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1.
Genes (Basel) ; 11(2)2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046085

RESUMO

Common bean (Phaseolus vulgaris L.) is a major legume and is frequently attacked by fungal pathogens, including Fusarium solani f. sp. phaseoli (FSP), which cause Fusarium root rot. FSP substantially reduces common bean yields across the world, including China, but little is known about how common bean plants defend themselves against this fungal pathogen. In the current study, we combined next-generation RNA sequencing and metabolomics techniques to investigate the changes in gene expression and metabolomic processes in common bean infected with FSP. There were 29,722 differentially regulated genes and 300 differentially regulated metabolites between control and infected plants. The combined omics approach revealed that FSP is perceived by PAMP-triggered immunity and effector-triggered immunity. Infected seedlings showed that common bean responded by cell wall modification, ROS generation, and a synergistic hormone-driven defense response. Further analysis showed that FSP induced energy metabolism, nitrogen mobilization, accumulation of sugars, and arginine and proline metabolism. Importantly, metabolic pathways were most significantly enriched, which resulted in increased levels of metabolites that were involved in the plant defense response. A correspondence between the transcript pattern and metabolite profile was observed in the discussed pathways. The combined omics approach enhances our understanding of the less explored pathosystem and will provide clues for the development of common bean cultivars' resistant to FSP.

2.
Opt Express ; 27(23): 32900-32911, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31878366

RESUMO

In this article, we developed a generalized coupled-mode theory for mixing an isolated state with a continuum having an intrinsic energy gap, which dubbed as "the bound states in the gapped continuum" (BIGC). We investigated the mixture interaction by mimicking the Su-Schrieffer-Heeger model in an optical coupled waveguide array (WA), and presented a unified engineering mechanism for topologically-protected zero modes, Fano resonance, and Tamm surface states, even though those phenomena are diverse in topological insulators, atomic physics and semiconductors, respectively. By tuning the on-site potential and coupling strength of the isolated state, we found the unified operating characteristics for zero modes, Fano resonance, and Tamm states, with demonstrating their localization, transmission spectra, and distinct evolution dynamics explicitly. As an extension for triple-modes coupling, two special sandwich-like configurations are studied: the isolated-continuous-isolated and continuous-isolated-continuous configurations lead to adiabatic eliminations and domain walls, respectively, revealing possible applications and wide connections in many fields of physics and optics.

3.
Phys Rev Lett ; 122(17): 173901, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31107095

RESUMO

Recent progress on Floquet topological phases has shed new light on time-dependant quantum systems, among which one-dimensional (1D) Floquet systems have been under extensive theoretical research. However, an unambiguous experimental observation of these 1D Floquet topological phases is still lacking. Here, by periodically bending an ultrathin metallic array of coupled corrugated waveguides, a photonic Floquet simulator was well designed and successfully fabricated to mimic the periodically driven Su-Schrieffer-Heeger model. Intriguingly, under moderate driven frequencies, we report the first observation of the anomalous Floquet topological π mode, propagating along the array's boundary. The different evolutionary behaviors between static and nonstatic topological end modes have been clearly demonstrated by the microwave near-field experiment. Furthermore, the experiment in the fast-driving regime also reveals the universal high-frequency behavior in driven systems. Our photonic simulator can serve as a versatile testing ground for various phenomena related to time-dependant 1D quantum phases, such as Thouless pumping and dynamical localization.

4.
Phys Rev Lett ; 122(18): 183204, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31144903

RESUMO

We reveal the classical and quantum regimes of free electron interaction with radiation, common to the general variety of radiation sources (e.g., a Smith-Purcell radiation), the dielectric laser accelerator, and photo-induced near-field electron microscopy (PINEM). Modeling the electron with initial conditions of a coherent quantum electron wave packet, its topology in phase space uniquely defines a universal distinction of three interaction regimes: point-particle-like acceleration, a quantum wave function (PINEM), and a newly reported regime of anomalous PINEM (APINEM). The quantum interference beat of APINEM is capable of improving the spectral resolution of postselective electron microscopy. The particle-wave duality transition between regimes reveals the history-dependent nature of quantum electron interaction with light.

5.
Braz. j. med. biol. res ; 52(1): e7718, 2019. graf
Artigo em Inglês | LILACS-Express | ID: biblio-974272

RESUMO

Pancreatic cancer is well known to be the most deadly malignancy with the worst survival rate of all cancers. High temperature requirement factor A1 (HtrA1) plays an important role in cancer cell proliferation, migration, apoptosis, and differentiation. This study aimed to explore the function of HtrA1 in pancreatic cancer cell growth and its underlying mechanism. We found that the expression of HtrA1 was lower in pancreatic cancer tissue compared to the adjacent normal tissue. Consistently, HtrA1 levels were also decreased in two human pancreatic cancer cell lines, PANC-1 and BXPC-3. Moreover, enforced expression of HtrA1 inhibited cell viability and colony formation of PANC-1 and BXPC-3 cells. Overexpression of HtrA1 promoted apoptosis and suppressed migratory ability of tumor cells. On the contrary, siRNA-mediated knockdown of HtrA1 promoted the growth potential of pancreatic cancer cells. In addition, we found that up-regulation of HtrA1 reduced the expression of Notch-1 in pancreatic cancer cells. On the contrary, knockdown of HtrA1 increased the expression levels of Notch-1. Furthermore, overexpression of Notch-1 abolished the anti-proliferative effect of HtrA1 on pancreatic cancer cells. Taken together, our findings demonstrated that HtrA1 could inhibit pancreatic cancer cell growth via regulating Notch-1 expression, which implied that HtrA1 might be developed as a novel molecular target for pancreatic cancer therapy.

6.
Braz J Med Biol Res ; 52(1): e7718, 2018 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-30484491

RESUMO

Pancreatic cancer is well known to be the most deadly malignancy with the worst survival rate of all cancers. High temperature requirement factor A1 (HtrA1) plays an important role in cancer cell proliferation, migration, apoptosis, and differentiation. This study aimed to explore the function of HtrA1 in pancreatic cancer cell growth and its underlying mechanism. We found that the expression of HtrA1 was lower in pancreatic cancer tissue compared to the adjacent normal tissue. Consistently, HtrA1 levels were also decreased in two human pancreatic cancer cell lines, PANC-1 and BXPC-3. Moreover, enforced expression of HtrA1 inhibited cell viability and colony formation of PANC-1 and BXPC-3 cells. Overexpression of HtrA1 promoted apoptosis and suppressed migratory ability of tumor cells. On the contrary, siRNA-mediated knockdown of HtrA1 promoted the growth potential of pancreatic cancer cells. In addition, we found that up-regulation of HtrA1 reduced the expression of Notch-1 in pancreatic cancer cells. On the contrary, knockdown of HtrA1 increased the expression levels of Notch-1. Furthermore, overexpression of Notch-1 abolished the anti-proliferative effect of HtrA1 on pancreatic cancer cells. Taken together, our findings demonstrated that HtrA1 could inhibit pancreatic cancer cell growth via regulating Notch-1 expression, which implied that HtrA1 might be developed as a novel molecular target for pancreatic cancer therapy.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Serina Peptidase 1 de Requerimento de Alta Temperatura A/metabolismo , Neoplasias Pancreáticas/metabolismo , Receptor Notch1/metabolismo , Apoptose , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Serina Peptidase 1 de Requerimento de Alta Temperatura A/genética , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Receptor Notch1/genética , Transdução de Sinais , Regulação para Cima
7.
Opt Express ; 26(24): 31636-31647, 2018 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-30650747

RESUMO

We propose a flexibly designed photonic system based on ultrathin corrugated metallic "H-bar" waveguide that supports spoof surface plasmon polariton (SPP) at microwave frequencies. Five designs were presented, in order to demonstrate flexibility according to varying height, period, core width, rotation, and shifting on the "H-bar" unit of the waveguide. The propagation constant between two hybrid designs of period and height structure was then shown in order to study the coupling effect. Next, we constructed a coupled waveguide array that followed the Su-Schrieffer-Heeger (SSH) model. This model was constructed by a hybrid design with the identical propagation constant of each waveguide, except it had dimerized spacing. The propagation feature of topological zero mode was then observed as theoretically expected in the dimerized array. Our proposed spoof SPP waveguide array has great flexibility to be used as a powerful experiment platform, particularly in photonic simulation of the quantum or topological phenomena described by Schrödinger equation in condensed matters.

8.
Exp Ther Med ; 14(5): 4356-4362, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29067114

RESUMO

Caveolin-1 (Cav-1) is a major component of caveolae and has been recently identified as a tumor suppressor. As little is known about Cav-1 in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC), the aim of the present study was to investigate the expression and significance of Cav-1 in HBV-associated HCC. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the mRNA expression level of Cav-1 in 40 cases of HBV-associated HCC, the corresponding 11 non-tumor cases of HBV-associated chronic hepatitis, 29 non-tumor cases of HBV-associated cirrhosis and 6 cases of normal liver tissues. Immunohistochemical analysis indicated the expression of Cav-1, cluster of differentiation 34 and vascular endothelial growth factor (VEGF) in HBV-associated HCC tissue samples. In addition, the association of Cav-1 expression with angiogenesis and clinicopathological characteristics of HBV-associated HCC was also analyzed. RT-PCR results demonstrated that the expression rate of Cav-1 mRNA in HBV-associated HCC, non-tumor HBV-associated chronic hepatitis and cirrhosis liver tissues and control normal liver tissues from patients with metastatic carcinoma was 92.5, 85.0 and 16.7%, respectively. mRNA expression level of Cav-1 was significantly increased in chronic hepatitis, cirrhosis and HBV-associated HCC livers compared with normal control livers (P<0.05 and P<0.01, respectively). Cav-1 protein was detected by immunohistochemistry in 80% of the samples of HBV-associated HCC. Furthermore, Cav-1 and VEGF protein expression levels were correlated with microvessel density (MVD; γs<0.46, P=0.01 and γs<0.31, P=0.05, respectively). In addition, Cav-1 expression and MVD were significantly associated with metastasis (P=0.031 and P=0.046, respectively). In conclusion, Cav-1 may have an important role in the carcinogenesis and progression of HBV-associated HCC and angiogenesis may be affected by Cav-1 during this process.

9.
Sci Rep ; 7(1): 12688, 2017 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-28978938

RESUMO

Here we introduce lattice defects in WTe2 by Ga+ implantation (GI), and study the effects of defects on the transport properties and electronic structures of the samples. Theoretical calculation shows that Te Frenkel defects is the dominant defect type, and Raman characterization results agree with this. Electrical transport measurements show that, after GI, significant changes are observed in magnetoresistance and Hall resistance. The classical two-band model analysis shows that both electron and hole concentration are significantly reduced. According to the calculated results, ion implantation leads to significant changes in the band structure and the Fermi surface of the WTe2. Our results indicate that defect engineering is an effective route of controlling the electronic properties of WTe2 devices.

10.
Oncotarget ; 8(7): 12301-12310, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-28135203

RESUMO

Ellagic aicd (EA), a dietary polyphenolic compound found in plants and fruits, possesses various pharmacological activities. This study investigated the effect of EA on human pancreatic carcinoma PANC-1 cells both in vitro and in vivo; and defined the associated molecular mechanisms. In vitro, the cell growth and repairing ability were assessed by CCK-8 assay and wound healing assay. The cell migration and invasion activity was evaluated by Tanswell assay. In vivo, PANC-1 cell tumor-bearing mice were treated with different concentrations of EA. We found that EA significantly inhibited cell growth, cell repairing activity, and cell migration and invasion in a dose-dependent manner. Treatment of PANC-1 xenografted mice with EA resulted in significant inhibition in tumor growth and prolong mice survival rate. Furthermore, flow cytometric analysis showed that EA increased the percentage of cells in the G1 phase of cell cycle. Western blot analysis revealed that EA inhibited the expression of COX-2 and NF-κB. In addition, EA reversed epithelial to mesenchymal transition by up-regulating E-cadherin and down-regulating Vimentin. In summary, the present study demonstrated that EA inhibited cell growth, cell repairing activity, cell migration and invasion in a dose-dependent manner. EA also effectively inhibit human pancreatic cancer growth in mice. The anti-tumor effect of EA might be related to cell cycle arrest, down-regulating the expression of COX-2 and NF-κB, reversing epithelial to mesenchymal transition by up-regulating E-cadherin and down-regulating Vimentin. Our findings suggest that the use of EA would be beneficial for the management of pancreatic cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , Ácido Elágico/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Antígenos CD , Western Blotting , Caderinas/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Relação Dose-Resposta a Droga , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , NF-kappa B/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Vimentina/metabolismo
11.
Nat Commun ; 7: 13142, 2016 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-27725682

RESUMO

The progress in exploiting new electronic materials has been a major driving force in solid-state physics. As a new state of matter, a Weyl semimetal (WSM), in particular a type-II WSM, hosts Weyl fermions as emergent quasiparticles and may harbour novel electrical transport properties. Nevertheless, such a type-II WSM material has not been experimentally observed. In this work, by performing systematic magneto-transport studies on thin films of a predicted material candidate WTe2, we observe notable negative longitudinal magnetoresistance, which can be attributed to the chiral anomaly in WSM. This phenomenon also exhibits strong planar orientation dependence with the absence along the tungsten chains, consistent with the distinctive feature of a type-II WSM. By applying a gate voltage, we demonstrate that the Fermi energy can be in-situ tuned through the Weyl points via the electric field effect. Our results may open opportunities for implementing new electronic applications, such as field-effect chiral devices.

12.
Oncotarget ; 7(31): 50635-50642, 2016 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-27246983

RESUMO

There is a high incidence of death due to variceal hemorrhage in patients with portal hypertension. Factors to consider when choosing selective devascularization in the treatment of variceal hemorrhage remain a controversy. This study aims to generate the prevalent clinical risk factors that affect the outcomes of selective devascularization procedures. Elucidating these features may guide future treatment of esophageal varices in patients with portal hypertension. We retrospectively analyzed medical records of 455 patients who underwent selective devascularization procedures in our center. Patients were subject to splenectomy, selective devascularization with or without esophageal transection. The mode of surgery recurred in comparable rates in both the group with major complications postoperatively (high-risk group which consisted of 63 patients) or the group without major postoperative complications (low-risk group, 392). Risk factors that negatively influenced outcomes of surgery include severe symptoms (89% in high risk group and 71% in low risk group), large volume of blood loss in the hemorrhage before surgery (81% in high risk group and 16% in low risk group), sever liver cirrhosis (83% in high risk group and 67% in low risk group), previous endotherapy, prolonged prothrombin time, and poor liver function. Selective devascularization is a feasible option to treat variceal hemorrhage in patients with portal hypertension.


Assuntos
Varizes Esofágicas e Gástricas/fisiopatologia , Hipertensão Portal/terapia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Varizes Esofágicas e Gástricas/terapia , Feminino , Hemorragia Gastrointestinal , Humanos , Cirrose Hepática , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Tempo de Protrombina , Estudos Retrospectivos , Fatores de Risco , Esplenectomia , Resultado do Tratamento , Adulto Jovem
13.
Adv Mater ; 28(3): 547-52, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26603698

RESUMO

By combining a high-κ dielectric substrate and a high density of charge carriers, Coulomb impurities in MoS2 can be effectively screened, leading to an unprecedented room-temperature mobility of ≈150 cm(2) V(-1) s(-1) and room-temperature phonon-limited transport in a monolayer MoS2 transistor for the first time.

14.
Adv Mater ; 27(35): 5230-4, 2015 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-26255894

RESUMO

The combination of high-quality Al2 O3 dielectric and thiol chemistry passivation can effectively reduce the density of interface traps and Coulomb impurities, leading to a significant improvement of the mobility and a transition of the charge transport from the insulating to the metallic regime. A record high mobility of 83 cm(2) V(-1) s(-1) (337 cm(2) V(-1) s(-1) ) is reached at room temperature (low temperature) for monolayer WS2 . A theoretical model for electron transport is also developed.

15.
Nat Commun ; 5: 5290, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25327957

RESUMO

Molybdenum disulfide is considered as one of the most promising two-dimensional semiconductors for electronic and optoelectronic device applications. So far, the charge transport in monolayer molybdenum disulfide is dominated by extrinsic factors such as charged impurities, structural defects and traps, leading to much lower mobility than the intrinsic limit. Here we develop a facile low-temperature thiol chemistry route to repair the sulfur vacancies and improve the interface, resulting in significant reduction of the charged impurities and traps. High mobility >80 cm(2) V(-1) s(-1) is achieved in backgated monolayer molybdenum disulfide field-effect transistors at room temperature. Furthermore, we develop a theoretical model to quantitatively extract the key microscopic quantities that control the transistor performances, including the density of charged impurities, short-range defects and traps. Our combined experimental and theoretical study provides a clear path towards intrinsic charge transport in two-dimensional dichalcogenides for future high-performance device applications.

16.
Adv Mater ; 26(20): 3275-81, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24677272

RESUMO

Memristive devices based on vertical heterostructures of graphene and TiOx show a significant power reduction that is up to ∼10(3) times smaller than that of conventional structures. This power reduction arises as a result of a tunneling barrier at the interface. The barrier is tunable, opening up the possibility of engineering several key memory characteristics.

17.
Appl Opt ; 50(31): G118-22, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-22086035

RESUMO

A polarization bifocal lens based on the polarization effect caused by asymmetrical hole arrays had been designed, fabricated, and characterized experimentally. By considering the fact that the skin depth of an infrared electromagnetic field inside metal is much shorter than the incident wavelength, a polarization bifocal lens composed of high deep-width ratio metallic holes was realized by using a gold-coated silicon structure to replace the one directly formed on a thick metal film. An infrared optical experiment setup is built based on the secondary imagery method for characterizing the focal length of the designed bifocal lens. The measured focal lengths of the fabricated bifocal lens coincide well with the designed values, which proves the validity for realizing the polarization elements with the proposed structure and the feasibility of the fabrication process.

18.
Zhonghua Wai Ke Za Zhi ; 46(1): 18-20, 2008 Jan 01.
Artigo em Chinês | MEDLINE | ID: mdl-18509995

RESUMO

OBJECTIVE: To investigate the risk factors for selective devascularization in patients with portal hypertension. METHODS: The clinical data of 160 patients with portal hypertension underwent selective devascularization were retrospectively analyzed. All the patients were divided into high-risk group and low-risk group according to the postoperative complications. Thirty-two clinical factors were analyzed using logistic regression. RESULTS: Single-factor analysis showed that history of jaundice, Child-Turcotte-Pugh classification, total bilirubin (before the operation), prolongation of prothrombin time, pre-operative free portal pressure, ascites, leukocyte count (1 week after the operation) and hemoglobin (1 week after the operation) were significantly different between the high-risk group and low-risk group (P < 0.05). Logistic regression analysis showed that decrease of free portal pressure, total bilirubin (before the operation), prolongation of prothrombin time, ascites, leukocyte count (1 week after the operation) and hemoglobin (1 week after the operation) were still significantly different between the two groups (chi2 = 53.337, P < 0.01). CONCLUSIONS: The risk factors of selective devascularization in patients with portal hypertension are decrease of free portal pressure, pre-operative total bilirubin, prolongation of prothrombin time, ascites, post-operative leukocyte count and hemoglobin.


Assuntos
Hipertensão Portal/cirurgia , Derivação Portossistêmica Cirúrgica/métodos , Adulto , Idoso , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Derivação Portossistêmica Cirúrgica/efeitos adversos , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
19.
Ann Clin Lab Sci ; 37(1): 39-48, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17311868

RESUMO

Few studies about angiogenesis in hepatocellular carcinoma (HCC) have been conducted and little is known about the significance of angiogenesis in HCC. In this study, the clinicopathological significance of tumor microvessel density (MVD) was assessed in 105 patients with HCC by immunohistochemical staining of CD105, CD34, and vascular endothelial growth factor (VEGF). Moreover, the use of the tissue microarray technique in evaluating angiogenesis of HCC was appraised. The MVD by CD105 immunostaining (MVD-CD105) was significantly lower in larger tumors (5 cm diameter as a cutoff point, p=0.001), more aggressive tumors, as indicated by venous infiltration (present vs absent, p=0.001), and tumors with advanced TNM stage (stage I & II vs stage III, p=0.011). A lower score of MVD by CD34 immunostaining (MVD-CD34) showed significant association only with venous invasion (p<0.001), whereas the MVD by CD105 immunostaining in tissue microarray (MVD-MA) was significantly lower only in larger sized tumors (p=0.043). Moreover, MVD-CD105 was positively associated with the expression intensity of VEGF (p=0.009), but not for MVD-CD34 (p=0.088). When median scores of MVD were used as cut-off points, the patients with higher score of MVD-CD105 had a significantly poorer prognosis in either disease-free or overall survival analysis (p=0.002 and p=0.009, respectively), whereas similar prognostic significance of MVD-CD34 was not observed in overall survival analysis (p=0.052) but was observed in disease-free survival analysis (p=0.022). No prognostic significance of MVD-MA was found in either disease-free or overall survival analysis (p=0.277 and p=0.712, respectively). These data demonstrate the superiority of CD105 over CD34 as a marker of angiogenesis in HCC and indicate that the tissue microarray technique is unsuitable for evaluating angiogenesis in HCC.


Assuntos
Antígenos CD/metabolismo , Biomarcadores/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Neovascularização Patológica/metabolismo , Receptores de Superfície Celular/metabolismo , Adulto , Antígenos CD34/metabolismo , China , Endoglina , Estudos de Avaliação como Assunto , Feminino , Humanos , Imuno-Histoquímica , Masculino , Análise em Microsséries/métodos , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida , Fator A de Crescimento do Endotélio Vascular/metabolismo
20.
Acta Pharmacol Sin ; 27(12): 1567-74, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17112410

RESUMO

AIM: The role of caveolin-1 (Cav-1) in angiogenesis remains poorly understood. The endothelial nitric oxide (NO) synthase (eNOS), a caveolin-interacting protein, was demonstrated to play a predominant role in vascular endothelial growth factor (VEGF) -induced angiogenesis. The purpose of our study was to examine the role of Cav-1 and the eNOS complex in NO-mediated angiogenesis. METHODS: Human umbilical vein endothelial cells (HUVEC) were isolated and cultured in 3-D fibrin gels to form capillary-like tubules by VEGF stimulation. The expression of Cav-1 and eNOS was detected by semiquantitative RT-PCR. The HUVEC were treated with antisense oligonucleotides to downregulate Cav-1 expression. Both transduced and non-infected HUVEC were cultured in fibrin gels in the presence or absence of VEGF (20 ng/mL) and NG-nitro-L-arginine methyl ester (L-NAME; 5 mmol/L). NO was measured using a NO assay kit and capillary-like tubules were quantified by tubule formation index using the Image J program. RESULTS: RT-PCR analysis revealed that Cav-1 levels steadily increased in a time-dependent manner and reached their maximum after 5 d of incubation, but there were no obvious changes in eNOS mRNA expression in response to VEGF in the fibrin gel model. VEGF (20 ng/mL) can promote NO production and the formation of capillary-like tubules, and this promoting effect of VEGF was blocked by the addition of L-NAME (5 mmol/L). When transduced HUVEC with the antisense Cav-1 oligonucleotides were plated in the fibrin gels, the capillary-like tubules were significantly fewer than those of the non-infected cells. The capillary-like tubules formation and NO production of transduced HUVEC with the antisense Cav-1 oligonucleotides cultured in fibrin gels showed no responses to the addition of VEGF (20 ng/mL) and L-NAME (5.0 mmol/L). CONCLUSION: NO was a critical angiogenic mediator in this model. Cav-1 was essential for NO-mediated angiogenesis and may be an important target of anti-angiogenesis therapy.


Assuntos
Caveolina 1/metabolismo , Células Endoteliais/metabolismo , Neovascularização Fisiológica/fisiologia , Óxido Nítrico Sintase Tipo III/biossíntese , Caveolina 1/genética , Células Cultivadas , Células Endoteliais/citologia , Humanos , NG-Nitroarginina Metil Éster/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/genética , Oligonucleotídeos Antissenso/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Veias Umbilicais/citologia , Fator A de Crescimento do Endotélio Vascular/farmacologia
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