Hisatoyo Hiraoka

Association of Hypoadiponectinemia With Coronary Artery Disease in Men

Background—Adiponectin is an adipocyte-derived plasma protein that accumulates in the injured artery and has potential antiatherogenic properties. This study was designed to determine whether a decreased plasma adiponectin level (hypoadiponectinemia) can be independently associated with the prevalence of coronary artery disease (CAD). Methods and Results—The consecutive 225 male patients were enrolled from inpatients who underwent coronary angiography. Voluntary blood donors (n=225) matched for age served as controls. Plasma adiponectin levels in the CAD patients were significantly lower than those in the control subjects. Multiple logistic regression analysis including plasma adiponectin level, diabetes mellitus, dyslipidemia, hypertension, smoking habits, and body mass index revealed that hypoadiponectinemia was significantly and independently correlated with CAD (P <0.0088). The entire study population was categorized in quartiles based on the distribution of plasma adiponectin levels. The interquartile cutoff points were 4.0, 5.5, and 7.0 &mgr;g/mL. The multivariate-adjusted odds ratios for CAD in the first, second, and third quartiles were 2.051 (95% confidence interval [CI], 1.288 to 4.951), 1.221 (95% CI, 0.684 to2.186), and 0.749 (95%CI, 0.392 to 1.418), respectively. Conclusions—Male patients with hypoadiponectinemia (<4.0 &mgr;g/mL) had a significant 2-fold increase in CAD prevalence, independent of well-known CAD risk factors.

Reciprocal Association of C-Reactive Protein With Adiponectin in Blood Stream and Adipose Tissue

Background—High-sensitive C-reactive protein (hs-CRP) is a well-known risk factor for coronary artery disease (CAD). Recently, we have demonstrated that adiponectin served as an antiatherogenic plasma protein which was secreted specifically from adipocytes. The present study investigated the association between adiponectin and CRP in the blood stream and adipose tissue. Methods and Results—We studied a total of 101 male patients, 71 of whom had angiographically documented coronary atherosclerosis. As a control group, 30 patients with normal coronary angiogram were included. The plasma hs-CRP levels were negatively correlated with the plasma adiponectin levels (r =−0.29, P <0.01). The plasma adiponectin concentrations were significantly lower and the hs-CRP levels were significantly higher in the CAD patients compared with control subjects. The mRNA levels of CRP and adiponectin were analyzed by quantitative real-time polymerase chain reaction method. We found that the CRP mRNA was expressed in human adipose tissue. A significant inverse correlation was observed between the CRP and adiponectin mRNA levels in human adipose tissue (r =−0.89, P <0.01). In addition, the CRP mRNA level of white adipose tissue in adiponectin deficient mice was higher than that of wild-type mice. Conclusions—The reciprocal association of adiponectin and CRP levels in both human plasma and adipose tissue might participate in the development of atherosclerosis.

Association of Hypoadiponectinemia With Impaired Vasoreactivity

Abstract—Endothelial dysfunction is a crucial feature in the evolution of atherosclerosis. Adiponectin is an adipocyte-specific plasma protein with antiatherogenic and antidiabetic properties. In the present study, we investigated the relation between adiponectin and endothelium-dependent vasodilation. We analyzed endothelial function in 202 hypertensive patients, including those who were not taking any medication. Forearm blood flow was measured by strain-gauge plethysmography. Plasma adiponectin level was highly correlated with the vasodilator response to reactive hyperemia in the total (r =0.257, P <0.001) and no-medication (r =0.296, P =0.026) groups but not with nitroglycerin-induced hyperemia, indicating that adiponectin affected endothelium-dependent vasodilation. Multiple regression analysis of data from all hypertensive patients revealed that plasma adiponectin level was independently correlated with the vasodilator response to reactive hyperemia. Vascular reactivity was also analyzed in aortic rings from adiponectin-knockout (KO) and wild-type (WT) mice. Adiponectin-KO mice showed obesity, hyperglycemia, and hypertension compared with WT mice after 4 weeks on an atherogenic diet. Endothelium-dependent vasodilation in response to acetylcholine was significantly reduced in adiponectin-KO mice compared with WT mice, although no significant difference was observed in endothelium-independent vasodilation in response to sodium nitroprusside. Our observations suggest that hypoadiponectinemia is associated with impaired endothelium-dependent vasorelaxation and that the measurement of plasma adiponectin level might be helpful as a marker of endothelial dysfunction.

Matrix Metalloproteinases as Novel Disease Markers in Takayasu Arteritis

Background—Takayasu arteritis (TA) is a chronic vasculitis that primarily affects large elastic arteries. Monitoring of disease activity is crucial because the disease tends to progress despite treatment with glucocorticoid and/or immunosuppressive agents. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) have generally been used as disease activity markers, but these are nonspecific inflammatory markers and lack the sensitivity and specificity to accurately monitor the disease status. Given the histological findings characterized by destruction of elastic fibers, we hypothesized that matrix metalloproteinases (MMPs) could be useful as markers of disease activity in TA. Methods and Results—A consecutive series of 25 patients with TA were enrolled in this study. According to the National Institutes of Health criteria of disease activity, 11 were in an active phase and the remaining 14 were in remission. Circulating levels of MMP-2, MMP-3, and MMP-9 were determined by ELISA in all patients with TA and controls. MMP-2 levels were higher in patients with TA than in controls, but no correlation was found between serum MMP-2 and disease activity score. In contrast, MMP-3 and MMP-9 levels in patients with active disease were higher than in patients in remission and controls, and a positive correlation was demonstrated between circulating levels of MMP-3 or MMP-9 and disease activity score. The high levels of MMP-3 and MMP-9 improved when patients underwent remission. Conclusions—The present results indicate that MMP-2 can be helpful in diagnosing TA and that MMP-3 and MMP-9 can be used as activity markers for TA.

Dominant expression of ATP-binding cassette transporter-1 on basolateral surface of Caco-2 cells stimulated by LXR/RXR ligands

ATP-binding cassette transporter-1 (ABCA1) is a cause of Tangier disease, which is a familial deficiency of plasma high density lipoproteins (HDL). This molecule is known to be expressed in the multiple tissues and organs including small intestines, liver, and macrophages in the blood vessels. Recent in vivo studies suggested that ABCA1 plays some roles in the flux of cholesterol in the intestines. One of the major questions to understand the roles of ABCA1 in the intestines is the expression pattern in the intestinal epithelial cells. To address this issue, we have investigated the expression and regulation of ABCA1 in Caco-2 cells cultured on Transwell as a model, especially focusing on possible polarized expression of ABCA1. The expression of ABCA1 was up-regulated during the differentiation and under the stimulation of LXR/RXR by the addition of 9-cis-retinoic acid (9-cis-RA) and 22-R-hydroxycholesterol (22-OH). Apolipoprotein-AI-mediated cholesterol efflux was dominant toward the basolateral side of polarized cells when stimulated by 9-cis-RA and 22-OH. The cell surface biotinylation experiment followed by Western blot analyses demonstrated a markedly dominant expression of ABCA1 on the basolateral surface, which was clearly confirmed by the confocal laser scanning microscopy. In conclusion, the present study demonstrates that ABCA1 is dominantly expressed on the basolateral surface of Caco-2 cells tested, suggesting that this molecule may play a role in the basolateral movement of cholesterol at least when stimulated by LXR/RXR ligands.

Vascular endothelial dysfunction resulting from l-arginine deficiency in a patient with lysinuric protein intolerance

Although L-arginine is the only substrate for nitric oxide (NO) production, no studies have yet been reported on the effect of an L-arginine deficiency on vascular function in humans. Lysinuric protein intolerance (LPI) is a rare autosomal recessive defect of dibasic amino acid transport caused by mutations in the SLC7A7 gene, resulting in an L-arginine deficiency. Vascular endothelial function was examined in an LPI patient who was shown to be a compound heterozygote for two mutations in the gene (5.3-kbp Alu-mediated deletion, IVS3+1G-->A). The lumen diameter of the brachial artery was measured in this patient and in healthy controls at rest, during reactive hyperemia (endothelium-dependent vasodilation [EDV]), and after sublingual nitroglycerin administration (endothelium-independent vasodilation [EIV]) using ultrasonography. Both EDV and NO(x) concentrations were markedly reduced in the patient compared with those for the controls. They became normal after an L-arginine infusion. EIV was not significantly different between the patient and controls. Positron emission tomography of the heart and a treadmill test revealed ischemic changes in the patient, which were improved by the L-arginine infusion. Thus, in the LPI patient, L-arginine deficiency caused vascular endothelial dysfunction via a decrease in NO production.

Polydisperse low-density lipoproteins in hyperalphalipoproteinemic chronic alcohol drinkers in association with marked reduction of cholesteryl ester transfer protein activity.

Long-term heavy alcohol intake is well known to increase serum high-density lipoprotein (HDL) cholesterol concentrations. Epidemiologic studies have shown that the protective effect of alcohol intake against coronary heart disease (CHD) is observed in moderate alcohol drinkers, but not in heavy ones. To clarify whether heavy alcohol intake may cause abnormalities in lipoprotein metabolism, we analyzed the plasma lipoproteins in eight male chronic heavy alcohol drinkers with marked hyperalphalipoproteinemia. Although their serum HDL cholesterol levels were remarkably high, ranging from 2.67 to 3.58 mmol/L, three patients had CHD and corneal arcus was present in seven patients. Cholesteryl ester transfer protein (CETP) activity was reduced in all subjects (7.3% +/- 4.2%/10 microL/18 h in alcohol drinkers v 20.5% +/- 2.4%/10 microL/18 h in control; mean +/- SD, P < .001). The CETP mass levels were also markedly reduced in these subjects. The analysis of low-density lipoprotein (LDL) on nondenaturing polyacrylamide gradient gel electrophoresis revealed that four subjects with severely low CETP activity (< 25% of control) had polydisperse LDLs, similar to those observed in genetic CETP deficiency. The other four subjects with approximately half the normal CETP activity had homogeneous but smaller-sized LDLs, as compared with control subjects. Particle size of HDL was larger than that of normal control HDL in all subjects. After cessation of alcohol intake, plasma HDL cholesterol levels were decreased and LDLs became more homogeneous and normal in size, in parallel with elevation of CETP activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of monocytes in vivo causes intracellular accumulation of lipoprotein-derived lipids and marked hypocholesterolemia—a possible pathogenesis of necrobiotic xanthogranuloma

Necrobiotic xanthogranuloma (NXG) is a rare histiocytic disease with generalized xanthomatosis. However, most cases with NXG are normolipidemic or hypolipidemic. The mechanism for the formation of xanthoma in NXG has not yet been clarified. We observed a case of NXG with severe hypocholesterolemia (total cholesterol: 1.69 mmol/l) and analyzed the function of monocytes in this case. Histological examinations by light microscopy revealed a large amount of lipid deposition in the patients freshly isolated monocytes. The patients monocytes showed a 3-fold increase in cholesteryl ester content and a 3-fold enhancement of acetyl low density lipoprotein (LDL) uptake compared with the control monocytes. However, no significant difference was noted in the expression of CD36 protein and the mRNA levels of scavenger receptor-class A (SR-A) between the monocytes of the patient and the control. The phagocytotic ability of the patients monocytes was enhanced 1.5-fold compared with that of the control monocytes. These findings suggest that the activated monocytes may have degraded the modified LDL via a pathway other than CD36 or SR-A, and accumulated a great amount of lipids in vivo. In conclusion, the present study has demonstrated a possible pathogenesis of NXG that the activation of monocytes in vivo may contribute to the intracellular accumulation of lipoprotein-derived lipids leading to non-inherited xanthomatosis and the marked hypocholesterolemia.

Frequency of intron 14 splicing defect of cholesteryl ester transfer protein gene in the Japanese general population — relation between the mutation and hyperalphalipoproteinemia

Cholesteryl ester transfer protein (CETP) deficiency, which has been found only in Japan, is characterized by marked hyperalphalipoproteinemia (HALP) and abnormalities of both low density and high density lipoproteins. We have reported that this deficiency is commonly associated with a G-->A mutation at the intron 14 splice donor site of the CETP gene (Yamashita et al., Biochem. Biophys. Res. Commun., 170 (1990) 1346-1351). In the current study, we determined the frequency of this mutation in Japanese subjects by using polymerase chain reaction. A single primer-template mismatch of one base pair from the CETP gene mutation permitted the introduction of a cleavage site for Nde I in mutant alleles but not in normal ones. Out of 171 patients with marked HALP whose serum HDL-cholesterol was more than 100 mg/dl, 6 (3.5%) subjects were homozygous and 48 (28.1%) were heterozygous for this mutation. Furthermore, in unrelated 512 healthy Japanese subjects, 5 (0.98%) were identified as heterozygotes. Relative allelic frequency of A at the intron 14 splice donor site was 0.0049 and the frequency of homozygous CETP deficiency was estimated to be approximately 1/42,000. These results demonstrate that this common mutation may be frequent in the Japanese population. Although HALP is very heterogenous, this mutation could be one of the major causes of marked HALP.

The white blood cell count is an independent predictor of no‐reflow and mortality following acute myocardial infarction in the coronary interventional era

BACKGROUND. In the era before the use of coronary reperfusion therapy, an elevated white blood cell (WBC) count was associated with a higher risk of adverse events following acute myocardial infarction (AMI). However, the relationship between WBC count and prognosis after AMI has not been investigated since coronary intervention was introduced. AIM. To evaluate whether a high WBC count within 48 hours of the onset of AMI predicts future adverse events in patients undergoing percutaneous coronary intervention (PCI). METHOD. We evaluated 1,016 patients who underwent PCI in the acute phase of MI using the Japanese Acute Coronary Syndrome Study (JACSS) database. RESULTS. WBC count was significantly associated with smoking, sudden onset AMI, and the no‐reflow phenomenon during PCI, as were age, peak creatine kinase level, and Killip class. An elevated WBC count was significantly associated with higher risk of in‐hospital mortality. Patients in the highest quartile of WBC count were about three times more likely to have a poor prognosis after AMI compared to those in the lowest quartile. CONCLUSIONS. The WBC count is of great significance for stratifying patient risk and can be used as a universal marker for predicting future adverse events following any treatment for AMI.