Beschreibung: Background— Hypoandrogenemia is associated with an increased risk of ischemic diseases. Because actions of androgens are exerted through androgen receptor (AR) activation, we studied hind-limb ischemia in AR knockout mice to elucidate the role of AR in response to ischemia. Methods and Results— Both male and female AR knockout mice exhibited impaired blood flow recovery, more cellular apoptosis, and a higher incidence of autoamputation after ischemia. In ex vivo and in vivo angiogenesis studies, AR-deficient vascular endothelial cells showed reduced angiogenic capability. In ischemic limbs of AR knockout mice, reductions in the phosphorylation of the Akt protein kinase and endothelial nitric oxide synthase were observed despite a robust increase in hypoxia-inducible factor 1α and vascular endothelial cell growth factor ( VEGF ) gene expression. In in vitro studies, siRNA-mediated ablation of AR in vascular endothelial cells blunted VEGF-stimulated phosphorylation of Akt and endothelial nitric oxide synthase. Immunoprecipitation experiments documented an association between AR and kinase insert domain protein receptor that promoted the recruitment of downstream signaling components. Conclusions— These results document a physiological role of AR in sex-independent angiogenic potency and provide evidence of novel cross-talk between the androgen/AR signaling and VEGF/kinase insert domain protein receptor signaling pathways.

Beschreibung: Objective— Cardiovascular diseases are associated with impaired flow-mediated vasodilation (FMD) and increase in carotid intima-media thickness (IMT). Both FMD and IMT are independent predictors for cardiovascular outcomes. When measuring FMD and nitroglycerine-induced vasodilation in the brachial artery, IMT can also be simultaneously assessed in the same brachial artery. The purpose of this study was to determine the relationships between IMT of the brachial artery, vascular function, and cardiovascular risk factors. Methods and Results— We measured brachial IMT, FMD, and nitroglycerine-induced vasodilation by ultrasound in 388 subjects who underwent health examination (mean age, 45±22 years; age range, 19–86), including patients with cardiovascular diseases. Univariate regression analysis revealed that brachial IMT significantly correlated with age ( r =0.71; P 〈0.001), body mass index ( r =0.27; P 〈0.001), systolic blood pressure ( r =0.40; P 〈0.001), diastolic blood pressure ( r =0.31; P 〈0.001), heart rate ( r =0.15; P =0.002), glucose level ( r =0.18; P =0.01), and smoking pack-years ( r =0.42; P 〈0.001), as well as Framingham risk score, a cumulative cardiovascular risk index for heart attack ( r =0.49; P 〈0.001). FMD and nitroglycerine-induced vasodilation were inversely associated with brachial IMT ( r =–0.39, P 〈0.001; r =–0.32, P 〈0.001, respectively). In addition, there was a significant relationship between brachial IMT and carotid IMT ( r =0.58; P 〈0.001). Multivariate analysis revealed that age, sex, hypertension, and brachial artery diameter were independent predictors of brachial IMT. Conclusion— These findings suggest that brachial IMT may be a marker of the grade of atherosclerosis and may be used as a marker of vascular function, providing additive information for stratifying subjects with cardiovascular risk factors.

Beschreibung: Background The aim of this study was to evaluate the temporal impact of the 2011 Japan earthquake and tsunami on the incidence of sudden cardiac and unexpected death (SCUD). Methods and Results We surveyed the impact of the disaster on the incidence and clinical characteristics of SCUD in Iwate. To perform complete identification of SCUD for 8 weeks before and 40 weeks after the disaster, medical records and death certificates relevant to SCUD were surveyed in the study area. Compared with the previous year's rate, the incidence (per 10 000 person-year) of SCUD for the initial 4 weeks after the disaster (acute phase) was double (33.5 vs 18.9), and thereafter the rate returned to the previous level. Significant relationships were found between weekly numbers of SCUD and seismic activity (intensity, r =0.43; P 〈0.005: frequency, r =0.46; P 〈0.002). The standardized incidence ratio (SIR) of SCUD in the acute phase was significantly increased compared with that of previous years (1.71, 95% CI 1.33 to 2.16). Increased SIRs were predominantly found in female subjects (1.73, 95% CI 1.22 to 2.37), the elderly (1.73, 95% CI 1.29 to 2.27), and residents living in the tsunami-stricken area (1.83, 95% CI 1.33 to 2.46). In addition, SIRs for weekdays (1.71, 95% CI 1.28 to 2.24) and nights-mornings (2.09, 95% CI 1.48 to 2.86) were amplified. Conclusions The present results suggest that the magnitude of a disaster, related stress, and population aging may cause a temporary increase in the incidence of SCUD with amplification of ordinary weekly and circadian variations.

Beschreibung: Rho-associated kinases play an important role in a variety of cellular functions. Although Rho-associated kinase activity has been shown to be an independent predictor for future cardiovascular events in a general population, there is no information on Rho-associated kinase activity in patients with acute coronary syndrome. We evaluated leukocyte Rho-associated kinase activity by Western blot analysis in 73 patients with acute coronary syndrome and 73 age- and gender-matched control subjects. Rho-associated kinase activity within 2 hours of acute coronary syndrome onset was higher in patients with acute coronary syndrome than in the control subjects (0.95±0.55 versus 0.69±0.31; P 〈0.001). Rho-associated kinase activity promptly increased from 0.95±0.55 to 1.11±0.81 after 3 hours and reached a peak of 1.21±0.76 after 1 day ( P =0.03 and P =0.03, respectively) and then gradually decreased to 0.83±0.52 after 7 days, 0.78±0.42 after 14 days, and 0.72±0.30 after 6 months ( P =0.22, P =0.29, and P =0.12, respectively). During a median follow-up period of 50.8 months, 31 first major cardiovascular events (death from cardiovascular causes, myocardial infarction, ischemic stroke, and coronary revascularization) occurred. After adjustment for age, sex, cardiovascular risk factors, and concomitant treatment with statins, increased Rho-associated kinase activity was associated with increasing risk of first major cardiovascular events (hazard ratio, 4.56; 95% confidence interval, 1.98–11.34; P 〈0.001). These findings suggest that Rho-associated kinase activity is dramatically changed after acute coronary syndrome and that Rho-associated kinase activity could be a useful biomarker to predict cardiovascular events in Japanese patients with acute coronary syndrome.

Beschreibung: Objective— Nitroglycerine-induced vasodilation has been used as a control test for flow-mediated vasodilation (FMD) to differentiate endothelium-dependent from endothelium-independent response when evaluating endothelial function in humans. Recently, nitroglycerine-induced vasodilation has also been reported to be impaired in patients with atherosclerosis. The purpose of this study was to determine the relationships between nitroglycerine-induced vasodilation and cardiovascular risk factors. Approach and Results— We measured nitroglycerine-induced vasodilation and FMD in 436 subjects who underwent health examinations (mean age, 53±19 years; age range, 19–86 years), including patients with cardiovascular diseases. There was a significant relationship between nitroglycerine-induced vasodilation and FMD ( r =0.42; P 〈0.001). Univariate regression analysis revealed that nitroglycerine-induced vasodilation correlated with age ( r =–0.34; P 〈0.001), systolic blood pressure ( r =–0.32; P 〈0.001), diastolic blood pressure ( r =–0.24; P 〈0.001), heart rate ( r =–0.21; P 〈0.001), glucose ( r =–0.23; P 〈0.001), and smoking pack-year ( r =–0.12; P =0.01), as well as Framingham risk score ( r =–0.30; P 〈0.001). Nitroglycerine-induced vasodilation was significantly smaller in patients with cardiovascular disease than in both subjects with and without cardiovascular risk factors (10.5±5.6% versus 13.7±5.4% and 15.3±4.3%; P 〈0.001, respectively), whereas there was no significant difference in nitroglycerine-induced vasodilation between subjects with and without cardiovascular risk factors. Multivariate analysis revealed that male sex, body mass index, hypertension, diabetes mellitus, baseline brachial artery diameter, and FMD were independent predictors of nitroglycerine-induced vasodilation. Conclusions— These findings suggest that nitroglycerine-induced vasodilation may be a marker of the grade of atherosclerosis. FMD should be interpreted as an index of vascular function reflecting both endothelium-dependent vasodilation and endothelium-independent vasodilation in subjects with impaired nitroglycerine-induced vasodilation.

Beschreibung: Background— Patients with Gilbert syndrome have mild unconjugated hyperbilirubinemia. It has been shown that bilirubin is an endogenous antioxidant. We evaluated the role of oxidative stress in endothelial function in patients with Gilbert syndrome under normal conditions without cardiovascular risk factors. Methods and Results— A total of 108 young men with Gilbert syndrome without cardiovascular risk factors and 108 age-matched healthy men (normal controls) were enrolled in this study. Serum concentrations of bilirubin were higher in patients with Gilbert syndrome than in control subjects (29.2±11.6 versus 9.4±2.7 μmol/L; P 〈0.001). Serum concentrations of malondialdehyde-modified low-density lipoprotein and urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG), as indices of oxidative stress, were lower in patients with Gilbert syndrome than in control subjects (61.8±24.5 versus 72.5±21.8 U/L, P =0.034; 7.8±2.4 versus 10.4±3.2 ng/mg creatinine, P =0.001, respectively). Flow-mediated vasodilation was greater in patients with Gilbert syndrome than in normal control subjects (7.2±2.2% versus 5.9±1.7%; P 〈0.001). Vascular responses to nitroglycerine were not significantly different between the 2 groups. Flow-mediated vasodilation correlated with serum concentration of bilirubin ( r =0.44, P 〈0.001), malondialdehyde-modified low-density lipoprotein ( r =–0.25, P =0.01), and urinary excretion of 8-OHdG ( r =–0.27, P =0.004) in patients with Gilbert syndrome but not in control subjects. In addition, serum concentration of bilirubin correlated with malondialdehyde-modified low-density lipoprotein ( r =–0.20, P =0.04) and 8-OHdG ( r =–0.21, P =0.02) in patients with Gilbert syndrome but not in control subjects. Conclusions— Patients with Gilbert syndrome had low levels of oxidative stress associated with hyperbilirubinemia and enhancement of endothelium-dependent vasodilation. Clinical Trial Registration— URL: http://www.umin.ac.jp . Unique identifier: UMIN000003409.

Beschreibung: The centromere is a chromosomal locus where a microtubule attachment site, termed kinetochore, is assembled in mitosis. In most eukaryotes, with the exception of holocentric species, each chromosome contains a single distinct centromere. A chromosome with an additional centromere undergoes successive rounds of anaphase bridge formation and breakage, or triggers a cell cycle arrest imposed by DNA damage and replication checkpoints. We report here a study in Schizosaccharomyces pombe to characterize a mutant ( cnp3-1 ) in a gene encoding a homolog of mammalian centromere-specific protein, CENP-C. At the restrictive temperature 36°, the Cnp3-1 mutant protein loses its localization at the centromere. In the cnp3-1 mutant, the level of the Cnp1 (a homolog of a centromere-specific histone CENP-A) also decreases at the centromere. Interestingly, the cnp3-1 mutant is prone to promiscuous accumulation of Cnp1 at non-centromeric regions, when Cnp1 is present in excess. Unlike the wild type protein, Cnp3-1 mutant protein is found at the sites of promiscuous accumulation of Cnp1, suggesting that Cnp3-1 may stabilize or promote accumulation of Cnp1 at non-centromeric regions. From these results, we infer the role of Cnp3 in restricting the site of accumulation of Cnp1 and thus to prevent formation of de novo centromeres.

Beschreibung: Inferred ancestral nucleotide states are increasingly employed in analyses of within- and between -species genome variation. Although numerous studies have focused on ancestral inference among distantly related lineages, approaches to infer ancestral states in polymorphism data have received less attention. Recently developed approaches that employ complex transition matrices allow us to infer ancestral nucleotide sequence in various evolutionary scenarios of base composition. However, the requirement of a single gene tree to calculate a likelihood is an important limitation for conducting ancestral inference using within-species variation in recombining genomes. To resolve this problem, and to extend the applicability of ancestral inference in studies of base composition evolution, we first evaluate three previously proposed methods to infer ancestral nucleotide sequences among within- and between-species sequence variation data. The methods employ a single allele, bifurcating tree, or a star tree for within-species variation data. Using simulated nucleotide sequences, we employ ancestral inference to infer fixations and polymorphisms. We find that all three methods show biased inference. We modify the bifurcating tree method to include weights to adjust for an expected site frequency spectrum, "bifurcating tree with weighting" (BTW). Our simulation analysis show that the BTW method can substantially improve the reliability and robustness of ancestral inference in a range of scenarios that include non-neutral and/or non-stationary base composition evolution.

Beschreibung: Objective— BubR1, a cell cycle–related protein, is an essential component of the spindle checkpoint that regulates cell division. Mice with BubR1 expression reduced to 10% of the normal level display a phenotype characterized by progeria; however, the involvement of BubR1 in vascular diseases is still unknown. We generated mice in which BubR1 expression was reduced to 20% ( BubR1 L/L mice) of that in wild-type mice ( BubR1 +/+ ) to investigate the effects of BubR1 on arterial intimal hyperplasia. Approach and Results— Ten-week-old male BubR1 L/L and age-matched wild-type littermates ( BubR1 +/+ ) were used in this study. The left common carotid artery was ligated, and histopathologic examinations were conducted 4 weeks later. Bone marrow transplantation was also performed. Vascular smooth muscle cells (VSMCs) were isolated from the thoracic aorta to examine cell proliferation, migration, and cell cycle progression. Severe neointimal hyperplasia was observed after artery ligation in BubR1 +/+ mice, whereas BubR1 L/L mice displayed nearly complete inhibition of neointimal hyperplasia. Bone marrow transplantation from all donors did not affect the reconstitution of 3 hematopoietic lineages, and neointimal hyperplasia was still suppressed after bone marrow transplantation from BubR1 +/+ mice to BubR1 L/L mice. VSMC proliferation was impaired in BubR1 L/L mice because of delayed entry into the S phase. VSMC migration was unaffected in these BubR1 L/L mice. p38 mitogen–activated protein kinase–inhibited VSMCs showed low expression of BubR1, and BubR1-inhibited VSMCs showed low expression of p38. Conclusions— BubR1 may represent a new target molecule for treating pathological states of vascular remodeling, such as restenosis after angioplasty.