A kindred with fish eye disease, corneal opacities, marked high-density lipoprotein deficiency, and statin therapy.

A kindred affected with fish eye disease (FED) from Oklahoma is reported. Two probands with corneal opacification had mean levels of high-density lipoprotein (HDL) cholesterol (C), apolipoprotein (apo) A-I, and apoA-I in very large alpha-1 HDL particles that were 9%, 17%, and 5% of normal, whereas their parents and 1 sibling had values that were 61%, 77%, and 72% of normal. The probands had no detectable lipoprotein-X, and had mean low-density lipoprotein cholesterol (LDL-C) and triglyceride levels that were elevated. Their mean lecithin cholesterol acyltransferase (LCAT) activities, cholesterol esterification rates, and free cholesterol levels were 8%, 42%, and 258% of normal, whereas their parents and 1 sibling had values that were 55%, 49%, and 114% of normal. The defect was due to 1 common variant in the LCAT gene in exon 1: c101t causing a proline34leucine substitution and a novel mutation c1177t causing a threonine37methionine substitution, with the former variant being found in the father and 1 sibling, and the latter mutation being found in the mother, and both mutations being present in the 2 probands. FED is distinguished from familial LCAT deficiency (FLD) by the lack of anemia, splenomegaly, and renal insufficiency as well as normal or increased LDL-C. Both FLD and FED cases have marked HDL deficiency and corneal opacification, and FED cases may have premature coronary heart disease in contrast to FLD cases. Therapy, using presently available agents, in FED should be to optimize LDL-C levels, and 1 proband responded well to statin therapy. The investigational use of human recombinant LCAT as an enzyme source is ongoing.

Lipid concentrations in postmenopausal women on letrozole after 5 years of tamoxifen: an NCIC CTG MA.17 sub-study.

To evaluate changes in serum lipid parameters (cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, and lipoprotein(a) [Lp(a)]), in postmenopausal women receiving letrozole after tamoxifen therapy. MA.17L is a sub-study of MA.17, a double-blind, placebo-controlled trial of extended adjuvant letrozole. Eligible postmenopausal women were non-hyperlipidemic and not on lipid-lowering drugs. This analysis considers the 183 patients on the letrozole arm. Lipid parameters evaluated at baseline, 6 months, 12 months, and yearly thereafter until completion of 5 years of letrozole. The median duration of letrozole treatment was 5.0 years with a range from 0.03 to 6.05 years. After 5 year tamoxifen, patients on letrozole experienced significant increases from baseline in total cholesterol, LDL cholesterol, and Lp(a) at all study time points but no statistically significant changes in triglycerides. Specifically, a statistically significant increase was found at 60 months in total cholesterol [mean percentage change from baseline (PC) 5.27; p = 0.003], HDL cholesterol (mean PC 6.75; p = 0.003), LDL cholesterol (mean PC 10.02; p = 0.001), Lp(a) (mean PC 105.95; p < 0.0001). 103 (56 %) women in the study had clinically significantly elevated levels of Lp(a) (106 % above baseline) after 5 years of therapy. The results were similar after excluding the 21 % of patients who had ever received anti-lipid treatment. Significant increases in total cholesterol, HDL cholesterol, LDL cholesterol, and, most notably, Lp(a) in postmenopausal women were observed following 5 years of adjuvant letrozole treatment and after 5 years of tamoxifen therapy and such patients should have monitoring of their lipid levels in clinical practice.

Efficacy and safety of disodium ascorbyl phytostanol phosphates in men with moderate dyslipidemia.

OBJECTIVE: This study investigated the efficacy, safety, tolerability, and pharmacokinetics of a novel cholesterol absorption inhibitor, FM-VP4, comprising disodium ascorbyl sitostanol phosphate (DASP) and disodium ascorbyl campestanol phosphate (DACP). METHODS: In phase 1, 30 men received a single dose of 100, 200, 400, 800, 1,600, or 2,000 mg FM-VP4 or placebo. In phase 2, 100 men were treated with 100, 200, 400, or 800 mg/day of FM-VP4 or placebo for 4 weeks. RESULTS: The drug was well tolerated at each single or multiple dose level. After 4 weeks of treatment, low-density lipoprotein cholesterol (LDL-C) levels changed by 2.7% in the placebo group and by 2.9%, -4.2%, and -4.6% in the 100, 200, and 800 mg/day groups, respectively, which was not statistically significant. However, 400 mg/day of FM-VP4 significantly decreased LDL-C by 6.5% (p=0.02). Phase 1 showed that DACP and DASP were absorbed into plasma with a median t(max) of 12 h for both components, and clearance was slow with a mean t(1/2lambda) of 57 h. During 4 weeks of treatment, steady state was reached by approximately 8 days. CONCLUSION: This study demonstrated that up to 800 mg/day of FM-VP4 is safe and well tolerated for at least 4 weeks. Furthermore, the higher doses significantly reduced LDL-C by 7% compared with baseline or by 10% compared with placebo, with the maximum effect reached at 400 mg/day.

Structural differences between wild-type and fish eye disease mutant of lecithin:cholesterol acyltransferase.

Fluorescence spectroscopy has been used to investigate the conformational changes that occur upon binding of wild type (WT) and mutant (Thr123Ile) lecithin:cholesterol acyltransferase (LCAT) to the potential substrates (dioleoyl-phosphatidyl choline [DOPC] and high density lipoprotein [HDL]). For a detailed analysis of structural differences between WT and mutant LCAT, we performed decompositional analysis of a set of tryptophan fluorescence spectra, measured at increasing concentrations of external quenchers (acrylamide and KI). The data obtained show that Thr123Ile mutation in LCAT leads to a conformation that is likely to be more rigid (less mobile/flexible) than that of the WT protein with a redistribution of charged residues around exposed tryptophan fluorophores. We propose that the redistribution of charged residues in mutant LCAT may be a major factor responsible for the dramatically reduced activity of the enzyme with HDL and reconstituted high density lipoprotein (rHDL).

Development and characterization of liposomal disodium ascorbyl phytostanyl phosphates (FM-VP4).

The specific objectives of this project were (1) to develop liposomal disodium ascorbyl phytostanyl phosphate (FM-VP4) formulations, (2) to develop a liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) assay for quantification of FM-VP4 in liposomal formulations and plasma sample, and (3) to characterize liposomal FM-VP4 formulations by finding optimal drug-to-lipid ratios and determining the degradation of FM-VP4 in liposomes. Section 2 describes an LC/MS/MS assay developed for the identification and quantification of FM-VP4 in liposomal formulations to provide estimates of drug concentrations and encapsulation efficiency. The extra step of removing plasma proteins prior to LC/MS/MS assay yields an analysis of FM-VP4 in plasma samples. Section 3 describes experiments designed to find the optimal drug-to-lipid ratio for liposomal FM-VP4 formulations by comparing encapsulation efficiencies and varying the lipid compositions. Additionally, this section details our degradation studies to determine if liposomes have any protective effects on FM-VP4; these studies tested various lipid compositions at 37 degrees C in rabbit plasma. The mechanism of how FM-VP4 lowers low-density lipoprotein (LDL) cholesterol and total cholesterol levels in various animal models is presently unknown. However, before the mechanism of action could be studied, FM-VP4 first had to be delivered efficiently into plasma or cultured cell. The low systemic bioavailability and cellular uptake of FM-VP4 further suggested the importance of finding an efficient delivery vehicle for this drug. This project proposed a framework for such delivery and paves the way for further investigation into how FM-VP4 works in vivo and in vitro.

Peroxisome proliferator-activated receptor (PPAR)-alpha: a pharmacological target with a promising future.

Peroxisome proliferator-activated receptor (PPAR)-alpha is a ligand-activated transcriptional factor that belongs to the family of nuclear receptors. PPAR-alpha regulates the expression of genes involved in fatty acid beta-oxidation and is a major regulator of energy homeostasis. Fibrates are PPAR-alpha agonists and have been used to treat dyslipidemia for several decades because of their triglyceride (TG) lowering and high-density lipoprotein cholesterol (HDL-C) elevating effects. More recent research has demonstrated anti-inflammatory and anti-thrombotic actions of PPAR-alpha agonists in the vessel wall as well. Thus, PPAR-alpha agonists decrease the progression of atherosclerosis by modulating metabolic risk factors and by their anti-inflammatory actions on the level of the vascular wall. This is confirmed by several clinical studies, in which fibrates have shown to reduce atherosclerotic plaque formation and the event rate of coronary heart disease (CHD), especially in patients suffering from metabolic syndrome (MS). MS is characterized by a group of metabolic risk factors that include obesity, raised blood pressure, dyslipidemia, insulin resistance or glucose intolerance, and a prothrombotic state, and its incidence in the Western world is rising to epidemic proportions. This review paper will focus on the functions of PPAR-alpha in fatty acid beta-oxidation, lipid metabolism, and vascular inflammation. Furthermore, PPAR-alpha genetics, the clinical use of PPAR-alpha activators and their future perspective will be discussed.

Development of novel water-soluble phytostanol analogs: disodium ascorbyl phytostanyl phosphates (FM-VP4): preclinical pharmacology, pharmacokinetics and toxicology.

FM-VP4 is a novel inhibitor of cholesterol absorption that has lipid lowering and body weight reducing properties. In vitro and in vivo studies were performed to investigate the lipid-lowering effects, mechanism of action, pharmacokinetics, and toxicity of FM-VP4. FM-VP4 decreased cholesterol accumulation in Caco-2 cells by approximately 50%; its activity appeared to be independent of pancreatic lipase, p-glycoprotein, or cholesterol incorporation in micelles. In animal studies, FM-VP4 was added to the diet or drinking water and the following results were obtained. In gerbils 2% FM-VP4 produced mean 56 and 53% reduction in total cholesterol (TC) after 4 and 8 weeks, respectively. This reduction was entirely due to the loss of the low-density lipoprotein (LDL) pool, which was reduced to undetectable levels at either time point. At 8 weeks, high-density lipoprotein (HDL) concentration had risen by a mean of 34% whereas total triglyceride (TG) concentrations had decreased by a mean of 60%. FM-VP4 also had a profound effect on body weight in these animals. At 8 weeks, the mean body weight was in the 4% FM-VP4 treatment group 25% lower than in the control group. No hepatic or renal toxicity was associated with these changes. In Apo E-deficient mice, after 4- and 8-week treatments FM-VP4 caused a significant decrease in both TC and TG concentrations compared to controls. After 12 weeks, the areas of atherosclerotic lesion involvement in the aortic roots were decreased by a mean of 80% in the 0.5, 1, and 2% FM-VP4 treatment groups compared to controls. Taken together, these results suggest that FM-VP4 is a potential new drug with lipid-lowering and weight loss potential, without apparent toxicity.

Disodium ascorbyl phytostanyl phosphate reduces plasma cholesterol concentrations and atherosclerotic lesion formation in apolipoprotein E-deficient mice.

Disodium ascorbyl phytostanyl phosphate (FM-VP4) consists of ascorbic acid covalently bound to phytostanols by a phosphodiester linkage and is derived as the disodium salt. The purpose of this study was to evaluate the lipid-lowering and antiatherosclerotic properties of FM-VP4 following administration to apolipoprotein E (ApoE)-deficient mice. Four-week-old male C57BL/6J mice with a homozygous deletion of the ApoE gene (apolipoprotein E knock-out) were administered 0 (control), 0.1%, 0.5%, 1.0%, and 2.0% (wt/vol) FM-VP4 in their drinking water or 2.0% FM-VP4 (wt/wt) in their diet for 12 consecutive weeks. All animals received a standard mouse chow diet consisting of 9.0% (wt/wt) fat and 0.2% (wt/wt) cholesterol. Plasma cholesterol and triglyceride levels were determined at baseline and at 4-week intervals (4, 8, and 12 weeks) throughout the term of the study. At the end of the study, mice were killed using CO(2) gas, and blood was taken from the heart. The heart and aorta were removed and sections of the aortic roots were stained with oil red O (ORO) and Movat's stain. The lesions found in this area were measured using a computer-assisted image analysis. Consumption of FM-VP4 by either food or drinking water routes was associated with an approximately 75% reduction in total plasma cholesterol levels and a 75% decrease in aortic atherosclerotic lesion area in ApoE-deficient mice over 12 weeks compared to controls. A trend in decreasing plasma triglyceride levels was also observed. Taken together these data suggest that FM-VP4 has both lipid-lowering and antiatherosclerotic properties following 12-week administration to ApoE-deficient mice.

Effects of disodium ascorbyl phytostanol phosphates (FM-VP4) on cholesterol accumulation within rat intestinal cells.

The objective of this study was to determine whether FM-VP4, a novel compound derived from plant sterols, can effectively reduce cholesterol accumulation within rat intestinal epithelial crypt (IEC-6) cells. EC-6 cells were cultured in Dulbecco's minimal essential medium (DMEM) containing 5% fetal bovine serum, 100 U/mL penicillin, 100 micro g/mL streptomycin, and 0.1 units/mL insulin at 37 degrees C under a humidified 5% CO2 atmosphere and seeded at 6.4 x 10(4) cells/well in 48-well plates. Experiments were initiated 14 days postconfluence. IEC-6 cells were exposed to [3H]cholesterol micelles (containing oleic and taurcholic acids), co-incubated with FM-VP4 (0, 10, 50, and 100 micro M) in Hepes Buffered Sterile Saline (HBSS). Cells were also preincubated with FM-VP4 prior to [3H]cholesterol micelle incubation to determine whether its effects are elicited intracellularly. The cellular localization of cholesterol was determined using digitonin. To determine the effects of cholesterol on the extent of FM-VP4 accumulation within IEC-6 cells, [3H]FM-VP4 was incubated with IEC-6 cells in the presence of unlabeled cholesterol micelles (0, 10, and 50 micro M). The extent of [3H]cholesterol or [3H]FM-VP4 associated with cell monolayers was determined after cell lysis using liquid scintillation counting in a Beckman LS6500 Scintillation Counter. Dose-response and time course studies were performed in which control (no FM-VP4 treatment) and FM-VP4 (10-100 micro M) were co-incubated with 50- micro M [3H]cholesterol micelles from 1 minute to 24 hours. Incubation with only 50- micro M FM-VP4 for less than 24 hours resulted in a 50% to 60% reduction (n = 6, P <.05) in [3H]cholesterol associated with the monolayer compared with control (n = 6). Preincubation of FM-VP4 did not elicit a significant reduction in cholesterol accumulation compared with control (n = 6). Approximately 25% of the total [3H]cholesterol associated with the cells was determined to be cytosolic, while 75% was noncytosolic in the presence and/or absence of FM-VP4. [3H]FM-VP4 was also shown to associate with IEC-6 cells at similar concentrations to cholesterol with the most pronounced inhibition of FM-VP4 accumulation occurring at a cholesterol concentration of 50 micro M. However, cholesterol-induced inhibition was detectable only after 1 hour of incubation. FM-VP4 inhibits cholesterol accumulation within IEC-6 cells and is most effective at equimolar concentrations with cholesterol. Our findings further suggest that the action of FM-VP4 is likely at the cell surface and not elicited intracellularly.

Influence of phytostanol phosphoryl ascorbate (FM-VP4) on insulin resistance, hyperglycemia, plasma lipid levels, and gastrointestinal absorption of exogenous cholesterol in Zucker (fa/fa) fatty and lean rats.

The purpose of this investigation was to determine the effects of Phytostanol Phosphoryl Ascorbate (FM-VP4) on insulin resistance, hyperglycemia, plasma lipid levels, body weight, and gastrointestinal absorption of exogenous cholesterol in Zucker (fa/fa) fatty and lean rats. A group of 12 age-matched male obese (n = 6) and lean (n = 6) Zucker rats were administered 250 mg/kg twice a day (as 2% FM-VP4 in drinking water) for 30 consecutive days. Fasted blood samples prior to and following treatment were taken from all rats for glucose, lipid, insulin, and leptin determination. An oral glucose tolerance test was also carried out at the end of the treatment protocol. In addition, male obese (n = 7) and lean (n = 8) Zucker rats were coadministered a single oral gavage of [(3)H]cholesterol plus cold cholesterol with or without FM-VP4 (20 mg/kg) dissolved in Intralipid and the plasma concentration of the radiolabel was determined 10 h following the dose. FM-VP4 30-day treatment did not alter body weight, morning glucose, insulin, lipids, and leptin concentrations. There was no alteration in glucose tolerance in the nondiabetic, normoglycemic lean group; however, there was a highly significant improvement in glucose tolerance in the fatty group following FM-VP4 treatment. In addition, the insulin response to oral glucose showed no significant change in nondiabetic lean rats, whereas there was a change in the insulin secretory profile in the fatty group following FM-VP4 treatment. Furthermore, following a single oral gavage of FM-VP4 resulted in a significant decrease in the percentage of radiolabeled cholesterol absorbed. These findings suggest that FM-VP4 treatment to fatty Zucker rats could result in increased glucose responsiveness of the insulin secreting pancreatic beta cells. Furthermore, our findings suggest that FM-VP4 may only be effective presystemically. Systemic administration of FM-VP4 is warranted to determine the therapeutic potential of this effect.

Comparison of cholesterol-lowering efficacy and anti-atherogenic properties of hydrogenated versus non-hydrogenated (Phytrol) tall oil-derived phytosterols in apo E-deficient mice.

The cholesterol-lowering and anti-atherogenic effects of non-hydrogenated (FCP-3P1 containing 69% beta-sitosterol, 16% sitostanol, and 13% campesterol) and hydrogenated (FCP-3P2 containing 77% sitostanol, 11% campestanol, and 8% beta-sitosterol) Phytrol trade mark have been compared in apo E-deficient mice. After consumption of 0.2% (w/w) cholesterol-enriched diet, the elevated plasma cholesterol levels observed in controls was significantly reduced by the addition of either 0.5%, 1% or 2% FCP-3P1 or FCP-3P2 at week 4. Compared to controls, the treatment of 0.5%, 1%, and 2% FCP-3P1 in the diet resulted in reduction in cholesterol concentrations by 33.6%, 46.8% and 52.4% at week 8, respectively, whereas the reduction in plasma cholesterol levels by 0.5%, 1%, and 2% FCP-3P2 was only 20.5%, 38.7% and 31.7% indicating lower cholesterol-lowering effect of the hydrogenated phytosterols at all doses as compared with non-hydrogenated phytosterols (FCP-3P1). By contrast, FCP-3P1 and FCP-3P2 showed comparable non-significant anti-atherogenic properties in treated animals after 14-week treatment. 0.5%, 1%, and 2% FCP-3P1 treated apo E-deficient mice had a mean aortic lesion area that was smaller than controls although the reduction of atherosclerotic lesions did not reach the statistical significance. In conclusion, this study did not show statistically significant differences between hydrogenated and non-hydrogenated plant sterols with regard to their cholesterol-lowering and anti-atherosclerotic properties in apo E-KO mice.

A randomized controlled trial of an extensive lifestyle management intervention (ELMI) following cardiac rehabilitation: study design and baseline data.

BACKGROUND: Cardiac rehabilitation programs (CRP) represent comprehensive interventions that are typically limited to four months. Following completion of CRP, it appears that risk factors and lifestyle behaviours may deteriorate. The Extensive Lifestyle Management Intervention (ELMI) Following Cardiac Rehabilitation trial will investigate the benefits of a randomized intervention to prevent these adverse changes. METHODS: Patients with ischemic heart disease (IHD) were randomized following a standard CRP to the ELMI or to usual care. The ELMI program is a case-managed intervention aimed at individualizing risk factor and lifestyle management based on current treatment guidelines. The program consists of cardiac rehabilitation sessions, telephone follow-up and risk factor and lifestyle counselling sessions. Health professionals work with participants using behavioural counselling and communications with participants' family physicians. Usual care participants return to their family physicians' care, and come to the study clinic only to undergo annual outcomes assessment. The primary outcome is change in IHD global risk after four years. Secondary outcomes include combined cardiovascular events, health care utilization, lifestyle adherence, quality of life and risk factors. RESULTS: Over 28 months, 302 men and women were randomized. This represented 29% of the total population screened. The average age of study participants is 64 years, 18% are women, 53% have had a previous myocardial infarction, 73% have undergone previous revascularization and 20% have diabetes mellitus. Ischemic heart disease risk factors for the entire cohort improved significantly after subjects had gone through previous CRPs. Baseline risk factors, lifestyle behaviours and medications were similar between the groups. CONCLUSIONS: This study population is representative of patients completing a standard CRP. Results of the ELMI trial will provide valuable information for the future design of CRPs.

Effect of cyclosporine A on the binding affinity and internalization of low-density lipoproteins in human skin fibroblasts.

The aim of this study was to elucidate the possible causes of elevated low-density lipoprotein (LDL)-cholesterol levels in patients with transplants who were treated with the immunosuppressant drug cyclosporine A (CSA). The binding and internalization of (125)I-LDL in the presence or absence of CSA at varying concentrations (5-15 microg/mL) within human skin fibroblasts were determined. In addition, the effect of LDL-associated CSA on the binding of LDL to its receptor was determined. CSA decreases LDL internalization without altering the extent and affinity of its binding to the LDL receptor. CSA did not alter the number of available LDL binding sites. Furthermore, the association of CSA with LDL did not affect the binding affinity of LDL to its receptor, suggesting that this binding may not be a mechanism by which CSA affects the subsequent clearance of LDL from the bloodstream. These findings suggest that CSA may cause an increase in plasma LDL-cholesterol in patients with transplants, thereby inhibiting LDL particle internalization without altering LDL receptor binding.

Influence of phytostanol phosphoryl ascorbate, FM-VP4, on pancreatic lipase activity and cholesterol accumulation within Caco-2 cells.

PURPOSE: The objective of this study was to determine how a novel hydrophilic phytostanol (FM-VP4) affects the cellular accumulation of [3H]cholesterol in human colon carcinoma (Caco-2) cell monolayers grown in Transwell chambers. METHODS: To determine cellular accumulation of cholesterol and FM-VP4, [3H]cholesterol- containing micelles (50 microM cholesterol containing 1.27x10 (-4)% [3H]cholesterol) or [3H]FM-VP4 (50 microM) was incubated on the apical side of differentiated Caco-2 cell monolayers for 1 to 4 h at 37 degrees C in the absence or presence of increasing concentrations (10-200 microM) of unlabeled FM-VP4 or cholesterol, respectively. RESULTS: The accumulation of [3H]cholesterol (presented in micelles) into Caco-2 cell monolayers in the presence of 50 microM FM-VP4 was significantly lower (33.7 +/- 7.0%) compared to control (59.8 +/- 5.2%, p<0.05) following 4 h of incubation. Conversely, cholesterol inhibited the accumulation of [3H]FM-VP4, although to a lesser extent, suggesting competition for binding sites. The inhibitory effects of FM-VP4 and cholesterol on each other were detectable after 1 h of incubation and increased with time. The extent of FM-VP4 inhibition of [3H]cholesterol accumulation was consistent whether FM-VP4 was co-incorporated into micelles or added separately in solution, suggesting that FM-VP4 does not elicit its effects through inhibition of cholesterol incorporation into micelles. In addition, pancreatic lipase activity ([3H]triolein hydrolysis) and p-glycoprotein (rhodamine 123 fluorescence) activity, were not affected by FM-VP4. CONCLUSIONS: In conclusion, FM-VP4 rapidly inhibits cholesterol accumulation within Caco-2 cell monolayers in a mode independent of pancreatic lipase activity, p-glycoprotein activity or cholesterol incorporation in micelles.