Alacepril, a sulfhydryl-containing angiotensin-converting enzyme inhibitor has been suggested to have antioxidant or free radical scavenging effects. Recently, small, dense low-density lipoprotein (LDL) has been reported to be particularly atherogenic due to its high susceptibility to oxidative modification. The effects of the oral administration of alacepril (50mg/day) on LDL particle size were examined in 12 patients with essential hypertension. The relative migratory distance (RMD) of the predominant densitometric peak of LDL from that of very low-density lipoprotein to that of high-density lipoprotein in a 3% polyacrylamide gel electrophoreis was determined as a measure of LDL particle size. RMD was shown to be inversely correlated with LDL particle diameter and RMD above 0.36 corresponded to a LDL particle diameter <25.5nm or small, dense LDL according to the preliminary experiment. Alacepril (50mg/day) was administered for 3 months. No significant alteration was observed in RMD values after administration of alacepril to the patients. However, RMD decreased in the 6 patients with small, dense LDL, suggesting that their LDL particle size had increased, and serum α-tocopherol levels increased in 5 of the 6 patients. In conclusion, the oral administration of 50mg of alacepril for 3 months enlarged LDL particle size and increased serum vitamin E levels in patients with small, dense LDL, suggesting its favorable effects on lipid metabolism by antioxidative reaction. Alacepril may be useful, especially in the treatment of hypertensive patients combined with dyslipidemia with small, dense LDL.
To investigate the relationship between micro- and macroangiopathy (MA) in type-2 diabetes, the prevalence and clinical characteristics of macroangiopathy were studied in subjects with peripheral and autonomic neuropathy. These complications were assessed in 829 diabetic patients on the basis of both clinical findings and non-invasive examinations. The prevalence of peripheral neuropathy (PN) and autonomic neuropathy (AN) was 45.5% and 27.6%, respectively. 21.1% of the subjects were complicated with both PN and AN. The prevalence of ischemic heart disease (IHD), cerebral infarction (CI), and arteriosclerosis obliterans (ASO) in subjects with neuropathy, especially complicated with both PN and AN, was significantly higher than in the subjects without neuropathy. Aging, duration of diabetes, HbAlc levels, high systolic blood pressure, and uremia were common risk factors for both PN and AN. In addition, smoking was associated with PN, and reduced concentrations of HDL-C with AN. These risk factors were also related with MA. Multivariate analysis indicated that AN could be an independent risk factor for all MA, on the other hand, PN was indicated for IHD and ASO. These data suggest that diabetic neuropathy is closely correlated with MA of the heart, brain and lower legs. Glycemic control, other risk factor management and evaluation of systemic MA using a non-invasive approach are important for subjects with neuropathy, especially for subjects complicated with both PN and AN.
Dyslipidemias with TG rich lipoprotein (TGRL) are regarded as powerful risk factors for atherosclerotic changes. PAGE is the usual method for detecting TGRL, especially remnant lipoprotein (RL).The authors divided the shapes of LDL on a PAGE densitograph (Lipophor kit, Quantimetrix Co. CA, & Jokoh Co. Tokyo) into types S (symmetry), E (eminent), A (asymmetry), N (nodular) and D (disrupted) and propose the usefulness of this SEAND classification as a tool for the treatment of dyslipidemias at lipid clinics. Fenofibrate 150mg/day made a significant improvement in each lipoprotein component and changed PAGE patterns from D or N to A or S in most cases. LDL-migration index (LDL-MI), which is calculated as LDL peak distance from VLDL peak, is divided by HDL peak distance from VLDL peak, and which indicates LDL particle size, decreased (0.43-0.40) and LDL cholesterol/apoB, which also depicts LDL particle size, increased (1.03-1.20).The effect of Fenofibrate was more potentiated in groups N and D than in S, E, A, significantly in the increment of HDL-cholesterol and decrement of apoB, C2, C3, E and LDL-MI, TG/apoB (1.86-1.25), TG/apoC2 (47.8-31.74), TG/apoC3 (17.69-13.14) and TG/apoE (40.31-27.64) which were thought to be important clinically noticeable markers for down sizing of the TGRL particle.Levels of serum uric acid decreased in all cases which involved abnormally high levels.In conclusion, this paper intended to clarify that for the evaluation of the effect of Fenofibrate on dyslipidemias, it would be useful to adopt the PAGE pattern classification and select cases with N, D and A as suitable indications.
Practice guidelines on the prevention and management of high cholesterol in adults are now available in many countries. These guidelines are expected to have significant implications for both primary and secondary prevention of cardiovascular disease. Although HMG-CoA reductase inhibitors are frequently prescribed for patients with hypercholesterolemia, a sufficient reduction in LDL-cholesterol levels can not always be achieved by its currently recommended dosage in Japan. Therefore, we compared the efficacy and safety of two three-month treatments; i. e. doubling the dosage of the HMG-CoA reductase inhibitor, fluvastatin to 40mg/day, and combined therapy using the HMG-CoA reductase inhibitor, fluvastatin at 20mg/day and colestimide at 3g/day. A cross-over procedure of the two treatments was applied in 8 patients (men/women=2/6, mean age 71 years) with hypercholesterolemia whose total cholesterol levels were more than 220mg/dl or LDL-cholesterol levels were more than 140mg/dl, despite treatment with 20mg/day of fluvastatin.Mean total cholesterol levels at enrollment were 246±14mg/dl (mean±SD). The combined therapy decreased them significantly to 217±27mg/dl, whereas doubling the dosage regimen did not (239±25mg/dl). The combined therapy also decreased the calculated LDL-cholesterol levels significantly from 154±14mg/dl to 118±18mg/dl. In contrast, doubling the dosage of fluvastatin did not have a significant effect (141±23mg/dl). The levels of HDL-cholesterol and triglyceride remained unchanged with both treatments. Throughout the whole study period, there were no adverse events including elevation of CK, fasting blood sugar, and liver enzymes. We conclude that a combined therapy using an HMG-CoA reductase inhibitor and colestimide is efficacious and safe to obtain a significant reduction in total and LDL-cholesterol levels in patients with hypercholesterolemia refractory to the conventional statin treatment.
Anorexia nervosa is known to induce various metabolic disorders such as low T3 syndrome, high levels of GH, liver function disorder, amenorrhea, hypokalemia, hypochloremia, hypoglycemia, and lymphopenia. We experienced a 20-year-old woman with anorexia nervosa who had severe liver dysfunction and hyper HDL-cholesterolemia (140mg/dl). The level of HDL-cholesterol changed in parallel with that of serum transaminase. With the recovery of serum transaminase levels, the level of HDL-choresterol normalized to 46mg/dl. In the analysis of CETP genes, she was heterozygotic in the CETP gene with exon 15 missense mutation. CETP activity and protein concentrations were at the lowend of the normal range.In reported cases of anorexia nervosa, the level of HDL-cholesterol is not necessarily elevated. Since the high level of HDL-cholesterol was significantly associated with her serum transaminases levels, we speculate that high serum levels of HDL-cholesterol may result from the decrease of HTGL activity due to liver dysfunction and the increase of LPL due to hyperactivity on the basis of CETP deficient heterozygotes.
In an attempt to assay native Lp (a), the anti-Lp (a) monoclonal antibody (161E2) was produced against synthetic antigen (Arg-Asn-Pro-Asp-Val-Ala-Pro). Characteristic properties of this 161E2 monoclonal antibody were identified to have reactivity to oxidative modification (treatment with CuCl22 and lipoxygenase), but to neither LDL, plasminogen nor native Lp (a). We developed a new ELISA method to measure Lp (a) modified by oxidative stress using this 161E2 monoclonal antibody as the capture and the labelled antibody, and conducted assay of the epitope in serum using BSA-peptide (16 peptides perl molecule of BSA) as the standard. Interestingly, hypertensive patients with complications showed a significantly higher level of oxidized Lp (a) in serum than did normotensive subjects (p<0.01), whereas there was no significant difference in native Lp (a) between normotensive and hypertensive subjects. The in vivo presence of the epitope was also confirmed with use of 161E2 monoclonal antibody-based immunostaining of arteriosclerotic tissue layer by positive response. Upon analyzing peptide homology of the epitope, it was shown to have high homology (88%) to the cytoplasmic domain of human α2A-adrenergic receptor.
In Japan, as consanguineous marriages are relatively frequent, it is possible to observe comparatively frequently the true homozygotes of FH. These patients inherit two identical LDL receptor gene mutations from their parents. By analyzing the LDL receptor mutations in 14 families with true homozygotes, we identified 9 different mutations. The true homozygotes are useful for characterizing the phenotype of each mutation due to the uniformity of the gene mutations. By analyzing these gene mutations together with their phenotypes in the fibroblasts of the patients, we could characterize several unique phenotypes of the LDL receptor such as internalization-defective, recycling-impaired, processing-impaired, truncated, degradation-enhanced and protein synthesis-impaired forms. From these studies we could determine the structure/function relationship of the LDL receptor protein.It is known that in some selected populations, limited numbers of mutations of LDL receptor gene predominate. In such areas, diagnosis of FH is easier. To determine if some common mutations exist in Japan, we examined the frequency of each mutation identified in our FH homozygotes. By analyzing 120 unrelated FH heterozygotes, we found that the five mutations, 1) 1845+2T→C, 2) K790X, 3) C317S, 4) P664L, and 5) L547V, are relatively frequent. These mutations comprised about 30% of the mutant alleles of Japanese FH. Although the frequency of each mutation is not as high as those of common mutations found in populations such as French Canadians or Afrikaaners, these frequencies reflect a sort of “founder effect” as Japanese people are mostly uniracial and Japan is geographically isolated.The natures of the LDL receptor gene mutations contributed to the clinical manifestation of FH in patients. Individuals bearing the receptor-defective type L547V mutation manifested lower plasma levels of LDL-cholesterol and had less aggressive coronary atherosclerosis than those bearing receptor-negative type mutations.
Previous epidemiological studies have reported that the serum selenium level was significantly inversely correlated with ischemic heart disease or carotid arterial atherosclerosis. In the present study, the influences of selenium deficiency were investigated in a rabbit experimental atherosclerosis model. Twenty-two New Zealand White rabbits were divided into a selenium deficient diet (<0.035ppm) group or control diet group. After the selenium levels in plasma and red blood cells decreased, each group was divided into 1.5% cholesterol loaded groups and non-loaded groups, and the four groups (control diet group, selenium deficient diet group, 1.5% cholesterol loaded group and 1.5% cholesterol loaded and selenium deficient diet group) were kept for 12 weeks. There were no significant differences in the plasma lipid levels in the cholesterol loaded groups and no significant difference in body weight in the cholesterol loaded and non-loaded groups in either the control diet groups or the selenium deficient groups. Only the plasma cholesterol level in the cholesterol non-loaded selenium deficient diet group was significantly higher than that in cholesterol non-loaded control diet group. Selenium levels and glutathione peroxidase activities in plasma and red blood cells in the selenium deficient diet groups were lower than those of control diet groups at the end of experiment, but not significantly. However, classical glutathione peroxidase (cGPx) activities in liver and kidney in the cholesterol loaded selenium deficient group and phospholipid hydroperoxide glutathione peroxidase (PH-GPx) activities in kidney in the cholesterol loaded and non-loaded selenium deficient groups were significantly lower than those of the control diet groups. In addition, the distributions of selenium between selenoprotein P, extra cellular glutathione peroxidase (eGPx) and albumin in plasma of cholesterol in the non-loaded groups were investigated using affinity columns. The ratio of eGPx was slightly lower in the selenium deficient diet group than that in the control diet group. The score of atherosclerotic lesions in the thoracic aorta in the cholesterol loaded selenium deficient diet group, obtained from the Sudan IV staining, was markedly higher than that in the cholesterol loaded control diet group (19.0±6.6% and 10.4±2.9%, respectively). In the cholesterol non-loaded group, foam cells were noted in the intima of aorta only in the selenium deficient diet group. Thus, selenium deficiency causes the progression of rabbit atherosclerosis regardless of cholesterol loading, perhaps due to the decrease in each GPx activity in plasma or tissues, or the increase in plasma cholesterol level.
Background—Understanding the precise molecular mechanisms underlying the phenomenon of restenosis after PTCA may help us to develop a new strategy for the treatment of restenosis after PTCA. The purpose of this study was to identify the genes involved in vascular restenosis. Methods and Results—Applying a differential hybridization method to a model of the balloon-injured rabbit aorta, we identified 6 cDNA clones that were upregulated after injury. Northern blot showed that 5 genes, but not apolipoprotein J (apoJ)/clusterin, were constitutively expressed in noninjured aorta and upregulated after balloon injury. ApoJ mRNA was not detectable in noninjured aorta (control), began to be expressed at 6 hours after injury, showed a peak level at 24 hours (a 48-fold increase), gradually declined, and returned to the control level at 24 weeks. Western blot and immunohistochemistry demonstrated no expression of apoJ protein in noninjured aorta, an expression of apoJ at 2 days after balloon injury, and a peak level (a 55-fold increase) at 2 to 8 weeks. The expression of apoJ protein continued until 24 weeks after injury. In situ hybridization revealed that apoJ mRNA was expressed in smooth muscle cells (SMCs) of media at 2 days after injury and in SMCs of media and neointima at 2 weeks. To analyze the function of apoJ, stably transfected rabbit SMCs were created. The expression of apoJ stimulated proliferation and migration of SMCs. Conclusions—ApoJ is dramatically induced in media and neointima after vascular injury, suggesting that apoJ contributes to restenosis after angioplasty.
Objective: Animal cells must regulate their cholesterol biosynthesis and uptake to supply sufficent amounts of cholesterol without risking overproduction. This coordination is achieved by a family of membrane-bound transcription factors called sterol regulatory element binding proteins (SREBPs). To enhance transcrtiption of genes encoding enzymes of cholesterol and fatty acid biosynthesis, the active NH2 terminal domain of SREBP is released from membranes of endoplasmic reticulum (ER) by two sequential cleavages. The first, regulated by sterols, is catalyzed Site-1 protease (S1P) that cleaves luminal loop of SREBPs. This reaction is mediated by a polytopic membrane protein called SREBP cleavage activating protein (SCAP) that complexes with SREBPs. SCAP appears to be a regulatory protein and serves as a sterol sensor. The second, not regulated by sterols, catalyzed by a hydrophobic zinc metallprotease, cleaves SREBPs within the first trans-membrane domain. Excess cholesterol block S1P activity thereby inhibits SREBP processing.A cruial component of this regulatory pathway is the Site-1 protease (S1P) that initiates sterol-regulated release from the ER by making the first cut in the SREBPs. S1P is the target of the feedback regulation, but nothing is known about the structure and properties of S1P. To identify S1P, we carried out expression cloning.Results: To clone S1P, we newly developed pCMV-PLAP-BP2, which encodes a fusion protein that contains placental alkaline phosphatase (PLAP) in the ER lumen flanked by cleavage sites for signal peptidase and S1P. In sterol deprived cells, cleavage by both proteases leads to PLAP secretion, but PLAP was not secreted in S1P deficient cells (SRD12B cells). We transfected pCMV-PLAP-BP2 plus pools of CHO cDNAs into SRD12B cells and monitored the PLAP secretion. We succeeded in identifying a cDNA that restores Site-1 cleavage. The cDNA encodes S1P; an intraluminal 1052-amino acid membrane bound subtilisin-like protease. We concluded that S1P is the sterol-regulated luminal protease that cleaves SREBPs and controls lipid metabolism in animal cells.
Rosuvastatin (Crestor) is indicated for: • Patients with primary hyperlipidemia and mixed dyslipidemias as an adjunct to diet to reduce elevated total-C, LDL-C, ApoB, nonHDL-C, and TG levels and to increase HDL-C • Patients with hypertriglyceridemia as an adjunct to diet • Patients with primary dysbetalipoproteinemia (Type III hyperlipoproteinemia) as an adjunct to diet. • Patients with homozygous familial hypercholesterolemia (HoFH) to reduce LDL-C, total-C and ApoB. • Slowing the progression of atherosclerosis as part of a treatment strategy to lower total-C and LDL-C as an adjunct to diet • Pediatric patients 10 to 17 years of age with heterozygous familia hypercholesterolemia (HeFH) to reduce elevated total-C, LDL-C, and ApoB after failing an adequate trial of dietary therapy. • Risk reduction of MI, stroke, and arterial revascularization procedures in patients without clinically evident CHD, but with multiple risk factors
