Effect of stimulation frequency on angiogenesis and gene expression in ischemic skeletal muscle of rabbit

2009 ◽  
Vol 87 (5) ◽  
pp. 396-401 ◽  
Author(s):  
Mei Shen ◽  
Jing Gao ◽  
Jianan Li ◽  
Juan Su
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Fetal Liver ◽  
Hypoxia Inducible Factor ◽  
Capillary Density ◽  
Control Group ◽  
Vegf Receptor ◽  
Vegf Mrna ◽  
Artery Ligation ◽  
40 Hz

To examine the comparative effects of different frequencies of electrical stimulation (ES) on angiogenesis and gene expression, New Zealand white rabbits with femoral artery ligation in one hindlimb and electrode implantation on the sciatic nerve of the same hindlimb were randomly assigned to 4 groups: control group, 1 Hz group, 10 Hz group, and 40 Hz group. The ES procedure involved 5 min stimulation, followed by 5 min rest, repeated 8 times daily for 4 consecutive weeks. The resting blood flow (RBF) was measured via the microspheres technique. Collateralization was evaluated by immunohistochemistry. Angiogenic factors were analyzed by real-time RT-PCR. Both RBF and capillary density were significantly increased in the 10 Hz and 40 Hz groups, but were not changed in the 1 Hz group. Vascular endothelial growth factor (VEGF) mRNA was highest in the 40 Hz group. Hypoxia-inducible factor 1α (HIF-1α) mRNA was significantly elevated only in the 40 Hz group. VEGF receptor fetal liver kinase 1 (Flk-1) mRNA was upregulated equally in the 10 Hz and 40 Hz groups, but fibroblast growth factor 2 (FGF-2) mRNA did not change in any group. Our results suggest that the optimal frequency of ES for angiogenesis is within the 10–40 Hz range.

BCR/ABL induces expression of vascular endothelial growth factor and its transcriptional activator, hypoxia inducible factor-1α, through a pathway involving phosphoinositide 3-kinase and the mammalian target of rapamycin

Blood ◽  
2002 ◽  
Vol 100 (10) ◽  
pp. 3767-3775 ◽  
Author(s):  
Matthias Mayerhofer ◽  
Peter Valent ◽  
Wolfgang R. Sperr ◽  
James D. Griffin ◽  
Christian Sillaber
Keyword(s):  
Gene Expression ◽  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Mammalian Target Of Rapamycin ◽  
Hypoxia Inducible Factor ◽  
Vascular Endothelial ◽  
Vegf Gene ◽  
Vegf Mrna ◽  
Phosphoinositide 3 Kinase ◽  
Endothelial Growth Factor

Recent data suggest that vascular endothelial growth factor (VEGF), a cytokine involved in autocrine growth of tumor cells and tumor angiogenesis, is up-regulated and plays a potential role in myelogenous leukemias. In chronic myelogenous leukemia (CML), VEGF is expressed at high levels in the bone marrow and peripheral blood. We show here that the CML-associated oncogene BCR/ABL induces VEGF gene expression in growth factor–dependent Ba/F3 cells. Whereas starved cells were found to contain only baseline levels of VEGF mRNA, Ba/F3 cells induced to express BCR/ABL exhibited substantial amounts of VEGF mRNA. BCR/ABL also induced VEGF promoter activity and increased VEGF protein levels in Ba/F3 cells. Moreover, BCR/ABL was found to promote the expression of functionally active hypoxia-inducible factor-1 (HIF-1), a major transcriptional regulator of VEGF gene expression. BCR/ABL-induced VEGF gene expression was counteracted by the phosphoinositide 3-kinase (PI3-kinase) inhibitor LY294002 and rapamycin, an antagonist of mammalian target of rapamycin (mTOR), but not by inhibition of the mitogen-activated protein kinase pathway. Similarly, BCR/ABL-dependent HIF-1α expression was inhibited by the addition of LY294002 and rapamycin. Together, our data show that BCR/ABL induces VEGF- and HIF-1α gene expression through a pathway involving PI3-kinase and mTOR. BCR/ABL-induced VEGF expression may contribute to the pathogenesis and increased angiogenesis in CML.

Phenotype of capillaries in skeletal muscle of nNOS-knockout mice

2013 ◽  
Vol 304 (12) ◽  
pp. R1175-R1182 ◽  
Author(s):  
Oliver Baum ◽  
Max Vieregge ◽  
Pascale Koch ◽  
Safak Gül ◽  
Sabine Hahn ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth Factor ◽  
Hypoxia Inducible Factor ◽  
Capillary Density ◽  
Vegf Receptor ◽  
Mrna Levels ◽  
Mean Velocity ◽  
Cross Sectional ◽  
The Mean ◽  
Edl Muscle

Because neuronal nitric oxide synthase (nNOS) has a well-known impact on arteriolar blood flow in skeletal muscle, we compared the ultrastructure and the hemodynamics of/in the ensuing capillaries in the extensor digitorum longus (EDL) muscle of male nNOS-knockout (KO) mice and wild-type (WT) littermates. The capillary-to-fiber (C/F) ratio (−9.1%) was lower ( P ≤ 0.05) in the nNOS-KO mice than in the WT mice, whereas the mean cross-sectional fiber area (−7.8%) and the capillary density (−3.1%) varied only nonsignificantly ( P > 0.05). Morphometrical estimation of the area occupied by the capillaries as well as the volume and surface densities of the subcellular compartments differed nonsignificantly ( P > 0.05) between the two strains. Intravital microscopy revealed neither the capillary diameter (+3% in nNOS-KO mice vs. WT mice) nor the mean velocity of red blood cells in EDL muscle (+25% in nNOS-KO mice vs. WT mice) to significantly vary ( P > 0.05) between the two strains. The calculated shear stress in the capillaries was likewise nonsignificantly different (3.8 ± 2.2 dyn/cm2 in nNOS-KO mice and 2.1 ± 2.2 dyn/cm2 in WT mice; P > 0.05). The mRNA levels of vascular endothelial growth factor (VEGF)-A were lower in the EDL muscle of nNOS-KO mice than in the WT littermates (−37%; P ≤ 0.05), whereas mRNA levels of VEGF receptor-2 (VEGFR-2) (−11%), hypoxia inducible factor-1α (+9%), fibroblast growth factor-2 (−14%), and thrombospondin-1 (−10%) differed nonsignificantly ( P > 0.05). Our findings support the contention that VEGF-A mRNA expression and C/F-ratio but not the ultrastructure or the hemodynamics of/in capillaries in skeletal muscle at basal conditions depend on the expression of nNOS.

Abstract 394: E2F1 Suppresses Cardiac Neovascularization by Downregulating VEGF and PlGF Expression

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Min Wu ◽  
Junlan Zhou ◽  
Min Cheng ◽  
Chan Boriboun ◽  
Dauren Biyashev ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Growth Factor ◽  
Cell Growth ◽  
Cardiac Function ◽  
Cardiac Fibroblasts ◽  
Vascular Endothelial Cell ◽  
Capillary Density ◽  
Border Zone ◽  
Vegf Receptor ◽  
Hypoxic Conditions

Objective: The E2F transcription factors are best characterized for their roles in cell-cycle regulation, cell growth, and cell survival. Here we investigated the potential role of E2F1 in cardiac neovascularization. Methods and Results: Myocardial infarction (MI) was induced in WT and E2F1 -/- mice. Compared to observations in WT mice, cardiac function, capillary density, and endothelial-cell (EC) proliferation were greater (P<0.01), infarct sizes were smaller (P<0.01), apoptotic ECs were less common (P<0.01); border-zone levels of vascular endothelial-cell growth factor (VEGF) (P<0.05) and placental growth factor (PlGF) (P<0.01) were higher; and border-zone p53 levels were lower (P<0.01); in E2F1 -/- mice. Blockade of VEGF receptor 2 (VEGFR2) signaling with the selective inhibitor SU5416 or with the VEGFR2-blocking antibody DC101 abolished the differences between E2F1 -/- mice and WT mice in cardiac function, infarct size, capillary density, EC proliferation, and EC apoptosis. Hypoxia-induced VEGF and PlGF upregulation was significantly greater in E2F1 -/- than in WT cardiac fibroblasts, and E2F1 overexpression suppressed PlGF upregulation in both WT and p53 -/- cells; however, VEGF upregulation was suppressed only in WT cells. E2F1 interacted with and stabilized p53 under hypoxic conditions, and both E2F1:p53 binding and the E2F1-induced suppression of VEGF promoter activity were absent in cells that expressed an N-terminally truncated E2F1 mutant. Conclusions: E2F1 limits cardiac neovascularization and functional recovery after MI by suppressing VEGF and PlGF upregulation through p53-dependent and -independent mechanisms, respectively.

Intravenous infusion of insulin-like growth factor I in fetal sheep reduces hepatic IGF-I and IGF-II mRNAs

1996 ◽  
Vol 271 (6) ◽  
pp. R1632-R1637 ◽  
Author(s):  
K. L. Kind ◽  
J. A. Owens ◽  
F. Lok ◽  
J. S. Robinson ◽  
K. J. Quinn ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Growth Factor ◽  
Intravenous Infusion ◽  
Feedback Inhibition ◽  
Fetal Liver ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Fetal Sheep ◽  
Igf I

Liver contains the highest concentrations of insulin-like growth factor (IGF) I mRNA in adult rats and sheep and is a major source of circulating IGF-I. In rats, inhibition of hepatic IGF-I production by exogenous IGF-I has been reported. In fetal sheep, skeletal muscle and liver are major sites of IGF-I synthesis and potential sources of circulating IGF-I. To determine whether feedback inhibition of IGF gene expression in fetal liver or muscle by IGF-I occurs, IGF-I and IGF-II mRNAs were measured in these tissues after intravenous infusion of recombinant human IGF-I into fetal sheep. Infusion of IGF-I (26 +/- 4 micrograms.h-1.kg-1; n = 6) or saline (n = 6) commenced on day 120 of pregnancy (term = 150 days) and continued for 10 days. Plasma concentrations of IGF-I were threefold higher in infused fetuses at 130 days of gestation (P < 0.0003), whereas those of IGF-II were unchanged. IGF-I infusion reduced the relative abundance of IGF-I mRNA (P < 0.0002) and IGF-II mRNA (P < 0.01) in fetal liver by approximately 50% but did not alter IGF-I or IGF-II mRNA in skeletal muscle. These results indicate that IGF-I inhibits the expression of both IGF-I and IGF-II genes in fetal liver and that IGF gene expression in fetal liver and muscle is differentially regulated by IGF-I.

Angiogenic Gene Expression in Down Syndrome Fetal Hearts

2015 ◽  
Vol 40 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Olga Sánchez ◽  
Carmen Domínguez ◽  
Aina Ruiz ◽  
Irene Ribera ◽  
Jaume Alijotas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Down Syndrome ◽  
Growth Factor ◽  
Heart Defects ◽  
Hypoxia Inducible Factor ◽  
Transcript Level ◽  
Heart Tissue ◽  
Angiogenic Factors ◽  
Heme Oxygenase 1 ◽  
Endothelial Growth Factor

Introduction: Forty percent of Down syndrome (DS) fetuses have congenital heart defects (CHD). An abnormal angiogenic environment has been described in euploid fetuses with CHD. However, the underlying pathophysiologic pathway that contributes to CHD in DS remains unknown. The objective was to compare the expression of angiogenic factors and chronic hypoxia genes in heart tissue from DS and euploid fetuses with and without CHD. Methods: The gene expression profile was determined by real-time PCR quantification in heart tissue from 33 fetuses with DS, 23 euploid fetuses with CHD and 23 control fetuses. Results: Angiogenic factors mRNA expression was significantly increased in the DS group compared to the controls (soluble fms-like tyrosine kinase-1, 81%, p = 0.007; vascular endothelial growth factor A, 57%, p = 0.006, and placental growth factor, 32%, p = 0.0227). Significant increases in the transcript level of hypoxia-inducible factor-2α and heme oxygenase 1 were also observed in the DS group compared to the controls. The expression of angiogenic factors was similar in DS fetuses and CHD euploid fetuses with CHD. Conclusion: Abnormal angiogenesis was detected in the hearts of DS fetuses with and without CHD. Our results suggest that DS determines an intrinsically angiogenic impairment that may be present in the fetal heart.

Microarray study of gene expression profiles in peripheral blood samples from lung cancer patients before and after erlotinib treatment

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e19072-e19072
Author(s):  
A. Irigoyen ◽  
C. Olmedo ◽  
J. Valdivia ◽  
A. Comino ◽  
C. Cano ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lung Cancer ◽  
Growth Factor ◽  
Healthy Volunteers ◽  
Cancer Patients ◽  
Peripheral Blood ◽  
Expression Profiles ◽  
Control Group ◽  
Blood Samples ◽  
Lung Cancer Patients

e19072 Background: The gene expression profile in peripheral blood samples from lung cancer patients is a potential predictor to treatment response. Methods: The study has been developed using 10 healthy volunteers as the control group and 10 lung cancer patients (stage IV). Written informed consent was obtained being the protocol approved by the local Clinical Research and Ethics Committee. Peripheral blood samples were obtained from lung cancer patients before (T0) and after treatment (T15d). RNA from peripheral blood samples was extracted and purified selecting 28S/18S ratios>1.5 to obtain cDNA and cRNA for hybridization of the 20,000 genes included in Human 20K CodeLink. An array from each participant was obtained in duplicate. For each array, 2 μg of cRNA was compared to 2 μg of healthy cRNA.. Significant genes were found using Significance Analysis of Microarrays which uses repeated permutations of the data. Results: The selected genes were expressed >3-fold with a false discovery rate =0.05. Before treatment (T0) when patients were compared to healthy volunteers there was an increase in the expression of: histone 1 H4c, transforming growth factor beta 2, endothelial cell growth factor 1 (platelet-derived), glucose-6-phosphatase catalytic 2, Relaxin 3 receptor 1, Insulin-like growth factor binding protein 2, RAS-like family 11 member B, and ELK4. After treatment (T15d), when each lung cancer patient's results were compared to their own before treatment results (T0), there was an increase in the expression of: Bcl2, myosin light polypeptide 4; interferon alpha-inducible protein 27; interferon gamma receptor 1; RASSF5, ARHGEF6, IGFBP5, tumor protein p53 inducible nuclear protein 1, peroxisome proliferative activated receptor gamma. Conclusions: The data presented identifies biologically relevant over-expressed genes in lung cancer. A validation of these results and the analysis of the genes that identify patients who will respond positively to erlotinib treatment is being carried out. No significant financial relationships to disclose.

scholarly journals Induction of Hypoxia-inducible Factor 1α Gene Expression by Vascular Endothelial Growth Factor

2008 ◽  
Vol 283 (17) ◽  
pp. 11435-11444 ◽  
Author(s):  
Juan José P. Deudero ◽  
Carlos Caramelo ◽  
María Carmen Castellanos ◽  
Fernando Neria ◽  
Ruth Fernández-Sánchez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Hypoxia Inducible Factor ◽  
Vascular Endothelial ◽  
Hypoxia Inducible Factor 1Α ◽  
Endothelial Growth Factor

scholarly journals Activation of vascular endothelial growth factor gene transcription by hypoxia-inducible factor 1.

1996 ◽  
Vol 16 (9) ◽  
pp. 4604-4613 ◽  
Author(s):  
J A Forsythe ◽  
B H Jiang ◽  
N V Iyer ◽  
F Agani ◽  
S W Leung ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Reporter Gene ◽  
Hypoxia Inducible Factor ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Vascular Endothelial ◽  
Hypoxia Inducible Factor 1 ◽  
Endothelial Growth Factor

Expression of vascular endothelial growth factor (VEGF) is induced in cells exposed to hypoxia or ischemia. Neovascularization stimulated by VEGF occurs in several important clinical contexts, including myocardial ischemia, retinal disease, and tumor growth. Hypoxia-inducible factor 1 (HIF-1) is a heterodimeric basic helix-loop-helix protein that activates transcription of the human erythropoietin gene in hypoxic cells. Here we demonstrate the involvement of HIF-1 in the activation of VEGF transcription. VEGF 5'-flanking sequences mediated transcriptional activation of reporter gene expression in hypoxic Hep3B cells. A 47-bp sequence located 985 to 939 bp 5' to the VEGF transcription initiation site mediated hypoxia-inducible reporter gene expression directed by a simian virus 40 promoter element that was otherwise minimally responsive to hypoxia. When reporters containing VEGF sequences, in the context of the native VEGF or heterologous simian virus 40 promoter, were cotransfected with expression vectors encoding HIF-1alpha and HIF-1beta (ARNT [aryl hydrocarbon receptor nuclear translocator]), reporter gene transcription was much greater in both hypoxic and nonhypoxic cells than in cells transfected with the reporter alone. A HIF-1 binding site was demonstrated in the 47-bp hypoxia response element, and a 3-bp substitution eliminated the ability of the element to bind HIF-1 and to activate transcription in response to hypoxia and/or recombinant HIF-1. Cotransfection of cells with an expression vector encoding a dominant negative form of HIF-1alpha inhibited the activation of reporter transcription in hypoxic cells in a dose-dependent manner. VEGF mRNA was not induced by hypoxia in mutant cells that do not express the HIF-1beta (ARNT) subunit. These findings implicate HIF-1 in the activation of VEGF transcription in hypoxic cells.

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