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1.
Nat Commun ; 14(1): 3040, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37268641

RESUMO

Light propagates in various ways depending on environment, including uniform medium, surface/interface and photonic crystals, which appears ubiquitously in daily life and has been exploited for advanced optics technology. We unveiled that a topological photonic crystal exhibits unique electromagnetic (EM) transport properties originating from the Dirac frequency dispersion and multicomponent spinor eigenmodes. Measuring precisely local Poynting vectors in microstrips of honeycomb structure where optics topology emerges upon a band gap opening in the Dirac dispersion and a p-d band inversion induced by a Kekulé-type distortion respecting C6v symmetry, we showed that a chiral wavelet induces a global EM transportation circulating in the direction counter to the source, which is intimately related to the topological band gap specified by a negative Dirac mass. This brand-new Huygens-Fresnel phenomenon can be considered as the counterpart of negative refraction of EM plane waves associated with upwardly convex dispersions of photonic crystals, and our present finding is expected to open a new window for photonic innovations.

2.
Huan Jing Ke Xue ; 44(2): 1003-1011, 2023 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-36775623

RESUMO

In order to understand the differences in the uptake and accumulation of several common exogenous selenium fertilizers by crops, a wheat pot experiment was conducted to study the availability changes in different selenium fertilizers (potassium selenate, potassium selenite, EDTA-chelated selenium, selenium powder, fly ash, and selenium-enriched straw) in soil and their effects on wheat growth and selenium uptake and distribution. The results showed that the change in availability of different exogenous selenium types in soil was different. During the whole growth period of wheat, the soil available selenium proportion of selenate, selenite, and EDTA-chelated selenium treatment was significantly higher than that of the control (CK), respectively, but there was no significant difference between the other treatments and the CK treatment. In the early stage of wheat growth, the soil available selenium proportion of selenate, selenite, and selenium powder treatment decreased gradually and tended to be stable in the later growth stage of wheat; however, the soil available selenium proportion of other exogenous selenium treatments showed a dynamic change of decreasing in the early period and increasing in the late period. The available selenium content in soil significantly affected the selenium uptake by wheat, and there was a significant positive correlation between them. Selenate application significantly increased the grain and leaf biomass of wheat, but other selenium fertilizers had no significant effect on wheat growth. The accumulation capacity of different exogenous selenium fertilizers for wheat followed the order of selenate>selenite, EDTA-chelated selenium>selenium powder, fly ash, and selenium-enriched straw. There was no significant difference between the selenium powder, fly ash, and selenium-enriched straw treatments and the CK treatment. Selenium was more easily transferred to and accumulated in the stems and leaves of wheat after the application of selenate, whereas selenium was more easily transferred to and accumulated in grains after the application of selenite and EDTA-chelated selenium.


Assuntos
Selênio , Solo , Ácido Selênico , Triticum , Fertilizantes/análise , Cinza de Carvão , Ácido Edético , Pós , Ácido Selenioso
5.
Cell Biol Int ; 44(1): 166-176, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31393052

RESUMO

Pulmonary artery adventitial fibroblasts, the most abundant cellular constituent of adventitia, are often the first to be activated and reprogrammed to then influence the tone and structure of the vessel wall in pulmonary arterial hypertension (PAH). Our previous study found that interruption of CD40 ligand (CD40L)-CD40 signaling improves the efficacy of transplanted endothelial progenitor cells in monocrotaline induced-PAH. However, whether CD40L-CD40 signaling is involved in the activation of adventitial fibroblasts in PAH and whether Drosophila behavior human splicing (DBHS) protein family members have any roles during adventitial fibroblasts activation are completely unclear. Here, we show that soluble CD40L (sCD40L) stimulation progressively increases pro-inflammatory activity, proliferation, and migration of pulmonary adventitial fibroblasts. Besides, sCD40L stimulation decreases splicing factor proline- and glutamine-rich protein (SFPQ) protein (one member of DBHS protein family) expression, while SFPQ overexpression suppresses sCD40L stimulation-induced proliferation and migration of pulmonary adventitial fibroblasts by repressing CD40 transcription. Moreover, ChIP assays found that sCD40L stimulation promotes histone H3 tri-methylation at lysine 4 (H3K4me3), H3K36me3, and H3K27 acetylation (H3K27ac) modifications on CD40 promoter region in pulmonary adventitial fibroblasts, while SFPQ overexpression decreases H3K36me3 modification and increases H3K36ac on CD40 promoter region by interacting with histone deacetylase-1 (HDAC1) to inhibit CD40 transcription. This in-depth study shows that CD40L-CD40 signaling promotes activation of pulmonary adventitial fibroblasts by increasing proliferation, migration, and pro-inflammatory activity of adventitial fibroblasts, and SFPQ could inhibit CD40 transcription though switching H3K36me3 to H3K36ac modifications on its promoter by interacting with HDAC1. This study, first, uncovers the roles of SFPQ on CD40L-CD40 signaling-mediated activation of pulmonary adventitial fibroblasts.

6.
Nat Nanotechnol ; 15(1): 67-72, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31844287

RESUMO

Topological insulators are materials that behave as insulators in the bulk and as conductors at the edge or surface due to the particular configuration of their bulk band dispersion. However, up to date possible practical applications of this band topology on materials' bulk properties have remained abstract. Here, we propose and experimentally demonstrate a topological bulk laser. We pattern semiconductor nanodisk arrays to form a photonic crystal cavity showing topological band inversion between its interior and cladding area. In-plane light waves are reflected at topological edges forming an effective cavity feedback for lasing. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. Our topological bulk laser works at room temperature and reaches the practical requirements in terms of cavity size, threshold, linewidth, side-mode suppression ratio and directionality for most practical applications according to Institute of Electrical and Electronics Engineers and other industry standards. We believe this bulk topological effect will have applications in near-field spectroscopy, solid-state lighting, free-space optical sensing and communication.

7.
J Sci Food Agric ; 99(4): 1898-1907, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30267426

RESUMO

BACKGROUND: The continuous cropping of peanuts is a primary cause of yield and quality loss. Solutions to this problem should be therefore developed to ensure the sustainability of peanut production. RESULTS: In this study, colonization by the endophytic fungus Phomopsis liquidambari was detected, which led to significantly improved rhizosphere soil microenvironment, enhanced N, P and K assimilation and suppressed incidence of peanut disease. Statistical analysis demonstrated that the yield enhancement was significantly correlated with improvement of the rhizosphere soil microenvironment and the peanut's physiological status by P. liquidambari colonization. In addition, P. liquidambari colonization also significantly improved peanut quality. CONCLUSION: Our results indicate that the practical application of the endophytic fungus P. liquidambari has a strong potential to alleviate the obstacles associated with continuous peanut cropping under field conditions. © 2018 Society of Chemical Industry.


Assuntos
Arachis/microbiologia , Ascomicetos/crescimento & desenvolvimento , Endófitos/crescimento & desenvolvimento , Doenças das Plantas/prevenção & controle , Arachis/química , Arachis/crescimento & desenvolvimento , Arachis/metabolismo , Nitrogênio/análise , Nitrogênio/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Doenças das Plantas/microbiologia , Potássio/análise , Potássio/metabolismo , Rizosfera , Microbiologia do Solo
8.
Cell Transplant ; 27(5): 786-795, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29882417

RESUMO

Accumulating evidence has demonstrated that endothelial progenitor cells (EPCs) could facilitate the reendothelialization of injured arteries by replacing the dysfunctional endothelial cells, thereby suppressing the formation of neointima. Meanwhile, other findings suggest that EPCs may be involved in the pathogenesis of age-related vascular remodeling. This review is presented to summarize the characteristics of EPCs and age-related vascular remodeling. In addition, the role of EPCs in age-related vascular remodeling and possible solutions for improving the therapeutic effects of EPCs in the treatment of age-related diseases are discussed.


Assuntos
Envelhecimento/fisiologia , Células Progenitoras Endoteliais/fisiologia , Remodelação Vascular/fisiologia , Animais , Humanos , Modelos Biológicos
10.
Cell Physiol Biochem ; 40(1-2): 195-206, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27855363

RESUMO

BACKGROUND/AIMS: Tanshinone IIA (Tan IIA) is effective in the treatment of inflammation and atherosclerosis. The adhesion of inflammatory cells to vascular endothelium plays important role in atherogenic processes. This study examined the effects of Tan IIA on expression of adhesion molecules in tumor necrosis factor-α (TNF-α)-induced endothelial progenitor cells (EPCs). METHODS: EPCs were pretreated with Tan IIA and stimulated with TNF-α. Mononuclear cell (MNC) adhesion assay was performed to assess the effects of Tan IIA on TNF-α-induced MNC adhesion. Expression of vascular cell adhesion molecule-1 (VCAM-1)/intracellular adhesion molecule-1 (ICAM-1) and activation of Nuclear factor κB (NF-κB) signaling pathway were measured. RESULTS: The results showed that the adhesion of MNCs to TNF-α-induced EPCs and expression of VCAM-1/ICAM-1 in EPCs were promoted by TNF-α, which were reduced by Tan IIA. TNF-α increased the amount of phosphorylation of NF-κB, IκB-α and IKKα/ß in cytosolic fractions and NF-κB p65 in nucleus, while Tan IIA reduced its amount. CONCLUSION: This study demonstrated a novel mechanism for the anti-inflammatory/anti-atherosclerotic activity of Tan IIA, which may involve down-regulation of VCAM-1 and ICAM-1 through partial blockage of TNF-α-induced NF-κB activation and IκB-α phosphorylation by the inhibition of IKKα/ß pathway in EPCs.


Assuntos
Abietanos/farmacologia , Células Progenitoras Endoteliais/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Molécula 1 de Adesão de Célula Vascular/metabolismo , Animais , Células da Medula Óssea/citologia , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Progenitoras Endoteliais/efeitos dos fármacos , Imunofluorescência , Proteínas I-kappa B/metabolismo , Imunofenotipagem , Masculino , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo
11.
Sci Rep ; 6: 35334, 2016 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-27734955

RESUMO

Excessive pig manure application probably degrades arable soil quality in some intensive pig farming areas. The responses of the nematode community to dosages of pig manure were investigated in Ferric Acrisols under 3-season peanut monoculture. Varying dosages of manure (1.75, 3.5, 7, 14 and 28 t·ha-1·yr-1) in combination with chemical fertilizer were applied to field plots, and chemical fertilizer alone was also applied as a control. With increasing manure application, the abundance of bacterivores and omnivores-predators increased, the abundance of plant parasites decreased, and fungivores abundance exhibited hump-shaped variation. Simpson diversity index and plant parasite index/maturity index of the nematode communities increased to a maximum level at a manure application rate of 3.5 t·ha-1·yr-1 and then sharply decreased. The changes in the soil nematode community were further determined to be correlated with chemical properties; available phosphorus had the strongest quadratic correlation with the two indices, implying that available phosphorus had a better indicative effect than other soil properties to nematode community. Available phosphorus in soil was deduced from 49 to 64 mg·kg-1 with the best nematode communities. Our results emphasized the importance of regular applications of manure in agriculture field to balance nematode diversity and build healthy agro-ecosystems.


Assuntos
Acidose/metabolismo , Ferro/química , Esterco , Nematoides/fisiologia , Solo/química , Agricultura , Animais , Produtos Agrícolas , Ecossistema , Monitoramento Ambiental , Fertilizantes , Concentração de Íons de Hidrogênio , Análise Multivariada , Fósforo/química , Suínos
12.
Plant Physiol Biochem ; 98: 1-11, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26584395

RESUMO

In peanut continuous cropping soil, the application of fungal endophyte Phomopsis liquidambari B3 showed peanut pod yield promotion and root nodule number increase. P. liquidambari improved soil environment by degrading allelochemicals and thus promoted peanut pod yield. Furthermore, peanut yield promotion is in part due to the root nodule increase since nodular nitrogen fixation provides the largest source of nitrogen for peanut. However, it is unknown whether this nodule number increase is induced by fungal endophyte. We therefore conducted several pot experiments using vermiculite to investigate the effects of P. liquidambari on peanut-bradyrhizobium nodulation. Our results showed that P. liquidambari co-inoculated with bradyrhizobium increased root nodule number and shoot accumulated nitrogen by 28.25% and 29.71%, respectively. Nodulation dynamics analysis showed that P. liquidambari accelerated nodule initiation and subsequent nodule development. Meanwhile, P. liquidambari was able to colonize the peanut root as an endophyte. The dynamics of P. liquidambari and bradyrhizobial root colonization analysis showed that P. liquidambari inoculation significantly increased the rate of bradyrhizobial colonization. Furthermore, P. liquidambari inoculation significantly increased flavonoids synthesis-related enzymes activities, two common types of flavonoid (luteolin and quercetin-peanut rhizobial nod gene inducer) secretion and lateral root (peanut rhizobial infection site) formation, indicating that P. liquidambari altered the peanut nodulation-related physiological and metabolic activities. These obtained results confirmed the direct contribution of P. liquidambari in enhancing peanut-bradyrhizobium interaction, nodulation and yield.


Assuntos
Arachis/crescimento & desenvolvimento , Ascomicetos/fisiologia , Bradyrhizobium/fisiologia , Nodulação , Simbiose , Arachis/microbiologia , Endófitos , Flavonoides/metabolismo , Nitrogênio/metabolismo , Fixação de Nitrogênio , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Microbiologia do Solo
13.
Mol Med Rep ; 12(3): 4055-4062, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26095681

RESUMO

Tanshinone ⅡA (Tan ⅡA) is a Traditional Chinese Medicine commonly used in Asian and Western countries for the prevention and treatment of cardiovascular disorders, such as atherosclerosis. Endothelial dysfunction and associated inflammatory processes have a critical role in the development of atherosclerosis. Endothelial progenitor cells (EPCs) have been demonstrated to be involved in certain aspects of the endothelial repair process. The present study aimed to investigate the putative protective effects of Tan ⅡA on EPCs injured by tumor necrosis factor­α (TNF­α). The potential effects of Tan ⅡA on TNF-α-stimulated EPC proliferation, migration, adhesion, in vitro tube formation ability and paracrine activity were investigated in the current study. The results indicated that TNF­α impaired EPC proliferation, migration, adhesion capacity and vasculogenesis ability in vitro as well as promoted EPC secretion of inflammatory cytokines, including monocyte chemoattractant protein­1 (MCP­1), interleukin­6 (IL­6) and soluble CD40 ligand (sCD40L). However, Tan ⅡA was able to reverse these effects. In conclusion, these findings demonstrated that Tan ⅡA may have the potential to protect EPCs against damage induced by TNF­α. Therefore, these results may provide evidence for the pharmacological basis of Tan ⅡA and its potential use in the prevention and treatment of early atherosclerosis associated with EPC and endothelial damage.


Assuntos
Abietanos/farmacologia , Células Progenitoras Endoteliais/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Fator de Necrose Tumoral alfa/toxicidade , Animais , Ligante de CD40/metabolismo , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/metabolismo , Células Progenitoras Endoteliais/citologia , Células Progenitoras Endoteliais/metabolismo , Interleucina-6/metabolismo , Masculino , Medicina Tradicional Chinesa , Microscopia de Fluorescência , Ratos , Ratos Sprague-Dawley
14.
Microbiol Res ; 169(12): 881-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24958248

RESUMO

The recently isolated fungal strain Phomopsis liquidambari B3 can degrade high concentrations of indole, indicating its potential for the bioremediation of indole-contaminated soil. In this study, a specific real-time PCR was developed to detect the survival of P. liquidambari B3 in soil. Subsequently, degradation activity of strain B3 and its effects on indigenous microbial community were analyzed. Results showed the amount of P. liquidambari B3 genomic DNA increased to a maximum 5.67 log (pgg(-1) dry soil) 10 days after inoculation of 5.04 log (pgg(-1) dry soil), and then gradually decreased with time and after 40 days it was below the detection limit. By the end of the experiment (day 40), bioaugmented microsoms showed a 93.7% decrease in indole, while the values for biostimulated and control microcosms were much lower. Higher microbial biomass and enzyme activities were observed in bioaugmented soil. Denaturing gradient gel electrophoresis analysis showed bioaugmentation increased richness of resident microbial community. These results indicate that P. liquidambari B3 is effective for the remediation of indole-contaminated soil and also provides valuable information about the behavior of the inoculant population during bioremediation, which could be directly used in the risk assessment of inoculant population and optimization of bioremediation process.


Assuntos
Ascomicetos/fisiologia , Indóis/metabolismo , Microbiota , Microbiologia do Solo , Poluentes do Solo/metabolismo , Ascomicetos/isolamento & purificação , Biodegradação Ambiental , Biomassa , Eletroforese em Gel de Gradiente Desnaturante , Endófitos/isolamento & purificação , Endófitos/fisiologia , Indóis/toxicidade , Viabilidade Microbiana , Reação em Cadeia da Polimerase em Tempo Real
15.
Int J Biol Sci ; 9(2): 164-73, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23412138

RESUMO

The high incidence of various soil-borne diseases in the monoculture field of peanut is a major production constraint in the red soil regions of southern China. The peanut root exudates are generally thought to play an important role in regulating soil-borne pathogens. The responses of the soil-borne pathogens, Fusarium oxysporum and F. solani to the peanut root exudates were studied using one susceptible cultivar Ganhua-5 (GH) and one mid-resistant cultivar Quanhua-7 (QH) as the test materials. The components and contents of the amino acids, sugars and phenolic acids in the peanut root exudates were determined. The results demonstrated that the root exudates from both susceptible and mid-resistant cultivars significantly promoted the spore germination, sporulation and mycelial growth of soil-borne pathogens, F. oxysporum, F. solani compared with the control. The extent of the stimulation was depended on the strains of the Fusarium tested, and gradually increased with the increased concentrations of peanut root exudates. HPLC analysis showed that the contents of sugars, alanine, total amino acids in the root exudates of GH were significantly higher than that in QH, whereas the contents of p-hydroxybenzoic acid, benzoic acid, p-coumaric acid and total phenolic acids were significantly lower than that in QH. Results of the study suggested that the differences in the root exudates from the different peanut cultivars were considered to regulate the wilt-resistance mechanism in the rhizosphere of peanut. The results are therefore crucial important to illustrate the mechanism of peanut replanted obstacle, and to develop its control techniques in the red soil regions of southern China.


Assuntos
Agricultura/métodos , Arachis/química , Fusarium/efeitos dos fármacos , Exsudatos de Plantas/farmacologia , Raízes de Plantas/química , Microbiologia do Solo , Alanina/análise , Aminoácidos/análise , Arachis/genética , China , Cromatografia Líquida de Alta Pressão , Fusarium/crescimento & desenvolvimento , Exsudatos de Plantas/análise , Especificidade da Espécie , Esporos Bacterianos/efeitos dos fármacos
16.
Cell Transplant ; 22(8): 1325-36, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23295102

RESUMO

A growing body of evidence in animal models and clinical studies supports the concept that endothelial progenitor cell (EPC)-mediated therapy ameliorates pulmonary arterial hypertension (PAH) and thus may represent a novel approach to treat it. Conversely, several experimental findings suggest that EPCs may be involved in PAH pathogenesis and disease progression. These discrepant results confuse the application of EPC transplantation as an effective treatment strategy for PAH. To improve the study of EPC transplantation in PAH therapy, it is high time that we resolve this dilemma. In this review, we examine the pathobiological changes of PAH, the characteristics of EPCs, and the underlying mechanisms of EPC effects on PAH.


Assuntos
Células Endoteliais/citologia , Hipertensão Pulmonar/terapia , Transplante de Células-Tronco , Células-Tronco/citologia , Animais , Modelos Animais de Doenças , Hipertensão Pulmonar Primária Familiar , Humanos , Hipertensão Pulmonar/patologia
17.
Front Biosci (Landmark Ed) ; 18(2): 725-33, 2013 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-23276956

RESUMO

The components of the root exudates from two transgenic insect-resistant cotton lines and their parental cotton lines, and their effects on the growth of Fusarium oxysporum were investigated. The results demonstrated that the resistance of transgenic insect-resistant cotton to F. oxysporum was significantly reduced compared with their parental lines. Likewise, the root exudates from transgenic insect-resistant cotton significantly promoted the spore germination and mycelial growth of cotton F. oxysporum. The types of compounds found in the root exudates of transgenic insect-resistant cotton were similar to those of the parental cotton, but the composition and relative content of the compounds were different. The type and content of the fatty acids and esters were significantly reduced in the root exudates of the transgenic insect-resistant cotton, as were certain specific materials, whereas several alkanes were increased. The inhibition of the soil-borne pathogen F. oxysporum caused by the root exudates from the transgenic insect-resistant cotton was decreased compared with the parental cotton. This result provides a scientific basis for the decline in disease resistance in transgenic insect-resistant cotton.


Assuntos
Exsudatos e Transudatos/química , Gossypium/genética , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Raízes de Plantas/química , Plantas Geneticamente Modificadas/química , Fusarium/efeitos dos fármacos , Germinação/efeitos dos fármacos , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/fisiologia
18.
Ying Yong Sheng Tai Xue Bao ; 23(10): 2693-700, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23359928

RESUMO

A pot experiment was conducted to investigate the effects of applying endophytic fungi Phomopsis liquidambari strain B3, Phomopsis sp. strain NJ4.1, and Ceratobasidum stevensii strain B6 on the soil biological characteristics and enzyme activities under continuously cropped peanut at its different growth stages. Compared with the control, applying B3 increased the peanut yield significantly by 19.8%, and applying NJ4.1, B3 and B6 increased the peanut nodule number significantly by 20.4%, 29.3% and 27.6%, respectively. In the three treatments of applying endophytic fungi, the average population of soil bacteria and actinomycetes in the whole growth period of peanut was higher than that of the control, and the soil microbial biomass carbon was significantly greater at germination and seedling stages. The soil microbial biomass nitrogen increased at germination stage, but decreased at flowering stage. The DGGE analysis indicated that at flowering stage, the soil bacteria and fungi in treatment B3 had the largest band number and diversity. From germination stage to maturing stage, the three treatments of applying endophytic fungi had higher activities of soil invertase and catalase than the control, but less difference in soil urease activity. It was suggested that applying endophytic fungi could improve the peanut continuous cropping soil environment, and applying B3 had the best effect.


Assuntos
Arachis/crescimento & desenvolvimento , Endófitos/fisiologia , Microbiologia do Solo , Solo/química , Agricultura/métodos , Biomassa , Catalase/metabolismo , Ecossistema , Germinação , Plântula , Simbiose/fisiologia , beta-Frutofuranosidase/metabolismo
19.
Cytotherapy ; 12(2): 251-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20196696

RESUMO

BACKGROUND AIMS: Cell labeling with superparamagnetic iron oxide (SPIO) nanoparticles enables non-invasive tracking of transplanted cells. The aim of this study was to investigate whether SPIO nanoparticles have an effect on endothelial progenitor cell (EPC) functional activity and the feasibility of a protocol for labeling swine- and rat-origin EPC using SPIO nanoparticles at an optimized low dosage. METHODS: EPC were isolated from the peripheral blood of swine and bone marrow of rat and characterized. After ex vivo cultivation, EPC were labeled with SPIO nanoparticles (to make a series of final concentrations, 50, 100, 200 and 400 microg/mL) or vehicle control. We also investigated the long-term effects of 200 microg/mL SPIO nanoparticles on EPC (4, 8, 12 and 16 days after labeling). The labeling efficiency was tested through Prussian blue (PB) staining and the intracellular iron uptake was also measured quantitatively and confirmed. EPC proliferation and migration were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell chamber assay, respectively. An EPC adhesion assay was performed by replating the cells on fibronectin-coated dishes and then counting the adherent cells. EPC apoptosis was evaluated using an Annexin V-FITC apoptosis kit. RESULTS: SPIO nanoparticles impaired EPC migration and promoted EPC adhesion. EPC proliferation and apoptosis were not affected. SPIO nanoparticles could label EPC efficiently at 200 microg/mL overnight without significantly affecting EPC functional activity. CONCLUSIONS: SPIO nanoparticles impaired the EPC migration ability and promoted the EPC adhesion capacity. EPC could be labeled efficiently at an appropriate concentration (200 microg/mL) without significantly affecting their functional activity.


Assuntos
Movimento Celular/efeitos dos fármacos , Células Endoteliais/citologia , Óxido Ferroso-Férrico/farmacologia , Nanopartículas/química , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dextranos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/ultraestrutura , Ferrocianetos/metabolismo , Ferro/metabolismo , Nanopartículas de Magnetita , Ratos , Ratos Sprague-Dawley , Coloração e Rotulagem , Células-Tronco/ultraestrutura , Sus scrofa
20.
J Physiol Sci ; 59(6): 429-37, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19636669

RESUMO

Previous studies have underlined the importance of endothelial dysfunction and microvascular occlusion in the pathogenesis of pulmonary artery hypertension (PAH). Since the endothelial progenitor cells (EPCs) are involved in maintaining endothelial homeostasis, we observed the change of peripheral EPCs in canines before and after PAH onset. PAH was induced by intra-pulmonary artery injection of dehydromonocrotaline (DHMC) in nine beagles. Before and 48 h and 6 weeks after DHMC injection, 40 ml peripheral blood was obtained from the femoral vein. Circulating EPCs were identified as CD133 + KDR + cells and numerated by fluorescence-activated cell sorter; the EPCs functional capacity was determined by in vitro tubule-forming assay. The senescence of EPCs was determined by beta-galactosidase staining. At each time point, 2 ml blood from femoral artery was obtained for arterial oxygen pressure (PaO(2)). Forty-eight hours after DHMC injection, treated beagles suffered from hypoxemia; however, both the number and the tubule-forming capacity of EPCs were transiently raised. Six weeks later, PAH was confirmed by obviously high mean pulmonary arterial pressure (20.2 +/- 1.64 vs. 11.3 +/- 2.0 mmHg, p < 0.05) and low PaO(2) (69.30 +/- 9.15 vs. 95.94 +/- 1.43 mmHg, p < 0.01) in beagles after DHMC treatment, and their EPCs exhibited a predominant decrease in either the number (206.1 +/- 26.8 vs. 632.8 +/- 42.8 cells/ml blood, p < 0.01) or the tubule-forming capacity (21.1 +/- 2.8 vs. 11.2 +/- 2.8 tubules/x200 field, p < 0.01). Additionally, senescence-associated beta-galactosidase-positive EPCs were significantly increased. Our data suggested that, after the acute stage of DHMC injury to pulmonary vessels, the EPCs from PAH beagles suffered from exhaustion and senescence.


Assuntos
Células Endoteliais/fisiologia , Endotélio Vascular/citologia , Hipertensão Pulmonar/induzido quimicamente , Células-Tronco/citologia , Células-Tronco/fisiologia , Animais , Técnicas de Cultura de Células , Separação Celular , Células Cultivadas , Senescência Celular , Modelos Animais de Doenças , Cães , Células Endoteliais/metabolismo , Citometria de Fluxo , Masculino , Monocrotalina/análogos & derivados , Monocrotalina/farmacologia , Neovascularização Fisiológica , Células-Tronco/metabolismo
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