Sodium dichloroacetate stimulates cardiac mitochondrial metabolism and improves cardiac conduction in the ovine fetus during labor.

Previous studies in our laboratory have suggested that the increase in stillbirth in pregnancies complicated by chronic maternal stress or hypercortisolemia is associated with cardiac dysfunction in late stages of labor and delivery. Transcriptomics analysis of the overly represented differentially expressed genes in the fetal heart of hypercortisolemic ewes indicated involvement of mitochondrial function. Sodium dichloroacetate (DCA) has been used to improve mitochondrial function in several disease states. We hypothesized that administration of DCA to laboring ewes would improve both cardiac mitochondrial activity and cardiac function in their fetuses. Four groups of ewes and their fetuses were studied: control, cortisol-infused (1 g/kg/day from 115 to term; CORT), DCA-treated (over 24 h), and DCA + CORT-treated; oxytocin was delivered starting 48 h before the DCA treatment. DCA significantly decreased cardiac lactate, alanine, and glucose/glucose-6-phosphate and increased acetylcarnitine/isobutyryl-carnitine. DCA increased mitochondrial activity, increasing oxidative phosphorylation (PCI, PCI + II) per tissue weight or per unit of citrate synthase. DCA also decreased the duration of the QRS, attenuating the prolongation of the QRS observed in CORT fetuses. The effect to reduce QRS duration with DCA treatment correlated with increased glycerophosphocholine and serine and decreased phosphorylcholine after DCA treatment. There were negative correlations of acetylcarnitine/isobutyryl-carnitine to both heart rate (HR) and mean arterial pressure (MAP). These results suggest that improvements in mitochondrial respiration with DCA produced changes in the cardiac lipid metabolism that favor improved conduction in the heart. DCA may therefore be an effective treatment of fetal cardiac metabolic disturbances in labor that can contribute to impairments of fetal cardiac conduction.

Intraamniotic digoxin administration versus intracardiac or funic potassium chloride administration to induce foetal demise before termination of pregnancy: a prospective study.

Different foeticide techniques and pharmacological agents have been used to achieve foetal asystole. This study aimed to compare the success of intraamniotic digoxin, intracardiac potassium chloride (KCl), and funic KCl in achieving foetal asystole and discuss procedural difficulties for physicians and clinical outcomes. This prospective observational study included 124 patients who received foeticide at 22-31 weeks of gestation. All procedures were performed transabdominally, and 1 mg of intraamniotic digoxin, funic KCl, or intracardiac KCl was administered. Procedure times, procedural difficulty scores, patient pain scores, decrease in haematocrit levels, induction and hospitalisation times, and the presence of chorioamnionitis were recorded. The foeticide success rates were 93.0, 95.1, and 97.5% for intraamniotic digoxin, intracardiac KCl, and funic KCl, respectively. Intraamniotic digoxin was associated with shorter procedure times, lower procedural difficulty scores, and lower patient pain scores (p < 0.001). Decreases in haematocrit, induction times, and chorioamnionitis were similar in all three procedures. Success rates and clinical results were similar for all three procedures. Foeticide with intra-amniotic digoxin has a high success rate, the procedure is easier to perform, and patients experience less procedural pain.IMPACT STATEMENTWhat is already known on this subject? Different foeticide techniques and pharmacological agents have been used to achieve foetal asystole. Pharmacological agents used in the foeticide procedure can be injected as intracardiac, funic, intrafetal, or intraamniotic, and the most commonly used are potassium chloride (KCl), digoxin, and lidocaine.What do the results of this study add? The success rates and clinical outcomes in achieving foetal asystole are similar for intracardiac KCl, funic KCl, and intra-amniotic digoxin procedures. Foeticide with intra-amniotic digoxin is less difficult to perform, and patients experience less pain associated with the procedure. All three techniques appear to be safe and have similar short-term obstetric outcomes.What are the implications of these findings for clinical practice and/or further research? Physicians may prefer foeticide with intra-amniotic digoxin as the procedure is technically simpler and has similar success rates to intracardiac or funic KCl administration. A prospective randomised study could better compare the advantages and limitations of the foeticide techniques.

Antenatal betamethasone redistributes central blood flows and preferentially augments right ventricular output and pump function in preterm fetal lambs.

The glucocorticosteroid betamethasone, which is routinely administered prior to anticipated preterm birth to enhance maturation of the lungs and the cardiovascular system, has diverse fetal regional blood flow effects ranging from increased pulmonary flow to decreased cerebral flow. The aim of this study was to test the hypothesis that these diverse effects reflect alterations in major central flow patterns that are associated with complementary shifts in left ventricular (LV) and right ventricular (RV) pumping performance. Studies were performed in anesthetized preterm fetal lambs (gestation = 127 ± 1 days, term = 147 days) with (n = 14) or without (n = 12) preceding betamethasone treatment via maternal intramuscular injection. High-fidelity central arterial blood pressure and flow signals were obtained to calculate LV and RV outputs and total hydraulic power. Betamethasone therapy was accompanied by 1) increased RV, but not LV, output; 2) a greater RV than LV increase in total power; 3) a redistribution of LV output away from the fetal upper body region and toward the lower body and placenta; 4) a greater proportion of RV output passing to the lungs, and a lesser proportion to the lower body and placenta; and 5) a change in the relative contribution of venous streams to ventricular filling, with the LV having increased pulmonary venous and decreased foramen ovale components, and the RV having lesser superior vena caval and greater inferior vena caval portions. Taken together, these findings suggest that antenatal betamethasone produces a widespread redistribution of central arterial and venous flows in the fetus, accompanied by a preferential rise in RV pumping performance.

Agrin Yes-associated Protein Promotes the Proliferation of Epicardial Cells.

ABSTRACT: Embryonic epicardial cells make an important contribution to cardiac development. However, their proliferation mechanism is still unclear. Epicardial cells from E12.5 fetal hearts were used in our study. Agrin was used to treat these cells. The expression of Aurora B, Ki67, and pH3 was measured by quantitative reverse transcription-polymerase chain reaction and immunofluorescence. The proportion of cells in G1/S/G2 phase was determined by flow cytometry. The results showed that agrin significantly increased the expression of ki67, pH3, and Aurora B in epicardial cells. Flow cytometry results showed that agrin significantly increased the proportion of epicardial cells in S phase. However, blocking yes-associated protein significantly downregulated the levels of ki67, pH3, and Aurora B and the proportion of epicardial cells in S phase. Thus, our results suggest that agrin may promote the proliferation of epicardial cells by regulating the yes-associated protein activity. This may be useful in exploring heart development mechanisms and preventing congenital heart disease.

Phosphodiesterases Expression during Murine Cardiac Development.

3'-5' cyclic nucleotide phosphodiesterases (PDEs) are a large family of enzymes playing a fundamental role in the control of intracellular levels of cAMP and cGMP. Emerging evidence suggested an important role of phosphodiesterases in heart formation, but little is known about the expression of phosphodiesterases during cardiac development. In the present study, the pattern of expression and enzymatic activity of phosphodiesterases was investigated at different stages of heart formation. C57BL/6 mice were mated and embryos were collected from 14.5 to 18.5 days of development. Data obtained by qRT-PCR and Western blot analysis showed that seven different isoforms are expressed during heart development, and PDE1C, PDE2A, PDE4D, PDE5A and PDE8A are modulated from E14.5 to E18.5. In heart homogenates, the total cAMP and cGMP hydrolytic activity is constant at the evaluated times, and PDE4 accounts for the majority of the cAMP hydrolyzing ability and PDE2A accounts for cGMP hydrolysis. This study showed that a subset of PDEs is expressed in developing mice heart and some of them are modulated to maintain constant nucleotide phosphodiesterase activity in embryonic and fetal heart.

Fetal ovine skeletal and cardiac muscle transcriptomics are differentially altered by increased maternal cortisol during gestation.

We have previously found that in utero exposure to excess maternal cortisol (1 mg/kg/day) in late gestation increases the incidence of stillbirth during labor and produces fetal bradycardia at birth. In the interventricular septum, mitochondrial DNA (mt-DNA) was decreased, and transcriptomics and metabolomics were consistent with altered mitochondrial metabolism. The present study uses transcriptomics to model effects of increased maternal cortisol on fetal biceps femoris. Transcriptomic modeling revealed that pathways related to mitochondrial metabolism were downregulated, whereas pathways for regulation of reactive oxygen species and activation of the apoptotic cascade were upregulated. Mt-DNA and the protein levels of cytochrome C were significantly decreased in the biceps femoris. RT-PCR validation of the pathways confirmed a significant decrease in SLC2A4 mRNA levels and a significant increase in PDK4, TXNIP, ANGPTL4 mRNA levels, suggesting that insulin sensitivity of the biceps femoris muscle may be reduced in cortisol offspring. We also tested for changes in gene expression in diaphragm by rt-PCR. PDK4, TXNIP, and ANGPTL4 mRNA were also increased in the diaphragm, but SLC2A4, cytochrome C protein, and mt-DNA were unchanged. Comparison of the change in gene expression in biceps femoris to that in cardiac interventricular septum and left ventricle showed few common genes and little overlap in specific metabolic or signaling pathways, despite reduction in mt-DNA in both heart and biceps femoris. Our results suggest that glucocorticoid exposure alters expression of nuclear genes important to mitochondrial activity and oxidative stress in both cardiac and skeletal muscle tissues, but that these effects are tissue-specific.

Effects of antenatal dexamethasone and hyperglycemia on cardiovascular adaptation to asphyxia in preterm fetal sheep.

Antenatal glucocorticoids improve outcomes among premature infants but are associated with hyperglycemia, which can exacerbate hypoxic-ischemic injury. It is still unclear how antenatal glucocorticoids or hyperglycemia modulate fetal cardiovascular adaptations to severe asphyxia. In this study, preterm fetal sheep received either saline or 12 mg im maternal dexamethasone, followed 4 h later by complete umbilical cord occlusion (UCO) for 25 min. An additional cohort of fetuses received titrated glucose infusions followed 4 h later by UCO to control for the possibility that hyperglycemia contributed to the cardiovascular effects of dexamethasone. Fetuses were studied for 7 days after UCO. Maternal dexamethasone was associated with fetal hyperglycemia (P < 0.001), increased arterial pressure (P < 0.001), and reduced femoral (P < 0.005) and carotid (P < 0.05) vascular conductance before UCO. UCO was associated with bradycardia, femoral vasoconstriction, and transient hypertension. For the first 5 min of UCO, fetal blood pressure in the dexamethasone-asphyxia group was greater than saline-asphyxia (P < 0.001). However, the relative increase in arterial pressure was not different from saline-asphyxia. Fetal heart rate and femoral vascular conductance fell to similar nadirs in both saline and dexamethasone-asphyxia groups. Dexamethasone did not affect the progressive decline in femoral vascular tone or arterial pressure during continuing UCO. By contrast, there were no effects of glucose infusions on the response to UCO. In summary, maternal dexamethasone but not fetal hyperglycemia increased fetal arterial pressure before and for the first 5 min of prolonged UCO but did not augment the cardiovascular adaptations to acute asphyxia.

Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience.

OBJECTIVES: To describe a single institutional experience managing fetuses with supraventricular tachycardia (SVT) and to identify associations between patient characteristics and fetal and postnatal outcomes. BACKGROUND: Sustained fetal SVT is associated with significant morbidity and mortality if untreated, yet the optimal management strategy remains unclear. METHODS: Retrospective cohort study including fetuses diagnosed with sustained SVT (>50% of the diagnostic echocardiogram) between 1985 and 2018. Fetuses with congenital heart disease were excluded. RESULTS: Sustained SVT was diagnosed in 65 fetuses at a median gestational age of 30 weeks (range, 14-37). Atrioventricular re-entrant tachycardia and atrial flutter were the most common diagnoses, seen in 41 and 16 cases, respectively. Moderate/severe ventricular dysfunction was present in 20 fetuses, and hydrops fetalis was present in 13. Of the 57 fetuses initiated on transplacental drug therapy, 47 received digoxin first-line, yet 39 of 57 (68%) required advanced therapy with sotalol, flecainide, or amiodarone. Rate or rhythm control was achieved in 47 of 57 treated fetuses. There were no cases of intrauterine fetal demise. Later gestational age at fetal diagnosis (odds ratio [OR], 1.1, 95% confidence interval [CI], 1.01-1.2, P = .02) and moderate/severe fetal ventricular dysfunction (OR, 6.1, 95% CI, 1.7-21.6, P = .005) were associated with postnatal SVT. Two postnatal deaths occurred. CONCLUSIONS: Fetuses with structurally normal hearts and sustained SVT can be effectively managed with transplacental drug therapy with minimal risk of intrauterine fetal demise. Treatment requires multiple antiarrhythmic agents in over half of cases. Later gestational age at fetal diagnosis and the presence of depressed fetal ventricular function, but not hydrops, predict postnatal arrhythmia burden.

Early L-T4 intervention improves fetal heart development in pregnant rats with subclinical hypothyroidism rats by activating BMP4/Smad4 signaling pathway.

BACKGROUND: It is unclear whether the offspring of subclinical hypothyroidism (SCH) pregnant rats still have abnormal cardiac development, and whether early intervention with L-T4 can improve the abnormality of these offspring. Therefore, the aim of this study was to investigate the effect of early L-T4 intervention on the heart development of offspring of SCH pregnant rats and its possible molecular mechanism. METHODS: Eighty female Wistar rats were randomly divided into Sham group (placebo control), SCH group, LT4-E10 group (L-T4 treatment started on the 10th day of gestation), and LT4-E13 group (L-T4 treatment started on the 13th day of gestation). Each group was further divided into E16 (16th day of gestation), E18 (18th day of gestation), P5 (5th day postnatal day), and P10 (10th day postnatal day) subgroups. The levels of serum TT4 and TSH, the ratio of heart weight to body weight of offspring rats, the expression of metabolic enzymes, and the histopathology of cardiomyocytes were determined. To elucidate the effects of L-T4 on cardiac development of offspring of SCH pregnant rats, the expression levels of GATA4, Nkx2-5 and proteins involved in BMP4/Smad4 signaling pathway were detected by immunohistochemistry, real time quantitative polymerase chain reaction and Western blotting to elucidate the molecular mechanism of L-T4 regulating the heart development of the offspring of SCH pregnant rats. RESULTS: Compared with Sham group, serum TSH was significantly increased in SCH pregnant rats. Moreover, early L-T4 intervention significantly reduced the levels of serum TSH. Compared with the offspring in the SCH group, early L-T4 intervention significantly increased the heart weight, heart weight to body weight ratio, the activities of succinate dehydrogenase (SDH), Na+/K+-ATPase and Ca2+-ATPase, but reduced myocardial cell shrinkage and nuclear staining, hyperemia/congestion and vacuolar degeneration. In addition, early L-T4 intervention not only significantly increased the mRNA and protein expression of Gata4 and Nkx2-5, but also increased the protein expression involved in BMP4/Smad4 signal pathway in myocardium of the offspring of SCH pregnant rats. CONCLUSIONS: Early L-T4 intervention can regulate the cardiac development of the offspring of SCH pregnant rats by activating BMP4/Smad4 signaling pathway and increasing the expression of Gata4 and Nkx2-5 proteins.

Research into the intervention effect of folic acid on arsenic-induced heart abnormalities in fetal rats during the periconception period.

BACKGROUND: The incidence of CHD is the highest among birth defects and is increasing year to year. CHD seriously harms the health of infants and young children and presents a large economic burden to families and society. The pathogenesis of CHD and preventive measures are the focus of current research. Our research aimed to explore the intervention effect of folic acid on heart abnormalities resulting from sodium arsenic (NaAsO2) exposure during the periconception period. METHODS: Sixty 35-day-old female SD rats were randomly divided into 5 groups with 12 rats in each group. Group A was the control group. The rats were given distilled water and ordinary chow. The rats in group B were given distilled water containing 75 mg/L NaAsO2 and ordinary chow. The rats in groups C, D, and E were given distilled water containing 75 mg/L NaAsO2 and chow containing 0.53 mg/kg, 5.3 mg/kg, and 10.6 mg/kg folic acid, respectively. The general condition of the embryos and the histopathology of the embryonic hearts were examined. The acetylation levels of histone H3K9 in heart tissues and the expression levels of Mef2C (which is related to heart development) were observed. RESULTS: The embryo weight and placental weight of groups B-E were significantly lower than those of group A (P < 0.05). The heart malformation rate of the fetal rats in groups B-E was significantly higher than that of the fetal rats in group A (P < 0.05). We found that the level of H3K9 acetylation in fetal rat cardiomyocytes in groups B-E was significantly higher than that in group A (P < 0.05) and that the level of H3K9 acetylation in groups C-E was lower than that in group B (P < 0.05). The mRNA level of Mef2C in fetal rat cardiomyocytes in group B-E was significantly higher than that in group A (P < 0.05), and the mRNA level of Mef2C in groups C-E was significantly lower than that in group B (P < 0.05). CONCLUSION: Supplementation with folic acid during the periconception period can interfere with the toxic effects of arsenic on the heart. The mechanism may be that lowering the acetylation levels of histone H3K9 in heart tissues leads to decreased expression levels of Mef2C, which may play a protective role in heart development in fetal rats.

Drug exposure during pregnancy and fetal cardiac function - a systematic review.

Background The aim of this systematic review was to describe the effects of drug exposure during pregnancy on fetal cardiac function. Methods We searched MEDLINE, Embase, Cochrane and SCOPUS for studies assessing fetal cardiac function in drug-exposed human pregnancies. Risk of bias was assessed by the Risk Of Bias In Non-randomized Studies of Interventions (ROBIN-I) tool. Results We included 32 studies on eight different drug groups. They included 51 outcome variables, which were all based on ultrasound techniques primarily assessing systolic function: pulsed wave Doppler, tissue Doppler imaging (TDI), and B- and M-mode. Overall, the risk of bias was moderate. ß2 agonists increased the systolic velocity in the ductus arteriosus and the fetal heart rate. ß-blockers caused unchanged or decreased systolic velocity of the pulmonary trunk. Corticosteroids increased the velocity in the ductus arteriosus. Furthermore, in growth-restricted fetuses with an increased myocardial performance index (MPI') on the right side, corticosteroids normalized this variable. Nonsteroidal anti-inflammatory drugs (NSAIDs), but not acetylsalicylic acid, increased the flow velocities in the ductus arteriosus, decreased the shortening fraction and increased the end-diastolic ventricular diameters. Metformin and insulin normalized the diastolic strain and global longitudinal strain in diabetic pregnancies. Highly active antiretroviral therapy (HAART) exposure increased the E/A ratio on the right side, prolonged the isovolumic relaxation time (IRT) and ejection time, shortened the isovolumic contraction time (ICT), and decreased left myocardial systolic peak velocities. Chemotherapy did not cause detectable changes. Conclusion Six of the eight drug groups caused detectable changes in fetal cardiac function. However, the evidence was hampered by only a few studies for some drugs.

Effects of nifedipine on fetal cardiac function in preterm labor.

Objectives To evaluate the effects of nifedipine treatment on fetal hemodynamics and cardiac function during preterm labor. This prospective study assessed several quantitative parameters of fetal cardiac circulation and function, and found no significant changes at 48 h after nifedipine treatment. These findings suggest that tocolytic nifedipine may be safe for fetuses. It supports clinicians to use nifedipine treatment for tocolysis without any cardiac effect on the fetus. Methods A prospective cohort study was conducted at a tertiary hospital between January 2016 and October 2017. A total of 45 pregnant women who required nifedipine for preterm labor were included in this study. Fetal Doppler ultrasound was performed and fetal systolic and diastolic function was measured prior to, and 48 h after, the first nifedipine treatment. Conventional Doppler parameters were used to evaluate fetal heart function and hemodynamic changes. Tricuspid annular plane systolic excursion, mitral annular plane systolic excursion and the sphericity index were also evaluated to assess changes in fetal cardiac morphology. Results No significant changes in fetal Doppler parameters were observed following nifedipine tocolysis. There was no significant difference in the fetal cardiac function parameters of both ventricles before vs. after nifedipine treatment. Tricuspid annular plane systolic excursion, mitral annular plane systolic excursion, and sphericity index values were unchanged following nifedipine treatment. Conclusions Oral administration of nifedipine did not to alter fetal cardiac function or morphology. Fetal cardiac parameters and various Doppler indices were unchanged following nifedipine treatment. Maternal nifedipine treatment does not appear to have any significant effect on fetal cardiac function.

Chronic maternal cortisol excess during late gestation leads to metabolic alterations in the newborn heart.

Our laboratory has previously shown in an ovine model of pregnancy that abnormal elevations in maternal cortisol during late gestation lead to increased fetal cardiac arrhythmias and mortality during peripartum. Furthermore, transcriptomic analysis of the fetal heart suggested alterations in TCA cycle intermediates and lipid metabolites in animals exposed to excess cortisol in utero. Therefore, we utilized a sheep model of pregnancy to determine how chronic increases in maternal cortisol alter maternal and fetal serum before birth and neonatal cardiac metabolites and lipids at term. Ewes were either infused with 1 mg·kg-1·day-1 of cortisol starting at gestational day 115 ( n = 9) or untreated ( n = 6). Serum was collected from the mother and fetus (gestational day 125), and hearts were collected following birth. Proton nuclear magnetic resonance (1H-NMR) spectroscopy was conducted to measure metabolic profiles of newborn heart specimens as well as fetal and maternal serum specimens. Mass spectrometry was conducted to measure lipid profiles of newborn heart specimens. We observed alterations in amino acid and TCA cycle metabolism as well as lipid and glycerophospholipid metabolism in newborn hearts after excess maternal cortisol in late gestation. In addition, we observed alterations in amino acid and TCA cycle metabolites in fetal but not in maternal serum during late gestation. These results suggest that fetal exposure to excess maternal cortisol alters placental and fetal metabolism before birth and limits normal cardiac metabolic maturation, which may contribute to increased risk of peripartum cardiac arrhythmias observed in these animals or later life cardiomyopathies.

Mechanisms of in utero cortisol effects on the newborn heart revealed by transcriptomic modeling.

We have identified effects of elevated maternal cortisol (induced by maternal infusion 1 mg·kg-1·day-1) on fetal cardiac maturation and function using an ovine model. Whereas short-term exposure (115-130-day gestation) increased myocyte proliferation and Purkinje fiber apoptosis, infusions until birth caused bradycardia with increased incidence of arrhythmias at birth and increased perinatal death, despite normal fetal cortisol concentrations from 130 days to birth. Statistical modeling of the transcriptomic changes in hearts at 130 and 140 days suggested that maternal cortisol excess disrupts cardiac metabolism. In the current study, we modeled pathways in the left ventricle (LV) and interventricular septum (IVS) of newborn lambs after maternal cortisol infusion from 115 days to birth. In both LV and IVS the transcriptomic model indicated over-representation of cell cycle genes and suggested disruption of cell cycle progression. Pathways in the LV involved in cardiac architecture, including SMAD and bone morphogenetic protein ( BMP) were altered, and collagen deposition was increased. Pathways in IVS related to metabolism, calcium signaling, and the actin cytoskeleton were altered. Comparison of the effects of maternal cortisol excess to the effects of normal maturation from day 140 to birth revealed that only 20% of the genes changed in the LV were consistent with normal maturation, indicating that chronic elevation of maternal cortisol alters normal maturation of the fetal myocardium. These effects of maternal cortisol on the cardiac transcriptome, which may be secondary to metabolic effects, are consistent with cardiac remodeling and likely contribute to the adverse impact of maternal stress on perinatal cardiac function.

ROS promote epigenetic remodeling and cardiac dysfunction in offspring following maternal engineered nanomaterial (ENM) exposure.

BACKGROUND: Nano-titanium dioxide (nano-TiO2) is amongst the most widely utilized engineered nanomaterials (ENMs). However, little is known regarding the consequences maternal ENM inhalation exposure has on growing progeny during gestation. ENM inhalation exposure has been reported to decrease mitochondrial bioenergetics and cardiac function, though the mechanisms responsible are poorly understood. Reactive oxygen species (ROS) are increased as a result of ENM inhalation exposure, but it is unclear whether they impact fetal reprogramming. The purpose of this study was to determine whether maternal ENM inhalation exposure influences progeny cardiac development and epigenomic remodeling. RESULTS: Pregnant FVB dams were exposed to nano-TiO2 aerosols with a mass concentration of 12.09 ± 0.26 mg/m3 starting at gestational day five (GD 5), for 6 h over 6 non-consecutive days. Aerosol size distribution measurements indicated an aerodynamic count median diameter (CMD) of 156 nm with a geometric standard deviation (GSD) of 1.70. Echocardiographic imaging was used to assess cardiac function in maternal, fetal (GD 15), and young adult (11 weeks) animals. Electron transport chain (ETC) complex activities, mitochondrial size, complexity, and respiration were evaluated, along with 5-methylcytosine, Dnmt1 protein expression, and Hif1α activity. Cardiac functional analyses revealed a 43% increase in left ventricular mass and 25% decrease in cardiac output (fetal), with an 18% decrease in fractional shortening (young adult). In fetal pups, hydrogen peroxide (H2O2) levels were significantly increased (~ 10 fold) with a subsequent decrease in expression of the antioxidant enzyme, phospholipid hydroperoxide glutathione peroxidase (GPx4). ETC complex activity IV was decreased by 68 and 46% in fetal and young adult cardiac mitochondria, respectively. DNA methylation was significantly increased in fetal pups following exposure, along with increased Hif1α activity and Dnmt1 protein expression. Mitochondrial ultrastructure, including increased size, was observed at both fetal and young adult stages following maternal exposure. CONCLUSIONS: Maternal inhalation exposure to nano-TiO2 results in adverse effects on cardiac function that are associated with increased H2O2 levels and dysregulation of the Hif1α/Dnmt1 regulatory axis in fetal offspring. Our findings suggest a distinct interplay between ROS and epigenetic remodeling that leads to sustained cardiac contractile dysfunction in growing and young adult offspring following maternal ENM inhalation exposure.

Magnetocardiographic identification of prolonged fetal corrected QT interval in women receiving treatment for opioid use disorder.

AIM: Pregnant women undergoing treatment for opioid use disorder (OUD) may be exposed to multiple QT prolonging agents. We used magnetocardiography to measure fetal QT intervals in mothers with OUD on buprenorphine therapy. METHODS: Fetal and maternal magnetocardiography was performed in pregnant women receiving buprenorphine-assisted treatment (Disorder group); these were matched by gestational age to pregnant women who were opiate naïve (Reference group). Corrected QT intervals were determined using Bazett's formula and compared between groups. RESULTS: A total of eight women in the Disorder group matched to eight in the Reference group. Seven of the mothers (88%) in the Disorder group were smokers; there were no smokers in the Reference group. The average fetal corrected QT was significantly longer (P = 0.022) in the Disorder group than that in the Reference group (505 milliseconds [ms] ± 68.6 [standard deviation] vs 383 ms ± 70.3 [standard deviation]). CONCLUSION: Novel data from this small sample demonstrate prolongation of fetal corrected QT in women with OUD participating in buprenorphine assisted therapy. Additional investigation from a larger sample is needed to clarify if fetal buprenorphine and/or tobacco exposure is associated with changes in fetal QT which would warrant further prenatal and postnatal testing.

Maternal engineered nanomaterial inhalation during gestation alters the fetal transcriptome.

BACKGROUND: The integration of engineered nanomaterials (ENM) is well-established and widespread in clinical, commercial, and domestic applications. Cardiovascular dysfunctions have been reported in adult populations after exposure to a variety of ENM. As the diversity of these exposures continues to increase, the fetal ramifications of maternal exposures have yet to be determined. We, and others, have explored the consequences of ENM inhalation during gestation and identified many cardiovascular and metabolic outcomes in the F1 generation. The purpose of these studies was to identify genetic alterations in the F1 generation of Sprague-Dawley rats that result from maternal ENM inhalation during gestation. Pregnant dams were exposed to nano-titanium dioxide (nano-TiO2) aerosols (10 ± 0.5 mg/m3) for 7-8 days (calculated, cumulative lung deposition = 217 ± 1 µg) and on GD (gestational day) 20 fetal hearts were isolated. DNA was extracted and immunoprecipitated with modified chromatin marks histone 3 lysine 4 tri-methylation (H3K4me3) and histone 3 lysine 27 tri-methylation (H3K27me3). Following chromatin immunoprecipitation (ChIP), DNA fragments were sequenced. RNA from fetal hearts was purified and prepared for RNA sequencing and transcriptomic analysis. Ingenuity Pathway Analysis (IPA) was then used to identify pathways most modified by gestational ENM exposure. RESULTS: The results of the sequencing experiments provide initial evidence that significant epigenetic and transcriptomic changes occur in the cardiac tissue of maternal nano-TiO2 exposed progeny. The most notable alterations in major biologic systems included immune adaptation and organismal growth. Changes in normal physiology were linked with other tissues, including liver and kidneys. CONCLUSIONS: These results are the first evidence that maternal ENM inhalation impacts the fetal epigenome.

The effect of maternal exposure to di-(2-ethylhexyl)-phthalate on fetal cardiac development in mice.

Accumulating evidence has suggested a link between maternal di-(2-ethylhexyl)-phthalate (DEHP) exposure and various developmental abnormalities. However, the evidence regarding the effect of maternal DEHP exposure on fetal cardiac development is scarce. The present study aimed to determine the effect of maternal DEHP exposure on fetal cardiac development in mice and explore the possible involved mechanism preliminarily. The C57BL mice were randomly divided into four groups: the vehicle group (corn oil, n = 10), 250 mg kg-1 DEHP group (n = 15), 500 mg kg-1 DEHP group (n = 20) and 1 g kg-1 DEHP group (n = 20). Pregnant dams in different group received respective intervention by gavage once daily from embryonic day (E)6.5 to E14.5. Maternal weights were monitored every day and samples were collected at E15.5. Hematoxylin and eosin staining was used to examine fetal cardiac malformations. Real-time quantitative polymerase chain reaction and western blot were applied to detect peroxisome proliferator-activated receptor (PPAR)α/PPARγ/Nkx2.5/Gata4/Tbx5/Mef2c/Chf1 mRNA and protein expression, respectively. Maternal DEHP exposure significantly decreased maternal body weight, fetal weight and placental weight, and remarkably elevated fetal cardiac malformations rate. The phenotypes of cardiac anomalies mainly include septal defects, ventricular myocardium noncompaction and cardiac hypoplasia. Higher doses DEHP (500 mg kg-1 and 1 g kg-1 ) could significantly decreased fetal cardiac Gata4/Mef2c/Chf1 expression, while PPARγ expression was upregulated. Maternal exposure to higher doses of DEHP could result in fetal cardiac development malformations in mice and it might have resulted from the inhibition of cardiac GATA4/Mef2c/Chf1 expression via PPARγ activation.

No histologic evidence of foetal cardiotoxicity following exposure to maternal hydroxychloroquine.

It is currently recommended that hydroxychloroquine (HCQ) be maintained during pregnancy in patients with systemic lupus erythematosus. Recent data suggest that this Toll-like receptor inhibitor may also reduce the recurrence rate of anti-SSA/Ro associated congenital heart block (CHB). This case report describes a unique situation in which a CHB-afflicted, HCQ-exposed pregnancy was electively terminated. The heart did not reveal any characteristic features of cardiotoxicity, providing further evidence supporting the safety of foetal exposure to HCQ.

[Effect of histone acetylation/deacetylation imbalances on key gene of planar cell polarity pathway].

OBJECTIVE: To investigate the effect of histone acetylation/deacetylation imbalances on embryonic hearts of mice and its effect on key genes of planar cell polarity (PCP) pathway-Vangl2, Scrib and Rac1 in H9C2 cells. METHODS: Forty pregnant C57/B6 mice were randomly assigned into three groups: blank group (n=10), vehicle group (n=10), and valproic acid (VPA)-treated group (n=20). In the VPA-treated group, VPA, a histone deacetylase (HDAC) inhibitor, was administered to each individual dam intraperitoneally at a single dose of 700 mg/kg on embryonic day 10.5 (E10.5). The vehicle and blank groups received equivalent saline or no interventions, respectively. Dams were sacrificed on E15.5, and death rates of embryos were evaluated. Subsequently, embryonic hearts of survival fetus were removed to observe cardiac abnormalities by hematoxylin-eosin (HE) staining. H9C2 cells were cultured and allotted to the blank, vehicle, and VPA-treated groups: the VPA treated group received VPA exposure at concentrations of 2.0, 4.0 and 8.0 mmol/L; the vehicle and blank groups received equivalent saline or no interventions, respectively. HDAC1-3 as well as Vangl2, Scrib and Rac1 mRNA and protein expression levels were determined by quantitative real-time PCR and Western blot, respectively. The total HDAC activity was analyzed by colorimetric assay. RESULTS: The fetus mortality rate after VPA treatment was 31.7%, with a significantly higher rate of cardiac abnormalities in comparison with the controls (P<0.05). In comparison with the blank and vehicle groups, HDAC1 mRNA was significantly increased at various concentrations of VPA treatment at all time points of exposure (P<0.05), together with a reduction of protein level after 48 and 72 hours of exposure (P<0.05). The inhibition of HDAC2 mRNA after various concentrations of VPA incubation was pronounced at 24 hours of exposure (P<0.05), while the protein levels were reduced at all time points (P<0.05). HDAC3 mRNA was prominently induced by VPA (4.0 and 8.0 mmol/L) at all time points of treatment (P<0.05). In contrast, the protein level was inhibited after VPA treatment (P<0.05). In comparison with the blank and vehicle groups, Vangl2 mRNA as well as Scrib mRNA/protein expression levels were markedly reduced after 48 and 72 hours of VPA treatment (P<0.05), together with a reduction of protein level in Vangl2 at 72 hours (P<0.05). Compared with the blank and vehicle groups, a significant repression in the total HDAC activity was observed in the VPA-treated group at concentrations of 4.0 and 8.0 mmol/L after 24 hours of treatment (P<0.05), and the effect persisted up to 48 and 72 hours, exhibiting pronounced inhibition at all concentrations (P<0.05). CONCLUSIONS: VPA might result in acetylation/deacetylation imbalances by inhibiting HDAC1-3 protein expression and total HDAC activity, leading to the down-regulation of mRNA and protein expression of Vangl2 and Scrib. This could be one of the mechanisms contributing to congenital heart disease.