocarcinoma , Transição Epitelial-Mesenquimal , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patologia , Humanos , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Prognóstico , Masculino , Metabolismo dos Lipídeos , Movimento Celular , Feminino , Proliferação de Células , Transcriptoma , Pessoa de Meia-Idade , Regulação Neoplásica da Expressão Gênica
13.
J Cell Mol Med ; 28(2): e18054, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38009813

RESUMO

This present study is aimed to investigate the role of microRNA-365 (miR-365) in the development of intervertebral disc degeneration (IDD). Nucleus pulposus (NP) cells were transfected by miR-365 mimic and miR-365 inhibitor, respectively. Concomitantly, the transfection efficiency and the expression level of miRNA were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Meanwhile, NP cells apoptosis was measured through propidium iodide (PI)-AnnexinV-fluorescein isothiocyanate (FITC) apoptosis detection kit. Subsequently, immunofluorescence (IF) staining was performed to assess the expression of collagen II, aggrecan and matrix metalloproteinase 13 (MMP-13). In addition, bioinformatic prediction and Luciferase reporter assay were used to reveal the target gene of miR-365. Finally, we isolated the primary NP cells from rats and injected NP-miR-365 in rat IDD models. The results showed that overexpression of miR-365 could effectively inhibit NP cells apoptosis and MMP-13 expression and upregulate the expression of collagen II and aggrecan. Conversely, suppression of miR-365 enhanced NP cell apoptosis and elevated MMP-13 expression, but decreased the expression of collagen II and aggrecan. Moreover, the further data demonstrated that miR-365 mediated NP cell degradation through targeting ephrin-A3 (EFNA3). In addition, the cells apoptosis and catabolic markers were increased in NP cells when EFNA3 upregulated. More importantly, the vivo data supported that miR-365-NP cells injection ameliorated IDD in rats models. miR-365 could alleviate the development of IDD by regulating NP cell apoptosis and ECM degradation, which is likely mediated by targeting EFNA3. Therefore, miR-365 may be a promising therapeutic avenue for treatment IDD through EFNA3.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , MicroRNAs , Núcleo Pulposo , Ratos , Animais , MicroRNAs/metabolismo , Degeneração do Disco Intervertebral/genética , Degeneração do Disco Intervertebral/metabolismo , Núcleo Pulposo/metabolismo , Metaloproteinase 13 da Matriz/genética , Metaloproteinase 13 da Matriz/metabolismo , Efrina-A3 , Agrecanas/genética , Agrecanas/metabolismo , Matriz Extracelular/metabolismo , Apoptose/genética , Colágeno/metabolismo , Disco Intervertebral/metabolismo
14.
Circulation ; 148(7): 565-574, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37401465

RESUMO

BACKGROUND: Frailty is associated with an increased risk of all-cause death and cardiovascular events. However, it is uncertain whether frailty modifies the efficacy and safety of intensive blood pressure control. METHODS: Data from SPRINT (Systolic Blood Pressure Intervention Trial) were used to construct a frailty index. Subgroup differences in intensive blood pressure control treatment effects and safety outcomes were measured on a relative and an absolute scale in patients with and without frailty (defined as a frailty index >0.21) using Cox proportional hazard models and generalized linear models, respectively. The primary outcome was a composite of myocardial infarction, acute coronary syndrome without myocardial infarction, stroke, heart failure, and cardiovascular death. RESULTS: A total of 9306 patients (mean age, 67.9±9.4 years), 2560 (26.7%) of whom had frailty, were included in our study. Over a median follow-up of 3.22 years, 561 primary outcomes were observed. Patients with frailty had a significantly higher risk of primary outcome in both the intensive and standard blood pressure control arms (adjusted hazard ratio, 2.10 [95% CI, 1.59-2.77] and 1.85 [95% CI, 1.46-2.35], respectively). Intensive treatment effects on primary and secondary outcomes were not significantly different on a relative scale (except for cardiovascular death [hazard ratio in patients with and without frailty, 0.91 (95% CI, 0.52-1.60) versus 0.30 (95% CI, 0.16-0.59), respectively; Pinteraction=0.01]) or absolute scale. There was no significant interaction between frailty and risks for serious adverse events with intensive treatment. CONCLUSIONS: Frailty status was a marker of high cardiovascular risk. Patients with frailty benefit similarly to other patients from intensive blood pressure control without an increased risk of serious adverse events.


Assuntos
Fragilidade , Hipertensão , Infarto do Miocárdio , Idoso , Humanos , Pessoa de Meia-Idade , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea , Fragilidade/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Hipertensão/complicações , Infarto do Miocárdio/tratamento farmacológico , Fatores de Risco , Resultado do Tratamento
15.
Glia ; 72(2): 396-410, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37909251

RESUMO

Neuropathic pain is a complex pain condition accompanied by prominent neuroinflammation involving activation of both central and peripheral immune cells. Metabolic switch to glycolysis is an important feature of activated immune cells. Hexokinase 2 (HK2), a key glycolytic enzyme enriched in microglia, has recently been shown important in regulating microglial functions. Whether and how HK2 is involved in neuropathic pain-related neuroinflammation remains unknown. Using a HK2-tdTomato reporter line, we found that HK2 was prominently elevated in spinal microglia. Pharmacological inhibition of HK2 effectively alleviated nerve injury-induced acute mechanical pain. However, selective ablation of Hk2 in microglia reduced microgliosis in the spinal dorsal horn (SDH) with little analgesic effects. Further analyses showed that nerve injury also significantly induced HK2 expression in dorsal root ganglion (DRG) macrophages. Deletion of Hk2 in myeloid cells, including both DRG macrophages and spinal microglia, led to the alleviation of mechanical pain during the first week after injury, along with attenuated microgliosis in the ipsilateral SDH, macrophage proliferation in DRGs, and suppressed inflammatory responses in DRGs. These data suggest that HK2 plays an important role in regulating neuropathic pain-related immune cell responses at acute phase and that HK2 contributes to neuropathic pain onset primarily through peripheral monocytes and DRG macrophages rather than spinal microglia.


Assuntos
Neuralgia , Traumatismos dos Nervos Periféricos , Humanos , Microglia/metabolismo , Hexoquinase/metabolismo , Hexoquinase/farmacologia , Doenças Neuroinflamatórias , Hiperalgesia/metabolismo , Macrófagos/metabolismo , Neuralgia/metabolismo , Gânglios Espinais/metabolismo , Medula Espinal/metabolismo , Traumatismos dos Nervos Periféricos/metabolismo
16.
Stroke ; 55(8): 2126-2138, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38920054

RESUMO

BACKGROUND: Dendritic cells (DCs) regulate the immune response associated with T lymphocytes, but their role in stroke remains unclear. In this study, we investigated the causal relationship between DCs and T-cell response in intracerebral hemorrhage (ICH) by focusing on TLRs (toll-like receptors) that may modulate the function of DCs. METHODS: We studied the effects of TLR4, TLR2, and TLR9 on DC-mediated T-cell response and the outcomes of ICH using male C57BL/6 and CD11c-DTx (diphtheria toxin) receptor mice. We administered specific agents intraperitoneally or orally and evaluated the results using flow cytometry, real-time polymerase chain reaction, Western blotting, immunofluorescence staining, histopathology, and behavioral tests. RESULTS: TLR4 and TLR2 activation induces DC maturation and reduces the ratio of regulatory T to T-helper 17 cells in the brain and periphery after ICH. When either of these receptors is activated, it can worsen neuroinflammation and exacerbate ICH outcomes. TLR9 also promotes DC maturation, stabilizing the number of DCs, particularly conventional DCs. TLR9 has the opposite effects on regulatory T/T-helper 17 balance, neuroinflammation, and ICH outcomes compared with TLR4 and TLR2. Upon stimulation, TLR4 and TLR9 may achieve these effects through the p38-MAPK (p38-mitogen-activated protein kinase)/MyD88 (myeloid differentiation primary response gene 88) and indoleamine 2,3-dioxygenase 1 (IDO1)/GCN2 (general control nonderepressible 2) signaling pathways, respectively. DCs act as intermediaries for TLR-mediated T-cell response. CONCLUSIONS: TLR-mediated opposing effects of DCs on T-cell response may provide novel strategies to treat ICH.


Assuntos
Hemorragia Cerebral , Células Dendríticas , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores , Células Th17 , Animais , Hemorragia Cerebral/imunologia , Hemorragia Cerebral/metabolismo , Células Dendríticas/imunologia , Linfócitos T Reguladores/imunologia , Camundongos , Células Th17/imunologia , Masculino , Receptores Toll-Like/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/imunologia
17.
J Am Chem Soc ; 146(1): 635-645, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38148276

RESUMO

Covalent organic frameworks (COFs) have undergone extensive research as heterogeneous catalysts for a wide range of significant reactions, but they have not yet been investigated in the realm of electrochemical asymmetric catalysis, despite their recognition as an economical and sustainable strategy for producing enantiopure compounds. Here, we report a mixed-linker strategy to design multicomponent two-dimensional (2D) chiral COFs with tunable layer stacking for highly enantioselective electrocatalysis. By crystallizing mixtures of triamines with and without the MacMillan imidazolidinone catalyst or aryl substituent (ethyl and isopropyl) and a dialdehyde derivative of thieno-[3,2-b]thiophene, we synthesized and structurally characterized a series of three-component homochiral 2D COFs featuring either AA or ABC stacking. The stacking modes that can be synthetically controlled through steric tuning using different aryl substituents affect their chemical stability and electrochemical performance. With the MacMillan catalyst periodically appended on their channels, all three COFs with conductive thiophene moieties can be highly enantioselective and recyclable electrocatalysts for the asymmetric α-arylation of aldehydes, affording alkylated anilines with up to 97% enantiomeric excess by an anodic oxidation/organocatalytic protocol. Presumably due to their higher charge transfer ability, the ABC stacking COFs exhibit improved reactivity compared to the AA stacking analogue. This work therefore advances COFs as electrocatalysts for asymmetric catalysis and may facilitate the design of more redox-active crystalline organic polymers for electrochemical enantioselective processes.

18.
J Am Chem Soc ; 146(10): 6733-6743, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38418379

RESUMO

Chiral covalent organic frameworks (CCOFs) have attracted extensive interest for their potential applications in various enantioselective processes. However, the exploitation of chirality-induced spin selectivity (CISS) that enables a new technology for the injection of spin polarized current without the need for a permanent magnetic layer within CCOFs remains a largely untapped area of research. Here, we demonstrate that, for the first time, COFs can be an attractive platform to develop spin filter materials with efficient CISS. This facilitates the design and synthesis of a new family of Zn(salen)-based 2D CCOFs, namely, CCOFs-9-12, by imine condensation of chiral 1,2-diaminocyclohexane and tri- or tetra(salicylaldehyde) derivatives. CCOF-9, distinguished by its unique C2 symmetric "armchair" tetrasubstituted pyrene conformation, exhibits the most pronounced chirality among these materials and serves as a solid-state host, enabling the enantioselective adsorption of racemic drugs with an enantiomeric excess (ee) of up to 97%. After substituting diamagnetic zinc(II) ions for paramagnetic cobalt(II), the resulting CCOF-9-Co not only retains its high crystallinity, porosity, and exceptional chirality but also exhibits enhanced conductivity, a crucial factor for the effective observation of CISS. Magnetic conductive atomic force microscopy showed that CCOF-9-Co exhibited a remarkable CISS effect with up to an 88-94% spin polarization ratio. This phenomenon is further confirmed by the increased intensity in the magnetic circular dichroism (MCD) when CCOF-9-Co is under an external magnetic field. This work therefore shows the tremendous potential of CCOFs for controlling spin selectivity and will stimulate the creation of new types of crystalline polymers with strong CISS effects for spin filters.

19.
J Neurochem ; 2024 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-39438982

RESUMO

T lymphocytes play a vital role in the immune-inflammatory response following a stroke. However, the specific mechanisms behind the contrasting functions of T cells in the brain and peripheral tissues after a stroke remain unclear and require further investigation. T-cell receptors (TCRs) are essential in controlling how T lymphocytes develop and become active. This study aims to gain a deeper understanding of the biological function of T lymphocytes by analyzing the TCR repertoire in patients who have experienced an acute ischemic stroke (AIS). High-throughput TCR sequencing was conducted on peripheral blood samples from 25 AIS patients and 10 healthy controls. We compared the percentage of T cells and the characteristics of the TCR repertoire, specifically focusing on the recombination of V(D)J gene fragments and the diversity of the complementarity determining region 3 (CDR3) of the Vß gene. Additionally, this study analyzed the potential biological significance of the skewed TCR repertoire in AIS patients. In patients with AIS, the proportion of circulating lymphocytes (LY%) decreased while the systemic immune-inflammatory index (SII) increased compared to healthy controls. The average number of TCR read pairs decreased, corresponding with the presence of lymphopenia. However, the recombination of V(D)J gene fragments, the number of CDR3 clonotypes, and the diversity of CDR3 was elevated in the peripheral blood of AIS patients. Furthermore, the increased number of CDR3 amino acid or nucleotide clonotypes was negatively correlated with neurologic deficits but positively correlated with AIS patients' systemic immune condition and functional outcomes. Our findings suggest that both immunosuppression and enhanced antigen-specific T-cell response may exist in the periphery of the AIS patients. Further investigation into the mechanisms underlying these opposing changes may lead to the discovery of novel targets to reverse immunosuppression or mitigate the detrimental effects of T cells in the lesioned brain of AIS patients.

20.
Anal Chem ; 96(29): 11682-11689, 2024 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-38979688

RESUMO

Cell death is a fundamental biological process with different modes including apoptosis and necrosis. In contrast to programmed apoptosis, necrosis was previously considered disordered and passive, but it is now being realized to be under regulation by certain biological pathways. However, the intracellular dynamics that coordinates with cellular structure changes during necrosis remains unknown, limiting our understanding of the principles of necrosis. Here, we characterized the spatiotemporal intracellular diffusion dynamics in cells undergoing necrosis, using three-dimensional single-particle tracking of quantum dots. We found temporally increased diffusion rates in necrotic cells and spatially enhanced diffusion heterogeneity in the cell periphery, which could be attributed to the reduced molecular crowding resulting from cell swelling and peripheral blebbing, respectively. Moreover, the three-dimensional intracellular diffusion transits from strong anisotropy to nearly isotropy, suggesting a remodeling of the cytoarchitecture that relieves the axial constraint on intracellular diffusion during necrosis. Our results reveal the remarkable alterations of intracellular diffusion dynamics and biophysical properties in necrosis, providing insight into the well-organized nonequilibrium necrotic cell death from a biophysical perspective.


Assuntos
Necrose , Pontos Quânticos , Pontos Quânticos/química , Humanos , Difusão , Células HeLa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA