These results suggest that extracorporeal cardiac SW therapy is an effective and noninvasive therapeutic strategy for ischemic heart disease.

Abstract-Primary pulmonary hypertension is a fatal disease characterized by endothelial dysfunction, hypercontraction and proliferation of vascular smooth muscle cells (VSMCs), and migration of inflammatory cells, for which no satisfactory treatment has yet been developed. We have recently demonstrated that intracellular signaling pathway mediated by Rho-kinase, an effector of the small GTPase Rho, is involved in the pathogenesis of arteriosclerosis. In the present study, we examined whether the Rho-kinase-mediated pathway is also involved in the pathogenesis of fatal pulmonary hypertension in rats. Animals received a subcutaneous injection of monocrotaline, which resulted in the development of severe pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular lesions in 3 weeks associated with subsequent high mortality rate. The long-term blockade of Rho-kinase with fasudil, which is metabolized to a specific Rho-kinase inhibitor hydroxyfasudil after oral administration, markedly improved survival when started concomitantly with monocrotaline and even when started after development of pulmonary hypertension. The fasudil treatment improved pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular lesions with suppression of VSMC proliferation and macrophage infiltration, enhanced VSMC apoptosis, and amelioration of endothelial dysfunction and VSMC hypercontraction. These results indicate that Rho-kinase-mediated pathway is substantially involved in the pathogenesis of pulmonary hypertension, suggesting that the molecule could be a novel therapeutic target for the fatal disorder. Key Words: pulmonary hypertension Ⅲ Rho-kinase Ⅲ vascular smooth muscle cells Ⅲ endothelial nitric oxide synthase Ⅲ macrophages P rimary pulmonary hypertension (PPH) is a lifethreatening disease characterized by a marked and sustained elevation of pulmonary artery pressure. The disease has no obvious causes and ultimately results in right ventricular (RV) failure and death. The pathological changes of hypertensive pulmonary arteries include endothelial injury, proliferation and hypercontraction of vascular smooth muscle cells (VSMCs), and migration of macrophages. 1-3 PPH continues to be a serious clinical problem with high morbidity and mortality. 4 In 1990s, Rho-kinase/ROK/ROCK was identified as an effector of the small GTPase Rho, 5-7 which plays an important role in various cellular functions, including smooth muscle contraction, actin cytoskeleton organization, cell adhesion and motility, cytokinesis, and gene expression. 8 -10 In a series of experimental and clinical studies, we have demonstrated that Rho-kinase-mediated pathway is substantially involved in the pathogenesis of arteriosclerosis. 11-17 These Rho-kinase-mediated alterations in blood vessels also may be involved in the pathogenesis of pulmonary hypertension (PH). In this study, we examined whether Rho-kinasemediated pathway is involved in the pathogenesis of rat model of fatal PH in vivo. Materials and MethodsThe present study was...

These results suggest that our extracorporeal cardiac shock wave therapy is also an effective and noninvasive therapy for improving left ventricular remodeling after acute myocardial infarction when started in the early phase of the disorder.

Pulmonary hypertension (PH) is a fatal disease characterized by endothelial dysfunction, hypercontraction and proliferation of vascular smooth muscle cells, and migration of inflammatory cells for which no satisfactory treatment has yet been developed. It has been recently demonstrated that Rho-kinase, an effector of the small GTPase Rho, is involved in the pathogenesis of arteriosclerosis and that long-term inhibition of Rho-kinase markedly ameliorates monocrotaline-induced PH in rats. However, it remains to be examined whether direct inhibition of Rho-kinase also ameliorates PH with a different etiology and whether endothelial nitric oxide synthase (eNOS) is involved in the beneficial effects of Rho-kinase inhibition. This study was designed to address those 2 important issues in a hypoxia-induced PH model using wild-type (WT) and eNOS-deficient (eNOS) mice. Long-term blockade of Rho-kinase with fasudil (100 mg/kg/d) for 3 weeks markedly improved PH and right ventricular hypertrophy in WT mice with a lesser but significant inhibition noted in eNOS mice. Fasudil upregulated eNOS with increased Akt phosphorylation in WT but not in eNOS mice. These results suggest that long-term inhibition of Rho-kinase also ameliorates hypoxia-induced PH in mice, for which eNOS activation may partially be involved.

Objective-We recently demonstrated that Rho-kinase, an effector of the small GTPase Rho, is substantially involved in the pathogenesis of arteriosclerosis. In this study, we examined whether Rho-kinase is also involved in in-stent restenosis and if so, what mechanism is involved. Methods and Results-Pigs underwent stent implantation in the left coronary artery with or without administration of fasudil (30 mg/kg per day orally), a specific Rho-kinase inhibitor, starting 2 days before the procedure for a duration of 4 weeks. On day 28, reductions in coronary diameter and neointimal formation associated with macrophage accumulation, collagen deposition, and transforming growth factor (TGF)-␤1 expression were noted at the stent site, and all were significantly suppressed by fasudil. On day 7, fasudil significantly increased the frequency of TUNEL-positive apoptotic cells, while it tended to reduce that of bromodeoxyuridine-positive proliferating cells in the neointima. Western blot analysis on day 7 demonstrated that phosphorylations of the ezrin/radixin/moesin family (a marker of Rho-kinase activity in vivo) and protein expression of monocyte chemoattractant protein-1and bcl-2 were upregulated at the stent site and were significantly suppressed by fasudil. Conclusions-These results indicate that long-term inhibition of Rho-kinase suppresses in-stent neointimal formation by multiple mechanisms, including reduced vascular inflammation, enhanced apoptosis, and decreased collagen deposition.

Abstract-Restenosis after percutaneous coronary intervention continues to be a serious problem in clinical cardiology.Recent advances in nanoparticle technology have enabled us to deliver an antiproliferative drug selectively to the balloon-injured artery for a longer time. NK911, which is a core-shell nanoparticle of polyethyleneglycol-based block copolymer encapsulating doxorubicin, accumulates in vascular lesions with increased permeability. We first confirmed that balloon injury caused a marked and sustained increase in vascular permeability (as evaluated by Evans blue staining) for a week in the rat carotid artery. We then observed that intravenous administration of just 3 times of NK911, but not doxorubicin alone, significantly inhibited the neointimal formation of the rat carotid artery at 4 weeks after the injury in both a single-and double-injury model. Immunostaining demonstrated that the effect of NK911 was due to inhibition of vascular smooth muscle proliferation but not to enhancement of apoptosis or inhibition of inflammatory cell recruitment. Measurement of vascular concentrations of doxorubicin confirmed the effective delivery of the agent to the balloon-injured artery by NK911 in both a single-and double-injury model. RNA protection assay demonstrated that NK911 inhibited expression of several cytokines but not that of apoptosis-related molecules. NK911 was well tolerated without any adverse systemic effects. These results suggest that nanoparticle technology to target vascular lesions with increased permeability is a promising and safe approach for the prevention of restenosis after balloon injury.

We have recently demonstrated that the low-energy extracorporeal cardiac shock wave (SW) therapy improves myocardial perfusion and cardiac function in a porcine model of chronic myocardial ischemia and also ameliorates myocardial ischemia in patients with severe coronary artery disease. The present study was designed to examine whether our SW therapy also is effective to ameliorate hindlimb ischemia in rabbits. Hindlimb ischemia was made by surgical excision of the entire unilateral rabbit femoral artery. One week after the operation, we performed the SW (n = 9) or sham-therapy (n = 9) to the ischemic region 3 times a week for 3 weeks. Three weeks after the SW therapy, the development of collateral arteries, the fl ow ratio of the ischemic/non-ischemic common iliac arteries, the blood pressure ratio of the ischemic/non-ischemic hindlimb, and the capillary density in the ischemic muscles were all signifi cantly increased in the SW group compared with the control group, indicating that the SW therapy induced therapeutic angiogenesis. Importantly, no adverse effect, such as muscle damage, hemorrhage, or thrombosis, was noted with the therapy. Finally, we examined the role of endothelial nitric oxide synthesis (eNOS) and vascular endothelial growth factor (VEGF) in the mechanisms of SW-induced angiogenesis on day 28. The expression levels of eNOS and VEGF proteins in ischemic hindlimb muscles tended to be increased in the SW group compared with the control group. These results suggest that our low-energy SW therapy also is effective and safe for the treatment of peripheral artery disease.shock wave therapy; angiogenesis; peripheral artery disease; blood fl ow; capillary density. Tohoku J. Exp. Med., 2008, 214 (2), 151-158.

Objective-Sudden cardiac death (SCD) still remains a serious problem. We have previously shown that remnant-like particles (RLP) are the major risk factor for SCD and that Rho-kinase plays a central role in the molecular mechanism of coronary vasospasm. In this study, we examined whether RLP from patients with SCD upregulate Rho-kinase associated with an enhanced coronary vasospastic activity. Methods and Results-We isolated RLP and non-RLP in very-low-density lipoprotein (VLDL) fraction from SCD patients without coronary stenosis. We performed in vivo study in which we treated the coronary artery with RLP or non-RLP fraction at the adventitia in pigs. After 1 week, intracoronary serotonin caused marked coronary hyperconstriction at the segment treated with RLP fraction but not with non-RLP fraction (PϽ0.001, nϭ6), and hydroxyfasudil, a selective Rho-kinase inhibitor, dose-dependently inhibited the spasm in vivo. In organ chamber experiments, serotonin caused hypercontraction of vascular smooth muscle cells (VSMC) from RLP-treated segment, which was significantly inhibited by hydroxyfasudil (PϽ0.001, nϭ6). In cultured human coronary VSMC, the treatment with RLP significantly enhanced the expression and activity of nϭ6 A lthough a significant progress has been made in the treatment of ischemic heart disease, sudden cardiac death (SCD) still remains a serious problem. 1 Furthermore, there are many cases of out-hospital SCD without significant coronary stenosis. 2 Although coronary vasospasm has been postulated as one of the major causes of SCD, 3-5 the triggers for the spasm still remain to be elucidated.Recently, a new method has been developed to isolate remnant-like particles (RLP), a major component of remnant lipoproteins mainly detected in very-low-density lipoprotein (VLDL) fraction, by using immunoaffinity gels coupled to anti-apoA-I and anti-apoB-100 antibodies. 6,7 With this method, it has been shown that plasma RLP level is an independent risk factor for coronary artery disease (CAD). 8,9 Furthermore, we have demonstrated that RLP are associated with severity of coronary atherosclerosis and also are the most significant risk factor for SCD without coronary stenosis in our postmortem studies. 2,10 RLP also are a major risk factor for myocardial infarction in patients with vasospastic angina with nearly normal coronary artery. 11 These findings suggest that RLP are substantially involved in the fatal events, such as coronary vasospasm and SCD.Recent studies have shown the important role of small GTPase Rho and its effector, Rho-kinase, in Caindependent regulation of smooth muscle contraction. 12 The Rho/Rho-kinase pathway modulates the phosphorylation level of myosin light chain (MLC) through inhibition of myosin phosphatase and contributes to the agonistinduced Ca-sensitization in smooth muscle contraction. 12 We have demonstrated that increased Rho-kinase activity in vascular sooth muscle cells (VSMC) plays a central role in the pathogenesis of coronary vasospasm in both animal models [13][14][15][16] ...