Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Modulation of pathological angiogenesis by curcumin (diferuloylmethane), the active principle of turmeric, seems to be an important possibility meriting mechanistic investigations. In this report, we have studied the effect of curcumin on the growth of Ehrlich ascites tumor cells and endothelial cells in vitro. Further, regulation of tumor angiogenesis by modulation of angiogenic ligands and their receptor gene expression in tumor and endothelial cells, respectively, by curcumin was investigated. Curcumin, when injected intraperitoneally (i.p) into mice, effectively decreased the formation of ascites fluid by 66% in EAT bearing mice in vivo. Reduction in the number of EAT cells and human umbelical vein endothelial cells (HUVECs) in vitro by curcumin, without being cytotoxic to these cells, is attributed to induction of apoptosis by curcumin, as is evident by an increase in cells with fractional DNA content seen in our results on FACS analysis. However, curcumin had no effect on the growth of NIH3T3 cells. Curcumin proved to be a potent angioinhibitory compound, as demonstrated by inhibition of angiogenesis in two in vivo angiogenesis assay systems, viz. peritoneal angiogenesis and chorioallantoic membrane assay. The angioinhibitory effect of curcumin in vivo was corroborated by the results on down-regulation of the expression of proangiogenic genes, in EAT, NIH3T3, and endothelial cells by curcumin. Our results on Northern blot analysis clearly indicated a time-dependent (0-24h) inhibition by curcumin of VEGF, angiopoietin 1 and 2 gene expression in EAT cells, VEGF and angiopoietin 1 gene expression in NIH3T3 cells, and KDR gene expression in HUVECs. Further, decreased VEGF levels in conditioned media from cells treated with various doses of curcumin (1 microM-1mM) for various time periods (0-24h) confirm its angioinhibitory action at the level of gene expression. Because of its non-toxic nature, curcumin could be further developed to treat chronic diseases that are associated with extensive neovascularization.
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PMID:Molecular mechanisms of anti-angiogenic effect of curcumin. 1235 44

Angiogenesis occurs in skeletal muscle in response to exercise training. To gain insight into the regulation of this process, we evaluated the mRNA expression of factors implicated in angiogenesis over the course of a training program. We studied sedentary control (n = 17) rats and both sedentary (n = 18) and exercise-trained (n = 48) rats with bilateral femoral artery ligation. Training consisted of treadmill exercise (4 times/day, 1-24 days). Basal mRNA expression in sedentary control muscle was inversely related to muscle vascularity. Angiogenesis was histologically evident in trained white gastrocnemius muscle by day 12. Training produced initial three- to sixfold increases in VEGF, VEGF receptors (KDR and Flt), the angiopoietin receptor (Tie-2), and endothelial nitric oxide synthase mRNA, which dissipated before the increase in capillarity, and a substantial (30- to 50-fold) but transient upregulation of monocyte chemoattractant protein 1 mRNA. These results emphasize the importance of early events in regulating angiogenesis. However, we observed a sustained elevation of the angiopoietin 2-to-angiopoietin 1 ratio, suggesting continued vascular destabilization. The response to exercise was (in general) tempered in high-oxidative muscles. These findings place importance on cellular events coupled to the onset of angiogenesis.
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PMID:Angiogenic growth factor expression in rat skeletal muscle in response to exercise training. 1254 34

Malignant plasma cells generally grow within the bone marrow microenvironment; however, they can also grow at extramedullary sites. To identify the tumour-specific alterations required for extramedullary growth, we analysed the expression profiles of a series of plasma cell neoplasms including primary multiple myeloma (MM), plasma cell leukaemia (PCL) and extramedullary plasmacytoma (EPC). Hierarchical clustering analysis segregated the EPCs from the remaining samples, and revealed an expression pattern associated with angiogenesis in the EPCs, involving higher expression of the genes TIE2, NOTCH3, CD31 and endoglin. Direct comparison of EPC samples with the MM samples identified 156 genes significantly upregulated and 85 genes significantly downregulated (P < 0.005, t-test) in the EPCs, including several genes involved in angiogenesis and adhesion that were upregulated (including angiopoietin 1, SPARC, Notch3 and fibronectin 1). Immunohistochemical staining demonstrated CD31 and endoglin protein expression in the EPC tumour cells, which are both angiogenesis related and could confer malignant plasma cells with the ability to grow outside the normal bone marrow environment. Defining how malignant plasma cell growth is regulated in the bone marrow versus at extramedullary sites will help to delineate the mechanisms underlying the dependence of tumour cell growth on angiogenesis and cell adhesion.
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PMID:Insights into extramedullary tumour cell growth revealed by expression profiling of human plasmacytomas and multiple myeloma. 1293 Mar 83

Smooth muscle cell proliferation around small pulmonary vessels is essential to the pathogenesis of pulmonary hypertension. Here we describe a molecular mechanism and animal model for this vascular pathology. Rodents engineered to express angiopoietin 1 (Ang-1) constitutively in the lung develop severe pulmonary hypertension. These animals manifest diffuse medial thickening in small pulmonary vessels, resulting from smooth muscle cell hyperplasia. This pathology is common to all forms of human pulmonary hypertension. We demonstrate that Ang-1 stimulates pulmonary arteriolar endothelial cells through a TIE2 (receptor with tyrosine kinase activity containing IgG-like loops and epidermal growth factor homology domains) pathway to produce and secrete serotonin (5-hydroxytryptamine), a potent smooth muscle mitogen, and find that high levels of serotonin are present both in human and rodent pulmonary hypertensive lung tissue. These results suggest that pulmonary hypertensive vasculopathy occurs through an Ang-1/TIE2/serotonin paracrine pathway and imply that these signaling molecules may be targets for strategies to treat this disease.
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PMID:Induction of pulmonary hypertension by an angiopoietin 1/TIE2/serotonin pathway. 1451 15

Distraction osteogenesis is a unique and effective way to treat limb length inequality resulting from congenital and posttraumatic skeletal defects. However, despite its widespread clinical use, the cellular and molecular mechanisms by which this surgical treatment promotes new bone formation are not well understood. Previous studies in distraction osteogenesis have noted increased blood flow and vessel formation within the zone of distraction. These observations suggest that distraction osteogenesis may be driven in part by an angiogenic process. Using immunohistological analysis, the expression of two different angiogenic factors (VEGF and bFGF) was shown to localize at the leading edge of the distraction gap, where nascent osteogenesis was occurring. These cells were spatially adjacent to new vessels that were identified by staining for factor VIII. Microarray analysis detected maximal mRNA expression for a wide variety of angiogenic factors including angiopoietin 1 and 2, both Tie receptors, VEGF-A and -D, VEGFR2, and neuropilin 1. Expression of these factors was found to be maximal during the phase of active distraction. Expression of mRNA for extracellular matrix proteins and BMPs was also maximal during this period. A comparison between the patterns of gene expression in fracture healing and distraction osteogenesis revealed similarities; however, the expression of a number of genes showed selective expression in these two types of bone healing. These data suggest that bone formation during distraction osteogenesis is accompanied by the robust induction of factors associated with angiogenesis and support further investigations to elucidate the mechanisms by which angiogenic events promote bone repair and regeneration.
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PMID:Expression of angiogenic factors during distraction osteogenesis. 1467 48

The vascular wall is mainly composed of endothelial cells (ECs) and smooth muscle cells (SMCs). The crosstalking between these two cell types is critical in the vascular maturation process. Genetic studies suggest that the Tie2/angiopoietin 1 (Ang1) pathway regulates vascular remodeling. However, the molecular mechanism is unclear. PDGF is a potent chemoattractant for SMCs, and TGF-beta regulates SMC differentiation. Here, we examined gene regulation. PDGF-B stimulation upregulated Ang1 expression in SMCs through the PI3K and PKC pathways. PDGF-B stimulation also produced an acute induction of TGF-beta expression in SMCs through the MAPK/ERK pathway. Interestingly, TGF-beta negatively regulated Ang1 expression induced by the PDGF-B stimulation in SMCs. Reciprocally, we observed that stimulation of ECs with either Ang1 or TGF-beta slightly downregulated PDGF expression. A combination of both TGF-beta with Ang1 produced much stronger downregulation of PDGF. Our data showed complex gene regulations that include both positive and negative regulations between ECs and SMCs to maintain vascular homeostasis.
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PMID:Angiopoietin 1, PDGF-B, and TGF-beta gene regulation in endothelial cell and smooth muscle cell interaction. 1475 87

Normal glomerular filtration depends on the combined properties of the three layers of glomerular capillary wall: glomerular endothelial cells (GEnC), basement membrane, and podocytes. Podocytes produce endothelial factors, including angiopoietin 1 (ang1), and vascular endothelial growth factor (VEGF), whereas GEnC express their respective receptors Tie2 and VEGFR2 in vivo. As ang1 acts to maintain the endothelium in other vascular beds, regulating some actions of VEGF, these observations suggest a mechanism whereby podocytes may direct the unique properties of the glomerular endothelium. This interaction was investigated by studies on the barrier properties of human GEnC in vitro. GEnC were examined for expression of endothelium-specific markers by immunofluorescence and Western blotting and for typical responses to TNF-alpha by a cell-based immunoassay. Expression of angiopoietin and VEGF receptors was examined similarly. Barrier properties of GEnC monolayers cultured on porous supports were investigated by measurement of transendothelial electrical resistance (TEER) and passage of labeled albumin. Responses to a cAMP analogue and thrombin were examined before those to ang1 and VEGF. Results confirmed the endothelial origin of GEnC and their expression of Tie2 and VEGFR2. GEnC formed monolayers with a mean TEER of 30 to 40 Omega/cm(2). The cAMP analogue and thrombin increased and decreased TEER by 34.4 and 14.8 Omega/cm(2), respectively, with corresponding effects on protein passage. Ang1 increased TEER by 11.4 Omega/cm(2) and reduced protein passage by 45.2%, whereas VEGF reduced TEER by 12.5 Omega/cm(2) but had no effect on protein passage. Both ang1 and VEGF modulate GEnC barrier properties, consistent with potential in vivo roles; ang1 stabilizing the endothelium and resisting angiogenesis while VEGF induces the high permeability to water, characteristic of the glomerular endothelium.
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PMID:Angiopoietin 1 and vascular endothelial growth factor modulate human glomerular endothelial cell barrier properties. 1497 58

Tie2, an endothelial cell-specific receptor kinase, has an important role in tumour angiogenesis. In an attempt to identify peptides that specifically interact with and block the Tie2 pathway, a phage-displayed peptide library was screened on a recombinant Tie2 receptor. One peptide, NLLMAAS, completely abolished the binding to Tie2 of both angiopoietin 2 and angiopoietin 1 (Ang1). We further show that NLLMAAS specifically suppresses both Ang1-induced ERK activity and migration in human umbilical endothelial cells. Moreover, in vivo, this peptide inhibits angiogenesis in the chick chorioallantoic membrane assay. NLLMAAS is the first peptide described to interact with Tie2. Our results demonstrate that it is an efficient and specific antagonist of the binding of Tie2 ligands, and suggest that this peptide or its derivates may have potential applications in the treatment of angiogenesis diseases. It also represents a potent tool to dissect the molecular mechanisms involved in the Tie2 pathway.
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PMID:A short synthetic peptide inhibits signal transduction, migration and angiogenesis mediated by Tie2 receptor. 1497 10

Grb2-associated binder (Gab) family of scaffolding adaptor proteins coordinate signaling cascades downstream of growth factor and cytokine receptors. In the heart, among EGF family members, neuregulin-1beta (NRG-1beta, a paracrine factor produced from endothelium) induced remarkable tyrosine phosphorylation of Gab1 and Gab2 via erythroblastic leukemia viral oncogene (ErbB) receptors. We examined the role of Gab family proteins in NRG-1beta/ErbB-mediated signal in the heart by creating cardiomyocyte-specific Gab1/Gab2 double knockout mice (DKO mice). Although DKO mice were viable, they exhibited marked ventricular dilatation and reduced contractility with aging. DKO mice showed high mortality after birth because of heart failure. In addition, we noticed remarkable endocardial fibroelastosis and increase of abnormally dilated vessels in the ventricles of DKO mice. NRG-1beta induced activation of both ERK and AKT in the hearts of control mice but not in those of DKO mice. Using DNA microarray analysis, we found that stimulation with NRG-1beta upregulated expression of an endothelium-stabilizing factor, angiopoietin 1, in the hearts of control mice but not in those of DKO mice, which accounted for the pathological abnormalities in the DKO hearts. Taken together, our observations indicated that in the NRG-1beta/ErbB signaling, Gab1 and Gab2 of the myocardium are essential for both maintenance of myocardial function and stabilization of cardiac capillary and endocardial endothelium in the postnatal heart.
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PMID:Gab family proteins are essential for postnatal maintenance of cardiac function via neuregulin-1/ErbB signaling. 1757 Nov 62

Expansion of the thyroid microvasculature is the earliest event during goiter formation, always occurring before thyrocyte proliferation; however, the precise mechanisms governing this physiological angiogenesis are not well understood. Using reverse transcriptase-polymerase chain reaction and immunohistochemistry to measure gene expression and laser Doppler to measure blood flow in an animal model of goitrogenesis, we show that thyroid angiogenesis occurred into two successive phases. The first phase lasted a week and involved vascular activation; this process was thyroid-stimulating hormone (TSH)-independent and was directly triggered by expression of vascular endothelial growth factor (VEGF) by thyrocytes as soon as the intracellular iodine content decreased. This early reaction was followed by an increase in thyroid blood flow and endothelial cell proliferation, both of which were mediated by VEGF and inhibited by VEGF-blocking antibodies. The second, angiogenic, phase was TSH-dependent and was activated as TSH levels increased. This phase involved substantial up-regulation of the major proangiogenic factors VEGF-A, fibroblast growth factor-2, angiopoietin 1, and NG2 as well as their receptors Flk-1/VEGFR2, Flt-1/VEGFR1, and Tie-2. In conclusion, goiter-associated angiogenesis promotes thyroid adaptation to iodine deficiency. Specifically, as soon as the iodine supply is limited, thyrocytes produce proangiogenic signals that elicit early TSH-independent microvascular activation; if iodine deficiency persists, TSH plasma levels increase, triggering the second angiogenic phase that supports thyrocyte proliferation.
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PMID:Iodine deficiency induces a thyroid stimulating hormone-independent early phase of microvascular reshaping in the thyroid. 1827 86


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