Mipomersen, an apolipoprotein B synthesis inhibitor, for lowering of LDL cholesterol concentrations in patients with homozygous familial hypercholesterolaemia: a randomised, double-blind, placebo-controlled trial

Background Homozygous familial hypercholesterolaemia is a rare genetic disorder in which both LDL-receptor alleles are defective, resulting in very high concentrations of LDL cholesterol in plasma and premature coronary artery disease. This study investigated whether an antisense inhibitor of apolipoprotein B synthesis, mipomersen, is effective and safe as an adjunctive agent to lower LDL cholesterol concentrations in patients with this disease. Methods This randomised, double-blind, placebo-controlled, phase 3 study was undertaken in nine lipid clinics in seven countries. Patients aged 12 years and older with clinical diagnosis or genetic confirmation of homozygous familial hypercholesterolaemia, who were already receiving the maximum tolerated dose of a lipid-lowering drug, were randomly assigned to mipomersen 200 mg subcutaneously every week or placebo for 26 weeks. Randomisation was computer generated and stratified by weight (<50 kg vs >= 50 kg) in a centralised blocked randomisation, implemented with a computerised interactive voice response system. All clinical, medical, and pharmacy personnel, and patients were masked to treatment allocation. The primary endpoint was percentage change in LDL cholesterol concentration from baseline. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00607373. Findings 34 patients were assigned to mipomersen and 17 to placebo; data for all patients were analysed. 45 patients completed the 26-week treatment period (28 mipomersen, 17 placebo). Mean concentrations of LDL cholesterol at baseline were 11.4 mmol/L (SD 3.6) in the mipomersen group and 10.4 mmol/L (3.7) in the placebo group. The mean percentage change in LDL cholesterol concentration was significantly greater with mipomersen (-24.7%, 95% CI 31.6 to 17.7) than with placebo (-3.3%, 12.1 to 5.5; p=0.0003). The most common adverse events were injection-site reactions (26 [76%] patients in mipomersen group vs four [24%] in placebo group). Four (12%) patients in the mipomersen group but none in the placebo group had increases in concentrations of alanine aminotransferase of three times or more the upper limit of normal. Interpretation Inhibition of apolipoprotein B synthesis by mipomersen represents a novel, effective therapy to reduce LDL cholesterol concentrations in patients with homozygous familial hypercholesterolaemia who are already receiving lipid-lowering drugs, including high-dose statins.

Metabolic syndrome features small, apolipoprotein A-I-poor, triglyceride-rich HDL3 particles with defective anti-apoptotic activity

The metabolic syndrome (MetS) phenotype is typically characterized by visceral obesity, insulin resistance, atherogenic dyslipidemia involving hypertriglyceridemia and subnormal levels of high density lipoprotein-cholesterol (HDL-C), oxidative stress and elevated cardiovascular risk. The potent antioxidative activity of small HDL3 is defective in MetS [Hansel B, et al. J Clin Endocrinol Metab 2004;89:4963-71]. We evaluated the functional capacity of small HDL3 particles from MetS subjects to protect endothelial cells from apoptosis induced by mildly oxidized low-density lipoprotein (oxLDL). MetS subjects presented an insulin-resistant obese phenotype, with hypertriglyceridemia, elevated apolipoprotein B and insulin levels, but subnormal HDL-C concentrations and chronic low grade inflammation (threefold elevation of C-reactive protein). When human microvascular endothelial cells (HMEC-1) were incubated with oxLDL (200 jig apolipoprotein B/ml) in the presence or absence of control HDL subfiractions (25 mu g protein/ml), small, dense HDL3b and 3c significantly inhibited cellular annexin V binding and intracellular generation of reactive oxygen species. The potent anti-apoptotic activity of small HDL3c particles was reduced (-35%; p < 0.05) in MetS subjects (n = 16) relative to normolipidemic controls (n = 7). The attenuated anti-apoptotic activity of HDL3c correlated with abdominal obesity, atherogenic dyslipidemia and systemic oxidative stress (p < 0.05), and was intimately associated with altered physicochemical properties of apolipoprotein A-I (apoA-I-poor HDL3c, involving core cholesteryl ester depletion and triglyceride enrichment. We conclude that in MetS, apoA-I-poor, small, dense HDL3c exert defective protection of endothelial cells from oxLDL-induced apoptosis, potentially reflecting functional anomalies intimately associated with abnormal neutral lipid core content. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Post-menopausal hormone therapy reduces autoantibodies to oxidized apolipoprotein B100

The aim of the study was to verify whether post-menopausal hormone replacement therapy (HRT) modifies autoantibody titers against oxidized low-density lipoprotein (LDL) (anti-LDLoxi), against epitopes of oxidized apolipoprotein B100 and common carotid intima-media thickness (IMT) in these women. Sixty-eight women in pre-menopause (PMW) and 216 in post-menopause (POMW) were recruited; eighty-three had undergone HRT for at least 12 months, where 48 received conjugated estrogens alone (EHRT) and 35 received conjugated estrogen and medroxyprogesterone acetate (CHRT). ELISA was used to determine autoantibodies. Lipoprotein lipase (LPL), hepatic lipase (HL), cholesterol ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activities were assayed by radiometric methods. IMT was measured using Doppler ultrasound. Anti-oxidized LDL and anti-D antibodies increased by 40% (p <= 0.003) and 42% (p <= 0.006), respectively, with menopause. There was a surprising and significant 7% reduction in anti-D2 antibody titers with HRT (p <= 0.050), indicating a positive effect of treatment on the immune response to oxidized LDL. Combined HRT decreased activities of HL and LPL. HRT did not change common carotid IMT, which was increased by 32% as expected after menopause (p <= 0.030). This study describes, for the first time, the protective effect of HRT on decreasing autoantibody titers against oxidized apolipoprotein B in LDL.

Anticorpos contra LDL-ox e síndrome coronariana aguda

FUNDAMENTO: A oxidação da lipoproteína de baixa densidade (LDL-ox) induz à formação de epítopos imunogênicos na molécula. A presença de autoanticorpos contra a LDL-ox tem sido demonstrada no soro de pacientes com doença arterial coronariana (DAC). Contudo, o papel desses autoanticorpos na fisiopatologia das síndromes coronarianas agudas (SCA) e o seu significado clínico permanecem indefinidos. OBJETIVO: Avaliar a associação entre autoanticorpos contra a LDL-ox e SCA. MÉTODOS: Os títulos de imunoglobulina G autoanticorpos contra a LDL-ox por cobre (antiLDL-ox) e contra o peptídeo sintético D derivado da apolipoproteína B (antipeptD) foram determinados por ensaio imunoenzimático (ELISA) em 90 pacientes, nas primeiras 12h de SCA (casos) e em 90 pacientes com DAC crônica (controles). RESULTADOS: Os resultados mostraram que os títulos de antiLDL-ox foram significativamente mais elevados (p = 0,017) nos casos (0,40 ± 0,22), do que nos controles (0,33 ± 0,23). Por outro lado, os títulos de antipeptD foram significativamente menores (p < 0,01) nos casos (0,28 ± 0,23) do que nos controles (0,45 ± 0,30). A diferença dos títulos de ambos anticorpos entre os dois grupos estudados foi independente de idade, sexo, hipertensão arterial, diabete melito, dislipidemia, índice de massa corporal, tabagismo, perfil lipídico, uso de estatinas e história familiar de DAC. CONCLUSÃO: Os resultados mostraram que os títulos de antiLDL-ox foram significativamente mais elevados nos pacientes com síndrome coronariana aguda quando comparados aos pacientes com doença arterial coronariana e podem estar associados à instabilidade da placa aterosclerótica.

Synergistic effect of simvastatin and ezetimibe on lipid and pro-inflammatory profiles in pre-diabetic subjects

Background: Ezetimibe specifically blocks the absorption of dietary and biliary cholesterol and plant sterols. Synergism of ezetimibe-statin therapy on LDL-cholesterol has been demonstrated, but data concerning the pleiotropic effects of this combination are controversial. Objective: This open-label trial evaluated whether the combination of simvastatin and ezetimibe also results in a synergistic effect that reduces the pro-inflammatory status of pre-diabetic subjects. Methods: Fifty pre-diabetic subjects were randomly assigned to one of 2 groups, one receiving ezetimibe (10 mg/day), the other, simvastatin (20 mg/d) for 12 weeks, followed by an additional 12-week period of combined therapy. Blood samples were collected at baseline, 12 and 24 weeks. RESULTS: Total cholesterol, LDL-cholesterol and apolipoprotein B levels decreased in all the periods analyzed (p < 0.01), but triglycerides declined significantly only after combined therapy. Both drugs induced reductions in C-reactive protein, reaching statistical significance after combining ezetimibe with the simvastatin therapy (baseline 0.59 +/- 0.14, simvastatin monotherapy 0.48 +/- 0.12 mg/dL and 0.35 +/- 0.12 mg/dL, p < 0.023). Such a reduction was independent of LDL-cholesterol change. However, mean levels of TNF-alpha and interleukin-6 and leukocyte count did not vary during the whole study. Conclusion: Expected synergistic lowering effects of a simvastatin and ezetimibe combination on LDL-cholesterol, apolipoprotein B and triglycerides levels were confirmed in subjects with early disturbances of glucose metabolism. We suggest an additive effect of this combination also on inflammatory status based on the reduction of C-reactive protein. Attenuation of pro-inflammatory conditions may be relevant in reducing cardiometabolic risk.

Brazil nut ingestion increased plasma selenium but had minimal effects on lipids, apolipoproteins, and high-density lipoprotein function in human subjects

The Brazil nut (Bertholletia excelsa) of the Amazon region is consumed worldwide. It is rich in both monounsaturated fatty acids and polyunsaturated fatty acids and is known for its high selenium content. This study tested the hypothesis whether the consumption of this nut could affect the plasma lipids and apolipoproteins and some functional properties of the antiatherogenic high-density lipoprotein (HDL). Fifteen normolipidemic subjects aged 27.3 +/- 3.9 years and with body mass index of 23.8 +/- 2.8 kg/m(2) consumed 45 g of Brazil nuts per day during a 15-day period. On days 0 and 15, blood was collected for biochemical analysis, determination of HDL particle size, paraoxonase 1 activity, and lipid transfer from a lipoprotein-like nanoparticle to the HDL fraction. Brazil nut ingestion did not alter HDL, low-density lipoprotein cholesterol, triacylglycerols, apolipoprotein A-1, or apolipoprotein B concentrations. HDL particle diameter and the activity of antioxidative paraoxonase 1, mostly found in the HDL fraction, Were also unaffected. Supplementation increased the reception of cholesteryl esters (P <.05) by the HDL yet did not alter the reception of phospholipids, free cholesterol, or triacylglycerols. As expected, plasma selenium was significantly increased. However, the consumption of Brazil nuts for short duration by normolipidemic subjects in comparable amounts to those tested for other nuts did not alter serum lipid profile. The only alteration in HDL function was the increase in cholesteryl ester transfer. This latter finding may be beneficial because it would improve the nonatherogenic reverse cholesterol transport pathway. (c) 2008 Elsevier Inc. All rights reserved.

Impedimetric immunosensor for electronegative low density lipoprotein (LDL(-)) based on monoclonal antibody adsorbed on (polyvinyl formal)-gold nanoparticles matrix

Monoclonal antibodies (MAb) have been commonly applied to measure LDL in vivo and to characterize modifications of the lipids and apoprotein of the LDL particles. The electronegative low density lipoprotein (LDL(-)) has an apolipoprotein B-100 modified at oxidized events in vivo. In this work, a novel LDL-electrochemical biosensor was developed by adsorption of anti-LDL(-) MAb on an (polyvinyl formal)-gold nanoparticles (PVF-AuNPs)-modified gold electrode. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to characterize the recognition of LDL-. The interaction between MAb-LDL(-) leads to a blockage in the electron transfer of the [Fe(CN)(6)](4-)/K(4)[Fe(CN)(6)](3-) redox couple, which may could result in high change in the electron transfer resistance (R(CT)) and decrease in the amperometric responses in CV analysis. The compact antibody-antigen complex introduces the insulating layer on the assembled surface, which increases the diameter of the semicircle, resulting in a high R(CT), and the charge transferring rate constant k(0) decreases from 18.2 x 10(-6) m/s to 4.6 x 10(-6) m/s. Our results suggest that the interaction between MAb and lipoprotein can be quantitatively assessed by the modified electrode. The PVF-AuNPs-MAb system exhibited a sensitive response to LDL(-), which could be used as a biosensor to quantify plasmatic levels of LDL(-). (C) 2011 Elsevier B.V. All rights reserved.

ABCB1 and ABCC1 expression in peripheral mononuclear cells is influenced by gene polymorphisms and atorvastatin treatment

This study investigated the effects of atorvastatin on ABCB1 and ABCC1 mRNA expression on peripheral blood mononuclear cells (PBMC) and their relationship with gene polymorphisms and lowering-cholesterol response. one hundred and thirty-six individuals with hypercholesterolemia were selected and treated with atorvastatin (10 mg/day/4 weeks). Blood samples were collected for serum lipids and apolipoproteins measurements and DNA and RNA extraction. ABCB1 (C3435T and G2677T/A) and ABCC1 (G2012T) gene polymorphisms were identified by polymerase chain reaction-restriction (PCR)-RFLP and mRNA expression was measured in peripheral blood mononuclear cells by singleplex real-time PCR. ABCB1 polymorphisms were associated with risk for coronary artery disease (CAD) (p < 0.05). After atorvastatin treatment, both ABCB1 and ABCC1 genes showed 50% reduction of the mRNA expression (p < 0.05). Reduction of ABCB1 expression was associated with ABCB1 G2677T/A polymorphism (p = 0.039). Basal ABCB1 mRNA in the lower quartile (<0.024) was associated with lower reduction rate of serum low-density lipoprotein (LDL) cholesterol (33.4 +/- 12.4%) and apolipoprotein B (apoB) (17.0 +/- 31.3%) when compared with the higher quartile (>0.085: LDL-c = 40.3 +/- 14.3%; apoB = 32.5 +/- 10.7%; p < 0.05). ABCB1 substrates or inhibitors did not affect the baseline expression, while ABCB1 inhibitors reversed the effects of atorvastatin on both ABCB1 and ABCC1 transporters. In conclusion, ABCB1 and ABCC1 mRNA levels in PBMC are modulated by atorvastatin and ABCB1 G2677T/A polymorphism. and ABCB1 baseline expression is related to differences in serum LDL cholesterol and apoB in response to atorvastatin. (C) 2008 Elsevier Inc. All rights reserved.

Association of polymorphisms of glutamate-cystein ligase and microsomal triglyceride transfer protein genes in non-alcoholic fatty liver disease

Background and Aims: Although the metabolic risk factors for non-alcoholic fatty liver disease (NAFLD) progression have been recognized, the role of genetic susceptibility remains a field to be explored. The aim of this study was to examine the frequency of two polymorphisms in Brazilian patients with biopsy-proven simple steatosis or non-alcoholic steatohepatitis (NASH): -493 G/T in the MTP gene, which codes the protein responsible for transferring triglycerides to nascent apolipoprotein B, and -129 C/T in the GCLC gene, which codes the catalytic subunit of glutamate-cystein ligase in the formation of glutathione. Methods: One hundred and thirty-one biopsy-proven NAFLD patients (n = 45, simple steatosis; n = 86, NASH) and 141 unrelated healthy volunteers were evaluated. Genomic DNA was extracted from peripheral blood cells, and the -129 C/T polymorphism of the GCLC gene was determined by restriction fragment length polymorphism (RFLP). The -493 G/T polymorphism of the MTP gene was determined by direct sequencing of the polymerase chain reaction products. Results: The presence of at least one T allele in the -129 C/T polymorphism of the GCLC gene was independently associated with NASH (odds ratio 12.14, 95% confidence interval 2.01-73.35; P = 0.007), whereas, the presence of at least one G allele in the -493 G/T polymorphism of the MTP gene differed slightly between biopsy-proven NASH and simple steatosis. Conclusion: This difference clearly warrants further investigation in larger samples. These two polymorphisms could represent an additional factor for consideration in evaluating the risk of NAFLD progression. Further studies involving a larger population are necessary to confirm this notion.

No correlation and low agreement of imaging and inflammatory atherosclerosis` markers in familial hypercholesterolemia

Our purpose was to study the determinants of coronary and carotid subclinical atherosclerosis, aortic stiffness and their relation with inflammatory biomarkers in familial hypercholesterolemia (FH) subjects. Furthermore, we evaluated the agreement degree of imaging and inflammatory markers` severity used for coronary heart disease (CHD) prediction. Coronary calcium scores (CCS), carotid intima media thickness (IMT), carotid-femoral pulse wave velocity (PWV), C reactive protein (CRP) and white blood cells count (WBC) were determined in 89 FH patients (39 +/- 14 years, mean LDL-C=279 mg/dl) and in 31 normal subjects (NL). The following values were considered as imaging and biomarkers` severity: CCS > 75th% for age and sex, IMT > 900 mu m, PWV > 12 m/s, and CRP > 3 mg/l. Coronary artery calcification (CAC) prevalence and severity, IMT, PWV and WBC values were higher in FH than in NL (all parameters, p < 0.05). After multivariate analysis, the following variables were considered independent determinants of (1) IMT: systolic blood pressure, 10-year CHD risk by Framingham risk scores (FRS) and apolipoprotein B (r(2)=0.33); (2) PWV: age (r(2)=0.35); (3) CAC as a continuous variable: male gender and LDL-cholesterol year score (LYS) (r(2)=0.32); (4) presence of CAC as dichotomous variable: FRS (p=0.0027) and LYS (p=0.0228). With the exception of a moderate agreement degree between IMT and PWV severity (kappa=0.5) all other markers had only a slight agreement level (kappa < 0.1). In conclusion, clinical parameters poorly explained IMT, CAC and PWV variability in FH subjects. Furthermore, imaging markers and inflammatory biomarkers presented a poor agreement degree of their severity for CHD prediction. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

Improved endothelial function with simvastatin but unchanged insulin sensitivity with simvastatin or ezetimibe

In addition to their expected effects on lipid profile, lipid-lowering agents may reduce cardiovascular events because of effects on nonclassic risk factors such as insulin resistance and inflammation. Ezetimibe specifically blocks the absorption of dietary and biliary cholesterol as well as plant sterols. Although it is known that an additional reduction of low-density lipoprotein cholesterol (LDL-C) levels can be induced by the combination of ezetimibe with statins, it is not known if this can enhance some pleiotropic effects, which may be useful in slowing the atherosclerotic process. This study assessed the effects of simvastatin and ezetimibe, in monotherapy or in combination, on markers of endothelial function and insulin sensitivity. Fifty prediabetic subjects with normo- or mild-to-moderate hypercholesterolemia were randomly allocated to 2 groups receiving either ezetimibe (10 mg/d) or simvastatin (20 mg/d) for 12 weeks, after which the drugs were combined for both groups for an additional 12-week period. Clinical and laboratory parameters were measured at baseline and after 12 and 24 weeks of therapy. Homeostasis model assessment of insulin resistance index and the area under the curve of insulin were calculated. As expected, both groups receiving drugs in isolation significantly reduced total cholesterol, LDL-C, apolipoprotein B, and triglyceride levels; and additional reductions were found after the combination period (P <.05). After 12 weeks of monotherapy, plasminogen activator inhibitor-1 levels and urinary albumin excretion were lower in the simvastatin than in the ezetimibe group. No change in homeostasis model assessment of insulin resistance index, area under the curve of insulin, and adiponectin levels was observed tiller either the monotherapies or the combined therapy. However, simvastatin combined with ezetimibe provoked significant reductions in E-selectin and intravascular cellular adhesion molecule-1 levels that were independent of LDL-C changes. Our findings support claims that simvastatin may be beneficial in preserving endothelial function in prediabetic subjects with normo- or mild-to-moderate hypercholesterolemia. Alternatively, a deleterious effect of ezetimibe on the endothelial function is suggested, considering the increase in intravascular cellular adhesion molecule I and E-selectin levels. Simvastatin and ezetimibe, in isolation or in combination, do not interfere with insulin sensitivity. (C) 2010 Elsevier Inc. All rights reserved.

Effects of Exercise Training on Hepatic Microsomal Triglyceride Transfer Protein Content in Rats

Microsomal triglyceride transfer protein (MTP) is a protein that exerts a central regulatory role in very-low-density lipoprotein (VLDL) assembly and secretion. The purpose of the study was to investigate the effects of all exercise-training program oil hepatic content of MTP and its relation to hepatic VLDL-triglyceride (VLDL-TG) production in response to lipid infusion. Female rats either fed a standard (SD) or all obesity-induced high-fat (HF; 43% as energy) diet for 8 weeks were Subdivided into sedentary (Sed) and trained (Tr) groups. Exercise training consisted Of Continuous running on a motor-driven rodent treadmill 5 times/week for 8 weeks. At the end of this period, all rats in the fasted state were intravenously infused with a 20% Solution of intralipid for 3 h followed by all injection of Triton WR1339 to block lipoprotein lipase. An additional control grout) consisting of Sed rats fed the SD diet was infused with saline (0.9% NaCl). Plasma TG accumulation was thereafter measured during 90 min to estimate VLDL-TG production. Under HF diet, hepatic MTP content and plasma TG accumulation after Triton blockade (thus reflecting VLDL-TG synthesis and secretion) were not changed in Sed rats, whereas liver TG content was highly increased (similar to 90%; p<0.01). Oil the other hand, training reduced liver MTP protein content in both SD(-18%) and HF(-23%) fed rats(p<0.05). Plasma VLDL-TG accumulation was also lower (p<0.05) in Tr than in Sed rats fed the HF diet. This effect was not observed in SD fed rats. Furthermore, the exercise training-induced decrease in VLDL-TG production in HF rats was associated with a decrease in liver TG levels. It is Concluded that in addition to a reduction in liver TG content, exercise training reduces VLDL synthesis and/or secretion in HF fed rats probably via MTP regulation.

Inflammation and adipose tissue: effects of progressive load training in rats

Introduction: Cytokines (IL-6, IL-10 and TNF-alpha) are increased after exhaustive exercise in the rat retroperitoneal (RPAT) and mesenteric adipose tissue (MEAT) pads. On the other hand, these cytokines show decreased expression in these depots in response to a chronic exercise protocol. However, the effect of exercise with overload combined with a short recovery period on pro-and anti-inflammatory cytokine expression is unknown. In the present study, we investigated the regulation of cytokine production in the adipose tissue of rats after an overtraining-inducing exercise protocol. Methods: Male Wistar rats were divided into four groups: Control (C), Trained (Tr), Overtrained (OT) and recovered overtrained (R). Cytokines (IL-6, TNF-alpha and IL-10) levels and Toll Like Receptor 4 (TLR4), Nuclear Factor kBBp65 (NF-kBp65), Hormone Sensitive Lipase (HSL) and, Perilipin protein expression were assessed in the adipose tissue. Furthermore, we analysed plasma lipid profile, insulin, testosterone, corticosterone and endotoxin levels, and liver triacylglycerol, cytokine content, as well as apolipoprotein B (apoB) and TLR4 expression in the liver. Results: OT and R groups exhibited reduced performance accompanied by lower testosterone and increased corticosterone and endotoxin levels when compared with the control and trained groups. IL-6 and IL-10 protein levels were increased in the adipose tissue of the group allowed to recover, in comparison with all the other studied groups. TLR-4 and NF-kBp65 were increased in this same group when compared with both control and trained groups. The protein expression of HSL was increased and that of Perilipin, decreased in the adipose in R in relation to the control. In addition, we found increased liver and serum TAG, along with reduced apoB protein expression and IL-6 and IL-10 levels in the of R in relation to the control and trained groups. Conclusion: In conclusion, we have shown that increases in pro-inflammatory cytokines in the adipose tissue after an overtraining protocol may be mediated via TLR-4 and NF-kBp65 signalling, leading to an inflammatory state in this tissue.

Vitellin-binding proteins in the nematode Oscheius tipulae (Nematoda, Rhabditida)

We describe the first application of a non-radioactive ligand-blotting technique to the characterization of proteins interacting with nematode vitellins. Chromatographically purified vitellins from the free-living nematode Oscheius tipulae were labeled with fluorescein in vitro. Ligand-blotting assays with horseradish peroxidase-conjugated anti-fluorescein antibodies showed that labeled vitellins reacted specifically with a polypeptide of approximately 100 kDa, which we named P100. This polypeptide is a specific worm`s vitellin-binding protein that is present only in adult worms. Blots containing purified O. tipulae vitellin preparations showed no detectable signal in the 100 kDa region, ruling out any possibility of yolk polypeptides self-assembling under the conditions used in our assay. Experiments done in the presence of alpha-methyl mannoside ruled out the possibility of vitellins binding to P100 through mannose residues. Triton X-114 fractionation of whole worm extracts showed that P100 is either a membrane protein or has highly hydrophobic regions. (C) 2008 Elsevier Inc. All rights reserved.

Effect of endurance training upon lipid metabolism in the liver of cachectic tumour-bearing rats

The syndrome of cancer cachexia is accompanied by several alterations in lipid metabolism, and the liver is markedly affected. Previous Studies showed that moderate exercise training may prevent liver fill accumulation through diminished delivery of lipids to the liver, increased hepatic oxidation and increased incorporation of triacylglycerol (TAG) into very low density lipoprotein (VLDL). Our aim was to examine the influence of moderate intensity training (8 weeks) upon TAG content, VLDL assembly and secretion, apolipoprotein B (apoB) and microsomal transfer protein (MTP) gene expression in the liver of cachectic tumour-bearing rats. Animals were randomly assigned to a sedentary control (SC), sedentary tumour-bearing (ST) or exercise-trained control (EC) or to all exercise trained tumour-bearing (ET) group. Trained rats ran on a treadmill (60% VO2max) for 60 min day(-1), 5 day week(-1), for 8 weeks. TAG content and the rate of VLDL secretion (followed for 3 h), its well its mRNA expression of apoB and MTP, and total cholesterol, VLDL-TAG, VLDL-cholesterol, high density lipoprotein cholesterol (HDL-cholesterol) and tumor weight were evaluated. VLDL-cholesterol showed a decrease in ST (p < 0.05) in relation to SC. Serum TAG, VLDL-TAG and tissue TAG content were all increased in ST (p < 0.01), when compared with SC. ST showed a lower rate of VLDL secretion (p < 0.05) and reduced expression of apoB (p < 0.001) and MTP (p < 0.001), when compared with SC. These parameters were restored to control values (p < 0.05) when the animals were submitted to the exercise training protocol. Tumour weight decreased 10-fold after training (p < 0.001). It is possible to affirm, therefore, that endurance training promoted the re-establishment of lipid metabolism in cachectic tumour-bearing animals, especially in relation to VLDL secretion and assembly. Copyright (C) 2008 John Wiley & Sons, Ltd.