Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 148
Filtrar
1.
Circ Res ; 134(6): 748-769, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38484026

RESUMO

Mammalian physiology and cellular function are subject to significant oscillations over the course of every 24-hour day. It is likely that these daily rhythms will affect function as well as mechanisms of disease in the central nervous system. In this review, we attempt to survey and synthesize emerging studies that investigate how circadian biology may influence the neurovascular unit. We examine how circadian clocks may operate in neural, glial, and vascular compartments, review how circadian mechanisms regulate cell-cell signaling, assess interactions with aging and vascular comorbidities, and finally ask whether and how circadian effects and disruptions in rhythms may influence the risk and progression of pathophysiology in cerebrovascular disease. Overcoming identified challenges and leveraging opportunities for future research might support the development of novel circadian-based treatments for stroke.


Assuntos
Relógios Circadianos , Ritmo Circadiano , Animais , Envelhecimento/fisiologia , Mamíferos
2.
Nature ; 583(7814): E14, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32533095

RESUMO

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

3.
Nature ; 582(7812): 395-398, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494010

RESUMO

Neuroprotectant strategies that have worked in rodent models of stroke have failed to provide protection in clinical trials. Here we show that the opposite circadian cycles in nocturnal rodents versus diurnal humans1,2 may contribute to this failure in translation. We tested three independent neuroprotective approaches-normobaric hyperoxia, the free radical scavenger α-phenyl-butyl-tert-nitrone (αPBN), and the N-methyl-D-aspartic acid (NMDA) antagonist MK801-in mouse and rat models of focal cerebral ischaemia. All three treatments reduced infarction in day-time (inactive phase) rodent models of stroke, but not in night-time (active phase) rodent models of stroke, which match the phase (active, day-time) during which most strokes occur in clinical trials. Laser-speckle imaging showed that the penumbra of cerebral ischaemia was narrower in the active-phase mouse model than in the inactive-phase model. The smaller penumbra was associated with a lower density of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive dying cells and reduced infarct growth from 12 to 72 h. When we induced circadian-like cycles in primary mouse neurons, deprivation of oxygen and glucose triggered a smaller release of glutamate and reactive oxygen species, as well as lower activation of apoptotic and necroptotic mediators, in 'active-phase' than in 'inactive-phase' rodent neurons. αPBN and MK801 reduced neuronal death only in 'inactive-phase' neurons. These findings suggest that the influence of circadian rhythm on neuroprotection must be considered for translational studies in stroke and central nervous system diseases.


Assuntos
Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Modelos Animais de Doenças , Neurônios/patologia , Neuroproteção , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/prevenção & controle , Animais , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/prevenção & controle , Glucose/deficiência , Humanos , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Infarto da Artéria Cerebral Média/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/fisiopatologia , Pesquisa Translacional Biomédica , Falha de Tratamento
4.
Stroke ; 55(7): 1904-1913, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38913800

RESUMO

BACKGROUND: The mitochondrial unfolded protein response (UPRmt) is an evolutionarily conserved mitochondrial response that is critical for maintaining mitochondrial and energetic homeostasis under cellular stress after tissue injury and disease. Here, we ask whether UPRmt may be a potential therapeutic target for ischemic stroke. METHODS: We performed the middle cerebral artery occlusion and oxygen-glucose deprivation models to mimic ischemic stroke in vivo and in vitro, respectively. Oligomycin and meclizine were used to trigger the UPRmt. We used 2,3,5-triphenyltetrazolium chloride staining, behavioral tests, and Nissl staining to evaluate cerebral injury in vivo. The Cell Counting Kit-8 assay and the Calcein AM Assay Kit were conducted to test cerebral injury in vitro. RESULTS: Inducing UPRmt with oligomycin protected neuronal cultures against oxygen-glucose deprivation. UPRmt could also be triggered with meclizine, and this Food and Drug Administration-approved drug also protected neurons against oxygen-glucose deprivation. Blocking UPRmt with siRNA against activating transcription factor 5 eliminated the neuroprotective effects of meclizine. In a mouse model of focal cerebral ischemia, pretreatment with meclizine was able to induce UPRmt in vivo, which reduced infarction and improved neurological outcomes. CONCLUSIONS: These findings suggest that the UPRmt is important in maintaining the survival of neurons facing ischemic/hypoxic stress. The UPRmt mechanism may provide a new therapeutic avenue for ischemic stroke.


Assuntos
Isquemia Encefálica , Glucose , Mitocôndrias , Neurônios , Resposta a Proteínas não Dobradas , Animais , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Camundongos , Glucose/deficiência , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Isquemia Encefálica/metabolismo , Masculino , Infarto da Artéria Cerebral Média/metabolismo , Oxigênio/metabolismo , Camundongos Endogâmicos C57BL , Células Cultivadas , Fármacos Neuroprotetores/farmacologia
5.
Stroke ; 55(6): 1650-1659, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38738428

RESUMO

BACKGROUND: Beyond neuronal injury, cell death pathways may also contribute to vascular injury after stroke. We examined protein networks linked to major cell death pathways and identified SLC22A17 (solute carrier family 22 member 17) as a novel mediator that regulates endothelial tight junctions after ischemia and inflammatory stress. METHODS: Protein-protein interactions and brain enrichment analyses were performed using STRING, Cytoscape, and a human tissue-specific expression RNA-seq database. In vivo experiments were performed using mouse models of transient focal cerebral ischemia. Human stroke brain tissues were used to detect SLC22A17 by immunostaining. In vitro experiments were performed using human brain endothelial cultures subjected to inflammatory stress. Immunostaining and Western blot were used to assess responses in SLC22A17 and endothelial tight junctional proteins. Water content, dextran permeability, and electrical resistance assays were used to assess edema and blood-brain barrier (BBB) integrity. Gain and loss-of-function studies were performed using lentiviral overexpression of SLC22A17 or short interfering RNA against SLC22A17, respectively. RESULTS: Protein-protein interaction analysis showed that core proteins from apoptosis, necroptosis, ferroptosis, and autophagy cell death pathways were closely linked. Among the 20 proteins identified in the network, the iron-handling solute carrier SLC22A17 emerged as the mediator enriched in the brain. After cerebral ischemia in vivo, endothelial expression of SLC22A17 increases in both human and mouse brains along with BBB leakage. In human brain endothelial cultures, short interfering RNA against SLC22A17 prevents TNF-α (tumor necrosis factor alpha)-induced ferroptosis and downregulation in tight junction proteins and disruption in transcellular permeability. Notably, SLC22A17 could repress the transcription of tight junctional genes. Finally, short interfering RNA against SLC22A17 ameliorates BBB leakage in a mouse model of focal cerebral ischemia. CONCLUSIONS: Using a combination of cell culture, human stroke samples, and mouse models, our data suggest that SLC22A17 may play a role in the control of BBB function after cerebral ischemia. These findings may offer a novel mechanism and target for ameliorating BBB injury and edema after stroke.


Assuntos
Barreira Hematoencefálica , Isquemia Encefálica , Junções Íntimas , Idoso , Animais , Feminino , Humanos , Masculino , Camundongos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Isquemia Encefálica/genética , Morte Celular , Células Endoteliais/metabolismo , Camundongos Endogâmicos C57BL , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/genética , Junções Íntimas/metabolismo
6.
Small ; 20(2): e2305019, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37661575

RESUMO

Na-based layered transition metal oxides with an O3-type structure are considered promising cathodes for sodium-ion batteries. However, rapid capacity fading, and poor rate performance caused by serious structural changes and interfacial degradation hamper their use. In this study, a NaPO3 surface modified O3-type layered NaNi1/3 Fe1/3 Mn1/3 O2 cathode is synthesized, with improved high-voltage stability through protecting layer against acid attack, which is achieved by a solid-gas reaction between the cathode particles and gaseous P2 O5 . The NaPO3 nanolayer on the surface effectively stabilizes the crystal structure by inhibiting surface parasitic reactions and increasing the observed average voltage. Superior cyclic stability is exhibited by the surface-modified cathode (80.1% vs 63.6%) after 150 cycles at 1 C in the wide voltage range of 2.0 V-4.2 V (vs Na+ /Na). Moreover, benefiting from the inherent ionic conduction of NaPO3 , the surface-modified cathode presents excellent rate capability (103 mAh g-1  vs 60 mAh g-1 ) at 10 C. The outcome of this study demonstrates a practically relevant approach to develop high rate and durable sodium-ion battery technology.

7.
Am J Pathol ; 193(2): 233-245, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36697118

RESUMO

As a common type of head and neck squamous cell carcinoma, oral squamous cell carcinoma (OSCC) is a lethal and deforming disease. Long noncoding RNAs have emerged as critical modulators in different malignancies. However, the role of fucosyltransferase 8 antisense RNA 1 (FUT8-AS1) in OSCC still remains elusive. In this study, quantitative RT-PCR and Western blot were used for the measurement of RNAs and proteins. Mechanism assays explored the putative correlation among genes. In vitro assays evaluated the changes in OSCC cell malignant phenotype, whereas in vivo assays highlighted the influence of FUT8-AS1 on tumor growth. FUT8-AS1, aberrantly up-regulated in OSCC tissues and cells, could exacerbate OSCC cell malignant behaviors. The cancerogenic property of FUT8-AS1 in OSCC was further confirmed via animal experiments. Furthermore, FUT8-AS1 enhanced the expression of transcription factor 4 (TCF4) via sponging miR-944 and recruiting fused in sarcoma (FUS), thus affecting OSCC cell biological behaviors via modulation on Wnt/ß-catenin signaling activity. In addition, TCF4 was validated as the transcriptional activator of FUT8-AS1. To conclude, TCF4-mediated FUT8-AS1 could exacerbate OSCC cell malignant behaviors and facilitate tumor growth via modulation on miR-944/FUS/TCF4.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , MicroRNAs , Neoplasias Bucais , RNA Longo não Codificante , Sarcoma , Animais , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas/patologia , RNA Antissenso , Via de Sinalização Wnt/genética , Retroalimentação , Fator de Transcrição 4/genética , Fator de Transcrição 4/metabolismo , Neoplasias Bucais/patologia , Progressão da Doença , Linhagem Celular Tumoral , MicroRNAs/genética , MicroRNAs/metabolismo , Sarcoma/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica
8.
Br J Nutr ; : 1-18, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38818723

RESUMO

The potential threshold for dietary energy intake (DEI) that might prevent protein-energy wasting (PEW) in chronic kidney disease (CKD) is uncertain. The subjects were non-dialysis CKD patients aged ≥ 14 years who were hospitalized from September 2019 to July 2022. PEW was measured by subjective global assessment (SGA). DEI and dietary protein intake (DPI) were obtained by 3-days diet recalls. Patients were divided into adequate DEI group and inadequate DEI group according to DEI ≥ 30 or < 30 kcal/kg/d. Logistic regression analysis and restricted cubic spline (RCS) were used in this study. We enrolled 409 patients, with 53.8% had hypertension and 18.6% had diabetes. The DEI and DPI was 27.63 ± 5.79 kcal/kg/day and 1.00 (0.90,1.20) g/kg/day, respectively. 69.2% of participants in inadequate DEI group. Malnutrition occurred in 18.6% of patients. Comparing to patients in adequate DEI group, those in inadequate DEI group had significantly lower total lymphocyte count (TLC), serum cholesterol (Chol) and low-density cholesterol (LDL), and a higher prevalence of PEW. For every 1kcal/kg/day increase in DEI, the incidence of PEW was reduced by 12.0% [odds ratio (OR): 0.880, 95% confidence interval (CI): 0.830 to 0.933, P < 0.001]. There was a nonlinear curve relationship between DEI and PEW (overall P < 0.001), and DEI ≥ 27.6 kcal/kg/d may have a preventive effect on PEW in CKD. Low DPI was also significantly associated with malnutrition, but not when DEI was adequate. Decreased energy intake may be a more important factor of PEW in CKD than protein intake.

9.
BMC Oral Health ; 23(1): 951, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-38041054

RESUMO

BACKGROUND: Burning mouth syndrome (BMS) is an oral-facial pain disorder involving the central and peripheral nervous systems, but the evidence for altered pain sensitivity remains inconclusive. The aim of this study was to investigate pain sensitivity and oral health-related quality of life (OHRQoL) in patients with BMS and to assess the relationship between them. METHODS: Fifty Chinese patients with BMS (57.82 ± 11.2 years) and fifty age- and gender-matched healthy subjects (55.64 ± 10.1 years) participated in the study. The Pain Sensitivity Questionnaire (PSQ) was used to assess participants' pain sensitivity. The Oral Health Impact Profile (OHIP-14) was used to evaluate participants' OHRQoL. RESULTS: The PSQ total score (p = 0.009), the PSQ minor score (p = 0.003) and the OHIP-14 score (p<0.05) of patients with BMS were significantly higher than those of the healthy subjects. Simple linear regression showed that the PSQ minor score was significantly associated with the OHIP-14 score in patients with BMS (ß = 0.338, p = 0.016). CONCLUSION: Patients with BMS have higher pain sensitivity than healthy subjects. Reducing pain sensitivity might help to improve the quality of life of patients with BMS.


Assuntos
Síndrome da Ardência Bucal , Qualidade de Vida , Humanos , População do Leste Asiático , Dor Facial , Pessoa de Meia-Idade , Idoso
10.
Stroke ; 53(12): e507-e511, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36321457

RESUMO

BACKGROUND: The immune response to acute cerebral ischemia is a major factor in stroke pathobiology. Circadian biology modulates some aspects of immune response. The goal of this study is to compare key parameters of immune response during the active/awake phase versus inactive/sleep phase in a mouse model of transient focal cerebral ischemia. METHODS: Mice were housed in normal or reversed light cycle rooms for 3 weeks, and then they were blindly subjected to transient focal cerebral ischemia. Flow cytometry was used to examine immune responses in blood, spleen, and brain at 3 days after ischemic onset. RESULTS: In blood, there were higher levels of circulating T cells in mice subjected to focal ischemia during zeitgeber time (ZT)1-3 (inactive or sleep phase) versus ZT13-15 mice (active or awake phase). In the spleen, organ weight and immune cell numbers were lower in ZT1-3 versus ZT13-15 mice. Consistent with these results, there was an increased infiltration of activated T cells into brain at ZT1-3 compared with ZT13-15. CONCLUSIONS: This proof-of-concept study indicates that there are significant diurnal effects on the immune response after focal cerebral ischemia in mice. Hence, therapeutic strategies focused on immune targets should be reassessed to account for the effects of diurnal rhythms and circadian biology in nocturnal rodent models of stroke.


Assuntos
Isquemia Encefálica , Ataque Isquêmico Transitório , Acidente Vascular Cerebral , Animais , Camundongos , Baço , Camundongos Endogâmicos C57BL , Encéfalo , Infarto Cerebral , Isquemia , Imunidade
11.
Stroke ; 53(12): 3741-3750, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36252110

RESUMO

BACKGROUND: It has been reported that the S1P (sphingosine 1-phosphate) receptor modulator fingolimod reduces infarction in rodent models of stroke. Recent studies have suggested that circadian rhythms affect stroke and neuroprotection. Therefore, this study revisited the use of fingolimod in mouse focal cerebral ischemia to test the hypothesis that efficacy might depend on whether experiments were performed during the inactive sleep or active wake phases of the circadian cycle. METHODS: Two different stroke models were implemented in male C57Bl/6 mice-transient middle cerebral artery occlusion and permanent distal middle cerebral artery occlusion. Occlusion occurred either during inactive or active circadian phases. Mice were treated with 1 mg/kg fingolimod at 30- or 60-minute postocclusion and 1 day later for permanent and transient middle cerebral artery occlusion, respectively. Infarct volume, brain swelling, hemorrhagic transformation, and behavioral outcome were assessed at 2 or 3 days poststroke. Three independent experiments were performed in 2 different laboratories. RESULTS: Fingolimod decreased peripheral lymphocyte number in naive mice, as expected. However, it did not significantly affect infarct volume, brain swelling, hemorrhagic transformation, or behavioral outcome at 2 or 3 days after transient or permanent focal cerebral ischemia during inactive or active circadian phases of stroke onset. CONCLUSIONS: Outcomes were not improved by fingolimod in either transient or permanent focal cerebral ischemia during both active and inactive circadian phases. These negative findings suggest that further testing of fingolimod in clinical trials may not be warranted unless translational studies can identify factors associated with fingolimod's efficacy or lack thereof.


Assuntos
Edema Encefálico , Isquemia Encefálica , Acidente Vascular Cerebral , Animais , Camundongos , Masculino , Cloridrato de Fingolimode/farmacologia , Cloridrato de Fingolimode/uso terapêutico , Infarto da Artéria Cerebral Média/tratamento farmacológico , Edema Encefálico/tratamento farmacológico , Esfingosina , Acidente Vascular Cerebral/tratamento farmacológico , Camundongos Endogâmicos C57BL , Hemorragia/tratamento farmacológico , Modelos Animais de Doenças
12.
Funct Integr Genomics ; 22(5): 891-903, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35624316

RESUMO

Oral squamous cell carcinoma (OSCC) is a common malignant tumor occurring in the oral cavity. Circular RNAs (circRNAs) play a crucial regulatory role in many cancers. This study aimed to investigate the function of circRNA plasmacytoma variant translocation 1 (PVT1) (circPVT1) in OSCC and its potential mechanism. The levels of circPVT1, solute carrier family 7 member 11 (SLC7A11), and microRNA-143-3p (miR-143-3p) were examined by quantitative real-time PCR (qRT-PCR) or western blot assay. Cell proliferation, apoptosis, migration, and invasion were evaluated by Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry, and transwell assay. The levels of apoptosis and proliferation-related proteins were examined by western blot. The targeting relationship between miR-143-3p and circPVT1 or SLC7A11 was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. The levels of mitogen-activated protein kinase (MAPK) pathway-related proteins were measured by western blot. Xenograft assay was used to assess tumor growth in vivo. CircPVT1 and SLC7A11 were upregulated, while miR-143-3p was downregulated in OSCC tissues and cells. Silencing of circPVT1 or SLC7A11 suppressed proliferation, migration, and invasion and promoted apoptosis in OSCC cells. CircPVT1 upregulated SLC7A11 expression via sponging miR-143-3p. SLC7A11 upregulation alleviated the effect of circPVT1 knockdown on OSCC cell progression. Besides, circPVT1 modulated MAPK signaling pathway by regulating miR-143-3p. Moreover, circPVT1 knockdown inhibited tumor growth in vivo. Knockdown of circPVT1 impeded OSCC progression via the miR-143-3p/SLC7A11 axis through MAPK signaling pathway.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , MicroRNAs , Neoplasias Bucais , Sistema y+ de Transporte de Aminoácidos/genética , Sistema y+ de Transporte de Aminoácidos/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , RNA Circular/genética , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética
13.
Semin Dial ; 35(3): 258-263, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34811817

RESUMO

BACKGROUND: MR (Magnetic resonance) peritoneography is sensible for continuous ambulatory peritoneal dialysis (CAPD)-related complications, which could offer excellent soft-tissue contrast and allows a multiplanar imaging evaluation of complications. However, there is no study about the optimal concentration of the gadolinium-based agents nor the side effects of gadolinium-based agents on peritoneum and residual renal function. METHOD: Five different groups of uremic rats and two groups of normal rats were injected with a 40-ml mixture of peritoneal dialysate and gadolinium-based agents at varying concentrations prior to MR peritoneography. Thereafter, MR image obtained was evaluated by two experienced radiologists blinded to the concentrations. Peritoneal morphology and thickness of the uremic rats were also assessed using hematoxylin and eosin and Masson staining. Residual renal function was evaluated using serum creatinine levels and hematoxylin and eosin (HE) staining of pathological kidney sections. RESULTS AND CONCLUSION: The gadolinium-based agents used in this experiment have no significant effect on residual renal function. There is no obvious difference in the image quality at the different gadolinium-based agents concentration. Due to the adverse effects of gadolinium-based agents in the previous studies, we suggest reducing the dose of gadolinium-based agents during MR peritoneography to the lowest limits.


Assuntos
Gadolínio , Peritônio , Animais , Amarelo de Eosina-(YS) , Gadolínio/efeitos adversos , Hematoxilina , Humanos , Rim/diagnóstico por imagem , Rim/fisiologia , Espectroscopia de Ressonância Magnética , Peritônio/diagnóstico por imagem , Peritônio/patologia , Ratos , Diálise Renal
14.
Handb Exp Pharmacol ; 273: 267-293, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33580391

RESUMO

The brain microenvironment is tightly regulated. The blood-brain barrier (BBB), which is composed of cerebral endothelial cells, astrocytes, and pericytes, plays an important role in maintaining the brain homeostasis by regulating the transport of both beneficial and detrimental substances between circulating blood and brain parenchyma. After brain injury and disease, BBB tightness becomes dysregulated, thus leading to inflammation and secondary brain damage. In this chapter, we overview the fundamental mechanisms of BBB damage and repair after stroke and traumatic brain injury (TBI). Understanding these mechanisms may lead to therapeutic opportunities for brain injury.


Assuntos
Lesões Encefálicas , Acidente Vascular Cerebral , Barreira Hematoencefálica , Células Endoteliais , Humanos , Pericitos
15.
Mediators Inflamm ; 2022: 4862763, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574272

RESUMO

Objective: Dysfunction of the enterocyte barrier is associated with the development of ulcerative colitis (UC). This study was aimed at exploring the effect of DNMT3a on enterocyte barrier function in the progression of UC and the underlying mechanism. Method: Mice were given 3.5% dextran sodium sulphate (DSS) in drinking water to induce colitis. The primary intestinal epithelial cells (IECs) were isolated and treated with lipopolysaccharide (LPS) to establish an in vitro inflammatory model. We detected mouse clinical symptoms, histopathological damage, enterocyte barrier function, B cell differentiation, DNA methylation level, and cytokine production. Subsequently, the effect of DNMT3a from IECs on B cell differentiation was explored by a cocultural experiment. Result: DSS treatment significantly reduced the body weight and colonic length, increased disease activity index (DAI), and aggravated histopathological damage. In addition, DSS treatment induced downregulation of tight junction (TJ) protein, anti-inflammatory cytokines (IL-10 and TGF-ß), and the number of anti-inflammatory B cells (CD1d+) in intestinal epithelial tissues, while upregulated proinflammatory cytokines (IL-6 and TNF-α), proinflammatory B cells (CD138+), and DNA methylation level. Further in vitro results revealed that DNMT3a silencing or TNFSF13 overexpression in IECs partly abolished the result of LPS-induced epithelial barrier dysfunction, as well as abrogated the effect of IEC-regulated B cell differentiation, while si-TACI transfection reversed these effects. Moreover, DNMT3a silencing decreased TNFSF13 methylation level and induced CD1d+ B cell differentiation, and the si-TNFSF13 transfection reversed the trend of B cell differentiation but did not affect TNFSF13 methylation level. Conclusion: Our study suggests that DNMT3a induces enterocyte barrier dysfunction to aggravate UC progression via TNFSF13-mediated interaction of enterocyte and B cells.


Assuntos
Linfócitos B/imunologia , Colite Ulcerativa , Colite , DNA Metiltransferase 3A/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Colite/tratamento farmacológico , Colite Ulcerativa/tratamento farmacológico , Citocinas/metabolismo , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Enterócitos/metabolismo , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Junções Íntimas/metabolismo
16.
Angew Chem Int Ed Engl ; 61(45): e202212243, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36124855

RESUMO

The insufficient charge separation and sluggish exciton transport severely limit the utilization of polymeric photocatalysts. To resolve the above issues, we incorporate bountiful carboxyl substituents within a novel benzodiimidazole oligomer and assemble it into a crystalline semiconductor. The photocatalyst is polar, hydrophilic, short-range crystalline, and capable of both hydrogen and oxygen evolution. The introduction of carboxyl side-groups adds asymmetry to the local structure and increases the built-in electric field. Further, accelerated carrier transfer is enabled via the short-range crystallinity. The superior hydrogen and oxygen production rates of 18.63 and 2.87 mmol g-1 h-1 represent one of the best performances ever reported among dual-functional polymeric photocatalysts. Our work initiates studies on high-performance oligomer photocatalysts, opening a new frontier to produce solar fuel.

17.
Stroke ; 52(11): 3670-3679, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34587791

RESUMO

Background and Purpose: Inflammatory mediators in blood have been proposed as potential biomarkers in stroke. However, a direct relationship between these circulating factors and brain-specific ischemic injury remains to be fully defined. Methods: An unbiased screen in a nonhuman primate model of stroke was used to find out the most responsive circulating biomarker flowing ischemic stroke. Then this phenomenon was checked in human beings and mice. Finally, we observed the temporospatial responsive characteristics of this biomarker after ischemic brain injury in mice to evaluate the direct relationship between this circulating factor and central nervous system­specific ischemic injury. Results: In a nonhuman primate model, an unbiased screen revealed CCL2 (C-C motif chemokine ligand 2) as a major response factor in plasma after stroke. In mouse models of focal cerebral ischemia, plasma levels of CCL2 showed a transient response, that is, rapidly elevated by 2 to 3 hours postischemia but then renormalized back to baseline levels by 24 hours. However, a different CCL2 temporal profile was observed in whole brain homogenate, cerebrospinal fluid, and isolated brain microvessels, with a progressive increase over 24 hours, demonstrating a mismatch between brain versus plasma responses. In contrast to the lack of correlation with central nervous system responses, 2 peripheral compartments showed transient profiles that matched circulating plasma signatures. CCL2 protein in lymph nodes and adipose tissue was significantly increased at 2 hours and renormalized by 24 hours. Conclusions: These findings may provide a cautionary tale for biomarker pursuits in plasma. Besides a direct central nervous system response, peripheral organs may also contribute to blood signatures in complex and indirect ways.


Assuntos
Biomarcadores/análise , Quimiocina CCL2/análise , AVC Isquêmico , Animais , Modelos Animais de Doenças , Humanos , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pesquisa Translacional Biomédica
18.
Stroke ; 52(6): 2180-2190, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33940951

RESUMO

Circadian biology modulates almost all aspects of mammalian physiology, disease, and response to therapies. Emerging data suggest that circadian biology may significantly affect the mechanisms of susceptibility, injury, recovery, and the response to therapy in stroke. In this review/perspective, we survey the accumulating literature and attempt to connect molecular, cellular, and physiological pathways in circadian biology to clinical consequences in stroke. Accounting for the complex and multifactorial effects of circadian rhythm may improve translational opportunities for stroke diagnostics and therapeutics.


Assuntos
Ritmo Circadiano/fisiologia , Mediadores da Inflamação/fisiologia , Acoplamento Neurovascular/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Animais , Ensaios Clínicos como Assunto/métodos , Humanos , Acidente Vascular Cerebral/diagnóstico
19.
IUBMB Life ; 73(1): 264-272, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33326690

RESUMO

Oral squamous cell carcinoma (OSCC) is a common malignant cancer with unfavorable prognosis, and the epithelial-to-mesenchymal transition (EMT) is a critical contributor to OSCC metastasis. Recently, we have shown that sirtuin 7 (Sirt7) is associated with EMT and OSCC metastasis by acetylating small mother against decapentaplegic 4 (Smad4). Nonetheless, the mechanism of Sirt7 downregulation in OSCC cells remains unknown. This study analyzed the potential microRNAs that were predicted to regulate Sirt7 expression by online databases. We identified miR-770 as an upstream regulator of Sirt7 that targets its 3'-untranslated region. The expression of miR-770 was observed to be negatively correlated with the mRNA expression of Sirt7 in metastatic OSCC tumors, and higher miR-770 expression was correlated with poorer OSCC patient survival. Our in vitro data indicated that miR-770 promoted OSCC cell migration and invasion, and this process was dependent on Sirt7/Smad4 signaling. Furthermore, in vivo metastasis experiments indicated that miR-770 overexpression led to more prominent OSCC metastasis and downregulated Sirt7 expression. Collectively, our results revealed a new role of Sirt7 downregulation in metastatic OSCC and suggested that miR-770 is a potential target in counteracting OSCC metastasis.


Assuntos
Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/secundário , MicroRNAs/genética , Neoplasias Bucais/patologia , Sirtuínas/metabolismo , Proteína Smad4/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Proliferação de Células , Transição Epitelial-Mesenquimal , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Camundongos Nus , Neoplasias Bucais/genética , Neoplasias Bucais/metabolismo , Invasividade Neoplásica , Prognóstico , Sirtuínas/genética , Proteína Smad4/genética , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Angew Chem Int Ed Engl ; 60(15): 8236-8242, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33491294

RESUMO

The overall water splitting efficiency is mainly restricted by the slow kinetics of oxygen evolution. Therefore, it is essential to develop active oxygen evolution catalysts. In this context, we designed and synthesized a tungsten oxide catalyst with oxygen vacancies for photocatalytic oxygen evolution, which exhibited a higher oxygen evolution rate of 683 µmol h-1 g-1 than that of pure WO3 (159 µmol h-1 g-1 ). Subsequent studies through transient absorption spectroscopy found that the oxygen vacancies can produce electron trapping states to inhibit the direct recombination of photogenerated carriers. Additionally, a Pt cocatalyst can promote electron trap states to participate in the reaction to improve the photocatalytic performance further. This work uses femtosecond transient absorption spectroscopy to explain the photocatalytic oxygen evolution mechanism of inorganic materials and provides new insights into the design of high-efficiency water-splitting catalysts.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA