Angiogenic Growth Factors (angiogenic + growth_factor)

Distribution by Scientific Domains


Selected Abstracts


Expression of Angiogenic Growth Factors in Paragangliomas,

THE LARYNGOSCOPE, Issue 1 2000
Robert W. Jyung MD
Abstract Objective/Hypothesis: To determine if angiogenic growth factors including vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) are expressed in human paragangliomas. Study Design: A histopathologic and molecular examination of paraganglioma specimens obtained from surgical cases or retrieved from the Pathology Department of the Massachusetts Eye and Ear Infirmary. Methods: Fresh tumor or archival, paraffin-embedded paraganglioma specimens were analyzed by immunohistochemistry, Western blotting, and ELISA. Results: Positive immunohistochemical staining for VEGF was observed in five of nine surgical specimens and in six of eight archival specimens (11/17, or 65%). PD-ECGF immunoreactivity was detected in four of five surgical specimens and six of eight archival specimens (10/13, or 77%). The presence of PD-ECGF was confirmed by Western blot assay and ELISA confirmed the presence of VEGF in tumor extract. Conclusions: Both VEGF and PD-ECGF are expressed in paragangliomas and may contribute to the extreme vascularity of these tumors. [source]


Detection of Hypoxia Inducible Factors and Angiogenic Growth Factors during Foetal Endochondral and Intramembranous Ossification

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2010
W. De Spiegelaere
With 6 figures and 1 table Summary During skeletogenesis, the development of a new vascular network, i.e. angiogenesis, is triggered by hypoxia through the activation of the hypoxia inducible factors (HIFs) HIF-1, and HIF-2,. HIFs regulate the expression of several genes, including those coding for angiogenic growth factors such as VEGFA, angiopoietin-1 (ANGPT1) and angiopoietin-2 (ANGPT2). The expression of HIFs and angiogenic growth factors is well documented in endochondral ossification, but few data exist on their expression during intramembranous ossification. In this study, the localization of these factors was examined using immunohistochemistry and RT-PCR in bones of porcine foetuses. Immunostaining for HIF-1, and HIF-2, was observed during endochondral ossification, whereas only HIF-2, was present at sites of intramembranous ossification. Furthermore, immunostaining for ANGPT2 was present at sites of endochondral and intramembranous ossification. In addition, gene transcripts for ANGPT1, ANGPT2 and VEGFA were detected with RT-PCR in laser capture microdissected isolates from both types of ossification. These results indicate that angiogenesis plays an important role during endochondral and intramembranous ossification. However, the different expression pattern of the HIF-, subunits suggests that alternative regulatory pathways trigger angiogenesis in these distinct types of ossification. [source]


Thalidomide for the Treatment of Refractory Multiple Myeloma: Association of Plasma Concentrations of Thalidomide and Angiogenic Growth Factors with Clinical Outcome

CANCER SCIENCE, Issue 9 2002
Tsunayuki Kakimoto
Recent reports showed that thalidomide has anti-angiogenic activity and is effective for the treatment of refractory multiple myeloma (MM). We examined the relationship between the clinical efficacy and adverse effects of thalidomide and the plasma concentrations of this drug as well as angiogenic growth factors in refractory MM. Ten out of twenty-four evaluable patients (42%) showed more than 25% reduction of M-protein, and eight (33%) achieved more than 50% reduction. These changes were associated with restoration of anemia and recovery of normal immunoglobulin level. Somnolence and headache, constipation, peripheral neuropathy and skin rash were frequently observed, but were well tolerated. However, grade 2,4 severe neutropenia was also observed in nine cases. These adverse effects other than neutropenia occurred more frequently in the patients with higher plasma concentrations of thalidomide (,2.0 ,g/ml at 12 h after the last administration) and were readily alleviated by dose reduction. In contrast, neutropenia developed regardless of the plasma concentration. Plasma concentrations of angiogenic growth factors were frequently elevated before treatment. After thalidomide treatment, these growth factor levels tend to decrease to near-normal ranges in responders but were still high in most non-responders. After thalidomide treatment, plasma vascular endothelial growth factor (VEGF) level was significantly reduced in responders (P=0.025), but not in non-responders (P=0.37). Reduction of plasma VEGF level might be an important indicator for anti-myeloma effect of thalidomide. [source]


MR imaging in assessing cardiovascular interventions and myocardial injury

CONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2007
Alexis Jacquier
Abstract Performing an MR-guided endovascular intervention requires (1) real-time tracking and guidance of catheters/guide wires to the target, (2) high-resolution images of the target and its surroundings in order to define the extent of the target, (3) performing a therapeutic procedure (delivery of stent or injection of gene or cells) and (4) evaluating the outcome of the therapeutic procedure. The combination of X-ray and MR imaging (XMR) in a single suite was designed for new interventional procedures. MR contrast media can be used to delineate myocardial infarcts and microvascular obstruction, thereby defining the target for local delivery of therapeutic agents under MR-guidance. Iron particles, or gadolinium- or dysprosium-chelates are mixed with the soluble injectates or stem cells in order to track intramyocardial delivery and distribution. Preliminary results show that genes encoded for vascular endothelial and fibroblast growth factor and cells are effective in promoting angiogenesis, arteriogenesis, perfusion and LV function. Angiogenic growth factors, genes and cells administered under MR-guided minimally invasive catheter-based procedures will open up new avenues in treating end-stage ischemic heart disease. The optimum dose of the therapeutic agents, delivery devices and real-time imaging techniques to guide the delivery are currently the subject of ongoing research. The aim of this review is to (1) provide an updated review of experiences using MR imaging to guide transcatheter therapy, (2) address the potential of cardiovascular magnetic resonance (MR) imaging and MR contrast media in assessing myocardial injury at a molecular level and labeling cells and (3) illustrate the applicability of the non-invasive MR imaging in the field of angiogenic therapies through recent clinical and experimental publications. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Angiogenic growth factors in tissue homogenates of HNSCC: expression pattern, prognostic relevance, and interrelationships

CANCER SCIENCE, Issue 7 2009
Michael Montag
Head and neck squamous cell carcinoma has still a poor prognosis. Since angiogenesis is crucial for tumor growth, a better understanding of the potential clinical relevance as well as the interactions between the numerous proangiogenic growth factors is essential to develop improved therapeutic strategies in these tumors. Expression levels of eight growth factors known to induce angiogenesis (HGF, bFGF, VEGF-A, VEGF-D, PDGF-AB, PDGF-BB, G-CSF, and GM-CSF) were quantitatively measured by ELISA in homogenates of 41 head and neck squamous cell carcinomas. In addition, microvessel density and protein localization of growth factors were assessed by immunohistochemistry. Statistical analysis was performed to assess interrelationships between growth factors analyzed and to correlate protein levels with patient outcome. In 90% of the tissues at least 4/8 growth factors analyzed were detectable. Highest amounts and most frequent expression were found for HGF, bFGF and VEGF-A while PDGF-AB and PDGF-BB were present in two-thirds and G-CSF and GM-CSF in approximately half of the cases. Although there was no significant relation to microvessel density, we identified significant associations for bFGF with HGF and G-CSF as well as of PDGF-AB with those of VEGF-A and PDGF-BB. For the first time we demonstrate that expression levels of HGF as well as that of bFGF and G-CSF in head and neck squamous tumors are negative prognostic factors for patient survival. Our data indicate a network of interrelated and prognostically relevant growth factors in these tumors that have to be taken into consideration when planning an antiangiogenic and antitumor therapy. (Cancer Sci 2009; 100: 1210,1218) [source]


Vascular endothelial growth factor and diabetic retinopathy: pathophysiological mechanisms and treatment perspectives

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2003
Ruth B. Caldwell
Abstract Retinal neovascularization and macular edema are central features of diabetic retinopathy, the major cause of blindness in the developed world. Current treatments are limited in their efficacy and are associated with significant adverse effects. Characterization of the molecular and cellular processes involved in vascular growth and permeability has led to the recognition that the angiogenic growth factor and vascular permeability factor vascular endothelial growth factor (VEGF) plays a pivotal role in the retinal microvascular complications of diabetes. Therefore, VEGF represents an exciting target for therapeutic intervention in diabetic retinopathy. This review highlights the current understanding of the mechanisms that regulate VEGF gene expression and mediate its biological effects and how these processes may become altered during diabetes. The cellular and molecular alterations that characterize experimental models of diabetes are considered in relation to the influence of high glucose-mediated oxidative stress on VEGF expression and on the mechanisms of VEGF's actions under hyperglycemic induction. Finally, potential therapeutic strategies for preventing VEGF overexpression or blocking its pathological effects in the diabetic retina are considered. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Hierarchically Assembled Mesenchymal Stem Cell Spheroids Using Biomimicking Nanofilaments and Microstructured Scaffolds for Vascularized Adipose Tissue Engineering

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010
Taek Gyoung Kim
Abstract Composite multicellular spheroids composed of mesenchymal stem cells (MSCs) and synthetic biodegradable nanofilaments are fabricated. Extracellular-matrix-mimicking nanofilaments, prepared from transverse fragmentation of semicrystalline poly(L -lactic acid) nanofibers and subsequent surface modification with cell adhesive peptides, are used to form composite multicellular spheroids with MSCs by cellular self-assembly. The size of the composite spheroids could be readily controlled with the integrated amount of the nanofilaments. The composite spheroids show enhanced adipogenic potential compared to homotypic spheroids. The resultant spheroids are used as building blocks for 3D biohybrid construction with the assistance of a microstructured scaffold fabricated by a direct polymer melt deposition process. An angiogenic growth factor, basic fibroblast growth factor, is also locally delivered in a sustained fashion from the heparinized scaffold surface for facile neovascularization of adipogenic tissue. The produced multiscaled and multifunctional hybrid MSC construct enable the successful formation of vascularized adipose tissue in vivo. [source]


Endothelial stimulation by small lymphocytic lymphoma correlates with secreted levels of basic fibroblastic growth factor

BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2003
Lisa Rimsza
Summary. Lymph nodes (LN) involved with small lympho- cytic lymphoma (SLL) reportedly contain increased numbers of microvessels that may constitute a therapeutic target in this disease. We investigated the secretion of the angiogenic growth factor, basic fibroblastic growth factor (bFGF), from primary tissue cultures of 15 LN with SLL and 10 reactive LN. bFGF was detected from the resulting conditioned media (CM) in 13/15 SLL samples (mean 92 ± 30, range 5,420 pg/ml) but was undetectable in CM from all reactive lymph nodes. CM was also used in a 72-h human umbilical vein endothelial cell (HUVEC) proliferation assay. HUVEC proliferation increased in the presence of SLL CM (70 ± 17%, range ,4,194%), proportional to secreted levels of bFGF (R2 = 0·95), and was reversed by depleting bFGF from CM. Previous SLL studies have examined either patient serum samples or paraffin-embedded lymph node tissue sections. This is the first study to examine the secretion of an angiogenic growth factor from primary cultures of lymph node cells. Our results indicate that bFGF is probably the primary mediator responsible for increased angiogenesis in involved nodes. These findings may be pertinent to future investigation into the mechanisms of increased angiogenesis in SLL. [source]


Expression of angiogenic factors in chronic myeloid leukaemia: role of the bcr/abl oncogene, biochemical mechanisms, and potential clinical implications

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2004
C. Sillaber
Abstract Chronic myeloid leukaemia (CML) is a stem cell disease characterized by an increased production and accumulation of clonal BCR/ABL,positive cells in haematopoietic tissues. The chronic phase of CML is inevitably followed by an accelerated phase of the disease, with consecutive blast crisis. However, depending on genetic stability, epigenetic events, and several other factors, the clinical course and survival appear to vary among patients. Recent data suggest that angiogenic cytokines such as vascular endothelial growth factor (VEGF), are up-regulated in CML, and play a role in the pathogenesis of the disease. These factors appear to be produced and released in leukaemic cells in patients with CML. In line with this notion, increased serum-levels of angiogenic growth factors are measurable in CML patients. In this study we provide an overview of angiogenic growth factors expressed in CML cells, discuss the possible pathogenetic role of these cytokines, the biochemical basis of their production in leukaemic cells, and their potential clinical implications. [source]


Vascular endothelial growth factor gene expression in middle cerebral artery occlusion in the rat

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2005
F. Lennmyr
Background:, Focal cerebral ischemia induces up-regulation of angiogenic growth factors such as vascular endothelial growth factor (VEGF), which may have both beneficial and harmful effects to the ischemic brain. Vascular endothelial growth factor is up-regulated in models of brain ischemia, but the underlying mechanisms in vivo remain unclear. In the present report we have investigated the concomitant changes in VEGF and glyceraldehyde dehydrogenase (GAPDH) mRNA expression in a model of permanent and transient cerebral ischemia. Methods:, Male Sprague-Dawley rats were exposed to permanent or transient (2 h) middle cerebral artery occlusion (PMCAO, TMCAO). Brain samples were collected at survival times ranging from 6 h to 1 week, and the levels of VEGF164 and GAPDH mRNA were determined using reverse-transcriptase real-time polymerase chain reaction (RT-PCR). Results:, The VEGF mRNA levels decreased gradually over the observation period in a similar manner in both PMCAO and TMCAO. Maximum levels, seen at early observation time points, did not significantly deviate from sham controls. No statistically significant changes in GAPDH mRNA levels were observed, but there was a tendency towards a postischemic decrease with subsequent return to control levels over time. The VEGF/GAPDH ratio followed a pattern of decrease similar to VEGF mRNA alone. Conclusion:, The VEGF mRNA levels at 6 h after MCAO remain near baseline and thereafter decline, regardless of whether the occlusion is permanent or transient (2 h). The findings raise the question of other than transcriptional regulation of VEGF in cerebral ischemia. [source]


Angiopoietin Affects Neutrophil Migration

MICROCIRCULATION, Issue 5 2005
DANIEL H. STURN
ABSTRACT Objective: After an ischemic event vascular growth factors are involved in regulating leukocyte infiltration in inflammatory processes. This study focused on effects of 2 other angiogenic growth factors, angiopoietin-1 and angiopoietin-2, on human neutrophils and on the involvement of the angiopoietin receptor Tie-2. Methods: Neutrophils were from venous blood of healthy donors and cell migration was studied by micropore filter assays. Receptor expression was investigated by reverse transcriptase,polymerase chain reaction (PCR) for mRNA and fluorescence-activated cell-sorter scanner (FACS) analysis. Signaling mechanisms required for angiopoietin-dependent effects were tested functionally by using signaling enzyme blockers. Results: The angiopoietins were chemotactic for neutrophils. They showed antagonistic effects on each other and both inhibited VEGF-directed migration of neutrophils. The effects of both angiopoietins were Tie-2 dependent. Tie-2 receptor immunoreactivity was confirmed on neutrophils by FACS. De novo synthesis is suggested by Tie-2 receptor mRNA expression as demonstrated by reverse transcriptase PCR. Conclusions: Data suggest that a Tie-2 receptor is expressed by human neutrophils whose active site ligation with either angiopoietin-1 or angiopoietin-2 exerts migratory effects on the one hand and arrests VEGF-mediated chemotaxis on the other. These effects suggest a role of angiopoietins in modulating neutrophilic inflammation. [source]


Angiogenesis Therapy for the Treatment of Erectile Dysfunction

THE JOURNAL OF SEXUAL MEDICINE, Issue 7 2010
Jeffrey J. Lysiak PhD
ABSTRACT Introduction., Over the past 15 years, significant advances have been made in the treatment of erectile dysfunction (ED). The most significant of these advances has been pharmacological treatment of ED with phosphodiesterase type 5 (PDE5) inhibitors. This therapy greatly increased the awareness of ED and has helped stimulate research into the underlying causes of ED. While treatment with PDE5 inhibitors continues to be the current therapy of choice, approximately 40% of men treated with PDE5 inhibitors fail to have significant improvement in erectile function and PDE5 inhibitors do not reverse the vasculopathic processes associated with ED. With this in mind, new therapies must be developed. The treatment with angiogenic growth factors such as vascular endothelial cell growth factor (VEGF) may be one such therapy. Aim., This review will focus on defining key terms in the angiogenic process, angiogenic growth factors, and different delivery methods, and summarize results from angiogenic therapies for the treatment of ED. Methods., A review of the literature was performed on all angiogenic therapies for the treatment of ED. A brief review on the angiogenic factors was also performed Results., Angiogenic therapies for the treatment of ED are possible and promising; however, further investigation is needed to advance clinically. Conclusions., Although numerous studies have now employed angiogenic factors for the possible treatment of ED in several animal models, we are still not at the point to begin human investigations. Future studies need to examine proper dosage of the angiogenic agent, route of delivery, time course for delivery, and combination therapies. Lysiak JJ, Kavoussi PK, Ellati RT, Steers WD, and Annex BH. Angiogenesis therapy for the treatment of erectile dysfunction. J Sex Med 2010;7:2554,2563. [source]


Expression of Angiogenic Growth Factors in Paragangliomas,

THE LARYNGOSCOPE, Issue 1 2000
Robert W. Jyung MD
Abstract Objective/Hypothesis: To determine if angiogenic growth factors including vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) are expressed in human paragangliomas. Study Design: A histopathologic and molecular examination of paraganglioma specimens obtained from surgical cases or retrieved from the Pathology Department of the Massachusetts Eye and Ear Infirmary. Methods: Fresh tumor or archival, paraffin-embedded paraganglioma specimens were analyzed by immunohistochemistry, Western blotting, and ELISA. Results: Positive immunohistochemical staining for VEGF was observed in five of nine surgical specimens and in six of eight archival specimens (11/17, or 65%). PD-ECGF immunoreactivity was detected in four of five surgical specimens and six of eight archival specimens (10/13, or 77%). The presence of PD-ECGF was confirmed by Western blot assay and ELISA confirmed the presence of VEGF in tumor extract. Conclusions: Both VEGF and PD-ECGF are expressed in paragangliomas and may contribute to the extreme vascularity of these tumors. [source]


Detection of Hypoxia Inducible Factors and Angiogenic Growth Factors during Foetal Endochondral and Intramembranous Ossification

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2010
W. De Spiegelaere
With 6 figures and 1 table Summary During skeletogenesis, the development of a new vascular network, i.e. angiogenesis, is triggered by hypoxia through the activation of the hypoxia inducible factors (HIFs) HIF-1, and HIF-2,. HIFs regulate the expression of several genes, including those coding for angiogenic growth factors such as VEGFA, angiopoietin-1 (ANGPT1) and angiopoietin-2 (ANGPT2). The expression of HIFs and angiogenic growth factors is well documented in endochondral ossification, but few data exist on their expression during intramembranous ossification. In this study, the localization of these factors was examined using immunohistochemistry and RT-PCR in bones of porcine foetuses. Immunostaining for HIF-1, and HIF-2, was observed during endochondral ossification, whereas only HIF-2, was present at sites of intramembranous ossification. Furthermore, immunostaining for ANGPT2 was present at sites of endochondral and intramembranous ossification. In addition, gene transcripts for ANGPT1, ANGPT2 and VEGFA were detected with RT-PCR in laser capture microdissected isolates from both types of ossification. These results indicate that angiogenesis plays an important role during endochondral and intramembranous ossification. However, the different expression pattern of the HIF-, subunits suggests that alternative regulatory pathways trigger angiogenesis in these distinct types of ossification. [source]


Low-molecular-weight heparins and angiogenesis,

APMIS, Issue 2 2006
KLAS NORRBY
The involvement of the vascular system in malignancy encompasses not only angiogenesis, but also systemic hypercoagulability and a pro-thrombotic state, and there is increasing evidence that pathways of blood coagulation and angiogenesis are reciprocally linked. In fact, cancer atients often display hypercoagulability resulting in markedly increased thromboembolism, which requires anti-coagulant treatment using heparins, for example. Clinical trials reveal that treatment with various low-molecular-weight heparins (LMWHs) improves the survival time in cancer patients receiving chemotherapy compared with those receiving unfractionated standard heparin (UFH) or no heparin treatment, as well as in cancer patients receiving LMWH as thrombosis prophylaxis during primary surgery. This anti-tumor effect of the heparins appears to be unrelated to their anti-coagulant activity, but the mechanisms involved are not fully understood. Tumor growth and spread are dependent on angiogenesis and it is noteworthy that the most potent endogenous pro- and anti-angiogenic factors are heparin-binding proteins that may be affected by systemic treatment with heparins. Heparin and other glycosaminoglycans play a role in vascular endothelial cell function, as they are able to modulate the activities of angiogenic growth factors by facilitating the interaction with their receptor and promoting receptor activation. To date, preclinical studies have demonstrated that only LMWH fragments produced by the heparinase digestion of UFH, i.e. tinzaparin, exert anti-angiogenic effects in any type of tissue in vivo. These effects are fragment-mass-specific and angiogenesis-type-specific. Data on the effect of various LMWHs and UFH on endothelial cell capillary tube formation and proliferation in vitro are also presented. We hope that this paper will stimulate and facilitate future research designed to elucidate whether the anti-angiogenic or anti-tumor effects of commercial LMWHs in their own right are agent specific and whether anti-angiogenic properties increase the anti-tumor properties of the LMWHs in the clinic. [source]


Endothelial injury and repair in systemic vasculitis of the young

ARTHRITIS & RHEUMATISM, Issue 6 2010
L. A. Clarke
Objective Endothelial injury is central to the pathogenesis of vasculitis. The purpose of this study was to assess how indices of endothelial injury and repair change during different stages of disease activity in children with primary systemic vasculitis (PSV). Methods Fifty children with PSV, 17 children with nonvasculitic inflammatory diseases (pediatric inflammatory disease controls), 35 healthy age- and sex-matched pediatric controls, and 27 healthy adult controls were included in the study. Biomarkers examined were endothelial microparticles (EMPs), circulating endothelial cells (CECs), angiogenic growth factors, and endothelial progenitor cells (EPCs). EMP binding to annexin V, EMPs expressing CD144 or E-selectin, and EPCs expressing vascular endothelial growth factor receptor 2 (VEGFR-2), CD133, and CD34 were examined by flow cytometry. CECs were enumerated using immunomagnetic bead extraction techniques, and VEGF and angiopoietin 2 (Ang-2) were measured by enzyme-linked immunosorbent assay. Results Levels of CD144+ EMPs, CECs, VEGF, and EPCs were all significantly elevated in children with active vasculitis as compared with healthy children, and the levels declined with remission-inducing therapy in the individual patients. Treatment-naive patients with active disease had significantly higher levels of VEGF and Ang-2 than did those with active disease who were receiving treatment, although the levels of CECs and EMPs remained high in both of these groups. Conclusion Elevation of the levels of CECs, EMPS, EPCs, VEGF, and Ang-2 occurs during active vasculitis in children. EPC responses to active vasculitis are different in children as compared with that observed in adults with vasculitis, and both CECs and EMPs can be used to monitor disease activity in children with vasculitis. [source]


Design of Fibrin Matrix Composition to Enhance Endothelial Cell Growth and Extracellular Matrix Deposition for In Vitro Tissue Engineering

ARTIFICIAL ORGANS, Issue 1 2009
Divya Pankajakshan
Abstract Tissue-engineered blood vessel substitutes should closely resemble native vessels in terms of structure, composition, mechanical properties, and function. Successful cardiovascular tissue engineering requires optimization of in vitro culture environment that would produce functional constructs. The extracellular matrix (ECM) protein elastin plays an essential role in the cardiovascular system to render elasticity to blood vessel wall, whereas collagen is responsible for providing mechanical strength. The objective of this study was to understand the significance of various ECM components on endothelial cell (EC) growth and tissue generation. We demonstrate that, even though fibrin is a good matrix for EC growth, fibronectin is the crucial component of the fibrin matrix that enhances EC adhesion, spreading, and proliferation. Vascular EC growth factor is known to influence in vitro growth of EC, but, so far, ECM deposition in in vitro culture has not been reported. In this study, it is shown that incorporation of a mixture of hypothalamus-derived angiogenic growth factors with fibrin matrix enhances synthesis and deposition of insoluble elastin and collagen in the matrix, within 10 days of in vitro culture. The results suggest that a carefully engineered fibrin composite matrix may support EC growth, survival, and remodeling of ECM in vitro and impart optimum properties to the construct for resisting the shear stress at the time of implantation. [source]


Oestrogen Promotes Coronary Angiogenesis even under Normoxic Conditions

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2008
Mehdi Nematbakhsh
Oestrogen has angiogenic properties under hypoxic condition, and if oestrogen also induces angiogenesis under normoxic condition, it could be used in combination with other angiogenic therapies in the treatment of ischaemic heart disease. In this study, we evaluated the angiogenic effect of high-dose oestrogen treatment in normoxic rat heart tissue. Fifty-two ovariectomized rats were randomized in oestrogen-treated and control groups. 17,-Oestradiol (1 mg/week) and normal saline (1 mg/week) were administered intramuscularly in the treatment and control groups for 2 months. After that, coronary capillary density and coronary vessel permeability were measured. The serum vascular endothelial growth factor (VEGF) level was also measured before and after the treatment. The results indicate that coronary capillary density (number of capillary per square millimetre) and coronary vessel permeability (fluorescence intensity) were significantly higher in the oestrogen-treated group than in the control group (628 ± 26 per mm2 versus 540 ± 26 per mm2; P < 0.05 and 207 ± 10 versus 147 ± 19 per gram tissue; P < 0.05). Oestrogen treatment increased serum VEGF level in the oestrogen-treated group compared to the control group (52 ± 3 versus 33 ± 6 pg/ml; P < 0.05), but interestingly VEGF was also increased in the control group after placebo treatment. It seems that high-dose oestrogen administration has angiogenic properties even in normoxic conditions. These angiogenic properties may result from oestrogen's direct effect on VEGF or other mechanisms, such as endothelial progenitor cell mobilization. Because of the broad effect of oestrogen on angiogenic growth factors and endothelial cells, more studies are required to clarify angiogenic properties of high-dose oestrogen. [source]


short report: High levels of serum angiogenic growth factors in patients with AL amyloidosis: comparisons with normal individuals and multiple myeloma patients

BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2010
Efstathios Kastritis
Summary Serum levels of five angiogenic cytokines were evaluated in 82 patients with primary systemic amyloidosis (AL). Angiopoietin-1, vascular endothelial growth factor, basic fibroblast growth factor and angiogenin were higher in AL patients than in controls (n = 35) and newly-diagnosed, symptomatic, myeloma patients (n = 35). Angiopoetin-1/Angiopoetin-2 ratio was lower in AL compared to controls but higher than in myeloma patients. Angiopoetin-2 correlated with cardiac dysfunction indices; however, none of the angiogenic growth factors was prognostically significant. The increased angiogenic cytokine levels observed in AL seem to represent either a toxic effect of amyloid fibrils or light chains, or a compensatory response to organ dysfunction. [source]