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)

Extracellular matrix expansion in the glomerular mesangium contributes to the development of glomerulosclerosis and chronic renal disease in arterial hypertension. Transforming growth factor-beta1 (TGF-beta1), matrix metalloproteinases (MMPs), and tissue inhibitors of MMPs (TIMPs) are involved in this process. Conflicting data are reported on the effects of angiotensin II (Ang II) and the response to angiotensin-converting enzyme inhibition on MMPs and TIMPs in early stages of hypertensive glomerular damage. We therefore investigated the effects of Ang II-dependent hypertension on MMP-2, MMP-9, TIMP-1, and TIMP-2 in isolated glomeruli of 8-week-old homozygous male rats overexpressing the mouse Ren2 gene [TGR(mRen2)27]. At this age, systolic blood pressure was already significantly elevated in Ren2 compared with Sprague-Dawley (SD) rats (197 +/- 38 versus 125 +/- 16 mm Hg, p < 0.01). Ren2 exhibited renal damage as determined by increased urinary albumin excretion, focal glomerulosclerosis, mesangial matrix expansion, and alpha-smooth muscle actin deposition. Quantification of mRNA levels in isolated glomeruli by real-time polymerase chain reaction showed a significant increase of TGF-beta1, a 2.3- and a 2.6-fold increase of MMP-2 and TIMP-1 in Ren2 compared with SD (p < 0.01, respectively) and no strain differences for TIMP-2. In contrast, MMP-9 mRNA expression was markedly suppressed to 10% of control levels in Ren2 (p < 0.01). Early treatment with ramipril completely prevented renal damage in Ren2 and restored mRNA expression of TGF-beta1, MMP-2, and TIMP-1 to SD control levels. Interestingly, down-regulation of MMP-9 mRNA, protein, and activity was not affected by ramipril, indicating that the protective effect of this compound is not attributable to restoration of MMP-9 in the glomerulus.
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PMID:Expression and response to angiotensin-converting enzyme inhibition of matrix metalloproteinases 2 and 9 in renal glomerular damage in young transgenic rats with renin-dependent hypertension. 1616 67

Recent histologic and immunocytochemical evidence of venous leg ulcers supports the hypothesis that lesions observed at different stages of chronic venous insufficiency may be associated with, and possibly caused by, an inflammatory process. Evidence has been obtained that venous valve deficiency may be associated with leukocyte infiltration into valve leaflets; therefore, it is hypothesized that an essential event in the inflammatory cascade is the enzymatic degradation of the valve leaflets and venous wall. The metalloproteinases (MMP) in veins exposed to elevated pressures up to 6 weeks were examined in a rat femoral fistula model with venous hypertension. Zymography shows increased activity of pro-MMP-2 at 3 and 6 weeks. MMP-2 and MMP-9 activity was predominantly observed at days 7 and 21 after creation of the fistula. The degree of extracellular matrix remodeling correlates with the morphological finding of macroscopic lesions. Therefore, the MMP-2 and MMP-9 activation is already present in veins days after exposure to elevated blood pressure and coincides with periods of early alterations in the valve morphology and early forms of reflux.
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PMID:Venous hypertension and the inflammatory cascade: major manifestations and trigger mechanisms. 1619 24

The adaptive changes that develop in the pressure-overloaded left ventricular (LV) myocardium include cardiomyocyte hypertrophy and interstitial fibrosis. Although the former is known to depend to a sizeable extent on sympathetic (over)activity, little information exists whether the same applies to the latter, ie, whether excess catecholamine exposure contributes to the imbalance between collagen deposition by fibroblasts and degradation by matrix metalloproteases (MMPs), eventually leading to LV collagen accumulation. Sprague-Dawley rats were subjected to abdominal aortic banding (B) or sham operation (S) and treated with beta-blockade (Bb, oral propranolol, 40 mg/kg per day), chemical sympathectomy (Sx, 6-hydroxydopamine, 150 mg/kg intraperitoneal twice per week) or vehicle (Vh). Ten weeks later, systolic blood pressure, LV weight, collagen abundance (computer-aided histology), zymographic matrix metalloproteinase (MMP)-2 activity and its specific tissue inhibitor concentration (TIMP-2) were measured. Both sympathectomy and beta-blockade failed to attenuate the banding-induced blood pressure elevation but significantly attenuated the attendant LV hypertrophy. As expected, pressure-overload hypertrophy was associated with interstitial fibrosis (collagen: 4.37+/-1.23% BVh versus 1.23+/-0.44% SVh, P<0.05), which was abolished by sympathectomy (2.55+/-1.31%, P=not significant versus SSx) but left unchanged by beta-blockade (4.11+/-1.23%, P<0.05 versus both SBb and BSx). beta-blockade, but not sympathectomy, was also associated with an increased TIMP-2/MMP-2 ratio (P<0.05), indicating reduced interstitial collagenolytic activity. In separate groups of banded and sham-operated rats, treatment with the alpha-receptor blocker doxazosin (10 mg/kg per day) displayed similar antifibrotic and biochemical effects as sympathectomy. Thus in the course of experimental pressure overload, the sympathetic nervous system plays a major pro-fibrotic role, which is mediated via alpha-adrenergic but not beta-adrenergic receptors.
Hypertension 2005 Nov
PMID:Sympathectomy or doxazosin, but not propranolol, blunt myocardial interstitial fibrosis in pressure-overload hypertrophy. 1621 89

Large artery stiffening increases cardiovascular risk and promotes isolated systolic hypertension which is more prevalent in elderly women than men. Variation in sex steroid levels between males and females and throughout life may modulate arterial stiffness. We hypothesized that sex steroids directly influence expression of important structural proteins which determine arterial biomechanical properties. Human aortic smooth muscle cells were incubated with physiological concentrations of 17beta-estradiol, progesterone, 17beta-estradiol and progesterone, or testosterone for 4 weeks. Collagen, elastin, and fibrillin-1 deposition was examined (histochemistry/immunohistochemistry). Gene and protein expression of 2 important matrix metalloproteinases (MMPs), MMPs 2 and 3, regulating matrix turnover was assessed. All sex steroids reduced collagen deposition relative to control (100%). However, the reduction was greater with female sex steroids than testosterone (control, 100%; 17beta-estradiol plus progesterone, 20+/-2%; testosterone 74+/-12%, P<0.001). Female sex steroids increased elastin deposition compared with control (control, 100%; 17beta-estradiol, 540+/-60%; progesterone, 290+/-40%; 17beta-estradiol plus progesterone, 400+/-80%, all P<0.01). The elastin/collagen ratio was >11-fold higher in the presence of 17beta-estradiol and progesterone compared with testosterone. Fibrillin-1 deposition was doubled in the presence of female sex steroids (17beta-estradiol plus progesterone) compared with testosterone (P<0.01). MMP-2 gene and protein expression was unaffected by any sex steroid. Testosterone increased both gene and protein expression of MMP-3 relative to both control and female sex steroids (P<0.01). This may contribute to degradation of elastic matrix proteins. In conclusion, female sex steroids promote an elastic matrix profile, which likely contributes to variation in large artery stiffness observed between sexes and with changes in hormonal status across the lifespan.
Hypertension 2005 Nov
PMID:Sex steroids modulate human aortic smooth muscle cell matrix protein deposition and matrix metalloproteinase expression. 1623 May 20

Carotid atherosclerotic plaque remodelling and increased risk of symptomatic plaque rupture seem to be partially mediated by matrix metalloproteinases (MMPs). In this study, we have investigated whether different MMPs are related to carotid atherosclerosis or to recent ischaemic brain disease. Eighty-four consecutive patients undergoing carotid endarterectomy for symptomatic and asymptomatic disease were studied. Plaques were analysed by ultrasound and later by morphology. Plasma MMP-2, MMP-8 and MMP-9 levels were quantified by ELISA. MMP expression and activity in carotid plaques was analysed by Western blotting and in situ zymography. Results were analysed with respect to plaque stability, morphology, symptomatic disease, presence of vascular risk factors and plasma markers of acute inflammation as high sensitivity C-reactive protein (hsCRP), fibrinogen, D-dimer and white blood cell counts. Patients with hypoechogenic plaques on ultrasound had more plasma MMP-8 (p = 0.04) and increased MMP activity as assessed by in situ zymography. Asymptomatic patients with plaque progression had more active intraplaque MMP-8 than asymptomatic patients without plaque progression. Presence of recent intraplaque haemorrhage or past history of CAD was related to increased activity of MMPs as assessed by in situ zymography (p < 0.01, CI 95% 0.8-1.0). Plasma MMP-8 and MMP-9, but not MMP-2 levels, decrease with time after ischaemic stroke. Patients with hypertension had more intraplaque active MMP-9 than normotensive (p = 0.03, CI 95% 0.7-1.0). Hypoechogenic carotid plaques had increased MMP activity and asymptomatic patients with plaque progression show increase intraplaque MMP-8 levels.
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PMID:Intraplaque MMP-8 levels are increased in asymptomatic patients with carotid plaque progression on ultrasound. 1625 88

Angiotensin (ANG) II (AngII) and aldosterone contribute to the development of interstitial cardiac fibrosis. We investigated the potential role of a Nox2-containing NADPH oxidase in aldosterone-induced fibrosis and the involvement of this mechanism in AngII-induced effects. Nox2-/- mice were compared with matched wild-type controls (WT). In WT mice, subcutaneous (s.c.) AngII (1.1 mg/kg/day for 2 wk) significantly increased NADPH oxidase activity, interstitial fibrosis (11.5+/-1.0% vs. 7.2+/-0.7%; P<0.05), expression of fibronectin, procollagen I, and connective tissue growth factor mRNA, MMP-2 activity, and NF-kB activation. These effects were all inhibited in Nox2-/- hearts. The mineralocorticoid receptor antagonist spironolactone inhibited AngII-induced increases in NADPH oxidase activity and the increase in interstitial fibrosis. In a model of mineralocorticoid-dependent hypertension involving chronic aldosterone infusion (0.2 mg/kg/day) and a 1% Na Cl diet ("ALDO"), WT animals exhibited increased NADPH oxidase activity, pro-fibrotic gene expression, MMP-2 activity, NF-kB activation, and significant interstitial cardiac fibrosis (12.0+/-1.7% with ALDO vs. 6.3+/-0.3% without; P<0.05). These effects were inhibited in Nox2-/- ALDO mice (e.g., fibrosis 6.8+/-0.8% with ALDO vs. 5.8+/-1.0% without ALDO; P=NS). These results suggest that aldosterone-dependent activation of a Nox2-containing NADPH oxidase contributes to the profibrotic effect of AngII in the heart as well as the fibrosis seen in mineralocorticoid-dependent hypertension.
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PMID:Aldosterone mediates angiotensin II-induced interstitial cardiac fibrosis via a Nox2-containing NADPH oxidase. 1672 Jul 35

Chronic hyperhomocysteinemia (HHcy) is an important factor in development of arterial hypertension. HHcy is associated with activation of matrix metalloproteinases (MMPs); however, it is unclear whether HHcy-dependent extracellular matrix (ECM) accumulation plays a role in arterial hypertrophy and hypertension. We tested the hypothesis that in HHcy the mechanism of arterial hypertension involves arterial dysfunction in response to ECM accumulation between endothelial and arterial smooth muscle cells and subsequent endothelium-myocyte (E-M) uncoupling. To decrease plasma Hcy, dietary supplementation with 3-deazaadenosine (DZA), the S-adenosylhomocysteine hydrolase inhibitor, was administered to cystathionine beta-synthase (CBS) knockout (KO) mice. Mice were grouped as follows: wild type (WT; control), WT+DZA, CBSKO, and CBSKO+DZA (n = 4/group). Mean aortic blood pressure and heart rate were monitored in real time with a telemetric system before, during, and after DZA treatment (6 wk total). In vivo aorta function and morphology were analyzed by M-mode and Doppler echocardiography in anesthetized mice. Aorta MMP activity in unfixed cryostat sections was measured with DQ gelatin. Aorta MMP-2, MMP-9, and connexin 43 expression were measured by RT-PCR and Western blot analyses, respectively. HHcy caused increased aortic blood pressure and resistance, tachycardia, and increased wall thickness and ECM accumulation in aortic wall vs. control groups. There was a linear correlation between aortic wall thickness and plasma Hcy levels. MMP-2, MMP-9, and connexin 43 expression were increased in HHcy. In the CBSKO+DZA group, aortic blood pressure and levels of MMP and connexin 43 were close to those found in control groups. However, removal of DZA reversed the aortic lumen-to-wall thickness ratio in CBSKO mice, suggesting, in part, a role of vascular remodeling in the increase in blood pressure in HHcy. The results show that arterial hypertension in HHcy mice is, in part, associated with arterial remodeling and E-M uncoupling in response to MMP activation.
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PMID:3-Deazaadenosine mitigates arterial remodeling and hypertension in hyperhomocysteinemic mice. 1681 86

There are conflicting data in the literature regarding the expression pattern of the vascular matrix metalloproteinase (MMP) system and their inhibitors (TIMPs) in human hypertension. The authors hypothesized that MMP-2, MMP-9, and TIMP-1 would be abnormal in hypertension, reflecting alterations in extracellular matrix (ECM) turnover. The authors measured plasma levels and activities of MMP-2, MMP-9, and TIMP-1 in 44 hypertensive patients and 44 controls. MMP-2 levels and activity were significantly higher in hypertensive group (p < .0001). Significant increase was also observed for MMP-9 level and activity (p < .0001) and for TIMP-1 (p < .0001) in hypertensive patients. Plasma levels and activities of MMP-2, MMP-9, and TIMP-1 are increased in hypertensive patients, which may reflect abnormal ECM metabolism.
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PMID:Matrix metalloproteinase-2, -9, and tissue inhibitor of metalloproteinase-1 in patients with hypertension. 1684 Jan 78

In this study, we focused on the effect of hypertension on the transcription factors nuclear factor kappaB (NFkappaB) and ets in the mechanisms of abdominal aortic aneurysm (AAA), and we investigated how hypertension affects the progression of AAA. AAA was produced by elastase perfusion in hypertensive rats and normotensive rats. The size of AAA rapidly increased in hypertensive rats as compared with normotensive rats. Western blot analysis demonstrated that the expression of matrix metalloproteinase (MMP)-2, -3 , -9, and -12, as well as intercellular adhesion molecule, was increased in hypertensive AAA rats, accompanied by upregulation of NFkappaB and ets. Moreover, in situ zymography showed that the activity of MMPs was increased in the aorta of a hypertensive AAA model as compared with that in a normotensive AAA model. Interestingly, transfection of chimeric decoy oligodeoxynucleotide (ODN) resulted in significant inhibition of aortic dilatation both in normotensive and hypertensive rats at 4 weeks after transfection. Destruction of elastic fibers was also significantly inhibited by transfection of chimeric decoy ODN in both hypertensive rats and normotensive rats. The expression of MMP-2, -3, -9, and -12, as well as intercellular adhesion molecule, was significantly attenuated by the chimeric decoy ODN, accompanied by inhibition of the migration of macrophages. Also, the effect of chimeric decoy ODN was confirmed in an organ culture. The present study demonstrated that hypertension accelerated the progression of experimental AAA through upregulation of NFkappaB and ets. Inhibition of NFkappaB and ets could be a novel therapeutic strategy to treat AAA in hypertensive patients.
Hypertension 2006 Oct
PMID:Hypertension accelerated experimental abdominal aortic aneurysm through upregulation of nuclear factor kappaB and Ets. 1694 Feb 14

Arterial remodeling occurs in response to mechanical and neurohumoral stimuli. We hypothesized that veins, which are not exposed to higher pressures in hypertension, would demonstrate less active remodeling than arteries. We assessed remodeling with two standard measures of arterial remodeling: vessel morphometry and the expression/function of matrix metalloproteinases (MMPs). Thoracic aorta and vena cava from sham normotensive and DOCA-salt hypertensive rats (110 +/- 4 and 188 +/- 8 mmHg systolic blood pressure, respectively) were used. Wall thickness was increased in DOCA-salt vs. sham aorta (301 +/- 23 vs. 218 +/- 14 mum, P < 0.05), as was medial area, but neither measure was altered in the vena cava. The aorta and vena cava expressed the gelatinases MMP-2, MMP-9, transmembrane proteinase MT1-MMP, and tissue inhibitor of metalloproteinase-2 (TIMP-2). Immunohistochemically, MMP-2 localized to smooth muscle in the aorta and densely in endothelium/smooth muscle of the vena cava. Western and zymographic analyses verified that MMP-2 was active in all vessels and less active in the vena cava than aorta. In hypertension, MMP-2 expression and activity in the aorta were increased (59.1 +/- 3.7 and 74.5 +/- 6.1 units in sham and DOCA, respectively, P < 0.05); similar elevations were not observed in the vena cava. MMP-9 was weakly expressed in all vessels. MT1-MMP was expressed by the aorta and vena cava and elevated in the vena cava from DOCA-salt rats. TIMP-2 expression was significantly increased in the aorta of DOCA rats compared with sham but was barely detectable in the vena cava of sham or DOCA-salt hypertensive rats. These findings suggest that large veins may not undergo vascular remodeling in DOCA-salt hypertension.
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PMID:Morphological and biochemical characterization of remodeling in aorta and vena cava of DOCA-salt hypertensive rats. 1723 46


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