Heparin cofactor II protects against angiotensin II-induced cardiac remodeling via attenuation of oxidative stress in mice.

Heparin cofactor II (HCII), a serine protease inhibitor, inhibits tissue thrombin action after binding with dermatan sulfate proteoglycans in the extracellular matrix of the vascular system. We previously reported that heterozygous HCII-deficient (HCII(+/-)) humans and mice demonstrate acceleration of vascular remodeling, including atherosclerosis. However, the action of HCII on cardiac remodeling never has been determined. HCII(+/+) and HCII(+/-) mice at age 25 weeks were infused with angiotensin II (Ang II; 2.0 mg/kg/d) for 2 weeks by an osmotic mini-pump. Echocardiography revealed acceleration of cardiac concentric remodeling in HCII(+/-) mice and larger left atrial volume in HCII(+/-) mice than in HCII(+/+) mice. Histopathologic studies showed more prominent interstitial fibrosis in both the left atrium and left ventricle in HCII(+/-) mice than in HCII(+/+) mice. Daily urinary excretion of 8-hydroxy-2'-deoxyguanosine, a parameter of oxidative stress, and dihydroethidium-positive spots, indicating superoxide production in the myocardium, were markedly increased in Ang II-treated HCII(+/-) mice compared to those in HCII(+/+) mice. Cardiac gene expression levels of atrial natriuretic peptides and brain natriuretic peptides, members of the natriuretic peptide family, Nox 4, Rac-1, and p67(phox) as components of NAD(P)H oxidase, and transforming growth factor-beta1 and procollagen III were more augmented in HCII(+/-) mice than in HCII(+/+) mice. However, administration of human HCII protein attenuated all of those abnormalities in Ang II-treated HCII(+/-) mice. Moreover, human HCII protein supplementation almost abolished cardiac fibrosis in Ang II-treated HCII(+/+) mice. The results indicate that HCII has a protective role against Ang II-induced cardiac remodeling through suppression of the NAD(P)H oxidase-transforming growth factor-beta1 pathway.


A phosphodiesterase-5 inhibitor vardenafil enhances angiogenesis through a protein kinase G-dependent hypoxia-inducible factor-1/vascular endothelial growth factor pathway.

We examined whether phosphodiesterase-5 (PDE5) inhibition can promote ischemia-induced angiogenesis. Unilateral hindlimb ischemia was generated by resecting right femoral artery in wild-type C3H/He mice, treated with either vehicle or a PDE5 inhibitor vardenafil (10 mg/kg per day). Four weeks after surgery, vardenafil significantly enhanced blood flow recovery and augmented capillary collateral formation in ischemic muscle (blood flow ratios of ischemic/nonischemic leg: 0.52+/-0.17 [vehicle] versus 0.92+/-0.09 [vardenafil], P<0.01). Vardenafil upregulated protein expression of vascular endothelial growth factor and hypoxia-inducible factor (HIF)-1 alpha in ischemic muscle and enhanced mobilization of Sca-1/Flk-1-positive endothelial progenitor cells (EPCs) in peripheral blood and bone marrow, contributing to neovascularization. Vardenafil also promoted capillary-like tube formation of human umbilical vein endothelial cells and increased the number of human blood mononuclear cell-derived EPCs in vitro. Furthermore, reporter assays showed that vardenafil and cGMP activated the transactivation activity of HIF-1 under hypoxia. These effects of vardenafil were markedly inhibited by genetic ablation of endothelial nitric oxide synthase, a soluble guanylate cyclase inhibitor, and a protein kinase G inhibitor, respectively. Our results suggest that PDE5 inhibition enhances ischemia-induced angiogenesis with mobilization of EPCs through a protein kinase G-dependent HIF-1/vascular endothelial growth factor pathway. PDE5 inhibition may have a therapeutic potential to treat ischemic cardiovascular diseases.

Arteriosclerosis, Thrombosis, and Vascular Biology


Moderate intake of red wine improves ischemia-induced neovascularization in diabetic mice-Roles of endothelial progenitor cells and nitric oxide.

Circulating endothelial progenitor cells (EPCs) play a significant role in postnatal neovascularization. Patients with diabetes have attenuated EPC functions and impaired angiogenic response after tissue ischemia. We investigated whether moderate red wine consumption can enhance blood flow recovery in response to tissue ischemia by enhancement of EPC functions in diabetic mice. Starting at 4 weeks after diabetes onset, red wine (4 ml/kg/day) or ethanol were administered to streptozotocin (STZ)-induced (type 1) diabetic mice and KKAy-Ta (type 2) mice. Unilateral hind limb ischemia surgery was conducted after 2 weeks of red wine or ethanol ingestion. Type 1 and type 2 diabetic mice given red wine, but not ethanol, had significantly increased collateral flow about 30% and augmented capillary density in ischemic tissues. These beneficial effects were markedly abolished by an eNOS inhibitor (L-NAME). Flow cytometry analysis showed impaired EPC-like cells (Sca-1+/Flk-1+) mobilization after ischemia surgery in diabetic mice, but augmented mobilization in red wine group (baseline vs. 2 days after operation: 0.88±0.06% vs. 1.73±0.29%, p=0.010). C-kit positive bone marrow cells isolated from diabetic mice given red wine had enhanced adhesion and migration compared to mice given vehicle. By in-vitro studies, incubation with red wine in high-glucose medium significantly reduced H2O2 production, and improved high glucose-suppressed EPC functions by nitric oxide-related mechanisms. Our findings demonstrate that red wine consumption enhances blood flow recovery after tissue ischemia in diabetic mice. These effects may partly derive from enhanced EPC functions by upregulation of eNOS activity.


Dehydroepiandrosterone sulfate is inversely associated with sex-dependent diverse carotid atherosclerosis regardless of endothelial function.

BACKGROUND: Dehydroepiandrosterone sulfate (DHEAS) is thought to be associated with life expectancy and anti-aging. However, its biological significance in atherosclerosis remains controversial. Therefore, the aim of this study was to determine whether DHEAS is associated with development of carotid atherosclerosis in subjects with cardiovascular risk factors. SUBJECTS AND METHODS: A total of 419 Japanese individuals (208 males and 211 females) were recruited from Tokushima University Hospital, Japan. In all subjects, maximum intima-media thickness (max-IMT) in all carotid arteries, and mean-IMT and mean blood flow volume (BFV) in the common carotid arteries (CCA) were measured by ultrasonography; endothelial function was assessed by flow-mediated vasodilation of the brachial artery (%FMD). Serum DHEAS and classical cardiovascular risk factors were also evaluated. Statistical significance was determined by multiple regression analysis to elucidate independent determinants of max-IMT, mean-IMT, mean CCA-BFV, and %FMD. RESULTS: Serum DHEAS levels were higher in males than in females. Multiple regression analysis revealed that DHEAS was an independent negative factor for both max-IMT and mean-IMT in males but not in females. In contrast, DHEAS was the sole positive factor for mean CCA-BFV in females but not in males. In addition, there was no significant relationship between %FMD and DHEAS regardless of sex and other confounding factors. CONCLUSION: Although DHEAS is not involved in endothelial function, DHEAS is inversely associated with sex-dependent diverse carotid atherosclerosis such as increased max-IMT and mean-IMT in males and decreased CCA-BFV in females.


Small-diameter vascular grafts of Bombyx mori silk fibroin prepared by a combination of electrospinning and sponge coating.


Images in cardiovascular medicine. Cardiac magnetic resonance imaging and 2-dimensional speckle tracking echocardiography in secondary cardiac amyloidosis.


Congenital ventricular aneurysm as an unexpected complication of monomorphic premature ventricular contractions.

Congenital ventricular diverticulum (CVD) in adults is a rare cardiac malformation, which includes fibrous type congenital ventricular aneurysm (CVA). CVA is often clinically asymptomatic and shows no abnormality in the electrocardiogram or chest X-ray. However, some cases of sudden death resulting from ventricular tachycardia, cardiac embolism or ventricular rupture have been reported. Therefore, physicians should perform further cardiac imaging studies to detect a CVA if ventricular arrhythmia originating from the left ventricle is observed. Here, we report two successfully followed cases of CVA which were diagnosed from premature ventricular contractions.


Impact of primitive cells in intracoronary thrombi on lesion prognosis: Temporal analysis of cellular constituents of thrombotic material obtained from patients with acute coronary syndrome.

Clinical evidence suggests that intracoronary thrombus formation is associated with a high incidence of late restenosis after successful coronary intervention in patients with myocardial infarction (MI). However, little is known about the mechanism by which intracoronary thrombi play pathological roles. We analysed the cellular constituents of 108 thrombi aspirated from coronary lesions with a thrombectomy device in 62 patients who underwent emergent coronary intervention for the treatment of acute (<24 h) or recent (24-72 h) ST-segment elevation MI (44 men, 18 women, aged 68.0+/-19.3 years). Immunohistological analysis of aspirated thrombotic materials revealed that the content of platelets, as determined by immunostaining for CD42a, had a negative correlation with the time after the onset of chest pain (correlation coefficient -0.683, p<0.01). Immunofluorescent staining for CD34 and breast cancer-resistant protein-1 (bcrp-1) detected primitive cells in intracoronary thrombi. Furthermore, the ratio of CD34-positive cells in intracoronary thrombi had a significant positive correlation with restenosis at follow-up coronary angiography (correlation coefficient 0.76, p=0.01). The findings of this study indicate that the early accumulation of primitive cells in platelet aggregates may play a role in neointimal growth after successful coronary intervention in patients with acute coronary syndrome.


Effects of additional administration of low-dose indapamide on patients with hypertension treated with angiotensin II receptor blocker.

BACKGROUND: Low-dose thiazide or thiazide-like diuretics have proven useful for the management of blood pressure in patients older than 65 years (elderly group). However, there are few reports about the antihypertensive effects of antihypertensive diuretic agents in patients younger than 65 years (middle-aged group). So, we evaluated the efficacy of low-dose indapamide on blood pressure. METHODS: Indapamide(1 mg) was given daily for 3 months and was then given every other day for 3 months to patients whose hypertension was poorly controlled with angiotensin II receptor blocker (ARB)-based treatment. RESULTS: After daily administration of indapamide, blood pressure was significantly decreased in both the middle-aged and elderly groups. Blood pressure was not significantly changed by every-other-day administration compared with that observed after daily administration in either group. The rate of attainment of the target blood pressure was 90.3% and 85.7% in the middle-aged and elderly groups, respectively. The serum uric acid levels were reduced after every-other-day administration compared to daily administration but tended to be higher than the levels at the baseline in both groups. CONCLUSIONS: The addition of low-dose indapamide is a useful strategy for the management of hypertension, as it reduced blood pressure without marked side effects.

Journal of Cardiovascular Pharmacology and Therapeutics


Endothelial nitric oxide synthase-independent protective action of statin against angiotensin II-induced atrial remodeling via reduced oxidant injury.

Activation of the renin-angiotensin system exacerbates atrial remodeling, leading to atrial fibrillation and thrombosis, especially in a condition with decreased NO bioavailability. Recently, it has been reported that statins reduce the incidence of atrial fibrillation through attenuation of atrial remodeling; however, the mechanisms have not been completely elucidated. Therefore, we aimed to clarify the beneficial effect of statin on atrial remodeling in condition with reduced NO bioavailability. Endothelial NO synthase(-/-) mice were sham operated or infused with angiotensin II (Ang II) via an osmotic minipump for 2 weeks, and Ang II-infused mice were divided into 3 treatment groups: pitavastatin, Tempol (a free radical scavenger), or vehicle. Echocardiography and electrocardiography showed that Ang II infusion caused left atrial enlargement and a high incidence of atrial fibrillation, whereas pitavastatin and Tempol prevented these abnormalities. In histological analysis, Ang II-induced atrial interstitial fibrosis, perivascular fibrosis, and cardiomyocyte hypertrophy were all attenuated by pitavastatin and Tempol. Immunohistochemical staining showed that Ang II downregulated thrombomodulin and tissue factor pathway inhibitor and upregulated tissue factor and plasminogen activator inhibitor 1 in the left atrium and that pitavastatin and Tempol corrected the thrombogenic condition. Moreover, pitavastatin and Tempol reduced Ang II-induced atrial superoxide production and atrial transforming growth factor-beta1 expression and Smad 2/3 phosphorylation. Atrial rac1-GTPase activity, known to activate NADPH oxidase, was attenuated by pitavastatin but not by Tempol. In conclusion, pitavastatin exerts endothelial NO synthase-independent protective actions against Ang II-induced atrial remodeling and atrial fibrillation with enhanced thrombogenicity through suppression of oxidant injury.


Ezetimibe ameliorates metabolic disorders and microalbuminuria in patients with hypercholesterolemia.

AIM: Ezetimibe, an inhibitor of Niemann-Pick C1-like 1 protein, has been shown to reduce the intestinal absorption of cholesterol. We investigated whether it also has beneficial effects on metabolic disorder and/or renal insufficiency in patients with hypercholesterolemia. METHODS: Ezetimibe was administered to 38 Japanese patients with hypercholesterolemia to obtain appropriate low-density lipoprotein cholesterol (LDL-chol) levels. Age- and sex-matched patients with hypercholesterolemia (n=38) were the controls. We evaluated the effects of ezetimibe before and 4 to 8 weeks after ezetimibe treatment. RESULTS: Ezetimibe significantly decreased LDL-chol levels and metabolic syndrome-related factors, including body weight, waist circumference, blood pressure; homeostasis model assessment insulin resistance (HOMA-IR), and urinary albumin excretion, were significantly reduced. In addition, it decreased the level of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-alpha, the urinary excretion of 8-hydroxy-2'-deoxyguanosine, a parameter of oxidative stress, and increased the urinary excretion of nitrate and nitrite (NOx). In the controls we observed no such changes. Excepting the decrease in the serum TNF-alpha level, the effects of ezetimibe were not correlated with decreased LDL-chol levels. CONCLUSION: Ezetimibe ameliorated the status of metabolic syndrome and microalbuminuria, reduced inflammation and oxidative stress, and increased nitric oxide bioavailability in a LDL-chol reduction-dependent and -independent manner.

Journal of Atherosclerosis and Thrombosis


Intake of Red Wine Increases the Number and Functional Capacity of Circulating Endothelial Progenitor Cells by Enhancing Nitric Oxide Bioavailability

Red wine (RW) consumption has been associated with a reduction of cardiovascular events, but limited data are available on potential mediating mechanisms. This study tested the hypothesis that intake of RW may promote the circulating endothelial progenitor cell (EPC) level and function through enhancement of nitric oxide bioavailability. Eighty healthy, young subjects were randomized and assigned to consume water (100 mL), RW (100 mL), beer (250 mL), or vodka (30 mL) daily for 3 weeks. Flow cytometry was used to quantify circulating EPC numbers, and in vitro assays were used to evaluate EPC functions. After RW ingestion, endothelial function determined by flow-mediated vasodilation was significantly enhanced; however, it remained unchanged after water, beer, or vodka intake. There were significantly increased numbers of circulating EPC (defined as KDR(+)CD133(+), CD34(+)CD133(+), CD34(+)KDR(+)) and EPC colony-forming units only in the RW group (all P<0.05). Only RW ingestion significantly enhanced plasma levels of nitric oxide and decreased asymmetrical dimethylarginine (both P<0.01). Incubation of EPC with RW (but not beer or ethanol) and resveratrol in vitro attenuated tumor necrosis factor-alpha-induced EPC senescence and improved tumor necrosis factor-alpha-suppressed EPC functions and tube formation. Incubation with nitric oxide donor sodium nitroprusside significantly ameliorated the inhibition of tumor necrosis factor-alpha on EPC proliferation, but incubation with endothelial nitric oxide synthase inhibitor l-NAME and PI3K inhibitor markedly attenuated the effect of RW on EPC proliferation. The intake of RW significantly enhanced circulating EPC levels and improved EPC functions by modifying nitric oxide bioavailability. These findings may help explain the beneficial effects of RW on the cardiovascular system. This study demonstrated that a moderate intake of RW can enhance circulating levels of EPC in healthy subjects by increasing nitric oxide availability. Direct incubation of EPC with RW and resveratrol can modify the functions of EPC, including attenuation of senescence and promotion of EPC adhesion, migration, and tube formation. These data suggest that RW ingestion may alter the biology of EPC, and these alterations may contribute to its unique cardiovascular-protective effect.

Arteriosclerosis, Thrombosis, and Vascular Biology


Diagnostic utility of cardiac magnetic resonance for detection of cardiac involvement in female carriers of Duchenne muscular dystrophy.


ピオグリタゾン投与による腹部大動脈瘤ぬおける抗動脈硬化作用

ピオグリタゾン投与による腹部大動脈瘤ぬおける抗動脈硬化作用


Successful Implantations of Autologous Peripheral Blood-Derived Mononuclear Cells Pretreated by Erythropoietin and Blood Donation in a Patient with Buerger Disease and Intractable Finger Ulcers

エリスロポエチン誘導末梢血単核球細胞移植が奏功した重症虚血性潰瘍を伴うBuerger病の1例

Japanese Journal of Cardiovascular Surgery

日本心臓血管外科学会雑誌


Long-term Patency of Small-diameter Vascular Graft Made from Fibroin, a Silk-based Biodegradable Material.

There is an increasing need for vascular grafts in the field of surgical revascularization. However, smaller vascular grafts made from synthetic biomaterials, particularly those <5 mm in diameter, are associated with a high incidence of thrombosis. Fibroin is a biodegradable protein derived from silk. Silk fibroin from Bombyx mori provides an antithrombotic surface and serves as a scaffold for various cell types in tissue engineering. We evaluated the potential of fibroin to generate a vascular prosthesis for small arteries. A small vessel with three layers was woven from silk fibroin thread. These fibroin-based grafts (1.5 mm diameter, 10 mm length) were implanted into the abdominal aorta of 10- to 14-week-old male Sprague-Dawley rats by end-to-end anastomosis. Polytetrafluoroethylene (PTFE)-based grafts were used as the control. To investigate the origin of the cells in the neointima and media, bone marrow transplantation was performed from green fluorescent protein (GFP) rats to wild-type rats. The patency of fibroin grafts at 1 year after implantation was significantly higher than that of PTFE grafts (85.1% vs 30%, P < .01). Endothelial cells and smooth muscle cells (SMCs) migrated into the fibroin graft early after implantation and became organized into endothelial and medial layers, as determined by anti-CD31 and anti-alpha-smooth muscle actin immunostaining. The total number of SMCs increased 1.6-fold from 1 month to 3 months. Vasa vasorum also formed in the adventitia. Sirius red staining of the fibroin grafts revealed that the content of collagen significantly increased at 1 year after implantation, with a decrease in fibroin content. GFP-positive cells contributed to organization of a smooth muscle layer. Small-diameter fibroin-based vascular grafts have excellent long-term patency. Bone marrow-derived cells contribute to vascular remodeling after graft implantation. Fibroin might be a promising material to engineer vascular prostheses for small arteries.


Synthetic prostacycline agonist, ONO-1301, ameliorates left ventricular dysfunction and cardiac fibrosis in cardiomyopathic hamsters.

Impairment of cardiac function in cardiomyopathy has been postulated to be related to decreased blood flow and increased collagen synthesis. Administration of growth factors was reported to attenuate left ventricular (LV) remodeling and dysfunction in animal models of dilated cardiomyopathy. We previously reported that ONO-1301, a synthetic prostacyclin agonist with thromboxane-synthase inhibitory activity, promotes production of hepatocyte growth factor and vascular endothelial growth factor from various cell types and ameliorate ischemia-induced LV dysfunction in mice and pigs. We evaluated therapeutic efficacy of ONO-1301 in the Syrian hamster (TO-2), a model of genetically determined dilated cardiomyopathy. Either vehicle or a slow releasing form of ONO-1301 (ONO-1301-PLGA, 10mg/kg/3 weeks) was administered subcutaneously every 3 weeks to TO-2 hamsters from 24 to 32 weeks of age (n=12 for each group). Age-matched F1B hamsters were used as a control. Plasma concentration of HGF was elevated in ONO-1301-PLGA group (p<0.05). Echocardiographic study demonstrated that LV fractional shortening was significantly improved in the ONO-1301-PLGA group (25+/-4%, p<0.01) compared with that in the vehicle group (19+/-2%). Cardiac fibrosis was significantly reduced by ONO-1301-PLGA (p<0.05) as determined by Azan-Mallory staining. Capillary density of left ventricle was markedly reduced in TO-2 hamsters. ONO-1301-PLGA significantly increased capillary density in TO-2 group (p<0.05). ONO-1301 improved LV dysfunction and reduced cardiac fibrosis in the hamster model of dilated cardiomyopathy. ONO-1301 might hold a therapeutic potential in the treatment of dilated cardiomyopathy.


Clinical Utility of Single Beat E/e' Obtained by Simultaneous Recording of Flow and Tissue Doppler Velocities in Atrial Fibrillation with Preserved Systolic Function.

We evaluated the usefulness of the ratio of the early diastolic transmitral flow velocity (E) to the mitral annular velocity (e') calculated from simultaneously recorded E and e' in atrial fibrillation (AF). The ratio of the E to the e' (E/e') has been reported as a useful index even in AF patients. However, E and e' were measured during different beats in the previous studies. Fifty-six AF patients with preserved systolic function (mean age 66 +/- 11 years) underwent routine echocardiographic study. The E/e' was calculated from the E and e' simultaneously recorded by the dual Doppler echocardiography. A single-beat E/e' was calculated from simultaneously recorded E and e' when the preceding RR interval/pre-preceding RR interval = 1. Brain natriuretic peptide (BNP) levels were also examined. Twenty-one patients underwent simultaneous pulmonary artery catheterization. The single-beat lateral E/e' correlated with pulmonary capillary wedge pressure (PCWP) (r = 0.74, p < 0.001). The single-beat lateral E/e' of >or=11 could predict elevated PCWP (>or=15 mm Hg) with a sensitivity of 90% and a specificity of 90%. The single-beat lateral E/e' also correlated well with the log BNP concentration. The single-beat lateral E/e' of >or=9.2 predicted a plasma BNP level of >or=200 pg/ml with 88% sensitivity and 84% specificity. The single-beat lateral E/e' correlated with plasma BNP level and PCWP in AF patients with preserved systolic function. In addition, the single-beat lateral E/e' (>or=11) was a good predictor of elevated PCWP (>or=15 mm Hg). Dual Doppler echocardiography offers an advantage of providing the single-beat lateral E/e' correctly even in AF patients, for the evaluation of left ventricular diastolic function.


Periadventitial adipose tissue plays a critical role in vascular remodeling.

Obesity is associated with a high incidence of cardiovascular complications. However, the molecular link between obesity and vascular disease is not fully understood. Most previous studies have focused on the association between cardiovascular disease and accumulation of visceral fat. Periadventitial fat is distributed ubiquitously around arteries throughout the body. Here, we investigated the impact of obesity on inflammation in the periadventitial adipose tissue and on lesion formation after vascular injury. High-fat, high-sucrose feeding induced inflammatory changes and decreased adiponectin expression in the periadventitial adipose tissue, which was associated with enhanced neointima formation after endovascular injury. Removal of periadventitial fat markedly enhanced neointima formation after injury, which was attenuated by transplantation of subcutaneous adipose tissue from mice fed on regular chow. Adiponectin-deficient mice showed markedly enhanced lesion formation, which was reversed by local delivery, but not systemic administration, of recombinant adiponectin to the periadventitial area. The conditioned medium from subcutaneous fat attenuated increased cell number of smooth muscle cells in response to platelet derived growth factor-BB. Our findings suggest that periadventitial fat may protect against neointimal formation after angioplasty under physiological conditions and that inflammatory changes in the periadventitial fat may have a direct role in the pathogenesis of vascular disease accelerated by obesity.


Protective Role of Clusterin / Apolipoprotein J Against Neointimal Hyperplasia via Antiproliferative Effect on Vascular Smooth Muscle Cells and Cytoprotective Effect on Endothelial Cells.

Clusterin is induced in vascular smooth muscle cells (VSMCs) during atherosclerosis and injury-induced neointimal hyperplasia. However, its functional roles in VSMCs and endothelial cells remain controversial and elusive. This study was undertaken to clarify the role of clusterin in neointimal hyperplasia and elucidate its mechanism of action. Adenovirus-mediated overexpression of clusterin (Ad-Clu) repressed TNF-alpha-stimulated expression of MCP-1, fractalkine, ICAM-1, VCAM-1, and MMP-9, leading to inhibition of VSMC migration. Both Ad-Clu and secreted clusterin suppressed VSMC proliferation by inhibiting DNA synthesis, but not by inducing apoptosis. Ad-Clu upregulated p53 and p21(cip1/waf1) but downregulated cyclins D and E, leading to suppression of pRb phosphorylation and subsequent induction of G1 arrest in VSMCs. Clusterin deficiency augmented VSMC proliferation in vitro and accelerated neointimal hyperplasia in vivo, but concomitantly impaired reendothelialization in wire-injured murine femoral arteries. Moreover, Ad-Clu significantly reduced neointimal thickening in balloon-injured rat carotid arteries. Clusterin also diminished TNF-alpha-induced apoptosis of human umbilical vein endothelial cells and restored endothelial nitric oxide synthase expression suppressed by TNF-alpha. These results suggest that upregulation of clusterin during vascular injury may be a protective response against, rather than a causative response to, the development of neointimal hyperplasia.


Matrix Metalloproteinase-9 Is Essential for Ischemia-Induced Neovascularization by Modulating Bone Marrow-Derived Endothelial Progenitor Cells.

Both matrix metalloproteinases (MMPs) and endothelial progenitor cells (EPCs) have been implicated in the process of neovascularization. Here we show that the impaired neovascularization in mice lacking MMP-9 is related to a defect in EPC functions in vasculogenesis. Hindlimb ischemia surgery was conducted in MMP-9(-/-) mice and wild-type (MMP-9(+/+)) mice. Blood flow recovery was markedly impaired in MMP-9(-/-) mice when compared with that in wild-type mice as determined by laser Doppler imaging. Flow cytometry demonstrated that the number of EPC-like cells (Sca-1(+)/Flk-1(+)) in peripheral blood increased in wild-type mice after hindlimb ischemia surgery and exogenous vascular endothelial growth factor stimulation, but not in MMP-9(-/-) mice. Plasma levels and bone marrow concentrations of soluble Kit-ligand (sKitL) were significantly elevated in wild-type mice in response to tissue ischemia, but not in MMP-9(-/-) mice. C-kit positive bone marrow cells of MMP-9(-/-) mice have attenuated adhesion and migration than those isolated from wild-type mice. In in vitro studies, incubation with selective MMP-9 inhibitor suppressed the colony formation, migration, and tube formation capacities of EPC. Transplantation of bone marrow cells from wild-type mice restored collateral flow formation in MMP-9(-/-) mice. These findings suggest that MMP-9 deficiency impairs ischemia-induced neovascularization, and these effects may occur through a reduction in releasing the stem cell-active cytokine, and EPC mobilization, migration, and vasculogenesis functions.


Impaired Recovery of Blood Flow Following Hind-Limb Ischemia in Mice Lacking Guanylyl Cyclase-A, a Receptor for Atrial and Brain Natriuretic Peptides.

Atrial and brain natriuretic peptides (ANP and BNP, respectively) function via guanylyl cyclase (GC)-A, resulting in diuresis, natriuresis, and blood vessel dilation. Here, we investigated the role of endogenous ANP/BNP-GC-A signaling on reparative vascular remodeling using a hind-limb ischemia model. In GC-A-deficient mice (GC-A-KO), hind-limb ischemia resulted in autoamputation or severe ulcers in 60% of mice (6/10) during the 28-day observation period. In wild-type (WT) mice, partial amputation or mild ulcers were detected in only 20% of mice (2/10). Laser Doppler perfusion imaging revealed that the recovery of blood flow in the ischemic limb was significantly inhibited in GC-A-KO mice compared with WT mice. Immunostainings with anti-PECAM-1 antibody demonstrated that, in GC-A-KO, the capillary density of the ischemic tissue was significantly diminished compared to WT. Furthermore, bone marrow transplantation showed the predominant role of GC-A on local ischemic tissue rather than on vascular progenitor cells mobilized from bone marrow during vascular remodeling. In cultured human endothelial cells, ANP treatment significantly stimulated mRNA expressions of vascular endothelial growth factor and endothelial nitric oxide synthase via Erk1/2-dependent mechanism. These results suggest that endogenous ANP and BNP play important roles in reparative vascular remodeling in ischemic tissue.

Arteriosclerosis, Thrombosis, and Vascular Biology


Local delivery of synthetic prostacycline agonist augments collateral growth and improves cardiac function in a swine chronic cardiac ischemia model.

It was reported that administration of angiogenic growth factors can augment collateral growth in ischemic tissues. It is assumed that angiogenic effects of cell transplantation may be mainly mediated by secretion of angiogenic cytokines. We tested feasibility of clinical use of ONO-1301, a synthetic small molecule that stimulates secretion of growth factors from various cell types, to treat patients with chronic myocardial ischemia. Effects of ONO-1301 on fibroblasts and endothelial cells were evaluated in vitro. We examined the efficacy of local delivery of ONO-1301 in models of rat hindlimb ischemia and swine chronic ischemic myocardium. ONO-1301 stimulated hepatocyte growth factor secretion from human fibroblasts. ONO-1301 promoted vascular-like tube formation by endothelial cells in vitro. Direct injection of a slow-release form of ONO-1301 (SR-ONO) to rat hindlimb ischemic muscle enhanced perfusion recovery. In a swine cardiac ischemia model, direct injection of SR-ONO into the ischemic myocardium significantly augmented collateral formation (SR-ONO vs. control; 1.7+/-0.2 vs. 1.0+/-0.2 Rentrop score), with improved local ventricular wall motion, reduced enlargement of left ventricular diastolic volume (49.5+/-1.9 mL vs. 59.7+/-4.2 mL) and increased cardiac index (4.2+/-0.1 vs. 3.4+/-0.2 L/min/m(2)). Histological analysis revealed that SR-ONO suppressed fibrosis in ischemic tissue (collagen volume fraction; 7.5+/-1.1% vs. 12.8+/-2.2%) and enhanced neovascularization (capillary density, 275.6 vs. 159.3/mm(2); arterioles 36.6 vs. 25.5 /mm(2)). Local delivery of SR-ONO might be effective for therapeutic angiogenesis and propose that local administration of slow-release of synthetic small molecules represents new strategy for therapeutic angiogenesis.


Fluvastatin accelerates re-endothelialization impaired by local sirolimus treatment.

Sirolimus-eluting stent reduces restenosis after percutaneous coronary intervention. However, accumulating evidence suggests that sirolimus potentially affects re-endothelialization, leading to late thrombosis. Statins have protective effects on endothelium. Recently, statins are reported to increase the number of circulating endothelial progenitor cells (EPCs) and accelerate re-endothelialization after vascular injury. Here, we tested the hypothesis that fluvastatin has beneficial effect on re-endothelialization after local sirolimus treatment. We performed wire-mediated vascular injury to both sides of femoral arteries of wild-type mice and bone marrow chimeric mice. Either sirolimus (100 microg) or DMSO was administered locally to the perivascular area of the injured arteries. All mice received either fluvastatin (5 mg/kg/day) or vehicle by gavage starting at one week before the surgery until sacrifice. At 4 weeks after the surgery, re-endothelialization of the sirolimus-treated artery was significantly less than that of DMSO-treated one in the vehicle-treated mice as determined by the percentage of CD31-positive area (P<0.05). Systemic administration of fluvastatin accelerated the re-endothelialization in the sirolimus-treated artery to the similar degree of that in the DMSO-treated artery (P=NS). Contribution of bone marrow-derived cells to re-endothelialization was seldom observed in bone marrow chimeric mice regardless of fluvastatin administration. Fluvastatin significantly ameliorated proliferation (2.5-folds) and migration activities (2.3-folds) of mature endothelial cells impaired by sirolimus treatment (P<0.05, respectively). Fluvastatin increased endothelial nitric oxide synthase expression and decreased plasminogen activator inhibitor-1 expression in mature endothelial cell in the presence of sirolimus (P<0.05, respectively). Our findings suggest that fluvastatin has protective effects against impaired re-endothelialization after sirolimus treatment.


Echographic detection of diethylnitrosamine-induced liver tumors in rats and the effect of the intratumoral injection of an inhibitor of c-Jun N-terminal kinase.

There have so far been few reports describing echographic studies of chemically-induced carcinogenesis in rodent livers. Using echography, we observed diethylnitrosamine-induced liver tumors in rats and examined the effect of an intratumoral injection of an inhibitor of c-Jun N-terminal kinase. Male Wistar rats were given 100 ppm of diethylnitrosamine for 6 weeks and their liver nodules were examined by echography weekly. The size of the nodules was measured and they were examined histologically. The effect of SP600125, an inhibitor of c-Jun N-terminal kinase, on the growth of rat hepatoma cell line McA-RH7777 was tested in vitro. Thereafter, SP600125 was injected into the liver nodules under echographic guidance in vivo and the changes in the proliferating cell nuclear antigen expression and size of the nodules were examined. The four distinct lobes of rat livers were clearly observed by transabdominal echography. The nodules in the livers were first detected 6 weeks after the treatment began, when they were as small as 1.6 mm in diameter. The nodules thereafter became more malignant histologically as they grew larger than 4 mm. SP600125 decreased the expression of proliferating cell nuclear antigen and the growth of McA-RH7777 cells. After SP600125 was injected in vivo, the proliferating cell nuclear antigen level and the growth rate of the rat liver nodules all significantly decreased. Our results indicate that echography is quite useful for follow-up studies of liver carcinogenesis in rats, and c-Jun N-terminal kinase might be another therapeutic target in liver neoplasms.

Journal of Gastroenterology and Hepatology


Heparin cofactor II is an independent protective factor against peripheral arterial disease in elderly subjects with cardiovascular risk factors.

AIM: Heparin cofactor II (HCII) specifically inactivates thrombin action at the injured vascular wall. We have reported that HCII is a protective factor against coronary in-stent restenosis and carotid atherosclerosis; however, it is unclear whether there is any correlation between plasma HCII levels and the development of peripheral arterial disease (PAD). METHODS: Plasma HCII activity and the ankle brachial pressure index (ABI) were determined in 494 elderly subjects with cardiovascular risk factors. PAD was diagnosed by ABI below 0.9, and 62 subjects were diagnosed with PAD. The relationship between factors that affect cardiovascular events and the prevalence of PAD was statistically evaluated. RESULTS: Mean HCII activity in PAD subjects was significantly lower than in non-PAD subjects (87.5+/-19.7% v.s. 94.6+/-17.8%, p=0.009). Multivariate logistic regression analysis showed that age (odds ratio [OR]: 1.062, p=0.0016), current smoking (OR 3.028, p=0.002) and diabetes mellitus (OR 2.656, p=0.008) were independent and progressive determinants of PAD. In contrast, HCII was an independent inhibitory factor of PAD (OR: 0.982, p=0.048). CONCLUSIONS: Plasma HCII activity is inversely related to the prevalence of PAD. HCII may function as the sole protective factor against PAD in elderly people with cardiovascular risk factors.

Journal of Atherosclerosis and Thrombosis


Inhibition of renin-angiotensin system attenuates periadventitial inflammation and reduces atherosclerotic lesion formation.

Recent evidence indicates that renin-angiotensin system (RAS) plays an important role in the pathogenesis of atherosclerosis. It was reported that inhibition of RAS with angiotensin II type 1 receptor blockers (ARBs) or angiotensin converting enzyme inhibitors (ACEIs) is effective in prevention of atherosclerosis. Here, we investigated the effects of an ARB or/and an ACEI on atherosclerosis development and periadventitial inflammation in apolipoprotein E (ApoE)-deficient mice. RT-PCR revealed that major RAS components were expressed in periaortic tissue. Ang II infusion significantly increased accumulation of bone marrow derived cells into both neointima (p<0.05) and periaortic tissue (p<0.01). Male ApoE- deficient mice were treated with either vehicle, TA606A (10mg/kg/day, ARB), imidapril (3mg/kg/day, ACEI) or TA606A plus imidapril (TA606A 10mg/kg/day+imidapril 3mg/kg/day, ARB+ACEI) for 24 weeks starting at 12 weeks of age. ARB, ACEI, and ARB+ACEI significantly reduced atherosclerotic lesion formation in aorta compared with vehicle (p<0.05), with reduced expression of monocyte chemoattractant protein-1 in periaortic tissues (p<0.01). Neither blood pressure nor heart rate was changed by the treatments at these lower doses. Imidapril significantly reduced lipid deposition in atheroma and plasminogen activator inhibitor-1 expression in periadventitial tissue (p<0.05, respectively). Imidapril and combination therapy significantly attenuated macrophage infiltration into the atherosclerotic plaque (p<0.05, respectively). All treatments reduced macrophage accumulation in the periadventitial tissue 12 weeks after treatment (p<0.05, respectively). These results suggest that inhibition of renin-angiotensin system attenuates periadventitial inflammation and reduces atherosclerotic lesion formation.


A new constitutively active mutant of AMP-activated protein kinase inhibits anoxia-induced apoptosis of vascular endothelial cell.

The inhibition of apoptotic changes in vascular endothelial cells is important for preventing vascular damage from hypoxia. AMP-activated protein kinase (AMPK) has recently been identified as playing a role in vascular protection. Although the chemical reagent 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) has been used to stimulate AMPK activity, AICAR has been associated with several nonspecific reactions. We therefore constructed a new constitutively active mutant of AMPK alpha 1 (NcaAMPK), which lacks the autoinhibitory domain in AMPK alpha 1 and in which threonine 172 has been replaced with aspartate. We investigated whether NcaAMPK has an anti-apoptotic effect in vascular endothelial cells under anoxic conditions. NcaAMPK, or green fluorescent protein (GFP) as a control, was overexpressed in human umbilical vein endothelial cells (HUVECs). After HUVECs were incubated for 40 h under normoxic or anoxic conditions, we examined cell viability, caspase 3/7 activity, and expression and phosphorylation levels of apoptosis-related proteins. Cell viabilities under anoxic conditions were improved in NcaAMPK-overexpressing cells. Anoxia increased caspase 3/7 activity, but NcaAMPK reduced this increase significantly. NcaAMPK overexpression increased protein kinase B/Akt Ser473 and endothelial nitric oxide synthase Ser1177 phosphorylation, but pretreatment with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) did not decrease the viability of NcaAMPK-overexpressing HUVECs. Furthermore, co-expression of a dominant-negative Akt reduced the improvement in cell viability and the suppression of poly (ADP-ribose) polymerase cleavage by NcaAMPK under anoxic conditions. In conclusion, NcaAMPK inhibited anoxia-induced apoptosis in vascular endothelial cells through Akt activation, suggesting that activation of AMPK might protect against ischemic vascular injury.


Telmisartan Decreases Plasma Levels of Asymmetrical Dimethyl-L-Arginine and Improves Lipid and Glucose Metabolism and Vascular Function

Telmisartan is an angiotensin II receptor blocker (ARB) and also an activator of peroxisome proliferator-activated receptor-gamma (PPAR-gamma). We investigated whether telmisartan improves vascular endothelial function in patients with essential hypertension with the production of endothelial nitric oxide synthase (eNOS) through PPAR-gamma.Telmisartan was administered to 15 patients with essential hypertension. To assess vascular function, asymmetric dimethylarginine (ADMA), an eNOS inhibitor synthesized by endothelial cells, and the pulse-wave velocity (PWV) were measured. The serum levels of lipid, glucose, and glycohemoglobin (HbA1c) were also evaluated before and after treatment. Telmisartan therapy significantly decreased the blood pressure and total- and LDL-cholesterol levels. HbA1c was also significantly improved but not in fasting plasma glucose. The serum levels of ADMA were significantly decreased (0.48 +/- 0.08 to 0.42 +/- 0.05 nmol/mL; P = 0.01). PWV values were significantly decreased by telmisartan from 1,822.5 +/- 352.3 to 1,661.5 +/- 299.8 cm/second (P = 0.04*). Telmisartan decreased PWV presumably via the activation of PPAR-gamma, suggesting that this agent improves vascular endothelial function via its pleiotropic effects, a mechanism that is different from its hypotensive effects.


Function and Role of Voltage-Gated Sodium Channel (NaV1.7) Expressed in Aortic Smooth Muscle Cells.

Voltage-gated Na(+) channel currents (I(Na)) are expressed in several types of smooth muscle cells. The purpose of this study was to evaluate the expression of I(Na), its functional role, pathophysiology in cultured human (hASMCs) and rabbit aortic smooth muscle cells (rASMCs), and its association with vascular intimal hyperplasia. In whole cell voltage clamp, I(Na) was observed at potential positive to -40 mV, was blocked by tetrodotoxin (TTX), and replacing extracellular Na(+) with N-methyl-d-glucamine in cultured hASMCs. In contrast to native aorta, cultured hASMCs strongly expressed SCN9A encoding Na(V)1.7, as determined by quantitative RT-PCR. I(Na) was abolished by the treatment with SCN9A small-interfering (si)RNA (P < 0.01). TTX and SCN9A siRNA significantly inhibited cell migration (P < 0.01, respectively) and horseradish peroxidase uptake (P < 0.01, respectively). TTX also significantly reduced the secretion of matrix metalloproteinase-2 6 and 12 h after the treatment (P < 0.01 and P < 0.05, respectively). However, neither TTX nor siRNA had any effect on cell proliferation. L-type Ca(2+) channel current was recorded, and I(Na) was not observed in freshly isolated rASMCs, whereas TTX-sensitive I(Na) was recorded in cultured rASMCs. Quantitative RT-PCR and immunostaining for Na(V)1.7 revealed the prominent expression of SCN9A in cultured rASMCs and aorta 48 h after balloon injury but not in native aorta. In conclusion, these studies show that I(Na) is expressed in cultured and diseased conditions but not in normal aorta. The Na(V)1.7 plays an important role in cell migration, endocytosis, and secretion. Na(V)1.7 is also expressed in aorta after balloon injury, suggesting a potential role for Na(V)1.7 in the progression of intimal hyperplasia.

American Journal of Physiology, Heart and Circulatory Physiology


Rosuvastatin prevents endothelial cell death and reduces atherosclerotic lesion formation in ApoE-deficient mice.

Accumulating evidence suggests that statins have beneficial effects which are independent of their lipid-lowering actions, on vascular cells. Here, we investigated whether the HMG-CoA reductase inhibitor rosuvastatin can inhibit atherosclerotic lesion development with favorable effects on endothelial cells in ApoE-deficient mice. Rosuvastatin rapidly phosphorylated Akt and endothelial nitric oxide synthase (eNOS) in human endothelial cells. Endothelial cell death induced by serum starvation was significantly inhibited by rosuvastatin (percent cell death; 45.9+/-2.4% vs. 37.3+/-1.1%, p<0.05). Eight-week-old ApoE-deficient mice were orally administered vehicle or rosuvastatin at a dose of 20mg/kg/day for 24 weeks. There was no significant difference in cholesterol profile. Rosuvastatin preserved endothelial lining at the aortic root (CD31-positive luminal side; 63.8+/-2.8% vs. 81.7+/-3.9%, p<0.05). En face Sudan IV staining of aorta revealed that rosuvastatin significantly decreased the atherosclerotic area (21.9+/-2.9% vs. 11.9+/-1.9%, p<0.05). Lipid deposition at the atherosclerotic area was also suppressed by rosuvastatin with more stabilized morphologic features as determined by oil red O staining (3.4+/-0.4% vs. 1.7+/-0.4%, p<0.05). Our findings indicate that rosuvastatin protects endothelial cells from death with phosphorylation of Akt and eNOS. These effects may contribute, at least in part, to the anti-atherosclerotic effects of rosuvastatin.


Flow-Mediated Vasodilation as a Diagnostic Modality for Vascular Failure.

Vascular endothelial dysfunction represents an initial step of "vascular failure," which we have recently proposed as a comprehensive syndrome of failed vascular functions that extends from risk factors to established atherosclerotic disease. The early detection of vascular failure is essential in order to appropriately intervene and prevent its progression. Many efforts have been made to assess vascular endothelial function, and one of the most promising methods is the measurement of endothelium-dependent flow-mediated vasodilation (FMD) using high-frequency ultrasonographic imaging and transient occlusion of the brachial artery. The reactive hyperemia caused by the transient brachial arterial occlusion induces the release of local nitric oxide, resulting in vasodilation that can be quantified as an index of vasomotor function. The noninvasive nature of this technique allows repeated measurements over time to study the effectiveness of various interventions that may affect vascular health. Although there are technical and interpretive limitations of this technique, FMD-guided therapeutic approaches for vascular failure should contribute to the improvement of cardiovascular mortality and morbidity.


Platypnea-orthodeoxia syndrome associated with patent foramen ovale and aortic ectasia.

A 59-year-old man was admitted for dyspnea on exertion and edema. The patient did not have any pulmonary diseases that could cause dyspnea. Transesophageal echocardiography on the tilting bed with contrast infusion revealed a right-to-left shunt through the patent foramen ovale. Therefore, he was diagosed as platypnea-orthodeoxia syndrome due to the patent foramen ovale. Surgical closure was done and all of his symptoms had improved.


Candesartan ameliorates cardiac dysfunction observed in ACE2-deficient mice.

The renin-angiotensin (Ang) system plays a critical role in the regulation of blood pressure, body fluid, electrolyte homeostasis, and organ remodeling under physiological and pathological conditions. The carboxypeptidase ACE2 is a homologue of angiotensin-converting enzyme (ACE). It has been reported that ACE2-deficient mice develop cardiac dysfunction with increased plasma levels of Ang II. However, the molecular mechanism by which genetic disruption of ACE2 results in heart dysfunction is not fully understood. Here, we generated mice with targeted disruption of the Ace2 gene and compared the cardiovascular function of ACE2(-/y) mice with that of their wild-type littermates. ACE2-deficient mice were viable and fertile and lacked any gross structural abnormalities. Echocardiographic study detected no functional difference between ACE2(-/y) and wild-type mice at 12 weeks of age. Twenty-four-week-old ACE2(-/y) mice displayed significantly enlarged hearts with impaired systolic and diastolic function. The Ang II level was elevated in the plasma and heart of ACE2(-/y) mice. Pharmacological blockade of Ang II type 1 receptor (AT1) with candesartan attenuated the development of cardiac dysfunction in ACE2(-/y) mice. These results suggest that enhanced stimulation of AT1 may play a role in the development of cardiac dysfunction observed in ACE2-deficient mice.


Hic-5, an adaptor protein expressed in vascular smooth muscle cells, modulates the arterial response to injury in vivo.

Focal adhesion components are targets for biochemical and mechanical stimuli that evoke crucial injury. Hic-5 (hydrogen peroxide-inducible clone 5) is a multidomain adaptor protein which is implicated in the regulation of integrin signaling in focal adhesion. The aim of this research was to test the hypothesis that Hic-5, a focal adhesion LIM protein expressed in smooth muscle cells, is involved in dynamic processes by pathological stimuli in the vessel wall. Here, we describe the analysis of the function of Hic-5 using a mouse model of vascular injury that may mimic balloon angioplasty. At 4 days after vascular injury, marked down-regulation of the Hic-5 expression was observed in the smooth muscle layer, and local delivery of the Hic-5 using adenovirus vectors repressed injury-induced neointimal expansion. In addition, Hic-5 reduced cells migration into three-dimensional collagen gels, and the forced expression of Hic-5 in cells embedded in the collagen gel matrix repressed the expression of uPA that participates in smooth muscle cell migration. These results suggest that Hic-5 modulates cellular responses to pathological stimuli in the vessel wall.

Biochemical and Biophysical Research Communications


A model of cerebrovascular injury in rats.

Although the pathophysiology of post-angioplasty restenosis has been extensively studied in extracranial arteries using transluminal vascular injury model in rodents, it is still not well known in the intracranial arteries, which have quite different structures from extracranial arteries. Here, we examined whether 1-min placement of modified intraluminal suture could induce an injury in the internal carotid artery (ICA) in rats and observed temporal profile of histological change after the injury. HE staining showed that the injured intracranial ICA was dilated, while the media was markedly thinned at 1 day after injury. The internal elastic lamina was not observed, and the media contained few cells. At 1 week after injury, a thin layer of neointimal hyperplasia was observed on the luminal side of the internal elastic lamina. Neointimal hyperplasia developed until at least 4 weeks after injury. Morphometric analysis demonstrated that the healing process of the injury was related to arterial remodeling. Immunohistochemical staining for alpha-smooth muscle actin and electron microscopic analysis showed that the neointima was composed of smooth muscle cells. Re-endothelialization was observed from 1 to 4 weeks after injury by immunohistochemical staining for von Willebrand's factor and electron microscopic analysis. Vascular endothelial growth factor was expressed in neointima on days 7 and 14. Interestingly, superoxide anion was not increased in injured arteries on day 3, when the infiltration of macrophages was intensive, but increased on day 7, when infiltrating macrophages almost disappeared. These findings might shed new light on pathophysiology of post-angioplasty restenosis in intracranial arteries.


Epac1 is upregulated during neointima formation and promotes vascular smooth muscle cell migration.

Vascular remodeling after mechanoinjury largely depends on the migration of smooth muscle cells, an initial key step to wound healing. However, the role of the second messenger system, in particular, the cAMP signal, in regulating such remodeling remains controversial. Exchange protein activated by cAMP (Epac) has been identified as a new target molecule of the cAMP signal, which is independent from PKA. We thus examined whether Epac plays a distinct role from PKA in vascular remodeling. To examine the role of Epac and PKA in migration, we used primary culture smooth muscle cells from both the fetal and adult rat aorta. A cAMP analog selective to PKA, 8-(4-parachlorophenylthio)-cAMP (pCPT-cAMP), decreased cell migration, whereas an Epac-selective analog, 8-pCPT-2'-O-Me-cAMP, enhanced migration. Adenovirus-mediated gene transfer of PKA decreased cell migration, whereas that of Epac1 significantly enhanced cell migration. Striking morphological differences were observed between pCPT-cAMP- and 8-pCPT-2'-O-Me-cAMP-treated aortic smooth muscle cells. Furthermore, overexpression of Epac1 enhanced the development of neointimal formation in fetal rat aortic tissues in organ culture. When the mouse femoral artery was injured mechanically in vivo, we found that the expression of Epac1 was upregulated in vascular smooth muscle cells, whereas that of PKA was downregulated with the progress of neointimal thickening. Our findings suggest that Epac1, in opposition to PKA, increases vascular smooth muscle cell migration. Epac may thus play an important role in advancing vascular remodeling and restenosis upon vascular injury.


Progression of Renal Dysfunction in Patients with Cardiovascular Disease.

It has been established that patients with chronic kidney disease (CKD) suffer from frequent cardiovascular events. On the other hand, recent studies suggest that renal damage tends to worsen in patients with cardiovascular diseases (CVD). Although the mechanisms for the cardiorenal association are unclear, the presence of arteriosclerotic risk factors common to both CVD and CKD is important. In arteriosclerosis, vascular derangement progresses not only in the heart but also in the kidney. In addition, heart failure, cardiac catheterization and hesitation of medical treatments due to renal dysfunction may explain the progression of renal damage. Therefore, the goal of treatments is a total control of arteriosclerotic risk factors. Medication should be selected among agents with protective effects on both heart and kidney. It is important to always consider the presence of CKD for the treatment of the cardiovascular disease and strictly control the risk factors.


Antiarrhythmogenic effect of reconstituted high-density lipoprotein against ischemia/reperfusion in rats

This study analyzed the antiarrhythmogenic effect of reconstituted high-density lipoprotein (rHDL) against ischemia/reperfusion in vivo. Recent studies have suggested that a reduction in the plasma HDL level may contribute to cardiac sudden death. Although there are currently only a few therapeutic strategies for increasing HDL, an exciting new therapeutic option, rHDL, has recently been developed to prevent coronary artery disease. To analyze the suppression of reperfusion arrhythmia by rHDL (apolipoprotein A-I with 1-palmitoyl-2-oleoyl-phosphatidyl-choline), 92 male Wistar rats were divided into 10 groups: rats that had been pre-treated with or without rHDL, apolipoprotein A-I, or 1-palmitoyl-2-oleoyl-phosphatidyl-choline in the presence or absence of inhibitors of Akt protein kinase, nitric oxide (NO), or extracellular-signal-regulated kinase (ERK) administered intravenously before left coronary artery occlusion. We also used human coronary artery endothelial cells and adenosine triphosphate-binding cassette transporter (ABC) A1-, ABCG1-, or scavenger receptor class B, type I-transfected ldlA7 cells systems. The duration of ventricular tachycardia or ventricular fibrillation after reperfusion in rHDL-pre-treated rats was much shorter than that in untreated rats. Apolipoprotein A-I or 1-palmitoyl-2-oleoyl-phosphatidyl-choline alone had no effect. The effect of rHDL was blocked by inhibitors of Akt, NO, and ERK. Plasma NO concentration in the rHDL group was significantly higher. In addition, rHDL activated phospho(p)-Akt, p-ERK, and p-endothelial NO synthesis in endothelial cells. The rHDL activated p-ERK in ABCA1- or ABCG1-transfected but not scavenger receptor class B, type I-transfected ldlA7 cells. The rHDL-induced NO production, probably mediated by ABCA1 or ABCG1 through an Akt/ERK/NO pathway in endothelial cells, may suppress reperfusion-induced arrhythmias. The HDL-based therapy may hold the promise of reducing the incidence of such arrhythmias after ischemia/reperfusion.

Journal of the American College of Cardiology


Both Notch1 and Notch2 contribute to the regulation of melanocyte homeostasis

Notch signaling affects a variety of mammalian stem cells, but there has been limited evidence that a specific Notch molecule regulates adult stem cells. Recently, it was reported that the reduced Notch signaling initiated at the embryonic stage results in a gradual hair graying phenotype after birth. Here we demonstrate that the oral administration of a gamma-secretase inhibitor (GSI) to wild-type adult C57/Bl6 mice led to a gradual increase in gray spots, which remained unchanged for at least 20 weeks after discontinuing the GSI. In GSI-treated mice, there was a severe decrease in unpigmented melanocytes in the bulge/subbulge region where melanocyte stem cells are located. While we confirmed that Notch1+/-Notch2+/- double heterozygous mice with a C57/Bl6 background were born with a normal hair color phenotype and gradually turned gray after the second hair cycle, in the c-kit mutant Wv background, Notch1+/- and Notch2+/- mice had larger white spots on the first appearance of hair than did the Wv/+ mice, which did not change throughout life. Notch1+/-Notch2+/-Wv/+ mice had white hair virtually all over the body at the first appearance of hair and the depigmentation continued to progress thereafter. Using a neural crest organ culture system, GSI blocked the generation of pigmented melanocytes when added to the culture during the period of melanoblast proliferation, but not during the period of differentiation. These observations imply roles of Notch signaling in both development of melanocyte during embryogenesis and maintenance of melanocyte stem cells in adulthood, while the degree of requirement is distinct in these settings: the latter is more sensitive than the former to the reduced Notch signaling. Furthermore, Notch1 and Notch2 cooperates with c-kit signaling during embryogenesis, and they cooperate with each other to regulate melanocyte homeostasis after birth.


Periostin is essential for cardiac healing after acute myocardial infarction

Acute myocardial infarction (AMI) is a common and lethal heart disease, and the recruitment of fibroblastic cells to the infarct region is essential for the cardiac healing process. Although stiffness of the extracellular matrix in the infarct myocardium is associated with cardiac healing, the molecular mechanism of cardiac healing is not fully understood. We show that periostin, which is a matricellular protein, is important for the cardiac healing process after AMI. The expression of periostin protein was abundant in the infarct border of human and mouse hearts with AMI. We generated periostin(-/-) mice and found no morphologically abnormal cardiomyocyte phenotypes; however, after AMI, cardiac healing was impaired in these mice, resulting in cardiac rupture as a consequence of reduced myocardial stiffness caused by a reduced number of alpha smooth muscle actin-positive cells, impaired collagen fibril formation, and decreased phosphorylation of FAK. These phenotypes were rescued by gene transfer of a spliced form of periostin. Moreover, the inhibition of FAK or alphav-integrin, which blocked the periostin-promoted cell migration, revealed that alphav-integrin, FAK, and Akt are involved in periostin signaling. Our novel findings show the effects of periostin on recruitment of activated fibroblasts through FAK-integrin signaling and on their collagen fibril formation specific to healing after AMI.


Orally administered eicosapentaenoic acid reduces and stabilizes atherosclerotic lesions in ApoE-deficient mice

Accumulating evidence demonstrates that dietary intake of n-3 polyunsaturated fatty acids (PUFAs) is associated with reduced incidence of cardiovascular events. However, the molecular mechanisms by which n-3 PUFAs prevent atherosclerosis are not fully understood. Here, we examined the effect of eicosapentaenoic acid (EPA), a major n-3 PUFA, on the pathogenesis of atherosclerosis in ApoE-deficient mice. Five-week-old ApoE-deficient male mice were fed on western-type diet supplemented with 5% (w/w) EPA (EPA group, n=7) or not (control group, n=5) for 13 weeks. An analysis of the fatty acid composition of liver homogenates revealed a marked increase of the n-3 PUFA content in the EPA group (n-3/n-6 ratio: 0.20+/-0.01 vs. 2.5+/-0.2, p<0.01). En face Sudan IV staining of the aorta and oil red O-staining of the aortic sinus revealed that EPA significantly suppressed the development of atherosclerotic lesions. We also observed anti-atherosclerotic effects of EPA in LDL-receptor-deficient mice. The lesions of the EPA group contained more collagen (19.6+/-2.4% vs. 32.9+/-3.9%, p<0.05) and smooth muscle cells (1.3+/-0.2% vs. 3.6+/-0.8%, p<0.05) and less macrophages (32.7+/-4.1% vs. 14.7+/-2.0%, p<0.05). Pretreatment with EPA attenuated the up-regulation of VCAM-1, ICAM-1 and MCP-1 in HUVECs as well as the expression of MMP-2 and MMP-9 in macrophage-like cells induced by TNF-alpha. The anti-inflammatory effects of EPA were abrogated when the expression of peroxisome proliferator-activated receptor alpha (PPARalpha) was suppressed. EPA may potentially reduce and stabilize atherosclerotic lesions through its anti-inflammatory effects.


Pioglitazone ameliorates endothelial dysfunction and restores ischemia-induced angiogenesis in diabetic mice

Angiogenesis, the formation of new blood vessels, is a physiological response to tissue ischemia. Clinical evidence suggests that diabetic patients have endothelial dysfunction and impaired angiogenesis in response to ischemia. Here, we investigated the impact of diabetes on ischemia-induced collateral growth, and tested the hypothesis that peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist augments collateral flow to ischemic tissue. We conducted unilateral hindlimb ischemia surgery in KKAy mice. Blood flow recovery was markedly impaired in diabetic mice compared with that in wild-type mice as determined by laser Doppler imaging. Treatment of KKAy mice with pioglitazone partially restored the blood flow recovery. Anti-CD31 immunostaining revealed that pioglitazone also significantly improved the capillary density in ischemic limb muscle. Endothelial NO synthase (eNOS) activity was ameliorated in diabetic mice treated with pioglitazone as determined by vasorelaxation in response to acetylcholine. Pioglitazone normalized vascular endothelial growth factor (VEGF) protein levels, which was decreased in ischemic muscle of KKAy mice, and up-regulated eNOS phosphorylation at Ser-1177 and Akt phosphorylation at Ser-473 in ischemic muscle. Pioglitazone had no beneficial effects on blood flow recovery in diabetic mice treated with N(G)-nitro-l-arginine methyl ester (L-NAME). Our findings demonstrate that pioglitazone significantly ameliorates endothelial dysfunction and enhances blood flow recovery after tissue ischemia in diabetic mice. Activation of eNOS appears to be essential for pioglitazone to promote angiogenesis in ischemic tissue.


Circulating progenitor cells contribute to neointimal formation in non-irradiated chimeric mice

Recent evidence suggests that bone marrow-derived cells may contribute to repair and lesion formation following vascular injury. In most studies, bone marrow-derived cells were tracked by transplanting exogenous cells into bone marrow that had been compromised by irradiation. It remains to be determined whether endogenous circulating progenitors actually contribute to arterial remodeling under physiological conditions. Here, we established a parabiotic model in which two mice were conjoined subcutaneously without any vascular anastomosis. When wild-type mice were joined with transgenic mice that expressed green fluorescent protein (GFP) in all tissues, GFP-positive cells were detected not only in the peripheral blood but also in the bone marrow of the wild-type mice. The femoral arteries of the wild-type mice were mechanically injured by insertion of a large wire. At 4 wk, there was neointima hyperplasia that mainly consisted of alpha-smooth muscle actin-positive cells. GFP-positive cells were readily detected in the neointima (14.8+/-4.5%) and media (31.1+/-8.8%) of the injured artery. Some GFP-positive cells expressed alpha-smooth muscle actin or an endothelial cell marker. These results indicate that circulating progenitors contribute to re-endothelialization and neointimal formation after mechanical vascular injury even in nonirradiated mice.


Critical role of bone marrow angiotensin II type 1 receptor in the pathogenesis of atherosclerosis in apolipoprotein E deficient mice

It is suggested that the angiotensin II (Ang II)-Ang II type 1 receptor (AT1R) pathway plays a pivotal role in the pathogenesis of atherosclerosis. Recently, bone marrow (BM) cells were reported to express AT1R. Here, we investigated the role of AT1R in BM in the pathogenesis of atherosclerosis. Genetic ablation or pharmacological blockade of AT1R led to a significant reduction and stabilization of atherosclerotic lesions in ApoE-/- mice. To elucidate the role of AT1R in BM, we generated several BM chimeric mice. Ang II promoted atherosclerosis progression in the BM chimeric mice that had AT1aR in BM, regardless of the absence of AT1aR in the recipient vasculature (P<0.05). BM chimeric mice whose BM AT1aR was disrupted showed significantly less atherosclerotic lesions in aorta (P<0.05) and more stable plaque with reduced accumulation of BM-derived cells compared with BM chimeric mice that had AT1aR-positive BM. Most of the BM-derived cells in atheroma were positive for a macrophage marker and expressed matrix metalloproteinase (MMP)-9 and monocyte chemoattractant protein-1. Our findings suggest that AT1R in BM plays an important role in the pathogenesis of atherosclerosis.

Arteriosclerosis, Thrombosis, and Vascular Biology


Delayed post-ischemic treatment with fluvastatin improved cognitive impairment after stroke in rats

Recent clinical evidences indicate that statins may have beneficial effects on the functional recovery after ischemic stroke. However, the effect of delayed postischemic treatment with statins is still unclear. In the present study, we evaluated the effects of fluvastatin in the chronic stage of cerebral infarction in a rat model. Rats exposed to permanent middle cerebral artery occlusion were treated for 3 months with fluvastatin beginning from 7 days after stroke. MRI, behavioral analysis, and immunohistochemistry were performed. Two months of treatment with fluvastatin showed the significant recovery in spatial learning without the decrease in serum total cholesterol level and worsening of infarction. Microangiography showed a significant increase in capillary density in the peri-infarct region in fluvastatin-treated rats after 3 months of treatment. Consistently, BrdU/CD31-positive cells were significantly increased in fluvastatin-treated rats after 7 days of treatment. MAP1B-positive neurites were also increased in the peri-infarct region in fluvastatin-treated rats. In addition, rats treated with fluvastatin showed the reduction of superoxide anion after 7 days of treatment and the reduction of A beta deposits in the thalamic nuclei after 3 months of treatment. Thus, delayed postischemic administration of fluvastatin had beneficial effects on the recovery of cognitive function without affecting the infarction size after ischemic stroke. Pleiotropic effects of fluvastatin, such as angiogenesis, neuritogenesis, and inhibition of superoxide production and A beta deposition, might be associated with a favorable outcome.


Angiotensin II receptor blocker inhibits neointimal hyperplasia through regulation of smooth muscle-like progenitor cells

Angiotensin II (ATII) type 1 receptor (AT1R) blocker (ARB) has been shown to inhibit neointimal formation. Bone marrow-derived mononuclear cells (BM-MNCs) give rise to smooth muscle (SM)-like cells at injured arterial wall and contribute to neointimal formation. However, role of the renin-angiotensin system in the homing process of SM-like cells during neointimal formation is unknown. When human BM-MNCs and peripheral blood MNCs (PB-MNCs) were cultured under treatment with PDGF-BB and bFGF, these cells gave rise to SM-like cells with expression of alphaSMA, SMemb, and SM1 proteins. RT-PCR showed the expression of AT1R, ATII type 2 receptor (AT2R), alphaSMA, and SMemb mRNAs. ATII accelerated the differentiation of SM-like cells, which was inhibited by an ARB CV11974 (P<0.05). We then examined the effects of ATII, CV11974, and AT2R antagonist PD123319 on neointimal formation and BM-derived SM-like cell incorporation at injured arteries in vivo. BM from green fluorescence protein (GFP)-transgenic mice was transplanted to irradiated WT mice. GFP-BM chimera mice were subjected to wire injury on the left femoral artery. ATII (100 ng/kg/min) stimulated whereas CV11974 (1 mg/kg/d) inhibited neointimal formation. Number of GFP+ alphaSMA+ cells at neointima correlated with the intima/media ratio (r=0.69, P<0.05). BM-derived SM-like progenitor cells contributed to the neointimal formation after arterial injury. ATII accelerated whereas ARB suppressed this process. These are new aspects of the ARB-mediated inhibition of atherosclerotic disease progression.


Strain-dependent embryonic lethality and exaggerated vascular remodeling in heparin cofactor II-deficient mice

Heparin cofactor II (HCII) specifically inhibits thrombin action at sites of injured arterial wall, and patients with HCII deficiency exhibit advanced atherosclerosis. However, the in vivo effects and the molecular mechanism underlying the action of HCII during vascular remodeling remain elusive. To clarify the role of HCII in vascular remodeling, we generated HCII-deficient mice by gene targeting. In contrast to a previous report, HCII(-/-) mice were embryonically lethal. In HCII(+/-) mice, prominent intimal hyperplasia with increased cellular proliferation was observed after tube cuff and wire vascular injury. The number of protease-activated receptor-1-positive (PAR-1-positive) cells was increased in the thickened vascular wall of HCII(+/-) mice, suggesting enhanced thrombin action in this region. Cuff injury also increased the expression levels of inflammatory cytokines and chemokines in the vascular wall of HCII(+/-) mice. The intimal hyperplasia in HCII(+/-) mice with vascular injury was abrogated by human HCII supplementation. Furthermore, HCII deficiency caused acceleration of aortic plaque formation with increased PAR-1 expression and oxidative stress in apoE-KO mice. These results demonstrate that HCII protects against thrombin-induced remodeling of an injured vascular wall by inhibiting thrombin action and suggest that HCII is potentially therapeutic against atherosclerosis without causing coagulatory disturbance.


A synthetic small molecule, ONO-1301, enhances endgenous growth factor expression and augments angiogenesis in ischemic heart

It has been shown previously that administration of angiogenic growth factors as genes or proteins can augment collateral growth in ischaemic tissues. In the present study, we have investigated the effect of ONO-1301, a synthetic prostacyclin agonist with thromboxane-synthase-inhibitory activity, on expression of endogenous growth factors and angiogenesis. ONO-1301 induced secretion of HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor) from cultured normal human dermal fibroblasts in a dose-dependent manner. Dibutyryl cAMP, an analogue of cAMP, and forskolin, an adenylate cyclase activator, mimicked the effect of ONO-1301. Conversely, Rp-cAMP (adenosine 3',5'-cyclic monophosphorothioate), an inhibitor of cAMP, partially inhibited the effect of ONO-1301, suggesting that cAMP mediated the effect of ONO-1301 in up-regulating the expression of HGF and VEGF, at least in part. ONO-1301 promoted tube-like formation by HUVECs (human umbilical vein endothelial cells) when co-cultured with fibroblasts, and the angiogenic effect of ONO-1301 was abrogated by administration of a neutralizing antibody against HGF or VEGF. To generate a slow-releasing form of ONO-1301, ONO-1301 was mixed with poly(DL-lactic-co-glycolic acid). The slow-releasing form of ONO-1301 was injected directly into the ischaemic myocardium of mice immediately after ligation of the left anterior descending artery. The slow-releasing form of ONO-1301 up-regulated HGF and VEGF expression and increased capillary density in the border zone (342.7+/-29.7 capillaries/mm(2) in controls compared with 557.2+/-26.7 capillaries/mm(2) in treated animals; P<0.01) at 7 days. The slow-releasing form of ONO-1301 ameliorated left ventricular enlargement after 28 days and improved survival rate. In conclusion, our results indicate that ONO-1301 up-regulated endogenous growth factors and promoted angiogenesis in response to acute ischaemia. Therefore ONO-1301 might have a therapeutic potential in treating ischaemic diseases.


Expression of hepatocyte growth factor and c-Met after spinal cord injury in rats

Since hepatocyte growth factor (HGF) plays a pivotal role in the development of the central nervous system and pathological conditions, we examined the long-term changes in the mRNA and protein expression of HGF and its receptor c-Met after spinal cord injury (SCI) in rats. HGF mRNA was significantly increased from 7 days after SCI in the injured segment, and the peak was at 7 days after SCI as assessed by real-time RT-PCR. Importantly, c-met mRNA expression was up-regulated from 1 day after SCI, and reached a peak at 14 days after SCI. Although up-regulation of HGF and c-met mRNA expression in the injured segment gradually decreased, the increased expression level persisted until 56 days after SCI. Consistent with HGF mRNA expression, HGF protein level was significantly increased mainly in the injured region, which persisted until 56 days after SCI. Immunohistochemistry showed that most of GFAP-positive reactive astrocytes expressed HGF and c-Met both on 14 days and 56 days after SCI. Staining with the mitotic indicator, bromodeoxyuridine (BrdU), revealed that a small number of BrdU-incorporated cells were co-localized with HGF/GFAP-positive or c-Met/GFAP-positive cells both on 14 and 56 days. These data suggest that HGF and c-Met were up-regulated mainly in the reactive astrocytes around the injured region in the subacute to chronic stage of spinal cord injury. Since HGF plays a critical role in neurotrophic activity, activation of the HGF/c-Met signaling system might be involved in the process of post-traumatic regeneration.


Protective role of HIF-2α against ischemic damage and oxidative stress in the kidney

Central to cellular responses to hypoxic environment is the hypoxia-inducible factor (HIF) transcriptional control system. A role for HIF-2alpha was investigated in a model of renal ischemia-reperfusion injury (IRI) associated with oxidative stress using HIF-2alpha knockdown mice. In these mice, HIF-2alpha expression was approximately one half that of wild-type mice, whereas HIF-1alpha expression was equivalent. HIF-2alpha knockdown mice were more susceptible to renal IRI, as indicated by elevated blood urea nitrogen levels and semiquantitative histologic analysis. Immunostaining with markers of oxidative stress showed enhanced oxidative stress in the kidney of HIF-2alpha knockdown mice, which was associated with peritubular capillary loss. Real-time quantitative PCR analysis showed decreased expression of antioxidative stress genes in the HIF-2alpha knockdown kidneys. Studies that used small interference RNA confirmed regulation of the antioxidative stress genes in cultured endothelial cells. Although HIF-2alpha knockdown mice were anemic, serum erythropoietin levels were not significantly increased, reflecting inappropriate response to anemia as a result of HIF-2alpha knockdown. Experiments that used hemodiluted mice with renal ischemia demonstrated that anemia of this degree did not affect susceptibility to ischemia. Knockdown of HIF-2alpha in inflammatory cells by bone marrow transplantation experiments demonstrated that HIF-2alpha in inflammatory cells did not contribute to susceptibility to renal IRI. Restoration of HIF-2alpha in endothelium by intercrossing with Tie1-Cre mice ameliorated renal injury by IRI, demonstrating a specific role of endothelial HIF-2alpha. These results suggest that HIF-2alpha in the endothelium has a protective role against ischemia of the kidney via amelioration of oxidative stress.

Journal of the American Society of Nephrology


Functional interaction between the transcription factor Kruppel-like factor 5 and poly(ADP-ribose) polymerase-1 in cardiovascular apoptosis

Krüppel-like factor 5 (KLF5) is a transcription factor important in regulation of the cardiovascular response to external stress. KLF5 regulates pathological cell growth, and its acetylation is important for this effect. Its mechanisms of action, however, are still unclear. Analysis in KLF5-deficient mice showed that KLF5 confers apoptotic resistance in vascular lesions. Mechanistic analysis further showed that it specifically interacts with poly(ADP-ribose) polymerase-1 (PARP-1), a nuclear enzyme important in DNA repair and apoptosis. KLF5 interacted with a proteolytic fragment of PARP-1, and acetylation of KLF5 under apoptotic conditions increased their affinity. Moreover, KLF5 wild-type (but not a non-acetylatable point mutant) inhibited apoptosis as induced by the PARP-1 fragment. Collectively, we have found that KLF5 regulates apoptosis and targets PARP-1, and further, for acetylation to regulate these effects. Our findings thus implicate functional interaction between the transcription factor KLF5 and PARP-1 in cardiovascular apoptosis.


Reconstituted high-density lipoprotein stimulates differentiation of endothelial progenitor cells and enhances ischemia-induced angiogenesis

Plasma high-density lipoprotein (HDL) levels have an inverse correlation with incidence of ischemic heart disease as well as other atherosclerosis-related ischemic conditions. However, the molecular mechanism by which HDL prevents ischemic disease is not fully understood. Here, we investigated the effect of HDL on differentiation of endothelial progenitor cells and angiogenesis in murine ischemic hindlimb model. Intravenous injection of reconstituted HDL (rHDL) significantly augmented blood flow recovery and increased capillary density in the ischemic leg. rHDL increased the number of bone marrow-derived cells incorporated into the newly formed capillaries in ischemic muscle. rHDL induced phosphorylation of Akt in human peripheral mononuclear cells. rHDL (50 to 100 microg apolipoprotein A-I/mL) promoted differentiation of peripheral mononuclear cells to endothelial progenitor cells in a dose-dependent manner. The effect of rHDL on endothelial progenitor cells differentiation was abrogated by coadministration of LY294002, an inhibitor of phosphatidylinositol 3-kinase. rHDL failed to promote angiogenesis in endothelial NO-deficient mice. rHDL directly stimulates endothelial progenitor cell differentiation via phosphatidylinositol 3-kinase/Akt pathway and enhances ischemia-induced angiogenesis. rHDL may be useful in the treatment of patients with ischemic cardiovascular diseases.

Arteriosclerosis, Thrombosis, and Vascular Biology


Mobilization of CD34-Positive bone marrow-derived cells after coronary stent implantation: impact on restenosis

Recently, accumulating evidence has indicated that bone marrow-derived stem cells are capable of differentiating into vascular cells. It has been hypothesized that the inflammatory response after vascular injury triggers the mobilization of endothelial and smooth muscle progenitor cells from bone marrow. We measured circulating CD34-positive mononuclear cells, activation of integrin Mac-1 on the surface of neutrophils, and plasma granulocyte-colony stimulating factor levels in 40 patients undergoing coronary stenting. After bare-metal stenting, CD34-positive cells increased, reaching a maximum on day 7 after stenting. The maximum change compared with baseline before stenting was more striking in patients with restenosis than without restenosis (332+/-108% versus 148+/-49%; P<0.05). In contrast, CD34-positive cells decreased after sirolimus-eluting stenting (72+/-21% on day 7). The change in CD34-positive cells on day 7 relative to baseline was closely correlated with that in activated Mac-1 at 48 hours (R=0.52, P<0.01) and that in granulocyte-colony stimulating factor levels at 24 hours (R=0.42, P<0.05). Cell culture assay on day 7 showed that mononuclear cells differentiated into CD31-positive endothelium-like cells after bare-metal stenting. In patients with restenosis, mononuclear cells differentiating into alpha-smooth muscle actin-positive smooth muscle-like cells also were observed. Implantation of sirolimus-eluting stents suppressed both types of differentiation. Stent implantation may induce differentiation of bone marrow cells into endothelial or smooth muscle cells. Endothelial cells may participate in reendothelialization, a protective reaction against vascular injury, whereas smooth muscle cells may participate in neointimal thickening and restenosis. Sirolimus-eluting stents appear to inhibit the mobilization and differentiation of bone marrow cells.


Diverse contribution of bone marrow-derived cells to vascular remodeling associated with pulmonary arterial hypertension and arterial neointimal formation

Recent evidence suggests that bone marrow (BM)-derived cells may differentiate into vascular cells that participate in arterial repair and/or lesion formation. However, it remains uncertain whether BM-derived cells also can participate in vascular remodeling associated with pulmonary arterial hypertension. The BM of Sprague-Dawley rats was reconstituted with that of green fluorescent protein-transgenic rats. The BM-chimeric rats were injected intraperitoneally with 60 mg/kg monocrotaline after unilateral subpneumonectomy, and they concurrently underwent wire-mediated endovascular injury in femoral artery. After 28 days, they had elevated right ventricular systolic pressure (58.8+/-5.4 versus 20.4+/-2.4 mm Hg in sham-control; P<0.01). The pulmonary arterioles were markedly thickened, with an infiltration of green fluorescent protein-positive macrophages into the perivascular areas. The endothelium of pulmonary arterioles contained only a few green fluorescent protein-positive cells, and green fluorescent protein-positive cells were seldom detected as smooth muscle cells in the lesions of thickened pulmonary arterioles. In contrast, BM-derived smooth muscle-like cells could be readily detected in the thickened neointima and media of the wire-injured femoral artery. Moreover, intravenous injection of 1x10(8) BM cells from young rats had no beneficial effects on pulmonary hypertension, pulmonary arterial remodeling, or survival in the aged rats treated with monocrotaline plus unilateral subpneumonectomy. No injected BM cell was identified as an endothelial cell or a smooth muscle cell. These results suggest that BM-derived cells can participate in arterial neointimal formation after mechanical injury, whereas they do not contribute substantially to pulmonary arterial remodeling associated with monocrotaline-induced pulmonary arterial hypertension in the pneumonectomized rats.


Atorvastatin attenuates transplant-associated coronary arteriosclerosis in a murine model of cardiac transplantation

Accelerated coronary arteriosclerosis remains a major problem for the long-term survival of cardiac transplant recipients. However, the pathogenesis of transplant vasculopathy is poorly understood and there is no effective therapy. HMG-CoA reductase inhibitors, or statins, are widely prescribed to lower plasma cholesterol level. Accumulating evidence indicates that statins have various effects on vascular cells which are independent of their lipid-lowering effect. We investigated whether orally administered atorvastatin, one of the most potent statins, inhibits the development of intima hyperplasia in a mouse model of cardiac transplantation. Cardiac allografts from DBA mice were transplanted heterotopically into B10.D2 mice. Mice were administered either vehicle or atorvastatin everyday by gavage. Morphometrical analysis revealed that atorvastatin significantly reduced the development of coronary arteriosclerosis on the cardiac allografts harvested at one month. Immunohistochemical analysis revealed that atorvastatin attenuated infiltration of inflammatory cells with reduced expression of TGF-beta and adhesion molecules. These results suggest that atorvastatin may be effective in preventing transplant-associated arteriosclerosis along with other immunosuppressive agents.


OPC-28326, a selective femoral arterial vasodilator, augments ischemia induced angiogenesis

OPC-28326, 4-(N-methyl-2-phenylethylamino)-1-(3,5-dimethyl-4-propionyl-aminobenzoyl) piperidine hydrochloride monohydrate, is a newly developed selective peripheral vasodilator and increases blood flow to lower extremities with alpha2-adrenergic antagonist property. Here, we investigated the effect of OPC-28326 on ischemia-induced angiogenesis. OPC-28326 enhanced tube formation by human aortic endothelial cells (HAECs). Moreover, OPC-28326 enhanced the number of microvessels sprouting from aortic rings embedded in collagen gel. OPC-28326 markedly induced phosphorylation of endothelial nitric oxide synthase (eNOS) in HAECs via phosphatidylinositol-3 kinase PI3K/Akt (PI3K/Akt) pathway. Next, the angiogenic effect of OPC-28326 was evaluated in a mouse hindlimb ischemia model. Blood flow recovery to the ischemic leg was significantly enhanced by OPC-28326. Furthermore, anti-CD31 immunostaining revealed that OPC-28326 increased capillary density in the ischemic muscle. However, OPC-28326 failed to promote blood flow recovery in ischemic hindlimb in eNOS-deficient mice. These results suggest that OPC-28326 promotes angiogenesis, which was associated with activation of eNOS via PI3K/Akt pathway. OPC-28326 might be promising to treat patients with ischemic vascular diseases.


Quantitative measurement of neurological deficit after mild (30 min) transient middle cerebral artery occlusion in rats

Although 30-min transient middle cerebral artery occlusion (30-min tMCAo) causes reproducible subcortical infarction in rats, it is difficult to evaluate the resulting neurological deficit using common behavioral tests such as the rota-rod test, adhesive-removal test, or narrow beam test. Establishment of a method of quantitative evaluation would help to develop a novel therapeutic approach to treat cerebral infarction. To solve this problem, we examined whether the neurological deficit could be detected by the Montoya staircase test or methamphetamine-induced rotation, which are commonly used in a Parkinson disease model induced by intrastriatal injection of 6-hydroxydopamine (6-OHDA). From 10 to 14 days after tMCAo, the Montoya staircase test showed significant clumsiness in forelimb tasks contralateral to the lesion side, whereas sham-operated rats showed no significant clumsiness in both forelimbs. The number of ipsilateral rotations induced by methamphetamine was also increased in tMCAo-rats at 21 days after tMCAo. Although Pearson's correlations coefficient showed that the results of these tests were correlated with the infarction volume, there was no significant correlation between the results of these two tests. These findings imply that the neurological deficit detected by both tests might reflect the severity of ischemic injury, but each test might evaluate different aspects of neurological deficit. Thus, the Montoya staircase test and methamphetamine-induced rotation are useful to evaluate neurological deficit in the chronic stage of subcortical infarction induced by 30-min tMCAo.


Transplantation of adipose stromal cells, but not mature adipocytes, augments ischemia-induced angiogenesis

Therapeutic angiogenesis has emerged as a promising therapy to treat patients with ischemic diseases. Transplantation of bone marrow cells (BMCs) is reported to augment collateral development in ischemic organs either by differentiating into vascular cells or by secreting angiogenic cytokines. Recent evidence suggests that adipose tissues secrete a number of humoral factors and contain pluripotent stem cells. Here, we evaluated the therapeutic potential of adipose tissue-derived cells to promote angiogenesis in a mouse model of hind limb ischemia. Stromal vascular fraction cells (SVFs) were isolated from inguinal adipose tissue. Endothelial-like cells or smooth muscle-like cells could be obtained from the culture of SVFs in the presence of growth factors. Freshly isolated BMCs, SVFs, or mature adipocytes were transplanted into the ischemic hind limb of mice. SVFs significantly augmented collateral development as determined by the restoration of blood perfusion and capillary density of the ischemic muscle. Angiogenic effects of SVFs were as potent as those of BMCs. Mature adipocytes showed no proangiogenic effects. The ischemic muscle contained endothelial cells or smooth muscle cells that derived from the transplanted SVFs and BMCs. These results suggest that SVFs might be used to promote angiogenesis in ischemic tissues.


Effects of adrenomedullin on acute ischemia-induced collateral development and mobilization of bone marrow-derived cells

Adrenomedullin exerts not only vasodilatory effects, but also angiogenic effects. In the present study, we investigated the effects of adrenomedullin on collateral formation and circulating bone-marrow-derived cells after acute tissue ischaemia. Bone marrow of 8-10-week-old female C57BL/6J mice was replaced with that from GFP (green fluorescent protein) transgenic mice (GFP mice). At 8 weeks after transplantation, hindlimb ischaemia was induced by resecting the right femoral artery and a plasmid expressing human adrenomedullin (50 mug) was injected into the ischaemic muscle, followed by in vivo electroporation on a weekly basis. Overexpression of adrenomedullin significantly enhanced the blood flow recovery compared with controls (blood flow ratio, 1.0+/-0.2 compared with 0.6+/-0.3 respectively, at week 4; P<0.05) and increased capillary density in the ischaemic leg as determined by anti-CD31 immunostaining of the ischaemic muscle (567+/-40 compared with 338+/-65 capillaries/mm(2) respectively, at week 5; P<0.05). There were more GFP-positive cells in the thigh muscle of the mice injected with adrenomedullin than in that of the control mice (29.6+/-4.5 compared with 16.5+/-3.3 capillaries/mm(2) respectively, at week 5; P<0.05). We repeated the same experiments using LacZ-knock-in mice instead of GFP mice, and obtained similar results. These findings suggest that adrenomedullin may augment ischaemia-induced collateral formation with some effects on circulating bone-marrow-derived cells.


Microbubble-induced increase in ablation of liver tumors by high-intensity focused ultrasound

We studied the possibility of using high-intensity focused ultrasound (HIFU) together with a microbubble agent to treat hepatocellular carcinoma. Development of liver tumors in rats was induced by administration of Dimethylnitrosamin (100ppm). Rats with liver tumors were anesthetized, underwent laparotomy, and were given the microbubble agent Levovist or saline intravenously. After the injection, the liver was exposed to HIFU for 30s (2.18MHz, 600W/cm(2), 40mm in diameter). Immediately after HIFU exposure, ultrasound images of the HIFU area were evaluated. Then the liver was excised and the volume of coagulated tissue was measured. The mean volumes of hyperechoic areas after HIFU were as follows (mm(3), Levovist versus saline: 355.3+/-180.7 versus 47.4+/-35.6, P<0.001, n=13). The volumes of liver tissue coagulated by HIFU were as follows (mm(3), Levovist versus saline: 275.3+/-120.0 versus 60.1+/-23.6, P<0.001, n=13). On microscopic examination of areas exposed to HIFU, implosion cysts were seen, and many cancer cells were found to have been destroyed completely (loss of cell membranes or nuclei). In conclusion, the microbubble agent Levovist can increase the volume of tissue coagulated by HIFU.


Chondromodulin-I maintains cardiac valvular function by preventing angiogenesis

The avascularity of cardiac valves is abrogated in several valvular heart diseases (VHDs). This study investigated the molecular mechanisms underlying valvular avascularity and its correlation with VHD. Chondromodulin-I, an antiangiogenic factor isolated from cartilage, is abundantly expressed in cardiac valves. Gene targeting of chondromodulin-I resulted in enhanced Vegf-A expression, angiogenesis, lipid deposition and calcification in the cardiac valves of aged mice. Echocardiography showed aortic valve thickening, calcification and turbulent flow, indicative of early changes in aortic stenosis. Conditioned medium obtained from cultured valvular interstitial cells strongly inhibited tube formation and mobilization of endothelial cells and induced their apoptosis; these effects were partially inhibited by chondromodulin-I small interfering RNA. In human VHD, including cases associated with infective endocarditis, rheumatic heart disease and atherosclerosis, VEGF-A expression, neovascularization and calcification were observed in areas of chondromodulin-I downregulation. These findings provide evidence that chondromodulin-I has a pivotal role in maintaining valvular normal function by preventing angiogenesis that may lead to VHD.


Angiotensin II Type 1 Receptor Blockade Attenuates In-Stent Restenosis by Inhibiting Inflammation and Progenitor Cells

The precise mechanism by which angiotensin II type 1 receptor blocker reduces in-stent restenosis in clinical trials is unclear. We, therefore, investigated the mechanism of in-stent neointima formation. Male cynomolgus monkeys and rabbits were fed a high-cholesterol diet and were allocated to untreated control and type 1 receptor blocker groups. Five days after grouping, multilink stents were implanted in the iliac artery. The type 1 receptor blocker reduced the development of in-stent neointima formation by approximately 30% in rabbits and monkeys. To investigate potential mechanisms, we examined the expression of renin-angiotensin system markers, all of which increased in monocytes and smooth muscle-like cells in the neointima and media within 7 days. The type 1 receptor blocker attenuated increased oxidative stress, the enhanced expression of markers of the rennin-angiotensin system and monocyte chemoattractant protein-1, and macrophage infiltration. The effects of type 1 receptor blocker on the differentiation of peripheral blood mononuclear cells into vascular progenitor cells were also examined. Treatment with type 1 receptor blocker suppressed the enhanced differentiation to smooth muscle progenitor cells induced by stenting. The type 1 receptor blocker attenuated in-stent neointima formation by inhibiting redox-sensitive inflammatory changes and by reducing recruitment of the progenitor cells. These potential actions of type 1 receptor blocker on inflammation and progenitor cells constitute a novel mechanism of suppression of in-stent restenosis by type 1 receptor blocker.