Vascular Cell最新文献

{"title":"Polysaccharides from astragali radix restore chemical-induced blood vessel loss in zebrafish.","authors":"Guang Hu,&nbsp;Gail B Mahady,&nbsp;Shang Li,&nbsp;Maggie Pui Man Hoi,&nbsp;You-Hua Wang,&nbsp;Simon Ming Yuen Lee","doi":"10.1186/2045-824X-4-2","DOIUrl":"https://doi.org/10.1186/2045-824X-4-2","url":null,"abstract":"<p><strong>Background: </strong>Astragali Radix has been used widely for the treatment of cardiovascular and cerebrovascular diseases, and to enhance endurance and stamina in traditional Chinese medicine (TCM) for over 2000 years. The polysaccharide constituents of Astragali Radix (ARP) are considered as one of the major constituents contributing to the multiple pharmacological effects of this medicinal plant. The purpose of the study is to evaluate the vascular regenerative activities of ARPs in a chemically-induced blood vessel loss model in zebrafish.</p><p><strong>Methods: </strong>Blood vessel loss was induced in both Tg(fli-1a:EGFP)y1 and Tg(fli-1a:nEGFP)y7 embryos by administration of 300 nM VEGFR tyrosine kinase inhibitor II (VRI) for 3 h at 24 hpf (hour post-fertilization). Then, the blood vessel damaged zebrafish were treated with ARPs for 21 h and 45 h after VRI withdrawal. Morphological changes in intersegmental vessels (ISVs) of zebrafish larvae were observed under the fluorescence microscope and measured quantitatively. The rescue effect of ARPs in the zebrafish models was validated by measuring the relative mRNA expressions of Kdrl, Kdr and Flt-1 using real-time PCR.</p><p><strong>Results: </strong>Two polysaccharide fractions, P4 (50000 D < molecular weight & diameter < 0.1 μm) and P5 (molecular diameter > 0.1 μm), isolated from Astragali Radix by ultrafiltration, produced a significant and dose-dependent recovery in VRI-induced blood vessel loss in zebrafish. Furthermore, the down-regulation of Flk-1 and Flt-1 mRNA expression induced by VRI was reversed by treatment with P4.</p><p><strong>Conclusion: </strong>The present study demonstrates that P4 isolated from Astragali Radix reduces VRI-induced blood vessel loss in zebrafish. These findings support the hypothesis that polysaccharides are one of the active constituents in Astragali Radix, contributing to its beneficial effect on treatment of diseases associated with a deficiency in angiogenesis.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-4-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30478928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RhoB controls endothelial cell morphogenesis in part via negative regulation of RhoA.","authors":"Grant A Howe,&nbsp;Christina L Addison","doi":"10.1186/2045-824X-4-1","DOIUrl":"https://doi.org/10.1186/2045-824X-4-1","url":null,"abstract":"<p><p> Recent studies have suggested a role for the small GTPase RhoB in the control of processes required for angiogenesis. However, the mechanisms whereby RhoB exerts control over these processes are not well understood. Given the role of vascular endothelial growth factor (VEGF) in pathological angiogenesis, we were interested in examining whether RhoB contributed to VEGF-induced angiogenic processes. To assess this, RhoB was specifically depleted in human umbilical vein endothelial cells (HUVEC), using siRNA-targeted strategies. The effects of RhoB depletion on VEGF-induced angiogenic activities were assessed using a variety of standard in vitro angiogenesis assays to assess endothelial cell viability, migration and capillary morphogenesis. Effects of RhoB depletion on signaling from other Rho family member proteins was also assessed using specific activity assays for RhoA and RhoC. We observed that although RhoB appeared dispensable for HUVEC viability, RhoB was required for endothelial cell migration, sprouting, and capillary morphogenesis. We also observed that siRNA-mediated depletion of RhoB in HUVEC resulted in increased RhoA activation in response to VEGF stimulation. This increased RhoA activation contributed to the cellular morphogenesis defects observed in RhoB-depleted cells, as inhibition of RhoA activity using C3 transferase, or inhibition of the activity of the downstream RhoA effectors Rho-dependent kinases I and II (ROCK I and II) led to a partial restoration of capillary morphogenesis in the absence of RhoB. Thus our data indicate that RhoB plays a significant role in VEGF-induced endothelial cell morphogenesis in part by negatively regulating the activity of RhoA and the RhoA/ROCK pathway.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-4-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30444952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lymphoid enhancer-binding factor 1, a representative of vertebrate-specific Lef1/Tcf1 sub-family, is a Wnt-beta-catenin pathway target gene in human endothelial cells which regulates matrix metalloproteinase-2 expression and promotes endothelial cell invasion.","authors":"Marina Planutiene,&nbsp;Kestutis Planutis,&nbsp;Randall F Holcombe","doi":"10.1186/2045-824X-3-28","DOIUrl":"https://doi.org/10.1186/2045-824X-3-28","url":null,"abstract":"<p><strong>Background: </strong>Wnt signaling is activated in many types of cancer and normal physiological processes. Various Wnt-related secreted factors may influence angiogenesis both in the tumor microenvironment and in normal tissues by direct action on endothelial cells. The mechanism of this Wnt action in angiogenesis is not well defined. We hypothesize that endothelial cells are responsive to Wnt signals and that Lef1, a member of the vertebrate-specific Wnt/beta-catenin throughput-inducing transcription factors' sub-family Lef1/Tcf1, mediates this responsiveness and promotes endothelial cell invasion.</p><p><strong>Methods: </strong>A human endothelial cell line, EAhy926 was exposed to Wnt3a or directly transfected with Lef1. Readouts included assessment of nuclear beta-catenin, Wnt throughput with a SuperTOPflash reporter assay, induction of Lef1 transcription, induction of matrix metalloproteinase (MMP)-2 transcription, cell proliferation and cell invasion through a matrix in vitro. The effects on MMP2 were also evaluated in the presence of Lef1 silencing siRNA.</p><p><strong>Results: </strong>Wnt3a increased nuclear beta-catenin and up-regulated Wnt/beta-catenin throughput. Wnt3a increased Lef1 transcription and activity of the Lef1 promoter. Both Wnt3a treatment and Lef1 overexpression induced MMP2 transcription but this effect was completely abrogated in the presence of Lef1 siRNA. Inhibition of Lef1 also reduced basal MMP2 levels suggesting that Lef1 regulates MMP2 expression even in the absence of exogenous Wnt pathway activation. Lef1 slightly increased proliferation of EAhy926 cells and increased invasion by more than two-fold.</p><p><strong>Conclusions: </strong>EAhy926 cells activate canonical Wnt signaling in response to Wnt3a ligand. The Wnt target Lef1 specifically regulates MMP2 expression in these cells and promotes endothelial cell invasion. The EAhy926 cell line provides a convenient alternative to primary human umbilical vein endothelial cells (HUVEC) in the study of angiogenesis and the role of Wnt signaling on endothelial cell function.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-28","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30325533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-culture of Retinal and Endothelial Cells Results in the Modulation of Genes Critical to Retinal Neovascularization.","authors":"Ravindra Kumar,&nbsp;Sandra Harris-Hooker,&nbsp;Ritesh Kumar,&nbsp;Gary Sanford","doi":"10.1186/2045-824X-3-27","DOIUrl":"https://doi.org/10.1186/2045-824X-3-27","url":null,"abstract":"<p><strong>Background: </strong>Neovascularization (angiogenesis) is a multistep process, controlled by opposing regulatory factors, which plays a crucial role in several ocular diseases. It often results in vitreous hemorrhage, retinal detachment, neovascularization glaucoma and subsequent vision loss. Hypoxia is considered to be one of the key factors to trigger angiogenesis by inducing angiogenic factors (like VEGF) and their receptors mediated by hypoxia inducible factor-1 (HIF-1α) a critical transcriptional factor. Another factor, nuclear factor kappa B (NFκB) also regulates many of the genes required for neovascularization, and can also be activated by hypoxia. The aim of this study was to elucidate the mechanism of interaction between HRPC and HUVEC that modulates a neovascularization response.</p><p><strong>Methods: </strong>Human retinal progenitor cells (HRPC) and human umbilical vein endothelial cells (HUVEC) were cultured/co-cultured under normoxia (control) (20% O2) or hypoxia (1% O2) condition for 24 hr. Controls were monolayer cultures of each cell type maintained alone. We examined the secretion of VEGF by ELISA and influence of conditioned media on blood vessel growth (capillary-like structures) via an angiogenesis assay. Total RNA and protein were extracted from the HRPC and HUVEC (cultured and co-cultured) and analyzed for the expression of VEGF, VEGFR-2, NFκB and HIF-1α by RT-PCR and Western blotting. The cellular localization of NFκB and HIF-1α were studied by immunofluorescence and Western blotting.</p><p><strong>Results: </strong>We found that hypoxia increased exogenous VEGF expression 4-fold in HRPC with a further 2-fold increase when cultured with HUVEC. Additionally, we found that hypoxia induced the expression of the VEGF receptor (VEGFR-2) for HRPC co-cultured with HUVEC. Hypoxia treatment significantly enhanced (8- to 10-fold higher than normoxia controls) VEGF secretion into media whether cells were cultured alone or in a co-culture. Also, hypoxia was found to result in a 3- and 2-fold increase in NFκB and HIF-1α mRNA expression by HRPC and a 4- and 6-fold increase in NFκB and HIF-1α protein by co-cultures, whether non-contacting or contacting.Treatment of HRPC cells with hypoxic HUVEC-CM activated and promoted the translocation of NFκB and HIF-1α to the nuclear compartment. This finding was subsequently confirmed by finding that hypoxic HUVEC-CM resulted in higher expression of NFκB and HIF-1α in the nuclear fraction of HRPC and corresponding decrease in cytoplasmic NFκB and HIF-1α. Lastly, hypoxic conditioned media induced a greater formation of capillary-like structures (angiogenic response) compared to control conditioned media. This effect was attenuated by exogenous anti-human VEGF antibody, suggesting that VEGF was the primary factor in the hypoxic conditioned media responsible for the angiogenic response.</p><p><strong>Conclusions: </strong>These findings suggest that intercellular communications between HRP","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-27","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30133502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoparticle mediated targeting of VEGFR and cancer stem cells for cancer therapy.","authors":"Rashmi K Ambasta,&nbsp;Archita Sharma,&nbsp;Pravir Kumar","doi":"10.1186/2045-824X-3-26","DOIUrl":"https://doi.org/10.1186/2045-824X-3-26","url":null,"abstract":"<p><p> Angiogenesis is a crucial process in tumor pathogenesis as it sustains malignant cells with nutrients and oxygen. It is well known that tumor cells secrete various growth factors, including VEGF, which triggers endothelial cells to form new capillaries. Prevention of expansion of new blood vessel networks results in reduced tumor size and metastasis. Production of VEGF is driven by hypoxia via transcriptional activation of the VEGF gene by HIF-1α.Tumours are now understood to contain different types of cells, and it is the cancer stem cells that retain the ability to drive the tumour's growth. They are called cancer stem cells because, like stem cells present in normal tissues of the body, they can self-renew and differentiate. These cancer stem cells are responsible for the relapse of cancer as they are found to be resistant to conventional modes of cancer therapy like chemotherapy and radiation.In this review, a novel mode of treatment of cancer is proposed, which utilizes the twin nanoparticle to target endothelial cells in the niche of cancer stem cell. The nanoparticle discussed in this review, is a twin nanoparticle of iron coated with gold, which targets VEGF positive cell in the vicinity of cancer stem cell. In the twin nanoparticle, one particle will recognize cancer stem cell, and another conjugated nanoparticle will recognize VEGF positive cells, thereby inhibiting endothelial cells in the proximity of cancer stem cell. This novel strategy will inhibit angiogenesis near cancer stem cell hence new tumour cannot grow and old tumour will be unable to metastasize.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-26","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30251866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of microRNAs in neural stem cell-supported endothelial morphogenesis.","authors":"Tamara Roitbak,&nbsp;Olga Bragina,&nbsp;Jamie L Padilla,&nbsp;Gavin G Pickett","doi":"10.1186/2045-824X-3-25","DOIUrl":"https://doi.org/10.1186/2045-824X-3-25","url":null,"abstract":"<p><p> Functional signaling between neural stem/progenitor cells (NSPCs) and brain endothelial cells (ECs) is essential to the coordination of organized responses during initial embryonic development and also during tissue repair, which occurs following brain injury. In this study, we investigated the molecular mechanisms underlying this functional signaling, using primary mouse brain ECs and NSPCs from embryonic mouse brain. EC/NSPC co-culture experiments have revealed that neural progenitors secrete factors supporting angiogenesis, which induce noticeable changes in endothelial morphology. We demonstrate that NSPCs influence the expression of mTOR and TGF-β signaling pathway components implicated in the regulation of angiogenesis. Endothelial morphogenesis, an essential component of vascular development, is a complex process involving gene activation and the upregulation of specific cell signaling pathways. Recently identified small molecules, called microRNAs (miRNAs), regulate the expression of genes and proteins in many tissues, including brain and vasculature. We found that NSPCs induced considerable changes in the expression of at least 24 miRNAs and 13 genes in ECs. Three NSPC-regulated EC miRNAs were identified as the potential primary mediators of this NSPC/EC interaction. We found that the specific inhibition, or overexpression, of miRNAs miR-155, miR-100, and miR-let-7i subsequently altered the expression of major components of the mTOR, TGF-β and IGF-1R signaling pathways in ECs. Overexpression of these miRNAs in ECs suppressed, while inhibition activated, the in vitro formation of capillary-like structures, a process representative of EC morphogenesis. In addition, we demonstrate that inhibition of FGF, VEGF, and TGF-β receptor signaling abolished NSPC-promoted changes in the endothelial miRNA profiles. Our findings demonstrate that NSPCs induce changes in the miRNA expression of ECs, which are capable of activating angiogenesis by modulating distinct cell signaling pathways.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-25","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30098519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of microtechnologies for the vascularization of engineered tissues.","authors":"Robert Gauvin,&nbsp;Maxime Guillemette,&nbsp;Mehmet Dokmeci,&nbsp;Ali Khademhosseini","doi":"10.1186/2045-824X-3-24","DOIUrl":"https://doi.org/10.1186/2045-824X-3-24","url":null,"abstract":"<p><p> Recent advances in medicine and healthcare allow people to live longer, increasing the need for the number of organ transplants. However, the number of organ donors has not been able to meet the demand, resulting in an organ shortage. The field of tissue engineering has emerged to produce organs to overcome this limitation. While tissue engineering of connective tissues such as skin and blood vessels have currently reached clinical studies, more complex organs are still far away from commercial availability due to pending challenges with in vitro engineering of 3D tissues. One of the major limitations of engineering large tissue structures is cell death resulting from the inability of nutrients to diffuse across large distances inside a scaffold. This task, carried out by the vasculature inside the body, has largely been described as one of the foremost important challenges in engineering 3D tissues since it remains one of the key steps for both in vitro production of tissue engineered construct and the in vivo integration of a transplanted tissue. This short review highlights the important challenges for vascularization and control of the microcirculatory system within engineered tissues, with particular emphasis on the use of microfabrication approaches.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-24","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40117227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges in translating vascular tissue engineering to the pediatric clinic.","authors":"Daniel R Duncan,&nbsp;Christopher K Breuer","doi":"10.1186/2045-824X-3-23","DOIUrl":"https://doi.org/10.1186/2045-824X-3-23","url":null,"abstract":"<p><p> The development of tissue-engineered vascular grafts for use in cardiovascular surgery holds great promise for improving outcomes in pediatric patients with complex congenital cardiac anomalies. Currently used synthetic grafts have a number of shortcomings in this setting but a tissue engineering approach has emerged in the past decade as a way to address these limitations. The first clinical trial of this technology showed that it is safe and effective but the primary mode of graft failure is stenosis. A variety of murine and large animal models have been developed to study and improve tissue engineering approaches with the hope of translating this technology into routine clinical use, but challenges remain. The purpose of this report is to address the clinical problem and review recent advances in vascular tissue engineering for pediatric applications. A deeper understanding of the mechanisms of neovessel formation and stenosis will enable rational design of improved tissue-engineered vascular grafts.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-23","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30063203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibition of cyclo-oxygenase 2 reduces tumor metastasis and inflammatory signaling during blockade of vascular endothelial growth factor.","authors":"Jason C Fisher,&nbsp;Jeffrey W Gander,&nbsp;Mary Jo Haley,&nbsp;Sonia L Hernandez,&nbsp;Jianzhong Huang,&nbsp;Yan-Jung Chang,&nbsp;Tessa B Johung,&nbsp;Paolo Guarnieri,&nbsp;Kathleen O'Toole,&nbsp;Darrell J Yamashiro,&nbsp;Jessica J Kandel","doi":"10.1186/2045-824X-3-22","DOIUrl":"https://doi.org/10.1186/2045-824X-3-22","url":null,"abstract":"<p><p> Vascular endothelial growth factor (VEGF) blockade is an effective therapy for human cancer, yet virtually all neoplasms resume primary tumor growth or metastasize during therapy. Mechanisms of progression have been proposed to include genes that control vascular remodeling and are elicited by hypoperfusion, such as the inducible enzyme cyclooxygenase-2 (COX-2). We have previously shown that COX-2 inhibition by the celecoxib analog SC236 attenuates perivascular stromal cell recruitment and tumor growth. We therefore examined the effect of combined SC236 and VEGF blockade, using the metastasizing orthotopic SKNEP1 model of pediatric cancer. Combined treatment perturbed tumor vessel remodeling and macrophage recruitment, but did not further limit primary tumor growth as compared to VEGF blockade alone. However, combining SC236 and VEGF inhibition significantly reduced the incidence of lung metastasis, suggesting a distinct effect on prometastatic mechanisms. We found that SC236 limited tumor cell viability and migration in vitro, with effects enhanced by hypoxia, but did not change tumor proliferation or matrix metalloproteinase expression in vivo. Gene set expression analysis (GSEA) indicated that the addition of SC236 to VEGF inhibition significantly reduced expression of gene sets linked to macrophage mobilization. Perivascular recruitment of macrophages induced by VEGF blockade was disrupted in tumors treated with combined VEGF- and COX-2-inhibition. Collectively, these findings suggest that during VEGF blockade COX-2 may restrict metastasis by limiting both prometastatic behaviors in individual tumor cells and mobilization of macrophages to the tumor vasculature.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-22","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30191140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic strain upregulates VEGF and attenuates proliferation of vascular smooth muscle cells.","authors":"Joseph F Schad,&nbsp;Kate R Meltzer,&nbsp;Michael R Hicks,&nbsp;David S Beutler,&nbsp;Thanh V Cao,&nbsp;Paul R Standley","doi":"10.1186/2045-824X-3-21","DOIUrl":"https://doi.org/10.1186/2045-824X-3-21","url":null,"abstract":"<p><strong>Objective: </strong>Vascular smooth muscle cell (VSMC) hypertrophy and proliferation occur in response to strain-induced local and systemic inflammatory cytokines and growth factors which may contribute to hypertension, atherosclerosis, and restenosis. We hypothesize VSMC strain, modeling normotensive arterial pressure waveforms in vitro, results in attenuated proliferative and increased hypertrophic responses 48 hrs post-strain.</p><p><strong>Methods: </strong>Using Flexcell Bioflex Systems we determined the morphological, hyperplastic and hypertrophic responses of non-strained and biomechanically strained cultured rat A7R5 VSMC. We measured secretion of nitric oxide, key cytokine/growth factors and intracellular mediators involved in VSMC proliferation via fluorescence spectroscopy and protein microarrays. We also investigated the potential roles of VEGF on VSMC strain-induced proliferation.</p><p><strong>Results: </strong>Protein microarrays revealed significant increases in VEGF secretion in response to 18 hours mechanical strain, a result that ELISA data corroborated. Apoptosis-inducing nitric oxide (NO) levels also increased 43% 48 hrs post-strain. Non-strained cells incubated with exogenous VEGF did not reproduce the antimitogenic effect. However, anti-VEGF reversed the antimitogenic effect of mechanical strain. Antibody microarrays of strained VSMC lysates revealed MEK1, MEK2, phospo-MEK1T385, T291, T298, phospho-Erk1/2T202+Y204/T185+T187, and PKC isoforms expression were universally increased, suggesting a proliferative/inflammatory signaling state. Conversely, VSMC strain decreased expression levels of Cdk1, Cdk2, Cdk4, and Cdk6 by 25-50% suggesting a partially inhibited proliferative signaling cascade.</p><p><strong>Conclusions: </strong>Subjecting VSMC to cyclic biomechanical strain in vitro promotes cell hypertrophy while attenuating cellular proliferation. We also report an upregulation of MEK and ERK activation suggestive of a proliferative phenotype. Hhowever, the proliferative response appears to be aborogated by enhanced antimitogenic cytokine VEGF, NO secretion and downregulation of Cdk expression. Although exogenous VEGF alone is not sufficient to promote the quiescent VSMC phenotype, we provide evidence suggesting that strain is a necessary component to induce VSMC response to the antimitogenic effects of VEGF. Taken together these data indicate that VEGF plays a critical role in mechanical strain-induced VSMC proliferation and vessel wall remodeling. Whether VEGF and/or NO inhibit signaling distal to Erk 1/2 is currently under investigation.</p>","PeriodicalId":23948,"journal":{"name":"Vascular Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/2045-824X-3-21","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30151571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}