The functional integrity of the vascular endothelium is an essential component required for the maintenance of vascular health, thus counteracting the onset of vascular diseases, including atherosclerosis and vascular complications of diabetes. In light of this important role, the vascular endothelium is expected to have a self-defense system. One candidate factor of such a system is vasohibin-1 (VASH1), a protein that is preferentially expressed in vascular endothelial cells (ECs). The unique features of VASH1 are its anti-angiogenic activity and ability to promote the stress tolerance and survival of ECs. This review summarizes current knowledge regarding VASH1 in terms of its roles in maintaining vascular integrity and protecting the vasculature against various forms of stress.

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Aim: The goal of the study was to investigate the relationships between coronary artery disease (CAD) and risk factors, including the serum levels of high-sensitivity C-reactive protein (hs-CRP), lipoprotein(a) (Lp(a)) and homocysteine, in Japanese patients with peripheral arterial disease (PAD).
Methods: Coronary angiography was performed in 451 patients with PAD, among whom the prevalence and clinical characteristics of CAD were analyzed. A multiple logistic analysis was used to evaluate the relationships between CAD and the risk factors. The relationships between the severity of coronary arterial lesions and the risk factors were evaluated using multiple regression analysis.
Results: The prevalence of CAD (≥70% luminal diameter narrowing or a history of CAD) and coronary artery stenosis (≥50%) was 55.9% and 74.1%, respectively, and the rate of CAD (≥70%) with single-, double- and triple-vessel disease was 25.9%, 13.5% and 10.6%, respectively. The prevalence of diabetes was higher among the patients with CAD than among those without. The serum levels of hs-CRP, Lp(a), and homocysteine were higher in the patients with CAD, whereas the estimated glomerular filtration rates and HDL-cholesterol levels were lower in these patients. According to the multiple logistic analysis, CAD was related to diabetes (hazard ratio [HR]: 2.253; 95% confidence interval [CI]: 1.137-4.464, p=0.020), hs-CRP (HR: 1.721; 95% CI: 1.030-2.875, p=0.038), Lp(a) (HR: 1.015; 95% CI: 1.001-1.029, p=0.041) and homocysteine (HR: 1.084; 95% CI: 1.012-1.162, p=0.021). Furthermore, diabetes and the D-dimer and LDL-cholesterol levels exhibited significant relationships with the number of stenotic coronary lesions in the stepwise multiple regression analysis (p＜0.05).
Conclusions: Diabetes, hs-CRP, Lp(a), homocysteine and lipid abnormalities are critical risk factors for CAD in Japanese patients with PAD.

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Aim: Low circulating 25-hydroxyvitamin D [25(OH)D] concentration has been linked to a high prevalence of cardiovascular disease. One explanation for this phenomenon is that there is an association between the serum 25(OH)D level and lipid profiles. However, studies examining this relationship are limited and have yielded inconsistent results. We thus aimed to evaluate the association between the serum 25(OH)D concentration and lipid profiles in Japanese men taking into consideration confounding factors, including the visceral fat area (VFA) and cardiorespiratory fitness.
Methods: A total of 136 men (age range: 20-79 years) participated in our study. Fasting blood samples were analyzed to determine the 25(OH)D, oxidized low-density lipoprotein (oxLDL), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), apolipoprotein (Apo)A-1 and ApoB levels. The VFA was evaluated on magnetic resonance imaging (MRI), and cardiorespiratory fitness was assessed by measuring the peak oxygen uptake (O₂ peak).
Results: The median 25(OH)D concentration was 35.6 nmol/L, and the prevalence of 25(OH)D deficiency was 78.7%. A multiple linear regression analysis revealed that the serum 25(OH)D concentration was inversely related to the LDL-C/HDL-C, TG, ApoB and ApoB/ApoA-1 values, even after adjusting for age, season, smoking status, alcohol consumption, medication use, vitamin D intake, calcium intake, VFA and cardiorespiratory fitness.
Conclusions: Serum 25(OH)D level is inversely correlated with the LDL-C/HDL-C, TG, ApoB and ApoB/ApoA-1 values in Japanese men, independent of the VFA and cardiorespiratory fitness.

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Aim: In this study, we investigated the genetic determinants of lesion characteristics and the severity of coronary artery disease (CAD) using a genome-wide association study (GWAS) and replication genotyping.
Methods: The discovery set for GWAS consisted of 667 patients exhibiting angiographically diagnosed CAD with symptoms. For replication genotyping, 837 age- and sex-matched CAD patients were selected. Genetic determinants of lesion characteristics (diffuse vs. non-diffuse lesions), the number of diseased vessels (multi-vessel vs. single vessel disease) and the modified Duke score (high vs. low), which indicates the severity of CAD, were analyzed after adjusting for confounding factors.
Results: Single nucleotide polymorphisms (SNPs) rs12917449, rs10152898 and rs231150 were associated with diffuse lesions, while rs1225006 and rs6745588 were associated with multi-vessel disease. However, on replication genotyping, no significant associations were found between any of these five SNPs and the lesion characteristics or CAD severity. In contrast, in the combined population of both the discovery and replication sets, genotypes rs125006 of CPNE4 and rs231150 of TRPS1 were found to be significantly associated with the modified Duke score. The addition of rs1225006 to conventional risk factors had significant incremental value in the model of the score.
Conclusions: The associations between five SNPs identified using GWAS and angiographic characteristics were not significant in the current replication study. However, two variants, particularly rs1225006, were found to be associated with the severity of CAD in the combined set. These results indicate the potential clinical implication of these variants with respect to the risk of CAD.

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Aim: Pentraxin 3 (PTX3) is a novel marker for the primary local activation of innate immunity and inflammatory responses. Although clinical and experimental evidence suggests that PTX3 is associated with atherosclerosis, the relationship between PTX3 and vascular remodeling after wall injury remains to be determined. We investigated the effects of PTX3 on neointimal hyperplasia following wire vascular injury.
Methods: PTX3 systemic knockout (PTX3-KO) mice and wild-type littermate (WT) mice were subjected to wire-mediated endovascular injury. At four weeks after wire-mediated injury, the areas of neointimal and medial hyperplasia were evaluated.
Results: The PTX3-KO mice exhibited higher hyperplasia/media ratios than the WT mice after wire injury, and the degree of Mac-3-positive macrophage accumulation was significantly higher in the PTX3-KO mice than in the WT mice. Furthermore, the PTX3-KO mice showed a much greater increase in the number of PCNA-stained cells in the vascular wall than that observed in the WT mice.
Conclusions: A deficiency of PTX3 results in deteriorated neointimal hyperplasia after vascular injury via the effects of macrophage accumulation and vascular smooth muscle cell proliferation and migration.

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Aim: This study aimed to examine whether cardiorespiratory fitness (CRF) is associated with arterial stiffening, evaluated using the cardio-ankle vascular index (CAVI), independent of visceral fat (VF) in middle-aged and elderly Japanese men. We also examined whether the relationship between CRF and the CAVI is modified by age and/or hypertension.
Methods: The CAVI was determined in 157 Japanese men (age range, 30-79 years), including 96 hypertensive subjects (61.1%). CRF was assessed by measuring the peak oxygen uptake (O₂peak). The subjects were divided into low- and high-CRF groups, and the VF area was assessed using magnetic resonance imaging.
Results: The O₂peak correlated with the CAVI following adjustment for age and body mass index in the middle-aged and elderly groups (all the subjects: r=−0.285, p＜0.001; middle-aged: r=−0.240, p=0.040; elderly: r=−0.225, p=0.049). VF also correlated with the CAVI (r=0.230, p=0.004). A multiple linear regression analysis revealed that age (β=0.406, p＜0.001) and the O₂peak (β=−0.186, p=0.015) were associated with the CAVI independently of VF and the mean blood pressure. Twoway ANCOVA adjusted for age demonstrated that the hypertensive individuals had higher CAVI values than the normotensive individuals in the low-CRF group, whereas no significant differences in the CAVI were observed in the high-CRF group (p for interaction ＜0.05).
Conclusions: In the present study, CRF was found to be associated with the CAVI, independent of age and VF, in hypertensive middle-aged and elderly Japanese men.

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Aim: The angiotensin I-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism has been reported to be implicated in susceptibility to coronary heart disease (CHD). However, this association remains inconclusive. The purpose of this study was to clarify the association between the I/D polymorphism of the ACE gene and the development of CHD in a Japanese general population and investigate whether the effects of traditional risk factors on the risk of CHD are heterogeneous among ACE genotypes.
Methods: The subjects included 2,125 community-dwelling individuals 40 years of age or older without cardiovascular disease for whom genetic information was available. All patients were prospectively followed for 19 years, and the association between the ACE polymorphism and the incidence of CHD was examined based on the interactions with traditional risk factors, such as hypercholesterolemia, hypertension, diabetes and smoking.
Results: A total of 161 CHD events occurred during the follow-up period. The age- and sex-adjusted incidence of CHD was not significantly different among the genotypes (5.8, 5.2, and 6.9 per 1,000person-years for genotypes II, ID and DD, respectively). In a stratified analysis, however, the ACE DD genotype was found to significantly accelerate the risk of developing CHD by hypercholesterolemia (hazard ratio [HR]=4.50, 95% confidence interval=2.02-10.04 for hypercholesterolemia with the DD genotype; HR=1.48, 95% CI=1.04-2.12 for hypercholesterolemia with the ID＋II genotype; P for interaction=0.01), even after adjusting for other confounding factors, whereas no such associations were observed for hypertension, diabetes or smoking.
Conclusions: The current findings suggest that the ACE DD genotype enhances the effect of hypercholesterolemia on the development of CHD in the general Japanese population.

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Aim: To investigate the prognosis and to clarify the predictors of both patient and limb survival among hemodialysis (HD) patients with critical limb ischemia (CLI) due to isolated below-the-knee (BK) disease.
Methods: An observational cohort study, analyzing a total of 546 HD patients with 681 limbs who underwent endovascular treatment (EVT) for CLI with isolated BK disease at 11 hospitals in Japan between March 2004 and June 2011, was performed.
Results: The mean patient age was 69.0±9.5 years, and 420 (76.9%) of the subjects were men. The number of patients classified with Rutherford stage 4, 5 and 6 disease was 103 (18.9%), 332 (60.8%) and 111 (20.3%), respectively. The mean HbA1c level was 6.48±1.20%, and 195 (35.7%) of the subjects were active smokers. During the follow-up period (mean: 557.5 days), 191 (35.0%) patients died and 82 (12.0%) limbs underwent major amputation. The freedom from all-cause death was 75.5%, 53.4% and 36.9% and freedom from major amputation was 86.7%, 83.9% and 83.9% at one, three and five years after EVT, respectively. Cox proportional hazard regression analyses revealed that a non-ambulatory status, low serum albumin level and ＜2 runoff vessels after EVT were significant predictors for both all-cause death and major amputation.
Conclusions: Although patient survival remains poor, the limb salvage rate after EVT is favorable among those on HD with CLI due to isolated BK disease. The present results allow for the risk stratification of HD patients with CLI undergoing EVT for isolated BK disease.

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Aim: The viscoelastic properties of the artery are known to be altered in patients with vascular diseases. However, few studies have evaluated the viscoelasticity of the vascular wall in humans. We sought to investigate the degree of viscoelastic deterioration of the carotid artery and assess its clinical implications.
Methods: Between January 2011 and June 2013, patients in whom the toe-brachial index was measured at the vascular laboratory were included in this single-institute retrospective observational study. I^＊, a parameter of viscoelastic deterioration, was computed using a non-invasive ultrasonic Doppler effect sensor on the carotid artery. I^＊ is a non-dimensional value, and I^＊＞0 is considered abnormal. Other patient characteristics were identified and tested for correlations with I^＊.
Results: The study included 383 patients. The mean I^＊ value was 0.13±0.22 with a normal distribution. Factors that increased the I^＊ value were a female sex (0.18±0.23 vs. 0.10±0.21, P＜0.001), age ≥ 60 (0.14±0.22 vs. 0.06±0.23, P＜0.05) and systolic blood pressure of ＞140 (0.15±0.22 vs. 0.10±0.22, P＜0.05). I^＊ abnormality was a significant risk factor for coronary artery disease (OR 2.20, 95% CI 1.00-4.80, P＜0.05) in a univariate analysis. In the multivariate analysis, I^＊ abnormality was also found to be an independent risk factor for coronary artery disease (OR 4.56, 95% CI 1.21-30.1, P＜0.05).
Conclusions: I^＊ may reflect the degree of atherosclerotic changes in the arterial wall and could possibly be used to predict coronary artery disease.

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Aim: RhoA is a critical factor in regulating the proliferation and migration of arterial smooth muscle cells (ASMCs) in patients with arteriosclerosis obliterans (ASO). RhoA is modulated by microRNA-133a (miR-133a) in cardiac myocytes and bronchial smooth muscle cells. However, the relationship between miR-133a and RhoA with respect to the onset of ASO in the lower extremities is uncertain.
Methods: We employed in situ hybridization (ISH) and immunohistochemistry (IHC) to detect the location of miR-133a and RhoA in ASO clinical samples, respectively. 5-ethynyl-2’-deoxyuridine (EdU), cell counting kit-8 (CCK-8), Transwell and wound closure assays were utilized to determine the features of human ASMC (HASMC) proliferation and migration. The expression of miR-133a in the HASMCs was assessed using quantitative real-time PCR (qRT-PCR), while that of RhoA was examined via qRT-PCR and Western blotting.
Results: We found miR-133a and RhoA to be primarily located in the ASMCs of ASO. miR-133a was significantly downregulated in the ASO tissues and proliferating HASMCs. In contrast, RhoA was upregulated in the ASO samples. The proliferation and migration of HASMCs was markedly promoted by the downregulation of miR-133a and inhibited by the upregulation of miR-133a. The Luciferase assay confirmed that RhoA was a direct target of miR-133a. The upregulation of miR-133a in the HASMCs decreased the RhoA expression at the protein level. Inversely, the downregulation of miR-133a increased the RhoA protein expression. Of note, the overexpression of RhoA in the HASMCs attenuated the anti-proliferative and anti-migratory effects of miR-133a.
Conclusions: Our data indicate that miR-133a regulates the functions of HASMCs by targeting RhoA and may be involved in the pathogenesis of ASO. These findings may lead to the development of potential therapeutic targets for ASO of the lower extremities.

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