51
|
Yuan Z, Tie A, Tarnopolsky M, Bakovic M. Genomic organization, promoter activity, and expression of the human choline transporter-like protein 1. Physiol Genomics 2006; 26:76-90. [PMID: 16609143 DOI: 10.1152/physiolgenomics.00107.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Choline transporter-like (CTL) proteins of the CTL1 family are novel transmembrane proteins implicated in choline transport for phospholipid synthesis. In this study, we characterized the 5'-flanking region of the human (h)CTL1 gene and examined some of the possible mechanisms of its regulation, including promoter activity, splicing, and expression. The transcription start site of the hCTL1 gene was mapped by 5'-rapid amplification of cDNA ends (RACE), and the presence of two splice variants, hCTL1a and hCTL1b, was investigated using isoform-specific PCR and 3'-RACE. The hCTL1 promoter region of approximately 900 bp was isolated from MCF-7 human breast cancer cells. The promoter was TATA-less and driven by a long stretch of GC-rich sequence in accordance with widespread expression of hCTL1 at both mRNA and protein levels. Deletion analyses demonstrated that a very strong promoter is contained within 500 bp of the transcription start site, and more upstream regions did not increase its activity. The core promoter that conferred the minimal transcription is within the -188/+27-bp region, and its activity varied in human breast cancer and mouse skeletal muscle cells. Multiple motifs within the promoter regulatory region bound nuclear factors from both cultured cells and normal human skeletal muscle. The motifs within the three regions [S1 (-92/-61 bp), S2 (-174/-145 bp), and S3 (-289/-260 bp)] contained overlapping binding sites for hematopoietic transcription factors and ubiquitous transcription factors, in line with the expected gene function. Genomic analyses demonstrated a high conservation of hCTL1 and mouse CTL1 proximal promoters. Accordingly, mRNA profiles demonstrated that human splice variants were expressed ubiquitously, as demonstrated for the mouse transcripts; however, they differed from the profiles of rat CTL1 transcripts, which were more restricted to neurons and intestinal tissues. The shorter hCTL1b variant contained the cytosolic COOH-terminal motif L651KKR654 for endoplasmic reticulum retrieval/retention. This retention signal was conserved in hCTL1b and rat and mouse CTL1b and is typical for transmembrane proteins of type 1 topology.
Collapse
Affiliation(s)
- Zongfei Yuan
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | | | | | | |
Collapse
|
52
|
Joshi A, Paratkar SG, Thorat BN. Modification of lecithin by physical, chemical and enzymatic methods. EUR J LIPID SCI TECH 2006. [DOI: 10.1002/ejlt.200600016] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
53
|
Ilcol YO, Yilmaz Z, Ulus IH. Endotoxin alters serum-free choline and phospholipid-bound choline concentrations, and choline administration attenuates endotoxin-induced organ injury in dogs. Shock 2005; 24:288-93. [PMID: 16135970 DOI: 10.1097/01.shk.0000174018.02688.4b] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This study in dogs was performed to assess circulating choline status during endotoxemia and to determine whether choline administration can protect dogs from endotoxin-induced tissue injuries. Baseline serum-free and phospholipid-bound choline concentrations were 19.2 +/- 0.6 micromol/L and 3700 +/- 70 micromol/L, respectively. After intravenous endotoxin infusion, serum-free choline concentrations decreased by 14% to 49% (P < 0.05-0.001) at 2 to 6 h after 0.02 mg/kg endotoxin, and increased by 23% to 98% (P < 0.05-0.001) at 1 to 48 h after 1 mg/kg endotoxin. Serum phospholipid-bound choline concentrations increased by 19% to 27% (P < 0.05) at 12 to 24 h or by 18% to 53% (P < 0.05-0.001) at 1 to 48 h after 0.02 or 1 mg/kg endotoxin, respectively. The changes in serum-free and -bound choline levels in response to endotoxin were accompanied by dose- and time-related elevations in serum cortisol and biochemical markers for tissue injury and/or organ dysfunction. Intravenous administration of choline (20 mg/kg) 5 min before, and 4 and 8 h after endotoxin (1 mg/kg) attenuated endotoxin-induced elevations in serum alanine aminotransferase (P < 0.05-0.001), aspartate aminotransferase (P < 0.05-0.001), gamma-glutamyl transferase (P < 0.05-0.001), alkaline phosphatase (P < 0.05-0.001), lactate dehydrogenase (P < 0.05-0.001), myocardial creatine kinase (P < 0.001), urea (P < 0.05-0.01), creatinine (P < 0.05), uric acid (P < 0.01-0.001), and tissue necrosis factor-alpha (P < 0.001). Choline also attenuated alanine aminotransferase (P < 0.05-0.01), alkaline phosphatase (P < 0.05-0.01), lactate dehydrogenase (P < 0.05-0.01), creatine kinase (P < 0.05-0.001), myocardial creatine kinase (P < 0.05-0.001), and uric acid (P < 0.05-0.01), but failed to alter the serum urea, creatinine, aspartate aminotransferase, and gamma-glutamyl transferase responses to 0.02 mg/kg endotoxin. These data show that choline status is altered during endotoxemia and that choline administration diminishes endotoxin-induced tissue injury.
Collapse
Affiliation(s)
- Yesim Ozarda Ilcol
- Department of Biochemistry, Uludag University Medical School, The Central Clinical Chemistry Laboratory, 16059 Bursa, Turkey.
| | | | | |
Collapse
|
54
|
Buang Y, Wang YM, Cha JY, Nagao K, Yanagita T. Dietary phosphatidylcholine alleviates fatty liver induced by orotic acid. Nutrition 2005; 21:867-73. [PMID: 15975496 DOI: 10.1016/j.nut.2004.11.019] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 11/08/2004] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We compared the effect of dietary phosphatidylcholine (PC) with that of triacylglycerol (TG), both with the same fatty acid profiles, on fatty infiltration in orotic acid (OA)-induced fatty liver of Sprague-Dawley rats. METHODS Rats were fed an OA-supplemented diets containing TG (TG+OA group) or PC (20% of dietary lipid, PC+OA group) for 10 d. Rats fed the TG diet without OA supplementation served as the basal group. RESULTS Administering OA significantly increased the weights and TG accumulation in livers of the TG+OA group compared with the basal group. These changes were attributed to significant increases in the activities of fatty acid synthase, malic enzyme, and glucose-6-phosphate dehydrogenase, which are fatty acid synthetic enzymes, and phosphatidate phosphohydrolase, a rate-limiting enzyme of TG synthesis. However, the PC+OA group did not show TG accumulation and OA-induced increases of these enzyme activities. Further, a significant increase in the activity of carnitine palmitoyl transferase, a rate-limiting enzyme of fatty acid beta-oxidation, was found in the PC+OA group. CONCLUSIONS Dietary PC appears to alleviate the OA-induced hepatic steatosis and hepatomegaly, mainly through the attenuation of hepatic TG synthesis and enhancement of fatty acid beta-oxidation in Sprague-Dawley rats.
Collapse
Affiliation(s)
- Yohanes Buang
- Department of Applied Biological Sciences, Saga University, Saga, Japan
| | | | | | | | | |
Collapse
|
55
|
Olthof MR, Brink EJ, Katan MB, Verhoef P. Choline supplemented as phosphatidylcholine decreases fasting and postmethionine-loading plasma homocysteine concentrations in healthy men. Am J Clin Nutr 2005. [DOI: 10.1093/ajcn/82.1.111] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Margreet R Olthof
- From the Wageningen Centre for Food Sciences and the Division of Human Nutrition, Wageningen University, Wageningen, Netherlands (MRO, MBK, and PV), and the Department of Physiological Sciences, Netherlands Organisation for Applied Scientific Research (TNO) Quality of Life, Zeist, Netherlands (EJB)
| | - Elizabeth J Brink
- From the Wageningen Centre for Food Sciences and the Division of Human Nutrition, Wageningen University, Wageningen, Netherlands (MRO, MBK, and PV), and the Department of Physiological Sciences, Netherlands Organisation for Applied Scientific Research (TNO) Quality of Life, Zeist, Netherlands (EJB)
| | - Martijn B Katan
- From the Wageningen Centre for Food Sciences and the Division of Human Nutrition, Wageningen University, Wageningen, Netherlands (MRO, MBK, and PV), and the Department of Physiological Sciences, Netherlands Organisation for Applied Scientific Research (TNO) Quality of Life, Zeist, Netherlands (EJB)
| | - Petra Verhoef
- From the Wageningen Centre for Food Sciences and the Division of Human Nutrition, Wageningen University, Wageningen, Netherlands (MRO, MBK, and PV), and the Department of Physiological Sciences, Netherlands Organisation for Applied Scientific Research (TNO) Quality of Life, Zeist, Netherlands (EJB)
| |
Collapse
|
56
|
Ishinaga M, Ueda A, Mochizuki T, Sugiyama S, Kobayashi T. Cholesterol intake is associated with lecithin intake in Japanese people. J Nutr 2005; 135:1451-5. [PMID: 15930451 DOI: 10.1093/jn/135.6.1451] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many dietary recommendations for the prevention of heart disease and hyperlipidemia include restriction of cholesterol intake. However, limiting cholesterol intake might also affect the intake of other nutrients. The daily intakes of cholesterol, lecithin, total fatty acids, and SFAs by 388 Japanese subjects (ages 6-59 y) were analyzed directly using the duplicate portion sampling technique. Intakes were 266.1 +/- 146.5 mg/d, 1.6 +/- 0.9 g/d, 39.3 +/- 16.8 g/d, and 12.8 +/- 6.9 g/d, respectively. There was a strong positive correlation between cholesterol and lecithin intakes (r = 0.864, P < 0.001), and when food intake was adjusted to 1 kg/d, the correlation remained high (r = 0.881, P < 0.001). In contrast, the correlation between total fatty acid and lecithin intakes was lower (r = 0.423, P < 0.001), and when food intake was adjusted to 1 kg/d, the correlation coefficient remained stable (r = 0.448, P < 0.001). These results strongly indicate that limiting cholesterol intake decreases lecithin intake. Lecithin intake can be estimated from the following regression equation: lecithin intake (g/d) = 0.005 x cholesterol intake (mg/d) + 0.16 (R2= 0.747, P < 0.001). Furthermore, the intake of choline derived from lecithin can be estimated by the following equation: choline (mg/d) = 0.724 x cholesterol (mg/d) + 21.5.
Collapse
Affiliation(s)
- Masataka Ishinaga
- Department of Health Sciences, Hiroshima Prefectural Women's University, Hiroshima, 734-8558 Japan.
| | | | | | | | | |
Collapse
|
57
|
Stoknes IS, Økland HMW, Falch E, Synnes M. Fatty acid and lipid class composition in eyes and brain from teleosts and elasmobranchs. Comp Biochem Physiol B Biochem Mol Biol 2005; 138:183-91. [PMID: 15193274 DOI: 10.1016/j.cbpc.2004.03.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Revised: 03/16/2004] [Accepted: 03/17/2004] [Indexed: 11/27/2022]
Abstract
The fatty acid and lipid class composition of the eyes and brain were determined for the following species: Atlantic cod (Gadus morhua), saithe (Pollachius virens), redfish (Sebastes marinus), Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), Portuguese dogfish (Centroscymnus coelolepis), black dogfish (Centroscyllium fabricii), and leafscale gulper shark (Centrophorus squamosus). Fatty acid analyses of eyes from teleosts in the present study indicated that the lean species contained high ratios of docosahexaenoic acid (DHA) versus eicosapentaenoic acid (EPA), and high ratios of n-3 fatty acids versus n-6 fatty acids, while these ratios were significantly lower for the fatty fish species. The lipid class analyses revealed that among both elasmobranchs and teleosts, phospholipid was the dominant class of lipids in the eyes of lean species, while triacylglycerol was the dominant class of lipids in fatty species. Analyses of the fatty acid composition of brains revealed that the deep-sea elasmobranchs, Portuguese dogfish, black dogfish, and leafscale gulper shark, contained a level of arachidonic acid (AA) that was higher than their level of EPA and about fivefold higher than what was found in the brains of teleosts. Such high levels of AA are not normally observed in fish brains; rather, they are generally observed in brains of higher vertebrates.
Collapse
Affiliation(s)
- Iren S Stoknes
- Moereforsking, Moereforsking Aalesund, Møre Research, Box 5075, Aalesund N-6021, Norway
| | | | | | | |
Collapse
|
58
|
Montpied P, Domingo N, Senft M, Portugal H, Petit P, Chanussot F. High-fat diets impede the lowering effect of cyclosporine a on rat brain lipids and interact with the expression of apolipoproteins E and J. Lipids 2005; 40:59-67. [PMID: 15825831 DOI: 10.1007/s11745-005-1360-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Cyclosporine A (CsA), a common immunosuppressive agent, produces hyperlipidemia and apolipoprotein profile alterations in plasma as well as neurological and psychiatric complications. In rats, 10 mg CsA/kg/d treatments for 3 wk induce alterations of the electroencephalogram, and of the blood and brain lipids. Using this model, we evaluated whether triacylglycerol (TG)- and lecithin (PC)-enriched diets, reported to decrease epileptic episodes (TG) and to improve memory, could modify the effects of CsA treatment on brain lipids and possibly change apolipoprotein (apo) E and apoJ gene expression. To evaluate this hypothesis, three groups of rats were treated for 3 wk with CsA and received a low-fat, PC, or TG diet. Three other groups were fed the above-mentioned diets and were treated with the CsA solvent. As a control, one group was fed only the low-fat diet. The CsA-mediated decreases in brain cholesterol and PC contents, under a low-fat diet, were eliminated by the TG and PC diets. These high-fat diets induced a global increase in hippocampal transcriptional activity, as revealed by elevated polyadenylated RNA levels. The apoE and apoJ mRNA levels in the cortex and hippocampus of rats receiving the solvent were not statistically different between the TG- and PC-enriched diets but showed important variations compared with the low-fat diet solvent-treated group. A differential effect between the two high-fat diets was observed in the hippocampus, resulting in a significant increase of the apoE to apoJ ratio with the PC diet. The balance between apoE and apoJ is presumed to be important in encephalopathic mechanisms, by its involvement through low levels of brain cholesterol and PC, that might be associated with mental disorders. Our results therefore suggest that diet enrichment with polyunsaturated fat might be beneficial during CsA therapy. However, if the high levels in PC used here are more beneficial on CsA peripheral side effects than similar enrichment in TG, this does not seem to be the case in the brain. Thus, lower levels in PC should be tested.
Collapse
Affiliation(s)
- Pascale Montpied
- Centre National de la Recherche Scientifique, UMR 5191-Ecole Normale Supérieure-LSH, BP7000-69342 Lyon cedex, France.
| | | | | | | | | | | |
Collapse
|
59
|
Abstract
OBJECTIVES The standard methods for quantifying fat absorption involve extraction of fat from fecal samples with heptane, ether and ethanol. These solvents do not quantitatively recover phospholipids. Malabsorption of dietary and biliary phosphatidylcholine could potentially result in choline deficiency. Therefore, the authors developed a method extracting and quantifying fecal phospholipids. METHODS Fecal samples were collected for 72 hours from 18 children with cystic fibrosis and 10 control children. Fat was extracted first with hexane/diethyl ether/ethanol and then with chloroform/methanol. Total fat was quantitated gravimetrically. Phospholipids in extracted fat were separated and quantified using high-performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD). Phospholipid quantification was validated with a phosphomolybdate colorimetric assay. RESULTS The combination of solvent systems used in this study significantly improved total fat (p < 0.05) and phospholipid (p < 0.001) extraction compared with either hexane/diethyl ether/ethanol or chloroform/methanol alone. Fecal phospholipid measured by HPLC-ELSD was significantly correlated with lipid-soluble phosphorous using the phosphomolybdate assay (r = 0.75, p < 0.001). This method also allows quantification of fecal phosphatidylcholine and lysophosphatidylcholine. CONCLUSIONS Hexane/diethyl ether/ethanol followed by chloroform/methanol extraction of fecal samples and quantification of phospholipids using HPLC-ELSD is a new method for investigating phospholipid malabsorption.
Collapse
Affiliation(s)
- Alice Chen
- Department of Paediatrics and Nutrition Research Program, University of British, Columbia, Vancouver, Canada
| | | |
Collapse
|
60
|
Murgia S, Mele S, Monduzzi M. Quantitative characterization of phospholipids in milk fat via 31P NMR using a monophasic solvent mixture. Lipids 2003; 38:585-91. [PMID: 12880117 DOI: 10.1007/s11745-003-1500-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The phospholipids (PL) occurring in both ewe and cow milk fat globule membrane were identified and quantitatively determined using 31P NMR spectroscopy with inverse gated decoupled sequences, which allowed a rigorous quantitative analysis. A strict relation between amount and distribution of PL and type of feeding was found. The method was calibrated over a mixture of PL standards. A recently introduced solvent constituted by a monophasic dimethylformamide/triethylamine/guanidinium hydrochloride solvent mixture was used. Compared to the traditional chloroform/methanol/water-EDTA solvent, the new solvent mixture shows very similar accuracy and precision from a quantitative point of view. The monophasic solvent overcomes the partition problems related to a biphasic system, and slightly enlarges the range of 31P NMR chemical shifts, thus improving the resolution. In addition, the new solvent apparently displays a lower chemical shift dependence on the various PL concentrations. The limit of the method is mainly determined by the formation of adducts between triethylamine and some PL, namely, PE, monomethylphosphatidylethanolamine, phosphatidylethanolamine plasmalogens, and some lyso-PL. However, the new 31P NMR signals arising from these adducts could be easily quantified in the determination of PE.
Collapse
Affiliation(s)
- Sergio Murgia
- Dipartimento di Scienze Chimiche, CSGI, Università di Cagliari, 09042 Monserrato-Cagliari, Italy.
| | | | | |
Collapse
|
61
|
Teberikler L, Koseoglu S, Akgerman A. Deoiling of Crude Lecithin Using Supercritical Carbon Dioxide in the Presence of Co-solvents. J Food Sci 2001. [DOI: 10.1111/j.1365-2621.2001.tb15185.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
62
|
Teberikler L, Koseoglu S, Akgerman A. Selective extraction of phosphatidylcholine from lecithin by supercritical carbon dioxide/ethanol mixture. J AM OIL CHEM SOC 2001. [DOI: 10.1007/s11746-001-0230-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
63
|
Lo YL. Phospholipids as multidrug resistance modulators of the transport of epirubicin in human intestinal epithelial Caco-2 cell layers and everted gut sacs of rats. Biochem Pharmacol 2000; 60:1381-90. [PMID: 11008132 DOI: 10.1016/s0006-2952(00)00451-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phospholipids have been increasingly used as carriers for the delivery of a variety of drugs. Studies using cancer chemotherapeutic agents such as epirubicin encapsulated in liposomes, which are made of phospholipids and other ingredients, have generally shown reduced toxicity and enhanced therapeutic efficacy. The recent investigation of the role of P-glycoprotein (P-gp) in phospholipid translocation has opened a new area of research on the possible use of phospholipids as multidrug resistance (MDR) modulators. This study investigated the effects of liposomal encapsulation, empty liposome pretreatment, or free lipid pretreatment on the uptake and transport of epirubicin in the human colon adenocarcinoma cell line Caco-2 and in everted gut sacs of rat jejunum and ileum. Epirubicin uptake experiments, using a flow cytometer, showed that both liposomal encapsulation and empty liposome pretreatment increased the intracellular accumulation of epirubicin in Caco-2 cells significantly. These two treatments substantially increased apical-to-basolateral absorption of epirubicin across Caco-2 monolayers and markedly improved mucosal-to-serosal absorption of epirubicin in rat jejunum and ileum. Enhancement also was observed with both liposome encapsulation and empty liposome pretreatment in the reduction of basolateral-to-apical efflux of epirubicin across Caco-2 monolayers. However, because diffusion of free dipalmitoyl phosphatidylcholine (DPPC) or dipalmitoyl phosphatidylethanolamine (DPPE) lipids across the cell membrane is very slow, these free lipids showed marginal effects on absorption and/or secretion of epirubicin in both Caco-2 cells and rat gut sacs. The study suggests that inhibition of P-gp or other transporter proteins located in the intestines may be partially involved in the reduction of epirubicin efflux. In conclusion, the therapeutic efficacy of epirubicin may be improved by using phospholipids as excipients and MDR modulators in the formulations. Liposomal formulations may have important applications to circumvent drug resistance in cancer chemotherapy.
Collapse
Affiliation(s)
- Y L Lo
- Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan Hsien, Taiwan 717, Republic of China.
| |
Collapse
|
64
|
Mastellone I, Polichetti E, Grès S, Domingo N, Marin V, Lorec AM, Farnarier C, Portugal H, Kaplanski G, Chanussot F. Dietary soybean phosphatidylcholines lower lipidemia: mechanisms at the levels of intestine, endothelial cell, and hepato-biliary axis. J Nutr Biochem 2000; 11:461-6. [PMID: 11091102 DOI: 10.1016/s0955-2863(00)00115-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The beneficial metabolic effects of dietary soybean lecithin on lipid metabolism are now more clearly established. The intestinal absorption of cholesterol is decreased by soybean phosphatidylcholine-enriched diet and results in a cholesterol-lowering effect. There is an enhancement of the cholesterol efflux by endothelial cells incubated with soybean phosphatidylcholines, and a stimulation of the reverse cholesterol transport by high density lipoprotein-phosphatidylcholines. As a result of all these processes, phosphatidylcholines provided by the soybean lecithin metabolism appear to be key molecules controlling the biodynamic exchanges of lipids. They regulate homeostasis of cholesterol and fatty acids by decreasing their synthesis and promoting cholesterol oxidation into bile salts. Finally, the outcome is the increase in bile secretion of these lipids and/or their metabolite forms. Such findings constitute promising goals in the field of nutritional effects of soybean lecithin in the treatment or prevention of hyperlipidemia and related atherosclerosis.
Collapse
Affiliation(s)
- I Mastellone
- INSERM U. 476, Hôpital Sainte Marguerite, Marseille, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
65
|
Twibell RG, Brown PB. Dietary choline requirement of juvenile yellow perch (Perca flavescens). J Nutr 2000; 130:95-9. [PMID: 10613773 DOI: 10.1093/jn/130.1.95] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We conducted an 11-wk feeding trial to determine the dietary choline requirement of juvenile yellow perch (Perca flavescens) and to investigate whether dietary phosphatidylcholine (PC) could meet this requirement. Six dietary treatments contained choline concentrations of <0.11, 0.23, 0.34, 0.75, 1.22 or 3.37 g/kg diet. Two additional diets contained 31 g of lecithin/kg diet, with or without supplemental choline chloride (4.0 g choline/kg diet). The total sulfur amino acid concentration was maintained at 1.0 g/100 g diet (methionine/cyst(e)ine, 49:51). Diets were fed to satiation twice daily to triplicate groups of yellow perch initially weighing 16.0 g/fish. Weight gain, feed intake and carcass proximate composition were significantly affected by dietary choline. Weight gains and feed intakes increased as dietary choline increased from 0 to 0.75 g/kg. Both values tended to plateau in fish fed dietary choline levels above 0.75 g/kg. Broken-line analyses of weight gain and feed intake data indicated the dietary choline requirement was 0.598 and 0.634 g/kg diet, respectively. Hepatic lipid concentrations and feed efficiency values were not significantly different. Whole-body fat concentrations increased significantly, whereas ash levels decreased significantly in fish fed increasing levels of dietary choline. Weight gain and feed intake of fish fed diets containing PC were not significantly different from fish fed 0.75 g/kg of dietary choline. However, hepatic lipid concentrations were significantly higher in fish fed the diet containing PC and no choline chloride. Thus, yellow perch require a maximum of 0.598-0.634 g of choline/kg diet for maximum growth and this requirement may potentially be met with 31 g of lecithin/kg diet.
Collapse
Affiliation(s)
- R G Twibell
- Purdue University, Department of Forestry and Natural Resources, West Lafayette, IN 47907-1159, USA
| | | |
Collapse
|
66
|
Lehman-McKeeman LD, Gamsky EA. Diethanolamine inhibits choline uptake and phosphatidylcholine synthesis in Chinese hamster ovary cells. Biochem Biophys Res Commun 1999; 262:600-4. [PMID: 10471370 DOI: 10.1006/bbrc.1999.1253] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diethanolamine (DEA), an alkanolamine used widely in industry, is hepatocarcinogenic in mice. The goal of this work was to determine whether DEA altered choline homeostasis in cultured cells, so as to ascertain whether the liver tumor response may be related to choline deficiency. CHO cells were cultured in Ham's F-12 medium containing DEA (0-1000 microgram/ml) and [(33)P]-phosphorus was used to label phospholipid pools. After 48 hours incubation, lipids were extracted and [(33)P]-labeled phospholipids were quantified by autoradiography after thin layer chromatographic separation. In control cells, phosphatidylcholine (PC) accounted for 51 +/- 0.7% of the total lipid (33)P incorporation. DEA had no effect on cell number or total phospholipid biosynthesis, but it significantly decreased the incorporation of (33)P into PC at concentrations >/=50 microgram/ml. DEA (>/=20 microgram/ml) also inhibited the uptake of [(3)H]-choline into CHO cells, with 95% inhibition observed at 250 microgram/ml. To determine whether supplemental choline prevented PC synthesis inhibition by DEA, CHO cells were cultured with or without excess choline (30 mM) and DEA (500 microgram/ml). DEA reduced PC synthesis to 27 +/- 3% of total phospholipids, but had no effect on PC synthesis in choline-supplemented cells. When [(14)C]-DEA was incubated with CHO cells, it was also incorporated into the phospholipid fraction. Collectively, these results indicate that DEA reversibly inhibits PC synthesis by blocking choline uptake and competing for utilization in the CDP-choline pathway in CHO cells.
Collapse
Affiliation(s)
- L D Lehman-McKeeman
- Human and Environmental Safety Division, Procter and Gamble Co., Cincinnati, Ohio, 45253, USA.
| | | |
Collapse
|
67
|
Nyberg L, Farooqi A, Bläckberg L, Duan RD, Nilsson A, Hernell O. Digestion of ceramide by human milk bile salt-stimulated lipase. J Pediatr Gastroenterol Nutr 1998; 27:560-7. [PMID: 9822324 DOI: 10.1097/00005176-199811000-00013] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND There is a renewed interest in metabolism of sphingolipids because of their role in signal transduction. Sphingomyelin is the dominating phospholipid in human milk but its metabolism and possible function in the gastrointestinal tract of breast fed infants is unknown. We explored whether bile salt-stimulated milk lipase has a role in sphingolipid metabolism. METHODS In vitro assays of sphingomyelinase and ceramidase activities, using radiolabeled substrates, human milk samples and purified native and recombinant variants of bile salt-stimulated milk lipase with or without known activators or inhibitors. RESULTS Human whey and purified lipase catalysed hydrolysis of palmitoyl-labeled ceramide with the highest rate around pH 8.5-9.0. 1 mg of lipase hydrolysed 0.7 micromol ceramide in one hour at pH 8.5 in presence of 4 mM bile salt. The activity of whey was inhibited by antibodies towards human bile salt-stimulated milk lipase, indicating that this lipase accounted for virtually all ceramidase activity in the milk. In contrast, bile salt-stimulated milk lipase showed no activity against sphingomyelin. However we give evidence of a separate, hitherto unknown, acid sphingomyelinase in human milk. Under the used in vitro conditions this sphingomyelinase could account for hydrolysis of half of milk sphingomyelin in one hour. CONCLUSIONS Human milk bile salt-stimulated milk lipase hydrolyses ceramide and may thus have a role in sphingomyelin digestion, but only after initial hydrolysis to ceramide and phosphorylcholine. Part of the latter could be carried out in the stomach by the acid milk sphingomyelinase now described. We speculate that these two milk enzymes may be of importance for optimal use of human milk sphingolipids.
Collapse
Affiliation(s)
- L Nyberg
- Swedish Dairies' Association, Lund
| | | | | | | | | | | |
Collapse
|
68
|
Rivera CA, Wheeler MD, Enomoto N, Thurman RG. A choline-rich diet improves survival in a rat model of endotoxin shock. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:G862-7. [PMID: 9756519 DOI: 10.1152/ajpgi.1998.275.4.g862] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study investigated whether dietary choline can prevent endotoxin shock. Female Sprague-Dawley rats fed chow or chow plus choline chloride (0.025-0.4%) for 3 days were given lipopolysaccharide (LPS) via the tail vein. Eighty-three percent and 56% of chow-fed rats survived after 2.5 or 5.0 mg/kg LPS, respectively. Choline increased survival in a dose-dependent manner, with maximal effects observed at 0.4%; this dose of choline prevented mortality completely after 2.5 or 5 mg/kg LPS. Choline also improved the microscopic appearance of the lungs and blunted increases in serum aspartate aminotransferase levels. Intracellular Ca2+ was monitored in liver and lung macrophages during LPS exposure. Ca2+ increases in macrophages from choline-fed rats were blunted by 40-60% compared with chow-fed controls. Feeding choline also blunted tumor necrosis factor-alpha production. Feeding glycine, which prevents macrophage activation via a chloride channel, in addition to choline was even more effective than feeding choline alone, suggesting that glycine and choline act via distinct sites. These data are consistent with the hypothesis that choline diminishes endotoxin shock by preventing macrophage activation.
Collapse
Affiliation(s)
- C A Rivera
- Laboratory of Hepatobiology and Toxicology, Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | | | | | | |
Collapse
|
69
|
Salvioli G, Ventura P, Pradelli J. Impact of nutrition on cognition and affectivity in the elderly: A review. Arch Gerontol Geriatr 1998. [DOI: 10.1016/s0167-4943(98)80068-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
70
|
Hepatoprotective properties of phospholiv, a preparation containing phosphatidylcholine from sunflower seeds and glycyrrhizic acid, in modeled cirrhosis of rat liver. Bull Exp Biol Med 1997. [DOI: 10.1007/bf02446996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
71
|
Shronts EP. Essential nature of choline with implications for total parenteral nutrition. JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION 1997; 97:639-46, 649; quiz 647-8. [PMID: 9183326 DOI: 10.1016/s0002-8223(97)00161-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Choline is known to be important in many metabolic pathways; at this time, however, it is not considered an essential nutrient for human beings. Current evidence strongly suggests that choline is "conditionally essential," particularly for patients receiving total parenteral nutrition (TPN). Studies in patients receiving long-term TPN have shown that low levels of plasma choline are common and can be associated with hepatic steatosis. Treatment of these patients with oral administration of choline improved plasma levels and decreased hepatic fat content; however, oral choline supplements are associated with poor compliance. More recently, investigators have evaluated intravenous administration of choline as a treatment for TPN-associated hepatic steatosis in patients with documented subnormal plasma free-choline levels. Initial results indicate that intravenous administration of choline may be an effective treatment for TPN-associated hepatic dysfunction.
Collapse
Affiliation(s)
- E P Shronts
- Department of Surgery, University of Minnesota, Minneapolis 55455, USA
| |
Collapse
|
72
|
Abstract
This paper gives a short account of the mechanisms regulating choline production. Although choline is absorbed from the GI tract and biosynthesized in the liver, its subsequent metabolism to choline esters and phospholipids seems to dominate in importance as to its regulatory role in maintaining a constant source of free choline extracellularly.
Collapse
Affiliation(s)
- J J Freeman
- College of Pharmacy, University of South Carolina, Columbia 29208, USA
| |
Collapse
|
73
|
Young SN. Behavioral effects of dietary neurotransmitter precursors: basic and clinical aspects. Neurosci Biobehav Rev 1996; 20:313-23. [PMID: 8811719 DOI: 10.1016/0149-7634(95)00022-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The levels and possibly function of several neurotransmitters can be influenced by the supply of their dietary precursors. The neurotransmitters include serotonin, dopamine, noradrenaline, histamine, acetylcholine and glycine, which are formed from tryptophan, tyrosine, histidine, choline and threonine. Tryptophan has been tested more than the other precursors in clinical trials and is currently available in some countries for the treatment of depression. Other uses for tryptophan and the therapeutic potential of other neurotransmitter precursors have not been tested adequately. Given the relative lack of toxicity of dietary components, further clinical trials with neurotransmitter precursors should be carried out.
Collapse
Affiliation(s)
- S N Young
- Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| |
Collapse
|