Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.171
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Cell ; 179(6): 1264-1275.e13, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31778653

RESUMO

TLR8 is among the highest-expressed pattern-recognition receptors in the human myeloid compartment, yet its mode of action is poorly understood. TLR8 engages two distinct ligand binding sites to sense RNA degradation products, although it remains unclear how these ligands are formed in cellulo in the context of complex RNA molecule sensing. Here, we identified the lysosomal endoribonuclease RNase T2 as a non-redundant upstream component of TLR8-dependent RNA recognition. RNase T2 activity is required for rendering complex single-stranded, exogenous RNA molecules detectable for TLR8. This is due to RNase T2's preferential cleavage of single-stranded RNA molecules between purine and uridine residues, which critically contributes to the supply of catabolic uridine and the generation of purine-2',3'-cyclophosphate-terminated oligoribonucleotides. Thus-generated molecules constitute agonistic ligands for the first and second binding pocket of TLR8. Together, these results establish the identity and origin of the RNA-derived molecular pattern sensed by TLR8.


Assuntos
Endorribonucleases/metabolismo , Proteólise , Receptor 8 Toll-Like/metabolismo , Motivos de Aminoácidos , Sequência de Bases , Linhagem Celular , Endorribonucleases/deficiência , Humanos , Modelos Moleculares , Monócitos/metabolismo , Células Mieloides/metabolismo , Isótopos de Nitrogênio , Oligonucleotídeos/metabolismo , Purinas/metabolismo , RNA/metabolismo , Staphylococcus aureus/metabolismo , Receptor 7 Toll-Like/metabolismo , Receptor 8 Toll-Like/agonistas , Receptor 8 Toll-Like/química , Uridina/metabolismo
2.
Immunity ; 57(7): 1482-1496.e8, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38697119

RESUMO

Toll-like receptor 7 (TLR7) is essential for recognition of RNA viruses and initiation of antiviral immunity. TLR7 contains two ligand-binding pockets that recognize different RNA degradation products: pocket 1 recognizes guanosine, while pocket 2 coordinates pyrimidine-rich RNA fragments. We found that the endonuclease RNase T2, along with 5' exonucleases PLD3 and PLD4, collaboratively generate the ligands for TLR7. Specifically, RNase T2 generated guanosine 2',3'-cyclic monophosphate-terminated RNA fragments. PLD exonuclease activity further released the terminal 2',3'-cyclic guanosine monophosphate (2',3'-cGMP) to engage pocket 1 and was also needed to generate RNA fragments for pocket 2. Loss-of-function studies in cell lines and primary cells confirmed the critical requirement for PLD activity. Biochemical and structural studies showed that PLD enzymes form homodimers with two ligand-binding sites important for activity. Previously identified disease-associated PLD mutants failed to form stable dimers. Together, our data provide a mechanistic basis for the detection of RNA fragments by TLR7.


Assuntos
Endorribonucleases , Receptor 7 Toll-Like , Receptor 7 Toll-Like/metabolismo , Receptor 7 Toll-Like/genética , Humanos , Endorribonucleases/metabolismo , Ligantes , Fosfolipase D/metabolismo , Fosfolipase D/genética , RNA/metabolismo , Células HEK293 , Lisossomos/metabolismo , Animais , Exonucleases/metabolismo , Camundongos , Sítios de Ligação
3.
Cell ; 170(1): 199-212.e20, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28666119

RESUMO

Type 2 diabetes (T2D) affects Latinos at twice the rate seen in populations of European descent. We recently identified a risk haplotype spanning SLC16A11 that explains ∼20% of the increased T2D prevalence in Mexico. Here, through genetic fine-mapping, we define a set of tightly linked variants likely to contain the causal allele(s). We show that variants on the T2D-associated haplotype have two distinct effects: (1) decreasing SLC16A11 expression in liver and (2) disrupting a key interaction with basigin, thereby reducing cell-surface localization. Both independent mechanisms reduce SLC16A11 function and suggest SLC16A11 is the causal gene at this locus. To gain insight into how SLC16A11 disruption impacts T2D risk, we demonstrate that SLC16A11 is a proton-coupled monocarboxylate transporter and that genetic perturbation of SLC16A11 induces changes in fatty acid and lipid metabolism that are associated with increased T2D risk. Our findings suggest that increasing SLC16A11 function could be therapeutically beneficial for T2D. VIDEO ABSTRACT.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/metabolismo , Basigina/metabolismo , Membrana Celular/metabolismo , Cromossomos Humanos Par 17/metabolismo , Técnicas de Silenciamento de Genes , Haplótipos , Hepatócitos/metabolismo , Heterozigoto , Código das Histonas , Humanos , Fígado/metabolismo , Modelos Moleculares , Transportadores de Ácidos Monocarboxílicos/química
4.
Mol Cell ; 82(23): 4428-4442.e7, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36395771

RESUMO

Transcriptional control is a highly dynamic process that changes rapidly in response to various cellular and extracellular cues, making it difficult to define the mechanism of transcription factor function using slow genetic methods. We used a chemical-genetic approach to rapidly degrade a canonical transcriptional activator, PAX3-FOXO1, to define the mechanism by which it regulates gene expression programs. By coupling rapid protein degradation with the analysis of nascent transcription over short time courses and integrating CUT&RUN, ATAC-seq, and eRNA analysis with deep proteomic analysis, we defined PAX3-FOXO1 function at a small network of direct transcriptional targets. PAX3-FOXO1 degradation impaired RNA polymerase pause release and transcription elongation at most regulated gene targets. Moreover, the activity of PAX3-FOXO1 at enhancers controlling this core network was surprisingly selective, affecting single elements in super-enhancers. This combinatorial analysis indicated that PAX3-FOXO1 was continuously required to maintain chromatin accessibility and enhancer architecture at regulated enhancers.


Assuntos
Proteômica , Sequências Reguladoras de Ácido Nucleico , Sequência de Bases , RNA Polimerases Dirigidas por DNA , Sequenciamento de Cromatina por Imunoprecipitação , Fatores de Transcrição
5.
EMBO J ; 42(18): e114331, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37526230

RESUMO

Satellite DNA is characterized by long, tandemly repeated sequences mainly found in centromeres and pericentromeric chromosomal regions. The recent advent of telomere-to-telomere sequencing data revealed the complete sequences of satellite regions, including centromeric α-satellites and pericentromeric HSat1-3, which together comprise ~ 5.7% of the human genome. Despite possessing constitutive heterochromatin features, these regions are transcribed to produce long noncoding RNAs with highly repetitive sequences that associate with specific sets of proteins to play various regulatory roles. In certain stress or pathological conditions, satellite RNAs are induced to assemble mesoscopic membraneless organelles. Specifically, under heat stress, nuclear stress bodies (nSBs) are scaffolded by HSat3 lncRNAs, which sequester hundreds of RNA-binding proteins. Upon removal of the stressor, nSBs recruit additional regulatory proteins, including protein kinases and RNA methylases, which modify the previously sequestered nSB components. The sequential recruitment of substrates and enzymes enables nSBs to efficiently regulate the splicing of hundreds of pre-mRNAs under limited temperature conditions. This review discusses the structural features and regulatory roles of satellite RNAs in intracellular architecture and gene regulation.


Assuntos
RNA Longo não Codificante , RNA Satélite , Humanos , RNA Satélite/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica , DNA Satélite/genética , Heterocromatina , Centrômero/metabolismo
6.
J Biol Chem ; 300(2): 105537, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38072042

RESUMO

The extremophile bacterium D. radiodurans boasts a distinctive cell envelope characterized by the regular arrangement of three protein complexes. Among these, the Type II Secretion System (T2SS) stands out as a pivotal structural component. We used cryo-electron microscopy to reveal unique features, such as an unconventional protein belt (DR_1364) around the main secretin (GspD), and a cap (DR_0940) found to be a separated subunit rather than integrated with GspD. Furthermore, a novel region at the N-terminus of the GspD constitutes an additional second gate, supplementing the one typically found in the outer membrane region. This T2SS was found to contribute to envelope integrity, while also playing a role in nucleic acid and nutrient trafficking. Studies on intact cell envelopes show a consistent T2SS structure repetition, highlighting its significance within the cellular framework.


Assuntos
Membrana Celular , Deinococcus , Extremófilos , Sistemas de Secreção Tipo II , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Microscopia Crioeletrônica , Deinococcus/metabolismo , Extremófilos/metabolismo , Sistemas de Secreção Tipo II/química , Sistemas de Secreção Tipo II/metabolismo , Transporte Proteico
7.
Annu Rev Nutr ; 44(1): 339-355, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38724017

RESUMO

The global prevalence of type 2 diabetes mellitus (T2D) is increasing rapidly, with an anticipated 600 million cases by 2035. While infectious diseases such as helminth infections have decreased due to improved sanitation and health care, recent research suggests a link between helminth infections and T2D, with helminths such as Schistosoma, Nippostrongylus, Strongyloides, and Heligmosomoides potentially mitigating or slowing down T2D progression in human and animal models. Helminth infections enhance host immunity by promoting interactions between innate and adaptive immune systems. In T2D, type 1 immune responses are suppressed and type 2 responses are augmented, expanding regulatory T cells and innate immune cells, particularly type 2 immune cells and macrophages. This article reviews recent research shedding light on the favorable effects of helminth infections on T2D. The potential defense mechanisms identified include heightened insulin sensitivity and reduced inflammation. The synthesis of findings from studies investigating parasitic helminths and their derivatives underscores promising avenues for defense against T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Helmintíase , Humanos , Animais , Helmintíase/imunologia , Diabetes Mellitus Tipo 2/imunologia , Helmintos/imunologia , Helmintos/fisiologia , Resistência à Insulina , Fatores de Risco
8.
FASEB J ; 38(8): e23610, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38661000

RESUMO

Variants at the SLC30A8 locus are associated with type 2 diabetes (T2D) risk. The lead variant, rs13266634, encodes an amino acid change, Arg325Trp (R325W), at the C-terminus of the secretory granule-enriched zinc transporter, ZnT8. Although this protein-coding variant was previously thought to be the sole driver of T2D risk at this locus, recent studies have provided evidence for lowered expression of SLC30A8 mRNA in protective allele carriers. In the present study, we examined multiple variants that influence SLC30A8 allele-specific expression. Epigenomic mapping has previously identified an islet-selective enhancer cluster at the SLC30A8 locus, hosting multiple T2D risk and cASE associations, which is spatially associated with the SLC30A8 promoter and additional neighboring genes. Here, we show that deletion of variant-bearing enhancer regions using CRISPR-Cas9 in human-derived EndoC-ßH3 cells lowers the expression of SLC30A8 and several neighboring genes and improves glucose-stimulated insulin secretion. While downregulation of SLC30A8 had no effect on beta cell survival, loss of UTP23, RAD21, or MED30 markedly reduced cell viability. Although eQTL or cASE analyses in human islets did not support the association between these additional genes and diabetes risk, the transcriptional regulator JQ1 lowered the expression of multiple genes at the SLC30A8 locus and enhanced stimulated insulin secretion.


Assuntos
Diabetes Mellitus Tipo 2 , Elementos Facilitadores Genéticos , Células Secretoras de Insulina , Transportador 8 de Zinco , Humanos , Transportador 8 de Zinco/genética , Transportador 8 de Zinco/metabolismo , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Sobrevivência Celular/genética , Variação Genética , Insulina/metabolismo , Linhagem Celular
9.
Brain ; 147(4): 1474-1482, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37878862

RESUMO

This study aimed to investigate the controversial association between metformin use and diabetes-associated dementia in elderly patients with type 2 diabetes mellitus (T2DM) and evaluate the potential protective effects of metformin, as well as its intensity of use and dose-dependency, against dementia in this population. The study used a time-dependent Cox hazards model to evaluate the effect of metformin use on the incidence of dementia. The case group included elderly patients with T2DM (≥60 years old) who received metformin, while the control group consisted of elderly patients with T2DM who did not receive metformin during the follow-up period. Our analysis revealed a significant reduction in the risk of dementia among elderly individuals using metformin, with an adjusted hazard ratio of 0.34 (95% confidence interval: 0.33 to 0.36). Notably, metformin users with a daily intensity of 1 defined daily dose (DDD) or higher had a lower risk of dementia, with an adjusted hazard ratio (95% confidence interval) of 0.46 (0.22 to 0.6), compared to those with a daily intensity of <1 DDD. Additionally, the analysis of cumulative DDDs of metformin showed a dose-response relationship, with progressively lower adjusted hazard ratio across quartiles (0.15, 0.21, 0.28, and 0.53 for quartiles 4, 3, 2 and 1, respectively), compared to never metformin users (P for trend < 0.0001). Metformin use in elderly patients with T2DM is significantly associated with a substantial reduction in the risk of dementia. Notably, the protective effect of metformin demonstrates a dose-dependent relationship, with higher daily and cumulative dosages of metformin showing a greater risk reduction.


Assuntos
Demência , Diabetes Mellitus Tipo 2 , Metformina , Humanos , Idoso , Pessoa de Meia-Idade , Metformina/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Hipoglicemiantes , Incidência , Comportamento de Redução do Risco , Demência/epidemiologia , Demência/prevenção & controle
10.
Exp Cell Res ; 442(2): 114268, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39343042

RESUMO

N6-methyladenosine (m6A) is the most general post-transcriptional modification of eukaryotic mRNAs and long-stranded non-coding RNAs. In this process, It has been shown that FTO associates with the m6A mRNA demethylase and plays a role in diabetic vascular endothelial dysfunction. In the present study, we detected FTO protein expression in HUVECs by Western blot and found that FTO was highly expressed in all disease groups relative to the control group. To explore the mechanism of FTO in T2DM vasculopathy, we performed an analysis by methylated RNA immunoprecipitation sequencing (MeRIP-seq) to elucidate the role of aberrant m6A modification and mRNA expression in endothelial dysfunction. The results showed 202 overlapping genes with varying m6A modifications and varied mRNA expression, and GO and KEGG enrichment analysis revealed that these genes were predominantly enriched in pathways associated with T2DM complications and endothelial dysfunction. By an integrated analysis of MeRIP-seq and RNA-seq results, the IGV plots showed elevated kurtosis of downstream candidate gene modifications, which may be downstream targets for FTO to exercise biological functions. HOXA9 and PLAU mRNA expression levels were significantly down after FTO inhibition. In the current work, we set up a typological profile of the m6A genes among HUVECs as well as uncovered a hidden relationship between RNA methylation modifications for T2DM vasculopathy-associated genes. Taken together, this study indicates that endothelial functional impairment is present in T2DM patients and may be related to aberrant expression of FTO.


Assuntos
Adenosina , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Células Endoteliais da Veia Umbilical Humana , Humanos , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Metilação , Imunoprecipitação , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Análise de Sequência de RNA
11.
Cereb Cortex ; 34(1)2024 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-38059685

RESUMO

In the perinatal period, reward and cognitive systems begin trajectories, influencing later psychiatric risk. The basal ganglia is important for reward and cognitive processing but early development has not been fully characterized. To assess age-related development, we used a measure of basal ganglia physiology, specifically brain tissue iron, obtained from nT2* signal in resting-state functional magnetic resonance imaging (rsfMRI), associated with dopaminergic processing. We used data from the Developing Human Connectome Project (n = 464) to assess how moving from the prenatal to the postnatal environment affects rsfMRI nT2*, modeling gestational and postnatal age separately for basal ganglia subregions in linear models. We did not find associations with tissue iron and gestational age [range: 24.29-42.29] but found positive associations with postnatal age [range:0-17.14] in the pallidum and putamen, but not the caudate. We tested if there was an interaction between preterm birth and postnatal age, finding early preterm infants (GA < 35 wk) had higher iron levels and changed less over time. To assess multivariate change, we used support vector regression to predict age from voxel-wise-nT2* maps. We could predict postnatal but not gestational age when maps were residualized for the other age term. This provides evidence subregions differentially change with postnatal experience and preterm birth may disrupt trajectories.


Assuntos
Recém-Nascido Prematuro , Nascimento Prematuro , Lactente , Feminino , Recém-Nascido , Humanos , Imageamento por Ressonância Magnética , Nascimento Prematuro/patologia , Ferro , Gânglios da Base/diagnóstico por imagem , Encéfalo/diagnóstico por imagem
12.
Proc Natl Acad Sci U S A ; 119(7)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35145023

RESUMO

Insulin resistance and ß-cell dysfunction are two main molecular bases yet to be further elucidated for type 2 diabetes (T2D). Accumulating evidence indicates that stimulator of interferon genes (STING) plays an important role in regulating insulin sensitivity. However, its function in ß-cells remains unknown. Herein, using global STING knockout (STING-/-) and ß-cell-specific STING knockout (STING-ßKO) mouse models, we revealed a distinct role of STING in the regulation of glucose homeostasis through peripheral tissues and ß-cells. Specially, although STING-/- beneficially alleviated insulin resistance and glucose intolerance induced by high-fat diet, it surprisingly impaired islet glucose-stimulated insulin secretion (GSIS). Importantly, STING is decreased in islets of db/db mice and patients with T2D, suggesting a possible role of STING in ß-cell dysfunction. Indeed, STING-ßKO caused glucose intolerance due to impaired GSIS, indicating that STING is required for normal ß-cell function. Islet transcriptome analysis showed that STING deficiency decreased expression of ß-cell function-related genes, including Glut2, Kcnj11, and Abcc8, contributing to impaired GSIS. Mechanistically, the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and cleavage under targets and tagmentation (CUT&Tag) analyses suggested that Pax6 was the transcription factor that might be associated with defective GSIS in STING-ßKO mice. Indeed, Pax6 messenger RNA and protein levels were down-regulated and its nuclear localization was lost in STING-ßKO ß-cells. Together, these data revealed a function of STING in the regulation of insulin secretion and established pathophysiological significance of fine-tuned STING within ß-cells and insulin target tissues for maintaining glucose homeostasis.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Intolerância à Glucose/induzido quimicamente , Glucose/metabolismo , Insulina/metabolismo , Proteínas de Membrana/metabolismo , Animais , Diabetes Mellitus Experimental , Dieta Hiperlipídica/efeitos adversos , Regulação para Baixo , Regulação da Expressão Gênica , Homeostase , Humanos , Insulina/sangue , Resistência à Insulina , Células Secretoras de Insulina , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout
13.
J Allergy Clin Immunol ; 153(3): 695-704, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38056635

RESUMO

BACKGROUND: Piwi-interacting RNAs (piRNAs), comprising the largest noncoding RNA group, regulate transcriptional processes. Whether piRNAs are associated with type 2 (T2)-high asthma is unknown. OBJECTIVE: We sought to investigate the association between piRNAs and T2-high asthma in childhood asthma. METHODS: We sequenced plasma samples from 462 subjects in the Childhood Asthma Management Program (CAMP) as the discovery cohort and 1165 subjects in the Genetics of Asthma in Costa Rica Study (GACRS) as a replication cohort. Sequencing reads were filtered first, and piRNA reads were annotated and normalized. Linear regression was used for the association analysis of piRNAs and peripheral blood eosinophil count, total serum IgE level, and long-term asthma exacerbation in children with asthma. Mediation analysis was performed to investigate the effect direction. We then ascertained if the circulating piRNAs were present in asthmatic airway epithelial cells in a Gene Expression Omnibus (GEO; www.ncbi.nlm.nih.gov/geo) public data set. RESULTS: Fifteen piRNAs were significantly associated with eosinophil count in CAMP (P ≤ .05), and 3 were successfully replicated in GACRS. Eleven piRNAs were associated with total IgE in CAMP, and one of these was replicated in GACRS. All 22 significant piRNAs were identified in epithelial cells in vitro, and 6 of these were differentially expressed between subjects with asthma and healthy controls. Fourteen piRNAs were associated with long-term asthma exacerbation, and effect of piRNAs on long-term asthma exacerbation are mediated through eosinophil count and serum IgE level. CONCLUSION: piRNAs are associated with peripheral blood eosinophils and total serum IgE in childhood asthma and may play important roles in T2-high asthma.


Assuntos
Asma , RNA de Interação com Piwi , Criança , Humanos , RNA Interferente Pequeno/genética , Asma/genética , Imunoglobulina E/genética , Fenótipo
14.
J Allergy Clin Immunol ; 154(3): 609-618, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38797239

RESUMO

BACKGROUND: Lactotransferrin (LTF) has an immunomodulatory function, and its expression levels are associated with asthma susceptibility. OBJECTIVES: We sought to investigate LTF messenger RNA (mRNA) expression levels in human bronchial epithelial cells (BECs) as an anti-type 2 (T2) asthma biomarker. METHODS: Association analyses between LTF mRNA expression levels in BECs and asthma-related phenotypes were performed in the Severe Asthma Research Program (SARP) cross-sectional (n = 155) and longitudinal (n = 156) cohorts using a generalized linear model. Correlation analyses of mRNA expression levels between LTF and all other genes were performed by Spearman correlation. RESULTS: Low LTF mRNA expression levels were associated with asthma susceptibility and severity (P < .025), retrospective and prospective asthma exacerbations, and low lung function (P < 8.3 × 10-3). Low LTF mRNA expression levels were associated with high airway T2 inflammation biomarkers (sputum eosinophils and fractional exhaled nitric oxide; P < 8.3 × 10-3) but were not associated with blood eosinophils or total serum IgE. LTF mRNA expression levels were negatively correlated with expression levels of TH2 or asthma-associated genes (POSTN, NOS2, and MUC5AC) and eosinophil-related genes (IL1RL1, CCL26, and IKZF2) and positively correlated with expression levels of TH1 and inflammation genes (IL12A, MUC5B, and CC16) and TH17-driven cytokines or chemokines for neutrophils (CXCL1, CXCL6, and CSF3) (P < 3.5 × 10-6). CONCLUSIONS: Low LTF mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations through upregulation of airway T2 inflammation. LTF is a potential anti-T2 biomarker, and its expression levels may help determine the balance of eosinophilic and neutrophilic asthma.


Assuntos
Asma , Biomarcadores , Lactoferrina , RNA Mensageiro , Humanos , Asma/genética , Asma/imunologia , Lactoferrina/genética , Feminino , Masculino , RNA Mensageiro/genética , Adulto , Pessoa de Meia-Idade , Estudos Transversais , Células Epiteliais/metabolismo , Células Epiteliais/imunologia , Células Th2/imunologia , Brônquios/imunologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-39423878

RESUMO

BACKGROUND: Signal Transducer and Activator of Transcription 6 (STAT6) is central to Type 2 (T2) inflammation and common non-coding variants at the STAT6 locus associate with various T2 inflammatory traits, including diseases, and its pathway is widely targeted in asthma treatment. OBJECTIVE: To test the association of a rare missense variant in STAT6, p.L406P, with T2 inflammatory traits, including the risk of asthma and allergic diseases, and to characterize its functional consequences in cell culture. METHODS: We tested association of p.L406P with plasma protein levels, white blood cell counts and the risk of asthma and allergic phenotypes. We tested significant associations in other cohorts using a burden test. The effects of p.L406P on STAT6 protein function were examined in cell lines and by comparing CD4+ T-cell responses from carriers and non-carriers of the variant. RESULTS: p.L406P associated with reduced plasma levels of STAT6 and IgE as well as with lower eosinophil and basophil counts in blood. It also protected against asthma, mostly driven by severe T2 high asthma. We showed that p.L406P led to lower IL-4-induced activation in luciferase reporter assays and lower levels of STAT6 in CD4+ T cells. We identified multiple genes with expression that was affected by the p.L406P genotype upon IL-4 treatment of CD4+ T cells; the effect was consistent with a weaker IL-4 response in carriers than non-carriers of p.L406P. CONCLUSIONS: We report a partial loss-of-function variant in STAT6, resulting in dampened IL-4 responses and protection from T2 high asthma, implicating STAT6 as an attractive therapeutic target.

16.
Nano Lett ; 24(30): 9406-9414, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39036992

RESUMO

Extremely small iron oxide nanoparticle (ESIONP)-based stimuli-responsive switchable MRI contrast agents (CAs) show great promise for accurate detection of tumors due to their outstanding advantages of high specificity and low background signal. However, currently developed ESIONP-based switchable CAs often suffer single-biomarker-induced responses, which lack absolute specificity to pathological tissues, potentially diminishing diagnostic accuracy. In this study, weak acidity and hypoxia, two of the most remarkable characteristics of tumors, are introduced as dual biomarker stimuli to construct an ESIONP-based switchable MRI CA (DKL-CA), with its signal switch controlled by a "dual-key-and-lock" strategy. Only when DKL-CA is exposed to a coexisting weakly acidic and hypoxic environment can monodispersed ESIONPs form nanoclusters, thereby realizing a switch from the T1 to T2 contrast. Moreover, DKL-CA exhibits favorable biosafety and the capacity for precise tumor diagnosis in tumor-bearing mice. Overall, DKL-CA paves the way for designing highly accurate ESIONP-based MRI CAs for tumor diagnosis.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Neoplasias , Meios de Contraste/química , Imageamento por Ressonância Magnética/métodos , Animais , Camundongos , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/diagnóstico , Nanopartículas Magnéticas de Óxido de Ferro/química , Linhagem Celular Tumoral
17.
Nano Lett ; 24(1): 331-338, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38108571

RESUMO

Solar-driven photothermal catalytic H2 production from lignocellulosic biomass was achieved by using 1T-2H MoS2 with tunable Lewis acidic sites as catalysts in an alkaline aqueous solution, in which the number of Lewis acidic sites derived from the exposed Mo edges of MoS2 was successfully regulated by both the formation of an edge-terminated 1T-2H phase structure and tunable layer number. Owing to the abundant Lewis acidic sites for the oxygenolysis of lignocellulosic biomass, the 1T-2H MoS2 catalyst shows high photothermal catalytic lignocellulosic biomass-to-H2 transformation performance in polar wood chips, bamboo, rice straw corncobs, and rice hull aqueous solutions, and the highest H2 generation rate and solar-to-H2 (STH) efficiency respectively achieves 3661 µmol·h-1·g-1 and 0.18% in the polar wood chip system under 300 W Xe lamp illumination. This study provides a sustainable and cost-effective method for the direct transformation of renewable lignocellulosic biomass to H2 fuel driven by solar energy.

18.
J Neurosci ; 43(16): 2874-2884, 2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-36948584

RESUMO

The hierarchically organized structures of the medial temporal lobe are critically important for episodic memory function. Accumulating evidence suggests dissociable information processing pathways are maintained throughout these structures including in the medial and lateral entorhinal cortex. Cortical layers provide an additional dimension of dissociation as the primary input to the hippocampus derives from layer 2 neurons in the entorhinal cortex, whereas the deeper layers primarily receive output from the hippocampus. Here, novel high-resolution T2-prepared functional MRI methods were successfully used to mitigate susceptibility artifacts typically affecting MRI signals in this region providing uniform sensitivity across the medial and lateral entorhinal cortex. During the performance of a memory task, healthy human subjects (age 25-33 years, mean age 28.2 ± 3.3 years, 4 female) showed differential functional activation in the superficial and deep layers of the entorhinal cortex associated with task-related encoding and retrieval conditions, respectively. The methods provided here offer an approach to probe layer-specific activation in normal cognition and conditions contributing to memory impairment.SIGNIFICANCE STATEMENT This study provides new evidence for differential neuronal activation in the superficial versus deep layers of the entorhinal cortex associated with encoding and retrieval memory processes, respectively, in cognitively normal adults. The study further shows that this dissociation can be observed in both the medial and the lateral entorhinal cortex. The study was achieved by using a novel functional MRI method allowing us to measure robust functional MRI signals in both the medial and lateral entorhinal cortex that was not possible in previous studies. The methodology established here in healthy human subjects lays a solid foundation for subsequent studies investigating layer-specific and region-specific changes in the entorhinal cortex associated with memory impairment in various conditions such as Alzheimer's disease.


Assuntos
Doença de Alzheimer , Memória Episódica , Adulto , Humanos , Feminino , Adulto Jovem , Córtex Entorrinal/diagnóstico por imagem , Córtex Entorrinal/fisiologia , Lobo Temporal/fisiologia , Hipocampo/diagnóstico por imagem , Hipocampo/fisiologia , Transtornos da Memória
19.
Diabetologia ; 67(3): 483-493, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38117293

RESUMO

AIMS/HYPOTHESIS: We aimed to determine whether the use of glucagon-like peptide-1 receptor agonists (GLP-1RA) in individuals with non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus decreases the risk of new-onset adverse cardiovascular events (CVEs) and mortality rate compared with other glucose-lowering drugs in a real setting at a population level. METHODS: We conducted a population-based propensity-matched retrospective cohort study using TriNetX. The cohort comprised patients over 20 years old who were newly treated with glucose-lowering drugs between 1 January 2013 and 31 December 2021, and followed until 30 September 2022. New users of GLP-1RAs were matched based on age, demographics, comorbidities and medication use by using 1:1 propensity matching with other glucose-lowering drugs. The primary outcome was the new onset of adverse CVEs, including heart failure, composite incidence of major adverse cardiovascular events (MACE; defined as unstable angina, myocardial infarction, or coronary artery procedures or surgeries) and composite cerebrovascular events (defined as the first occurrence of stroke, transient ischaemic attack, cerebral infarction, carotid intervention or surgery), and the secondary outcome was all-cause mortality. Cox proportional hazards models were used to estimate HRs. RESULTS: The study involved 2,835,398 patients with both NAFLD and type 2 diabetes. When compared with the sodium-glucose cotransporter 2 (SGLT2) inhibitors group, the GLP-1RAs group showed no evidence of a difference in terms of new-onset heart failure (HR 0.97; 95% CI 0.93, 1.01), MACE (HR 0.95; 95% CI 0.90, 1.01) and cerebrovascular events (HR 0.99; 95% CI 0.94, 1.03). Furthermore, the two groups had no evidence of a difference in mortality rate (HR 1.06; 95% CI 0.97, 1.15). Similar results were observed across sensitivity analyses. Compared with other second- or third-line glucose-lowering medications, the GLP-1RAs demonstrated a lower rate of adverse CVEs, including heart failure (HR 0.88; 95% CI 0.85, 0.92), MACE (HR 0.89; 95% CI 0.85, 0.94), cerebrovascular events (HR 0.93; 95% CI 0.89, 0.96) and all-cause mortality rate (HR 0.70; 95% CI 0.66, 0.75). CONCLUSIONS/INTERPRETATION: In individuals with NAFLD and type 2 diabetes, GLP-1RAs are associated with lower incidences of adverse CVEs and all-cause mortality compared with metformin or other second- and third-line glucose-lowering medications. However, there was no significant difference in adverse CVEs or all-cause mortality when compared with those taking SGLT2 inhibitors.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Insuficiência Cardíaca , Hepatopatia Gordurosa não Alcoólica , Humanos , Adulto Jovem , Adulto , Diabetes Mellitus Tipo 2/epidemiologia , Hipoglicemiantes/uso terapêutico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/complicações , Agonistas do Receptor do Peptídeo 1 Semelhante ao Glucagon , Glucose , Estudos Retrospectivos , Estudos de Coortes , Resultado do Tratamento , Insuficiência Cardíaca/complicações , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas
20.
J Cell Mol Med ; 28(1): e18015, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37938877

RESUMO

Insulin resistance is a significant contributor to the development of type 2 diabetes (T2D) and is associated with obesity, physical inactivity, and low maximal oxygen uptake. While intense and prolonged exercise may have negative effects, physical activity can have a positive influence on cellular metabolism and the immune system. Moderate exercise has been shown to reduce oxidative stress and improve antioxidant status, whereas intense exercise can increase oxidative stress in the short term. The impact of exercise on pro-inflammatory cytokine production is complex and varies depending on intensity and duration. Exercise can also counteract the harmful effects of ageing and inflamm-ageing. This review aims to examine the molecular pathways altered by exercise in non-obese individuals at higher risk of developing T2D, including glucose utilization, lipid metabolism, mitochondrial function, inflammation and oxidative stress, with the potential to improve insulin sensitivity. The focus is on understanding the potential benefits of exercise for improving insulin sensitivity and providing insights for future targeted interventions before onset of disease.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Obesidade/metabolismo , Antioxidantes/metabolismo , Estresse Oxidativo , Exercício Físico , Insulina/metabolismo
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa