Intravitreal fasudil monotherapy for treatment of refractory diabetic macular edema: A prospective interventional case series

BACKGROUND

Suboptimal response to conventional treatments in refractory diabetic macular edema (rDME) encourages efforts to identify new therapeutic options.

PURPOSE

To evaluate the effect of three monthly intravitreal injections of a Rho-associated protein kinase (ROCK) inhibitor (Fasudil, Asahi Kasei Pharma Corporation, Tokyo, Japan) in eyes with rDME.

METHODS

Ten eyes of 10 patients with DME unresponsive to at least six previous intravitreal bevacizumab (IVB) injections were recruited and underwent 3 consecutive monthly intravitreal injection of 0.025mg/0.05mL Fasudil. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) were evaluated as functional and anatomical response indicators, respectively.

RESULTS

The mean age was 60.1±5.1 years (range, 53-68). Five cases responded to treatment, two with both anatomical and functional responses (reduction of CMT from 521 to 395 and from 390 to 301 microns and improvement of BCVA from 0.3 to 0.1 LogMAR and 0.6 to 0.4 LogMAR, respectively) and three with only functional improvement (0.7 to 0.4; 0.7 to 0.4; and 0.3 to 0.1 LogMAR). Of note, cases with no significant change in CMT showed morphologic improvement of the retinal microstructure to some extent. No adverse event was observed during the study period.

CONCLUSION

Monotherapy with intravitreal injection of ROCK inhibitors appears to have moderate visual benefits in eyes with DME refractory to IVB. Such effects may be functionally significant without obvious anatomical improvement.

A Close Look at the Clinical Efficacy of Rho-Associated Protein Kinase Inhibitor Eye Drops for Fuchs Endothelial Corneal Dystrophy

ABSTRACT

The current understanding on the clinical efficacy of Rho-associated protein kinase (ROCK) inhibitor for treating Fuchs endothelial corneal dystrophy is summarized to clarify whether the "off-label" ROCK-inhibitor eye-drop application are appropriate. ROCK-inhibitor eye drops may eventually be deemed a cutting-edge therapy for Fuchs endothelial corneal dystrophy patients with acute corneal endothelial defect.

Alleviation of the doxorubicin-induced nephrotoxicity by fasudil in vivo and in vitro

OBJECTIVE

Treatment with the chemotherapeutic agent, doxorubicin (DOX), is limited by side effects. We have previously demonstrated that fasudil, a Rho/ROCK inhibitor, has antioxidant, anti-inflammatory and anti-apoptotic effects in contrast-induced acute kidney injury model. The present study to investigated the possible protective effect of fasudil, on DOX-induced nephrotoxicity.

MATERIALS AND METHOD

In vivo: Forty male C57BL/6 male mice were randomly divided into 4 groups: Control group, DOX treatment group (DOX group), DOX + low dose fasudil (DOX + L group), DOX + high dose fasudil (DOX + H group). Mice in 2-4 groups received DOX (2.5 mg/kg, i.p.) once a week for 8 weeks. The 3 and 4 group were given 2 mg/kg/d or 10 mg/kg/d fasudil before DOX injection. respectively. Meanwhile, the control group received saline. At the end of week eight, blood samples were collected for biochemical testing. The kidneys were removed for histological, immunohistochemical, Western blot, quantitative real-time PCR (qRT-PCR), and molecular detection. In vitro: NRK-52E cells were treated with 40 uM fasudil for 12 h, then incubated with 1 uM DOX for 24 h. Cells then collected for qRT-PCR and Western blot.

RESULTS

In vivo, fasudil treatment ameliorated DOX-induced immunofluorescence reaction of DNA damage-related factors (8-OHdG), decreased the expression of Bax, Caspase-3, p16, p21 and p53, and increased the expression of protein of Bcl-2, Bmi-1 and Sirt-1. In the mouse model, administration of fasudil significantly ameliorated DOX-induced kidney damage, suppressed cell apoptosis and senescence, ameliorated redox imbalance and DNA damage. At the same time, DOX produced obvious kidney damage revealed by kidney functions changes: increased serum creatinine (SCr) and blood urea nitrogen (BUN) concentrations. In addition, kidney tissue staining in the DOX group showed abnormal structure and fibroproliferative disorders. And DOX could promote the oxidation and senescence of kidney cells, leading to increased expression of 8-OHdG and senescence and apoptosis-related factors. On the contrary, fasudil treatment can effectively inhibit redox imbalance and DNA damage caused by DOX, and inhibit cell senescence and apoptosis. Fasudil can inhibit excessive activation of Rho/ROCK signaling pathway, thereby improving kidney tissue fibrosis and recovery kidney function.

CONCLUSION

Fasudil has a protective effect on DOX-induced nephrotoxicity in mice and NRK-52E cells, which can inhibit oxidative stress and DNA damage, inhibit apoptosis, and delays cell senescence by inhibiting RhoA/Rho kinase (ROCK) signaling pathway.

Ursolic acid reverses liver fibrosis by inhibiting interactive NOX4/ROS and RhoA/ROCK1 signalling pathways

Liver fibrosis is the reversible deposition of extracellular matrix (ECM) and scar formation after liver damage by various stimuli. The interaction between NOX4/ROS and RhoA/ROCK1 in liver fibrosis is not yet clear. Ursolic acid (UA) is a traditional Chinese medicine with anti-fibrotic effects, but the molecular mechanism underlying these effects is still unclear. We investigated the interaction between NOX4/ROS and RhoA/ROCK1 during liver fibrosis and whether these molecules are targets for the anti-fibrotic effects of UA. First, we confirmed that UA reversed CCl4-induced liver fibrosis. In the NOX4 intervention and RhoA intervention groups, related experimental analyses confirmed the decrease in CCl4-induced liver fibrosis. Next, we determined that the expression of NOX4 and RhoA/ROCK1 was decreased in UA-treated liver fibrotic mice. Furthermore, RhoA/ROCK1 expression was decreased in the NOX4 intervention group, but there was no significant change in the expression of NOX4 in the RhoA intervention group. Finally, we found that liver fibrotic mice showed a decline in their microbiota diversity and abundance, a change in their microbiota composition, and a reduction in the number of potential beneficial bacteria. However, in UA-treated liver fibrotic mice, the microbiota dysbiosis was ameliorated. In conclusion, the NOX4/ROS and RhoA/ROCK1 signalling pathways are closely linked to the development of liver fibrosis. UA can reverse liver fibrosis by inhibiting the NOX4/ROS and RhoA/ROCK1 signalling pathways, which may interact with each other.

CAR, a Homing Peptide, Prolongs Pulmonary Preferential Vasodilation by Increasing Pulmonary Retention and Reducing Systemic Absorption of Liposomal Fasudil

Here, we sought to elucidate the role of CAR (a cyclic peptide) in the accumulation and distribution of fasudil, a drug for pulmonary arterial hypertension (PAH), in rat lungs and in producing pulmonary specific vasodilation in PAH rats. As such, we prepared liposomes of fasudil and CAR-conjugated liposomal fasudil and assessed the liposomes for CAR conjugation, physical properties, entrapment efficiencies, in vitro release profiles, and stabilities upon incubation in cell culture media, storage, and aerosolization. We also studied the cellular uptake of fasudil in different formulations, quantified heparan sulfate (HS) in pulmonary arterial smooth muscle cells (PASMCs), and investigated the distribution of the liposomes in the lungs of PAH rats. We assessed the drug accumulation in a close and recirculating isolated perfused rat lung model and studied the pharmacokinetics and pharmacological efficacy of the drug and formulations in Sugen/hypoxia-induced PAH rats. The entrapment efficiency of the liposomal fasudil was 95.5 ± 4.5%, and the cumulative release was 93.95 ± 6.22%. The uptake of CAR liposomes by pulmonary arterial cells and their distribution and accumulation in the lungs were much greater than those of no-CAR-liposomes. CAR-induced increase in the cellular uptake was associated with an increase in HS expression by rat PAH-PASMCs. CAR, when conjugated with liposomal fasudil and given via an intratracheal instillation, extended the elimination half-life of the drug by four-fold compared with fasudil-in-no-CAR-liposomes given via the same route. CAR-conjugated liposomal fasudil, as opposed to fasudil-in-no-CAR-liposomes and CAR pretreatment followed by fasudil-in-no-CAR-liposomes, reduced the mean pulmonary arterial pressure by 40-50% for 6 h, without affecting the mean systemic arterial pressure. On the whole, this study suggests that CAR aids in concentrating the drug in the lungs, increasing the cellular uptake, extending the half-life of fasudil, and eliciting a pulmonary-specific vasodilation when the peptide remains conjugated on the liposomal surface, but not when CAR is given as a pretreatment or alone as an admixture with the drug.

Fasudil combined with methylcobalamin or lipoic acid can improve the nerve conduction velocity in patients with diabetic peripheral neuropathy: A meta-analysis

BACKGROUND

Fasudil (F) plus methylcobalamin (M) or lipoic acid (L) treatment has been suggested as a therapeutic approach for diabetic peripheral neuropathy (DPN) in numerous studies. However, the effect of the combined use still remains dubious.

OBJECTIVE

The aim of this report was to evaluate the efficacy of F plus M or L (F + M or F + L) for the treatment of DPN compared with that of M or L monotherapy, respectively, in order to provide the basis and reference for clinical rational drug use.

METHODS

Randomized controlled trials (RCTs) of F for DPN published up to September 2017 were searched. Relative risk (RR), mean difference (MD), and 95% confidence interval (CI) were calculated and heterogeneity was assessed with the I test. Sensitivity analyses were also performed. The outcomes measured were as follows: the clinical efficacy, median motor nerve conduction velocities (NCVs) (MNCVs), median sensory NCV (SNCV), peroneal MNCV, peroneal SNCV, and adverse effects.

RESULTS

Thirteen RCTs with 1148 participants were included. Clinical efficacy of F + M combination therapy was significantly better than M monotherapy (8 trials; RR 1.26, 95% CI 1.17-1.35, P < .00001, I = 0%), the efficacy of F + L combination therapy was also obviously better than L monotherapy (4 trials; RR 1.27, 95% CI 1.16-1.39, P < .00001, I = 0%). Compared with monotherapy, the pooled effects of combination therapy on NCV were (MD 6.69, 95% CI 4.74-8.64, P < .00001, I = 92%) for median MNCV, (MD 6.71, 95% CI 1.77-11.65, P = .008, I = 99%) for median SNCV, (MD 4.18, 95% CI 2.37-5.99, P < .00001, I = 94%) for peroneal MNCV, (MD 5.89, 95% CI 3.57-8.20, P < .00001, I = 95%) for peroneal SNCV. Furthermore, there were no serious adverse events associated with drug intervention.

CONCLUSION

Combination therapy with F plus M or L was superior to M or L monotherapy for improvement of neuropathic symptoms and NCVs in DPN patients, respectively. Moreover, no serious adverse events occur in combination therapy.

Inhaled Fasudil Lacks Pulmonary Selectivity in Thromboxane-Induced Acute Pulmonary Hypertension in Newborn Lambs

INTRODUCTION

Pulmonary hypertension (PH) is a potentially deadly disease for infants and adults with few existing medical interventions and no cure. In PH, increased blood pressure in the pulmonary artery eventually leads to heart failure. Fasudil, an antagonist of Rho-kinase, causes vasodilation leading to decreased systemic artery pressure and pulmonary artery pressure (PAP). This study compared the effects of fasudil administered as either an intravenous infusion or inhaled aerosol in newborn lambs.

HYPOTHESIS

Inhaled aerosol delivery of fasudil will provide selective pulmonary vasodilation when compared with intravenous administration.

METHODS

Newborn lambs (∼11 days) were surgically instrumented and mechanically ventilated under anesthesia. A pulmonary artery catheter and ultrasonic flow probe were inserted to measure hemodynamics. Acute PH was pharmaceutically induced via continuous intravenous infusion of thromboxane. After achieving a 2- to 3-fold elevation of PAP, fasudil was administered either as intravenous infusion (2.5 mg/kg) or inhaled aerosol (100 mg of fasudil in 2 mL of saline). Changes in PAP, mean systemic arterial pressure (MABP), pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), cardiac output, and heart rate were assessed. In addition, plasma concentrations of fasudil were measured.

RESULTS

Both routes of fasudil delivery produced significant decreases in PAP and PVR but also produced similar decreases in MABP and SVR. The C_max for intravenous fasudil was greater than that for inhaled fasudil.

CONCLUSIONS

These results suggest inhaled fasudil lacks pulmonary selectivity when compared with intravenous fasudil.

[Japanese Guidelines for the Management of Stroke 2015: overview of the chapter on Subarachnoid Hemorrhage]

After an interval of 6 years, the Japanese Guidelines for the Management of Stroke were revised in 2015 in accordance with recent advances in clinical knowledge. The chapter on subarachnoid hemorrhage includes new and revised recommendations for diagnosis, treatment selection, and management of vasospasm. The chapter on diagnosis recommends re-examination of vascular images at regular intervals in cases in which cerebral aneurysm was not detected on the first examination. The section dealing with treatment selection for cerebral aneurysmal emphasizes that the method for aneurysm obliteration should be selected based on consultation with both surgical and endovascular specialists. The role of triple-H therapy(i.e., induced hypertension, hypervolemia, and hemodilution) has changed from a preventive measure to a treatment option for symptomatic cerebral vasospasm.

Influence of Rho kinase inhibitor fasudil on late endothelial progenitor cells in peripheral blood of COPD patients with pulmonary artery hypertension

OBJECTIVE

To investigate the influence of Fasudil, a Rho inhibitor on the number and functions of the late endothelial progenitor cells in peripheral blood of chronic obstructive pulmonary diseases (COPD) patients with pulmonary artery hypertension.

BACKGROUND

It is not clear yet, whether Rho Kinase Inhibitor Fasudil can reduced pulmonary artery pressure through improving lung endothelial function.

METHODS

80 COPD patients with pulmonary artery hypertension were selected and divided into two groups: the treatment group and the control group, which had 40 patients, respectively. Changes in the number and function of the late endothelial progenitor cells in peripheral blood of the patients before and after the treatment were compared between the two groups. The changes on the pulmonary artery pressure were also compared.

RESULTS

The number of the late endothelial progenitor cells in peripheral blood of the treatment group increased and the function was enhanced. The pulmonary artery pressure was reduced. The difference before and after the treatment and with the control group was statistically significant (p < 0.05).

CONCLUSIONS

The Rho-kinase inhibitor Fasudil increased the number and enhanced the function of the late endothelial progenitor cells in peripheral blood of COPD patients with pulmonary artery hypertension (Tab. 3, Fig. 2, Ref. 17).

Fasudil and SOD packaged in peptide-studded-liposomes: Properties, pharmacokinetics and ex-vivo targeting to isolated perfused rat lungs

The present study investigated the feasibility of encapsulating two drugs, fasudil and superoxide dismutase (SOD), into liposomes for targeted and inhalational delivery to the pulmonary vasculature to treat pulmonary arterial hypertension (PAH). Nanosized liposomes were prepared by a thin-film formation and extrusion method, and the drugs were encapsulated by a modified freeze-thaw technique. The peptide CARSKNKDC (CAR), a pulmonary-specific targeting sequence, was conjugated on the surface of liposomes. Formulations were optimized for various physicochemical properties, tested for their ex-vivo and in-vivo drug absorption after intratracheal administration, and evaluated for short-term safety in healthy rats. The homogenous nanosized liposomes contained both SOD (~55% entrapment) and fasudil (~40% entrapment), and were stable at 4°C and after nebulization. Liposomes released the drugs in a controlled-release fashion. Compared with plain liposomes, CAR-liposomes increased the uptake by pulmonary endothelial and smooth muscle cells by ~2-fold. CAR-liposomes extended the biological half-lives of SOD and fasudil by ~3-fold. Ex-vivo studies demonstrated that CAR-liposomes were better retained in the lungs than plain liposomes. Bronchoalveolar lavage studies indicated the safety of peptide-equipped liposomes as pulmonary delivery carriers. Overall, this study demonstrates that CAR-liposomes may be used as inhalational carriers for SOD plus fasudil-based combination therapy for PAH.

Prophylactic intra-arterial administration of fasudil hydrochloride for vasospasm following subarachnoid haemorrhage

PURPOSE

We evaluated patients treated with prophylactic intra-arterial administration of fasudil hydrochloride (IAF) after subarachnoid haemorrhage (SAH).

MATERIALS AND METHODS

Between August 1998 and December 2012, 92 patients with aneurysmal SAH were treated with IAF for angiographic vasospasm without ischemic symptoms after their follow-up angiography. Patients comprised 50 women and 42 men, aged 24-83 (mean 56.6) years. IAF consisted of 15 mg of fasudil hydrochloride dissolved in 20 ml physiological saline and injected through a catheter during approximately 15 min, after diagnostic angiography. The clinical outcome was evaluated using the Glasgow Outcome Scale (GOS) at discharge and ischemic lesions resulting from vasospasm were assessed on computed tomography (CT) scan at discharge.

RESULTS

Forty-eight patients underwent surgical clipping and 44 patients underwent endovascular coiling. Angiographic improvement was observed in all patients (100 %). At discharge, 76 (83.0 %) of 92 patients showed good recovery on GOS. Nine patients developed progression of delayed ischemic neurological deficits (DIND) and three of these patients had ischemic lesions on CT scans. No patient had any significant changes in vital signs or any other adverse effects resulting from IAF.

CONCLUSION

IAF therapy was safe and effective for patients with vasospasm following SAH. Prophylactic IAF therapy may prevent symptomatic vasospasm.

Acute hemodynamic response of infused fasudil in patients with pulmonary arterial hypertension: a randomized, controlled, crossover study

BACKGROUND

The Rho-kinase pathway has been shown to be involved in the pathogenesis of PAH. As yet, however, the acute effects of the Rho-kinase inhibitor fasudil have not been compared with established pulmonary selective vasodilators in patients with PAH. We compared the acute effects of intravenous fasudil with inhaled iloprost in patients with pulmonary arterial hypertension (PAH).

METHODS

Using a crossover design, 50 patients with PAH (idiopathic PAH, PAH associated with repaired left-to-right cardiac shunts, or connective tissue disease) were randomized to iloprost inhalation (5 μg) and intravenous fasudil (30 mg over 30 min). Hemodynamic data were collected at baseline and during acute drug exposure.

RESULTS

Comparable decreases were observed in mean pulmonary artery pressure (-4.6 ± 4.3 mmHg vs. -4.8 ± 4.2 mmHg) and pulmonary vascular resistance (-3.0 ± 3.0 Wood U vs. -2.2 ± 2.7 Wood U) with fasudil infusion and iloprost inhalation, respectively, during acute challenge. However, fasudil infusion resulted in a more pronounced increase in mean cardiac output and mixed venous oxygen saturation compared with iloprost inhalation (13.7 ± 17.1% vs. 6.9 ± 15.0%; p=0.044 and 4.5 ± 5.3% vs. 2.7 ± 8.2%; p=0.044, respectively). Whereas inhaled iloprost resulted in a non-significant increase in mean systemic arterial oxygen saturation (0.8 ± 3.6%), infused fasudil resulted in a non-significant reduction (-0.6 ± 1.1%).

CONCLUSION

Infused fasudil improved pulmonary hemodynamics in patients with PAH without significant toxicity.

[The Effects of Inhibitors of Rho- and tyrosine c-Src-kinases on serotonin-induced constrictions of the aorta and mesenteric artery in rats]

We found that the inhibitor of Rho-kinase fasudil selectively inhibited constriction of isolated rings of the aorta and mesenteric artery in rats in response to application of the agonists of 5HT2A-(DOI and TBC-2) and 5HT1A-receptors (8-OH-DPAT) and did not influence vasoconstriction induced by serotonin. We demonstrate for the first time that application of the agonists of 5HT2C-receptors (MK 212 and SCH 23390) did not influence the tone of "intact" vessels. The marked vasoconstrictory effect of the agonists of 5HT2C-receptors was observed in the vessels preconstricted due to angiotensin II or vasopressin. We found that the inhibitor of Rho-kinase did not influence negatively on MK 212 or SCH 23390-induced constriction of isolated rings of the aorta and mesenteric artery in rats. We suppose.that, in the presence of fasudil, serotonin induces constriction of vessels through the interaction with 5HT2C-receptors and signal transduction from these receptors does not involve Rho-kinase activity. We found that fasudil attenuated vasoconstriction induced by norepinephrine and vasopressin by 40%. We.demonstrated that tyrosine c-Src-kinase plays the most important role in signal transduction from 5HT-receptors because its effects are specific with relation to these receptors.

Roles of Rho guanine nucleotide triphosphatases in hippocampal mossy fiber sprouting in the pentylenetetrazole kindling model

BACKGROUND

One unique feature of chronic human and experimental epilepsy is hippocampal dentate granule cell axon (mossy fiber) sprouting which creates an aberrant positive-feedback circuit that may be epileptogenic. However, the mechanism underlying this process remains unclear. Rho guanine nucleotide triphosphatases (RhoGTP ases) Rac1 and RhoA are important regulators of axon growth and synaptic plasticity and can be blocked by treatment with fasudil. We hypothesized that Rac1 and RhoA are involved in aberrant mossy fiber sprouting (MFS).

METHODS

A temporal lobe epilepsy model was established by intraperitoneal pentylenetetrazole (PTZ) injection for animals in PTZ group, and fasudil was injected 30 minutes prior to PTZ injection for animals in PTZ + Fas group. The expression of Rac1 and RhoA in the rat hippocampus was tested at different time points by immunohistochemistry, Western blot and quantitative real-time PCR. Mossy fiber sprouting in the hippocampus was evaluated by Timm staining.

RESULTS

Rac1 and RhoA were significantly up-regulated in the PTZ group, and as predicted, the degree of aberrant MFS was correspondingly increased. However, the expression of Rac1 and RhoA was not inhibited in the PTZ + Fas group, and the epileptiform activity, EEG and aberrant MFS were not suppressed following PTZ + Fas treatment.

CONCLUSIONS

RhoGTPases play a role in MFS but fasudil is not sufficient to inhibit RhoGTPases and MFS in the PTZ kindling model.

Starch-coated magnetic liposomes as an inhalable carrier for accumulation of fasudil in the pulmonary vasculature

In this study, we tested the feasibility of magnetic liposomes as a carrier for pulmonary preferential accumulation of fasudil, an investigational drug for the treatment of pulmonary arterial hypertension (PAH). To develop an optimal inhalable formulation, various magnetic liposomes were prepared and characterized for physicochemical properties, storage stability and in vitro release profiles. Select formulations were evaluated for uptake by pulmonary arterial smooth muscle cells (PASMCs) - target cells - using fluorescence microscopy and HPLC. The efficacy of the magnetic liposomes in reducing hyperplasia was tested in 5-HT-induced proliferated PASMCs. The drug absorption profiles upon intratracheal administration were monitored in healthy rats. Optimized spherical liposomes - with mean size of 170 nm, zeta potential of -35mV and entrapment efficiency of 85% - exhibited an 80% cumulative drug release over 120 h. Fluorescence microscopic study revealed an enhanced uptake of liposomes by PASMCs under an applied magnetic field: the uptake was 3-fold greater compared with that observed in the absence of magnetic field. PASMC proliferation was reduced by 40% under the influence of the magnetic field. Optimized liposomes appeared to be safe when incubated with PASMCs and bronchial epithelial cells. Compared with plain fasudil, intratracheal magnetic liposomes containing fasudil extended the half-life and area under the curve by 27- and 14-fold, respectively. Magnetic-liposomes could be a viable delivery system for site-specific treatment of PAH.

The protective effect of fasudil pretreatment combined with ischemia postconditioning on myocardial ischemia/reperfusion injury in rats

OBJECTIVE

Ischemic postconditioning (IPO) and pharmacological pretreatment may reduce myocardial necrosis and apoptosis during ischemia/reperfusion. This study aimed to determine the protective effect of fasudil pretreatment combined with IPO on myocardial ischemia/reperfusion injury in rats and explore the possible mechanisms.

MATERIALS AND METHODS

The SD rats were induced by intraperitoneal injection of fasudil hydrochloride (1 or 10 mg/kg) 60 min before the initiation of ischemia, while the control rats were given the same volume of saline. The hearts were hung on the Langendorff perfusion apparatus and underwent 30 min global ischemia and 120 min reperfusion. The IPO protocol was induced by six cycles of 10 sec ischemia and 10 sec reperfusion at the onset of reperfusion. The hemodynamic changes were measured, myocardial infarct size was determined by triphenyltetrazolium chloride (TTC) staining, cardiomyocyte apoptosis was detected by TUNEL staining, lactate dehydrogenase (LDH) was analyzed from coronary effluents, phosphorylation of Akt and eNOS, as well as expression of Bcl-2 and Bax were measured by western blotting analysis.

RESULTS

The high-dose fasudil (10 mg/kg) pretreatment group and IPO group significantly improved post-ischemia cardiac function, reduced myocardial infarct size, attenuated cardiomyocyte apoptosis, decreased the release of LDH, increased expression of phospho-Akt, phospho-eNOS and Bcl-2, and reduced expression of Bax compared with the control group (p < 0.05). In addition, the high-dose fasudil pretreatment combined with IPO group could further improved post-ischemia cardiac function, reduced myocardial infarct size, attenuated cardiomyocyte apoptosis, decreased the release of LDH, increased expression of phospho-Akt, phospho-eNOS and Bcl-2, and reduced expression of Bax compared with the single treatment groups (p < 0.05).

CONCLUSIONS

The combination of high-dose fasudil pretreatment and IPO had a synergistic protective effect on myocardial ischemia/reperfusion injury, which was mediated via upregulating the PI3K/Akt/eNOS pathway, increasing expression of antiapoptotic Bcl-2, and decreasing expression of proapoptotic Bax.

Systemic Availability of the Active Metabolite Hydroxy-Fasudil After Administration of Fasudil to Different Sites of the Human Gastrointestinal Tract

This study evaluated the gastrointestinal absorption of fasudil, a novel Rho kinase inhibitor for the treatment of stable angina, at different sites using remote-controlled capsules and assessed the feasibility of developing an extended-release formulation. Ten healthy male volunteers were enrolled, and 8 subjects completed this single-dose, open-label, randomized, 5-way crossover study. Forty milligrams of fasudil HCl was administered as solution to the distal ileum and ascending colon, as powder to the ascending colon, and orally as an immediate-release tablet and solution. All treatments were well-tolerated and no serious adverse events were observed. The mean systemic availabilities of M3 relative to the oral solution were 1.04 (distal ileum, solution), 1.14 (ascending colon, solution), 1.27 (ascending colon, powder) and 1.04 (oral tablet), indicating similar systemic availability of M3 after administration of fasudil HCl to different gastrointestinal sites. The results suggest that development of a once-a-day extended-release formulation for fasudil HCl should be readily achievable.

[Effect of Fasudil on miroglia and astrocytes in experimental autoimmune encephalomyelitis mice]

AIM

To explore the therapeutic effect of Fasudil and its possible mechanisms in experimental autoimmune encephalomyelitis (EAE) mice, mainly focusing on the roles of microglia and astrocytes in the treatment.

METHODS

Female adult C57BL/6 mice were immunized with MOG35-55 to induce chronic EAE. Fasudil was injected on day 3 p.i. (early Fasudil treatment), or at the onset of EAE (late Fasudil treatment). Normal saline was injected in other mice as EAE controls in a similar manner. Clinical score and body mass were recorded every other day. The expressions of iNOS on microglia and p-NF-κB/p65 on astrocytes were measured by immunohistochemistry and Western blotting. The levels of IL-1β and TNF-α in spinal cord homogenate were determined by ELISA.

RESULTS

Fasudil delayed onset and ameliorated the severity of EAE. Fasudil inhibited the expression of iNOS on microglia and p-NF-κB/p65 on astrocytes in spinal cords, accompanied by the inhibition of inflammatory factors IL-1β and TNF-α.

CONCLUSION

Fasudil exhibits therapeutic effect on EAE, possibly through inhibiting inflammatory molecules on microglia and astrocyte.

Rho-kinase inhibition improves vasodilator responsiveness during hyperinsulinemia in the metabolic syndrome

In patients with the metabolic syndrome (MetS), the facilitatory effect of insulin on forearm vasodilator responsiveness to different stimuli is impaired. Whether the RhoA/Rho kinase (ROCK) pathway is involved in this abnormality is unknown. We tested the hypotheses that, in MetS patients, ROCK inhibition with fasudil restores insulin-stimulated vasodilator reactivity and that oxidative stress plays a role in this mechanism. Endothelium-dependent and -independent forearm blood flow responses to acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, were assessed in MetS patients (n = 8) and healthy controls (n = 5) before and after the addition of fasudil (200 μg/min) to an intra-arterial infusion of insulin (0.1 mU/kg/min). In MetS patients (n = 5), fasudil was also infused without hyperinsulinemia. The possible involvement of oxidative stress in the effect of fasudil during hyperinsulinemia was investigated in MetS patients (n = 5) by infusing vitamin C (25 mg/min). In MetS patients, compared with saline, fasudil enhanced endothelium-dependent and -independent vasodilator responses during insulin infusion (P < 0.001 and P = 0.008, respectively), but not in the absence of hyperinsulinemia (P = 0.25 and P = 0.13, respectively). By contrast, fasudil did not affect vasoreactivity to ACh and SNP during hyperinsulinemia in controls (P = 0.11 and P = 0.56, respectively). In MetS patients, fasudil added to insulin and vitamin C did not further enhance vasodilation to ACh and SNP (P = 0.15 and P = 0.43, respectively). In the forearm circulation of patients with the MetS, ROCK inhibition by fasudil improves endothelium-dependent and -independent vasodilator responsiveness during hyperinsulinemia; increased oxidative stress seems to be involved in the pathophysiology of this phenomenon.

Subdose of fasudil suppresses myocardial fibrosis in aldosterone-salt-treated uninephrectomized rats

Rho/Rho kinase (ROCK) pathway plays an important role in pathological cardiovascular conditions. In the present study, the effect of a subdose of fasudil, a selective ROCK inhibitor, on systemic hypertension and myocardium fibrosis induced by aldosterone was investigated in uninephrectomized Sprague-Dawley rats (SD). Treatment with a fasudil (10 mg/kg x day, s.c.) for 5 weeks decreased the activity of ROCK activity for more than 53% as determined by the expression of phosphorylated Myosin phosphatase target subunit 1 (MYPT1). Although this dose of fasudil did not signifantly prevent hypertension, it remarkably alleviated myocardium hypertrophy and fibrosis. The elevated transcriptional expression of transforming growth factors beta1 (TGF-beta1), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and collagen I and III was also decreased. These results demonstrated that fasudil can protect the myocardium from injury by aldosterone at a subhypertensive dose.

Inhalation of Stachybotrys chartarum evokes pulmonary arterial remodeling in mice, attenuated by Rho-kinase inhibitor

Stachybotrys chartarum, a ubiquitous fungus in our environment, has been suspected of causing respiratory symptoms in humans, such as acute infant pulmonary hemorrhage and asthma. We previously established a mouse model in which repeated inhalation of Stachybotrys chartarum spores caused pulmonary hypertension. To further investigate the model, particularly in the pulmonary circulation, mice were intra-tracheally injected with spores, 18 times over 12 weeks. Severe muscularization was observed in the small- to medium-sized pulmonary arteries. Bronchoalveolar lavage fluid revealed an increase in eosinophils accompanied by high concentrations of Th2-associated cytokines, IL-4, IL-5, but not Th1-associated IFN-γ. The remodeling was temporary, resolving after cessation of spore inhalation. Chronic inhibition of the RhoA/Rho-kinase pathway by fasudil attenuated pulmonary arterial remodeling. These data suggest that Stachybotrys-mediated remodeling is caused by Th2-associated inflammation and can be resolved by Rho-kinase inhibition, either through direct effects on smooth muscle hypertrophy or through indirect effects on vascular inflammation. These data also show that extensive pulmonary vascular remodeling, often thought of as a fixed lesion, will spontaneously resolve in the absence of underlying molecular etiology.

Characterization of dysferlin deficient SJL/J mice to assess preclinical drug efficacy: fasudil exacerbates muscle disease phenotype

The dysferlin deficient SJL/J mouse strain is commonly used to study dysferlin deficient myopathies. Therefore, we systematically evaluated behavior in relatively young (9-25 weeks) SJL/J mice and compared them to C57BL6 mice to determine which functional end points may be the most effective to use for preclinical studies in the SJL/J strain. SJL/J mice had reduced body weight, lower open field scores, higher creatine kinase levels, and less muscle force than did C57BL6 mice. Power calculations for expected effect sizes indicated that grip strength normalized to body weight and open field activity were the most sensitive indicators of functional status in SJL/J mice. Weight and open field scores of SJL/J mice deteriorated over the course of the study, indicating that progressive myopathy was ongoing even in relatively young (<6 months old) SJL/J mice. To further characterize SJL/J mice within the context of treatment, we assessed the effect of fasudil, a rho-kinase inhibitor, on disease phenotype. Fasudil was evaluated based on previous observations that Rho signaling may be overly activated as part of the inflammatory cascade in SJL/J mice. Fasudil treated SJL/J mice showed increased body weight, but decreased grip strength, horizontal activity, and soleus muscle force, compared to untreated SJL/J controls. Fasudil either improved or had no effect on these outcomes in C57BL6 mice. Fasudil also reduced the number of infiltrating macrophages/monocytes in SJL/J muscle tissue, but had no effect on muscle fiber degeneration/regeneration. These studies provide a basis for standardization of preclinical drug testing trials in the dysferlin deficient SJL/J mice, and identify measures of functional status that are potentially translatable to clinical trial outcomes. In addition, the data provide pharmacological evidence suggesting that activation of rho-kinase, at least in part, may represent a beneficial compensatory response in dysferlin deficient myopathies.

Role of rho-kinase in the regulation of vascular tone in hypertensive renal transplant recipients

Activation of rho-kinase (ROK) is involved in the development of hypertension as it is a potent regulator of vascular smooth muscle cell (VSMC) contractility. Here we evaluated whether activation of ROK is present in hypertensive kidney transplant recipients (NTX). We tested the effect of the ROK-inhibitor fasudil on the regulation of forearm blood flow (FBF) in NTX and in healthy control subjects (CTL). In addition potential modulating effects of ROK-inhibition on local vascular nitric oxide (NO) release were studied. The effect of intra-arterial infusion of fasudil on FBF was studied by venous-occlusion plethysmography in NTX and CTL. To unmask the role of NO fasudil was infused with/without clamping of vascular NO in NTX and CTL. To unravel the basal NO-mediated tone the NO-synthase inhibitor l-NMMA was infused. Fasudil markedly but comparably increased FBF in NTX and CTL. The vascular response to fasudil was blunted during NO-clamp in CTL (104+/-18% vs. 244+/-48% for NO-clamp+fasudil vs. fasudil alone; baseline=0%, P<0.05) but not in NTX. The l-NMMA-induced vasoconstriction was impaired in NTX compared to CTL. In NTX and CTL basal vascular tone equally depends on ROK. Fasudil-induced vasodilatation is partly mediated by vascular NO in CTL but not in NTX. The greater NO-insensitive fasudil-induced increase in FBF in NTX suggests an increased ROK-mediated VSMC constrictor tone in these patients. Basal NO-mediated tone is attenuated in hypertensive NTX.

[Role of coil embolization and arterial injection in elderly subarachnoid hemorrhage patients: preliminary report]

With the recent advanced aging seen in society, the number of elderly patients with aneurismal subarachnoid hemorrhage (SAH) is increasing. We focused on current management of SAH in patients who were over 75 years old. From January 1st, 2004 to the end of June, 2007, we had treated 170 SAH patients including 39 who were over 75 years old. We divided the patients into three groups : Coiling Group, Clipping Group, and conservative treatment group (Conservative Group). We analyzed the Hunt-Kosnik grade (H-K), the rate of symptomatic vasospasm, the rate of shunting operation, the Glasgow Outcome Scale (GOS) at 30 days after the onset of SAH, bed rest periods and rate of shunt operation retrospectively. The Conservative Group included many H-K poor grade cases. Symptomatic vasospasm occurred significantly less in the Coiling Group. Rates of shunting operation did not have any significant change. GOS of the Coiling Group and Clipping Group had no significant change, due to the effectiveness of arterial injection for vasospasm. Patients in the Coiling Group started walking significantly earlier than members of other groups. Twenty-five percent of the Clipping Group needed a shunt operation but no patients of the Coiling Group needed a shunt. For elderly SAH patients, we recommend doing coil embolization or clipping and maintaining the patients' activity in daily life. Interventional treatment is necessary to improve results for elderly SAH patients.

Administration of the Rho-kinase inhibitor fasudil before ischemia or just after reperfusion, but not 30 min after reperfusion, protects the stunned myocardium in swine

OBJECTIVES

We assessed the effect of administration time for fasudil treatment of the stunned myocardium in 40 anesthetized open chest swine.

MATERIALS AND METHODS

All swine were subjected to 12 min ischemia followed by reperfusion to generate stunned myocardium. Group A (n = 11) received saline in place of fasudil both before ischemia and after reperfusion. Group B (n = 10) received 30 min intravenous fasudil at a rate of 13 mug/kg/min starting 45 min before ischemia and received saline after reperfusion. Groups C (n = 10) and D (n = 9) received saline before ischemia, and received fasudil at a rate of 13 microg kg(-1) min(-1) starting just before reperfusion in group C and 30 min after reperfusion in group D. In both groups, treatment lasted 30 min. Myocardial contractility was assessed by percent segment shortening (%SS).

RESULTS AND DISCUSSION

Three swine in group A, 2 swine in each of groups B and C, and one swine in group D had ventricular fibrillation or tachycardia after reperfusion and were excluded from further analysis. The changes of %SS from baseline at 90 min after reperfusion in groups B and C were 68 +/- 8% and 75 +/- 8%, respectively, which were significantly higher than in group A or D (47 +/- 10% or 43 +/- 8%).

CONCLUSION

We conclude that fasudil administered before ischemia or just after reperfusion, but not 30 min after reperfusion, protects the stunned myocardium.

Rho kinase inhibitor improves motor dysfunction and hypoalgesia in a rat model of lumbar spinal canal stenosis

STUDY DESIGN

Immunohistochemical and behavioral study using a rat cauda equina compression model.

OBJECTIVE

To investigate, after cauda equina compression by spinal canal stenosis (SCS), Rho activation in the spinal cord and cauda equina, and the effect of intrathecal administration of a Rho kinase inhibitor on hypoalgesia and motor dysfunction.

SUMMARY OF BACKGROUND DATA

Compression of the cauda equina caused by SCS is a common clinical disorder associated with sensory disturbance and intermittent claudication. Cauda equina compression is thought to reduce blood flow and result in nerve degeneration caused by various cytokines. Rho, a member of the small GTPases, is a signal transmitter. It promotes Wallerian degeneration, decreases blood flow in the spinal cord and brain, and increases expression of several cytokines. Currently, Rho kinase inhibitor is used clinically to treat progressive nerve damage due to cerebrovascular disorders. However, its effect for SCS has not been evaluated.

METHODS

Forty-two 6-week-old male Sprague-Dawley rats (200-250 g) were used. For the SCS model (n = 27), a small piece of silicon was placed under the lamina of the fourth lumbar vertebra. In the sham-operated group, laminectomies were performed at L5 only (n = 15). We examined mechanical sensitivity and motor function using von Frey hairs and a treadmill, and immunohistochemically localized Rho in the spinal ventral neurons, axons, and Schwann cells in the cauda equina. We also examined the effects of intrathecally administered Rho kinase inhibitor for hypoalgesia or motor dysfunction caused by SCS.

RESULTS

We observed motor dysfunction and hypoalgesia and activated Rho-immunoreactive cells in spinal ventral neuroreported to induce neurite and axonal outgrowth in the spinal cord and brain after nervous system injury. In addition, 1 report showed that Rho kinase was involved in Wallerian degeneration that was rescued by Rho kinase inhibitor. Furthermore, it is thought that Rho is involved in TNF-alpha and interleukin (IL) production in the central nervous system, and the production was inhibited by administering Rho kinase inhibitor in the central nervous system. Regardns, axons, and Schwann cells in the cauda equina. Intrathecal administration of Rho kinase inhibitor improved mechanical hypoalgesia and motor dysfunction caused by SCS.

CONCLUSION

Activated Rho may play an important role in nerve damage in the cauda equina in SCS. Rho kinase inhibitor may be a useful tool in determining the pathomechanism of cauda equina syndrome caused by SCS.

Vasodilator effects of fasudil, a Rho-kinase inhibitor, on retinal arterioles in stroke-prone spontaneously hypertensive rats

PURPOSE

The aim of this study was to examine the vasodilator effect of fasudil, a Rho-kinase inhibitor, on retinal arterioles in stroke-prone spontaneously hypertensive rats (SHRSPs) and in age-matched normotensive Wistar-Kyoto rats (WKYs).

METHODS

Rats (12-14 weeks-old) were anesthetized with thiobutabarbital (120 mg/kg, intraperitoneal). Fundus images were captured with a digital camera that was equipped with a special objective lens. The vasodilator responses of retinal arterioles were assessed by measuring changes in the diameters of the vessels.

RESULTS

The baseline diameter of the retinal arteriole was significantly smaller in SHRSPs than in WKYs. Fasudil (50-200 microg/kg/min, intravenous) dose-dependently increased the diameter of the retinal arteriole and decreased the systemic blood pressure in both groups. The vasodilator effect of fasudil on the retinal arteriole in SHRSPs was greater than in WKYs.

CONCLUSIONS

These results suggest that fasudil has beneficial effects on retinal vascular complications associated with chronic hypertension.

Fasudil attenuates sympathetic nervous activity in the adrenal medulla of spontaneously hypertensive rats

We investigated the effects of fasudil, a Rho kinase inhibitor, on hypertension in spontaneously hypertensive rats and on the catecholamine synthetic pathway. Ten-week-old male SHR and Wistar-Kyoto rats were administered fasudil (10 mg/kg/day s.c.) for 4 days. Systolic blood pressure was measured using the tail-cuff method. Catecholamine levels were measured with high-performance liquid chromatography-ECD methods. Tyrosine hydroxylase protein levels were measured in Western blot analysis. The tyrosine hydroxylase mRNA level was measured using real-time PCR methods. Fasudil significantly decreased systolic blood pressure in spontaneously hypertensive rats, but not in Wistar-Kyoto rats. Fasudil also significantly decreased catecholamine, tyrosine hydroxylase protein, and tyrosine hydroxylase mRNA levels in the adrenal medulla of spontaneously hypertensive rats. These results suggest that the depressor effects of fasudil on hypertension in spontaneously hypertensive rats may be related to inhibition of the catecholamine synthetic pathway.

[Effects of fasudil on neuropathic pain-like state in mice]

The aim of the present study was to investigate the role of protein kinases within the spinal cord in the development of a neuropathic pain-like state induced by partial sciatic nerve ligation in mice. Thermal hyperalgesia induced by nerve ligation in mice was markedly suppressed by either repeated intrathecal (i.t.) pre-treatment or post-treatment with the selective protein kinase (PKC) inhibitor RO-32-0432 and the selective Rho kinase inhibitor Y-27632. In contrast, sciatic nerve ligation-induced thermal hyperalgesia was not observed by repeated i.t. pre-treatment with the selective PKA inhibitor KT5720. Interestingly, thermal hyperalgesia induced by nerve ligation in mice was significantly suppressed by repeated i.t. post-treatment with fasudil, which possesses the inhibitory effect of several protein kinases including PKC and Rho kinase. Collectively, these findings suggest that a long-lasting activation of PKC and RhoA/Rho kinase pathways in the spinal cord may be responsible for the development of thermal hyperalgesia induced by nerve ligation in mice. The present data raise the fascinating possibility that i.t. or epidural administration with fasudil may be useful for the treatment of neuropathic pain.

Rho kinase contributes to basal vascular tone in humans: role of endothelium-derived nitric oxide

Our objective was to determine the role of the Rho-associated kinase (ROK) for the regulation of FBF (FBF) and to unmask a potential role of ROK for the regulation of endothelium-derived nitric oxide (NO). Moreover, the effect of fasudil on the constrictor response to endothelin-1 was recorded. Regarding background, phosphorylation of the myosin light chain (MLC) determines the calcium sensitivity of the contractile apparatus. MLC phosphorylation depends on the activity of the MLC kinase and the MLC phosphatase. The latter enzyme is inhibited through phosphorylation by ROK. ROK has been suggested to inhibit NO generation, possibly via the inhibition of the Akt pathway. In this study, the effect of intra-arterial infusion of the ROK inhibitor fasudil on FBF in 12 healthy volunteers was examined by venous occlusion plethysmography. To unmask the role of NO, fasudil was infused during NO clamp. As a result, fasudil markedly increased FBF in a dose-dependent manner from 2.34 ± 0.21 to 6.96 ± 0.93 ml/100 ml forearm volume at 80 μg/min ( P < 0.001). At 1,600 μg/min, fasudil reduced systolic, diastolic, and mean arterial pressure while increasing heart rate. Fasudil abolished the vasoconstrictor effect of endothelin-1. The vascular response to fasudil (80 μmol/min) was blunted during NO clamp (104 ± 18% vs. 244 ± 48% for NO clamp + fasudil vs. fasudil alone; data as ratio between infused and noninfused arm with baseline = 0%, P < 0.05). In conclusion, 1) basal peripheral and systemic vascular tone depends on ROK; 2) a significant portion of fasudil-induced vasodilation is mediated by NO, suggesting that vascular bioavailable NO is negatively regulated by ROK; and 3) the constrictor response to endothelin involves the activation of ROK.

The Rho-Associated Kinase Inhibitor Fasudil Hydrochloride Enhances Neural Regeneration after Axotomy in the Peripheral Nervous System

BACKGROUND

The Rho family of small GTPases is responsible for various processes involving actin cytoskeleton in eukaryotic cells, including neurite outgrowth. Several substances found at the peripheral nerve injury site were shown to activate one member of this family, Rho. The activation of Rho leads to neurite outgrowth inhibition and the development of posttraumatic neuropathic pain. The authors used the clinically tested Rho-associated kinase inhibitor fasudil hydrochloride to enhance the functional recovery of the peripheral nerve in the rat.

METHODS

In the peroneal nerve interpositional graft model, the authors administered fasudil (experimental groups) or saline (control groups) (1) intraperitoneally and (2) directly into the graft by microinjection (n = 6 animals per experimental condition). Neural recovery was assessed during postoperative follow-up lasting 80 days by peroneal functional index, electrophysiologic, and histomorphometric analyses.

RESULTS

The peroneal functional index returned to values not significantly different from preoperative values on days 55 (fasudil injected into the graft) and 60 (fasudil injected intraperitoneally) in the experimental groups. In the control groups, this took 70 (saline injected intraperitoneally) and 75 days (saline injected into the graft). These results are supported by electrophysiologic and histomorphologic assessments.

CONCLUSIONS

The authors determined that fasudil hydrochloride was capable of accelerating the functional regeneration after peripheral nerve axotomy, which is consistent with the results of reports about Rho cascade disruption in the central nervous system. Because fasudil hydrochloride is a clinically tested drug, it could be used to enhance neural regeneration in human patients as well.

Cold-induced cutaneous vasoconstriction is mediated by Rho kinase in vivo in human skin

Cutaneous vasoconstriction (VC) is the initial thermoregulatory response to cold exposure and can be elicited through either whole body or localized skin cooling. However, the mechanisms governing local cold-induced VC are not well understood. We tested the hypothesis that Rho kinase participates in local cold-induced cutaneous VC. In seven men and women (20-27 yr of age), up to four ventral forearm skin sites were instrumented with intradermal microdialysis fibers for localized drug delivery during cooling. Skin blood flow was monitored at each site with laser-Doppler flowmetry while local skin temperature was decreased and maintained at 24 degrees C for 40 min. Cutaneous vascular conductance (CVC; laser-Doppler flowmetry/mean arterial pressure) was expressed as percent change from 34 degrees C baseline. During the first 5 min of cooling, CVC decreased at control sites (lactated Ringer solution) to -45 +/- 6% (P < 0.001), increased at adrenoceptor-antagonized sites (yohimbine + propranolol) to 15 +/- 14% (P = 0.002), and remained unchanged at both Rho kinase-inhibited (fasudil) and adrenoceptor-antagonized + Rho kinase-inhibited sites (yohimbine + propranolol + fasudil) (-9 +/- 1%, P = 0.4 and -6 +/- 2%, P = 0.4, respectively). During the last 5 min of cooling, CVC further decreased at all sites when compared with baseline values (control, -77 +/- 4%, P < 0.001; adrenoceptor antagonized, -61 +/- 3%, P < 0.001; Rho kinase inhibited, -34 +/- 7%, P < 0.001; and adrenoceptor antagonized + Rho kinase inhibited sites, -35 +/- 3%, P < 0.001). Rho kinase-inhibited and combined treatment sites were significantly attenuated when compared with both adrenoceptor-antagonized (P < 0.01) and control sites (P < 0.0001). Rho kinase mediates both early- and late-phase cold-induced VC, supporting in vitro findings and providing a putative mechanism through which both adrenergic and nonadrenergic cold-induced VC occurs in an in vivo human thermoregulatory model.

Rho kinase inhibition improves endothelial function in human subjects with coronary artery disease

Investigations from basic biology suggest that activation of the Rho/Rho kinase pathway reduces the bioavailability of nitric oxide (NO) and thereby promotes atherosclerosis and its clinical complications. Yet, little information is available about the relationship of the Rho/Rho kinase pathway to NO bioavailability in humans with atherosclerosis. Accordingly, we determined whether inhibition of Rho kinase augments NO bioavailability and improves endothelial function in human subjects with coronary artery disease (CAD). Thirteen CAD subjects and 16 age- and sex-matched healthy controls were randomly assigned to receive the Rho kinase inhibitor, fasudil, or placebo for 1 month each in a double-blind crossover trial. Flow-mediated, endothelium-dependent and nitroglycerin-induced, endothelium-independent vasodilation were assessed by brachial artery ultrasonography. Rho kinase activity was measured in peripheral leukocytes. Fasudil increased endothelium-dependent vasodilation in CAD subjects from 9.4+/-1.9% to 13.4+/-1.9% (P=0.001) but not in healthy controls (from 11.3+/-1.4% to 7.7+/-1.1%; P=0.07). Endothelium-independent vasodilation was not affected by fasudil in either CAD or healthy subjects. Fasudil reduced Rho kinase activity by 59+/-18% in CAD subjects (P=0.001) but not in healthy subjects (by 3+/-6%; P=0.60). The change in endothelium-dependent vasodilation achieved with fasudil relative to placebo was inversely proportional to Rho kinase inhibition (ie, greater Rho kinase inhibition was associated with larger improvement in endothelium-dependent vasodilation) (r=-0.48; P=0.01). These findings suggest that Rho/Rho kinase activation promotes endothelial dysfunction in humans with atherosclerosis. Inhibition of the Rho/Rho kinase pathway should provide a useful strategy to restore NO bioavailability in humans with atherosclerosis.

Chronic Administration of an Oral Rho Kinase Inhibitor Prevents the Development of Vasculogenic Erectile Dysfunction in a Rat Model

INTRODUCTION

It has been shown that the Rho/Rho kinase calcium sensitizing pathway has been implicated in the pathogenesis of erectile dysfunction as well as systemic atherosclerosis.

AIMS

To test whether chronic treatment of an oral Rho kinase inhibitor (fasudil, 5-Isoquinolinesulfonyl homopiperazine) could prevent the development of both vasculogenic erectile dysfunction and pelvic atherosclerosis in a rat model.

METHODS

Rats (3 months old) were divided into three groups (N = 10 in each group): control (group 1); atherosclerosis (group 2); and fasudil-treated (group 3). Groups 2 and 3 received atherosclerosis-prone treatment (6 weeks of 1% cholesterol diet and early 2 weeks of N(G)-nitro-L-arginine methyl ester [3 mg/mL/day] treatment, but group 3 was concurrently treated with fasudil (30 mg/kg/day) for 6 weeks.

MAIN OUTCOME MEASURES

The amount of systemic endothelial injury (plasma von Willebrand factor) and pelvic atherosclerosis was determined. Erectile function, cavernosal Rho kinase activity, and expressions of total and phosphorylated endothelial nitric oxide synthase (eNOS) were also determined.

RESULTS

Group 2 showed a significant amount of pelvic atherosclerosis and endothelial injury. The rats also showed elevated cavernosal Rho kinase activity and impaired erectile function. Immunoblot showed a decreased total as well as phosphorylated eNOS expression. The treatment with fasudil partly but significantly ameliorated the development of pelvic atherosclerosis and plasma level of von Willebrand factor. The treatment also normalized the erectile function, cavernosal Rho kinase activity, and total eNOS expression. The overexpression of phospho-eNOS was observed in group 3.

CONCLUSIONS

These results indicate that the Rho/Rho kinase pathway is substantially involved in the development of erectile dysfunction and pelvic atherosclerosis, both of which could be prevented by chronic treatment with fasudil. Thus, Rho kinase might be considered a novel target for the prevention of vasculogenic erectile dysfunction.

Delayed treatment with Rho-kinase inhibitor does not enhance axonal regeneration or functional recovery after spinal cord injury in rats

Axonal regeneration in the central nervous system is blocked by many different growth inhibitory factors. Some of these inhibitors act on neurons by activating RhoA and Rho-kinase, an effector of RhoA. Several studies have shown that Rho-kinase inhibition immediately after spinal cord injury enhances axonal sprouting and functional recovery. In this study, we ask whether delayed treatment with Rho-kinase inhibitor is effective in promoting regeneration and functional recovery. We administered Fasudil, a Rho-kinase inhibitor, locally to the injury site 4 weeks or immediately after contusion of the thoracic spinal cord in rats. Although the immediate treatment significantly stimulated axonal sprouting and recovery of hindlimb function, treatment started 4 weeks after surgery had no effect on fiber sprouting or locomotor recovery. Our findings suggest that RhoA/Rho-kinase alone may not account for the irreversible arrest of axon outgrowth in the chronic stage of injury in the central nervous system.

Long-term inhibition of Rho kinase suppresses intimal thickening in autologous vein grafts in rabbits

BACKGROUND

Rho kinase plays an important role in vascular smooth muscle cell (VSMC) contraction and other cellular functions, such as proliferation, migration, and apoptosis. Recent studies have demonstrated that long-term inhibition of Rho kinase suppresses coronary artery spasm and vascular lesion formation after arterial injury. In the cardiovascular surgery field, intimal thickening in vein grafts is the major cause of late graft failure, for which no effective treatment has yet been developed. In this study, we examined whether long-term inhibition of Rho kinase suppresses intimal thickening in autologous vein grafts in rabbits.

METHODS

Male rabbits were randomly divided into two groups and received normal chow (control group) or a special chow containing 0.09% fasudil (fasudil group). After oral administration, fasudil is metabolized to a specific Rho kinase inhibitor, hydroxyfasudil. Each group underwent reversed autologous vein graft surgery with the internal jugular vein into the left common carotid artery. At 1, 2, and 4 weeks after the operation, we examined the extent of intimal thickening of the graft and VSMC proliferation and apoptosis.

RESULTS

The intimal thickening was significantly suppressed in the fasudil group compared with the control group at 2 and 4 weeks after the operation. In the fasudil group, VSMC proliferation was suppressed at 1 and 2 weeks after the operation, whereas VSMC apoptosis was enhanced at 2 weeks after the procedure.

CONCLUSIONS

These results indicate that Rho kinase is substantially involved in the pathogenesis of intimal thickening of vein grafts and that it is an important therapeutic target for the prevention of graft failure.

In vivo X-ray angiography in the mouse brain using synchrotron radiation

BACKGROUND AND PURPOSE

We, for the first time, performed in vivo x-ray angiography in the mouse brain using SPring-8, a third-generation synchrotron radiation facility.

METHODS

A thin PE-50 tube was placed in the unilateral external carotid artery in adult male C57BL/6J mice. While maintaining the blood flow in the internal carotid artery, 33 muL of contrast agent was injected and then selective angiography of the hemisphere was performed.

RESULTS

The average diameters of cerebral artery were as follows: 142.5+/-7.90 microm in middle cerebral artery, 138.3+/-9.35 microm in anterior cerebral artery, 120.5+/-5.53 microm in posterior cerebral artery, and 162.6+/-10.87 microm in internal carotid artery (n=5). To demonstrate the changes in diameter, we induced hypercapnia and detected the dilatation of the vessels between 121% and 124% of the original diameters (n=5). We also repeated angiography in the mice before and after intracarotid injection of vasodilatation drugs papaverine hydrochloride, ATP disodium, and fasudil hydrochloride hydrate and demonstrated the chronological changes in the diameters in each artery at 1, 5, 15, and 30 minutes after injection (n=1 for each drug).

CONCLUSIONS

Using only a minimum volume of the contrast agent, synchrotron radiation enables us to study x-ray angiography in the mouse brain. The morphology of the vessels can be clearly observed under physiological conditions. The diameters and their changes can also be successfully studied in vivo.

Safe and efficient drug delivery system with liposomes for intrathecal application of an antivasospastic drug, fasudil

Pharmacological treatment for cerebral ischemia and cerebral vasospasm following subarachnoid hemorrhage (SAH) cannot attain sufficiently high concentrations of the drugs in the cerebrospinal fluid (CSF) without precipitating systemic side effects. We recently developed a liposomal drug delivery system for intrathecal application that can maintain effective concentrations of cerebral vasodilator, fasudil, in the CSF. A single intrathecal injection of liposomal fasudil could maintain a therapeutic drug concentration in the CSF over a period time due to their sustained-release property, significantly decreasing infarct size in a rat model of acute ischemia and reducing vasoconstriction of the rat and dog basilar artery in a model of SAH. In this review, we are introducing our new less-invasive intrathecal drug delivery system that provides an alternative and safe method to deliver therapeutic agents.

Long-term administration of rho-kinase inhibitor ameliorates renal damage in malignant hypertensive rats

We have shown recently that fasudil, a Rho-kinase inhibitor, has renoprotective effects in salt-sensitive hypertensive rats. We hypothesized that activation of Rho-kinase is involved in the pathogenesis of glomerulosclerosis in malignant hypertensive rats. To test this hypothesis, we studied the following 4 groups: control Wistar-Kyoto rats, untreated deoxycorticosterone-acetate salt spontaneously hypertensive rats (DOCA-SHR), low-dose fasudil-treated DOCA-SHR, and high-dose fasudil-treated DOCA-SHR. After 3 weeks of treatment, the effects of fasudil were examined. DOCA-SHR was characterized by increased blood pressure (BP); increased kidney weight; decreased renal function; increased proteinuria; abnormal histological findings; increased monocyte/macrophage infiltration; increased urinary 8-isoprostran levels; increased gene expression of collagen I, collagen III, transforming growth factor-beta, and reduced nicotinamide-adenine dinucleotide phosphate oxidase subunits (p40phox, p47phox, and p67phox); and decreased gene expression of endothelial NO synthase (eNOS) in the renal cortex as compared with Wistar-Kyoto rats. Long-term high-dose fasudil treatment significantly improved renal function and histological findings without changing BP, as compared with untreated DOCA-SHR. Interestingly, long-term fasudil treatment significantly decreased monocyte/macrophage infiltration and urinary 8-isoprostran excretion, in association with decreased mRNA levels of transforming growth factor-beta, collagen I, collagen III, and NADPH oxidase subunits (p40phox, p47phox, and p67phox), and increased mRNA levels of eNOS in the renal cortex. Long-term low-dose fasudil treatment tended to improve these variables slightly but did not affect most of them significantly. Our results suggest that long-term fasudil treatment provides renoprotective effects independent of BP-lowering activity. These renoprotective effects are associated with inhibition of extracellular matrix gene expression, monocyte/macrophage infiltration, oxidative stress, and upregulation of eNOS gene expression.

Rho-kinase inhibitor improves increased vascular resistance and impaired vasodilation of the forearm in patients with heart failure

BACKGROUND

Rho-kinase is suggested to have an important role in enhanced vasoconstriction in animal models of heart failure (HF). Patients with HF are characterized by increased vasoconstriction and reduced vasodilator responses to reactive hyperemia and exercise. The aim of the present study was to examine whether Rho-kinase is involved in the peripheral circulation abnormalities of HF in humans with the Rho-kinase inhibitor fasudil.

METHODS AND RESULTS

Studies were performed in patients with HF (HF group, n=26) and an age-matched control group (n=26). Forearm blood flow was measured with a strain-gauge plethysmograph during intra-arterial infusion of graded doses of fasudil or sodium nitroprusside. Resting forearm vascular resistance (FVR) was significantly higher in the HF group than in the control group. The increase in forearm blood flow evoked by fasudil was significantly greater in the HF group than in the control group. The increased FVR was decreased by fasudil in the HF group toward the level of the control group. By contrast, FVR evoked by sodium nitroprusside was comparable between the 2 groups. Fasudil significantly augmented the impaired ischemic vasodilation during reactive hyperemia after arterial occlusion of the forearm in the HF group but not in the control group. Fasudil did not augment the increased FVR evoked by phenylephrine in the control group significantly.

CONCLUSIONS

These results indicate that Rho-kinase is involved in increased FVR and impaired vasodilation of the forearm in patients with HF.

Intro-arterial Administration of Fasudil Hydrochloride for Vasospasm Following Subarachnoid Hemorrhage-Analysis of Time-Density Curve With Digital Subtraction Angiography-

The cerebral circulatory dynamics were evaluated before and after intra-arterial administration of fasudil hydrochloride in 20 patients with angiographic vasospasm after subarachnoid hemorrhage (SAH). The region of interest time-density curves obtained before and after intra-arterial administration of fasudil hydrochloride were compared in the proximal portion of the middle cerebral artery in the early arterial phase, the distal portion of the middle cerebral artery in the late arterial phase, and the transverse sinus in the venous phase. In the early arterial phase, the time to peak and the time to half-peak were significantly reduced. In the late arterial phase and venous phase, the time to peak was significantly reduced. These results suggest that intra-arterial administration of fasudil hydrochloride induced dilation of the proximal arteries, and improved cerebral microcirculation. The present study suggests that intra-arterial administration of fasudil hydrochloride is effective as a treatment for vasospasm following SAH.

Beneficial Acute Effects of Rho-Kinase Inhibitor in Patients With Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a poor prognostic disease with limited treatment options. Rho-kinase is involved in the pathophysiology of several diseases underlying smooth muscle hypercontraction, so the purpose of this study was to investigate the efficacy of fasudil, a Rho-kinase inhibitor, in patients with PAH.

METHODS AND RESULTS

Fasudil 30 mg was intravenously injected over 30 min in 8 patients (all female, mean +/- SD, 41+/-11 years) with PAH. The lowest total pulmonary resistance (TPR) time was within 30-60 min after administration. Administration of fasudil decreased TPR from 1,069+/-573 dyne . s . cm (-5) to 809+/-416 dyne . s . cm(-5) (p<0.005) and mean pulmonary arterial pressure from 41.3+/-12.8 mmHg to 37.9+/-14.6 mmHg (p<0.05). The cardiac index was increased from 2.42+/-0.73 L . min(-1) . m(-2) to 2.84+/-0.79 L . min(-1) . m(-2) (p<0.02). Systemic vascular resistance and systolic systemic arterial pressure (SAP) were decreased (p<0.005, p=0.09, respectively), but the decrease in SAP was small (-6.4+/-9.1 mmHg).

CONCLUSION

These results suggest that Rho-kinase is involved in the pathogenesis of human PAH and that fasudil is a novel therapeutic agent.

External Carotid Artery Aneurysm Developing After Embolization of a Ruptured Posterior Inferior Cerebellar Artery Aneurysm in a Patient With Cervicocephalic Fibromuscular Dysplasia-Case Report-

A 30-year-old man presented with an aneurysm of the left posterior inferior cerebellar artery manifesting as subarachnoid hemorrhage and cerebellar infarction. Angiography demonstrated string-of-beads sign typical of fibromuscular dysplasia (FMD) in the extracranial carotid and vertebral arteries. The aneurysm and the parent artery were successfully embolized with Guglielmi detachable coils. Severe vasospasm developed 1 week after admission, and was treated several times by selective injection of vasodilator. A new aneurysm of the left external carotid artery became evident 1 month later, whereas only slight dilation had previously been apparent. This angiographic sequence demonstrated a new arterial dissection. Despite the possibility of damage to the artery during multiple catheterizations, arterial wall changes caused by FMD appear to have been primarily responsible. This case emphasizes the need for particular care in performing vascular interventional procedures in the presence of FMD.

Smoking, Endothelial Function, and Rho-Kinase in Humans

Objective— Smoking is associated with endothelial dysfunction and activated Rho-kinase in vascular smooth muscle cells (VSMCs) in humans. The purpose of this study was to elucidate the relationship between endothelial function and Rho-kinase activity in forearm VSMCs in healthy young men.

Methods and Results— We evaluated the forearm blood flow (FBF) responses to acetylcholine (ACh), fasudil, a Rho-kinase inhibitor, and sodium nitroprusside (SNP) in male smokers (n=10) and nonsmokers (n=14). FBF was measured by using a strain-gauge plethysmography. The vasodilatory effect of ACh was significantly smaller in smokers than that in nonsmokers. The vasodilatory effect of fasudil was significantly greater in smokers than that in nonsmokers. The vasodilatory effects of SNP in the 2 groups were similar. There was a significant correlation between the maximal FBF response to fasudil and that to ACh ( r =−0.67; P <0.01). There was no significant correlation between the maximal FBF response to fasudil and that to SNP. The intra-arterial coinfusion of fasudil significantly increased the FBF response to ACh in smokers but not in nonsmokers. There were no significant differences between FBF response to fasudil alone and that in combination with N G -monomethyl- l -arginine in smokers and in nonsmokers. The intra-arterial coinfusion ascorbic acid did not alter the FBF response to fasudil in both groups.

Conclusions— These findings suggest that smoking is involved in not only endothelial dysfunction but also activation of Rho-kinase in VSMCs in forearm circulation, and that there is a significant correlation between endothelial function and Rho-kinase activity in VSMCs.

[Cerebral circulation dynamics following fasudil intravenous infusion: a CT perfusion study]

Using CT perfusion studies we evaluated changes in the cerebral circulation before and after the intravenous administration of fasudil 60 mg in 8 patients 7 to 14 days after a subarachnoid hemorrhage. The mean duration to the peak of the time-density curve and the average peak value did not change. In areas with cerebral blood perfusion (CBP) less than 40 ml/100 g/min, the CBP increased from 34.4 +/- 4.7 ml/100 g/min to 41.0 +/- 8.2 ml/100 g/min (p < 0.01) after fasudil infusion, the cerebral blood volume (CBV) rose from 2.41 +/- 0.53 ml/100 g to 2.55 +/- 0.5 ml/100 g (p < 0.05), and the mean transit time (MTT) decreased from 5.09 +/- 1.13 s to 4.82 +/- 0.89 s (p < 0.05). In areas where the CBP was more than 41 ml/100 g/min, the CBP did not change (from 51.8 +/- 7.6 ml/100 g/min to 50.4 +/- 8.4 ml/100 g/min), the CBV decreased (from 2.75 +/- 0.62 ml/100 g to 2.67 +/- 0.55 ml/100 g, p < 0.05), and the MTT did not change (from 3.80 +/- 0.76 s to 3.77 +/- 0.72 s). These results suggest that intravenous infusion of fasudil 60 mg increases cerebral blood flow and cerebral blood volume and shortens MTT in areas with decreased blood flow due to vasospasm.

Inhaled Rho Kinase Inhibitors Are Potent and Selective Vasodilators in Rat Pulmonary Hypertension

We have found in chronically hypoxic rats that acute intravenous administration of the Rho kinase inhibitor Y-27632 nearly normalizes the pulmonary hypertension (PH) but has no pulmonary vascular selectivity. In this study, we tested if oral or inhaled Y-27632 would be an effective and selective pulmonary vasodilator in hypoxic PH. Although acute oral Y-27632 caused a marked and sustained decrease in mean pulmonary arterial pressure (MPAP), it also decreased mean systemic arterial pressure (MSAP). In contrast, 5 minutes of inhaled Y-27632 decreased MPAP without reducing MSAP. The hypotensive effect of inhaled Y-27632 on hypoxic PH was greater than that of inhaled nitric oxide, and the effect lasted for at least 5 hours. Inhaled fasudil, another Rho kinase inhibitor, caused selective MPAP reductions in monocrotaline-induced PH and in spontaneous PH in fawn-hooded rats, as well as in chronically hypoxic rats. These results suggested that inhaled Y-27632 was more effective than inhaled nitric oxide as a selective pulmonary vasodilator in hypoxic PH, and that Rho kinase-mediated vasoconstriction was also involved in the other models of PH. Inhaled Rho kinase inhibitors might be useful for acute vasodilator testing in patients with PH, and future work should evaluate their efficacy in the long-term treatment of PH.

Treatment of Cerebral Vasospasm with Intra-arterial Fasudil Hydrochloride

OBJECTIVE

Symptomatic cerebral vasospasm is a major cause of disability and death in patients with aneurysmal subarachnoid hemorrhage. The purpose of this study was to determine the efficacy of intra-arterial infusion (IAF) of fasudil hydrochloride for symptomatic vasospasm in terms of neurological improvement and the angiographic features of cerebral vessels.

METHODS

A consecutive series of 23 patients underwent IAF therapy for the treatment of symptomatic vasospasm after subarachnoid hemorrhage. Angiographic vasospasm was assessed before and after the IAF treatment. Immediate clinical effect was assessed within 24 hours after the IAF treatment, and the Glasgow Outcome Scale was used to evaluate late clinical outcome at 3 months after the onset.

RESULTS

IAF treatment was performed on 34 occasions for 23 patients (16 women, 7 men). Angiographic improvement was observed on all occasions (100%), and immediate clinical improvement was observed on 15 occasions (44.1%). At 3-month follow-up, 15 patients (65.2%) showed good recovery or moderate disability on the Glasgow Outcome Scale.

CONCLUSION

IAF therapy was effective in dilating spastic arteries, and clinical improvement was observed in approximately half of the fasudil hydrochloride infusions. Our findings suggested that the IAF therapy was safe and effective for patients with symptomatic vasospasm after subarachnoid hemorrhage.

[Intra-arterial administration of fasudil hydrochloride: duration of action]

Intra-arterial infusion (IA) of fasudil hydrochloride for cerebral vasospasm is performed in many institutions and is associated with few side effects. Nonetheless, as optimum dose and duration of action remain unknown, the present study aimed to clarify these variables. We performed intra-arterial injection of fasudil hydrochloride for eight patients with cerebral vasospasm 7-13 days after subarachnoid hemorrhage. Fasudil hydrochloride was administered via the internal carotid artery without selective microcatheterization, at a concentration and speed of 30 mg/20 ml/10-15 min, using a total dose of 30-60 mg. Cerebral angiography was used to measure change in blood vessel diameter at 19 points, and perfusion CT was used to detect changes in cerebral blood perfusion (CBP), cerebral blood volume (CBV), and mean transit time (MTT) at 12 hemispheres. Investigations were performed before IA, immediately after IA (post IA), and 4.5 to 6 hours later. For central vessels, (A1, M1) mean change in diameter (cm) measured pre IA, post IA, and 4.5-6 hours later was 1.2 +/- 0.68, 1.5 +/- 0.72, and 1.2 +/- 0.7, respectively. For peripheral vessels (peripheral to A1, M1, and the ophthalmic artery) change in diameter (cm) was 0.65 +/- 0.16, 0.97 +/- 0.24, and 0.71 +/- 0.24, respectively. Average CBP (m/100g/min) in the infused hemisphere at pre IA, post IA, and 4.5-6 hours later was 41.6 +/- 3.56, 46.4 +/- 5.82, 41.6 +/- 7.42, respectively. Average CBV (ml/100g) was 2.72 +/- 0.21, 2.73 +/- 0.21, 2.91 +/- 0.42, respectively and average MTT (sec) was 5.16 +/- 0.38, 4.57 +/- 0.70, 5.55 +/- 1.0, respectively. Changes in peripheral vessel diameter and in MTT were statistically significant. Therefore, when performing intra-arterial administration of fasudil hydrochloride, clinicians should be aware that vasodilator effect is less than 6 hours.