Constriction Of Ductus Arteriosus Research Articles

Maternal supplementation with docosahexaenoic acid does not cause constriction of fetal ductus arteriosus: randomized controlled trial.

Docosahexaenoic acid (DHA) is recommended routinely in pregnancy to promote fetal development. DHA has anti-inflammatory activity, but its effects on the fetal heart and circulation are unknown. This study aimed to investigate whether maternal DHA supplementation in the third trimester affects maternal prostaglandin levels and fetal ductus arteriosus flow dynamics. This was a double-blind randomized controlled trial with parallel groups conducted between 2018 and 2021. Pregnant women aged over 18 years with a normal fetus at 27-28 weeks' gestation showing no cardiac/extracardiac anomalies or ductal constriction were eligible for the trial. Women consuming substances with a known inhibitory effect on prostaglandin metabolism, such as non-steroidal anti-inflammatory drugs and polyphenol-rich foods, were excluded. The intervention group received oral supplementation of omega-3 with 450 mg/day of DHA for 8 weeks and the placebo group received capsules of soy lecithin for 8 weeks. Anthropometric measurements, assessment of polyphenol and omega-3 consumption, fetal morphological ultrasound examination, fetal Doppler echocardiographic examination and blood sample collection were performed at the start of the study and the latter two were repeated at follow-up. Prostaglandin E2 (PGE2) level and echocardiographic parameters were compared between the intervention and placebo groups and between baseline and follow-up. A total of 24 participants were included in each group. After 8 weeks, there were no significant differences between the intervention and placebo groups in maternal serum PGE2 level or Doppler echocardiographic parameters of ductal flow. No case of ductus arteriosus constriction was observed. The expected intragroup changes in cardiac morphology, as a result of advancing gestation, were present. Maternal DHA supplementation in the third trimester at a clinically recommended dose did not result in inhibition of PGE2 or constriction of the ductus arteriosus. These findings should be confirmed in postmarket surveillance studies with larger patient numbers in order to test the full safety profile of DHA and provide robust clinical reassurance. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Excessive maternal iced-tea intake-reversible cause of premature ductus arteriosus constriction

Premature ductus arteriosus constriction is a rare entity associated with high neonatal morbidity and mortality. Most cases are idiopathic, with the major known cause being maternal use of nonsteroidal anti-inflammatory drugs. Polyphenol-rich foods have been proven to have a deleterious fetal hemodynamic effect that can lead to premature ductal constriction. We report a case of a neonate diagnosed with premature ductal arteriosus closure, whose only risk factor was an excessive maternal intake of commercial iced-tea during pregnancy. The authors aim to raise awareness to the impact of polyphenol-rich food consumption on ductus arteriosus, since maternal dietary advice can have a major preventive role. Furthermore, a timely diagnosis and intervention can prevent significant morbidity and mortality.

Discovery and Characterization of VU0542270, the First Selective Inhibitor of Vascular Kir6.1/SUR2B KATP Channels.

Vascular smooth muscle KATP channels critically regulate blood flow and blood pressure by modulating vascular tone and therefore represent attractive drug targets for treating several cardiovascular disorders. However, the lack of potent inhibitors that can selectively inhibit Kir6.1/SUR2B (vascular KATP) over Kir6.2/SUR1 (pancreatic KATP) has eluded discovery despite decades of intensive research. We therefore screened 47,872 chemically diverse compounds for novel inhibitors of heterologously expressed Kir6.1/SUR2B channels. The most potent inhibitor identified in the screen was an N-aryl-N'-benzyl urea compound termed VU0542270. VU0542270 inhibits Kir6.1/SUR2B with an IC50 of approximately 100 nM but has no apparent activity toward Kir6.2/SUR1 or several other members of the Kir channel family at doses up to 30 µM (>300-fold selectivity). By expressing different combinations of Kir6.1 or Kir6.2 with SUR1, SUR2A, or SUR2B, the VU0542270 binding site was localized to SUR2. Initial structure-activity relationship exploration around VU0542270 revealed basic texture related to structural elements that are required for Kir6.1/SUR2B inhibition. Analysis of the pharmacokinetic properties of VU0542270 showed that it has a short in vivo half-life due to extensive metabolism. In pressure myography experiments on isolated mouse ductus arteriosus vessels, VU0542270 induced ductus arteriosus constriction in a dose-dependent manner similar to that of the nonspecific KATP channel inhibitor glibenclamide. The discovery of VU0542270 provides conceptual proof that SUR2-specific KATP channel inhibitors can be developed using a molecular target-based approach and offers hope for developing cardiovascular therapeutics targeting Kir6.1/SUR2B. SIGNIFICANCE STATEMENT: Small-molecule inhibitors of vascular smooth muscle KATP channels might represent novel therapeutics for patent ductus arteriosus, migraine headache, and sepsis; however, the lack of selective channel inhibitors has slowed progress in these therapeutic areas. Here, this study describes the discovery and characterization of the first vascular-specific KATP channel inhibitor, VU0542270.

Prenatal Diagnosis of Ductus Arteriosus Anomalies: A Single-Center Study.

To evaluate the fetal ductus arteriosus anomalies diagnosed by fetal echocardiography. The perinatal outcomes and associated cardiac and genetic anomalies are also explored. The fetal echocardiography records of 2366 fetuses were evaluated retrospectively. Thirty-seven pregnancies prenatally diagnosed with ductus arteriosus anomalies and evaluated after delivery were enrolled in the study. Perinatal and obstetric outcomes were analyzed. The incidence of ductus arteriosus anomaly in our series was 1.5% (37/2366). The most frequent ductus arteriosus anomaly detected was right-sided ductus arteriosus followed by aneurysm, constriction and bilateral ductus arteriosus with an incidence of 51.3%, 27.1%, 18.9% and 2.7%, respectively. There were 19 fetuses with right-sided ductus arteriosus, of which 15 had tetralogy of Fallot. There were 2 chromosomal anomalies (22q11 microdeletion) in this group. Of the 7 fetuses with ductus arteriosus constriction, 3 (3/7, 42.9%) died in-utero. There were 2 (2/10, 20%) neonatal deaths due to hypoplastic left heart syndrome in the ductus arteriosus aneurysm group. Various types of ductus arteriosus anomalies can be diagnosed prenatally. Perinatal outcomes mostly dependent on the type of the ductus arteriosus anomaly and accompanying cardiac malformations.

Electron Leak From the Mitochondrial Electron Transport Chain Complex I at Site IQ Is Crucial for Oxygen Sensing in Rabbit and Human Ductus Arteriosus.

Background As partial pressure of oxygen (pO2) rises with the first breath, the ductus arteriosus (DA) constricts, diverting blood flow to the pulmonary circulation. The DA's O2 sensor resides within smooth muscle cells. The DA smooth muscle cells' mitochondrial electron transport chain (ETC) produces reactive oxygen species (ROS) in proportion tooxygen tension, causing vasoconstriction by regulating redox-sensitive ion channels and enzymes. To identify which ETC complex contributes most to DA O2 sensing and determine whether ROS mediate O2 sensing independent of metabolism, we used electron leak suppressors, S1QEL (suppressor of site IQ electron leak) and S3QEL (suppressor of site IIIQo electron leak), which decrease ROS production by inhibiting electron leak from quinone sites IQ and IIIQo, respectively. Methods and Results The effects of S1QEL, S3QEL, and ETC inhibitors (rotenone and antimycin A) on DA tone, mitochondrial metabolism, O2-induced changes in intracellular calcium, and ROS were studied in rabbit DA rings, and human and rabbit DA smooth muscle cells. S1QEL's effects on DA patency were assessed in rabbit kits, using micro computed tomography. In DA rings, S1QEL, but not S3QEL, reversed O2-induced constriction (P=0.0034) without reducing phenylephrine-induced constriction. S1QEL did not inhibit mitochondrial metabolism or ETC-I activity. In human DA smooth muscle cells, S1QEL and rotenone inhibited O2-induced increases in intracellular calcium (P=0.02 and 0.001, respectively), a surrogate for DA constriction. S1QEL inhibited O2-induced ROS generation (P=0.02). In vivo, S1QEL prevented O2-induced DA closure (P<0.0001). Conclusions S1QEL, but not S3QEL, inhibited O2-induced rises in ROS and DA constriction ex vivo and in vivo. DA O2 sensing relies on pO2-dependent changes in electron leak at site IQ in ETC-I, independent of metabolism. S1QEL offers a therapeutic means to maintain DA patency.

Actin Polymerization Increases in The Ductus Arteriosus During The Developmental Transition to Lung Ventilation

The Ductus Arteriosus (DA) is an embryonic blood vessel that connects the descending aorta and the pulmonary artery during fetal development. It functions as a right-to-left shunt diverting blood away from the nonventilated lungs and to the descending aorta. The DA serves a comparable physiological role in all terrestrial vertebrates during their embryonic development. Following birth or hatching, the DA constricts in response to increase in arterial oxygen tension brought on by initiation of lung ventilation, and it closes to stop the embryonic shunt. We examined the extent of actin polymerization in the DA during the transition to lung ventilation at hatching in the chicken. We isolated and fixed DA from developing chickens on embryonic days 15 and 19 (ED15 and ED19), during internal pipping (IP) and external pipping (EP), and in hatchlings. Vessel sections were fluorescently stained with Alexa Fluor 488 (DNase 1) for G-actin, Alexa Fluor 568 (Phalloidin) for F-actin, and TOPRO-3 for nuclei staining. Fluorescence microscopy was used to image the sections and quantify F-actin to G-actin levels within the DA for each age. From the images, F-actin to G-actin ratios were determined. Embryonic stages exhibited strong G-actin staining with minimal F-actin staining. During hatching, F-actin staining became more pronounced, exhibiting clearer fiber patterns in the tunica media. F-actin to G-actin ratios increased significantly in the DA from ED15 through hatching, suggesting actin polymerization in the DA increased as the chickens progressed from day 19 to external pipping (EP). These results suggest that increases in actin polymerization play a role in ductus arteriosus constriction at hatching in chickens. This research is funded by grant R15HL14887 from the NIH-NHLBI. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Reopening of ductus arteriosus in idiopathic premature constriction or closure of ductus arteriosus: A case series.

There is no consensus on managing pregnancy when the fetus is diagnosed with idiopathic premature constriction or closure of the ductus arteriosus (PCDA). Knowing whether the ductus reopens is valuable information for managing idiopathic PCDA. We conducted a case-series study to investigate the natural perinatal course of idiopathic PCDA and examined factors associated with ductal reopening. We retrospectively collected information about the perinatal course and echocardiographic findings at our institution, which, on principle, does not determine delivery timing based on fetal echocardiographic results. We also examined perinatal factors related to the reopening of the ductus arteriosus. Thirteen cases of idiopathic PCDA were included in the analysis. The ductus reopened in 38% of cases. Among cases diagnosed in < 37 weeks of gestation, 71% reopened, which was confirmed seven days after diagnosis (interquartile range 4-7). Diagnosis earlier in gestation was associated with ductal reopening (p = 0.006). Two cases (15%) developed persistent pulmonary hypertension. No fetal hydrops or death occurred. The ductus is likely to reopen when prenatally diagnosed before 37 weeks gestation. There were no complications due to our pregnancy management policy. In idiopathic PCDA, especially if the prenatal diagnosis is made before 37 weeks of gestational age, continuing the pregnancy with careful monitoring of the fetus's well-being is recommended.

Evaluation of changes of cardiac morphology and function in fetuses with ductus arteriosus constriction by Speckle-tracking echocardiography.

Premature ductus arteriosus constriction (DA Con) can result in right ventricular enlargement, right ventricular hypertrophy, and tricuspid regurgitation. This study retrospectively analyzed 34 singleton fetuses that underwent fetal echocardiography with a diagnosis of DA Con (16 cases with mild to moderate, and 18 cases with moderate to severe) and 45 healthy fetuses. The morphology and function parameters of cardiac, as well as the 24-Segment of ventricles, were compared between the DA Con group and controls, and between the mild to moderate and moderate to severe groups, using the fetal heart quantification (FHQ) technology. There were no significant difference in left ventricular parameters in DA Con group when compared to controls. Moreover, fetal 4CV-GSI was significantly reduced, as well as the sphericity index (SI), fractional shortening (FS), global longitudinal strain (GS) and fractional area change (FAC) of right ventricle, especially in the basal-middle segments. Compared with the mild to moderate group, LV-FS increased and RV-FS decreased in moderate to severe group. The results showed that the fetal heart in the DA Con group was different from the controls in morphology and function. FHQ technology provides a comprehensive assessment for the evaluation of cardiac morphological and functional changes in DA Con fetuses.

Fetal adverse effects following NSAID or metamizole exposure in the 2nd and 3rd trimester: an evaluation of the German Embryotox cohort

BackgroundNon-steroidal anti-inflammatory drugs (NSAID) are frequently used to treat pain, fever and inflammatory conditions. Due to evidenced fetotoxicity, treatment with NSAID and metamizole should be avoided in the 3rd trimester of pregnancy. There is an ongoing debate on fetotoxic risk of 2nd trimester use which is why we have conducted this study.MethodsIn this observational cohort study outcome of pregnancies with NSAID and/or metamizole exposure in the 2nd and/or 3rd trimester (study cohort n = 1092) was compared with pregnancies exposed to NSAID and/or metamizole in the 1st trimester only (comparison cohort, n = 1154). The WHO-UMC system was used to assess causality between study medication and study endpoints. Prenatal study endpoints were constriction of ductus arteriosus Botalli, oligohydramnios, late spontaneous abortion (SAB) or stillbirth. Postnatal study endpoints were patent ductus arteriosus (PDA), anomalies of the right heart ventricle, primary pulmonary hypertension (PPHT), and neonatal impairment of kidney function.ResultsDuctus arteriosus constriction was diagnosed in 5/1092 (0.5%) in the study cohort versus 0/1154 pregnancies in the comparison cohort. In one fetus, ductus arteriosus constriction and oligohydramnios occurred already in the late 2nd trimester after long-term NSAID exposure. Oligohydramnios was diagnosed in 41/1092 (3.8%) in the study cohort versus 29/1154 (2.5%) cases in the comparison cohort [RR, 1.5 (95% CI 0.9–2.4)]. Limited to 2nd trimester, oligohydramnios occurred in 8/904 (0.9%) versus 2/1154 (0.2%) pregnancies [RR, 5.1 (95% CI 1.1–24.0)]. At least in four of the 2nd trimester exposed pregnancies NSAID exposure lasted several weeks. Late SAB or stillbirth occurred in 14/1092 (1.3%) versus 17/1154 (1.5%). Postnatal cardiovascular or renal pathology did not differ between the cohorts.ConclusionsNSAID use in the 2nd trimester limited to a few days does not appear to pose a relevant risk. Use for longer periods in the advanced 2nd trimester, however, may cause oligohydramnios and ductus arteriosus constriction similar to effects observed after 3rd trimester use.

Cardiac Function Assessment in Fetuses With Ductus Arteriosus Constriction: A Two-Dimensional Echocardiography and FetalHQ Study.

BackgroundFetal ductal constriction (DC) is associated with excessive polyphenol-rich food (PRF) consumption during pregnancy. However, the effect of this hemodynamic change on fetal cardiac function still needs to be elucidated. Therefore, this study aimed to evaluate the cardiac function of fetuses with PRF-related DC and to describe serial observations of cardiac function changes.MethodsWe compared the traditional echocardiographic indices, including morphological, hemodynamic, and functional parameters, between study fetuses and controls. For global and segmental deformation analysis of the left and right ventricles, fetalHQ with the speckle-tracking technique was used to calculate sphericity index (SI), global longitudinal strain (GLS), fractional shortening (FS), fractional area change (FAC), etc. In addition, follow-up data were compared with the generalized linear model.ResultsA total of 60 DC fetuses and 60 gestational-matched controls were enrolled in our study, with 20 DC fetuses undertaking a follow-up echocardiogram after 2–3 weeks. Compared with controls, there was a distinct decrease in right ventricular GLS (RVGLS) (−13.39 ± 3.77 vs. −21.59 ± 2.51, p < 0.001), RVFAC (22.20 ± 9.56 vs. 36.01 ± 4.84, p < 0.001), left ventricular GLS (LVGLS) (−19.52 ± 3.24 vs. −23.81 ± 2.01 p < 0.001), and LVFAC (39.64 ± 7.32 vs. 44.89 ± 4.91, p = 0.004). For 24-segment FS analysis, DC fetuses showed lower FS in left ventricular (LV) segments 18–24, with no difference in LV segments 1–17. Right ventricular (RV) FS in segments 4–23 was also reduced in the DC group. The 24-segment SI analysis indicated significantly lower SI in DC than those in controls for LV segments 1–14 and RV segments 19–24. We found that the pulsatility index (PI) of ductus arteriosus (DA) was an independent variable for RVGLS (β = −0.29, p = 0.04). In 20 DC fetuses with follow-up echocardiograms, no obvious difference in myocardial deformation was found between the initial examination and follow-up data.ConclusionLeft and right ventricular performances were both impaired in DC fetuses, along with a series of morphological and hemodynamic changes. Although the state of DA constriction improved on second examinations, cardiac function was not completely restored.

Fetal pulmonary hypertension: dysregulated microRNA-34c-Notch1 axis contributes to impaired angiogenesis in an ovine model.

Persistent pulmonary hypertension of the newborn (PPHN) occurs when pulmonary vascular resistance (PVR) fails to decrease at birth. Decreased angiogenesis in the lung contributes to the persistence of high PVR at birth. MicroRNAs (miRNAs) regulate gene expression through transcript binding and degradation. They were implicated in dysregulated angiogenesis in cancer and cardiovascular disease. We investigated whether altered miRNA levels contribute to impaired angiogenesis in PPHN. We used a fetal lamb model of PPHN induced by prenatal ductus arteriosus constriction and sham ligation as controls. We performed RNA sequencing of pulmonary artery endothelial cells (PAECs) isolated from control and PPHN lambs. We observed a differentially expressed miRNA profile in PPHN for organ development, cell-cell signaling, and cardiovascular function. MiR-34c was upregulated in PPHN PAECs compared to controls. Exogenous miR34c mimics decreased angiogenesis by control PAEC and anti-miR34c improved angiogenesis of PPHN PAEC in vitro. Notch1, a predicted target for miR-34c by bioinformatics, was decreased in PPHN PAECs, along with Notch1 downstream targets, Hey1 and Hes1. Exogenous miR-34c decreased Notch1 expression in control PAECs and anti-miR-34c restored Notch1 and Hes1 expression in PPHN PAECs. We conclude that increased miR-34c in PPHN contributes to impaired angiogenesis by decreasing Notch1 expression in PAECs. Adds a novel mechanism for the regulation of angiogenesis in persistent pulmonary hypertension of the newborn. Identifies non-coding RNAs that are involved in the altered angiogenesis in PPHN and thus the potential for future studies to identify links between known pathways regulating angiogenesis. Provides preliminary data to conduct studies targeting miR34c expression in vivo in animal models of pulmonary hypertension to identify the mechanistic role of miR34c in angiogenesis in the lung vasculature.

The effect of celecoxib for treatment of preterm labor on fetuses during the second trimester of pregnancy: A pilot case series

ObjectiveAlthough cyclooxygenase inhibitors effectively suppress uterine contraction, constriction of the fetal ductus arteriosus (DA) and oligohydramnios are major concerns. Celecoxib, a selective cyclooxygenase 2 inhibitor, is a potential potent tocolytic agent, but there are no studies that have evaluated the beneficial or adverse effects of celecoxib use on fetuses for more than 48 hours in pregnant women. We therefore aimed to evaluate the effect of middle-long-term celecoxib administration on the fetus during the second trimester of pregnancy, particularly in terms of fetal DA and amniotic fluid volume. Materials and methodsWe retrospectively extracted and reviewed data from patients with preterm labor who received celecoxib for tocolysis for more than 48 hours between 2016 and 2020. Celecoxib was used for tocolysis only when treatment of patients with conventional tocolytic agents was ineffective. Data on the peak systolic velocity in ductus arteriosus (PSV-DA) and the maximum vertical pocket (MVP) were collected. ResultsA total of 15 patients were eligible. The median gestational age at celecoxib introduction was 22.6 weeks, and the median period of administration was 9 days (range 3–40 days). The median gestational age at delivery was 27.1 weeks, and the median duration from initial celecoxib administration to delivery was 40 days. The Z scores of PSV-DA and MVP did not change significantly after celecoxib administration. During administration, PSV-DA exceeded the 95th percentile of the corresponding normal reference range in three cases, but the levels returned to normal after reduction or discontinuation of treatment. There was no oligohydramnios during the treatment. ConclusionCelecoxib administration for more than 48 hours in the second trimester of pregnancy might be safe and tolerable in terms of fetal PSV-DA and amniotic fluid volume as long as careful ultrasound monitoring is performed. Celecoxib could be an alternative for preterm labor when conventional tocolysis is not effective.

Oral versus intravenous paracetamol for patent ductus arteriosus closure in preterm infants.

To examine whether oral administration of paracetamol as a first-line agent had a greater effect on the closure of a patent ductus arteriosus than the intravenous route. We performed a retrospective study of preterm infants (<37 weeks of gestation) between 2012 and 2020 treated with oral or intravenous paracetamol as the first line for patent ductus arteriosus (PDA) constriction and compared rates of ductal closure, course duration, cumulative dose, PDA characteristics, and serum levels. Over the study period, 80 preterm infants received paracetamol, of which 50 received paracetamol as first-line treatment to augment constriction of the PDA. Closure rate was higher in the oral group (n = 15/19, 79%) compared to the intravenous group (n = 8/20, 40%, p < 0.01), and remained significant after adjusting for gestational age, length of treatment, and postnatal age (OR 0.14, 95% CI 0.03-0.67, p = 0.014, RR 0.51, 95% CI 0.28-0.91). Eleven preterm infants received a combination of both oral and intravenous paracetamol with a closure rate of 45% (n = 5). Oral administration of paracetamol as a first-line agent is more efficacious to constrict the PDA than the intravenous route, irrespective of gestational age or course duration. Our retrospective study comparing the use of oral versus intravenous paracetamol as the first line for patent ductus arteriosus (PDA) constriction in preterm infants demonstrates that oral administration of paracetamol is more efficacious to constrict the PDA than the intravenous route, irrespective of gestational age or course duration. To our knowledge, this is the first published study (prospective or retrospective) to compare the efficacy of oral versus intravenous paracetamol as a first-line treatment for PDA closure in preterm infants. Our finding may improve the rate of PDA closure when paracetamol is used as a first-line agent.

A exploratory study on pharmacological actions of acetaminophen on ductus arteriosus constriction based on a systematic review and database analysis using Japanese Adverse Drug Event Report database

A exploratory study on pharmacological actions of acetaminophen on ductus arteriosus constriction based on a systematic review and database analysis using Japanese Adverse Drug Event Report database

Abstract 12927: The Human Ductus Arteriosus Smooth Muscle Cell Transcriptome Indicates a Central Role for Mitochondria in Postnatal Oxygen Sensing

Introduction: The ductus arteriosus (DA) connects the fetal pulmonary artery and aorta, diverting placentally oxygenated blood from the developing lungs to the systemic circulation. The DA constricts in response to increased oxygen (O 2 ) immediately post-partum, resulting in functional DA closure, with anatomic closure ensuing within the first days of life. Failure of DA closure results in patent ductus arteriosus (PDA), a common complication of extreme preterm birth. The DA response to O 2 , though modulated by the endothelium, is intrinsic to DA smooth muscle cells (DASMC). DA constriction is mediated by mitochondria-derived reactive oxygen species, which increase in proportion to PaO 2 . The molecular signature of the DASMC response to O 2 is not well understood. Methods &amp; Results: DASMC were isolated from DA obtained from 10 infants at the time of congenital heart surgery. Cells were purified by flow cytometry, negatively sorted to eliminate fibroblasts (CD90+) or endothelial cells (CD31+). DASMC purity was confirmed by α-smooth muscle actin staining. Cells were grown for 96 hours in hypoxia (2.5% O 2 ) or normoxia (19% O 2 ) and confocal calcium imaging confirmed O 2 -responsiveness of all cell lines: O 2 exposure increased intracellular calcium 18.1%±4.4% and decreased cell length 27%±1.5% relative to hypoxic baseline. RNA sequencing (Seq) of the cells grown in hypoxia and normoxia revealed significant regulation of 1344 genes (corrected p&lt;0.05). Gene Ontology (GO) analysis provided an unbiased assessment of genes differentially regulated by O 2 , revealing enrichment of functional groups including mitochondria, cellular respiration and transcription. Multiple subunits of electron transport chain complex I, NDUF (NADH:ubiquinone oxidoreductase) family genes, are upregulated in hDASMC following normoxia. Upregulated NDUF genes were validated with qPCR (t-test p&lt;0.05): NDUFS5 (Seq = 0.62-fold, PCR = 3.8-fold), NDUFA9 (Seq = 0.8-fold, Seq = 4.3-fold), NDUFA13 (Seq = 0.7-fold, PCR = 6.1-fold), and NDUFS8 (Seq = 0.6-fold, PCR = 7.1-fold). Conclusion: This first examination of the effects of O 2 on human DA transcriptomics supports a putative role for mitochondria as O 2 sensors, with mitochondrial subunits as potential future therapeutic targets for PDA.

Improvement in fetal pulmonary hypertension and maturity after reversal of ductal constriction: prospective cohort study.

To test the hypotheses that estimated mean pulmonary arterial pressure (MPAP) decreases and pulmonary vascular maturation, assessed by the ratio of pulmonary arterial flow acceleration time to ejection time (AT/ET ratio), increases after reversal of fetal ductus arteriosus constriction by reducing maternal intake of the causal agent (prostaglandin inhibitors, such as polyphenol-rich foods or non-steroidal anti-inflammatory drugs), and that these effects are independent of gestational age, which are inferences not yet demonstrated in the clinical setting. This was a prospective cohort study comparing Doppler echocardiographic ductal flow dynamics, MPAP and pulmonary arterial flow AT/ET ratio in third-trimester fetuses (≥ 28 weeks' gestation) with ductus arteriosus constriction, at the time of diagnosis and after 2 weeks of reduced maternal intake of prostaglandin inhibitors either by suspending the use of pharmacological agents with potential for prostaglandin inhibition or by restricting the consumption of polyphenol-rich foods. MPAP was estimated using the Dabestani equation (MPAP = 90 - (0.62 × AT)), and pulmonary vascular maturity was assessed using the AT/ET ratio, according to reported validation studies. Student's t-test was used for comparison of variables at diagnosis with those after reversal of ductal constriction. Change in MPAP and pulmonary AT/ET ratio between the two assessments was compared with the expected change in the same gestational period in normal fetuses based on reference curves of MPAP and pulmonary AT/ET ratio constructed in normal fetuses from healthy pregnant women at 19-37 weeks' gestation, encompassing the same gestational age range as the study group (28-37 weeks). Seventy pregnancies with fetal ductus arteriosus constriction were included in the study. After 2 weeks of reduced maternal intake of prostaglandin inhibitors, normalization of mean systolic (change from 1.86 ± 0.34 m/s at diagnosis to 1.38 ± 0.41 m/s; P < 0.001) and diastolic (change from 0.41 ± 0.11 m/s to 0.21 ± 0.065 m/s; P < 0.001) ductal velocities and of mean pulsatility index (change from 1.99 ± 0.20 to 2.55 ± 0.42; P < 0.001) was demonstrated. MPAP decreased between the assessments (change from 66.7 ± 6.90 mmHg at diagnosis to 54.5 ± 6.70 mmHg after 2 weeks; P < 0.001) and mean pulmonary AT/ET ratio increased (change from 0.20 ± 0.06 to 0.33 ± 0.07; P < 0.001). Change in MPAP between diagnosis and after 2 weeks of reduced maternal intake of prostaglandin inhibitors was -12.2 ± 0.30 mmHg, which was 5.3-times higher than that in 305 normal fetuses over 2 weeks during the same gestational period (-2.3 ± 0.19 mmHg) (P < 0.001), and change in pulmonary AT/ET ratio between the two assessments was 0.13 ± 0.08, which was 8.7-times higher than that in normal fetuses in the same gestational period (0.015 ± 0.08) (P < 0.001). Resolution of fetal ductal constriction is followed by a fall in MPAP and by an increase in pulmonary vascular maturity, to a significantly greater degree than is observed in normal fetuses in the same gestational-age period. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Cinaciguat Prevents Postnatal Closure of Ductus Arteriosus by Vasodilation and Anti-remodeling in Neonatal Rats.

Closure of the ductus arteriosus (DA) involves vasoconstriction and vascular remodeling. Cinaciguat, a soluble guanylyl cyclase (sGC) activator, was reported with vasodilatory and anti-remodeling effects on pulmonary hypertensive vessels. However, its effects on DA are not understood. Therefore, we investigated whether cinaciguat regulated DA patency and examined its underlying mechanisms. In vivo, we found that cinaciguat (10 mg/kg, i.p. at birth) prevented DA closure at 2 h after birth with luminal patency and attenuated intimal thickening. These anti-remodeling effects were associated with enhanced expression of cyclic guanosine monophosphate (cGMP) in DA. Ex vivo, cinaciguat dilated oxygen-induced DA constriction dose-dependently. Such vasodilatory effect was blunted by KT-5823, a PKG inhibitor. In DA smooth muscle cells (DASMCs), we further showed that cinaciguat inhibited angiotensin II (Ang II)-induced proliferation and migration of DASMCs. In addition, cinaciguat inhibited Ang II-induced mitochondrial reactive oxygen species (ROS) production. Finally, Ang II-activated MAPKs and Akt were also inhibited by cinaciguat. In conclusion, cinaciguat prevents postnatal DA closure by vasodilation and anti-remodeling through the cGMP/PKG pathway. The mechanisms underlying anti-remodeling effects include anti-proliferation and anti-migration, with attenuation of mitochondrial ROS production, MAPKs, and Akt signaling. Thus, this study implicates that sGC activation may be a promising novel strategy to regulate DA patency.

The molecular mechanisms of oxygen-sensing in human ductus arteriosus smooth muscle cells: A comprehensive transcriptome profile reveals a central role for mitochondria

The ductus arteriosus (DA) connects the fetal pulmonary artery and aorta, diverting placentally oxygenated blood from the developing lungs to the systemic circulation. The DA constricts in response to increases in oxygen (O2) with the first breaths, resulting in functional DA closure, with anatomic closure occurring within the first days of life. Failure of DA closure results in persistent patent ductus arteriosus (PDA), a common complication of extreme preterm birth. The DA's response to O2, though modulated by the endothelium, is intrinsic to the DA smooth muscle cells (DASMC). DA constriction is mediated by mitochondrial-derived reactive oxygen species, which increase in proportion to arterial partial pressure of oxygen (PaO2). The resulting redox changes inhibit voltage-gated potassium channels (Kv) leading to cell depolarization, calcium influx and DASMC constriction. To date, there has not been an unbiased assessment of the human DA O2-sensors using transcriptomics, nor are there known molecular mechanisms which characterize DA closure. DASMCs were isolated from DAs obtained from 10 term infants at the time of congenital heart surgery. Cells were purified by flow cytometry, negatively sorting using CD90 and CD31 to eliminate fibroblasts or endothelial cells, respectively. The purity of the DASMC population was confirmed by positive staining for α-smooth muscle actin, smoothelin B and caldesmon. Cells were grown for 96 h in hypoxia (2.5% O2) or normoxia (19% O2) and confocal imaging with Cal-520 was used to determine oxygen responsiveness. An oxygen-induced increase in intracellular calcium of 18.1% ± 4.4% and SMC constriction (−27% ± 1.5% shortening) occurred in all cell lines within five minutes. RNA sequencing of the cells grown in hypoxia and normoxia revealed significant regulation of 1344 genes (corrected p < 0.05). We examined these genes using Gene Ontology (GO). This unbiased assessment of altered gene expression indicated significant enrichment of the following GOterms: mitochondria, cellular respiration and transcription. The top regulated biologic process was generation of precursor metabolites and energy. The top regulated cellular component was mitochondrial matrix. The top regulated molecular function was transcription coactivator activity. Multiple members of the NADH-ubiquinone oxidoreductase (NDUF) family are upregulated in human DASMC (hDASMC) following normoxia. Several of our differentially regulated transcripts are encoded by genes that have been associated with genetic syndromes that have an increased incidence of PDA (Crebb binding protein and Histone Acetyltransferase P300). This first examination of the effects of O2 on human DA transcriptomics supports a putative role for mitochondria as oxygen sensors.

Decreased Cyclic Guanosine Monophosphate-Protein Kinase G Signaling Impairs Angiogenesis in a Lamb Model of Persistent Pulmonary Hypertension of the Newborn.

Impaired angiogenesis function in pulmonary artery endothelial cells (PAEC) contributes to persistent pulmonary hypertension of the newborn (PPHN). Decreased nitric oxide (NO) amounts in PPHN lead to impaired mitochondrial biogenesis and angiogenesis in the lung; the mechanisms remain unclear. We hypothesized that decreased cyclic guanosine monophosphate (cGMP)-PKG (protein kinase G) signaling downstream of NO leads to decreased mitochondrial biogenesis and angiogenesis in PPHN. PPHN was induced by ductus arteriosus constriction from 128-136 days' gestation in fetal lambs. Control animals were gestation-matched lambs that did not undergo ductal constriction. PAEC isolated from PPHN lambs were treated with the sGC (soluble guanylate cyclase) activator cinaciguat, the PKG activator 8-bromo-cGMP, or the PDE-V (PDE type V) inhibitor sildenafil. Lysates were immunoblotted for mitochondrial transcription factors and electron transport chain C-I (complex I), C-II, C-III, C-IV, and C-V proteins. The invitro angiogenesis of PAEC was evaluated by using tube-formation and scratch-recovery assays. cGMP concentrations were measured by using an enzyme immunoassay. Fetal lambs with ductal constriction were given sildenafil or control saline through continuous infusion in utero, and the lung histology, capillary counts, vessel density, and right ventricular pressure were assessed at birth. PPHN PAEC showed decreased mitochondrial transcription factor levels, electron transport chain protein levels, and invitro tube formation and cell migration; these were restored by cinaciguat, 8-bromo-cGMP, and sildenafil. Cinaciguat and sildenafil increased cGMP concentrations in PPHN PAEC. Radial alveolar and capillary counts and vessel density were lower in PPHN lungs, and the right ventricular pressure and Fulton Index were higher in PPHN lungs; these were improved by in utero sildenafil infusion. cGMP-PKG signaling is a potential therapeutic target to restore decreased mitochondrial biogenesis and angiogenesis in PPHN.

Maternal ingestion of cocoa causes constriction of fetal ductus arteriosus in rats

Maternal consumption of polyphenol-rich foods has been associated with fetal ductus arteriosus constriction (DAC), but safety of chocolate exposure in fetal life has not been studied. This experimental study tested the hypothesis that maternal cocoa consumption in late pregnancy causes fetal DAC, with possible associated antioxidant effects. Pregnant Wistar rats, at the 21st gestational day, received by orogastric tube cocoa (720 mg/Kg) for 12 h, indomethacin (10 mg/Kg), for 8 h, or only water, before cesaren section. Immediately after withdrawal, every thorax was obtained and tissues were fixed and stained for histological analysis. The ratio of the narrowest part of the pulmonary artery to the fetal ductus inner diameter and increased ductal inner wall thickness characterized ductal constriction. Substances reactive to thiobarbituric acid were quantified. Statistical analysis used ANOVA and Tukey test. Cocoa (n = 33) and indomethacin (n = 7) reduced fetal internal ductus diameter when compared to control (water, n = 25) (p < 0.001) and cocoa alone increased ductus wall thickness (p < 0.001), but no change was noted in enzymes activity. This pharmacological study shows supporting evidences that there is a cause and effect relationship between maternal consumption of cocoa and fetal ductus arteriosus constriction. Habitual widespread use of chocolate during gestation could account for undetected ductus constriction and its potentially severe consequences, such as perinatal pulmonary hypertension, cardiac failure and even death. For this reason, dietary guidance in late pregnancy to avoid high chocolate intake, to prevent fetal ductal constriction, may represent the main translational aspect of this study.