Advanced maternal age alters cardiac functional and structural adaptations to pregnancy in rats.

A significant number of pregnancies occur at advanced maternal age (>35 yr), which is a risk factor for pregnancy complications. Healthy pregnancies require massive hemodynamic adaptations, including an increased blood volume and cardiac output. There is growing evidence that these cardiovascular adaptations are impaired with age, however, little is known about maternal cardiac function with advanced age. We hypothesized that cardiac adaptations to pregnancy are impaired with advanced maternal age. Younger (4 mo; ∼early reproductive maturity in humans) and aged (9 mo; ∼35 yr in humans) pregnant Sprague-Dawley rats were assessed and compared with age-matched nonpregnant controls. Two-dimensional echocardiographic images were obtained (ultrasound biomicroscopy; under anesthesia) on gestational day 19 (term = 22 days) and compared with age-matched nonpregnant rats (n = 7-9/group). Left ventricular structure and function were assessed using short-axis images and transmitral Doppler signals. During systole, left ventricular anterior wall thickness increased with age in the nonpregnant rats, but there was no age-related difference between the pregnant groups. There were no significant pregnancy-associated differences in left ventricular wall thickness. Calculated left ventricular mass increased with age in nonpregnant rats and increased with pregnancy only in young rats. Compared with young pregnant rats, the aortic ejection time of aged pregnant rats was greater and Tei index was lower. Overall, the greater aortic ejection time and lower Tei index with age in pregnant rats suggest mildly altered cardiac adaptations to pregnancy with advanced maternal age, which may contribute to adverse outcomes in advanced maternal age pregnancies.NEW & NOTEWORTHY We demonstrated that even before the age of reproductive senescence, rats show signs of age-related alterations in cardiac structure that suggests increased cardiac work. Our data also demonstrate, using an in vivo echocardiographic approach, that advanced maternal age in a rat model is associated with altered cardiac function and structure relative to younger pregnant controls.

Excessive hypercholesterolemia in pregnancy impairs rat uterine artery function via activation of Toll-like receptor 4.

Hypercholesterolemia in pregnancy is a physiological process required for normal fetal development. In contrast, excessive pregnancy-specific hypercholesterolemia increases the risk of complications, such as preeclampsia. However, the underlying mechanisms are unclear. Toll-like receptor 4 (TLR4) is a membrane receptor modulated by high cholesterol levels, leading to endothelial dysfunction; but whether excessive hypercholesterolemia in pregnancy activates TLR4 is not known. We hypothesized that a high cholesterol diet (HCD) during pregnancy increases TLR4 activity in uterine arteries, leading to uterine artery dysfunction. Sprague Dawley rats were fed a control diet (n=12) or HCD (n=12) during pregnancy (gestational day 6-20). Vascular function was assessed in main uterine arteries using wire myography (vasodilation to methacholine and vasoconstriction to phenylephrine; with and without inhibitors for mechanistic pathways) and pressure myography (biomechanical properties). Exposure to a HCD during pregnancy increased maternal blood pressure, induced proteinuria, and reduced the fetal-to-placental weight ratio for both sexes. Excessive hypercholesterolemia in pregnancy also impaired vasodilation to methacholine in uterine arteries, whereby at higher doses, methacholine caused vasoconstriction instead of vasodilation in only the HCD group, which was prevented by inhibition of TLR4 or prostaglandin H synthase 1. Endothelial nitric oxide synthase expression and nitric oxide levels were reduced in HCD compared with control dams. Vasoconstriction to phenylephrine and biomechanical properties were similar between groups. In summary, excessive hypercholesterolemia in pregnancy impairs uterine artery function, with TLR4 activation as a key mechanism. Thus, TLR4 may be a target for therapy development to prevent adverse perinatal outcomes in complicated pregnancies.

Sex-Specific Effects of Prenatal Hypoxia and a Placental Antioxidant Treatment on Cardiac Mitochondrial Function in the Young Adult Offspring.

Prenatal hypoxia is associated with placental oxidative stress, leading to impaired fetal growth and an increased risk of cardiovascular disease in the adult offspring; however, the mechanisms are unknown. Alterations in mitochondrial function may result in impaired cardiac function in offspring. In this study, we hypothesized that cardiac mitochondrial function is impaired in adult offspring exposed to intrauterine hypoxia, which can be prevented by placental treatment with a nanoparticle-encapsulated mitochondrial antioxidant (nMitoQ). Cardiac mitochondrial respiration was assessed in 4-month-old rat offspring exposed to prenatal hypoxia (11% O2) from gestational day (GD)15-21 receiving either saline or nMitoQ on GD 15. Prenatal hypoxia did not alter cardiac mitochondrial oxidative phosphorylation capacity in the male offspring. In females, the NADH + succinate pathway capacity decreased by prenatal hypoxia and tended to be increased by nMitoQ. Prenatal hypoxia also decreased the succinate pathway capacity in females. nMitoQ treatment increased respiratory coupling efficiency in prenatal hypoxia-exposed female offspring. In conclusion, prenatal hypoxia impaired cardiac mitochondrial function in adult female offspring only, which was improved with prenatal nMitoQ treatment. Therefore, treatment strategies targeting placental oxidative stress in prenatal hypoxia may reduce the risk of cardiovascular disease in adult offspring by improving cardiac mitochondrial function in a sex-specific manner.

Placenta-Derived Extracellular Vesicles From Preeclamptic Pregnancies Impair Vascular Endothelial Function via Lectin-Like Oxidized LDL Receptor-1.

BACKGROUND: Preeclampsia is a complex syndrome that includes maternal vascular dysfunction. Syncytiotrophoblast-derived extracellular vesicles from preeclampsia placentas (preeclampsia-STBEVs) were shown to induce endothelial dysfunction, but an endothelial transmembrane mediator is still unexplored. The LOX-1 (lectin-like oxidized low-density lipoprotein receptor-1) is a transmembrane scavenger receptor that can cause endothelial dysfunction, and its expression is increased in the endothelium of preeclampsia women. In this study, we hypothesized that LOX-1 mediates the effects of preeclampsia-STBEVs on endothelial function. METHODS: Preeclampsia-STBEVs were collected by perfusion of placentas from women with preeclampsia and in vitro and ex vivo endothelial cell function were assessed. RESULTS: In human umbilical vein endothelial cells, inhibition of LOX-1 with LOX-1 blocking antibody (TS20) reduced the uptake of preeclampsia-STBEVs (61.3±8.8%). TS20 prevented the activation of ERK (extracellular signal-regulated kinase, a kinase downstream of LOX-1) and reduced the activation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells; 21.1±8.0%) and nitrative stress (23.2±10.3%) that was induced by preeclampsia-STBEVs. Vascular function was assessed by wire myography in isolated mesenteric arteries from pregnant rats that were incubated overnight with preeclampsia-STBEVs±TS20. TS20 prevented endothelium-dependent vasodilation impairment induced by preeclampsia-STBEVs. Nitric oxide contribution to the relaxation was reduced by preeclampsia-STBEVs, which was prevented by TS20. Superoxide dismutase or apocynin, an inhibitor of NOX (nicotinamide adenine dinucleotide phosphate oxidase), restored the impaired endothelium-dependent vasodilation in arteries exposed to preeclampsia-STBEVs. CONCLUSIONS: Taken together, our findings demonstrate that LOX-1 mediates the endothelial dysfunction induced by preeclampsia-STBEVs. Our study further expands on the mechanisms that may lead to adverse outcomes in preeclampsia and proposes LOX-1 as a potential target for future interventions.

Increased stiffness of omental arteries from late pregnant women at advanced maternal age.

Advanced maternal age (≥35 years) is a risk factor for poor pregnancy outcomes. Pregnancy requires extensive maternal vascular adaptations, and with age, our blood vessels become stiffer and change in structure (collagen and elastin). However, the effect of advanced maternal age on the structure of human resistance arteries during pregnancy is unknown. As omental resistance arteries contribute to blood pressure regulation, assessing their structure in pregnancy may inform on the causal mechanisms underlying pregnancy complications in women of advanced maternal age. Omental fat biopsies were obtained from younger (<35 years) or advanced maternal age (≥35 years) women during caesarean delivery (n = 7-9/group). Arteries (200-300 µm) were isolated and passive mechanical properties (circumferential stress and strain) assessed with pressure myography. Collagen (Masson's Trichrome) and elastin (Verhoff) were visualized histologically and % positively-stained area was assessed. Median maternal age was 32 years (range 25-34) for younger, and 38 years (range 35-42) for women of advanced maternal age. Circumferential strain was lower in arteries from advanced maternal age versus younger women but circumferential stress was not different. Omental artery collagen levels were similar, while elastin levels were lower with advanced maternal age versus younger pregnancies. The collagen:elastin ratio was greater in arteries from advanced maternal age versus younger women. In conclusion, omental arteries from women of advanced maternal age were less compliant with less elastin compared with arteries of younger controls, which may affect how vascular stressors are tolerated during pregnancy. Understanding how vascular aging affects pregnancy adaptations may contribute to better pregnancy outcomes.

Placenta-targeted treatment with nMitoQ prevents an endothelin receptor-A pathway cardiac phenotype observed in adult male offspring exposed to hypoxia in utero.

Prenatal hypoxia is associated with enhanced susceptibility to cardiac ischemia-reperfusion (I/R) injury in adult offspring, however, the mechanisms remain to be fully investigated. Endothelin-1 (ET-1) is a vasoconstrictor that acts via endothelin A (ETA) and endothelin B (ETB) receptors and is essential in maintaining cardiovascular (CV) function. Prenatal hypoxia alters the ET-1 system in adult offspring possibly contributing to I/R susceptibility. We previously showed that ex vivo application of ETA antagonist ABT-627 during I/R prevented the recovery of cardiac function in prenatal hypoxia-exposed males but not in normoxic males nor normoxic or prenatal hypoxia-exposed females. In this follow-up study, we examined whether placenta-targeted treatment with a nanoparticle-encapsulated mitochondrial antioxidant (nMitoQ) during hypoxic pregnancies could alleviate this hypoxic phenotype observed in adult male offspring. We used a rat model of prenatal hypoxia where pregnant Sprague-Dawley rats were exposed to hypoxia (11% O2) from gestational days (GD) 15-21 after injection with 100 µL saline or nMitoQ (125 µM) on GD15. Male offspring were aged to 4 mo and ex vivo cardiac recovery from I/R was assessed. Offspring born from hypoxic pregnancies and treated with nMitoQ had increased cardiac recovery from I/R in the presence of ABT-627 compared with their untreated counterparts where ABT-627 prevented recovery. Cardiac ETA levels were increased in males born from hypoxic pregnancies with nMitoQ treatment compared with saline controls (Western blotting). Our data indicate a profound impact of placenta-targeted treatment to prevent an ETA receptor cardiac phenotype observed in adult male offspring exposed to hypoxia in utero.NEW & NOTEWORTHY In this follow-up study, we showed a complete lack of recovery from I/R injury after the application of an ETA receptor antagonist (ABT-627) in adult male offspring exposed to hypoxia in utero while maternal treatment with nMitoQ during prenatal hypoxia exposure prevented this effect. Our data suggest that nMitoQ treatment during hypoxic pregnancies may prevent a hypoxic cardiac phenotype in adult male offspring.

The effect of tauroursodeoxycholic Acid (TUDCA) treatment on placental endoplasmic reticulum (ER) stress in a rat model of advanced maternal age.

Advanced maternal age (≥35 years) is associated with an increased risk of pregnancy complications such as fetal growth restriction and preeclampsia. We previously demonstrated poor pregnancy outcomes (reduced fetal body weight), altered vascular function, and increased expression of endoplasmic reticulum (ER) stress markers (phospho-eIF2α and CHOP) in mesenteric arteries from a rat model of advanced maternal age. Further, treatment of aged dams during pregnancy with an ER stress inhibitor, tauroursodeoxycholic acid (TUDCA) increased fetal body weight (both male and female), tended to improve uterine artery function, and reduced expression of phospho-eIF2α and CHOP in systemic arteries. Placental ER stress has been linked to poor pregnancy outcomes in complicated pregnancies but whether placental ER stress is evident in advanced maternal age is not known. In addition, sex-specific changes in the placental labyrinth and junctional zones from male and female offspring in advanced maternal age have not been investigated. Therefore, the current study aimed to investigate the effect of TUDCA intervention on placental ER stress. We hypothesize that placental ER stress is increased in a rat model of advanced maternal age that is alleviated by TUDCA intervention for both sexes. Placental ER stress markers (GRP78, phospho-eIF2α, ATF-4, CHOP, ATF-6α, and sXBP-1) were quantified by Western blot in placentas from male and female offspring; the labyrinth and junction zones were analyzed separately. In the placental labyrinth zone from male offspring, only GRP78 (p = 0.007) was increased in aged dams compared to young dams; TUDCA treatment reduced the placental expression of GRP78 in aged dams (p = 0.003). In addition, TUDCA reduced the levels of phospho-eIF2α (p = 0.021), ATF-4 (p = 0.016), and CHOP (p = 0.012) in aged dams but no effect was observed in young TUDCA-treated dams. In the placental labyrinth zone from female offspring, an increased level of phospho-eIF2α (p = 0.005) was observed in aged dams compared to young dams, and TUDCA treatment had no effect in both young and aged groups. In the placental junctional zone from male and female offspring, no changes in the expression of GRP78, phospho-eIF2α, ATF-4, CHOP, and ATF-6α was observed with or without TUDCA treatment in both young and aged groups, however, a reduced expression of sXBP-1 protein was observed in from both male (p = 0.001) and female (p = 0.031) placentas from aged-TUDCA treated dams compared to aged control. In conclusion, our data highlight the complexity and sex-specificity of ER stress responses in advanced maternal age with TUDCA treatment maintaining ER stress proteins to basal levels and improving fetal growth in both male and female offspring.

Sex-Specific Differences in the Placental Unfolded Protein Response in a Rodent Model of Gestational Hypoxia.

Gestational hypoxia is a major contributor to fetal growth restriction (FGR) and perinatal morbidity and mortality and has been closely linked to the activation of the unfolded protein response (UPR) in the placenta. Recent studies on adverse pregnancy conditions show differential adaptive responses in pregnancies carrying male or female fetuses. Here, we use an established rat model of hypoxic pregnancy and FGR to test the hypothesis that chronic hypoxia promotes sexually dimorphic activation of the placental UPR. Our data showed that gestational hypoxia increased glucose regulatory protein 78 (GRP78) expression in male placentae, increased activating transcription factor 6 activation (ATF6) in female placentae, and did not induce changes in other UPR markers. In addition, gestational hypoxia reduced fetal weight only in males and ATF6 activation correlated with an increase in the fetal crown-rump-length/body weight ratio only in females. These results suggest sex-specific divergence in the placental adaptive response to gestational hypoxia, which may account for the sexual dimorphism observed in placental function and pregnancy outcomes in complicated pregnancies.

A High Cholesterol Diet During Late Pregnancy Impairs Long-Term Maternal Vascular Function in Mice.

BACKGROUND: Gestational dyslipidemia is associated with pregnancy complications including preeclampsia. However, whether gestational dyslipidemia leads postpartum vascular dysfunction, which could increase the risk for cardiovascular complications later in life, is not known. Here, we aimed to determine whether a gestational dyslipidemia affects postpartum vascular health and induces early signs of atherosclerosis. METHODS: Pregnant C57BL/6 mice received a high cholesterol diet or control diet from gestational day 13.5 until term. After delivery, all mice received the control diet for ≈3 months postpartum (PP). Age-matched nulliparous females were on the same diets for equal periods. After 3 months, all mice were euthanized, serum was collected, and aortas were isolated to assess vascular function (wire myography) and markers of oxidative stress and early atherosclerosis. RESULTS: PP-high cholesterol diet females had increased circulating cholesterol levels compared with PP-control diet mice, without effect of the diet in nulliparous mice. Methacholine-induced vasodilation was impaired, and nitric oxide contribution reduced, by the high cholesterol diet in aortas of PP mice, but not in nulliparous mice. Exposure to oxidized low-density-protein cholesterol further impaired methylcholine-induced vasodilation in PP-high cholesterol diet aortas only. Compared with PP-control diet mice, aortic inducible nitric oxide synthase expression, reactive oxygen species and nitrotyrosine levels were increased in aortas from PP-high cholesterol diet mice. No differences in aortic lipid deposition and macrophage infiltration were found. CONCLUSIONS: Exposure to a high cholesterol diet in pregnancy impairs vascular function postpartum. Our results support the hypothesis that gestational dyslipidemia impacts maternal vascular function after pregnancy, which could potentially predispose these women to future cardiovascular complications.

The Long-Term Effects of Prenatal Hypoxia on Coronary Artery Function of the Male and Female Offspring.

Prenatal hypoxia predisposes the offspring to the development of cardiovascular (CV) dysfunction in adult life. Using a rat model, we assessed the effect of prenatal hypoxia on vasoconstrictive and vasodilative mechanisms in left anterior descending coronary arteries of 4- and 9.5-month-old offspring. Endothelium-dependent relaxation to methylcholine and vasoconstriction responses to endothelin-1 (ET-1) were assessed by wire myography. Prenatal hypoxia impaired endothelium-dependent vasodilation in 4- and 9.5-month-old offspring. Inhibition of nitric oxide (NO) synthase prevented coronary artery relaxation in all groups. Inhibition of prostaglandin H synthase (PGHS) improved relaxation in prenatally hypoxic males and tended to improve vasorelaxation in females, suggesting that impaired vasodilation was mediated via increased PGHS-dependent vasoconstriction. An enhanced contribution of endothelium-dependent hyperpolarization to coronary artery vasodilation was observed in prenatally hypoxic males and females. No changes in endothelial NO synthase (eNOS) and PGHS-1 expressions were observed, while PGHS-2 expression was decreased in only prenatally hypoxic males. At 4 months, ET-1 responses were similar between groups, while ETB inhibition (with BQ788) tended to decrease ET-1-mediated responses in only prenatally hypoxic females. At 9.5 months, ET-1-mediated responses were decreased in only prenatally hypoxic females. Our data suggest that prenatal hypoxia has long-term similar effects on the mechanisms of impaired endothelium-dependent vasodilation in coronary arteries from adult male and female offspring; however, coronary artery contractile capacity is impaired only in prenatally hypoxic females. Understanding the mechanistic pathways involved in the programming of CV disease may allow for the development of therapeutic interventions.

Placenta-derived extracellular vesicles from preeclamptic and healthy pregnancies impair ex vivo vascular endothelial function.

Preeclampsia (PE) is a pregnancy syndrome characterized by new-onset hypertension and end-organ dysfunction. The pathophysiology of PE remains undetermined, but it is thought that maternal vascular dysfunction plays a central role, potentially due, in part, to the release of syncytiotrophoblast-derived extracellular vesicles (STBEVs) into the maternal circulation by a dysfunctional placenta. STBEVs from normal pregnancies (NP) impair vascular function, but the effect of PE STBEVs (known to differ in composition with elevated circulating levels) on vascular function are not known. We hypothesized that PE STBEVs have more detrimental effects on vascular function compared with NP STBEVs. STBEVs were collected by perfusion of placentas from women with NP or PE. Mesenteric arteries from pregnant rats were incubated overnight with NP or PE STBEVs, and vascular function was assessed by wire myography. NP and PE STBEVs impaired endothelial function, partially by reducing nitric oxide (NO) bioavailability. Incubation of human umbilical vein endothelial cells with NP and PE STBEVs increased nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB) activation, reactive oxygen species, nitrotyrosine levels, and reduced NO levels. However, PE STBEVs increased NF-κB activation and nitrotyrosine levels to a lesser extent than NP STBEVs. Taken together, no greater impact of PE STBEVs compared with NP STBEVs on endothelial function was found. However, the impaired vascular function by PE STBEVs and increased levels of STBEVs in PE suggest PE STBEVs may contribute to maternal vascular dysfunction in PE. Our study further expands on the potential mechanisms that lead to adverse outcomes in PE and provides potential targets for future interventions.

Advanced Maternal Age Impairs Uterine Artery Adaptations to Pregnancy in Rats.

Advanced maternal age (≥35 years) is associated with pregnancy complications. Aging impairs vascular reactivity and increases vascular stiffness. We hypothesized that uterine artery adaptations to pregnancy are impaired with advanced age. Uterine arteries of nonpregnant and pregnant (gestational day 20) young (4 months) and aged (9 months; ~35 years in humans) Sprague-Dawley rats were isolated. Functional (myogenic tone, n = 6−10/group) and mechanical (circumferential stress-strain, n = 10−24/group) properties were assessed using pressure myography and further assessment of elastin and collagen (histology, n = 4−6/group), and matrix metalloproteinase-2 (MMP-2, zymography, n = 6/group). Aged dams had worse pregnancy outcomes, including smaller litters and fetal weights (both p < 0.0001). Only in arteries of pregnant young dams did higher pressures (>100 mmHg) cause forced vasodilation. Across the whole pressure range (4−160 mmHg), myogenic behavior was enhanced in aged vs. young pregnant dams (p = 0.0010). Circumferential stress and strain increased with pregnancy in young and aged dams (p < 0.0001), but strain remained lower in aged vs. young dams (p < 0.05). Arteries from young nonpregnant rats had greater collagen:elastin ratios than the other groups (p < 0.05). In aged rats only, pregnancy increased MMP-2 active capacity. Altered functional and structural vascular adaptations to pregnancy may impair fetal growth and development with advanced maternal age.

The Effect of Tauroursodeoxycholic Acid (TUDCA) Treatment on Pregnancy Outcomes and Vascular Function in a Rat Model of Advanced Maternal Age.

Advanced maternal age (≥35 years) increases the risk of vascular complications in pregnancy that can result in fetal growth restriction and preeclampsia. Endoplasmic reticulum (ER) stress has been linked to adverse pregnancy outcomes in these complicated pregnancies. However, the role of ER stress in advanced maternal age is not known. We hypothesize that increased ER stress contributes to altered vascular function and poor pregnancy outcomes, and that treatment with the ER-stress inhibitor TUDCA will improve pregnancy outcomes. First, young and aged non-pregnant/pregnant rats were used to assess ER stress markers in mesenteric arteries; mesenteric artery phospho-eIF2α and CHOP expression were increased in aged dams compared to young dams. In a second study, young and aged control and TUDCA-treated dams were studied on gestational day (GD) 20 (term = 22 days). TUDCA treatment was provided via the drinking water throughout pregnancy (GD0-GD20; calculated dose of 150 mg/kg/day TUDCA). ER stress markers were quantified in mesenteric arteries, blood pressure was measured, pregnancy outcomes were recorded, mesenteric and main uterine arteries were isolated and vascular function was assessed by wire myography. Aged dams had increased phospho-eIF2α and CHOP expression, reduced fetal weight, reduced litter size, and impaired uterine artery relaxation. In the aged dams, TUDCA treatment reduced phospho-eIF2α and CHOP expression, reduced blood pressure, improved fetal body weight, and tended to improve uterine artery function compared to control-treated aged dams. In conclusion, our data illustrate the role of ER stress, as well as TUDCA as a potential therapeutic that may benefit pregnancy outcomes in advanced maternal age.

Intergenerational effects of prenatal hypoxia exposure on uterine artery adaptations to pregnancies in the female offspring.

Prenatal hypoxia is a common complication of pregnancy and is associated with detrimental health outcomes, such as impaired cardiac and vascular function, in adult offspring. Exposure to prenatal hypoxia reportedly impacts the reproductive system of female offspring. Whether exposure to prenatal hypoxia influences pregnancy adaptations and outcomes in these female offspring is unknown. We hypothesised that prenatal hypoxia impairs uterine artery adaptations in pregnancies of the adult offspring. Pregnancy outcomes and uterine artery function were assessed in 14-16 weeks old non-pregnant and late pregnant (gestational day 20; term = 22 days) adult female offspring born to rats exposed to prenatal normoxia (21% oxygen) or hypoxia (11% oxygen, between days 15-21 of gestation). Compared with normoxia controls, prenatal hypoxia was associated with pregnant adult offspring having reduced placental weights in their litters, and uterine artery circumferential stress that increased with pregnancy. Overall, prenatal hypoxia adversely, albeit mildly, compromised pregnancies of adult offspring.

Chicken muscle hydrolysate reduces blood pressure in spontaneously hypertensive rats, upregulates ACE2, and ameliorates vascular inflammation, fibrosis, and oxidative stress.

Spent hens are egg-laying chicken reaching the end of their egg-laying cycle and are seen as a by-product to the egg industry. A spent hen muscle protein hydrolysate prepared by food-grade thermoase PC10F (SPH-T) has previously shown antihypertensive potential. In the present work, we further investigated its antihypertensive effect and underlying mechanisms in spontaneously hypertensive rats. There are three groups: untreated, low dose (250 mg SPH-T/kg/day body weight), and high dose (1,000 mg SPH-T/kg/day body weight). Oral administration of SPH-T over a period of 20 days reduced systolic blood pressure by 25.7 mm Hg (p < 0.001) and 11.9 mm Hg (p < 0.05), respectively, for the high- and low-dose groups. The high-dose treatment decreased the circulating level of angiotensin II (from 25.0 to 5.7 pg/ml) while increased angiotensin-converting enzyme 2 (ACE2) (from 1.3 to 3.3 IU/ml) and angiotensin (1-7) (from 37.0 to 70.1 pg/ml) significantly (p < 0.05). Furthermore, the high-dose group doubled the aortic expression of ACE2 while reduced the expression of angiotensin (Ang) II type 1 receptor (by 35%). Circulating inflammatory cytokines including tumor necrosis factor alpha and monocyte chemoattractant protein-1 as well as vascular inflammatory proteins including inducible nitric oxide synthase and vascular cell adhesion molecule-1 were attenuated by ∼15%-50% by the treatment; nitrosative stress (35%) and type I collagen synthesis (50%) in the aorta were also attenuated significantly (p < 0.05). Moreover, SPH-T possessed an umami taste (no obvious bitter taste) as analyzed by electronic tongue. PRACTICAL APPLICATION: Hypertension is a global health concern, afflicting more than 20% of adults worldwide. Uncovering the antihypertensive effect of spent hen protein hydrolysate underpinned its functional food nutraceutical applications for the prevention and treatment of hypertension.

Sex-specific effects of prenatal hypoxia on the cardiac endothelin system in adult offspring.

Fetal hypoxia, a major consequence of complicated pregnancies, impairs offspring cardiac tolerance to ischemia-reperfusion (I/R) insult; however, the mechanisms remain unknown. Endothelin-1 (ET-1) signaling through the endothelin A receptors (ETA) is associated with cardiac dysfunction. We hypothesized that prenatal hypoxia exacerbates cardiac susceptibility to I/R via increased ET-1 and ETA levels, whereas ETA inhibition ameliorates this. Pregnant Sprague-Dawley rats were exposed to normoxia (21% O2) or hypoxia (11% O2) on gestational days 15-21. Offspring were aged to 4 mo, and hearts were aerobically perfused or subjected to ex vivo I/R, with or without preinfusion with an ETA antagonist (ABT-627). ET-1 levels were assessed with ELISA in aerobically perfused and post-I/R left ventricles (LV). ETA and ETB levels were assessed by Western blotting in nonperfused LV. As hypothesized, ABT-627 infusion tended to improve post-I/R recovery in hypoxic females (P = 0.0528); however, surprisingly, ABT-627 prevented post-I/R recovery only in the hypoxic males (P < 0.001). ET-1 levels were increased in post-I/R LV in both sexes regardless of the prenatal exposure (P < 0.01). ETA expression was similar among all groups, whereas ETB (isoform C) levels were decreased in prenatally hypoxic females (P < 0.05). In prenatally hypoxic males, ETA signaling may be essential for tolerance to I/R, whereas in prenatally hypoxic females, ETA may contribute to cardiac dysfunction. Our data illustrate that understanding the prenatal history has critical implications for treatment strategies in adult chronic diseases.NEW & NOTEWORTHY We demonstrated that prenatal hypoxia (a common condition of pregnancy) can have profound differential effects on treatment strategies in adult cardiovascular disease. Our data using a rat model of prenatal hypoxia demonstrated that, as adults, although inhibition of endothelin (ETA) receptors before an ex vivo cardiac ischemic insult improved recovery in females, it strikingly prevented recovery in males. Our data indicate a sex-specific effect of prenatal hypoxia on the cardiac ET-1 system in adult offspring.

Programming of weight and obesity across the lifecourse by the maternal metabolic exposome: A systematic review.

Exposome research aims to comprehensively understand the multiple environmental exposures that influence human health. To date, much of exposome science has focused on environmental chemical exposures and does not take a lifecourse approach. The rising prevalence of obesity, and the limited success in its prevention points to the need for a better understanding of the diverse exposures that associate with, or protect against, this condition, and the mechanisms driving its pathogenesis. The objectives of this review were to 1. evaluate the evidence on the maternal metabolic exposome in the programming of offspring growth/obesity and 2. identify and discuss the mechanisms underlying the programming of obesity. A systematic review was conducted following PRISMA guidelines to capture articles that investigated early life metabolic exposures and offspring weight and/or obesity outcomes. Scientific databases were searched using pre-determined indexed search terms, and risk of bias assessments were conducted to determine study quality. A final total of 76 articles were obtained and extracted data from human and animal studies were visualised using GOfER diagrams. Multiple early life exposures, including maternal obesity, diabetes and adverse nutrition, increase the risk of high weight at birth and postnatally, and excess adipose accumulation in human and animal offspring. The main mechanisms through which the metabolic exposome programmes offspring growth and obesity risk include epigenetic modifications, altered placental function, altered composition of the gut microbiome and breast milk, and metabolic inflammation, with downstream effects on development of the central appetite system, adipose tissues and liver. Understanding early life risks and protectors, and the mechanisms through which the exposome modifies health trajectories, is critical for developing and applying early interventions to prevent offspring obesity later in life.

Increased oxidative stress and endothelial activation in umbilical veins from pregnancies diagnosed with preeclampsia.

Vascular dysfunction is a hallmark of cardiovascular disease (CVD). Offspring from preeclamptic pregnancies are at risk of CVD later in life. Whether fetal vasculature from preeclamptic pregnancies displays signs of vascular dysfunction (i.e., oxidative/nitrosative stress, endothelial activation) associated with increased expression of lectin-like oxidized LDL receptor-1 (LOX-1) and angiotensin-II type-1 receptor (AT1) is unknown. We demonstrated increased superoxide, nitrotyrosine and ICAM-1 levels in umbilical vein tissues of preeclamptic vs. normal pregnancies; without changes in LOX-1 and AT1 levels. Our findings suggest that the fetal vasculature may be impacted in preeclampsia, which could contribute to an increased risk of offspring CVD.

Altered Vascular Adaptations to Pregnancy in a Rat Model of Advanced Maternal Age.

Advanced maternal age (≥35 years old) increases the risk of pregnancy complications such as preeclampsia and fetal growth restriction. We previously demonstrated vascular dysfunction and abnormal pregnancy outcomes in a rat model of advanced maternal age. However, vascular adaptations to pregnancy in aging were not studied. We hypothesize that advanced maternal age is associated with a more vasoconstrictive phenotype due to reduced nitric oxide (NO) and increased activity of matrix metalloproteinases (MMPs), contributing to impaired vascular adaptations to pregnancy. A rat model of advanced maternal age was used: young (4 months) and aged (9.5 months; ∼35 years in humans) non-pregnant and pregnant rats. On gestational day 20 (term = 22 days; non-pregnant rats were aged-matched), blood pressure and heart rate were measured (tail cuff plethysmography) and vascular function was assessed in mesenteric arteries (wire myography). Endothelium-dependent relaxation to methylcholine (MCh) was assessed in the presence/absence of nitric oxide synthase inhibitor (L-NAME), or inhibitors of endothelium-dependent hyperpolarization (EDH; apamin and TRAM-34). Vasoconstriction responses to big endothelin-1 (bigET-1), in the presence/absence of MMPs-inhibitor (GM6001) or endothelin converting enzyme (ECE-1) inhibitor (CGS35066), in addition, ET-1 responsiveness, were measured. Blood pressure was elevated only in aged non-pregnant rats (p < 0.001) compared to all other groups. MCh responses were not different, however, L-NAME decreased maximum vasodilation in young (p < 0.01) and aged pregnant rats (p < 0.001), and decreased MCh sensitivity in young non-pregnant rats (p < 0.01), without effects in aged non-pregnant rats. EDH contribution to relaxation was similar in young non-pregnant, and aged non-pregnant and pregnant rats, while EDH-mediated relaxation was absent in young pregnant rats (p < 0.001). BigET-1 responses were enhanced in aged non-pregnant (p < 0.01) and pregnant rats (p < 0.05). No significant changes in bigET-1 conversion occurred in the presence of MMP-inhibitor, whereas ECE-1 inhibition reduced bigET-1 constriction in aged rats (p < 0.01). No differences in ET-1 sensitivity were observed. In conclusion, contrary to our hypothesis, reduced blood pressure, and an increased EDH-dependent contribution to vasodilation suggest a compensatory mechanism that may reflect beneficial adaptations in these aged rats that were able to maintain pregnancy. These data increase our understanding of how the vascular adaptive pathways in pregnancy compensate for advanced maternal age.

Placental treatment improves cardiac tolerance to ischemia/reperfusion insult in adult male and female offspring exposed to prenatal hypoxia.

Offspring born from complicated pregnancies are at greater risk of cardiovascular disease in adulthood. Prenatal hypoxia is a common pregnancy complication that results in placental oxidative stress and impairs fetal development. Adult offspring exposed to hypoxia during fetal life are more susceptible to develop cardiac dysfunction, and show decreased cardiac tolerance to an ischemia/reperfusion (I/R) insult. To improve offspring cardiac outcomes, we have assessed the use of a placenta-targeted intervention during hypoxic pregnancies, by encapsulating the mitochondrial antioxidant MitoQ into nanoparticles (nMitoQ). We hypothesized that maternal nMitoQ treatment during hypoxic pregnancies improves cardiac tolerance to I/R insult in adult male and female offspring. Pregnant Sprague-Dawley rats were exposed to normoxia (21 % O2) or hypoxia (11 % O2) from gestational day 15-20, after injection with 100 µL saline or nMitoQ (125 µM) on GD15 (n=6-8/group). Male and female offspring were aged to 4 months. Both male and female offspring from hypoxic pregnancies showed reduced cardiac tolerance to I/R (assessed ex vivo using the isolated working heart technique) which was ameliorated by nMitoQ treatment. To identify potential molecular mechanisms for the changes in cardiac tolerance to I/R, cardiac levels/phosphorylation of proteins important for intracellular Ca2+ cycling were assessed with Western blotting. In prenatally hypoxic male offspring, improved cardiac recovery from I/R by nMitoQ was accompanied by increased cardiac phospholamban and phosphatase 2Ce levels, and a trend to decreased Ca2+/calmodulin-dependent protein kinase IIδ phosphorylation. In contrast, in female offspring, nMitoQ treatment in hypoxic pregnancies increased phospholamban and protein kinase Cε phosphorylation. Maternal nMitoQ treatment improves cardiac tolerance to I/R insult in adult offspring and thus has the potential to improve the later-life trajectory of cardiovascular health of adult offspring born from pregnancies complicated by prenatal hypoxia.