Apolipoproteins Research Papers - Academia.edu (original) (raw)

To determine the effects of anabolic steroids on serum lipid and apoprotein levels, 14 white male body builders who self-administered steroids for 2 to 3 months (steroid users) were studied; 10 agreed to screening while they were taking... more

To determine the effects of anabolic steroids on serum lipid and apoprotein levels, 14 white male body builders who self-administered steroids for 2 to 3 months (steroid users) were studied; 10 agreed to screening while they were taking the drugs (ON treatment) and also at about 3 months following their suspension (OFF treatment).

All, but no tendency to precocious atherosclerosis is present. To elucidate this paradox, the structure of HDL, the potential of serum to promote cholesterol effiux from cultured cells, and the in vivo metabolism of HDL were examined in a... more

All, but no tendency to precocious atherosclerosis is present. To elucidate this paradox, the structure of HDL, the potential of serum to promote cholesterol effiux from cultured cells, and the in vivo metabolism of HDL were examined in a 53-year-old Woman with a FED syndrome in association with a markedly decreased lecithin:cholesterol acyltransferase (LCAT) activity in HDL due to a mutation of the LCAT gene (Arglse -~ Cys). HDLs isolated by uitracentrifugation were small and enriched in unesterified cholesterol and phospholipids at the expense of cholesteryl esters and proteins, The apolipoprotein content showed an enrichment in apo E and apo AIV, whereas apo AI and apo All were dramatically reduced. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE} and immunoblotting using specific antibodies showed that the apo E was free or covalently bound to apo All. These particles analyzed by electron microscopy were small and round lipoproteins with a size similar to the smallest fraction of normal HDL3. The potential capacity of the serum to promote efflux from the cells was approximately 40% of control serum levels, but FED HDLs were as efficient as control HDLs in promoting cholesterol efflux from cells. To assess the metabolism of HDL apolipoproteins, in vivo apolipoprotein kinetic studies were performed using endogenous labeling techniques in the patient with FED and three control subjects. All subjects were administered D3-1abeled leucine by primed constant infusion for up to 10 hours. The fractional synthetic rates (FSRs) of apo AI and apo All in the patient were 0.674 and 0,594 per day, clearly higher than in controls, 0.210 +-0.053 and 0.148 +-0.014 per day for apo AI and apo All, respectively. Apo AI and apo All production rates in the patient with FED were normal, 11.32 and 2.62 mgJkg • d, respectively, as compared with those in normal subjects, 11.45 + 1.23 and 2.68 -+ 0.17 mg/kg • d. These data established that hypoalphalipoproteinemia in FED was caused by marked hypercatabolism of apo AI and apo All. This hypercatabolism could be the consequence of structural abnormalities due to the selective LCAT deficiency, in conclusion, two steps of reverse cholesterol transport, cholesterol efflux and apo-HDL metabolism, appeared particularly efficient. This efficiency could participate in the absence of premature atherosclerosis in FED patients as regards the low HDL level.

Background and Aims. Oxidative stress is considered an important factor in the development of diabetic complications that causes a variety of changes such as oxidative modification of membrane lipids, nucleic acids and cellular proteins.... more

Background and Aims. Oxidative stress is considered an important factor in the development of diabetic complications that causes a variety of changes such as oxidative modification of membrane lipids, nucleic acids and cellular proteins. Dyslipidemia is frequently associated with diabetes and cardiovascular disease. In this context, the objective of this study was to evaluate oxidative modifications of plasma proteins and lipids in non dyslipidemic type 2 diabetic (T2D) patients, in dyslipidemic T2D patients treated or not with simvastatin and in healthy subjects to investigate whether treatment with low doses of simvastatin plays a protective role on the lipid and protein oxidative damage in these patients. Methods. We determined oxidative damage of plasma proteins by carbonyl assay and total thiol group determination. We also characterized the membrane damage in terms of lipid peroxidation by measuring malonaldehyde (MDA) in nondyslipidemic T2D patients, dyslipidemic T2D patients treated with simvastatin (20 mg/day), dyslipidemic T2D patients not treated with simvastatin and in healthy age-matched control subjects. Results. Our results showed that dyslipidemic T2D patients not treated with simvastatin had significantly higher plasma protein carbonyl groups and MDA when compared to dyslipidemic T2D patients treated with simvastatin and control group. Thiol concentrations from dyslipidemic T2D patients not treated with simvastatin were significantly lower than treated patients and controls. It was verified that the thiols groups were inversely correlated with apolipoprotein B and positively correlated with apolipoprotein AeI. Conclusions. These results demonstrated that treatment with low doses of simvastatin can minimize the protein and lipid oxidative damage in dyslipidemic T2D patients. Ó

High-density lipoprotein (HDL) cholesterol levels are a strong inverse predictor of cardiovascular events. However, it is not clear whether this association is maintained at very low levels of low-density lipoprotein (LDL) cholesterol.

Background & aims: Epidemiological data suggest that moderate red wine consumption reduces cardiovascular mortality and the incidence of diabetes. However, whether these effects are due to ethanol or to non-alcoholic components of red... more

Background & aims: Epidemiological data suggest that moderate red wine consumption reduces cardiovascular mortality and the incidence of diabetes. However, whether these effects are due to ethanol or to non-alcoholic components of red wine still remains unknown. The aim of the present study was to compare the effects of moderate consumption of red wine, dealcoholized red wine, and gin on glucose metabolism and the lipid profile. Methods: Sixty-seven men at high cardiovascular risk were randomized in a crossover trial. After a run-in period, all received each of red wine (30 g alcohol/d), the equivalent amount of dealcoholized red wine, and gin (30 g alcohol/d) for 4 week periods, in a randomized order. Fasting plasma glucose and insulin, homeostasis model assessment of insulin resistance (HOMA-IR), plasma lipoproteins, apolipoproteins and adipokines were determined at baseline and after each intervention. Results: Fasting glucose remained constant throughout the study, while mean adjusted plasma insulin and HOMA-IR decreased after red wine and dealcoholized red wine. HDL cholesterol, Apolipoprotein A-I and A-II increased after red wine and gin. Lipoprotein(a) decreased after the red wine intervention. Conclusions: These results support a beneficial effect of the non-alcoholic fraction of red wine (mainly polyphenols) on insulin resistance, conferring greater protective effects on cardiovascular disease to red wine than other alcoholic beverages. www.isrctn.org: ISRCTN88720134. Clinical Nutrition xxx (2012) 1e7 Please cite this article in press as: Chiva-Blanch G, et al., Effects of red wine polyphenols and alcohol on glucose metabolism and the lipid profile: A randomized clinical trial, Clinical Nutrition (2012), http://dx.Please cite this article in press as: Chiva-Blanch G, et al., Effects of red wine polyphenols and alcohol on glucose metabolism and the lipid profile: A randomized clinical trial, Clinical Nutrition (2012), http://dx.

The cDNA sequence for apolipophorin-III from two strains of Bombyx mori (N4 and P50) and the Japanese and Chinese strains of Bombyx mandarina were determined. Both the cDNA and deduced amino acid sequences of the four apolipophorin-IIIs... more

The cDNA sequence for apolipophorin-III from two strains of Bombyx mori (N4 and P50) and the Japanese and Chinese strains of Bombyx mandarina were determined. Both the cDNA and deduced amino acid sequences of the four apolipophorin-IIIs were highly similar (95-98%). The four Bombyx sequences also showed significant similarity to the sequence of apolipophorin-III from another lepidopteran, Manduca sexta (83-84%), particularly in the five amphipathic a-helices that are proposed to play a critical role in the binding of apolipophorin-III to lipophorin. In the coding region, the nucleotide sequences for the Chinese strain of B. mandarina and the P50 strain of B. mori were identical, supporting the suggestion that P50 is the current strain most closely related to the original domesticated strain. The N4 strain of B. mori is more closely related to these two strains than is the Japanese strain of B. mandarina, suggesting that Japanese strain of B. mandarina separated from the Chinese strain of B. mandarina before domestication of B. mori. Arch.

Our purpose is to review recent findings highlighting the metabolic and functional diversity of HDL subspecies. Recent findings HDL heterogeneity -both structural and functional -is the main focus of this review. Recent work indicates... more

Our purpose is to review recent findings highlighting the metabolic and functional diversity of HDL subspecies. Recent findings HDL heterogeneity -both structural and functional -is the main focus of this review. Recent work indicates that the metabolism and functionality of HDL particles differ greatly among HDL subspecies. With the introduction of new and improved methodology (e.g., proteomics), new aspects of the structural complexity and functionality of HDL have been revealed. It has been confirmed that HDL functionsincluding, but not limited to decreasing inflammation, apoptosis, macrophage adhesion to the endothelium and insulin resistance -are due to HDL's ability to remove cholesterol from cells (reverse cholesterol transport). A new level of HDL complexity has recently been revealed by investigating the lipid composition of HDL with gas chromatography, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. There are about 100 different HDL-associated proteins; however, there are many more lipid species potentially associated with HDL particles.

High density lipoprotein (HDL) has many properties, which contribute to its atheroprotective role. However, some recent clinical trials have identified subjects with the progression of atherosclerosis despite normal levels of HDL... more

High density lipoprotein (HDL) has many properties, which contribute to its atheroprotective role. However, some recent clinical trials have identified subjects with the progression of atherosclerosis despite normal levels of HDL cholesterol. This raises the question if all subfractions of HDL have the same properties. Moreover, recent investigations have shown that both acute and chronic inflammation may lead to structural and functional changes of HDL, which render the particles proinflammatory. Although therapeutic agents that increase HDL levels are now quite well established it is not clear whether they influence HDL quality.

The inverse relationship between plasma levels of high-density lipoprotein (HDL) and cardiovascular disease has been extensively described . However, several lines of evidence have indicated that HDL functionality can be impaired under... more

The inverse relationship between plasma levels of high-density lipoprotein (HDL) and cardiovascular disease has been extensively described . However, several lines of evidence have indicated that HDL functionality can be impaired under pathological conditions , suggesting that the assessment of HDL function might be more relevant than that of HDL-cholesterol (HDL-C) plasma levels.

Background and aim: Most but not all studies in children, adolescents and young adults with a family history of coronary artery disease have reported an increase in lipoprotein(a) (Lp(a)) concentrations. The aim of this study was to... more

Background and aim: Most but not all studies in children, adolescents and young adults with a family history of coronary artery disease have reported an increase in lipoprotein(a) (Lp(a)) concentrations. The aim of this study was to assess if healthy children, adolescents and young adults with a parental history of premature myocardial infarction (PHPMI) have increased Lp(a) levels and are at higher risk of elevated (>30 mg/dl) Lp(a) concentrations. Methods and results: One hundred fifty healthy children, adolescents and young adults with PHPMI (55% males; age 18 AE 6.7 years) and 150 age-(AE1 year) and gender-matched control subjects participated in the study. Concentrations of total plasma cholesterol, low-density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)-cholesterol, apolipoprotein (Apo) A-I and B, triglycerides and Lp(a) were determined after fasting for 14 h. Participants with PHPMI had higher concentrations of LDL-cholesterol (107.9 AE 31.1 vs. 99.2 AE 28.7 mg/dl, p Z 0.01), Apo B (89.6 AE 26.4 vs. 82.8 AE 20.2 mg/dl, p Z 0.011) and Lp(a) (26.7 AE 34.0 vs. 19.2 AE 23.2 mg/dl, p Z 0.012) and lower HDL-cholesterol concentrations (47.9 AE 11.3 vs. 50.7 AE 13.9 mg/dl, p Z 0.038) than participants without PHPMI. Thirty percent of PHPMI positive subjects had elevated Lp(a) concentrations vs. 16.7% of PHPMI negative subjects (p Z 0.009; relative risk 2.14; 95% CI 1.23e3.73). In a conditional logistic regression analysis, Lp(a) concentration was significantly and independently associated with PHPMI. a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / n m c d Nutrition, Metabolism & Cardiovascular Diseases (2008) 18, 492e496

Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this Study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative... more

Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this Study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative modification. On the basis of repeated coronary angi0graphy, 28 coronary bypass patients were divided into two groups: group A, 12 patients with i and group B, 16 patients without progression of coronary atheroselerosis. The lag time, reflecting the resistance of LDL to oxidative modification, was significantly smaller in group A asl compared with group B (81 4-10 and 93 4-15 rain, respectively). Besides differences in cholesterol and apolipoprotein B concentrations, the difference in susceptibility of LDL to oxidation significantly contributes to the differences between the progression and the nonprogression group (P = 0.02). In the combined groups of patients, the lag phase of LDL for oxidation was positively correlated with LDL cholesterol ester to protein ratio (r = 0.53, P = 0.01). It is concluded that LDL samples obtained from coronary bypass patients differ with respect to their oxidizability depending on progression of atherosclerosis following coronary bypass surgery.

The risk of coronary heart disease (CHD) is lower in women than in men, but increases in women after menopause. Some of the gender, age, and menopausal-related differences in CHD risk may relate to differences in lipoprotein subspecies.... more

The risk of coronary heart disease (CHD) is lower in women than in men, but increases in women after menopause. Some of the gender, age, and menopausal-related differences in CHD risk may relate to differences in lipoprotein subspecies. We therefore examined these subspecies in three groups of healthy subjects: premenopausal women (W, n = 72, mean age 41.2 f 6.5), postmenopausal women (PMW, n = 74,55.8 k 7.4), and men (M, n = 139,48.8 k 10.

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. Decrease of the LPL enzymatic activity leads to elevated triglycerides (TG) and reduced high-density lipoprotein (HDL-C levels), both risk factors for cardiovascular disease... more

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. Decrease of the LPL enzymatic activity leads to elevated triglycerides (TG) and reduced high-density lipoprotein (HDL-C levels), both risk factors for cardiovascular disease (CVD). Therefore, mutations, which decrease the LPL activity, may confer susceptibility to CVD. Here, the informational spectrum method (ISM), a virtual spectroscopy method for structure/function analysis of nucleotide and protein sequences, is applied for identification of evolutionary highly conserved information encoded by the primary structure of LPL. It was demonstrated that mutations, which alter the LPL enzymatic activity also alter this information. On the basis of this finding, an efficient and simple bioinformatics criterion for assessment of the pathogenic effect of LPL nonsynonymous single nucleotide substitution as a risk factor of CVD has been proposed. Proteins 2008. © 2007 Wiley-Liss, Inc.

Apolipoprotein L1 (APOL1) is a major component of the human innate immune response against African trypanosomes. Although the mechanism of the trypanolytic activity of circulating APOL1 has been recently clarified, the intracellular... more

Apolipoprotein L1 (APOL1) is a major component of the human innate immune response against African trypanosomes. Although the mechanism of the trypanolytic activity of circulating APOL1 has been recently clarified, the intracellular function(s) of APOL1 in human cells remains poorly defined. Like that of many genes linked to host immunity, APOL1 expression is induced by proinflammatory cytokines gamma interferon (IFN-␥) and tumor necrosis factor alpha (TNF-␣). Additionally, IFN-␥-polarized macrophages that potently restrict HIV-1 replication express APOL1, which suggests that APOL1 may contribute to HIV-1 suppression. Here, we report that APOL1 inhibits HIV-1 replication by multiple mechanisms. We found that APOL1 protein targeted HIV-1 Gag for degradation by the endolysosomal pathway. Interestingly, we found that APOL1 stimulated both endocytosis and lysosomal biogenesis by promoting nuclear localization of transcription factor EB (TFEB) and expression of TFEB target genes. Moreover, we demonstrated that APOL1 depletes cellular viral accessory protein Vif, which counteracts the host restriction factor APOBEC3G, via a pathway involving degradation of Vif in lysosomes and by secretion of Vif in microvesicles. As a result of Vif depletion by APOL1, APOBEC3G was not degraded and reduced infectivity of progeny virions. In support of this model, we also showed that endogenous expression of APOL1 in differentiated U937 monocytic cells stimulated with IFN-␥ resulted in a reduced production of virus particles. This finding supports the hypothesis that induction of APOL1 contributes to HIV-1 suppression in differentiated monocytes. Deciphering the precise mechanism of APOL1-mediated HIV-1 restriction may facilitate the design of unique therapeutics to target HIV-1 replication.

Background: The lipid-modulatory effects of high intakes of the fish-oil fatty acids eicosapentaenoic acid (EPA) and docosahexae- noic acid (DHA) are well established and likely to contribute to cardioprotective benefits.... more

Background: The lipid-modulatory effects of high intakes of the fish-oil fatty acids eicosapentaenoic acid (EPA) and docosahexae- noic acid (DHA) are well established and likely to contribute to cardioprotective benefits. Objectives:WeaimedtodeterminetheeffectofmoderateEPAand DHA intakes (2 g EPADHA/d) on the plasma fatty acid profile, lipid and apolipoprotein concentrations, lipoprotein subclass distri- bution, and markers of oxidative status. We also aimed to examine

Exchangeable apolipoproteins have been the subject of intense biomedical investigation for decades. However, only in recent years the elucidation of the three-dimensional structure reported for several members of the apolipoprotein family... more

Exchangeable apolipoproteins have been the subject of intense biomedical investigation for decades. However, only in recent years the elucidation of the three-dimensional structure reported for several members of the apolipoprotein family has provided insights into their functions at a molecular level for the first time. Moreover, the role of exchangeable apolipoproteins in several cellular events distinct from lipid metabolism has recently been described. This review summarizes these contributions, which have not only allowed the identification of the apolipoprotein domains that determine substrate binding specificity and/or affinity but also the plausible molecular mechanism(s) involved. r

High-density lipoprotein (HDL) is a lipid and protein complex that consists of apolipoproteins and lower level HDL-associated enzymes. HDL dysfunction is a factor in atherosclerosis and decreases patient survival. Mass spectrometry- (MS-)... more

High-density lipoprotein (HDL) is a lipid and protein complex that consists of apolipoproteins and lower level HDL-associated enzymes. HDL dysfunction is a factor in atherosclerosis and decreases patient survival. Mass spectrometry- (MS-) based proteomics provides a high throughput approach for analyzing the composition and modifications of complex HDL proteins in diseases. HDL can be separated according to size, surface charge, electronegativity, or apoprotein composition. MS-based proteomics on subfractionated HDL then allows investigation of lipoprotein roles in diseases. Herein, we review recent developments in MS-based quantitative proteomic techniques, HDL proteomics and lipoprotein modifications in diseases, and HDL subfractionation studies. We also discuss future directions and perspectives in MS-based proteomics on HDL.

Many epidemiological data indicate the presence of a strong familial component of longevity that is largely determined by genetics, and a number of possible associations between longevity and allelic variants of genes have been described.... more

Many epidemiological data indicate the presence of a strong familial component of longevity that is largely determined by genetics, and a number of possible associations between longevity and allelic variants of genes have been described. A breakthrough strategy to get insight into the genetics of longevity is the study of centenarians, the best example of successful ageing. We review the main results regarding nuclear genes as well as the mitochondrial genome, focusing on the investigations performed on Italian centenarians, compared to those from other countries. These studies produced interesting results on many putative "longevity genes". Nevertheless, many discrepancies are reported, likely due to the population-specific interactions between gene pools and environment. New approaches, including large-scale studies using high-throughput techniques, are urgently needed to overcome the limits of traditional association studies performed on a limited number of polymorphis...

This study sought to determine the prevalence of lipid and lipoprotein abnormalities and their association with the risk of a first acute myocardial infarction (AMI) among Asians.

Keloids and non-diabetic kidney disease are both fibrotic processes that disproportionately affect persons of African descent. Despite similarities in these conditions, the authors identified no studies to date investigating a shared... more

Keloids and non-diabetic kidney disease are both fibrotic processes that disproportionately affect persons of African descent. Despite similarities in these conditions, the authors identified no studies to date investigating a shared genetic etiology. MYH9 and APOL1 are in linkage disequilibrium and have both been associated with non-diabetic kidney disease. MYH9 codes for a non-muscle myosin that is involved in cell adhesion and locomotion and is known to be overexpressed in keloids. Variations in APOL1 confer resistance to subspecies of Trypanosoma brucei, which may explain why otherwise deleterious genetic alterations in this haplotype could have gained prominence. We feel that the pathophysiological and epidemiological overlap between keloids and non-diabetic kidney disease support a common genetic origin and further investigation into keloids and the MYH9-APOL1 haplotype and keloids is warranted. Furthermore, we feel this haplotype might offer insight into thrombosis, stroke and other conditions that disproportionately affect persons of African descent.

Background In the BIGPRO 1 trial, one year of treatment with metformin in non-diabetic obese subjects with a central fat distribution had no signi®cant effect on fasting plasma triglyceride concentration or on blood pressure despite a... more

Background In the BIGPRO 1 trial, one year of treatment with metformin in non-diabetic obese subjects with a central fat distribution had no signi®cant effect on fasting plasma triglyceride concentration or on blood pressure despite a decrease in weight, fasting plasma insulin and glucose concentrations. To re-evaluate the effect of metformin on fasting triglyceride concentration and on blood pressure, the BIGPRO 1.2 trial included nondiabetic men (n=168) with a fasting plasma triglyceride concentration i1.7 and j6.5 mmol/l, high blood pressure (systolic i140 and j180 and/or diastolic i90 and j105 mmHg, or treatment for hypertension) and a waistto-hip ratio i0.95.

Exceptional longevity is associated with substantial heritability. The ε4 allele in apolipoprotein E and the linked G allele in rs2075650 of TOMM40 have been associated with increased mortality and the ε2 allele with decreased mortality,... more

Exceptional longevity is associated with substantial heritability. The ε4 allele in apolipoprotein E and the linked G allele in rs2075650 of TOMM40 have been associated with increased mortality and the ε2 allele with decreased mortality, although inconsistently. Offspring from long-lived families and spouse controls were recruited at 3 sites in the United States and Denmark. We used generalized estimating equations to compare the likelihood of carrying risk alleles in offspring (n ¼ 2307) and spouse controls (n ¼ 764), adjusting for age, sex, level of education, and family membership. The likelihood of carrying an APOE ε4 allele or a G allele in rs2075650 was lower (odds ratio [OR], 0.75; p ¼ 0.005 and OR, 0.70; p ¼ 0.002) and the likelihood of carrying an APOE ε2 allele was higher (OR, 1.5; p ¼ 0.007) among family members in the offspring generation than among their spouse controls. Our findings support the hypothesis that both reduction in the frequency of the ε4 allele and increase in the frequency of the ε2 allele contribute to longevity.

Apolipophorin III (apoLp-III) is a prototypical apolipoprotein used for structure-function studies. Besides its crucial role in lipid transport, apoLp-III is able to associate with fungal and bacterial membranes and stimulate cellular... more

Apolipophorin III (apoLp-III) is a prototypical apolipoprotein used for structure-function studies. Besides its crucial role in lipid transport, apoLp-III is able to associate with fungal and bacterial membranes and stimulate cellular immune responses. We recently demonstrated binding interaction of apoLp-III of the greater wax moth, Galleria mellonella, with lipopolysaccharides (LPS). In the present study, the requirement of helix bundle opening for LPS binding interaction was investigated. Using site-directed mutagenesis, two cysteine residues were introduced in close spatial proximity (P5C/A135C). When the helix bundle was locked by disulfide bond formation, the tethered helix bundle failed to associate with LPS. In contrast, the mutant protein regained its ability to bind upon reduction with dithiothreitol. Thus, helix bundle opening is a critical event in apoLp-III binding interaction with LPS. This mechanism implies that the hydrophobic interior of the protein interacts directly with LPS, analogous to that observed for lipid interaction. (P.M.M. Weers).

Anti-oestrogen therapy is being used in an attempt to prevent breast cancer but no intermediate end points of the effect of tamoxifen on the normal breast are available. Therefore, the purpose of this study was to develop a physiological... more

Anti-oestrogen therapy is being used in an attempt to prevent breast cancer but no intermediate end points of the effect of tamoxifen on the normal breast are available. Therefore, the purpose of this study was to develop a physiological measure of oestrogen action on the breast. We measured oestrogen-stimulated and -inhibited proteins in breast secretions from women on and off anti-oestrogen therapy. Two oestrogen-stimulated proteins (pS2 and cathepsin D) and oestrogen-inhibited proteins (CP15, gross cystic disease fluid protein 15; Apo,: apolipoprotein D) were measured. Premenopausal women had significantly higher pS2 and cathepsin D in association with lower Apo D and CP15 secretion levels compared to post-menopausal women. Sequential nipple aspirates from women treated with the luteinizing hormone releasing hormone agonist goserelin (n = 9), tamoxifen (n = 9) and hormone replacement therapy (HRT) (n = 26) were measured. Following treatment with goserelin, median nipple secretion...

Atypical antipsychotics induce pre-diabetic symptoms in some but not all patients, characterized most notably by elevated weight. The side effect profiles of the various drugs in the class differ, however, raising the possibility of... more

Atypical antipsychotics induce pre-diabetic symptoms in some but not all patients, characterized most notably by elevated weight. The side effect profiles of the various drugs in the class differ, however, raising the possibility of drug-specific mechanisms for similar side effects. We used physiogenomic analysis, an approach previously employed to study the genetics of drug and diet response, to discover and compare genetic associations with weight profiles observed in patients treated with olanzapine and risperidone as an approach to unraveling contrasting mechanistic features of both drugs. A total of 29 single nucleotide polymorphisms (SNPs) were selected from 13 candidate genes relevant to two potential pharmacological axes of psychotropic-related weight profiles, appetite peptides and peripheral lipid homeostasis. We applied physiogenomic analysis to a cross-section of 67 and 101 patients being treated with olanzapine and risperidone, respectively, and assessed genetic associations with the weight profiles. Weight profiles in patients treated with olanzapine were significantly associated with SNPs in the genes for apolipoprotein E, apolipoprotein A4 and scavenger receptor class B, member 1. Weight profiles in patients treated with risperidone were significantly associated with SNPs in the genes for leptin receptor, neuropeptide Y receptor Y5 and paraoxonase 1. These results are consistent with contrasting mechanisms for the weight profile of patients treated with these drugs. Genes associated with olanzapine weight profiles may be related to peripheral lipid homeostatic axes, whereas those associated with risperidone's may be related to brain appetite peptide regulation. Future physiogenomic studies will include neurotransmitter receptor SNPs and validation in independent samples.

Apolipoprotein L is a newly recognized compo- nent of human plasma lipoproteins. Mainly associated with apoA-I-containing lipoproteins, it is a marker of distinct HDL subpopulations. In an effort to gain inference as to its as yet unknown... more

Apolipoprotein L is a newly recognized compo- nent of human plasma lipoproteins. Mainly associated with apoA-I-containing lipoproteins, it is a marker of distinct HDL subpopulations. In an effort to gain inference as to its as yet unknown function, we studied biological determinants of apoL levels in human plasma. The distribution of apoL in normal subjects is asymmetric, with marked skewing

It was previously reported that a protein-free microemulsion (LDE) with structure roughly resembling that of the lipid portion of low density lipoprotein (LDL) was presumably taken up by LDL receptors when injected into the bloodstream.... more

It was previously reported that a protein-free microemulsion (LDE) with structure roughly resembling that of the lipid portion of low density lipoprotein (LDL) was presumably taken up by LDL receptors when injected into the bloodstream. In contact with plasma, LDE acquires apolipoproteins (apo) including apo E that would be the ligand for receptor binding. Currently, apo were associated to LDE by incubation with high density lipoprotein (HDL). LDE-apo uptake by mononuclear cells showed a saturation kinetics, with an apparent K(m) of 13.1 ng protein/mL. LDE-apo is able to displace LDL uptake by mononuclear cells with a Ki of 11.5 ng protein/mL. LDE without apo is, however, unable to displace LDL. The uptake of 14C-HDL is not dislocated by increasing amounts of LDE-apo, indicating that HDL and LDE-apo do not bind to the same receptor sites. In human hyperlipidemias, LDE labeled with 14C-cholesteryl ester behaved kinetically as expected for native LDL. LDE plasma disappearance curve obtained from eight hypercholesterolemic patients was markedly slower than that from 10 control normolipidemic subjects [fractional clearance rate (FCR) = 0.02 +/- 0.01 and 0.12 +/- 0.04 h-1, respectively; P < 0.0001]. On the other hand, in four severely hypertriglyceridemic patients, LDE FCR was not significantly different from the controls (0.07 +/- 0.03 h-1). These results suggest that LDE can be a useful device to study lipoprotein metabolism.

We studied 11 female alcoholics before and after ethanol withdrawal of 2 weeks and 10 healthy normolipidaemic, nonalcoholic women of similar age. In alcoholic women the HDL2 mass was increased by 63% (P < 0.01) on admission and... more

We studied 11 female alcoholics before and after ethanol withdrawal of 2 weeks and 10 healthy normolipidaemic, nonalcoholic women of similar age. In alcoholic women the HDL2 mass was increased by 63% (P < 0.01) on admission and normalized (P < 0.01) during abstention. The concentrations of HDL3 cholesterol and its mass remained unchanged throughout the study. Consistently with the fall of HDL2 gradient gel electrophoresis analyses also demonstrated decrease of the cholesterol concentration of HDL2b and HDL2a (P < 0.05) during alcohol withdrawal. On admission the apo A-II concentration was increased by 48% (P < 0.01) and it was normalized (P < 0.001) during abstention. Among apo A-I containing lipoproteins the most prominent change occurred in Lp A-I:A-II, which fell by 32% (P < 0.01) during 1 week's alcohol withdrawal. During abstention the lipoprotein (a) concentration increased in 10 out of 11 women. In patients cholesteryl ester transfer (CETP) activity increased by 35% (P < 0.01) during 1 week of ethanol withdrawal. On admission postheparin plasma lipoprotein (LPL) and hepatic lipase activities were increased by 25% (P = NS); during 1 week's abstention they both returned to the control level (P < 0.05- < 0.01). In conclusion, chronic alcoholic women display multiple changes of lipoprotein metabolism which are rapidly reversed during abstinence. In contrast to alcoholic men, studied previously by us using the same study design and methods, there was no significant elevation of HDL3 cholesterol and apo A-I. The data suggest that alcohol interferes with several regulatory steps of HDL metabolism which are partly gender dependent.

Neutral lipid transport in mammals is complicated involving many types of apolipoprotein. The exchangeable apolipoproteins mediate the transfer of hydrophobic lipids between tissues and particles, and bind to cell surface receptors.... more

Neutral lipid transport in mammals is complicated involving many types of apolipoprotein. The exchangeable apolipoproteins mediate the transfer of hydrophobic lipids between tissues and particles, and bind to cell surface receptors. Amphipathic α-helices form a common structural motif that facilitates their lipid binding and exchangeability. ApoLp-III, the only exchangeable apolipoprotein found in insects, is a model amphipathic α-helix bundle protein and its three dimensional structure and function mimics that of the mammalian proteins apoE and apoAI. Even the intracellular exchangeable lipid droplet protein TIP47/perilipin 3 contains an α-helix bundle domain with high structural similarity to that of apoE and apoLp-III. Here, we investigated the interaction of apoLp-III from Locusta migratoria with lipid monolayers. Consistent with earlier work we find that insertion of apoLp-III into fluid lipid monolayers is highest for diacylglycerol. We observe a preference for saturated and more highly ordered lipids, suggesting a new mode of interaction for amphipathic α-helix bundles. X-ray reflectivity shows that apoLp-III unfolds at a hydrophobic interface and flexible loops connecting the amphipathic α-helices stay in solution. X-ray diffraction indicates that apoLp-III insertion into diacylglycerol monolayers induces additional ordering of saturated acyl-chains. These results thus shed important new insight into the protein-lipid interactions of a model exchangeable apolipoprotein with significant implications for its mammalian counterparts.

Cardiovascular disease is the primary cause of death in Brazil. Recent studies have shown that low birth weight and preterm birth are linked to a higher prevalence of cardiovascular disease. The aim of the present study was to compare the... more

Cardiovascular disease is the primary cause of death in Brazil. Recent studies have shown that low birth weight and preterm birth are linked to a higher prevalence of cardiovascular disease. The aim of the present study was to compare the levels of lipids and apolipoproteins and atherogenic indexes between term and near-term newborn infants. A sample of umbilical cord blood was obtained from 135 newborns (66 males) divided into two groups: 25 near-term neonates (35-36.6 weeks of gestational age) and 110 term neonates (37-42 weeks of gestational age). The total cholesterol concentrations were higher in the near-term neonates than in the term group (94.04 ± 8.02 vs 70.42 ± 1.63 mg/dl, P < 0.01), due to an increase in the LDL-cholesterol fraction in the near-term group (57.76 ± 6.39 vs 34.38 ± 1.29 mg/dl, P < 0.001). The atherogenic indexes (total cholesterol/HDL-cholesterol, LDL-cholesterol/HDL-cholesterol and apolipoprotein B/apolipoprotein A-I) were higher in the near-term group (P < 0.001, P < 0.001, and P < 0.05, respectively). The gestational age of the newborns was inversely correlated with total cholesterol and LDL-cholesterol, and also with the total cholesterol/HDL-cholesterol and LDL-cholesterol/ HDL-cholesterol indexes. These findings demonstrate that the lipid profile is worse in the group of near-term neonates compared with the term group. Future studies are needed to determine if this atherogenic profile in near-term neonates can affect body metabolism, increasing the risk for cardiovascular diseases in adult life.

Objectives The uptake of drugs by chylomicrons is a key element in both intestinal lymphatic transport and postprandial alterations in the disposition profile of lipophilic drugs. The aim of this article was to elucidate the factors that... more

Objectives The uptake of drugs by chylomicrons is a key element in both intestinal lymphatic transport and postprandial alterations in the disposition profile of lipophilic drugs. The aim of this article was to elucidate the factors that affect this phenomenon. Methods The degree of association of 22 model lipophilic molecules with rat chylomicrons was assessed and correlated in silico with calculated physicochemical properties. The in-silico model was then validated using an external set of molecules. The uptake by chylomicrons was also compared to the association with a marketed artificial emulsion. Key findings The most important physicochemical property that affects the affinity to chylomicrons was found to be LogD 7.4 ; however, a multiparameter model was required to describe properly the uptake process. The in-silico model (R 2 Y = 0.91, R 2 X = 0.91 and Q 2 = 0.82) that was created using a combination of eight molecular descriptors enabled successful prediction of the affinity of the external set of molecules to chylomicrons. The association with the artificial emulsion was statistically different from the uptake by chylomicrons for four (out of nine) molecules. Conclusions The association of drugs with chylomicrons is a complex process, which involves the lipophilic core as well as surface apoproteins. The in-silico model based on multiple physicochemical properties of the drugs is able to predict successfully the degree of association with chylomicrons.

The newly recognised apolipoprotein (apo) AV gene (APOAV) has been linked to fasting plasma triglyceride (TG) concentrations with some polymorphisms associated with elevated fasting TGs. Since fasting plasma TGs are mainly determined by... more

The newly recognised apolipoprotein (apo) AV gene (APOAV) has been linked to fasting plasma triglyceride (TG) concentrations with some polymorphisms associated with elevated fasting TGs. Since fasting plasma TGs are mainly determined by the hepatic production of TG-rich particles (very low density lipoprotein; VLDL), and fasting TGs are the major determinants of postprandial lipaemia, we have evaluated the effects of an APOAV polymorphism on postprandial triglyceridaemia, which is largely determined by the intestinal production and clearance of chylomicrons. For this purpose, diurnal capillary triglyceridaemia (reflecting postprandial lipaemia) was determined in a cohort of 88 healthy volunteers (48 males and 40 females) in relation with a -1131T>C variant in the promoter of APOAV. Thirteen of these subjects (7 males and 6 females) were carriers of the -1131C allele, which has been associated with higher fasting plasma TG levels. The carriers had higher fasting capillary TG concentrations, although plasma TGs were not significantly different from non-carriers in this cohort. Surprisingly, total diurnal triglyceridaemia calculated as the area under the capillary TG curve was similar in carriers compared to non-carriers but after correction for fasting capillary TG levels, incremental diurnal triglyceridaemia was significantly lower in carriers (1.74 (5.27) mmol/h/l) than in non-carriers (4.91 (4.90) mmol/h/l; p = 0.036). The same trends were found for both males and females when analysed separately. Since dietary intake, which is a major determinant of incremental diurnal triglyceridaemia, did not differ between the two groups, we believe that these differences are at least partly explained by the APOAV.

The pathologic lesions of Alzheimer's disease (AD) are characterized by accumulation of protein aggregates consisting of intracellular or extracellular misfolded proteins. The amyloid-β (Aβ) protein accumulates extracellularly in senile... more

The pathologic lesions of Alzheimer's disease (AD) are characterized by accumulation of protein aggregates consisting of intracellular or extracellular misfolded proteins. The amyloid-β (Aβ) protein accumulates extracellularly in senile plaques and cerebral amyloid angiopathy, whereas the hyperphosphorylated tau protein accumulates intracellularly as neurofibrillary tangles. "Professional chaperones", such as the heat shock protein family, have a function in the prevention of protein misfolding and subsequent aggregation. "Amateur" chaperones, such as apolipoproteins and heparan sulfate proteoglycans, bind amyloidogenic proteins and may affect their aggregation process. Professional and amateur chaperones not only colocalize with the pathological lesions of AD, but may also be involved in conformational changes of Aβ, and in the clearance of Aβ from the brain via phagocytosis or active transport across the blood-brain barrier. Thus, both professional and amateur chaperones may be involved in the aggregation, accumulation, persistence, and clearance of Aβ and tau and in other Aβ-associated reactions such as inflammation associated with AD lesions, and may, therefore, serve as potential targets for therapeutic intervention.

The present work analyzed the function of lipid transfer particle (LTP) in the process of exporting diacylglycerol from larval Manduca sexta midgut cells to lipophorin. When midgut sacs, which had been prelabeled in vivo with [ 3 H]oleic... more

The present work analyzed the function of lipid transfer particle (LTP) in the process of exporting diacylglycerol from larval Manduca sexta midgut cells to lipophorin. When midgut sacs, which had been prelabeled in vivo with [ 3 H]oleic acid, were incubated in vitro with a lipophorin-containing medium, a significant amount of radiolabeled diacylglycerol was transferred to lipophorin. Negligible amounts of diacylglycerol were released into lipophorin-free medium. In contrast, lipid-labeled lipophorin did not transfer diacylglycerol to the midgut sacs. The transfer of diacylglycerol from the midgut sac to lipophorin was blocked by preincubation of midgut sacs with antibody against LTP. Diacylglycerol transfer was restored to control values by the addition of purified LTP to midgut sacs that had been treated with antibody against LTP. Under these conditions the amount of diacylglycerol transferred was a function of the LTP concentration. These are the first results showing that LTP is required to export diacylglycerol from the midgut to lipophorin.

Apolipoprotein AV (ApoAV) gene variant, -1131T>C, is associated with increased triglyceride concentrations in all ethnic groups studied. An MseI based RFLP analysis is the most commonly used method for genotyping this SNP. We genotyped... more

Apolipoprotein AV (ApoAV) gene variant, -1131T>C, is associated with increased triglyceride concentrations in all ethnic groups studied. An MseI based RFLP analysis is the most commonly used method for genotyping this SNP. We genotyped a large cohort comprising 1185 Asian Indians and 173 UK Caucasians for -1131T>C using an ARMS-PCR based tetra-primer method. For quality control, we re-genotyped approximately 10% random samples from this cohort utilizing the MseI RFLP, which showed a 2.9% (3/102) genotyping error rate between the two methods. To investigate further, we sequenced the 900 bp region around the -1131T>C polymorphism in 25 Asian Indians and 15 UK Caucasians and found a number of polymorphisms including the -987C>T polymorphism. Further analysis of the -987C>T SNP showed a higher rare allele frequency of 0.23 in Asian Indians (n = 158) compared to 0.09 in the UK Caucasians (n = 157). This SNP is located 4 bp from the 3' end of the RFLP forward primer and...