Search

Diabetic pregnancy is correlated with increased risk of metabolic and neurological disorders in the offspring putatively mediated epigenetically. Little is known about epigenetic changes already present in fetuses of diabetic pregnancies. We aimed at characterizing the perinatal environment after preexisting maternal diabetes mellitus and at identifying relevant epigenetic changes in the fetus. We focused on the transcription factor Srebf2 (sterol regulatory element binding transcription factor 2), a master gene in regulation of cholesterol metabolism. We tested whether diabetic pregnancy induces epigenetic changes in the Srebf2 promoter and if they become manifest in altered Srebf2 gene expression. We worked with a transgenic rat model of type 2 diabetes mellitus (Tet29) in which the insulin receptor is knocked down by doxycycline-induced RNA interference. Doxycycline was administered preconceptionally to Tet29 and wild-type control rats. Only Tet29 doxycycline dams were hyperglycemic, hyperinsulinemic, and hyperlipidemic. Gene expression was analyzed with quantitative real-time reverse transcriptase polymerase chain reaction and CpG promoter methylation with pyrosequencing. Immunohistochemistry was performed on fetal brains. Fetuses from diabetic Tet29 dams were hyperglycemic and growth restricted at the end of pregnancy. They further displayed decreased liver and brain weight with concomitant decreased microglial activation in the hippocampus in comparison to fetuses of normoglycemic mothers. Importantly, diabetic pregnancy induced CpG hypermethylation of the Srebf2 promoter in the fetal liver and brain, which was associated with decreased Srebf2 gene expression. In conclusion, diabetic and hyperlipidemic pregnancy induces neurological, metabolic, and epigenetic alterations in the rat fetus. Srebf2 is a potential candidate mediating intrauterine environment-driven epigenetic changes and later diabetic offspring health., (© 2018 American Heart Association, Inc.)

Since it is known that placental overexpression of the human anti-angiogenic molecule sFlt-1, the main candidate in the progression of preeclampsia, lead to intrauterine growth restriction (IUGR) in mice by lentiviral transduction of mouse blastocysts, we hypothesize that sFlt-1 influence placental morphology and physiology resulting in fetal IUGR. We therefore examined the effect of sFlt-1 on placental morphology and physiology at embryonic day 18.5 with histologic and morphometric analyses, transcript analyses, immunoblotting, and methylation studies. Interestingly, placental overexpression of sFlt-1 leads to IUGR in the fetus and results in lower placental weights. Moreover, we observed altered trophoblast differentiation with reduced expression of IGF2, resulting in a smaller placenta, a smaller labyrinth, and the loss of glycogen cells in the junctional zone. Changes in IGF2 are accompanied by small changes in its DNA methylation, whereas overall DNA methylation is unaffected. In addition, the expression of placental nutrient transporters, such as the glucose diffusion channel Cx26, is decreased. In contrast, the expression of the fatty acid transporter CD36 and the cholesterol transporter ABCA1 is significantly increased. In conclusion, placental sFlt-1 overexpression resulted in a reduction in the differentiation of the spongiotrophoblast into glycogen cells. These findings of a reduced exchange area of the labyrinth and glycogen stores, as well as decreased expression of glucose transporter, could contribute to the intrauterine growth restriction phenotype. All of these factors change the intrauterine availability of nutrients. Thus, we speculate that the alterations triggered by increased anti-angiogenesis strongly affect fetal outcome and programming. J. Cell. Biochem. 118: 1316-1329, 2017. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Objective: To investigate whether differences between late-onset preeclampsia (PE) and intrauterine growth restriction (IUGR) can be explained by differential placental expression patters of sFlt-1, Flt-1, and placental growth factor (PlGF)., Methods: Placental tissues and maternal blood samples from seven patients with PE, five IUGR, and seven age-matched controls were studied for mRNA and protein levels as well as protein localization and expression intensity., Results: Placental PlGF mRNA and protein expression were not altered by placental dysfunction while placental villous trophoblast expression intensity of PlGF was increased., Conclusion: High sFlt-1 concentrations may account for diminished maternal serum PlGF levels.

Objective: To investigate whether differences between early preeclampsia and early fetal growth restriction can be explained by differential placental expression patterns of sFlt-1, Flt-1, and PlGF., Methods: Placental tissues and maternal blood samples from six cases of preeclampsia, seven IUGR, and six age-matched controls were studied for mRNA and protein levels as well as protein localization and expression intensity., Results: Neither placental PlGF mRNA and protein expression nor placental villous trophoblast expression intensity of PlGF was altered by placental dysfunction., Conclusion: High sFlt-1 concentrations may account for diminished maternal serum PlGF levels.

Preeclampsia is associated with chronic inflammation and an imbalance among T-helper cell subtypes with an increase in T-helper 17 (T H 17) cells. The objective of this study was to determine a role for T H 17s, from the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia, in the etiology of hypertension and chronic inflammation during pregnancy. CD4 + /CD25 - T cells were isolated from rat spleens, cultured in T H 17 media, and were verified as T H 17s via flow cytometry. On day 12 of gestation, 1×10 6 T H 17 cells from RUPP rats were adoptively transferred into NP rats, carotid catheters were inserted on day 18, and on day 19, mean arterial pressure (MAP) was recorded, serum and plasma were collected, and oxidative stress and production of agonistic autoantibodies to the ANG II type I receptor (AT 1 -AA) were analyzed. MAP increased from 100.3 ± 1.7 mmHg in normal pregnant (NP; n = 17) to 124.8 ± 2.1 mmHg in RUPP (n = 22; P < 0.0001) and to 110.8 ± 2.8 mmHg in NP+RUPP T H 17 (n = 11). Pup weights in NP+RUPP T H 17s were decreased to 1.92 ± 0.09 g from 2.39 ± 0.14 in NP rats (P < 0.01). AT 1 -AA significantly increased from 0.1 ± 0.2 beats/min in NP to 15.6 ± 0.7 beats/min in NP+RUPP T H 17s. IL-6 was 22.3 ± 5.7 pg/ml in NP and increased to 60.45 ± 13.8 pg/ml in RUPP (P < 0.05) and 75.9 ± 6.8 pg/ml in NP+RUPP T H 17 rats (P < 0.01). Placental and renal oxidative stress were 238 ± 27.5 and 411 ± 129.9 relative light units·min -1 ·mg -1 in NP and 339 ± 104.6 and 833 ± 331.1 relative light units·min -1 ·mg -1 in NP+RUPP T H 17, respectively. In conclusion, RUPP T H 17 cells induced intrauterine growth restriction and increased blood pressure, AT 1 -AA, IL-6, and tissue oxidative stress when transferred to NP rats, indicating a role for autoimmune associated T H 17 cells, to cause much of the pathophysiology associated with preeclampsia., (Copyright © 2016 the American Physiological Society.)

Preeclampsia is a multisystemic syndrome during pregnancy that is often associated with intrauterine growth retardation. Immunologic dysregulation, involving T cells, is implicated in the pathogenesis. The aim of this study was to evaluate the effect of upregulating regulatory T cells in an established transgenic rat model for preeclampsia. Application of superagonistic monoclonal antibody for CD28 has been shown to effectively upregulate regulatory T cells. In the first protocol (treatment protocol), we applied 1 mg of CD28 superagonist or control antibody on days 11 and 15 of pregnancy. In the second protocol (prevention protocol), the superagonist or control antibody was applied on days 1, 5, and 9. Superagonist increased regulatory T cells in circulation and placenta from 8.49±2.09% of CD4-positive T cells to 23.50±3.05% and from 3.85±1.45% to 23.27±7.64%, respectively. Blood pressure and albuminuria (30.6±15.1 versus 14.6±5.5 mg/d) were similar in the superagonist or control antibody-treated preeclamptic group for both protocols. Rats treated with CD28 superagonist showed increased pup weights in the prevention protocol (2.66±0.03 versus 2.37±0.05 g) and in the treatment protocol (3.04±0.04 versus 2.54±0.1 g). Intrauterine growth retardation, calculated by brain:liver weight ratio, was also decreased by the superagonist in both protocols. Further analysis of brain development revealed a 20% increase in brain volume by the superagonist. Induction of regulatory T cells in the circulation and the uteroplacental unit in an established preeclamptic rat model had no influence on maternal hypertension and proteinuria. However, it substantially improved fetal outcome by ameliorating intrauterine growth retardation., (© 2015 American Heart Association, Inc.)

The renin-angiotensin (Ang) system is important during placental development. Dysregulation of the renin-Ang system is important in preeclampsia (PE). Female rats transgenic for the human angiotensinogen gene crossed with males transgenic for the human renin gene develop the PE syndrome, whereas those of the opposite cross do not. We used this model to study the role of Ang II in trophoblast invasion, which is shallow in human PE but deeper in this model. We investigated the following groups: PE rats, opposite-cross rats, Ang II-infused rats (1000 ng/kg per day), and control rats. Ang II infusion increased only circulating Ang II levels (267.82 pg/mL), opposite cross influenced only uteroplacental Ang II (13.52 fmol/mg of protein), and PE increased both circulating (251.09 pg/mL) and uteroplacental (19.24 fmol/mg of protein) Ang II. Blood pressure and albuminuria occurred in the models with high circulating Ang II but not in the other models. Trophoblast invasion increased in PE and opposite-cross rats but not in Ang II-infused rats. Correspondingly, uterine artery resistance index increased in Ang II-infused rats but decreased in PE rats. We then studied human trophoblasts and villous explants from first-trimester pregnancies with time-lapse microscopy. Local Ang II dose-dependently increased migration by 75%, invasion by 58%, and motility by 282%. The data suggest that local tissue Ang II stimulates trophoblast invasion in vivo in the rat and in vitro in human cells, a hitherto fore unrecognized function. Conceivably, upregulation of tissue Ang II in the maternal part of the placenta represents an important growth factor for trophoblast invasion and migration.

Background: The human placenta, a tissue with a lifespan limited to the period of pregnancy, is exposed to varying shear rates by maternal blood perfusion depending on the stage of development. In this study, we aimed to investigate the effects of fluidic shear stress on the human trophoblast transcriptome and metabolism. Results: Based on a trophoblast cell line cultured in a fluidic flow system, changes caused by shear stress were analyzed and compared to static conditions. RNA sequencing and bioinformatics analysis revealed an altered transcriptome and enriched gene ontology terms associated with amino acid and mitochondrial metabolism. A decreased GLUT1 expression and reduced glucose uptake, together with downregulated expression of key glycolytic rate-limiting enzymes, hexokinase 2 and phosphofructokinase 1 was observed. Altered mitochondrial ATP levels and mass spectrometry data, suggested a shift in energy production from glycolysis towards mitochondrial oxidative phosphorylation. This shift in energy production could be supported by increased expression of glutamic-oxaloacetic transaminase variants in response to shear stress as well as under low glucose availability or after silencing of GLUT1. The shift towards amino acid metabolic pathways could be supported by significantly altered amino acid levels, like glutamic acid, cysteine and serine. Downregulation of GLUT1 and glycolytic rate-limiting enzymes, with concomitant upregulation of glutamic-oxaloacetic transaminase 2 was confirmed in first trimester placental explants cultured under fluidic flow. In contrast, high fluid shear stress decreased glutamic-oxaloacetic transaminase 2 expression in term placental explants when compared to low flow rates. Placental tissue from pregnancies with intrauterine growth restriction are exposed to high shear rates and showed also decreased glutamic-oxaloacetic transaminase 2, while GLUT1 was unchanged and glycolytic rate-limiting enzymes showed a trend to be upregulated. The results were generated by using qPCR, immunoblots, quantification of immunofluorescent pictures, padlock probe hybridization, mass spectrometry and FRET-based measurement. Conclusion: Our study suggests that onset of uteroplacental blood flow is accompanied by a shift from a predominant glycolytic- to an alternative amino acid converting metabolism in the villous trophoblast. Rheological changes with excessive fluidic shear stress at the placental surface, may disrupt this alternative amino acid pathway in the syncytiotrophoblast and could contribute to intrauterine growth restriction. [ABSTRACT FROM AUTHOR]

The placenta is a temporary organ with a unique structure and function to ensure healthy fetal development. Placental dysfunction is involved in pre-eclampsia (PE), fetal growth restriction, preterm birth, and gestational diabetes mellitus (GDM). A diabetic state affects maternal and fetal health and may lead to functional alterations of placental metabolism, inflammation, hypoxia, and weight, amplifying the fetal stress. The placental molecular adaptations to the diabetic environment and the adaptive spatio–temporal consequences to elevated glucose or insulin are largely unknown (2). We aimed to identify gene expression signatures related to the diabetic placental pathology of placentas from women with diabetes mellitus. Human placenta samples (n = 77) consisting of healthy controls, women with either gestational diabetes mellitus (GDM), type 1 or type 2 diabetes, and women with GDM, type 1 or type 2 diabetes and superimposed PE were collected. Interestingly, gene expression differences quantified by total RNA sequencing were mainly driven by fetal sex rather than clinical diagnosis. Association of the principal components with a full set of clinical patient data identified fetal sex as the single main explanatory variable. Accordingly, placentas complicated by type 1 and type 2 diabetes showed only few differentially expressed genes, while possible effects of GDM and diabetic pregnancy complicated by PE were not identifiable in this cohort. We conclude that fetal sex has a prominent effect on the placental transcriptome, dominating and confounding gene expression signatures resulting from diabetes mellitus in settings of well-controlled diabetic disease. Our results support the notion of placenta as a sexual dimorphic organ. [ABSTRACT FROM AUTHOR]

Intrauterine growth restriction (IUGR) is a condition whereby a fetus is unable to achieve its genetically determined potential size. IUGR is a global health challenge due to high mortality and morbidity amongst affected neonates. It is a multifactorial condition caused by maternal, fetal, placental, and genetic confounders. Babies born of diabetic pregnancies are usually large for gestational age but under certain conditions whereby prolonged uncontrolled hyperglycemia leads to placental dysfunction, the outcome of the pregnancy is an intrauterine growth restricted fetus with clinical features of malnutrition. Placental dysfunction leads to undernutrition and hypoxia, which triggers gene modification in the developing fetus due to fetal adaptation to adverse utero environmental conditions. Thus, in utero gene modification results in future cardiovascular programming in postnatal and adult life. Ongoing research aims to broaden our understanding of the molecular mechanisms and pathological pathways involved in fetal programming due to IUGR. There is a need for the development of effective preventive and therapeutic strategies for the management of growth-restricted infants. Information on the mechanisms involved with in utero epigenetic modification leading to development of cardiovascular disease in adult life will increase our understanding and allow the identification of susceptible individuals as well as the design of targeted prevention strategies. This article aims to systematically review the latest molecular mechanisms involved in the pathogenesis of IUGR in cardiovascular programming. Animal models of IUGR that used nutrient restriction and hypoxia to mimic the clinical conditions in humans of reduced flow of nutrients and oxygen to the fetus will be discussed in terms of cardiac remodeling and epigenetic programming of cardiovascular disease. Experimental evidence of long-term fetal programming due to IUGR will also be included. [ABSTRACT FROM AUTHOR]