Immune State Conversion of the Mesenteric Lymph Node in a Mouse Breast Cancer Model.

Secondary lymphoid tissues, such as the spleen and lymph nodes (LNs), contribute to breast cancer development and metastasis in both anti- and pro-tumoral directions. Although secondary lymphoid tissues have been extensively studied, very little is known about the immune conversion in mesenteric LNs (mLNs) during breast cancer development. Here, we demonstrate inflammatory immune conversion of mLNs in a metastatic 4T1 breast cancer model. Splenic T cells were significantly decreased and continuously suppressed IFN-γ production during tumor development, while myeloid-derived suppressor cells (MDSCs) were dramatically enriched. However, T cell numbers in the mLN did not decrease, and the MDSCs only moderately increased. T cells in the mLN exhibited conversion from a pro-inflammatory state with high IFN-γ expression to an anti-inflammatory state with high expression of IL-4 and IL-10 in early- to late-stages of breast cancer development. Interestingly, increased migration of CD103+CD11b+ dendritic cells (DCs) into the mLN, along with increased (1→3)-ß-D-glucan levels in serum, was observed even in late-stage breast cancer. This suggests that CD103+CD11b+ DCs could prime cancer-reactive T cells. Together, the data indicate that the mLN is an important lymphoid tissue contributing to breast cancer development.

Cholesterol and triglyceride concentrations in lipoproteins as related to carotid intima-media thickness.

Since distinct cholesterol and triglyceride concentrations in major lipoproteins and their subclasses may be related to atherosclerosis, we investigated the relationship of cholesterol and triglyceride concentrations in lipoprotein subclasses and the severity of carotid intima-media thickness (IMT), a surrogate marker of subclinical atherosclerosis. We studied 116 apparently healthy Japanese men (53 ± 9 years) without a history of cardiovascular diseases who were not taking any medication. Carotid IMT was measured by means of high-resolution vascular ultrasound. Plasma cholesterol and triglyceride concentrations in major lipoproteins and their subclasses were determined by HPLC with gel permeation columns. By univariate analyses, carotid IMT was the most closely related to age (r = 0.528, P < 0.001), followed by smoking habit expressed as pack-year cigarette consumption (r = 0.409, P < 0.001). In addition to total cholesterol and LDL cholesterol, carotid IMT was significantly associated with cholesterol and triglyceride concentrations in several LDL and VLDL subclasses. Stepwise multiple linear regression analysis revealed that age (ß = 0.436, P < 0.001), smoking (pack-years) (ß = 0.225, P = 0.007), and large LDL cholesterol (ß = 0.175, P = 0.023) were independent predictors of determining carotid IMT (adjusted R(2) = 0.347, P < 0.001). These results indicate that large LDL cholesterol is an important, independent determinant of carotid IMT in healthy men.

Synthesis of all possible isomers corresponding to the proposed structure of montanacin E, and their antitumor activity.

Total synthesis of 4 and its three diastereomers is described. The key steps involve stereoselective formation of the tetrahydrofuran ring by a cascade cyclization of hydroxy tosylate 7 and an intermolecular cross metathesis between a tetrahydrofuran 5 and a gamma-lactone 6. Spectroscopic data of 4 and biosynthetic hypothesis strongly suggest it to be montanacin E. Inhibitory activities of 4 and its isomers against six human solid tumor cell lines were also evaluated.

Impact of low-density lipoprotein particle size on carotid intima-media thickness in patients with type 2 diabetes mellitus.

Small low-density lipoprotein (LDL) particles and modifications to LDL such as glycation and oxidation have been linked to the pathogenesis of atherosclerosis in patients with diabetes. We investigated whether LDL particle size, or the levels of glycated LDL or malondialdehyde-modified LDL (MDA-LDL) are associated with carotid intima-media thickness (IMT) in patients with type 2 diabetes mellitus. One hundred seventy-two patients with type 2 diabetes mellitus were enrolled. Carotid IMT was measured by high-resolution ultrasound, and LDL particle size and serum glycated LDL and MDA-LDL levels were determined. The 3 variables were significantly correlated with one another. Univariate analyses defined statistically significant correlations of carotid IMT with LDL size, hemoglobin A(1c), glycated LDL, MDA-LDL, high-density lipoprotein (HDL) cholesterol, and age. The strongest association of IMT was with LDL size (r = -0.406, P < .0001), followed by that with HDL cholesterol (r = -0.225, P = .004). A stepwise multiple regression analysis revealed that LDL size and HDL cholesterol are independent predictors of carotid IMT. Neither glycated LDL nor MDA-LDL had a significant independent contribution to the severity of carotid IMT in the multivariate model. Low-density lipoprotein particle size, but not the glycated LDL or MDA-LDL level, was independently associated with carotid IMT in patients with type 2 diabetes mellitus regardless of antidiabetic and lipid-lowering medications. These results suggest that the measurement of LDL size may be more useful than quantification of modified LDLs for assessing atherosclerosis in patients with type 2 diabetes mellitus. Small LDL particles may be the most important predictor for the risk of cardiovascular disease in diabetic patients.

Combined therapy with PPARalpha agonist and L-carnitine rescues lipotoxic cardiomyopathy due to systemic carnitine deficiency.

OBJECTIVE: Peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors that belong to the nuclear hormone receptor superfamily and are key regulators of fatty acid oxidation (FAO) in the heart. Systemic carnitine deficiency (SCD) causes disorders of FAO and induces hypertrophic cardiomyopathy with lipid accumulation. We hypothesized that activation of PPARalpha by fenofibrate, a PPARalpha agonist, in addition to conventional L-carnitine supplementation may exert beneficial effects on the lipotoxic cardiomyopathy in juvenile visceral steatosis (JVS) mouse, a murine model of SCD. METHODS: Both wild-type (WT) and JVS mice were fed a normal chow, 0.2% fenofibrate containing chow (FE), a 0.1% L-carnitine containing chow (CA) or a 0.1% L-carnitine + 0.2% fenofibrate containing chow (CA + FE) from 4 weeks of age. Four to 8 animals per group were used for each experiment and 9 to 11 animals per group were used for survival analysis. RESULTS: At 8 weeks of age, JVS mice exhibited marked ventricular hypertrophy, which was more attenuated by CA + FE than by CA or FE alone. CA + FE markedly reduced the high plasma and myocardial triglyceride levels and increased the low myocardial ATP content to control levels in JVS mice. In JVS mice, myocardial 1,2-diacylglycerol (DAG) was significantly increased and showed a distinct fatty acid composition with elevation of 18:1(n-7,9) and 18:2(n-6) fatty acids compared with that in WT mice. CA + FE significantly altered the fatty acid composition of DAG and inhibited the membrane translocation of cardiac protein kinase C beta2 in JVS mice. Furthermore, CA + FE prevented the progressive left ventricular dysfunction and dramatically improved the survival rate in JVS mice (survival rate at 400 days after birth: 89 vs. 0%, P < 0.0001). CONCLUSIONS: PPARalpha activation, in addition to l-carnitine supplementation, may rescue the detrimental lipotoxic cardiomyopathy in SCD by improving cardiac energy and lipid metabolism as well as systemic lipid metabolism.

Upregulation of renal eNOS by high-sodium diet facilitates hypertension in doxorubicin-treated rats through enhanced oxidative stress.

It is known that renal nitric oxide (NO) is an important controller of urinary sodium excretion. A defect in the kidney's NO system could cause salt-sensitive hypertension. Since it has been demonstrated that doxorubicin binds to the reductase domain of endothelial NO synthase (eNOS) and generates superoxide in vitro, we tested our hypothesis that a high-sodium diet would upregulate the expression of eNOS and enhance oxidative stress in the kidney of doxorubicin-treated rats, resulting in a facilitation of hypertension. At 4 weeks after treatment with doxorubicin in Sprague-Dawley rats, the systolic blood pressure significantly increased only in the high-sodium diet group. The expressions of eNOS protein in the renal cortex and medulla were significantly higher in high-sodium groups than in normal-sodium groups, regardless of doxorubicin treatment. In rats treated with doxorubicin, a biomarker of oxidative damage 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunohistological staining of renal tissues showed strong staining of the proximal and distal tubules. In particular, rats with doxorubicin in the high-sodium diet group demonstrated a significant increase in urinary exertion of 8-OHdG as well as more prominently stained tubules against 8-OHdG antibody, but markedly lower urinary NO(x) excretion than in rats without doxorubicin, even than in the untreated, low-sodium group. In conclusion, these results indicate that the oxidative stress induced by doxorubicin impairs NO production in the kidney. As such, doxorubicin treatment appears to contribute to the development of salt-sensitive hypertension through reductive activation of upregulated eNOS by a high-sodium diet instead of NO production.

Dietary fish oil attenuates cardiac hypertrophy in lipotoxic cardiomyopathy due to systemic carnitine deficiency.

OBJECTIVE: 1,2-Diacylglycerol (DAG), a lipid second messenger that activates protein kinase C (PKC), is increased with a distinct fatty acid composition in the heart of the juvenile visceral steatosis (JVS) mouse, which develops pathological cardiac hypertrophy with lipid accumulation induced by the perturbation of fatty acid beta-oxidation due to systemic carnitine deficiency. Fish oil (FO) may exert its beneficial effects on the cardiomyopathy in JVS mice by modifying the molecular species composition of myocardial DAG. To test this hypothesis, we investigated the effects of dietary FO on the hypertrophied hearts in JVS mice. METHODS: Both control and JVS mice were fed a FO diet (containing 10% FO) or a standard diet from 4 weeks of age. RESULTS: At 8 weeks of age, the ventricular-to-body weight ratio in JVS mice was 2.7-fold higher than that in controls (9.9 +/- 0.1 vs. 3.7 +/- 0.1 mg/g, P < 0.01) and was reduced by dietary FO (7.7 +/- 0.1 mg/g, P < 0.01 vs. JVS mice). In JVS mice, myocardial DAG levels were elevated by 2.3-fold with a distinct fatty acid composition with increases in C18:1n-7,9 and C18:2n-6 fatty acids compared with controls; dietary FO had no effects on the total DAG levels but significantly altered the fatty acid composition of DAG with reduction of both fatty acid species. Immunoblot analysis showed that dietary FO prevented the membrane translocation of cardiac PKCs alpha, beta2, and epsilon in JVS mice. Dietary FO did not affect the plasma and myocardial total carnitine levels in JVS mice. Furthermore, dietary FO significantly improved the progressive left ventricular dysfunction and survival rate in JVS mice. CONCLUSIONS: Dietary FO may attenuate cardiac hypertrophy with improvements in cardiac function and survival in JVS mice via modification of the molecular species composition of myocardial DAG and the consequent inhibition of PKC redistribution. These results suggest the implication of the molecular species composition of DAG in the pathogenesis of lipotoxic cardiomyopathy due to perturbations of fatty acid beta-oxidation.

Association of Circulating Follistatin-Like 1 Levels with Inflammatory and Oxidative Stress Markers in Healthy Men.

OBJECTIVES: Follistatin-like 1 (Fstl1) is a circulating glycoprotein that plays a crucial role in cardiovascular diseases and inflammation-related disorders. We have shown that Fstl1 acts as an anti-inflammatory factor that protects against ischemic heart disease and chronic kidney disease. Here we examined whether plasma level of Fstl1 associates with markers of inflammation and oxidative stress in apparently healthy Japanese men. METHODS AND RESULTS: Plasma Fstl1 levels were measured by enzyme-linked immunosorbent assay. Circulating Fstl1 concentrations positively correlated with levels of fasting immune-reactive insulin (FIRI), high-sensitive CRP (hsCRP) and derivatives of reactive oxidative metabolites (dROMs), an indicator of oxidative stress. The levels of hsCRP positively associated with Fstl1, body mass index (BMI), triglyceride, FIRI and dROMs levels. dROMs levels positively associated with Fstl1, Hemoglobin A1c and hsCRP levels. Multiple regression analysis with confounding factors revealed that Fstl1 levels, together with BMI and FIRI, correlated with hsCRP and that Fstl1 levels correlated with dROMs. CONCLUSION: Our observations indicate that measurement of plasma Fstl1 levels can be valuable for assessment of pro-inflammatory and oxidative stress conditions.

Changes in distinct species of 1,2-diacylglycerol in cardiac hypertrophy due to energy metabolic disorder.

OBJECTIVE: The juvenile visceral steatosis (JVS) mouse, a genetic model of systemic carnitine deficiency resulting from carnitine transport mutation, develops cardiac hypertrophy. We determined two putative lipid messengers, 1,2-diacylglycerol (DAG) and ceramide, in JVS and carnitine palmitoyltransferase-I (CPT-I) inhibitor etomoxir-treated mice because these lipids function as co-messengers in the myocardium via modification of protein kinase C activity. METHODS: JVS mice were evaluated at 4 and 8 weeks of age. The effect of long-term etomoxir treatment (45 mg/day) (ET) on mice was investigated in control mice from 4 to 8 weeks of age. As a model of inhibited cardiac hypertrophy, carnitine-treated JVS (CT) mice were produced. Myocardial DAG and ceramide levels and their fatty acid composition were measured. RESULTS: The heart/body weight ratio increased by 100% in JVS mice compared with that in controls, while that of CT mice was normalized in comparison with controls at 8 weeks of age. DAG markedly increased in both JVS and ET mice compared with that in controls (1,677+/-84, 1,258+/-49, and 585+/-58 ng/dry wt, respectively; P<0.01 for controls versus JVS or ET mice), whereas it was decreased significantly in CT mice compared with that in JVS mice (1,066+/-54 ng/dry wt, P<0.01). Furthermore, the fatty acid composition of DAG was similar in JVS and ET mice; in particular, 18:1 and 18:2 were significantly elevated in the myocardium (P<0.01 versus controls). On the other hand, that of DAG in CT mice was similar to that of the control group. In contrast, no difference was observed in myocardial ceramide levels among the groups. CONCLUSIONS: Pharmacological intervention with etomoxir mimics changes in the lipid second messenger characteristic of genetic JVS mice. The results suggest that the increases in distinct DAG species might be involved in the pathogenesis of cardiac hypertrophy as a result of disorder of fatty acid transport.

Impact of alpha-tocopherol on cardiac hypertrophy due to energy metabolism disorder: the involvement of 1,2-diacylglycerol.

OBJECTIVE: The juvenile visceral steatosis (JVS) mouse, a murine model of systemic carnitine deficiency, shows a disorder of fatty acid oxidation and develops cardiac hypertrophy associated with lipid accumulation. Recently, alpha-tocopherol was shown to decrease 1,2-diacylglycerol (DAG) levels. We investigated the involvement of DAG in cardiac hypertrophy due to energy metabolism disorder by evaluating the effects of alpha-tocopherol administration on the hearts of JVS mice. METHODS: Both JVS and control mice were fed a high alpha-tocopherol diet or a standard diet from 4 to 8 weeks of age. Myocardial DAG levels and fatty acid composition were assessed at 8 weeks of age. RESULTS: The ventricular to body weight ratio in the JVS mice was significantly higher than that in the control mice [11.2+/-0.1 (mean+/-S.E.M.) versus 3.8+/-0.1 mg/g, P<0.01], and was reduced by alpha-tocopherol treatment (9.7+/-0.2 mg/g, P<0.01 versus JVS mice). However, echocardiographic analysis showed the exaggeration of left ventricular dilatation in the alpha-tocopherol treated JVS mice (P<0.01 versus JVS mice). The myocardial thiobarbituric-acid-reactive substance level was not affected by alpha-tocopherol treatment. The myocardial DAG level was 2.5-fold higher in the JVS mice compared with that in the control mice (2004+/-136 versus 806+/-36 ng/mg dry weight, P<0.01) with a significant increase in 18:1 and 18:2 fatty acids. alpha-Tocopherol treatment reduced myocardial DAG levels in the JVS mice (1443+/-49 ng/mg dry weight, P<0.01 versus JVS mice) without any alteration of the fatty acid composition. CONCLUSIONS: alpha-Tocopherol treatment may partially reduce cardiac hypertrophy but it may also depress cardiac function in the JVS mice by decreasing the myocardial DAG level. An increase in DAG might be involved in the development of cardiac hypertrophy and in the maintenance of cardiac function in energy metabolism disorder of the heart.

The polymorphism of the beta3-adrenergic receptor gene is associated with reduced low-density lipoprotein particle size.

People with a predominance of small, dense low-density lipoprotein (LDL) particles appear to be at increased risk for coronary disease, independent of LDL cholesterol levels. The Trp64Arg variant of the beta3-adrenergic receptor gene is reported to be associated with abdominal obesity and resistance to insulin, and as a consequence, this variant may be a genetic factor in the development of atherosclerosis. Therefore, we investigated whether the beta3-adrenergic receptor polymorphism contributes to the distribution of LDL particle size in 136 Japanese subjects, aged 33 to 59 years, who visited for a routine annual checkup. None of these subjects were taking any medication. The diameter of LDL particles was determined at their peak size using nondenaturing 2% to 16% polyacrylamide gradient gels using fresh plasma samples. The genotype frequencies were: Trp/Trp, 71.3%; Try/Arg, 22.1%; and Arg/Arg, 6.6%, with allele frequencies of 0.82 for Trp64 and 0.18 for Arg64. The subjects with the Arg/Arg genotype had significantly higher levels of fasting plasma insulin and triglycerides and an insulin resistance index of homeostasis model assessment (HOMA-R), and significantly smaller LDL particle size than did the subjects with the Trp/Trp genotype. After adjusting for fasting insulin, body mass index (BMI), and HOMA-R index, there was no longer an observed difference in LDL particle size. The number of the Arg64 allele in individuals was significantly related with fasting insulin, BMI, triglycerides, glycosylated hemoglobin (HbA1c), and fasting glucose, and it was inversely related with LDL particle size. After adjusting for triglyceride, fasting insulin levels, and HOMA-R index, LDL particle size was no longer inversely correlated with the Arg allele. These findings suggest that the Trp64Arg variant in the beta3-adrenergic receptor gene may be associated with reducing LDL particle size, probably due to insulin resistance.

Association of circulating C1q/TNF-related protein 1 levels with coronary artery disease in men.

OBJECTIVE: Obesity is a major risk factor for cardiovascular disease. Recent evidence demonstrates that dysregulation of fat-derived hormones, also known as adipokines, is linked with the pathogenesis of obesity-related disorders including coronary artery disease (CAD). Here, we investigated whether circulating level of an adipokine C1q/TNF-related protein (CTRP) 1 is associated with the prevalence of CAD. METHODS AND RESULTS: Consecutive 76 male CAD patients were enrolled from inpatients that underwent coronary angiography. Sixty four healthy male subjects served as controls. Plasma CTRP1 concentration was determined by enzyme-linked immunosorbent assay. CTRP1 levels were correlated positively with systolic blood pressure (BP) and triglyceride levels, and negatively with HDL cholesterol levels in all subjects. Plasma levels of CTRP1 were significantly higher in CAD patients than in control subjects (CAD: 443.3±18.6 ng/ml, control: 307.8±21.5 ng/ml, p<0.001). Multiple logistic regression analysis with body mass index, systolic BP, glucose, total cholesterol, HDL cholesterol, triglyceride, adiponectin and CTRP1 revealed that CTRP1 levels, together with systolic BP and HDL cholesterol, correlated with CAD. CONCLUSIONS: Our data indicate the close association of high CTRP1 levels with CAD prevalence, suggesting that CTRP1 represents a novel biomarker for CAD.

Circulating cathepsin K as a potential novel biomarker of coronary artery disease.

BACKGROUND: Cathepsin K (CatK) is one of the most potent mammalian collagenases involved in atherosclerosis-based vascular disease. We investigated whether circulating CatK is associated with the prevalence of coronary artery disease (CAD). METHODS: Two-hundred fifty-two consecutive subjects were enrolled from among patients who underwent coronary angiography and intravascular ultrasound analyses. One-hundred thirty-two age-matched subjects served as controls. Plasma CatK, intact procollagen type I N-terminal propeptide (I-PINP), and linked carboxy-terminal telopeptide of collagen type I (ICTP) were measured. RESULTS: Patients with CAD had higher CatK levels (44.0 ± 31.2 versus 15.5 ± 8.3 ng/mL, P < 0.001) and ICTP/I-PINP ratios (0.2 ± 0.1 versus 0.04 ± 0.03, P < 0.001) than the controls. Patients with acute coronary syndrome had higher CatK levels than those with stable angina pectoris. Overall, linear regression analysis showed that the CatK levels correlated positively with ICTP/I-PINP ratios (r = 0.41, P < 0.001). Multiple logistic regression analysis showed that CatK levels were independent predictors of CAD (odds ratio, 1.15; 95% CI, 1.07 to 1.23; P < 0.01). Furthermore, CatK levels were also correlated positively with percent plaque volumes and inversely with percent fibrous volumes by intravascular ultrasound. CONCLUSIONS: These data indicated that high levels of CatK are closely linked with the presence of CAD and that CatK serves as a novel biomarker for CAD.

Omentin as a novel biomarker of metabolic risk factors.

BACKGROUND: Omentin is an adipocytokine that is abundantly expressed in visceral fat tissue. We investigated the association of omentin with the number of metabolic risk factors. FINDING: The study population comprised 201 Japanese men who underwent annual health checkups. Plasma omentin levels were determined by enzyme-linked immunosorbent assay. We divided the subjects into 4 groups according to omentin levels. A reduction of plasma omentin levels significantly correlated with an increase in the mean number of metabolic risk factors such as increased waist circumference, dyslipidemia, high blood pressure and glucose intolerance. CONCLUSIONS: Circulating omentin levels negatively correlated with the multiplicity of metabolic risk factors, suggesting that omentin acts as a biomarker of metabolic disorders.

Small low-density lipoprotein cholesterol concentration is a determinant of endothelial dysfunction by peripheral artery tonometry in men.

AIM: Endothelial dysfunction is an initial step in the progression of atherosclerosis. Precise measurements of lipoprotein subclass distribution by high-performance liquid chromatography (HPLC) have been established. Here, we investigated the potential associations between lipoprotein subclass cholesterol concentrations and endothelial dysfunction evaluated by digital reactive hyperemia peripheral arterial tonometry (PAT). METHODS: We recruited 120 apparently healthy Japanese men. Endothelial function was assessed by digital reactive hyperemia PAT, expressed as the logarithmic-scaled reactive hyperemia index (RHI). Plasma cholesterol concentrations in lipoproteins and their subclasses were determined by HPLC with gel permeation columns. RESULTS: RHI was inversely correlated with age (r=-0.258, p=0.004), followed by LDL cholesterol (r=-0.236, p=0.010) and small LDL cholesterol (r=-0.223, p=0.014). In addition, RHI was significantly inversely associated with heart rate, hemoglobin A1c, total cholesterol, medium LDL cholesterol, apolipoprotein B100, and non-HDL cholesterol. In stepwise multiple regression analysis, age (ß=-0.266, p=0.024), small LDL cholesterol (ß=-0.213, p=0.015), and heart rate (ß=-0.183, p=0.036) were found to be independent determinants of RHI (adjusted R(2) =0.132, p<0.001). CONCLUSIONS: Small LDL cholesterol concentration was an important, independent determinant of endothelial dysfunction in men.

High serum concentrations of pentosidine, an advanced glycation end product, are associated with low normal value of ankle-brachial index in apparently healthy men.

The ankle-brachial index (ABI) is widely used for peripheral arterial disease screening and is associated with future cardiovascular events. Pentosidine, an advanced glycation end product, accumulates with age and in diabetes and end-stage renal disease; but the significance of elevated serum pentosidine is not well known. We investigated the relationship of the ABI to circulating pentosidine concentrations as well as other atherogenic factors in apparently healthy men. The study group consisted of a total of 170 apparently healthy men (age, 55 ± 9 years). Serum pentosidine concentrations were measured by enzyme-linked immunosorbent assay. The mean ABI and pentosidine concentrations of the whole study group were 1.16 ± 0.07 (range, 0.98-1.35) and 36.1 ± 10.6 ng/mL (range, 11.2-81.0), respectively. Univariate analysis showed that the ABI was inversely correlated with pentosidine (P = .0004), small low-density lipoprotein (LDL) cholesterol (P = .017), LDL cholesterol (P = .019), apolipoprotein B (P = .024), fasting insulin (P = .028), very small LDL cholesterol (P = .036), difference in ABIs between legs (P = .037), malondialdehyde-modified LDL (P = .044), and homeostasis model assessment of insulin resistance (P = .047). Stepwise multiple linear regression analysis revealed that increased pentosidine, fasting insulin, small LDL cholesterol, difference in ABIs between legs, difference in systolic blood pressure between arms, and reduced body mass index were independent determinants of reduced ABI (adjusted R(2) = 0.237, P < .0001). Serum pentosidine was an important, independent determinant of ABI in healthy men. Subjects with an ABI less than 1.10 showed higher pentosidine concentrations.

Association of a fat-derived plasma protein omentin with carotid artery intima-media thickness in apparently healthy men.

Obesity is causally linked with the development of atherosclerosis. Omentin is an adipocytokine whose concentrations are reduced in obese individuals. Here we examined the relationship between plasma omentin levels and carotid intima-media thickness (IMT), a marker of early atherosclerosis, in apparently healthy Japanese men. Participants were 100 Japanese men who underwent a medical checkup. Maximal IMT (max-IMT) and mean-IMT in common carotid artery were measured by high-resolution carotid ultrasound system. Plasma omentin concentrations were determined by enzyme-linked immunosorbent assay. Circulating omentin levels correlated negatively with body mass index, waist circumference, fasting glucose, creatinine, max-IMT and mean-IMT, and positively with estimated glomerular filtration rates (eGFR). Single regression analysis demonstrated that max-IMT associated with age, eGFR and omentin levels, and that mean-IMT associated with age, fasting glucose, eGFR and omentin levels. Multiple regression analysis revealed that omentin levels, together with age, correlated with max-IMT and mean-IMT. Our data document that circulating omentin levels independently and negatively associate with carotid IMT in this population, suggesting that measurement of omentin may be useful for assessment of carotid IMT.

Circulating omentin is associated with coronary artery disease in men.

OBJECTIVE: Obesity is closely associated with an increased risk for cardiovascular morbidity and mortality. Omentin is a fat-derived secreted factor that is downregulated in obesity. We investigated whether circulating omentin associates with the prevalence of coronary artery disease (CAD). METHODS: The consecutive 78 male subjects were enrolled from patients who underwent coronary angiography. Sixty one age-matched male subjects served as controls. Plasma omentin concentration was measured by enzyme-linked immunosorbent assay. RESULTS: Plasma levels of omentin correlated negatively with body mass index (BMI), systolic blood pressure, hemoglobin A1c and total cholesterol levels, and positively with HDL cholesterol and adiponectin levels. Circulating omentin was independently associated with hemoglobin A1c and HDL cholesterol in a multiple regression analysis. Plasma levels of omentin were markedly lower in CAD patients than in control subjects (CAD: 102.8 ± 69.0 ng/ml, control: 454.7 ± 128.6 ng/ml, P < 0.001). Multiple logistic regression analysis with BMI, systolic blood pressure, glucose, hemoglobin A1c, HDL cholesterol, adiponectin and omentin revealed that plasma omentin levels were independently correlated with CAD. CONCLUSION: These data indicate that low levels of omentin are closely linked with the presence of CAD and that omentin serves as a novel biomarker for CAD.

Unmetabolized fenofibrate, but not fenofibric acid, activates AMPK and inhibits the expression of phosphoenolpyruvate carboxykinase in hepatocytes.

AIMS: A lipid-lowering agent, fenofibrate, has been reported to reduce hepatic glucose production and the expression of phosphoenolpyruvate carboxykinase (PEPCK), a rate-limiting enzyme for gluconeogenesis in the liver. However, the precise mechanisms of these effects have remained unclear. MAIN METHODS: Rat hepatoma-derived H4IIE cells and murine myoblast-derived C2C12 cells were incubated with the ester form of fenofibrate and fenofibric acid, a metabolite of fenofibrate ester, and the phosphorylation of AMPK, acetyl-CoA carboxylase (ACC), PEPCK mRNA expression and glucose production were assessed. KEY FINDINGS: Incubation of H4IIE hepatoma cells with the ester form of fenofibrate increased the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) and decreased PEPCK mRNA expression and glucose production. Fenofibrate-induced reductions in PEPCK expression and glucose production were abrogated by compound C, a specific AMPK inhibitor. Fenofibric acid, a metabolite of fenofibrate ester, had no effects on AMPK phosphorylation, PEPCK gene expression, or glucose production in H4IIE cells. Fenofibrate-treated mice exhibited increases in AMPK phosphorylation and a decrease in PEPCK expression in the liver but not in skeletal muscles, suggesting that unmetabolized fenofibrate accumulated and affected AMPK only in the liver. SIGNIFICANCE: These results demonstrate that fenofibrate inhibits PEPCK gene expression and hepatic glucose production in the liver via AMPK activation, even though the metabolite loses its effects on AMPK and does not work in vivo in myocytes. This novel feature of fenofibrate may provide additional benefit for the treatment of patients with disorders of both lipid and glucose metabolism.

Low folate levels may be an atherogenic factor regardless of homocysteine levels in young healthy nonsmokers.

Low folate and high homocysteine levels are emerging as important risk factors for atherosclerosis and predictors of early coronary heart disease. We evaluated folate and homocysteine levels, compared them with endothelial function, and analyzed their association with the methylenetetrahydrofolate reductase (MTHFR) and endothelial nitric oxide synthase genotypes. We recruited 71 young healthy male nonsmokers without overt cardiovascular or renal disease. Plasma homocysteine levels were enhanced 2-fold in the subjects with the MTHFR 677T/T compared with the others (P = .0001) and also enhanced in the subjects with the endothelial nitric oxide synthase -786C allele (P = .031). Homocysteine levels were independently predicted only by the MTHFR genotype. A relationship between folate and homocysteine levels was not significant. Plasma folate levels were associated independently either with high-density lipoprotein cholesterol levels or with endothelial function in the brachial artery. These results suggest that low folate levels may be a risk factor for cardiovascular diseases regardless of homocysteine levels and that the subjects with lower folate levels should be recommended for dietary folic acid supplementation to elevate endothelial function and probably increase high-density lipoprotein cholesterol levels.