A postmarketing surveillance study of fasudil treatment after aneurysmal subarachnoid hemorrhage

Therapeutic potential of berries in age-related neurological disorders

Aging significantly impacts several age-related neurological problems, such as stroke, brain tumors, oxidative stress, neurodegenerative diseases (Alzheimer's, Parkinson's, and dementia), neuroinflammation, and neurotoxicity. Current treatments for these conditions often come with side effects like hallucinations, dyskinesia, nausea, diarrhea, and gastrointestinal distress. Given the widespread availability and cultural acceptance of natural remedies, research is exploring the potential effectiveness of plants in common medicines. The ancient medical system used many botanical drugs and medicinal plants to treat a wide range of diseases, including age-related neurological problems. According to current clinical investigations, berries improve motor and cognitive functions and protect against age-related neurodegenerative diseases. Additionally, berries may influence signaling pathways critical to neurotransmission, cell survival, inflammation regulation, and neuroplasticity. The abundance of phytochemicals in berries is believed to contribute to these potentially neuroprotective effects. This review aimed to explore the potential benefits of berries as a source of natural neuroprotective agents for age-related neurological disorders.

SAFE-ROCK: A Phase I Trial of an Oral Application of the ROCK Inhibitor Fasudil to Assess Bioavailability, Safety, and Tolerability in Healthy Participants

BACKGROUND

The intravenous (IV) formulation of Rho-kinase (ROCK) inhibitor fasudil has been approved for the treatment of subarachnoid haemorrhage since 1995. Additionally, fasudil has shown promising preclinical results for various chronic diseases, including neurodegenerative diseases such as amyotrophic lateral sclerosis, Parkinson's disease, and dementia, in which long-term intravenous (IV) administration might not be suitable.

OBJECTIVE

The objective of this study was to assess the absolute bioavailability of oral, in comparison to IV, application of the approved formulation of fasudil (ERIL®) and to evaluate the safety and tolerability of the oral application of fasudil.

METHODS

This was a phase I, single-center, open-label, randomized, two period cross-over clinical trial in healthy women and men. By applying a cross-over design, each subject served as their own control. Two treatments were investigated, separated by a wash out phase of at least 3 days. Oral fasudil was administered once on day 1 to assess pharmacokinetics and three times on day 2, at an interval of 8 ± 1 h, to assess safety and gastrointestinal tolerability. For pharmacometrics of IV fasudil, it was administered once on day 1. Plasma profiles of fasudil and its active metabolite hydroxyfasudil after oral or IV administration were measured by liquid chromatography electrospray tandem mass spectrometry. Tolerability was assessed as proportion of subjects without significant drug intolerance, and safety was assessed by the proportion of subjects without clinical or laboratory treatment-associated serious adverse events. Gastrointestinal safety was assessed by applying the gastrointestinal symptom rating scale (GSRS).

RESULTS

Fourteen subjects aged 30-70 years were included in this trial. After oral administration, fasudil concentrations in blood were mostly very low [1.4 g/L; coefficient of variation (CV) 41.0%]. After IV application, the peak concentration was 100.6 µg/L (CV 74.2%); however, a high variance in peak concentrations were assessed for both treatments. The maximal concentrations of hydroxyfasudil in blood were similar after oral and IV treatment [111.6 µg/L (CV 24.1%) and 108.4 µg/L (CV 19.7%), respectively]. Exposure of hydroxyfasudil (assessed as AUC0-tz) differed between both treatments, with 449 µg × h/L after IV treatment and 309 µg × h/L after oral treatment. Therefore, the absolute bioavailability of hydroxyfasudil after the oral treatment was approximately 69% of the IV treatment. No serious adverse events (SAEs) occurred during this trial, and good tolerability of oral fasudil (90 mg/day) was documented.

CONCLUSIONS

Oral fasudil was generally well tolerated in the studied population, and no safety concerns were identified. However, systemic bioavailability of oral hydroxyfasudil corresponded to 69%, and dose adjustments need to considered. The results presented here lay grounds for future trials of fasudil in chronic diseases, which require an oral long-term application. This trial was registered with EudraCT (no. 2019-001805-26).

Comparison of efficacy between clazosentan and fasudil hydrochloride-based management of vasospasm after subarachnoid hemorrhage focusing on older and WFNS grade V patients: a single-center experience in Japan

Subarachnoid hemorrhage often leads to poor outcomes owing to vasospasm, even after successful aneurysm treatment. Clazosentan, an endothelin receptor inhibitor, has been proven to be an effective treatment for vasospasms in a Japanese randomized controlled trial. However, its efficacy in older patients (≥ 75 years old) and those with World Federation of Neurosurgical Societies (WFNS) grade V has not been demonstrated. We retrospectively evaluated the efficacy of clazosentan in older patients and those with WFNS grade V, using real-world data. Patients with subarachnoid hemorrhage treated before and after the introduction of clazosentan were retrospectively evaluated. The patients were categorized into two groups (clazosentan era versus pre-clazosentan era), in which vasospasm management and outcomes were compared. Vasospasms were managed with fasudil hydrochloride-based (pre-clazosentan era) or clazosentan-based treatment (clazosentan era). Seventy-eight patients were included in this study: the clazosentan era (n = 32) and pre-clazosentan era (n = 46). Overall, clazosentan significantly reduced clinical vasospasms (clazosentan era: 31.3% versus pre-clazosentan era: 60.9%, p = 0.01), delayed cerebral ischemia (DCI) (9.4% versus 39.1%, p = 0.004), and vasospasm-related morbidity and mortality (M/M) (3.1% versus 19.6%, p = 0.03). In subgroup analysis of older patients or those with WFNS grade V, no significant difference was observed in clinical outcomes, although both DCI and vasospasm-related M/M were lower in the clazosentan era. Clazosentan was more effective than fasudil-based management in preventing DCI and reducing vasospasm-related M/M. Clazosentan could be used safely in older patients and those with WFNS grade V, although clinical outcomes in these patients were comparable to those of conventional treatment.

Protocol for a randomized, placebo-controlled, double-blind phase IIa study of the safety, tolerability, and symptomatic efficacy of the ROCK-inhibitor Fasudil in patients with Parkinson's disease (ROCK-PD)

Background

The Rho-kinase (ROCK) inhibitor Fasudil has shown symptomatic and disease-modifying effects in Parkinson's disease (PD) models in vitro and in vivo. In Japan, Fasudil has been approved for the treatment of subarachnoid haemorrhage since 1995 and shows a favourable safety profile.

Objectives/design

To investigate the safety, tolerability, and symptomatic efficacy of ROCK-inhibitor Fasudil in comparison to placebo in a randomized, national, multicenter, double-blind phase IIa study in patients with PD.

Methods/analysis

We plan to include 75 patients with at least 'probable' PD (MDS criteria), Hoehn and Yahr stages 1-3, and age 30-80 years in 13 German study sites. Patients must be non-fluctuating and their response to PD medication must have been stable for 6 weeks. Patients will be randomly allocated to treatment with the oral investigational medicinal product (IMP) containing either Fasudil in two dosages, or placebo, for a total of 22 days. As primary analysis, non-inferiority of low/high dose of Fasudil on the combined endpoint consisting of occurrence of intolerance and/or treatment-related serious adverse events (SAEs) over 22 days will be assessed in a sequential order, starting with the lower dose. Secondary endpoints will include tolerability alone over 22 days and occurrence of treatment-related SAEs (SARs) over 22 and 50 days and will be compared on group level. Additional secondary endpoints include efficacy on motor and non-motor symptoms, measured on established scales, and will be assessed at several timepoints. Biomaterial will be collected to determine pharmacokinetics of Fasudil and its active metabolite, and to evaluate biomarkers of neurodegeneration.

Ethics/registration/discussion

After positive evaluation by the competent authority and the ethics committee, patient recruitment started in the 3rd quarter of 2023. ROCK-PD is registered with Eudra-CT (2021-003879-34) and clinicaltrials.gov (NCT05931575). Results of this trial can pave way for conducting extended-duration studies assessing both symptomatic efficacy and disease-modifying properties of Fasudil.

Preventing Fluid Retention After Subarachnoid Haemorrhage During Administration of Endothelin Receptor Antagonist

Prevention of delayed cerebral infarction (DCI) due to cerebral vasospasm after subarachnoid haemorrhage (SAH) has been done with intravenous Rho kinase inhibitors (ROCKI), ozagrel sodium (TXA2I), selective ROCKI infusion (ROCKI i.a.), and cerebrospinal fluid (CSF) drainage. The endothelin receptor antagonist (ERA, clazosentan) became available in 2022 and is said to be highly recommended for DCI prevention, while fluid retention such as pleural effusion and pulmonary oedema accumulation is often experienced. We investigated the relationship between patient background, fluid retention, and ERA. Ten consecutive SAH patients treated with ERA from July to December 2022 were included. We examined the results of blood sampling on admission, echocardiography, chest computed tomography (CT), with postoperative DCI, and hydrocephalus requiring cerebrospinal fluid shunt (hydro), and symptomatic fluid retention requiring albumin and furosemide (third fluid space). Two males and eight females, mean age 63 years, mean preoperative World Federation Neurosurgical Surgeons (WFNS) grade 3.5, mean creatinine 0.94, mean brain natriuretic peptide (NT-proBNP). In 1883, two patients with Takotsubo cardiomyopathy and four patients with neurogenic pulmonary oedema are present. All patients underwent coil embolisation, and postoperative CSF drainage, ROCKI, TXA2I systemic administration, and ROCKI i.a. There were one DCI, three hydro, and five third fluid cases. Concerning the third fluid, the only significant difference was found in the age. An improvement in fluid retention after ERA discontinuation in old patients was shown. Our experience suggests that age may be the most influential factor. Based on these results, we have also found that by avoiding the use of ERA in patients older than 80 years, strictly limiting the infusion volume when using ERA, and actively using the drugs for heart failure early on, the frequency of suffering from third fluid space is reduced.

Real-world data of clazosentan in combination therapy for aneurysmal subarachnoid hemorrhage: a multicenter retrospective cohort study

Aneurysmal subarachnoid hemorrhage (aSAH) may lead to cerebral vasospasm, significantly associated with morbidity and mortality. In double-blind, placebo-controlled phase 3 studies, clazosentan reduces cerebral vasospasm-related morbidity and all-cause mortality in patients with aSAH. There are no reports about the clinical efficacy of clazosentan combination therapy with some other drugs. Initially, we explored the efficacy of clazosentan combination therapy with cilostazol, statin, and antiepileptic drugs. Subsequently, we assessed the add-on effect of fasudil to clazosentan combination therapy for aSAH patients. This multicenter, retrospective, observational cohort study included Japanese patients with aSAH between June 2022 and March 2023. The primary outcome was the ordinal score on the modified Rankin Scale (mRS; range, 0-6, with elevated scores indicating greater disability) at discharge. Among the 47 cases (women 74.5%; age 64.4 ± 15.0 years) undergoing clazosentan combination therapy, 29 (61.7%) resulted in favorable outcomes. Overall, vasospasm occurred in 16 cases (34.0%), with four cases (8.5%) developing vasospasm-related delayed cerebral ischemia (DCI). Both hypotension and vasospasm-related DCI were related to unfavorable outcome at discharge. Fasudil were added in 18 (38.3%) cases. Despite adding fasudil to clazosentan combination therapy, the incidence of aSAH-related vasospasm did not decrease. Added-on fasudil to combination therapy related to pulmonary edema, vasospasm, and vasospasm-related DCI, and unfavorable outcomes. Clazosentan combination therapy could potentially result in favorable outcomes for aSAH patients to prevent post-aSAH vasospasm-related DCI. The add-on effect of fasudil to combination therapy did not demonstrate a significant impact in reducing aSAH-related vasospasm or improving outcomes at discharge.

Interactions between Angiotensin Type-1 Antagonists, Statins, and ROCK Inhibitors in a Rat Model of L-DOPA-Induced Dyskinesia

Statins have been proposed for L-DOPA-induced dyskinesia (LID) treatment. Statin anti-dyskinetic effects were related to the inhibition of the Ras-ERK pathway. However, the mechanisms responsible for the anti-LID effect are unclear. Changes in cholesterol homeostasis and oxidative stress- and inflammation-related mechanisms such as angiotensin II and Rho-kinase (ROCK) inhibition may be involved. The nigra and striatum of dyskinetic rats showed increased levels of cholesterol, ROCK, and the inflammatory marker IL-1β, which were reduced by the angiotensin type-1 receptor (AT1) antagonist candesartan, simvastatin, and the ROCK inhibitor fasudil. As observed for LID, angiotensin II-induced, via AT1, increased levels of cholesterol and ROCK in the rat nigra and striatum. In cultured dopaminergic neurons, angiotensin II increased cholesterol biosynthesis and cholesterol efflux without changes in cholesterol uptake. In astrocytes, angiotensin induced an increase in cholesterol uptake, decrease in biosynthesis, and no change in cholesterol efflux, suggesting a neuronal accumulation of cholesterol that is reduced via transfer to astrocytes. Our data suggest mutual interactions between angiotensin/AT1, cholesterol, and ROCK pathways in LID, which are attenuated by the corresponding inhibitors. Interestingly, these three drugs have also been suggested as neuroprotective treatments against Parkinson's disease. Therefore, they may reduce dyskinesia and the progression of the disease using common mechanisms.

Fasudil compensates podocyte injury via CaMK4/Rho GTPases signal and actin cytoskeleton-dependent activation of YAP in MRL/lpr mice

Deposition of immune complexes in the glomerulus leads to irreversible renal damage in lupus nephritis (LN), of which podocyte malfunction arises earlier. Fasudil, the only Rho GTPases inhibitor approved in clinical settings, possesses well-established renoprotective actions; yet, no studies addressed the amelioration derived from fasudil in LN. To clarify, we investigated whether fasudil exerted renal remission in lupus-prone mice. In this study, fasudil (20 mg/kg) was intraperitoneally administered to female MRL/lpr mice for 10 weeks. We report that fasudil administration swept antibodies (anti-dsDNA) and attenuated systemic inflammatory response in MRL/lpr mice, accompanied by preserving podocyte ultrastructure and averting immune complex deposition. Mechanistically, it repressed the expression of CaMK4 in glomerulopathy by preserving nephrin and synaptopodin expression. And fasudil further blocked cytoskeletal breakage in the Rho GTPases-dependent action. Further analyses showed that beneficial actions of fasudil on the podocytes required intra-nuclear YAP activation underlying actin dynamics. In addition, in vitro assays revealed that fasudil normalized the motile imbalance by suppressing intracellular calcium enrichment, thereby contributing to the resistance of apoptosis in podocytes. Altogether, our findings suggest that the precise manners of crosstalks between cytoskeletal assembly and YAP activation underlying the upstream CaMK4/Rho GTPases signal in podocytes is a reliable target for podocytopathies treatment, and fasudil might serve as a promising therapeutic agent to compensate for the podocyte injury in LN.

Rho-kinase inhibitor restores glomerular fatty acid metabolism in diabetic kidney disease

The small GTPase Rho and its effector Rho-kinase (ROCK) are activated in the diabetic kidney, and recent studies decade have demonstrated that ROCK signaling is an integral pathway in the progression of diabetic kidney disease. We previously identified the distinct role of ROCK1, an isoform of ROCK, in fatty acid metabolism in diabetic glomeruli. However, the effect of pharmacological intervention for ROCK1 is not clear. In the present study, we show that the inhibition of ROCK1 by Y-27632 and fasudil restores fatty acid oxidation in the glomeruli. Mechanistically, these compounds optimize fatty acid utilization and redox balance in mesangial cells via AMPK phosphorylation and the subsequent induction of PGC-1α. A further in vivo study showed that the inhibition of ROCK1 suppressed the downregulation of the fatty acid oxidation-related gene expression in glomeruli and mitochondrial fragmentation in the mesangial cells of db/db mice. These observations indicate that ROCK1 could be a promising therapeutic target for diabetic kidney disease through a mechanism that improves glomerular fatty acid metabolism.

Short-Term Treatment with Rho-Associated Kinase Inhibitor Preserves Keratinocyte Stem Cell Characteristics In Vitro

Primary keratinocytes including keratinocyte stem cells (KSCs) can be cultured as epidermal sheets in vitro and are attractive for cell and gene therapies for genetic skin disorders. However, the initial slow growth of freshly isolated keratinocytes hinders clinical applications. Rho-associated kinase inhibitor (ROCKi) has been used to overcome this obstacle, but its influence on the characteristics of KSC and its safety for clinical application remains unknown. In this study, primary keratinocytes were treated with ROCKi Y-27632 for six days (short-term). Significant increases in colony formation and cell proliferation during the six-day ROCKi treatment were observed and confirmed by related protein markers and single-cell transcriptomic analysis. In addition, short-term ROCKi-treated cells maintained their differentiation ability as examined by 3D-organotypic culture. However, these changes could be reversed and became indistinguishable between treated and untreated cells once ROCKi treatment was withdrawn. Further, the short-term ROCKi treatment did not reduce the number of KSCs. In addition, AKT and ERK pathways were rapidly activated upon ROCKi treatment. In conclusion, short-term ROCKi treatment can transiently and reversibly accelerate initial primary keratinocyte expansion while preserving the holoclone-forming cell population (KSCs), providing a safe avenue for clinical applications.

The Therapeutic Role of Rho Kinase Inhibitor, Fasudil, on Pulmonary Hypertension; a Systematic Review and Meta-Analysis

BACKGROUND

Pulmonary hypertension (PH) is a pathophysiological disorder, which involves multiple clinical conditions such as the upregulation of the Rho/ROCK signaling pathway. On the other hand, fasudil as a Rho kinase inhibitor has been investigated in the treatment of PH in some clinical studies.

OBJECTIVES

The present systematic review and meta-analysis aimed to evaluate the human clinical trials regarding the efficacy of fasudil in the management of PH.

METHODS

Databases were searched with pre-defined search terms, up to December 2021. Efficacy measures were such as mean pulmonary arterial pressure (mPAP), systolic PAP (sPAP), pulmonary vascular resistance (PVR), systolic vascular resistance (SVR) and cardiac index (CI).

RESULTS

A total of 12 studies involving 575 PH patients were included in our research. Eight short-term trials and four mid-term trials were found (no clinical trials on the long-term effects). Short-term trials had a before-after study design and measuring pulmonary hemodynamic parameters' intervention revealed a statistically significant improvement of mPAP, sPAP, PVR, SVR, and CI in the meta-analysis of five eligible studies. Three mid-term trials also revealed improvement in some pulmonary hemodynamic parameters with fasudil and in another mid-term trial, fasudil significantly decreased rehospitalization and mortality in PH patients. No serious adverse effects with fasudil were reported in these trials.

CONCLUSION

Fasudil therapy is efficacious and probably safe in the improvement of some hemodynamics in PH patients along short and mid-term periods. However, long-term randomized controlled trials comparing fasudil with placebo and other treatments are warranted for confirmation of these benefits.

Rho-kinase inhibition improves haemodynamic responses and circulating ATP during hypoxia and moderate intensity handgrip exercise in healthy older adults

Abstract

Skeletal muscle haemodynamics and circulating adenosine triphosphate (ATP) responses during hypoxia and exercise are blunted in older (OA) vs. young (YA) adults, which may be associated with impaired red blood cell (RBC) ATP release. Rho‐kinase inhibition improves deoxygenation‐induced ATP release from OA isolated RBCs. We tested the hypothesis that Rho‐kinase inhibition (via fasudil) in vivo would improve local haemodynamic and ATP responses during hypoxia and exercise in OA. Healthy YA (25 ± 3 years; n = 12) and OA (65 ± 5 years; n = 13) participated in a randomized, double‐blind, placebo‐controlled, crossover study on two days (≥5 days between visits). A forearm deep venous catheter was used to administer saline/fasudil and sample venous plasma ATP ([ATP]_V). Forearm vascular conductance (FVC) and [ATP]_V were measured at rest, during isocapnic hypoxia (80% SpO2), and during graded rhythmic handgrip exercise that was similar between groups (5, 15 and 25% maximum voluntary contraction (MVC)). Isolated RBC ATP release was measured during normoxia/hypoxia. With saline, ΔFVC was lower (P < 0.05) in OA vs. YA during hypoxia (∼60%) and during 15 and 25% MVC (∼25–30%), and these impairments were abolished with fasudil. Similarly, [ATP]_V and ATP effluent responses from normoxia to hypoxia and rest to 25% MVC were lower in OA vs. YA and improved with fasudil (P < 0.05). Isolated RBC ATP release during hypoxia was impaired in OA vs. YA (∼75%; P < 0.05), which tended to improve with fasudil in OA (P = 0.082). These data suggest Rho‐kinase inhibition improves haemodynamic responses to hypoxia and moderate intensity exercise in OA, which may be due in part to improved circulating ATP.

Key points

Skeletal muscle blood flow responses to hypoxia and exercise are impaired with age. Blunted increases in circulating ATP, a vasodilator, in older adults may contribute to age‐related impairments in haemodynamics.

Red blood cells (RBCs) are a primary source of circulating ATP, and treating isolated RBCs with a Rho‐kinase inhibitor improves age‐related impairments in deoxygenation‐induced RBC ATP release.

In this study, treating healthy older adults systemically with the Rho‐kinase inhibitor fasudil improved blood flow and circulating ATP responses during hypoxia and moderate intensity handgrip exercise compared to young adults, and also tended to improve isolated RBC ATP release.

Improved blood flow regulation with fasudil was also associated with increased skeletal muscle oxygen delivery during hypoxia and exercise in older adults.

This is the first study to demonstrate that Rho‐kinase inhibition can significantly improve age‐related impairments in haemodynamic and circulating ATP responses to physiological stimuli, which may have therapeutic implications.

Comparison of Symptomatic Vasospasm after Surgical Clipping and Endovascular Coiling

Vasospasm, initial neurological damage, rebleeding, and periprocedural complications are associated prognostic factors for clinical outcomes after aneurysmal subarachnoid hemorrhage (SAH). In this study, factors related to delayed ischemic neurological deficit (DIND) are evaluated using data from our institute for the last 18 years. Data from 2001 to 2018 of patients with aneurysmal SAH who underwent surgical clipping (SC) or endovascular coiling (EC) within 7 days of onset were retrospectively analyzed. Cases of mortality within 5 days after treatment were excluded. Multivariate analysis was used to identify the risk factors for DIND. In total, 840 cases of SAH were assessed; among these cases, 384 (45.7%) and 456 (54.3%) were treated with SC and EC, respectively. The frequency of DIND in the EC group was significantly less than that in the SC group (11.8% vs. 17.7%; p = 0.016). In the results of multivariate analysis, internal carotid artery (ICA) aneurysm and hemorrhagic complications were the risk factors for DIND. Cilostazol administration and EC were significant factors for vasospasm prevention after aneurysmal SAH (odds ratio of ICA aneurysm: 1.59, hemorrhagic complications: 1.76, SC: 1.51, and cilostazol administration: 0.51, respectively). Cilostazol administration was also a significant factor in patients who were treated with EC. ICA aneurysm, treatment strategy, hemorrhagic complications, and cilostazol administration were associated with DIND. Oral administration of cilostazol and avoiding hemorrhagic complications were effective in DIND prevention. If both treatments are available for ruptured aneurysms, clinicians should choose EC on the basis of its ability to prevent DIND.

Mechanoregulation of Vascular Endothelial Growth Factor Receptor 2 in Angiogenesis

The endothelial cells that compose the vascular system in the body display a wide range of mechanotransductive behaviors and responses to biomechanical stimuli, which act in concert to control overall blood vessel structure and function. Such mechanosensitive activities allow blood vessels to constrict, dilate, grow, or remodel as needed during development as well as normal physiological functions, and the same processes can be dysregulated in various disease states. Mechanotransduction represents cellular responses to mechanical forces, translating such factors into chemical or electrical signals which alter the activation of various cell signaling pathways. Understanding how biomechanical forces drive vascular growth in healthy and diseased tissues could create new therapeutic strategies that would either enhance or halt these processes to assist with treatments of different diseases. In the cardiovascular system, new blood vessel formation from preexisting vasculature, in a process known as angiogenesis, is driven by vascular endothelial growth factor (VEGF) binding to VEGF receptor 2 (VEGFR-2) which promotes blood vessel development. However, physical forces such as shear stress, matrix stiffness, and interstitial flow are also major drivers and effectors of angiogenesis, and new research suggests that mechanical forces may regulate VEGFR-2 phosphorylation. In fact, VEGFR-2 activation has been linked to known mechanobiological agents including ERK/MAPK, c-Src, Rho/ROCK, and YAP/TAZ. In vascular disease states, endothelial cells can be subjected to altered mechanical stimuli which affect the pathways that control angiogenesis. Both normalizing and arresting angiogenesis associated with tumor growth have been strategies for anti-cancer treatments. In the field of regenerative medicine, harnessing biomechanical regulation of angiogenesis could enhance vascularization strategies for treating a variety of cardiovascular diseases, including ischemia or permit development of novel tissue engineering scaffolds. This review will focus on the impact of VEGFR-2 mechanosignaling in endothelial cells (ECs) and its interaction with other mechanotransductive pathways, as well as presenting a discussion on the relationship between VEGFR-2 activation and biomechanical forces in the extracellular matrix (ECM) that can help treat diseases with dysfunctional vascular growth.

Rho Kinases in Embryonic Development and Stem Cell Research

The Rho-associated coiled-coil containing kinases (ROCKs or Rho kinases) belong to the AGC (PKA/PKG/PKC) family of serine/threonine kinases and are major downstream effectors of small GTPase RhoA, a key regulator of actin-cytoskeleton reorganization. The ROCK family contains two members, ROCK1 and ROCK2, which share 65% overall identity and 92% identity in kinase domain. ROCK1 and ROCK2 were assumed to be functionally redundant, based largely on their major common activators, their high degree kinase domain homology, and study results from overexpression with kinase constructs or chemical inhibitors. ROCK signaling research has expanded to all areas of biology and medicine since its discovery in 1996. The rapid advance is befitting ROCK’s versatile functions in modulating various cell behavior, such as contraction, adhesion, migration, proliferation, polarity, cytokinesis, and differentiation. The rapid advance is noticeably driven by an extensive linking with clinical medicine, including cardiovascular abnormalities, aberrant immune responsive, and cancer development and metastasis. The rapid advance during the past decade is further powered by novel biotechnologies including CRISPR-Cas and single cell omics. Current consensus, derived mainly from gene targeting and RNA interference approaches, is that the two ROCK isoforms have overlapping and distinct cellular, physiological and pathophysiology roles. In this review, we present an overview of the milestone discoveries in ROCK research. We then focus on the current understanding of ROCK signaling in embryonic development, current research status using knockout and knockin mouse models, and stem cell research.

Emerging targets in drug discovery against neurodegenerative diseases: Control of synapsis disfunction by the RhoA/ROCK pathway

Synaptic spine morphology is controlled by the activity of Rac1, Cdc42 and RhoA, which need to be finely balanced, and in particular RhoA/ROCK prevents the formation of new protrusions by stabilizing actin formation. These processes are crucial to the maturation process, slowing the de novo generation of new spines. The RhoA/ROCK also influences plasticity processes, and selective modulation by ROCK1 of MLC-dependent actin dynamics leads to neurite retraction, but not to spine retraction. ROCK1 is also responsible for the reduction of the readily releasable pool of synaptic vesicles. These and other evidences suggest that ROCK1 is the main isoform acting on the presynaptic neuron. On the other hand, ROCK2 seems to have broad effects on LIMK/cofilin-dependent plasticity processes such as cofilin-dependent PSD changes. The RhoA/ROCK pathway is an important factor in several different brain-related pathologies via both downstream and upstream pathways. In the aggregate, these evidences show that the RhoA/ROCK pathway has a central role in the etiopathogenesis of a large group of CNS diseases, which underscores the importance of the pharmacological modulation of RhoA/ROCK as an important pathway to drug discovery in the neurodegenerative disease area. This article aims at providing the first review of the role of compounds acting on the RhoA/ROCK pathway in the control of synaptic disfunction.

Cerebral Autoregulation in Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating stroke subtype with a high rate of mortality and morbidity. The poor clinical outcome can be attributed to the biphasic course of the disease: even if the patient survives the initial bleeding emergency, delayed cerebral ischemia (DCI) frequently follows within 2 weeks time and levies additional serious brain injury. Current therapeutic interventions do not specifically target the microvascular dysfunction underlying the ischemic event and as a consequence, provide only modest improvement in clinical outcome. SAH perturbs an extensive number of microvascular processes, including the “automated” control of cerebral perfusion, termed “cerebral autoregulation.” Recent evidence suggests that disrupted cerebral autoregulation is an important aspect of SAH-induced brain injury. This review presents the key clinical aspects of cerebral autoregulation and its disruption in SAH: it provides a mechanistic overview of cerebral autoregulation, describes current clinical methods for measuring autoregulation in SAH patients and reviews current and emerging therapeutic options for SAH patients. Recent advancements should fuel optimism that microvascular dysfunction and cerebral autoregulation can be rectified in SAH patients.

Involvement of Cerebral Blood Flow on Neurological and Behavioral Functions after Subarachnoid Hemorrhage in Mice

OBJECTIVE

Cerebral Blood Flow (CBF) change after Subarachnoid Hemorrhage (SAH) is strongly associated with brain injuries such as early brain injury and delayed cerebral ischemia. We evaluated the correlation between CBF using Laser Speckle Flow Imaging (LSFI) after SAH and neurological findings in the sub-acute phase.

METHOD

An SAH was induced by endovascular perforation in male mice. CBF was quantitatively measured by using LSFI at six time points, immediately to 14 days after SAH induction. Behavior tests and survival rate were evaluated. The mice were divided into recovery and hypo-perfusion groups according to their CBF at 1 day after the procedure.

RESULT

Forty mice were included in this study. Five mice (20%) were included in the hypo-perfusion group, and the remaining 20 (80%) mice were classified as the recovery group. The decrease of CBF in the recovery group was observed until 1 day after the procedure. However, the decrease of CBF in the hypo-perfusion group was prolonged until 7 days after the procedure. Neurological findings and survival rates in the hypo-perfusion group were significantly worse than those in the recovery group. The low alternation cases (≤ 50%) in the Y-maze test in the recovery group (n = 5) had significantly lower CBF at 1 day after the procedure.

CONCLUSION

Low blood flow at 1 day after SAH was associated with worse survival rate, neurological findings, and memory disturbance. Early improvement in CBF may be associated with an improved prognosis after SAH.

Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a neurologic emergency that requires immediate patient stabilization and prompt diagnosis and treatment. Early measures should focus on principles of advanced cardiovascular life support. The aneurysm should be evaluated and treated in a comprehensive stroke center by a multidisciplinary team capable of endovascular and, operative approaches. Once the aneurysm is secured, the patient is best managed by a dedicated neurocritical care service to prevent and manage complications, including a syndrome of delayed neurologic decline. The goal of such specialized care is to prevent secondary injury, reduce length of stay, and improve outcomes for survivors of the disease.

RhoA activation-mediated vascular permeability in capillary malformation-arteriovenous malformation syndrome: a hypothesis

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a class of capillary anomalies that are associated with arteriovenous malformations and arteriovenous fistulas, which carry a risk of hemorrhages. There are no broadly effective pharmacological therapies currently available. Most CM-AVMs are associated with a loss of RASA1, resulting in constitutive activation of RAS signaling. However, protein interaction analysis revealed that RASA1 forms a complex with Rho GTPase-activating protein (RhoGAP), a negative regulator of RhoA signaling. Herein, we propose that loss of RASA1 function results in constitutive activation of RhoA signaling in endothelial cells, resulting in enhanced vascular permeability. Therefore, strategies aimed at curtailing RhoA activity should be tested as an adjunctive therapeutic approach in cell culture studies and animal models of RASA1 deficiency.

Rho kinase inhibitor fasudil reduces l-DOPA-induced dyskinesia in a rat model of Parkinson's disease

BACKGROUND AND PURPOSE

Rho kinase (ROCK) activation is involved in neuroinflammatory processes leading to progression of neurodegenerative diseases such as Parkinson's disease. Furthermore, ROCK plays a major role in angiogenesis. Neuroinflammation and angiogenesis are mechanisms involved in developing l-DOPA-induced dyskinesias (LID). However, it is not known whether ROCK plays a role in LID and whether ROCK inhibitors may be useful against LID.

EXPERIMENTAL APPROACH

In rats, we performed short- and long-term dopaminergic lesions using 6-hydroxydopamine and developed a LID model. Effects of dopaminergic lesions and LID on the RhoA/ROCK levels were studied by western blot, real-time PCR analyses and ROCK activity assays in the substantia nigra and striatum. The effects of the ROCK inhibitor fasudil on LID were particularly investigated.

KEY RESULTS

Short-term 6-hydroxydopamine lesions increased nigrostriatal RhoA/ROCK expression, apparently related to the active neuroinflammatory process. However, long-term dopaminergic denervation (completed and stabilized lesions) led to a decrease in RhoA/ROCK levels. Rats with LID showed a significant increase of RhoA and ROCK expression. The development of LID was reduced by the ROCK inhibitor fasudil (10 and 40 mg·kg^-1 ), without interfering with the therapeutic effect of l-DOPA. Interestingly, treatment of 40 mg·kg^-1 of fasudil also induced a significant reduction of dyskinesia in rats with previously established LID.

CONCLUSION AND IMPLICATIONS

The present results suggest that ROCK is involved in the pathophysiology of LID and that ROCK inhibitors such as fasudil may be a novel target for preventing or treating LID. Furthermore, previous studies have revealed neuroprotective effects of ROCK inhibitors.

Inhibition of Rho kinase suppresses capsular contraction following lens injury in mice

PURPOSE:

We investigated the effect of systemic fasudil hydrochloride and an inhibitor of nuclear translocation of myocardin-related transcription factor-A (MRTF-A) on capsular contraction in a puncture-injured lens in mice.

MATERIALS AND METHODS:

Lens injury of an anterior capsular break was achieved in male adult C57Bl/6 mice under general and topical anesthesia at 1 h after systemic fasudil hydrochloride (intraperitoneal, 10 mg/kg body weight) or vehicle administration. The mice were allowed to heal after instillation of ofloxacin ointment, for 5 and 10 days with daily administration of fasudil hydrochloride or vehicle. In another series of experiment, we examined the effect of systemic administration of an MRTF-A inhibitor (CCG-203971, 100 mg/kg twice a day) on fibrogenic reaction and tissue contraction in an injured lens on day 5 or 10. The eye was processed for histology and immunohistochemistry for SM22, proliferating cell nuclear antigen (PCNA), or MRTF-A. In hematoxylin and eosin - stained samples, the distance between each edge of the break of the anterior capsule was measured and statistically analyzed.

RESULTS:

A cluster of lens cell accumulation was formed adjacent to the edge of the capsular break on day 5. It contained cells labeled for SM22 and PCNA. The size of the cell cluster was larger in fasudil group of mice than in control mice on day 5. Systemic fasudil or CCG-203971 suppressed an excess contraction of the capsular break at certain time points.

CONCLUSION:

Systemic administration of fasudil hydrochloride could be a treatment strategy of postoperative capsular contraction following cataract-intraocular lens surgery.

Effect of treatment modality and cerebral vasospasm agent on patient outcomes after aneurysmal subarachnoid hemorrhage in the elderly aged 75 years and older

Objective

We sought to examine whether the effect of treatment modality and drugs for cerebral vasospasm on clinical outcomes differs between elderly and non-elderly subarachnoid hemorrhage (SAH) patients in Japan.

Methods

We analyzed the J-ASPECT Study Diagnosis Procedure Combination database (n = 17,343) that underwent clipping or coiling between 2010 and 2014 in 579 hospitals. We stratified patients into two groups according to their age (elderly [≥75 years old], n = 3,885; non-elderly, n = 13,458). We analyzed the effect of treatment modality and anti-vasospasm agents (fasudil hydrochloride, ozagrel sodium, cilostazol, statin, eicosapentaenoic acid [EPA], and edaravone) on in-hospital poor outcomes (mRS 3–6 at discharge) and mortality using multivariable analysis.

Results

The elderly patients were more likely to be female, have impaired levels of consciousness and comorbidity, and less likely to be treated with clipping and anti-vasospasm agents, except for ozagrel sodium and statin. In-hospital mortality and poor outcomes were higher in the elderly (15.8% vs. 8.5%, 71.7% vs. 36.5%).

Coiling was associated with higher mortality (odds ratio 1.43, 95% confidence interval 1.2–1.7) despite a lower proportion of poor outcomes (0.84, 0.75–0.94) in the non-elderly, in contrast to no effect on clinical outcomes in the elderly.

A comparable effect of anti-vasospasm agents on mortality was observed between non-elderly and elderly for fasudil hydrochloride (non-elderly: 0.20, 0.17–0.24), statin (0.63, 0.50–0.79), ozagrel sodium (0.72, 0.60–0.86), and cilostazol (0.63, 0.51–0.77). Poor outcomes were inversely associated with fasudil hydrochloride (0.59, 0.51–0.68), statin (0.84, 0.75–0.94), and EPA (0.83, 0.72–0.94) use in the non-elderly. No effect of these agents on poor outcomes was observed in the elderly.

Conclusions

In contrast to the non-elderly, no effect of treatment modality on clinical outcomes were observed in the elderly. A comparable effect of anti-vasospasm agents was observed on mortality, but not on functional outcomes, between the non-elderly and elderly.

Acute lung injury: The therapeutic role of Rho kinase inhibitors

Acute lung injury (ALI) is a pulmonary illness with high rates of mortality and morbidity. Rho GTPase and its downstream effector, Rho kinase (ROCK), have been demonstrated to be involved in cell adhesion, motility, and contraction which can play a role in ALI. The electronic databases of Google Scholar, Scopus, PubMed, and Web of Science were searched to obtain relevant studies regarding the role of the Rho/ROCK signaling pathway in the pathophysiology of ALI and the effects of specific Rho kinase inhibitors in prevention and treatment of ALI. Upregulation of the RhoA/ROCK signaling pathway causes an increase of inflammation, immune cell migration, apoptosis, coagulation, contraction, and cell adhesion in pulmonary endothelial cells. These effects are involved in endothelium barrier dysfunction and edema, hallmarks of ALI. These effects were significantly reversed by Rho kinase inhibitors. Rho kinase inhibition offers a promising approach in ALI [ARDS] treatment.

Perioperative Use of Rho-Kinase Inhibitors has Beneficial Effect on Corneal Endothelium after Phacoemulsification

PURPOSE:

Does perioperative use of Rho-Kinase (ROCK) inhibitors have beneficial effect on corneal endothelial cells after phacoemulsification? SETTING: This study was conducted at King Abdulaziz University Hospital in Riyadh.

DESIGN:

This was a prospective study assessing the effect of ROCK inhibitors on corneal endothelium after phacoemulsification.

METHODOLOGY:

Three patients have used ROCK inhibitor 1 day before and 1 week after phacoemulsification surgery, and specular microscopy and Pentacam were done preoperatively and 3 months postoperatively.

RESULTS:

Endothelial cell density decreased to 11.3%, 9.45%, and 4.09% in eyes with ROCK inhibitors and 23.9% in one eye without ROCK inhibitor.

CONCLUSION:

Perioperative ROCK inhibitor use has a possible protective effect on corneal endothelium.

RhoA-ROCK Signaling as a Therapeutic Target in Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. TBIs, which range in severity from mild to severe, occur when a traumatic event, such as a fall, a traffic accident, or a blow, causes the brain to move rapidly within the skull, resulting in damage. Long-term consequences of TBI can include motor and cognitive deficits and emotional disturbances that result in a reduced quality of life and work productivity. Recovery from TBI can be challenging due to a lack of effective treatment options for repairing TBI-induced neural damage and alleviating functional impairments. Central nervous system (CNS) injury and disease are known to induce the activation of the small GTPase RhoA and its downstream effector Rho kinase (ROCK). Activation of this signaling pathway promotes cell death and the retraction and loss of neural processes and synapses, which mediate information flow and storage in the brain. Thus, inhibiting RhoA-ROCK signaling has emerged as a promising approach for treating CNS disorders. In this review, we discuss targeting the RhoA-ROCK pathway as a therapeutic strategy for treating TBI and summarize the recent advances in the development of RhoA-ROCK inhibitors.

Elevated BMP and Mechanical Signaling Through YAP1/RhoA Poises FOP Mesenchymal Progenitors for Osteogenesis

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease characterized by the formation of extraskeletal bone, or heterotopic ossification (HO), in soft connective tissues such as skeletal muscle. All familial and sporadic cases with a classic clinical presentation of FOP carry a gain-of-function mutation (R206H; c.617 G > A) in ACVR1, a cell surface receptor that mediates bone morphogenetic protein (BMP) signaling. The BMP signaling pathway is recognized for its chondro/osteogenic-induction potential, and HO in FOP patients forms ectopic but qualitatively normal endochondral bone tissue through misdirected cell fate decisions by tissue-resident mesenchymal stem cells. In addition to biochemical ligand-receptor signaling, mechanical cues from the physical environment are transduced to activate intracellular signaling, a process known as mechanotransduction, and can influence cell fates. Utilizing an established mesenchymal stem cell model of mouse embryonic fibroblasts (MEFs) from the Acvr1R206H/+ mouse model that mimics the human disease, we demonstrated that activation of the mechanotransductive effectors Rho/ROCK and YAP1 are increased in Acvr1R206H/+ cells. We show that on softer substrates, a condition associated with low mechanical signaling, the morphology of Acvr1R206H/+ cells is similar to the morphology of control Acvr1+/+ cells on stiffer substrates, a condition that activates mechanotransduction. We further determined that Acvr1R206H/+ cells are poised for osteogenic differentiation, expressing increased levels of chondro/osteogenic markers compared with Acvr1+/+ cells. We also identified increased YAP1 nuclear localization in Acvr1R206H/+ cells, which can be rescued by either BMP inhibition or Rho antagonism. Our results establish RhoA and YAP1 signaling as modulators of mechanotransduction in FOP and suggest that aberrant mechanical signals, combined with and as a result of the increased BMP pathway signaling through mutant ACVR1, lead to misinterpretation of the cellular microenvironment and a heightened sensitivity to mechanical stimuli that promotes commitment of Acvr1R206H/+ progenitor cells to chondro/osteogenic lineages.

Efficacy of fasudil for the treatment of aneurysmal subarachnoid hemorrhage: A systematic review protocol of randomized controlled trial

BACKGROUND

This study aims to systematically assess the efficacy and safety of fasudil for the treatment of aneurysmal subarachnoid hemorrhage (ASH).

METHODS

This study will include all of randomized controlled trials on the efficacy and safety of fasudil for the treatment of ASH. Ten electronic databases of PubMed, Embase, Cochrane Library, Google Scholar, Web of Science, Ovid, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure will be searched from inception to the May 1, 2019 without language restrictions. We will also search gray literatures to avoid missing any other potential studies. Two authors will independently perform study selection, data extraction and management, and methodologic quality assessment. The primary outcome is limbs function. The secondary outcomes comprise of muscle strength, muscle tone, quality of life, and adverse events.

RESULTS

This study will provide a comprehensive literature search on the current evidence of fasudil for the treatment of ASH from primary and secondary outcomes.

CONCLUSION

The results of this study will present evidence to determine whether fasudil is an effective and safety treatment for patients with ASH.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019136215.

The Rho Kinase Isoforms ROCK1 and ROCK2 Each Contribute to the Development of Experimental Pulmonary Fibrosis

Pulmonary fibrosis is thought to result from dysregulated wound repair after repetitive lung injury. Many cellular responses to injury involve rearrangements of the actin cytoskeleton mediated by the two isoforms of the Rho-associated coiled-coil-forming protein kinase (ROCK), ROCK1 and ROCK2. In addition, profibrotic mediators such as transforming growth factor-β, thrombin, and lysophosphatidic acid act through receptors that activate ROCK. Inhibition of ROCK activation may be a potent therapeutic strategy for human pulmonary fibrosis. Pharmacological inhibition of ROCK using nonselective ROCK inhibitors has been shown to prevent fibrosis in animal models; however, the specific roles of each ROCK isoform are poorly understood. Furthermore, the pleiotropic effects of this kinase have raised concerns about on-target adverse effects of ROCK inhibition such as hypotension. Selective inhibition of one isoform might be a better-tolerated strategy. In the present study, we used a genetic approach to determine the roles of ROCK1 and ROCK2 in a mouse model of bleomycin-induced pulmonary fibrosis. Using ROCK1- or ROCK2-haploinsufficient mice, we found that reduced expression of either ROCK1 or ROCK2 was sufficient to protect them from bleomycin-induced pulmonary fibrosis. In addition, we found that both isoforms contribute to the profibrotic responses of epithelial cells, endothelial cells, and fibroblasts. Interestingly, ROCK1- and ROCK2-haploinsufficient mice exhibited similar protection from bleomycin-induced vascular leak, myofibroblast differentiation, and fibrosis; however, ROCK1-haploinsufficient mice demonstrated greater attenuation of epithelial cell apoptosis. These findings suggest that selective inhibition of either ROCK isoform has the potential to be an effective therapeutic strategy for pulmonary fibrosis.

An Update on the Association of Protein Kinases with Cardiovascular Diseases

Background:

Protein kinases are the enzymes involved in phosphorylation of different proteins which leads to functional changes in those proteins. They belong to serine-threonine kinases family and are classified into the AGC (Protein kinase A/ Protein kinase G/ Protein kinase C) families of protein and Rho-associated kinase protein (ROCK). The AGC family of kinases are involved in G-protein stimuli, muscle contraction, platelet biology and lipid signaling. On the other hand, ROCK regulates actin cytoskeleton which is involved in the development of stress fibres. Inflammation is the main signal in all ROCK-mediated disease. It triggers the cascade of a reaction involving various proinflammatory cytokine molecules.

Methods:

Two ROCK isoforms are found in mammals and invertebrates. The first isoforms are present mainly in the kidney, lung, spleen, liver, and testis. The second one is mainly distributed in the brain and heart.

Results:

ROCK proteins are ubiquitously present in all tissues and are involved in many ailments that include hypertension, stroke, atherosclerosis, pulmonary hypertension, vasospasm, ischemia-reperfusion injury and heart failure. Several ROCK inhibitors have shown positive results in the treatment of various disease including cardiovascular diseases.

Conclusion:

ROCK inhibitors, fasudil and Y27632, have been reported for significant efficiency in dropping vascular smooth muscle cell hyper-contraction, vascular inflammatory cell recruitment, cardiac remodelling and endothelial dysfunction which highlight ROCK role in cardiovascular diseases.

Synthesis and pharmacological evaluation of novel isoquinoline N-sulphonylhydrazones designed as ROCK inhibitors

In this study, we synthesized a new congener series of N-sulphonylhydrazones designed as candidate ROCK inhibitors using the molecular hybridization of the clinically approved drug fasudil (1) and the IKK-β inhibitor LASSBio-1524 (2). Among the synthesized compounds, the N-methylated derivative 11 (LASSBio-2065) showed the best inhibitory profile for both ROCK isoforms, with IC50 values of 3.1 and 3.8 µM for ROCK1 and ROCK2, respectively. Moreover, these compounds were also active in the scratch assay performed in human breast cancer MDA-MB 231 cells and did not display toxicity in MTT and LDH assays. Molecular modelling studies provided insights into the possible binding modes of these N-sulphonylhydrazones, which present a new molecular architecture capable of being optimized and developed as therapeutically useful ROCK inhibitors.

Endovascular Treatment for Vasospasm after Aneurysmal Subarachnoid Hemorrhage Based on Data of JR-NET3

Endovascular treatments for vasospasm after subarachnoid hemorrhage are typically performed for patients who are refractory to recommended medical therapies. We analyzed the current status of endovascular treatments based on the data of Japanese Registry of Neuroendovascular Therapy (JR-NET)3, and evaluated factors related to improvement of imaging findings and neurological condition, and to mechanical hemorrhage complications. We collected data of 1211 treatments performed from 2010 to 2014. Target vessels for treatments were anterior circulation (n = 1079), posterior circulation (n = 91), and both (n = 32); the distribution of vasospasm was the proximal vessel (n = 754) to the Circle of Willis, distal vessel (n = 329), and both (n = 119). Of the treatments, 948 cases (78.3%) were intra-arterial administration of vasodilators and 259 (21.4%) were percutaneous transluminal angioplasty (PTA); 879 cases were the first intervention. The treatment time from onset was within 3 h in 378 (31.2%) cases, between 3 and 6 h in 349 (28.8%) cases, and over 6 h in 245 (20.2%) cases. The statistically significant factors associated with improvement on imaging findings was the first treatment, and treatment within 3 h from onset compared with that after 6 h. Additionally, the first and early treatments after the symptoms were associated with significantly improved neurological condition. All complications of mechanical hemorrhage occurred along with PTA. The findings show that endovascular treatment for vasospasm was effective, especially for cases who suffered from symptomatic vasospasm with a short interval after onset.

Therapeutically Targeting Platelet-Derived Growth Factor-Mediated Signaling Underlying the Pathogenesis of Subarachnoid Hemorrhage-Related Vasospasm

INTRODUCTION

Vasospasm accounts for a large fraction of the morbidity and mortality burden in patients sustaining subarachnoid hemorrhage (SAH). Platelet-derived growth factor (PDGF)-β levels rise following SAH and correlate with incidence and severity of vasospasm.

METHODS

The literature was reviewed for studies investigating the role of PDGF in the pathogenesis of SAH-related vasospasm and efficacy of pharmacological interventions targeting the PDGF pathway in ameliorating the same and improving clinical outcomes.

RESULTS

Release of blood under high pressure into the subarachnoid space activates the complement cascade, which results in release of PDGF. Abluminal contact of blood with cerebral vessels increases their contractile response to PDGF-β and thrombin, with the latter upregulating PDGF-β receptors and augmenting effects of PDGF-β. PDGF-β figures prominently in the early and late phases of post-SAH vasospasm. PDGF-β binding to the PDGF receptor-β results in receptor tyrosine kinase domain activation and consequent stimulation of intracellular signaling pathways, including p38 mitogen-activated protein kinase, phosphatidylinositol-3-kinase, Rho-associated protein kinase, and extracellular regulated kinase 1 and 2. Consequent increases in intracellular calcium and increased expression of genes mediating cellular growth and proliferation mediate PDGF-induced augmentation of vascular smooth muscle cell contractility, hypertrophy, and proliferation.

CONCLUSION

Treatments with statins, serine protease inhibitors, and small molecular pathway inhibitors have demonstrated varying degrees of efficacy in prevention of cerebral vasospasm, which is improved with earlier institution.

Current and Future Treatments for Persistent Pulmonary Hypertension in the Newborn

Persistent pulmonary hypertension in newborn (PPHN) is a serious and possibly fatal syndrome characterized by sustained foetal elevation of pulmonary vascular resistance at birth. PPHN may manifest secondary to other conditions as meconium aspiration syndrome, infection and congenital diaphragmatic hernia. This MiniReview provides the reader with an overview of current and future treatment options for patients with PPHN without congenital diaphragmatic hernia. The study is based on systematic searches in the databases PubMed and Cochrane Library and registered studies on Clinicaltrials.gov investigating PPHN. Inhaled nitric oxide (iNO) is well documented for treatment of PPHN, but 30% fail to respond to iNO. Other current treatment options could be sildenafil, milrinone, prostaglandin analogues and bosentan. There are several ongoing trials with sildenafil, but evidence is lacking for the other treatments and/or for the combination with iNO. Currently, there is no evidence for effect in PPHN of other treatments, for example tadalafil, macitentan, ambrisentan, riociguat and selexipag used for pulmonary arterial hypertension in adults. Experimental studies in animal models for PPHN suggest effect of a series of approaches including recombinant human superoxide dismutase, L-citrulline, Rho-kinase inhibitors and peroxisome proliferator-activated receptor-γ agonists. We conclude that iNO is the most investigated and the only approved pulmonary vasodilator for infants with PPHN. In the iNO non-responders, sildenafil currently seems to be the best alternative either alone or in combination with iNO. Systematic and larger clinical studies are required for testing the other potential treatments of PPHN.

Rho GTPases in Intellectual Disability: From Genetics to Therapeutic Opportunities

Rho-class small GTPases are implicated in basic cellular processes at nearly all brain developmental steps, from neurogenesis and migration to axon guidance and synaptic plasticity. GTPases are key signal transducing enzymes that link extracellular cues to the neuronal responses required for the construction of neuronal networks, as well as for synaptic function and plasticity. Rho GTPases are highly regulated by a complex set of activating (GEFs) and inactivating (GAPs) partners, via protein:protein interactions (PPI). Misregulated RhoA, Rac1/Rac3 and cdc42 activity has been linked with intellectual disability (ID) and other neurodevelopmental conditions that comprise ID. All genetic evidences indicate that in these disorders the RhoA pathway is hyperactive while the Rac1 and cdc42 pathways are consistently hypoactive. Adopting cultured neurons for in vitro testing and specific animal models of ID for in vivo examination, the endophenotypes associated with these conditions are emerging and include altered neuronal networking, unbalanced excitation/inhibition and altered synaptic activity and plasticity. As we approach a clearer definition of these phenotype(s) and the role of hyper- and hypo-active GTPases in the construction of neuronal networks, there is an increasing possibility that selective inhibitors and activators might be designed via PPI, or identified by screening, that counteract the misregulation of small GTPases and result in alleviation of the cognitive condition. Here we review all knowledge in support of this possibility.

Inhibiting Rho kinase promotes goal-directed decision making and blocks habitual responding for cocaine

The prelimbic prefrontal cortex is necessary for associating actions with their consequences, enabling goal-directed decision making. We find that the strength of action–outcome conditioning correlates with dendritic spine density in prelimbic cortex, suggesting that new action–outcome learning involves dendritic spine plasticity. To test this, we inhibited the cytoskeletal regulatory factor Rho kinase. We find that the inhibitor fasudil enhances action–outcome memory, resulting in goal-directed behavior in mice that would otherwise express stimulus-response habits. Fasudil transiently reduces prelimbic cortical dendritic spine densities during a period of presumed memory consolidation, but only when paired with new learning. Fasudil also blocks habitual responding for cocaine, an effect that persists over time, across multiple contexts, and depends on actin polymerization. We suggest that Rho kinase inhibition promotes goal-oriented action selection by augmenting the plasticity of prelimbic cortical dendritic spines during the formation of new action–outcome memories.

Action-outcome learning requires the prelimbic prefrontal cortex. Here the authors report that fasudil, a Rho kinase inhibitor, reduces dendritic spine densities on prelimbic neurons in an activity-dependent manner, stimulating goal-directed actions, and reducing habitual responding for cocaine.

Protective Effect of a Rho-kinase Inhibitor on Bladder Dysfunction in a Rat Model of Chronic Bladder Ischemia

OBJECTIVE

To investigate the effect of fasudil, a Rho-kinase inhibitor, on chronic ischemia-related bladder dysfunction.

MATERIALS AND METHODS

Male Sprague-Dawley rats (16 weeks old) were divided into control, chronic bladder ischemia (CBI), and CBI with fasudil treatment (CBI-Fa) groups. The CBI and CBI-Fa groups underwent balloon endothelial injury of bilateral iliac arteries and received a 2% cholesterol diet for 8 weeks after the procedure to induce CBI. The CBI-Fa group was given oral fasudil (30 mg/kg/day) using zonde for 8 weeks after the procedure. The control group received a regular diet for 8 weeks. After cystometry in a conscious state, rats from each group were euthanized, and the bladders and common iliac arteries were harvested for pharmacologic and histologic examination.

RESULTS

Mean wall thickness of the common iliac arteries was significantly greater in the CBI group than in controls. Contractile responses of muscle strips were significantly lower in CBI group rats than in controls. In the CBI group, micturition interval was significantly shorter, and bladder capacity was significantly lower compared with those in controls. In the CBI-Fa group, arterial wall thickening was significantly suppressed compared with the CBI group. Significant improvements in muscle strip contractility and cystometric parameters were seen in the CBI-Fa group compared with the CBI group.

CONCLUSION

Our results suggest that chronic treatment with fasudil could prevent neointimal formation in arteries and bladder dysfunction in this rat model. Fasudil may be therapeutically useful in protecting bladder function in chronically ischemic bladders.

ROCK-1 mediates diabetes-induced retinal pigment epithelial and endothelial cell blebbing: Contribution to diabetic retinopathy

In diabetic retinopathy, the exact mechanisms leading to retinal capillary closure and to retinal barriers breakdown remain imperfectly understood. Rho-associated kinase (ROCK), an effector of the small GTPase Rho, involved in cytoskeleton dynamic regulation and cell polarity is activated by hyperglycemia. In one year-old Goto Kakizaki (GK) type 2 diabetic rats retina, ROCK-1 activation was assessed by its cellular distribution and by phosphorylation of its substrates, MYPT1 and MLC. In both GK rat and in human type 2 diabetic retinas, ROCK-1 is activated and associated with non-apoptotic membrane blebbing in retinal vessels and in retinal pigment epithelium (RPE) that respectively form the inner and the outer barriers. Activation of ROCK-1 induces focal vascular constrictions, endoluminal blebbing and subsequent retinal hypoxia. In RPE cells, actin cytoskeleton remodeling and membrane blebs in RPE cells contributes to outer barrier breakdown. Intraocular injection of fasudil, significantly reduces both retinal hypoxia and RPE barrier breakdown. Diabetes-induced cell blebbing may contribute to ischemic maculopathy and represent an intervention target.

Effects of fasudil on pulmonary hypertension in clinical practice

Pulmonary hypertension (PH) is a pathophysiologic disorder that may involve multiple clinical conditions and can complicate the majority of cardiovascular and respiratory diseases. The presence of PH is associated with worse outcomes, but the efficacy of current therapy is still unsatisfactory. Because Rho-kinase (ROCK) plays an important role in the pathogenesis of PH, the ROCK inhibitor fasudil is expected to contribute to PH treatment. In animal models of PH, fasudil reduced pulmonary artery pressure (PAP) and improved survival. Furthermore, the short-term efficacy and safety of fasudil in the treatment of PH are demonstrated in clinical trials. Both PAP and pulmonary vascular resistance in patients with PH are significantly decreased by intravenous or inhaled fasudil without apparent side effect. However, no clinical trial has assessed the long-term efficacy of fasudil in the treatment of PH. Limited data suggest that the mid-term use of fasudil could improve exercise capacity and reduce in-hospital mortality. We also discuss the combined use of fasudil and other drugs for PH treatment. However, these combinations have not yet been evaluated in a clinical trial. According to animal studies, the combination of fasudil with beraprost or sildenafil shows synergistic effects, whereas the combination of fasudil with bosentan has no additional ameliorating effects on PH development.

Modulation of Microglial Activity by Rho-Kinase (ROCK) Inhibition as Therapeutic Strategy in Parkinson's Disease and Amyotrophic Lateral Sclerosis

Neurodegenerative diseases are characterized by the progressive degeneration of neurons in the central and peripheral nervous system (CNS, PNS), resulting in a reduced innervation of target structures and a loss of function. A shared characteristic of many neurodegenerative diseases is the infiltration of microglial cells into affected brain regions. During early disease stages microglial cells often display a rather neuroprotective phenotype, but switch to a more pro-inflammatory neurotoxic phenotype in later stages of the disease, contributing to the neurodegeneration. Activation of the Rho kinase (ROCK) pathway appears to be instrumental for the modulation of the microglial phenotype: increased ROCK activity in microglia mediates mechanisms of the inflammatory response and is associated with improved motility, increased production of reactive oxygen species (ROS) and release of inflammatory cytokines. Recently, several studies suggested inhibition of ROCK signaling as a promising treatment option for neurodegenerative diseases. In this review article, we discuss the contribution of microglial activity and phenotype switch to the pathophysiology of Parkinson’s disease (PD) and Amyotrophic lateral sclerosis (ALS), two devastating neurodegenerative diseases without disease-modifying treatment options. Furthermore, we describe how ROCK inhibition can influence the microglial phenotype in disease models and explore ROCK inhibition as a future treatment option for PD and ALS.

Rho Kinase Inhibition with Fasudil in the SOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis-Symptomatic Treatment Potential after Disease Onset

Despite an improved understanding of the genetic background and the pathomechanisms of amyotrophic lateral sclerosis (ALS) no novel disease-modifying therapies have been successfully implemented in clinical routine. Riluzole still remains the only clinically approved substance in human ALS treatment with limited efficacy. We have previously identified pharmacological rho kinase (ROCK) inhibitors as orally applicable substances in SOD1.G93A transgenic ALS mice (SOD1^G93A), which are able to extend survival time and improve motor function after presymptomatic treatment. Here, we have evaluated the therapeutic effect of the orally administered ROCK inhibitor Fasudil starting at a symptomatic disease stage, more realistically reflecting the clinical situation. Oral Fasudil treatment was initiated at a symptomatic stage at 80 days of life (d80) with 30 or 100 mg/kg body weight in both female and male mice. While baseline neurological scoring and survival were not influenced, Fasudil significantly improved motor behavior in male mice. Spinal cord pathology of motoneurons (MN) and infiltrating microglial cells (MG) at disease end-stage were not significantly modified. Although treatment after symptom onset was less potent than treatment in asymptomatic animals, our study shows the therapeutic benefits of this well-tolerated substance, which is already in clinical use for other indications.

Epithelial cell migration as a potential therapeutic target in early lung cancer

Lung cancer is the most lethal cancer type worldwide, with the majority of patients presenting with advanced stage disease. Targeting early stage disease pathogenesis would allow dramatic improvements in lung cancer patient survival. Recently, cell migration has been shown to be an integral process in early lung cancer ontogeny, with preinvasive lung cancer cells shown to migrate across normal epithelium prior to developing into invasive disease. TP53 mutations are the most abundant mutations in human nonsmall cell lung cancers and have been shown to increase cell migration via regulation of Rho-GTPase protein activity. In this review, we explore the possibility of targeting TP53-mediated Rho-GTPase activity in early lung cancer and the opportunities for translating this preclinical research into effective therapies for early stage lung cancer patients.

Preinvasive lung cancer cell migration is a potential novel therapeutic target in early lung cancerhttp://ow.ly/FJGm305JxMQ

Treatment of cerebral vasospasm following aneurysmal subarachnoid haemorrhage: a systematic review and meta-analysis

OBJECTIVES

To examine the clinical outcome of aneurysmal subarachnoid haemorrhage (aSAH) patients exposed to cerebral vasospasm (CVS)-targeted treatments in a meta-analysis and to evaluate the efficacy of intra-arterial (IA) approaches in patients with severe/refractory vasospasm.

METHODS

Randomised controlled trials, prospective and retrospective observational studies reporting clinical outcomes of aSAH patients exposed to CVS targeted treatments, published between 2006-2016 were searched using PubMed, EMBASE and the Cochrane Library. The main endpoint was the proportion of unfavourable outcomes, defined as a modified Rankin score of 3-6 at last follow-up.

RESULTS

Sixty-two studies, including 26 randomised controlled trials, were included (8,976 patients). At last follow-up 2,490 of the 8,976 patients had an unfavourable outcome, including death (random-effect weighted-average, 33.7%; 99% confidence interval [CI], 28.1-39.7%; Q value, 806.0; I ² = 92.7%). The RR of unfavourable outcome was lower in patients treated with Cilostazol (RR = 0.46; 95% CI, 0.25-0.85; P = 0.001; Q value, 1.5; I ² = 0); and in refractory CVS patients treated by IA intervention (RR = 0.68; 95% CI, 0.57-0.80; P < 0.0001; number needed to treat with IA intervention, 6.2; 95% CI, 4.3-11.2) when compared with the best available medical treatment.

CONCLUSIONS

Endovascular treatment may improve the outcome of patients with severe-refractory vasospasm. Further studies are needed to confirm this result.

KEY POINTS

• 33.7% of patients with cerebral Vasospasm following aneurysmal subarachnoid-hemorrhage have an unfavorable outcome. • Refractory vasospasm patients treated using endovascular interventions have lower relative risk of unfavourable outcome. • Subarachnoid haemorrhage patients with severe vasospasm may benefit from endovascular interventions. • The relative risk of unfavourable outcome is lower in patients treated with Cilostazol.

Central Angiotensin-II Increases Blood Pressure and Sympathetic Outflow via Rho Kinase Activation in Conscious Rabbits

Elevated sympathetic tone and activation of the renin-angiotensin system are pathophysiologic hallmarks of hypertension, and the interactions between these systems are particularly deleterious. The importance of Rho kinase as a mediator of the effects of angiotensin-II (AngII) in the periphery is clear, but the role of Rho kinase in sympathoexcitation caused by central AngII is not well established. We hypothesized that AngII mediates its effects in the brain by the activation of the RhoA/Rho kinase pathway. Chronically instrumented, conscious rabbits received the following intracerebroventricular infusion treatments for 2 weeks via osmotic minipump: AngII, Rho kinase inhibitor Fasudil, AngII plus Fasudil, or a vehicle control. AngII increased mean arterial pressure over the course of the infusion, and this effect was prevented by the coadministration of Fasudil. AngII increased cardiac and vascular sympathetic outflow as quantified by the heart rate response to metoprolol and the depressor effect of hexamethonium; coadministration of Fasudil abolished both of these effects. AngII increased baseline renal sympathetic nerve activity in conscious animals and impaired baroreflex control of sympathetic nerve activity; again Fasudil coinfusion prevented these effects. Each of these end points showed a statistically significant interaction between AngII and Fasudil. Quantitative immunofluorescence of brain slices confirmed that Rho kinase activity was increased by AngII and decreased by Fasudil. Taken together, these data indicate that hypertension, elevated sympathetic outflow, and baroreflex dysfunction caused by central AngII are mediated by Rho kinase activation and suggest that Rho kinase inhibition may be an important therapeutic target in sympathoexcitatory cardiovascular diseases.

Rho Kinases and Cardiac Remodeling

Hypertensive cardiac remodeling is characterized by left ventricular hypertrophy and interstitial fibrosis, which can lead to heart failure with preserved ejection fraction. The Rho-associated coiled-coil containing kinases (ROCKs) are members of the serine/threonine protein kinase family, which mediates the downstream effects of the small GTP-binding protein RhoA. There are 2 isoforms: ROCK1 and ROCK2. They have different functions in different types of cells and tissues. There is growing evidence that ROCKs contribute to the development of cardiovascular diseases, including cardiac fibrosis, hypertrophy, and subsequent heart failure. Recent experimental studies using ROCK inhibitors, such as fasudil, have shown the benefits of ROCK inhibition in cardiac remodeling. Mice lacking each ROCK isoform also exhibit reduced myocardial fibrosis in a variety of pathological models of cardiac remodeling. Indeed, clinical studies with fasudil have suggested that ROCKs could be potential novel therapeutic targets for cardiovascular diseases. In this review, we summarize the current understanding of the roles of ROCKs in the development of cardiac fibrosis and hypertrophy and discuss their therapeutic potential for deleterious cardiac remodeling. (Circ J 2016; 80: 1491-1498).

Rho Kinases in Health and Disease: From Basic Science to Translational Research

Rho-associated kinases ROCK1 and ROCK2 are key regulators of actin cytoskeleton dynamics downstream of Rho GTPases that participate in the control of important physiologic functions, S including cell contraction, migration, proliferation, adhesion, and inflammation. Several excellent review articles dealing with ROCK function and regulation have been published over the past few years. Although a brief overview of general molecular, biochemical, and functional properties of ROCKs is included, an effort has been made to produce an original work by collecting and synthesizing recent studies aimed at translating basic discoveries from cell and experimental models into knowledge of human physiology, pathophysiological mechanisms, and medical therapeutics. This review points out the specificity and distinct roles of ROCK1 and ROCK2 isoforms highlighted in the last few years. Results obtained from genetically modified mice and genetic analysis in humans are discussed. This review also addresses the involvement of ROCKs in human diseases and the potential use of ROCK activity as a biomarker or a pharmacological target for specific inhibitors.