Search results for "lipid droplet"
showing 10 items of 54 documents
On the pathogenesis of atherosclerosis: enzymatic transformation of human low density lipoprotein to an atherogenic moiety.
1995
Combined treatment with trypsin, cholesterol esterase, and neuraminidase transforms LDL, but not HDL or VLDL, to particles with properties akin to those of lipid extracted from atherosclerotic lesions. Single or double enzyme modifications, or treatment with phospholipase C, or simple vortexing are ineffective. Triple enzyme treatment disrupts the ordered and uniform structure of LDL particles, and gives rise to the formation of inhomogeneous lipid droplets 10-200 nm in diameter with a pronounced net negative charge, but lacking significant amounts of oxidized lipid. Enzymatically modified LDL (E-LDL), but not oxidatively modified LDL (ox-LDL), is endowed with potent complement-activating c…
Etude des mécanismes physiologiques et moléculaires permettant la prise en charge des substrats hydrophobes par la levure Yarrowia lipolytica au nive…
2012
Yarrowia lipolytica can grow on many hydrophobic substrates and metabolize them via the β-oxidation pathway or store them into lipid bodies. The first contact between the cell and the hydrophobic substrates is by the cell wall. In this step, cell-wall proteins (CWP), β-glucane and chitin of the cell wall could play an important role for the adhesion and uptake of hydrophobic substrates. The aim of this work was to study the effect of a hydrophobic carbon source (compared with glucose) and the culture medium composition on the cell wall composition and the melanin production by Y. lipolytica. The results of our biochemical and molecular analysis showed that the presence of methyl oleate and …
Mechanism of lipid-body formation in prokaryotes: how bacteria fatten up
2004
Neutral lipid accumulation is frequently observed in some Gram-negative prokaryotes like Acinetobacter sp. and most actinomycetes, including the pathogenic Mycobacterium tuberculosis and antibiotic producing streptomycetes. We examined the formation of wax ester- and triacylglycerol (TAG)-bodies in Acinetobacter calcoaceticus and Rhodococcus opacus using microscopic, immunological and biophysical methods. A general model for prokaryotic lipid-body formation is proposed, clearly differing from the current models for the formation of lipid inclusions in eukaryotes and of poly(hydroxyalkanoic acid) (PHA) inclusions in prokaryotes. Formation of lipid-bodies starts with the docking of wax ester …
Abnormal Lipopigments and Lysosomal Residual Bodies in Metachromatic Leukodystrophy
1990
Ultrastructurally, metachromatic leukodystrophy (MLD) is marked by characteristic features such as herringbone, prismatic and tufaceous patterns which are typically encountered within oligodendrocytes of the central nervous system (CNS) and in Schwann cells (PNS). These patterns can be documented in late infantile, juvenile, and adult forms. In the latter, aging of the ailing individual adds another component, the accumulation of lipopigments which are marked by an opaque supposedly lipid droplet and a granular component. While MLD-specific lysosomal residual bodies occur in myelinforming cells, lipopigments accrue in neurons and to a lesser degree in astrocytes. MLD represents a unique exa…
Correlative Raman-Electron-Light (CREL) Microscopy Analysis of Lipid Droplets in Melanoma Cancer Stem Cells.
2022
Among all neoplasms, melanoma is characterized by a very high percentage of cancer stem cells (CSCs). Several markers have been proposed for their identification, and lipid droplets (LDs) are among them. Different techniques are used for their characterization such as mass spectrometry, imaging techniques, and vibrational spectroscopies. Some emerging experimental approaches for the study of LDs are represented by correlative light–electron microscopy and by correlative Raman imaging–scanning electron microscopy (SEM). Based on these scientific approaches, we developed a novel methodology (CREL) by combining Raman micro-spectroscopy, confocal fluorescence microscopy, and SEM coupled with an…
Oat and lipolysis: Food matrix effect
2019
International audience; Oat is rich in a wide range of phytochemicals with various physico-chemical, colloidal and interfacial properties. These characteristics are likely to influence human lipid metabolism and the subsequent effect on health following oat consumption. The aim of this work was to investigate the impact of oat materials varying in complexity on the lipolysis process. The composition, structure and digestibility of different lipid systems (emulsions, oil bodies and oil enriched in phytosterols) were determined. The surface activities of phytosterols were examined using the pendant drop technique. Differences in lipid digestibility of the oat oil emulsions and the oil bodies …
Primo ricerche sulla ultrastruttura dell'uovo delle Ascidie
1959
Summary The cytoplasmic constituents of the unfertilized eggs of Ciona intestinalis were separated by centrifugation and studied at the electron microscope, with the following results. Lipid droplets collect at the centripetal pole; they are boundered by a thin membrane. The yolk granules are homogeneous in appearance; a few have a granular structure. Mitochondria contain numerous cristae; they accumulate in two different layers centripetally and centrifugally to the yolk granules layer respectively. Basophilic material collects at both poles of the egg in two hyaline caps: a centripetal one constituted by small Vesicles and a centrifugal represented by dense clumps. The latter, as well as …
Curcumin and Andrographolide Co-Administration Safely Prevent Steatosis Induction and ROS Production in HepG2 Cell Line
2023
Non-alcoholic fatty liver disease (NAFLD) is an emerging chronic liver disease worldwide. Curcumin and andrographolide are famous for improving hepatic functions, being able to reverse oxidative stress and release pro-inflammatory cytokines, and they are implicated in hepatic stellate cell activation and in liver fibrosis development. Thus, we tested curcumin and andrographolide separately and in combination to determine their effect on triglyceride accumulation and ROS production, identifying the differential expression of genes involved in fatty liver and oxidative stress development. In vitro steatosis was induced in HepG2 cells and the protective effect of curcumin, andrographolide, and…
Effects of Long-Term Physical Activity and BCAA Availability on the Subcellular Associations between Intramyocellular Lipids, Perilipins and PGC-1&al…
2023
Cellular skeletal muscle lipid metabolism is of paramount importance for metabolic health, specifically through its connection to branched-chain amino acids (BCAA) metabolism and through its modulation by exercise. In this study, we aimed at better understanding intramyocellular lipids (IMCL) and their related key proteins in response to physical activity and BCAA deprivation. By means of confocal microscopy, we examined IMCL and the lipid droplet coating proteins PLIN2 and PLIN5 in human twin pairs discordant for physical activity. Additionally, in order to study IMCLs, PLINs and their association to peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in cytosolic…
Renal Lipotoxicity-Associated Inflammation and Insulin Resistance Affects Actin Cytoskeleton Organization in Podocytes
2015
In the last few decades a change in lifestyle has led to an alarming increase in the prevalence of obesity and obesity-associated complications. Obese patients are at increased risk of developing hypertension, heart disease, insulin resistance (IR), dyslipidemia, type 2 diabetes and renal disease. The excess calories are stored as triglycerides in adipose tissue, but also may accumulate ectopically in other organs, including the kidney, which contributes to the damage through a toxic process named lipotoxicity. Recently, the evidence suggests that renal lipid accumulation leads to glomerular damage and, more specifically, produces dysfunction in podocytes, key cells that compose and maintai…