Urotensin-ⅡReceptor Antagonist SB-710411 Protects Rat Heart against Ischemia-Reperfusion Injury via RhoA/ROCK Pathway

EXPLORATION OF THE UROCONTRIN A SCAFFOLD YIELDS NEW UROTENSINERGIC SYSTEM ALLOSTERIC MODULATOR AND COMPETITIVE ANTAGONISTS

The urotensinergic system, involved in the development and/or progression of numerous pathological conditions, is composed of one G protein-coupled receptor (UT) and two endogenous ligands known as urotensin II (UII) and urotensin II-related peptide (URP). These two structurally related hormones, which exert common and divergent effects, are thought to play specific biological roles. In recent years, we have characterized an analog termed urocontrin A (UCA), i.e. [Pep⁴]URP, which is capable of discriminating the effects of UII from URP. Such an action could allow the delineation of the respective functions of these two endogenous ligands. In an effort to define the molecular determinants involved in this behavior and to improve the pharmacological profile of UCA, we introduced modifications from urantide, considered for some time as a lead compound for the development of UT antagonists, into UCA and assessed the binding, contractile activity and G protein signaling of these newly developed compounds. Our results show that UCA and its derivatives exert probe-dependent effects on UT antagonism, and we have further identified [Pen², Pep⁴]URP as a G_q biased ligand with an insurmountable antagonism in our aortic ring contraction assay.

Long non-coding RNA NORAD aggravates acute myocardial infarction by promoting fibrosis and apoptosis via miR-577/COBLL1 axis

Acute myocardial infarction (AMI) is one of the most common and serious cardiovascular diseases. With high morbidity and mortality, AMI has attracted the most attention. Emerging studies indicated that long noncoding RNAs (lncRNAs) play an important role in the progression of AMI. However, the role of NORAD in AMI remained unclear. The current study aimed to investigate the function and mechanism of NORAD in AMI. Bioinformatics tools and a wide range of assays including RT-qPCR, flow cytometry, TTC staining, western blot, luciferase reporter and caspase-3 activity assays were conducted to investigate the function and mechanism of NORAD in AMI. We found out that NORAD was significantly upregulated in AMI rats. Knockdown of NORAD alleviated H9c2 cell injury by reducing apoptosis and decreasing expression levels of fibrogenic factors. In addition, NORAD inhibition ameliorated AMI in a rat model by decreasing infarct size and fibrosis. We confirmed that NORAD bound to miR-577, which was downregulated in ischemia-reperfusion (I/R) rats and hypoxia-exposed H9c2 cells. Additionally, miR-577 combined with the 3'UTR of COBLL1, which was upregulated in I/R rats and hypoxia-exposed H9c2 cells. At last, rescue assay validated that the suppressive effects of NORAD knockdown on apoptosis and expression levels of fibrogenic factors were counteracted by COBLL1 overexpression. Overall, NORAD aggravates acute myocardial infarction by promoting fibrosis and apoptosis via the miR-577/COBLL1 axis. This novel discovery suggested that NORAD may serve as a potential therapeutic target for AMI patients.

MiR-467a-5p aggravates myocardial infarction by modulating ZEB1 expression in mice

Myocardial infarction (MI) is a great threat to patients all over the word. MicroRNAs (miRNAs) are a group of non-coding RNAs and can regulate initiation and progression of MI. The current research aimed to investigate the role of miR-467a-5p in MI. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to detective relative expression of miR-467a-5p in cardiac tissues and mouse cardiomyocytes (MCMs). Hematoxylin and eosin staining was used to reveal the histology of the myocardium. Echocardiography was utilized to reveal cardiac function of mice. Flow cytometer analysis was used to reveal cell apoptosis. Luciferase reporter assay was applied for determining the binding capacity between molecules. We discovered that the level of miR-467a-5p was up-regulated in MI mice and in MCMs induced by H₂O₂ or hypoxia. Functionally, an elevation of left ventricular end-diastolic diameter and left ventricular end-systolic diameter, as well as a decrease of left ventricular ejection fraction and left ventricular fractional shortening were observed in MI mice. In addition, deficiency of miR-467a-5p improved MI in mice by increasing the contents of lactate dehydrogenase, creatine kinase and malondialdehyde and reducing the activity of superoxide dismutase in serum. Moreover, silencing of miR-467a-5p reversed hypoxia-induced apoptosis of MCMs. Mechanistically, zinc finger E-box binding homeobox 1 (ZEB1) was confirmed as the target of miR-467a-5p. Moreover, miR-467a-5p negatively regulated ZEB1 level in MI mice and MCMs. Finally, the promotive effect of miR-467a-5p inhibition on cell apoptosis was reversed by knockdown of ZEB1. All the experimental results demonstrate that miR-467a-5p aggravates MI by modulating ZEB1 expression in mice, which may provide a novel therapeutic strategy for MI.

Electroacupuncture Pretreatment Regulates Apoptosis of Myocardial Ischemia-Reperfusion Injury in Rats Through RhoA/p38MAPK Pathway Mediated by miR-133a-5p

The electroacupuncture (EA) pretreatment possesses a beneficial effect on myocardial ischemia/reperfusion (I/R) injury. However, the molecular mechanism of the EA effect is not fully understood. The study aimed to explore the protective effect of EA pretreatment on myocardial ischemia-reperfusion injury (MIRI) and apoptosis-related mechanisms in rats. Rats underwent in vivo myocardial ischemia-reperfusion, EA pretreatment, or intravenous injection of antagomirs. Cardiac function, infarct area, and myocardial cell apoptosis were measured. Meanwhile, the expressions of MKK3, MKK6, p38MAPK, Bax, Bcl-2, and Caspase-3 were also detected. We found that EA pretreatment significantly reduced infarct area and myocarpal cell apoptosis and enhanced cardiac function. EA pretreatment decreased the expression of Bax, Caspase-3, MKK3, MKK6, p38MAPK, Bax, and Caspase-3. In conclusion, The EA pretreatment down regulated the expression of MKK3, MKK6, and p38MAPK through the RhoA/p38MAPK pathway. EA pretreatment protect MIRI rats from apoptosis by down regulating the expression of MKK3, MKK6, and p38MAPK, thereby reducing the expression of Bax, Caspase-3 and up regulating the expression of Bcl-2, which mechanism is closely related to the RhoA/p38MAPK pathway mediated by miR-133a-5p.

The peptide compound urantide regulates collagen metabolism in atherosclerotic rat hearts and inhibits the JAK2/STAT3 pathway

The aim of the present study was to investigate the effect of urantide on collagen metabolism in the hearts of rats with atherosclerosis (AS) by evaluating the expression of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway constituents. Urantide was delivered to rats with AS via tail vein injection for 3, 7 and 14 days. Serological indicators were identified by an automated biochemical analyzer. Histomorphological changes in the cardiac tissue of rats were observed by pathological staining techniques. The expression of genes and proteins was assessed using reverse transcription-quantitative PCR and western blot analysis, respectively. Localization of proteins was detected by immunofluorescence. Overexpression of urotensin II (UII) and its receptor, G protein-coupled receptor 14 (GPR14), was observed in the hearts of rats with AS and the expression of both proteins significantly declined after urantide administration. Triglyceride, total cholesterol, low-density lipoprotein, high-density lipoprotein and calcium levels were improved in rats with AS following treatment with urantide. Notably, urantide was able to antagonize the UII/GPR14 system. Urantide treatment resulted in markedly decreased expression levels of matrix metalloproteinase 2 (MMP-2), collagen type I/III, and genes and proteins in the JAK2/STAT3 pathway. By contrast, TIMP metallopeptidase inhibitor 2 (TIMP-2) levels were increased. In addition, the MMP-2/TIMP-2 protein ratio was significantly decreased in rats treated with urantide compared with AS rats with no urantide treatment. Constituents of the JAK2/STAT3 pathway and collagen type I/III were found to be localized in the diseased tissue and blood vessels of the hearts of rats with AS. In conclusion, urantide was able to effectively block the UII/GPR14 system by regulating the JAK2/STAT3 pathway and collagen metabolism. Inhibition of the UII/GPR14 system may prevent and potentially treat atherosclerotic myocardial fibrosis. Based on the current results, it was hypothesized that collagen metabolism may be associated with the JAK2/STAT3 pathway.

Urotensin-#receptor antagonist SB-706375 protected isolated rat heart from ischaemia-reperfusion injury by attenuating myocardial necrosis via RhoA/ROCK/RIP3 signalling pathway

SB-706375 is a selective receptor antagonist of human urotensin-II (hU-II), which can block the aorta contraction induced by hU-II in rats. The effect of SB-706375 on myocardial ischaemia-reperfusion (I/R) injury is unclear. The major objective of this study was to investigate whether SB-706375 has a protective effect on myocardial I/R injury in rats and explore its possible mechanisms. Isolated hearts of Adult Sprague-Dawley were perfused in a Langendorff apparatus, and haemodynamic parameters, lactate dehydrogenase (LDH), creatine phosphokinase-MB (CK-MB), cardiac troponin I (cTnI), RhoA, and the protein expressions of U-II receptor (UTR), receptor-interacting protein 3 (RIP3), Rho-associated coiled-coil-containing protein kinase 1 (ROCK1) and Rho-associated coiled-coil-containing protein kinase 2 (ROCK2) were assessed. We found that SB-706375 (1 × 10-6 and 1 × 10-5 mol/L) significantly inhibited the changes of haemodynamic parameters and reduced LDH and CK-MB activities and also cTnI level in the coronary effluents in the heart subjected to myocardial I/R injury. Further experiments studies showed that SB-706375 obviously prevented myocardial I/R increased RhoA activity and UTR, RIP3, ROCK1, and ROCK2 protein expressions. ROCK inhibition abolished the improving effect of SB-706375 on myocardial I/R-induced haemodynamic change in the isolated perfused rat heart. These findings suggested that SB-706375 provides cardio-protection against I/R injury in isolated rats by blocking UTR-RhoA/ROCK-RIP3 pathway.

Upregulation of miR-93 and inhibition of LIMK1 improve ventricular remodeling and alleviate cardiac dysfunction in rats with chronic heart failure by inhibiting RhoA/ROCK signaling pathway activation

Objective: There are some researches about the role of microRNA (miRNA) in chronic heart failure (CHF) were performed, but the study about miR-93’s function in CHF is scarcely investigated. Thus, we determined to probe into the effects of miR-93 in rats with CHF by targeting LIMK1 through regulating RhoA/ROCK pathway.

Results: We found increased LIMK1 and decreased miR-93 in CHF rats, and up-regulation of miR-93 inhibited LIMK1, RhoA and ROCK1 expression in CHF rats. Up-regulation of miR-93 or inhibition of LIMK1 decreased oxidative stress, inflammatory factors, as well as apoptosis-related indicators in CHF rats. LIMK1 was confirmed as a direct target gene of miR-93.

Conclusion: Our study provides evidence that upregulated miR-93 and downregulated LIMK1 improve ventricular remodeling and reduce cardiac dysfunction in CHF rats by inhibiting RhoA/ROCK signaling pathway activation.

Methods: First, rat models of CHF were established by aortic coarctation, and the rats were injected with miR-93 mimics, LIMK1-siRNA or overexpressed-LIMK1. Then expression of miR-93, LIMK1, RhoA, and ROCK1 expression in myocardial tissues were detected, after which indices of cardiac ultrasound, hemodynamics, and oxidative stress, inflammatory factors, apoptosis-related indicators were detected via a series of assays. Finally, the targeting relationship of miR-93 and LIMK1 was verified.

MicroRNA-325-3p protects the heart after myocardial infarction by inhibiting RIPK3 and programmed necrosis in mice

BACKGROUND

Receptor-interacting serine-threonine kinase 3 (RIPK3)-mediated necroptosis has been implicated in the progression of myocardial infarction (MI), but the underlying mechanisms, particularly whether microRNAs (miRNAs) are involved, remain largely unknown.

RESULTS

A microarray analysis was used to screen for miR-325-3p expression in myocardial tissues from MI mice, and the expression was confirmed with qRT-PCR. The levels of myocardial enzymes were measured using commercial kits, and an echocardiography system was utilized for the detection of cardiac function parameters. The pathological features and infarction sizes of cardiac tissues were examined using H&E, TCC and Masson's trichrome staining, and the amount of cell apoptosis was determined using an in situ TUNEL assay. Cardiomyocytes were isolated and then subjected to hypoxia induction in vitro. The expression of the RIPK1, RIPK3 and phosphorylated MLKL (p-MLKL) proteins was measured using a Western blot. The mouse cardiomyocyte cell viability was analyzed by an MTT assay. The mRNA target of miR-325-3p was predicted using TargetScan v7.2 and then validated using a dual-luciferase reporter assay. The overexpression of miR-325-3p evidently decreased the expression levels of lactate dehydrogenase (LDH), phosphocreatine kinase (CK), superoxide dismutase (SOD) and malondialdehyde (MDA), inhibited left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD), and promoted left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVES). In addition, miR-325-3p overexpression attenuated the degree of injury to the cardiac tissue, decreased the infarct sizes and downregulated the expression of the necrosis-related proteins RIPK1, RIPK3 and p-MLKL.

CONCLUSIONS

The RIPK1/RIPK3/p-MLKL axis-induced necroptosis that occurred during MI was mediated by a miRNA module, miR-325-3p, which can effectively ameliorate the symptoms of MI by suppressing the expression of RIPK3.

Oxygen-Glucose Deprivation/Reoxygenation Induces Human Brain Microvascular Endothelial Cell Hyperpermeability Via VE-Cadherin Internalization: Roles of RhoA/ROCK2

The destruction of the blood-brain barrier (BBB) contributes to a spectrum of neurological diseases such as stroke, and the hyperpermeability of endothelial cells is one of the characters of stroke, which is possibly exacerbated after reperfusion. However, the underlying mechanisms involving hyperpermeability after reperfusion between the endothelial cells remain poorly understood. Therefore, in the present study, the human microvascular endothelial cells (HBMECs) were exposed to oxygen-glucose deprivation/reperfusion (OGD/R) to mimic ischemic stroke condition in vitro with the aim to investigate the potential mechanisms induced by OGD/R. The permeability of cultured HBMECs was measured using FITC-labeled dextran in a Transwell system and transendothelial electrical resistance (TEER), while the RhoA activity was detected by pull-down assay. In addition, the phosphorylation of MYPT1, which reflects the activation of ROCK and the internalization of VE-cadherin, was detected by Western blot. It showed that OGD/R treatment significantly increased the permeability of HBMEC monolayers and facilitated the internalization of VE-cadherin in HBMEC monolayers. Pull-down assay showed that RhoA activation was obviously enhanced after OGD/R treatment, while RhoA and ROCK inhibitor significantly reversed OGD/R-induced HBMEC monolayers hyperpermeability and the internalization of VE-cadherin. Meanwhile, the knockdown assay showed that RhoA small interfering RNA (siRNA) led to similar effects. The inactivation of the downstream effector protein ROCK was also examined. Intriguingly, ROCK2 rather than ROCK1 exerted its adverse effects on HBMEC monolayer integrity, since ROCK2 knockdown markedly reverses the injury of OGD/R in HBMEC monolayers. In conclusion, the present study provides evidence that OGD/R may induce HBMEC monolayer hyperpermeability via RhoA/ROCK2-mediated VE-cadherin internalization, which may provide an impetus for the development of therapeutics targeting BBB damage in ischemic stroke.

Role of CSE-Produced H2S on Cerebrovascular Relaxation via RhoA-ROCK Inhibition and Cerebral Ischemia-Reperfusion Injury in Mice

The role of CSE-produced H₂S on cerebrovascular relaxation and cerebral ischemia-reperfusion (I/R) injury was investigated using CSE knockout (CSE^-/-) and wild-type (CSE^+/+) mice. The relaxation of the cerebral basilar artery (BA) to CSE-produced H₂S and its mechanism were detected. The results revealed that both NaHS, a donor of exogenous H₂S, and ROCK inhibitor Y27632 could induce significant relaxation of the BA, but the relaxation of the BA to NaHS was significantly attenuated by Y27632. In addition, removal of endothelium could reduce the relaxation of the BA to Y27632; CSE knockout also significantly attenuated Y27632-induced BA relaxation with endothelium rather than without endothelium. By contrast, the contraction of the BA from CSE^-/- mice to RhoA agonist LPA or U₄₆₆₁₉ was stronger than that from CSE^+/+ mice. Furthermore, RhoA activity and ROCK protein expression remarkably increased in the BA vascular smooth muscle cells (VSMCs) from CSE^-/- mouse, which were inhibited by NaHS pretreatment. These findings revealed that the CSE-produced H₂S induced cerebrovascular relaxation is generated from endothelial cells and the mechanism of vascular relaxation may relate to inhibition of RhoA-ROCK pathway. We next sought to confirm the protective effect of CSE-produced H₂S on cerebral I/R injury produced by middle cerebral artery occlusion and bilateral common carotid artery occlusion in mice. We investigated the changes of neurological deficit, cerebral infarct, brain water content, LDH decrease, MDA increase as well as impairment of learning and memory function. The results showed that the cerebral injury became more grievous in CSE^-/-mice than that in CSE^+/+mice, which could be remarkably alleviated by NaHS pretreatment.

Total flavones of Rhododendron simsii Planch flower protect isolated rat heart from ischaemia-reperfusion injury and its mechanism of UTR-RhoA-ROCK pathway inhibition

Objectives

Total flavones of Rhododendron simsii Planch flower (TFR) are an effective part extracted from the flower. The present study was designed to investigate the protective effect of TFR in isolated rat heart following global ischaemia-reperfusion and the possible underlying mechanisms.

Methods

Langendorff perfusion apparatus was used to perfuse isolated rat heart which was subjected to global ischaemia-reperfusion. The hemodynamic parameters were continuously monitored. Coronary flow as well as lactate dehydrogenase (LDH), creatine phosphokinase-MB (CK-MB) and cardiac troponin I (cTnI) in coronary effluents was measured. RhoA activity and urotensin receptor (UTR) and Rho-related coiled-coil-forming protein kinase (ROCK) protein expressions in rat myocardium were examined, respectively. Cardiac dysfunction was indicated by the alterations of hemodynamic parameters and the reduced coronary flow.

Key findings

Total flavones of Rhododendron simsii Planch flower significantly improved ischaemia-reperfusion–induced cardiac dysfunction and leakages of LDH, CK-MB and cTnI, and inhibited myocardial ischaemia-reperfusion–increased RhoA activity and UTR, ROCK1 and ROCK2 protein expressions. The improvement of TFR in the cardiac dysfunction and the leakage of LDH, CK-MB and cTnI were markedly attenuated under the UTR blockade and ROCK inhibition. TFR-inhibited RhoA activity was decreased under the UTR blockade.

Conclusions

Total flavones of Rhododendron simsii Planch flower had a protective effect on ischaemia-reperfusion injury in isolated rat heart, which may be attributed to the blocking of UTR and subsequent inhibition of the RhoA-ROCK pathway.

The Multivariate Regression Statistics Strategy to Investigate Content-Effect Correlation of Multiple Components in Traditional Chinese Medicine Based on a Partial Least Squares Method

Amultivariate regression statisticstrategy was developed to clarify multi-components content-effect correlation ofpanaxginseng saponins extract and predict the pharmacological effect by components content. In example 1, firstly, we compared pharmacological effects between panax ginseng saponins extract and individual saponin combinations. Secondly, we examined the anti-platelet aggregation effect in seven different saponin combinations of ginsenoside Rb1, Rg1, Rh, Rd, Ra3 and notoginsenoside R1. Finally, the correlation between anti-platelet aggregation and the content of multiple components was analyzed by a partial least squares algorithm. In example 2, firstly, 18 common peaks were identified in ten different batches of panax ginseng saponins extracts from different origins. Then, we investigated the anti-myocardial ischemia reperfusion injury effects of the ten different panax ginseng saponins extracts. Finally, the correlation between the fingerprints and the cardioprotective effects was analyzed by a partial least squares algorithm. Both in example 1 and 2, the relationship between the components content and pharmacological effect was modeled well by the partial least squares regression equations. Importantly, the predicted effect curve was close to the observed data of dot marked on the partial least squares regression model. This study has given evidences that themulti-component content is a promising information for predicting the pharmacological effects of traditional Chinese medicine.

Silymarin ameliorates expression of urotensin II (U-II) and its receptor (UTR) and attenuates toxic oxidative stress in the heart of rats with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD). Urotensin II ((U-II)) and its receptor (UTR) are involved in the progression of CVD through enhancement in the production of reactive oxygen species (ROS). Since silymarin (SMN) is a natural agent with anti-diabetic effects, this study aimed to investigate the antioxidant potency of SMN on the expression of (U-II)/UTR system and oxidative stress status in the heart of type 2 diabetic rats. Thirty-six male Wistar rats were randomly divided into six groups (n = 6). Control and diabetic groups treated with or without SMN (60 and 120 mg/kg/day) for 2 months. Fasting blood sugar (FBS), insulin, lipid profile, creatine kinase-MB ((CK-MB)), lactate dehydrogenase (LDH) and markers of oxidative stress were measured by spectrophotometric methods while (U-II) and UTR gene expression was determined by qPCR method. SMN significantly reduced the FBS level, increased the concentration of insulin and improved HOMA-IR. SMN prevented diabetes-induced weight loss, and attenuated the increased levels of total oxidative status (TOS), malondialdehyde (MDA), and nitric oxide (NO). Diabetes-induced reduction of total thiol molecules content (TTM) was normalized to the normal level in SMN treated rats. SMN significantly modulated serum lipid profile, reduced the expression of (U-II) and UTR in the heart, and improved histopathological changes in the heart tissues. Therefore, the current study indicated that SMN ameliorated unpleasant diabetic characteristics via down-regulation of (U-II) and UTR gene expression and modulation of oxidative stress in the heart tissue of type 2 diabetic rats.

The Protective Effect of Total Flavones from Rhododendron simsii Planch. on Myocardial Ischemia/Reperfusion Injury and Its Underlying Mechanism

Objectives

Total flavones from Rhododendron simsii Planch. (TFR) are the effective part extracted from the flowers of Rhododendron simsii Planch. and have obvious protective effects against cerebral ischemic or myocardial injuries in rabbits and rats. However, their mechanism of cardioprotection is still unrevealed. Therefore, the present study was designed to investigate the effect of TFR on myocardial I/R injury and the underlying mechanism.

Methods

TFR groups were treated by gavage once a day for 3 days at a dose of 20, 40, and 80 mg/kg, respectively, and then the model of myocardial I/R injury was established. Myocardial infarction, ST-segment elevation, and the expression of UTR, ROCK1, ROCK2, and p-MLC protein in rat myocardium were determined at 90 min after reperfusion. UTR siRNA in vivo transfection and competition binding assay method were used to study the relationship between the protective effect of TFR and UTR.

Results

The expression of UTR protein markedly decreased in myocardium of UTR siRNA transfection group rats. TFR could significantly reduce the infarct size and inhibit the increase of RhoA activity and ROCK1, ROCK2, and p-MLC protein expressions both in WT and UTR knockdown rats. The reducing rate of TFR in myocardial infarction area, RhoA activity, and ROCK1, ROCK2, and p-MLC protein expressions in UTR knockdown rats decreased markedly compared with that in WT rats. In addition, TFR had no obvious effect on the increase of ΣST in UTR knockdown rats in comparison with that in model group. In particular, TFR could significantly inhibit the combination of [¹²⁵I]-hu-II and UTR, and IC₅₀ was 0.854 mg/l.

Conclusions

The results indicate that the protective effect of TFR on I/R injury may be correlated with its blocking UTR and the subsequent inhibition of RhoA/ROCK signaling pathway.

Fasudil attenuates soluble fms-like tyrosine kinase-1 (sFlt-1)-induced hypertension in pregnant mice through RhoA/ROCK pathway

Preeclampsia (PE) has become the leading cause of maternal and fetal morbidity and mortality in the world, which is characterized by a systemic maternal inflammatory response associated with endothelial dysfunction, hypertension, and proteinuria. The development of PE is still barely predictable and thus challenging to prevent and manage clinically. Fasudil (FSD), the first-generation Rho/ROCK inhibitor, has been studied widely and applied in clinical practice with high safety and efficacy in treating hypertension and other cardiovascular diseases. However, few studies have focused on the effect of fasudil on preeclampsia in vivo and in vitro. Therefore, the aim of this study is to investigate the effects of fasudil on hypoxia/reoxygenation injury in vitro and its role on preeclamptic animal model. Here, we found that RhoA/ROCK pathway was significantly activated in H/R-challenged endothelial cells and in placenta and umbilical vessel of PE mice. And fasudil pre-treatment can protect vascular endothelial cells from H/R-induced apoptosis. In addition, inhibition of RhoA/ROCK pathway with fasudil can reduce the high blood pressure and urine protein levels as well as the concentration of s-Flt in peripheral and umbilical blood in a dose-dependent manner, thus resulting in prevention of the development of PE. Thus, Fasudil attenuates soluble fms-like tyrosine kinase-1 (sFlt-1)-induced hypertension in pregnant mice through RhoA/ROCK pathway, which would become a potential strategy for PE therapy.

Effects of Total Flavone from Rhododendron simsii Planch. Flower on Postischemic Cardiac Dysfunction and Cardiac Remodeling in Rats

This study investigated the effect of total flavone from Rhododendron simsii Planch. flower (TFR) on postischemic cardiac dysfunction and ventricular remodeling and was to test the hypothesis that TFR has an antiventricular remodeling effect through inhibition of urotensin-II receptor- (UTR-) mediated activation of RhoA-ROCK pathways. Twenty-four hours after ligation of the left anterior descending coronary artery, male Sprague-Dawley rats were randomized to receive 4-week treatment with saline (model group) or TFR. Compared to the model group, TFR treatment restored cardiac function, attenuated cardiomyocyte hypertrophy, and reduced interstitial fibrosis. Expression levels of several fibrosis-related factors, including alpha-smooth muscle actin, transforming growth factor-beta 1, matrix metalloproteinase-2, and collagen type I, were increased after MI. TFR treatment attenuated the upregulation of these factors, downregulated UTR expression, and markedly diminished the expression of RhoA and ROCK1/2. These results suggested that TFR could improve cardiac function and ameliorate ventricular remodeling through blocking UTR-mediated activation of RhoA-ROCK pathways in myocardial infarction rats.

Effect of QSKL on MAPK and RhoA Pathways in a Rat Model of Heart Failure

Qishenkeli (QSKL) is one of the Chinese medicine formulae for treating heart failure and has been shown to have an antifibrotic effect. However, the mechanism of its therapeutic effects remains unclear. In this study, we aimed to explore whether QSKL could exert an antifibrotic effect by attenuating ras homolog family member A (RhoA) and mitogen activated protein kinase (MAPK) pathways. Rats were randomly divided into sham group, model group, QSKL group, and positive control group. Heart failure was induced by ligation of the left ventricle anterior descending artery. Cardiac functions were measured by echocardiography and collagen deposition was assessed by Masson staining. Expressions of the key molecules involved in the RhoA and MAPK pathways were also measured. Twenty-one days after surgery, cardiac functions were severely impaired and collagen deposition was remarkable, while QSKL treatment could improve heart functions and alleviate collagen deposition. Further results demonstrated that the effects may be mediated by suppressing expressions of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). Moreover, expressions of RhoA, Rho-associated protein kinase 1/2 (ROCK1/2), and phosphorylated myosin light chain (p-MLC) were also downregulated by QSKL compared with the model group. The cardioprotective mechanism of QSKL on heart failure is probably mediated by regulating both the MAPK and RhoA signaling pathways.