Posters IO. Intracellular Lipid Trials (MTP/Drugs afseingj
a6 w
LYSOSOMAL ENZYMES RELEASED FROM MACROPHAGES CAN MODIFY LDL IN VITRO AND ARE PRESENT EXTRACELLULARLY IN HUMAN ATHEROSCLEROTIC LESIONS
M.O. Pentikainen, J.K. Hakala, R. Oksjoki, P Lame, PT. Kovanen. Whuri Research Institute, Kalliolinnantie 4, FIN-00140 Helsinki, Finland In addition to oxidation, hydrolytic modifications of LDL have been suggested to contribute to LDL modification in the arterial intima. Here we provide evidence that lysosomal hydrolases released from macrophages during phagocytosis could be a factor modifying LDL. Immunohistochemical analysis of early and advanced human coronary atherosclerotic lesions revealed staining for lysosomal acid lipase and cathepsin D both in macrophages and in the extracellular matrix, in vitro experiments showed that human monocyte-derived macrophages in culture secreted catalytically active cathepsin D and lysosomal acid lipase into the medium when phagocytosis was stimulated with opsonized zymosan. LDL incubated in such macrophage-conditioned medium underwent proteolytic degradation and hydrolysis of cholesteryl esters and triglycerides. Cultured macrophages and smooth muscle cells avidly took up the hydrolase-modified LDL and foam cells were formed. Taken together, the present results suggest that macrophage-derived acid hydrolases are involved in LDL modification and in foam cell formation in the arterial intima. m
Lipid ‘Ikials (MTPiDrugs
affecting)
HOMEOSTASIS IS CONTROLLED BY PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA IN HUMAN MACROPHAGES
Elevation in plasma lipoprotein (a) [Lp(a)] has been considered as an independent risk factor for coronary artery disease, however prospective and epidemiological studies have reported contlicting results. We have previously shown that Lp(a) is enriched in a phospholipase Aa, named platelet activating factor acetylhydrolase (PAF-AH). Thus, a functional characteristic of Lp(a), which has not been adequately studied yet, is its capability to hydrolyze and inactivate platelet activating factor (PAF) and oxidized phospholipids, molecules that exert potent pro-mflammatory and pro-atherogenic activities. The PAF-AH activity on Lp(a) purified by aflinity chromatography in comparison with enzyme activity on LDL isolated by ultracentrifugation was studied in 94 patients (72 males, mean age 61.5 years) with a history of an acute coronary syndrome (ACS) and in 33 age- and gender-matched normal subjects without evidence of coronary artery disease (NS). Plasma Lp(a) levels and ape(a) isoform size expressed as number of K4 repeats were also determined. The median (range) plasma Lp(a) levels were significantly elevated in ACS compared to NS [lg.9 (0.8-84.1) mg/dl vs 8.1 (0.8-55.0) mg/dl, P < 0.011. The percentage of low molecular weight ape(a) isoforms (<26K4) in ACS was higher compared to NS (65.9% vs 34.5%, P < 0.005). The specific activity of Lp(a)-PAF-AH in ACS was significantly lower than in NS (4.3f0.7 nmol/mg lipoprotein maas/min vs 13.gf0.2, respectively, p < 0.0001). There was no difference in the specific activity of LDL-PAF-AH between the two groups. The low PAF-AH activity on Lp(a), unlike the LDL-associated enzyme, is a feature characteristic of Lp(a) in ACS and confers this lipoprotein with a diminished anti-inflammatory potency that may be an additional, to the high plasma Lp(a) levels, contributing factor in the pathogenesis of ACS. PLATELETS ACTIVATED PAF-ACETYLHYDROLASE MICROPARTICLES
10. Intracellular IP162 CHOLESTEROL
REDUCED PAF-ACETYLHYDROLASE ACTMTY ON Lp(a) IN PATIENTS WITH ACUTE CORONARY SYNDROMES
L.D. Tsironis’, C.S. Katsouras*, J.A. Goudevenos*, L.K. Michalis2, M. Elis&, D.A. Sideris*, A.D. Tselepis’.‘Department of Chemistry; Departments of 2Cardiologv; ‘Internal Medicine, Medical School, University of Ioannina, 45110 loannina, Greece
w
also induces the shedding of platelet microparticles (PMPs). We investigated the possible existence of PAF-AH in PMPs and whether the mechanism of PMPs shedding is associated with that of PAF-AH secretion. Washed human platelets were activated with 0.5LVml of thrombin at 37°C under continuous stirring for up to 60 minutes. PMP generation was studied by flow cytometry using monoclonal antibodies (CD4la and CD61) whereas PAFAH activity was determined by the trichloroacetic acid precipitation method. The platelet-free supernatant underwent ultracentrifugation at 100,000 x g for 120 min at 4°C to sediment the PMPs. There was a steady increase in PMP generation and PAF-AH secretion during platelet activation, reaching a mean value of 16.5 x lo6 PMPs/mJ and a mean PAF-AH activity of 1.42 mnol/ml/hour, at 60 min of activation. The total enzyme activity in the supernatant of aggregated platelets was associated with PMPs and co precipitated by ultracentrifugation. Interestingly, PMPs were enriched in PAF-AH activity compared to platelets (lO.Of2.0 mnol/mg of protein/hour in PMPs vs. 4.950.3 mnol/mg of protein/hour for platelets, P < 0.01, n = 4). This is the tirst study showing that thrombin-activated platelets secrete PAF-AH through platelet-derived microparticles. Thus PMPs may represent an alternative to the lipoprotein delivery system for PAF-AH to sites of inflammation and atherogenesis.
S. Lestavel, G. Chinetti, R. Barbeau, J.C. Fruchart, \! Clavey, B. Staels. INSERM lJ325, Institut Pasteur de Lille. Universite de Lille 2. I rue du Pr Calmette, 59019 Lille, Fmnce
Macrophages are key players in several chronic inflammatory diseases, including atherosclerosis. Fatty streaks contain large numbers of lipid-laden macrophages (foam cells) derived from circulating monocytes that adhere to activated endothelium and migrate into the arterial wall. Peroxisome Proliferator-Activated Receptor alpha (PPARa) is a ligand-activated transcription factor which controls the fi-oxidative degradation of fatty acids. Given the patho-physiological impact of cellular lipid accumulation on atherosclerosis development, the goal of the study was to investigate the role of PPARa on cholesterol homeostasis and foam cell formation of primary human macrophages. Human monocyte-derived macrophages were cholesterol-loaded with acetylated LDL in presence or not of a synthetic PPARa ligand (Wy14643). We determined the macrophages cholesterol content and the rate of cholesteryl ester formation within the cells by measuring the rate of incorporation of t4C-oleate into cholesteryl esters. Here we show that PPARa activation does not intluence acetylated LDLinduced foam cell formation of primary human macrophages. Moreover, treatment with Wy14643 led to a decrease in cholesteryl ester content. Wy14643 reduced oleate incorporation into the cholesteryl ester fraction, an effect which suggests the inhibition of the ACAT enzymatic activity. In addition to their effects on the stimulation of the apoAI-induced cholesterol removal by the ABCAl pathway, action of PPARa activators on the reduction of cholesteryl ester storage in loaded macrophages may contribute to their effects on regression of coronary atherosclerosis.
IP163
BY THROMBIN SECRETE IN THE FORM OF
J.V. Mitsios’, J. Goudevenos*, M. Elisaf3, A.D. Tselepis’ Laboratory of BiochemiWy; ‘Departinent of Chemistry; 2Department of Cardiology 3Department of Internal Medicine, Medical School, University of loannina, 45 1IO loannina, Greece Platelet Activating Factor (PAF)-acetylhydrolase (PAF-AH) is a phospholipase A2 which preferentially degrades and inactivates PAF and oxidized phospholipids, molecules that play crucial roles in inflammation and atherogenesis. PAF-AH circulates in plasma complexed to lipoproteins and also exists in the platelet cytosol. Platelet activation with thrombin results in PAFAH secretion by a yet unknown mechanism. Platelet activation with thrombin
EFFECT OF ATORVASTATIN ON SERUM LIPID PROFILE AND HMGCoA REDUCTASE GENE EXPRESSION IN PERIPHERAL BLOOD MONONUCLEAR CELLS IN SUBJECTS WITH HETEROZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA
L.A. Salazar1*3,M.H. Hiram’, N. Forti*, J. Diamens, SD. Giantrim*, R.D.C. Hirata'. ‘Faculty of Pharmaceutical Sciences; 2Heart Institute (InCor), Universify of Sao Paula, Sao Paulo, SP, Bra&; ‘Faculty of Medicine, lJnivers& of La Frontera, Temuco, Chile The enzyme 3-hydroxy-3-methylghttaryl coenzyme A (HMG-CoA) reductase plays an important role in cholesterol synthesis. Inhibitors of the HMG-CoA reductase (statins) are know to reduce low-density lipoprotein (LDL) cholesterol and cardiovascular mortality in patients with Familial Hypercholesterolemia (FH). The present study evaluated the intluence of Atorvaatatin on serum lipid levels and HMG-CoA reductase mRNA expression in subjects with heterozygous FH. Twenty-five unrelated patients (5 men and 20 women) with elevated total and LDL-cholesterol levels; aged
72nd EAS Congress
Posters 11. Lipid Lowering Drugs~Novel 554-19 yr. participated in our 4-week study. Patients with secondary forms of dyslipidemia and those with diabetes mellitus, hypothyroidism or obesity were excluded. Other lipid lowering medications were discontinued for at least 1 month before the study. Subsequently, FH patients were treated with 10 mg of Atorvastatin per day. Blood samples were collected at weeks 0 (baseline) and 4. Serum muscle (CK), liver (ALT, AST, g-GT) enzymes, and lipid profile (TC, LDL-C, triglyeerides, HDL-C, Apo A1, Apo B) were determined. Whole blood was obtained to evaluate HMG-CoA reductase gene expression in peripheral blood mononuclear cells (PBMC) by RTPCR assay. Atorvastatin, at week 4, significantly reduced TC, LDL-C and ApoB levels from baseline (by -25%, -31%, and -21%, respectively, P < 0.01) in 19 patients (Responders, RE). On the other hand, 6 patients presented less than 15% of reduction on LDL-C levels (No responders group, NR). Our data also showed that Atorvastatin increased significantly the HMG-CoA reductase mRNA expression in RE patients when compared to baseline levels (P < 0.0001). Besides that, NR patients showed lower HMG-CoA reductase mRNA expression when compared to RE at week 0 and 4 (P < 0.0001). This study shows an important association between the lipid-lowering response to Atorvastatin and HMG-CoA reductase mRNA expression in PBMC in subjects with FH from Brazil. Therefore, these data support the possibility that the differences on lipid-lowering response to Atorvastatin in these patients may be associated to variations on HMG-CoA reductase gene expression. Financial Support: FAPESP-Brazil
11. Lipid Lowering Drugs/Novel ~-~
ROSUVASTATIN IS M O R E E F F E C T I V E THAN PRAVASTATIN O R SIMAVASTATIN AT IMPROVING T H E LIPID PROFILES OF H Y P E R C H O L E S T E R O L A E M I C PATIENTS
R. Paoletti 1, M. Fahmy, G. Mahla, R. Caplan, A. Raza. 1Department of Pharmacological Sciences, University of Milan, Milan, Italy Many patients fail to reach target LDL-C levels despite the availability of several HMG-CoA reductase inhibitors (statins). Rosuvastatin (ROS) is a new statin that has show reductions in LDL-C levels of up to 65% in a dose-ranging programme. This randomised, double-blind, parallelgroup, multicentre trial (Trial 4522IL/0027) compared the efficacy of ROS with pravastatin (PRA) and simvastatin (SIM) in reducing LDL-C and in achieving a target LDL-C goal (<3 mmol/L). (1) Entry criteria were age ~> 18 yrs; fasting LDL-C ~> 4.14 and <6.50 mmol/L; and fasting triglycerides < 4.52 mmol/L. After a 6-wk dietary lead-in, 502 patients were randomised to receive once-daily ROS 5 mg (n = 120) or 10 m g (n = 115), PRA 20 mg (n = 137), or SIM 20 mg (n = 130) for 12 wks. At all time points, ROS 5 and 10 mg were statistically significantly better than either PRA 20 mg or SIM 20 mg in reducing LDL-C [Table]. More patients treated with ROS met the LDL-C goal compared with PRA and SIM; for high-risk patients, this trend was similar [Table]. Patients receiving ROS 5 or 10 mg also had significantly greater reductions in total cholesterol and apolipoprotein B levels (p < 0.05) and significantly greater improvements in lipid ratios (p ~< 0.01). ROS was well tolerated at both doses and the occurrence of adverse events was similar among all treatment groups. In summary, ROS 5 and 10 mg were more effective than PRA 20 mg and SIM 20 mg at improving the lipid profiles of hypercholesterolaemic patients, and more patients, especially high-risk patients, achieved their target LDL-C goal with either dose of ROS than with PRA or SIM.
% Patients achieving
% Changefrombaselinein LDL-Clevels(ANOVA) Wk 2 Wk 6 Wk 10
Wk 12
LDL-Cgoal at Wk 12 Overall High risk*
ROS 5mg 391 ROS 10mg -431 PRA20 mg -25 SIM20mg -34
~123 491 -28 -37
63 83 20 50
-432 -481 -27 -39
-423 -471 -29 -38
62 80 18 50
lp < 0.001 vs. PRA, SIM; 2p < 0.001 vs. PRA,p < 0.05 vs. SIM; 3p < 0.00l vs. PRA,p < 0.005 vs. SIM; *High-risk:patientswith'a 10-yrCHD risk > 20% or inclusionin a high-riskpatient population(eg, heterozygousfamilialhypercholesterolaemia,diabetesmellitus). References
[1] 2"d Joint Task Force of European and other Societies on Coronary Prevention. Eur Heart d 1998; 19: 1434-503.
~-~
87
EFFICACY AND SAFETY OF ATORVASTATIN VERSUS SIMVASTATIN IN MIXED DYSLIPIDEMIC PATIENTS W I T H AND W I T H O U T TYPE 2 DIABETES DURING 54 W E E K S
W. Insull 1, S. Kafonek2, D.B. Goldner 3, E Zieve4. For the ASSET Investigators; 1Baylor College of Medicine, Houston, TX; 2Pfizer Inc., New York; 3Heart Care Group, Allentown, PA," 4Hunter Homes McGuire VA Medical Center, Richmond, VA, USA This 54-week, open-label randomized trial compared the efficacy and safety of atorvastatin with simvastatin in mixed dyslipidemic patients with and without type 2 diabetes. Following a 4-week dietary lead-in phase, 1424 patients with mixed dyslipidemia (triglyceride 21)0-600 mg/dL [2.26--6:77 mmol/L]) were randomized to receive once-daily doses of either atorvastatin 10 m g (n = 730) or simvastatin 10 mg (n = 694). After treatment for 6, 12 and 18 weeks, doses were doubled in patients not meeting their National Cholesterol Education Program (NCEP) LDL-C treatment goal to a maximum of atorvastatin 80 mg/day and simvastatin 40 mg/day. Patients were followed for 54 weeks. The primary efficacy parameters were the percent change in LDLC from baseline, and the overall percent of patients achieving (NCEP) goals. After 6 weeks, atorvastatin produced significantly greater (p < 0.0001) reductions from baseline than simvastatin in LDL-C (37.2% vs 29.6%), total C (27.6% vs 21.5%), triglyceride (22.1% vs 16.0%), LDL-C/HDLC (41.1% vs 33.7%) and apo B (28.3% vs 21.2%). After treatment for 54 weeks, atorvastatin maintained significantly greater reductions in all these lipid parameters compared with simvastatin (all P < 0.001). Atorvastatin and simvastatin produced increases in HDL-C from baseline at Week 6 (7.4% versus 6.9%) and at Week 54 (5.9% versus 8.5%). The overall percent of patients reaching the LDL-C goal after 54 weeks of treatment was 73.3% for atorvastatin-treated patients compared with 57.3% for simvastatin-treated patients (P < 0.0001). When the percent of patients reaching their NCEP LDL-C goal was analysed by baseline CHD risk category, more atorvastatin-treated patients in each risk group reached their goal than did patients receiving simvastatin, at both Week 6 and Week 54. Subgroup analyses at 6 weeks and 54 weeks revealed that the significantly greater LDL-C-lowering efficacy of atorvastatin versus simvastatin was observed both in patients with and without type 2 diabetes. No clinically important changes in primary safety parameters nor group differences in treatment-related adverse events occurred. Glycemic control was unaltered. Atorvastatin, at its starting dose of 10 mg/day, is significantly more effective than simvastatin 10 mg/day at lowering LDL-C and treating to NCEP goals, in mixed dyslipidemia patients with and without diabetes.
~ - ~ A
N E W STATIN, ROSUVASTATIN, PRODUCES SIGNIFICANT I M P R O V E M E N T S IN SERUM LIPIDS AND LIPID RATIOS IN PATIENTS W I T H
HYPERCHOLESTEROLAEMIA A.G. Olsson1, R.J. Caplan, J. McKellar, A. Raza~ J.S. Pears. ~Clinical Research Group; University Hospital, Link6ping, Sweden A dose-ranging programme with rosuvastatin evaluated the effects of this new statin, (ROS) on lipids and 4 lipid ratios in patients with hypercholesterolaemia. After a 6-wk dietary run-in, men (18-70 yrs) and postmenopausal women (50-79 yrs) with fasting LDL-C > 4.14 but <6.21 mmol/L and TG < 3.39 mmol/L were enrolled into a randomised, placebocontrolled, parallel-group, multicentre trial conducted in two phases. A total of 206 patients entered the trial (185 patients in per-protocol analysis). An initial 6-wk trial (4522IL/0008) assessed effects of once-daily oral doses of double-blind placebo (PLA) or ROS (1-40 mg/day) or openlabel atorvastatin (ATV; 10 or 80 nag), as a benchmark; a follow-up trial (4522IL/0023) extended the ROS dose range to 80 mg. Percentage change (% change) from baseline to wk 6 in LDL-C and other lipid parameters were analysed. All ROS doses significantly (p < 0.001 vs PLA) lowered LDL-C in a dose-dependent manner (% change, 34%-65%). Significant reductions, compared with PLA, were also observed at all ROS dose levels for all 4 lipid ratios (p < 0.001). (Table) All treatments were well tolerated. Although no statistical comparison was performed between ROS and ATV, numerically greater improvements in lipids and ratios were seen with ROS than ATe.
72nd EAS Congress