Changes in serum cholesterol levels determine future risk of cardiovascular events in patients with acute coronary syndrome in the Japanese Coronary Artery Disease (JCAD) Study

BACKGROUND

Although increased attention is given to assess absolute values of serum cholesterol profiles as optimal markers for preventing future cardiovascular (CV) events, changes in cholesterol profiles also have the potential to be associated with CV disease outcome in Japanese patients with acute coronary syndrome (ACS).

METHODS

From the database of the Japanese Coronary Artery Disease (JCAD) study, 2664 patients with ACS who had serial measurements of serum cholesterol profile parameters were enrolled. These patients were followed-up for a mean period of 2.7 years. The endpoint was all CV events. Baseline clinical characteristics of patients with and without CV events were adjusted by the propensity score matching analysis.

RESULTS

None of the serum absolute cholesterol profiles at baseline and 6 months later was associated with CV events, except for baseline serum total cholesterol level. However, large improvements in cholesterol profiles correlated with better CV disease outcome.

CONCLUSIONS

This subanalysis of JCAD demonstrated the importance of serial assessment of serum cholesterol profiles for secondary prevention of CV events in Japanese patients with ACS. Changes in serum cholesterol profiles, rather than their absolute values, correlated with future CV events.

TNFα signals through specialized factories where responsive coding and miRNA genes are transcribed

Tumour necrosis factor alpha (TNFα) is a potent cytokine that signals through nuclear factor kappa B (NFκB) to activate a subset of human genes. It is usually assumed that this involves RNA polymerases transcribing responsive genes wherever they might be in the nucleus. Using primary human endothelial cells, variants of chromosome conformation capture (including 4C and chromatin interaction analysis with paired-end tag sequencing), and fluorescence in situ hybridization to detect single nascent transcripts, we show that TNFα induces responsive genes to congregate in discrete 'NFκB factories'. Some factories further specialize in transcribing responsive genes encoding micro-RNAs that target downregulated mRNAs. We expect all signalling pathways to contain this extra leg, where responding genes are transcribed in analogous specialized factories.

A multicenter study design to assess the clinical usefulness of semi-automatic measurement of flow-mediated vasodilatation of the brachial artery

Flow-mediated vasodilatation of the brachial artery (FMD) is a marker which is related to endothelial nitric oxide bioavailability. Commercially available ultrasound machines equipped with online computer-assisted semi-automatic analysis software to measure FMD have recently become available in Japan. These devices enable more convenient examination, enhanced reproducibility of FMD measurement, and a shortened examination time. Using such devices, in the present multicenter prospective study we propose to: 1) establish standardized FMD values and determine the annual rates of FMD change in healthy subjects; 2) confirm the predictive value of FMD for future cardiovascular events in Japanese subjects; 3) evaluate the potential usefulness of a multimarker strategy, including measurements of FMD, pulse-wave velocity (PWV), ankle-brachial pressure index, biochemical markers, and proteomic biomarkers obtained by mass spectroscopic analysis to assess the prognosis of subjects with coronary artery disease; and 4) clarify the usefulness of FMD measurement to predict the rate of progression of carotid atherosclerosis, arterial stiffness and microalbuminuria in subjects with hypertension or diabetes mellitus. In total, we estimate that approximately 4000 Japanese subjects in 3 different study groups will eventually be enrolled in this prospective observational investigation. We anticipate that the present study will provide important evidence for the usefulness of FMD measurement in the risk stratification for cardiovascular disease.

Development and implementation of an advanced coronary angiography and intervention database system

The 'evidence' in evidence-based medicine (EBM) is often limited to knowledge obtained from randomized controlled clinical trials (RCT). Most RCTs, however, have strict enrollment criteria which make patient background characteristics and clinical histories significantly different from those encountered in actual practice. Thus it is important to accumulate and analyze data obtained in daily practice to gain insight into a larger clinical picture. Recent developments in information technology and its lowered cost have enabled us to record clinical activity in much greater detail at a lower cost. These factors prompted us to design and develop a coronary angiography and intervention reporting system (CAIRS) to collect data and analyze outcomes of coronary intervention. The resulting advanced CAIRS can record detailed data on coronary angiographic and interventional procedures.To date, data on 10,025 cases of coronary angiography, of which 3,574 were interventional, have been collected over a 5.5 year period. There were 4,343 unique patients, 3,115 (71.7%) of which were male. The overall mean age was 67.0 ± 11.5. The mean age of males was 66.3 ± 11.4 and that of females was 69.0 ± 11.4. About one-third of the patients never underwent a PCI procedure at our institution. For patients that underwent at least one PCI procedure at our institution, the prescription rate of statin increased from 50.8% in 2005 to 80.3% in 2011, while those of nitrate and ticlopidine decreased from 36.7% and 90.8% in 2005 to 21.3% and 0.8% in 2011, respectively. We have also implemented the same system at another institution and compared the data on stent usage between the two institutions, which revealed vastly different stent usage profiles.In conclusion, we have successfully developed and implemented an advanced coronary angiography and intervention reporting system which we call CAIRS. Implementing the same system at multiple institutions and analyzing data collected from several institutions will provide detailed and timely insight into the 'real world' of coronary angiography and interventional procedures and their outcome.

Frequency and impact of lifestyle modification in patients with coronary artery disease: the Japanese Coronary Artery Disease (JCAD) study

BACKGROUND

Lifestyle modifications such as exercise and diet interventions in patients with coronary artery disease (CAD) are widely regarded as important, but little is known about their frequency in clinical practice and their impact on all-cause mortality.

METHODS

The JCAD study is a cohort study of 13,812 patients with CAD (≥75% stenosis in ≥1 of 3 major coronary arteries). Patients were enrolled from April 2000 through March 2001 at 202 institutions throughout Japan. Exercise and diet interventions were defined based on Japanese national guidelines. Cox proportional hazards models were used to calculate hazard ratios (HRs) for all-cause mortality with 95% CIs.

RESULTS

We studied 11,893 patients in the JCAD study. Over 3 years of follow-up, there were 474 deaths; 4,237 patients (35.6%) underwent exercise intervention, and 8,642 patients (72.7%) underwent diet intervention from the time of discharge. Mortality was lower in patients who underwent an exercise or diet intervention than in patients who did not: HR 0.68 (95% CI 0.56-0.84) and 0.75 (95% CI 0.62-0.91), respectively. After adjustment for age, sex, institution, hypertension, hyperlipidemia, diabetes, obesity, current drinking, current smoking, and the use of antiplatelet agents, β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and statins, the associations with these interventions remain statistically significant: HR 0.73 (95% CI 0.55-0.96) for exercise and 0.74 (95% CI 0.58-0.95) for diet interventions.

CONCLUSIONS

Exercise and diet interventions have a beneficial impact on all-cause mortality in patients with CAD, yet these interventions are surprisingly infrequent. Lifestyle interventions should be more actively promoted.

Distribution of histone3 lysine 4 trimethylation at T3-responsive loci in the heart during reversible changes in gene expression

Expression in the adult heart of a number of cardiac genes, including the two genes comprising the cardiac myosin heavy chain locus (Myh), is controlled by thyroid hormone (T3) levels, but there is minimal information concerning the epigenetic status of the genes when their expressions change. We fed mice normal chow or a propyl thio uracil (PTU, an inhibitor of T3 production) diet for 6 weeks, or the PTU diet for 6 weeks followed by normal chow for a further 2 weeks. Heart ventricles from these groups were then used for ChIP-seq analyses with an antibody to H3K4me3, a well-documented epigenetic marker of gene activation. The resulting data show that, at the Myh7 locus, H3K4me3 modifications are induced primarily at 5' transcribed region in parallel with increased expression of beta myosin heavy chain (MHC). At the Myh6 locus, decreases in H3K4me3 modifications occurred at the promoter and 5' transcribed region. Extensive H3K4me3 modifications also occurred at the intergenic region between the two Myh genes, which extended into the 3' transcribed region of Myh7. The PTU-induced changes in H3K4me3 levels are, for the most part, reversible but are not invariably complete. We found full restoration of Myh6 gene expression upon PTU withdrawal; however, the H3K4me3 pattern was only partially restored at Myh6, suggesting that full reexpression of Myh6 does not require that the H3K4me3 modifications return fully to the untreated conditions. Together, our data show that the H3K4me3 modification is an epigenetic marker closely associated with changes in Myh gene expression.

Evaluating Japanese patients with the Marfan syndrome using high-throughput microarray-based mutational analysis of fibrillin-1 gene

Marfan syndrome (MS) is an inherited connective tissue disorder, and detailed evaluations of multiple organ systems are required for its diagnosis. Genetic testing of the disease-causing fibrillin-1 gene (FBN1) is also important in this diagnostic scheme. The aim of this study was to define the clinical characteristics of Japanese patients with MS and enable the efficient and accurate diagnosis of MS with mutational analysis using a high-throughput microarray-based resequencing system. Fifty-three Japanese probands were recruited, and their clinical characteristics were evaluated using the Ghent criteria. For mutational analysis, an oligonucleotide microarray was designed to interrogate FBN1, and the entire exon and exon-intron boundaries of FBN1 were sequenced. Clinical evaluation revealed more pulmonary phenotypes and fewer skeletal phenotypes in Japanese patients with MS compared to Caucasians. The microarray-based resequencing system detected 35 kinds of mutations, including 23 new mutations. The mutation detection rate for patients who fulfilled the Ghent criteria reached 71%. Of note, splicing mutations accounted for 19% of all mutations, which is more than previously reported. In conclusion, this comprehensive approach successfully detected clinical phenotypes of Japanese patients with MS and demonstrated the usefulness and feasibility of this microarray-based high-throughput resequencing system for mutational analysis of MS.

Reproducibility and diagnostic accuracy of three-layer speckle tracking echocardiography in a swine chronic ischemia model

BACKGROUND

The subendocardial myocardium normally has higher systolic strain than the subepicardial myocardium and can be damaged first in face of ischemia. We investigated the reproducibility and feasibility of novel three-layer speckle tracking system and compared the diagnostic accuracy with experienced visual interpretation.

METHODS

An ameroid constrictor was placed around the proximal left circumflex (LCX) coronary artery in 19 pigs. Four weeks later, subtotal stenosis was confirmed in all pigs by coronary angiogram. Two dead pigs and three pigs with pathological infarction were excluded. Transthoracic left ventricle (LV) short-axis echocardiograms were recorded at rest before and 4 weeks after the operation. LV posterior wall motion was scored by two experienced doctors and analyzed by the speckle tracking system (n = 14).

RESULTS

Strain variables gave reasonable intra/interobserver reproducibility (mean absolute percentage errors = 13/19, intraclass correlation coefficients = 0.97/0.92). All strain variables and visual wall-motion scores changed significantly during stenosis (P < 0.05). Of all variables, endocardial strains, particularly the circumferential strain demonstrated the highest area under curve (AUC), showing better diagnostic accuracy than experienced visual interpretation (sensitivity 0.93 vs. 0.79, specificity 0.93 vs. 0.73, AUC 0.95 vs. 0.77, P < 0.05).

CONCLUSION

Three-layer speckle tracking is a feasible and reproducible modality. In particular, endocardial speckle tracking provides incremental value in accurately identifying regional ischemia even in the rest echocardiography.

Intensively lowering both low-density lipoprotein cholesterol and blood pressure does not reduce cardiovascular risk in Japanese coronary artery disease patients

BACKGROUND

Despite mounting evidence of the benefit of intensive lowering of low-density lipoprotein-cholesterol (LDL-C) in coronary artery disease (CAD) patients, it has not been shown that intensive lowering of both LDL-C and blood pressure (BP) reduces cardiovascular events in these patients.

METHODS AND RESULTS

498 patients with hypertension and hypercholesterolemia with ≥ 75% stenosis in at least one major coronary artery, were recruited from 17 cardiovascular centers in eastern Japan. Patients were randomly assigned to conventional therapy (CT) or intensive therapy (IT). CT aimed to reduce BP to < 140/90 mm Hg and LDL-C to <100mg/dl, and IT aimed for < 120/80 mm Hg and < 80 mg/dl, respectively. The primary endpoint was a composite of all deaths, non-fatal myocardial infarction, unstable angina pectoris, coronary artery bypass graft surgery, non-fatal stroke, non-fatal major vascular disease, and peripheral artery disease. The mean follow-up period was 3.2 years. The achieved systolic BP was 126.8 mm Hg for the CT group, and 121.3 mm Hg for the IT group (P < 0.001). The achieved LDL-C was 92.1mg/dl for the CT group, and 79.6 mg/dl for the IT group (P < 0.001). We detected the primary endpoint in 18 (7.1%) patients in the CT group, and 26 (10.7%) in the IT group (hazard ratio 1.53, 95% confidence interval 0.84-2.80, P = 0.164).

CONCLUSIONS

We could not show that intensively lowering both BP and LDL-C reduced cardiovascular risks in Japanese CAD patients with hypertension and hypercholesterolemia (UMIN-CTR UMIN000000571).

Prognostic effects of combined treatment with calcium channel blockers and statins in patients with coronary narrowing: from the Japanese Coronary Artery Disease study

Calcium channel blockers (CCB) and statins are frequently prescribed for patients with coronary artery disease (CAD) complicated by hypertension and/or hypercholesterolemia. CCB have pleiotropic actions beyond their blood pressure-lowering effect, while statins have pleiotropic actions beyond their cholesterol-lowering effect. We assessed the hypothesis that combined treatment with CCB and statins has additional prognostic benefits resulting from potential additive or synergistic pleiotropic actions of both classes of drugs in the Japanese CAD (JCAD) study population. The JCAD study consisted of 13,812 patients with angiographically demonstrable significant coronary narrowing in at least 1 of 3 major coronary arteries who were followed-up for a mean of 2.7 years (follow-up rate, 88.4%). The primary endpoint of the present study was all cardiovascular events. We compared the event rate between patients receiving neither CCB nor statins and those receiving each drug alone or as a combination treatment using propensity score matching analysis. The rate of all events was 62.8 per 1,000 patient-years in the JCAD study. Kaplan-Meier analysis with the log-rank test showed no statistically significant difference in the event rate in each comparison. In conclusion, there may be no additional prognostic benefit beyond the blood-pressure-lowering and cholesterol-lowering effects in the combined treatment with CCB and statins for angiographically documented CAD patients.

Relationship between renal dysfunction and severity of coronary artery disease in Japanese patients

BACKGROUND

The relationship between renal dysfunction and the severity of coronary artery disease (CAD) was examined.

METHODS AND RESULTS

The severity of CAD in 572 patients was graded according to the number of stenotic coronary arteries, and the estimated glomerular filtration rate (eGFR) was monitored for 3 years. Patients were stratified into 3 eGFR groups: normal (>75 ml x min(-1) x 1.73 m(-2)), mild reduction (60-75) and chronic kidney disease (CKD: <60). There were 161 patients in the CKD group. The average number of stenotic coronary arteries was larger in the CKD group than in the other groups (normal vs mild reduction vs CKD =1.35+/-0.07 (SE) vs 1.22+/-0.08 vs 1.69+/-0.08 vessel disease (VD), P<0.001). During the 3-year follow-up, the renal function of 13.8% of the patients worsened. Those who showed more deterioration of eGFR had more severe CAD than those who did not (1.20+/-0.06 vs 1.61+/-0.06 VD, P<0.001). Multivariate analysis revealed that the severity of CAD was independently and significantly associated with the deterioration of eGFR.

CONCLUSIONS

Patients with CKD had more severe CAD, which may explain the high rate of cardiovascular events in these patients. Moreover, the prognosis of renal function was poor in patients with severe CAD, and CAD was found to be an independent risk factor for worsening of renal dysfunction.

Demographics and changes in medical/interventional treatment of coronary artery disease patients over a 3.5-year period in Japan: the Japanese Coronary Artery Disease Study: trend examination

BACKGROUND

Cardiovascular medicine has undergone rapid changes in recent years, but there are insufficient reports using large cohorts regarding these changes for Japanese coronary artery disease (CAD) patients. Hence, a large-scale prospective observational study was needed.

METHODS AND RESULTS

A total of 36,298 patients were registered over 6 periods. Patients with hypertension, hyperlipidemia, obesity, and impaired glucose tolerance increased in number, while those with old myocardial infarction (MI), smoking habit, and family history of CAD decreased. Regarding the trends in interventional procedures, stent use increased in both the whole cohort and the acute MI subgroup, while the use of only medical control decreased. Regarding prescription trends, angiotensin-receptor blockers increased while nitrates decreased.

CONCLUSIONS

In a period of 3.5 years, significant changes were observed for both interventional procedures and medication, which might be related to the well-timed compliance of physicians with published evidence. However, these changes were not related to changes in the event rates, at least over the short term. Although careful attention should be paid in interpreting the results, because this is an observational study and the background of patients in each cohort might have been heterogeneous, such investigations should be constantly conducted for evidence-based practice.

Elevated serum C-reactive protein levels predict cardiovascular events in the Japanese coronary artery disease (JCAD) study

BACKGROUND

Accumulating evidence indicates that C-reactive protein (CRP) is an independent predictive factor for atherosclerotic vascular disease in Caucasians. Accordingly, this study sought to investigate the relationship between the serum level of CRP and cardiovascular events of Japanese patients with coronary artery disease (CAD).

METHODS AND RESULTS

The Japanese CAD (JCAD) study enrolled 15,628 patients who had significant diameter stenosis (>or=75%) in at least 1 coronary artery. Of these, 6,802 patients had their baseline serum CRP data available. Patients were followed up for a mean of 2.7 years (follow-up rate 88.3%). The primary endpoint of the JCAD study was all events. Baseline covariates possibly influencing the event rate were adjusted between the 2 groups with and without elevated serum CRP level. Kaplan-Meier analysis demonstrated a 30% higher all-events rate in patients with a serum level of CRP >or=0.1 mg/dl (P=0.0002). Cox proportional hazard analysis also showed that a serum level of CRP >or=0.1 mg/dl was an independent predictor of all events (P=0.0001), and of cardiac events and cardiac death (P=0.0005).

CONCLUSIONS

Elevated serum level of CRP is an independent predictor of cardiovascular events in JCAD patients.

Genetic variations of Mrf-2/ARID5B confer risk of coronary atherosclerosis in the Japanese population

A phenotypic change of smooth muscle cells (SMCs) is considered to be critical in the pathogenesis of atherosclerotic lesions such as coronary artery disease (CAD). Mrf-2/ARID5B, a member of the AT-rich interaction domain family of transcription factors, is highly expressed in the cardiovascular system and is believed to play essential roles in the phenotypic change of SMCs through its regulation of SMC differentiation. In addition, recent studies on gene-engineered mice suggested that this transcriptional factor is involved in obesity and adipogenesis, which are critical aspects for the pathogenesis of atherosclerosis. Thus, we hypothesized that genetic variations of the Mrf-2 gene might be associated with susceptibility to CAD. We investigated 11 common genetic variations of Mrf-2 to determine whether they were associated with susceptibility to CAD in 475 CAD subjects and 310 control subjects. The prevalence of homozygotes for the minor allele G of SNP4 (rs2893880) and minor allele G of SNP6 (rs7087507) were significantly more frequent in the control subjects than in patients with CAD (P=0.0002, rs2893880, P=0.0058, rs7087507). Four nearby SNPs (SNP4 to SNP7) (rs2893880, rs10740055, rs7087507 and rs10761600) showed almost complete linkage disequilibrium, and haplotype analysis revealed that the haplotype G (rs2893880)-C (rs10740055)-G (rs7087507)-A (rs10761600) was also significantly negatively associated with susceptibility to CAD (P=0.049). Moreover, these negative disease associations still existed after logistic regression analysis was taken into account to eliminate confounding conventional coronary risk factors. The results implicate possible disease relevance of the polymorphisms in the Mrf-2 gene with susceptibility to CAD. However, a larger scale prospective study is needed to clarify these findings.

The Japanese national health screening and intervention program aimed at preventing worsening of the metabolic syndrome

Similar to the healthcare systems in other industrialized countries, the Japanese healthcare system is facing the problem of increasing medical expenditure. In Japan, this situation may be primarily attributed to advanced technological developments, an aging population, and increasing patient demand. Japan also faces the problem of a declining youth population due to a low birth rate. Taken together, these problems present the healthcare system with a very difficult financial situation. Several reforms have been undertaken to contain medical expenditure, such as increasing employee copayment for health insurance from 10% to 20% in 1997 and from 20% to 30% in 2003 in order to curb unnecessary visits to medical institutions. Since the aging of the Japanese population is inevitable, a suitable method to contain medical expenditure may be to screen individuals who are likely to develop lifestyle-related diseases and conduct early intervention programs for them to prevent the development of diseases such as myocardial infarction or stroke that are costly to treat. If this goal is attained, it may contribute to the containment of medical expenditure as well as to improving the quality of life of the elderly. Therefore, the Japanese Ministry of Health, Labor and Welfare has decided to introduce a nationwide health screening and intervention program specifically targeting the metabolic syndrome commencing April 2008. Here, we discuss (1) the background of the Japanese healthcare system and the problems facing it, (2) the underlying objective and details of the new screening program, and (3) the expected impact of the program.

Rationale and design of a study to examine lower targets for low-density lipoprotein-cholesterol and blood pressure in coronary artery disease patients

BACKGROUND

The benefits of coronary risk modification through medication and other methods have been shown in many clinical studies. Recently, aggressive lowering of low-density lipoprotein-cholesterol (LDL-C) has been shown to confer additive benefits in patients with coronary artery disease (CAD). However, it has not been shown in Japanese patients with CAD if multiple aggressive medical interventions for coronary risk factors are beneficial compared with standard regimens, so a prospective, randomized, open-label, blinded-endpoint (PROBE) multicenter study was designed to evaluate whether aggressive lowering of LDL-C and blood pressure in Japanese hypertensive, hypercholesterolemic CAD patients bestows additional benefits compared with regimens based on current Japanese guidelines.

METHODS AND RESULTS

Seventeen hospitals in Japan are participating in the Japanese Coronary Artery Disease II (JCADII) study. Hypertensive and hypercholesterolemic patients who have >or=75% stenosis in at least one major coronary artery according to American Heart Association guidelines will be allocated randomly to receive either conventional or aggressive therapy. Standard therapy for hypertension and hypercholesterolemia aims to reduce blood pressure to <140/90 mmHg and LDL-C concentration to <100 mg/dl. Aggressive therapy aims for targets of <120/80 mmHg and <80 mg/dl, respectively. We plan to recruit 500 patients and follow them up for 3 years. Antihypertensive agents, when used, include the angiotensin receptor blockers candesartan and/or losartan. Antihypercholesterolemic agents, when used, include at least one of the following statins: pravastatin, simvastatin, and atorvastatin.

CONCLUSION

The JCADII study will provide important information concerning medical treatment of coronary risk factors in Japanese patients with CAD (UMIN-ID: UMIN000000571).

Comparison of cardiovascular events in patients with angiographically documented coronary narrowing with combined renin-angiotensin system inhibitor plus statin versus renin-angiotensin system inhibitor alone versus statin alone (from the Japanese Coronary Artery Disease Study)

Statins and renin-angiotensin system (RAS) inhibitors are 2 classes of drugs prescribed frequently in clinical practice that may have pleiotropic effects in addition to cholesterol-lowering and blood pressure-lowering effects, respectively. Combined treatment with statins and RAS inhibitors may have additional benefits beyond each monotherapy. We assessed the usefulness of the combined treatment in the Japanese Coronary Artery Disease (JCAD) Study population. In the JCAD Study, 13,812 patients with angiographically shown narrowing in > or =1 of 3 major coronary arteries were followed up for a mean of 2.7 years. The primary end point of the study was all cardiovascular events. In the present study, baseline covariates possibly influencing the event rate were adjusted between the control and treatment groups. Although there were no statistically significant differences in event rates between patients receiving neither statins nor RAS inhibitors and those receiving either drug, Kaplan-Meier analysis showed a 22% decrease (p = 0.0286) in the event rate with combined treatment. In conclusion, statins combined with RAS inhibitors may decrease cardiovascular events in patients with coronary artery disease.

Transcriptional activation by hypoxia and low-density lipoprotein loading in cultured vascular smooth muscle cells

AIM

The aim of this study was to investigate transcriptional activation in vascular SMC cultured under hypoxic conditions and high low-density lipoprotein (LDL) levels.

METHODS

We cultured vascular SMC under hypoxic conditions and high LDL levels, and RNA expression profiles for more than 5800 were analyzed by DNA microarray. We performed promoter sequence analysis of genes induced by the combination of hypoxia and high LDL level conditions.

RESULTS

In human coronary arterial SMC, the combination of hypoxia and high LDL level conditions induced the expression of 40 genes. Genes induced during the first 24 hours were known to be involved in inflammation, while late genes induced during 48 to 72 hours were composed primarily of genes involved in lipid and/or glucose metabolism. Promoter sequence analysis of these genes revealed that 39 of the 40 genes possessed multiple hypoxic response elements (HRE). The most induced gene in the combination of hypoxia and high LDL level conditions was the leptin gene. Functional analysis of the 3 kb leptin promoter revealed that HRE at-166 mediated transcriptional activation by hypoxia, but 3 kb reporter constructs can not reproduce the additive affect of LDL under hypoxia.

CONCLUSION

These results support the hypothesis that an HRE-mediated mechanism may be involved in transcriptional activation during lipid deposition in vascular SMC induced by hypoxia and LDL loading, but additional mechanisms may be involved in the synergistic action induced by LDL.

Pleiotropic effects of statins on cardiovascular events in the Japanese Coronary Artery Disease study

We analyzed 6317 patients with a baseline LDL-cholesterol level of 70 to 130 mg/dL among 13,812 patients of the Japanese Coronary Artery Disease (JCAD) study. We divided the patients into 2 groups according to statin treatment and its lipophilicity. We compared the incidence of all-cause events between 2000 statin-treated patients and 4317 patients without statins during a median follow-up period of 1092 days (range 0 to 1676 days). After propensity score matching (n=1641, for each group), Kaplan-Meier analysis showed 25% reduction in the incidence of all-cause events with statin treatment (p=0.0016). The incidence of all-cause events was also compared between 1139 patients with hydrophilic statin and 861 patients with lipophilic statin. After propensity score matching (n=778, for each group), Kaplan-Meier analysis showed no significant difference in the incidence of all-cause events with respect to lipophilicity. Subgroup analysis of the JCAD study suggested a lipid-independent beneficial treatment effect of statins on all-cause events, and these favorable effects were comparable between the hydrophilic and lipophilic statins.

Amelioration of hypertensive heart failure by amlodipine may occur via antioxidative effects

Although recent clinical studies have suggested that long-acting calcium channel blockers (CCBs) have beneficial effects on heart failure, the precise mechanism is unknown. In this study, Dahl salt-sensitive rats fed a high salt diet were treated with the long-acting CCB amlodipine, the low-molecular-weight membrane permeable superoxide dismutase mimetic 4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl (Tempol), or saline from 11 weeks after birth. The cardiac geometry and function, and gene expression profiles were determined at 17 weeks. Dahl salt-sensitive rats fed a high salt diet followed by saline as a non-treatment control (HS group) showed a marked increase in blood pressure and developed concentric hypertrophy at 11 weeks, followed by left ventricular (LV) dilation and congestive heart failure by 17 weeks. The treatment with amlodipine (AMLO group) or Tempol (TEMP group) significantly inhibited the development of LV hypertrophy and cardiac dysfunction. Analysis using an Affymetrix GeneChip U34 revealed that the expression levels of 195 genes were changed by the treatment with amlodipine. Among these 195 genes, 110 genes were increased in HS rats and decreased in AMLO rats. And of these 110 genes, 54 genes were also decreased in TEMP rats. In contrast, 85 genes were decreased in HS rats and increased in AMLO rats. Of these 85 genes, 38 genes were also increased in TEMP rats. Approximately 48% of the genes were changed in similar fashion in AMLO and TEMP rats, suggesting that amlodipine shows beneficial effects on heart failure mainly via antioxidative mechanisms.

Rheumatoid synovial endothelial cells produce macrophage colony-stimulating factor leading to osteoclastogenesis in rheumatoid arthritis

OBJECTIVES

Periarticular osteoporosis and joint destruction are major complications in rheumatoid arthritis (RA), caused by osteoclast-mediated bone resorption. However, the mechanisms of monocyte/osteoclast maturation and role of RA endothelial cells (RAECs) in the control of osteoclastogenesis remain unclear. The present study was designed to determine the most important factors that influence monocyte accumulation and osteoclast formation among the many factors produced by RAEC.

METHODS

We analysed the expression profiles of various genes in human endothelial cells from various organs (RA synovium, umbilical vein, skin, liver sinusoid, renal glomerulus and brain) using oligonucleotide microarrays. Specifically, up-regulated gene in RAECs was assessed by real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and immunostaining of RA synovia. Migration of monocytes was assessed by the chemotactic chamber EZ-TAXIScan. Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) formation was observed by microscopy.

RESULTS

Among many epithelial-expressed factors, macrophage colony-stimulating factor (M-CSF) gene was abundantly expressed specifically in RAECs. Genes of fibroblast growth factor-2, interleukin-6 and osteoprotegerin were also overexpressed in RAECs. Migration of monocytes and osteoclast formation in co-cultures promoted by culture supernatants of RAECs were inhibited by M-CSF neutralizing antibody.

CONCLUSIONS

M-CSF produced by RAECs is involved in osteoclastogenesis from monocytes, migration and TRAP-positive MNC formation.

α-Tocopherol induces calnexin in renal tubular cells: Another protective mechanism against free radical-induced cellular damage

Pre-administration of alpha-tocopherol is protective against oxidative renal tubular damage and subsequent carcinogenesis by ferric nitrilotriacetate (Fe-NTA) in rats. We searched for mechanisms other than the scavenging effect of alpha-tocopherol with microarray analyses, which implicated calnexin, a chaperone for glycoproteins. Renal mRNA levels of calnexin significantly increased 3h after an injection of Fe-NTA in rats fed a standard diet whereas those fed an alpha-tocopherol-supplemented diet showed an increase prior to injection, but after injection showed a decrease in renal calnexin mRNA levels, with unaltered protein levels. In experiments using LLC-PK1 cells, addition of alpha-tocopherol was protective against oxidative stress by H2O2, concomitant with calnexin induction. Knockdown of calnexin by siRNA significantly reduced this protection. Furthermore, COS-7 cells transfected with the calnexin gene were more resistant to H2O2. Together with the fact that alpha-tocopherol induced N-acetylglucosaminyltransferase 3, our data suggest that alpha-tocopherol modifies glycoprotein metabolism partially by conferring mild ER stress. This adds another molecular mechanism of alpha-tocopherol toward cancer prevention.

Gene expression profiling of potential peroxisome proliferator-activated receptor (PPAR) target genes in human hepatoblastoma cell lines inducibly expressing different PPAR isoforms

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors and commonly play an important role in the regulation of lipid homeostasis. To identify human PPARs-responsive genes, we established tetracycline-regulated human hepatoblastoma cell lines that can be induced to express each human PPAR and investigated the gene expression profiles of these cells.

RESULTS

The expression of each introduced PPAR gene was investigated using the various concentrations of doxycycline in the culture media. We found that the expression of each PPAR subtype was tightly controlled by the concentration of doxycycline in these established cell lines. DNA microarray analyses using these cell lines were performed with or without adding each subtype ligand and provided much important information on the PPAR target genes involved in lipid metabolism, transport, storage and other activities. Interestingly, it was noted that while ligand-activated PPARdelta induced target gene expression, unliganded PPARdelta repressed these genes. The real-time RT-PCR was used to verify the altered expression of selected genes by PPARs and we found that these genes were induced to express in the same pattern as detected in the microarray analyses. Furthermore, we analysed the 5'-flanking region of the human adipose differentiation-related protein (adrp) gene that responded to all subtypes of PPARs. From the detailed analyses by reporter assays, the EMSAs, and ChIP assays, we determined the functional PPRE of the human adrp gene.

CONCLUSION

The results suggest that these cell lines are important tools used to identify the human PPARs-responsive genes.

The use of a supercooling refrigerator improves the preservation of organ grafts

Current medical transplantation confronts major problems such as the shortage of donors and geographical restrictions that inhibit efficient utilization of finite donor organs within their storage lives. To overcome these issues, expanding organ preservation time has become a major concern. We investigated whether a strategy which best preserves organ grafts can be achieved by the use of a newly developed refrigerating chamber, which is capable of establishing a supercooled and unfrozen state stably by generating an electrostatic field in its inside. When adult rat organs such as heart, liver, and kidneys were stored in the supercooled conditions, the levels of major biochemical markers leaked from the preserved organs were significantly lower than in the ordinary hypothermic storage. No apparent tissue damages were observed histologically after the supercooled preservation. Our results suggest that the use of this supercooling refrigerator improves organ preservation and may provide an innovative technique for human organ transplantation.

Identification of CCR2, flotillin, and gp49B genes as new G-CSF targets during neutrophilic differentiation

Granulocyte colony-stimulating factor (G-CSF) is a cytokine that stimulates myeloid progenitor cells to proliferate and differentiate into neutrophilic granulocytes. To identify genes induced by G-CSF during neutrophil differentiation, interleukin-3-dependent murine myeloid precursor FDC-P1 cells expressing the G-CSF receptor were stimulated with G-CSF, and the gene expression profile was characterized by DNA microarray analysis. In addition to known signal transducer and activator of transcription-3 target genes, such as suppressor of cytokine signaling-3 (SOCS3), JunB, and p19(INK4D), we newly identified several G-CSF targets, including genes for the CC chemokine receptor-2 (CCR2), raft proteins flotillin-1 and flotillin-2, and immunoglobulin-like receptor gp49B. Real-time, quantitative polymerase chain reaction analyses revealed that the expression of these genes was induced in various myeloid cell lines by G-CSF. Furthermore, when HoxA9-immortalized bone marrow progenitors were induced by G-CSF to differentiate into mature neutrophils, all of these genes were strongly activated. These genes could be categorized into three groups based on their time-course of expression: immediate-early (approximately 20 min, SOCS3), mid-early (2-4 h, flotillin-1/2 and gp49B), and late (>12 h, CCR2). This suggests that different transcriptional mechanisms are involved in the regulation of these genes. We show that bone marrow neutrophils express functional CCR2, which suggest that CC chemokines may play previously unknown roles in neutrophil activation and chemotaxis.

Bilirubin From Heme Oxygenase-1 Attenuates Vascular Endothelial Activation and Dysfunction

Objective— Heme oxygenase-1 (HO-1), the rate-limiting enzyme of heme degradation, has recently been considered to have protective roles against various pathophysiological conditions. Since we demonstrated that HO-1 overexpression inhibits atherosclerotic formation in animal models, we examined the effect of HO modulation on proinflammatory cytokine production, endothelial NO synthase (eNOS) expression, and endothelium-dependent vascular relaxation responses.

Methods and Results— After HO-1 induction by heme arginate (HA), vascular endothelial cell cultures were exposed to oxidized low-density lipoprotein (oxLDL) or tumor necrosis factor-α (TNF-α). HA pretreatment significantly attenuated the production of vascular cell adhesion molecule-1, monocyte chemotactic protein-1, and macrophage colony-stimulating factor, suggesting that HO-1 induction attenuates proinflammatory responses. In addition, HO-1 overexpression also alleviated endothelial dysfunction as judged by restoration of attenuated eNOS expression after exposure to oxLDL and TNF-α. Importantly, impaired endothelium-dependent vascular relaxation responses in thoracic aortic rings from high-fat-fed LDL receptor knockout mice were also improved. These effects were observed by treatment with bilirubin not by carbon monoxide.

Conclusions— These results suggest that the antiatherogenic properties of HO-1 may be mediated predominantly through the action of bilirubin by inhibition of vascular endothelial activation and dysfunction in response to proinflammatory stresses.

Vascular Endothelial Growth Factor- and Thrombin-induced Termination Factor, Down Syndrome Critical Region-1, Attenuates Endothelial Cell Proliferation and Angiogenesis

Activation and dysfunction of the endothelium underlie many vascular disorders including atherosclerosis, tumor growth, and inflammation. Endothelial cell activation is mediated by many different extra-cellular signals, which result in overlapping yet distinct patterns of gene expression. Here we show, in DNA microarray analyses, that vascular endothelial growth factor (VEGF) and thrombin result in dramatic and rapid upregulation of Down syndrome critical region (DSCR)-1 gene encoding exons 4-7, a negative feedback regulator of calcium-calcineurin-NF-AT signaling. VEGF- and thrombin-mediated induction of DSCR-1 involves the cooperative binding of NF-ATc and GATA-2/3 to neighboring consensus motifs in the upstream promoter. Constitutive expression of DSCR-1 in endothelial cells markedly impaired NF-ATc nuclear localization, proliferation, and tube formation. Under in vivo conditions, overexpression of DSCR-1 reduced vascular density in matrigel plugs and melanoma tumor growth in mice. Taken together, these findings support a model in which VEGF- and thrombin-mediated induction of endothelial cell proliferation triggers a negative feedback loop consisting of DSCR-1 gene induction and secondary inhibition of NF-AT signaling. As a natural brake in the angiogenic process, this negative pathway may lend itself to therapeutic manipulation in pathological states.

Global analysis of shear stress-responsive genes in vascular endothelial cells

DNA microarray gene expression analysis was conducted in human umbilical vein endothelial cells (HUVECs) and coronary artery endothelial cells (HCAECs) exposed to laminar or turbulent shear stress. Approximately 3% of the total 5600 gene in HUVECs and HCAECs increased their expression more than two-fold or decreased it to less than half the static control in response to an arterial level of laminar shear stress (15 dynes/cm(2) for 24 hours). The proportions of shear-stress-responsive genes decreased to around 2% under the venous level of laminar shear stress (1.5 dynes/cm(2)) in both cell lines. Turbulent shear stress of 1.5 dynes/cm(2) altered the expression of 1.1% of all genes in the HCAECs. Laminar shear stress, but not turbulent shear stress, decreased the expression of a number of genes involved in DNA synthesis and the cell cycle in both HUVECs and HCAECs. Clustering analysis showed a variety of temporal profiles of gene expression in HUVECs exposed to laminar shear stress of 15 dynes/cm(2) for 3, 6, 12, 24, and 48 hours. Turbulent shear stress affected expression of many genes that play a role in vascular remodeling, including genes encoding plasminogen activators and their inhibitor, endothelin-1, transforming growth factor-beta, collagen type IV, and ephrin A1.

A Comparison of Differences in the Gene Expression Profiles of Phorbol 12-myristate 13-acetate Differentiated THP-1 Cells and Human Monocyte-derived Macrophage

In order to characterize the monocytic cell line THP-1 and its mature, macrophage-like form treated with phorbol 12-myristate 13-acetate (PMA), we have conducted an oligonucleotide microarray assay and compared the results with those from an assay of human monocytes and macrophages. We found that early THP-1 cells have a pattern of gene expression distinct from monocytes, and when treated with PMA, certain genes which are induced in macrophages, such as apolipoprotein-E, matrix metalloproteinase 9 and alpha2 macroglobulin are also induced in the PMA-treated THP-1 cells (THP1PMA cells). However, these were some genes which are conversely regulated among macrophages and THP1PMA cells such as interleukin-1-beta and the overall correlation coefficient was not very high. It is shown that, although certain morphological and other characteristics of PMA-differentiated THP-1 cells are similar to macrophages, from a transcriptomic view, the two are different. This suggests a need for careful recognition of and allowance for this difference when interpreting the results of experiments done with THP-1 cells in which it is otherwise assumed they are representative of the macrophage.

Gene Expression Profile Revealed Different Effects of Angiotensin II Receptor Blockade and Angiotensin-Converting Enzyme Inhibitor on Heart Failure

Although recent clinical studies have indicated that angiotensin II receptor blocker is as effective in treating heart failure as an angiotensin-converting enzyme inhibitor, it is unknown whether their effects are different. Dahl salt-sensitive rats were treated with an angiotensin-converting enzyme inhibitor benazepril, and an angiotensin II receptor blocker candesartan from 11 weeks old. We examined cardiac geometry and function by echocardiography, and histology and gene expression by high-density oligonucleotide arrays using Affymetrix U34 (Affymetrix, Santa Clara, CA, U.S.A.). Dahl salt-sensitive rats fed a high salt diet showed a marked increase in blood pressure and developed concentric hypertrophy at 11 weeks, followed by left ventricle dilation and congestive heart failure by 20 weeks after birth. Although both medications had only a mild antihypertensive effect, they strongly suppressed the development of cardiac hypertrophy, fibrosis and heart failure to the same extent. Gene expression pattern examined by Affymetrix GeneChip (Affymetrix) is quite different between the two drug groups, indicating that angiotensin II receptor blocker and angiotensin-converting enzyme inhibitor prevent heart failure by different mechanisms.

Identification of gene expression profile in tolerizing murine cardiac allograft by costimulatory blockade

The induction of specific tolerance would be the ultimate achievement in transplant immunology, but the precise mechanisms of immunologic tolerance remain largely unknown. Here, we investigated global gene expression analysis in tolerizing murine cardiac allografts by means of oligonucleotide microarrays. Tolerance induction was achieved in cardiac allografts from BALB/c to C57BL/6 mice by daily intraperitoneal injection of anti-CD80 and anti-CD86 monoclonal antibodies (mAbs). Comparative analysis revealed 64 genes to be induced more extensively in the tolerizing than in the syngeneic isografts, and 16 genes than in the rejecting allografts. Two genes were specifically upregulated in the tolerizing allografts. In the tolerizing allografts there were induced marked expressions of a number of genes for pro-inflammatory factors, including interferon-gamma-inducible cytokines and chemokines, as well as apoptosis-related genes, which were also upregulated in the rejecting allografts. Moreover, these gene expression patterns continued to be upregulated more than 70 days posttransplant. These results provide evidence that immunologic tolerance can be induced and maintained in the presence of prominent pro-inflammatory gene expression in vivo.

Extensive oligonucleotide microarray transcriptome analysis of the rat cerebral artery and arachnoid tissue

Cerebral vessels have certain distinct anatomical and developmental characteristics which are well known, but their characteristic genetic expression profile remains as yet only poorly understood. We investigated gene expression in the rat cerebral artery in comparison with the rat descending aorta, two locations which have obviously different anatomical and developmental characteristics. Since the contamination of cerebral small arteries by arachnoid tissue is to a certain extent inevitable, we also performed a gene expression analysis of arachnoid tissue as a background. In an effort to obtain the necessary quality and quantity of total RNA, a novel freeze-fracture apparatus minimizing the time required for the entire procedure from tissue separation to RNA preparation was used. With the material obtained, a group of genes highly expressed in each tissue was detected by oligonucleotide microarray analysis. In the circle of Willis, peptide-19 (PEP-19), connexin-37 (CXN-37), growth arrest-and DNA damage-inducible gene (GADD45), and the putative G protein coupled receptor RA1c, Notch-1, and jagged-1 were predominantly expressed. In arachnoid tissue, bone morphologic protein (BMP)-7, BMP-6, beta defensin-1, neuroendocrine protein 7B2, thiol-specific antioxidant protein, IL-18, beta-chain clathrin-associated protein complex AP-1, and angiopoietin-2 were highly expressed. In the aorta, most of the abundantly expressed genes related to lipid metabolism. By means of oligonucleotide microarray analysis, the distinct gene expression profiles in the circle of Willis arachnoid tissue, and aorta were made evident. From these findings it is reasonable to conclude that a functional interaction exists between the circle of Willis and arachnoid tissue.