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Maternal obesity (MO) is a significant cause of increased cardiometabolic risk in offspring, who present endothelial dysfunction at birth. Alterations in physiologic and cellular redox status are strongly associated with altered gene regulation in arterial endothelium. However, specific mechanisms by which the pro-oxidant fetal environment in MO could modulate the vascular gene expression and function during the offspring's postnatal life are elusive. We tested if oxidative stress could reprogram the antioxidant-coding gene's response to a pro-oxidant challenge through an epigenetic transcriptional memory (ETM) mechanism. A pro-oxidant double-hit protocol was applied to human umbilical artery endothelial cells (HUAECs) and EA.hy 926 endothelial cell lines. The ETM acquisition in the HMOX1 gene was analyzed by RT-qPCR. HMOX1 mRNA decay was evaluated by Actinomycin-D treatment and RT-qPCR. To assess the chromatin accessibility and the enrichment of NRF2, RNAP2, and phosphorylation at serin-5 of RNAP2, at HMOX1 gene regulatory regions, were used DNase HS-qPCR and ChIP-qPCR assays, respectively. The CpG methylation pattern at the HMOX1 core promoter was analyzed by DNA bisulfite conversion and Sanger sequencing. Data were analyzed using two-way ANOVA, and p < 0.05 was statistically significant. Using a pro-oxidant double-hit protocol, we found that the Heme Oxygenase gene (HMOX1) presents an ETM response associated with changes in the chromatin structure at the promoter and gene regulatory regions. The ETM response was characterized by a paused-RNA Polymerase 2 and NRF2 enrichment at the transcription start site and Enhancer 2 of the HMOX1 gene, respectively. Changes in DNA methylation pattern at the HMOX1 promoter were not a hallmark of this oxidative stress-induced ETM. These data suggest that a pro-oxidant milieu could trigger an ETM at the vascular level, indicating a potential epigenetic mechanism involved in the increased cardiovascular risk in the offspring of women with obesity., (© 2024 Wiley Periodicals LLC.)

Fetal growth restriction (FGR) is a common outcome in human suboptimal gestation and is related to prenatal origins of cardiovascular dysfunction in offspring. Despite this, therapy of human translational potential has not been identified. Using human umbilical and placental vessels and the chicken embryo model, we combined cellular, molecular, and functional studies to determine whether N-acetylcysteine (NAC) and hydrogen sulphide (H 2 S) protect cardiovascular function in growth-restricted unborn offspring. In human umbilical and placental arteries from control or FGR pregnancy and in vessels from near-term chicken embryos incubated under normoxic or hypoxic conditions, we determined the expression of the H 2 S gene CTH (i.e. cystathionine γ-lyase) (via quantitative PCR), the production of H 2 S (enzymatic activity), the DNA methylation profile (pyrosequencing) and vasodilator reactivity (wire myography) in the presence and absence of NAC treatment. The data show that FGR and hypoxia increased CTH expression in the embryonic/fetal vasculature in both species. NAC treatment increased aortic CTH expression and H 2 S production and enhanced third-order femoral artery dilator responses to the H 2 S donor sodium hydrosulphide in chicken embryos. NAC treatment also restored impaired endothelial relaxation in human third-to-fourth order chorionic arteries from FGR pregnancies and in third-order femoral arteries from hypoxic chicken embryos. This NAC-induced protection against endothelial dysfunction in hypoxic chicken embryos was mediated via nitric oxide independent mechanisms. Both developmental hypoxia and NAC promoted vascular changes in CTH DNA and NOS3 methylation patterns in chicken embryos. Combined, therefore, the data support that the effects of NAC and H 2 S offer a powerful mechanism of human translational potential against fetal cardiovascular dysfunction in complicated pregnancy. KEY POINTS: Gestation complicated by chronic fetal hypoxia and fetal growth restriction (FGR) increases a prenatal origin of cardiovascular disease in offspring, increasing interest in antenatal therapy to prevent against a fetal origin of cardiovascular dysfunction. We investigated the effects between N-acetylcysteine (NAC) and hydrogen sulphide (H 2 S) in the vasculature in FGR human pregnancy and in chronically hypoxic chicken embryos. Combining cellular, molecular, epigenetic and functional studies, we show that the vascular expression and synthesis of H 2 S is enhanced in hypoxic and FGR unborn offspring in both species and this acts to protect their vasculature. Therefore, the NAC/H 2 S pathway offers a powerful therapeutic mechanism of human translational potential against fetal cardiovascular dysfunction in complicated pregnancy., (© 2024 The Author(s). The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Objective: The aim of the study is to assess the correlation of renal regional tissue saturation of oxygen (RrSO 2 ) measured by near-infrared spectroscopy (NIRS) in preterm neonates to venous oxygen saturation (SvO 2 ) obtained from umbilical venous catheters (UVCs), arterial oxygen saturation (SaO 2 ) obtained from umbilical artery catheters (UACs), and capillary oxygen saturation (ScO 2 ) from capillary heel blood draws., Study Design: A secondary analysis of a prospective RrSO 2 monitoring study in preterm neonates born <32 weeks gestational age. Neonates with any blood gas obtained during RrSO 2 monitoring were included. RrSO 2 was compared with simultaneous O 2 saturation using non-parametric Mann Whitney U-test and Spearman correlation coefficient., Results: In 35 neonates, 25 UVC, 151 UAC, and 68 heel capillary specimens were obtained. RrSO 2 was lower than the median SvO 2 (58.8 vs. 78.9, p <0.01), SaO 2 (51.0 vs. 93.2, p <0.01), and ScO 2 (62.2 vs. 94.25, p <0.01). RrSO 2 values correlated to both SaO 2 and ScO 2 ( r  = 0.32; p <0.01, r  = 0.26; p  = 0.03), but not SvO 2 ( r  = 0.07; p  = 0.74)., Conclusion: In this secondary analysis, RrSO 2 was consistently lower than blood gas O 2 saturations and correlated with SaO 2 and ScO 2 but not SvO 2 . Lack of a correlation to SvO 2 could be due to the small UVC sample size limiting statistical power. Future studies should prospectively evaluate if RrSO 2 truly primarily reflects venous oxygenation in preterm neonates., Key Points: · Renal oxygenation correlates with arterial and capillary oxygen saturation.. · Renal oxygenation did not correlate with venous oxygenation from umbilical venous catheters.. · Studies are needed to determine if renal oxygenation primarily reflects venous or arterial oxygen.., Competing Interests: None declared., (Thieme. All rights reserved.)

The objective of this study is to investigate the expression and influence of adenosine triphosphate-sensitive potassium channel (KATP) in human umbilical arterial smooth muscle cells (HUASMCs) of patients with hypertensive disorders of pregnancy (HDP). Western blotting was used to detect the protein expression levels of KATP inwardly rectifying potassium channel (Kir)6.1 and sulphonylurea receptor (SUR)2B subunits in HUASMCs from patients with normal parturients (NP), gestational hypertension (GH), chronic hypertension (CH), preeclampsia (PE) and chronic hypertension with superimposed preeclampsia (CHSP), respectively. There was no significant difference in the protein expression of Kir6.1 subunit in NP group, GH group, CH group, PE group and CHSP group (P > 0.05). The protein expression of SUR2B subunit was gradually decreased in NP group, GH group, CH group, PE group and CHSP group, with statistically significant difference among the groups (P < 0.05). The altered expression level of KATP SUR2B subunit may be involved in the pathogenesis of HDP. The severity of HDP may be related to the degree of decrease of SUR2B subunit., (© 2024. The Author(s).)

Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in the plastics industry, including food container, toys, and medical equipment. We analyzed the effect of BPA in human umbilical artery contractility and expression of some proteins modulating this function, such as ionic channels and proteins involved in the cGMP pathway. Using standard organ bath technique, rings of human umbilical arteries without endothelium were contracted by 5-HT (1 μM) and histamine (10 μM) and the effect of different concentrations of BPA (1 nM-100 μM) was analyzed. The results showed that BPA is a vasodilator of these arteries in a concentration-dependent way. Besides, qPCR studies on human umbilical smooth muscle cells (HUSMC) allowed to analyze the effects of BPA on gene expression. Thus, 12-h exposition to BPA induced reduction of expression of L-type calcium channels (LTCC), alpha subunit of BK Ca channels, and Kvβ1 and Kvβ3 from Kv channels. BPA also decreased the expression of soluble guanylate cyclase (sGC) and natriuretic peptide receptor type A (NPRA), meanwhile increasing that of PKG, proteins involved in vasodilation of human umbilical arteries (HUA) by cGMP. Further studies will be necessary to increase knowledge about the implications of these changes induced by BPA exposure., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Carvacrol (CRV) is the main compound of essential oils extracted primarily from Thymus and Origanum species. Its various biological activities were confirmed: antioxidant, anti-inflammatory, antibacterial, antifungal, anti-tumour, antinematodal, and vasorelaxant action. Although vasodilation mediated by CRV was previously described, the exact mechanism of its action has not yet been established. Hence, the aim of this study was to investigate CRV vasoactivity on human umbilical arteries (HUA) and the different pathways involved in its mechanism of action using the tissue bath methodology. CRV caused a significant decrease in vascular tension of 5-HT-pre-contracted umbilical arteries, with EC 50 of 442.13 ± 33.8 µmol/L (mean ± standard error of the mean-SEM). At 300 µmol/L, CRV shifted downward the 5-HT concentration-response curve with a statistical significance of p  < 0.001 obtained for the four highest concentrations. At a concentration of 1 mmol/L, CRV completely abolished BaCl 2 -induced contraction in Ca 2+ -free Krebs-Ringer bicarbonate solution and the BAY K 8644-induced contraction in Krebs-Ringer bicarbonate solution ( p  < 0.001). Isopentenyl pyrophosphate, the antagonist of TRPV 3 channel, was able to decrease the efficacy of CRV ( p  < 0.001). The blocking of L-type Ca 2+ channels on smooth muscle cells is the most probable mechanism of CRV-induced vasorelaxation. However, the role of TRPV 3 channels in CRV-induced vasodilation of HUA cannot be excluded either.

Aims: We investigated the changes in large-conductance Ca 2+ -activated K + (BK Ca ) channels from human umbilical arterial smooth muscle cells experiencing gestational diabetes mellitus (GDM)., Main Methods: Whole-cell patch-clamp technique, arterial tone measurement, RT-PCR, Quantitative real-time PCR, western blot were performed in human umbilical arterial smooth muscle cells., Key Findings: Whole-cell BK Ca current density was decreased in the GDM group compared with the normal group. The vasorelaxant effects of the synthetic BK Ca channel activator NS-1619 (10 μM) were impaired in the GDM group compared with the normal group. Reverse-transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, and western blot analyses suggested that the mRNA, total RNA, and protein expression levels of the BK Ca channel were decreased in the GDM group relative to the normal group. In addition, the expression levels of protein kinase A and protein kinase G, which regulate BK Ca channel activity, remained unchanged between the groups. Applying the BK Ca channel inhibitor paxilline (10 μM) induced vasoconstriction and membrane depolarization of isolated umbilical arteries in the normal group but showed less of an effect on umbilical arteries in the GDM group., Significance: Our results demonstrate for the first time impaired BK Ca current and BK Ca channel-induced vasorelaxation activities that were not caused by impaired BK Ca channel-regulated protein kinases, but by decreased expression of the BK Ca channels, in the umbilical arteries of GDM patients., (Copyright © 2021. Published by Elsevier Inc.)

Objective: To investigate the predictive value of pre-induction digital examination, sonographic measurements and parity for the prediction of non-reassuring fetal status and cord arterial pH < 7.2 prior to the induction of labor (IOL)., Method: This was a prospective observational study, including 384 term pregnancies undergoing IOL. Before the IOL, the Bishop score (BS) by digital examination, sonographic Doppler parameters and the estimated fetal weight (EFW) was assessed. The fetal cord arterial was sampled to measure the pH at delivery. Multivariate logistic regression analysis was performed to identify independent predictors of non-reassuring fetal status and low cord arterial pH., Results: Forty four cases (11.5%) had non-reassuring fetal status, and 76 cases (19.8%) had fetal cord arterial pH < 7.2. In the non-reassuring fetal status group, the incidence of cord arterial pH < 7.2 was significantly higher than that in the normal fetal heart rate group (χ 2  = 6.401, p = 0.011). Multivariate analysis indicated that significant independent predictors of non-reassuring fetal status were nulliparity (adjusted odds ratio [AOR]: 3.746, p = 0.003), EFW < 10 th percentile (AOR: 3.764, p = 0.003) and cerebroplacental ratio (CPR) < 10 th centile (AOR:4.755, p < 0.001). In the prediction of non-reassuring fetal status, the performance of the combination of nulliparity and EFW < 10th percentile was improved by the addition of CPR < 10th percentile (AUC: 0.681, (95%CI: 0.636 to 0.742) vs 0.756, (95%CI:0.713 to 0.795)), but the difference was not significant (DeLong test: z = 1.039, p = 0.053).. None of the above variables were predictors of cord arterial pH < 7.2., Conclusion: The risk of fetal acidosis has increased in cases of non-reassuring fetal status. Nulliparity, small for gestational age and CPR < 10th centile are independent predictors for non-reassuring fetal status in term fetuses, though the addition of CPR < 10th centile could not significantly improve the screening accuracy.

Aims: Human umbilical cord vessels (HUCV) release dopamine and nitric oxide (NO). This study aims to verify whether HUCV release nitrocatecholamines such as 6-nitrodopamine (6-ND)., Main Methods: Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was used to identify 6-ND release from HUCV rings incubated in Krebs-Henseileit's solution. Vascular reactivity of HUCV rings was tested (with and without endothelium integrity) by suspension of the rings in an organ bath under isometric tension and application of 6-ND and other known mediators., Key Findings: LC-MS/MS revealed a basal release of 6-ND from endothelium intact from both human umbilical artery (HUA) and vein (HUV). The endothelium intact release was inhibited by the pre-treatment with NO synthesis inhibitor L-NAME (100 μM). In contrast to dopamine, noradrenaline and adrenaline, 6-ND did not contract HUCV, even in presence of L-NAME or ODQ. 6-ND (10 μM) produced a rightward shift of the concentration-response curves to dopamine (pA2: 5.96 in HUA and 5.72 in HUV). Contractions induced by noradrenaline and adrenaline were not affected by pre-incubation with 6-ND (10 μM). In U-46619 (10 nM) pre-contracted endothelium intact tissues, 6-ND and the dopamine D 2 -receptor antagonist haloperidol induced concentration-dependent relaxations of HUA and HUV. Incubation with the dopamine D 1 -receptor antagonist SCH-23390 (10 nM) abolished relaxation induced by fenoldopam but did not affect those induced by 6-ND., Significance: 6-ND is released by HUCV and acts as a selective dopamine D 2 -receptor antagonist in this tissue. This represents a novel mechanism by which NO may modulate vascular reactivity independently of cGMP production., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The aim of this study is to establish the expression of ATP-sensitive potassium channels(KATP) in human umbilical arteries with severe pre-eclampsia. Real-time quantitative PCR and western blotting were used to detect the mRNA and protein expression levels of KATP channel subunits Kir6.1 and SUR2B in human umbilical arteries from normal pregnant and those with severe pre-eclampsia, early onset severe pre-eclampsia and late onset severe pre-eclampsia. The mRNA and protein levels of SUR2B in the severe pre-eclampsia group were lower than those in the normal group (P < 0.001), and the expression of Kir6.1 was not statistically significant between the two groups (P > 0.05). The mRNA and protein levels of SUR2B in early onset severe pre-eclampsia group were lower than those in late onset severe pre-eclampsia group (P < 0.001). There was no significant difference in expression of Kir6.1 between the two groups (P > 0.05). The mRNA and protein expression levels of SUR2B in pregnant women with severe pre-eclampsia were lower than those in normal pregnant women, suggesting that the expression of the SUR2B of the KATP channel may be related to the occurrence and development of severe pre-eclampsia. Compared with late onset severe pre-eclampsia, the mRNA and protein expression levels of SUR2B were lower in the umbilical arteries of women with early onset severe pre-eclampsia, suggesting that the occurrence time of severe pre-eclampsia may be related to the extent reduced expression of the SUR2B of the KATP channel.

Progesterone acts directly on vascular smooth muscle cells (VSMCs) through activation of membrane progesterone receptor α (mPRα)-dependent signaling to rapidly decrease cytosolic Ca 2+ concentrations and induce muscle relaxation. However, it is not known whether this progesterone action involves uptake of Ca 2+ by the sarco/endoplasmic reticulum (SR) and increased sarco/endoplasmic reticulum Ca 2+ -ATPase (SERCA) activity. The present results show that treatment of cultured human VSMCs with progesterone and the selective mPR agonist Org OD-02-0 (OD 02-0) but not with the nuclear PR agonist R5020 increased SERCA protein expression, which was blocked by knockdown of mPRα with siRNA. Moreover, treatments with progesterone and OD 02-0, but not with R5020, increased phospholamban (PLB) phosphorylation, which would result in disinhibition of SERCA function. Progesterone and OD 02-0 significantly increased Ca 2+ levels in the SR and caused VSMC relaxation. These effects were blocked by pretreatment with cyclopiazonic acid (CPA), a SERCA inhibitor, and by knockdown of SERCA2 with siRNA, suggesting that SERCA2 plays a critical role in progesterone induction of VSMC relaxation. Treatment with inhibitors of inhibitory G proteins (Gi, NF023), MAP kinase (AZD 6244), Akt/Pi3k (wortmannin), and a Rho activator (calpeptin) blocked the progesterone- and OD 02-0-induced increase in Ca 2+ levels in the SR and SERCA expressions. These results suggest that the rapid effects of progesterone on cytosolic Ca 2+ levels and relaxation of VSMCs through mPRα involve regulation of the functions of SERCA2 and PLB through Gi, MAP kinase, and Akt signaling pathways and downregulation of RhoA activity. NEW & NOTEWORTHY The rapid effects of progesterone on cytosolic Ca 2+ levels and relaxation of VSMCs through mPRα involve regulation of the functions of SERCA2 and PLB through Gi, MAP kinase, and Akt signaling pathways and downregulation of RhoA activity.

Although cardiovascular devices are mostly implanted in arteries or to replace arteries, in vitro studies on implant endothelialization are commonly performed with human umbilical cord-derived venous endothelial cells (HUVEC). In light of considerable differences, both morphologically and functionally, between arterial and venous endothelial cells, we here compare HUVEC and human umbilical cord-derived arterial endothelial cells (HUAEC) regarding their equivalence as an endothelial cell in vitro model for cardiovascular research. No differences were found in either for the tested parameters. The metabolic activity and lactate dehydrogenase, an indicator for the membrane integrity, slightly decreased over seven days of cultivation upon normalization to the cell number. The amount of secreted nitrite and nitrate, as well as prostacyclin per cell, also decreased slightly over time. Thromboxane B2 was secreted in constant amounts per cell at all time points. The Von Willebrand factor remained mainly intracellularly up to seven days of cultivation. In contrast, collagen and laminin were secreted into the extracellular space with increasing cell density. Based on these results one might argue that both cell types are equally suited for cardiovascular research. However, future studies should investigate further cell functionalities, and whether arterial endothelial cells from implantation-relevant areas, such as coronary arteries in the heart, are superior to umbilical cord-derived endothelial cells.

Arterial marker genes EphrinB2 and HEY2 are essential for cardiovascular development and postnatal neovascularization. Our previous study confirmed that E2F1 could activate the transcription of EphrinB2 and HEY2 in human mesenchymal stem cells; however, the detailed mechanism has not been resolved yet. In this study, we focused on the interaction between E2F1 and DNMT3A, a de novo DNA methyltransferase, on regulating the expression of EphrinB2 and HEY2, and explored the potential mechanisms. Gain- and loss-of-function experiments implicated the positive effect of E2F1 on the expression of EphrinB2 and HEY2 and tube formation in human umbilical artery endothelial cells. Accumulation of DNMT3A decreased the levels of EphrinB2 and HEY2, and impaired tube formation induced by E2F1, while inhibiting DNMT3A by RNA interference augmented their expression and angiogenesis in E2F1-trasfected cells. We then asked whether the low expressions of EphrinB2 and HEY2 induced by DNMT3A are related to the methylation status of their promoters. Surprisingly, the methylation status of the CpG islands in the promoter region was not significantly affected by overexpression of exogenous DNMT3A. Furthermore, the interaction between E2F1 and DNMT3A was confirmed by co-immunoprecipitation. DNMT3A could inhibit the transcription of EphrinB2 and HEY2 promoters by affecting the binding of E2F1 to its recognition sequences as revealed by luciferase reporter assay and chromatin immunoprecipitation. These results identified a novel mechanism underlying the cooperation of DNMT3A with E2F1 on regulating target gene expression, and revealed their roles in the angiogenic process., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Clinical conditions associated with hypoxia and oxidative stress, such as fetal growth restriction (FGR), results in endothelial dysfunction. Previous reports show that changes in eNOS expression under these conditions are tightly controlled by DNA methylation and histone posttranslational modifications. However, the contribution of an orchestrating epigenetic mechanism, such as miRNAs, on the NO-related genes expression has not been addressed. We aimed to determine the levels of miRNAs highly expressed in normal endothelial cells (EC), miR-21 and miR-126, in FGR human umbilical artery EC (HUAEC), and their effects on hypoxia-dependent regulation of both, NO-related and oxidative stress-related genes. Results were validated by transcriptome analysis of HUAEC cultured under chronic low oxygen conditions. Cultured FGR-HUAEC showed decreased hsa-miR-21, DDAH1, SOD1, and NRF2, but increased miR-126, NOX4, and eNOS levels, compared with controls. MiR-21-5p levels in FGR were associated with increased hg-miR-21 gene promoter methylation, with no changes in hg-miR-126 gene promoter methylation. HUAEC exposed to hypoxia showed a transient increase in eNOS and DDAH11, paralleled by decrease miR-21-5p levels, but no changes in miR-126-3p and the other genes under study. Transcriptome profiling showed an inverse relationship among miR-21 and several transcripts targeted by miR-21 in HUAEC exposed to hypoxia, meanwhile miR-21-5p-mimic decreased eNOS and DDAH1 transcripts stability, blocking their induction by hypoxia. Consequently, FGR programs a hypoxia-related miRNA that contributes to the regulation of the NO pathway, involving a direct effect of miR-21-5p on eNOS transcript stability, not previously reported. Moreover, hypoxia downregulates miR-21-5p, contributing to increasing the expression of NO-related genes in arterial endothelial cells., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Prenatal testosterone (T) excess results in reproductive and metabolic perturbations in female sheep that closely recapitulate those seen in women with polycystic ovary syndrome (PCOS). At the neuroendocrine level, prenatal T-treated sheep manifest increased pituitary sensitivity to GnRH and subsequent LH hypersecretion. In this study, we investigated the early effects of gestational T-treatment on LH secretion and pituitary function in the female sheep fetus. Additionally, because prenatal T effects can be mediated via the androgen receptor or due to changes in insulin homeostasis, prenatal co-treatment with an androgen antagonist (flutamide) or an insulin sensitizer (rosiglitazone) were tested., Methods: Pregnant sheep were treated from gestational day (GD) 30 to 90 with either: 1) vehicle (control); 2) T-propionate (~ 1.2 mg/kg); 3) T-propionate and flutamide (15 mg/kg/day); and 4) T-propionate and rosiglitazone (8 mg/day). At GD 90, LH concentrations were determined in the uterine artery (maternal) and umbilical artery (fetal), and female fetuses were euthanized. Pituitary glands were collected, weighed, and protein level of several key regulators of LH secretion was determined., Results: Fetal pituitary weight was significantly reduced by prenatal T-treatment. Flutamide completely prevented the reduction in pituitary weight, while rosiglitazone only partially prevented this reduction. Prenatal T markedly reduced fetal LH concentrations and flutamide co-treatment partially restored LH to control levels. Prenatal T resulted in a marked reduction in LH-β protein level, which was associated with a reduction in GnRH receptor and estrogen receptor-α levels and an increase in androgen receptor. With the exception of androgen receptor, flutamide co-treatment completely prevented these alterations in the fetal pituitary, while rosiglitazone largely failed to prevent these changes. Prenatal T-treatment did not alter the protein levels of insulin receptor-β and activation (phosphorylation) of the insulin signaling pathways., Conclusions: These findings demonstrate that prenatal T-treatment results in reduced fetal LH secretion, reduced fetal pituitary weight, and altered protein levels of several regulators of gonadotropin secretion. The observations that flutamide co-treatment prevented these changes suggest that programming during fetal development likely occurs via direct androgen actions.

The umbilical artery lumen closes rapidly at birth, preventing neonatal blood loss, whereas the umbilical vein remains patent longer. Here, analysis of umbilical cords from humans and other mammals identified differential arterial-venous proteoglycan dynamics as a determinant of these contrasting vascular responses. The umbilical artery, but not the vein, has an inner layer enriched in the hydrated proteoglycan aggrecan, external to which lie contraction-primed smooth muscle cells (SMC). At birth, SMC contraction drives inner layer buckling and centripetal displacement to occlude the arterial lumen, a mechanism revealed by biomechanical observations and confirmed by computational analyses. This vascular dimorphism arises from spatially regulated proteoglycan expression and breakdown. Mice lacking aggrecan or the metalloprotease ADAMTS1, which degrades proteoglycans, demonstrate their opposing roles in umbilical vascular dimorphism, including effects on SMC differentiation. Umbilical vessel dimorphism is conserved in mammals, suggesting that differential proteoglycan dynamics and inner layer buckling were positively selected during evolution., Competing Interests: SN, JS, VP, SM, CK, AO, CN, CH, BC, MD, NS, KT, MV, DS, EP, JH, SA No competing interests declared, (© 2020, Nandadasa et al.)

Electrical field stimulation (EFS) induces contractions of both snake aorta and human umbilical cord vessels (HUCV) which were dependent on the presence of the endothelium. This study aimed to establish the nature of the mediator(s) responsible for EFS-induced contractions in HUCV. Rings with or without endothelium from human umbilical artery (HUA) or vein (HUV) were mounted in organ bath chambers containing oxygenated, heated Krebs-Henseleit's solution. Basal release of dopamine (DA), noradrenaline, and adrenaline was measured by LC-MS-MS. Cumulative concentration-response curves were performed with dopamine in the absence and in the presence of L-NAME or of dopamine antagonists. EFS studies were performed in the presence and absence of L-NAME, the α-adrenergic blockers prazosin and idazoxan, and the dopamine antagonists SCH-23390 and haloperidol. Tyrosine hydroxylase (TH) and dopa-decarboxylase (DDC) were studied by immunohistochemistry and fluorescence in situ hybridizations. Basal release of dopamine requires an intact endothelium in both HUA and HUV. TH and DDC are present only in the endothelium of both HUA and HUV as determined by immunohistochemistry. Dopamine induced contractions in HUA only in the presence of L-NAME. Dopamine-induced contractions in HUV were strongly potentiated by L-NAME. The EFS-induced contractions in both HUA and HUV were potentiated by L-NAME and inhibited by the D2-like receptor antagonist haloperidol. The α-adrenergic antagonists prazosin and idazoxan and the D1-like receptor antagonist SCH-23390 had no effect on the EFS-induced contractions of HUA and HUV. Endothelium-derived dopamine is a major modulator of HUCV reactivity in vitro., (© 2020 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.)

The decellularization of long segments of tubular tissues such as blood vessels may be improved by perfusing decellularization solution into their lumen. Particularly, transmural flow that may be introduced by the perfusion, if any, is beneficial to removing immunogenic cellular components in the vessel wall. When human umbilical arteries (HUAs) were perfused at a transmural pressure, however, very little transmural flow was observed. We hypothesized that a watertight lining at the abluminal surface of HUAs hampered the transmural flow and tested the hypothesis by subjecting the abluminal surface to enzyme digestion. Specifically, a highly viscous collagenase solution was applied onto the surface, thereby restricting the digestion to the surface. The localized digestion resulted in a water-permeable vessel without damaging the vessel wall. The presence of the abluminal lining and its successful removal were also supported by evidence from SEM, TEM, and mechanical testing. The collagenase-treated HUAs were decellularized with 1% sodium dodecyl sulfate (SDS) solution under either rotary agitation, simple perfusion, or pressurized perfusion. Regardless of decellularization conditions, the decellularization of HUAs was significantly enhanced after the abluminal lining removal. Particularly, complete removal of DNA was accomplished in 24 h by pressurized perfusion of the SDS solution. We conclude that the removal of the abluminal lining can improve the perfusion-assisted decellularization.

Carveol is a monoterpene present in the structure of many plant products. It has a variety of biological activities: antioxidant, anticancer and vasorelaxation. However, studies investigating the effect of monoterpenoids on human vessels have not yet been described. Thus, the present study aimed to characterize the effect of (-)-carveol on human umbilical arteries (HUAs). HUA ring preparations were isolated and subjected to isometric tension recordings of umbilical artery smooth muscle contractions. (-)-Carveol exhibited a significant vasorelaxant effect on KCl and 5-HT-induced contractions, obtaining EC 50 values of 344.25 ± 8.4 and 175.82 ± 4.05 µM, respectively. The participation of calcium channels in the relaxation produced by (-)-carveol was analyzed using vessels pre-incubated with (-)-carveol (2000 µM) in a calcium-free medium, where the induction of contractions was abolished. The vasorelaxant effect of (-)-carveol on HUAs was reduced by tetraethylammonium (TEA), which increased the (-)-carveol EC 50 to 484.87 ± 6.55 µM. The present study revealed that (-)-carveol possesses a vasorelaxant activity in HUAs, which was dependent on the opening of calcium and potassium channels. These results pave the way for further studies involving the use of monoterpenoids for the vasodilatation of HUAs. These molecules have the potential to treat diseases such as pre-eclampsia, which is characterized by resistance in umbilical arteries.

Our objective was to determine whether chorionicity affects umbilical cord blood acid-base parameters of the second twin. This was a retrospective cohort of twin pregnancies delivered at ≥23 weeks of gestation at a tertiary hospital from 2010 to 2016. Patients were included if arterial and venous umbilical cord gas results were available for both newborns and chorionicity was confirmed histologically. Exclusion criteria included intrauterine fetal demise of either twin prior to labor, major fetal anomalies, monoamnionicity, uncertain chronicity and twin-to-twin transfusion syndrome. The primary outcome evaluated was the umbilical artery (UA) pH of the second twin. A total of 593 dichorionic (DC) and 86 monochorionic (MC) twin pregnancies were included. No difference in UA pH was observed between MC and DC twins. Among vaginal deliveries (n = 97), the UA pH of the first twin was higher than the second twin (7.26 vs. 7.24; p = .01). Twin-to-twin delivery interval (TTDI) ≥20 min was associated with a higher UA pH in the first twin compared to the second twin (7.25 vs. 7.16, respectively; p = .006). Multivariable logistic regression was used to predict arterial pH < 7.20 for the second twin; the most predictive factors were arterial pH < 7.20 for the first twin, chronic hypertension and prolonged TTDI. Chorionicity was not associated with any acid-base parameter of umbilical cord blood in either the first or second twin. No differences in neonatal outcomes were observed based on chorionicity or birth order. Populations with a lower cesarean delivery rate may yield different findings.

Introduction: Natriuretic peptides (NPs) play a pivotal role in maintaining fetal circulation; however, little is known about their metabolism. The aim of the present study was to elucidate the metabolism of plasma NPs in the fetoplacental circulation., Methods: Plasma NP concentrations in maternal vein and umbilical artery (UA) and vein (UV) samples from fetuses with congenital heart defect (n = 86) or arrhythmia (n = 31) and controls (n = 127) were analyzed., Results: Levels of plasma atrial NP (ANP) and brain NP (BNP) showed good correlation between UV versus UA samples (p < 0.01). In all three fetus groups, the regression coefficients between UV and UA plasma ANP levels were close to 0.5, while those between UV and UA plasma BNP levels were close to 1. The molecular forms of immunoreactive ANP in UA plasma showed a single peak corresponding to mature ANP, while those of immunoreactive BNP in UA plasma showed two major peaks and several minor peaks corresponding to mature BNP-32 and its partially digested peptides, as well as glycosylated and non-glycosylated BNP precursors (proBNP). No correlation was found between fetuses and mothers in terms of either plasma ANP or BNP levels., Conclusions: The mother and fetus independently secrete and metabolize both ANP and BNP. Fetal plasma ANP consists exclusively of the mature form, and the placenta and umbilical vessels are possible major sites of ANP metabolism. In contrast, fetal plasma BNP consists predominantly of the precursor forms, which may contribute to protecting BNP from metabolism in the fetoplacental circulation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: Rapamycin has a protective cardiovascular effect and inhibits proliferation and migration of vascular smooth muscle cells. We investigated the effects of rapamycin on proliferation of cultured human umbilical arterial smooth muscle cells (HUASMCs) by determining interleukin-6 (IL-6) levels. Materials and methods: Adherent third-generation primary-cultured HUASMCs were used in the study, and MTT assay was used to measure the effects of different rapamycin concentrations on cell proliferation at various time points (3-96 h). RT-PCR was used to measure IL-6 mRNA expression and ELISA was used to measure IL-6 protein expression. Results: After three passages, HUASMCs displayed >90% confluence. Inhibition of cell proliferation by rapamycin was both time and dose dependent. When the action concentration of rapamycin was 100 ng·mL -1 , the inhibitory effect was strongest after 48 h (30.25 ± 2.40)%, and the follow-up study was conducted after 48 h. When the action time of rapamycin was 48 h, the inhibitory effect of 150 ng·mL -1 at the action concentration was the strongest, and the inhibitory rate was (42.88 ± 3.84)%. There was no significant difference between the inhibitory effect and the action concentration of 100 ng·mL -1 ( p >.05). Moreover, low (2 ng·mL -1 ), moderate (10 ng·mL -1 ), and high (100 ng·mL -1 ) rapamycin concentrations down-regulated both IL-6 mRNA and expression factor in a dose-dependent manner. Discussion and conclusions: Rapamycin inhibits proliferation of HUASMCs in vitro and through down-regulation of IL-6 expression.

Aims: Oscillatory shear stress (OSS) is an atheroprone haemodynamic force that occurs in areas of vessel irregularities and is implicated in the pathogenesis of atherosclerosis. Changes in signalling and transcriptional programme in response to OSS have been vigorously studied; however, the underlying changes in the chromatin landscape controlling transcription remain to be elucidated. Here, we investigated the changes in the regulatory element (RE) landscape of endothelial cells under atheroprone OSS conditions in an in vitro model., Methods and Results: Analyses of H3K27ac chromatin immunoprecipitation-Seq enrichment and RNA-Seq in primary human umbilical vein endothelial cells 6 h after onset of OSS identified 2806 differential responsive REs and 33 differentially expressed genes compared with control cells kept under static conditions. Furthermore, gene ontology analyses of putative RE-associated genes uncovered enrichment of WNT/HIPPO pathway and cytoskeleton reorganization signatures. Transcription factor (TF) binding motif analysis within RE sequences identified over-representation of ETS, Zinc finger, and activator protein 1 TF families that regulate cell cycle, proliferation, and apoptosis, implicating them in the development of atherosclerosis. Importantly, we confirmed the activation of EGR1 as well as the YAP/TAZ complex early (6 h) after onset of OSS in both cultured human vein and artery endothelial cells and, by undertaking luciferase assays, functionally verified their role in RE activation in response to OSS., Conclusions: Based on the identification and verification of specific responsive REs early upon OSS exposure, we propose an expanded mechanism of how OSS might contribute to the development of atherosclerosis., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Background: Phenylephrine is the first-line vasoactive drug in the cesarean section under spinal anesthesia. The rate of hypotension remains high after intravenous preventive use of phenylephrine. However, few studies have investigated the effect of preventive intramuscular phenylephrine via a longer period of usage on fetal and maternal outcomes., Methods: A total of 99 healthy parturients undergoing elective cesarean delivery were randomly allocated into three groups: M group (preventive intramuscular use of 5 mg phenylephrine), V group (preventive intravenous use of 100 μg phenylephrine), and P group (0.9% normal saline placebo). Rescue phenylephrine, ephedrine and atropine were used intraoperatively to adjust blood pressure and heart rate. The primary outcome was umbilical artery pH., Results: Significant differences in umbilical artery pH (M group: 7.32 ± 0.05 versus V group: 7.25 ± 0.04 versus P group: 7.21 ± 0.03, P < 0.05), fetal acidosis (M group: 3% [n = 33] versus V group: 15% [n = 33] versus P group: 30% [n = 33], P = 0.01) and maternal intraoperative hypotension (M group: 12% [33] versus V group: 39% [33] versus P group: 73% [33], P < 0.0001) were identified among the groups. Multiple linear regression analysis demonstrated that treating arms, neonatal birthweight and the interval from the end of anesthesia to baby delivery were associated with umbilical artery pH., Conclusion: Compared with the preventive intravenous use of phenylephrine and placebo, preventive intramuscular phenylephrine exhibited a better neonatal acid-base status and more stable maternal hemodynamics in elective cesarean under spinal anesthesia., (Copyright © 2019 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

The increase in fetal and neonatal morbidity and mortality associated with twin pregnancies correlates with an increased risk of preterm delivery, low birth weight, and intrauterine growth restriction (IUGR). Although the pathogenesis of IUGR is unclear and thus management remains a major challenge, feto-placental blood vessels are compromised, and altered umbilical blood flow is observed. In this pilot observational study we investigated the effects of pravastatin plus l-arginine on umbilical artery (umb art) blood flow. Between 2013 and 2016, five women received daily doses l-arginine and pravastatin when an umb art pulsatility index above limits for gestational age was observed and concerns about selective growth restrictions arose. All patients showed selective absent or reversed end-diastolic umbilical artery Doppler flow (AREDV) associated with increased perinatal mortality. Pravastatin (PRAV) plus l-arginine (l-Arg) treatment diminished umb art resistance significantly and allowed pregnancy to continue. No signs of acidosis or hypoxia, normal cardiotocography tracing, normal fetal movement and fetal weight gain were observed in the twins that showed abnormal umb art Dopplers. All neonates were born around 33 weeks (median 33 weeks, IQR [31.4-33.0]), thus diminishing substantially the chances for any prematurity-associated adverse neonatal outcomes. The infants now show normal growth and development. In in vitro studies, pravastatin induced relaxation of aortic rings. Murine studies identified were performed to investigate the mechanism behind PRAV+L-Arg beneficial effects. A nitric oxide (NO)-dependent synergistic vasorelaxant effect of PRAV+L-Arg was demonstrated using aortic rings. Increased levels of placental NO and increased synthesis of eNOS in placental endothelial cells were observed in mice treated with PRAV+L-Arg compared to untreated mice and mice treated with PRAV- or L-Arg alone. This study suggests that PRAV plus L-Arg might be a good therapeutic option to improve blood flow in umbilical arteries prolonging pregnancy and improving pregnancy outcomes in twins. A RCT should be organized to confirm these results., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Cytokines modulate fetal well-being and contribute to parturition. Their origin in fetal blood, whether maternal, placental or fetal, at the time of parturition remains unclear., Objective: To determine fetal and placental contributions to circulating fetal cytokines by measuring umbilical arterial (UmA) and venous (UmV) concentration differences in uncomplicated term pregnancies in the absence and presence of labor., Methods: Term uncomplicated pregnancies were assessed: Group 1 were not in labor and delivered by elective cesarean section (n = 20); Group 2 delivered vaginally following uncomplicated pregnancy and labor (n = 30). UmA and UmV blood was collected before delivery of the placenta to measure circulating cytokines. Placental tissue was collected for histology and to determine cytokine contents and localization., Results: Group 1 UmA and UmV IL-10 concentrations were similar (504 ± 15 and 468 ± 16 pg/ml, respectively; P ≥ 0.1); other cytokines were below level of detection. During labor, IL-10 concentrations increased 15-34%, but placental contents decreased. Group 2 UmA IL-6 and IL-8 concentrations increased (P < 0.001) to 16.7 ± 1.6 and 18.4 ± 4.3 pg/ml, respectively, but were less (P < 0.001) in UmV, 0.29 ± 0.2 and 0.74 ± 0.3 pg/ml, respectively, demonstrating placental clearances ≥97%. This was associated with >6-fold increases in placental IL-6/IL-8 contents (P < 0.001) and chorioamniotic infiltration of activated maternal neutrophils. IL-6 and IL-10 were localized to villous syncytiotrophoblasts., Conclusions: In uncomplicated term pregnancies fetal circulating IL-10 is likely of placental origin, whereas IL-6/IL-8 are derived from the fetus, increase during parturition, and circulating levels are modulated by non-saturable placental clearance, revealing a novel pathway for fetal-placental crosstalk and signaling., (Published by Elsevier Ltd.)

Background: Previous studies implicated cardiotonic steroids, including Na/K-ATPase inhibitor marinobufagenin (MBG), in the pathogenesis of preeclampsia (PE). Immunoneutralization of heightened MBG by Digibind, a digoxin antibody, reduces blood pressure (BP) in patients with PE, and anti-MBG monoclonal antibody lessens BP in a rat model of PE. Recently, we demonstrated that MBG induces fibrosis in cardiovascular tissues via a mechanism involving inhibition of Fli-1, a nuclear transcription factor and a negative regulator of collagen-1 synthesis., Objectives and Methods: We hypothesized that in PE, elevated placental MBG levels are associated with development of fibrosis in umbilical arteries. Eleven patients with PE (mean BP 124 ± 4 mmHg; age 29 ± 2 years; 39 weeks gest. age) and 10 gestational age-matched normal pregnant subjects (mean BP 92 ± 2 mmHg; controls) were enrolled in the clinical study., Results: PE was associated with a higher placental (0.04 ± 0.01 vs. 0.49 ± 0.11 pmol/g; p < 0.01) and plasma MBG (0.5 ± 0.1 vs. 1.6 ± 0.5 nmol/L; p < 0.01), lower Na/K-ATPase activity in erythrocytes (2.7 ± 0.2 vs. 1.5 ± 0.2 µmol Pi/mL/hr; p < 0.01), 9-fold decrease of Fli-1 level and 2.5-fold increase of collagen-1 in placentae ( p < 0.01) vs. control. Incubation of umbilical arteries from control patients with 1 nmol/L MBG was associated with four-fold decrease in Fli-1 level and two-fold increase in collagen-1 level vs. those incubated with placebo ( p < 0.01), i.e., physiological concentration of MBG mimicked effect of PE in vitro. Collagen-1 abundance in umbilical arteries from PE patients was 4-fold higher than in control arteries, and this PE-associated fibrosis was reversed by monoclonal anti-MBG antibody ex vivo., Conclusion: These results demonstrate that elevated placental MBG level is implicated in the development of fibrosis of the placenta and umbilical arteries in PE.

Some studies in animals suggest that TBT may constitute a risk factor for cardiovascular diseases. Hence, the main purpose of this study was to investigate in human umbilical artery (HUA) the effect of TBT on vascular reactivity, manly in serotonin (5-HT) and histamine receptors. Using standard organ bath techniques, rings of HUA without endothelium were contracted by 5-HT and histamine. We also investigated the effect of TBT on the expression of the receptors using Real-time PCR. The results show that TBT short term effects include concentration-dependent relaxation. Moreover, at long term exposures, the arteries treated with 100 μM of TBT do not have contraction capacity when 5-HT is added, and the gene expression of 5-HT2A receptor decrease. Regarding histamine, it was demonstrated that TBT induces a concentration-dependent relaxation and the H1 gene expression levels decrease. In conclusion TBT modifies the activity and expression of 5-HT and histamine receptors., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Purpose: To assess the relationship between peak systolic velocity in the middle cerebral artery (MCA-PSV) and fetal hypoxia in diabetic pregnant women requiring insulin therapy., Methods: The data of diabetic pregnant women using insulin who were followed in our departments were reviewed retrospectively. The relationships between MCA-PSV and umbilical cord pO2, pCO2, base deficit, hemoglobin, and birth weight were analyzed., Results: A total of 120 cases were included in the final analysis. The median (Q 1 - Q 3 ) gestational age at Doppler evaluation was 37 weeks 3 days (37-38 weeks and 2 days), and the mean ± SD gestational age at delivery was 38 weeks 4 days ± 3days. The mean ± SD hemoglobin A1c (HbA1c) level was 5.7% ± 1.0% and, median (Q 1 -Q 3 ) daily total insulin dose was 25 U (10U-48U). There was no statistically significant correlation between MCA-PSV and pH, PO2, PCO2, base deficit, Hb, and birth weight (Spearman correlation, r:-.001[P = .99], r:-.011[P = .90], r:-.052 [P = .51], r: .049[P = .59], r: .049 [P = .59], r: .030 [P = .75], respectively). Using binary logistic regression analysis, no independent factor for the prediction of fetal acidosis (venous pH < 7.23), and metabolic acidosis (base deficit >6.3 mmol/L) was detected., Conclusion: MCA-PSV is not a good indicator of fetal polycythemia or chronic hypoxia in fetuses of diabetic pregnant women. Fetal well-being should be monitored with other tools in these circumstances., (© 2018 Wiley Periodicals, Inc.)

The purpose of this review is to present an update of the main mechanisms involved in the physiological regulation of contraction and relaxation of the human umbilical artery (HUA) smooth muscle cells. A literature review was performed based on the analysis of papers available on PubMed. The most important and relevant studies regarding the regulation of the HUA are presented in this article. The vascular smooth muscle is a highly specialized structure, whose main function is to regulate the vascular tonus. This is controlled by a balance between the cellular signaling pathways that mediate contraction and relaxation. The cells responsible for the contractile property of this muscle are the smooth muscle cells (SMC), and an excellent source of these cells is the HUA, involved in fetoplacental circulation. Since the umbilical blood vessels are not innervated, the HUA tonus is modulated by vasoactive substances that regulate the contractile process. The main vasoactive substances that induce contraction are serotonin, histamine, thromboxane, bradykinin, endothelin 1 and prostaglandin F2α, that are linked to the activation of proteins G q and G i/0 . On the other hand, the main vasorelaxation mechanisms are the activation of adenyl and guanil cyclases, potassium channels and the inhibition of calcium channels. The SMC from the HUA allow the study of different cellular mechanisms and their functions. Therefore, these cells are an important tool to study the mechanisms regulating the contractility of this artery, allowing to detect potential therapeutic targets to treat HUA disorders (gestational hypertension and pre-eclampsia)., (© 2018 Japan Society of Obstetrics and Gynecology.)

Background: Spinal anesthesia for cesarean delivery is associated with a high incidence of hypotension. Phenylephrine results in higher umbilical artery pH than ephedrine when used to prevent or treat hypotension in healthy women. We hypothesized that phenylephrine compared to ephedrine would result in higher umbilical artery pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia., Methods: This study was a randomized double-blind clinical trial. Nonlaboring women with preeclampsia scheduled for cesarean delivery with spinal anesthesia at Prentice Women's Hospital of Northwestern Medicine were randomized to receive prophylactic infusions of phenylephrine or ephedrine titrated to maintain systolic blood pressure >80% of baseline. Spinal anesthesia consisted of hyperbaric 0.75% bupivacaine 12 mg, fentanyl 15 µg, and morphine 150 µg. The primary outcome was umbilical arterial blood pH and the secondary outcome was umbilical artery base excess., Results: One hundred ten women were enrolled in the study and 54 per group were included in the analysis. There were 74 and 72 infants delivered in the ephedrine and phenylephrine groups, respectively. The phenylephrine:ephedrine ratio for umbilical artery pH was 1.002 (95% confidence interval [CI], 0.997-1.007). Mean [standard deviation] umbilical artery pH was not different between the ephedrine 7.20 [0.10] and phenylephrine 7.22 [0.07] groups (mean difference -0.02, 95% CI of the difference -0.06 to 0.07; P = .38). Median (first, third quartiles) umbilical artery base excess was -3.4 mEq/L (-5.7 to -2.0 mEq/L) in the ephedrine group and -2.8 mEq/L (-4.6 to -2.2mEq/L) in the phenylephrine group (difference -0.6 mEq/L, 95% CI of the difference -1.6 to 0.3 mEq/L; P = .10). When adjusted for gestational age and infant gender, umbilical artery pH did not differ between groups. There were also no differences in the umbilical artery pH stratified by magnesium therapy or by the severity of preeclampsia., Conclusions: We were unable to demonstrate a beneficial effect of phenylephrine on umbilical artery pH compared with ephedrine. Our findings suggest that phenylephrine may not have a clinically important advantage compared with ephedrine with regard to improved neonatal acid-base status when used to prevent spinal anesthesia-induced hypotension in women with preeclampsia undergoing cesarean delivery.

In vitro tissue engineering of vascular grafts requires dynamic conditioning in a bioreactor system for in vitro tissue maturation and remodeling to receive a mechanically adequate and hemocompatible implant. The goal of the current work was to develop a bioreactor system for the conditioning of vascular grafts which is (i) able to create a wide range of flow, pressure and frequency conditions, including physiological ones; (ii) compact and easy to assemble; (iii) transportable; (iv) disposable. The system is driven by a small centrifugal pump controlled via a custom-made control unit, which can also be operated on batteries to allow for autonomous transportation. To show the potential of the newly developed bioreactor system small-caliber vascular composite grafts (n = 5, internal diameter = 3 mm, length = 12.5 cm) were fabricated using a fibrin scaffold embedding human umbilical artery smooth muscle cells and a polyvinylidene fluoride warp-knitted macroporous mesh. Subsequently, the vascular grafts were endothelialized and mounted in the bioreactor system for conditioning. The conditioning parameters remained within the predefined range over the complete conditioning period and during operation on batteries as tested for up to 25 h. Fabrication and pre-conditioning under arterial pressure and shear stress conditions resulted in robust and hemocompatible tissue-engineered vascular grafts. Analysis of immunohistochemical stainings against extracellular matrix and cell-specific proteins revealed collagen I and collagen III deposition. The luminal surface was confluently covered with endothelial cells. The developed bioreactor system showed cytocompatibility and pH, pO 2 , pCO 2 , glucose and lactate stayed constant. Sterility was maintained during the complete fabrication process of the vascular grafts. The potential of a versatile and mobile system and its functionality by conditioning tissue-engineered vascular grafts under physiological pressure and flow conditions could be demonstrated.

Poly(glycerol sebacate) (PGS) has been used successfully as a scaffolding material for soft tissue engineering. PGS scaffolds, however, are usually mechanically isotropic, which may restrict their use in tissue repairs as many soft tissues in the body have anisotropic mechanical behaviors. Although various methods have been used to fabricate anisotropic scaffolds, it remains challenging to make anisotropic scaffolds from thermoset PGS. Here a new, simple method to fabricate an anisotropic PGS membrane which can then be used to construct thicker three-dimensional anisotropic scaffolds was developed. First, an aligned sacrificial poly(vinyl alcohol) fibrous membrane was prepared by electrospinning. The fibrous membrane was then partially immersed in PGS prepolymer solution, resulting in a composite membrane upon drying. After curing, the sacrificial fibers within the membrane were removed by water, supposedly leaving aligned cylindrical pores in the membrane. Both SEM and AFM illustrated aligned grooves on the surface of the resultant PGS membrane, indicating the successful removal of sacrificial fibers. The PGS membrane was validated to be mechanically anisotropic using uniaxial tensile testing along and perpendicular to the predominant pore direction. The in vitro cytocompatibility of the PGS membrane was confirmed. As a demonstration of its potential application in vascular tissue engineering, a tubular scaffold was constructed by wrapping a stack of two axisymmetric pieces of the anisotropic PGS membranes on a mandrel. The compliance of the scaffold was found to depend on the pitch angle of its double helical structure, imitating the anisotropic mechanical behavior of the arterial media. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 760-770, 2018., (© 2017 Wiley Periodicals, Inc.)

How the fetal-placental arterial connection is made and positioned relative to the embryonic body axis, thereby ensuring efficient and directed blood flow to and from the mother during gestation, is not known. Here we use a combination of genetics, timed pharmacological inhibition in living mouse embryos, and three-dimensional modeling to link two novel architectural features that, at present, have no status in embryological atlases. The allantoic core domain (ACD) is the extraembryonic extension of the primitive streak into the allantois, or pre-umbilical tissue; the vessel of confluence (VOC), situated adjacent to the ACD, is an extraembryonic vessel that marks the site of fetal-placental arterial union. We show that genesis of the fetal-placental connection involves the ACD and VOC in a series of steps, each one dependent upon the last. In the first, Brachyury (T) ensures adequate extension of the primitive streak into the allantois, which in turn designates the allantoic-yolk sac junction. Next, the streak-derived ACD organizes allantoic angioblasts to the axial junction; upon signaling from Fibroblast Growth Factor Receptor-1 (FGFR1), these endothelialize and branch, forming a sprouting VOC that unites the umbilical and omphalomesenteric arteries with the fetal dorsal aortae. Arterial union is followed by the appearance of the medial umbilical roots within the VOC, which in turn designate the correct axial placement of the lateral umbilical roots/common iliac arteries. In addition, we show that the ACD and VOC are conserved across Placentalia, including humans, underscoring their fundamental importance in mammalian biology. We conclude that T is required for correct axial positioning of the VOC via the primitive streak/ACD, while FGFR1, through its role in endothelialization and branching, further patterns it. Together, these genetic, molecular and structural elements safeguard the fetus against adverse outcomes that can result from vascular mispatterning of the fetal-placental arterial connection., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Key Points: Intrauterine growth restriction (IUGR) is associated with vascular dysfunction, oxidative stress and signs of endothelial epigenetic programming of the umbilical vessels. There is no evidence that this epigenetic programming is occurring on systemic fetal arteries. In IUGR guinea pigs we studied the functional and epigenetic programming of endothelial nitric oxide synthase (eNOS) (Nos3 gene) in umbilical and systemic fetal arteries, addressing the role of oxidative stress in this process by maternal treatment with N-acetylcysteine (NAC) during the second half of gestation. The present study suggests that IUGR endothelial cells have common molecular markers of programming in umbilical and systemic arteries. Notably, maternal treatment with NAC restores fetal growth by increasing placental efficiency and reverting the functional and epigenetic programming of eNOS in arterial endothelium in IUGR guinea pigs., Abstract: In humans, intrauterine growth restriction (IUGR) is associated with vascular dysfunction, oxidative stress and signs of endothelial programming in umbilical vessels. We aimed to determine the effects of maternal antioxidant treatment with N-acetylcysteine (NAC) on fetal endothelial function and endothelial nitric oxide synthase (eNOS) programming in IUGR guinea pigs. IUGR was induced by implanting ameroid constrictors on uterine arteries of pregnant guinea pigs at mid gestation, half of the sows receiving NAC in the drinking water (from day 34 until term). Fetal biometry and placental vascular resistance were followed by ultrasound throughout gestation. At term, umbilical arteries and fetal aortae were isolated to assess endothelial function by wire-myography. Primary cultures of endothelial cells (ECs) from fetal aorta, femoral and umbilical arteries were used to determine eNOS mRNA levels by quantitative PCR and analyse DNA methylation in the Nos3 promoter by pyrosequencing. Doppler ultrasound measurements showed that NAC reduced placental vascular resistance in IUGR (P < 0.05) and recovered fetal weight (P < 0.05), increasing fetal-to-placental ratio at term (∼40%) (P < 0.001). In IUGR, NAC treatment restored eNOS-dependent relaxation in aorta and umbilical arteries (P < 0.05), normalizing eNOS mRNA levels in EC fetal and umbilical arteries (P < 0.05). IUGR-derived ECs had a decreased DNA methylation (∼30%) at CpG -170 (from the transcription start site) and this epigenetic signature was absent in NAC-treated fetuses (P < 0.001). These data show that IUGR-ECs have common molecular markers of eNOS programming in umbilical and systemic arteries and this effect is prevented by maternal treatment with antioxidants., (© 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.)

We investigated whether histological evidence of early atherosclerosis was present in the umbilical artery of 21 pregnancies complicated by severe perinatal inflammation, and 21 controls matched for gestational age, sex and birth weight. Severe chorioamnionitis with funisitis was associated with increased numbers of CD68 and CD45 positive cells (both P < 0.01), indicating accumulation of monocyte-derived macrophages in lesion-susceptible regions. A down-regulation of SMA expression (P = 0.01) was also observed. These preliminary findings suggest that chorioamnionitis with funisitis may promote changes in the intima and media of the umbilical artery similar to that seen in early atherosclerosis., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The response of blood vessels to physiological and pathological stimuli partly depends on the cross talk between endothelial cells (EC) lining the luminal side and smooth muscle cells (SMC) building the inner part of the vascular wall. Thus, the in vitro analysis of the pathophysiology of blood vessels requires coculture systems of EC and SMC. We have developed and validated a modified three-dimensional sandwich coculture (3D SW-CC) of EC and SMC using open μ-Slides with a thin glass bottom allowing direct imaging. The culture dish comprises an intermediate plate to minimize the meniscus resulting in homogenous cell distribution. Human umbilical artery SMC were sandwiched between coatings of rat tail collagen I. Following SMC quiescence, human umbilical vein EC were seeded on top of SMC and cultivated until confluence. By day 7, EC had formed a confluent monolayer and continuous vascular endothelial (VE)-cadherin-positive cell/cell contacts. Below, spindle-shaped SMC had formed parallel bundles and showed increased calponin expression compared to day 1. EC and SMC were interspaced by a matrix consisting of laminin, collagen IV, and perlecan. Basal messenger RNA (mRNA) expression levels of E-selectin, angiopoietin-1, calponin, and intercellular adhesion molecule 1 (ICAM-1) of the 3D SW-CC was comparable to that of a freshly isolated mouse inferior vena cava. Addition of tumor necrosis factor alpha (TNF α) to the 3D SW-CC induced E-selectin and ICAM-1 mRNA and protein induction, comparable to the EC and SMC monolayers. In contrast, the addition of activated platelets induced a significantly delayed but more pronounced activation in the 3D SW-CC compared to EC and SMC monolayers. Thus, this 3D SW-CC permits analyzing the cross talk between EC and SMC that mediate cellular quiescence as well as the response to complex activation signals., Competing Interests: Statement No competing financial interests exist.

Background: Previous studies have shown that pregnant women have higher salivary cortisol levels when the fetus is female. These findings suggest a basis for the sex differences observed in many offspring outcomes after exposure to in utero stress, but it is not known if fetal adrenal glucocorticoid synthesis differs by sex., Methods: Arterial and venous umbilical cord blood samples were collected immediately after scheduled cesarean delivery (n=52, 25 female). Cortisol and corticosterone concentrations were quantified by liquid chromatography coupled to tandem mass spectrometry., Results: Sex differences were observed for fetal arterial and venous cortisol and venous corticosterone, with higher levels present when the fetus was female. However, sex differences were not observed for fetal synthesis of cortisol, suggesting that the fetus does not control the differences observed in cord blood glucocorticoids., Conclusions: The presence of sex differences in umbilical cord glucocorticoid concentrations in the absence of sex differences in glucocorticoid synthesis by the fetal adrenal gland suggests that these differences have a maternal or placental origin. Thus, the in utero glucocorticoids in circulation are sex-specific and may have developmental importance for sex differences in psychiatric and neurodevelopment disorders that display sex biases., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Placental vascular dysfunction was suggested to be critical for placental ischemia-initiated hypertension in preeclampsia, although the contributions of endothelium involved are unclear. The present study found, unlike non-placental vessels, acetylcholine showed no vasodilatation effect on placental vessels, indicating that endothelial-derived nitric oxide (NO) was extremely weak in placental vessels. Placental vascular responses to exogenous NO from sodium nitroprusside (SNP) were significantly different from non-placental vessels. These results were further confirmed in sheep, and rat vessels. In preeclamptic placental vessels, acetylcholine also showed no vasodilatation effects, while vascular responses to SNP were suppressed, associated with impaired cGMP/sGC pathway in vascular smooth muscle cells (VSMCs). The current theory on placental ischemia-initiated hypertension in preeclampsia focused on changes in placental vascular functions, including endothelial dysfunction. This study found the placental endothelium contributed very poorly to vasodilatation, and altered vascular functions in preeclampsia mainly occurred in VSMCs instead of endothelial cells. The findings contribute importantly to understanding the special feature of placental vascular functions and its pathophysiological changes in the development of hypertension in preeclampsia.

Sex has largely been neglected in cell studies. Therefore, we investigated the occurrence of sexual dimorphism in human umbilical artery smooth muscle cells (HUASMCs). In particular, we investigated the existence of sex differences in basal and in drug-induced autophagy, a process involved in cardiovascular diseases. HUASMCs were isolated from healthy and normal weight male and female newborns (MHUASMCs and FHUASMCs, respectively). Expression of the primary molecules involved in the autophagic process [beclin-1 and microtubule-associated protein 1 light chain 3 (LC3)], and PmTOR were detected using western blotting in basal conditions, after serum starvation, rapamycin and verapamil treatments. The level of constitutive autophagy, measured as the LC3II/I ratio, was similar in male and female HUASMCs in the basal condition. Serum starvation promoted autophagy in both cell types, but the increase was more pronounced in FHUASMCs, while 250nM rapamycin induced autophagy only in female cells. Moreover, the level of verapamil-induced autophagy was not different between the two sexes. Notably, in the basal condition, Beclin-1 was more elevated in MHUASMCs than in FHUASMCs, and the difference disappeared after serum starvation and exposure to rapamycin. After exposure to verapamil, the differences in Beclin-1 increased, with more elevated expression levels in female cells. PmTor did not differ in basal conditions, but it was significantly down-regulated by starvation only in FHUASMCs and by rapamycin both in male and female cells. Finally, a strong negative correlation was observed between the newborn's weight and basal autophagy in female cells and between the newborn's weight and the LC3II/I ratio in male verapamil-treated cells. These results indicate that sex-differences begin in utero, are parameter-specific and drug specific suggesting that HUASMCs are a suitable model for the screening of drugs and to study the influence of sex. The sex differences in the autophagy suggest sexually different pharmacodynamics effects of verapamil and rapamycin., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Gender is a crucial determinant of life span, but little is known about gender differences in free radical homeostasis and inflammatory signaling. The aim of the study was to determine gender-related differences concerning oxidative stress and inflammatory signaling of healthy neonates and mothers., Methods: Fifty-six mothers with normal gestational course and spontaneous delivery were selected. Blood samples were collected from the mother (at the beginning of delivery and start of expulsive period) and from neonate (from umbilical cord vein and artery)., Results: The mothers of girls featured a higher total antioxidant status and lower plasma hydroperoxides than the mother of boys. Regarding the neonates, the girls featured a higher total antioxidant status and lower plasma membrane hydroperoxides in umbilical cord artery together with higher catalase, glutathione peroxidase, and superoxide dismutase activities. Lower levels of interleukin 6, tumor necrosis factor alpha, and prostaglandin E2 were observed in the mothers of girls and higher level of soluble tumor necrosis factor receptor II. In the neonates, lower levels of interleukin 6 and tumor necrosis factor alpha were observed in umbilical artery and higher soluble tumor necrosis factor receptor II in umbilical cord vein and artery of girls., Conclusion: An association between gender, oxidative stress, and inflammation signaling exists, leading to a renewed interest in the neonate's sex as a potential risk factor to several alterations.

Placental amino acid transfer is essential for fetal development and its impairment is associated with poor fetal growth. Amino acid transfer is mediated by a broad array of specific plasma membrane transporters with overlapping substrate specificity. However, it is not fully understood how these different transporters work together to mediate net flux across the placenta. Therefore the aim of this study was to develop a new computational model to describe how human placental amino acid transfer functions as an integrated system. Amino acid transfer from mother to fetus requires transport across the two plasma membranes of the placental syncytiotrophoblast, each of which contains a distinct complement of transporter proteins. A compartmental modelling approach was combined with a carrier based modelling framework to represent the kinetics of the individual accumulative, exchange and facilitative classes of transporters on each plasma membrane. The model successfully captured the principal features of transplacental transfer. Modelling results clearly demonstrate how modulating transporter activity and conditions such as phenylketonuria, can increase the transfer of certain groups of amino acids, but that this comes at the cost of decreasing the transfer of others, which has implications for developing clinical treatment options in the placenta and other transporting epithelia., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)

Arginase-2 counteracts endothelial nitric oxide synthase (eNOS) activity in human endothelium, and its expression is negatively controlled by histone deacetylase (HDAC2). Conversely NO inhibits HDAC and previous studies suggest that arginase-2 is up-regulated by NO. We studied whether NO regulates arginase-2 expression in umbilical artery endothelial cells (HUAEC) increasing ARG2 promoter accessibility. HUAEC exposed to NOC-18 (NO donor, 1-100 μM, 0-24 h) showed an increase in arginase-2 but a decrease in eNOS mRNA levels in a time-dependent manner, with a maximal effect at 100 μM (24 h). Conversely NOS inhibition with L-NAME (100 μM) reduced arginase-2 mRNA and protein levels, an effect reverted by co-incubation with NOC-18. Treatment with TSA paralleled the effects of NO on arginase-2 and eNOS at mRNA and protein levels, with maximal effect at 10 μM. Co-incubation of NOC-18 (100 μM) with a sub-maximal concentration of TSA (1 μM) potentiated the increase in arginase-2 mRNA levels, whilst L-NAME prevented TSA-dependent arginase-2 induction. The effects on arginase-2 mRNA were paralleled by changes in chromatin accessibility, as well as increased levels of H3K9 and H4K12 acetylation, at ARG2 proximal (-579 to -367 and -280 to -73 bp from TSS) and core (-121 to +126 bp from TSS) promoter. Finally NO-dependent arginase-2 induction was prevented by pre-incubation for 10 min with the cysteine blocker MMTS (10 mM). These data showed for the first time that NO up-regulates arginase-2 expression in primary cultured human endothelial cells by an epigenetic-mediated mechanism increasing ARG2 promoter accessibility suggesting a negative regulatory loop for eNOS activity., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Physiological studies on fetal blood in narrow glass tubes have suggested that fetal optimal hematocrit (hct) might be as high as 60%. A theoretical 'ideal' hct can also be predicted with a theoretical curve of hematocrit/viscosity (h/η) ratio vs hct constructed with Quemada's model. We used the database of one of our previous papers on fetal hemorheology to reinterpret its results with this concept. A series of 28 intrauterine cord punctures (between 19 and 33 weeks gestation) with doppler measurements of resistance in umbilical arteries was studied. The theoretical 'optimal hematocrit' was well correlated to actual (r = 0.857, p < 0.01) but systematically lower (Bland-Altman plot +12.1[8.52-15.7]) than the actual one. Umbilical artery resistance index is correlated with actual hematocrit (r = 0.407, p < 0.05), the discrepancy between ideal and actual (r = - 0.542, p < 0.05) but not predicted ideal hematocrit, suggesting that the discrepancy between ideal and actual may reflect an adaptative decrease aiming at reducing vascular resistance. These findings indicate that prediction of ideal hematocrit with Quemada's equation makes sense in fetal blood, and suggest that a 'viscoregulatory mechanism' maintains hematocrit below this theoretical value in order to avoid excess vascular resistance.

Cell membrane proteins are believed to play a critical role in the pathogenesis of autoimmune diseases. However, few membrane autoantigens have been linked with Behçet's disease. Here, a cell-chip was performed to identify autoantibody target cells, and the suspected autoantigens were detected using immunoblotting. The amino acid sequences of the detected proteins were determined using LC-MALDI-TOF/TOF. Putative proteins were recombinantly expressed and purified, and a corresponding ELISA was developed and clinically validated using real clinical samples. It was found that a 36-kDa membrane protein--annexin A2--was detected in approximately one-third of the patients' blood circulation. The immunohistochemistry results showed that annexin A2 was highly expressed in vascular endothelial cells. Moreover, vascular involvement was significantly higher in the anti-annexin A2 antibody-positive group versus the anti-annexin A2 antibody-negative group among all the clinical samples analyzed, indicating that annexin A2 is a novel endothelial cell membrane antigen involved in Behçet's disease.

The scaffolds prepared from the tissue decellularization conserve the porous 3-D structure and provide an optimal matrix for the tissue regeneration. Since decade, the enzymatic digestion, chemical reagent treatment and mechanical actions such as eversion and abrasion have been used to remove the cells from the intact matrix. In this study, we optimized an enzymatic method to decellularize the umbilical artery to construct a 3-D porous scaffold which is suitable for the culture of mesenchymal stem cells (MSCs). The scaffold maintained the interconnected porous structure. It remained the similar high water content 95.3 ± 1% compared to 94.9 ± 0.6% in the intact umbilical artery (p>0.05). The decellularization process decreased the stress from 0.24 ± 0.05 mPa to 0.15 ± 0.06 mPa (p<0.05). However the decellularization did not change the strain of the artery (45 ± 15% vs. 53 ± 10%, p>0.05). When the scaffold was transplanted to the subcutaneous tissue in the wild type mice, there were less T cells appeared in the surrounding tissue which meant the decreased the immunogenicity by decellularization. This scaffold also supported the adhesion and proliferation of the MSCs. In this study, we constructed a biological compatible porous scaffold from the decellularized umbilical artery which may provide a suitable scaffold for cell-matrix interaction studies and for tissue engineering.

Epidemiological studies suggest that the impact of preeclampsia does not only affect the mother but also the children. We know that adverse events in utero may predispose individuals to premature cardiovascular disease in adulthood, but we do not know the mechanisms. To gain insights into the mechanisms of cardiovascular dysfunction in the offspring of preeclampsia, we employed a global stable isotope labeled profiling strategy using iTRAQ reagents, followed by 2D-LC-MS/MS. We identified 1521 non-redundant proteins, and 1496 of these were quantified. Further analysis identified 53 differentially expressed proteins in umbilical artery; 22 proteins were up-regulated and 31 proteins were down-regulated. K-means clustering analysis showed that there was a specific protein expression profile in the umbilical artery which could distinguish between normal and preeclampsia patients. These 53 proteins were analyzed by Ingenuity Pathway Analysis (IPA) and were found to play important roles in the angiogenesis, vasculogenesis, and development of the cardiovascular system. In addition, the differential expression of three cardiovascular relative proteins (aldose reductase, fibronectin-1, fibrillin-1) was independently verified using western blot. These results may supply new insights into the mechanisms of vascular dysfunction in the offspring of preeclampsia patients., Biological Significance: Increasing evidence suggests that the children who were exposed to preeclampsia in utero have an increased cardiovascular risk, and vascular dysfunction has been found in some children born of preeclampsia. However, the mechanism remains largely unknown. In this study, we identified 1521 non-redundant proteins, and 1496 of these were quantified. Further analysis identified 53 differentially expressed proteins in the umbilical artery from preeclampsia patients; 22 proteins were up-regulated and 31 proteins were down-regulated. Some of these differentially expressed proteins have been shown to play important roles in cardiovascular system development. Our results provide new insights into the potential mechanisms underlying the changed blood pressure of offspring of mothers with preeclampsia, and, the elevation of their risk of cardiovascular abnormality in later life., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Major achievements in creating decellularized whole tissue scaffolds have drawn considerable attention to decellularization as a promising approach for tissue engineering. Developing a tissue-engineered small-diameter (≤2 mm) vascular graft, using decellularized human umbilical arteries (hUAs), for reconstructive surgery is a challenging task. Polymers used in the past, proved unsuitable due to serious adverse effects and autologous vessels are available only in 40% of patients. In this study, histological and proteomic analysis was performed to evaluate the efficiency of two decellularization protocols. In decellularization protocol A, hUAs were incubated in 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS) and sodium dodecyl sulfate (SDS) followed by incubation in alpha minimal essential medium (α-MEM) with foetal bovine serum (FBS) while in decellularization protocol B the hUAs were incubated in Hypotonic Tris and SDS followed by incubation in nuclease solution. Histological analysis of decelullarised hUA with both protocols revealed good preservation of extracellular cell matrix (ECM) proteins and immunofluorescent staining detected collagen I and fibronectin. The DNA content within the hUAs after decellularization with protocol A was 6.2% and with protocol B 17.3%. Proteomic analysis identified cytoplasmic enzymes such as, dehydrogenase X, α-enolase and peptidyl-prolyl cis-trans isomerase A only in native samples, while, cytoskeletal proteins such as a-actin, filamin and ECM proteins like collagens were found both in native and decellularised hUA. In conclusion, both decellularization protocols effectively removed the cellular material while the ECM remained intact. Future studies are warranted to elucidate the specific effects of altered structure-function relationships on the overall fate of decellularized hUAs.

Background: Splanchnic tissue oxygenation monitoring has been performed at both the liver and the infra-umbilical regions. It is unknown whether these measurements could be substituted one for the other when interpreting splanchnic oxygenation since they have not been measured simultaneously before., Aims: To evaluate the feasibility and safety of liver and infra-umbilical near-infrared spectroscopy (NIRS) monitoring in preterm infants with suspected necrotizing enterocolitis (NEC) and to assess the correlation and agreement between NIRS measurements performed simultaneously at the two abdominal locations., Study Design and Subjects: This study was part of a prospective observational cohort study. Preterm infants who were suspected of NEC or who had been diagnosed with NEC were included., Outcome Measures: Liver oxygen saturation and infra-umbilical oxygen saturation were monitored simultaneously and continuously for 48h by NIRS., Results: NIRS monitoring was performed in 20 out of 24 infants for the entire 48-hour study period. No adverse effects were observed. Values of liver and infra-umbilical oxygen saturation correlated weakly (Spearman's rho=0.244, P<.001). On the Bland-Altman plot liver oxygen saturation was higher than infra-umbilical oxygen saturation (mean difference 6.6%, SD 22.5%)., Conclusions: Using NIRS as method for monitoring oxygen saturation simultaneously in both the liver and infra-umbilical regions is safe and feasible. Additionally, we demonstrated that values of liver and infra-umbilical oxygen saturation cannot be randomly substituted one for the other for the purpose of assessing splanchnic oxygenation., (Copyright © 2014 Elsevier Ltd. All rights reserved.)