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1.
Proc Natl Acad Sci U S A ; 120(13): e2217576120, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36943878

RESUMO

Diabetes can result in impaired corneal wound healing. Mitochondrial dysfunction plays an important role in diabetic complications. However, the regulation of mitochondria function in the diabetic cornea and its impacts on wound healing remain elusive. The present study aimed to explore the molecular basis for the disturbed mitochondrial metabolism and subsequent wound healing impairment in the diabetic cornea. Seahorse analysis showed that mitochondrial oxidative phosphorylation is a major source of ATP production in human corneal epithelial cells. Live corneal biopsy punches from type 1 and type 2 diabetic mouse models showed impaired mitochondrial functions, correlating with impaired corneal wound healing, compared to nondiabetic controls. To approach the molecular basis for the impaired mitochondrial function, we found that Peroxisome Proliferator-Activated Receptor-α (PPARα) expression was downregulated in diabetic human corneas. Even without diabetes, global PPARα knockout mice and corneal epithelium-specific PPARα conditional knockout mice showed disturbed mitochondrial function and delayed wound healing in the cornea, similar to that in diabetic corneas. In contrast, fenofibrate, a PPARα agonist, ameliorated mitochondrial dysfunction and enhanced wound healing in the corneas of diabetic mice. Similarly, corneal epithelium-specific PPARα transgenic overexpression improved mitochondrial function and enhanced wound healing in the cornea. Furthermore, PPARα agonist ameliorated the mitochondrial dysfunction in primary human corneal epithelial cells exposed to diabetic stressors, which was impeded by siRNA knockdown of PPARα, suggesting a PPARα-dependent mechanism. These findings suggest that downregulation of PPARα plays an important role in the impaired mitochondrial function in the corneal epithelium and delayed corneal wound healing in diabetes.


Assuntos
Diabetes Mellitus Experimental , PPAR alfa , Camundongos , Humanos , Animais , PPAR alfa/genética , PPAR alfa/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Córnea/metabolismo , Cicatrização/fisiologia , Camundongos Knockout , Mitocôndrias/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(48): e2208934119, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36409895

RESUMO

In ischemic retinopathy, overactivated retinal myeloid cells are a crucial driving force of pathological angiogenesis and inflammation. The cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) signaling are key regulators of inflammation. This study aims to investigate the association of cGAS-STING signaling with ischemic retinopathy and the regulation of its activation. We found that protein levels of cGAS and STING were markedly up-regulated in retinal myeloid cells isolated from mice with oxygen-induced retinopathy (OIR). Knockout of Sting and pharmacological inhibition of STING both alleviated retinal neovascularization (NV) and reduced retinal vascular leakage in OIR. Further, Sting knockout and STING inhibitor also alleviated leukocyte adhesion to retinal vasculature and infiltration into the retina as well as microglial activation in OIR. These results suggest that cGAS-STING signaling played a pathogenic role in retinal myeloid cell activation and NV in ischemic retinopathy. To identify the regulation of cGAS-STING signaling in OIR, we evaluated the role of transcription factor peroxisome proliferator-activated receptor α (PPARα). The results demonstrated that PPARα was down-regulated in OIR retinas, primarily in myeloid cells. Furthermore, Pparα knockout significantly up-regulated cGAS and STING levels in retinal CD11b+ cells, while PPARα agonist inhibited cGAS-STING signaling and cytosolic mitochondrial DNA (mtDNA) release, a causative feature for cGAS activation. Knockout of Sting ameliorated retinal NV, hyperpermeability, and leukostasis in Pparα-/- mice with OIR. These observations suggest that PPARα regulates cGAS-STING signaling, likely through mtDNA release, and thus, is a potential therapeutic target for ischemic retinopathy.


Assuntos
PPAR alfa , Doenças Retinianas , Animais , Camundongos , Modelos Animais de Doenças , DNA Mitocondrial , Inflamação , Isquemia/complicações , Proteínas de Membrana/metabolismo , Camundongos Knockout , Neovascularização Patológica , Nucleotidiltransferases/metabolismo , PPAR alfa/genética , Doenças Retinianas/genética
3.
Phys Chem Chem Phys ; 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39129465

RESUMO

Cracks originating from thermal expansion and thermally induced phase transitions significantly hinder thermal conduction in certain energetic materials. For 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) crystals, a classic explosive, their temperature-dependent thermal conductivity serves as a crucial parameter determining safety and stability. In this work, the thermal conductivity of HMX single crystals before and after thermal damage under different heating conditions was measured and calculated, as well as the thermal conductivity of different regions of each single crystal. A threefold discrepancy in thermal conductivity was observed between room temperature and the phase transition temperature of the HMX crystal. The different effects of different types of damage and cracks, characterized by using 3D X-ray computed tomography (CT), on the thermal conduction process of the crystal were further analyzed. The results indicate that different heating methods influence the phase transformation of the crystals and the distributions of fast cracks and small cracks. The strong directivity of the fast cracks will significantly impact the thermal conductivity along two horizontal directions, whereas small cracks exert the greatest influence on the primary direction of heat conduction. The relevant conclusions were also verified by finite element analysis (FEA) modeling.

4.
Nano Lett ; 23(20): 9392-9398, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37819081

RESUMO

Anode-free all-solid-state lithium metal batteries (ASLMBs) promise high energy density and safety but suffer from a low initial Coulombic efficiency and rapid capacity decay, especially at high cathode loadings. Using operando techniques, we concluded these issues were related to interfacial contact loss during lithium stripping. To address this, we introduce a conductive carbon felt elastic layer that self-adjusts the pressure at the anode side, ensuring consistent lithium-solid electrolyte contact. This layer simultaneously provides electronic conduction and releases the plating pressure. Consequently, the first Coulombic efficiency dramatically increases from 58.4% to 83.7% along with a >10-fold improvement in cycling stability. Overall, this study reveals an approach for enhancing anode-free ASLMB performance and longevity by mitigating lithium stripping inefficiency through self-adjusting interfacial pressure enabled by a conductive elastic interlayer.

5.
Phys Chem Chem Phys ; 25(23): 15756-15766, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37254560

RESUMO

As a new type of energetic material, cocrystal explosives demonstrate many excellent properties, such as high energy density and low sensitivity, due to the interaction between the molecules of the two components. The known decomposition temperature is 235 °C for CL-20/HMX cocrystals at a faster heating rate. CL-20 molecules could separate from the cocrystal matrix and decompose at a higher temperature, much lower than the decomposition temperature. The current work provided deep insight into the isothermal structural evolution of CL-20/HMX cocrystals with slow roasting at 190 °C. We found that the initial decomposition originates from separating CL-20 molecules from the surface along the (010) plane of the cocrystals. The gas products, such as NO2 and NO, escape from the largest exposed surface of the (010) plane and generates microbubbles and microholes. At the same time, the residual HMX molecules form δ-phase HMX crystals and shrink the volume by 72%. By increasing the time held at 190 °C, the decomposition of CL-20 molecules and recrystallization of the residual HMX molecules form a gully-like structure on the (010) plane of the CL-20/HMX cocrystal. After a long time at 190 °C, the CL-20 component completely decomposes, and all HMX molecules recrystallize in the δ-HMX form. The interaction between HMX and CL-20 molecules makes the decomposition rate of the CL-20/HMX cocrystal much slower than that of the CL-20 pure crystal with a similar decomposition activation energy during isothermal heating. This work can help to deeply understand the safety of CL-20/HMX cocrystal explosives at a temperature lower than the recognized decomposition temperature.

6.
J Biol Chem ; 297(4): 101185, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34509473

RESUMO

Very low-density lipoprotein receptor (VLDLR) is a multifunctional transmembrane protein. Beyond the function of the full-length VLDLR in lipid transport, the soluble ectodomain of VLDLR (sVLDLR) confers anti-inflammatory and antiangiogenic roles in ocular tissues through inhibition of canonical Wnt signaling. However, it remains unknown how sVLDLR is shed into the extracellular space. In this study, we present the first evidence that a disintegrin and metalloprotease 17 (ADAM17) is responsible for sVLDLR shedding in human retinal pigment epithelium cells using pharmacological and genetic approaches. Among selected proteinase inhibitors, an ADAM17 inhibitor demonstrated the most potent inhibitory effect on sVLDLR shedding. siRNA-mediated knockdown or CRISPR/Cas9-mediated KO of ADAM17 diminished, whereas plasmid-mediated overexpression of ADAM17 promoted sVLDLR shedding. The amount of shed sVLDLR correlated with an inhibitory effect on the Wnt signaling pathway. Consistent with these in vitro findings, intravitreal injection of an ADAM17 inhibitor reduced sVLDLR levels in the extracellular matrix in the mouse retina. In addition, our results demonstrated that ADAM17 cleaved VLDLR only in cells coexpressing these proteins, suggesting that shedding occurs in a cis manner. Moreover, our study demonstrated that aberrant activation of Wnt signaling was associated with decreased sVLDLR levels, along with downregulation of ADAM17 in ocular tissues of an age-related macular degeneration model. Taken together, our observations reveal the mechanism underlying VLDLR cleavage and identify a potential therapeutic target for the treatment of disorders associated with dysregulation of Wnt signaling.


Assuntos
Proteína ADAM17/metabolismo , Degeneração Macular/metabolismo , Receptores de LDL/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Via de Sinalização Wnt , Proteína ADAM17/antagonistas & inibidores , Proteína ADAM17/genética , Animais , Modelos Animais de Doenças , Humanos , Degeneração Macular/genética , Camundongos , Camundongos Knockout , Domínios Proteicos , Receptores de LDL/genética
7.
Exp Eye Res ; 225: 109300, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36328302

RESUMO

The purpose of the study was to investigate the role of Prolactin-Induced Protein (PIP) in corneal wound healing, in vivo and in vitro. In C57BL/6J mice, corneal epithelia was removed using an ocular burr. Phosphate buffered saline (PBS) or PIP (0.5 and 1.0 µg/mL) was applied topically or subconjunctivally injected. PIP accelerated wound closure as early as 24 h. PIP treatment promoted corneal wound healing and epithelial integrity and thickness. Integrin α6, integrin ß4, Thrombospondin-1, and TGF-ß1 expressions were all downregulated by PIP after wound closure. In vitro, scratch assays were performed using primary human epithelial cells (HCECs) and human corneal fibroblasts (HCFs), stimulated with PIP at various dosages. PIP treatment promoted both HCECs and HCFs migration. PIP upregulated expression of integrin α6, integrin ß4, and Thrombospondin-1 in HCECs. Expression of TGF-ß1 in HCECs and expression of smooth muscle actin (SMA) and Type III Collagen (Col III) in HCFs were significantly downregulated at 150 ng/mL PIP. PIP exhibits noteworthy anti-fibrotic potentiality. While the mechanism of how PIP is impactful on the corneal wound healing cascade is unknown, our findings are novel and further studies are warranted in order to unravel any therapeutic potential.


Assuntos
Lesões da Córnea , Fator de Crescimento Transformador beta1 , Camundongos , Animais , Humanos , Fator de Crescimento Transformador beta1/farmacologia , Fator de Crescimento Transformador beta1/metabolismo , Prolactina/farmacologia , Integrina alfa6 , Camundongos Endogâmicos C57BL , Cicatrização/fisiologia , Trombospondinas
8.
FASEB J ; 35(12): e22058, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34820908

RESUMO

Subretinal fibrosis is a key pathological feature in neovascular age-related macular degeneration (nAMD). Previously, we identified soluble very low-density lipoprotein receptor (sVLDLR) as an endogenous Wnt signaling inhibitor. This study investigates whether sVLDLR plays an anti-fibrogenic role in nAMD models, including Vldlr-/- mice and laser-induced choroidal neovascularization (CNV). We found that fibrosis factors including P-Smad2/3, α-SMA, and CTGF were upregulated in the subretinal area of Vldlr-/- mice and the laser-induced CNV model. The antibody blocking Wnt co-receptor LRP6 significantly attenuated the overexpression of fibrotic factors in these two models. Moreover, there was a significant reduction of sVLDLR in the interphotoreceptor matrix (IPM) in the laser-induced CNV model. A transgenic strain (sVLDLR-Tg) with sVLDLR overexpression in the IPM was generated. Overexpression of sVLDLR ameliorated the profibrotic changes in the subretinal area of the laser-induced CNV model. In addition, Wnt and TGF-ß signaling synergistically promoted fibrogenesis in human primary retinal pigment epithelium (RPE) cells. CRISPR/Cas9-mediated LRP6 gene knockout (KO) attenuated this synergistic effect. The disruption of VLDLR expression promoted, while the overexpression of sVLDLR inhibited TGF-ß-induced fibrosis. These findings suggest that overactivated Wnt signaling enhances the TGF-ß pathway in subretinal fibrosis. sVLDLR confers an antifibrotic effect, at least partially, through the inhibition of Wnt signaling and thus, has therapeutic potential for fibrosis.


Assuntos
Neovascularização de Coroide/complicações , Modelos Animais de Doenças , Fibrose/prevenção & controle , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Degeneração Macular/complicações , Receptores de LDL/fisiologia , Epitélio Pigmentado da Retina/patologia , Animais , Sistemas CRISPR-Cas , Células Cultivadas , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Fibrose/etiologia , Fibrose/metabolismo , Fibrose/patologia , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/antagonistas & inibidores , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Epitélio Pigmentado da Retina/metabolismo , Proteínas Smad/genética , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Via de Sinalização Wnt
9.
J Phys Chem A ; 126(23): 3745-3757, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35648656

RESUMO

Van der Waals (vdW) chemistry in simple molecular systems may be important for understanding the structure and properties of the interiors of the outer planets and their satellites, where pressures are high and such components may be abundant. In the current study, Raman spectra and visual observation are employed to investigate the phase separation and composition determination for helium-nitrogen mixtures with helium concentrations from 20 to 95% along the 295 K isothermal compression. Fluid-fluid-solid triple-phase equilibrium and several equilibria of two phases including fluid-fluid and fluid-solid have been observed in different helium-nitrogen mixtures upon loading or unloading pressure. The homogeneous fluid in helium-nitrogen mixtures separates into a helium-rich fluid (F1) and a nitrogen-rich fluid (F2) with increasing pressure. The triple-phase point occurs at 295 K and 8.8 GPa for a solid-phase (N2)11He vdW compound, fluid F1 with around 50% helium, and fluid F2 with 95% helium. Helium concentrations of F1 coexisted with the (N2)11He vdW compound or δ-N2 in helium-nitrogen mixtures with different helium concentrations between 40 and 50% and between 20 and 40%, respectively. In addition, the helium concentration of F2 is the same in helium-nitrogen mixtures with different helium concentrations and decreases upon loading pressure. Pressure-induced nitrogen molecule ordering at 32.6 GPa and a structural phase transition at 110 GPa are observed in (N2)11He. In addition, at 187 GPa, a pressure-induced transition to an amorphous state is identified.

10.
Clin Sci (Lond) ; 134(13): 1613-1629, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32602547

RESUMO

PURPOSE: Elevated blood levels of C-reactive protein (CRP) are associated with both type 1 and type 2 diabetes and diabetic complications, such as diabetic retinopathy (DR). However, its pathogenic role in DR remains unknown. The present study aims to investigate the potential role of CRP in DR pathogenesis and explore its underlying mechanism. MATERIALS AND METHODS: Human CRP transgenic (hCRP-Tg) rats were employed for streptozotocin (STZ)-induced diabetic and oxygen-induced retinopathy (OIR) models. The retina function was monitored by electroretinography (ERG) and retinal thickness was measured by optical coherence tomography (OCT). TUNEL and cell death ELISA were performed to measure the apoptosis. Oxidative stress was detected by the measurement of reactive oxygen species (ROS) in cells and 3-Nitrotyrosine staining in tissue sections. RESULTS: In non-diabetic condition, hCRP-Tg with elevated hCRP levels in the retinas demonstrated declined ERG responses and decreased retinal thickness. In STZ-induced diabetic condition, overexpression of hCRP deteriorated retinal neurodegeneration as shown by ERG and apoptosis assays. hCRP also exacerbated retinal leukostasis and acellular capillary formation induced by diabetes. In the OIR model, overexpression of hCRP exacerbated retinal neovascularization (NV). In retinal cell lines, hCRP treatment induced cell death and over-production of ROS. Furthermore, hCRP-induced overexpression of pro-inflammatory, pro-oxidative, and pro-angiogenic factors was associated with up-regulation of CD32 and the NF-κB signaling in the retinas. CONCLUSIONS: Elevated hCRP levels play a pathogenic role in DR. Targeting the hCRP-CD32-NF-κB pathway may represent a novel therapeutic strategy for DR.


Assuntos
Proteína C-Reativa/metabolismo , Retinopatia Diabética/metabolismo , Animais , Animais Geneticamente Modificados , Apoptose , Proteína C-Reativa/genética , Retinopatia Diabética/complicações , Retinopatia Diabética/genética , Retinopatia Diabética/patologia , Humanos , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Retina/metabolismo , Retina/patologia , Neovascularização Retiniana/etiologia , Neovascularização Retiniana/genética , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia , Transdução de Sinais
11.
IUBMB Life ; 71(2): 213-222, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30360015

RESUMO

This study aimed to identify the genes related to epilepsy and their effects on epilepsy, as well as the underlying mechanism. Using microarray analysis, differentially expressed genes (DEGs) were screened out and then used to build weighted gene coexpression networks using WGCNA. Module membership and evaluation of gene significance (GS) were adopted to detect hub genes. The DAVID online tool was used to understand the function of modules and target genes. The Licl-pilocarpine chronic rat epilepsy model was used to simulate mesial temporal lobe epilepsy with an initial precipitating injury. Hippocampal expression of the proteins solute carrier family 1 member 2 (SLC1A2), glial fibrillary acidic protein, interleukin-1ß (IL-1ß), tumor necrosis factor α (TNF-α), and N-methyl-d-aspartic acid receptor (NMDAR) was determined by ELISA and Western blot. Nissl staining was used to measure neuronal loss. Immunohistochemistry was performed to assess the percentage of positive cells to reflect the distribution of NMDAR1. Here, 3232 potential genes highly correlated with epilepsy were selected from the screened DEGs, among which SLC1A2 was related to brain development and its expression was significantly decreased in epilepsy patients. According to Gene Ontology and KEGG analysis, SLC1A2 mediates epilepsy through the glutamatergic synapse pathway. Tissue experiments suggested that Slc1a2 could genuinely ameliorate epilepsy through the glutamatergic synapse pathway, mitigate neuronal loss, and suppress astrocytosis and inflammatory responses. Our study suggested that low hippocampal content of SLC1A2 is a potential biomarker of epilepsy and may affect the function of neurons through the glutamatergic synapse pathway. © 2018 IUBMB Life, 71(1):213-222, 2019.


Assuntos
Epilepsia do Lobo Temporal/genética , Transportador 2 de Aminoácido Excitatório/genética , Neurônios/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Sinapses/metabolismo , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Biomarcadores/metabolismo , Morte Celular , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Epilepsia do Lobo Temporal/fisiopatologia , Transportador 2 de Aminoácido Excitatório/metabolismo , Regulação da Expressão Gênica , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Cloreto de Lítio/administração & dosagem , Masculino , Neurônios/patologia , Pilocarpina/administração & dosagem , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapses/patologia , Transmissão Sináptica , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
12.
J Am Chem Soc ; 139(23): 7893-7903, 2017 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-28535684

RESUMO

Many industrial catalysts are composed of metal particles supported on metal oxides (MMO). It is known that the catalytic activity of MMO materials is governed by metal and metal oxide interactions (MMOI), but how to optimize MMO systems via manipulation of MMOI remains unclear, due primarily to the ambiguous nature of MMOI. Herein, we develop a Pt/NbOx/C system with tunable structural and electronic properties via a modified arc plasma deposition method. We unravel the nature of MMOI by characterizing this system under reactive conditions utilizing combined electrochemical, microscopy, and in situ spectroscopy. We show that Pt interacts with the Nb in unsaturated NbOx owing to the oxygen deficiency in the MMO interface, whereas Pt interacts with the O in nearly saturated NbOx, and further interacts with Nb when the oxygen atoms penetrate into the Pt cluster at elevated potentials. While the Pt-Nb interactions do not benefit the inherent activity of Pt toward oxygen reduction reaction (ORR), the Pt-O interactions improve the ORR activity by shortening the Pt-Pt bond distance. Pt donates electrons to NbOx in both Pt-Nb and Pt-O cases. The resultant electron eficiency stabilizes low-coordinated Pt sites, hereby stabilizing small Pt particles. This determines the two characteristic features of MMO systems: dispersion of small metal particles and high catalytic durability. These findings contribute to our understandings of MMO catalytic systems.


Assuntos
Carbono/química , Nióbio/química , Óxidos/química , Oxigênio/química , Platina/química , Catálise , Técnicas Eletroquímicas , Oxirredução , Tamanho da Partícula , Propriedades de Superfície
13.
Langmuir ; 33(37): 9246-9253, 2017 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-28445640

RESUMO

Anion immunity toward the oxygen reduction reaction (ORR) has tremendous implications in electrocatalysis with applications for fuel cells, metal-air batteries, and oxygen depolarized cathodes (ODCs) in the anodic evolution of chlorine. The necessity of exploring ORR catalysts with immunity to anion adsorption is particularly significant considering that platinum group metal (PGM) catalysts are costly and highly vulnerable to impurities such as halides. Herein, we report a metal organic framework (MOF)-derived Fe-N-C catalyst that exhibits a dramatically improved half-wave potential of 240 mV compared to the state-of-the-art RhxSy/C catalyst in a rotating disk electrode in the presence of Cl-. The Fe-N4 active sites in Fe-N-C are intrinsically immune to Cl- poisoning, in contrast to Pt/C, which is severely susceptible to Cl- poisoning. As a result, the activity of Fe-N-C decreases only marginally in the presence of Cl-, far exceeding that of Pt/C. The viability of this catalyst as ODCs is further demonstrated in real-life hydrochloric acid electrolyzers using highly concentrated HCl solution saturated with Cl2 gas as the electrolyte. The introduction of Fe-N-C materials as ODC catalysts here overcomes the limitations of (i) the low intrinsic ORR activity of RhxSy/C as the state-of-the-art ODC catalyst; (ii) the vulnerability to Cl- poisoning of Pt/C as the state-of-the-art ORR catalyst; and (iii) the high cost of precious metals in these two materials, resulting in a cost-effective ODC catalyst with the overall performance exceeding that of all previously reported materials.

14.
Cell Biol Int ; 40(2): 204-13, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26503216

RESUMO

Gastric cancer is the second leading cause of cancer-related mortality worldwide. Adoptive cell therapy (ACT) for gastric cancer is a novel therapy modality. However, the therapeutic effectiveness in vivo is still limited. The objective of this study was to assess the value of interleukin-15 (IL-15)-transferred cytokine-induced killer (CIK) cells in ACT for gastric cancer. IL-15-IRES-TK retroviral vector was constructed and transferred into the CIK cells. A gastric tumor-bearing nude mice model was constructed by subcutaneously injecting gastric cancer cells, BGC-823. Gastric tumor-bearing nude mice were randomly divided into three groups (five mice each group) and injected with physiological saline, CIK cells, and IL-15-IRES-TK-transfected CIK cells for 2 weeks, respectively. IL-15-IRES-TK-transferred CIK cells were prepared successfully and flow cytometry (FCM) analysis indicated that the transfection rate reached 85.7% after 5 days culture. In vivo experiment, we found that CIK cells retarded tumor growth by reducing tumor volume and tumor weight, as well as increasing tumor inhibition rate. Furthermore, IL-15-IRES-TK-transferred CIK cells showed a much stronger inhibition on tumor growth than CIK cells alone. Tumor morphology observation and growth indexes also showed that IL-15-transfected CIK cells had stronger cytotoxicity to tumor tissue than CIK cells. IL-15-IRES-TK transfection could elevate the effects of CIK cells to gastric carcinoma. The engineered CIK cells carrying IL-15-IRES-TK may be used in the ACT for gastric carcinoma, but prudent clinical trial is still indispensable.


Assuntos
Imunoterapia Adotiva/métodos , Interleucina-15/imunologia , Células T Matadoras Naturais/imunologia , Neoplasias Gástricas/terapia , Animais , Antineoplásicos/farmacologia , Apoptose/imunologia , Linhagem Celular Tumoral , Células Matadoras Induzidas por Citocinas/efeitos dos fármacos , Humanos , Interleucina-15/biossíntese , Interleucina-15/genética , Masculino , Camundongos , Camundongos Nus , Distribuição Aleatória , Neoplasias Gástricas/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Tumour Biol ; 36(6): 4535-43, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25627006

RESUMO

Addition of immunoregulation factor to an oncolytic adenovirus being constructed is a developmental step in tumor gene therapy; however, cytokine IL-15 has not been frequently used as a potential cancer therapy agent. Here, we constructed an E2F-1 promoter oncolytic adenovirus based on type 5 adenovirus, which induces viral replication and proliferation in targeted tumor cells. We inserted the IL-15 gene into the E3 region of the model and found that human IL-15 expressing oncolytic adenovirus (Ad-E2F/IL15) shows a more intense antitumor effect than simple oncolytic viruses (Ad-E2F) do. Precisely because IL-15 can activate natural killer (NK) cells, CD8(+)T cells, and other immune cells, in antitumor therapy, Ad-E2F/IL15 was used in combination with cytotoxic T lymphocytes (CTL) to create a virus that can induce IL-15 gene expression while lysing tumors and stimulating the activity and function of adoptive immune cells. The therapeutic effect of this therapy is clearly stronger than that of a single application of oncolytic viruses or CTL, and hence, it could be a potential new tumor therapy.


Assuntos
Neoplasias do Colo/imunologia , Neoplasias do Colo/terapia , Interleucina-15/genética , Terapia Viral Oncolítica , Linfócitos T Citotóxicos/imunologia , Imunidade Adaptativa/genética , Adenoviridae/genética , Adenoviridae/imunologia , Linhagem Celular Tumoral , Neoplasias do Colo/virologia , Regulação da Expressão Gênica/imunologia , Vetores Genéticos , Humanos , Interleucina-15/uso terapêutico , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Vírus Oncolíticos/genética , Vírus Oncolíticos/imunologia , Replicação Viral/genética , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Neurosurg Rev ; 38(1): 39-47; discussion 47, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25199810

RESUMO

Clinical practice guidelines (CPGs) play an important role in healthcare. The guideline development process should be precise and rigorous to ensure that the results are reproducible and not vague. To determine the quality of guidelines, the Appraisal of Guidelines and Research and Evaluation (AGREE) instrument was developed and introduced. The aim of the present study was to assess the methodological quality of clinical practice guidelines on glioma. Eight databases (including MEDLINE and Embase) were searched till to August, 2013. The methodological quality of the guidelines was assessed by four authors independently using the AGREE II instrument. Fifteen relevant guidelines were included from 940 citations. The overall agreement among reviewers was moderate (intra-class correlation coefficient = 0.83; 95% confidence interval [CI], 0.66-0.92). The mean scores were moderate for the domains "scope and purpose" (59.54) and "clarity of presentation" (65.46); however, there were low scores for the domains "stakeholder involvement" (43.80), "rigor of development" (39.01), "applicability" (31.89), and "editorial independence" (30.83). Only one third of the guidelines described the systematic methods for searching, and nearly half of the (47%) guidelines did not give a specific recommendation. Only four of 15 described a procedure for updating the guideline; meanwhile, just six guidelines in this field can be considered to be evidence-based. The quality and transparency of the development process and the consistency in the reporting of glioma guidelines need to be improved. And the quality of reporting of guidelines was disappointing. Many other methodological disadvantages were identified. In the future, glioma CPGs should be based on the best available evidence and rigorously developed and reported. Greater efforts are needed to provide high-quality guidelines that serve as a useful and reliable tool for clinical decision-making in this field.


Assuntos
Medicina Baseada em Evidências , Glioma/cirurgia , Procedimentos Neurocirúrgicos/normas , Procedimentos Neurocirúrgicos/tendências , Guias de Prática Clínica como Assunto , Tomada de Decisões , Humanos , Melhoria de Qualidade/tendências
17.
Tumour Biol ; 35(2): 1113-22, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24037896

RESUMO

Due to the anatomical structure of the rectum, the treatment of rectal cancer remains challenging. Ad-E2F, an oncolytic adenovirus containing the E2F-1 promoter, can selectively replicate within and kill cancer cells derived from solid tumors. Thus, this virus provides a novel approach for the treatment of rectal cancer. Given the poor efficacy and possible adverse reactions that arise from the use of oncolytic virus alone and the results of our analysis of the efficacy of Ad-E2F in the treatment of rectal cancer, we investigated the use of oncolytic adenovirus in combination with adoptive immunotherapy using cytokine-induced killer (CIK) cells as a therapeutic treatment for rectal cancer. Our results illustrated that E2F-1 gene expression is higher in rectal cancer tissue than in normal tissue. Furthermore, the designed oncolytic adenovirus Ad-E2F is capable of selectively killing colorectal cell lines but has no significant effect on CIK cells. The results of in vitro and in vivo experiments demonstrated that combined therapy with Ad-E2F and CIK cells produce stronger antitumor effects than the administration of Ad-E2F or CIK cells alone. For low rectal cancers that are suitable for intratumoral injection, local injections of oncolytic viruses in combination with CIK cell-based adoptive immunotherapy may be suitable as a novel comprehensive therapeutic approach.


Assuntos
Fator de Transcrição E2F1/biossíntese , Imunoterapia , Terapia Viral Oncolítica , Neoplasias Retais/imunologia , Neoplasias Retais/terapia , Adenoviridae , Terapia Combinada , Células Matadoras Induzidas por Citocinas/imunologia , Fator de Transcrição E2F1/imunologia , Regulação Neoplásica da Expressão Gênica , Humanos , Vírus Oncolíticos/imunologia , Regiões Promotoras Genéticas , Neoplasias Retais/virologia
18.
Nano Lett ; 13(11): 5212-7, 2013 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-24102207

RESUMO

The irreversible chemomechanical degradation is a critical issue in the development of high-capacity electrode materials for the next-generation lithium (Li)-ion batteries. Here we report the self-healing behavior of gallium nanodroplets (GaNDs) under electrochemical cycling at room temperature, observed with in situ transmission electron microscopy (TEM). During lithiation, the GaNDs underwent a liquid-to-solid phase transition, forming a crystalline phase (LixGa) with ~160% volume expansion. Owing to the uneven Li flow during lithiation, the fully lithiated GaNDs exhibited highly distorted morphologies. Upon delithiation, the reverse phase transition occurred, accompanied with the nucleation and growth of a nanosized void. After the GaNDs were fully delithiated, the nanovoid gradually annihilated. Our analysis, along with phase field modeling and experimental measurements of the void growth and annihilation, provides mechanistic insights into the void formation and annihilation mechanism. The GaNDs may function as an effective healing agent in durable composite electrodes for high-performance Li-ion batteries, wherein active components, such as Si, are susceptible to fracture.

19.
RSC Adv ; 14(30): 21635-21643, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38979456

RESUMO

Lamellar membranes obtained by stacking 2D layers possess ample transport pathways due to their intricate network of interlayer gaps. This makes them suitable for molecular separation applications. However, controlling the surface chemistry of the nanochannels within the membrane to tune the desired transport properties of water and ions is challenging. Ti3C2T x has been considered for water desalination because of its hydrophilic surface and negative surface charge. Most of the studies of Ti3C2T x membranes have presented promising salt rejection values in forward osmosis mode, which is less practical for water purification. Here, we investigate two types of reverse osmosis MXene-based lamellar membranes consisting of Ti3C2T x nanosheets hybridized with (i) WS2 nanosheets and (ii) polyvinyl phosphonic acid (PVPA). When hydrophilic and flexible Ti3C2T x nanosheets are interleaved with softer and more hydrophobic WS2 nanosheets in 2 : 1 mass ratio, nano capillaries with Janus chemistry are created with comparable rejection to bare Ti3C2T x membrane and threefold higher permeance values. Further, we find that decorating Ti3C2T x nanosheets with anionic polymers improves salt rejection. Our Ti3C2T x /PVPA composite membranes reject ∼97% of divalent ions and ∼80% of monovalent ions with ∼0.2 Lm-2 h-1 bar-1 of water permeance when tested with brackish water, and exhibit significantly improved chlorine resistance and cost benefits over the commercial Toray membranes.

20.
Clin Neurol Neurosurg ; 240: 108250, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38552364

RESUMO

Hypoxia is a prevalent characteristic of numerous neurological disorders including stroke, Alzheimer's disease, and Parkinson's disease. Extracellular vesicles (EVs) are minute particles released by cells that contain diverse biological materials, including proteins, lipids, and nucleic acids. They have been implicated in a range of physiological and pathological processes including intercellular communication, immune responses, and disease progression. EVs are believed to play a pivotal role in modulating the microenvironment of hypoxia-associated neurological diseases. These EVs are capable of transporting hypoxia-inducible factors such as proteins and microRNAs to neighboring or remote cells, thereby influencing their behavior. Furthermore, EVs can traverse the blood-brain barrier, shielding the brain from detrimental substances in the bloodstream. This enables them to deliver their payload directly to the brain cells, potentially intensifying the effects of hypoxia. Nonetheless, the capacity of EVs to breach the blood-brain barrier presents new opportunities for drug delivery. The objective of this study was to elucidate the role of EVs as mediators of information exchange during tissue hypoxia, a pathophysiological process in ischemic stroke and malignant gliomas. We also investigated their involvement in the progression and regression of major diseases of the central nervous system, which are pertinent to the development of therapeutic interventions for neurological disorders.


Assuntos
Vesículas Extracelulares , Humanos , Vesículas Extracelulares/metabolismo , Doenças do Sistema Nervoso/etiologia , Doenças do Sistema Nervoso/metabolismo , Hipóxia/metabolismo , Barreira Hematoencefálica/metabolismo , Animais
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