High saturated fatty acid (SFA) diets contribute to the development of insulin resistance, whereas fish oil-derived n-3 polyunsaturated fatty acids (PUFA) increase the secretion of adiponectin (Ad), an adipocyte-derived protein that stimulates fatty acid oxidation (FAO) and improves skeletal muscle insulin response. We sought to determine if fish oil could ...

PURPOSE: The objective was to confirm the anti-obesity activity of a silk peptide (SP) and a silkworm pupa peptide (SPP) in rats fed a high-fat diet (HFD) and to elucidate their action mechanism(s) in a preadipocyte culture system. METHODS: In an in vitro mechanistic study, the differentiation and maturation of ...

The aim of this work was to investigate the effect of a daily mixed nutritional supplement upon body composition, physical performance, and circulating anabolic hormones in soldiers undergoing arduous training. Thirty males received either a habitual diet alone (CON, n = 15) or with the addition of a daily mixed supplement (SUP, ...

The present study was conducted to characterise the in vitro antimicrobial activities of 3 essential oils [oregano, rosemary, and a commercial blend of essential oils (BEO)] against pathogenic and non pathogenic bacteria and to evaluate their effects on broiler chicken performances. The chemical composition of the essential oils was determined ...

A study was conducted with male and female adult broiler breeders to determine the effect of feeding a fish oil supplement on selected immune activities. The fish oil was added to the diet such that the n-6:n-3 ratios could meet certain levels. Four hundred Ross 308 broiler breeder hens and ...

1. The study was conducted to investigate the efficacy of Saccharomyces cerevisiae extract (SC) on haematological parameters, immune function, and the antioxidant defence system in breeder hens fed a diet contaminated with low level aflatoxin (AF). 2. Forty-eight Ross 308 breeder hens were fed on diets containing AF (0 or ...

The aim was to investigate the influence of a daily mixed nutritional supplement during an 8-week arduous training programme on immune indices and mediators including circulating leucocyte counts; bacterially stimulated neutrophil degranulation; interleukin-6 (IL-6), cortisol and saliva secretory immunoglobulin-A (SIgA). Thirty men (mean (SD): age 25 (3) years; body mass, 80.9 ...

BACKGROUND & AIMS: Age-related inflammation and insulin resistance (IR) have been implicated in the inability of old muscles to properly respond to anabolic stimuli such as amino acids (AA) or insulin. Since fatty acids can modulate inflammation and IR in muscle cells, we investigated the effect of palmitate-enriched diet and ...

Atherosclerosis has been characterized as a chronic inflammatory response to cholesterol deposition in arteries. Plasma high density lipoprotein (HDL) levels bear a strong independent inverse relationship with atherosclerotic cardiovascular disease. One central antiatherogenic role of HDL is believed to be its ability to remove excessive peripheral cholesterol back to the ...

Increased blood cholesterol is an independent risk factor for atherosclerotic cardiovascular disease. Cholesterol homeostasis in the body is controlled mainly by endogenous synthesis, intestinal absorption, and hepatic excretion. Niemann-Pick C1-Like 1 (NPC1L1) is a polytopic transmembrane protein localized at the apical membrane of enterocytes and the canalicular membrane of hepatocytes. ...

The objective of this study was to determine if dietary cation-anion balance (DCAB) affects the concentration of S that can be tolerated by growing and finishing cattle without adversely affecting performance. Angus cross and Bradford steers (n = 114; average initial BW = 252.8 kg) were blocked by BW and ...

BACKGROUND: Mixing salt-tolerant plants with other plants may affect rumen fermentation, which could result in an increase of feed conversion rate. The objective of this study was to evaluate the effects of partially or entirely replacing the corn stover with a mixture of salt-tolerant forage (Dahurian wildrye grass, weeping alkaligrass ...

The mechanisms of endosomal and lysosomal cholesterol traffic are still poorly understood. We showed previously that unesterified cholesterol accumulates in the late endosomes and lysosomes of fibroblasts deficient in both lysosome associated membrane protein-2 (LAMP-2) and LAMP-1, two abundant membrane proteins of late endosomes and lysosomes. In this study we ...

Accumulating evidence indicates a link between cholesterol and age-related macular degeneration. Yet, little is known about cholesterol elimination from the retina and retinal pigment epithelium (RPE), the two layers that are damaged in this blinding disease. Several different pathways of enzymatic cholesterol removal exist in extraocular tissues. The authors tested ...

Background Sphingomyelin (SM) is present in dietary products and cell plasma membranes. We previously showed that dietary SM inhibited cholesterol absorption in rats. In the intestinal tract, SM is mainly hydrolyzed by alkaline sphingomyelinase (alk-SMase) to ceramide.Aims We investigated the influence of SM and its hydrolytic products ceramide and sphingosine ...

macrophages cannot limit the uptake of lipids and rely on cholesterol efflux mechanisms for maintaining cellular cholesterol homeostasis. Important mediators of macrophage cholesterol efflux are ATP-binding cassette transporter 1 (ABCA1), which mediates the efflux of cholesterol to lipid-poor apolipoprotein AI, and scavenger receptor class B type I (SR-BI), which promotes ...

The transmembrane protein Niemann-Pick C1 Like 1 (NPC1L1) belongs to the Niemann-Pick C1 (NPC1) family of cholesterol transporters and is mainly expressed in the liver and the small intestine. NPC1L1 is believed to be the main transporter responsible for the absorption of dietary cholesterol. Like NPC1, NPC1L1 contains a sterol ...

Abstract Reverse cholesterol transport is the process by which extrahepatic cells, including macrophage-derived foam cells in arterial atherosclerotic plaque, transport excessive cholesterol back to the liver for bile acid synthesis and excretion, thus lowering the peripheral lipid burden. Cholesterol efflux from peripheral cells is the first step in this process, ...

Serum opacity factor (SOF) is a streptococcal protein that disrupts the structure of human high density lipoproteins (HDL) releasing lipid-free apo A-I while forming a large cholesteryl ester-rich particle and a small neo HDL. Given its low cholesterol and high phospholipid contents, we tested the hypotheses that neo HDL is ...

Cholesterol efflux mechanisms are essential for macrophage cholesterol homeostasis. HDL, an important cholesterol efflux acceptor, comprises a class of heterogeneous particles that induce cholesterol efflux via distinct pathways. This review focuses on the understanding of the different cholesterol efflux pathways and physiological acceptors involved, and their regulation in atherosclerotic lesions. ...

The prion diseases are neurodegenerative disorders characterized by the conversion of the PrPc (normal cellular prion) to the PrPsc (misfolded isoform). The accumulation of PrPsc within the central nervous system (CNS) leads to neurocytotoxicity by increasing oxidative stress. In addition, many neurodegenerative disorders including prion, Parkinson's and Alzheimer's diseases may ...

Recent evidence suggests that the major pathways mediating cell cholesterol homeostasis respond to a common signal: active membrane cholesterol. Active cholesterol is the fraction that exceeds the complexing capacity of the polar bilayer lipids. Increments in plasma membrane cholesterol exceeding this threshold have an elevated chemical activity (escape tendency) and ...

We tested the hypothesis that aldosterone causes a loss of the normal anticontractile function of healthy fat via a hypoxia-related pathway, which can be rescued using spironolactone. Healthy rat mesenteric arteries ( approximately 250%muM diameter) and perivascular fat were investigated using wire myography and Perl's Prussian blue staining for activated ...

AIM/ BACKGROUND: Various interactions between Caveolae membrane domains, multidrug resistance transporter P-glycoprotein (P-gp) and cholesterol have been suggested. We tested the assumption that anthracycline-induced P-gp and Caveolin-1 have correlated effects on cholesterol distribution in plasma membrane. The present study was performed in four lymphoblastic K562 cell lines expressing none (KS), ...

Cholesterol is a known risk factor in aortic stenosis and valve degeneration, and the liver X receptor (LXR) is a regulator of cholesterol and phospholipid metabolism. It was hypothesized that an LXR agonist would reduce calcium and lipid deposition in aortic valves. Apolipoprotein E-/- (ApoE-/-) mice fed a high-fat diet ...

To investigate whether cholesterol efflux to high-density lipoprotein (HDL) via ATP-binding cassette transporter G1 (ABCG1) modulates the interaction of caveolin (Cav) 1 and endothelial NO synthase (eNOS). ABCG1 promotes cholesterol and 7-oxysterol efflux from endothelial cells (ECs) to HDL. It was previously reported that ABCG1 protects against dietary cholesterol-induced endothelial ...

Cholesterol homeostasis in the enterocyte is regulated by the interplay of multiple genes that ultimately determines the net amount of cholesterol reaching the circulation from the small intestine. The effect of deleting these genes, particularly acyl CoA:cholesterol acyl transferase 2 (ACAT2), on cholesterol absorption and fecal sterol excretion is well ...

The etiology of Alzheimer's disease (AD) is complex with oxidative stress being a possible contributory factor to pathogenesis and disease progression. TASTPM transgenic mice expressing familial AD-associated amyloid precursor protein (APPswe) and presenilin transgenes (PS1M146V) show increased brain amyloid beta (Abeta) levels and Abeta plaques from 3 months. We tested ...

Lipid and cholesterol metabolism in the postprandial phase is associated with both quantitative and qualitative remodeling of HDL particle subspecies that may influence their anti-atherogenic functions in the reverse cholesterol transport pathway. We evaluated the capacity of whole plasma or isolated HDL particles to mediate cellular free cholesterol (FC) efflux, ...

Net flux of cholesterol represents the difference between efflux and influx and can result in net cell-cholesterol accumulation, net cell-cholesterol depletion, or no change in cellular cholesterol content. We measured radiolabeled cell-cholesterol efflux and cell-cholesterol mass using cholesterol-normal and -enriched J774 and elicited mouse peritoneal macrophage cells. Net cell-cholesterol effluxes ...

Recent findings suggest that altered cholesterol homeostasis may contribute to the pathophysiology of Huntington's disease (HD). To understand the underlying mechanisms, here we used a combination of two-photon microscopy, epifluorescence, and biochemical methods to visualize and quantify lipid distribution in cell cultures expressing mutant huntingtin. Such expression promotes lipid imbalance, ...

Brain cholesterol, which is synthesized locally, is a major component of myelin and cell membranes and participates in neuronal functions, such as membrane trafficking, signal transduction, neurotransmitter release, and synaptogenesis. Here we show that brain cholesterol biosynthesis is reduced in multiple transgenic and knock-in Huntington's disease (HD) rodent models, arguably ...

The mechanisms of intracellular cholesterol transport are largely unknown. In this issue of Cell Metabolism, Wang et al. (2010) identify amino acid residues on the lumenal lysosomal protein Niemann-Pick C2 (NPC2) that are required for intralysosomal transfer of endocytosed cholesterol to membrane-bound NPC1 via a process that avoids movement of ...

A precise and sensitive method for measuring cellular free and esterified cholesterol is required in order to perform studies of macrophage cholesterol loading, metabolism, storage, and efflux. Until now, the use of an enzymatic cholesterol assay, commonly used for aqueous phase plasma cholesterol assays, has not been optimized for use ...

Targeted gene delivery offers immense potential for clinical applications. Liposomes decorated with targeting ligands have been extensively used for both in vitro and in vivo gene delivery. Lipoplexes with high cholesterol content that result in cholesterol domain formation within the complexes have been shown to exhibit enhanced transfection in vitro ...

Altered lipid metabolism has been implicated as a critical player in osteoarthritis (OA). Our study aimed to investigate the expression of genes regulating cholesterol efflux in human chondrocytes and to study the effect of an LXR agonist on cholesterol efflux and lipid accumulation in osteoarthritic chondrocytes. ATP-binding-cassette transporter A1 (ABCA1), ...

The niacin receptor GPR109A is a G(i)-protein-coupled receptor which mediates the effects of niacin on inhibiting intracellular triglyceride lipolysis in adipocytes. However, the role of GPR109A in mediating the effects of niacin on high density lipoprotein (HDL) metabolism is unclear. We found niacin has no effect on HDL-C in GPR109A ...

Cholesterol has been linked to the pathogenesis of sporadic Alzheimer's disease (AD) as a risk factor increasing beta-amyloid (Abeta) and oxidative stress levels. Caffeine has antioxidant properties and has been demonstrated to reduce Abeta levels in transgenic mouse models of familial AD. However, the effects of caffeine on cholesterol-induced sporadic ...

Amyloid beta (Abeta) is a key molecule in the pathogenesis of Alzheimer's disease, but its physiological function remains unclear. Abeta is produced from amyloid precursor protein (APP) by beta- and gamma-secretases, which is enhanced by high levels of cellular cholesterol, so cholesterol is a risk factor for Alzheimer's disease. This ...

Alzheimer's disease (AD) is a neurodegenerative disorder and the leading cause of dementia in the elderly. The two hallmark lesions in AD brain are deposition of amyloid plaques and neurofibrillary tangles (NFTs). Hypercholesteremia is one of the risk factors of AD. But its role in the pathogenesis of AD is ...

Dysregulated macrophage cholesterol homoeostasis lies at the heart of early and developing atheroma, and removal of excess cholesterol from macrophage foam cells, by efficient transport mechanisms, is central to stabilization and regression of atherosclerotic lesions. The present study demonstrates that transient overexpression of STARD3 {START [StAR (steroidogenic acute regulatory protein)-related ...

Cholesterol is the most abundant lipid component of the plasma membrane, and thus the equilibrium between free cholesterol and raft cholesterol act as a determinant of raft function and cell signalling. The mechanisms that regulate the lipid raft cholesterol levels are largely unknown. Here we demonstrate that SERPINA1 (alpha1-antitrypsin), an ...

Niemann-Pick type C1 disease is an autosomal-recessive lysosomal storage disorder. Loss of function of the npc1 gene leads to abnormal accumulation of free cholesterol and sphingolipids within the late endosomal and lysosomal compartments resulting in progressive neurodegeneration and dysmyelination. Here, we show that oligodendroglial cells secrete cholesterol by exosomes when ...

Adipose tissue is a major reservoir of cholesterol and, as such, it may play a significant role in cholesterol homeostasis. The aims of this study were to obtain a quantitative characterization of apolipoprotein A-I (apoA-I)-dependent lipid efflux from adipocytes and examine the role of ATP-binding cassette transporter A1 (ABCA1) in ...

ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 mediate the efflux of cholesterol and other sterols. Both transporters are expressed on the fetal capillaries of the placenta and are involved in maternal-to-fetal cholesterol delivery. In this study, we report that ABCA1 and ABCG1 are also present on the syncytiotrophoblast, the maternal ...

Despite its importance for mammalian cell biology and human health, there are many basic aspects of cholesterol homeostasis that are not well understood. Even for the well-characterized delivery of cholesterol to cells via lipoproteins, a novel regulatory mechanism has been discovered recently, involving a serum protein called PCSK9, which profoundly ...

Acyl-coenzyme A: cholesterol acyltransferase1 (ACAT1) is an endoplasmic reticulum (ER)-resident enzyme that catalyzes the conversion of cholesterol into cholesteryl esters. We previously showed that cholesterol-loaded macrophages produce numerous ER-derived vesicles with elevated ACAT1 enzyme activity; some of these vesicles were shown to be closely associated with Golgi-related organelle(s). The aim ...

PURPOSE OF REVIEW: Regulation of cholesterol homeostasis is a complex interplay of a multitude of metabolic pathways situated in different organs. The liver plays a central role and has received most attention of the research community. In this review, we discuss recent progress in the understanding of the emerging role ...

Several lines of evidence support a strong relationship between cholesterol and Alzheimer's disease pathogenesis. Membrane cholesterol is known to modulate amyloid precursor protein (APP) endocytosis and amyloid-beta (Abeta) secretion. Here we show in a human cell line model of endocytosis (HEK293 cells) that cholesterol exerts these effects in a dose-dependent ...

Intravenous administration of apolipoprotein (apo) A-I complexed with phospholipid has been shown to rapidly reduce plaque size in both animal models and humans. Short synthetic amphipathic peptides can mimic the antiatherogenic properties of apoA-I and have been proposed as alternative therapeutic agents. In this study, we investigated the atheroprotective effect ...