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Journal articles on the topic 'Sterols'
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1
Tang, Rui, Junhao Liang, Xiangfeng Jing, and Tongxian Liu. "Discrepancy in Sterol Usage between Two Polyphagous Caterpillars, Mythimna separata and Spodoptera frugiperda." Insects 13, no. 10 (September 27, 2022): 876. http://dx.doi.org/10.3390/insects13100876.
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Insects are sterol auxotrophs and typically obtain sterols from food. However, the sterol demand and metabolic capacity vary greatly among species, even for closely related species. The low survival of many insects on atypical sterols, such as cholestanol and cholestanone, raises the possibility of using sterol-modified plants to control insect herbivore pests. In this study, we evaluated two devastating migratory crop pests, Mythimna separata and Spodoptera frugiperda, in response to atypical sterols and explored the reasons that caused the divergences in sterol nutritional biology between them. Contrary to M. separata, S. frugiperda had unexpectedly high survival on cholestanone, and nearly 80% of the individuals pupated. Comparative studies, including insect response to multiple diets and larval body sterol/steroids analysis, were performed to explain their differences in cholestanone usage. Our results showed that, in comparison to M. separata, the superiority of S. frugiperda on cholestanone can be attributed to its higher efficiency of converting ketone into available stanol and its lower demand for sterols, which resulted in a better survival when cholesterol was unavailable. This research will help us to better understand insect sterol nutritional biology and the potential of using atypical sterols to control herbivorous insect pests.
2
Lobastova, Tatyana, Victoria Fokina, Irina Pozdnyakova-Filatova, Sergey Tarlachkov, Andrey Shutov, and Marina Donova. "Insight into Different Stages of Steroid Degradation in Thermophilic Saccharopolyspora hirsuta VKM Ac-666T Strain." International Journal of Molecular Sciences 23, no. 24 (December 18, 2022): 16174. http://dx.doi.org/10.3390/ijms232416174.
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Steroids are abundant molecules in nature, and various microorganisms evolved to utilize steroids. Thermophilic actinobacteria play an important role in such processes. However, very few thermophiles have so far been reported capable of degrading or modifying natural sterols. Recently, genes putatively involved in the sterol catabolic pathway have been revealed in the moderately thermophilic actinobacterium Saccharopolyspora hirsuta VKM Ac-666T, but peculiarities of strain activity toward sterols are still poorly understood. S. hirsuta catalyzed cholesterol bioconversion at a rate significantly inferior to that observed for mesophilic actinobacteria (mycobacteria and rhodococci). Several genes related to different stages of steroid catabolism increased their expression in response to cholesterol as was shown by transcriptomic studies and verified by RT–qPCR. Sequential activation of genes related to the initial step of cholesterol side chain oxidation (cyp125) and later steps of steroid core degradation (kstD3, kshA, ipdF, and fadE30) was demonstrated for the first time. The activation correlates with a low cholesterol conversion rate and intermediate accumulation by the strain. The transcriptomic analyses revealed that the genes involved in sterol catabolism are linked functionally, but not transcriptionally. The results contribute to the knowledge on steroid catabolism in thermophilic actinobacteria and could be used at the engineering of microbial catalysts.
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Byakov, Artem, Mikhail Karpov, Nikolai Strizhov, and Marina Donova. "Creation and Characterization of Mycolicibacterium Smegmatis mc2155 with Deletions in Genes Encoding Sterol Oxidation Enzymes." BIO Web of Conferences 57 (2023): 03004. http://dx.doi.org/10.1051/bioconf/20235703004.
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The fast-growing saprotrophic strain Mycolicibacterium smegmatis mc2155 is capable of utilizing plant and animal sterols and can be used for creation of genetically engineered strains producing biologically active steroids. Oxidation of the 3β-hydroxyl group and Δ5(6)→Δ4(5) double bond isomerization followed by formation of stenones from sterols are considered as the initial stage of steroid catabolism in some actinobacteria. The study of the mechanism of steroid nucleus 3β-hydroxyl group oxidation is relevant for the creation of a method of the microbiological production of valuable 3β-hydroxy-5-en-steroids. A mutant strain of M. smegmatis with deletions in three genes (MSMEG_1604, MSMEG_5228 and MSMEG_5233) encoding known enzymes exhibiting 3β-hydroxysteroid dehydrogenase activity was constructed by homologous recombination coupled with double selection. The resulting mutant retained macromorphological properties and the ability to convert cholesterol. 3-Keto-4-en-steroids were found among the sterol catabolism intermediates. Experimentally obtained data indicate the presence of a previously undetected intracellular enzyme that performs the function of 3β-hydroxysteroid dehydrogenase/Δ5(6)→Δ4(5) isomerase.
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Morikawa, T., M. Mizutani, and D. Ohta. "Cytochrome P450 subfamily CYP710A genes encode sterol C-22 desaturase in plants." Biochemical Society Transactions 34, no. 6 (October 25, 2006): 1202–5. http://dx.doi.org/10.1042/bst0341202.
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Sterols are isoprenoid-derived lipids that are produced via the mevalonate pathway and are involved in various cellular functions in eukaryotes such as maintenance of membrane integrity and biosynthetic precursors of steroid hormones. Among cellular sterols, Δ22-sterols containing a double bond at C-22 in the sterol side chain specifically occur in fungi (ergosterol) and plants (stigmasterol and brassicasterol), and several lines of experimental evidence have suggested specific physiological roles of Δ22-sterols in plants. Fungal cytochrome P450 (P450), CYP61, has been established as the sterol C-22 desaturase functioning at the penultimate step in the ergosterol biosynthetic pathway. On the other hand, no particular sequence has been assigned as to the enzyme responsible for the introduction of the double bond into the sterol side chain in plants. In this review, we summarize our recent findings demonstrating that CYP710A P450 family genes encode the plant sterol C-22 desaturases to produce stigmasterol and brassicasterol/crinosterol from β-sitosterol and 24-epi-campesterol respectively.
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Urbina, J. A., G. Visbal, L. M. Contreras, G. McLaughlin, and R. Docampo. "Inhibitors of delta24(25) sterol methyltransferase block sterol synthesis and cell proliferation in Pneumocystis carinii." Antimicrobial Agents and Chemotherapy 41, no. 7 (July 1997): 1428–32. http://dx.doi.org/10.1128/aac.41.7.1428.
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Detailed analysis of the endogenous sterol content of purified Pneumocystis carinii preparations by gas-liquid chromatography coupled to mass spectrometry suggested that this parasite can both synthesize de novo steroid skeletons (to produce delta7 sterols) and take them from the infected host (leading to delta5 sterols). In both cases the final products are 24-alkyl sterols, resulting from the action of delta24(25) and delta24(24') sterol methyltransferases, enzymes not present in vertebrates. To investigate the physiological significance of these sterols, cultures of P. carinii in embryonic lung cells were exposed to 22,26-azasterol (20-piperidin-2-yl-5alpha-pregnan-3beta-20(R)-diol), a compound previously shown to inhibit both enzymes and to halt cell proliferation in fungi and protozoa. This compound produced a dose-dependent reduction in the parasite proliferation, with a 50% inhibitory concentration of 0.3 microM and 80% reduction of growth after 96 h at 10 microM. Correspondingly, parasites treated with the azasterol at 10 microM for 48 h accumulated 24-desalkyl sterols such as zymosterol (cholesta-8,24-dien-3beta-ol) and cholesta-8,14,24-trien-3beta-ol to ca. 40% of the total mass of endogenous sterols. This is the first report on the antiproliferative effects of a sterol biosynthesis inhibitor on P. carinii and indicate that sterol methyltransferase inhibitors could be the basis of a novel and specific chemotherapeutic approach to the treatment of P. carinii infections.
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Shen, Yan, Volker Thiel, Pablo Suarez-Gonzalez, Sebastiaan W. Rampen, and Joachim Reitner. "Sterol preservation in hypersaline microbial mats." Biogeosciences 17, no. 3 (February 7, 2020): 649–66. http://dx.doi.org/10.5194/bg-17-649-2020.
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Abstract. Microbial mats are self-sustaining benthic ecosystems composed of highly diverse microbial communities. It has been proposed that microbial mats were widespread in Proterozoic marine environments, prior to the emergence of bioturbating organisms at the Precambrian–Cambrian transition. One characteristic feature of Precambrian biomarker records is that steranes are typically absent or occur in very low concentrations. This has been explained by low eukaryotic source inputs, or degradation of primary produced sterols in benthic microbial mats (“mat-seal effect”). To better understand the preservational pathways of sterols in microbial mats, we analyzed freely extractable and carbonate-bound lipid fractions as well as decalcified extraction residues in different layers of a recent calcifying mat (∼1500 years) from the hypersaline Lake 2 on the island of Kiritimati, central Pacific. A variety of C27–C29 sterols and distinctive C31 4α-methylsterols (4α-methylgorgosterol and 4α-methylgorgostanol, biomarkers for dinoflagellates) were detected in freely extractable and carbonate-bound lipid pools. These sterols most likely originated from organisms living in the water column and the upper mat layers. This autochthonous biomass experienced progressive microbial transformation and degradation in the microbial mat, as reflected by a significant drop in total sterol concentrations, up to 98 %, in the deeper layers, and a concomitant decrease in total organic carbon. Carbonate-bound sterols were generally low in abundance compared to the freely extractable portion, suggesting that incorporation into the mineral matrix does not play a major role in the preservation of eukaryotic sterols in this mat. Likewise, pyrolysis of extraction residues suggested that sequestration of steroid carbon skeletons into insoluble organic matter was low compared to hopanoids. Taken together, our findings argue for a major mat-seal effect affecting the distribution and preservation of steroids in the mat studied. This result markedly differs from recent findings made for another microbial mat growing in the nearby hypersaline Lake 22 on the same island, where sterols showed no systematic decrease with depth. The observed discrepancies in the taphonomic pathways of sterols in microbial mats from Kiritimati may be linked to multiple biotic and abiotic factors including salinity and periods of subaerial exposure, implying that caution has to be exercised in the interpretation of sterol distributions in modern and ancient microbial mat settings.
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Kopylov, Arthur T., Kristina A. Malsagova, Alexander A. Stepanov, and Anna L. Kaysheva. "Diversity of Plant Sterols Metabolism: The Impact on Human Health, Sport, and Accumulation of Contaminating Sterols." Nutrients 13, no. 5 (May 12, 2021): 1623. http://dx.doi.org/10.3390/nu13051623.
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The way of plant sterols transformation and their benefits for humans is still a question under the massive continuing revision. In fact, there are no receptors for binding with sterols in mammalians. However, possible biotransformation to steroids that can be catalyzed by gastro-intestinal microflora, microbial cells in prebiotics or cytochromes system were repeatedly reported. Some products of sterols metabolization are capable to imitate resident human steroids and compete with them for the binding with corresponding receptors, thus affecting endocrine balance and entire physiology condition. There are also tremendous reports about the natural origination of mammalian steroid hormones in plants and corresponding receptors for their binding. Some investigations and reports warn about anabolic effect of sterols, however, there are many researchers who are reluctant to believe in and have strong opposing arguments. We encounter plant sterols everywhere: in food, in pharmacy, in cosmetics, but still know little about their diverse properties and, hence, their exact impact on our life. Most of our knowledge is limited to their cholesterol-lowering influence and protective effect against cardiovascular disease. However, the world of plant sterols is significantly wider if we consider the thousands of publications released over the past 10 years.
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Vidkjær, Nanna H., Karl-Martin V. Jensen, René Gislum, and Inge S. Fomsgaard. "Profiling and Metabolism of Sterols in the Weaver Ant Genus Oecophylla." Natural Product Communications 11, no. 1 (January 2016): 1934578X1601100. http://dx.doi.org/10.1177/1934578x1601100114.
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Sterols are essential to insects because they are vital for many biochemical processes, nevertheless insects cannot synthesize sterols but have to acquire them through their diet. Studies of sterols in ants are sparse and here the sterols of the weaver ant genus Oecophylla are identified for the first time. The sterol profile and the dietary sterols provided to a laboratory Oecophylla longinoda colony were analyzed. Most sterols originated from the diet, except one, which was probably formed via dealkylation in the ants and two sterols of fungal origin, which likely originate from hitherto unidentified endosymbionts responsible for supplying these two compounds. The sterol profile of a wild Oecophylla smaragdina colony was also investigated. Remarkable qualitative similarities were established between the two species despite the differences in diet, species, and origin. This may reflect a common sterol need/aversion in the weaver ants. Additionally, each individual caste of both species displayed unique sterol profiles.
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Raederstorff, D., and M. Rohmer. "Sterol biosynthesis de nova via cycloartenol by the soil amoeba Acanthamoeba polyphaga." Biochemical Journal 231, no. 3 (November 1, 1985): 609–15. http://dx.doi.org/10.1042/bj2310609.
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The soil amoeba Acanthamoeba polyphaga is capable of synthesizing its sterols de novo from acetate. The major sterols are ergosterol and poriferasta-5,7,22-trienol. Furthermore C28 and C29 sterols of still unknown structure with an aromatic B-ring are also synthesized by the amoeba. The first cyclic sterol precursor is cycloartenol, which is the sterol precursor in all photosynthetic phyla. No trace of lanosterol, which is the sterol precursor in animals and fungi, could be detected. These results show that at least some of the biochemical processes of Acanthamoeba polyphaga might be phylogenetically related to those of unicellular algae. Addition of exogenous sterols to the culture medium does not influence the sterol biosynthesis and the sterol composition of the cells.
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Behmer, S. T., D. O. Elias, and E. A. Bernays. "Post-ingestive feedbacks and associative learning regulate the intake of unsuitable sterols in a generalist grasshopper." Journal of Experimental Biology 202, no. 6 (March 15, 1999): 739–48. http://dx.doi.org/10.1242/jeb.202.6.739.
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Behavioural studies of the grasshopper Schistocerca americana were undertaken to identify the mechanisms that regulate the intake of dietary sterols. In the first experiment, grasshoppers were allowed to feed on spinach, a plant containing only unsuitable sterols; immediately after this first meal, a suitable or unsuitable sterol was injected into the haemolymph. Grasshoppers injected with unsuitable sterols had second meals on spinach that were significantly shorter than those of grasshoppers injected with suitable sterols, indicating that unsuitable dietary sterols are detected post-ingestively. In the second experiment, grasshoppers were fed food containing only unsuitable sterols and were then presented with glass-fibre discs containing different concentrations of a suitable sterol or sucrose only (the control). The results suggest that grasshoppers do not use a direct feedback operating on mouthpart chemoreceptors to regulate their intake of suitable sterols. In the third experiment, grasshoppers were presented with artificial diets containing different sterols and flavours, and feeding was observed over a sequence of meals. The results from both the first and last experiments suggest a role for associative learning in regulating the intake of unsuitable sterols.
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Najle, Sebastián R., María Celeste Molina, Iñaki Ruiz-Trillo, and Antonio D. Uttaro. "Sterol metabolism in the filasterean Capsaspora owczarzaki has features that resemble both fungi and animals." Open Biology 6, no. 7 (July 2016): 160029. http://dx.doi.org/10.1098/rsob.160029.
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Sterols are essential for several physiological processes in most eukaryotes. Sterols regulate membrane homeostasis and participate in different signalling pathways not only as precursors of steroid hormones and vitamins, but also through its role in the formation of lipid rafts. Two major types of sterols, cholesterol and ergosterol, have been described so far in the opisthokonts, the clade that comprise animals, fungi and their unicellular relatives. Cholesterol predominates in derived bilaterians, whereas ergosterol is what generally defines fungi. We here characterize, by a combination of bioinformatic and biochemical analyses, the sterol metabolism in the filasterean Capsaspora owczarzaki , a close unicellular relative of animals that is becoming a model organism. We found that C. owczarzaki sterol metabolism combines enzymatic activities that are usually considered either characteristic of fungi or exclusive to metazoans. Moreover, we observe a differential transcriptional regulation of this metabolism across its life cycle. Thus, C. owczarzaki alternates between synthesizing 7-dehydrocholesterol de novo, which happens at the cystic stage, and the partial conversion—via a novel pathway—of incorporated cholesterol into ergosterol, the characteristic fungal sterol, in the filopodial and aggregative stages.
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Witkowska, Anna Maria, Anna Waśkiewicz, Małgorzata Elżbieta Zujko, Iwona Mirończuk-Chodakowska, Alicja Cicha-Mikołajczyk, and Wojciech Drygas. "Assessment of Plant Sterols in the Diet of Adult Polish Population with the Use of a Newly Developed Database." Nutrients 13, no. 8 (August 7, 2021): 2722. http://dx.doi.org/10.3390/nu13082722.
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Plant sterols are compounds with multiple biological functions, mainly cholesterol-reducing. There are no comprehensive databases on plant sterols, which makes it difficult to estimate their intake in the Polish population. This work attempted to use international food databases, additionally supplemented by scientific data from the literature, to create a database of plant sterols, which would cover various kinds of foods and dishes consumed in Poland. The aim was to assess the size and sources of dietary plant sterols in the adult population of Poland. The literature search was conducted using PubMed, Web of Science, Scopus, and Google Scholar to identify possible sources of published food composition data for plant sterols. The study group consisted of 5690 participants of the WOBASZ II survey. We identified 361 dietary sources of plant sterols based on the consumption of foods and dishes reported by participants. Cereals and fats provided 61% of the total plant sterols, and together with vegetables and fruits, this totaled 80%. The median intake of plant sterols in the Polish population was 255.96 mg/day, and for men and women 291.76 and 230.61 mg/day, respectively. Canola oil provided the most plant sterols at 16.92%, followed by white bread at 16.65% and soft margarine at 8.33%. The study found that plant sterol intake in Poland is comparable to other populations, and women’s diets are more dense in plant sterols. Due to the lack of literature sources on plant sterol content in some foods, future studies should expand and complete the databases on plant sterol content in foods.
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Heese-Peck, Antje, Harald Pichler, Bettina Zanolari, Reika Watanabe, Günther Daum, and Howard Riezman. "Multiple Functions of Sterols in Yeast Endocytosis." Molecular Biology of the Cell 13, no. 8 (August 2002): 2664–80. http://dx.doi.org/10.1091/mbc.e02-04-0186.
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Sterols are essential factors for endocytosis in animals and yeast. To investigate the sterol structural requirements for yeast endocytosis, we created a variety of ergΔ mutants, each accumulating a distinct set of sterols different from ergosterol. Mutant erg2Δerg6Δ anderg3Δerg6Δ cells exhibit a strong internalization defect of the α-factor receptor (Ste2p). Specific sterol structures are necessary for pheromone-dependent receptor hyperphosphorylation, a prerequisite for internalization. The lack of phosphorylation is not due to a defect in Ste2p localization or in ligand–receptor interaction. Contrary to most known endocytic factors, sterols seem to function in internalization independently of actin. Furthermore, sterol structures are required at a postinternalization step of endocytosis. ergΔ cells were able to take up the membrane marker FM4-64, but exhibited defects in FM4-64 movement through endosomal compartments to the vacuole. Therefore, there are at least two roles for sterols in endocytosis. Based on sterol analysis, the sterol structural requirements for these two processes were different, suggesting that sterols may have distinct functions at different places in the endocytic pathway. Interestingly, sterol structures unable to support endocytosis allowed transport of the glycosylphosphatidylinositol-anchored protein Gas1p from the endoplasmic reticulum to Golgi compartment.
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Merah, Othmane, and Zephirin Mouloungui. "Tetraploid Wheats: Valuable Source of Phytosterols and Phytostanols." Agronomy 9, no. 4 (April 19, 2019): 201. http://dx.doi.org/10.3390/agronomy9040201.
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Phytosterols are known as healthy compounds obtained mainly from oilseed crops. Cereals were also studied for their sterols content. Few insights have been devoted to other tetraploid species than emmer and durum wheats. This work examined phytosterol and phytostanol content in seed of six tetraploid wheat species cultivated during two successive years under rainfed organic conditions in Auch (near Toulouse, France). Sterols (free and esterified sterols) were measured by gas-chromatography-flame ionisation detector. Mean value of sterols + stanols content was 99.5 mg 100 g−1 DW. The main sterol was β-sitosterol. Results showed a year effect on sterol content, whatever the wheat species. This could be explained by the differences in climatic conditions prevailing during plant cycle and grain filling. A large variability for sterols content was found between species and within each species. Emmer wheat revealed the lowest values for all sterols and stanols. Higher values of sterols were obtained in durum wheat. This work is the first report studying T. carthlicum, T. polonicum, T. turgidum, T. timopheevi. These species exhibited intermediate values of sterol contents between emmer and durum wheats. Wheat tetraploid species showed interesting levels of sterols and could serve as a great source of these healthy compounds mainly in Mediterranean region where they are consumed as wholegrain. Variation in climatic conditions could help to manage the level of these secondary metabolites.
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Mahmood-Khan, Zahid, and Eric R. Hall. "Removal of individual sterols during secondary treatment of pulp mill effluents." Water Quality Research Journal 47, no. 1 (February 1, 2012): 56–65. http://dx.doi.org/10.2166/wqrjc.2012.032.
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Analysis of plant sterols in pulp mill effluents is complex and several investigations have combined wood extractives with sterols or have reported total sterols collectively. The present study exclusively focuses on the fate of individual sterols generated in pulp and paper manufacturing as they pass through activated sludge biotreatment system. Before secondary treatment the pulp mill effluents contained 33% ß-sitosterol, 26% campesterol, 22% ß-sitostanol, 17% stigmasterol and 2% ergosterol (1,000–1,800 μg/L mean total sterols). After treatment, the effluents contained 44% ß-sitosterol, 22% campesterol, 18% ß-sitostanol, 14% stigmasterol and 2% ergosterol (176–428 μg/L mean total sterols). Each sterol fraction showed different removal efficiency. ß-Sitosterol, the major fraction, was removed relatively poorly (65%) while campesterol was removed most efficiently (81%) compared with the removal of other fractions (ß-sitostanol 74% and stigmasterol 64%). The differential removal of sterol fractions altered the sterol profile during different stages of the secondary treatment. Owing to its poor removal, ß-sitosterol is the most persistent fraction in treated/untreated pulp mill effluents. Typically, 21% of the incoming sterols were contained in secondary effluents and 23% in waste sludge without biodegradation. Optimizing the design/operation of treatment systems for removal of ß-sitosterol and stigmasterol would improve the performance of effluent treatment facilities.
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Kapetanovic, Radomir, Dusan Sladic, Simeon Popov, Mario Zlatovic, Zoran Kljajic, and Miroslav Gasic. "Sterol composition of the Adriatic sea algae Ulva lactuca, Codium dichotomum, Cystoseira adriatica and Fucus virsoides." Journal of the Serbian Chemical Society 70, no. 12 (2005): 1395–400. http://dx.doi.org/10.2298/jsc0512395k.
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The sterol composition of two green algae and two brown algae from the South Adriatic was determined. In the green alga Ulva lactuca, the principal sterols were cholesterol and isofucosterol. In the brown alga Cystoseira adriatica, the main sterols were cholesterol and stigmast-5-en-3?-ol, while the characteristic sterol of the brown algae, fucosterol, was found only in low concentration. The sterol fractions of the green alga Codium dichotomum and the brown alga Fucus virsoides contained practically only one sterol each, comprising more than 90 % of the total sterols (clerosterol in the former and fucosterol in the latter).
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Elenkov, Ivayh, Simeon Popov, and Stoitze Andreev. "Sterol Composition of the Black Sea Sponges Hymeniacidon sanguinea (Grant) and Halichondria panicea (Pallas)." Zeitschrift für Naturforschung C 54, no. 11 (November 1, 1999): 972–76. http://dx.doi.org/10.1515/znc-1999-1119.
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Abstract The sterol composition of Hymeniacidon sanguinea and Halichondria panicea from the Black Sea was investigated. Both sponges contain similar mixtures of stanols and of dietary Δ5-sterols. Main sterols appeared to be C27-sterols, which could be connected with a common diet for the both sponges. Saturated short side chain sterols have been found in Hymeniacidon sanguinea. Three of them were novel for sponges. A possibility for the transformation of some dietary sterols into stands is discussed.
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FRAGA, MARÍA J., JAVIER FONTECHA, LUCIDIA LOZADA, ISABEL MARTÍNEZ-CASTRO, and MANUELA JUÁREZ. "Composition of the sterol fraction of caprine milk fat by gas chromatography and mass spectrometry." Journal of Dairy Research 67, no. 3 (August 2000): 437–41. http://dx.doi.org/10.1017/s0022029900004258.
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The sterol fraction of milk is of nutritional interest because high levels of cholesterol in plasma (modulated by the cholesterol ingested) are associated with an increasing risk of cardiovascular disease. In addition, some sterols (ergosterol and 7-dehydrocholesterol) are provitamins (D2 and D3 respectively). At the same time, through the study of the sterol fraction, vegetable fats can be detected in milk and dairy products. Sterols are a minor fraction of total milk fat, the main sterol being cholesterol (3 mg/g fat, equivalent to 100 mg/l cows' milk). Small quantities of other sterols (7-dehydrocholesterol, 22-dehydrocholesterol, ergosterol, fucosterol, lanosterol, lathosterol, 24-methylenecholesterol) and several phytosterols have been reported in cows' milk (Walstra & Jennes, 1984). International Dairy Federation (1992) states that in the sterol profile of genuine milk fat there may appear, in addition to the peak of 7-dehydrocholesterol which ranges from 0·7 to 4% of total sterols, < 1% of minor sterols with retention times corresponding to phytosterols.Values for the cholesterol content of goats' milk vary considerably, from 211 mg/l (Pantulu et al. 1975) to 125 mg/l (Lu, 1993), partly owing to the use of different analysis techniques. Some of these values were obtained using non-specific colorimetric methods, which are inaccurate in the presence of cholesterol precursors or phytosterols (Clark et al. 1983; Haugh & Harzer, 1984). Some minor peaks have been assumed to be sterols but have not been identified (García-Olmedo & Barrera, 1985).Conventional methods of sample preparation for sterol analysis prior to gas chromatography (GC), which involve saponification of fat with or without isolation of the sterol fraction by thin layer chromatography, are tedious and time-consuming. Transesterification with KOH–methanol has been successfully used as a rapid alternative for obtaining the unsaponifiable fraction.This paper describes the identification of sterols (cholesterol and other minor sterols) in goats' milk fat using an alkali-catalysed transesterification procedure prior to GC and GC–mass spectrometry (GC–MS) analysis.
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Sriti, Jazia, Manel Neffati, Kamel Msaada, Thierry Talou, and Brahim Marzouk. "Biochemical Characterization of Coriander Cakes Obtained by Extrusion." Journal of Chemistry 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/871631.
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This study was designed to examine the effect of operating conditions such as nozzle diameter on fatty acid, sterol, and tocol composition of coriander cakes. Eight fatty acids were identified, with petroselinic acid accounting for 75–77% of the total fatty acids, followed by linoleic, oleic, and palmitic acids, accounting for 12-13%, 5%, and 3%, respectively, of the total fatty acids.β-Sitosterol was the major sterol in all oils with 33–35% of total sterols. The next major sterols in all oils were stigmasterol (24% of total sterols) and Δ7-stigmasterol (15% of total sterols). Coriander cake contained higher amounts of total tocotrienol whereγ-tocotrienol was the main compound.
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Rogowska, Agata, Cezary Pączkowski, and Anna Szakiel. "Modulation of Steroid and Triterpenoid Metabolism in Calendula officinalis Plants and Hairy Root Cultures Exposed to Cadmium Stress." International Journal of Molecular Sciences 23, no. 10 (May 18, 2022): 5640. http://dx.doi.org/10.3390/ijms23105640.
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The present study investigated the changes in the content of steroids and triterpenoids in C. officinalis hairy root cultures and plants exposed to cadmium stress. The observed effects included the content and composition of analyzed groups of compounds, particularly the proportions among individual sterols (e.g., stigmasterol-to-sitosterol ratio), their ester and glycoside conjugates. The total sterol content increased in roots (by 30%) and hairy root culture (by 44%), whereas it decreased in shoots (by 15%); moreover, these effects were inversely correlated with Cd-induced growth suppression. Metabolic alterations of sterols and their forms seemed to play a greater role in the response to Cd stress in roots than in shoots. The symptoms of the competition between general metabolites (sterols) and specialized metabolites (triterpenoids) were also observed, i.e., the increase of the sterol biosynthesis parallel to the decrease of the triterpenoid content in C. officinalis plant roots and hairy root culture, and the inverse phenomenon in shoots. The similarity of the metabolic modifications observed in the present study on C. officinalis plant roots and hairy roots confirmed the possibility of application of plant in vitro cultures in initial studies for physiological research on plant response to environmental stresses.
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Yao, Xiaorui, Jianjiang Lu, Zilong Liu, Dan Ran, and Yating Huang. "Distribution of sterols and the sources of pollution in surface sediments of Ulungur lake, Xinjiang." Water Science and Technology 67, no. 10 (May 1, 2013): 2342–49. http://dx.doi.org/10.2166/wst.2013.107.
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Domestic sewage discharged into lakes brings great pressure to the ecological environment. This study selected sediment from an inland lake as a research object to evaluate pollution of the environment. Eight sterols were used to evaluate the content of pollutants, while the ratios of sterols were used as the index to analyze the sources of pollution. The correlations were analyzed between sterols and total organic carbon (TOC), salinity and particle size. The distribution and composition of sterol compounds were determined in 12 surface sediment samples collected from Ulungur lake. The total concentrations of detected sterols in the sediments ranged from 1.3 to 36.3 μg/g.dw. The most abundant sterol detected was β-sitosterol (STI) with average concentrations of 2.6 μg/g.dw, followed by cholesterol (CHOE), stigmasterol (STIG) and stigmastanol (STAN). The concentration of coprostanol (COP) was between 0.03 and 1.66 μg/g.dw. Through correlation analysis, it was found that there was a significant correlation between fecal sterols and plant sterols. So the plant sterols shall not be neglected in evaluating the sources of pollution for their impact to identify the fecal sources. The study suggests that the composition and distribution of sterols in surface sediment provide useful information for environmental contamination monitoring and assessment in the inland lake.
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Wilbrink, M. H., M. Petrusma, L. Dijkhuizen, and R. van der Geize. "FadD19 of Rhodococcus rhodochrous DSM43269, a Steroid-Coenzyme A Ligase Essential for Degradation of C-24 Branched Sterol Side Chains." Applied and Environmental Microbiology 77, no. 13 (May 20, 2011): 4455–64. http://dx.doi.org/10.1128/aem.00380-11.
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ABSTRACTThe actinobacterial cholesterol catabolic gene cluster contains a subset of genes that encode β-oxidation enzymes with a putative role in sterol side chain degradation. We investigated the physiological roles of several genes, i.e.,fadD17,fadD19,fadE26,fadE27, andro04690DSM43269, by gene inactivation studies in mutant strain RG32 ofRhodococcus rhodochrousDSM43269. Mutant strain RG32 is devoid of 3-ketosteroid 9α-hydroxylase (KSH) activity and was constructed following the identification, cloning, and sequential inactivation of fivekshAgene homologs in strain DSM43269. We show that mutant strain RG32 is fully blocked in steroid ring degradation but capable of selective sterol side chain degradation. Except for RG32ΔfadD19, none of the mutants constructed in RG32 revealed an aberrant phenotype on sterol side chain degradation compared to parent strain RG32. Deletion offadD19in strain RG32 completely blocked side chain degradation of C-24 branched sterols but interestingly not that of cholesterol. The additional inactivation offadD17in mutant RG32ΔfadD19also did not affect cholesterol side chain degradation. Heterologously expressed FadD19DSM43269nevertheless was active toward steroid-C26-oic acid substrates. Our data identified FadD19 as a steroid-coenzyme A (CoA) ligase with an essentialin vivorole in the degradation of the side chains of C-24 branched-chain sterols. This paper reports the identification and characterization of a CoA ligase with anin vivorole in sterol side chain degradation. The high similarity (67%) between the FadD19DSM43269and FadD19H37Rvenzymes further suggests that FadD19H37Rvhas anin vivorole in sterol metabolism ofMycobacterium tuberculosisH37Rv.
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Raychaudhuri, Sumana, Young Jun Im, James H. Hurley, and William A. Prinz. "Nonvesicular sterol movement from plasma membrane to ER requires oxysterol-binding protein–related proteins and phosphoinositides." Journal of Cell Biology 173, no. 1 (April 3, 2006): 107–19. http://dx.doi.org/10.1083/jcb.200510084.
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Sterols are moved between cellular membranes by nonvesicular pathways whose functions are poorly understood. In yeast, one such pathway transfers sterols from the plasma membrane (PM) to the endoplasmic reticulum (ER). We show that this transport requires oxysterol-binding protein (OSBP)–related proteins (ORPs), which are a large family of conserved lipid-binding proteins. We demonstrate that a representative member of this family, Osh4p/Kes1p, specifically facilitates the nonvesicular transfer of cholesterol and ergosterol between membranes in vitro. In addition, Osh4p transfers sterols more rapidly between membranes containing phosphoinositides (PIPs), suggesting that PIPs regulate sterol transport by ORPs. We confirmed this by showing that PM to ER sterol transport slows dramatically in mutants with conditional defects in PIP biosynthesis. Our findings argue that ORPs move sterols among cellular compartments and that sterol transport and intracellular distribution are regulated by PIPs.
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Muchembled, Jérôme, Anissa Lounès-Hadj Sahraoui, Anne Grandmougin-Ferjani, and Michel Sancholle. "Changes in sterol composition with ontogeny of Blumeria graminis conidia." Canadian Journal of Botany 78, no. 10 (October 1, 2000): 1288–93. http://dx.doi.org/10.1139/b00-106.
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The total sterol composition of conidia of the obligate plant pathogen Blumeria (= Erysiphe) graminis f.sp. tritici has been analysed as a function of their ontogeny during sporulation. Two main classes of sterols were characterized: 24-ethylsterols (24-ethylcholesta-5,22-dienol, 24-ethylcholesterol, and Δ5-avenasterol) and 24-methylsterols (24-methylenecholesterol and episterol). Our results show that sterol composition is greatly modified during ontogeny of B. graminis conidia both at the qualitative and quantitative levels. In particular, 24-methylsterols, e.g., 24-methylenecholesterol and episterol, are the major sterols in old conidia whereas 24-ethylsterols, e.g., 24-ethylcholesta-5,22-dienol, 24-ethylcholesterol, and Δ5-avenasterol, are the main sterols in young conidia.Key words: Erysiphe, wheat powdery mildew, sterols, ontogeny.
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Solanko, Katarzyna A., Maciej Modzel, Lukasz M. Solanko, and Daniel Wüstner. "Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport." Lipid Insights 8s1 (January 2015): LPI.S31617. http://dx.doi.org/10.4137/lpi.s31617.
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Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann–Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications.
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Zhu, Qian, Jingjing Wu, Daxue He, and Xuemei Lian. "Effects of Plant Sterols Intake on Systematic and Tissue Specific Lipid Metabolism in C57BL/6J Mice." Current Developments in Nutrition 5, Supplement_2 (June 2021): 388. http://dx.doi.org/10.1093/cdn/nzab037_098.
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Abstract Objectives To investigate the effects of plant sterols intake on systematic and tissue specific lipid metabolism in C57BL/6J mice. Methods Male C57BL/6J mice were randomly divided into control diet group (CS) and plant sterol group (PS, 2% plant sterols). After 28 weeks of continuous feeding, the serum of the mice were collected for biochemical and mass spectrometry tests. Serum levels of total cholesterol (TC), triglyceride (TG) and free sterols were determined. The livers and lungs were collected for free sterol quantification and RNA-seq analysis. Results Compared with the CS group, 2% plant sterols intake significantly reduced the levels of TC in the serum of mice (P < 0.05), with the TG level unchanged. The quantitative results of free sterols showed that the concentration of campesterol were increased, and the cholestanol levels were decreased significantly in the serum and liver of the PS group mice. The results of RNA-seq analysis were used to further evaluate its impact on the lipid metabolism related gene expression profile in the livers and lungs. The results showed that HMGCR, SQLE, HMGCS1, SREBF1, and other genes related to cholesterol synthesis in the PS group were significantly up-regulated in the liver, but not in the lung; Among the first 20 targeting pathways related to the action of plant sterols, the liver differentially expressed genes were enriched in lipid metabolism (steroid biosynthesis, terpenoid skeleton biosynthesis, peroxisome, bile acid secretion, PPAR, MAPK, fatty acid metabolism.), inflammation related (Cell adhesion molecules, leukocyte trans-endothelial migration) and amino acid metabolism (glutathione, valine, leucine and isoleucine metabolism). The differential genes in lung tissue are enriched in lipid metabolism (acetone metabolism, fatty acid metabolism, insulin resistance, terpenoid skeleton biosynthesis, iron death, PPAR), cell function (internal Swallowing, aging) and vascular smooth muscle contraction etc. Conclusions Differentially expressed gene networks reflect the multi-dimensional regulation of plant sterols on tissue specific lipid metabolism, which lays a good foundation for further revealing its mechanism. Funding Sources Yihaikerry Nutrition and Food Safety Foundation, Chinese Nutrition Society; Project of Technology Innovation and Application, Chongqing, China
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Jing, Xiangfeng, and Spencer T. Behmer. "Insect Sterol Nutrition: Physiological Mechanisms, Ecology, and Applications." Annual Review of Entomology 65, no. 1 (January 7, 2020): 251–71. http://dx.doi.org/10.1146/annurev-ento-011019-025017.
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Insects, like all eukaryotes, require sterols for structural and metabolic purposes. However, insects, like all arthropods, cannot make sterols. Cholesterol is the dominant tissue sterol for most insects; insect herbivores produce cholesterol by metabolizing phytosterols, but not always with high efficiency. Many insects grow on a mixed-sterol diet, but this ability varies depending on the types and ratio of dietary sterols. Dietary sterol uptake, transport, and metabolism are regulated by several proteins and processes that are relatively conserved across eukaryotes. Sterol requirements also impact insect ecology and behavior. There is potential to exploit insect sterol requirements to ( a) control insect pests in agricultural systems and ( b) better understand sterol biology, including in humans. We suggest that future studies focus on the genetic mechanism of sterol metabolism and reverse transportation, characterizing sterol distribution and function at the cellular level, the role of bacterial symbionts in sterol metabolism, and interrupting sterol trafficking for pest control.
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Raychaudhuri, S., and W. A. Prinz. "Uptake and trafficking of exogenous sterols in Saccharomyces cerevisiae." Biochemical Society Transactions 34, no. 3 (May 22, 2006): 359–62. http://dx.doi.org/10.1042/bst0340359.
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The proper distribution of sterols among organelles is critical for numerous cellular functions. How sterols are sorted and moved among membranes remains poorly understood, but they are transported not only in vesicles but also by non-vesicular pathways. One of these pathways moves exogenous sterols from the plasma membrane to the endoplasmic reticulum in the yeast Saccharomyces cerevisiae. We have found that two classes of proteins play critical roles in this transport, ABC transporters (ATP-binding-cassette transporters) and oxysterol-binding protein-related proteins. Transport is also regulated by phosphoinositides and the interactions of sterols with other lipids. Here, we summarize these findings and speculate on the role of non-vesicular sterol transfer in determining intracellular sterol distribution and membrane function.
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Gomes, M. H. R., and M. A. Resende. "Fonsecaea pedrosoi: lipid composition and determination of susceptibility to amphotericin B." Canadian Journal of Microbiology 38, no. 3 (March 1, 1992): 209–14. http://dx.doi.org/10.1139/m92-035.
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Conidia and mycelial cells of Fonsecaea pedrosoi ATCC 46428 were obtained for analyses of lipid composition. Total lipids, phospholipids, sterols, and qualitative sterols and fatty acid composition were determined. A higher lipid content was detected in conidia than in mycelial cells of Fonsecaea pedrosoi, which could not be attributed to total sterols and phospholipids. In both forms of this fungus, ergosterol was the only sterol detected. The minimal inhibitory concentration of amphotericin B was lower for conidia than for mycelium. Key words: Fonsecaea pedrosoi, chromoblastomycosis, sterol, amphotericin B, lipid composition.
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Batth, Rituraj, Clément Nicolle, Ilenuta Simina Cuciurean, and Henrik Toft Simonsen. "Biosynthesis and Industrial Production of Androsteroids." Plants 9, no. 9 (September 3, 2020): 1144. http://dx.doi.org/10.3390/plants9091144.
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Steroids are a group of organic compounds that include sex hormones, adrenal cortical hormones, sterols, and phytosterols. In mammals, steroid biosynthesis starts from cholesterol via multiple steps to the final steroid and occurs in the gonads, adrenal glands, and placenta. This highly regulated pathway involves several cytochrome P450, as well as different dehydrogenases and reductases. Steroids in mammals have also been associated with drug production. Steroid pharmaceuticals such as testosterone and progesterone represent the second largest category of marketed medical products. There heterologous production through microbial transformation of phytosterols has gained interest in the last couple of decades. Phytosterols being the plants sterols serve as inexpensive substrates for the production of steroid derivatives. Various genes and biochemical pathways involved in phytosterol degradation have been identified in many Rhodococcus and Mycobacterium species. Apart from an early investigation in mammals, presence of steroids such as androsteroids and progesterone has also been demonstrated in plants. Their main role is linked with growth, development, and reproduction. Even though plants share some chemical features with mammals, the biosynthesis is different, with the first C22 hydroxylation as an example. This is performed by CYP11A1 in mammals and CYP90B1 in plants. Moreover, the entire plant steroid biosynthesis is not fully elucidated. Knowing this pathway could provide new processes for the industrial biotechnological production of steroid hormones in plants.
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Ajagbe, Bridget O., Rgia A. Othman, and Semone B. Myrie. "Plant Sterols, Stanols, and Sitosterolemia." Journal of AOAC INTERNATIONAL 98, no. 3 (May 1, 2015): 716–23. http://dx.doi.org/10.5740/jaoacint.sgeajagbe.
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Abstract Phytosterolemia (sitosterolemia) is a rare autosomal recessive sterol storage disease caused by mutations in either of the adenosine triphosphate (ATP) binding cassette transporter genes; (ABC) G5 or ABCG8, leading to impaired elimination of plant sterols and stanols, with their increased accumulation in the blood and tissues. Thus the disease is characterized by substantially elevated serum plant sterols and stanols, with moderate to high plasma cholesterol levels, and increased risk of premature atherosclerosis. Hematologic abnormalities including macrothrombocytopenia, stomatocytosis and hemolysis are frequently observed in sitosterolemia patients. Currently, ezetimibe, a sterol absorption inhibitor, is used as the routine treatment for sitosterolemia, with reported improvement in plant sterol levels and hemolytic parameters. This review summarizes the research related to the health impact of plant sterols and stanols on sitosterolemia.
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Krzaczek, Tadeusz, and Monika Gawrońska-Grzywacz. "Sterol composition from inflorescences of Hieracium pilosella L." Acta Societatis Botanicorum Poloniae 75, no. 1 (2011): 29–32. http://dx.doi.org/10.5586/asbp.2006.005.
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The fraction of sterol acetates from the inflorescences of <em>Hieracium pilosella</em> has been isolated in the typical way from petroleum ether extract. By means of the weight method the total amount of sterols was determined (0.2659%). The mixtures of sterol acetates and free sterols were investigated using GC-MS techniques. The occurrence of about 18 sterols has been observed. Cholesterol, cholest-8(14)-en-3b-ol, cholesta-5.7-dien-3b-ol, cholest-7-en-3b-ol, ergosta-5.24-dien-3b-ol, campesterol, stigmasterol, b-sitosterol, fucosterol, 5a-stigmast-7-en-3a-ol were identified. The probable structures of lophenol, isofucosterol, 5a-stigmasta-7.24-dien-3b-ol, lanosta-9(11).24-dien-3b-ol and 24-ethylidene lophenol were stated on the basis of literature data. The last 4 sterols occur in a vestigial quantity, which made its identification impossible. Sitos erol and cholesterol are remarkably dominating sterols in the fraction.
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Hernández, Agustín, David T. Cooke, and David T. Clarkson. "Effects of Abnormal-Sterol Accumulation onUstilago maydis Plasma Membrane H+-ATPase Stoichiometry and Polypeptide Pattern." Journal of Bacteriology 180, no. 2 (January 15, 1998): 412–15. http://dx.doi.org/10.1128/jb.180.2.412-415.1998.
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ABSTRACT Accumulation of 14α-methylated sterols or Δ8-sterols in Ustilago maydis affected three aspects of the plasma membrane H+-ATPase. Proton transport was reduced in Δ8-sterol-accumulating samples, due to an altered H+/ATP stoichiometry. ATP hydrolytic activity was increased, but no direct correlation with the extent or type of abnormal sterol accumulated could be drawn. Finally, Western blot analysis with antibodies against yeast PMA1 revealed a second lighter band (99-kDa band) in all samples from abnormal-sterol-accumulating sporidia. The conclusions are that the 99-kDa band and a reduced stoichiometry are directly linked to the presence of abnormal sterols, while changes in hydrolytic activity are linked only indirectly.
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Gylling, Helena, and Tatu A. Miettinen. "The effect of plant stanol- and sterol-enriched foods on lipid metabolism, serum lipids and coronary heart disease." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 42, no. 4 (July 1, 2005): 254–63. http://dx.doi.org/10.1258/0004563054255605.
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Phytosterols are plant sterols, mainly campesterol and sitosterol, and their respective stanols (5α-saturated derivatives), which chemically resemble cholesterol. They are present in a normal diet and are absorbed proportionally to cholesterol, but to a much lesser extent, such that less than 0.1% of serum sterols are plant sterols. Phytosterols inhibit intestinal cholesterol absorption, and fat-soluble plant stanol esters were introduced as a functional food for lowering serum cholesterol in the early 1990s; plant sterol esters entered the market at the end of the 1990s. Inhibition of the intestinal absorption of cholesterol stimulates cholesterol synthesis, a factor which limits serum cholesterol lowering to about 10% with phytosterols. Enrichment of the diet with plant stanol esters reduces absorption and serum concentrations of both cholesterol and plant sterols, whereas enrichment of the diet with plant sterol esters, especially in combination with statins, lowers serum cholesterol but increases serum plant sterol levels. Recent studies have suggested that high-serum plant sterol levels may be associated with increased coincidence of coronary heart disease. Estimates of coronary heart disease reduction by 20-25% with plant sterols/stanols is based mainly on short-term studies. Long-term cholesterol lowering, needed for the prevention of coronary heart disease, may be successful with plant stanol esters, which lower serum cholesterol in both genders over at least a year.
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Čermák, J., M. Rychtera, P. Nechvíle, J. Náhlík, K. Melzoch, J. Šindelář, J. Vovsík, and J. Votruba. "Influence of the specific growth rate on formation of sterols in yeast Saccharomyces cerevisiae during fed-batch cultivation." Czech Journal of Food Sciences 18, No. 3 (January 1, 2000): 110–14. http://dx.doi.org/10.17221/8321-cjfs.
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Ergosterol is a major sterol in yeast cells. Intermediates of ergosterol biosynthesis or products of ergosterol biotransformation occur in cells too. Sterols mainly form components of cell membranes. Fluidity of membranes is affected by sterols. The amount of sterols in cells can be influenced above all by cultivation conditions and by the yeast genotype. Specific growth rate is an important factor which affects the amount of sterols present in yeast cells. We carried out a series of 24-hour cultivations to find out the impact of specific growth rate on sterol biosynthesis. Inflow of synthetic medium to the bioreactor was controlled by means of a profile of carbon dioxide concentration in the outlet gases. This profile was acquired by simulation according to a mathematical model of cultivation. Profile of carbon dioxide concentration corresponded to a precalculated profile of specific growth rate. Cultivation was divided into two phases with different growth rate values. A constant value of the specific growth rate was maintained in the 1st phase. The specific growth rate value decreased by controlling the inflow in the 2nd phase (beginning at 12th hour of cultivation). Other cultivations were carried out using so-called physiological control which consisted in determining the immediate physiological state (e.g., RQ) and the choice of control strategy according to the metabolic state. Selected control strategy ensures an immediate action (inflow of the medium). If the specific growth rate decreased in the 1st phase, the amount of total sterols in yeast dry biomass increased (to 2.7% in yeast dry biomass). But the purity of ergosterol decreased (amount of sterol contaminants increased up to 23.3% in the sterol fraction). If a constant value of respiratory quotient was maintained (at about 1.1), the amount of total sterols in yeast dry biomass and the purity of ergosterol were constant. If the value of respiratory quotient was changed in the growth and final phase of cultivation, the amount of total sterols in yeast dry biomass increased (to 2.83% in yeast dry biomass). However, the purity of ergosterol decreased (amount of sterol contaminants increased up to 21.2% in sterol fraction).
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Shao, Minglong, Youxi Zhao, Yu Liu, Taowei Yang, Meijuan Xu, Xian Zhang, and Zhiming Rao. "Intracellular Environment Improvement of Mycobacterium neoaurum for Enhancing Androst-1,4-Diene-3,17-Dione Production by Manipulating NADH and Reactive Oxygen Species Levels." Molecules 24, no. 21 (October 25, 2019): 3841. http://dx.doi.org/10.3390/molecules24213841.
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As one of the most significant steroid hormone precursors, androst-1,4-diene-3,17-dione (ADD) could be used to synthesize many valuable hormone drugs. The microbial transformation of sterols to ADD has received extensive attention in recent years. In a previous study, Mycobacterium neoaurum JC-12 was isolated and converted sterols to the major product, ADD. In this work, we enhanced ADD yield by improving the cell intracellular environment. First, we introduced a nicotinamide adenine dinucleotide (NADH) oxidase from Bacillus subtilis to balance the intracellular NAD+ availability in order to strengthen the ADD yield. Then, the catalase gene from M. neoaurum was also over-expressed to simultaneously scavenge the generated H2O2 and eliminate its toxic effects on cell growth and sterol transformation. Finally, using a 5 L fermentor, the recombinant strain JC-12yodC-katA produced 9.66 g/L ADD, which increased by 80% when compared with the parent strain. This work shows a promising way to increase the sterol transformation efficiency by regulating the intracellular environment.
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Nakakuni, Yamasaki, Yoshitake, Takehara, and Yamamoto. "Methyl Ether-Derivatized Sterols and Coprostanol Produced via Thermochemolysis Using Tetramethylammonium Hydroxide (TMAH)." Molecules 24, no. 22 (November 7, 2019): 4040. http://dx.doi.org/10.3390/molecules24224040.
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Sterols are widely distributed in nature from lipids in organisms to sediments. As a conventional method, extraction and derivatization with TMS have been applied for sterol analysis, requiring a long preparation time for gas chromatography–mass spectrometry analysis. In this study, for sterol analysis, thermochemolysis using tetramethylammonium hydroxide (TMAH) was applied. This method performs hydrolysis and methylation simultaneously; thus, free and ether-bonding sterols can be analyzed as sterol methyl ethers in a relatively short time period. A sediment sample from a tideland (the Yatsu tideland, Japan) was analyzed using the TMAH method, and we detected more than 10 sterols, which include cholest-5-en-3β-ol (cholesterol), 24-ethylcholest-5-en-3β-ol (sitosterol), 24-methylcholesta-5,22E-3β-ol (brassicasterol), 24-ethylcholesta-5,24(28)Z-dien-3β-ol (isofucosterol), 4α,23,24-trimethyl-5α(H)-cholest-22E-en-3β- ol (dinosterol), and 5β(H)-cholestan-3β-ol (coprostanol). The detection of the various sterols can be attributed to multiple natural and artificial sources around the Yatsu tideland. In this paper, the mass spectra of these sterols are provided together with an interpretation of their fragmentation patterns. Additionally, the fecal pollution in the Yatsu tideland is discussed in the context of the detection of coprostanol.
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Lee, Ryan W. Y., and Elaine Tierney. "Hypothesis: The Role of Sterols in Autism Spectrum Disorder." Autism Research and Treatment 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/653570.
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A possible role for sterols in the development of autism spectrum disorder (ASD) has not been proven, but studies in disorders of sterol biosynthesis, chiefly Smith-Lemli-Opitz syndrome (SLOS), enable hypotheses on a causal relationship to be discussed. Advances in genetic technology coupled with discoveries in membrane physiology have led to renewed interest for lipids in the nervous system. This paper hypothesizes on the role of sterol dysfunction in ASD through the framework of SLOS. Impaired sonic hedgehog patterning, alterations in membrane lipid rafts leading to abnormal synaptic plasticity, and impaired neurosteroid synthesis are discussed. Potential therapeutic agents include the development of neuroactive steroid-based agents and enzyme-specific drugs. Future investigations should reveal the specific mechanisms underlying sterol dysfunction in neurodevelopmental disorders by utilizing advanced imaging and molecular techniques.
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Okoro, Linus, and Roland Winter. "Pressure Perturbation Calorimetric Studies on Phospholipid-Sterol Mixtures." Zeitschrift für Naturforschung B 63, no. 6 (June 1, 2008): 769–78. http://dx.doi.org/10.1515/znb-2008-0627.
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Sterols regulate biological processes and sustain the lateral structure of cellular membranes. The sterol cholesterol, its precursor lanosterol, the plant sterols stigmasterol and ergosterol as well as 7-dehydrocholesterol were added up to 36 mol-% to vesicles of the phospholipid 1,2-dipalmitoyl-snglycero- 3-phosphatidylcholine (DPPC). The aim of this study was to investigate the influence of the sterol side chain and ring structure on the volumetric properties of the lipid bilayer system by using pressure perturbation calorimetry (PPC), a relatively new and efficient technique, to study the thermal expansion coefficient and volumetric properties of biomolecules. The experiments were carried out in the temperature range from 10 to 85 °C, i. e., at temperatures below and above the chain-melting transition temperatures of the lipid mixtures. Additionally, corresponding differential scanning calorimetric (DSC) measurements were carried out.Whereas the conformational properties of the different sterols have a significant effect on the order parameter of the lipid acyl-chains, the thermodynamic parameters of these sterols are less influenced by the differential structural changes of the sterols. For lanosterol and stigmasterol, marked differences are found, however.
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Wen, Di, Zhi Chen, Jiamin Wen, and Qiangqiang Jia. "Sterol Regulation of Development and 20-Hydroxyecdysone Biosynthetic and Signaling Genes in Drosophila melanogaster." Cells 12, no. 13 (June 28, 2023): 1739. http://dx.doi.org/10.3390/cells12131739.
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Ecdysteroids are crucial in regulating the growth and development of insects. In the fruit fly Drosophila melanogaster, both C27 and C28 ecdysteroids have been identified. While the biosynthetic pathway of the C27 ecdysteroid 20-hydroxyecdysone (20E) from cholesterol is relatively well understood, the biosynthetic pathway of C28 ecdysteroids from C28 or C29 dietary sterols remains unknown. In this study, we found that different dietary sterols (including the C27 sterols cholesterol and 7-dehydrocholesterol, the C28 sterols brassicasterol, campesterol, and ergosterol, and the C29 sterols β-sitosterol, α-spinasterol, and stigmasterol) differentially affected the expression of 20E biosynthetic genes to varying degrees, but similarly activated 20E primary response gene expression in D. melanogaster Kc cells. We also found that a single dietary sterol was sufficient to support D. melanogaster growth and development. Furthermore, the expression levels of some 20E biosynthetic genes were significantly altered, whereas the expression of 20E signaling primary response genes remained unaffected when flies were reared on lipid-depleted diets supplemented with single sterol types. Overall, our study provided preliminary clues to suggest that the same enzymatic system responsible for the classical C27 ecdysteroid 20E biosynthetic pathway also participated in the conversion of C28 and C29 dietary sterols into C28 ecdysteroids.
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Zgheib, S., M. C. Gromaire, C. Lorgeoux, M. Saad, and G. Chebbo. "Sterols: a tracer of organic matter in combined sewers." Water Science and Technology 57, no. 11 (June 1, 2008): 1705–12. http://dx.doi.org/10.2166/wst.2008.285.
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The important organic pollution of combined wet weather flows (WWF), its acute impact on receiving waters have been widely demonstrated. The main three possibly origins for this organic pollution are: runoff water (streets and roofs), wastewater and erosion of sewer sediments in combined sewer system. This work, for tracing the origin of organic particles bound in combined sewer system, has been focused on the innovative use of sterols. So, eight sterols have been selected and analysed for each kind of sample. Results are represented in contents of sterols (μg g−1) and in sterol profiles (%).The comparison of contents and profiles leads the separation between two groups: runoff water, characterized by the total absence of coprostanol, epicoprostanol and coprostanone, and the group of sewer deposits (gross bed sediment (GBS), organic layer (OL), biofilms) and wastewater. Moreover, sewer deposits and wastewater can be distinguished by their sterol contents and profiles. To evaluate their contribution to WWF a comparison between sterol signatures is done which shows that these effluents have a strong similarity in profiles and in contents of sterols to the organic layer.
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Silbernagel, Guenther, Iris Baumgartner, and Winfried März. "Cardiovascular Safety of Plant Sterol and Stanol Consumption." Journal of AOAC INTERNATIONAL 98, no. 3 (May 1, 2015): 739–41. http://dx.doi.org/10.5740/jaoacint.sgesilbernagel.
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Abstract Plant sterols and stanols as components of functional foods are widely used for cholesterol lowering. The regular intake of these functional foods is associated with a decrease in low density lipoprotein cholesterol of about 10 % and an increase in plasma plant sterol or stanol concentrations by about a factor of 2. There is no doubt that a decrease in low density lipoprotein cholesterol is beneficial to cardiovascular health. However, due to the concomitant increase in circulating plant sterols safety issues associated with the intake of plant sterol containing functional foods have been raised. Herein, we will review and evaluate those arguments raised against the use of plant sterols and stanols.
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Begcevic Brkovic, Ilijana, Madlen Reinicke, Soroth Chey, Ingo Bechmann, and Uta Ceglarek. "Characterization of Non-Cholesterol Sterols in Microglia Cell Membranes Using Targeted Mass Spectrometry." Cells 12, no. 7 (March 23, 2023): 974. http://dx.doi.org/10.3390/cells12070974.
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Background: Non-cholesterol sterols, as well as plant sterols, cross the blood–brain barrier and, thus, can be incorporated into cell membranes, affecting the cell’s inflammatory response. The aim of our work was to develop an analytical protocol for a quantitative assessment of the sterol composition within the membrane microdomains of microglia. Methods: A protocol for cell membrane isolation using OptiPrepTM gradient ultracentrifugation, in combination with a targeted mass spectrometry (LC-MS/MS)-based assay, was developed and validated for the quantitative analysis of free sterols in microglia cell membranes. Results: Utilizing an established LC-MS/MS assay, cholesterol and seven non-cholesterol sterols were analyzed with a limit of detection from 0.001 to 0.05 mg/L. Applying the detergent-free isolation of SIM-A9 microglia cell membranes, cholesterol (CH), desmosterol (DE), lanosterol (LA) stigmasterol (ST), beta-sitosterol (SI) and campesterol (CA) were quantified with coefficients of variations between 6 and 29% (fractions 4–6, n = 5). The highest concentrations of non-CH sterols within the microglia plasma membranes were found in the microdomain region (DE>LA>SI>ST>CA), with ratios to CH ranging from 2.3 to 435 lower abundancies. Conclusion: By applying our newly developed and validated analytical protocol, we show that the non-CH sterol concentration is about 38% of the total sterol content in microglia membrane microdomains. Further investigations must clarify how changes in the non-sterol composition influence membrane fluidity and cell signaling.
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Slantchev, Krasimir, Kamen Stefanov, Katya Seizova, Simeon Popov, and Stoitse Andreev. "Chemical Composition of the Lipophylic Extract from the Tunicate Botryllus schlosseri." Zeitschrift für Naturforschung C 55, no. 9-10 (October 1, 2000): 794–98. http://dx.doi.org/10.1515/znc-2000-9-1020.
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Abstract Eighteen sterols were identified in Botryllus schlosseri, stanols being the main sterols. The sterol composition is in agreement with our recent paper on taxonomic separation of tunicates into three groups. Again we found in invertebrates of the Black Sea sterols with a (22Z)-double bond. This confirms the presence of such sterols in nature. The composition of the phospholipids appeared to be complex, and twelve groups of them were identified in Botryllus schlossen. The main representatives of phospholipids appeared to be phosphatidylcholine and phosphatidylethanolamine. Only four volatile compounds were identified, which is unusual for marine invertebrates.
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Takeshima, Mika, Mari H. Ogihara, and Hiroshi Kataoka. "Sterol Characteristics in Silkworm Brain and Various Tissues Characterized by Precise Sterol Profiling Using LC-MS/MS." International Journal of Molecular Sciences 20, no. 19 (September 29, 2019): 4840. http://dx.doi.org/10.3390/ijms20194840.
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Sterols, especially cholesterol (Chl), are fundamental for animal survival. Insects lacking the ability to synthesize Chl are sterol auxotrophic animals and utilize dietary Chl and phytosterols to survive. The sterols obtained from a diet are distributed to the tissues; however, sterol homeostasis in insect tissues remains to be elucidated. This study sought to understand the sterol characteristics of insect tissues through detailed sterol quantification and statistics. The combination of sterol quantification using liquid chromatography tandem mass spectrometry (LC-MS/MS) and principal component analysis (PCA) revealed tissue-specific sterol characteristics in the silkworm, Bombyx mori, a phytophagous insect. We found that insect tissues have tissue-intrinsic sterol profiles. The brain has a unique sterol composition as compared to other tissues—high concentration of Chl and less accumulation of phytosterols. Other tissues also have intrinsic sterol characteristics, which when defined by dietary sterols or Chl metabolites, indicate preference for a sterol and consistently manage their own sterol homeostasis. Though most tissues never change sterol profiles during development, the brain drastically changes its sterol profile at the wandering stage, indicating that it could alter sterol composition in preparation for metamorphosis. These results suggest the existence of tissue- and sterol-specific systems for sterol homeostasis in insects.
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Karamysheva, Zemfira N., Samrat Moitra, Andrea Perez, Sumit Mukherjee, Elena B. Tikhonova, Andrey L. Karamyshev, and Kai Zhang. "Unexpected Role of Sterol Synthesis in RNA Stability and Translation in Leishmania." Biomedicines 9, no. 6 (June 19, 2021): 696. http://dx.doi.org/10.3390/biomedicines9060696.
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Leishmania parasites are trypanosomatid protozoans that cause leishmaniasis affecting millions of people worldwide. Sterols are important components of the plasma and organellar membranes. They also serve as precursors for the synthesis of signaling molecules. Unlike animals, Leishmania does not synthesize cholesterol but makes ergostane-based sterols instead. C-14-demethylase is a key enzyme involved in the biosynthesis of sterols and an important drug target. In Leishmania parasites, the inactivation of C-14-demethylase leads to multiple defects, including increased plasma membrane fluidity, mitochondrion dysfunction, hypersensitivity to stress and reduced virulence. In this study, we revealed a novel role for sterol synthesis in the maintenance of RNA stability and translation. Sterol alteration in C-14-demethylase knockout mutant leads to increased RNA degradation, reduced translation and impaired heat shock response. Thus, sterol biosynthesis in Leishmania plays an unexpected role in global gene regulation.
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Child, P., and A. Kuksis. "Investigation of the role of micellar phospholipid in the preferential uptake of cholesterol over sitosterol by dispersed rat jejunal villus cells." Biochemistry and Cell Biology 64, no. 8 (August 1, 1986): 847–53. http://dx.doi.org/10.1139/o86-113.
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The uptake of radioactive cholesterol and sitosterol by rat jejunal villus cells was examined using mixed micellar solutions containing sodium taurocholate, equimolar mixtures of the two sterols, and a variety of phospholipid types. The addition of phospholipid to the incubation solutions reduced the cellular absorption of both sterols and gave rise to uptake kinetics that were linear with time. In the presence of egg yolk phospholipid, uptake of the sterols by villus cells occurred with a modest preference for cholesterol over sitosterol. The ratio of accumulated cholesterol/sitosterol increased from 1.0 initially to 1.23 ± 0.04 (n = 18) after a 30-min incubation at 37 °C. The selectivity displayed in the villus cells increased significantly as egg phosphatidyléthanolamine was added to the egg phosphatidylcholine (PC) preparation in micellar solution. It was markedly decreased when dipalmitoyl PC or the primarily saturated egg yolk sphingomyelin were incorporated into the micelles. In every case examined, phospholipid was taken up by the cells concurrently with the sterols. The selectivity between cholesterol and sitosterol was maintained when the donor species were multilamellar vesicles composed of egg PC and the sterols, but not when the donor particles were albumin-stabilized sterol dispersions or taurocholate solutions in the absence of PC. The results show that the selective absorption of cholesterol over the plant sterol occurs only in the presence of unsaturated phospholipid. The phospholipid may act by influencing the permeability of the cellular membranes to the two sterols or the rate of sterol desorption from the phospholipid-containing micellar or liposomal carriers. The selective recognition of cholesterol may, therefore, be a general property of phospholipid-containing structures that is expressed at several stages of the absorptive process.
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Cabianca, Alessandro, Laurin Müller, Katharina Pawlowski, and Paul Dahlin. "Changes in the Plant β-Sitosterol/Stigmasterol Ratio Caused by the Plant Parasitic Nematode Meloidogyne incognita." Plants 10, no. 2 (February 4, 2021): 292. http://dx.doi.org/10.3390/plants10020292.
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Sterols play a key role in various physiological processes of plants. Commonly, stigmasterol, β-sitosterol and campesterol represent the main plant sterols, and cholesterol is often reported as a trace sterol. Changes in plant sterols, especially in β-sitosterol/stigmasterol levels, can be induced by different biotic and abiotic factors. Plant parasitic nematodes, such as the root-knot nematode Meloidogyne incognita, are devastating pathogens known to circumvent plant defense mechanisms. In this study, we investigated the changes in sterols of agricultural important crops, Brassica juncea (brown mustard), Cucumis sativus (cucumber), Glycine max (soybean), Solanum lycopersicum (tomato) and Zea mays (corn), 21 days post inoculation (dpi) with M. incognita. The main changes affected the β-sitosterol/stigmasterol ratio, with an increase of β-sitosterol and a decrease of stigmasterol in S. lycopersicum, G. max, C. sativus and Z. mays. Furthermore, cholesterol levels increased in tomato, cucumber and corn, while cholesterol levels often were below the detection limit in the respective uninfected plants. To better understand the changes in the β-sitosterol/stigmasterol ratio, gene expression analysis was conducted in tomato cv. Moneymaker for the sterol 22C-desaturase gene CYP710A11, responsible for the conversion of β-sitosterol to stigmasterol. Our results showed that the expression of CYP710A11 was in line with the sterol profile of tomato after M. incognita infection. Since sterols play a key role in plant-pathogen interactions, this finding opens novel insights in plant nematode interactions.
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Ntanios, Fady Y., and Guus S. M. J. E. Duchateau. "A healthy Diet rich in Carotenoids is effective in Maintaining normal Blood Carotenoid Levels during the Daily use of Plant Sterol-enriched Spreads." International Journal for Vitamin and Nutrition Research 72, no. 1 (January 1, 2002): 32–39. http://dx.doi.org/10.1024/0300-9831.72.1.32.
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Blood cholesterol levels are affected by diet and in particular by the type and amount of fat intake. In recent years, vegetable oil spreads containing plant sterols/stanols (as their fatty acid esters) have been developed. Numerous clinical trials on spreads with added plant sterols/stanols have shown that they have much greater cholesterol-lowering properties than conventional vegetable oil spreads. Plant sterols decrease both dietary and biliary cholesterol absorption in the small intestine, with a consequential increase in excretion of cholesterol. It is also recognized that plant sterol/stanol-enriched, cholesterol-lowering spreads, if consumed regularly, may induce a 10–20% decrease in plasma carotenoids, adjusted for changes in plasma lipids. A 10–20% decrease in plasma carotenoids falls well within the seasonal variation observed in individuals. Our current understanding of the physiological functions of carotenoids does not indicate any health risk associated with the slight decrease in their blood levels due to the intake of plant sterol/stanol. The questions that have been raised, though, are how plant sterols/stanols affect plasma carotenoid levels, and in addition, what quantity of fruits and vegetables (the richest dietary sources of carotenoids) would have to be consumed to improve plasma carotenoid levels? The current mini-review covers the cholesterol-lowering effect of plant sterols, their mechanisms of action and effect on blood carotenoids, and concludes with the potential heath benefits of daily intake of plant sterol-enriched spreads.
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Girardi Piva, Giovana, Erick Casalta, Jean-Luc Legras, Catherine Tesnière, Jean-Marie Sablayrolles, David Ferreira, Anne Ortiz-Julien, Virginie Galeote, and Jean-Roch Mouret. "Characterization and Role of Sterols in Saccharomyces cerevisiae during White Wine Alcoholic Fermentation." Fermentation 8, no. 2 (February 21, 2022): 90. http://dx.doi.org/10.3390/fermentation8020090.
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Responsible for plasma membrane structure maintenance in eukaryotic organisms, sterols are essential for yeast development. The role of two sterol sources in Saccharomyces cerevisiae during wine fermentation is highlighted in this review: ergosterol (yeast sterol produced by yeast cells under aerobic conditions) and phytosterols (plant sterols imported by yeast cells from grape musts in the absence of oxygen). These compounds are responsible for the maintenance of yeast cell viability during white wine fermentation under stress conditions, such as ethanol stress and sterol starvation, to avoid sluggish and stuck fermentations.