共查询到20条相似文献,搜索用时 15 毫秒
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Shaoyuan Li Yan Zheng Yaqin Liu Xiuhua Geng Xiaofeng Liu Liyuan Zou Qing Wang Xiaohai Yang Kemin Wang 《Journal of molecular recognition : JMR》2020,33(5)
Understanding the binding of split aptamer/its target could become a breakthrough in the application of split aptamer. Herein, vascular endothelial growth factor (VEGF), a major biomarker of human diseases, was used as a model, and its interaction with split aptamer was explored with single molecule force spectroscopy (SMFS). SMFS demonstrated that the interaction force of split aptamer/VEGF165 was 169.44 ± 6.59 pN at the loading rate of 35.2 nN/s, and the binding probability of split aptamer/VEGF165 was dependent on the concentration of VEGF165. On the basis of dynamic force spectroscopy results, one activation barrier in the dissociation process of split aptamer/VEGF165 complexes was revealed, which was similar to that of the intact aptamer/VEGF165. Besides, the dissociation rate constant (koff) of split aptamer/VEGF165 was close to that of intact aptamer/VEGF165, and the interaction force of split aptamer/VEGF165 was higher than the force of intact aptamer/VEGF165. It indicated that split aptamer also possessed high affinity with VEGF165. The work can provide a new method for exploring the interaction of split aptamer/its targets at single‐molecule level. 相似文献
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Jörg Wilting Bodo Christ Matthias Bokeloh Herbert A. Weich 《Cell and tissue research》1993,274(1):163-172
The effect of vascular endothelial growth factor (VEGF165) on the chorioallantoic membrane (CAM) of 13-day-old chick embryos was studied. The factor was applied in doses of 0.5–4 g for a period of up to 4 days. Macroscopical, histological and immunohistological studies were carried out. The localization of the factor was examined with an anti-VEGF antibody. The mitogenicity of VEGF165 and basic fibroblast growth factor (bFGF) were studied by means of the BrdU-anti-BrdU method. Furthermore, the effect of heparin alone and in combination with VEGF165 was investigated. VEGF165 specifically induces angiogenesis in doses of 0.5 g and more. A brush-like formation of blood vessels can be seen in the region of the precapillary vessels. Angiogenesis also takes place in the region of the capillaries and the venules. Histologically we found indications of sprouting as well as of intussusceptive capillary growth. The presence of the factor in the application area could be demonstrated with the anti-VEGF antibody for a period of 3 days. The factor is located in the chorionic epithelium and the intraepithelial capillaries. The BrdU-studies show that VEGF165 induces strong endothelial cell proliferation, whereas bFGF elicits fibrocyte proliferation and minor endothelial cell proliferation. Heparin induces squamous metaplasia of the chorionic and allantoic epithelium in combination with an aggregation of fibrocytes. We could not detect any enhancement of VEGF165 by heparin.This paper is dedicated to Professor R. Ortmann on the occasion of his 80th birthday 相似文献
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Yan Tan En-hua Xiao Li-zhi Xiao You-hong Yuan Cong Ma Quan-liang Shang Du-jun Bian Yan-hui Li Zhu Chen Qian Chang 《Cytotechnology》2012,64(6):635-647
A short half-life and low levels of growth factors in an injured microenvironment necessitates the sustainable delivery of growth factors and stem cells to augment the regeneration of injured tissues. Our aim was to investigate the ability of VEGF165 expressing bone marrow mesenchymal stem cells (BMMSCs) to differentiate into hepatocytes when cultured with hepatocyte growth factor (HGF) and epidermal growth factor (EGF) in vitro. We isolated, cultured and identified rabbit BMMSCs, then electroporated the BMMSCs with VEGF165-pCMV6-AC-GFP plasmid. G418 was used to select transfected cells and the efficiency was up to 70%. The groups were then divided as follows: Group A was electroporated with pCMV6-AC-GFP plasmid + HGF + EGF and Group B was electroporated with VEGF165-pCMV6-AC-GFP plasmid +HGF + EGF. After 14 days, BMMSCs were induced into short spindle and polygonal cells. Alpha-fetoprotein (AFP) was positive and albumin (ALB) was negative in Group A, while both AFP and ALB were positive in group B on day 10. AFP and ALB in both groups were positive on day 20, but the quantity of AFP in group B decreased with prolonged time and was about 43.5% less than group A. The quantity of the ALB gene was increased with prolonged time in both groups. However, there was no significant difference between group A and B on day 10 and 20. Our results demonstrated that VEGF165-pCMV6-AC-GFP plasmid modified BMMSCs still had the ability to differentiate into hepatocytes. The VEGF165 gene promoted BMMSCs to differentiate into hepatocyte-like cells under the induction of HGF and EGF, and reduced the differentiation time. These results have implications for cell therapies. 相似文献
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Anghel A Mut-Vitcu B Savu L Marian C Seclaman E Iman R Neghina AM Dragulescu SI 《Genomic Medicine》2007,1(1-2):47-55
The present study focuses on the application of a therapeutic strategy in patients with chronic severe lower limb ischaemia
using a plasmid vector encoding the vascular endothelial growth factor (phVEGF165). It has been shown that VEGF promotes neo-vascularization and blood vessel network formation and thus might have the ability
to improve blood-flow at the level of the affected limbs. However, little information is available regarding the necessary
level of expression of VEGF and its possible related adverse effects. We have subcloned VEGF
165
isoform into pCMV-Script expression vector (Stratagene) under the control of the CMV promoter. Three patients with chronic
ischaemia of the lower limb, considered as not suitable for surgical re-vascularization, received intramuscular injection
with 0.5 ml saline solution containing 1011 copies of VEGF
165
plasmid. The clinical evolution has been monitored by angiography and estimated by walking time on the rolling carpet (Gardner
protocol). Two months after therapy, all three patients showed complete relief of rest pain, improvement of ischaemic ulcer
lesions and increased walking distance on the rolling carpet most probably due to appearance of newly formed collateral vessels. 相似文献
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Alternative splicing contributes to the complexity of proteome by producing multiple mRNAs from a single gene. Affymetrix exon arrays and experiments in vivo or in vitro demonstrated that alternative splicing was regulated by mechanical stress. Expression of mechano-growth factor (MGF) which is the splicing isoform of insulin-like growth factor 1(IGF-1) and vascular endothelial growth factor (VEGF) splicing variants such as VEGF121, VEGF165, VEGF206, VEGF189, VEGF165 and VEGF145 are regulated by mechanical stress. However, the mechanism of this process is not yet clear. Increasing evidences showed that the possible mechanism is related to Ca2+ signal pathway and phosphorylation signal pathway. This review proposes possible mechanisms of mechanical splicing regulation. This will contribute to the biomechanical study of alternative splicing. 相似文献
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Mélanie Di Benedetto Anna Starzec Roger Vassy Gérard-Yves Perret Michel Crépin 《Biochimica et Biophysica Acta (BBA)/General Subjects》2008
We previously demonstrated that a non sulfated analogue of heparin, phenylacetate carboxymethyl benzylamide dextran (NaPaC) inhibited angiogenesis. Here, we observed that NaPaC inhibited the VEGF165 binding to both VEGFR2 and NRP-1 and abolished VEGFR2 activity. Further, we explored the effects of NaPaC on VEGF165 interactions with its receptors, VEGFR2 and NRP-1, co-receptor of VEGFR2. Surface plasmon resonance and affinity gel electrophoresis showed that NaPaC interacted directly with VEGF165, VEGFR2 and NRP-1 but not with heparin-independent factor such as VEGF121. NaPaC completely inhibited the heparin binding to VEGF165, NRP-1 and VEGFR2. We found that NaPaC bound to all three molecules, VEGF165, VEGFR2 and NRP-1, but was more effective in inhibiting heparin binding to VEGF165. These results suggested that heparin binding sites of VEGFR2 and NRP-1 were different from those of VEGF165. 相似文献
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Weibin Du Jintao Hu Xiaolong Huang Zhenwei Wang Huateng Zhou Yadong Yang Huahui Hu Rongliang Chen Fuxiang Shen Renfu Quan 《Journal of cellular and molecular medicine》2023,27(15):2136-2149
The preparation of biodegradable scaffolds loaded with cells and cytokine is a feature of tissue-engineered skin. IPSCs-based tissue-engineered skin treatment for wound repair is worth exploring. Healthy human skin fibroblasts were collected and reprogrammed into iPSCs. After gene modification and induction, CK19+/Integrinβ1+/CD200+ VEGF165 gene-modified iPS-HFSCsGFP were obtained and identified by a combination of immunofluorescence and RT-qPCR. Astragalus polysaccharide-containing 3D printed degradable scaffolds were prepared and co-cultured with VEGF165 gene-modified iPS-HFSCsGFP, and the biocompatibility and spatial structure of the tissue-engineered skin was analysed by cell counting kit-8 (CCK8) assay and scanning electron microscopy. Finally, the tissue-engineered skin was transplanted onto the dorsal trauma of nude mice, and the effect of tissue-engineered skin on the regenerative repair of total skin defects was evaluated by a combination of histology, immunohistochemistry, immunofluorescence, RT-qPCR, and in vivo three-dimensional reconstruction under two-photon microscopy. CK19+/Integrinβ1+/CD200+ VEGF165 gene-modified iPS-HFSCsGFP, close to the morphology and phenotype of human-derived hair follicle stem cells, were obtained. The surface of the prepared 3D printed degradable scaffold containing 200 μg/mL astragalus polysaccharide was enriched with honeycomb-like meshwork, which was more conducive to the proliferation of the resulting cells. After tissue-engineered skin transplantation, combined assays showed that it promoted early vascularization, collagen and hair follicle regeneration and accelerated wound repair. VEGF165 gene-modified iPS-HFSCsGFP compounded with 3D printed degradable scaffolds containing 200 μg/mL astragalus polysaccharide can directly and indirectly participate in vascular, collagen, and hair follicle regeneration in the skin, achieving more complete structural and functional skin regenerative repair. 相似文献
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Previous NMR structural studies of the heparin-binding domain of vascular endothelial growth factor (VEGF165) revealed a novel fold comprising two subdomains, each containing two disulfide bridges and a short two-stranded antiparallel -sheet. The mutual orientation of the two subdomains was poorly defined by the NMR data. Heteronuclear relaxation data suggested that this disorder resulted from a relative lack of experimental restraints due to the limited size of the interface, rather than inherent high-frequency flexibility. Refinement of the structure using 1HN-15N residual dipolar coupling restraints results in significantly improved definition of the relative subdomain orientations. 相似文献
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Akimichi Ohsaka Satoko Hirota-Komatsu Norio Komatsu 《Biochemical and biophysical research communications》2009,390(4):1171-1176
We investigated whether the gene expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR and neuropilin-1 [NRP-1]) could be specifically regulated during the megakaryocytic differentiation of human thrombopoietin (TPO)-dependent UT-7/TPO cells. Undifferentiated UT-7/TPO cells expressed a functional VEGFR-2, leading to VEGF binding and VEGF165-induced tyrosine phosphorylation, cell proliferation, and apoptosis inhibition. The megakaryocytic differentiation of UT-7/TPO cells on treatment with phorbol myristate acetate (PMA) was accompanied by a marked up-regulation of NRP-1 mRNA and protein expression and by an increase in VEGF-binding activity, which was mainly mediated by VEGFR-2. VEGF165 promoted the formation of complexes containing NRP-1 and VEGFR-2 in undifferentiated UT-7/TPO cells in a dose-dependent manner. Unlike human umbilical vein endothelial cells, PMA-differentiated UT-7/TPO cells exhibited complex formation between NRP-1 and VEGFR-2 even in the absence of VEGF165. These findings suggest that NRP-1-VEGFR-2-complex formation may contribute to effective cellular functions mediated by VEGF165 in megakaryocytic cells. 相似文献
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ADAM family consists of a number of transmembrane proteins that contain a disintegrin and metalloprotease domain. ADAMs are involved in a highly diverse set of biological processes, including fertilization, neurogenesis, myogenesis and inflammatory response. The ADAM proteins have both cell adhesion and protease activities.Adam22 is highly expressed in human brain. Theadam22-/- mice presented severe ataxia and died before weaning, but the function of ADAM22 is still unknown. 14-3-3 β interacting with ADAM22 was detected by using yeast two-hybrid assay. The specificity of interaction between ADAM22 and 14-3-3β was proved byin vitro binding assay and immunoprecipitation. The major 14-3-3β binding site was located in the last 28 amino acid residues of ADAM22 cytoplasmic tail. Protein 14-3-3β is abundant and plays an important role in mediating cell diffusion, migration and cell cycle control. The interaction of ADAM22 and 14-3-3β suggests that the ADAM22 may play a crucial role in neural function and development. 相似文献
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ZHU Pengcheng SANG Yingying XU Rener ZHAO Jing LI Changben ZHAO Shouyuan 《中国科学:生命科学英文版》2002,45(6):577-582
ADAM family consists of a number of transmembrane proteins that contain a disintegrin and metalloprotease domain. ADAMs are involved in a highly diverse set of biological processes, including fertilization, neurogenesis, myogenesis and inflammatory response. The ADAM proteins have both cell adhesion and protease activities. Adam22 is highly expressed in human brain. The adam22-/- mice presented severe ataxia and died before weaning, but the function of ADAM22 is still unknown. 14-3-3β interacting with ADAM22 was detected by using yeast two-hybrid assay. The specificity of interaction between ADAM22 and 14-3-3β was proved by in vitro binding assay and immunoprecipitation. The major 14-3-3β binding site was located in the last 28 amino acid residues of ADAM22 cytoplasmic tail. Protein 14-3-3β is abundant and plays an important role in mediating cell diffusion, migration and cell cycle control. The interaction of ADAM22 and 14-3-3β suggests that the ADAM22 may play a crucial role in neural function and development. 相似文献
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PrPC interacts with tetraspanin-7 through bovine PrP154-182 containing alpha-helix 1 总被引:1,自引:0,他引:1
Guo M Huang T Cui Y Pan B Shen A Sun Y Yi Y Wang Y Xiao G Sun G 《Biochemical and biophysical research communications》2008,365(1):154-157
The cellular prion protein (PrPC) is highly conserved in the evolution of mammals, and therefore, thought to have important cellular functions. Despite decades of intensive research, the physiological function of PrPC remains enigmatic. We carried out a yeast two-hybrid screen on a bovine brain cDNA expression library and identified the transmembrane protein tetraspanin-7 (CD231), as a PrPC interacting protein. We confirmed the interaction between PrPC and tetraspanin-7 by yeast two-hybrid assay, immunofluorescent co-localization, and immunocoprecipitation. Our mutational studies further demonstrated that PrPC specifically binds tetraspanin-7 through the region corresponding to bovine PrP154-182 containing alpha-helix 1. 相似文献
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Background
VEGF proteolysis by plasmin or matrix metalloproteinases (MMPs) is believed to play an important role in regulating vascular patterning in vivo by releasing VEGF from the extracellular matrix (ECM). However, a quantitative understanding of the kinetics of VEGF cleavage and the efficiency of cell-mediated VEGF release is currently lacking. To address these uncertainties, we develop a molecular-detailed quantitative model of VEGF proteolysis, used here in the context of an endothelial sprout.Methodology and Findings
To study a cell''s ability to cleave VEGF, the model captures MMP secretion, VEGF-ECM binding, VEGF proteolysis from VEGF165 to VEGF114 (the expected MMP cleavage product of VEGF165) and VEGF receptor-mediated recapture. Using experimental data, we estimated the effective bimolecular rate constant of VEGF165 cleavage by plasmin to be 328 M−1s−1 at 25°C, which is relatively slow compared to typical MMP-ECM proteolysis reactions. While previous studies have implicated cellular proteolysis in growth factor processing, we show that single cells do not individually have the capacity to cleave VEGF to any appreciable extent (less than 0.1% conversion). In addition, we find that a tip cell''s receptor system will not efficiently recapture the cleaved VEGF due to an inability of cleaved VEGF to associate with Neuropilin-1.Conclusions
Overall, VEGF165 cleavage in vivo is likely to be mediated by the combined effect of numerous cells, instead of behaving in a single-cell-directed, autocrine manner. We show that heparan sulfate proteoglycans (HSPGs) potentiate VEGF cleavage by increasing the VEGF clearance time in tissues. In addition, we find that the VEGF-HSPG complex is more sensitive to proteases than is soluble VEGF, which may imply its potential relevance in receptor signaling. Finally, according to our calculations, experimentally measured soluble protease levels are approximately two orders of magnitude lower than that needed to reconcile levels of VEGF cleavage seen in pathological situations. 相似文献18.
Dawid G. Nowak Elianna Mohamed Amin Emma S. Rennel Coralie Hoareau-Aveilla Melissa Gammons Gopinath Damodoran Masatoshi Hagiwara Steven J. Harper Jeanette Woolard Michael R. Ladomery David O. Bates 《The Journal of biological chemistry》2010,285(8):5532-5540
Vascular endothelial growth factor (VEGF) is produced either as a pro-angiogenic or anti-angiogenic protein depending upon splice site choice in the terminal, eighth exon. Proximal splice site selection (PSS) in exon 8 generates pro-angiogenic isoforms such as VEGF165, and distal splice site selection (DSS) results in anti-angiogenic isoforms such as VEGF165b. Cellular decisions on splice site selection depend upon the activity of RNA-binding splice factors, such as ASF/SF2, which have previously been shown to regulate VEGF splice site choice. To determine the mechanism by which the pro-angiogenic splice site choice is mediated, we investigated the effect of inhibition of ASF/SF2 phosphorylation by SR protein kinases (SRPK1/2) on splice site choice in epithelial cells and in in vivo angiogenesis models. Epithelial cells treated with insulin-like growth factor-1 (IGF-1) increased PSS and produced more VEGF165 and less VEGF165b. This down-regulation of DSS and increased PSS was blocked by protein kinase C inhibition and SRPK1/2 inhibition. IGF-1 treatment resulted in nuclear localization of ASF/SF2, which was blocked by SPRK1/2 inhibition. Pull-down assay and RNA immunoprecipitation using VEGF mRNA sequences identified an 11-nucleotide sequence required for ASF/SF2 binding. Injection of an SRPK1/2 inhibitor reduced angiogenesis in a mouse model of retinal neovascularization, suggesting that regulation of alternative splicing could be a potential therapeutic strategy in angiogenic pathologies. 相似文献
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Yu Hou ZeBin Mao XueLei Wei Lin Lin LianXu Chen HaiJun Wang Xin Fu JiYing Zhang Changlong Yu 《Matrix biology》2009,28(6):324-335
Repaired Achilles tendons typically take weeks before they are strong enough to handle physiological loads. Gene therapy is a promising treatment for Achilles tendon defects. The aim of the present study was to evaluate the histological/biomechanical effects of Transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor 165 (VEGF165) gene transfer on Achilles tendon healing in rabbits. Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs) were transduced with adenovirus carrying human TGF-β1 cDNA (Ad-TGF-β1), human VEGF165 cDNA (Ad-VEGF165), or both (PIRES-TGF-β1/VEGF165) Viruses, no cDNA (Ad-GFP), and the BMSCs without gene transfer and the intact tendon were used as control. BMSCs were surgically implanted into the experimentally injured Achilles tendons. TGF-β1 distribution, cellularity, nuclear aspect ratio, nuclear orientation angle, vascular number, collagen synthesis, and biomechanical features were measured at 1, 2, 4, and 8 weeks after surgery. The TGF-β1 and TGFβ1/VEGF165 co-expression groups exhibited improved parameters compared with other groups, while the VEGF165 expression group had a negative impact. In the co-expression group, the angiogenesis effects of VEGF165 were diminished by TGF-β1, while the collagen synthesis effects of TGF-β1 were unaltered by VEGF165. Thus treatment with TGF-β1 cDNA-transduced BMSCs grafts is a promising therapy for acceleration and improvement of tendon healing, leading to quicker recovery and improved biomechanical properties of Achilles tendons. 相似文献
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The characteristics of rheumatoid arthritis (RA) pathology include the infiltration of inflammatory leukocytes, the proliferation
of synovial cells, and the presence of extensive angiogenesis, referred to as rheumatoid pannus. Fas ligand is critical to
the homeostatic regulation of the immune response, but its role in the angiogenic process of RA remains to be defined. In
this study, we investigated whether soluble Fas ligand (sFasL) induces synoviocyte apoptosis and regulates angiogenesis of
endothelial cells in RA. The levels of sFasL were elevated in the synovial fluids of RA patients when compared to those of
osteoarthritis (OA) patients, and they correlated inversely with vascular endothelial growth factor165 (VEGF165) concentrations. sFasL, ranging from 10 to 100 ng/ml, induced the apoptosis of RA fibroblast-like synoviocytes (FLS) in vitro, and thereby decreased VEGF165 production. In addition, sFasL inhibited VEGF165-induced migration and chemotaxis of endothelial cells to basal levels in a manner independent of the Fas-mediated cell death.
sFasL dose-dependently suppressed the VEGF165-stimulated increase in pAkt expression in endothelial cells, which might be associated with its anti-migratory effect on
endothelial cells. Moreover, sFasL strongly inhibited neovascularization in the Matrigel plug in vivo. Our data suggest that sFasL shows anti-angiogenic activity within RA joints not only by inducing apoptosis of VEGF165-producing cells but also by blocking VEGF165-induced migration of endothelial cells, independent of Fas-mediated apoptosis. 相似文献