scholarly journals Lipid-dependent Bidirectional Traffic of Apolipoprotein B in Polarized Enterocytes

2004 ◽  
Vol 15 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Etienne Morel ◽  
Sylvie Demignot ◽  
Danielle Chateau ◽  
Jean Chambaz ◽  
Monique Rousset ◽  
...  

Enterocytes are highly polarized cells that transfer nutrients across the intestinal epithelium from the apical to the basolateral pole. Apolipoprotein B (apoB) is a secretory protein that plays a key role in the transepithelial transport of dietary fatty acids as triacylglycerol. The evaluation of the control of apoB traffic by lipids is therefore of particular interest. To get a dynamic insight into this process, we used the enterocytic Caco-2 cells cultured on microporous filters, a system in which the apical and basal compartments can be delimited. Combining biochemical and morphological approaches, our results showed that, besides their role in protection from degradation, lipids control the intracellular traffic of apoB in enterocytes. A supply of fatty acids and cholesterol is sufficient for the export of apoB from the endoplasmic reticulum and its post-Golgi traffic up to the apical brush-border domain, where it remains until an apical supply of complex lipid micelles signals its chase down to the basolateral secretory domain. This downward traffic of apoB involves a microtubule-dependent process. Our results demonstrate an enterocyte-specific bidirectional process for the lipid-dependent traffic of a secretory protein.

2021 ◽  
Vol 8 ◽  
Author(s):  
Virak Visudtiphole ◽  
Jutatip Khudet ◽  
Panomkorn Chaitongsakul ◽  
Siwat Plaisen ◽  
Jittima Siriwattano ◽  
...  

Long-chain polyunsaturated fatty acids (LC-PUFAs) are essential for growth and health of larval marine animals. Marine animals have a limited capability for LC-PUFA synthesis, and the larvae must obtain LC-PUFAs from diet. The protist Aurantiochytrium limacinum (AL) is abundant in 22:6 n-3 (docosahexaenoic acid, DHA), 22:5 n-3 (docosapentaenoic acid, DPA) and 16:0 fatty acids, which qualifies it as an LC-PUFA source for feed application. Therefore, in this study, a common feed containing lower amounts of total LC-PUFAs, Thalasiosira weissflogii, was replaced with AL at graded proportions and supplied to Penaeus monodon larvae from mysis (M) 1 to post-larval (PL) 2 stages to supplement LC-PUFAs in the diet. After that, all shrimp from PL2 to PL12 were continuously reared and subjected to the same diet regime, which was a combination of Artemia and commercial dried feed. The AL-supplemented PL2 shrimp demonstrated marked accumulation of the key fatty acids present in AL—16:0, DPA and DHA. The supplemented larvae showed no difference in growth during the supplementation period from M1 to PL2; however, average body weight and biomass were increased in PL12 shrimp that were fed earlier with AL. Lipidomic analysis revealed that profiles of fatty acids but not lipid classes/subclasses in PL shrimp reflected the supplied diet. The main saturated fatty acid (SFA, 16:0) predominantly accumulated in acylglycerols, which are energy-reserve lipids, in PL2 shrimp. Both LC-PUFAs (DHA and DPA) were preferentially deposited in phospholipids or structural lipids. Furthermore, while the amounts of both LC-PUFAs increased along with the amount of supplied AL, that of the SFA did not. This suggests that LC-PUFAs were prioritized to be stored over SFA when both types of fatty acids were present in high amounts. This analysis substantiates the importance of LC-PUFAs and provides an insight into how different types of the dietary fatty acids were differentially accumulated in lipid classes and subclasses for their biological functions.


1998 ◽  
Vol 79 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Andrew M. Salter ◽  
E. Heather Mangiapane ◽  
Andrew J. Bennett ◽  
Jennifer S. Bruce ◽  
Michael A. Billett ◽  
...  

While it is well established that the fatty acid composition of dietary fat is important in determining plasma lipoprotein cholesterol concentrations, the effects of changing the absolute quantities of the individual fatty acids are less clear. In the present study Golden Syrian hamsters were fed on isoenergetic, low cholesterol (0·05 g/kg) diets containing 100, 150 or 200 g added fat/kg. This consisted of triolein (TO) alone, or equal proportions of TO and either trimyristin (TM), tripalmitin (TP) or tristearin (TS). Each trial also included a control group fed on a diet containing 50g TO/kg. As the mass of TO in the diet increased, plasma VLDL-cholesterol concentrations rose. The TM-rich diets produced a concentration-dependent increase in total plasma cholesterol which was a result of significant increases in both VLDL and HDL levels. The TP-rich diets increased plasma LDL- and HDL-cholesterol levels in a concentration-dependent manner. TS-containing diets did not increase the cholesterol content of any of the major lipoprotein fractions. Hepatic LDL-receptor mRNA concentrations were significantly decreased in animals fed on TP, while apolipoprotein B mRNA concentrations were significantly increased. Thus, on a low-cholesterol diet, increasing the absolute amount of dietary palmitic acid increases LDL-cholesterol more than either myristic or stearic acid. These effects on lipoprotein metabolism may be exerted through specific modulation of the expression of the LDL receptor and apolipoprotein B genes.


1996 ◽  
Vol 76 (03) ◽  
pp. 369-371 ◽  
Author(s):  
T A B Sanders ◽  
G J Miller ◽  
Tamara de Grassi ◽  
Najat Yahia

SummaryFactor VII coagulant activity (FVIIc) is associated with an increased risk of fatal ischaemic heart disease (IHD). Several reports have suggested that dietary fat intake or hypertriglyceridaemia are associated with elevated levels of FVII. This study demonstrates that an intake of long-chain fatty acids sufficient to induce postprandial lipaemia in healthy subjects leads to a substantial elevation in both FVIIc and the concentration of FVII circulating in the activated form. Such an increase in FVIIc could not be induced by medium-chain triglycerides. These results suggest that the consumption of a sufficient amount of long-chain triglycerides to induce postprandial lipaemia induces the activation of FVII.


2020 ◽  
Vol 16 (2) ◽  
pp. 142-154 ◽  
Author(s):  
Hadi Emamat ◽  
Zahra Yari ◽  
Hossein Farhadnejad ◽  
Parvin Mirmiran

Recent evidence has highlighted that fat accumulation, particularly abdominal fat distribution, is strongly associated with metabolic disturbance. It is also well-recognized that the metabolic responses to variations in macronutrients intake can affect body composition. Previous studies suggest that the quality of dietary fats can be considered as the main determinant of body-fat deposition, fat distribution, and body composition without altering the total body weight; however, the effects of dietary fats on body composition have controversial results. There is substantial evidence to suggest that saturated fatty acids are more obesogen than unsaturated fatty acids, and with the exception of some isomers like conjugate linoleic acid, most dietary trans fatty acids are adiposity enhancers, but there is no consensus on it yet. On the other hand, there is little evidence to indicate that higher intake of the n-3 and the n-6 polyunsaturated fatty acids can be beneficial in attenuating adiposity, and the effect of monounsaturated fatty acids on body composition is contradictory. Accordingly, the content of this review summarizes the current body of knowledge on the potential effects of the different types of dietary fatty acids on body composition and adiposity. It also refers to the putative mechanisms underlying this association and reflects on the controversy of this topic.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1219
Author(s):  
Marek Bunse ◽  
Peter Lorenz ◽  
Florian C. Stintzing ◽  
Dietmar R. Kammerer

The present study aimed at the identification and quantitation of phenolic compounds, fatty acids, and further characteristic substances in the seeds of Geum urbanum L. and Geum rivale L. For this purpose, individual components of extracts recovered with MeOH, CH2Cl2, and by cold-pressing, respectively, were characterized by HPLC-DAD/ESI-MSn and GC/MS and compared with reference compounds. For both Geum species, phenolic compounds, such as flavonoids and gallic acid derivatives, and triterpenes, such as saponins and their aglycones, were detected. Surprisingly, both Geum species revealed the presence of derivatives of the triterpenoid aglycons asiatic acid and madecassic acid, which were characterized for the first time in the genus Geum. Furthermore, the fatty acids of both species were characterized by GC–MS after derivatization. Both species showed a promising fatty-acid profile in terms of nutritional properties because of high proportions of unsaturated fatty acids. Linoleic acid and linolenic acid were most abundant, among other compounds such as palmitic acid and stearic acid. In summary, the present study demonstrates the seeds of G. urbanum and G. rivale to be a valuable source of unsaturated fatty acids and bioactive phenolics, which might be exploited for nutritional and cosmetic products and for phytotherapeutic purposes.


Sign in / Sign up

Export Citation Format

Share Document