Placental essential fatty acid transport and prostaglandin synthesis (original) (raw)

The effect of dietary supplementation with linoleic acid to late gestation ewes on the fatty acid composition of maternal and fetal plasma and tissues and the synthetic capacity of the placenta for 2-series prostaglandins

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids, 2004

Linoleic acid (18:2n-6) is metabolised to arachidonic acid (20:4n-6), the precursor for 2-series prostaglandins (PGs). Increased consumption of 18:2n-6 during pregnancy may thus modify PG synthesis during labour. We have investigated whether increased 18:2n-6 composition during gestation altered the fatty acid consumption and PG synthesis of maternal and fetal tissues in the sheep. Ewes were fed a control diet or a diet providing 40% more 18:2n-6 from 96 days gestation. Half of each group received dexamethasone on day 136 to upregulate the PG synthetic pathways promoting parturition. Maternal and fetal tissues were collected at 138 days. The 18:2n-6 diet significantly increased the 20:4n-6 content of maternal plasma, fetal plasma and allantochorion (51-81%) phosphatidylcholine, and fetal liver (40%) and maternal caruncular endometrium (57%) phosphatidylethanolamine. Increased 18:2n-6 intake increased production of PGF 2a and PGE 2 in all placental tissues (maternal caruncular and intercaruncular endometrium and fetal allantochorion) by 23-98%, whereas dexamethasone increased it by 32-142%. This suggests that consumption of an 18:2n-6-enriched diet in late pregnancy enhanced placental PG production by increasing the supply of 20:4n-6. Variations in the extent to which the diet altered the polyunsaturated fatty acid (PUFA) content of the different tissues indicated complex interactions between nutrient availability and metabolic adaptation. D

Transport mechanisms for long-chain polyunsaturated fatty acids in the human placenta

The American Journal of Clinical Nutrition, 2000

To understand the placental role in the processes responsible for the preferential accumulation of maternal longchain polyunsaturated fatty acids (LCPUFAs) in the fetus, we investigated fatty acid uptake and metabolism in the human placenta. A preference for LCPUFAs over nonessential fatty acids has been observed in isolated human placental membranes as well as in BeWo cells, a human placental choriocarcinoma cell line. A placental plasma membrane fatty acid binding protein (p-FABP pm) with a molecular mass of Ϸ40 kDa was identified. The purified p-FABP pm preferentially bound with essential fatty acids (EFAs) and LCPUFAs over nonessential fatty acids. Oleic acid was taken up least and docosahexaenoic acid (DHA) most by BeWo cells, whereas no such discrimination was observed in HepG2 liver cells. Studies on the distribution of radiolabeled fatty acids in the cellular lipids of BeWo cells showed that DHA is incorporated mainly into the triacylglycerol fraction, followed by the phospholipid fraction; the reverse is true for arachidonic acid (AA). The greater cellular uptake of DHA and its preferential incorporation into the triacylglycerol fraction suggests that both uptake and transport modes of DHA by the placenta to the fetus are different from those of AA. p-FABP pm antiserum preferentially decreased the uptake of LCPUFAs and EFAs by BeWo cells compared with preimmune serum. Together, these results show the preferential uptake of LCPUFAs by the placenta that is most probably mediated via the p-FABP pm .

Effects of n-6 polyunsaturated fatty acids on prostaglandin production in ovine fetal chorion cells in vitro in late gestation ewes

Placenta, 2011

Objective: To use an in vitro model of the ovine placenta to determine effects of n-6 polyunsaturated fatty acid (PUFA) supplementation on prostaglandin (PG) production. PGs are key regulators of fetal maturation and parturition. Study design: Fetal allantochorion tissue (FC) was collected in late pregnancy (day 135). FC cells were isolated and cultured with 0e100 mM of linoleic acid (LA), g-linolenic acid (GLA) or arachidonic acid (AA) in serum free medium and challenged with control medium, lipopolysaccharide (LPS, 0.1 mg/ml), dexamethasone (DEX, 5 mM) or a combination of LPS (0.1 mg/ml) with DEX (5 mM). Spent medium was harvested at 2 h and 24 h post challenge for measuring PGs. Main outcome measures: To assess the effects of treatment on placental 1-and 2-series PGE production. Results: LA supplementation inhibited both PGE 1 and PGE 2 production. GLA predominantly stimulated PGE 1 generation, although it also increased PGE 2 production. AA supplementation predominantly increased PGE 2 production, but also stimulated PGE 1 . DEX treatment with or without LPS inhibited PG production. Supplementation with n-6 PUFAs attenuated or neutralised the stimulatory effect of LPS challenge on FC cells for both PGE 1 and PGE 2 production. Conclusion: These data show that supplementation with n-6 PUFAs alters placental PG production, but their precise effects depend on their position in the biosynthetic pathway for PG synthesis. This study supports the possibility that GLA containing oils, widely promoted as dietary supplements, might reduce the risk of pre-term labour by inhibiting the responsiveness of PGE 2 production to LPS challenge in the placenta.

Maternal dietary fatty acids and their roles in human placental development

Prostaglandins, Leukotrienes and Essential Fatty Acids, 2020

Fatty acids are essential for feto-placental growth and development. Maternal fatty acids and their metabolites are involved in every stage of pregnancy by supporting cell growth and development, cell signaling, and modulating other critical aspects of structural and functional processes. Early placentation process is critical for placental growth and function. Several fatty acids modulate angiogenesis as observed by increased tube formation and secretion of angiogenic growth factors in first-trimester human placental trophoblasts. Long-chain fatty acids stimulate angiogenesis in these cells via vascular endothelium growth factor (VEGF), angiopoietinlike protein 4 (ANGPTL4), fatty acid-binding proteins (FABPs), or eicosanoids. Inadequate placental angiogenesis and trophoblast invasion of the maternal decidua and uterine spiral arterioles leads to structural and functional deficiency of placenta, which contributes to preeclampsia, pre-term intrauterine growth restriction, and spontaneous abortion and also affects overall fetal growth and development. During the third trimester of pregnancy, placental preferential transport of maternal plasma long-chain polyunsaturated fatty acids is of critical importance for fetal growth and development. Fatty acids cross the placental microvillous and basal membranes by mainly via plasma membrane fatty acid transport system (FAT, FATP, p-FABPpm, & FFARs) and cytoplasmic FABPs. Besides, a member of the major facilitator superfamily-MFSD2a, present in the placenta is involved in the supply of DHA to the fetus. Maternal factors such as diet, obesity, endocrine, inflammation can modulate the expression and activity of the placental fatty acid transport activity and thereby impact fetoplacental growth and development. In this review, we discuss the maternal dietary fatty acids, and placental transport and metabolism, and their roles in placental growth and development.

The phospholipid composition of human placenta, endometrium and amniotic fluid: A comparative study

Lipids, 1972

The contents of lecithin in human lung, liver, spleen, kidney, heart muscle, skeletal muscle, placenta, endometrium, amniotic flud, and brain gray and white matter are 52.1–54.2%, 44.2–45.8%, 42.6–44.5%, 35.1–37.2%, 42.5–43.0%, 48.0–50.0%, 45.5–46.4%, 42.0–43.0%, 65.0–66.0%, 23.9–24.3% and 24.7–24.9% respectively in total phospholipids. The level of diphosphatidyl glycerol is much lower in placenta, lung and spleen, and almost absent in amniotic fluid and brain; the heart muscle has 8.6%. The content of phosphatidyl serine is high in endometrium and brain. The content of sphingomyelin is high in lung, spleen, kidney and brain as compared to liver, heart muscle, skeletal muscle and endometrium. It is suggested that the phospholipid composition of various human tissues is characteristic for that class.

Activities of enzymes of phospholipid and fatty acid synthesis in fetal and adult rat type II pneumocytes

Biochimica et biophysica acta, 1988

Although differentiated fetal and adult type II pneumocytes are ultrastructurally similar, it is not known whether there are metabolic differences between them. We measured the activities of selected enzymes of phospholipid and fatty acid synthesis in fetal and adult rat type II cells, in late gestation fetal rat lung explants and in intact lung from rat fetuses of comparable gestational age. The activity of 1-acylglycerophosphocholine acyltransferase was significantly greater in adult type II cells than in fetal type II cells, fetal explants or intact fetal lung. The activity of CDP diacylglycerol:glycerol-3-phosphate 3-phosphatidyltransferase was similar in fetal and adult type II cells, but significantly lower in explants and intact fetal lung. There was a significant positive correlation between the percentage of alveolar epithelial cells in the cultures and tissue studied and CDP diacylglycerol:glycerol-3-phosphate 3-phosphatidyltransferase activity. This suggests that the prev...

Phospholipid composition of neonatal guinea pig liver and plasma: Effect of postnatal food restriction

Lipids, 1996

Preterm guinea pigs were delivered on day 65 of gestation (term = 68 d) and were allowed either free or restricted access to food for the subsequent 48 h. Plasma phosphatidylcholine (PC) concentration increased postnatally from 190 (range 144-307) to 751 (426-1039) and 883 (758-977) pM for fed and starved pups, respectively. Plasma PC composition in both groups of pups was characterized by selective and equivalent relative increases to individual molecular species containing 18:0 at the sn-1 position. Hepatic PC concentration increased from 6.75 (5.41-8.20)to 8.65 (6.54-10.63) and 9.23 (8.18-10.17) tJmol/g for fed and starved pups, respectively, and, under all conditions, hepatic PC molecular composition closely mirrored that of plasma PC. These results support the hypothesis that the molecular species composition of plasma PC for the guinea pig in the immediate postnatal period is determined largely by the composition of the hepatic PC pool destined for lipoprotein secretion. Hepatic PC composition and concentration of the starved neonatal guinea pig were maintained independently of any dietary nutrient intake, at the expense of mobilization of extra hepatic lipid reserves. While this adaptive mechanism has inherent limited survival potential in neonatal starvation, it has implications for studies measuring plasma phospholipid fatty acid compositions as biochemical markers of dietary fat intake in preterm infants. Lipids 31, 489-495 (1996).

The effect of gestational age on expression of genes involved in uptake, trafficking and synthesis of fatty acids in the rat placenta

Gene, 2016

Gestation triggers a tight coordination among maternal tissues to provide fatty acids (FA) to the fetus through placental transport; however, there is insufficient evidence regarding regulation of proteins involved in placental transport of FA according to gestational age. The aim of this study was to determine the role of gestational age on the mRNA expression of proteins involved in FA uptake, trafficking and synthesis in the rat placenta to support fetal demands. Gene expression of encoding proteins for placental transport and synthesis of FA was measured in placenta. Also, FA composition was measured in placenta, fetuses and newborns. mRNA expression of lipoprotein lipase (lpl) and fatp-1 (for uptake) was 4.4- and 1.43-fold higher, respectively, during late gestation than at P14, but expression of p-fabp-pm decreased 0.37-fold at late pregnancy in comparison with P14. Only mRNA fabp-4 member for trafficking of FA was 2.95-fold higher at late gestation than at P14. mRNA of fasn a...