scholarly journals Regulation of Nutrient Transport across the Placenta

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Susanne Lager ◽  
Theresa L. Powell

Abnormal fetal growth, both growth restriction and overgrowth, is associated with perinatal complications and an increased risk of metabolic and cardiovascular disease later in life. Fetal growth is dependent on nutrient availability, which in turn is related to the capacity of the placenta to transport these nutrients. The activity of a range of nutrient transporters has been reported to be decreased in placentas of growth restricted fetuses, whereas at least some studies indicate that placental nutrient transport is upregulated in fetal overgrowth. These findings suggest that changes in placental nutrient transport may directly contribute to the development of abnormal fetal growth. Detailed information on the mechanisms by which placental nutrient transporters are regulated will therefore help us to better understand how important pregnancy complications develop and may provide a foundation for designing novel intervention strategies. In this paper we will focus on recent studies of regulatory mechanisms that modulate placental transport of amino acids, fatty acids, and glucose.

2007 ◽  
Vol 113 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Thomas Jansson ◽  
Theresa L. Powell

Adverse influences during fetal life alter the structure and function of distinct cells, organ systems or homoeostatic pathways, thereby ‘programming’ the individual for an increased risk of developing cardiovascular disease and diabetes in adult life. Fetal programming can be caused by a number of different perturbations in the maternal compartment, such as altered maternal nutrition and reduced utero–placental blood flow; however, the underlying mechanisms remain to be fully established. Perturbations in the maternal environment must be transmitted across the placenta in order to affect the fetus. Here, we review recent insights into how the placenta responds to changes in the maternal environment and discuss possible mechanisms by which the placenta mediates fetal programming. In IUGR (intrauterine growth restriction) pregnancies, the increased placental vascular resistance subjects the fetal heart to increased work load, representing a possible direct link between altered placental structure and fetal programming of cardiovascular disease. A decreased activity of placental 11β-HSD-2 (type 2 isoform of 11β-hydroxysteroid dehydrogenase) activity can increase fetal exposure to maternal cortisol, which programmes the fetus for later hypertension and metabolic disease. The placenta appears to function as a nutrient sensor regulating nutrient transport according to the ability of the maternal supply line to deliver nutrients. By directly regulating fetal nutrient supply and fetal growth, the placenta plays a central role in fetal programming. Furthermore, perturbations in the maternal compartment may affect the methylation status of placental genes and increase placental oxidative/nitrative stress, resulting in changes in placental function. Intervention strategies targeting the placenta in order to prevent or alleviate altered fetal growth and/or fetal programming include altering placental growth and nutrient transport by maternally administered IGFs (insulin-like growth factors) and altering maternal levels of methyl donors.


2002 ◽  
Vol 15 (2) ◽  
pp. 211-230 ◽  
Author(s):  
Alan W Bell ◽  
Richard A Ehrhardt

AbstractFetal macronutrient requirements for oxidative metabolism and growth are met by placental transport of glucose, amino acids, and, to a lesser extent that varies with species, fatty acids. It is becoming possible to relate the maternal–fetal transport kinetics of these molecules in vivo to the expression and distribution of specific transporters among placental cell types and subcellular membrane fractions. This is most true for glucose transport, although apparent inconsistencies among data on the roles and relative importance of the predominant placenta glucose transporters, GLUT-1 and GLUT-3, remain to be resolved. The quantity of macronutrients transferred to the fetus from the maternal bloodstream is greatly influenced by placental metabolism, which results in net consumption of large amounts of glucose and, to a lesser extent, amino acids. The pattern of fetal nutrient supply is also altered considerably by placental conversion of glucose to lactate and, in some species, fructose, and extensive transamination of amino acids. Placental capacity for transport of glucose and amino acids increases with fetal demand as gestation advances through expansion of the exchange surface area and increased expression of specific transport molecules. In late pregnancy, transport capacity is closely related to placental size and can be modified by maternal nutrition. Preliminary evidence suggests that placental expression and function of specific transport proteins are influenced by extracellular concentrations of nutrients and endocrine factors, but, in general, the humoral regulation of placental capacity for nutrient transport is poorly understood. Consequences of normal and abnormal development of placental transport functions for fetal growth, especially during late gestation, and, possibly, for fetal programming of postnatal disorders, are discussed.


2016 ◽  
Vol 62 (4) ◽  
pp. 582-592 ◽  
Author(s):  
Miguel Ruiz-Canela ◽  
Estefania Toledo ◽  
Clary B Clish ◽  
Adela Hruby ◽  
Liming Liang ◽  
...  

Abstract BACKGROUND The role of branched-chain amino acids (BCAAs) in cardiovascular disease (CVD) remains poorly understood. We hypothesized that baseline BCAA concentrations predict future risk of CVD and that a Mediterranean diet (MedDiet) intervention may counteract this effect. METHODS We developed a case-cohort study within the Prevención con Dieta Mediterránea (PREDIMED), with 226 incident CVD cases and 744 noncases. We used LC-MS/MS to measure plasma BCAAs (leucine, isoleucine, and valine), both at baseline and after 1 year of follow-up. The primary outcome was a composite of incident stroke, myocardial infarction, or cardiovascular death. RESULTS After adjustment for potential confounders, baseline leucine and isoleucine concentrations were associated with higher CVD risk: the hazard ratios (HRs) for the highest vs lowest quartile were 1.70 (95% CI, 1.05–2.76) and 2.09 (1.27–3.44), respectively. Stronger associations were found for stroke. For both CVD and stroke, we found higher HRs across successive quartiles of BCAAs in the control group than in the MedDiet groups. With stroke as the outcome, a significant interaction (P = 0.009) between baseline BCAA score and intervention with MedDiet was observed. No significant effect of the intervention on 1-year changes in BCAAs or any association between 1-year changes in BCAAs and CVD were observed. CONCLUSIONS Higher concentrations of baseline BCAAs were associated with increased risk of CVD, especially stroke, in a high cardiovascular risk population. A Mediterranean-style diet had a negligible effect on 1-year changes in BCAAs, but it may counteract the harmful effects of BCAAs on stroke.


2021 ◽  
Author(s):  
Chang Cui ◽  
Caichi Wu ◽  
Pengwei Zhu ◽  
Jun Wang ◽  
Ziwei Ma ◽  
...  

Abstract Background Our previous study found that sow dietary leucine supplementation signicicantly improved fetal intrauterine growth and newborn piglet birth weight. But we still have limited knowledge how leucine regulated placental functions to promote the nutrient supply to fetus to support its intrauterine development. Methods 150 sows at day 90 of gestiation were divided into three groups and fed with either control diet (CON), CON + 0.4% Leu or CON + 0.8% Leu separately until parturition. Placental metabolomics, full spectrum amino acids and nutrient transporters were systematically analyzed. Results Leu supplementation lead to an altered placental metabolism with higher amount of metabolites related to glycolysis and fatty acids oxidatation, and more amino acids accumulation in placenta. Besides, nutrient transporters including amino acids transporters, glucose transporters and fatty acids transporters in placenta were globally enhanced and several enzymes related to energy metabolism including hexokinase, succinatede hydrogenase, lactated hydrogenase, glycogen phosphorylase and hydroxyaryl-CoA-dehydrogenase were significantly increased with no change in antioxidative status in the groups with Leu supplementation. Futhermore, Leu supplementation significantly increased phosphalation of PI3K, Akt, and mTOR in placenta compared with control group. Conclusions Leu supplementation during late gestation globally altered placental metabolism, nutrient transport (amino acids, glucose, and fatty acids) via modulation of the PI3K/Akt/mTOR signalling pathway.


Author(s):  
Raimo Jauhiainen ◽  
Jagadish Vangipurapu ◽  
Annamaria Laakso ◽  
Teemu Kuulasmaa ◽  
Johanna Kuusisto ◽  
...  

Abstract Background and aims To investigate the significance of nine amino acids as risk factors for incident cardiovascular disease events in 9,584 Finnish men. Materials and Methods A total of 9,584 men (age 57.4±7.0 years, body mass index 27.2±4.2 kg/m 2) from the METSIM study without cardiovascular disease and type 1 diabetes at baseline were included in this study. A total of 662 coronary artery disease (CAD) events, 394 ischemic stroke events, and 966 cardiovascular disease (CVD, CAD and stroke combined) events were recorded in a 12.3-year follow-up. Amino acids were measured using nuclear magnetic resonance platform. Results In Cox regression analysis phenylalanine and tyrosine were significantly associated with increased risk of CAD and CVD events, and phenylalanine with increased risk of ischemic stroke after the adjustment for confounding factors. Glutamine was significantly associated with decreased risk of stroke and CVD events and nominally with CAD events. Alanine was nominally associated with CAD events. Conclusion We identified alanine as a new amino acid associated with increased risk of CAD and glutamine as a new amino acid associated with decreased risk of ischemic stroke. We also confirmed that phenylalanine and tyrosine were associated with CAD, ischemic stroke, and CVD events.


2012 ◽  
Vol 4 (2) ◽  
pp. 101-115 ◽  
Author(s):  
F. Gaccioli ◽  
S. Lager ◽  
T. L. Powell ◽  
T. Jansson

The mechanisms linking maternal nutrition to fetal growth and programming of adult disease remain to be fully established. We review data on changes in placental transport in response to altered maternal nutrition, including compromized utero-placental blood flow. In human intrauterine growth restriction and in most animal models involving maternal undernutrition or restricted placental blood flow, the activity of placental transporters, in particular for amino acids, is decreased in late pregnancy. The effect of maternal overnutrition on placental transport remains largely unexplored. However, some, but not all, studies in women with diabetes giving birth to large babies indicate an upregulation of placental transporters for amino acids, glucose and fatty acids. These data support the concept that the placenta responds to maternal nutritional cues by altering placental function to match fetal growth to the ability of the maternal supply line to allocate resources to the fetus. On the other hand, some findings in humans and mice suggest that placental transporters are regulated in response to fetal demand signals. These observations are consistent with the idea that fetal signals regulate placental function to compensate for changes in nutrient availability. We propose that the placenta integrates maternal and fetal nutritional cues with information from intrinsic nutrient sensors. Together, these signals regulate placental growth and nutrient transport to balance fetal demand with the ability of the mother to support pregnancy. Thus, the placenta plays a critical role in modulating maternal–fetal resource allocation, thereby affecting fetal growth and the long-term health of the offspring.


2018 ◽  
Vol 25 (35) ◽  
pp. 4507-4517 ◽  
Author(s):  
Mauro Rigato ◽  
Gian Paolo Fadini

Background: Circulating progenitor cells (CPCs) and endothelial progenitor cells (EPCs) are immature cells involved in vascular repair and related to many aspects of macro and microvascular disease. <p> Objective: We aimed to review studies reporting the prognostic role of CPCs/EPCs measurement on development of cardiovascular disease and microangiopathy. <p> Methods and Results: We reviewed the English language literature for prospective observational studies reporting the future development of cardiovascular disease or microangiopathy in patients having a baseline determination of CPCs/EPCs. We retrieved 34 studied reporting on cardiovascular outcomes and 2 studies reporting on microvascular outcomes. Overall, a reduced baseline level of CPCs/EPCs was associated with a significant increased risk of cardiovascular events, all-cause death, and onset/progression of microangiopathy. The most predictive phenotypes were CD34+ and CD34+CD133+. The main limitation was related to the high heterogeneity among studies in terms of patient characteristics and cell phenotypes. <p> Conclusion: The present review shows that a reduced level of circulating progenitor cells is a risk factor for the development of future cardiovascular events and death. In addition, low CPCs/EPCs levels predict the onset or worsening of microalbuminuria and retinopathy in diabetic patients.


2020 ◽  
Vol 26 (43) ◽  
pp. 5617-5627
Author(s):  
Mirjana Stojković ◽  
Miloš Žarković

The prevalence of subclinical hypothyroidism (SH) is 3-10%. The prevalence of subclinical hyperthyroidism (SHr) is 0.7-9.7%. Thyroid hormones affect cardiac electrophysiology, contractility, and vasculature. SH is associated with an increased risk of coronary heart disease (CHD), especially in subjects under 65. SHr seems to be associated with a slightly increased risk of CHD and an increase in CHD-related mortality. Both SH and SHr carry an increased risk of developing heart failure (HF), especially in those under 65. Both SH and SHr are associated with worse prognoses in patients with existing HF. SH is probably not associated with atrial fibrillation (AF). SHr, low normal thyroid-stimulating hormone (TSH) and high normal free thyroxine (FT4) are all associated with the increased risk of AF. An association between endothelial dysfunction and SH seems to exist. Data regarding the influence of SHr on the peripheral vascular system are conflicting. SH is a risk factor for stroke in subjects under 65. SHr does not increase the risk of stroke. Both SH and SHr have an unfavourable effect on cardiovascular disease (CVD) and all-cause mortality. There is a U-shaped curve of mortality in relation to TSH concentrations. A major factor that modifies the relation between subclinical thyroid disease (SCTD) and mortality is age. SH increases blood pressure (BP). SHr has no significant effect on BP. Lipids are increased in patients with SH. In SHr, high-density lipoprotein cholesterol and lipoprotein( a) are increased. SCTD should be treated when TSH is over 10 mU/l or under 0.1 mU/l. Treatment indications are less clear when TSH is between normal limits and 0.1 or 10 mU/L. The current state of knowledge supports the understanding of SCTD’s role as a risk factor for CVD development. Age is a significant confounding factor, probably due to age-associated changes in the TSH reference levels.


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