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1.
Opt Lett ; 48(24): 6573-6576, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38099802

RESUMO

We propose a Mach-Zehnder interferometer based on an in-fiber ZnO microwire structure for ultraviolet sensing. The device undergoes femtosecond laser micromachining and chemical etching on a single-mode optical fiber initially, creating a microgroove that extends to half of the core's depth, into which a single ZnO microwire is transferred. The ZnO microwire and the remaining core are used as the sensing arm and the reference arm, respectively, forming a Mach-Zehnder interferometer. To enhance the stability and the sensitivity, ZnO nanoparticles are filled into the microgroove after the ZnO microwire is transferred. The fabricated device exhibits a sensitivity of 0.86 nm/(W·cm-2) for ultraviolet sensing, along with a response time of 115 ns (rise time) and 133 µs (decay time), respectively. The proposed sensor exhibits good ultraviolet sensitivity, offering a novel approach for ultraviolet sensing technology.

2.
Am J Physiol Lung Cell Mol Physiol ; 317(3): L381-L391, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31242025

RESUMO

Ghrelin has proven to be protective against sepsis-induced acute lung injury (ALI) via anti-inflammatory effects. However, its mechanisms remain poorly understood. Alveolar macrophages (AMs) play a key role in mediating inflammatory responses during sepsis-induced ALI by secretion of cytokines and chemokines. This study was undertaken to investigate whether ghrelin suppresses inflammatory effects of AMs and therefore may help to attenuate sepsis-induced ALI. A sepsis model in rats was achieved using cecal ligation and puncture. Ghrelin treatment markedly improved histopathological changes in the lungs and reduced pulmonary inflammation in septic rats. NF-κB translocation and p-Akt and inducible nitric oxide synthase (iNOS) activities in AMs from septic rats were suppressed by ghrelin. In vitro data indicated that ghrelin decreased the levels of LPS-induced IL-1ß, TNF-α, and IL-6, NF-κB translocation, and iNOS and Akt activities of AMs. Furthermore, the NF-κB/iNOS pathway or Akt signaling was positively correlated with LPS-induced inflammatory production of AMs in vitro. In conclusion, ghrelin exerts a protective role against sepsis-induced ALI probably by reducing the production of inflammatory cytokines from AMs via inhibition of the NF-κB/iNOS pathway or Akt signaling.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Grelina/farmacologia , Macrófagos Alveolares/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Sepse/complicações , Lesão Pulmonar Aguda/patologia , Animais , Citocinas/metabolismo , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Macrófagos Alveolares/metabolismo , Masculino , Óxido Nítrico Sintase Tipo II/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Sepse/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos
3.
Cell Physiol Biochem ; 49(5): 1840-1855, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30231236

RESUMO

BACKGROUND/AIMS: In the process of abnormal apoptosis of pulmonary alveolar type II epithelial A549 cells in acute respiratory distress syndrome (ARDS), inducible nitric oxide synthase (iNOS) activity in the lung, nitric oxide (NO) production, and the level of protein S-nitrosylation were increased. However, the role of excessive NO production in sepsis-induced ARDS is controversial. Additionally, ghrelin is a growth hormone that exerts an inhibitory role in cell apoptosis. We examined the effect of NO and S-nitrosylation on apoptosis of A549 cells induced by Lipopolysaccharide (LPS) and molecular mechanism underlying the anti-apoptotic effect of ghrelin in this process. METHODS: Flow cytometry and qPCR were used to detect lentiviral infection efficiency and iNOS gene level, respectively. Extracellular and intracellular NO levels were observed by Griess assay kit and DAF-FM DA. Mitochondrial transmembrane potential, apoptosis rate and SNO levels were determined by flow cytometry, Biotin-Switch method and immunofluoresence staining. The expression of iNOS, apoptotic proteins and JNK were assessed by immunoblot analysis. RESULTS: The results showed about two times increase in iNOS expression and intracellular NO levels response to LPS exposure at 24 hours (P< 0.05), while not in extracellular NO levels. NO donors, S-nitroso-N-acetylpenicillamine (SNAP) significantly raised (36.7%, P< 0.05; 38.4%, P< 0.05; 41.8%, P< 0.05) extracellular NO levels without influencing the intracellular NO levels. LPS increased the apoptosis rate (42.4%±2.6% vs 2.8%±1%, P< 0.05) of A549 accompanied by increased Bax levels and decreased Bcl-2 levels through activating JNK signaling, which was reversed when we diminished the iNOS expression in A549 cells using lentiviral vectors encoding iNOS shRNA in the presence of LPS (24.8%±3.8% vs 42.4%±2.6%, P< 0.05). However, the apoptosis rate was increased when SNAP was added (38.8%±1.3% vs 24.8%±3.8%, P< 0.05). Furthermore, we investigated whether ghrelin exert a protective role against LPS-induced apoptosis and the potential mechanism involved in. Ghrelin alone appeared to decrease iNOS expression (32.3%, P< 0.05; 42.3%, P< 0.05), which showed no signifiant difference between LPS+ghrelin group and LPS group. However, this study showed that ghrelin decreased the intracellular NO production (38.9%, P< 0.05), protein S-nitrosylation levels (33.5%, P< 0.05), Bax protein expression (70.2%, P< 0.05), whereas increasing Bcl-2 protein expression (14.1%, P< 0.05) and mitochondrial transmembrane potential (∆ΨM) (20.7%, P< 0.05) in the presence of LPS. CONCLUSION: The data suggested that NO derived from iNOS induced by LPS stimulation exerts an important role in promoting apoptosis of A549 cells, and ghrelin abolished intracellular NO production and protein S-nitrosylation levels, abrogating the apoptosis of A549 cells partly through inhibiting mitochondrial-dependent pathways.


Assuntos
Apoptose/efeitos dos fármacos , Grelina/farmacologia , Lipopolissacarídeos/farmacologia , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico/metabolismo , Células A549 , Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , S-Nitroso-N-Acetilpenicilamina/farmacologia , Proteína X Associada a bcl-2/metabolismo
4.
Hum Mutat ; 38(11): 1500-1510, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28714182

RESUMO

Adolescent idiopathic scoliosis (AIS) is a complex genetic disorder characterized by three-dimensional spinal curvatures, affecting 2%-3% of school age children, yet the causes underlying AIS are not well understood. Here, we first conducted a whole-exome sequencing and linkage analysis on a three-generation Chinese family with autosomal-dominant (AD) AIS, and then performed targeted sequencing in a discovery cohort comprising 20 AD AIS families and 86 simplex patients, and finally identified three disease-associated missense variants (c.886G> A, c.1943C> T, and c.1760C> T) in the MAPK7 gene (encoding mitogen-activated protein kinase 7). Genotyping of the three rare variants in a Chinese replication cohort comprising 1,038 simplex patients and 1,841 controls showed that their combined allele frequency was significantly over-represented in patients as compared with controls (2.0% [41/2,076] vs. 0.7% [27/3,682]; odds ratio = 2.7; P = 2.8 × 10-5 ). In vitro, we demonstrated that the three MAPK7 mutants disrupted nuclear translocation in cellular models, which is necessary for the normal function of MAPK7. In vivo, we also conducted CRISPR/Cas9-mediated deletion of mapk7 in zebrafish recapitulating the characteristic phenotype of idiopathic scoliosis. Taken together, our findings suggest that rare coding variants in MAPK7 predispose to AIS, providing clues to understanding the mechanisms of AIS.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Proteína Quinase 7 Ativada por Mitógeno/genética , Fases de Leitura Aberta , Escoliose/diagnóstico , Escoliose/genética , Adolescente , Alelos , Animais , Criança , Modelos Animais de Doenças , Feminino , Frequência do Gene , Marcação de Genes , Ligação Genética , Genótipo , Humanos , Masculino , Proteína Quinase 7 Ativada por Mitógeno/química , Mutação , Fenótipo , Radiografia , Escoliose/cirurgia , Relação Estrutura-Atividade , Sequenciamento do Exoma , Peixe-Zebra
5.
Biochem Biophys Res Commun ; 474(1): 83-90, 2016 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-27103436

RESUMO

Ghrelin is a gastric acyl-peptide that plays an inhibitory role in cell apoptosis. Herein we investigate the protective effects of ghrelin in LPS-induced apoptosis of human alveolar epithelial A549 cells, along with the possible molecular mechanisms. LPS exposure impaired cell viability and increased apoptosis of A549 cells significantly in concentration- and time-dependent manners embodied in increased Bax and cleaved caspase-3 production, coupled with decreased Bcl-2 levels. Simultaneously, LPS remarkably decreased the expression of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinas (ERK) in A549 cells. However, ghrelin'pretreatment ameliorated LPS-caused alterations in the ratio of Bax/Bcl-2 and cleaved caspase-3 expression, whereas activated the PI3K/Akt and ERK signaling. These results demonstrate that ghrelin lightens LPS-induced apoptosis of human alveolar epithelial cells partly through activating the PI3K/Akt and ERK pathway and thereby might benefit alleviating septic ALI.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/fisiologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Grelina/administração & dosagem , Lipopolissacarídeos/administração & dosagem , Células A549 , Células Epiteliais Alveolares/citologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Humanos
6.
Exp Clin Cardiol ; 18(2): e115-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23940448

RESUMO

BACKGROUND: The authors previously reported a murine model of left ventricular hypertrophy (LVH) and regression using a suture technique of transverse aortic arch constriction and subsequent removal. A number of issues have limited the widespread adoption of this method. The present study assessed a modification of this model using a titanium clip. METHODS: Male C57BL/6 mice (n=95) underwent minimally invasive aortic banding for three, four or six weeks with or without subsequent band removal for one week. Hearts were evaluated both structurally and functionally using heart weight/body weight ratios, transthoracic echocardiography and direct left ventricular pressure measured using catheterization. RESULTS: Clip banding resulted in a threefold gradient across the transverse aortic arch. Pressure overload induced concentric LVH by three weeks that progressively decompensated. By six weeks, hearts were significantly dilated, with poor left ventricular function. Clips were removed in a minimally invasive procedure after each time point. When overloaded for either three or four weeks, removal of the clip with subsequent pressure relief enabled regression of LVH and restoration of function. When removed after six weeks of banding, mouse hearts were unable to reverse remodel and maintained elevated left ventricular end-diastolic pressures and lung congestion. CONCLUSIONS: The application and removal of a titanium clip successfully induced pressure overload and relief associated with the serial development and reversal of LVH. Compared with similar models using suture ligation and release, this method was found to be a simple, effective (no slipped bands) and reproducible method to study murine LVH, heart failure and its regression.

7.
Biosensors (Basel) ; 14(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38248392

RESUMO

Fiber-optic biosensors have garnered significant attention and witnessed rapid development in recent years owing to their remarkable attributes such as high sensitivity, immunity to electromagnetic interference, and real-time monitoring. They have emerged as a potential tool in the realm of biomarker detection for low-concentration and small molecules. In this paper, a portable and cost-effective optical fiber biosensor based on surface plasmon resonance for the early detection of breast cancer is demonstrated. By utilizing the aptamer human epidermal growth factor receptor 2 (HER2) as a specific biomarker for breast cancer, the presence of the HER2 protein can be detected through an antigen-antibody binding technique. The detection method was accomplished by modifying a layer of HER2 aptamer on the flat surface of a gold-coated D-shaped polymer optical fiber (core/cladding diameter 120/490 µm), of which the residual thickness after side-polishing was about 245 µm, the thickness of the coated gold layer was 50 nm, and the initial wavelength in pure water was around 1200 nm. For low-concentration detection of the HER2 protein, the device exhibited a wavelength shift of ~1.37 nm with a concentration of 1 µg/mL (e.g., 5.5 nM), which corresponded to a limit of detection of ~5.28 nM. Notably, the response time of the biosensor was measured to be as fast as 5 s. The proposed biosensor exhibits the potential for early detection of HER2 protein in initial cancer serum and offers a pathway to early prevention of breast cancer.


Assuntos
Neoplasias , Ressonância de Plasmônio de Superfície , Humanos , Fibras Ópticas , Tecnologia de Fibra Óptica , Ouro , Oligonucleotídeos , Polímeros
8.
Biomacromolecules ; 12(3): 642-9, 2011 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-21268575

RESUMO

To improve the transfection efficiency of chitosan as a nonviral gene delivery vector, a dendronized chitosan derivative was prepared by a copper-catalyzed azide alkyne cyclization reaction of propargyl focal point poly(amidoamine) dendron with 6-azido-6-deoxy-chitosan. Its structure was characterized by (1)H NMR and FTIR analyses and its buffering capacity was evaluated by acid-base titration. In particular, its complexation with plasmid DNA was investigated by agarose gel electrophoresis, zeta potential, and particle size analyses as well as transmission electron microscopy observation. Compared to unmodified chitosan, such a chitosan derivative has better water solubility and buffering capacity. Compared to commonly used polyethyleneimine (PEI, 25 kDa), it could exhibit enhanced transfection efficiency in some cases and lower cell toxicity, as confirmed by in vitro transfection and cytotoxicity tests in human kidney 293T and human nasopharyngeal carcinoma CNE2 cell lines. In addition, the effect of serum on its transfection efficiency was also studied.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Dendrímeros/química , Transfecção/métodos , Soluções Tampão , Linhagem Celular Tumoral , Humanos , Teste de Materiais , Plasmídeos , Solubilidade
9.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 28(1): 195-8, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21485212

RESUMO

Polyethylenimine (PEI) is a kind of nanometer nonviral vector frequently applied in gene transfection. It is simple and easy to prepare and to modify and relatively safe compared to viral vectors. In recent years, PEI has been utilized in many research areas for gene delivery to stem cells in vitro or targeted gene delivery to cells in the brain. This review reveals that the cytotoxicity and low transfection efficiency of PEI requires to be improved. However brain-targeted modification indicates the promising prospect of PEI for gene therapy in cerebrovascular diseases.


Assuntos
Terapia Genética , Vetores Genéticos , Nanoestruturas/química , Polietilenoimina/química , Transplante de Células-Tronco/métodos , Humanos , Transfecção/métodos
10.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 28(6): 1148-53, 2011 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-22295704

RESUMO

The aim of this study is to investigate the growth and proliferation of bone marrow mesenchymal stem cells (BMSCs) three-dimensionally cultured in Pluronic F-127 gel, in order to explore the cellular compatibility of gel and to investigate the feasibility of BMSCs differentiating into adipocytes in gel. Rat BMSCs were isolated from adult bone marrow, and then cultured and amplified in vitro. The BMSCs derived from the 4th passage were seeded on the scaffolds and incubated in adipogenic stimuli culture to differentiate into adipocytes. BMSCs were dispersed into gel and cultured in vitro for two weeks then the status of adhesion, growth and proliferation of the cells were observed. The edipogenic differentiation of the BMSCs was assessed by cellular morphology and further confirmed by Oil Red O staining. BMSCs were able to attach, grow and proliferate well in Pluronic F-127 gel. The BMSCs differentiated into adipocytes in gel in the presence of adipogenic stimuli over a period of 2 weeks. After only 4 days of adipogenic induction, small lipid droplets were observed within BMSCs in gel wells treated with differentiation media. At the end of 14 days, in the presence of differentiation media in gel, the size of the lipid droplets increased to occupy most of the cytoplasm, consistent with differentiation of BMSCs into adipocytes. Lipid droplets in differentiating BMSCs were positively stained with Oil Red O in the presence of differentiation media in the Pluronic F-127 treatment. We demostrated BMSCs incubated in the 3D Pluronic F-127 gel scaffolds could be induced and differentiated into adipocytes. The system for inducing differentiation of BMSCs into adipocytes is promising to apply in the construction of tissue engineering adipose tissue and the repair of fat injury, and Pluronic F-127 gel may be a suitable scaffold for cellular therapy of BMSCs.


Assuntos
Tecido Adiposo/citologia , Diferenciação Celular/efeitos dos fármacos , Hidrogéis/química , Células-Tronco Mesenquimais/citologia , Poloxâmero/química , Adipócitos/citologia , Animais , Células da Medula Óssea/citologia , Células Cultivadas , Ratos , Ratos Sprague-Dawley , Engenharia Tecidual
11.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 28(1): 104-9, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21485194

RESUMO

This study was aimed to develop non-toxic, high transfection efficiency polyethyleneimine(PEI) cationic nanoparticles. The exosyndrome of PEI cationic nanoparticles was measured by zeta sizer, ultraviolet and visible spectroscopy. The condensation ability and the resistance to DNaseI of pEGFP-N1/PEI and pEGFP-N1/PEI modified polyethylene glycol(PEG) were evaluated by agarose gel electrophoresis. The cell toxicity of polyethyleneimine cationic nanoparticles was measured by using MTT test. The orthogonal design was used to optimize the transfection efficiency with the N/P ratio, the grafting ratio and the gene dosage as the factors. The experimental results showed that pEGFP-N1/PEI nanoparticles have lower cell toxicity, better composite ability and better resistance to DNAseI. The highest transfection efficiency of PEI cationic nanoparticles was 91% by using the PEI nanoparticles with the N/P ratio 40:1 and gene dosages 6 microg/well. PEI cationic nanoparticle modified by PEG effectively transferred DNA to hepatoma carcinoma cells and it is a non-toxic, with high transfection efficiency, and a promising non-viral carrier for gene delivery. The transfection efficiency will be improved by optimizing the experiment condition.


Assuntos
Carcinoma Hepatocelular/genética , Técnicas de Transferência de Genes , Neoplasias Hepáticas/genética , Polietilenoimina/química , Transfecção/métodos , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/patologia , Nanopartículas/química , Polietilenoglicóis/química
12.
Cell Biol Int ; 34(11): 1063-8, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20629637

RESUMO

To improve the survival and/or differentiation of grafted BMSCs (bone marrow stem cells) represents one of the challenges for the promising cell-based therapy. Considerable reports have implicated Sal B (salvianolic acid B), a potent aqueous extract of Salvia miltiorrhiza, in enhancing the survival of cells under various conditions. In this study, we investigated the effect of Sal B on H2O2-induced apoptosis in rat BMSCs, focusing on the survival signalling pathways. Results indicated that the MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] inhibitor (PD98059) and 10 µM Sal B remarkably prevented BMSCs from H2O2-induced apoptosis through attenuating caspase-3 activation, which is accompanied by the significant up-regulation of Bcl-2. In addition, the ROS (reactive oxygen species) accumulation was also reduced after Sal B treatment. Furthermore, Sal B inhibited the ERK1/2 phosphorylations stimulated by H2O2. Taken together, our results showed that H2O2-induced apoptosis in BMSCs via the ROS/MEK/ERK1/2 pathway and Sal B may exert its cytoprotection through mediating the pathway.


Assuntos
Apoptose , Benzofuranos/farmacologia , Células da Medula Óssea/enzimologia , Sistema de Sinalização das MAP Quinases , Estresse Oxidativo/efeitos dos fármacos , Células-Tronco/enzimologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Citoproteção , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Flavonoides/farmacologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo
13.
Cell Biol Int ; 33(3): 411-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19356708

RESUMO

Reactive oxygen species (ROS) play essential roles in apoptosis and in the regulation of several transcription factors under both physiological and pathological conditions. However, the effects of ROS on MSCs are not well known, and therefore we have investigated the effects of preconditioning with hydrogen peroxide (H(2)O(2)) on the level of expression of the chemokine receptor, CXCR4, stromal cell-derived factor-1alpha (SDF-1alpha)-dependent migration and apoptosis in MSCs. Preconditioning with 20microM H(2)O(2) significantly increased the level of expression of CXCR4 mRNA and protein, and MSCs migration toward SDF-1alpha; increased expression of CXCR4 and SDF-1alpha-induced MSCs migration was attenuated by extracellular signal-regulated kinase (ERK) inhibitor PD98059. Preconditioning with 20microM H(2)O(2) significantly protected MSCs against apoptosis induced by 500microM H(2)O(2). These results suggest that preconditioning with H(2)O(2) can increase MSCs migration toward SDF-1alpha and protect MSCs against apoptosis.


Assuntos
Apoptose , Células da Medula Óssea/citologia , Células-Tronco Mesenquimais/citologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Movimento Celular , Quimiocina CXCL12/metabolismo , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Peróxido de Hidrogênio/metabolismo , Masculino , Células-Tronco Mesenquimais/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores CXCR4/metabolismo , Regulação para Cima
14.
Biosci Rep ; 39(5)2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-30992390

RESUMO

Neural stem cells (NSCs) transplantation is one of the most promising strategies for the treatment of CA-induced brain damage. The transplanted NSCs could differentiate into new neuron and replace the damaged one. However, the poor survival of NSCs in severe hypoxic condition is the limiting step to make the best use of this kind of therapy. In the present study, we investigated whether the overexpression of miR-26a improves the survival of NSCs in hypoxic environment in vitro and in vivo. In vitro hypoxia injury model is established in NSCs by CoCl2 treatment, and in vivo cardiac arrest (CA) model is established in Sprague-Dawley (SD) rats. Quantitative real-time polymerase chain reaction is used to detect the mRNA level and Western blot is used to examine the protein level of indicated genes. TUNEL staining and flow cytometry are applied to evaluate apoptosis. Dual-luciferase reporter assay is utilized to analyze the target gene of miR-26a. The expression of miR-26a is reduced in both in vitro and in vivo hypoxic model. MiR-26a directly targets 3'-UTR of glycogen synthase kinase 3ß (GSK-3ß), resulting in increased ß-catenin expression and decreased apoptosis of NSCs. Overexpression of miR-26a in transplanted NSCs improves the survival of NSCs and neurological function in CA rats. MiR-26a prevents NSCs from apoptosis by activating ß-catenin signaling pathway in CA-induced brain damage model. Modulating miR-26a expression could be a potential strategy to attenuate brain damage induced by CA.


Assuntos
Parada Cardíaca/complicações , Hipóxia Encefálica/etiologia , Hipóxia Encefálica/terapia , MicroRNAs/genética , Células-Tronco Neurais/transplante , beta Catenina/genética , Animais , Apoptose , Hipóxia Celular , Células Cultivadas , Regulação para Baixo , Feminino , Parada Cardíaca/genética , Parada Cardíaca/metabolismo , Hipóxia Encefálica/genética , Hipóxia Encefálica/metabolismo , Masculino , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Ratos Sprague-Dawley , Regulação para Cima , Via de Sinalização Wnt , beta Catenina/metabolismo
15.
Brain Res ; 1195: 104-12, 2008 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-18206136

RESUMO

Transplantation of bone marrow-derived mesenchymal stem cells (BMSCs) can promote functional recovery of brain after stroke with the mechanism regulating the BMSCs migration to ischemic penumbra poorly understood. Interaction between stromal cell-derived factor-1alpha (SDF-1alpha) and its cognate receptor CXCR4 is crucial for homing and migration of multiple stem cell types. Their potential role in mediating BMSC migration in ischemic brain has not been demonstrated. In this study, ischemic brain lesion model was created in rats by permanent middle cerebral artery occlusion and green fluorescent protein (GFP)-labeled BMSCs were intravenously injected. Immunohistochemical staining showed that BMSCs were able to enter the route from olfactory areas to cortex of the rat brain. Significant recovery of modified Neurological Severity Score was observed at days 14 and 28. Interestingly, the SDF-1alpha mRNA and protein were predominantly localized in the ischemic penumbral, peaked by 3-7 days and retained at least 14 days post-transplantation. On the other hand, the CXCR4 expression by BMSCs was elevated under hypoxia. The pre-treatment with the CXCR4-specific antagonist AMD3100 significantly prevented the migration of BMSCs to the injured brain. Taken together, these observations indicate that systemically administered BMSCs can migrate to the ischemic lesion of brain along with the olfactory-thalamus and hippocampus-cortex route. The interaction of locally produced SDF-1alpha and CXCR4 expressed on the BMSC surface plays an important role in the migration of transplanted cells, suggesting that it might be a potential approach to modulate the expression of the two molecules in order to further facilitate the therapeutic effects using BMSCs.


Assuntos
Células da Medula Óssea/fisiologia , Isquemia Encefálica/terapia , Movimento Celular/fisiologia , Quimiocina CXCL12/fisiologia , Receptores CXCR4/fisiologia , Animais , Transplante de Medula Óssea/fisiologia , Isquemia Encefálica/patologia , Movimento Celular/genética , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipocampo/metabolismo , Hipocampo/patologia , Imuno-Histoquímica , Masculino , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Receptores CXCR4/genética , Transplante de Células-Tronco , Células Estromais/citologia , Células Estromais/fisiologia , Células Estromais/transplante
16.
Sheng Wu Gong Cheng Xue Bao ; 34(10): 1650-1659, 2018 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-30394032

RESUMO

In order to provide a basic theory for the materials of repairing central nervous system injury, we have studied the growth and differentiation of neural stem cells (NSCs) on poly (L-lysine) modified silk fibroin film. First, we used poly (L-lysine) to modify silk fibroin film and confirmed by UV-vis and 1H NMR spectra. Then NSCs were isolated and seeded on the silk fibroin film (Silk group), poly (L-lysine) (PLL group) and poly (L-lysine) modified Silk fibroin film (Silk-PIL group). The proliferation of NSCs was evaluated by Cell Counting Kit-8 (CCK-8) assay on days 1, 3, 5 and 7 after seeding. Immunofluorescence was used to analyze the differentiation of NSCs at the 7th day. The levels of apoptosis were detected by Western blotting and TUNEL. The mRNA level of brain derived neurotrophic factor (BDNF) was identified by real-time PCR. UV-vis and 1H NMR spectra confirmed that poly (L-lysine) was successfully grafted onto the silk fibroin film. From the 3rd day after seeding to the 7th day, the CCK-8 test showed that proliferation rate of NSCs in the Silk-PIL was significantly higher than Silk group (P<0.05) but had no significant difference compared with PLL group (P>0.05). Immunofluorescence staining displayed that more NSCs in Silk-PIL group were differentiated into neuron compared with Silk group (P<0.05), however, there was no significant difference compared with PLL group (P>0.05). The number of NSCs differentiated into astrocytes was not significantly different between the three groups. Western blotting and TUNEL test presented that the degree of apoptosis of NSCs in the Silk-PIL group was significantly lower than Silk group (P<0.05). RT-PCR exhibited that mRNA level of brain derived neurotrophic factor (BDNF) of NSCs was higher in Silk-PIL group compared with Silk group (P<0.05) but had no significant difference compared with PLL group (P>0.05). Thus, poly (L-lysine) modified silk fibroin film could promote the proliferation of NSCs and reduce NSCs apoptosis. Furthermore, it also can enhance the differentiation of NSCs into neurons. It is expected to become a new type of tissue engineering scaffold carrying NSCs to repair central nervous system injury.


Assuntos
Diferenciação Celular , Fibroínas/química , Células-Tronco Neurais/citologia , Polilisina/química , Alicerces Teciduais , Animais , Contagem de Células , Células Cultivadas , Engenharia Tecidual
17.
ACS Nano ; 11(8): 7710-7718, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28719748

RESUMO

We systematically investigate the long-neglected low-temperature fusing behavior of silver micro/nanodendrites and demonstrate the feasibility of employing this intriguing property for the printed electronics application, i.e., printed fuse-links. Fuse-links have experienced insignificant changes since they were invented in the 1890s. By introducing silver micro/nanodendrites-based electrically conductive composites (ECCs) as a printed fusible element, coupled with the state-of-the-art printed electronics technology, key performance characteristics of a fuse-link are dramatically improved as compared with the commercially available counterparts, including an expedient fabrication process, lower available rated current (40% of the minimum value of Littelfuse 467 series fuses), shorter response time (only 3.35% of the Littelfuse 2920L030 at 1.5 times of the rated current), milder surface temperature rise (16.89 °C lower than FGMB) and voltage drop (only 24.26% of FGMB) in normal operations, easier to mass produce, and more flexible in product design. This technology may inspire the development of future printed electronic components.

18.
Brain Res ; 1634: 34-44, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26607252

RESUMO

Determination of the exogenous factors that regulate differentiation of neural stem/progenitor cells into neurons, oligodendrocytes and astrocytes is an important step in the clinical therapy of spinal cord injury (SCI). The Notch pathway inhibits the differentiation of neural stem/progenitor cells and Lingo-1 is a strong negative regulator for myelination and axon growth. While Lingo-1 shRNA and N-[N-(3, 5-difluorophenacetyl)-1-alanyl]-S-Phenylglycinet-butylester (DAPT), a Notch pathway inhibitor, have been used separately to help repair SCI, the results have been unsatisfactory. Here we investigated and elucidated the preliminary mechanism for the effect of Lingo-1 shRNA and DAPT on neural stem/progenitor cells differentiation. We found that neural stem/progenitor cells from E14 rat embryos expressed Nestin, Sox-2 and Lingo-1, and we optimized the transduction of neural stem/progenitor cells using lentiviral vectors encoding Lingo-1 shRNA. The addition of DAPT decreased the expression of Notch intracellular domain (NICD) as well as the downstream genes Hes1 and Hes5. Expression of NeuN, CNPase and GFAP in DAPT treated cells and expression of NeuN in Lingo-1 shRNA treated cells confirmed differentiation of neural stem/progenitor cells into neurons, oligodendrocytes and astrocytes. These results revealed that while Lingo-1 shRNA and Notch signaling inhibitor DAPT both promoted differentiation of neural stem cells into neurons, only DAPT was capable of driving neural stem/progenitor cells differentiation into oligodendrocytes and astrocytes. Since we were able to show that both Lingo-1 shRNA and DAPT could drive neural stem/progenitor cells differentiation, our data might aid the development of more effective SCI therapies using Lingo-1 shRNA and DAPT.


Assuntos
Diferenciação Celular , Dipeptídeos/administração & dosagem , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Receptores Notch/antagonistas & inibidores , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/fisiologia , Diferenciação Celular/efeitos dos fármacos , Lentivirus , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurônios/efeitos dos fármacos , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/fisiologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos
19.
J Med Food ; 19(6): 528-34, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26872103

RESUMO

The objective of our study was to investigate whether curcumin protects against reserpine-induced gastrointestinal mucosal lesions (GMLs) in rats and to explore the mechanism of curcumin's action. Sprague-Dawley rats were randomly divided into four groups: control group, reserpine-treated group, reserpine treatment group with curcumin at high dose (200 mg/kg), and reserpine treatment group with curcumin at low dose (100 mg/kg). Rats in reserpine-treated group were induced by intraperitoneally administered reserpine (0.5 mg/kg) for 28 days. TUNEL staining and hematoxylin and eosin staining were used to evaluate the apoptotic cells and morphologic changes. In addition, to explore the mechanism of curcumin in protecting GMLs, we used serum of experimental rats to assess the level of vasoactive intestinal peptide (VIP), gastrin, interleukin-6, interleukin-10, tumor necrosis factor-α and interferon-γ by ELISA and radioimmunoassay. The protein levels of NF-κB, p-IκB-α, IκB-α, Bcl-2, Bax, and cleaved-caspase-3 were examined by western blot analysis. Data were analyzed with SPSS 19.0 software package. Curcumin treatment prevented tissue damage and cell death in the reserpine-treated rats and effectively decreased inflammatory response and balanced the expression of VIP and gastrin in the reserpine-treated rats. NF-κB, p-IκB-α, Bax, and cleaved-caspase-3 were increased in the reserpine group, but the curcumin high-dose group inhibited them. Curcumin can target the IκB-α/NF-κB pathway to inhibit inflammatory response and regulate the level of VIP and gastrin in reserpine-induced GML rats.


Assuntos
Anti-Hipertensivos/efeitos adversos , Curcumina/administração & dosagem , Mucosa Gástrica/efeitos dos fármacos , Gastrinas/genética , Gastroenteropatias/tratamento farmacológico , Proteínas I-kappa B/metabolismo , NF-kappa B/metabolismo , Reserpina/efeitos adversos , Peptídeo Intestinal Vasoativo/genética , Animais , Mucosa Gástrica/lesões , Mucosa Gástrica/metabolismo , Gastrinas/metabolismo , Gastroenteropatias/etiologia , Gastroenteropatias/genética , Gastroenteropatias/metabolismo , Humanos , Proteínas I-kappa B/genética , Masculino , NF-kappa B/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Peptídeo Intestinal Vasoativo/metabolismo
20.
Oncotarget ; 7(13): 17220-9, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-26967384

RESUMO

Tumor cells co-express vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) that interact each other to support a self-sustainable cell growth. So far, this autocrine VEGF loop is not reported in human intrahepatic cholangiocarcinoma (ICC). Apatinib is a highly selective VEGFR2 inhibitor, but its effects on ICC have not been investigated. In this study, we reported that VEGF and phosphorylated VEGFR2 were expressed at a significantly high level in ICC patient tissues (P<0.05). In vitro, treating ICC cell lines RBE and SSP25 with recombinant human VEGF (rhVEGF) induced phosphorylation of VEGFR1 (pVEGFR1) and VEGFR2 (pVEGFR2); however, only the VEGFR2 played a role in the anti-apoptotic cell growth through activating a PI3K-AKT-mTOR anti-apoptotic signaling pathway which generated more VEGF to enter this autocrine loop. Apatinib inhibited the anti-apoptosis induced by VEGF signaling, and promoted cell death in vitro. In addition, Apatinib treatment delayed xenograft tumor growth in vivo. In conclusion, the autocrine VEGF/VEGFR2 signaling promotes ICC cell survival. Apatinib inhibits anti-apoptotic cell growth through suppressing the autocrine VEGF signaling, supporting a potential role for using Apatinib in the treatment of ICC.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias dos Ductos Biliares/metabolismo , Colangiocarcinoma/metabolismo , Piridinas/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/patologia , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transdução de Sinais/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
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