Aim: Among the many factors related to bone marrow cell mobilization, local inflammation induced by cytokines may drive bone marrow cells to the vascular wall, resulting in a thickened neointima. However, the relationship between inflammatory reactions and bone marrow cell invasion has not yet been fully clarified. Methods: We inserted a large wire into the femoral artery in male balb/c(WT), interleukin (IL)-6-knockout(KO) and bone marrow-transplanted(BMT) mice that had received bone marrow cells from KO mice. Immunohistochemistry was performed to evaluate the degree of intimal hyperplasia and inflammation following vascular injury. Results: Three days after the vascular injury, the number of CD34/Sca-1-positive cells in the blood was higher in the KO mice. The numbers of apoptotic cells in the neointima was lower in the KO and BMT mice at two hours after injury. The morphometric analysis performed at one and four weeks after injury showed that the intima/media ratio was significantly lower in the KO and BMT mice, while CD34-positive cells were much more frequent in the WT mice. Furthermore, re-endothelialization appeared earlier in the KO and BMT mice than in the WT mice. No differences in the levels of vascular endothelial growth factor or hepatocyte growth factor were observed in the mice sera between the WT, KO and BMT mice after injury. The in vitro culture of bone marrow cells showed more differentiated smooth muscle-like cells in the WT mice than in the KO mice. Conclusions: IL-6 is involved in neointimal formation following vascular injury, possibly acting through inflammatory effects inducing the production of bone marrow cells.
Aim: Endothelial lipase(EL) is a determinant of plasma levels of high-density lipoprotein cholesterol(HDL-C). However, little is known about the impact of EL activity on plasma lipid profile. We aimed to establish a new method to evaluate EL-specific phospholipase activity in humans. Methods: Plasma samples were obtained from 115 patients with coronary artery disease(CAD) and 154 patients without CAD. Plasma EL protein was immunoprecipitated using an anti-EL monoclonal antibody after plasma non-specific immunoglobulins were removed by incubation with ProteinA. The phospholipase activity of the immunoprecipitated samples was measured using a fluorogenic phospholipase substrate, Bis-BODIPY FL C11-PC. Results: The EL-specific phospholipase assay revealed that plasma EL activity was inversely correlated with HDL-C levels(R=−0.3088, p＜0.0001). In addition, the EL activity was associated with cigarette smoking. Furthermore, EL activity in CAD patients was significantly higher than that in nonCAD patients. Concomitantly, the HDL-C level in CAD patients were significantly lower than that in non-CAD patients. Conclusion: We have established a method for human plasma EL-specific phospholipase activity by combination of EL immunoprecipitation and a fluorogenic phospholipid substrate. Plasma EL activity was associated with not only plasma HDL-C levels but also the risks for CAD.
Aim: The ankle-brachial index(ABI) is an easy-to-use, non-invasive and reliable diagnostic tool for assessing peripheral arterial occlusive disease(PAOD). The CHADS2(congestive heart failure, hypertension, age ≧75 years, diabetes, prior stroke) score is a simple and popular clinical parameter that is used to assess the risk of stroke in patients with atrial fibrillation(AF). Because all five components of the CHADS2 score are risk factors for PAOD, the score should have a strong correlation with the presence of PAOD. However, there are limited studies regarding the association between the CHADS2 score and PAOD in patients without AF. Therefore, the aim of the present study was to investigate whether the CHADS2 score is positively associated with PAOD in patients without AF. Methods: A total of 1,320 patients without AF were included in this study. The ABI was measured using an ABI-form device. PAOD was defined as an ABI of ＜0.9 in either leg. Results: Among the 1,320 subjects(mean age: 60.3±13.4 years), the prevalence of an ABI of ＜0.9 was 5.7%. A multivariate analysis showed that an increased age(odds ratio [OR], 1.054; p＜0.001), decreased estimated glomerular filtration rate (OR, 0.971; p＜0.001) and increased CHADS2 score(OR, 1.861; p＜0.001) were independently associated with an ABI of ＜0.9. Conclusions: Our study demonstrated that the CHADS2 score is significantly associated with an ABI of ＜0.9 in non-AF patients. Further prospective studies are needed to examine the ability of the CHADS2 score to predict the incidence of PAOD.
Aim: Leukotrienes are important lipid inflammatory mediators that play a pivotal role in the pathogenesis of atherosclerosis. We aimed to construct a network of interactions between leukotrienes and inflammatory biomarkers and evaluate the expression of key members of the leukotriene pathway and leukotriene-induced inflammatory molecules in patients with coronary artery disease(CAD) and healthy controls. Methods: Leukotrienes and their regulatory inflammatory molecules reported in the literature were used to construct a biological network employing Gene spring GX v12.5. Key leukotriene genes and their closely interacting members were selected for expression study in 64 patients and 64 matched controls. Four single nucleotide polymorphisms(SNPs) (rs6538697, rs2660898, rs17525495 and rs1978331) in the leukotriene A4 hydrolase(LTA4H) gene were genotyped using SYBR green method, and plasma leukotriene B4(LTB4) levels were measured using ELISA. Results: The expression levels of arachidonate 5-lipoxygenase(ALOX5), LTA4H, tumor necrosis factor(TNF) and interleukin-8 (IL-8) genes were significantly higher in patients than in the controls(p＜0.05). IL-8(r=0.35-0.47) and TNF (r=0.42-0.53) expression levels exhibited strong correlations with the leukotriene genes. The SNPs rs17525495 and rs1978331 were associated with LTA4H mRNA expression, while LTA4H and IL-8 levels were associated with CAD. The addition of these two markers to the conventional risk factors improved the c-statistics(area under the receiver operating characteristic(ROC) curve) from 0.75 to 0.93(p＜0.01), with a Net Reclassification Index of 0.45(p＜0.01) and Integrated Discrimination Improvement of 0.26(p＜0.01). Conclusions: Leukotrienes and inflammatory genes, in particular, LTA4H and IL-8, exhibit close association in subjects with cardiovascular disease. Assessing these markers may provide incremental value for predicting cardiovascular risk beyond that obtained with classical risk factors.
Aim: Remnant lipoproteins are atherogenic and increased in patients with type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD) and other conditions. Thus far, information is limited regarding the synthesis and absorption of cholesterol in CKD patients and a possible link to the remnant levels. We examined possible alterations in serum markers of cholesterol synthesis and absorption and their potential associations with remnant lipoproteins in patients with CKD. Methods: The subjects included 146 consecutive patients with T2DM in various stages of CKD. We measured the levels of remnant lipoprotein cholesterol (RemL-C), lathosterol (a cholesterol synthesis marker) and campesterol (a cholesterol absorption marker). The urinary albumin to creatinine ratio (U-ACR) and estimated glomerular filtration rate (eGFR) were used to describe the degree of CKD. Results: The median (interquartile range) levels of RemL-C, lathosterol and campesterol were 14.5 (11.5-23.4) mg/dL, 2.1 (1.7-2.9) μg/mL and 2.3 (1.7-3.0) μg/mL, respectively. The RemL-C level was positively correlated with the U-ACR and inversely correlated with the eGFR. The RemL-C level was positively correlated with both the lathosterol and campesterol levels. The lathosterol level was not significantly correlated with the U-ACR, although it was positively correlated with the eGFR. In contrast, the campesterol level was positively correlated with the ACR and inversely with the eGFR. In the multiple regression analysis, both lathosterol and campesterol were positively associated with the RemL-C level, independent of the U-ACR, eGFR and other variables. Conclusions: The serum campesterol concentrations are higher in patients with a greater degree of albuminuria and a lower renal funtion. In this study, the markers of cholesterol absorption and synthesis were independent determinants of the RemL-C level. Increased intestinal cholesterol absorption may be an additional mechanism for remnant accumulation in T2DM patients with CKD.
Aim: To investigate the prevalence of hyperuricemia and the association between the serum uric aci(SUA) levels and incidence of metabolic syndrome(MetS) in the Mongolian area of China. Methods: This cross-sectional survey was based on a population of 1,426 subjects(809 men and 617 women) 20-80 years of age who were recruited from Inner Mongolia, China. Metabolic and anthropometric indicators were measured according to standard methods. Hyperuricemia was defined as an SUA level of ≥7.0 mg/dL for men and ≥6.0 mg/dL for women. MetS was diagnosed based on the consensus criteria released in 2009 from a joint collaboration organization. Results: The prevalence of hyperuricemia was 17.7% in men and 5.2% in women. The prevalence of MetS in men was higher than that observed in women(36.7% vs 17.8%). Waist circumference, BMI and the level of triglycerides were most strongly correlated with the SUA level in both sexes. Men with hyperuricemia had an increased risk of MetS [OR(95%CI)=2.95(2.00-4.35)], while men with a “normal” SUA level(＞5.0 mg/dL and ＜6.3 mg/dL) had a higher risk of MetS, central obesity and hypertriglyceridemia than men in the lower level group(≤5 mg/dL). Women with a higher SUA level(≥4.3 mg/dL) had an increased risk of MetS, central obesity, hypertriglyceridemia and hypertension compared with women in the lowest tertile SUA group(≤3.5 mg/dL). Conclusions: The SUA level is significantly associated with various metabolic indicators. In this study, waist circumference and the level of triglycerides were most strongly correlated with the SUA level in both sexes. Individuals with a normal level of SUA had an increased risk of MetS and other metabolic disorders. Further research on appropriate cut-off values for pre-hyperuricemia is expected, and the early detection of hyperuricemia is essential for the prevention of MetS.