Circulating MicroRNAs in the Second Trimester From Pregnant Women Who Subsequently Developed Preeclampsia: Potential Candidates as Predictive Biomarkers and Pathway Analysis for Target Genes of miR-204-5p.

MicroRNAs (miRNAs) play an important role in the pathophysiology of preeclampsia (PE). However, the expression of circulating miRNAs was not analyzed in the second trimester of pregnancy, a period of major relevance to identify predictive biomarkers for PE. Therefore, we examined the expression profiles of 84 circulating miRNAs using a PCR array in plasma collected between 20 and 25 weeks of gestation from pregnant women, who subsequently developed PE and those who remained healthy during pregnancy, randomly selected from a prospective cohort. Overall, 23 miRNAs had a fold change > 2.0 and were considered to be upregulated in plasma from pregnant women who subsequently developed PE, even before the onset of clinical symptoms of PE. However, only miR-204-5p was statistically significant (P = 0.0082). Experimentally validated interactions for the target genes of miR-204-5p extracted from miRTarBase were used in the gene set functional enrichment analysis to identify Reactome pathways. The network connecting the 37 target genes for miR-204-5p revealed pathways of known pathophysiological relevance during the early development of PE and included key genes related to PE, such as BDNF, MMP-9, MALAT1, TGFBR2, and SIRT1. We further depicted downstream targets of SIRT1 that are related to the vascular endothelial function or implicated in the pathophysiology of PE, namely, FOXO1, NFκB, HIF-1α, NOS3, and PPAR-γ. Our novel findings provide for circulating miRNAs upregulated in the second trimester on plasma from pregnant women who subsequently developed PE that is potentially related to the early development of PE, which may guide further studies focused on the validation of potential predictive biomarkers in PE.

Resveratrol and grape juice: Effects on redox status and nitric oxide production of endothelial cells in in vitro preeclampsia model.

Preeclampsia (PE) is a hypertensive disorder of pregnancy and it is one of the main causes of maternal and fetal morbidity and mortality worldwide. It is known that oxidative stress plays a role in its pathophysiology, therefore we investigated the effects of trans-resveratrol, a potent antioxidant, on the Nrf2/ARE pathway, nitric oxide (NO) production, and reactive oxygen species (ROS) levels in an in vitro model of PE. Plasma from PE patients increased ARE activity in endothelial cells compared with plasma from healthy pregnant (HP), and the addition of resveratrol was able to potentiate this increase only in PE. Resveratrol also decreased ROS levels in the cells incubated with plasma from PE. Based on these results, we performed a pilot clinical study to compare the effects of serum from PE women before and 1 h after ingestion of polyphenol-rich whole red grapefruit juice incubated on endothelial cells, since grapefruit contains large amounts of resveratrol. Serum from PE patients, obtained one hour after juice intake, decreased antioxidants markers in cells compared with the serum before juice intake, besides, it increased NO production. In conclusion, resveratrol and polyphenol-rich red grape juice have potentially beneficial effects on endothelial cells incubated with PE plasma/serum, which could aid in the management of PE.

SIRT1-dependent effects of resveratrol and grape juice in an in vitro model of preeclampsia.

Preeclampsia (PE) is a multifactorial hypertensive disorder of pregnancy that is partly responsible for both maternal and fetal morbidity and mortality levels worldwide. It has been recently discovered that sirtuin-1 (SIRT1) is reduced in the circulation and in an in vitro model of PE. Therefore, in this study, we investigated the effects of trans-resveratrol, a potent antioxidant and activator of SIRT1, on oxidative stress and nitric oxide (NO) production in an in vitro model of PE compared to gestational hypertensive (GH) and healthy pregnant (HP) women. Furthermore, we also evaluated the effects of an acute intake of grape juice on women with PE to assess whether it could mimic in vitro trans-resveratrol supplementation. (1) In the GH group, resveratrol decreased intracellular reactive oxygen species (ROS) and increased their antioxidant capacity, while inhibiting SIRT1 reestablished previous levels. (2) In PE, inhibition of SIRT1 increased antioxidant activity. (3) Intracellular NO and supernatant nitrite levels were increased by inhibiting SIRT1 in the PE group. (4) Grape juice intake increased intracellular NO levels versus before grape juice intake control; however, the inhibition of SIRT1 before grape juice intake initially increased NO, but decreased it 1 h after grape juice intake. In conclusion, activating SIRT1 by using resveratrol alone may not be beneficial to women with PE, and GH and PE seem to have different responsive mechanisms to this molecule. Furthermore, grape juice intake seems to have different effects compared to resveratrol supplementation alone in this in vitro model of PE, demonstrating the potential of the combination of other biologically active molecules from grape juice over the SIRT1-eNOS-NO in PE treatment.

Interaction Between NOS3 and HMOX1 on Antihypertensive Drug Responsiveness in Preeclampsia.

OBJECTIVE: We examined the interaction of polymorphisms in the genes heme oxygenase-1 (HMOX1) and nitric oxide synthase (NOS3) in patients with preeclampsia (PE) as well as the responsiveness to methyldopa and to total antihypertensive therapy. METHODS: The genes HMOX1 (rs2071746, A/T) and NOS3 (rs1799983, G/T) were genotyped using TaqMan allele discrimination assays (Applied Biosystems, Foster City, CA, USA ), and the levels of enzyme heme oxygenase-1 (HO-1) were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: We found interactions between genotypes of the HMOX-1 and NOS3 genes and responsiveness to methyldopa and that PE genotyped as AT presents lower levels of protein HO-1 compared with AA. CONCLUSION: We found interactions between the HMOX-1 and NOS3 genes and responsiveness to methyldopa and that the HMOX1 polymorphism affects the levels of enzyme HO-1 in responsiveness to methyldopa and to total antihypertensive therapy. These data suggest impact of the combination of these two polymorphisms on antihypertensive responsiveness in PE.

OBJETIVO: Examinamos a interação dos polimorfismos nos genes heme oxigenase-1 (HMOX1) eóxido nítrico sintase (NOS3) em pacientes com pré-eclâmpsia (PE)bem como as capacidades de resposta à metildopa e à terapia anti-hipertensiva. MéTODOS: Os polimorfismos nos genes HMOX1 (rs2071746, A/T) e NOS3 (rs1799983, G/T) foram genotipados usando TaqMan allele discrimination assays (Applied Biosystems, Foster City, CA, EUA), e os níveis da enzima heme oxigenase-1 (HO-1) foram medidos por enzyme-linked immunosorbent assay (ELISA). RESULTADOS: Foram encontradas interações entre os genótipos da HMOX-1 e NOS3 e responsividade à metildopa, e que pacientes genotipados como AT apresentam níveis mais baixos de proteína HO-1 em comparação com o genótipo AA. CONCLUSãO: Foram encontradas interações entre os genes HMOX-1 e NOS3 e responsividade à metildopa e que o polimorfismo localizado no gene HMOX1 afeta os níveis de enzima HO-1 na resposta à metildopa e à terapia anti-hipertensiva. Esses dados sugerem o impacto da combinação desses dois polimorfismos na resposta anti-hipertensiva na PE.

Resveratrol improves endothelial cell markers impaired by plasma incubation from women who subsequently develop preeclampsia.

In this study, we demonstrated that plasma collected from women who subsequently developed preeclampsia caused increased heme oxygenase-1 (HO-1) production and decreased levels of nitric oxide (NO) markers in endothelial cells (HUVECs). Conversely, no changes in HO-1 or NO markers were found when HUVECs were treated with plasma from women who remained healthy throughout pregnancy. These alterations in HO-1 and NO markers were prevented by cotreatment with the polyphenol resveratrol, which also improved GSH levels. In addition, we evaluated changes induced by plasma incubation in the expression of genes and their related pathways associated with antioxidant defenses, such as Nrf2, ARE activity, and GSR. Collectively, our findings suggest that even before the appearance of clinical symptoms of preeclampsia, plasma from affected women is able to induce modifications in endothelial cells with respect to HO-1 production and NO markers. We believe that this in vitro strategy may offer an attractive alternative to the exploitation of candidate markers or screening molecules, such as resveratrol, for the prevention and management of preeclampsia.

AMP-activated protein kinase activation and NADPH oxidase inhibition by inorganic nitrate and nitrite prevent liver steatosis.

Advanced age and unhealthy dietary habits contribute to the increasing incidence of obesity and type 2 diabetes. These metabolic disorders, which are often accompanied by oxidative stress and compromised nitric oxide (NO) signaling, increase the risk of adverse cardiovascular complications and development of fatty liver disease. Here, we investigated the therapeutic effects of dietary nitrate, which is found in high levels in green leafy vegetables, on liver steatosis associated with metabolic syndrome. Dietary nitrate fuels a nitrate-nitrite-NO signaling pathway, which prevented many features of metabolic syndrome and liver steatosis that developed in mice fed a high-fat diet, with or without combination with an inhibitor of NOS (l-NAME). These favorable effects of nitrate were absent in germ-free mice, demonstrating the central importance of host microbiota in bioactivation of nitrate. In a human liver cell line (HepG2) and in a validated hepatic 3D model with primary human hepatocyte spheroids, nitrite treatment reduced the degree of metabolically induced steatosis (i.e., high glucose, insulin, and free fatty acids), as well as drug-induced steatosis (i.e., amiodarone). Mechanistically, the salutary metabolic effects of nitrate and nitrite can be ascribed to nitrite-derived formation of NO species and activation of soluble guanylyl cyclase, where xanthine oxidoreductase is proposed to mediate the reduction of nitrite. Boosting this nitrate-nitrite-NO pathway results in attenuation of NADPH oxidase-derived oxidative stress and stimulation of AMP-activated protein kinase and downstream signaling pathways regulating lipogenesis, fatty acid oxidation, and glucose homeostasis. These findings may have implications for novel nutrition-based preventive and therapeutic strategies against liver steatosis associated with metabolic dysfunction.

Circulating Heme Oxygenase-1: Not a Predictor of Preeclampsia but Highly Expressed in Pregnant Women Who Subsequently Develop Severe Preeclampsia.

Preeclampsia is the major cause of maternal and fetal deaths worldwide. Circulating biomarker concentrations to predict preeclampsia must be determined. Therefore, the objective was to evaluate heme oxygenase-1 (HO-1) concentration in both plasma and urine samples from pregnant women before the development of preeclampsia and to identify a potential biomarker for preeclampsia development. We performed a case-control study nested in a prospective study cohort at University Hospital of the Ribeirao Preto Medical School, University of São Paulo (HCFMRP-USP), Ribeirao Preto, Brazil. Of 1400 pregnant women evaluated at 20-25 weeks of gestation, 460 delivered in hospitals outside our institution. Of 940 pregnant women who completed the protocol, 30 developed preeclampsia (cases, 14 cases of severe preeclampsia and 16 cases of mild preeclampsia). Healthy pregnant women (controls, n = 90) were randomly selected from the remaining 910 participants. HO-1 concentration was evaluated in plasma/urine samples by using a commercial enzyme-linked immunosorbent assay kit. We found similar HO-1 levels in the plasma and urine for case and control groups. In the subgrouped preeclampsia, lower plasma HO-1 levels were found in mild compared with severe preeclampsia. We conclude that plasma HO-1 levels were not altered at 20-25 weeks of gestation before the manifestation of preeclampsia symptoms. Pregnant women who subsequently develop severe preeclampsia show higher expression of HO-1. This may be indicative of important underlying pathophysiologic mechanisms that differentiate between mild and severe preeclampsia and may possibly be related to a higher prooxidative status even before the development of clinical symptoms.

Clinical and Experimental Evidences of Hydrogen Sulfide Involvement in Lead-Induced Hypertension.

Lead- (Pb-) induced hypertension has been shown in humans and experimental animals and cardiovascular effects of hydrogen sulfide (H2S) have been reported previously. However, no studies examined involvement of H2S in Pb-induced hypertension. We found increases in diastolic blood pressure and mean blood pressure in Pb-intoxicated humans followed by diminished H2S plasmatic levels. In order to expand our findings, male Wistar rats were divided into four groups: Saline, Pb, NaHS, and Pb + NaHS. Pb-intoxicated animals received intraperitoneally (i.p.) 1st dose of 8 µg/100 g of Pb acetate and subsequent doses of 0.1 µg/100 g for seven days and sodium hydrosulfide- (NaHS-) treated animals received i.p. NaHS injections (50 µmol/kg/twice daily) for seven days. NaHS treatment blunted increases in systolic blood pressure, increased H2S plasmatic levels, and diminished whole-blood lead levels. Treatment with NaHS in Pb-induced hypertension seems to induce a protective role in rat aorta which is dependent on endothelium and seems to promote non-NO-mediated relaxation. Pb-intoxication increased oxidative stress in rats, while treatment with NaHS blunted increases in plasmatic MDA levels and increased antioxidant status of plasma. Therefore, H2S pathway may be involved in Pb-induced hypertension and treatment with NaHS exerts antihypertensive effect, promotes non-NO-mediated relaxation, and decreases oxidative stress in rats with Pb-induced hypertension.

Preeclamptic plasma stimulates the expression of miRNAs, leading to a decrease in endothelin-1 production in endothelial cells.

Preeclampsia is a major cause of maternal and fetal morbidity and mortality worldwide. It is a multisystem pregnancy syndrome characterized by general endothelial dysfunction caused mainly by plasma factors and debris in endothelial cells. It is widely accepted that endothelin-1 (ET-1) is involved in the pathophysiology of preeclampsia, and so it is of interest to ascertain whether the ET-1 gene (EDN1) can be targeted with tools such as miRNAs. Therefore, we investigated the relationship between the expression of miRNAs that putatively target EDN1 (and so affect ET-1 levels) in HUVECs incubated with plasma from preeclamptic women. EDN1 expression and ET-1 levels in HUVECs incubated with plasma from women with preeclampsia were similar to those in plasma from healthy pregnant women. Expression of miRNAs let-7a, -7b, and -7c, and to a lesser degree 125a and 125b, was increased in preeclampsia. Expression of miRNAs of the let-7 family was significantly negatively correlated with ET-1 levels in preeclampsia. Transfection of the preeclampsia cultures with mimic miRNA let-7 decreased ET-1 levels. Our findings show that preeclamptic plasma stimulates the expression of miRNAs in HUVECs, leading to a decrease in ET-1levels, which suggests that therapeutic miRNAs may aid in the management of preeclampsia.

Maternal hypertension and feto-placental growth restriction is reversed by sildenafil: Evidence of independent effects of circulating nitric oxide levels.

Sildenafil has shown nitric oxide (NO)-independent pleiotropic effects, however the mechanisms involved are unclear. We investigated the protective effects of sildenafil against hypertension in pregnancy and feto-placental growth restriction induced by NO inhibition, and if sodium nitrite-derived NO formation influences sildenafil effects. We evaluated the plasmatic levels of NO metabolites, cyclic guanosine monophosphate (cGMP), oxidative stress and myeloperoxidase, which are involved in endothelial dysfunction during hypertension in pregnancy. Also, we performed in vitro experiments to examine cell viability and NO synthesis in human umbilical vein endothelial cells (HUVECs) cultures incubated with plasma from healthy or hypertensive pregnant rats treated (or not) with both drugs, either alone or in association. Sildenafil blunted hypertension in pregnancy and protected against feto-placental growth restriction induced by NO inhibition and these effects of sildenafil alone were similar to those presented by its association with sodium nitrite. Protective effects of sildenafil were observed even with low plasmatic NO levels and were not followed by increases in cGMP levels. Also, sildenafil, but not sodium nitrite, blunted the increases in myeloperoxidase activity. Both drugs (isolated or in association) presented antioxidant effects. Plasma from hypertensive pregnant rats treated with sildenafil, but not sodium nitrite alone, increased the viability of HUVECs. NO synthesis in HUVECs cultures was increased with plasma from rats treated with both drugs. We conclude that sildenafil effects are not dependent of circulating NO levels in hypertension and feto-placental growth restriction. These findings may reflect a protection against myeloperoxidase and pro-oxidant activation in hypertension in pregnancy.

Myeloperoxidase in Hypertensive Disorders of Pregnancy and Its Relation With Nitric Oxide.

Elevated levels of myeloperoxidase have been demonstrated in women with preeclampsia where it may contribute to endothelial dysfunction mediated, in part, by nitric oxide impairment. In this study, we investigated myeloperoxidase in hypertensive disorders of pregnancy and its contribution to the impairment of the vasodilator nitric oxide. We found higher levels of myeloperoxidase in supernatant from human umbilical vein endothelial cells cultures incubated with plasma from preeclampsia group compared with healthy pregnant women. Further, we measured plasma concentration and activity of myeloperoxidase in 219 healthy pregnant women, 130 gestational hypertension (on antihypertensive therapy or not), and 143 preeclampsia patients (on antihypertensive therapy or not). We found that patients with preeclampsia and gestational hypertension without antihypertensive treatment showed higher levels and activity of this enzyme, respectively. Moreover, the inhibition of myeloperoxidase activity in vitro improved nitric oxide bioavailability. Our results indicate a higher cardiovascular risk in pregnant women with hypertensive disorders, and that active myeloperoxidase may play a role in endothelial dysfunction in these conditions by impairment of nitric oxide availability. Besides, the use of antihypertensive drugs seems to decrease enzyme levels suggesting a new protective feature for these drugs.

Antihypertensive therapy in pre-eclampsia: effects of plasma from nonresponsive patients on endothelial gene expression.

AIM: Over 40% of patients with pre-eclampsia are nonresponsive to antihypertensive therapy, but the underlying mechanisms are unknown. We examined the effects of plasma from nonresponsive and responsive patients on endothelial gene expression. PATIENTS & METHODS: PCR array was performed in human umbilical vein endothelial cells (HUVEC) incubated with plasma from nonresponsive (n = 4) and responsive (n = 4) patients. Gene networks and interactions with antihypertensive drugs used in pre-eclampsia were identified by Ingenuity Pathway Analysis. RESULTS: Nifedipine and hydralazine act by upregulate or downregulate genes found to be downregulated or upregulated in HUVEC incubated with plasma from nonresponsive patients. CONCLUSION: Our novel findings suggest that plasma from nonresponsive and responsive patients evoke different responses in HUVEC, and might advance the pharmacogenomics research in pre-eclampsia.