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1.
Cancer Gene Ther ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594465

RESUMO

Telomerase is associated with cellular aging, and its presence limits cellular lifespan. Telomerase by preventing telomere shortening can extend the number of cell divisions for cancer cells. In adult pancreatic cells, telomeres gradually shorten, while in precancerous lesions of cancer, telomeres in cells are usually significantly shortened. At this time, telomerase is still in an inactive state, and it is not until before and after the onset of cancer that telomerase is reactivated, causing cancer cells to proliferate. Methylation of the telomerase reverse transcriptase (TERT) promoter and regulation of telomerase by lactate dehydrogenase B (LDHB) is the mechanism of telomerase reactivation in pancreatic cancer. Understanding the role of telomeres and telomerase in pancreatic cancer will help to diagnose and initiate targeted therapy as early as possible. This article reviews the role of telomeres and telomerase as biomarkers in the development of pancreatic cancer and the progress of research on telomeres and telomerase as targets for therapeutic intervention.

2.
Sci Rep ; 13(1): 18727, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907515

RESUMO

The existing biomarkers are insufficient for predicting the prognosis of pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary mucinous neoplasm (IPMN) is a precursor to PDAC; therefore, identifying biomarkers from differentially expressed genes (DEGs) of PDAC and IPMN is a new and reliable strategy for predicting the prognosis of PDAC. In this study, four datasets were downloaded from the Gene Expression Omnibus database and standardized using the R package 'limma.' A total of 51 IPMN and 81 PDAC samples were analyzed, and 341 DEGs in PDAC and IPMN were identified; DEGs were involved in the extracellular matrix and tumor microenvironment. An acceptable survival prognosis was demonstrated by SDC1 and ITGA2, which were highly expressed during in vitro PDAC cell proliferation, apoptosis, and migration. SDC1high was enriched in interferon alpha (IFN-α) response and ITGA2high was primarily detected in epithelial-mesenchymal transition (EMT), which was verified using western blotting. We concluded that SDC1 and ITGA2 are potential prognostic biomarkers for PDAC associated with IPMN. Downregulation of SDC1 and ITGA2 expression in PDAC occurs via a mechanism involving possible regulation of IFN-α response, EMT, and immunity, which may act as new targets for PDAC therapy.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Intraductais Pancreáticas , Neoplasias Pancreáticas , Humanos , Biomarcadores Tumorais/genética , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Prognóstico , Sindecana-1/genética , Microambiente Tumoral , Neoplasias Pancreáticas
3.
Front Cardiovasc Med ; 10: 1267525, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37915739

RESUMO

Background: Recently, attention has been paid to the protective properties of active ingredients in Salvia miltiorrhiza (AISM) against organ toxicity induced by chemotherapy drugs. Purpose of the present systematic review is to evaluate the chemoprotective effects and mechanisms of AISM on in vitro and in vivo models of doxorubicin-induced cardiotoxicity (DIC). Methods: According to the PRISMA guideline, the current systematic review was conducted in the Web of Science, PubMed, Embase, and the Cochrane Library to collect all relevant in vitro and in vivo studies on "the role of AISM on DIC" published up until May 2023. The SYRCLE's tool was used to identify potential risk of bias. Results: Twenty-two eligible articles were included in this systematic review. Eleven types of active ingredients in Salvia miltiorrhiza were used for DIC, which have the following effects: improvement of physical signs and biochemical indicators, reduction of cardiac function damage caused by DIC, protection of heart tissue structure, enhancement of myocardial cell viability, prevention of cardiomyocyte apoptosis, increase of the chemosensitivity of cancer cells to Doxorubicin, etc. The cardioprotective mechanism of AISM involves inhibiting apoptosis, attenuating oxidative stress, suppressing endoplasmic reticulum (ER) stress, decreasing inflammation, improving mitochondrial structure and function, affecting cellular autophagy and calcium homeostasis. The quality scores of included studies ranged from 4 to 7 points (a total of 10 points), according to SYRCLE's risk of bias tool. Conclusion: This systematic review demonstrated that AISM have chemoprotective effects on DIC in vivo and in vitro models through several main mechanisms such as anti-apoptosis, antioxidant effects, anti-ER stress, and anti-inflammatory.

4.
Front Pharmacol ; 14: 1220983, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37484013

RESUMO

Curcumin is a natural active ingredient from traditional Chinese medicine (TCM) that has multi-target characteristics to exert extensive pharmacological activities and thus has been applied in the treatment of various diseases such as cancer, cardiovascular diseases, nervous system, and autoimmune disorders. As an important class of membranous organelles in the intracellular membrane system, lysosomes are involved in biological processes such as programmed cell death, cell metabolism, and immune regulation, thus affecting tumor initiation and progression. It has been shown that curcumin can modulate lysosomal function through the aforementioned pathways, thereby affecting tumor proliferation, invasion, metastasis, drug resistance, and immune function. This review briefly elaborated the regulatory mechanisms of lysosome biogenesis and summarized curcumin-related studies with its anti-tumor effect, providing a reference for the clinical application of curcumin and anti-tumor research targeting lysosomes.

5.
Front Pharmacol ; 14: 1195104, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37383719

RESUMO

Cancer is one of the most lethal diseases. Globally, the number of cancers is nearly 10 million per year. Gynecological cancers (for instance, ovarian, cervical, and endometrial), relying on hidden diseases, misdiagnoses, and high recurrence rates, have seriously affected women's health. Traditional chemotherapy, hormone therapy, targeted therapy, and immunotherapy effectively improve the prognosis of gynecological cancer patients. However, with the emergence of adverse reactions and drug resistance, leading to the occurrence of complications and poor compliance of patients, we have to focus on the new treatment direction of gynecological cancers. Because of the potential effects of natural drugs in regulating immune function, protecting against oxidative damage, and improving the energy metabolism of the body, natural compounds represented by polysaccharides have also attracted extensive attention in recent years. More and more studies have shown that polysaccharides are effective in the treatment of various tumors and in reducing the burden of metastasis. In this review, we focus on the positive role of natural polysaccharides in the treatment of gynecologic cancer, the molecular mechanisms, and the available evidence, and discuss the potential use of new dosage forms derived from polysaccharides in gynecologic cancer. This study covers the most comprehensive discussion on applying natural polysaccharides and their novel preparations in gynecological cancers. By providing complete and valuable sources of information, we hope to promote more effective treatment solutions for clinical diagnosis and treatment of gynecological cancers.

6.
Food Funct ; 14(4): 2045-2058, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36723265

RESUMO

Live and heat-killed Bifidobacterium has been proven to have anti-inflammatory and antioxidant effects. In this study, we evaluated the effects of live and heat-killed Bifidobacterium animalis J-12 (J-12) on the oral ulceration of LVG golden Syrian hamsters after buccal membrane injection with methyl viologen dichloride. Results showed that interleukin-1ß, glutathione, and malondialdehyde in serum were downregulated by the gavage of live and heat-killed J-12 bacteria. The J-12 live and heat-killed bacteria can reduce the expression of matrix metalloproteinase-9 by reducing the expression of nuclear factor kappa-B, thus reducing the expression of anti-inflammatory factors lipoxin A4 and prostaglandin E2. Reducing the expression of caspase-3 and adenosine diphosphate ribose polymerase resulted in a reduction of ulcer tissue DNA damage. In addition, regulating the structure of the intestinal flora prevented the process of oral ulcer formation. This study shows that J-12 can reduce the risk of oral ulcer formation while also having a positive effect on inhibiting existing oral ulcer growth.


Assuntos
Bifidobacterium animalis , Microbioma Gastrointestinal , Úlceras Orais , Cricetinae , Animais , Humanos , Mesocricetus , Temperatura Alta , Anti-Inflamatórios , Bactérias
7.
Entropy (Basel) ; 25(2)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36832550

RESUMO

Although the performance of qubits has been improved in recent years, the differences in the microscopic atomic structure of the Josephson junctions, the core devices prepared under different preparation conditions, are still underexplored. In this paper, the effects of the oxygen temperature and upper aluminum deposition rate on the topology of the barrier layer in the aluminum-based Josephson junctions have been presented by classical molecular dynamics simulations. We apply a Voronoi tessellation method to characterize the topology of the interface and central regions of the barrier layers. We find that when the oxygen temperature is 573 K and the upper aluminum deposition rate is 4 Å/ps, the barrier has the fewest atomic voids and the most closely arranged atoms. However, if only the atomic arrangement of the central region is considered, the optimal rate of the aluminum deposition is 8 Å/ps. This work provides microscopic guidance for the experimental preparation of Josephson junctions, which helps to improve the performance of qubits and accelerate the practical application of quantum computers.

8.
Front Oncol ; 12: 1009700, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36505775

RESUMO

Background: As a malignant digestive system tumor, pancreatic cancer has unique metabolic characteristics. In recent years, the study of pancreatic cancer metabolism is in full swing, which provides a new direction for the treatment of pancreatic cancer patients. However, there is no systematic report of pancreatic cancer metabolism. In this paper, bibliometrics and visualization methods were used to analyze the number of publications, countries/regions, authors, institutions, journals, co-cited references, and keywords of pancreatic cancer metabolism articles, to summarize the research trends and predict research hotspots. Methods: We searched, screened and downloaded articles on pancreatic cancer metabolism through the Web of Science Core Collection (WoSCC). Using CiteSpace, VOSviewer and Bibliometrix Package to analyze publications, countries/regions, authors, institutions, journals, co-cited references, and keywords of pancreatic cancer metabolism to identify research trends and predict research hotspots. Results: According to the inclusion and exclusion criteria, a total of 5,255 articles were retrieved during the period 1943-2022. The number of publications on pancreatic cancer metabolism is increasing year by year. The United States (n=1602, 30.49%), China (n=1074, 20.44%), and Italy (n=313, 5.96%) are the three countries with the largest number of publications and citations, and there is close cooperation between countries. LI J (n=55) is the most prolific author. FUDAN UNIV (n=348) is the most published institution. CANCERS (n=118), PLOS ONE (n=93), and CANCER RESEARCH (n=80) are the most popular journals in this field. "Nutriment-deficient environment", "cancer chemoprevention" and "targeting cancer stem cell" are the main areas of focus. "immunotherapy", "ferroptosis" and "targeted therapy" are hot keywords in recent years. Taking pancreatic cancer metabolism as an entry point to study the role of traditional Chinese medicine (TCM) mainly focuses on curcumin and resveratrol, lack of broader and deeper research on TCM. Conclusions: The number of publications on pancreatic cancer metabolism has generally increased, and scholars have generally paid more attention to this field. "immunotherapy", "ferroptosis" and "targeted therapy" are the current research hotspots. The in-depth study of pancreatic cancer metabolism will provide new ideas for the treatment of pancreatic cancer.

9.
Aging (Albany NY) ; 14(15): 6047-6065, 2022 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-35963621

RESUMO

Numerous neurochemical changes occur with aging and stroke mainly affects the elderly. Our previous study has found interferon regulatory factor 5 (IRF5) and 4 (IRF4) regulate neuroinflammation in young stroke mice. However, whether the IRF5-IRF4 regulatory axis has the same effect in aged brains is not known. In this study, aged (18-20-month-old), microglial IRF5 or IRF4 conditional knockout (CKO) mice were subjected to a 60-min middle cerebral artery occlusion (MCAO). Stroke outcomes were quantified at 3d after MCAO. Flow cytometry and ELISA were performed to evaluate microglial activation and immune responses. We found aged microglia express higher levels of IRF5 and lower levels of IRF4 than young microglia after stroke. IRF5 CKO aged mice had improved stroke outcomes; whereas worse outcomes were seen in IRF4 CKO vs. their flox controls. IRF5 CKO aged microglia had significantly lower levels of IL-1ß and CD68 than controls; whereas significantly higher levels of IL-1ß and TNF-α were seen in IRF4 CKO vs. control microglia. Plasma levels of TNF-α and MIP-1α were decreased in IRF5 CKO vs. flox aged mice, and IL-1ß/IL-6 levels were increased in IRF4 CKO vs. controls. The anti-inflammatory cytokines (IL-4/IL-10) levels were higher in IRF5 CKO, and lower in IRF4 CKO aged mice vs. their flox controls. IRF5 and IRF4 signaling drives microglial pro- and anti-inflammatory response respectively; microglial IRF5 is detrimental and IRF4 beneficial for aged mice in stroke. IRF5-IRF4 axis is a promising target for developing new, effective therapeutic strategies for the cerebral ischemia.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Animais , Infarto da Artéria Cerebral Média , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Camundongos , Microglia/metabolismo , Acidente Vascular Cerebral/genética , Fator de Necrose Tumoral alfa/farmacologia
10.
Catal Sci Technol ; 12: 3804-3816, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35965882

RESUMO

Contiguous metal foams offer a multitude of advantages over conventional powders as supports for nanostructured heterogeneous catalysts; most critically a preformed 3-D porous framework ensuring full directional coverage of supported catalyst, and intrinsic ease of handling and recyclability. Nonetheless, metal foams remain comparatively underused in thermal catalysis compared to more conventional supports such as amorphous carbon, metal oxides, zeolites and more recently MOFs. Herein, we demonstrate a facile preparation of highly-reactive, robust, and easy to handle Ni foam-supported Cu-based metal catalysts. The highly sustainable synthesis requires no specialized equipment, no surfactants or additive redox reagents, uses water as solvent, and CuCl2(H2O)2 as precursor. The resulting material seeds as well-separated micro-crystalline Cu2(OH)3Cl evenly covering the Ni foam. Calcination above 400 °C transforms the Cu2(OH)3Cl to highly porous CuO. All materials display promising activity towards the reduction of 4-nitrophenol and methyl orange. Notably, our leading CuO-based material displays 4-nitrophenol reduction activity comparable with very reactive precious-metal based systems. Recyclability studies highlight the intrinsic ease of handling for the Ni foam support, and our results point to a very robust, highly recyclable catalyst system.

11.
Stroke ; 52(10): 3362-3373, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34353112

RESUMO

Background and Purpose: CD200 (cluster of differentiation 200), a highly glycosylated protein primarily expressed on neurons in the central nervous system, binds with its receptor CD200R to form an endogenous inhibitory signal against immune responses. However, little is known about the effect of neuronal CD200 signaling in cerebral ischemia. The aim of this study was to investigate how neuronal CD200 signaling impacts poststroke inflammation and the ischemic injury. Methods: CD200 tma1lf/fl:Thy1CreER mice were treated with tamoxifen to induce conditional gene knockout (ICKO) of neuronal CD200. The mice were subjected to a 60-minute transient middle cerebral artery occlusion. Stroke outcomes, apoptotic cell death, immune cell infiltration, microglia activation, and other inflammatory profiles were evaluated at 3 and 7 days after stroke. Results: Infarct volumes were significantly larger, and behavioral deficits more severe in ICKO versus control mice at 3 days after middle cerebral artery occlusion. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay also revealed a significant increase in apoptotic neuronal death in CD200 ICKO mice. An enhancement in lymphocytic infiltration and microglial proinflammatory responses were revealed by flow cytometry at 3 and 7 days after stroke in ICKO mice, accompanied by an increased microglial phagocytosis activity. Plasma proinflammatory cytokine (TNFα [tumor necrosis factor alpha] and IL [interleukin]-1ß) levels significantly increased at 3 days, and IL-1ß/IL-6 levels increased at 7 days in ICKO versus control animals. ICKO led to significantly lower baseline level of CD200 both in brain and plasma. Conclusions: Neuronal CD200 inhibits proinflammatory responses and is protective against stroke injury.


Assuntos
Antígenos CD/análise , AVC Isquêmico/prevenção & controle , Neurônios/fisiologia , Neuroproteção , Acidente Vascular Cerebral/prevenção & controle , Animais , Antígenos CD/genética , Apoptose , Citocinas/metabolismo , Imunidade Celular , Infarto da Artéria Cerebral Média/complicações , Inflamação/etiologia , Inflamação/prevenção & controle , AVC Isquêmico/psicologia , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/imunologia , Infiltração de Neutrófilos , Transdução de Sinais , Resultado do Tratamento
12.
Aging (Albany NY) ; 13(12): 15917-15941, 2021 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-34139671

RESUMO

The G-quadruplex (G4-DNA or G4) is a secondary DNA structure formed by DNA sequences containing multiple runs of guanines. While it is now firmly established that stabilized G4s lead to enhanced genomic instability in cancer cells, whether and how G4s contribute to genomic instability in brain cells is still not clear. We previously showed that, in cultured primary neurons, small-molecule G4 stabilizers promote formation of DNA double-strand breaks (DSBs) and downregulate the Brca1 gene. Here, we determined if G4-dependent Brca1 downregulation is unique to neurons or if the effects in neurons also occur in astrocytes and microglia. We show that primary neurons, astrocytes and microglia basally exhibit different G4 landscapes. Stabilizing G4-DNA with the G4 ligand pyridostatin (PDS) differentially modifies chromatin structure in these cell types. Intriguingly, PDS promotes DNA DSBs in neurons, astrocytes and microglial cells, but fails to downregulate Brca1 in astrocytes and microglia, indicating differences in DNA damage and repair pathways between brain cell types. Taken together, our findings suggest that stabilized G4-DNA contribute to genomic instability in the brain and may represent a novel senescence pathway in brain aging.


Assuntos
Astrócitos/metabolismo , Quadruplex G , Microglia/metabolismo , Neurônios/metabolismo , Aminoquinolinas/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/ultraestrutura , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Sequência de Bases , Linhagem Celular , Cromatina/efeitos dos fármacos , Cromatina/metabolismo , Cromatina/ultraestrutura , Dano ao DNA , Camundongos , Microglia/efeitos dos fármacos , Microglia/ultraestrutura , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Ácidos Picolínicos/farmacologia , Regiões Promotoras Genéticas/genética , Ratos
13.
J Neuroinflammation ; 18(1): 70, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33712031

RESUMO

BACKGROUND: Stroke is a sexually dimorphic disease. Previous studies have found that young females are protected against ischemia compared to males, partially due to the protective effect of ovarian hormones, particularly estrogen (E2). However, there are also genetic and epigenetic effects of X chromosome dosage that contribute to stroke sensitivity and neuroinflammation after injury, especially in the aged. Genes that escape from X chromosome inactivation (XCI) contribute to sex-specific phenotypes in many disorders. Kdm5c and kdm6a are X escapee genes that demethylate H3K4me3 and H3K27me3, respectively. We hypothesized that the two demethylases play critical roles in mediating the stroke sensitivity. METHODS: To identify the X escapee genes involved in stroke, we performed RNA-seq in flow-sorted microglia from aged male and female wild type (WT) mice subjected to middle cerebral artery occlusion (MCAO). The expression of these genes (kdm5c/kdm6a) were confirmed in four core genotypes (FCG) mice and in post-mortem human stroke brains by immunohistochemistry (IHC), Western blot, and RT-PCR. Chromatin immunoprecipitation (ChIP) assays were conducted to detect DNA levels of inflammatory interferon regulatory factor (IRF) 4/5 precipitated by histone H3K4 and H3K27 antibodies. Manipulation of kdm5c/kdm6a expression with siRNA or lentivirus was performed in microglial culture, to determine downstream pathways and examine the regulatory roles in inflammatory cytokine production. RESULTS: Kdm5c and kdm6a mRNA levels were significantly higher in aged WT female vs. male microglia, and the sex difference also existed in ischemic brains from FCG mice and human stroke patients. The ChIP assay showed the IRF 4/5 had higher binding levels to demethylated H3K4 or H3K27, respectively, in female vs. male ischemic microglia. Knockdown or over expression of kdm5c/kdm6a with siRNA or lentivirus altered the methylation of H3K4 or H3K27 at the IRF4/5 genes, which in turn, impacted the production of inflammatory cytokines. CONCLUSIONS: The KDM-Histone-IRF pathways are suggested to mediate sex differences in cerebral ischemia. Epigenetic modification of stroke-related genes constitutes an important mechanism underlying the ischemic sexual dimorphism.


Assuntos
Epigênese Genética/genética , Inflamação/genética , AVC Isquêmico/genética , Caracteres Sexuais , Cromossomo X/genética , Idoso , Idoso de 80 Anos ou mais , Animais , Imunoprecipitação da Cromatina , Citocinas/biossíntese , Feminino , Genótipo , Histona Desmetilases/genética , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , RNA Interferente Pequeno/genética , Transdução de Sinais/genética
14.
Transl Stroke Res ; 12(4): 602-614, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32761315

RESUMO

Immune responses to neonatal hypoxic ischemic encephalopathy (HIE) exacerbate brain injury. Phagocytes, including microglia, play a central role in the immune response, but how the activation of phagocytes is regulated remains elusive. Previously, we have reported that interferon regulatory factor 5 (IRF5) signaling is closely correlated with a pro-inflammatory microglial phenotype in adult mice after stroke. The present study investigated IRF5's regulatory role in post-HIE inflammation. Male IRF5 conditional knockout (CKO) and IRF5fl/fl postnatal day 10 (P10) pups were subjected to the Rice-Vannucci model (RVM) to induce HIE. Outcomes including morphological and neurobehavioral changes were evaluated at day 7 after HIE. Microglia/macrophage phenotypes and inflammatory responses were evaluated by flow cytometry (FC), RT-PCR, and multiplex cytokine assays. Lenti-IRF5 virus was administered in microglia-neuron co-cultures to evaluate the effects of microglial IRF5 upregulation in ischemic neurons exposed to oxygen-glucose deprivation (OGD). Deletion of phagocytic IRF5 resulted in significantly decreased IRF5 expression, attenuated pro-inflammatory and enhanced anti-inflammatory responses to HIE, and improved outcomes compared with IRF5fl/fl control pups. In vitro lentivirus transfection experiments revealed that overexpression of IRF5 in microglia amplified pro-inflammatory signals and exacerbated OGD-induced neuronal apoptosis and neurite fragmentation. IRF5 signaling mediates microglial pro-inflammatory activation and also affects anti-inflammatory responses. Phagocytic IRF5 signaling is detrimental in HIE and is a potential therapeutic target for post-ischemic inflammation.


Assuntos
Hipóxia-Isquemia Encefálica , Animais , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Microglia/metabolismo , Transdução de Sinais
15.
J Hazard Mater ; 388: 121729, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31787400

RESUMO

A series of ceria-zirconia solid solutions (CexZr1-xO2) were prepared by co-precipitation method and then sulfated with SO2 + O2 at 200 °C. Subsequent testing with the selective catalytic reduction of NO by NH3 (NH3-SCR) showed that the activity of the sulfated CexZr1-xO2 catalysts oxide catalysts exhibited a volcano-type tendency with increasing Zr content. Furthermore, the sulfated Ce0.6Zr0.4O2 catalyst showed the most desirable NH3-SCR activity at 250-300 °C, and exhibited much better SO2 resistance at 250 °C. Detailed characterization results demonstrated that Ce0.6Zr0.4O2 could adsorb more surface sulfate species and then produce more stable acid sites than pure CeO2 at 200 °C. After sulfation treatment, more Ce3+ and oxygen vacancies were formed on the surface of Ce0.6Zr0.4O2. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) experiments suggested that the nitrates species deposited on the surface of as-prepared Ce0.6Zr0.4O2, which showed no reactivity, could barely deposit on the same sample after sulfation. While, the sulfated Ce0.6Zr0.4O2 had more reactive acid sites to participate in the NH3-SCR and the reaction proceeded via Eley-Rideal mechanism. This work proved that sulfation treatment could be used in designing an efficient cerium-zirconium based NH3-SCR catalyst with great application prospect.

16.
Behav Brain Res ; 369: 111931, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31047922

RESUMO

Neonatal hypoxic ischemia encephalopathy (HIE) leads to major deficits in language development. While clinically there is a known correlation in the degree of HIE injury and subsequent language disability, there are no treatments beyond speech and language therapy; therefore, experimental studies with a HIE animal model to test new interventions and therapeutics are warranted. Neonatal rodents normally ultrasonically vocalize at postnatal day 7 (PND 7) to PND 14 in response to removal from their mothers. At 6-8 weeks of age juvenile male rodents ultrasonically vocalize in response to exposure to a mature female mouse. Changes in ultrasonic vocalization (USV) production after neonatal brain injury, such ashypoxic ischemia (HI), have not been studied. This study examines the acute and long-term ultrasonic vocalization ability of mice after HI at PND 10. Pups were subjected to HI, sham, or naïve conditions; where in HI and sham surgeries the right common carotid artery was exposed, in the HI this artery was double ligated. The HI and sham pups were then exposed to60minof hypoxia. Naïve pups did not undergo surgery and were subjected to60minof room air. At 3 days following surgery, HI and sham pups vocalize less than nonsurgical naïve controls; yet "juvenile" mice of 6-8 weeks old that underwent HI at PND 10 vocalize less than sham and naïve mice. We conclude that HI injury has significant impact on later adult vocalization.


Assuntos
Hipóxia-Isquemia Encefálica/fisiopatologia , Vocalização Animal/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/metabolismo , Lesões Encefálicas/fisiopatologia , Modelos Animais de Doenças , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Isquemia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Ondas Ultrassônicas
17.
Acta Neuropathol ; 136(1): 89-110, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29752550

RESUMO

The peripheral immune system plays a critical role in aging and in the response to brain injury. Emerging data suggest inflammatory responses are exacerbated in older animals following ischemic stroke; however, our understanding of these age-related changes is poor. In this work, we demonstrate marked differences in the composition of circulating and infiltrating leukocytes recruited to the ischemic brain of old male mice after stroke compared to young male mice. Blood neutrophilia and neutrophil invasion into the brain were increased in aged animals. Relative to infiltrating monocyte populations, brain-invading neutrophils had reduced phagocytic potential, and produced higher levels of reactive oxygen species and extracellular matrix-degrading enzymes (i.e., MMP-9), which were further exacerbated with age. Hemorrhagic transformation was more pronounced in aged versus young mice relative to infarct size. High numbers of myeloperoxidase-positive neutrophils were found in postmortem human brain samples of old (> 71 years) acute ischemic stroke subjects compared to non-ischemic controls. Many of these neutrophils were found in the brain parenchyma. A large proportion of these neutrophils expressed MMP-9 and positively correlated with hemorrhage and hyperemia. MMP-9 expression and hemorrhagic transformation after stroke increased with age. These changes in the myeloid response to stroke with age led us to hypothesize that the bone marrow response to stroke is altered with age, which could be important for the development of effective therapies targeting the immune response. We generated heterochronic bone marrow chimeras as a tool to determine the contribution of peripheral immune senescence to age- and stroke-induced inflammation. Old hosts that received young bone marrow (i.e., Young → Old) had attenuation of age-related reductions in bFGF and VEGF and showed improved locomotor activity and gait dynamics compared to isochronic (Old → Old) controls. Microglia in young heterochronic mice (Old → Young) developed a senescent-like phenotype. After stroke, aged animals reconstituted with young marrow had reduced behavioral deficits compared to isochronic controls, and had significantly fewer brain-infiltrating neutrophils. Increased rates of hemorrhagic transformation were seen in young mice reconstituted with aged bone marrow. This work suggests that age alters the immunological response to stroke, and that this can be reversed by manipulation of the peripheral immune cells in the bone marrow.


Assuntos
Envelhecimento , Citocinas/metabolismo , Infarto da Artéria Cerebral Média/imunologia , Infarto da Artéria Cerebral Média/fisiopatologia , Células Mieloides/patologia , Neutrófilos/patologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Medula Óssea/patologia , Modelos Animais de Doenças , Comportamento Exploratório/fisiologia , Transtornos Neurológicos da Marcha/etiologia , Força da Mão/fisiologia , Hemoglobinas/metabolismo , Elevação dos Membros Posteriores/fisiologia , Humanos , Infarto da Artéria Cerebral Média/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
18.
J Hazard Mater ; 353: 340-347, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29680692

RESUMO

The Fe-Zr binary oxide adsorbents have higher arsenic adsorptive capacities than either iron oxide or zirconium oxide alone, indicating a strong synergistic effect exists between Fe and Zr oxides. However, no generally accepted in-depth explanations have been reached on the origin of this better performance. In the present study, the component phases, the active surface sites, the structure of the adsorbed As(V) surface species, and the mechanism of the synergistic effect, were investigated and elucidated using multiple advanced experimental techniques combined with quantum chemical calculations. Goethite and lepidocrocite were identified as the main Fe oxide components while amorphous zirconium hydroxide was the main Zr oxide component, respectively. A monodentate-mononuclear complex and a bidentate-binuclear complex were revealed to be dominant on the surface, respectively, when at lower and higher initial As(V) concentrations. Density functional theory calculations indicated that As(V) preferred to bind with Zr-OH rather than Fe-OH. This was verified with the As K-edge EXAFS results and XPS observations. The synergistic effect was due to a short-range ordering state, the enlarged contents of amorphous and poorly-crystalline fractions, and increased hydroxyl surface site density. These results lead to the realization that the above properties are preferred in future adsorbent preparations.

19.
Cell Transplant ; 27(9): 1328-1339, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29692197

RESUMO

Neonatal hypoxic-ischemic encephalopathy (HIE) is increasingly recognized as a sexually dimorphic disease. Male infants are not only more vulnerable to ischemic insult; they also suffer more long-term cognitive deficits compared with females with comparable brain damage. The innate immune response plays a fundamental role in mediating acute neonatal HIE injury. However, the mechanism underlying the sex difference in chronic HIE is still elusive. The present study investigated the sex difference in HIE outcomes and inflammatory response in the chronic stage (30 days after HIE). Postnatal day 10 (P10) male and female C57BL/6 pups were subjected to 60-min Rice-Vanucci model (RVM) to induce HIE. Brain atrophy and behavioral deficits were analyzed to measure stroke outcomes at 30 days of HIE. Flow cytometry (FC) was performed to examine central (microglial activation) and peripheral immune responses. Serum levels of cytokines and sex hormones were determined by enzyme-linked immunosorbent assay (ELISA). Neurogenesis was quantified by 5-Bromo-2'-deoxyuridine (BrdU) incorporation with neurons. Results showed males had worse HIE outcomes than females at the endpoint. Female microglia exhibited a more robust anti-inflammatory response that was corresponding to an enhanced expression of CX3C chemokine receptor 1 (CX3CR1) than males. More infiltration of peripheral lymphocytes was seen in male vs. female HIE brains. Cytokine levels of tumor necrosis factor (TNF)-α and interleukin (IL)-10 were more upregulated in males and females respectively than their counterparts. Neurogenesis was more highly induced in females vs. males. No significant difference in circulating hormonal level was found between males and females after HIE. We conclude that a sex dichotomy in pro- and anti-inflammatory response underlies the sex-specific chronic HIE outcomes, and an enhanced neurogenesis in females also contribute to the sex difference.


Assuntos
Encéfalo/imunologia , Hipóxia-Isquemia Encefálica/imunologia , Inflamação/imunologia , Animais , Encéfalo/patologia , Receptor 1 de Quimiocina CX3C/análise , Receptor 1 de Quimiocina CX3C/imunologia , Doença Crônica , Citocinas/sangue , Citocinas/imunologia , Feminino , Hipóxia-Isquemia Encefálica/sangue , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/patologia , Inflamação/sangue , Inflamação/complicações , Inflamação/patologia , Lectinas Tipo C/análise , Lectinas Tipo C/imunologia , Leucócitos/imunologia , Leucócitos/patologia , Masculino , Receptor de Manose , Lectinas de Ligação a Manose/análise , Lectinas de Ligação a Manose/imunologia , Camundongos Endogâmicos C57BL , Microglia/imunologia , Microglia/patologia , Receptores de Superfície Celular/análise , Receptores de Superfície Celular/imunologia , Fatores Sexuais
20.
Aging (Albany NY) ; 8(7): 1432-41, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27405096

RESUMO

Stroke is a sexually dimorphic disease. Elderly women not only have higher stroke incidence than age-matched men, but also have poorer recovery and higher morbidity and mortality after stroke. In older, post-menopausal women, gonadal hormone levels are similar to that of men. This suggests that tissue damage and functional outcomes are influenced by biologic sex (XX vs. XY) rather than the hormonal milieu at older ages. We employed the Four Core Genotype (FCG) mouse model to study the contribution of sex chromosome complement and gonadal hormones to stroke sensitivity in aged mice in which the testis determining gene (Sry) is removed from the Y chromosome, allowing for the generation of XX males and XY females. XXF, XXM, XYF, XYM and XYwt aged mice were subjected to middle cerebral artery occlusion (MCAO). XXF and XXM mice had significantly larger infarct volumes than XYF and XYM cohorts respectively. There was no significant difference in hormone levels among aged FCG mice. XXF/XXM mice also had more robust microglial activation and higher serum levels of pro-inflammatory cytokines than XYF/XYM cohort respectively. We concluded that the sex chromosome complement contributes to ischemic sensitivity in aged animals and leads to sex differences in innate immune responses.


Assuntos
Suscetibilidade a Doenças , Estradiol/sangue , Cromossomos Sexuais , Acidente Vascular Cerebral/etiologia , Testosterona/sangue , Animais , Citocinas , Feminino , Genótipo , Masculino , Camundongos , Microglia/patologia , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/patologia
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