Rho-kinase as a therapeutic target in vascular diseases: striking nitric oxide signaling

ROCK inhibitor fasudil reduces the expression of inflammatory factors in LPS-induced rat pulmonary microvascular endothelial cells via ROS/NF-κB pathway

Background

Inflammation plays a major role in the pulmonary artery hypertension (PAH) and the acute lung injury (ALI) diseases. The common feature of these complications is the dysfunction of pulmonary microvascular endothelial cells (PMVECs). Fasudil, the only Rho kinase (ROCK) inhibitor used in clinic, has been proved to be the most promising new drug for the treatment of PAH, with some anti-inflammatory activity. Therefore, in the present study, the effect of fasudil on lipopolysaccharide (LPS)-induced inflammatory injury in rat PMVECs was investigated.

Methods

LPS was used to make inflammatory injury model of rat PMVECs. Thereafter, the mRNA and protein expression of pro-inflammatory factors was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) assay respectively. Intracellular reactive oxygen species (ROS) levels were measured by the confocal laser scanning system. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of malondialdehyde (MDA) were determined by using commercial kits according to the manufacturer’s instructions. Western blot assay was used to detect the protein expression of nuclear factor kappa B (NF-κB) p65.

Results

Fasudil effectively prevented inflammatory injury induced by LPS, which is manifested by the decrease of pro-inflammatory cytokines interleukin-6 (IL-6) and monocyte chenotactic protein-1 (MCP-1). Meanwhile, fasudil dramatically reduced the levels of ROS and MDA, and also elevated the activities of SOD and GSH-Px. Furthermore, the nuclear translocation of NF-κB p65 induced by LPS was also suppressed by fasudil. Additionally, the ROS scavengers N-Acetylcysteine (N-Ace) was also found to inhibit the nuclear translocation of NF-κB and the mRNA expression of IL-6 and MCP-1 induced by LPS, which suggested that ROS was essential for the nuclear translocation of NF-κB.

Conclusions

The present study revealed that fasudil reduced the expression of inflammatory factors, alleviated the inflammatory and oxidative damage induced by LPS in rat PMVECs via ROS-NF-κB signaling pathway.

Uncaria Rhynchophylla attenuates angiotensin Ⅱ-induced myocardial fibrosis via suppression of the RhoA/ROCK1 pathway

Uncaria rhynchophylla (UR), a traditional Chinese medicine, has been proven effective in treating hypertensive patients in China. However, the mechanisms of action of UR in reducing hypertension and myocardial fibrosis are still unclear. The purpose of this study was to explore the role of UR in an angiotensin Ⅱ (Ang Ⅱ) induced mouse model. The mice were randomly divided into 5 groups and infused with Ang Ⅱ (500 ng/kg/min) or saline, then administered UR (0.78, 1.56 or 3.12 g/kg/d) or saline for 4 weeks. UR treatment significantly attenuated the elevation of blood pressure caused by Ang Ⅱ. It enhanced myocardial function and attenuated the increase in the heart weight index and the pathological changes in the Ang Ⅱ-induced hypertensive mice. Furthermore, UR treatment inhibited cardiac fibrosis and significantly down-regulated collagen I, collagen Ⅲ, and α-SMA protein expression in cardiac tissues. UR also attenuated the expression of RhoA, ROCK1, CTGF, and TGF-β1. In cultured cardiac fibroblasts stimulated with Ang Ⅱ, UR significantly down-regulated the expression of Collagen I, Collagen III, RhoA, ROCK1, and α-SMA. In summary, UR can significantly attenuate Ang Ⅱ-induced hypertension and cardiac fibrosis, partly via suppression of the RhoA/ROCK1 signaling pathway.

A computational model of mutual antagonism in the mechano-signaling network of RhoA and nitric oxide

BACKGROUND

RhoA is a master regulator of cytoskeletal contractility, while nitric oxide (NO) is a master regulator of relaxation, e.g., vasodilation. There are multiple forms of cross-talk between the RhoA/ROCK pathway and the eNOS/NO/cGMP pathway, but previous work has not studied their interplay at a systems level. Literature review suggests that the majority of their cross-talk interactions are antagonistic, which motivates us to ask whether the RhoA and NO pathways exhibit mutual antagonism in vitro, and if so, to seek the theoretical implications of their mutual antagonism.

RESULTS

Experiments found mutual antagonism between RhoA and NO in epithelial cells. Since mutual antagonism is a common motif for bistability, we sought to explore through theoretical simulations whether the RhoA-NO network is capable of bistability. Qualitative modeling showed that there are parameters that can cause bistable switching in the RhoA-NO network, and that the robustness of the bistability would be increased by positive feedback between RhoA and mechanical tension.

CONCLUSIONS

We conclude that the RhoA-NO bistability is robust enough in silico to warrant the investment of further experimental testing. Tension-dependent bistability has the potential to create sharp concentration gradients, which could contribute to the localization and self-organization of signaling domains during cytoskeletal remodeling and cell migration.

Chemo-informatics guided study of natural inhibitors targeting rho GTPase: a lead for treatment of glaucoma

Glaucoma, the most perilous disease leading to blindness is a result of optical neuropathy. Accumulation of aqueous humor in the posterior chamber due to a large difference in the rate of formation and its drainage in the anterior chamber causes an increase in intraocular pressure (IOP) leading to damage of nerve cells. A literature survey has revealed that inhibition of the Rho guanosine triphosphatases (rho GTPase) pathway by specific inhibitors leads to the relaxation of contractile cells involved in the aqueous outflow pathway. Relaxation of the strained contractile cells results in increased outflow thereby releasing IOP. In the present study molecular docking has been used to screen twenty seven bioactive (17 natural compounds and 10 conventional drugs) compounds that may play a significant role in relaxing contractile cells by inhibiting rho-GTPase protein. Docking results showed that among all-natural bioactive compounds Cyanidin and Delphinidine have a good binding affinity (- 8.4 kcal/mol) than the top screened conventional drug molecule Mitomycin, (- 6.3 kcal/mol) when docked with rho-GTPase protein. Cyanidin and Delphinidin belong to anthocyanidin, a glycoside form of anthocyanins from Vaccinium myrtillus L. and Punica granatum. The resembling potential of Cyanidin and Delphinidin concerning the drug Mitomycin was confirmed through simulation analysis. Molecular dynamics study (MDS) for 100 ns, showed that the rho GTPase-Delphinidine complex structure was energetically more stable than rho GTPase-Cyaniding complex in comparison to rho GTPase-Mitomycin complex. The comparative study of both the selected hits (Cyanidin and Delphinidin) was assessed by RMSD, RMSF, Rg, SASA, H-bond, PCA MM/PBSA analysis. The analysis revealed that Delphinidine is more potent to inhibit the rho GTPase as compare to Cyaniding and available conventional drugs in terms of stability and binding free energy. Based on the results, these molecules have good pharmacokinetic and pharmacodynamics properties and will prove to be a promising lead compound as a future drug for Glaucoma.

The Involvement of the RhoA/ROCK Signaling Pathway in Hypersensitivity Reactions Induced by Paclitaxel Injection

A high incidence of hypersensitivity reactions (HSRs) largely limits the use of paclitaxel injection. Currently, these reactions are considered to be mediated by histamine release and complement activation. However, the evidence is insufficient and the molecular mechanism involved in paclitaxel injection-induced HSRs is still incompletely understood. In this study, a mice model mimicking vascular hyperpermeability was applied. The vascular leakage induced merely by excipients (polyoxyl 35 castor oil) was equivalent to the reactions evoked by paclitaxel injection under the same conditions. Treatment with paclitaxel injection could cause rapid histamine release. The vascular exudation was dramatically inhibited by pretreatment with a histamine antagonist. No significant change in paclitaxel injection-induced HSRs was observed in complement-deficient and complement-depleted mice. The RhoA/ROCK signaling pathway was activated by paclitaxel injection. Moreover, the ROCK inhibitor showed a protective effect on vascular leakage in the ears and on inflammation in the lungs. In conclusion, this study provided a suitable mice model for investigating the HSRs characterized by vascular hyperpermeability and confirmed the main sensitization of excipients in paclitaxel injection. Histamine release and RhoA/ROCK pathway activation, rather than complement activation, played an important role in paclitaxel injection-induced HSRs. Furthermore, the ROCK inhibitor may provide a potential preventive approach for paclitaxel injection side effects.

Vascular Endothelial (VE)-Cadherin, Endothelial Adherens Junctions, and Vascular Disease

Endothelial cell-cell adherens junctions (AJs) supervise fundamental vascular functions, such as the control of permeability and transmigration of circulating leukocytes, and the maintenance of existing vessels and formation of new ones. These processes are often dysregulated in pathologies. However, the evidence that links dysfunction of endothelial AJs to human pathologies is mostly correlative. In this review, we present an update of the molecular organization of AJ complexes in endothelial cells (ECs) that is mainly based on observations from experimental models. Furthermore, we report in detail on a human pathology, cerebral cavernous malformation (CCM), which is initiated by loss-of-function mutations in the genes that encode the three cytoplasmic components of AJs (CCM1, CCM2, and CCM3). At present, these represent a unique example of mutations in components of endothelial AJs that cause human disease. We describe also how studies into the defects of AJs in CCM are shedding light on the crucial regulatory mechanisms and signaling activities of these endothelial structures. Although these observations are specific for CCM, they support the concept that dysfunction of endothelial AJs can directly contribute to human pathologies.

Fasudil inhibits neutrophil-endothelial cell interactions by regulating the expressions of GRP78 and BMPR2

Regulation of leukocyte-endothelial cell interactions and of vascular permeability plays a critical role in the maintenance of functional pulmonary microvascular barriers. Little is yet known about the effect of the Rho-associated protein kinase (ROCK) inhibitor fasudil on leukocyte-endothelial cell interactions or the underlying mechanism. In the present study, as evaluated using co-culture systems of neutrophils and human pulmonary microvascular endothelial cells (HPMECs), fasudil dose-dependently suppressed neutrophil chemotaxis by decreasing the production of chemotactic factors in lipopolysaccharide (LPS)-treated HPMECs. The inhibitory role of fasudil in neutrophil chemotaxis was mediated by down-regulation of the chaperone glucose-regulated protein 78 (GRP78), since the inhibition was abolished by 4-phenyl butyric acid (a chemical chaperone mimicking GRP78). In addition, fasudil inhibited LPS-induced neutrophil-endothelial adhesion by reducing the expression of intercellular adhesion molecule (ICAM)-1. By use of lentiviral transfection in HPMECs, bone morphogenic protein receptor 2 (BMPR2) overexpression suppressed the LPS-induced increase of both ICAM-1 expression and neutrophil-endothelial adhesion, whereas knocking down BMPR2 abolished the inhibitory role of fasudil in both ICAM-1 expression and neutrophil-endothelial adhesion. Moreover, fasudil alleviated LPS-induced hyperpermeability of HPMEC monolayers by leading to the recovery of intercellular junctions, thereafter reduced neutrophil transendothelial cell migration. Therefore, fasudil inhibited leukocyte-endothelial cell interactions and vascular hyperpermeability through modulation of GRP78 and BMPR2 expression, suggesting a potential role for ROCK as a switch for inhibiting leukocyte-endothelial cell interactions.

Rho-associated protein kinases as therapeutic targets for both vascular and parenchymal pathologies in Alzheimer's disease

The causes of late-onset Alzheimer's disease are unclear and likely multifactorial. Rho-associated protein kinases (ROCKs) are ubiquitously expressed signaling messengers that mediate a wide array of cellular processes. Interestingly, they play an important role in several vascular and brain pathologies implicated in Alzheimer's etiology, including hypertension, hypercholesterolemia, blood-brain barrier disruption, oxidative stress, deposition of vascular and parenchymal amyloid-beta peptides, tau hyperphosphorylation, and cognitive decline. The current review summarizes the functions of ROCKs with respect to the various risk factors and pathologies on both sides of the blood-brain barrier and present support for targeting ROCK signaling as a multifactorial and multi-effect approach for the prevention and amelioration of late-onset Alzheimer's disease. This article is part of the Special Issue "Vascular Dementia".

Research advances in kinase enzymes and inhibitors for cardiovascular disease treatment

The targeting of protein kinases has great future potential for the design of new drugs against cardiovascular diseases (CVDs). Enormous efforts have been made toward achieving this aim. Unfortunately, kinase inhibitors designed to treat CVDs have suffered from numerous limitations such as poor selectivity, bad permeability and toxicity. So, where are we now in terms of discovering effective kinase targeting drugs to treat CVDs? Various drug design techniques have been approached for this purpose since the discovery of the inhibitory activity of Staurosporine against protein kinase C in 1986. This review aims to provide context for the status of several emerging classes of direct kinase modulators to treat CVDs and discuss challenges that are preventing scientists from finding new kinase drugs to treat heart disease.

AT1 receptor signaling pathways in the cardiovascular system

The importance of the renin angiotensin aldosterone system in cardiovascular physiology and pathophysiology has been well described whereas the detailed molecular mechanisms remain elusive. The angiotensin II type 1 receptor (AT1 receptor) is one of the key players in the renin angiotensin aldosterone system. The AT1 receptor promotes various intracellular signaling pathways resulting in hypertension, endothelial dysfunction, vascular remodeling and end organ damage. Accumulating evidence shows the complex picture of AT1 receptor-mediated signaling; AT1 receptor-mediated heterotrimeric G protein-dependent signaling, transactivation of growth factor receptors, NADPH oxidase and ROS signaling, G protein-independent signaling, including the β-arrestin signals and interaction with several AT1 receptor interacting proteins. In addition, there is functional cross-talk between the AT1 receptor signaling pathway and other signaling pathways. In this review, we will summarize an up to date overview of essential AT1 receptor signaling events and their functional significances in the cardiovascular system.

Lycopene Ameliorates Transplant Arteriosclerosis in Vascular Allograft Transplantation by Regulating the NO/cGMP Pathways and Rho-Associated Kinases Expression

Objective. Transplant arteriosclerosis is considered one of the major factors affecting the survival time of grafts after organ transplantation. In this study, we proposed a hypothesis of whether lycopene can protect grafted vessels through regulating key proteins expression involved in arteriosclerosis. Methods. Allogeneic aortic transplantation was performed using Brow-Norway rats as donors and Lewis rats as recipients. After transplantation, the recipients were divided into two groups: the allograft group and the lycopene group. Negative control rats (isograft group) were also established. Histopathological staining was performed to observe the pathological changes, and the expression levels of Ki-67, caspase-3, Rho-associated kinases, intercellular adhesion molecules (ICAM-1), and eNOS were assessed. Western blotting analysis and real-time PCR were also performed for quantitative analysis. Results. The histopathological staining showed that vascular stenosis and intimal thickening were not evident after lycopene treatment. The Ki-67, ROCK1, ROCK2, and ICAM-1 expression levels were significantly decreased. However, eNOS expression in grafted arteries and plasma cGMP concentration were increased after lycopene treatment. Conclusions. Lycopene could alleviate vascular arteriosclerosis in allograft transplantation via downregulating Rho-associated kinases and regulating key factor expression through the NO/cGMP pathways, which may provide a potentially effective method for transplant arteriosclerosis in clinical organ transplantation.

Y-27632 Increases Sensitivity of PANC-1 Cells to EGCG in Regulating Cell Proliferation and Migration

Background

The study aimed to investigate the inhibitory effect of (1R,4r)-4-((R)-1-aminoethyl)-N-(pyridin-4-yl) cyclohexanecarboxamide (Y-27632) and (−)-epigallocatechin-3-gallate (EGCG) on the proliferation and migration of PANC-1 cells. EGCG, found in green tea, has been previously shown to be one of the most abundant and powerful catechins in cancer prevention and treatment. Y-27632, a selective inhibitor of rho-associated protein kinase 1, is widely used in treating cardiovascular disease, inflammation, and cancer.

Material/Methods

PANC-1 cells, maintained in Dulbecco’s Modified Eagle’s Medium, were treated with dimethyl sulfoxide (control) as well as different concentrations (20, 40, 60, and 80 μg/mL) of EGCG for 48 h. In addition, PANC-1 cells were treated separately with 60 μg/mL EGCG, 20 μM Y-27632, and EGCG combined with Y-27632 (60 μg/mL EGCG + 20 μM Y-27632) for 48 h. The effect of EGCG and Y-27632 on the proliferation and migration of PANC-1 cells was evaluated using Cell Counting Kit-8 and transwell migration assays. The expression of peroxisome proliferator–activated receptor alpha (PPARα) and Caspase-3 mRNA was determined by Quantitative real-time polymerase chain reaction (RT-qPCR).

Results

EGCG (20–80 μg/mL) inhibited cell viability in a dose-dependent manner. Y-27632 enhanced the sensitivity of PANC-1 cells to EGCG (by increasing the expression of PPARα and Caspase-3 mRNA) and suppressed cell proliferation. PANC-1 cell migration was inhibited by treatment with a combination of EGCG and Y-27632.

Conclusions

Y-27632 increases the sensitivity of PANC-1 cells to EGCG in regulating cell proliferation and migration, which is likely to be related to the expression of PPARα mRNA and Caspase-3 mRNA.

Role of the Rho GTPase/Rho kinase signaling pathway in pathogenesis and treatment of glaucoma: Bench to bedside research

Glaucoma is a leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is considered to be a predominant risk factor for primary open angle glaucoma, the most prevalent form of glaucoma. Although the etiological mechanisms responsible for increased IOP are not completely clear, impairment in aqueous humor (AH) drainage through the conventional or trabecular pathway is recognized to be a primary cause in glaucoma patients. Importantly, lowering of IOP has been demonstrated to reduce progression of vision loss and is a mainstay of treatment for all types of glaucoma. Currently however, there are limited therapeutic options available for lowering IOP especially as it relates to enhancement of AH outflow through the trabecular pathway. Towards addressing this challenge, bench and bedside research conducted over the course of the last decade and a half has identified the significance of inhibiting Rho kinase for lowering IOP. Rho kinase is a downstream effector of Rho GTPase signaling that regulates actomyosin dynamics in numerous cell types. Studies from several laboratories have demonstrated that inhibition of Rho kinase lowers IOP via relaxation of the trabecular meshwork which enhances AH outflow. By contrast, activation of Rho GTPase/Rho kinase signaling in the trabecular outflow pathway increases IOP by altering the contractile, cell adhesive and permeability barrier characteristics of the trabecular meshwork and Schlemm's canal tissues, and by influencing extracellular matrix production and fibrotic activity. This article, written in honor of the late David Epstein, MD, summarizes findings from both basic and clinical studies that have been instrumental for recognition of the importance of the Rho/Rho kinase signaling pathway in regulation of AH outflow, and in the development of Rho kinase inhibitors as promising IOP- lowering agents for glaucoma treatment.

Role of Rho-mediated ROCK-Semaphorin3A signaling pathway in the pathogenesis of Parkinson's disease in a mouse model

OBJECTIVE

The present study aims to elucidate the role of Rho-mediated ROCK-Semaphorin3A signaling pathway in the pathogenesis of Parkinson's disease (PD) in a mouse model.

METHODS

One-hundred twelve eight-week male C57BL/6 mice were selected. The mouse model of PD was constructed by intraperitoneal injection of MPTP. All mice were divided into four groups (28 mice in each group): Blank group, Model group, Rho knockout (Rho+/-) group and ROCK knockout (ROCK+/-) group. Changes of behavior of the mice were studied through automatic moving test and rotarod test. Immunohistochemistry (IHC) was used to detect the expressions of TH, CD11b and GFAP. High performance liquid chromatograph (HPLC) was performed for detection of dopamine and its metabolic product. The mRNA and protein expressions of Rho, ROCK, Sema3A, PlexinA and NRP-1 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting.

RESULTS

Rho and ROCK knockout improved the damage caused by MPTP on the behavior of mice and protected dopaminergic neurons from injury, along with the increases of dopamine and its metabolic product. The mRNA and protein expressions of Rho, ROCK, Sema3A, PlexinA and NRP-1 were increased in PD mice in the Model group compared with those in the Blank group. Compared to the Model group, the mRNA and protein expressions of Rho, ROCK, Sema3A, PlexinA and NRP-1 were reduced in the Rho+/- and ROCK+/- groups.

CONCLUSION

These findings indicate that Rho and ROCK knockout may improve the behavior of mice and prevent MPTP-induced dopaminergic neurons damage by regulating Sema3A, PlexinA and NRP-1 in a mouse model of PD.

Interventional Transcatheter Closure Ameliorates the Leukocyte Rho Kinase Activities among Patients with Patent Ductus Arteriosus

BACKGROUND

Patent ductus arteriosus (PDA) causes increased pulmonary blood flow, which can lead to pulmonary arterial hypertension (PAH). Rho-associated coiled-coil containing protein kinase (ROCK) may play an important pathophysiological role in PAH. We hypothesized that the increased pulmonary artery (PA) flow from PDA could activate ROCK.

METHODS

Patients who received a PDA transcatheter closure in our hospital were consecutively enrolled in this study. Basic demographics and clinical hemodynamic data of the study participants were recorded. Then, ROCK activity was measured before and after the PDA occlusion procedure. ROCK activity was defined as the phosphorylation ratio of myosin-binding subunit by Western blot measurement. We also sub-divided patients into the coil group and occluder group based on the occlusion device used in each patient's procedure.

RESULTS

From January 2009 to December 2011, 25 patients with a median age of 2.3 years, ranging from 10 months to 72 years were enrolled. The mean PDA size was 0.31 ± 0.14 cm, the mean Qp/Qs shunt was 1.54 ± 0.41, and the mean systolic pulmonary artery pressure was 26.9 ± 10.3 mmHg. There were 10 patients (one boy and nine girls) in the coil group and 15 patients (four boys and eleven girls) in the occluder group. Following the closure of the PDA, ROCK activity significantly decreased (1.78 ± 2.25 vs. 0.77 ± 0.69, p < 0.01). There was a strong correlation between the leukocyte ROCK activity with the systolic PA pressure (y = 5.4608x + 22.54, R2 = 0.5539, p < 0.05), but not the Qp/Qs value. Both subgroups showed significant changes of ROCK activity after the procedure. Interestingly, when comparing the coil group with the occluder group, the decrease in ROCK activity was more apparent in the occluder group.

CONCLUSIONS

The findings of this study indicated that ROCK activity is higher in patients with PDA and correlates with PA pressure. The decrease in ROCK activity following the device closure suggests that ROCK may be an important biomarker for PDA patency.

KEY WORDS

Patent ductus arteriosus (PDA); Pulmonary arterial pressure; Rho kinase; Transcatheter closure.

Increased Rho-kinase-mediated prostate contractions associated with impairment of β-adrenergic-cAMP-signaling pathway by chronic nitric oxide deficiency

Impairment of nitric oxide (NO) - cyclic GMP signaling pathway is likely to contribute to human begnin prostate hyperplasia (BPH). In the present study we have used a model of chronic NO synthesis inhibition to evaluate the functional alterations of prostate smooth muscle (PSM) machinery, and involvement of Rho-kinase pathway. Wistar rats were treated with the NO inhibitor N(ω)-nitro-l-arginine methyl ester (L-NAME, 20mg/kg/day; 4 weeks), after which contractile responses to phenylephrine (α1-adrenoceptor agonist; 1nM to 100µM), carbachol (muscarinic agonist; 1nM to 1mM) and α,β-methylene ATP (P2X receptor agonist; 1-10µM), as well as to electrical-field stimulation (EFS; 1-32Hz) were evaluated. PSM relaxations to isoproterenol (non-selective β-adrenoceptor agonist, 0.1nM to 10µM) and sodium nitroprusside (NO donor, 1nM to 10mM) were also evaluated. The ratio prostate weight/body weight was 22% greater (P<0.05) in L-NAME compared with control group. The PSM contractions to phenylephrine, carbachol and α,β-methylene ATP were higher in L-NAME (Emax: 3.85±0.25, 3.52±0.35 and 2.03±0.2mN, respectively) compared with control group (Emax: 3.08±0.17, 2.37±0.18 and 1.57±0.18mN, respectively). The PSM contractions induced by EFS were also significantly greater in L-NAME group. Prior incubation with the Rho-kinase inhibitor Y27632 (1µM) fully reversed the enhanced contractions to phenylephrine and carbachol. Isoproterenol-induced PSM relaxations were 34% lower in L-NAME group, which was associated with reduced levels of cAMP in prostate tissue. The relaxations to sodium nitroprusside remained unaltered in L-NAME group. In summary, chronic NO deficiency leads to increased Rho-kinase-mediated PSM contractile responses accompanied by impairment of β-adrenergic-cAMP-signaling pathway.

Rho kinase as a target for cerebral vascular disorders

The development of novel pharmaceutical treatments for disorders of the cerebral vasculature is a serious unmet medical need. These vascular disorders are typified by a disruption in the delicate Rho signaling equilibrium within the blood vessel wall. In particular, Rho kinase overactivation in the smooth muscle and endothelial layers of the vessel wall results in cytoskeletal modifications that lead to reduced vascular integrity and abnormal vascular growth. Rho kinase is thus a promising target for the treatment of cerebral vascular disorders. Indeed, preclinical studies indicate that Rho kinase inhibition may reduce the formation/growth/rupture of both intracranial aneurysms and cerebral cavernous malformations.