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)

Rupture of atherosclerotic plaque resulting in intravascular thrombosis and myocardial infarction (MI), while a common sequelae of de novo atherosclerotic lesions, is an uncommon consequence of restenosis. We hypothesize that the rarity of MI associated with restenotic lesions is a result of cellular and biochemical modifications induced by the local response to mechanical injury rendering the site resistant to rupture. Clinical and angiographic features of patients presenting with symptomatic primary (n = 24) or restenotic coronary lesions (n = 12) who underwent directional atherectomy were compared. Histologic analysis and immunostaining for 92-kDa gelatinase were performed on each atherectomy specimen. There was no significant difference between the 2 groups regarding age, gender, incidence of diabetes, smoking, hypertension, hypercholesterolemia, or previous MI. Lesion length, extent, and distribution of disease and percent stenosis were not significantly different between groups. However, 8% of primary lesions were hypercellular compared with 75% of restenotic specimens (p = 0.0001). Hypercellularity in restenotic specimens was shown by adjacent section staining to be composed of smooth muscle cells. Ninety-two kDa gelatinase was expressed in 79% of primary lesions versus 0% of restenotic specimens (p = 0.0001). Thrombus was identified in 54% of primary lesions versus 22% of restenotic lesions (p <0.05). These findings suggest that, independent of clinical or angiographic influences, balloon injury induces increased lesion cellularity and reduced expression of 92-kDa gelatinase, possibly resulting in a reduced propensity for plaque rupture and thrombosis.
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PMID:Differential expression of 92-kDa gelatinase in primary atherosclerotic versus restenotic coronary lesions. 910 98

Glomerular hypertension has been established as a major factor contributing to glomerular scarring. Underlying cellular mechanisms leading to matrix accumulation are largely unknown. The isolated effect of oscillating hyperbaric pressure [OP; P(max) 50 mmHg (1 mmHg=0.133 kPa), P(mean) 24 mmHg, with a fixed oscillation of 60/min] on matrix-degrading protease secretion by rat mesangial cells (MCs) was analysed using a pressure chamber model described previously [Mertens, Espenkott, Venjakob, Heintz, Handt and Sieberth (1998) Hypertension 32, 945-952]. MCs were grown under atmospheric pressure (AP) or a controlled OP, and protease synthesis and gene transcription were analysed. A distinct biphasic cellular response to OP with stimulated gelatinase A protein expression and enzyme activity during the initial 24 h, and subsequent inhibition, was apparent, as shown by gelatin zymography. Gelatinase B activity remained unchanged. The abundance of gelatinase A transcripts, determined by reverse transcriptase-PCR, indicated a concordant regulation of gene transcription. To elucidate underlying regulatory events, reporter constructs were transfected. In these experiments, a recently identified response element, RE-1, conferred a significant stimulatory effect within the initial 4 h of OP. Nuclear protein/RE-1 binding studies revealed additional complexes from 5 min up to 3 h after OP exposure, with intensities dependent on P(max). STAT3 was identified as a component of these novel complexes. Down-regulation of cis-activity after 48 h of OP exposure was not transferred via the proximal 1686 bp of the gelatinase A regulatory sequence. In conclusion, hyperbaric OP elicits time-dependent changes in rat MC gelatinase A gene transcription.
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PMID:Mesangial cell gelatinase A synthesis is attenuated by oscillating hyperbaric pressure. 1187 97

High fat diet (HFD) induces both arterial hypertension and tachycardia in dogs. Changes in heart rate occur early and are in part due to a decrease in the parasympathetic drive to the heart secondary to down-regulation of atrial muscarinic M2 receptors (Pelat et al. Hypertension 1999; 340: 1066-72). These data suggest that HFD is able to modify genic expression at atrial level. Thus, the aim of this work was to perform a systematic study of the genic expression profile in dogs made obese and hypertensive by 9 weeks of HFD. Blood pressure and heart rate were measured by telemetry implanted 15 days before starting regimen in 6 HFD and in 6 control dogs. HFD was the normal canine diet administered to controls but mixed with 300 g of beef fat. At the end of the experience, animals were sacrified and right atria were collected. Gene regulation was assessed in pooled tissue samples from both groups using suppressive substractive hybridization and microarray analysis. Genes with induction or repression rates of at least 20% when compared to controls were sequenced. As previously reported HFD induced a significant increase in body weight, blood pressure and heart rate when compared to controls. The results of SSH experiments led to the identification of 32 genes which are differentially regulated in atria from HFD dogs. Most are genes encoding proteins which have been previously shown to be regulated during various cardiopathies (MMP9, Na/K-ATPase 3...). These changes indicate the existence of early remodeling processes of atrial myocardium secondary to HFD. Other group of genes encodes proteins with no role identified in heart up today (lec-3, ERK-3, TRIP1, nucleophosmin...) or which function remains totally unknown. This work confirms that HFD is associated with early changes in gene expression in atrium. These changes are unlikely to be related to ventricular hypertrophy which is observed only during long-term HFD. Further studies are necessary to demonstrate the role of these modifications in the pathophysiological mechanisms leading to the increase in heart rate in this model of obesity-related arterial hypertension.
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PMID:[Early atrial gene regulation of obesity-related arterial hypertension]. 1236 82

Susceptibility to ischemic damage to the subcortical white matter of the brain has a strong genetic basis. Dysregulation of matrix metalloproteinases (MMPs) contributes to loss of cerebrovascular integrity and white matter injury. We investigated whether sequence variation in the genes encoding MMP3 and MMP9 is associated with variation in leukoaraiosis volume, determined by magnetic resonance imaging, in non-Hispanic whites and African-Americans using family-based association tests. Seven hundred and fifty-six white and 671 African-American individuals from sibships ascertained through two or more siblings with hypertension were genotyped for 7 and 8 haplotype-tagging polymorphisms in the MMP3 and MMP9 genes, respectively. MMP3 sequence variation was significantly associated with variation in leukoaraiosis volume in Whites. Two common haplotypes with opposing relationships to leukoaraiosis volume were identified. MMP9 sequence variation was also significantly associated with variation in leukoaraiosis volume in both African-Americans and Whites. Different haplotypes contributed to these associations in the two racial groups. These findings add to the growing body of evidence from animal models and human clinical studies suggesting a role of MMPs in ischemic white matter injury. They provide the basis for further investigation of the role of these genes in susceptibility and/or progression to clinical disease.
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PMID:Family-based association study of matrix metalloproteinase-3 and -9 haplotypes with susceptibility to ischemic white matter injury. 1702 75

Sympathetic nerve activity increases in the heart during cardiac failure. Here, we hypothesized that beta1 integrins play a protective role in chronic beta-adrenergic receptor-stimulated cardiac myocyte apoptosis and heart failure. L-isoproterenol (iso; 400 microg/kg per hour) was infused in a group of wild-type (WT) and beta1 integrin heterozygous knockout (hKO) mice. Left ventricular structural and functional remodeling was studied at 7 and 28 days of iso-infusion. Western blot analysis demonstrated reduced beta1 integrin levels in the myocardium of hKO-sham. Iso-infusion increased heart weight:body weight ratios in both groups. However, the increase was significantly higher in WT-iso. M-mode echocardiography indicated increased left ventricular end-diastolic diameter, percentage of fractional shortening, and ejection fraction in the WT-iso group. The percentage of fractional shortening and ejection fraction were significantly lower in hKO-iso versus hKO-sham and WT-iso. Peak left ventricular developed pressure and left ventricular end-diastolic pressure measured using Langendorff-perfusion analyses were significantly higher in the WT-iso group (P<0.05 versus WT-sham and hKO-Iso). The number of TUNEL-positive myocytes was significantly higher in hKO-iso hearts 7 and 28 days after iso-infusion. The increase in myocyte cross-sectional area and fibrosis was higher in the WT-iso group. Matrix metalloproteinase-9 protein levels were significantly higher in WT-iso, whereas matrix metalloproteinase-2 levels were increased in hKO-iso hearts. Iso-infusion increased phosphorylation of c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2 in both groups. The increase in c-Jun N-terminal kinase phosphorylation was significantly higher in hKO-iso (P<0.001 versus WT-iso). Thus, beta1 integrins play a crucial role in beta-adrenergic receptor-stimulated myocardial remodeling with effects on cardiac myocyte hypertrophy, apoptosis, and left ventricular function.
Hypertension 2007 Apr
PMID:Beta1 integrins modulate beta-adrenergic receptor-stimulated cardiac myocyte apoptosis and myocardial remodeling. 1729 73

Beneficial effects of thiazolidinediones, peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, on cardiovascular injuries have been reported. However, the effects of these agonists on left ventricular (LV) hypertrophy have not been clarified. To investigate whether pioglitazone improves LV hypertrophy, we used 32-week-old stroke-prone spontaneously hypertensive rats (SHR-SP) that had been treated or not treated with pioglitazone (10 mg/kg/day) for 8 weeks, and Wistar Kyoto rats (WKY). We evaluated LV geometry by echocardiography; myocyte hypertrophy, tissue fibrosis, and appearance of myofibroblasts by histological examination; mRNA expression by real-time polymerase chain reaction (PCR); protein expression by Western blot; activities of matrix metalloproteinase (MMP) by zymography; and production of reactive oxygen species (ROS) by electron spin resonance spectroscopy or thiobarbituric acid reactive substances (TBARS). SHR-SP showed concentric hypertrophy of the LV, but WKY did not. The myocyte diameter, fraction of tissue fibrosis, and number of myofibroblasts were greater in SHR-SP. mRNA expressions of collagen type I and type III, tissue growth factor (TGF)-beta1, and brain natriuretic peptide (BNP); protein expression of connective tissue growth factor (CTGF); activities of MMP2 and MMP9; and ROS were increased in SHR-SP. Pioglitazone did not decrease blood pressure, but partially normalized LV geometry in addition to decreasing myocyte diameter, interstitial fibrosis and number of myofibroblasts; mRNA levels of collagen type I and BNP; MMP2 activity; and protein level of CTGF. However, the mRNA level of collagen type III and TGF-beta1, MMP9 activity, and ROS production were not improved. In conclusion, pioglitazone reversed the concentric LV remodeling independently from blood pressure or oxidative stress in chronic hypertension.
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PMID:Beneficial effects of pioglitazone on left ventricular hypertrophy in genetically hypertensive rats. 1803 80

We hypothesize that pulmonary arterial hypertension (PAH)-associated genes identified by expression profiling of peripheral blood mononuclear cells (PBMCs) from patients with idiopathic pulmonary arterial hypertension (IPAH) can also be identified in PBMCs from scleroderma patients with PAH (PAH-SSc). Gene expression profiles of PBMCs collected from IPAH (n = 9), PAH-SSc (n = 10) patients, and healthy controls (n = 5) were generated using HG_U133A_2.0 GeneChips and were processed by the RMA/GCOS_1.4/SAM_1.21 data analysis pipeline. Disease severity in consecutive patients was assessed by functional status and hemodynamic measurements. The expression profiles were analyzed using PAH severity-stratification, and identified candidate genes were validated with real-time polymerase chain reaction (PCR). Transcriptomics of PBMCs from IPAH patients was highly comparable with that of PMBCs from PAH-SSc patients. The PBMC gene expression patterns significantly correlate with right atrium pressure (RA) and cardiac index (CI), which are known predictors of survival in PAH. Array stratification by RA and CI identified 364 PAH-associated candidate genes. Gene ontology (GO) analysis revealed significant (Z(score) > 1.96) alterations in angiogenesis genes according to PAH severity: matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF) were significantly upregulated in mild as compared with severe PAH and healthy controls, as confirmed by real-time PCR. These data demonstrate that PBMCs from patients with PAH-SSc carry distinct transcriptional expression. Furthermore, our findings suggest an association between angiogenesis-related gene expression and severity of PAH in PAH-SSc patients. Deciphering the role of genes involved in vascular remodeling and PAH development may reveal new treatment targets for this devastating disorder.
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PMID:Identification of candidate genes in scleroderma-related pulmonary arterial hypertension. 1835 67

Remodeling of the pulmonary artery is a major feature of pulmonary artery hypertension, and CPU86017, a derivative of berberine, is known to effectively alleviate hypoxic pulmonary hypertension (HPH). CPU86017 is a racemate, possessing two chiral centers: 7N and 13aC. We have compared the effects of four CPU86017 isomers, SS [(+)-7S, 13aS-CPU86017], SR [(-)-7S, 13aR-CPU86017], RR [(-)-7R, 13aR-CPU86017] and RS [(+)-7R, 13aS-CPU86017], on HPH. Sprague-Dawley rats were exposed to hypoxic conditions (10 +/- 0.5% O2 for 8 h per day) for 4 weeks and treated with CPU86017, SS, SR, RR or RS (4 mg/kg, subcutaneously) from day 15 to 28. After 4 weeks of exposure to hypoxia, remodeling of the right ventricle and the small pulmonary arteries (<150 microm) was very pronounced, and extra-cellular matrix (ECM) had been excessively produced in association with abnormal mRNA and protein expression of matrix metalloproteinase 9 (MMP9) and mRNA of tissue inhibitor of matrix metalloproteinase 1 and 2 (TIMP1, TIMP2). Expression of endothelin receptor A was upregulated, while that connexin 40 was downregulated. The administration of CPU86017 and its four isomers attenuated the changes, with the isomer RS exhibiting the most favorable effect on HPH rats. We propose that an activated endothelin pathway associated with an unbalanced MMP-TIMP system may contribute to the over-accumulation of ECM and the remodeling of the pulmonary arterioles in HPH. CPU86017 and its four isomers attenuate ECM accumulation and vascular remodeling by normalizing both the MMP-TIMP system and the ET system. The RS isomer is superior to the racemate CPU86017 in attenuating HPH.
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PMID:CPU86017 and its isomers improve hypoxic pulmonary hypertension by attenuating increased ETA receptor expression and extracellular matrix accumulation. 1854 32

Expression of bone morphogenetic protein receptor 1A (BMPR1A) is attenuated in the lung vessels of patients with pulmonary arterial hypertension, but the functional impact of this abnormality is unknown. We ablated Bmpr1a in cardiomyocytes and vascular smooth muscle cells (VSMCs) by breeding mice possessing a loxP allele of Bmpr1a (Bmpr1aflox) expressing R26R with SM22alpha-Cre mice. SM22alpha-Cre;R26R;Bmpr1aflox/flox mice died soon after embryonic day 11 (E11) with massive vascular and pericardial hemorrhage and impaired brain development. At E10.5, SM22alpha-Cre;R26R;Bmpr1aflox/flox embryos showed thinning of the myocardium associated with reduced cell proliferation. These embryos also had severe dilatation of the aorta and large vessels with impaired investment of SMCs that was also related to reduced proliferation. SM22alpha-Cre;R26R;Bmpr1aflox/flox mice showed collapsed telencephalon in association with impaired clearing of brain microvessels in areas where reduced apoptosis was observed. Transcript and protein levels of matrix metalloproteinase (MMP) 2 and 9 were reduced in E9.5 and E10.5 SM22alpha-Cre;R26R;Bmpr1aflox/flox embryos, respectively. Knock-down of BMPR1A by RNA interference in human pulmonary artery SMCs reduced MMP2 and MMP9 activity, attenuated serum-induced proliferation, and impaired PDGF-BB-directed migration. RNA interference of MMP2 or MMP9 recapitulated these abnormalities, supporting a functional interaction between BMP signaling and MMP expression. In human brain microvascular pericytes, knock-down of BMPR1A reduced MMP2 activity and knock-down of either BMPR1A or MMP2 caused resistance to apoptosis. Thus, loss of Bmpr1a, by decreasing MMP2 and/or MMP9 activity, can account for vascular dilatation and persistence of brain microvessels, leading to the impaired organogenesis documented in the brain.
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PMID:SM22alpha-targeted deletion of bone morphogenetic protein receptor 1A in mice impairs cardiac and vascular development, and influences organogenesis. 1866 63

We investigated the involvement of matrix metalloproteinases (MMPs), tissue inhibitor (TIMP) and endothelin-1 (ET-1) in the renal damage in spontaneously hypertensive rats (SHR) following nitric oxide (NO) deprivation. SHR received Nomega-nitro-L-arginine methyl ester (L-NAME) from 5 wk-old for a period of 30 days. An ETA antagonist, FR139317 was used. We gave SHR FR139317 alone and cotreatment with L-NAME. L-NAME caused systemic hypertension, decrease in plasma nitrate/nitrite, increases in blood urea nitrogen and creatinine, impairment of glomerular dynamics. NO deprivation reduced the renal tissue cGMP, but it increased the collagen volume fraction, number of sclerotic glomeruli, arteriolar injury score and glomerular injury score. In addition, L-NAME elevated the plasma ET-1 at day 5. Cotreatment with FR139317 alleviated the L-NAME-induced functional and structural changes of renal glomeruli. L-NAME administration for 5 to 10 days resulted in decreases in MMP2 and MMP9 with increasing TIMP2. After L-NAME for 15 days, opposite changes (increases in MMP2 and MMP9 with a decrease in TIMP2) were observed. FR139317 cotreatment ameliorated the L-NAME-induced changes in MMP2 and MMP9 throughout the 30-day observation period. The ETA antagonist cotreatment attenuated the L-NAME-induced increase in TIMP2 before day 15, but not after day 20. The results indicate that ET-1, MMPs and TIMP are involved at the early stage (before 10 days) of glomerular sclerosis and arteriosclerosis with functional impairment following NO deprivation. The changes in MMPs and TIMP at the late stage (after 20 days) may be a compensatory response to prevent further renal damage.
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PMID:Endothelin and gelatinases in renal changes following blockade of nitric oxide synthase in hypertensive rats. 1893 14


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