Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathogenesis of pulmonary hypertension in patients with chronic obstructive pulmonary disease is not understood. We have previously shown increased levels of mediators that control vasoconstriction (endothelin-1), vascular cell proliferation (endothelin-1 and vascular endothelial growth factor), and vasodilation (endothelial nitric oxide synthase) in the intrapulmonary arteries of animals exposed to cigarette smoke. To determine whether these mediators could be implicated in the structural remodeling of the arterial vasculature and increased pulmonary arterial pressure caused by chronic cigarette smoke exposure, guinea pigs were exposed to daily cigarette smoke for 6 mo. Pulmonary arterial pressures were measured. Intrapulmonary artery structure was analyzed by morphometry, artery mediator protein expression by immunohistochemistry, and artery mediator gene expression by laser capture microdissection and real-time RT-PCR. We found that the smoke-exposed animals developed increases in pulmonary arterial pressure and increased muscularization of the small pulmonary arteries. Gene expression and protein levels of all three mediators were increased, and pulmonary arterial pressure correlated both with the levels of mediator production and with the degree of arterial muscularization. We conclude that chronic smoke exposure produces increased vasoactive mediator expression in the small intrapulmonary arteries and that these mediators are associated with vascular remodeling as well as increased pulmonary arterial pressure. These findings support the idea that hypertension in chronic obstructive pulmonary disease is a result of direct cigarette smoke-mediated effects on the vasculature and suggest that interference with endothelin and VEGF production and activity or augmentation of nitric oxide levels may be beneficial.
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PMID:Vasoactive mediators and pulmonary hypertension after cigarette smoke exposure in the guinea pig. 1621 Apr 40

Advanced hypertension (HT), associated with left ventricular hypertrophy (LVH), impairs myocardial microvascular function and structure and leads to increased myocardial hypoxia and growth factor activation. However, the effect of HT on microvascular architecture and its relation to microvascular function, before the development of LVH (early HT), remains unclear. By way of method, pigs were studied after 12 wk of renovascular HT (n = 7) or control (n = 7) animals. Myocardial microvascular function (blood volume and blood flow at baseline and in response to adenosine) was assessed by using electron beam computed tomography (CT). Microvascular architecture was subsequently studied ex vivo using micro-CT, and microvessels (diameter, <500 microm) were counted in situ in three-dimensional images (40-microm on-a-side cubic voxels). Myocardial expression of vascular endothelial growth factor, basic fibroblast growth factor, and hypoxia-inducible factor-1alpha were also measured. By way of results, left ventricular muscle mass was similar between the groups. The blood volume response to intravenous adenosine was attenuated in HT animals compared with normal animals (+7.4 +/- 17.0 vs. +46.2 +/- 12.3% compared with baseline, P = 0.48 and P = 0.01, respectively). Microvascular spatial density in HT animals was significantly elevated compared with normal animals (246 +/- 26 vs. 125 +/- 20 vessels/cm2, P < 0.05) and correlated inversely with the blood volume response to adenosine. Growth factors expression was increased in HT animals compared with control animals. In conclusion, early HT elicits changes in myocardial microvascular architecture, which are associated with microvascular dysfunction and precede changes in muscle mass. These observations underscore the direct and early effects of HT on the myocardial vasculature.
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PMID:Functional and structural remodeling of the myocardial microvasculature in early experimental hypertension. 1621 46

Preeclampsia is a major cause of maternal, fetal, and neonatal mortality worldwide. Although the etiology of preeclampsia is still unclear, recent studies suggest that its major phenotypes, high blood pressure and proteinuria, are due in part to excess circulating soluble fms-like tyrosine kinase-1 concentrations. Soluble fms-like tyrosine kinase-1 is an endogenous antiangiogenic protein that is made by the placenta and acts by neutralizing the proangiogenic proteins vascular endothelial growth factor and placental growth factor. High serum soluble fms-like tyrosine kinase-1 and low serum free placental growth factor and free vascular endothelial growth factor have been observed in preeclampsia. Abnormalities in these circulating angiogenic proteins are not only present during clinical preeclampsia but also antedate clinical symptoms by several weeks. Therefore, this raises the possibility of measuring circulating angiogenic proteins in the blood and the urine as a diagnostic and screening tool for preeclampsia. The availability of a test to predict preeclampsia would be a powerful tool in preventing preeclampsia-induced mortality, especially in developing nations, where high-risk specialists are limited. This review will summarize our current understanding of the role of circulating angiogenic proteins in the pathogenesis and clinical diagnosis/prediction of preeclampsia.
Hypertension 2005 Nov
PMID:Circulating angiogenic factors in the pathogenesis and prediction of preeclampsia. 1623 May 16

The anti-angiogenic agent bevacizumab (Avastin) has been rationally designed to target vascular endothelial growth factor (VEGF), a key mediator of tumor angiogenesis. Based on its limited roles in adults, VEGF inhibition using bevacizumab would be expected to have limited side effects. Furthermore, because its mechanism of action is different to that of standard chemotherapeutic agents, bevacizumab would not be expected to cause typical cytotoxic agent-related toxicity or to exacerbate the toxicity of concomitant chemotherapy. We have reviewed clinical trials published to date, primarily in metastatic colorectal cancer, and describe the safety profile of bevacizumab. The review focuses on hypertension, proteinuria, arterial thrombosis, effects on wound healing, bleeding and gastrointestinal (GI) perforation, which are the principal bevacizumab-related events seen in clinical trials. These events are for the most part mild to moderate in severity and clinically manageable (hypertension, proteinuria, minor bleeding) or occur uncommonly (wound healing complications, GI perforations and arterial thrombosis). The side-effect profile of bevacizumab makes it a suitable adjunct to standard chemotherapy in settings where efficacy has been demonstrated, and it is now approved for use in the USA, the European Union and other markets worldwide.
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PMID:Managing patients treated with bevacizumab combination therapy. 1630 33

Endothelial NO synthase (eNOS) produces superoxide when depleted of (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) and L-arginine by uncoupling the electron flow from NO production. High expression of eNOS has been reported to have beneficial effects in atherosclerotic arteries after relatively short periods of time. However, sustained high expression of eNOS may have disadvantageous vascular effects because of uncoupling. We investigated NO and reactive oxygen species (ROS) production in a microvascular endothelial cell line (bEnd.3) with sustained high eNOS expression and absent inducible NOS and neuronal NOS expression using 4,5-diaminofluorescein diacetate and diacetyldichlorofluorescein as probes, respectively. Unstimulated cells produced both NO and ROS. After stimulation with vascular endothelial growth factor (VEGF), NO and ROS production increased. VEGF-induced ROS production was even further increased by the addition of extra L-arginine. Nomega-nitro-L-arginine methyl ester decreased ROS production. These findings strongly suggest that eNOS is a source of ROS in these cells. Although BH4 levels were increased as compared with another endothelial cell line, eNOS levels were >2 orders of magnitude higher. The addition of BH4 resulted in increased NO production and decreased generation of ROS, indicating that bEnd.3 cells produce ROS through eNOS uncoupling because of relative BH4 deficiency. Nevertheless, eNOS-dependent ROS production was not completely abolished by the addition of BH4, suggesting intrinsic superoxide production by eNOS. This study indicates that potentially beneficial sustained increases in eNOS expression and activity could lead to eNOS uncoupling and superoxide production as a consequence. Therefore, sustained increases of eNOS or VEGF activity should be accompanied by concomitant supplementation of BH4.
Hypertension 2006 Jan
PMID:Tetrahydrobiopterin, but not L-arginine, decreases NO synthase uncoupling in cells expressing high levels of endothelial NO synthase. 1634 67

Hypoxia induces gene expression of specific genes such as erythropoietin (Epo) and vascular endothelial growth factor (VEGF) that allow physiological adaptation to the environmental conditions at the cellular, local, and systemic levels. Reduced oxygenation is also a common precursor of many pathological processes, including coronary artery defects, ischemia, and malignant tumour formation. The hypoxia-inducible transcription factor HIF-1, a heterodimer consisting of the oxygen-regulated alpha-subunit and the constitutively expressed beta or ARNT-subunit, serves as a master regulator of oxygen-dependent gene expression. We observed that upon hypoxic exposure of HeLa cells in tonometer, accumulation of HIF-1alpha occurred within two minutes, while reoxygenation strongly reduced HIF-1alpha levels within four to eight minutes. Thus, hypoxia leads to a rapid cellular adaptation. In another line of investigation, we analysed the impact of hypoxia-independent overexpression of Epo in transgenic mice. Despite a hematocrit of about 80% the transgenic mice did not develop hypertension or thromboembolic complications.
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PMID:Mammalian gene expression in hypoxic conditions. 1635 33

Angiogenesis, a complex, coordinated process resulting in the assembly and maturation of new blood vessels, is critical for the growth of tumors. Several lines of evidence argue for angiogenesis inhibition in the treatment of colorectal cancer (CRC) : 1) angiogenesis (as measured by microvessel count), and the expression of pro-angiogenesis factors, such as vascular endothelial growth factor (VEGF), the key regulator of normal and pathological angiogenesis, have been reported to correlate with advanced disease and a worse prognosis ; 2) the expression of VEGF has been shown to correlate with RAS mutations, alterations in the APC-WNT signaling pathway, and overexpression of cyclo-oxygenase-2, which all are frequent in CRC ; 3) bevacizumab, a humanized anti-VEGF monoclonal antibody, is a potent inhibitor of tumor growth of various CRC cell lines in murine xenografts ; 4) the addition of bevacizumab to systemic chemotherapy has been shown to be significantly superior to chemotherapy alone in terms of objective tumor response rate, progression-free survival, and overall survival in patients with metastatic CRC, in the frontline, and more recently in the second-line setting, without worsening of chemotherapy-related toxicity. However, several potential specific adverse events, such as thrombosis, hemorrhages, proteinuria, arterial hypertension, and bowel perforations have been described. Whether the antitumoral efficacy of bevacizumab could be increased when combined to low-dose (metronomic) chemotherapy, or radiotherapy (in rectal cancer), is under development, as well other VEGF-targeted approaches (e.g., dominantnegative mutants, antisense oligonucleotides, antibodies directed against VEGF receptors (VEGFR), VEGFR tyrosine kinase inhibitors, soluble VEGFR,...), or other anti-angiogenesis agents (e.g., thalidomide, celecoxib, angiozyme...).
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PMID:[Therapeutic strategies using VEGF inhibitors in colorectal cancer]. 1638 67

While diabetes mellitus is most often associated with hypertension, dyslipidemia, and obesity, these factors do not fully account for the increased burden of cardiovascular disease in patients with the disease. This strengthens the need for comprehensive studies investigating the underlying mechanisms mediating diabetic cardiovascular disease and, more specifically, diabetes-associated atherosclerosis. In addition to the recognized metabolic abnormalities associated with diabetes mellitus, upregulation of putative pathological pathways such as advanced glycation end products, the renin-angiotensin system, oxidative stress, and increased expression of growth factors and cytokines have been shown to play a causal role in atherosclerotic plaque formation and may explain the increased risk of macrovascular complications. This review discusses the methods used to assess the development of atherosclerosis in the clinic as well as addressing novel biomarkers of atherosclerosis, such as low-density lipoprotein receptor-1. Experimental models of diabetes-associated atherosclerosis are discussed, such as the streptozocin-induced diabetic apolipoprotein E knockout mouse. Results of major clinical trials with inhibitors of putative atherosclerotic pathways are presented. Other topics covered include the role of HMG-CoA reductase inhibitors and fibric acid derivatives with respect to their lipid-altering ability, as well as their emerging pleiotropic anti-atherogenic actions; the effect of inhibiting the renin-angiotensin system by either ACE inhibition or angiotensin II receptor antagonism; the effect of glycemic control and, in particular, the promising role of thiazolidinediones with respect to their direct anti-atherogenic actions; and newly emerging mediators of diabetes-associated atherosclerosis, such as advanced glycation end products, vascular endothelial growth factor and platelet-derived growth factor. Overall, this review aims to highlight the observation that various pathways, both independently and in concert, appear to contribute toward the pathology of diabetes-associated atherosclerosis. Furthermore, it reflects the need for combination therapy to combat this disease.
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PMID:Diabetes mellitus-associated atherosclerosis: mechanisms involved and potential for pharmacological invention. 1648 46

The incidence of diabetes is increasing at an alarming rate to the point where it is becoming an epidemic. An ageing population, sedentary lifestyle and an unhealthy diet are considered to have contributed toward this. What we must now consider is not only the burden of the disease but the complications that arise from diabetes, in particular kidney and heart disease. Foremost, more than half of the diabetic population will die from cardiovascular-related causes. Whilst diabetes is most often associated with hypertension, dyslipidaemia and obesity, these factors do not fully account for the increased burden of cardiovascular disease in people with diabetes. This strengthens the need for comprehensive studies investigating the underlying mechanisms mediating diabetic cardiovascular disease, and more specifically, diabetes-associated atherosclerosis. In addition to the recognised metabolic abnormalities associated with diabetes, upregulation of putative pathological pathways such as advanced glycation endproducts, renin-angiotensin system, oxidative stress and increased expression of growth factors and cytokines have been observed in the setting of diabetes. All of these have been shown to play a causal role in atherosclerotic plaque formation and thus may explain the increased risk of macrovascular complications in those patients with diabetes. In this review the effect of inhibiting the renin-angiotensin system with angiotensin converting enzyme inhibition and a comparison to angiotensin II receptor antagonism is discussed, with the results of clinical trails reflecting the more recently discovered, non-haemodynamic, proatherogenic actions of angiotensin II. The need for experimental models of diabetes-associated atherosclerosis will be covered, with particular emphasis given to the streptozotocin-diabetic apolipoprotein E knockout mouse. Finally, growth factors, including vascular endothelial growth factor and platelet-derived growth factor are discussed in detail.
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PMID:Preventing atherosclerosis with angiotensin-converting enzyme inhibitors: emphasis on diabetic atherosclerosis. 1650 70

Preeclampsia is characterized by the clinical triad of new hypertension, proteinuria, and edema after 20 wk of gestation. Recent evidence suggests that disturbances in angiogenic factors (such as vascular endothelial growth factor and placental growth factor) signaling and endothelial health may play a major role in the pathogenesis of preeclampsia. Exogenous administration of soluble fms-like tyrosine kinase-1 (sFlt-1; a circulating anti-angiogenic protein) results in a preeclampsia-like phenotype in rats. This chapter describes the methods we use in our laboratory to create the sFlt-1 induced-rat model of preeclampsia.
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PMID:In vivo rat model of preeclampsia. 1651 96


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