Placental Epigenome Impacts Fetal Development: Effects of Maternal Nutrients and Gut Microbiota.

Evidence is emerging on the role of maternal diet, gut microbiota, and other lifestyle factors in establishing lifelong health and disease, which are determined by transgenerationally inherited epigenetic modifications. Understanding epigenetic mechanisms may help identify novel biomarkers for gestation-related exposure, burden, or disease risk. Such biomarkers are essential for developing tools for the early detection of risk factors and exposure levels. It is necessary to establish an exposure threshold due to nutrient deficiencies or other environmental factors that can result in clinically relevant epigenetic alterations that modulate disease risks in the fetus. This narrative review summarizes the latest updates on the roles of maternal nutrients (n-3 fatty acids, polyphenols, vitamins) and gut microbiota on the placental epigenome and its impacts on fetal brain development. This review unravels the potential roles of the functional epigenome for targeted intervention to ensure optimal fetal brain development and its performance in later life.

Modulation of fetoplacental growth, development and reproductive function by endocrine disrupters.

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-ß estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions.

Gestational exposure to bisphenol S induces microvesicular steatosis in male rat offspring by modulating metaflammation.

Prenatal exposure to endocrine-disrupting bisphenol A (BPA) shows a long-lasting programming effect on an organ's metabolic function and predisposes it to the risk of adult metabolic diseases. Although a reduced contaminant risk due to "BPA-free" exposure is proposed, limited data on a comparative assessment of gestational exposure to BPS and BPA and their effects on metaflammation in predisposing liver metabolic disease is reported. Pregnant Wistar rats were exposed to BPS and BPA (0.0, 0.4, 4.0 µg/kg bw) via gavage from gestational day 4 to 21, and effects were assessed in the 90 d male offspring. Prenatal BPS-exposed offspring showed a more obesogenic effect than BPA, including changes in body fat distribution, feed efficiency, and leptin signalling. The BPS exposure induced the adipocyte hypertrophy of visceral adipose to a greater extent than BPA. The adipose hypertrophy was augmented by tissue inflammation, endoplasmic reticulum (ER) stress, and apoptosis due to increased expression of pro-inflammatory (IL6, IL1ß, CRP, COX2) cytokines, ER stress modulator (CHOP), and apoptotic effector (Caspase 3). The enlarged, stressed, inflamed adipocytes triggered de novo lipogenesis in the bisphenol-exposed offspring liver due to increased expression of cholesterol and lipid biogenesis mediators (srebf1, fasn, acaca, PPARα) concomitant with elevated triacylglycerol (TG) and cholesterol (TC), resulted in impaired hepatic clearance of lipids. The lipogenic effects were also promoted by increased expression of HSD11ß1. BPS exposure increased absolute liver weight, discoloration, altered liver lobes more than in BPA. Liver histology showed numerous lipid droplets, and hepatocyte ballooning, upregulated ADRP expression, an increased expression of pro-inflammatory mediators (IL6, CRP, IL1ß, TNFα, COX2), enhanced lipid peroxidation in the BPS-exposed offspring's liver suggest altered metaflammation leads to microvesicular steatosis. Overall, gestational BPS exposure demonstrated a higher disruption in metabolic changes than BPA, involving excess adiposity, liver fat, inflammation, and predisposition to steatosis in the adult male offspring.

Dietary omega-3 fatty acid deficiency from pre-pregnancy to lactation affects expression of genes involved in hippocampal neurogenesis of the offspring.

Maternal n-3 PUFA (omega-3) deficiency can affect brain development in utero and postnatally. Despite the evidence, the impacts of n-3 PUFA deficiency on the expression of neurogenesis genes in the postnatal hippocampus remained elusive. Since postnatal brain development requires PUFAs via breast milk, we examined the fatty acid composition of breast milk and hippocampal expression of neurogenesis genes in n-3 PUFA deficient 21d mice. In addition, the expression of fatty acid desaturases, elongases, free fatty acids signaling receptors, insulin and leptin, and glucose transporters were measured. Among the genes involved in neurogenesis, the expression of brain-specific tenascin-R (TNR) was downregulated to a greater extent (∼31 fold), followed by adenosine A2A receptor (A2AAR), dopamine receptor D2 (DRD2), glial cell line-derived neurotrophic factor (GDNF) expression in the n-3 PUFA deficient hippocampus. Increasing dietary LA to ALA (50:1) elevated the ARA to DHA ratio by ∼8 fold in the n-3 PUFA deficient breast milk, with an overall increase of total n-6/n-3 PUFAs by ∼15:1 (p<0.05) compared to n-3 PUFA sufficient (LA to ALA: 2:1) diet. The n-3 PUFA deficient mice exhibited upregulation of FADS1, FADS2, ELOVL2, ELOVL5, ELOVL6, GPR40, GPR120, LEPR, IGF1 and downregulation of GLUT1, GLUT3, and GLUT4 mRNA expression in hippocampus (p<0.05). Maternal n-3 PUFA deficiency affects the hippocampal expression of key neurogenesis genes in the offspring with concomitant expression of desaturase and elongase genes, suggesting the importance of dietary n-3 PUFA for neurodevelopment.

Bioactives and their roles in bone metabolism of osteoarthritis: evidence and mechanisms on gut-bone axis.

Bioactives significantly modify and maintain human health. Available data suggest that Bioactives might play a beneficial role in chronic inflammatory diseases. Although promised, defining their mechanisms and opting to weigh their benefits and limitations is imperative. Detailed mechanisms by which critical Bioactives, including probiotics and prebiotics such as dietary lipids (DHA, EPA, alpha LA), vitamin D, polysaccharides (fructooligosaccharide), polyphenols (curcumin, resveratrol, and capsaicin) potentially modulate inflammation and bone metabolism is limited. Certain dietary bioactive significantly impact the gut microbiota, immune system, and pain response via the gut-immune-bone axis. This narrative review highlights a recent update on mechanistic evidence that bioactive is demonstrated demonstrated to reduce osteoarthritis pathophysiology.

Cytoplasmic fatty acid-binding proteins in metabolic diseases and cancers.

Cytoplasmic fatty acid-binding proteins (FABPs) are multipurpose proteins that can modulate lipid fluxes, trafficking, signaling, and metabolism. FABPs regulate metabolic and inflammatory pathways, its inhibition can improve type 2 diabetes mellitus and atherosclerosis. In addition, FABPs are involved in obesity, metabolic disease, cardiac dysfunction, and cancers. FABPs are promising tissue biomarkers in solid tumors for diagnostic and/or prognostic targets for novel therapeutic strategies. The signaling responsive elements of FABPs and determinants of FABP-mediated functions may be exploited in preventing or treating these diseases.

Fatty acids and evolving roles of their proteins in neurological, cardiovascular disorders and cancers.

The dysregulation of fat metabolism is involved in various disorders, including neurodegenerative, cardiovascular, and cancers. The uptake of long-chain fatty acids (LCFAs) with 14 or more carbons plays a pivotal role in cellular metabolic homeostasis. Therefore, the uptake and metabolism of LCFAs must constantly be in tune with the cellular, metabolic, and structural requirements of cells. Many metabolic diseases are thought to be driven by the abnormal flow of fatty acids either from the dietary origin and/or released from adipose stores. Cellular uptake and intracellular trafficking of fatty acids are facilitated ubiquitously with unique combinations of fatty acid transport proteins and cytoplasmic fatty acid-binding proteins in every tissue. Extensive data are emerging on the defective transporters and metabolism of LCFAs and their clinical implications. Uptake and metabolism of LCFAs are crucial for the brain's functional development and cardiovascular health and maintenance. In addition, data suggest fatty acid metabolic transporter can normalize activated inflammatory response by reprogramming lipid metabolism in cancers. Here we review the current understanding of how LCFAs and their proteins contribute to the pathophysiology of three crucial diseases and the mechanisms involved in the processes.

Conjugated Linoleic Acid and Its Beneficial Effects in Obesity, Cardiovascular Disease, and Cancer.

Conjugated linoleic acid (CLA) is a dietary polyunsaturated fatty acid found in animal fats suchas red meat and dairy products [1].[...].

Plastics derived endocrine-disrupting compounds and their effects on early development.

Despite the fact that the estrogenic effects of bisphenols were first described 80 years ago, recent data about its potential negative impact on birth outcome parameters raises a strong rationale to investigate further. The adverse health effects of plastics recommend to measure the impacts of endocrine-disrupting compounds (EDCs) such as bisphenols (BPA, BPS, BPF), bis(2-ethylhexyl) phthalate, and dibutyl phthalate (DBP) in human health. Exposure to these compounds in utero may program the diseases of the testis, prostate, kidney and abnormalities in the immune system, and cause tumors, uterine hemorrhage during pregnancy and polycystic ovary. These compounds also control the processes of epigenetic transgenerational inheritance of adult-onset diseases by modulating DNA methylation and epimutations in reproductive cells. The early developmental stage is the most susceptible window for developmental and genomic programming. The critical stages of the events for a normal human birth lie between the many transitions occurring between spermatogenesis, egg fertilization and the fully formed fetus. As the cells begin to grow and differentiate, there are critical balances of hormones, and protein synthesis. Data are emerging on how these plastic-derived compounds affect embryogenesis, placentation and feto-placental development since pregnant women and unborn fetuses are often exposed to these factors during preconception and throughout gestation. Impaired early development that ultimately influences fetal outcomes is at the center of many developmental disorders and contributes an independent risk factor for adult chronic diseases. This review will summarize the current status on the impact of exposure to plastic derived EDCs on the growth, gene expression, epigenetic and angiogenic activities of the early fetal development process and their possible effects on birth outcomes.

Maternal dietary fatty acids and their roles in human placental development.

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), angiopoietin-like 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 feto-placental 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.

Curcumin stimulates angiogenesis through VEGF and expression of HLA-G in first-trimester human placental trophoblasts.

Curcumin has a protective role in placental diseases like preeclampsia and preterm birth. Very little is known about its functional effects on growth, angiogenesis, and epigenetic activities of human first trimester placenta. HTR8/SVneo trophoblasts cells were used as model for human first trimester placenta. Effects of curcumin (≥80%) in these cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), radioactive thymidine uptake, quantitative real-time polymerase chain reaction (qRT-PCR), promoter DNA methylation, qRT-PCR array, tube formation, wound healing, and immunoblot assays. PC3 (prostate cancer), JEG-3 (trophoblast), and HMEC-1 (endothelial) cells were used as control in various experiments. Unlike in PC3 cells, curcumin stimulated growth, proliferation, and viability in HTR8/SVneo cells. Curcumin increased tube formation, and messenger RNA (mRNA) expression of angiogenic factors such as vascular endothelial growth factor A (VEGFA) and protein expression of proangiogenic factor VEGF receptor-2 and fatty acid-binding protein-4 (FABP4) in these cells. Curcumin-stimulated tube formation was associated with an increased expression of VEGFR2 and FABP4. The stimulatory effects of curcumin were inhibited by VEGFR2 (SU5416) and FABP4 (BMS309403) inhibitors. Curcumin also significantly increased both mRNA and protein expression of HLA-G in HTR8/SVneo cells. Curcumin increased mRNA expression of DNMT3A and NOTCH signaling system whereas down-regulated mRNA expression of HSD11ß2. Curcumin enhanced hypomethylation of gene promoters against oxidative stress and DNA damage pathway mediators. Curcumin promotes cell growth, migration, and thus angiogenic potential of these cells. Increased expression of HLA-G by curcumin, hitherto unknown, is a novel finding since HLA-G not only favors the immune environment for invasive trophoblasts but also positively modulates angiogenesis.

Fatty acid-binding protein3 expression in BeWo cells, a human placental choriocarcinoma cell line.

Cellular uptake of long chain fatty acids in human placental trophoblasts is thought to be mediated by several membrane- and cytoplasmic fatty acid-binding proteins (FABP). FABP3 was shown to be involved in long chain polyunsaturated fatty acids (LCPUFA) uptake in human trophoblastic choriocarcinoma cells, BeWo as the uptake of arachidonic acid,20:4n-6 (ARA) was decreased in FABP3-knockdown BeWo cells. However, the regulation of expression of FABP3 in these cells is not yet well known. The aim of the present study was to examine the FABP3 expression by LCPUFAs, insulin and LXR agonists in BeWo cells. Among all these fatty acids tested, only ARA dose-dependently stimulated the expression of FABP3 protein in these cells after 24h incubation while other fatty acids had no such effect. In addition, LXR agonist and insulin dose-dependently increased FABP3 protein expression in these cells after 24h incubation. Insulin-stimulated FABP3 protein expression was accompanied with an increased arachidonic acid uptake. Differentiated BeWo cells had lesser expression of FABP3 protein than in the undifferentiated cells as the cellular differentiation state was measured by hCG production. In preeclamptic placental tissue, lowered expression of FABP3 protein was observed compared with those in normal pregnancy. All these data indicate that FABP3 may in be part involved in ARA uptake in these cells and its expression may be regulated by ARA, insulin, LXR and the state of cellular differentiation.

Tube formation in the first trimester placental trophoblast cells: Differential effects of angiogenic growth factors and fatty acids.

The study aims to investigate whether cytosolic fatty acid-binding protein-4 (FABP4) is involved in angiogenic growth factors- and fatty acid-induced tube formation in first trimester placental trophoblast cells, HTR8/SVneo. We determined the tube formation both at basal as well as stimulated levels in the absence and presence of inhibitors of FABP4 and VEGF signaling pathways. Basal level of tube formation was maximally reduced in the presence of 50 µM of FABP4 inhibitor compared with those by VEGF signaling pathway inhibitors (rapamycin, L-NAME, and p38 MAP kinase inhibitor). Whereas docosahexaenoic acid, 22:6n-3 (DHA)-, and VEGF-induced tube formation was maximally inhibited by p38 MAP kinase inhibitor (63.7 and 34.5%, respectively), however, leptin-induced tube formation was inhibited maximally by FABP4 inhibitor (50.7%). ANGPTL4 and oleic acid (OA)-induced tube formation was not blocked by any of these inhibitors. The FABP4 inhibitor inhibited cell growth stimulated by DHA, leptin, VEGF, and OA (P < 0.05) but was not affected by ANGPTL4. VEGF, leptin, and OA also increased FABP4 protein level in these cells, though the uptake of fatty acids by these cells was not affected by the presence of FABP4 inhibitor. Our data demonstrate that FABP4 may be involved in part in the basal level, and stimulated tube formation by VEGF, DHA, and leptin, whereas it has little or no effect in ANGPTL4- and OA-induced tube formation in these cells. Thus, FABP4 may play a differential role in fatty acids and angiogenic growth factors-mediated tube formation in the first trimester trophoblast cells in vitro.

Connective tissue growth factor induces tube formation and IL-8 production in first trimester human placental trophoblast cells.

OBJECTIVES: To study the roles of connective tissue growth factor (CTGF) on tube formation (as a measure of cellular angiogenesis) and expression of angiogenesis-associated genes in first-trimester human extravillous trophoblast cells. STUDY DESIGN: The effects of recombinant human CTGF on tube forming ability were studied in the first trimester trophoblast cells using matrigel system. The expressions of genes involved in angiogenesis were studied using real time PCR microarray. RESULTS: hCTGF (26nM) stimulated tube formation and enhanced tube length in these cells compared with control cells. However, hCTGF-stimulated tube formation was not inhibited by SU5416, a selective inhibitor of the membrane-bound tyrosine kinase activity of VEGF-2 receptor (Flk-1/KDR) indicating VEGF was not involved in the process. This was also supported by the observation that CTGF did not stimulate the expression of angiogenic factors VEGF or ANGPTL4 as determined by PCR array. To further elucidate roles of hCTGF in tube formation we then measured expression of several genes involved in angiogenesis signalling pathways. Among the genes, hCTGF increased expression of IL-8 mRNA by ∼6-fold and its protein secretion by ∼20-fold in these cells. Exogenously added IL-8 also stimulated the tube formation and proliferation in these cells. CONCLUSIONS: hCTGF-induced tube formation is independent of VEGF. hCTGF stimulates production of IL-8, an important angiogenic factor in these cells. However their interrelationship in this process is yet to be known.

Fatty acid-induced angiogenesis in first trimester placental trophoblast cells: possible roles of cellular fatty acid-binding proteins.

Angiogenesis is involved in the growth of new blood vessels from the existing one. Consequently, angiogenesis plays an indispensable role in tissue growth and repair including early placentation processes. Besides angiogenic growth factors (vascular endothelial growth factor (VEGF), angiopoietin-like 4 (ANGPTL4), placental growth factor (PlGF), platelet derived growth factor (PDGF), fibroblast growth factors (FGF)), dietary fatty acids (c>16) also directly or indirectly modulate angiogenic processes in tumors and other cell systems. Usually n-3 fatty acids inhibit whereas n-6 fatty acids stimulate angiogenesis in tumors and other cells. Contrary to this, docosahexaenoic acid, 22:6n-3 (DHA) and other fatty acids including conjugated linoleic acid stimulate angiogenesis in placental first trimester cells. In addition to the stimulation of expression of major angiogenic factors such as VEGF and ANGPTL4, fatty acids also stimulate expression of intracellular fatty acid-binding proteins (FABPs) FABP-4 and FABP-3 those are known to directly modulate angiogenesis. Emerging data indicate that FABPs may be involved in the angiogenesis process. This paper reviews the fatty acid mediated angiogenesis process and the involvement of their binding proteins in these processes.

cis-9,trans-11 conjugated linoleic acid stimulates expression of angiopoietin like-4 in the placental extravillous trophoblast cells.

A number of studies have been carried out to examine the biological function of conjugated linoleic acid (CLA) and its potential health benefits. However, not much is known about how CLA isomers mediate their effect on angiogenesis and vascularization during early placentation. In this paper we demonstrate that cis-9,trans-11(c9,t11)-CLA stimulated the expression of angiopoietin like-4 (ANGPTL4) mRNA and protein accompanied by tube formation in first trimester placental trophoblast cells, HTR8/SVneo whereas the other CLA isomer, trans-10,cis-12 (t10,c12)-CLA had no such effects. c9,t11-CLA however did not stimulate expression of the most potent angiogenic factor, vascular endothelial growth factor (VEGF) in these cells. Silencing ANGPTL4 in these cells significantly reduced the stimulatory effect of c9,t11-CLA on tube formation, indicating the involvement of ANGPTL4. In addition, c9,t11-CLA increased the mRNA expression of several pro-angiogenic factors such as fatty acid binding protein-4 (FABP4), cyclooxygenase-2 (COX-2) and adipose differentiation-related protein (ADRP) in HTR8/SVneo cells. c9,t11-CLA also induced the uptake of docosahexaenoic acid, 22:6n-3 (DHA), a stimulator of tube formation in these cells. Triacsin C, an acylCoA synthetase inhibitor, attenuated c9,t11-CLA induced DHA uptake, tube formation and cellular proliferation in HTR8/SVneo cells. Our data suggest that the c9,t11-CLA isomer may regulate angiogenic processes during early placentation via increased expression of ANGPTL4 and other pro-angiogenic factors such as FABP4, COX-2 and ADRP with concomitant increase in the uptake of DHA in these cells.

Leptin induces tube formation in first-trimester extravillous trophoblast cells.

OBJECTIVES: To study the roles of leptin on tube formation (as a measure of cellular angiogenesis) and expression of associated genes in first-trimester human extravillous trophoblast cells. STUDY DESIGN: The effects of leptin on tube formation and fatty acid uptake in first trimester extravillous placental trophoblast cells, HTR8/SVneo, were investigated. We also investigated the effects of leptin on the expression of genes involved in angiogenesis and lipid metabolism in these cells. RESULTS: Leptin at 25 ng/ml maximally stimulated tube formation in the first trimester placental trophoblast cells, HTR8/SVneo, by increasing tube length as well as numbers (10,100 ± 150 pixels) compared with those of control cells (2900 ± 50 pixels) p>0.05. Leptin-induced tube formation was not inhibited by the selective inhibitor of VEGF, indicating that its action was independent of VEGF. Leptin, however, significantly increased the expression of genes those are involved in angiogenesis pathways such as PECAM1, JAG1, CDH5, IL8, NRP1, SPHK1, S1PR1, CXCL 1 and 6, FGF1, EFNA3 and AKT1, as determined by PCR array. Leptin did not, however, stimulate expression of the primary angiogenic factors known in placenta such as VEGF or ANGPTL4, as determined by both qRTPCR and PCR array assays. Leptin increased 7-fold expression of FABP4, which is known to be involved in VEGF-mediated angiogenesis in endothelial cells. In addition, leptin treatment resulted a 48% increase in the uptake of docosahexaenoic acid, 22:6n-3 (DHA) which also stimulates tube formation in these cells. CONCLUSIONS: Leptin may play an important role in early placentation by stimulating several genes involved in angiogenic signalling pathway and fatty acid metabolism.