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Lipid Droplets (lipid + droplet)
Kinds of Lipid Droplets Selected AbstractsUltrastructure of the ovary and oogenesis in six species of patellid limpets (Gastropoda: Patellogastropoda) from South AfricaINVERTEBRATE BIOLOGY, Issue 3 2000Alan N. Hodgson Abstract. The ultrastructural features of the ovary and oogenesis have been described in 6 species of patellid limpets from South Africa. The ovary is a complex organ that is divided radially into numerous compartments or lacunae by plate-like, blind-ended, hollow trabeculae that extend from the outer wall of the ovary to its central lumen. Trabeculae are composed of outer epithelial cells, intermittent smooth muscle bands, and extensive connective tissue. Oocytes arise within the walls of the trabeculae and progressively bulge outward into the ovarian lumen during growth while partially surrounded by squamous follicle cells. During early vitellogenesis, the follicle cells lift from the surface of the underlying oocytes and microvilli appear in the perivitelline space. Follicle cells restrict their contact with the oocytes to digitate foot processes that form desmosomes with the oolamina. When vitellogenesis is initiated, the trabecular epithelial cells hypertrophy and become proteosynthetically active. Yolk synthesis involves the direct incorporation of extraoocytic precursors from the lumen of the trabeculae (hemocoel) into yolk granules via receptor-mediated endocytosis. Lipid droplets arise de novo and Golgi complexes synthesize cortical granules that form a thin band beneath the oolamina. A fibrous jelly coat forms between the vitelline envelope and the overlying follicle cells in all species. [source] Effect of intracellular lipid droplets on cytosolic Ca2+ and cell death during ischaemia,reperfusion injury in cardiomyocytesTHE JOURNAL OF PHYSIOLOGY, Issue 6 2009Ignasi Barba Lipid droplets (LD) consist of accumulations of triacylglycerols and have been proposed to be markers of ischaemic but viable tissue. Previous studies have described the presence of LD in myocardium surviving an acute coronary occlusion. We investigated whether LD may be protective against cell death secondary to ischaemia,reperfusion injury. The addition of oleate,bovine serum albumin complex to freshly isolated adult rat cardiomyocytes or to HL-1 cells resulted in the accumulation of intracellular LD detectable by fluorescence microscopy, flow cytometry and 1H-nuclear magnetic resonance spectroscopy. Simulated ischaemia,reperfusion of HL-1 cells (respiratory inhibition at pH 6.4 followed by 30 min of reperfusion) resulted in significant cell death (29.7 ± 2.6% of total lactate dehydrogenase release). However, cell death was significantly attenuated in cells containing LD (40% reduction in LDH release compared with control cells, P= 0.02). The magnitude of LD accumulation was inversely correlated (r2= 0.68, P= 0.0003) with cell death. The protection associated with intracellular LD was not a direct effect of the fatty acids used to induce their formation, because oleate added 30 min before ischaemia, during ischaemia or during reperfusion did not form LD and did not protect against cell death. Increasing the concentration of free oleate during reperfusion progressively decreased the protection afforded by LD. HL-1 cells labelled with fluo-4, a Ca2+ -sensitive fluorochrome, fluorescence within LD areas increased more throughout simulated ischaemia and reperfusion than in the cytosolic LD-free areas of the same cells. As a consequence, cells with LD showed less cytosolic Ca2+ overload than control cells. These results suggest that LD exert a protective effect during ischaemia,reperfusion by sequestering free fatty acids and Ca2+. [source] Regulated expression by PPAR, and unique localization of 17,-hydroxysteroid dehydrogenase type 11 protein in mouse intestine and liverFEBS JOURNAL, Issue 18 2007Yasuhide Yokoi 17,-Hydroxysteroid dehydrogenase type 11 (17,-HSD11) is a member of the short-chain dehydrogenase/reductase family involved in the activation and inactivation of sex steroid hormones. We recently identified 17,-HSD11 as a gene that is efficiently regulated by peroxisome proliferator-activated receptor-, PPAR, in the intestine and the liver [Motojima K (2004) Eur J Biochem271, 4141,4146]. In this study, we characterized 17,-HSD11 at the protein level to obtain information about its physiologic role in the intestine and liver. For this purpose, specific antibodies against 17,-HSD11 were obtained. Western blotting analysis showed that administration of a peroxisome proliferator-activated receptor-, agonist induced 17,-HSD11 protein in the jejunum but not in the colon, and to a much higher extent than in the liver of mice. A subcellular localization study using Chinese hamster ovary cells and green fluorescent protein-tagged 17,-HSD11 showed that it was mostly localized in the endoplasmic reticulum under normal conditions, whereas it was concentrated on lipid droplets when they were induced. A pulse-chase experiment suggested that 17,-HSD11 was redistributed to the lipid droplets via the endoplasmic reticulum. Immunohistochemical analysis using tissue sections showed that 17,-HSD11 was induced mostly in intestinal epithelia and hepatocytes, with heterogeneous localization both in the cytoplasm and in vesicular structures. A subcellular fractionation study of liver homogenates confirmed that 17,-HSD11 was localized mostly in the endoplasmic reticulum when mice were fed a normal diet, but was distributed in both the endoplasmic reticulum and the lipid droplets of which formation was induced by feeding a diet containing a proliferator-activated receptor-, agonist. Taken together, these data indicate that 17,-HSD11 localizes both in the endoplasmic reticulum and in lipid droplets, depending on physiologic conditions, and that lipid droplet 17,-HSD11 is not merely an endoplasmic reticulum contaminant or a nonphysiologically associated protein in the cultured cells, but a bona fide protein component of the membranes of both intracellular compartments. [source] Possible involvement of protein kinase C in the induction of adipose differentiation-related protein by Sterol ester in RAW 264.7 macrophagesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2001Jin-Shan Chen Abstract The accumulation of lipid droplets in macrophages contributes to the formation of foam cells, an early event in atherosclerosis. It is, therefore, important to elucidate the mechanisms by which lipid droplets accumulate and are utilized. Sterol ester (SE)-laden RAW 264.7 macrophages accumulated lipid droplets in a time-dependent manner up to 16 h, which was enhanced by cotreatment with 0.1 ,M phorbol 12-myristate 13-acetate (PMA). Inhibition of protein kinase C (PKC) activity by cotreatment with 0.3 ,M calphostin C CAL for 16 h resulted in coalescence of small lipid droplets into large ones and increased accumulation of lipid droplets, although to a lesser extent than after PMA cotreatment. Immunostaining for adipose differentiation-related protein (ADRP) revealed a fluorescent rim at the surface of each medium to large lipid droplet. ADRP appearance correlated with lipid droplet accumulation and was regulated by PMA in a time-dependent manner. Induction of ADRP expression by PMA or CAL required SE, since ADRP levels in PMA- or CAL-treated non-SE-laden macrophages were comparable to those in untreated cells. Removal of SE from the incubation medium resulted in the concomitant dissolution of lipid droplets and down-regulation of ADRP. In conclusion, the above results suggest that ADRP may be an important protein in the regulation of lipid droplet metabolism in lipid-laden macrophages and that this regulation may be mediated by PKC activity. J. Cell. Biochem. 83: 187,199, 2001. © 2001 Wiley-Liss, Inc. [source] Light and Transmission Electron Microscopy of Immature Camelus Dromedarius OocyteANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2004H. Nili Summary In order to provide a consistent system for laboratory production of embryos, the characteristics of immature camel oocyte must first be described. The objective of this study was to define ultrastructural features of immature camel oocyte. Ovaries were obtained from camels at a local abattoir, and then transported to the laboratory within 2 h. Camelus cumulus oocyte complexes (COCs) were aspirated from 2,6 mm follicles using a 22-gauge needle. Excellent and good quality COCs were selected and prepared for transmission electron microscopy study using a cavity slide. The fine structure of camel oocyte is morphologically similar to that of other mammalian oocytes. However, some minor differences exist between COC of camel and other mammalian species. Different size and shape of membrane-bound vesicles, lipid droplet, mitochondria and cortical granules were distributed throughout the ooplasm. Discrete or in association with endoplasmic reticulum, Golgi complexes were observed in the periphery of the oocytes. The majority of the oocytes were in the germinal vesicle stage. [source] Changes in skeletal muscle size, fibre-type composition and capillary supply after chronic venous occlusion in ratsACTA PHYSIOLOGICA, Issue 4 2008S. Kawada Abstract Aim:, We have previously shown that surgical occlusion of some veins from skeletal muscle results in muscle hypertrophy without mechanical overloading in the rat. The present study investigated the changes in muscle-fibre composition and capillary supply in hypertrophied muscles after venous occlusion in the rat hindlimb. Methods:, Sixteen male Wistar rats were randomly assigned into two groups: (i) sham operated (sham-operated group; n = 7); (ii) venous occluded for 2 weeks (2-week-occluded group; n = 9). At the end of the experimental period, specimens of the plantaris muscle were dissected from the hindlimbs and subjected to biochemical and histochemical analyses. Results:, Two weeks after the occlusion, both the wet weight of plantaris muscle relative to body weight and absolute muscle weight showed significant increases in the 2-week-occluded group (,15%) when compared with those in the sham-operated group. The concentrations of muscle glycogen and lactate were higher in the 2-week-occluded group, whereas staining intensity of muscle lipid droplets was lower in the 2-week-occluded group than those in the sham-operated group. The percentage of type I muscle fibre decreased, whereas that of type IIb fibre increased in the 2-week-occluded group when compared with the sham-operated group. Although the expression of vascular endothelial growth factor-188 mRNA increased, the number of capillaries around the muscle fibres tended to decrease (P = 0.07). Conclusion:, Chronic venous occlusion causes skeletal muscle hypertrophy with fibre-type transition towards faster types and changes in contents of muscle metabolites. [source] In vivo analysis of MT-based vesicle transport by confocal reflection microscopyCYTOSKELETON, Issue 2 2009Imre Gáspár Abstract The use of confocal reflection microscopy (CRM) for the in vivo analysis of microtubule (MT) mediated transport of lipid droplets in the developing Drosophila egg primordia is described here. The developing Drosophila oocytes are ideal objects to study MT-mediated transport in vivo: transport of e.g. the lipid droplets can be conveniently, selectively and sensitively monitored through CRM and the egg primordia are readily available for physical, chemical and/or genetic manipulations. CRM is a non-destructive way to follow vesicle movement and allows high frame rate image recording. When combined with fluorescence imaging, CRM offers simultaneous visualization of the cargo and the protein(s) of interest, i.e. a motor or a cargo adapter, thus allowing a better understanding of MT-mediated transport and spatiotemporal coordination of the transport machinery. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source] Effect of tributyltin on testicular development in Sebastiscus marmoratus and the mechanism involved,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2009Jiliang Zhang Abstract Organotin compounds, such as tributyltin (TBT), that have been used as antifouling biocides can induce masculinization in female mollusks. However, few studies addressing the effects of TBT on fishes have been reported. The present study was conducted to investigate the effects of TBT at environmentally relevant concentrations (1,10, and 100 ng/L) on testicular development in Sebastiscus marmoratus and to gain insight into its mechanism of action. After exposure for 48 d, the gonadosomatic index had decreased in a dose-dependent manner. Although the testosterone levels in the testes were elevated and the 17,-estradiol levels were decreased, spermatogenesis was suppressed. Moreover, ,-glutamyl transpeptidase activity (which is used as a Sertoli cell marker) was decreased in a dose-dependent manner after TBT exposure, and serious interstitial fibrosis was observed in the interlobular septa of the testes in the 100 ng/L TBT test group. Increases in the retinoid × receptors and peroxisome proliferator activated receptor , expression and the progressive enlargement of lipid droplets in the testes were observed after TBT exposure. Estrogen receptor , levels in the testes of the fish exposed to TBT decreased in a dose-dependent manner. The reduction of estrogen receptor , mRNA resulted from the decrease of 17,-estradiol levels, and the progressive enlargement of lipid droplets may have contributed to the dysfunction of the Sertoli cells, which then disrupted spermatogenesis. [source] Regulated expression by PPAR, and unique localization of 17,-hydroxysteroid dehydrogenase type 11 protein in mouse intestine and liverFEBS JOURNAL, Issue 18 2007Yasuhide Yokoi 17,-Hydroxysteroid dehydrogenase type 11 (17,-HSD11) is a member of the short-chain dehydrogenase/reductase family involved in the activation and inactivation of sex steroid hormones. We recently identified 17,-HSD11 as a gene that is efficiently regulated by peroxisome proliferator-activated receptor-, PPAR, in the intestine and the liver [Motojima K (2004) Eur J Biochem271, 4141,4146]. In this study, we characterized 17,-HSD11 at the protein level to obtain information about its physiologic role in the intestine and liver. For this purpose, specific antibodies against 17,-HSD11 were obtained. Western blotting analysis showed that administration of a peroxisome proliferator-activated receptor-, agonist induced 17,-HSD11 protein in the jejunum but not in the colon, and to a much higher extent than in the liver of mice. A subcellular localization study using Chinese hamster ovary cells and green fluorescent protein-tagged 17,-HSD11 showed that it was mostly localized in the endoplasmic reticulum under normal conditions, whereas it was concentrated on lipid droplets when they were induced. A pulse-chase experiment suggested that 17,-HSD11 was redistributed to the lipid droplets via the endoplasmic reticulum. Immunohistochemical analysis using tissue sections showed that 17,-HSD11 was induced mostly in intestinal epithelia and hepatocytes, with heterogeneous localization both in the cytoplasm and in vesicular structures. A subcellular fractionation study of liver homogenates confirmed that 17,-HSD11 was localized mostly in the endoplasmic reticulum when mice were fed a normal diet, but was distributed in both the endoplasmic reticulum and the lipid droplets of which formation was induced by feeding a diet containing a proliferator-activated receptor-, agonist. Taken together, these data indicate that 17,-HSD11 localizes both in the endoplasmic reticulum and in lipid droplets, depending on physiologic conditions, and that lipid droplet 17,-HSD11 is not merely an endoplasmic reticulum contaminant or a nonphysiologically associated protein in the cultured cells, but a bona fide protein component of the membranes of both intracellular compartments. [source] Heterologous expression of AtClo1, a plant oil body protein, induces lipid accumulation in yeastFEMS YEAST RESEARCH, Issue 3 2009Marine Froissard Abstract Proteomic approaches on lipid bodies have led to the identification of proteins associated with this compartment, showing that, rather than the inert fat depot, lipid droplets appear as complex dynamic organelles with roles in metabolism control and cell signaling. We focused our investigations on caleosin [Arabidopsis thaliana caleosin 1 (AtClo1)], a minor protein of the Arabidopsis thaliana seed lipid body. AtClo1 shares an original triblock structure, which confers to the protein the capacity to insert at the lipid body surface. In addition, AtClo1 possesses a calcium-binding domain. The study of plants deficient in caleosin revealed its involvement in storage lipid degradation during seed germination. Using Saccharomyces cerevisiae as a heterologous expression system, we investigated the potential role of AtClo1 in lipid body biogenesis and filling. The green fluorescent protein-tagged protein was correctly targeted to lipid bodies. We observed an increase in the number and size of lipid bodies. Moreover, transformed yeasts accumulated more fatty acids (+46.6%). We confirmed that this excess of fatty acids was due to overaccumulation of lipid body neutral lipids, triacylglycerols and steryl esters. We showed that the original intrinsic properties of AtClo1 protein were sufficient to generate a functional lipid body membrane and to promote overaccumulation of storage lipids in yeast oil bodies. [source] ,-Synuclein, oxidative stress and apoptosis from the perspective of a yeast model of Parkinson's diseaseFEMS YEAST RESEARCH, Issue 8 2006Stephan N. Witt Abstract The neuronal protein ,-synuclein (,-syn) has been suggested to be one of the factors linked to Parkinson's disease (PD). Several organisms, including the rat, mouse, worm, and fruit fly, are being used to study ,-syn pathobiology. A new model organism was recently added to this armamentarium: the budding yeast Saccharomyces cerevisiae. The yeast system recapitulates many of the findings made with higher eukaryotes. For example, yeast cells expressing ,-syn accumulate lipid droplets, have vacuolar/lysosomal defects, and exhibit markers of apoptosis, including the externalization of phosphatidylserine, the release of cytochrome c, and the accumulation of reactive oxygen species. This MiniReview focuses on the mechanisms by which ,-syn induces oxidative stress and the mechanisms by which yeast cells respond to this stress. Three classes of therapeutics are discussed. [source] Morphology and ultrastructure of the swimming larvae of Crambe crambe (Demospongiae, Poecilosclerida)INVERTEBRATE BIOLOGY, Issue 4 2001María J. Uriz Abstract. We describe the morphology and ultrastructure of the free-swimming larvae of the sponge Crambe crambe, one of the most abundant encrusting sponges on shallow rocky bottoms of the western Mediterranean. Larvae of C. crambe are released in July and August. The larva is uniformly flagellated except at the posterior zone. Flagellated cells are extraordinarily slender, elongate, and sinuous and form a pseudo-stratified layer. Their distal zone contains abundant mitochondria, some small vesicles, a Golgi complex, and the basal apparatus of the flagellum. Abundant lipid droplets are present throughout the cell. The nucleus is most often in a basal position. The flagellum projects from the bottom of an asymmetrical socket formed by cytoplasmic expansions. The basal body extends in a conical tuft and a laminar rootlet in close association with the Golgi system. The cells at the posterior pole are flat and polygonal on the surface, with long overlapping pseudopodia in the typical shape of a pinacoderm. Sparse collagen is present throughout the whole larva including the flagellated layer. Archeocytes and sclerocytes are abundant in the posterior region. Typical collencytes and spherulous cells seem to be absent. Intracellular and extracellular rod-like bacteria with conspicuous fimbria occur exclusively in the posterior region of the larva. The asymmetrical cytoplasmic prolongations, which surround the flagellum, and the basal apparatus of the flagellum are suggested as the sites of stimulus reception and triggering of locomotor responses, respectively. This ultrastructural study of the larva of C. crambe has shown features directly linked to its behavior and ecology. [source] PPAR,1 synthesis and adipogenesis in C3H10T1/2 cells depends on S-phase progression, but does not require mitotic clonal expansionJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2004Young C. Cho Abstract Adipogenesis is typically stimulated in mouse embryo fibroblast (MEF) lines by a standard hormonal combination of insulin (I), dexamethasone (D), and methylisobutylxanthine (M), administered with a fresh serum renewal. In C3H10T1/2 (10T1/2) cells, peroxisome proliferator-activated receptor ,1 (PPAR,1) expression, an early phase key adipogenic regulator, is optimal after 36 h of IDM stimulation. Although previous studies provide evidence that mitotic clonal expansion of 3T3-L1 cells is essential for adipogenesis, we show, here, that 10T1/2 cells do not require mitotic clonal expansion, but depend on cell cycle progression through S-phase to commit to adipocyte differentiation. Exclusion of two major mitogenic stimuli (DM without insulin and fresh serum renewal) from standard IDM protocol removed mitotic clonal expansion, but sustained equivalent PPAR,1 synthesis and lipogenesis. Different S-phase inhibitors (aphidicolin, hydroxyurea, l -mimosine, and roscovitin) each arrested cells in S-phase, under hormonal stimulation, and completely blocked PPAR,1 synthesis and lipogenesis. However, G2/M inhibitors effected G2/M accumulation of IDM stimulated cells and prevented mitosis, but fully sustained PPAR,1 synthesis and lipogenesis. DM stimulation with or without fresh serum renewal elevated DNA synthesis in a proportion of cells (measured by BrdU labeling) and accumulation of cell cycle progression in G2/M-phase without complete mitosis. By contrast, standard IDM treatments with fresh serum renewal caused elevated DNA synthesis and mitotic clonal expansion while achieved equivalent level of adipogenesis. At most, one-half of the 10T1/2 mixed cell population differentiated to mature adipocytes, even when clonally isolated. PPAR, was exclusively expressed in the cells that contained lipid droplets. IDM stimulated comparable PPAR,1 synthesis and lipogenesis in isolated cells at low cell density (LD) culture, but in about half of the cells and with sensitivity to G1/S, but not G2/M inhibitors. Importantly, growth arrest occurred in all differentiating cells, while continuous mitotic clonal expansion occurred in non-differentiating cells. Irrespective of confluence level, 10T1/2 cells differentiate after progression through S-phase, where adipogenic commitment induced by IDM stimulation is a prerequisite for PPAR, synthesis and subsequent adipocyte differentiation. © 2003 Wiley-Liss, Inc. [source] Possible involvement of protein kinase C in the induction of adipose differentiation-related protein by Sterol ester in RAW 264.7 macrophagesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2001Jin-Shan Chen Abstract The accumulation of lipid droplets in macrophages contributes to the formation of foam cells, an early event in atherosclerosis. It is, therefore, important to elucidate the mechanisms by which lipid droplets accumulate and are utilized. Sterol ester (SE)-laden RAW 264.7 macrophages accumulated lipid droplets in a time-dependent manner up to 16 h, which was enhanced by cotreatment with 0.1 ,M phorbol 12-myristate 13-acetate (PMA). Inhibition of protein kinase C (PKC) activity by cotreatment with 0.3 ,M calphostin C CAL for 16 h resulted in coalescence of small lipid droplets into large ones and increased accumulation of lipid droplets, although to a lesser extent than after PMA cotreatment. Immunostaining for adipose differentiation-related protein (ADRP) revealed a fluorescent rim at the surface of each medium to large lipid droplet. ADRP appearance correlated with lipid droplet accumulation and was regulated by PMA in a time-dependent manner. Induction of ADRP expression by PMA or CAL required SE, since ADRP levels in PMA- or CAL-treated non-SE-laden macrophages were comparable to those in untreated cells. Removal of SE from the incubation medium resulted in the concomitant dissolution of lipid droplets and down-regulation of ADRP. In conclusion, the above results suggest that ADRP may be an important protein in the regulation of lipid droplet metabolism in lipid-laden macrophages and that this regulation may be mediated by PKC activity. J. Cell. Biochem. 83: 187,199, 2001. © 2001 Wiley-Liss, Inc. [source] Costly carotenoids: a trade-off between predation and infection risk?JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2005I. T. VAN DER VEEN Abstract Carotenoid reserves in copepods seem costly in terms of predation risk because they make individuals conspicuous. However, carotenoids also seem to play an important role in immune defence as free radical scavengers. To test whether predation risk influences carotenoid levels and whether changes in carotenoid levels are related to changes in immune defence, I examined individual changes in large carotenoid and other lipid droplets upon exposure to predation risk and subsequent exposure to parasites in the copepod Macrocyclops albidus. Copepods reduced carotenoid reserves upon exposure to predators, through which they potentially avoided the costs of being conspicuous under predation risk. Thus, the size of carotenoid reserves is a plastic trait. Such a decrease in carotenoid reserves may also have a negative impact on the copepods' immune system as individuals that decreased their reserves suffered higher parasite prevalence upon exposure to the cestode Schistocephalus solidus. These results suggest that carotenoid reserves may be individually optimized to trade-off each individual's unique costs (predation risk) and benefits (immune defence) of having these reserves. [source] The ovarian morphology of Scorpaena notata shows a specialized mode of oviparityJOURNAL OF FISH BIOLOGY, Issue 4 2002M. Muńoz Scorpaena notata is an oviparous species with external fertilization that deposits its eggs in a gelatinous matrix. The internal epithelium of the ovarian wall is chiefly responsible for the production of this matrix, which is particularly abundant and viscous during the spawning period. The oocytes lack lipid droplets, so flotation and transport of the eggs is probably accomplished by means of the matrix that surrounds them. The ovarian stroma is situated along the centre of the gonad and the developing oocytes are connected to it by peduncles. The paucity and small size of the cortical alveoli of the oocytes are notable, as is the thinness of the zona radiata. These are characteristics that would be typical of viviparous species. The histological and ultrastructural observations lead to the conclusion that this species presents a type of oviparity more highly specialized than that of the majority of teleosts. [source] Design of Nano-Laminated Coatings to Control Bioavailability of Lipophilic Food ComponentsJOURNAL OF FOOD SCIENCE, Issue 1 2010David Julian McClements ABSTRACT:, There is currently a lack of effective delivery systems to encapsulate, protect, and release bioactive lipophilic components, such as ,-3 fatty acids, conjugated linoleic acid, tributyrin, vitamins, antioxidants, carotenoids, and phytosterols, which is holding back the development of functional foods designed to combat diseases such as coronary heart disease, diabetes, hypertension, and cancer. Delivery systems consisting of lipid droplets encapsulated by nano-laminated biopolymer coatings have great potential for use in the food industry for the encapsulation, protection, and release of bioactive lipids. This article reviews the potential impact of the physicochemical characteristics of nano-laminated biopolymer coatings on the bioavailability of encapsulated lipids. The effects of layer thickness, composition, electrical charge, permeability, and environmental responsiveness on digestion, release, and absorption of lipophilic components are highlighted. The possibility of designing nano-laminated biopolymer coatings to increase, decrease, or control the bioavailability of encapsulated lipids is shown. Data generated from,in vitro,digestion models and animal feeding studies are presented. This knowledge could be used by the food industry to produce functional foods designed to improve human health and wellness. [source] Effects of Various Fiber Additions on Lipid Digestion during,In Vitro,Digestion of Beef PattiesJOURNAL OF FOOD SCIENCE, Issue 9 2009S.J. Hur ABSTRACT:, The purpose of this study was to examine the effect of various fiber additions on lipid digestion during the,in vitro,digestion of beef patties. The control patties were prepared with 90.5% lean meat and 9.5% tallow. Treatments consisted of 90% lean meat with 9.5% tallow and either 0.5% cellulose, 0.5% chitosan, or 0.5% pectin. The beef patties were then passed through an,in vitro,digestion model that simulated the composition of the mouth, stomach, and small intestine juices. The change in structure and properties of the lipid droplets was monitored by laser scanning confocal fluorescence microscopy. In general, there was a decrease in lipid droplet diameter as the droplets moved from mouth to stomach to small intestine. The amount of free fatty acid dramatically increased after,in vitro,digestion in all beef patties. The amount of free fatty acid was, however, lower in beef patties containing chitosan and pectin than other beef patties after,in vitro,digestion. Beef patties containing various fibers had lower thiobarbituric acid-reactive substances (TBARS) values than samples with no fibers. Among the samples to which fibers were added, chitosan and pectin had lower TBARS than beef patties with cellulose. The cholesterol content decreased after,in vitro,digestion in all beef patties but was not different among the beef patties before and after,in vitro,digestion. These results enhance our understanding of the physicochemical and structural changes that occur to ground beef within the gastrointestinal tract. [source] Core-Shell Biopolymer Nanoparticles Produced by Electrostatic Deposition of Beet Pectin onto Heat-Denatured ,-Lactoglobulin AggregatesJOURNAL OF FOOD SCIENCE, Issue 6 2008R. Santipanichwong ABSTRACT:, The purpose of this study was to produce and characterize core-shell biopolymer particles based on electrostatic deposition of an anionic polysaccharide (beet pectin) onto amphoteric protein aggregates (heat-denatured ,-lactoglobulin [,-lg]). Initially, the optimum conditions for forming stable protein particles were established by thermal treatment (80 °C for 15 min) of 0.5 wt%,-lg solutions at different pH values (3 to 7). After heating, stable submicron-sized (d= 100 to 300 nm) protein aggregates could be formed in the pH range from 5.6 to 6. Core-shell biopolymer particles were formed by mixing a suspension of protein aggregates (formed by heating at pH 5.8) with a beet pectin solution at pH 7 and then adjusting the pH to values where the beet pectin is adsorbed (< pH 6). The impact of pH (3 to 7) and salt concentration (0 to 250 mM NaCl) on the properties of the core-shell biopolymer particles formed was then established. The biopolymer particles were stable to aggregation from pH 4 to 6, but aggregated at lower pH values because they had a relatively small ,-potential. The biopolymer particles remained intact and stable to aggregation up to 250 mM NaCl at pH 4, indicating that they had good salt stability. The core-shell biopolymer particles prepared in this study may be useful for encapsulation and delivery of bioactive food components or as substitutes for lipid droplets. [source] Gut-associated cells of derocheilocaris remanei (crustacea, mystacocarida)JOURNAL OF MORPHOLOGY, Issue 3 2002Isabel Fernández Abstract The gut-associated cells (GA-cells) of the mystacocarid Derocheilocaris remanei were investigated by transmission electron microscopy. These cells are characterized by a dense cytoplasm, the presence of clear vesicles adjacent to the gut epithelium, glycogen, and lipid droplets. GA-cells envelop the midgut and hindgut and send blunt cytoplasmic extensions to the gut epithelium through its basal lamina. The GA-cells also extend dorsolateral projections to the body wall by means of intermediate cells. In addition to a mechanical function of suspending and stabilizing the gut, these cells may affect the flow of the hemocoelic fluid and may be implicated in the processes of transport, assimilation, and storage of nutrients. J. Morphol. 251:276,283, 2002. © 2002 Wiley-Liss, Inc. [source] Multilineage mesenchymal differentiation potential of human trabecular bone-derived cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2002Ulrich Nöth Abstract Explant cultures of adult human trabecular bone fragments give rise to osteoblastic cells, that are known to express osteoblast-related genes and mineralize extracellular matrix. These osteoblastic cells have also been shown to undergo adipogenesis in vitro and chondrogenesis in vivo. Here we report the in vitro developmental potential of adult human osteoblastic cells (hOB) derived from explant cultures of collagenase-pretreated trabecular bone fragments. In addition to osteogenic and adipogenic differentiation, these cells are capable of chondrogenic differentiation in vitro in a manner similar to adult human bone marrow-derived mesenchymal progenitor cells. High-density pellet cultures of hOB maintained in chemically defined serum-free medium, supplemented with transforming growth factor-,1, were composed of morphologically distinct, chondrocyte-like cells expressing mRNA transcripts of collagen types II, IX and X, and aggrecan. The cells within the high-density pellet cultures were surrounded by a sulfated prote-oglycan-rich extracellular matrix that immunostained for collagen type II and proteoglycan link protein. Osteogenic differentiation of hOB was verified by an increased number of alkaline phosphatase-positive cells, that expressed osteoblast-related transcripts such as alkaline phosphatase, collagen type I, osteopontin and osteocalcin, and formed mineralized matrix in monolayer cultures treated with ascorbate, ,-glycerophosphate, and bone morphogenetic protein-2. Adipogenic differentiation of hOB was determined by the appearance of intracellular lipid droplets, and expression of adipocyte-specific genes, such as lipoprotein lipase and peroxisome proliferator-activated receptor ,2, in monolayer cultures treated with dexamethasone, indomethacin, insulin and 3-isobutyl-l-methylxanthine. Taken together, these results show that cells derived from collagenase-treated adult human trabecular bone fragments have the potential to differentiate into multiple mesenchymal lineages in vitro, indicating their developmental plasticity and suggesting their mesenchymal progenitor nature. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Effects of Eriobotrya japonica seed extract on oxidative stress in rats with non-alcoholic steatohepatitisJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2010Saburo Yoshioka Abstract Objectives Non-alcoholic steatohepatitis is associated with the deposition of lipid droplets in the liver, and is characterised histologically by the infiltration of inflammatory cells, hepatocellular degeneration and liver fibrosis. Oxidative stress may play an important role in the onset and deterioration of non-alcoholic steatohepatitis. We previously reported that an Eriobotrya japonica seed extract, extracted in 70% ethanol, exhibited antioxidant actions in vitro and in vivo. In this study, we examined the effect of this extract in a rat model of non-alcoholic steatohepatitis. Methods The seed extract was given in the drinking water to fats being fed a methionine-choline-deficient diet for 15 weeks. Key findings Increases in alanine aminotransferase and aspartate aminotransferase levels were significantly inhibited in rats fed the seed extract compared with the group on the diet alone. Formation of fatty droplets in the liver was also inhibited. Antioxidant enzyme activity in liver tissue was higher than in the diet-only group and lipid peroxidation was reduced compared with rats that also received the extract. Expression of 8-hydroxy-2,-deoxyguanosine and 4-hydroxy-2-nonenal was lower in the rats given the seed extract than in the diet-only group. In the former, liver tissue levels of transforming growth factor-, and collagen were also decreased. Conclusions Thus, the E. japonica seed extract inhibited fatty liver, inflammation and fibrosis, suggesting its usefulness in the treatment of non-alcoholic steatohepatitis. [source] CARS microscopy of lipid stores in yeast: the impact of nutritional state and genetic backgroundJOURNAL OF RAMAN SPECTROSCOPY, Issue 7 2009Christian Brackmann Abstract We have developed a protocol for sub-micrometer resolved and chemically specific imaging of lipid storage in vivo employing coherent anti-Stokes Raman scattering (CARS) microscopy of one of the most important model organisms Saccharomyces cerevisiae,the yeast cell. By probing the carbon,hydrogen vibration using the nonlinear process of CARS, lipid droplets in the yeast cells clearly appear, as confirmed by comparative studies on relevant labeled organelles using two-photon fluorescence microscopy. From the images, unique quantitative data can be deduced with high three-dimensional resolution, such as the volume, shape, number, and intracellular location of the neutral lipid stores. We exemplify the strength and usability of the method for two cases: the impact on lipid storage of the nutritional condition (starvation and type of carbon source available) as well as of genetic modification of two fundamental metabolic regulation pathways involving carbohydrate and lipid storage (BCY1 and DGA1, LRO1, ARE1/2 deletions), respectively. While the impact of carbon source on the total cellular lipid volume was minimal, long-term starvation induces a significant accumulation of lipid droplets. We also confirm that the lipid-storage-deficient mutant is indeed unable to synthesize lipid droplets, and that the inability of the bcy1 -mutant to store carbohydrates is compensated by a two-fold increase in stored neutral lipids. We note that there is a significant cell-to-cell variability in neutral lipid storage in general, i.e. that there is a correspondence to the noise found for gene expression also in lipidomics. Copyright © 2009 John Wiley & Sons, Ltd. [source] Circumscribed palmar hypokeratosis: clinical evolution and ultrastructural study after prolonged treatment with topical calcipotriolJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 4 2005F Urbina Abstract Circumscribed palmar hypokeratosis is a recently described condition that consists of a solitary area of depressed skin affecting the palm (or sole). Its histopathological features include a thinned horny layer, a slightly diminished granular cell layer, and intraepidermal vacuolated cells. Prolonged treatment with topical calcipotriol resulted in complete recovery of the affected zone in the case reported here. A second biopsy of the lesion taken at around the fourth year of therapy showed a normalization of the granular layer, a reduction in the intraepidermal vacuolated cells, and a somewhat thicker horny layer. An ultrastructural study carried out at the same time showed a reduction in keratin bundles and keratohyalin granules, and an increase in lipid droplets up to the horny layer. These findings and the therapeutic response to topical calcipotriol support the concept that circumscribed palmar hypokeratosis is a focalized abnormal keratinization defect morphologically expressed at the granular and horny layers. [source] Molecular Reproduction & Development: Volume 77, Issue 2MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2010Article first published online: 16 DEC 200 Stratified porcine oocyte treated with actinomycin D to compact the nucleolus. The brown, pigmented organelles are lipid droplets. Kyogoku et al. (in this issue) show this compacted nucleolus supports the development of enucleolated full-grown oocytes. [source] An environmentally-relevant mixture of organochlorines and its vehicle control, dimethylsulfoxide, induce ultrastructural alterations in porcine oocytesMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2006Céline Campagna Abstract Organochlorine chemicals accumulate in the environment, particularly in the Arctic, and constitute potential developmental hazards to wildlife and human health. Although some of their harmful effects are recognized, their mechanisms of action within the target cells need to be better understood. This study was designed to test the hypothesis that an environmentally-relevant organochlorine mixture alters oocyte ultrastructure in the porcine model. Immature cumulus,oocyte complexes (COCs), partially cultured (18 hr) COCs without treatment or exposed to the organochlorine mixture or its vehicle (0.1% dimethysulfoxide; DMSO) during culture were processed for light and transmission electronic microscopy (TEM). The organochlorines induced major ultrastructural changes in the COCs: decreased density of the lipid droplets, increased smooth endoplasmic reticulum (SER) volume and increased interactions among SER, mitochondria, lipid droplets and vesicles. We suggest that these ultrastructural changes facilitate energy formation necessary to produce metabolizing enzymes. Other ultrastructural changes may reflect some degree of organochlorine toxicity: fewer gap junctions and decreased electron density of the cortical granules. Unexpectedly, the DMSO control treatment also induced similar ultrastructural changes, but to a lesser degree than the organochlorine mixture. This study is the first to demonstrate the effect of environmental contaminants on mammalian oocyte ultrastructure. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] An investigation of human brain tumour lipids by high-resolution magic angle spinning 1H MRS and histological analysisNMR IN BIOMEDICINE, Issue 7 2008Kirstie S. Opstad Abstract NMR-visible lipid signals detected in vivo by 1H MRS are associated with tumour aggression and believed to arise from cytoplasmic lipid droplets. High-resolution magic angle spinning (HRMAS) 1H MRS and Nile Red staining were performed on human brain tumour biopsy specimens to investigate how NMR-visible lipid signals relate to viable cells and levels of necrosis across different grades of glioma. Presaturation spectra were acquired from 24 adult human astrocytoma biopsy samples of grades II (8), III (2) and IV (14) using HRMAS 1H MRS and quantified using LCModel to determine lipid concentrations. Each biopsy sample was then refrozen, cryostat sectioned, and stained with Nile Red, to determine the number of lipid droplets and droplet size distribution, and with Haematoxylin and Eosin, to determine cell density and percentage necrosis. A strong correlation (R,=,0.92, P,<,0.0001) was found between the number of Nile Red-stained droplets and the ,1.3,ppm lipid proton concentration by 1H MRS. Droplet sizes ranged from 1 to 10,µm in diameter, and the size distribution was constant independent of tumour grade. In the non-necrotic biopsy samples, the number of lipid droplets correlated with cell density, whereas in the necrotic samples, there were greater numbers of droplets that showed a positive correlation with percentage necrosis. The correlation between 1H MRS lipid signals and number of Nile Red-stained droplets, and the presence of lipid droplets in the non-necrotic biopsy specimens provide good evidence that the in vivo NMR-visible lipid signals are cytoplasmic in origin and that formation of lipid droplets precedes necrosis. Copyright © 2008 John Wiley & Sons, Ltd. [source] Correlation between the occurrence of 1H-MRS lipid signal, necrosis and lipid droplets during C6 rat glioma developmentNMR IN BIOMEDICINE, Issue 4 2003Sonja Zoula Abstract The aim of this study was to investigate the possible correlation between the 1H MRS mobile lipid signal, necrosis and lipid droplets in C6 rat glioma. First, the occurrence of necrosis and lipid droplets was determined during tumor development, by a histological analysis performed on 34 rats. Neither necrosis nor lipid droplets were observed before 18 days post-implantation. At later stages of development, both necrosis and lipid droplets were apparent, the lipid droplets being mainly located within the necrotic areas. Using a second group of eight rats, a temporal correlation was evidenced between mobile lipid signal detected by in vivo single-voxel one- (136,ms echo time) and two-dimensional J -resolved 1H MR spectroscopy, and the presence of necrosis and lipid droplets on the histological sections obtained from the brains of the same rats. Finally, spatial distribution of the mobile lipid signal was analyzed by chemical-shift imaging performed on a third group of eight animals, at the end of the tumor growth. The spectroscopic image corresponding to the resonance of mobile lipids had its maximum intensity in the center of the tumor where necrotic regions were observed on the histological sections. These necrotic areas contained large amounts of lipid droplets. All these results suggest that mobile lipids detected in vivo by 1H MRS (136,ms echo time) in C6 rat brain glioma arise mainly from lipid droplets located in necrosis. Copyright © 2003 John Wiley & Sons, Ltd. [source] Expression of p73 in normal skin and proliferative skin lesionsPATHOLOGY INTERNATIONAL, Issue 12 2004Makoto Kamiya The p73 gene is a member of the p53 gene family and the structure and functions of p73 protein are similar to those of ,p53. ,However, ,these ,two ,proteins ,have ,different ,roles. In the present study, p73 protein was found immunohistochemically to be distributed in the basal cells of the epidermis, columnar basal cells in the hair follicle and peripheral cells without lipid droplets in the sebaceous and meibomian glands; it was expressed strongly in tumor cells in basal cell carcinomas and in the basal cell-like cells in seborrheic keratosis, and weakly or negatively in the squamous cell-like cells in seborrheic keratosis and in the tumor cells in squamous cell carcinomas. No relationship was detected between p73 and p53 protein distribution and between p73 protein expression and the proliferative potential, as shown by the Ki-67 immunopositive cell ratio. The present study shows that p73 protein is likely to play important roles in skin differentiation rather than proliferation or carcinogenesis of the skin. [source] Adrenal rest tumor of the liver: A case report with immunohistochemical investigation of steroidogenesisPATHOLOGY INTERNATIONAL, Issue 3 2000Kazumori Arai Abstract A case of adrenal rest tumor arising in the liver of a 62-year-old male with chronic hepatitis type C is reported. The tumor was clinically non-functioning and required distinction from hepatocellular carcinoma. The yellowish,brown tumor measured 25 × 18 × 15 mm and was located in the subcapsular portion of the right hepatic lobe. Histologically, the tumor presented features similar to those of the adrenal cortex and was predominantly composed of pale cells. Electron micrograph revealed lipid droplets and mitochondria with tubulo,vesicular cristae, consistent with the characteristics of steroid-producing cells. Immunohistochemically, the tumor expressed the adrenal 4 binding protein and a number of enzymes involved in the synthesis of adrenocortical steroids. At surgery, the right adrenal gland was present independently from the liver. This hepatic tumor was considered to be an adrenal rest tumor with steroidogenic capability. [source] | ||||||||||||||||||||||||||||||||||