Simultaneous Rho kinase inhibition in circulating leukocytes and in cardiovascular tissue in rats with high angiotensin converting enzyme levels

The ROCK-ezrin signaling pathway mediates LPS-induced cytokine production in pulmonary alveolar epithelial cells

BACKGROUND

Ezrin/radixin/moesin (ERM) proteins are members of the protein 4.1 superfamily and function as linkers that connect the actin cytoskeleton to the plasma membrane of cells. ERM also play critical role in the Lipopolysaccharide (LPS)-induced inflammatory response. However, the signaling mechanisms involved in this process remain unclear. In this study, we aimed to investigate the potential role of the rho-associated coiled-coil containing protein kinase (ROCK) pathway in LPS-induced ezrin phosphorylation and cytokine production in pulmonary alveolar epithelial cells.

METHODS

Cultured A549 and HPAEpiC cells were treated with LPS. The expression and localization of ezrin in A549 and HPAEpiC cells were then analyzed by western blotting and immunoflurescence. Activation of RhoA/ROCK was assessed by western blotting and RhoA activity assays. The interaction of ezrin with Syk and myeloid differentiation factor 88 (MyD88)/IL-1R-associated kinase 1 (IRAK-1) was investigated by co-immunoprecipitation. The activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) was measured with electrophoretic mobility shift assays and by western blotting. ELISA and western blotting were performed to detect the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and high mobility group box 1 protein (HMGB1) release into the culture supernatant, and cellular HMGB1 levels.

RESULTS

LPS induced ezrin phosphorylation in a concentration- and time-dependent manner. The blockade of RhoA/ROCK inhibited LPS-induced ezrin phosphorylation and its translocation from the cytoplasm to the cell membrane. Co-immunoprecipitation assays further revealed that ezrin associated with Syk constitutively, but only associated with MyD88/IRAK-1 upon LPS challenge. Moreover, LPS-induced p38 and nuclear NF-κB activation was found to be ezrin dependent. The suppression of ezrin by siRNA or the blockade of ROCK activation with Y-27632 reduced the production of TNF-α, IL-1β, and HMGB1 in response to LPS.

CONCLUSIONS

Our findings reveal a novel regulatory mechanism involving ezrin in the LPS-induced production of pro-inflammatory cytokines, and highlight the importance of the RhoA/ROCK-ezrin/Syk-MyD88/IRAK1 axis. Data presented in this manuscript provide novel insights into the signaling pathways activated in pulmonary alveolar epithelial cells by LPS. Video Abstract.

Hydrochlorothiazide Reduces Cardiac Hypertrophy, Fibrosis and Rho-Kinase Activation in DOCA-Salt Induced Hypertension

BACKGROUND

Thiazides are one of the most common antihypertensive drugs used for hypertension treatment and hydrochlorothiazide (HCTZ) is the most frequently used diuretic for hypertension treatment. The Rho/Rho-kinase (ROCK) path plays a key function in cardiovascular remodeling. We hypothesized that in preclinical hypertension HCTZ reduces myocardial ROCK activation and consequent myocardial remodeling.

METHODS

The preclinical model of deoxycorticosterone (DOCA)-salt hypertension was used (Sprague-Dawley male rats). After 3 weeks, in 3 different groups: HCTZ, the ROCK inhibitor fasudil or spironolactone was added (3 weeks). After 6 weeks myocardial hypertrophy and fibrosis, cardiac levels of profibrotic proteins, mRNA levels (RT PCR) of pro remodeling and pro oxidative molecules and ROCK activity were determined.

RESULTS

Blood pressure, myocardial hypertrophy and fibrosis were reduced significantly by HCTZ, fasudil and spironolactone. In the heart, increased levels of the pro-fibrotic proteins Col-I, Col-III and TGF-β1 and gene expression of pro-remodeling molecules TGF-β1, CTGF, MCP-1 and PAI-1 and the pro-oxidative molecules gp91phox and p22phox were significantly reduced by HCTZ, fasudil and spironolactone. ROCK activity in the myocardium was increased by 54% (P < 0.05) as related to the sham group and HCTZ, spironolactone and fasudil, reduced ROCK activation to control levels.

CONCLUSIONS

HCTZ reduced pathologic LVH by controlling blood pressure, hypertrophy and myocardial fibrosis and by decreasing myocardial ROCK activation, expression of pro remodeling, pro fibrotic and pro oxidative genes. In hypertension, the observed effects of HCTZ on the myocardium might explain preventive outcomes of thiazides in hypertension, specifically on LVH regression and incident heart failure.

Left Cardiac Remodelling Assessed by Echocardiography Is Associated with Rho-Kinase Activation in Long-Distance Runners

This single-blind and cross-sectional study evaluated the role of Rho-kinase (ROCK) as a biomarker of the cardiovascular remodelling process assessed by echocardiography in competitive long-distance runners (LDRs) during the training period before a marathon race. Thirty-six healthy male LDRs (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V˙ O₂-peak: 56.5 ± 7.3 mL·kg^-1·min^-1) were separated into two groups according to previous training level: high-training (HT, n = 16) ≥ 100 km·week^-1 and low-training (LT, n = 20) ≥ 70 and < 100 km·week^-1. Also, twenty-one healthy nonactive subjects were included as a control group (CTR). A transthoracic echocardiography was performed and ROCK activity levels in circulating leukocytes were measured at rest (48 h without exercising) the week before the race. The HT group showed a higher left ventricular mass index (LVMi) and left atrial volume index (LAVi) than other groups (p < 0.05, for both); also, higher levels of ROCK activity were found in LDRs (HT = 6.17 ± 1.41 vs. CTR = 1.64 ± 0.66 (p < 0.01); vs. LT = 2.74 ± 0.84; (p < 0.05)). In LDRs a direct correlation between ROCK activity levels and LVMi (r = 0.83; p < 0.001), and LAVi (r = 0.70; p < 0.001) were found. In conclusion, in male competitive long-distance runners, the load of exercise implicated in marathon training is associated with ROCK activity levels and the left cardiac remodelling process assessed by echocardiography.

ROCK Inhibition as Potential Target for Treatment of Pulmonary Hypertension

Pulmonary hypertension (PH) is a cardiovascular disease caused by extensive vascular remodeling in the lungs, which ultimately leads to death in consequence of right ventricle (RV) failure. While current drugs for PH therapy address the sustained vasoconstriction, no agent effectively targets vascular cell proliferation and tissue inflammation. Rho-associated protein kinases (ROCKs) emerged in the last few decades as promising targets for PH therapy, since ROCK inhibitors demonstrated significant anti-remodeling and anti-inflammatory effects. In this review, current aspects of ROCK inhibition therapy are discussed in relation to the treatment of PH and RV dysfunction, from cell biology to preclinical and clinical studies.

Reverse Remodeling in Human Heart Failure after Cardiac Resynchronization Therapy Is Associated With Reduced RHO-Kinase Activation

Background: Reverse remodeling is a clinically relevant endpoint in heart failure with reduced ejection fraction (HFrEF). Rho-kinase (ROCK) signaling cascade activation correlates with cardiac remodeling and left ventricular (LV) systolic dysfunction in HFrEF patients. Cardiac resynchronization therapy (CRT) is effective in HFrEF, especially when there is a left bundle block, as this treatment may stimulate reverse remodeling, thereby improving quality of life and prolonging survival for patients with this severe condition. Here, we evaluate the hypothesis that ROCK activation is reduced after effective CRT in HFrEF. Methods: ROCK activation in circulating leukocytes was evaluated in 28 HFrHF patients, using Western blot (myosin light chain phosphatase subunit 1 phosphorylation, MYPT1p/t), before and three months after initiation of CRT. LV systolic function and remodeling were assessed by echocardiography. Results: Three months after CRT, LV ejection fraction increased an average of 14.5% (p < 0.001) in 13 patients (responders), while no change was observed in 15 patients (non-responders). End-systolic diameter decreased 16% (p < 0.001) in responders, with no change in non-responders. ROCK activation in PBMCs decreased 66% in responders (p < 0.05) but increased 10% in non-responders (NS). LV end-diastolic diameter was also 5.2 mm larger in non-responders vs. responders (p = 0.058). LV ejection fraction, systolic diameter, and ROCK activation levels were similar in both groups at baseline. Conclusion: In HFrEF patients, 3 months of effective CRT induced reverse myocardial remodeling, and ROCK activation was significantly decreased in circulating leukocytes. Thus, decreased ROCK activation in circulating leukocytes may reflect reverse cardiac remodeling in patients with heart failure.

Effect of Early Normotension with Olmesartan on Rho-kinase Activity in Hypertensive Patients

BACKGROUND

Angiotensin II is a potent activator of the Rho-kinase (ROCK) pathway, through which it exerts some of its adverse vasoconstrictor effects. Clinical evidence on the effects of blocking the angiotensin II receptor 1 on ROCK activity in hypertensive patients is scarce.

OBJECTIVE

To demonstrate that ROCK activity in peripheral blood mononuclear cells (PMBCs) in patients with essential hypertension is reduced earlier than previously observed, along with blood pressure (BP) lowering on treatment with olmesartan.

METHODS

Prospective pilot open study; 17 hypertensive patients were treated with progressive olmesartan doses starting with 20 mg qd. BP was measured at 3, 6 and 9 weeks after treatment initiation. If treatment failed to normalize BP after 3 weeks, olmesartan dose was increased to 40 mg qd, and if still hypertensive after 6 weeks, 12.5 mg of hydrochlorothiazide qd was added. ROCK activity was measured at baseline and 9 weeks after treatment as myosin phosphatase target subunit 1 phosphorylation (MYPT1-p/T ratio) in PBMC.

RESULTS

Mean baseline BP was 162 ± 4.9/101 ± 2.4 mmHg. After 9 weeks of treatment, both systolic and diastolic BP were reduced by 41 and 22 mmHg, respectively (p<0.05). Mean pretreatment MYPT1- p/T ratio in PMBCs was significantly reduced by 80% after 9 weeks with olmesartan (p<0.01).

CONCLUSION

Normotension achieved after 9 weeks in 82% of the patients treated with olmesartan was associated with a significant reduction of ROCK activity in PBMC.

Luteolin alleviates myocardial ischemia reperfusion injury in rats via Siti1/NLRP3/NF-κB pathway

The purpose of this study was to investigate the effects of luteolin (Lu) on myocardial ischemia-reperfusion (I/R) injury in rats. I/R model was established by ligating left anterior descending branch of coronary artery in rats. Cardiac hemodynamic measurement, myocardial infarction and damage assessment, antioxidant enzymes activities analysis, and various biochemical indexes of myocardial tissue were measured. Finally, the expression of proteins levels of Siti1/NLRP3/NF-κB pathway of myocardial tissue in rat were measured by Western Blotting. Lu obviously reduced the myocardial infarction in rats. Compared with sham group, I/R rats showed significant increase in LDH and CK-MB levels. In Lu group, LDH and CK-MB in I/R rats significantly decreased. In addition, Lu significantly reduced leukocyte infiltration compared with the sham group. On the other hand, Lu pretreatment effectively decreased the levels of cytokines in serum. The Siti1/NLRP3/NF-κBpathway in I/R group was significantly imbalance that in I/R group. Lu significantly restored the above protein changes. Lu may reduce I/R by regulation of Sirt1/NLRP3/NF-κBpathway.

Rho kinase cascade activation in circulating leukocytes in patients with diabetes mellitus type 2

Background

The intracellular ROCK signaling pathway is an important modulator of blood pressure and of cardiovascular and renal remodeling when Rho-kinase activity is increased. Besides, in preclinical models of diabetes, ROCK activation has also a role in abnormal glucose metabolism as well as in subsequent vascular and myocardial dysfunction. In humans, there are a few data assessing ROCK activation in patients with type 2 diabetes mellitus (T2D) and no studies assessing upstream/downstream components of the ROCK pathway. We assessed here levels of ROCK activation and some of the RhoA/ROCK cascade molecules in peripheral blood mononuclear cells (PBMCs) in T2D patients under current treatment.

Methods

Cross-sectional observational study comparing 28 T2D patients under current antidiabetic treatment with 31 consecutive healthy subjects, matched by age and gender. Circulating levels of malondialdehyde, angiotensin II and inflammatory cytokines IL-6 and IL-8 were determined in all subjects. ROCK activation in PMBCs, upstream and downstream cascade proteins, and levels of the proinflammatory molecules VCAM, ICAM-1 and IL-8 were determined in their PMBCs by Western blot.

Results

Compared to healthy controls, ROCK activation in T2D patients measured by 2 direct ROCK targets in PBMCs was increased by 420 and 570% (p < 0001) and it correlated significantly with serum glucose levels. p38 MAPK phosphorylation (downstream from ROCK) and JAK-2 (upstream from ROCK) were significantly higher in the T2D patients by 580% and 220%, respectively. In T2D patients, significantly increased PBMC levels of the proinflammatory molecules VCAM-1, ICAM-1 and IL-8 were observed compared to control subjects (by 180%, 360% and 260%, respectively). Circulating levels of Ang II and MDA were significantly higher in T2D patients by 29 and 63%, respectively.

Conclusions

T2D patients under treatment with glucose-lowering drugs, antihypertensive treatment as well as with statins have significantly increased ROCK activation in their circulating leukocytes along with higher phosphorylation of downstream cascade proteins despite pharmacologic treatment, along with increased plasma angiotensin II and MDA levels. ROCK inhibition might have an additional role in the prevention and treatment of T2D.

Rho-kinase pathway activation and apoptosis in circulating leucocytes in patients with heart failure with reduced ejection fraction

Background

Increased Rho‐kinase activity in circulating leucocytes is observed in heart failure with reduced ejection fraction (HFrEF). However, there is little information in HFrEF regarding other Rho‐kinase pathway components an on the relationship between Rho‐kinase and apoptosis. Here, Rho‐kinase activation levels and phosphorylation of major downstream molecules and apoptosis levels were measured for the first time both in HFrEF patients and healthy individuals.

Methods

Cross‐sectional study comparing HFrEF patients (n = 20) and healthy controls (n = 19). Rho‐kinase activity in circulating leucocytes (peripheral blood mononuclear cells, PBMCs) was determined by myosin light chain phosphatase 1 (MYPT1) and ezrin‐radixin‐moesin (ERM) phosphorylation. Rho‐kinase cascade proteins phosphorylation p38‐MAPK, myosin light chain‐2, JAK and JNK were also analysed along with apoptosis.

Results

MYPT1 and ERM phosphorylation were significantly elevated in HFrEF patients, (3.9‐ and 4.8‐fold higher than in controls, respectively). JAK phosphorylation was significantly increased by 300% over controls. Phosphorylation of downstream molecules p38‐MAPK and myosin light chain‐2 was significantly higher by 360% and 490%, respectively, while JNK phosphorylation was reduced by 60%. Catecholamine and angiotensin II levels were significantly higher in HFrEF patients, while angiotensin‐(1‐9) levels were lower. Apoptosis in circulating leucocytes was significantly increased in HFrEF patients by 2.8‐fold compared with controls and significantly correlated with Rho‐kinase activation.

Conclusion

Rho‐kinase pathway is activated in PMBCs from HFrEF patients despite optimal treatment, and it is closely associated with neurohormonal activation and with apoptosis. ROCK cascade inhibition might induce clinical benefits in HFrEF patients, and its assessment in PMBCs could be useful to evaluate reverse remodelling and disease regression.

Mangiferin Attenuates Myocardial Ischemia-Reperfusion Injury via MAPK/Nrf-2/HO-1/NF-κB In Vitro and In Vivo

The aim of this study was to investigate the cardioprotective effect of mangiferin (MAF) in vitro and in vivo. Oxidative stress and inflammatory injury were detected in coronary artery ligation in rats and also in hypoxia-reoxygenation- (H/R-) induced H9c2 cells. MAF inhibited myocardial oxidative stress and proinflammatory cytokines in rats with coronary artery occlusion. The ST segment of MAF treatment groups also resumed. Triphenyltetrazolium chloride (TTC) staining and pathological analysis showed that MAF could significantly reduce myocardial injury. In vitro data showed that MAF could improve hypoxia/reoxygenation- (H/R-) induced H9c2 cell activity. In addition, MAF could significantly reduce oxidative stress and inflammatory pathway protein expression in H/R-induced H9c2 cells. This study has clarified the protective effects of MAF on myocardial injury and also confirmed that oxidative stress and inflammation were involved in the myocardial ischemia-reperfusion injury (I/R) model.

Huang Qi Tong Bi Decoction Attenuates Myocardial Ischemia-Reperfusion Injury via HMGB1/TLR/NF-κB Pathway

The aim of this study was to study the protective effect of Huang Qi Tong Bi Decoction (HQTBT) on the heart of rats. Ischemia-reperfusion injury was established by coronary artery ligation. Proinflammatory cytokines were decreased by XFZY in coronary artery ligated rats. ST segment was also restored with the treatment of HQTBT. Triphenyltetrazole chloride (TTC) staining and pathological analysis showed that HQTBT reduced myocardial injury. Besides, the expressions of HMGB1/TLR/NF-κB pathway in rats were significantly decreased by HQTBT. This study shows that HQTBT inhibited inflammatory reaction on myocardial injury in rats.

Y-27632, a Rho-kinase inhibitor, attenuates myocardial ischemia-reperfusion injury in rats

The present study aimed to evaluate the cardioprotective effects of a Rho‑kinase inhibitor, Y‑27632, and the underlying mechanisms. A rat model of myocardial ischemia‑reperfusion (I/R) injury was generated by ligation of the coronary artery, and global ischemia of isolated rat hearts was conducted using the Langendorff system. Staining with triphenyltetrazolium chloride (TTC) and hematoxylin and eosin was performed to analyze the myocardial infarct size and histopathological alterations of the I/R‑induced rat heart. In addition, coronary flow, myocardial contractility and an electrocardiogram were analyzed. The effects of Y‑27632 on inflammatory cytokines and cardiac enzymes in the serum were assessed by ELISA. The expression of apoptosis‑ and inflammation‑associated proteins was also analyzed via western blotting. Rats in the Y‑27632 group exhibited alleviated myocardial I/R injury according to TTC staining and histopathological diagnosis. Additionally, Y‑27632 restored the ST segment. The data of coronary flow and myocardial contractility in isolated rat hearts indicated that Y‑27632 improved heart function following I/R. The levels of inflammatory cytokines and cardiac enzymes in the serum were downregulated by Y‑27632. The mitogen‑activated protein kinase (MAPK) and nuclear factor (NF)‑κB signaling pathways were inhibited by Y‑27632. Furthermore, apoptosis‑associated protein expression in rats and the isolated hearts was effectively inhibited by Y‑27632. In conclusion, the findings of the present study indicated that Y‑27632 attenuated myocardial injury via inhibiting the activation of the MAPK and NF‑κB signaling pathways; thus, apoptosis and the inflammatory response were suppressed.

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).

Curcumin attenuates myocardial ischemia-reperfusion injury

Background

Cardiovascular diseases (CVDs) are at a badly high-risk of morbidity and mortality in the world.

Methods

Our study was attempted to investigate the cardioprotective role of curcumin. Hearts injury was assessed in isolated hearts and the rats of coronary artery ligated.

Results and Conclusions

The inhibition of pro-inflammatory cytokines was observed by curcumin in coronary artery ligated rats. ST segment was also reduced by curcumin. Triphenyltetrazolium chloride staining (TTC) staining and pathological analysis were also showed that curcumin could dramatically alleviate myocardial injury. Besides, the results in vitro also demonstrated that curcumin could improved the function of isolated hearts. Besides, the expressions of inflammation-related pathway in both rats and isolated hearts treated with curcumin were significantly decreased. The present study investigated the protective effects of curcumin on myocardial injury and its mechanism.