Kaoru Takemura

Enhanced expression of PAI-1 in visceral fat: possible contributor to vascular disease in obesity.

The presence of obesity increases the risk of thrombotic vascular diseases. The role of fat accumulation and its effect on plasminogen activator inhibitor–1 (PAI–1) levels was investigated in humans and animals. Plasma PAI–1 levels were closely correlated with visceral fat area but not with subcutaneous fat area in human subjects. PAI–1 mRNA was detected in both types of fat tissue in obese rats but increased only in visceral fat during the development of obesity. These data suggest that an enhanced expression of the PAI–1 gene in visceral fat may increase plasma levels and may have a role in the development of vascular disease in visceral obesity.

Visceral fat accumulation as an important risk factor for obstructive sleep apnoea syndrome in obese subjects

Objectives. It is well known that obstructive sleep apnoea (OSA) is frequently associated with obesity. In the current study, we investigated the correlation between abdominal visceral fat accumulation and the presence of OSA in obese subjects.

Lipoprotein(a) Enhances the Expression of Intercellular Adhesion Molecule-1 in Cultured Human Umbilical Vein Endothelial Cells

BACKGROUND We reported an increase in serum lipoprotein(a) [Lp(a)] levels in patients with thromboangiitis obliterans, suggesting that Lp(a) could also contribute to the pathogenesis of cardiovascular diseases by a mechanism different from atherosclerosis. Adhesion molecules were shown to contribute to the development of not only atherosclerotic but also inflammatory vascular diseases. METHODS AND RESULTS We evaluated the effect of Lp(a) on the expression of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin in human umbilical vein endothelial cells by a cell ELISA. Lp(a) dramatically enhanced the levels of ICAM-1 in a dose-dependent manner. A discernible increase in ICAM-1 expression was observed at a physiological concentration of 0.26 mmol cholesterol/L Lp(a) after 48-hour incubation. A 1.8-fold increase in ICAM-1 expression was observed 48 hours after the addition of Lp(a) (1.04 mmol cholesterol/L). Northern blot analysis demonstrated that the amount of ICAM-1 mRNA was increased after treatment with Lp(a). In contrast to ICAM-1, the expression of VCAM-1 and E-selectin was not significantly affected by Lp(a). Lp(a-) [apolipoprotein(a)- removed Lp(a) by reduction with dithiothreitol] and LDL had no significant effect on the expression of ICAM-1. In contrast, recombinant apolipoprotein(a) protein alone significantly enhanced ICAM-1 expression. Lp(a) decreased the level of active transforming growth factor (TGF)-beta in the conditioned medium. Furthermore, recombinant TGF-beta significantly decreased the Lp(a)-induced ICAM-1 expression. These findings suggested that Lp(a) may enhance the ICAM-1 expression by decreasing active TGF-beta level. CONCLUSIONS Lp(a) could contribute to the development of cardiovascular diseases by enhancing the expression of ICAM-1 in endothelial cells.

Combined treatment with chenodeoxycholic acid and pravastatin improves plasma cholestanol levels associated with marked regression of tendon xanthomas in cerebrotendinous xanthomatosis

We studied the effect of chenodeoxycholic acid (CDCA) and a competitive HMG-CoA reductase inhibitor, pravastatin, on clinical symptoms and sterol metabolism in a 36-year-old Japanese man with cerebrotendinous xanthomatosis (CTX). He had marked tendon xanthomas and mild dementia, with obvious electroencephalographic (EEG) abnormalities. He was treated for 2 years with CDCA alone (0.6 g/d) and then for a further year with the combination of pravastatin (10 mg/d) and CDCA (0.6 g/d). For the following year, he was given pravastatin alone, and then was returned to combined treatment again. The plasma cholestanol level before treatment was 3.12 mg/dL, which was 20 times above the control level. After CDCA alone, the plasma cholestanol was reduced to 1.96 mg/dL, and this was further reduced to 0.92 mg/dL by combination therapy with CDCA and pravastatin. However, after the discontinuation of CDCA, his cholestanol levels returned to the pretreatment levels despite the continuing of pravastatin treatment. When the combination therapy was restarted, his cholestanol level was once again markedly reduced. His clinical symptoms showed a close association with the plasma cholestanol level; the xanthomas regressed remarkably and the mental retardation improved in association with normalization of EEG findings during treatment with CDCA alone or in combination with pravastatin. However, during treatment with pravastatin alone, his tendon xanthomas enlarged again and slow waves reappeared on the EEG. Because inhibition of cholesterol synthesis by treatment with the HMG-CoA reductase inhibitor alone was not effective in causing a reduction of cholestanol, the increase in plasma cholestanol levels in CTX may not have been solely due to increased cholesterol synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-macrophage-related accumulation of cholesterol during probucol treatment in familial hypercholesterolemia: report of two cases

Two patients receiving long-term (3-4 years) treatment with probucol for familial hypercholesterolemia (FH) developed diffuse yellow lesions over the upper eyelids suggesting lipid storage in those tissues (diffuse lipid-storage lesions). Interestingly, each patient had shown a substantial reduction in their cholesterol levels together with a marked regression of their tendon xanthomas or typical xanthelasmas during treatment. To evaluate the role of probucol in this unusual finding we conducted histological and immunochemical evaluations of the lesions (removed surgically) and compared them with those of a non-probucol-treated subject with FH and typical audinal xanthelasma. In both probucol-treated patients the lesions were filled with foam cells and contained large amounts of cholesteryl ester. However, immunochemical analysis of the lesions of one patient using anti-monocyte monoclonal antibody (HAM56) demonstrated that they were not composed of macrophage-derived foam cells in contrast to those of the non-probucol-treated subject which stained clearly with anti-monocyte monoclonal antibody. In each case the foam cells did not react with muscle-actin-specific monoclonal antibody (HHF35). It appears that non-macrophage-related diffuse lipid-storage lesions may occur even during treatment with probucol despite the reduction in cholesterol levels and the regression of xanthomas, suggesting that probucol may alter the distribution of cholesterol from the macrophage to other cells.

A compound heterozygote for familial hypercholesterolaemia with a homozygous mother

Homozygous familial hypercholesterolaemia (FH) is a rare disorder in which the patients develop severe hypercholesterolaemia and premature coronary atherosclerosis from childhood. Here we report a unique family with clustering of homozygous FH. The proband was a 25‐year‐old man, who showed marked hypercholesterolaemia, multiple xanthomas and severe coronary atherosclerosis. His mother also showed the typical characteristics of homozygous FH. Sequencing analysis of the low‐density lipoprotein receptor gene revealed that he was a compound heterozygote, carrying two different point mutations. One was a novel mutation, FH Wakayama (Cys→A Ser at 317), derived from his mother, and the other was a recurrent mutation, FH Niigata (T→A C at 1845+2, 5′ splice signal in intron 12), derived from his father. The proband we report seems to be a very rare case of an FH homozygote born from a homozygous mother.