Rho kinase activation in circulating leukocytes is related to hypertensive myocardial remodeling.

Rho-kinase has relevant functions in blood pressure modulation and cardiovascular remodeling. Rho-kinase activity is determined in circulating leukocytes measuring phosphorylation of its target myosin phosphatase target subunit 1 (MYPT1), but its relationship with Rho-kinase activity in the myocardium and in vasculature in hypertension has not been evaluated.The aim was to determine the degree of association between Rho-kinase cascade activation in circulating leukocytes with cardiac and aortic Rho-kinase pathway activation in a model of hypertension and to analyze it with a cause-effect perspective.Hypertensive deoxycorticosterone (DOCA)-salt rats received the Rho-kinase antagonist fasudil (DOCA-Fas, 100 mg/kg/day, 3 weeks). Results were compared with an untreated DOCA-salt and a sham group.Rho-kinase inhibition reduced significantly blood pressure, cardiac hypertrophy, myocardial collagen and macrophage infiltration, but not aortic wall hypertrophy. Fasudil decreased significantly Rho-kinase activity in peripheral blood mononucleated cells (PBMC), myocardium and aortic wall to similar levels as in the sham group. A significant correlation was found between PBMC Rho-kinase activity and cardiac remodeling, specifically with hypertrophy (r = 0.51, P≤0.01), myocardial collagen (r = 0.40, P≤0.05) and ED1 immunostaining (r = 0.48, P≤0.01). In the untreated hypertensive group, increased levels (P<0.05) of the proinflammatory molecules p65 NF-κB, vascular cell adhesion molecule 1 and interleukin-6 antibody in the myocardium, aortic wall and PBMC were observed and were reduced with fasudil (P<0.05).In conclusion, in this hypertension model, Rho-kinase and its pathway activation determined in circulating leukocytes reflect the activation of this pathway in the myocardium and in the aortic wall and are significantly related to myocardial remodeling (hypertrophy, fibrosis and inflammation).

Increased rho-kinase activity in hypertensive patients with left ventricular hypertrophy.

BACKGROUND: There is experimental evidence on the role of Rho-kinase (ROCK) activation in cardiac hypertrophy but no information on its role in human hypertension and left ventricular hypertrophy (LVH). We hypothesized that ROCK activity is higher in hypertensive patients with LVH compared with hypertensive patients without LVH. METHODS: We conducted a cross-sectional study comparing untreated hypertensive patients with (n = 41) and without LVH (n = 46) determined by echocardiography with a healthy normotensive control group (n = 51). Measurements included LV mass, dimensions, and function and ROCK activity determined in circulating leukocytes by measuring Western blot levels of phosphorylated to total myosin light chain phosphatase 1 (MYPT1-p/t). RESULTS: Compared with normotensive subjects, MYPT1-p/t was significantly increased by 4.5-fold in the hypertensive patients without LVH and by 9-fold in the hypertensive patients with LVH. Compared with the hypertension without LVH group, MYPT1-p/t was significantly increased by 2-fold in the hypertension with LVH gorup. In patients with eccentric LVH, the mean MYPT1-p/t ratio was significantly higher by 4-fold compared with hypertensive patients without eccentric LVH. Patients with an E/e' ratio ≥15 (n = 6) showed a higher MYPT1-p/t ratio (by 26%) compared with patients with a lower E/e' ratio (P ≤ 0.01). CONCLUSIONS: ROCK activity is higher in hypertensive patients with LVH compared with hypertensive patients without LVH, and it is further increased when eccentric LVH is present. Thus, in hypertension, ROCK activation is related to pathological cardiac remodeling and might have a role as an LVH marker.

Rho kinase inhibition activates the homologous angiotensin-converting enzyme-angiotensin-(1-9) axis in experimental hypertension.

BACKGROUND: Angiotensin II (Ang II) levels depend on renin, angiotensin-converting enzyme (ACE), and on the homologous angiotensin-converting enzyme (ACE2). Increased ACE and Ang II levels are associated with higher Rho kinase activity. However, the relationship between Rho kinase activation and ACE2 in hypertension is unknown. OBJECTIVE: The role of the Rho kinase signaling pathway in both enzymatic activity and aortic gene expression of ACE2 in deoxycorticosterone acetate (DOCA) hypertensive rats was assessed in the present study. METHODS AND RESULTS: Compared with sham animals, Rho kinase activity was higher by 400% (P<0.05) in the aortic wall of the DOCA hypertensive rats. In addition to blood pressure reduction, the specific Rho kinase inhibitor fasudil reduced aortic Rho kinase activity to levels observed in the sham control group and increased ACE2 enzymatic activity (by 83% in plasma and by 52% in the aortic wall, P<0.05), ACE2, and endothelial nitric oxide synthase (eNOS) aortic mRNA levels (by 340 and 40%, respectively, P<0.05) with respect to the untreated hypertensive DOCA rats. Fasudil also increased significantly plasma levels of Ang-(1-9) in normotensive and in the hypertensive rats. Aortic mRNA and protein levels of transforming growth factor-ß1 (TGF-ß1), plasminogen activator inhibitor 1 (PAI-1), and monocyte chemoattractant protein 1 (MCP-1) were significantly (P<0.05) higher in the untreated DOCA rats and were normalized by fasudil administration. CONCLUSION: In experimental hypertension, Rho-associated, coiled-coil containing protein kinase (ROCK) inhibition reduces blood pressure and increases ACE2 levels and activity. At the same time, ROCK inhibition reduces angiotensin II and increases Ang-(1-9) plasma levels. Fasudil also increases vascular eNOS mRNA levels and reduces aortic overexpression of the remodeling promotion proteins TGF-ß1, PAI-1, and MCP-1. This effect might additionally contribute to the antihypertensive and antiremodeling effects of ROCK inhibition in hypertension.

Increased levels of oxidative stress, subclinical inflammation, and myocardial fibrosis markers in primary aldosteronism patients.

BACKGROUND: Patients with primary aldosteronism experience greater left ventricular hypertrophy and a higher frequency of cardiovascular events than do essential hypertensive patients with comparable blood pressure levels. Aldosterone has been correlated with increased oxidative stress, endothelial inflammation, and fibrosis, particularly in patients with heart disease. AIM: To evaluate oxidative stress, subclinical endothelial inflammation, and myocardial fibrosis markers in patients with primary aldosteronism and essential hypertension. DESIGN AND INDIVIDUALS: We studied 30 primary aldosteronism patients and 70 control essential hypertensive patients, matched by age, sex and median blood pressure. For all patients, we measured the serum levels of aldosterone, plasma renin activity, malondialdehyde (MDA), xanthine oxidase, metalloproteinase-9, ultrasensitive C-reactive protein and amino terminal propeptides of type I (PINP), and type III procollagen. We also evaluated the effect of PA treatment in 19 PA individuals. RESULTS: PA patients showed elevated levels of MDA (1.70 ± 0.53 versus 0.94 ± 0.65 µmol/l, P <0.001) and PINP (81.7 ± 50.6 versus 49.7 ± 27 mg/l, P = 0.002) compared with essential hypertensive controls. We found a positive correlation between MDA, PINP, and the serum aldosterone/plasma renin activity ratio in primary aldosteronism patients. Clinically, treating primary aldosteronism patients decreased MDA and PINP levels. CONCLUSION: We detected higher levels of MDA and PINP in primary aldosteronism patients, suggesting increased oxidative stress and myocardial fibrosis in these individuals. Treating primary aldosteronism patients reduced MDA and PINP levels, which may reflect the direct effect of aldosterone greater than endothelial oxidative stress and myocardial fibrosis, possibly mediated by a mineralocorticoid receptor.

Angiotensin I-converting enzyme gene polymorphism influences chronic hypertensive response in the rat Goldblatt model.

BACKGROUND AND OBJECTIVE: In humans, the insertion/deletion polymorphism in the angiotensin (Ang) I converting enzyme (ACE) gene significantly determines ACE activity. The deletion allele induces higher ACE levels and is associated with hypertension in men. In the rat, a microsatellite marker in the ACE gene allows differentiation of the ACE alleles among strains with different ACE levels. We evaluated the effect of genetically determined ACE expression on the development of renovascular hypertension in the rat. METHODS AND RESULTS: Systolic BP (SBP), ACE and angiotensin II (Ang II) levels were measured using the Goldblatt (Gb) model (two kidneys, one clip) in homozygous males of two inbred strains (F2) of Lewis x Brown-Norway (BN) rats. SBP was significantly higher in the BN-Gb rats compared to the Lewis-Gb rats throughout the study (F = 239.6, P < 0.001). An interaction was observed between SBP and strain (F = 2.92, P < 0.01). Plasma ACE activity was 100% higher in the BN-Gb than in the Lewis-Gb rats (P < 0.05). Ang II plasma levels were higher in the BN-sham than in the Lewis-sham rats (255 +/- 22 versus 161 +/- 16 pg/ml, P < 0.05), increased in both Gb groups and correlated significantly with SBP (r = 0.58, P < 0.01). CONCLUSIONS: Genetically determined ACE expression in male rats enhances the chronic hypertensive response after the induction of renovascular hypertension. A relationship between circulating Ang II and the development of hypertension was also observed in this experimental model of genetically modulated hypertension.