Background-Fetal growth restriction (FGR) affects 5% to 10% of newborns and is associated with increased cardiovascular mortality in adulthood. The most commonly accepted hypothesis is that fetal metabolic programming leads secondarily to diseases associated with cardiovascular disease, such as obesity, diabetes mellitus, and hypertension. Our main objective was to evaluate the alternative hypothesis that FGR induces primary cardiac changes that persist into childhood. Methods and Results-Within a cohort of fetuses with growth restriction identified in fetal life and followed up into childhood, we randomly selected 80 subjects with FGR and compared them with 120 normally grown fetuses, matched for gender, birth date, and gestational age at birth. Cardiovascular assessment was performed in childhood (mean age of 5 years). Compared with control subjects, children with FGR had a different cardiac shape, with increased transversal diameters and more globular cardiac ventricles. Although left ejection fraction was similar among the study groups, stroke volume was reduced significantly, which was compensated for by an increased heart rate to maintain output in severe FGR. This was associated with subclinical longitudinal systolic dysfunction (decreased myocardial peak velocities) and diastolic changes (increased E/EЈ ratio and E deceleration time). Children with FGR also had higher blood pressure and increased intima-media thickness. For all parameters evaluated, there was a linear increase with the severity of growth restriction. Conclusions-These findings suggest that FGR induces primary cardiac and vascular changes that could explain the increased predisposition to cardiovascular disease in adult life. If these results are confirmed, the impact of strategies with beneficial effects on cardiac remodeling should be explored in children with FGR. (Circulation. 2010;121:2427-2436.)Key Words: remodeling Ⅲ pregnancy Ⅲ pediatrics Ⅲ cardiomyopathy Ⅲ hypoxia C ardiovascular disease is the main cause of death in adults. Most factors that lead to chronic cardiovascular disease are already present in childhood. 1,2 Epidemiological evidence has long suggested a link between low birth weight and increased cardiovascular mortality in adulthood. 3 This association is essentially mediated through fetal growth restriction (FGR), 4 a condition defined as a birth weight below the 10th percentile for gestational age that affects 5% to 10% of all newborns. 5 The mechanistic pathways underlying the relationship between FGR and cardiovascular risk are poorly understood. 6 A number of studies support that it might be explained in part by fetal metabolic programming leading to diseases associated with cardiovascular disease, such as obesity, diabetes mellitus, and hypertension 6 ; however, it remains unclear whether FGR induces primary changes in the heart that might predispose to cardiovascular dysfunction later in life. Clinical Perspective on p 2436It has long been known that intrauterine growth retardation is associated with dilated ...
We recently derived mouse expanded potential stem cells (EPSCs) from individual blastomeres by inhibiting the critical molecular pathways that predispose their differentiation 1. EPSCs had enriched molecular signatures of blastomeres and possessed the developmental potency for all embryonic and extraembryonic cell lineages. Here, we report the derivation of porcine EPSCs, which express key pluripotency genes, are genetically stable, permit genome editing, differentiate to derivatives of the three germ layers in chimeras, and produce primordial germ celllike cells in vitro. Under similar conditions, human ESCs and iPSCs can be converted, or somatic cells directly reprogrammed, to EPSCs that display the molecular and functional attributes reminiscent of porcine EPSCs. Significantly, trophoblast stem cell-like cells can be generated from both human and porcine EPSCs. Our pathwayinhibition paradigm thus opens a new avenue for generating mammalian pluripotent stem cells, and EPSCs present an unique cellular platform for translational research in biotechnology and regenerative medicine.
Abstract-Preeclampsia is an inflammatory disorder in which serum levels of vascular endothelial growth factor (VEGF) and its soluble receptor-1 (sVEGFR-1, also known as sFlt-1) are elevated. We hypothesize that VEGF and placenta growth factor (PlGF) are dysregulated in preeclampsia due to high levels of sVEGFR-1, which leads to impaired placental angiogenesis. Analysis of supernatants taken from preeclamptic placental villous explants showed a four-fold increase in sVEGFR-1 than normal pregnancies, suggesting that villous explants in vitro retain a hypoxia memory reflecting long-term fetal programming. The relative ratios of VEGF to sVEGFR-1 and PlGF to sVEGFR-1 released from explants decreased by 53% and 70%, respectively, in preeclampsia compared with normal pregnancies. Exposure of normal villous explants to hypoxia increased sVEGFR-1 release compared with tissue normoxia (PϽ0.001), as did stimulation with tumor necrosis factor-␣ (PϽ0.01). Conditioned medium (CM) from normal villous explants induced endothelial cell migration and in vitro tube formation, which were both attenuated by pre-incubation with exogenous sVEGFR-1 (PϽ0.001). In contrast, endothelial cells treated with preeclamptic CM showed substantially reduced angiogenesis compared with normal CM (PϽ0.001), which was not further decreased by the addition of exogenous sVEGFR-1, indicating a saturation of the soluble receptor. Removal of sVEGFR-1 by immunoprecipitation from preeclamptic CM significantly restored migration (PϽ0.001) and tube formation (PϽ0.001) to levels comparable to that induced by normal CM, demonstrating that elevated levels of sVEGFR-1 in preeclampsia are responsible for inhibiting angiogenesis. Our finding demonstrates the dysregulation of the VEGF/PlGF axis in preeclampsia and offers an entirely new therapeutic approach to its treatment.
Background-Preeclampsia is characterized clinically by hypertension and proteinuria. Soluble Flt-1 (sFlt-1; also known as soluble vascular endothelial growth factor receptor-1 [VEGFR-1]) and soluble endoglin (sEng) are elevated in preeclampsia, and their administration to pregnant rats elicits preeclampsia-like symptoms. Heme oxygenase-1 (HO-1) and its metabolite carbon monoxide (CO) exert protective effects against oxidative stimuli. Thus, we hypothesized that HO-1 upregulation may offer protection against preeclampsia by inhibiting sFlt-1 and sEng release. Methods and Results-Preeclamptic villous explants secreted high levels of sFlt-1 and sEng. Adenoviral overexpression of HO-1 in endothelial cells inhibited VEGF-mediated sFlt-1 release and interferon-␥-and tumor necrosis factor-␣-induced sEng release, whereas HO-1 inhibition potentiated sFlt-1 and sEng production from endothelial cells and placental villous explants. Consistent with these findings, mice lacking HO-1 produced higher levels of sFlt-1 and sEng compared with wild-type mice. Using selective ligands (VEGF-E and placental growth factor) and a receptor-specific inhibitor (SU-1498), we demonstrated that VEGF-induced sFlt-1 release was VEGFR-2 dependent. Furthermore, CO-releasing molecule-2 (CORM-2) or CO decreased sFlt-1 release and inhibited VEGFR-2 phosphorylation. Treatment of endothelial cells with statins upregulated HO-1 and inhibited the release of sFlt-1, whereas vitamins C and E had no effect. Conclusions-The present study demonstrates that the HO-1/CO pathway inhibits sFlt-1 and sEng release, providing compelling evidence for a protective role of HO-1 in pregnancy, and identifies HO-1 as a novel target for the treatment of preeclampsia. Key Words: endothelium Ⅲ endothelium-derived factors Ⅲ heme oxygenase-1 Ⅲ preeclampsia Ⅲ pregnancy Ⅲ statins Ⅲ angiogenesis C ardiovascular disease and preeclampsia share some common risk factors, such as insulin resistance, obesity, diabetes mellitus, and inflammation. 1,2 The disruption of endothelial homeostasis and inflammation are fundamental to the initiation and progression of atherosclerosis 3 and preeclampsia. 4 Preeclampsia is a maternal systemic endothelial disease defined clinically as hypertension and proteinuria after 20 weeks' gestation that affects 3% to 8% of all pregnancies and women.5 Women with a history of preeclampsia and their offspring are at greater risk of developing cardiovascular disease later in life. 6,7 Clinical Perspective p 1797Preeclampsia involves dysregulated placental angiogenesis, 8 resulting in the release of soluble antiangiogenic factors that induce systemic endothelial dysfunction. 9 Two key antiangiogenic circulating factors that give the highest strength of association with preeclamptic outcome are soluble Flt-1 (sFlt-1) and soluble endoglin (sEng). 10 -12 Maternal serum levels of sFlt-1 are elevated 5 weeks before the clinical onset of preeclampsia. 10,13-16 sEng, a placenta-derived 65-kDa cleaved form of endoglin (also known as CD105), a coreceptor for transform...
One classical feature of cancer cells is their metabolic acquisition of a highly glycolytic phenotype. Carbon monoxide (CO), one of the products of the cytoprotective molecule heme oxygenase-1 (HO-1) in cancer cells, has been implicated in carcinogenesis and therapeutic resistance. However, the functional contributions of CO and HO-1 to these processes are poorly defined. In human prostate cancers, we found that HO-1 was nuclear localized in malignant cells, with low enzymatic activity in moderately differentiated tumors correlating with relatively worse clinical outcomes. Exposure to CO sensitized prostate cancer cells but not normal cells to chemotherapy, with growth arrest and apoptosis induced in vivo in part through mitotic catastrophe. CO targeted mitochondria activity in cancer cells as evidenced by higher oxygen consumption, free radical generation and mitochondrial collapse. Collectively, our findings indicated that CO transiently induces an anti-Warburg effect by rapidly fueling cancer cell bioenergetics, ultimately resulting in metabolic exhaustion.
H ydrogen sulfide (H 2 S), a gaseous signaling molecule, promotes vasodilatation 1 and stimulates angiogenesis in the vasculature.2 H 2 S has anti-inflammatory properties 3 and is also cytoprotective against cellular damage induced by lethal hypoxia or reperfusion injury. 4,5 Cystathionine γ-lyase (CSE) is the principal enzyme responsible for the endogenous production of H 2 S.6 Chronic administration of the CSE inhibitor DL-propargylglycine (PAG) leads to elevated blood pressure and vascular remodeling in the rat, 7 and both CSE and H 2 S levels are reduced in pulmonary hypertensive rats. 8Mice genetically deficient in CSE develop age-dependent hypertension, severe hyperhomocysteinemia, and endothelial dysfunction. 9 Clearly, H 2 S has multiple roles in health and disease, 10,11 but its role in pregnancy-induced hypertension is unknown. Editorial see p 2472 Clinical Perspective on p 2522Preeclampsia is a hypertensive syndrome that affects 4% to 7% of all pregnancies and is a major contributor to maternal and fetal morbidity and mortality worldwide. 12 The exact etiology of preeclampsia is unknown; abnormal placentation 13,14 and imbalance in angiogenic factors 15,16 have been implicated in preeclampsia pathogenesis. Importantly, circulating levels of soluble fms-like tyrosine kinase-1 (sFlt-1), the endogenous inhibitor of vascular endothelial growth factor and placental Background-The exact etiology of preeclampsia is unknown, but there is growing evidence of an imbalance in angiogenic growth factors and abnormal placentation. Hydrogen sulfide (H 2 S), a gaseous messenger produced mainly by cystathionine γ-lyase (CSE), is a proangiogenic vasodilator. We hypothesized that a reduction in CSE activity may alter the angiogenic balance in pregnancy and induce abnormal placentation and maternal hypertension. Methods and Results-Plasma levels of H 2 S were significantly decreased in women with preeclampsia (P<0.01), which was associated with reduced placental CSE expression as determined by real-time polymerase chain reaction and immunohistochemistry. Inhibition of CSE activity by DL-propargylglycine reduced placental growth factorproduction from first-trimester (8-12 weeks gestation) human placental explants and inhibited trophoblast invasion in vitro. Knockdown of CSE in human umbilical vein endothelial cells by small-interfering RNA increased the release of soluble fms-like tyrosine kinase-1 and soluble endoglin, as assessed by enzyme-linked immunosorbent assay, whereas adenoviral-mediated CSE overexpression in human umbilical vein endothelial cells inhibited their release. Administration of DL-propargylglycine to pregnant mice induced hypertension and liver damage, promoted abnormal labyrinth vascularization in the placenta, and decreased fetal growth. Finally, a slow-releasing H 2 S-generating compound, GYY4137, inhibited circulating soluble fms-like tyrosine kinase-1 and soluble endoglin levels and restored fetal growth in mice that was compromised by DL-propargylglycine treatment, demonstrating that the effect ...
The known responses of vascular endothelial growth factor (VEGF) are mediated through VEGF receptor-2 (VEGFR-2/KDR) in endothelial cells. However, it is unknown whether VEGFR-1 (Flt-1) is an inert decoy or a signaling receptor for VEGF during physiological or pathological angiogenesis. Here we report that VEGF-stimulated nitric oxide (NO) release is inhibited by blockade of VEGFR-1 and that VEGFR-1 via NO negatively regulates of VEGFR-2-mediated proliferation and promotes formation of capillary networks in human umbilical vein endothelial cells (HUVECs). Inhibition of VEGFR-1 in a murine Matrigel angiogenesis assay induced large aneurysm-like structures. VEGF-induced capillary growth over 14 days was inhibited by anti-VEGFR-2-blocking antibody as determined by reduced tube length between capillary connections (P < 0.0001) in an in vitro angiogenesis assay. In contrast, loss of VEGFR-1 activity with a neutralizing anti-VEGFR-1 antibody resulted in an increase in the accumulation of endothelial cells (P < 0.0001) and a dramatic decrease in the number of capillary connections that were restored by the addition of NO donor. Porcine aortic endothelial (PAE) cells expressing human VEGFR-1 but not VEGFR-2 plated on growth factor-reduced Matrigel rearranged into tube-like structures that were prevented by anti-VEGFR-1 antibody or a cGMP inhibitor. VEGF stimulated NO release from VEGFR-1- but not VEGFR-2-transfected endothelial cells and placenta growth factor-1 stimulated NO release in HUVECs. Blockade of VEGFR-1 increased VEGF-mediated HUVEC proliferation that was inhibited by NO donors, and potentiated by NO synthase inhibitors. These data indicate that VEGFR-1 is a signaling receptor that promotes endothelial cell differentiation into vascular tubes, in part by limiting VEGFR-2-mediated endothelial cell proliferation via NO, which seems to be a molecular switch for endothelial cell differentiation.
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