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Introduction: Fetal hypoxia has long-term effects on postnatal reproductive functions and the mitochondrial impairments of ovarian granulosa cells may be one of the causes. Melatonin applied to mitigate mitochondrial dysfunction and autophagy in mammalian cells has been reported. However, the potential mechanisms by which fetal hypoxia damages reproductive function in neonatal female mice and the melatonin effects on this problem remain unclear., Objectives: This research aimed to explore the mechanism that fetal hypoxia damages reproductive function in neonatal female mice and attempt to improve the reproductive function by treating with melatonin in vivo and in vitro., Methods: We established a fetal hypoxia model and confirmed that fetal hypoxia affects ovarian function by inducing GC excessive autophagy. Transcriptomic analysis, gene interference, cell immunofluorescence, immunohistochemistry and western blot were conducted to explore and verify the underlying mechanisms in mice GCs and KGN cells. Finally, melatonin treatment was executed on hypoxia-treated mice GCs and KGN cells and melatonin injection to fetal-hypoxia-treated mice to determine its effect., Results: The results of in vitro experiments found that fetal hypoxia led to mitochondrial dysfunction in ovarian GCs causing autophagic cell death. And the PI3K/Akt/FoxO pathway mediated the occurrence of this process by transcriptome analysis of ovarian GCs from normal and fetal hypoxia mice, which was further verified in mice GCs and KGN cells. Additionally, melatonin administration prevented autophagic injuries and mitochondrial impairments in hypoxia-treated mice GCs and KGN cells. Meanwhile, in vivo experiments by melatonin injection ameliorated oxidative stress of ovary in fetal-hypoxia-treated mice and improved their low fertility., Conclusion: Our data found that fetal hypoxia causes ovarian GCs excessive autophagy leading to low fertility in neonatal female mice and mitigated by melatonin. These results provide a potential therapy for hypoxic stress-related reproductive disorders., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Production and hosting by Elsevier B.V.)

Intrauterine hypoxia (gestation days 15-19, pO 2 65 mm Hg, duration 4 h) led to an increase in the expression of p53, beclin-1, endothelial NO synthase (eNOS), and caspase-3 proteins in cardiomyocytes and reduced the number of mast cells in the heart of 60-day-old albino rats. Administration of a non-opiate analogue of leu-enkephalin (NALE peptide: Phe-D-Ala-Gly-Phe-Leu-Arg, 100 μg/kg) on days 2-6 of the neonatal period decreased the severity of delayed posthypoxic myocardial reaction. The content of eNOS + cardiomyocytes and the total number of mast cells of these animals did not differ from the control parameters; the content of p53 + cardiomyocytes was significantly lower than in animals exposed to intrauterine hypoxia. The cardioprotective activity of NALE was partially neutralized by co-administration with the NO synthase inhibitor (L-NAME, 50 mg/kg). Correction of the delayed posthypoxic changes, similar to the effects of NALE peptide, was observed after neonatal administration of its arginine-free analogue, G peptide (Phe-D-Ala-Gly-Phe-Leu-Gly; 100 μg/kg). Non-opiate analogues of leu-enkephalin NALE and G peptides can be considered as promising substances capable of preventing long-term cardiac consequences of intrauterine hypoxia., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Prenatal hypoxia, a common pregnancy complication, leads to impaired cardiovascular outcomes in the adult offspring. It results in impaired vasodilation in coronary and mesenteric arteries of the adult offspring, due to reduced nitric oxide (NO). Thromboxane A 2 (TxA 2 ) is a potent vasoconstrictor increased in cardiovascular diseases, but its role in the impact of prenatal hypoxia is unknown. To prevent the risk of cardiovascular disease by prenatal hypoxia, we have tested a maternal treatment using a nanoparticle-encapsulated mitochondrial antioxidant (nMitoQ). We hypothesized that prenatal hypoxia enhances vascular TxA 2 responses in the adult offspring, due to decreased NO modulation, and that this might be prevented by maternal nMitoQ treatment., Methods: Pregnant Sprague-Dawley rats received a single intravenous injection (100 µL) of vehicle (saline) or nMitoQ (125 µmol/L) on gestational day (GD)15 and were exposed to normoxia (21% O 2 ) or hypoxia (11% O 2 ) from GD15 to GD21 (term = 22 days). Coronary and mesenteric arteries were isolated from the 4-month-old female and male offspring, and vasoconstriction responses to U46619 (TxA 2 analog) were evaluated using wire myography. In mesenteric arteries, L-NAME (pan-NO synthase (NOS) inhibitor) was used to assess NO modulation. Mesenteric artery endothelial (e)NOS, and TxA 2 receptor expression, superoxide, and 3-nitrotyrosine levels were assessed by immunofluorescence., Results: Prenatal hypoxia resulted in increased U46619 responsiveness in coronary and mesenteric arteries of the female offspring, and to a lesser extent in the male offspring, which was prevented by nMitoQ. In females, there was a reduced impact of L-NAME in mesenteric arteries of the prenatal hypoxia saline-treated females, and reduced 3-nitrotyrosine levels. In males, L-NAME increased U46619 responses in mesenteric artery to a similar extent, but TxA 2 receptor expression was increased by prenatal hypoxia. There were no changes in eNOS or superoxide levels., Conclusions: Prenatal hypoxia increased TxA 2 vasoconstrictor capacity in the adult offspring in a sex-specific manner, via reduced NO modulation in females and increased TP expression in males. Maternal placental antioxidant treatment prevented the impact of prenatal hypoxia. These findings increase our understanding of how complicated pregnancies can lead to a sex difference in the programming of cardiovascular disease in the adult offspring., (© 2024. The Author(s).)

Fetal hypoxia and maternal stress frequently culminate in neuropsychiatric afflictions in life. To replicate this condition, we employed a model of prenatal severe hypoxia (PSH) during days 14-16 of rat gestation. Subsequently, both control and PSH rats at 3 months old were subjected to episodes of inescapable stress to induce learned helplessness (LH). The results of the open field test revealed an inclination towards depressive-like behavior in PSH rats. Following LH episodes, control (but not PSH) rats displayed significant anxiety. LH induced an increase in glucocorticoid receptor (GR) levels in extrahypothalamic brain structures, with enhanced nuclear translocation in the hippocampus (HPC) observed both in control and PSH rats. However, only control rats showed an increase in GR nuclear translocation in the amygdala (AMG). The decreased GR levels in the HPC of PSH rats correlated with elevated levels of hypothalamic corticotropin-releasing hormone (CRH) compared with the controls. However, LH resulted in a reduction of the CRH levels in PSH rats, aligning them with those of control rats, without affecting the latter. This study presents evidence that PSH leads to depressive-like behavior in rats, associated with alterations in the glucocorticoid system. Notably, these impairments also contribute to increased resistance to severe stressors.

Gestational hypoxia inhibits mitochondrial function in the fetal heart and placenta contributing to fetal growth restriction and organ dysfunction. NAD + deficiency may contribute to a metabolic deficit by inhibiting oxidative phosphorylation and ATP synthesis. We tested the effects of nicotinamide riboside (NR), an NAD + precursor, as a treatment for reversing known mitochondrial dysfunction in hypoxic fetal hearts. Pregnant guinea pigs were housed in room air (normoxia) or placed in a hypoxic chamber (10.5%O 2 ) for the last 14 days of gestation (term = 65 days) and administered either water or NR (1.6 mg/ml) in the drinking bottle. Fetuses were excised at term, and NAD + levels of maternal liver, placenta, and fetal heart ventricles were measured. Indices of mitochondrial function (complex IV activity, sirtuin 3 activity, protein acetylation) and ATP synthesis were measured in fetal heart ventricles of NR-treated/untreated normoxic and hypoxic animals. Hypoxia reduced fetal body weight in both sexes (p = 0.01), which was prevented by NR. Hypoxia had no effect on maternal liver NAD + levels but decreased (p = 0.04) placenta NAD + levels, the latter normalized with NR treatment. Hypoxia had no effect on fetal heart NAD + but decreased (p < 0.05) mitochondrial complex IV and sirtuin 3 activities, ATP content, and increased mitochondrial acetylation, which were all normalized with maternal NR. Hypoxia increased (p < 0.05) mitochondrial acetylation in female fetal hearts but had no effect on other mitochondrial indices. We conclude that maternal NR is an effective treatment for normalizing mitochondrial dysfunction and ATP synthesis in the hypoxic fetal heart., (© 2023. The Author(s).)

Introduction: Previous studies have shown that fetal hypoxia predisposes individuals to develop addictive disorders in adulthood. However, the specific impact of maternal stress, mediated through glucocorticoids and often coexisting with fetal hypoxia, is not yet fully comprehended., Methods: To delineate the potential effects of these pathological factors, we designed models of prenatal severe hypoxia (PSH) in conjunction with maternal stress and prenatal intrauterine ischemia (PII). We assessed the suitability of these models for our research objectives by measuring HIF1α levels and evaluating the glucocorticoid neuroendocrine system. To ascertain nicotine dependence, we employed the conditioned place aversion test and the startle response test. To identify the key factor implicated in nicotine addiction associated with PSH, we employed techniques such as Western blot, immunohistochemistry, and correlational analysis between chrna7 and nr3c1 genes across different brain structures., Results: In adult rats exposed to PSH and PII, we observed increased levels of HIF1α in the hippocampus (HPC). However, the PSH group alone exhibited reduced glucocorticoid receptor levels and disturbed circadian glucocorticoid rhythms. Additionally, they displayed signs of nicotine addiction in the conditioned place aversion and startle response tests. We also observed elevated levels of phosphorylated DARPP-32 protein in the nucleus accumbens (NAc) indicated compromised glutamatergic efferent signaling. Furthermore, there was reduced expression of α7 nAChR, which modulates glutamate release, in the medial prefrontal cortex (PFC) and HPC. Correlation analysis revealed strong associations between chrna7 and nr3c1 expression in both brain structures., Conclusion: Perturbations in the glucocorticoid neuroendocrine system and glucocorticoid-dependent gene expression of chrna7 associated with maternal stress response to hypoxia in prenatal period favor the development of nicotine addiction in adulthood., (© 2024 S. Karger AG, Basel.)

Chronic intrauterine hypoxia is a significant pregnancy complication impacting fetal heart growth, metabolism, and mitochondrial function, contributing to cardiovascular programming of the offspring. PGC1α (peroxisome proliferator-activated receptor γ co-activator 1α) is the master regulator of mitochondrial biogenesis. We investigated the effects of hypoxia on PGC1α expression following exposure at different gestational ages. Time-mated pregnant guinea pigs were exposed to normoxia (NMX, 21% O 2 ) or hypoxia (HPX, 10.5% O 2 ) at either 25-day (early-onset) or 50-day (late-onset) gestation, and all fetuses were extracted at term (term = ~65-day gestation). Expression of nuclear PGC1α, sirtuin 1 (SIRT1), AMP-activated protein kinase (AMPK), and mitochondrial sirtuin 3 (SIRT3) was measured, along with SIRT3 activity and mitochondrial acetylation of heart ventricles of male and female fetuses. Early-onset hypoxia increased (P<0.05) fetal cardiac nuclear PGC1α and had no effect on mitochondrial acetylation of either growth-restricted males or females. Late-onset hypoxia had either no effect or decreased (P<0.05) PCC1α expression in males and females, respectively, but increased (P<0.05) mitochondrial acetylation in both sexes. Hypoxia had variable effects on expression of SIRT1, AMPK, SIRT3, and SIRT3 activity depending on the sex. The capacity of the fetal heart to respond to hypoxia differs depending on the gestational age of exposure and sex of the fetus. Further, the effects of late-onset hypoxia on fetal heart function impose a greater risk to male than female fetuses, which has implications toward cardiovascular programming effects of the offspring., (© 2023. The Author(s).)

Fetal hypoxemia decreases insulin and increases cortisol and norepinephrine concentrations and may restrict growth by decreasing glucose utilization and altering substrate oxidation. Specifically, we hypothesized that hypoxemia would decrease fetal glucose oxidation and increase lactate and pyruvate production. We tested this by measuring whole body glucose oxidation and lactate production, and molecular pathways in liver, muscle, adipose, and pancreas tissues of fetuses exposed to maternal hypoxemia for 9 days (HOX) compared with control fetal sheep (CON) in late gestation. Fetuses with more severe hypoxemia had lower whole body glucose oxidation rates, and HOX fetuses had increased lactate production from glucose. In muscle and adipose tissue, expression of the glucose transporter GLUT4 was decreased. In muscle, pyruvate kinase ( PKM ) and lactate dehydrogenase B ( LDHB ) expression was decreased. In adipose tissue, LDHA and lactate transporter ( MCT1 ) expression was increased. In liver, there was decreased gene expression of PKLR and MPC2 and phosphorylation of PDH, and increased LDHA gene and LDH protein abundance. LDH activity, however, was decreased only in HOX skeletal muscle. There were no differences in basal insulin signaling across tissues, nor differences in pancreatic tissue insulin content, β-cell area, or genes regulating β-cell function. Collectively, these results demonstrate coordinated metabolic responses across tissues in the hypoxemic fetus that limit glucose oxidation and increase lactate and pyruvate production. These responses may be mediated by hypoxemia-induced endocrine responses including increased norepinephrine and cortisol, which inhibit pancreatic insulin secretion resulting in lower insulin concentrations and decreased stimulation of glucose utilization. NEW & NOTEWORTHY Hypoxemia lowered fetal glucose oxidation rates, based on severity of hypoxemia, and increased lactate production. This was supported by tissue-specific metabolic responses that may result from increased norepinephrine and cortisol concentrations, which decrease pancreatic insulin secretion and insulin concentrations and decrease glucose utilization. This highlights the vulnerability of metabolic pathways in the fetus and demonstrates that constrained glucose oxidation may represent an early event in response to sustained hypoxemia and fetal growth restriction.

Perinatal brain injury is a multifactorial process. In utero placental physiology plays a major role in neuroprotection and the normal development of the fetal central nervous system. Advances in placental pathology have clarified several specific mechanisms of injury and the histologic lesions most strongly associated with them. This review provides an updated summary of the relevant placental anatomy and physiology, the specific placental pathways leading to brain injury, the revised Amsterdam classification system for placental pathology, and the known associations of specific placental lesions with subtypes of adverse neurologic outcomes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Mitochondrial dysfunction is an underlying cause of childhood neurological disease secondary to the crucial role of mitochondria in proper neurodevelopment. We hypothesized that chronic intrauterine hypoxia (HPX) induces mitochondrial deficits by altering mitochondrial biogenesis and dynamics in the fetal brain. Pregnant guinea pigs were exposed to either normoxia (NMX, 21%O 2 ) or HPX (10.5%O 2 ) starting at 28-day (early onset, EO-HPX) or 50-day (late onset, LO-HPX) gestation until term (65 days). Near-term male and female fetuses were extracted from anesthetized sows, and mitochondria were isolated from excised fetal forebrains (n = 6/group). Expression of mitochondrial complex subunits I-V (CI-CV), fission (Drp-1), and fusion (Mfn-2) proteins was measured by Western blot. CI and CIV enzyme activities were measured by colorimetric assays. Chronic HPX reduced fetal body wts and increased (P < 0.05) brain/body wt ratios of both sexes. CV subunit levels were increased in EO-HPX males only and CII levels increased in LO-HPX females only compared to NMX. Both EO- and LO-HPX decreased CIV activity in both sexes but had no effect on CI activity. EO-HPX increased Drp1 and decreased Mfn2 levels in males, while LO-HPX had no effect on either protein levels. In females, both EO-HPX and LO-HPX increased Drp1 but had no effect on Mfn2 levels. Chronic HPX alters abundance and activity of select complex subunits and shifts mitochondrial dynamics toward fission in a sex-dependent manner in the fetal guinea pig brain. This may be an underlying mechanism of reduced respiratory efficiency leading to disrupted metabolism and increased vulnerability to a second neurological injury at the time of birth in HPX fetal brains., (© 2021. Society for Reproductive Investigation.)

Objective: To investigate associations between exposure to fetal hypoxia and indicators of metabolic health in young adult offspring of women with type 1 diabetes (OT1D)., Methods: 156 OT1D born between 7/1995 and 12/2000 at Helsinki University Hospital, Finland, were invited for follow-up between 3/2019 and 11/2019. A control group of 442 adults born from non-diabetic pregnancies, matched for date and place of birth, was obtained from the Finnish Medical Birth Register. In total, 58 OT1D and 86 controls agreed to participate. All OT1D had amniotic fluid (AF) sampled for erythropoietin (EPO) measurement within two days before delivery in order to diagnose fetal hypoxia. In total, 29 OTID had an AF EPO concentration <14.0 mU/l, defined as normal, and were categorized into the low EPO (L-EPO) group. The remaining 29 OT1D had AF EPO ≥14.0 mU/ml, defined as fetal hypoxia, and were categorized into the high EPO (H-EPO) group. At the age of 18-23 years, participants underwent a 2-h 75g oral glucose tolerance test (OGTT) in addition to height, weight, waist circumference, body composition, blood pressure, HbA 1c , cholesterol, triglyceride, high-sensitivity CRP and leisure-time physical activity measurements., Results: Two OT1D were diagnosed with diabetes and excluded from further analyses. At young adult age, OT1D in the H-EPO group had a higher BMI than those in the L-EPO group. In addition, among female participants, waist circumference and body fat percentage were highest in the H-EPO group. In the OGTTs, the mean (SD) 2-h post-load plasma glucose (mmol/L) was higher in the H-EPO [6.50 (2.11)] than in the L-EPO [5.21 (1.10)] or control [5.67 (1.48)] offspring (p=0.009). AF EPO concentrations correlated positively with 2-h post-load plasma glucose [r=0.35 (95% CI: 0.07 to 0.62)] and serum insulin [r=0.44 (95% CI: 0.14 to 0.69)] concentrations, even after adjusting for maternal BMI, birth weight z-score, gestational age at birth and adult BMI. Control, L-EPO and H-EPO groups did not differ with regards to other assessed parameters., Conclusions: High AF EPO concentrations in late pregnancy, indicating fetal hypoxia, are associated with increased adiposity and elevated post-load glucose and insulin concentrations in young adult OT1D., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Klemetti, Teramo, Kautiainen, Wasenius, Eriksson and Laine.)

Compared with acyanotic congenital heart disease (CHD), cyanotic CHD has an increased risk of lifelong mortality and morbidity. These adverse outcomes may be attributed to delayed cardiomyocyte maturation, since the transition from a hypoxic fetal milieu to oxygen-rich postnatal environment is disrupted. We established a rodent model to replicate hypoxic myocardial conditions spanning perinatal development, and tested the hypothesis that chronic hypoxia impairs cardiac development. Pregnant mice were housed in hypoxia beginning at embryonic day 16 . Pups stayed in hypoxia until postnatal day ( P ) 8 when cardiac development is nearly complete. Global gene expression was quantified at P8 and at P30 , after recovering in normoxia. Phenotypic testing included electrocardiogram, echocardiogram, and ex vivo electrophysiology study. Hypoxic P8 animals were 47% smaller than controls with preserved heart size. Gene expression was grossly altered by hypoxia at P8 (1,427 genes affected), but normalized after recovery ( P30 ). Electrocardiograms revealed bradycardia and slowed conduction velocity in hypoxic animals at P8 , with noticeable resolution after recovery ( P30 ). Notable differences that persisted after recovery ( P30 ) included a 65% prolongation in ventricular effective refractory period, sinus node dysfunction, 23% reduction in ejection fraction, and 16% reduction in fractional shortening in animals exposed to hypoxia. We investigated the impact of chronic hypoxia on the developing heart. Perinatal hypoxia was associated with changes in gene expression and cardiac function. Persistent changes to the electrophysiological substrate and contractile function warrant further investigation and may contribute to adverse outcomes observed in the cyanotic CHD population. NEW & NOTEWORTHY We utilized a new mouse model of chronic perinatal hypoxia to simulate the hypoxic myocardial conditions present in cyanotic congenital heart disease. Hypoxia caused numerous abnormalities in cardiomyocyte gene expression, the electrophysiologic substrate of the heart, and contractile function. Taken together, alterations observed in the neonatal period suggest delayed cardiac development immediately following hypoxia.

Perinatal hypoxia induces permanent structural and functional changes in the lung and its pulmonary circulation that are associated with the development of pulmonary hypertension (PH) in later life. The mechanistic target of the rapamycin (mTOR) pathway is vital for fetal lung development and is implicated in hypoxia-associated PH, yet its involvement in the developmental programming of PH remains unclear. Pregnant C57/BL6 dams were placed in hyperbaric (760 mmHg) or hypobaric chambers during gestation (505 mmHg, day 15 through postnatal day 4 ) or from weaning through adulthood (420 mmHg, postnatal day 21 through 8 wk). Pulmonary hemodynamics and right ventricular systolic pressure (RVSP) were measured at 8 wk. mTOR pathway proteins were assessed in fetal ( day 18.5 ) and adult lung (8 wk). Perinatal hypoxia induced PH during adulthood, even in the absence of a sustained secondary hypoxic exposure, as indicated by reduced pulmonary artery acceleration time (PAAT) and peak flow velocity through the pulmonary valve, as well as greater RVSP, right ventricular (RV) wall thickness, and RV/left ventricular (LV) weight. Such effects were independent of increased blood viscosity. In fetal lung homogenates, hypoxia reduced the expression of critical downstream mTOR targets, most prominently total and phosphorylated translation repressor protein (4EBP1), as well as vascular endothelial growth factor, a central regulator of angiogenesis in the fetal lung. In contrast, adult offspring of hypoxic dams tended to have elevated p4EBP1 compared with controls. Our data suggest that inhibition of mTORC1 activity in the fetal lung as a result of gestational hypoxia may interrupt pulmonary vascular development and thereby contribute to the developmental programming of PH. NEW & NOTEWORTHY We describe the first study to evaluate a role for the mTOR pathway in the developmental programming of pulmonary hypertension. Our findings suggest that gestational hypoxia impairs mTORC1 activation in the fetal lung and may impede pulmonary vascular development, setting the stage for pulmonary vascular disease in later life.

Gestational diabetes mellitus (GDM) is a major pregnancy-related disorder with an increasing prevalence worldwide. GDM is associated with altered placental vascular functions and has severe consequences for fetal growth. There is no commonly accepted medication for GDM due to safety considerations. Actions of the currently limited therapeutic options focus exclusively on lowering the blood glucose level without paying attention to the altered placental vascular reactivity and remodelling. We used the fat-sucrose diet/streptozotocin (FSD/STZ) rat model of GDM to explore the efficacy of cinnamaldehyde (Ci; 20 mg/kg/day), a promising antidiabetic agent for GDM, and glyburide/metformin-HCl (Gly/Met; 0.6 + 100 mg/kg/day), as a reference drug for treatment of GDM, on the placenta structure and function at term pregnancy after their oral intake one week before mating onward. Through genome-wide transcriptome, biochemical, metabolome, metal analysis and histopathology we obtained an integrated understanding of their effects. GDM resulted in maternal and fetal hyperglycemia, fetal hyperinsulinemia and placental dysfunction with subsequent fetal anemia, hepatic iron deficiency and high serum erythropoietin level, reflecting fetal hypoxia. Differentially-regulated genes were overrepresented for pathways of angiogenesis, metabolic transporters and oxidative stress. Despite Ci and Gly/Met effectively alleviated the maternal and fetal glycemia, only Ci offered substantial protection from GDM-associated placental vasculopathy and prevented the fetal hypoxia. This was explained by Ci's impact on the molecular regulation of placental angiogenesis, metabolic activity and redox signaling. In conclusion, Ci provides a dual impact for the treatment of GDM at both maternal and fetal levels through its antidiabetic effect and the direct placental vasoprotective action. Lack of Gly/Met effectiveness to restore it's impaired functionality demonstrates the vital role of the placenta in developing efficient medications for GDM., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Introduction: Fetal hypoxic events with unclear predictive value are a common indication for placenta examination. We evaluated whether the use of CD15 immunostaining can improve the assessment of severity and duration of fetal hypoxia., Methods: We compared placentas (37-42 gestational weeks) from stillborns/newborns with birth asphyxia (BA) and non-hypoxic newborns. Placental findings were studied in following groups: (1) acute BA (n = 11) due to placental abruption, (2) non-acute BA (n = 121) due to non-acute conditions, (3) non-BA (n = 46) in pregnancies with preeclampsia and gestational diabetes, and (4) controls (n = 30)., Results: A high expression of CD15 in feto-placental resistance vessels (FRVs) was present in non-acute BA (95.9%), but absent in acute BA, non-BA and controls (p < 0.0001). Furthermore, we found no causal relationship of high expression of CD15 in FRVs to coexisting placental conditions, including severity and mechanisms/patterns of placental injury, fetal erythroblastosis, and maternal conditions. According to a multivariate analysis, only a high expression of CD15 in FRVs was independently associated with severe non-acute fetal hypoxia ([OR] = 15.52; 95% [CI] = 5.92-40.67)., Discussion: We have defined a characteristic pattern of CD15 expression in FRVs that allows to interpret various clinical/placental conditions with respect to fetal hypoxia, with an improved predictability compared to conventional analyses. This approach represents a novel diagnostic strategy for placenta examination, which could indirectly assess severity and duration of intrauterine hypoxia in a heterogeneous population of newborns., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Pulmonary hypertension (PH) in newborns and adults is a disease that can lead to right heart failure and result in a shorter lifespan. PH was induced by maintaining pregnant rats in a hypoxic chamber for 4 h twice a day, from days 7‑21 of pregnancy. Hypoxia was confirmed by a decrease in the partial pressure of oxygen (PaO2) and the oxygen saturation (SaO2) of arterial blood in the aorta. The body weight of newborns from hypoxic rats was ~20% decreased compared with the control newborns of normoxic rats. The vascular wall thickness/vascular diameter values of hypoxia treated pubs were increased compared with that of control newborns 7 days after birth; however, it decreased to similar levels than in the control group after 3 months, and then further decreased to significantly lower levels than in the control group at 6 months after birth. At birth, the lung tissues of newborns from hypoxic rats exhibited an increase in the levels of mRNA and proteins associated with PH such as HIF‑1α, HIF‑2α, V2R, TGF‑β, TNF‑α, Ang‑2 and α‑SMA. At 3 and 6 months after birth, the levels of both V2R mRNA and protein in offspring from hypoxic rats were at least 2‑fold higher, whereas the expression of all other factors decreased compared with the control offspring. By contrast, HIF‑2α and Ang‑2 expression levels were significantly increased in the 6‑month‑old control offspring from normoxic rats. V2R overexpression in pups induced by hypoxia in maternal rats was sustained until their adulthood. V2R may be a marker for detecting PH.

Hypoxia is one of the most frequent and severe stresses to an organism's homeostatic mechanisms, and hypoxia during gestation has profound adverse effects on the heart development increasing the occurrence of congenital heart defects (CHDs). Cardiac progenitor cells (CPCs) are responsible for early heart development and the later occurrence of heart disease. However, the mechanism of how hypoxic stress affects CPC fate decisions and contributes to CHDs remains a topic of debate. Here we examined the effect of hypoxic stress on the regulations of CPC fate decisions and the potential mechanism. We found that experimental induction of hypoxic responses compromised CPC function by regulating CPC proliferation and differentiation and restraining cardiomyocyte maturation. In addition, echocardiography indicated that fetal hypoxia reduced interventricular septum thickness at diastole and the ejection time, but increased the heart rate, in mouse young adult offspring with a gender-related difference. Further study revealed that hypoxia upregulated microRNA-210 expression in Sca-1 + CPCs and impeded the cell differentiation. Blockage of microRNA-210 with LNA-anti-microRNA-210 significantly promoted differentiation of Sca-1 + CPCs into cardiomyocytes. Thus, the present findings provide clear evidence that hypoxia alters CPC fate decisions and reveal a novel mechanism of microRNA-210 in the hypoxic effect, raising the possibility of microRNA-210 as a potential therapeutic target for heart disease.

Chronic fetal hypoxia and infection are examples of adverse conditions during complicated pregnancy, which impact cardiac myogenesis and increase the lifetime risk of heart disease. However, the effects that chronic hypoxic or inflammatory environments exert on cardiac pacemaker cells are poorly understood. Here, we review the current evidence and novel avenues of bench-to-bed research in this field of perinatal cardiogenesis as well as its translational significance for early detection of future risk for cardiovascular disease.

The brain is a metabolically demanding organ and its health directly depends on brain oxygen dynamics to prevent hypoxia and ischemia. Localized brain tissue oxygen is characterized by a baseline level combined with spontaneous oscillations. These oscillations are attributed to spontaneous changes of vascular tone at the level of arterioles and their frequencies depend on age. Specifically, lower frequencies are more typical for neonates than for adults. We have built a mathematical model which analyses the diffusion abilities of oxygen based on the frequency of source brain oxygen oscillations and neuronal demand. We have found that a lower frequency of spontaneous oscillations of localized brain tissue oxygen can support higher amplitudes of oxygen concentration at areas distant from a source relative to oscillations at higher frequencies. Since hypoxia and ischemia are very common events during early development and the neurovascular unit is underdeveloped in neonates, our results indicate that lower frequency oxygen oscillations can represent an effective passive method of neonatal brain protection against hypoxia. These results can have a potential impact on future studies aiming to find new treatment strategies for brain ischemia.

Background: Intrauterine growth restriction (IUGR) is a pregnancy condition where fetal growth is reduced, and offspring from IUGR pregnancies are at increased risk for type II diabetes as adults. The liver is susceptible to fetal undernutrition experienced by IUGR infants and animal models of growth restriction. This study aimed to examine hepatic expression changes in a maternal nutrient restriction (MNR) mouse model of IUGR to understand fetal adaptations that influence adult metabolism., Methods: Liver samples of male offspring from MNR (70% of ad libitum starting at E6.5) or control pregnancies were obtained at E18.5 and differential expression was assessed by RNAseq and western blots., Results: Forty-nine differentially expressed (FDR < 0.1) transcripts were enriched in hypoxia-inducible pathways including Fkbp5 (1.6-fold change), Ccng2 (1.5-fold change), Pfkfb3 (1.5-fold change), Kdm3a (1.2-fold change), Btg2 (1.6-fold change), Vhl (1.3-fold change), and Hif-3a (1.3-fold change) (FDR < 0.1). Fkbp5, Pfkfb3, Kdm3a, and Hif-3a were confirmed by qPCR, but only HIF-2a (2.2-fold change, p = 0.002) and HIF-3a (1.3 p = 0.03) protein were significantly increased., Conclusion: Although a moderate impact, these data support evidence of fetal adaptation to reduced nutrients by increased hypoxia signaling in the liver.

Antenatal hypoxia caused epigenetic reprogramming of methylome and transcriptome in the developing heart and increased the risk of heart disease later in life. Herein, we investigated the impact of gestational hypoxia in proteome and metabolome in the hearts of fetus and adult offspring. Pregnant rats were treated with normoxia or hypoxia (10.5% O 2 ) from day 15 to 21 of gestation. Hearts were isolated from near-term fetuses and 5 month-old offspring, and proteomics and metabolomics profiling was determined. The data demonstrated that antenatal hypoxia altered proteomics and metabolomics profiling in the heart, impacting energy metabolism, lipid metabolism, oxidative stress, and inflammation-related pathways in a developmental and sex dependent manner. Of importance, integrating multi-omics data of transcriptomics, proteomics, and metabolomics profiling revealed reprogramming of the mitochondrion, especially in two clusters: (a) the cluster associated with "mitochondrial translation"/"aminoacyl t-RNA biosynthesis"/"one-carbon pool of folate"/"DNA methylation"; and (b) the cluster with "mitochondrion"/"TCA cycle and respiratory electron transfer"/"acyl-CoA dehydrogenase"/"oxidative phosphorylation"/"complex I"/"troponin myosin cardiac complex". Our study provides a powerful means of multi-omics data integration and reveals new insights into phenotypic reprogramming of the mitochondrion in the developing heart by fetal hypoxia, contributing to an increase in the heart vulnerability to disease later in life.

Introduction: The most adverse perinatal outcome of intrahepatic cholestasis of pregnancy (ICP) is sudden fetal death related to acute fetoplacental hypoxia. Corticotrophin-releasing hormone (CRH), urocortin (UCN), and Wolfram syndrome 1 (WFS1) proteins may have a compensatory response to hypoxic stress., Methods: A total of 108 singleton pregnant women were divided into three groups: control, late-onset ICP, and early-onset ICP. Enzyme-linked immunosorbent assays were used to detected maternal serum CRH, UCN, and WFS1 levels. Western blotting and real-time polymerase chain reaction were conducted to quantify placental protein and mRNA levels of CRH, UCN, and WFS1. Pearson correlation scatterplots and Pearson correlation matrix were employed to testify the correlation., Results: Placental WFS1 had a positive relation with placental UCN (r = 0.69, P < 0.05) and serum UCN (r = 0.36, P < 0.05). Placental CRH was positively correlated with maternal serum CRH (r = 0.53, P < 0.05). Maternal serum and placental levels of CRH, UCN, and WFS1 significantly increased in the early-onset ICP group compared with the control group (P < 0.05). Placental levels of UCN and WFS1 in the early-onset ICP group were significantly elevated and higher in comparison with the late-onset ICP group (P < 0.05). However, the transcriptional levels of CRH, UCN, and WFS1 were impaired in the early-onset ICP group., Discussion: Our study revealed that transcription and translation of WFS1, CRH, and UCN were altered during pregnancies complicated by early-onset ICP. This disrupted compensatory response mediated by WFS1 and CRH family peptides in early-onset ICP may play a significant role in the pathogenesis of sudden fetal death in acute fetal hypoxia., (Copyright © 2019. Published by Elsevier Ltd.)

We studied the role of bone marrow mesenchymal stem cells (MSCs) in our established model of bronchopulmonary dysplasia (BPD) induced by intrauterine hypoxia in the rat. First, we found that intrauterine hypoxia can reduce the number of MSCs in lungs and bone marrow of rat neonates, whereas the administration of granulocyte colony-stimulating factor or busulfan to either motivate or inhibit bone marrow MSCs to lungs altered lung development. Next, in vivo experiments, we confirmed that intrauterine hypoxia also impaired bone marrow MSC proliferation and decreased cell cycling activity. In vitro, by using the cultured bone marrow MSCs, the proliferation and the cell cycling activity of MSCs were also reduced when N -methyl-d-aspartic acid (NMDA) was used as an NMDA receptor (NMDAR) agonist. When MK-801 or memantine as NMDAR antagonists in vitro or in vivo was used, the reduction of cell cycling activity and proliferation were partially reversed. Furthermore, we found that intrauterine hypoxia could enhance the concentration of glutamate, an amino acid that can activate NMDAR, in the bone marrow of neonates. Finally, we confirmed that the increased concentration of TNF-ɑ in the bone marrow of neonatal rats after intrauterine hypoxia induced the release of glutamate and reduced the cell cycling activity of MSCs, and the latter could be partially reversed by MK-801. In summary, intrauterine hypoxia could decrease the number of bone marrow MSCs that could affect lung development and lung function through excessive activation of NMDAR that is partially caused by TNF-ɑ.

Key Points: Exposure to chronic hypoxia during gestation influences long-term health and development, including reproductive capacity, across generations. If the peri-conceptual environment in the developing oviduct is affected by gestational hypoxia, then this could have implications for later fertility and the health of future generations. In the present study, we show that the oviducts of female rats exposed to chronic hypoxia in utero have reduced telomere length, decreased mitochondrial DNA biogenesis and increased oxidative stress The results of the present study show that exposure to chronic gestational hypoxia leads to accelerated ageing of the oviduct in early adulthood and they help us understand how exposure to hypoxia during development could influence reproductive health across generations., Abstract: Exposure to chronic hypoxia during fetal development has important effects on immediate and long-term outcomes in offspring. Adverse impacts in adult offspring include impairment of cardiovascular function, metabolic derangement and accelerated ovarian ageing. However, it is not known whether other aspects of the female reproductive system may be similarly affected. In the present study, we examined the impact of chronic gestational hypoxia on the developing oviduct. Wistar rat dams were randomized to either normoxia (21%) or hypoxia (13%) from day 6 post-mating until delivery. Post-delivery female offspring were maintained in normoxia until 4 months of age. Oviductal gene expression was assayed at the RNA (quantitative RT-PCR) and protein (western blotting) levels. Oviductal telomere length was assayed using Southern blotting. Oviductal telomere length was reduced in the gestational hypoxia-exposed animals compared to normoxic controls (P < 0.01). This was associated with a specific post-transcriptional reduction in the KU70 subunit of DNA-pk in the gestational hypoxia-exposed group (P < 0.05). Gestational hypoxia-exposed oviducts also showed evidence of decreased mitochondrial DNA biogenesis, reduced mtDNA copy number (P < 0.05) and reduced gene expression of Tfam (P < 0.05) and Pgc1α (P < 0.05). In the hypoxia-exposed oviducts, there was upregulation of mitochondrial-specific anti-oxidant defence enzymes (MnSOD; P < 0.01). Exposure to chronic gestational hypoxia leads to accelerated ageing of the oviduct in adulthood. The oviduct plays a central role in early development as the site of gamete transport, syngamy, and early development; hence, accelerated ageing of the oviductal environment could have important implications for fertility and the health of future generations., (© 2019 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Hypoxic-ischemic brain damage (HIBD) occurs due to intrauterine hypoxia ischemia influencing the energy supply for fetal brain cells, which affects the metabolism of the brain to make the brain suffer a severe damage. Erythropoietin (EPO), which regulates hemacytopoiesis, is a kind of cytokine. EPO is sensitive to hypoxia ischemia. In this study, we aimed to investigate the effect of EPO on the expression of Fas/FasL in brain tissues of neonatal rats with HIBD. Neonatal rats were assigned randomly to sham, HIBD, and EPO groups. Five time points for observation were 6, 12, 24, 48, and 72 h after the HIBD rat model had been established, respectively. In the HIBD group, Fas/FasL expression began to rise at 6 h, reached the peak at 12-24 h, and dropped from 24 h. In the EPO group, the expression of Fas/FasL was lower than those in HIBD group at 12, 24, and 48 h (P<0.05). Our findings suggest that EPO may reduce cell apoptosis after hypoxic-ischemic damage through reduction of the expression of Fas and FasL, and that optimal therapeutic time window is 6-24 h after HIBD.

Evidence derived from human clinical studies and experimental animal models shows a causal relationship between adverse pregnancy and increased cardiovascular disease in the adult offspring. However, translational studies isolating mechanisms to design intervention are lacking. Sheep and humans share similar precocial developmental milestones in cardiovascular anatomy and physiology. We tested the hypothesis in sheep that maternal treatment with antioxidants protects against fetal growth restriction and programmed hypertension in adulthood in gestation complicated by chronic fetal hypoxia, the most common adverse consequence in human pregnancy. Using bespoke isobaric chambers, chronically catheterized sheep carrying singletons underwent normoxia or hypoxia (10% oxygen [O2]) ± vitamin C treatment (maternal 200 mg.kg-1 IV daily) for the last third of gestation. In one cohort, the maternal arterial blood gas status, the value at which 50% of the maternal hemoglobin is saturated with oxygen (P50), nitric oxide (NO) bioavailability, oxidative stress, and antioxidant capacity were determined. In another, naturally delivered offspring were raised under normoxia until early adulthood (9 months). Lambs were chronically instrumented and cardiovascular function tested in vivo. Following euthanasia, femoral arterial segments were isolated and endothelial function determined by wire myography. Hypoxic pregnancy induced fetal growth restriction and fetal oxidative stress. At adulthood, it programmed hypertension by enhancing vasoconstrictor reactivity and impairing NO-independent endothelial function. Maternal vitamin C in hypoxic pregnancy improved transplacental oxygenation and enhanced fetal antioxidant capacity while increasing NO bioavailability, offsetting constrictor hyper-reactivity and replenishing endothelial function in the adult offspring. These discoveries provide novel insight into mechanisms and interventions against fetal growth restriction and adult-onset programmed hypertension in an animal model of complicated pregnancy in a species of similar temporal developmental milestones to humans., Competing Interests: The authors have declared that no competing interests exist.

Placental hypoxia can stimulate oxidative stress and mitochondrial dysfunction reducing placental efficiency and inducing fetal growth restriction (FGR). We hypothesized that chronic hypoxia inhibits mitochondrial function in the placenta as an underlying cause of cellular mechanisms contributing to FGR. Pregnant guinea pigs were exposed to either normoxia (NMX) or hypoxia (HPX; 10.5% O2) at 25 day gestation until term (65 day). Guinea pigs were anesthetized, and fetuses and placentas were excised at either mid (40 day) or late gestation (64 day), weighed, and placental tissue stored at -80°C until assayed. Mitochondrial DNA content, protein expression of respiratory Complexes I-V, and nitration and activity rates of Complexes I and IV were measured in NMX and HPX male (N = 6 in each treatment) and female (N = 6 in each treatment) placentas. Mitochondrial density was not altered by HPX in either mid- or late-term placentas. In mid gestation, HPX slightly increased expression of Complexes I-III and V in male placentas only, but had no effect on either Complex I or IV activity rates or nitrotyrosine expression. In late gestation, HPX significantly decreased CI/CIV activity rates and increased CI/CIV nitration in male but not female placentas exhibiting a sexual dimorphism. Complex I-V expression was reduced from mid to late gestation in both male and female placentas regardless of treatment. We conclude that chronic HPX decreases mitochondrial function by inhibiting Complex I/IV activity via increased peroxynitrite in a sex-related manner. Further, there may be a progressive decrease in energy metabolism of placental cell types with gestation that increases the vulnerability of placental function to intrauterine stress.

Introduction: We have recently developed an extra-uterine environment for neonatal development (EXTEND) capable of supporting premature fetal lambs and have been able to replicate hypoxic in utero conditions by controlling fetal oxygen delivery. In this study, we investigated the fetal mitochondrial response to hypoxia., Methods: Eight premature fetal lambs were delivered via hysterotomy and transitioned to extra-uterine support for 3 weeks. The lambs were divided into 2 groups: normoxic fetuses which maintained physiologic oxygen delivery and hypoxic fetuses in which oxygen delivery was significantly reduced. Control fetuses were delivered via hysterotomy but not cannulated. Measurements of mitochondrial membrane potential (MMP) were performed in peripheral blood mononuclear cells., Results: There were no significant differences in MMP between normoxic EXTEND fetuses and controls. Hypoxic fetuses had significantly more depolarized mitochondria compared to normoxic fetuses overall, and these changes were specifically appreciated in weeks 1 and 2, but not by week 3. Hypoxic fetuses had significantly elevated levels of HIF-1α compared to normoxic fetuses in the first 2 weeks., Discussion: Normoxic fetal lambs supported by EXTEND demonstrate normal mitochondrial function as evidenced by equivalent membrane potentials compared to control fetuses. Hypoxic fetuses exhibit mitochondrial dysfunction, though they do show evidence of adaptation after 3 weeks of hypoxic exposure., (© 2018 S. Karger AG, Basel.)

Using electrocorticogram (ECoG) analysis, we compared age-related dynamics of general neuronal activity and convulsive epileptiform responsiveness induced by intracortical microinjections of 4-aminopyridine (4-AP) in control Wistar rats and those subjected to prenatal hypoxia (Hx; E14; 7% O2, 3 h). The studies were carried out in three age periods roughly corresponding to childhood (P20-27), adolescence (P30-45), and adulthood (P90-120). It was found that in the process of postnatal development of the control rats, the peak of the ECoG power spectrum density (PSD) of the theta rhythm during wakefulness shifted from the low to the higher frequency, while in the Hx rats this shift had the opposite direction. Moreover, the Hx rats had different frequency characteristics of the ECoG PSD and longer episodes of spike-and-wave discharges caused by 4-AP injections compared to the controls. The total ECoG PSD of slow-wave sleep (1-5 Hz) was also dramatically decreased in the process of development of the Hx rats. Such alterations in PSD could be explained by the changes in balance of the excitation and inhibition processes in the cortical networks. Analyzing protein levels of neurotransmitter transporters in the brain structures of the Hx rats, we found that the content of the glutamate transporter EAAT1 was higher in the parietal cortex in all age groups of Hx rats while in the hippocampus it decreased during postnatal development compared to controls. Furthermore, the content of the vesicular acetylcholine transporter in the parietal cortex, and of the inhibitory GABA transporter 1 in the hippocampus, was also affected by prenatal Hx. These data suggest that prenatal Hx results in a shift in the excitatory and inhibitory balance in the rat cortex towards excitation, making the rat's brain more vulnerable to the effects of proconvulsant drugs and predisposing animals to epileptogenesis during postnatal life., (© 2019 S. Karger AG, Basel.)

Adverse intrauterine conditions cause fetal growth restriction and increase the risk of adult cardiovascular disease. We hypothesize that intrauterine hypoxia impairs fetal heart function, is sustained after birth, and manifests as both cardiac and mitochondrial dysfunction in offspring guinea pigs (GPs). Pregnant GPs were exposed to 10.5% O 2 (HPX) at 50 days of gestation (full term = 65 days) or normoxia (NMX) for the duration of the pregnancy. Pups were allowed to deliver vaginally and raised in a NMX environment. At 90 days of age, mean arterial pressure (MAP) was measured in anesthetized GPs. NMX and prenatally HPX offspring underwent echocardiographic imaging for in vivo measurement of left ventricular cardiac morphology and function, and O 2 consumption rates and complex IV enzyme activity were measured from isolated cardiomyocytes and mitochondria, respectively. Prenatal HPX increased ( P < 0.01) MAP (52.3 ± 1.3 and 58.4 ± 1.1 mmHg in NMX and HPX, respectively) and decreased ( P < 0.05) stroke volume (439.8 ± 54.5 and 289.4 ± 15.8 μl in NMX and HPX, respectively), cardiac output (94.4 ± 11.2 and 67.3 ± 3.8 ml/min in NMX and HPX, respectively), ejection fraction, and fractional shortening in male, but not female, GPs. HPX had no effect on left ventricular wall thickness or end-diastolic volume in either sex. HPX reduced mitochondrial maximal respiration and respiratory reserve capacity and complex IV activity rates in hearts of male, but not female, GPs. Prenatal HPX is a programming stimulus that increases MAP and decreases cardiac and mitochondrial function in male offspring. Sex-related differences in the contractile and mitochondrial responses suggest that female GPs are protected from cardiovascular programming of prenatal HPX.

Exposure to prenatal hypoxia in rats leads to intrauterine growth restriction (IUGR), decreases fetal cardiomyocyte proliferation and increases the risk to develop cardiovascular diseases (CVD) later in life. The tumor necrosis factor-related weak inducer of apoptosis (TWEAK) induces cardiomyocyte proliferation through activation of the fibroblast growth factor-inducible molecule 14 (Fn-14) receptor. The TWEAK/Fn-14 pathway becomes quiescent shortly after birth, however, it becomes upregulated with CVD; suggesting that it could be a link between the increased susceptibility to CVD in pregnancies complicated by hypoxia/IUGR. We hypothesized that offspring exposed to prenatal hypoxia will exhibit reduced cardiomyocyte proliferation due to reduced Fn-14 expression and that the TWEAK/Fn-14 pathway will be expressed in those adult offspring. We exposed pregnant Sprague Dawley rats to control (21% oxygen) or hypoxic (11% oxygen) conditions from gestational days 15 to 21. Ventricular cardiomyocytes were isolated from male and female, control and hypoxic offspring at postnatal day 1. Proliferation was assessed in the presence or absence of r-TWEAK (72 h, 100 ng/ml). Prenatal hypoxia was not associated with differences in Fn-14 protein expression in either male or female offspring. Cardiomyocytes from prenatal hypoxic male, but not female, offspring had decreased proliferation compared with controls. Addition of r-TWEAK increased cardiomyocyte proliferation in all offspring. In adult offspring of all groups, the TWEAK/Fn-14 pathway was not detectable. Cardiomyocyte proliferation was reduced in only male offspring exposed to prenatal hypoxia but this was not due to changes in the Fn-14 pathway. Studies addressing other pathways associated with CVD and prenatal hypoxia are needed.

Intrauterine growth restriction, a common consequence of prenatal hypoxia, is a leading cause of fetal morbidity and mortality with a significant impact on population health. Hypoxia may increase placental oxidative stress and lead to an abnormal release of placental-derived factors, which are emerging as potential contributors to developmental programming. Nanoparticle-linked drugs are emerging as a novel method to deliver therapeutics targeted to the placenta and avoid risking direct exposure to the fetus. We hypothesize that placental treatment with antioxidant MitoQ loaded onto nanoparticles (nMitoQ) will prevent the development of cardiovascular disease in offspring exposed to prenatal hypoxia. Pregnant rats were intravenously injected with saline or nMitoQ (125 μM) on gestational day (GD) 15 and exposed to either normoxia (21% O 2 ) or hypoxia (11% O 2 ) from GD15-21 (term: 22 days). In one set of animals, rats were euthanized on GD 21 to assess fetal body weight, placental weight and placental oxidative stress. In another set of animals, dams were allowed to give birth under normal atmospheric conditions (term: GD 22) and male and female offspring were assessed at 7 and 13 months of age for in vivo cardiac function (echocardiography) and vascular function (wire myography, mesenteric artery). Hypoxia increased oxidative stress in placentas of male and female fetuses, which was prevented by nMitoQ. 7-month-old male and female offspring exposed to prenatal hypoxia demonstrated cardiac diastolic dysfunction, of which nMitoQ improved only in 7-month-old female offspring. Vascular sensitivity to methacholine was reduced in 13-month-old female offspring exposed to prenatal hypoxia, while nMitoQ treatment improved vasorelaxation in both control and hypoxia exposed female offspring. Male 13-month-old offspring exposed to hypoxia showed an age-related decrease in vascular sensitivity to phenylephrine, which was prevented by nMitoQ. In summary, placental-targeted MitoQ treatment in utero has beneficial sex- and age-dependent effects on adult offspring cardiovascular function., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Hypoxia is one of the most common and severe challenges to the maintenance of homeostasis. Oxygen sensing is a property of all tissues, and the response to hypoxia is multidimensional involving complicated intracellular networks concerned with the transduction of hypoxia-induced responses. Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. Hypoxia during gestation impacts both the mother and fetal development through interactions with an individual's genetic traits acquired over multiple generations by natural selection and changes in gene expression patterns by altering the epigenetic code. Changes in the epigenome determine "genomic plasticity," i.e., the ability of genes to be differentially expressed according to environmental cues. The genomic plasticity defined by epigenomic mechanisms including DNA methylation, histone modifications, and noncoding RNAs during development is the mechanistic substrate for phenotypic programming that determines physiological response and risk for healthy or deleterious outcomes. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue. The complex molecular and epigenetic interactions that may impact an individual's physiology and developmental programming of health and disease later in life are discussed.

Introduction: There is a need for prophylaxis to reduce placental-associated intrauterine growth restriction (IUGR). Pomegranate juice (PJ) is replete with phytochemicals having biological effects at non-pharmacological concentrations. We test the hypothesis that exposure of pregnant mice to hypoxia late in gestation induces cellular stress in the placenta, which can be ameliorated by antecedent maternal consumption of PJ., Materials and Methods: We exposed pregnant mice to 12% or 21% oxygen, with food ad libitum or restricted, and with consumption of PJ or glucose between 12.5 and 18.5 days post conception (dpc). We examined the outcomes of the nine groups (n = 10) at 18.5 dpc, quantifying fetal and placental weights and placental labyrinthine and junctional zone depths and areas. We assayed cellular stress by expression of Hsp90 and apoptosis by TUNEL staining and expression of cleaved caspase 3., Results: Maternal exposure to 12% oxygen or food restriction in 21% oxygen, induced IUGR, compared to control. The labyrinth to junctional zone ratio was lower in hypoxic ad libitum, compared to normoxic food-restricted, placentas. Antenatal PJ prior to and during hypoxic exposure significantly improved fetal growth, reduced Hsp90 expression, and limited apoptosis in the labyrinth, while enhancing junctional zone apoptosis., Discussion: Maternal exposure to hypoxia induces IUGR, cell stress, and apoptosis in mouse placentas. The labyrinth and junctional zone of the mouse placenta are differentially sensitive to FiO 2 and to PJ. PJ offers benefits in the prophylaxis of IUGR in the mouse, but PJ effects on the junctional zone require further study., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Hypoxia during pregnancy could cause abnormal development and lead to increased risks of vascular diseases in adults. This study determined angiotensin II (AII)-mediated vascular dysfunction in offspring middle cerebral arteries (MCA)., Methods and Results: Pregnant rats were subjected to hypoxia. Vascular tension in offspring MCA by AII with or without inhibitors, calcium channel activities, and endoplasmic reticulum calcium stores were tested. Whole-cell patch clamping was used to investigate voltage-dependent calcium channel currents. mRNA expression was tested using quantitative real-time polymerase chain reaction. AII-mediated MCA constriction was greater in male offspring exposed to prenatal hypoxia. AT1 and AT2 receptors were involved in the altered AII-mediated vasoconstriction. Prenatal hypoxia increased baseline activities of L-type calcium channel currents in MCA smooth muscle cells. However, calcium currents stimulated by AII were not significantly changed, whereas nifedipine inhibited AII-mediated vasoconstrictions in the MCA. Activities of IP 3 /ryanodine receptor-operated calcium channels, endoplasmic reticulum calcium stores, and sarcoendoplasmic reticulum membrane Ca 2+ -ATPase were increased. Prenatal hypoxia also caused dysfunction of vasodilatation via the endothelium NO synthase. The mRNA expressions of AT1A, AT1B, AT2R, Cav1.2α1C, Cav3.2α1H, and ryanodine receptor RyR2 were increased in the prenatal-hypoxia group., Conclusions: Hypoxia in pregnancy could induce dysfunction in both contraction and dilation in the offspring MCA. AII-increased constriction in the prenatal-hypoxia group was not mainly dependent on the L-type and T-type calcium channels; it might predominantly rely on the AII receptors, IP 3 /ryanodine receptors, and the endoplasmic reticulum calcium store as well as calcium ATPase., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

In 60-day-old male rats after antenatal hypoxia, the body weight and the absolute weight of the cerebral hemispheres were significantly lower than in the progeny of intact animals. Analysis of brain sections stained with silver nitrate revealed reduced number of nucleoli in neocortical layer II and hippocampal CA1 neurons and smaller area of neuronal nuclei in neocortical layer V and total area of nucleoli in neurons of all studied zones. The animals demonstrated increased locomotor activity in the elevated plus-maze test. Chemiluminescent analysis of brain homogenates revealed the presence of oxidative stress at the organ level. Neonatal administration of non-opioid analog of leu-enkephalin (peptide NALE) after antenatal hypoxia normalized body weight, neutralized morphometric changes in the nucleoli and nuclei of neurons in the neocortex and hippocampus, and improved oxidative status of the brain. In 30- and 60-day-old male rats subjected to antenatal hypoxia and receiving peptide NALE during the neonatal period, behavioral responses were partially normalized. Non-opioid analog of leu-enkephalin can be a promising drug for correction of cerebral consequences of antenatal hypoxia.

Key Points: Chronic fetal hypoxaemia is a common pregnancy complication associated with intrauterine growth restriction that may influence respiratory outcome at birth. We investigated the effect of maternal chronic hypoxia for a month in late gestation on signalling pathways regulating fetal lung maturation and the transition to air-breathing at birth using isobaric hypoxic chambers without alterations to maternal food intake. Maternal chronic hypoxia in late gestation increases fetal lung expression of genes regulating hypoxia signalling, lung liquid reabsorption and surfactant maturation, which may be an adaptive response in preparation for the successful transition to air-breathing at birth. In contrast to other models of chronic fetal hypoxaemia, late gestation onset fetal hypoxaemia promotes molecular regulation of fetal lung maturation. This suggests a differential effect of timing and duration of fetal chronic hypoxaemia on fetal lung maturation, which supports the heterogeneity observed in respiratory outcomes in newborns following exposure to chronic hypoxaemia in utero., Abstract: Chronic fetal hypoxaemia is a common pregnancy complication that may arise from maternal, placental and/or fetal factors. Respiratory outcome of the infant at birth likely depends on the duration, timing and severity of the hypoxaemic insult. We have isolated the effect of maternal chronic hypoxia (MCH) for a month in late gestation on fetal lung development. Pregnant ewes were exposed to normoxia (21% O 2 ) or hypoxia (10% O 2 ) from 105 to 138 days of gestation (term ∼145 days). At 138 days, gene expression in fetal lung tissue was determined by quantitative RT-PCR. Cortisol concentrations were determined in fetal plasma and lung tissue. Numerical density of surfactant protein positive cells was determined by immunohistochemistry. MCH reduced maternal PaO2 (106 ± 2.9 vs. 47 ± 2.8 mmHg) and fetal body weight (4.0 ± 0.4 vs. 3.2 ± 0.9 kg). MCH increased fetal lung expression of the anti-oxidant marker CAT and decreased expression of the pro-oxidant marker NOX-4. MCH increased expression of genes regulating hypoxia signalling and feedback (HIF-3α, KDM3A, SLC2A1, EGLN-3). There was no effect of MCH on fetal plasma/lung tissue cortisol concentrations, nor genes regulating glucocorticoid signalling (HSD11B-1, HSD11B-2, NR3C1, NR3C2). MCH increased expression of genes regulating sodium (SCNN1-B, ATP1-A1, ATP1-B1) and water (AQP-4) movement in the fetal lung. MCH promoted surfactant maturation (SFTP-B, SFTP-D, ABCA3) at the molecular level, but did not alter the numerical density of surfactant positive cells in lung tissue. MCH in late gestation promotes molecular maturation of the fetal lung, which may be an adaptive response in preparation for the successful transition to air-breathing at birth., (© 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.)

Fetal insulin secretion is inhibited by acute hypoxemia. The relationship between prolonged hypoxemia and insulin secretion, however, is less well defined. To test the hypothesis that prolonged fetal hypoxemia impairs insulin secretion, studies were performed in sheep fetuses that were bled to anemic conditions for 9 ± 0 days (anemic, n = 19) and compared with control fetuses ( n = 15). Arterial hematocrit and oxygen content were 34% and 52% lower, respectively, in anemic vs. control fetuses ( P < 0.0001). Plasma glucose concentrations were 21% higher in the anemic group ( P < 0.05). Plasma norepinephrine and cortisol concentrations increased 70% in the anemic group ( P < 0.05). Glucose-, arginine-, and leucine-stimulated insulin secretion all were lower ( P < 0.05) in anemic fetuses. No differences in pancreatic islet size or β-cell mass were found. In vitro, isolated islets from anemic fetuses secreted insulin in response to glucose and leucine as well as control fetal islets. These findings indicate a functional islet defect in anemic fetuses, which likely involves direct effects of low oxygen and/or increased norepinephrine on insulin release. In pregnancies complicated by chronic fetal hypoxemia, increasing fetal oxygen concentrations may improve insulin secretion., (Copyright © 2017 the American Physiological Society.)

Hypoxic ischemic insults predispose to perinatal brain injury. Pro-inflammatory cytokines are important in the evolution of this injury. Interleukin-1β (IL-1β) is a key mediator of inflammatory responses and elevated IL-1β levels in brain correlate with adverse neurodevelopmental outcomes after brain injury. Impaired blood-brain barrier (BBB) function represents an important component of hypoxic-ischemic brain injury in the fetus. In addition, ischemia-reperfusion increases cytokine transport across the BBB of the ovine fetus. Reducing pro-inflammatory cytokine entry into brain could represent a novel approach to attenuate ischemia-related brain injury. We hypothesized that infusions of neutralizing IL-1β monoclonal antibody (mAb) reduce IL-1β transport across the BBB after ischemia in the fetus. Fetal sheep were studied 24-h after 30-min of carotid artery occlusion. Fetuses were treated with placebo- or anti-IL-1β mAb intravenously 15-min and 4-h after ischemia. Ovine IL-1β protein expressed from IL-1β pGEX-2T vectors in Escherichia coli (E. coli) BL-21 cells was produced, purified, and radiolabeled with 125 I. BBB permeability was quantified using the blood-to-brain transfer constant (K i ) with 125 I-radiolabeled-IL-1β. Increases in anti-IL-1β mAb were observed in the brain of the mAb-treated group (P<0.001). Blood-to-brain transport of 125 I-IL-1β was lower (P<0.04) across brain regions in the anti-IL-1β mAb-treated than placebo-treated ischemic fetuses. Plasma 125 I-IL-1β counts were higher (P<0.001) in the anti-IL-1β mAb- than placebo-treated ischemic fetuses. Systemic infusions of anti-IL-1β mAb reduce IL-1β transport across the BBB after ischemia in the ovine fetus. Our findings suggest that conditions associated with increases in systemic pro-inflammatory cytokines and neurodevelopmental impairment could benefit from an anti-cytokine therapeutic strategy., (Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.)

Impaired transplacental supply of oxygen leads to intrauterine growth restriction, one of the most important causes of perinatal mortality and respiratory morbidity. Breathing rhythm depends on the central respiratory network modulated by catecholamines. We investigated the impact of growth restriction, using prenatal hypoxia, on respiratory frequency, on central respiratory-like rhythm, and on its catecholaminergic modulation after birth. At birth, respiratory frequency was increased and confirmed in en bloc medullary preparations, where the frequency of the fourth cervical (C4) ventral root discharge was increased, and in slice preparations containing the pre-Bötzinger complex with an increased inspiratory rhythm. The inhibition of C4 burst discharge observed in pontomedullary preparations was stronger in the growth-restricted group. These results cannot be directly linked by the tyrosine hydroxylase activity increase of A 1 /C 1 and A 2 /C 2 cell groups in the medulla since blockade of α 1 - and α 2 -adrenergic receptors did not abolish the difference between both groups. However, in pontomedullary preparations, the stronger inhibition of C4 burst discharge is probably supported by an increased inhibition of A 5 , a respiratory rhythm inhibitor pontine group of neurons displaying increased tyrosine hydroxylase activity, because blockade of α 2 -adrenergic receptors abolished the difference between the two groups. Taken together, these results indicate that growth restriction leads to a perturbation of the breathing frequency, which finds, at least in part, its origin in the modification of catecholaminergic modulation of the central breathing network., (Copyright © 2016 the American Physiological Society.)

Hepatic glucose production (HGP) normally begins just prior to birth. Prolonged fetal hypoglycemia, intrauterine growth restriction, and acute hypoxemia produce an early activation of fetal HGP. To test the hypothesis that prolonged hypoxemia increases factors which regulate HGP, studies were performed in fetuses that were bled to anemic conditions (anemic: n = 11) for 8.9 ± 0.4 days and compared with control fetuses (n = 7). Fetal arterial hematocrit and oxygen content were 32% and 50% lower, respectively, in anemic vs. controls (P < 0.005). Arterial plasma glucose was 15% higher in the anemic group (P < 0.05). Hepatic mRNA expression of phosphonenolpyruvate carboxykinase (PCK1) was twofold higher in the anemic group (P < 0.05). Arterial plasma glucagon concentrations were 70% higher in anemic fetuses compared with controls (P < 0.05), and they were positively associated with hepatic PCK1 mRNA expression (P < 0.05). Arterial plasma cortisol concentrations increased 90% in the anemic fetuses (P < 0.05), but fetal cortisol concentrations were not correlated with hepatic PCK1 mRNA expression. Hepatic glycogen content was 30% lower in anemic vs. control fetuses (P < 0.05) and was inversely correlated with fetal arterial plasma glucagon concentrations. In isolated primary fetal sheep hepatocytes, incubation in low oxygen (3%) increased PCK1 mRNA threefold compared with incubation in normal oxygen (21%). Together, these results demonstrate that glucagon and PCK1 may potentiate fetal HGP during chronic fetal anemic hypoxemia., (Copyright © 2016 the American Physiological Society.)

The guinea pig is a frequently used animal model for human pregnancy complications, such as oxygen deprivation or hypoxia, which result in altered brain development. To investigate the impact of in utero chronic hypoxia on brain development, pregnant guinea pigs underwent either normoxic or hypoxic conditions at about 70 % of 65-day term gestation. After delivery, neurochemical profiles consisting of 19 metabolites and macromolecules were obtained from the neonatal cortex, hippocampus, and striatum from birth to 12 weeks postpartum using in vivo (1)H MR spectroscopy at 9.4 T. The effects of chronic fetal hypoxia on the neurochemical profiles were particularly significant at birth. However, the overall developmental trends of neurochemical concentration changes were similar between normoxic and hypoxic animals. Alterations of neurochemicals including N-acetylaspartate (NAA), phosphorylethanolamine, creatine, phosphocreatine, and myo-inositol indicate neuronal loss, delayed myelination, and altered brain energetics due to chronic fetal hypoxia. These observed neurochemical alterations in the developing brain may provide insights into hypoxia-induced brain pathology, neurodevelopmental compromise, and potential neuroprotective measures.

We hypothesized that repetitive umbilical cord occlusions (UCOs) with worsening fetal acidemia will lead to an inflammatory response within the brain and thereby brain injury which will be exacerbated by chronic hypoxemia and low-grade infection. Chronically instrumented fetal sheep served as controls (N = 10) or underwent repeated UCOs for up to 4 hours or until arterial pH was <7.00. Normoxic-UCO (N = 9) and hypoxic-UCO (N = 5) fetuses had arterial O2 saturation pre-UCOs of >55% and <55%, respectively, whereas lipopolysaccharide (LPS) UCO fetuses (N = 6) received LPS intra-amniotic (2 mg/h) starting 1 hour pre-UCOs. Animals were euthanized at 48 hours of recovery with fetal brains processed for assessment of inflammation (microglia and mast cell counts) and injury (necrosis-hematoxylin and eosin-and apoptosis-cleaved caspase-3 and terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL]). Repetitive UCOs resulted in severe acidemia in most animals with pH approaching 7.00 for all 3 UCO groups. However, there was no significant effect on measures of brain inflammation or injury, except in the LPS-UCO animals where TUNEL-positive cells were increased in the hippocampus, although small animal numbers in the hypoxic-UCO group may have limited the ability to detect significance in their TUNEL cell findings. We were therefore unable to confirm our working hypothesis since the near-term ovine fetal brain showed remarkable tolerance for these cord occlusion insults and likely involving protective metabolic mechanisms, despite the severe acidemia noted., (© The Author(s) 2015.)

Congenital medullary dysplasia with obstructive nephropathy is a common congenital disorder observed in paediatric patients and represents the foremost cause of renal failure. However, the molecular processes regulating normal papillary outgrowth during the postnatal period are unclear. In this study, transcriptional profiling of the renal medulla across postnatal development revealed enrichment of non-canonical Wnt signalling, vascular development, and planar cell polarity genes, all of which may contribute to perinatal medulla/papilla maturation. These pathways were investigated in a model of papillary hypoplasia with functional obstruction, the Crim1(KST264/KST264) transgenic mouse. Postnatal elongation of the renal papilla via convergent extension was unaffected in the Crim1(KST264/KST264) hypoplastic renal papilla. In contrast, these mice displayed a disorganized papillary vascular network, tissue hypoxia, and elevated Vegfa expression. In addition, we demonstrate the involvement of accompanying systemic hypoxia arising from placental insufficiency, in appropriate papillary maturation. In conclusion, this study highlights the requirement for normal vascular development in collecting duct patterning, development of appropriate nephron architecture, and perinatal papillary maturation, such that disturbances contribute to obstructive nephropathy., (Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Transient hypoxia in pregnancy stimulates a physiological reflex response that redistributes blood flow and defends oxygen delivery to the fetal brain. We designed the present experiment to test the hypotheses that transient hypoxia produces damage of the cerebral cortex and that ketamine, an antagonist ofNMDAreceptors and a known anti-inflammatory agent, reduces the damage. Late gestation, chronically catheterized fetal sheep were subjected to a 30-min period of ventilatory hypoxia that decreased fetal PaO2from 17 ± 1 to 10 ± 1 mmHg, or normoxia (PaO217 ± 1 mmHg), with or without pretreatment (10 min before hypoxia/normoxia) with ketamine (3 mg/kg, i.v.). One day (24 h) after hypoxia/normoxia, fetal cerebral cortex was removed andmRNAextracted for transcriptomics and systems biology analysis (n = 3-5 per group). Hypoxia stimulated a transcriptomic response consistent with a reduction in cellular metabolism and an increase in inflammation. Ketamine pretreatment reduced both of these responses. The inflammation response modeled with transcriptomic systems biology was validated by immunohistochemistry and showed increased abundance of microglia/macrophages after hypoxia in the cerebral cortical tissue that ketamine significantly reduced. We conclude that transient hypoxia produces inflammation of the fetal cerebral cortex and that ketamine, in a standard clinical dose, reduces the inflammation response., (© 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.)

Chronic hypoxia is a common complication of pregnancy, arising through malperfusion of the placenta or pregnancy at high altitude. The present study investigated the effects of hypoxia on the growth of the placenta, which is the organ that interfaces between the mother and her fetus. Mice were housed in an hypoxic environment for the whole of gestation. An atmosphere of 13% oxygen induced fetal growth restriction (1182 ± 9 mg, n = 90 vs. 1044 ± 11 mg, n = 62, P < 0.05) but enhanced placental weight (907 ± 11 mg, n = 90 vs. 998 ± 15 mg, n = 62,P < 0.05). Stereological analyses revealed an increase in the volume of maternal blood spaces in the placenta, consistent with increased flow. At the molecular level, we observed activation of the protein kinase B (Akt)-mechanistic target of rapamycin growth and proliferation pathway. Chronic hypoxia also triggered mild endoplasmic reticulum stress, a conserved homeostatic response that mediates translational arrest through phosphorylation of eukaryotic initiation factor 2 subunit α. Surprisingly, although subunits of the mitochondrial electron transport chain complexes were reduced at the protein level, there was no evidence of intracellular energy depletion. Finally, we demonstrated sex-specific placental responses to chronic hypoxia. Placentas from male fetuses were heavier (1082 ± 2 mg, n = 30 vs. 928 ± 2 mg, n = 34, P < 0.05) and less susceptible to hypoxia-induced oxidative stress than those from females. Their capacity to adapt may explain why male fetuses were significantly less growth restricted at embryonic day 18.5 than their female counterparts. These findings are consistent with the concept that male fetuses are more aggressive with respect to their nutrient demands, which may place them at greater risk of adverse outcomes under limiting conditions., (© 2015 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

A functioning placental renin-angiotensin system (RAS) appears necessary for uncomplicated pregnancy and is present during placentation, which occurs under low oxygen tensions. Placental RAS is increased in pre-eclampsia (PE), characterised by placental dysfunction and elevated oxidative stress. We investigated the effect of high altitude hypoxia on the RAS and hypoxia-inducible factors (HIFs) by measuring mRNA and protein expression in term placentae from normotensive (NT) and PE women who delivered at sea level or above 3100 m, using an explant model of hypoxia-reoxygenation to assess the impact of acute oxidative stress on the RAS and HIFs. Protein levels of prorenin (P = 0.049), prorenin receptor (PRR; P = 0.0004), and angiotensin type 1 receptor (AT1R, P = 0.006) and type 2 receptor (AT2R, P = 0.002) were all significantly higher in placentae from NT women at altitude, despite mRNA expression being unaffected. However, mRNA expression of all RAS components was significantly lower in PE at altitude than at sea level, yet PRR, angiotensinogen (AGT) and AT1R proteins were all increased. The increase in transcript and protein expression of all the HIFs and NADPH oxidase 4 seen in PE compared to NT at sea level was blunted at high altitude. Experimentally induced oxidative stress stimulated AGT mRNA (P = 0.04) and protein (P = 0.025). AT1R (r = 0.77, P < 0.001) and AT2R (r = 0.81, P < 0.001) mRNA both significantly correlated with HIF-1β, whilst AT2R also correlated with HIF-1α (r = 0.512, P < 0.013). Our observations suggest that the placental RAS is responsive to changes in tissue oxygenation: this could be important in the interplay between reactive oxygen species as cell-signalling molecules for angiogenesis and hence placental development and function., (© 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.)

Inhibition of hypoxia signalling leads to respiratory distress syndrome (RDS), whereas administration of vascular endothelial growth factor (VEGF), the most widely characterized hypoxia responsive factor, protects from RDS. In the lung of the chronically hypoxaemic placentally restricted (PR) fetus, there is altered regulation of hypoxia signalling. This leads to reduced surfactant maturation in late gestation and provides evidence for the increased risk of RDS in growth restricted neonates at birth. We evaluated the effect of recombinant human VEGF administration with respect to bypassing the endogenous regulation of hypoxia signalling in the lung of the normally grown and PR sheep fetus. There was no effect of VEGF administration on fetal blood pressure or fetal breathing movements. We examined the effect on the expression of genes regulating VEGF signalling (FLT1 and KDR), angiogenesis (ANGPT1, AQP1, ADM), alveolarization (MMP2, MMP9, TIMP1, COL1A1, ELN), proliferation (IGF1, IGF2, IGF1R, MKI67, PCNA), inflammation (CCL2, CCL4, IL1B, TNFA, TGFB1, IL10) and surfactant maturation (SFTP-A, SFTP-B, SFTP-C, SFTP-D, PCYT1A, LPCAT, LAMP3, ABCA3). Despite the effects of PR on the expression of genes regulating airway remodelling, inflammatory signalling and surfactant maturation, there were very few effects of VEGF administration on gene expression in the lung of both the normally grown and PR fetus. There were, however, positive effects of VEGF administration on percentage tissue, air space and numerical density of SFTP-B positive alveolar epithelial cells in fetal lung tissue. These results provide evidence for the stimulatory effects of VEGF administration on structural maturation in the lung of both the normally grown and PR fetus., (© 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.)

Genes near adenosine monophosphate-activated protein kinase-α1 (PRKAA1) have been implicated in the greater uterine artery (UtA) blood flow and relative protection from fetal growth restriction seen in altitude-adapted Andean populations. Adenosine monophosphate-activated protein kinase (AMPK) activation vasodilates multiple vessels but whether AMPK is present in UtA or placental tissue and influences UtA vasoreactivity during normal or hypoxic pregnancy remains unknown. We studied isolated UtA and placenta from near-term C57BL/6J mice housed in normoxia (n = 8) or hypoxia (10% oxygen, n = 7-9) from day 14 to day 19, and placentas from non-labouring sea level (n = 3) or 3100 m (n = 3) women. Hypoxia increased AMPK immunostaining in near-term murine UtA and placental tissue. RT-PCR products for AMPK-α1 and -α2 isoforms and liver kinase B1 (LKB1; the upstream kinase activating AMPK) were present in murine and human placenta, and hypoxia increased LKB1 and AMPK-α1 and -α2 expression in the high- compared with low-altitude human placentas. Pharmacological AMPK activation by A769662 caused phenylephrine pre-constricted UtA from normoxic or hypoxic pregnant mice to dilate and this dilatation was partially reversed by the NOS inhibitor l-NAME. Hypoxic pregnancy sufficient to restrict fetal growth markedly augmented the UtA vasodilator effect of AMPK activation in opposition to PE constriction as the result of both NO-dependent and NO-independent mechanisms. We conclude that AMPK is activated during hypoxic pregnancy and that AMPK activation vasodilates the UtA, especially in hypoxic pregnancy. AMPK activation may be playing an adaptive role by limiting cellular energy depletion and helping to maintain utero-placental blood flow in hypoxic pregnancy., (© 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.)