Expression Of Rho-associated Protein Kinase Research Articles

Increased expression of Rho-associated protein kinase 2 confers astroglial Stat3 pathway activation during epileptogenesis

Patients with TLE are prone to tolerance to antiepileptic drugs. Based on the perspective of molecular targets for drug resistance, it is necessary to explore effective drug resistant genes and signaling pathways for the treatment of TLE. We performed gene expression profiles in hippocampus of patients with drug-resistant TLE and identified ROCK2 as one of the 20 most significantly increased genes in hippocampus. In vitro and in vivo experiments were performed to identify the potential role of ROCK2 in epileptogenesis. In addition, the activity of Stat3 pathway was tested in rat hippocampal tissues and primary cultured astrocytes. The expression levels of ROCK2 in the hippocampus of TLE patients were significantly increased compared with the control group, which was due to the hypomethylation of ROCK2 promoter. Fasudil, a specific Rho-kinase inhibitor, alleviated epileptic seizures in the pilocarpine rat model of TLE. Furthermore, ROCK2 activated the Stat3 pathway in pilocarpine-treated epilepsy rats, and the spearman correlation method confirmed that ROCK2 is associated with Stat3 activation in TLE patients. In addition, ROCK2 was predominantly expressed in astrocytes during epileptogenesis, and induced epileptogenesis by activating astrocyte cell cycle progression via Stat3 pathway. The overexpressed ROCK2 plays an important role in the pathogenesis of drug-resistant epilepsy. ROCK2 accelerates astrocytes cell cycle progression via the activation of Stat3 pathway likely provides the key to explaining the process of epileptogenesis.

HDAC5 inhibition reduces angiotensin II-induced vascular contraction, hypertrophy, and oxidative stress in a mouse model

Non-specific histone deacetylase (HDAC) inhibition reduces high blood pressure in essential hypertensive animal models. However, the exact HDAC isoforms that play a critical role in controlling hypertension are not known. Here, we investigated the role of HDAC5 in vascular contraction, hypertrophy, and oxidative stress in the context of angiotensin II (Ang II)-induced hypertension.Genetic deletion of HDAC5 and treatment with class IIa HDAC inhibitors (TMP269 and TMP195) prevented Ang II-induced increases in blood pressure and arterial wall thickness. Hdac5-knockout mice were also resistant to the thromboxane A2 agonist (U46619)-induced vascular contractile response. Furthermore, the expression of Rho-associated protein kinase (ROCK) 2 was downregulated in the aortas of Ang II-treated Hdac5-knockout mice. Knockdown of HDAC5, RhoA, or ROCK2 reduced collagen gel contraction, whereas silencing of ROCK1 increased it. VSMC hypertrophy reduced on knocking down HDAC5, ROCK1, and ROCK2. Here we showed that genetic deletion of HDAC5 and pharmacological inhibition of class IIa HDACs ameliorated Ang II-induced ROS generation. Moreover, ROCK1 and ROCK2, the downstream targets of HDAC5, influenced ROS generation. The relative protein levels of HDAC5, ROCK1, and ROCK2 were increased both in the cytoplasm and nuclear fraction in response to Ang II stimulation in vascular smooth muscle cells. Inhibition of HDAC5 expression or activity reduced vascular hypertrophy, vasoconstriction, and oxidative stress in the Ang II-induced hypertension model. These findings indicate that HDAC5 may serve as a potential target in the treatment of hypertension.

Role of Extracellular Calcium and Calcium Sensitization in the Anti-Contractile Effect of Perivascular Adipose Tissue in Pregnant Rat Aorta

Previous studies have shown that the anti-contractile effect of the perivascular adipose tissue (PVAT) is attenuated in pregnancy. In the present investigation, we have examined the possibility that this loss of anti-contractile effect could be due to changes in calcium mobilization. PVAT exerted anti-contractile effect against 5-hydroxytryptamine (5-HT)-induced contractions of aorta segments from pregnant and non-pregnant rats and this anti-contractile effect was attenuated in segments from pregnant rats. Nifedipine (10–6 mol/L), an inhibitor of L-type dihydropyridine calcium channels, significantly reduced 5-HT-induced contraction of aorta segments from non-pregnant and pregnant rats with and without PVAT. The inhibitory effect of nifedipine against 5-HT-induced contractions was attenuated in PVAT-free aorta segments from pregnant rats. However, while PVAT reduced the effectiveness of nifedipine in aorta segments from non-pregnant rats, it partially restored the inhibitory effect of nifedipine in aorta segments from pregnant rats. Inhibitors of calcium sensitization, Y-27632 (10–6 mol/L) and GF 109203X (10–6 mol/L), significantly reduced 5-HT-induced contractions of PVAT-free aorta segments from non-pregnant and pregnant rats. Both inhibitors, however, were less effective in aorta segments from pregnant rats. The presence of PVAT reduced the effectiveness of Y-27632 and GF 109203X in aorta segments from pregnant and non-pregnant rats. Protein expression of Rho-associated protein kinase (ROCK) I and II was detected in aorta segments and PVAT from pregnant and non-pregnant rats. There was a reduction in the expression of both isoforms in aorta segments but not PVAT from pregnant rats. In addition, there was no significant difference in the expression of ROCK-I and ROCK-II in PVAT from pregnant and non-pregnant rats. We concluded that the loss of anti-contractile effect of PVAT in aorta segments from pregnant rats could be due to increased influx of extracellular calcium through nifedipine-sensitive dihydropyridine channels.

MiR-592 suppresses the development of glioma by regulating Rho-associated protein kinase.

MicroRNAs are a class of small noncoding RNAs that regulate the translation of target mRNA transcripts. MiR-592 has been considered to play important roles in the initiation and progression of cancer by targeting various molecules in several human cancers, but its role in glioma has not been explored. This study aims to explore the suppressive mechanism of miR-592 in the regulation of glioma development, an effect that is crucial for the further exploration of miR-592 as a novel therapeutic target for glioma. Our results proved that the expression of miR-592 was lower and the expression of Rho-associated protein kinase (ROCK1) was higher in glioma tissue than in adjacent tissue and that lower miR-592 expression was associated negatively with ROCK1 expression. Then, we showed that miR-592 was downregulated in glioma and could suppress the growth of the glioma cell lines U87 and U251. ROCK1, which is a known oncogene, was identified as a direct target of miR-592. A luciferase reporter assay indicated that miR-592 regulates ROCK1 expression through binding to its 3'-UTR. Furthermore, our results showed that miR-592 targets the ROCK1 transcript and suppresses glioma cell growth and invasive growth, thereby providing a potential therapeutic target for glioma treatment.

Reduced Peripheral Blood Mononuclear Cell ROCK1 and ROCK2 Levels in Obstructive Sleep Apnea Syndrome

Background/Aim: Obstructive sleep apnea syndrome (OSAS) is associated with intermittent episodes of hypoxia, endothelial dysfunction and associated cardiovascular problems. Our aim was to investigate whether OSAS-related hypoxia alters the expression of rho-associated protein kinase (ROCK), a marker of chronic hypoxia and endothelial dysfunction. Materials and Methods: ROCK1 and ROCK2 levels were measured by immunoblotting in peripheral blood mononuclear cells (PBMC) of 47 OSAS patients and 17 healthy controls. Results: OSAS patients showed significantly lower PBMC ROCK1 and ROCK2 levels than healthy controls in the morning, but not in the evening. ROCK1/2 levels were correlated with blood triglyceride, visceral adiposity index, minimum oxygen saturation, C-reactive protein concentration, lymphocyte levels and sleep efficiency. Conclusion: Intermittent hypoxia induced by OSAS does not permanently alter ROCK protein expression levels. OSAS appears to be associated with endothelial dysfunction through inflammation and lipid metabolism pathways.

Reduced Peripheral Blood Mononuclear Cell ROCK1 and ROCK2 Levels in Obstructive Sleep Apnea Syndrome.

Obstructive sleep apnea syndrome (OSAS) is associated with intermittent episodes of hypoxia, endothelial dysfunction and associated cardiovascular problems. Our aim was to investigate whether OSAS-related hypoxia alters the expression of rho-associated protein kinase (ROCK), a marker of chronic hypoxia and endothelial dysfunction. ROCK1 and ROCK2 levels were measured by immunoblotting in peripheral blood mononuclear cells (PBMC) of 47 OSAS patients and 17 healthy controls. OSAS patients showed significantly lower PBMC ROCK1 and ROCK2 levels than healthy controls in the morning, but not in the evening. ROCK1/2 levels were correlated with blood triglyceride, visceral adiposity index, minimum oxygen saturation, C-reactive protein concentration, lymphocyte levels and sleep efficiency. Intermittent hypoxia induced by OSAS does not permanently alter ROCK protein expression levels. OSAS appears to be associated with endothelial dysfunction through inflammation and lipid metabolism pathways.

MicroRNA-148b inhibits proliferation and the epithelial-mesenchymal transition and increases radiosensitivity in non-small cell lung carcinomas by regulating ROCK1.

Non-small cell lung cancer (NSCLC) accounts for ~80% of all types of lung cancer, which has the highest morbidity and mortality of all types of cancer worldwide. It is important to identify novel biomarkers and the molecular mechanism of NSCLC to improve current treatments of NSCLC. The present study aimed to investigate the effect of miR-148b expression on the proliferation, epithelial-mesenchymal transition (EMT) and radiosensitivity of NSCLC cells. It was demonstrated that miR-148b expression was significantly decreased in NSCLC tissues and cell lines. A549 cells were then transfected with a miR-148b mimic and a miR-148b inhibitor. Transfection with the miR-148b mimic decreased proliferation whereas transfection with the miR-148b inhibitor increased the proliferation of A549 cells. Additionally, the miR-148b mimic increased E-cadherin expression and decreased N-cadherin and vimentin expression. By contrast, transfection with the miR-148b inhibitor decreased E-cadherin expression and increased N-cadherin and vimentin expression. Irradiation-induced cell death was significantly promoted by the miR-148b mimic but inhibited by the miR-148b inhibitor. The miR-148b mimic significantly decreased the expression of Rho-associated protein kinase 1 (ROCK1) and it was demonstrated that overexpression of ROCK1 significantly inhibited the effects of miR-148b on cell proliferation, the EMT and irradiation-induced cell death. Therefore, the current study revealed that miR-148b inhibited NSCLC cell proliferation and the EMT, and increased the radiosensitivity of NSCLC cells by inhibiting ROCK1 expression. Therefore, miR-148b/ROCK1 signaling may be a novel therapeutic target to inhibit the growth of NSCLC cells and enhance the effects of radiotherapy to treat patients with NSCLC.

Design and evaluation of EphrinA1 mutants with cerebral protective effect

The activation of EphA2 receptor by its natural ligand EphrinA1 causes blood brain barrier dysfunction, and inactivation of EphA2 reduces BBB damage in ischemic stroke. Thus, EphA2 targeted antagonists may serve as neuroprotective agents. We engineered four mutants of EphrinA1, EM1, EM2, EM3 and EM4, respectively. The computational analysis showed that these four mutants were capable of interacting with EphA2. Their potential neuroprotective effects were examined in mouse focal ischemia/reperfusion (I/R) model. EM2 exhibited strong neuroprotective effects, including reduced brain infarct volume, neuronal apoptosis, cerebral edema, and improved neurological scores. The EM2-mediated protection was associated with a comparative decrease in BBB leakage, inflammatory infiltration, and higher expression levels of tight junction proteins, such as zonula occludens-1 and Occludin. I/R-induced high expression of Rho-associated protein kinase 2 (ROCK2) was down-regulated after EM2 treatment. Moreover, EM2 reduced agonist doxazosin-induced EphA2 phosphorylation and cells rounding in PC3 cells, indicating EphA2-antagonizing activity of EM2. These finding provided evidences of the neuroprotection of EphA2 antagonist and a novel approach for ischemic stroke treatment. These results also suggested that a receptor agonist can be switched to an antagonist by substituting one or more relevant residues.

Effects of hydrogen on expression of ROCK1 and mDia1 in intestinal tissues of septic mice

Objective To evaluate the effects of hydrogen on the expression of Rho-associated protein kinase 1(ROCK1)and mammalian diaphanous-related formin 1(mDia1)in intestinal tissues of septic mice. Methods Ninety male C57BL/6 mice, weighing 20-25 g, aged 6 weeks, were divided into 3 groups(n=30 each)using a random number table: control group(group C), sepsis group(group S)and sepsis plus hydrogen group(group SH). Sepsis was produced by cecal ligation and puncture(CLP). Group SH inhaled 2% hydrogen for 1 h starting from 1 and 6 h after CLP.Twenty mice in each group were selected and observed for 7-day survival rate.Ten mice in each group were sacrificed at 24 h after CLP, and blood samples were obtained from hearts to measure the activity of serum diamine oxidase(DAO)and to count the colony-forming units after bacterial culture.The small intestinal samples were obtained for microscopic examination of pathological changes and for determination of ROCK1 and mDia1 positive cell rates(using immunohistochemical staining)and expression of intestinal epithelial junctional protein E-cadherin(by immunofluorescent staining). Intestinal damage was assessed and scored.The ratio of ROCK1 to mDia1 positive cell rates(ROCK1/mDia1 ratio)was calculated. Results Compared with group C, the survival rate was significantly decreased, the serum DAO activity, colony counts and intestinal damage scores were increased, ROCK1 and mDia1 positive cell rates were increased, and the expression of E-cadherin was down-regulated in S and SH groups, ROCK1/mDia1 ratio was increased in group S(P 0.05). Compared with group S, the survival rate was significantly increased, the serum DAO activity, colony counts and intestinal damage scores were decreased, the ROCK1 positive cell rate was decreased, the mDia1 positive cell rate was increased, ROCK1/mDia1 ratio was decreased, and the expression of E-cadherin was up-regulated in group SH(P<0.05). Conclusion The mechanism by which hydrogen improves intestinal barrier function may be related to down-regulation of ROCK1 expression, up-regulation of mDia1 expression and correction of the imbalance in ROCK1/mDia1 ratio in intestinal tissues of septic mice. Key words: Hydrogen; Sepsis; rho-associated kinases; rhoA GTP-binding protein; Intestinal mucosa