The Apelinergic System in Pregnancy.

The apelinergic system is a highly conserved pleiotropic system. It comprises the apelin receptor apelin peptide jejunum (APJ) and its two peptide ligands, Elabela/Toddler (ELA) and apelin, which have different spatiotemporal localizations. This system has been implicated in the regulation of the adipoinsular axis, in cardiovascular and central nervous systems, in carcinogenesis, and in pregnancy in humans. During pregnancy, the apelinergic system is essential for embryo cardiogenesis and vasculogenesis and for placental development and function. It may also play a role in the initiation of labor. The apelinergic system seems to be involved in the development of placenta-related pregnancy complications, such as preeclampsia (PE) and intrauterine growth restriction, but an improvement in PE-like symptoms and birth weight has been described in murine models after the exogenous administration of apelin or ELA. Although the expression of ELA, apelin, and APJ is altered in human PE placenta, data related to their circulating levels are inconsistent. This article reviews current knowledge about the roles of the apelinergic system in pregnancy and its pathophysiological roles in placenta-related complications in pregnancy. We also discuss the challenges in translating the actors of the apelinergic system into a marker or target for therapeutic interventions in obstetrics.

SLC20a1/PiT-1 is required for chorioallantoic placental morphogenesis.

The placenta mediates the transport of nutrients, such as inorganic phosphate (Pi), between the maternal and fetal circulatory systems. The placenta itself also requires high levels of nutrient uptake as it develops to provide critical support for fetal development. This study aimed to determine placental Pi transport mechanisms using in vitro and in vivo models. We observed that Pi (P33) uptake in BeWo cells is sodium dependent and that SLC20A1/Slc20a1 is the most highly expressed placental sodium-dependent transporter in mouse (microarray), human cell line (RT-PCR) and term placenta (RNA-seq), supporting that normal growth and maintenance of the mouse and human placenta requires SLC20A1/Slc20a1. Slc20a1 wild-type (Slc20a1+/+) and knockout (Slc20a1-/-) mice were produced through timed intercrosses and displayed yolk sac angiogenesis failure as expected at E10.5. E9.5 tissues were analyzed to test whether placental morphogenesis requires Slc20a1. At E9.5, the developing placenta was reduced in size in Slc20a1-/-. Multiple structural abnormalities were also observed in the Slc20a1-/-chorioallantois. We determined that monocarboxylate transporter 1 protein (MCT1+) cells were reduced in developing Slc20a1-/-placenta, confirming that Slc20a1 loss reduced trophoblast syncytiotrophoblast 1 (SynT-I) coverage. Next, we examined the cell type-specific Slc20a1 expression and SynT molecular pathways in silico and identified Notch/Wnt as a pathway of interest that regulates trophoblast differentiation. We further observed that specific trophoblast lineages express Notch/Wnt genes that associate with endothelial cell tip-and-stalk cell markers. In conclusion, our findings support that Slc20a1 mediates the symport of Pi into SynT cells, providing critical support for their differentiation and angiogenic mimicry function at the developing maternal-fetal interface.

Cellular Complexity of Hemochorial Placenta: Stem Cell Populations, Insights from scRNA-seq, and SARS-CoV-2 Susceptibility.

Purpose of Review: The placenta is a transient organ that forms de novo and serves a critical role in supporting fetal growth and development. Placental oxygen, nutrients, and waste are transported through processes that depend on vascular structure and cell type-specific expression and localization of membrane transporters. Understanding how the placenta develops holds great significance for maternal-fetal medicine. The purpose of this review is to examine current information regarding placental progenitor populations. Recent Findings: Recent advancements in single-cell RNA sequencing (scRNA-seq) provide unprecedented depth for the investigation of cell type-specific gene expression patterns in the placenta. Thus far, several mouse placenta scRNA-seq studies have been conducted which produced and analyzed transcriptomes of placental progenitors and cells of the fully developed placenta between embryonic day (E) 7.0 and E12.5. Together with human placenta scRNA-seq data which, in part, has been produced through coordinated research campaigns in the scientific community to understand the potential for SARS-CoV-2 infection, these mammalian studies lend fundamental insight into the cellular and molecular composition of hemochorial placentae found in both mouse and human. Summary: Single-cell placenta research has advanced understanding of tissue-resident stem cells and molecules that are poised to support maternal-fetal communication and nutrient transport. Herein, we provide context for these recent findings by reviewing placental anatomy and cell populations, and discuss recent scRNA-seq mouse placenta findings. Further research is needed to evaluate the utility of placental stem cells in the development of new therapeutic approaches for the treatment of wound healing and disease.

Inorganic Phosphate in the Pathogenesis of Pregnancy-Related Complications.

Inorganic phosphate (Pi) is an essential nutrient that fulfills critical roles in human health. It enables skeletal ossification, supports cellular structure and organelle function, and serves key biochemical roles in energetics and molecular signaling. Pi homeostasis is modulated through diet, intestinal uptake, renal reabsorption, and mobilization of stores in bone and extracellular compartments. Disrupted Pi homeostasis is associated with phosphate wasting, mineral and bone disorders, and vascular calcification. Mechanisms of Pi homeostasis in pregnancy remain incompletely understood. The study presented herein examined biological fluid Pi characteristics over the course of gestation. Correlations with gestation age, pregnancy number, preterm birth, preeclampsia, diabetes mellitus, and placental calcification were evaluated during the last trimester. The results support that maternal urinary Pi levels increased during the third trimester of pregnancy. Reduced levels were observed with previous pregnancy. Amniotic fluid Pi levels decreased with gestation while low second trimester levels associated with preterm birth. No significant difference in urinary Pi levels was observed between preeclampsia and controls (8.50 ± 2.74 vs. 11.52 ± 2.90 mmol/L). Moreover, increased maternal urinary Pi was associated with preexisting diabetes mellitus in preeclampsia. Potential confounding factors in this study are maternal age at delivery and body mass index (BMI)-information which we do not have access to for this cohort. In conclusion, Pi levels provide clinical information regarding the pathogenesis of pregnancy-related complications, supporting that phosphate should be examined more closely and in larger populations.

New Frontiers in Placenta Tissue Imaging.

The placenta is a highly vascularized organ with unique structural and metabolic complexities. As the primary conduit of fetal support, the placenta mediates transport of oxygen, nutrients, and waste between maternal and fetal blood. Thus, normal placenta anatomy and physiology is absolutely required for maintenance of maternal and fetal health during pregnancy. Moreover, impaired placental health can negatively impact offspring growth trajectories as well as increase the risk of maternal cardiovascular disease later in life. Despite these crucial roles for the placenta, placental disorders, such as preeclampsia, intrauterine growth restriction (IUGR), and preterm birth, remain incompletely understood. Effective noninvasive imaging and image analysis are needed to advance the obstetrician's clinical reasoning toolkit and improve the utility of the placenta in interpreting maternal and fetal health trajectories. Current paradigms in placental imaging and image analysis aim to improve the traditional imaging techniques that may be time-consuming, costly, or invasive. In concert with conventional clinical approaches such as ultrasound (US), advanced imaging modalities can provide insightful information on the structure of placental tissues. Herein we discuss such imaging modalities, their specific applications in structural, vascular, and metabolic analysis of placental health, and emerging frontiers in image analysis research in both preclinical and clinical contexts.

Selective pro-apoptotic and antimigratory effects of polyphenol complex catechin:lysine 1:2 in breast, pancreatic and colorectal cancer cell lines.

Cancer is a major cause of death in both developed and developing countries. Polyphenols, abundantly found in plants, possess many anticarcinogenic properties, including inhibition of cancer cell proliferation, tumor growth, angiogenesis, metastasis and inflammation, as well as pro-apoptotic effects. Our study aimed to investigate the effects of a complex of (+)-catechin with 2 lysines (Cat:Lys) on cancer and non-cancer cells. For this, the in vitro effects of Cat:Lys on the viability, growth, proliferation, apoptosis, nutrient uptake and migration of breast, pancreatic and colorectal cancer and non-cancer cell lines was evaluated. We found that Cat:Lys exerted antiproliferative and cytotoxic effects in all breast, pancreatic and colorectal cell lines tested, but with a much less marked amplitude in non-cancer cell lines. It nevertheless interfered with nutrient (3H-deoxy-D-glucose and 3H-lactate) uptake and with lactate production in both cancer and non-cancer cell lines. Cat:Lys was found to possess selective antimigratory effects in breast, pancreatic and colorectal cancer cell lines compared to non-cancer cell lines. Cat:Lys also exerted pro-apoptotic effects in all the cancer cell lines that we tested, but not in non-cancer breast and pancreatic cell lines. The antimigratory, but not the pro-apoptotic, effects of Cat:Lys were found to be mediated by JAK2/STAT3 and Wnt pathway inhibition. In conclusion, Cat:Lys is a strong candidate for the development of new, effective anticancer agents against cancer.

Virulence, attachment and invasion of Caco-2 cells by multidrug-resistant bacteria isolated from wild animals.

Wild animals may be considered important reservoirs for bacterial pathogens and, consequently, possible sources of infection for humans. In this study, selected multidrug-resistant bacteria (Acinetobacter spp., Aeromonas salmonicida, Klebsiella pneumoniae, Pseudomonas fluorescens and Shewanella putrefaciens) isolated from wild animals were characterized on their ability to attach and invade/internalize human colonic carcinoma (Caco-2) cells. In addition, the viability of these bacteria to survive under simulated human gastrointestinal tract conditions as well as the production of virulence factors (homoserine lactones signal molecules, gelatinases, proteases, siderophores and biofilm formation) were studied. The results suggests that all the bacteria presented the capacity to attach and internalize into Caco-2 cells. A. salmonicida and P. fluorescens exhibited the highest ability to internalize. These bacteria were also found to be the highest proteases producers. A. salmonicida and K. pneumoniae survived under simulated human gastrointestinal conditions. These were the bacteria with the highest capacity to produce biofilms. K. pneumoniae was the only bacterium producing siderophores. Taken together, the present results reinforce the need for the "One Health" initiative, underscoring the environment and the animals as important reservoirs of infectious determinants.

Placentation-related processes in a human first-trimester extravillous trophoblast cell line (HTR-8/SVneo cells) are affected by several xenobiotics.

Our aim was to investigate the effect of some xenobiotics on placentation-related processes in an extravillous trophoblastic cell line (HTR-8/SVneo cells). Amphetamine, MDMA, theophylline, and fluoxetine, but not nicotine, cocaine, and caffeine, had a negative effect on cell proliferation rates, culture growth, viability, or migratory capacity. These compounds have a detrimental effect in placentation-related processes of HTR-8/SVneo cells.

Involvement of mTOR, JNK and PI3K in the negative effect of ethanol and metformin on the human first-trimester extravillous trophoblast HTR-8/SVneo cell line.

Our aim was to investigate the effect of two xenobiotics to which pregnant woman may be exposed, the drug of abuse ethanol (EtOH) (and its metabolite acetaldehyde (ACA)) and the therapeutic agent metformin (METF), on placentation-related processes in an extravillous trophoblastic (EVTs) cell line (HTR-8/SVneo cells). EtOH, ACA and METF (24 h) significantly reduced cell proliferation rates, culture growth, viability and migratory capacity of HTR-8/SVneo cells. Moreover, both EtOH (100 µM) and METF (1 mM) increased the apoptosis index and inhibited 3H-deoxy-D-glucose (3H-DG) and 3H-folic acid (3H-FA) uptake. mTOR, JNK and PI3K intracellular signaling pathways were involved in the effect of EtOH upon 3H-FA uptake and in the effect of METF upon cell viability, and mTOR and JNK in the effect of EtOH upon cell viability and 3H-DG uptake. We show that EtOH and METF have a detrimental effect in placentation-related processes of HTR-8/SVneo cells. Moreover, mTOR, JNK and PI3K appear to mediate some of these negative effects.

Effect of metformin on estrogen and progesterone receptor-positive (MCF-7) and triple-negative (MDA-MB-231) breast cancer cells.

This work aimed to investigate the effect of metformin on cellular glucose uptake and metabolism by breast cancer cells, as a mechanism contributing to its anticancer properties. Estrogen and progesterone receptor-positive (MCF-7) and triple-negative (MDA-MB-231) breast cancer cell lines were used as in vitro models of breast cancer. Short-term (26 min) exposure of MCF-7 and MDA-MB-231 cells to metformin inhibited uptake of 3H-deoxy-D-glucose (3H-DG). In contrast, long-term (24 h) exposure to metformin (5 µM-1 mM) concentration-dependently increased 3H-DG uptake in both cell lines. This effect was associated with an increase in lactate production but was not associated with changes in GLUT1 mRNA expression. Long-term exposure of MCF-7 and MDA-MB-231 cells to metformin (5 µM-1 mM) concentration-dependently reduced cell viability and culture mass and slightly increased cell proliferation rates. Combination of metformin (1 mM) with the facilitative glucose transporter (GLUT) inhibitor kaempferol (30 µM) did not change the effect of metformin on culture growth. In conclusion, short-term exposure to metformin reduces cellular glucose uptake, probably by direct inhibition of GLUT1. However, after long-term exposure to metformin, cellular uptake of glucose is significantly increased, not associated to changes in GLUT1 transcription rates. We suggest that, in the long-term, metformin induces a compensatory increase in glucose uptake in response to cellular energy depletion resulting from its inhibitory effect on mitochondrial oxidative phosphorylation machinery. Metformin-induced dependence of breast cancer cells on glycolytic pathway, associated with an anticarcinogenic effect of the drug, provides a biochemical basis for the design of new therapeutic strategies.

The effect of oxidative stress induced by tert-butylhydroperoxide under distinct folic acid conditions: An in vitro study using cultured human trophoblast-derived cells.

Preeclampsia is a pregnancy disorder characterized by high maternal blood pressure, fetal growth restriction and intrauterine hypoxia. Folic acid is a vitamin required during pregnancy. In this work, we investigated the relationship between preeclampsia and the intake of distinct doses of folic acid during pregnancy. Considering that preeclampsia is associated with increased placental oxidative stress levels, we investigated the effect of oxidative stress induced by tert-butylhydroperoxide (TBH) in human trophoblast-derived cells cultured upon deficient/low, physiological and supra-physiological folic acid levels. The negative effect of TBH upon thiobarbituric acid reactive substances (TBARS), total, reduced and oxidized glutathione, cell viability, cell proliferation, culture growth and cell migration was more marked under folic acid excess. This study suggests more attention on the dose administered, and ultimately, on the overall folic acid levels during pregnancy, in the context of preeclampsia risk.

Arachidonic Acid Reverses Xanthohumol-Induced Insufficiency in a Human First-Trimester Extravillous Trophoblast Cell Line (HTR-8/SVneo Cells).

We previously described a negative effect of xanthohumol (XN) upon placentation-related processes. We aimed to better characterize this effect by investigating the effect of XN upon the uptake of arachidonic acid (ARA), a crucial nutrient during pregnancy, by the HTR-8/SVneo human first-trimester extravillous trophoblast cell line and its relationship with the negative effect of XN upon placentation-related processes. Uptake of 14C-ARA (100 nM) was time dependent and inhibited by short-term (26 minutes) or long-term (24 hours) exposure to XN. Xanthohumol (24 hours; 5 µM) behaved as an uncompetitive inhibitor of 14C-ARA uptake; the mammalian target of rapamycin, tyrosine kinases, and c-Jun N-terminal kinases intracellular pathways were involved in this effect; and it markedly reduced long-chain acyl-CoA synthetase 1 messenger RNA levels. Moreover, the effects of XN (24 hours; 5 µM) upon cell proliferation, culture growth, migration, viability, and apoptosis index were prevented by high extracellular ARA but not by the peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist rosiglitazone. We thus conclude that ARA is an essential nutrient regulating cell viability, proliferation, culture growth, migration, and apoptosis of HTR-8/SVneo cells and that the deleterious effects of XN involve inhibition of ARA cellular uptake but appears to be independent of PPAR-γ activation.

In vitro studies on the inhibition of colon cancer by amino acid derivatives of bromothiazole.

The investment in cancer research is critical to find more and better treatments, but essentially to save lives. Here, we describe the synthesis and characterization on new bromothiazole derivatives with amino acids and with core of nitazoxanide, an FDA-approved antiprotozoal drug. Using a human adenocarcinoma-derived cell line (the Caco-2 cell line), we then investigated the antiproliferative (3H-thymidine incorporation) and cytotoxic (extracellular lactate dehydrogenase activity) effect of these derivatives. All the derivatives caused a concentration-dependent decrease in cell proliferation and viability. At their highest concentration, all compounds were able to reduce 3H-thymidine incorporation by more than 80%, corresponding to a more marked antiproliferative effect than butyrate. As to their cytotoxic effect, it was comparable to that of butyrate. The ability of bromo substituent in thiazole ring with new sequences of amino acids in inducing cell death and apoptosis in Caco-2 cells (and other cell lines) is now being studied.

Insulin Exhibits an Antiproliferative and Hypertrophic Effect in First Trimester Human Extravillous Trophoblasts.

Our aim was to investigate the effect of high levels of glucose, insulin, leptin, and tumor necrosis factor alpha, biomarkers of diabetes in pregnancy, in the process of placentation, using as a cell model a first trimester extravillous human trophoblast cell line (HTR8/SVneo cells). Exposure of HTR8/SVneo cells for 24 hours to either glucose (20 mmol/L) or leptin (25-100 ng/mL) did not cause significant changes in cell proliferation and viability. Tumor necrosis factor alpha (24 hours; 10-100 ng/L) caused a small decrease (10%) in cell proliferation and an increase (9%) in cell viability; however, both effects disappeared when exposure time was increased. Insulin (24 hours; 1-10 nmol/L) caused a concentration- and time-dependent decrease (10%-20%) in cell proliferation; the effect of insulin (10 nmol/L) was more pronounced after a 48 hours exposure (35%). In contrast, exposure to insulin (10 nmol/L; 48 hours) showed no significant effect on cell viability, apoptosis, and migration capacity. Insulin appears to cause hypertrophy of HTR8/SVneo cells as it reduces the cell mitotic index while increasing the culture protein content. The antiproliferative effect of insulin seems to involve activation of mammalian target of rapamycin, phosphoinositide 3-kinase, and p38 mitogen-activated protein kinase. Finally, simvastatin and the polyphenol quercetin potentiated the antiproliferative effect of insulin; on the contrary, the polyphenol resveratrol, the polyunsaturated fatty acids eicosapentaenoic and docosahexaenoic acids, and folic acid were not able to change it. In conclusion, we show that insulin has an antiproliferative and hypertrophic effect on a first trimester extravillous human trophoblast cell line. So insulin might affect the process of placentation.

Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex.

In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu2(µ-adenine)2(phen)2(H2O)2](NO3)4·0.5H2O (phen=1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu-Cu distance of 3.242(3)Å. Intramolecular and intermolecular π⋯π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87±0.06µM (HeLa) and 0.44±0.06µM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09×10(5)M(-1) was obtained from UV-vis absorption studies.

Modulation of the uptake of critical nutrients by breast cancer cells by lactate: Impact on cell survival, proliferation and migration.

This work aimed to characterize the uptake of folate and glucose by breast cancer cells and to study the effect of lactate upon the transport of these nutrients and upon cell viability, proliferation and migration capacity. Data obtained showed that: a) MCF7 cells uptake (3)H-folic acid ((3)H-FA) at physiological but not at acidic pH; b) T47D cells accumulate (3)H-FA and (14)C-5-methyltetrahydrofolate ((14)C-5-MTHF) more efficiently at acidic than at physiological pH; c) (3)H-deoxyglucose ((3)H-DG) uptake by T47D cells is sodium-independent, inhibited by cytochalasin B (CYT B) and stimulated by insulin. Regarding the effect of lactate, in T47D cells, acute (26 min) and chronic (24 h) exposure to lactic acid (LA) stimulated (3)H-FA uptake. Acute exposure to LA also stimulated (3)H-DG uptake and chronic exposure to LA significantly stimulated T47D cell migratory capacity. In conclusion, the transport of folates is strikingly different in two phenotypically similar breast cancer cell lines: MCF7 and T47D cells. Additionally, lactate seems to act as a signaling molecule which increases the uptake of nutrients and promotes the migration capacity of T47D cells.

Xanthohumol impairs glucose uptake by a human first-trimester extravillous trophoblast cell line (HTR-8/SVneo cells) and impacts the process of placentation.

In this study, we aimed to investigate modulation of glucose uptake by the HTR-8/SVneo human first-trimester extravillous trophoblast cell line by a series of compounds and to study its consequences upon cell proliferation, viability and migration. We observed that uptake of (3)H-deoxy-d-glucose ((3)H-DG; 10 nM) was time-dependent, saturable, inhibited by cytochalasin B (50 and 100 µM), phloretin (0.5 mM) and phloridzin (1 mM), insulin-insensitive and sodium-independent. In the short term (30 min), neither 5-HT (100-1000 µM), melatonin (10 nM) nor the drugs of abuse ethanol (100 mM), nicotine (100 µM), cocaine (25 µM), amphetamine (10-25 µM) and 3,4-methylenedioxy-N-methamphetamine (10 µM) affected (3)H-DG uptake, while dexamethasone (100-1000 µM), fluoxetine (100-300 µM), quercetin, epigallocatechin-3-gallate (30-1000 µM), xanthohumol (XH) and resveratrol (1-500 µM) decreased it. XH was the most potent inhibitor [IC50 = 3.55 (1.37-9.20) µM] of (3)H-DG uptake, behaving as a non-competitive inhibitor of (3)H-DG uptake, both after short- and long-term (24 h) treatment. The effect of XH (5 µM; 24 h) upon (3)H-DG uptake involved mammalian target of rapamycin, tyrosine kinases and c-Jun N-terminal kinases intracellular pathways. Moreover, XH appeared to decrease cellular uptake of lactate due to inhibition of the monocarboxylate transporter 1. Additionally, XH (24 h; 5 µM) decreased cell viability, proliferation, culture growth and migration. The effects of XH upon cell viability and culture growth, but not the antimigratory effect, were mimicked by low extracellular glucose conditions and reversed by high extracellular glucose conditions. We thus suggest that XH, by inhibiting glucose cellular uptake and impairing HTR-8/SVneo cell viability and proliferation, may have a deleterious impact in the process of placentation.

Excess perigestational folic acid exposure induces metabolic dysfunction in post-natal life.

The aim of this study was to understand whether high folic acid (HFA) exposure during the perigestational period induces metabolic dysfunction in the offspring, later in life. To do this, female Sprague-Dawley rats (G0) were administered a dose of folic acid (FA) recommended for pregnancy (control, C, 2 mg FA/kg of diet, n=5) or a high dose of FA (HFA, 40 mg FA/kg of diet, n=5). Supplementation began at mating and lasted throughout pregnancy and lactation. Body weight and food and fluid intake were monitored in G0 and their offspring (G1) till G1 were 13 months of age. Metabolic blood profiles were assessed in G1 at 3 and 13 months of age (3M and 13M respectively). Both G0 and G1 HFA females had increased body weight gain when compared with controls, particularly 22 (G0) and 10 (G1) weeks after FA supplementation had been stopped. G1 female offspring of HFA mothers had increased glycemia at 3M, and both female and male G1 offspring of HFA mothers had decreased glucose tolerance at 13M, when compared with matched controls. At 13M, G1 female offspring of HFA mothers had increased insulin and decreased adiponectin levels, and G1 male offspring of HFA mothers had increased levels of leptin, when compared with matched controls. In addition, feeding of fructose to adult offspring revealed that perigestational exposure to HFA renders female progeny more susceptible to developing metabolic unbalance upon such a challenge. The results of this work indicate that perigestational HFA exposure the affects long-term metabolic phenotype of the offspring, predisposing them to an insulin-resistant state.

The chemopreventive effect of the dietary compound kaempferol on the MCF-7 human breast cancer cell line is dependent on inhibition of glucose cellular uptake.

Our aim was to investigate the effect of several dietary polyphenols on glucose uptake by breast cancer cells. Uptake of (3)H-deoxy-D-glucose ((3)H-DG) by MCF-7 cells was time-dependent, saturable, and inhibited by cytochalasin B plus phloridzin. In the short-term (26 min), myricetin, chrysin, genistein, resveratrol, kaempferol, and xanthohumol (10-100 µM) inhibited (3)H-DG uptake. Kaempferol was found to be the most potent inhibitor of (3)H-DG uptake [IC50 of 4 µM (1.6-9.8)], behaving as a mixed-type inhibitor. In the long-term (24 h), kaempferol (30 µM) was also able to inhibit (3)H-DG uptake, associated with a 40% decrease in GLUT1 mRNA levels. Interestingly enough, kaempferol (100 µM) revealed antiproliferative (sulforhodamine B and (3)H-thymidine incorporation assays) and cytotoxic (extracellular lactate dehydrogenase activity determination) properties, which were mimicked by low extracellular (1 mM) glucose conditions and reversed by high extracellular (20 mM) glucose conditions. Finally, exposure of cells to kaempferol (30 µM) induced an increase in extracellular lactate levels over time (to 731 ± 32% of control after a 24 h exposure), due to inhibition of MCT1-mediated lactate cellular uptake. In conclusion, kaempferol potently inhibits glucose uptake by MCF-7 cells, apparently by decreasing GLUT1-mediated glucose uptake. The antiproliferative and cytotoxic effect of kaempferol in these cells appears to be dependent on this effect.

Maternal undernutrition and fetal developmental programming of obesity: the glucocorticoid connection.

An adequate maternal nutrition during pregnancy is crucial for the health outcome of offspring in adulthood. Maternal undernutrition during critical periods of fetal development can program the fetus for metabolic syndrome (MetS) later in life, especially when postnatally challenged with a hypernutritive diet. Adipogenesis, which begins in utero and accelerates in neonatal life, is a major candidate for developmental programming. During fetal development, the hypothalamic-pituitary-adrenal (HPA) axis is extremely susceptible to programming, and the HPA tone is increased throughout life in undernourished conditions. As a consequence, an alteration in the expression and function of glucocorticoid (GC) receptors and of the major GC regulatory enzymes (11ß-hydroxysteroid dehydrogenase 1 and -2) occurs. In this review, we will give insights into the role of maternoplacental adverse interactions under the specific context of maternal undernutrition, for later-in-life MetS development, with a special emphasis on the role of GCs.