New scope in angiogenesis: role of vascular endothelial growth factor (VEGF), NO, lipid peroxidation, and vitamin E in the pathophysiology of pre-eclampsia among Egyptian females

Evaluation of oxidative stress markers in subtypes of preeclampsia: A systematic review and meta-analysis

Studies about oxidative stress biomarkers revealed different phenotypes between early and late preeclampsia (PE). Despite that, there is extensive evidence of oxidative stress in investigations that combinate forms different of preeclampsia. This study reviews the oxidative stress profile in the PE subtypes and evaluates which markers are altered in the blood and placental tissue. A search was conducted in databases such as MEDLINE, EMBASE, LILACS, and Web of Science without restricting the year and language of publication. The quality of the studies was evaluated by the Newcastle-Ottawa scale and Joanna Briggs Institute for analytical Cross-Sectional Studies. After 13,319 screened records, 65 were included in the systematic review. The markers of stress oxidative of damage and reactive species were those selected, such as malondialdehyde (MDA), lipid peroxide, advanced protein oxidation products, carbonyl protein, 8-hydroxy-2'-deoxyguanosine, total oxidant status, hydrogen peroxide, nitric oxide (NO). We described the antioxidant activity, including the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase, free glutathione, and total antioxidant capacity (TAC). We results demonstrated that oxidative stress is related to pathophysiology of PE, there were increased lipid peroxidation in the blood and placenta, and in blood a reduction of NO levels and of TAC, like lower enzymatic activity of GPx, CAT in PE, and SOD in mild PE. In addition, altered levels of MDA in the placenta and blood show that placental changes have repercussions on the clinical syndrome and are related to the severity of the disease.

Sodium butyrate aggravates glucose dysregulation and dyslipidemia in high fat-fed Wistar rats

Sodium butyrate (NaB), a short chain fatty acid (SCFA) has been shown to improve metabolic, glucose and lipid signaling. High fat diet elicits increased risk of cardiometabolic disease due to dysmetabolism, altered endothelial function and elevated oxidant activities. This study aims at evaluating the effect of NaB on high fat diet-fed female Wistar rats, and the possible role of vascular endothelial growth factor (VEGF). Twenty female Wistar rats with mean weight of 120 ± 5 g were divided randomly after one week of acclimatization into four groups: Control diet (CTR), High fat diet (HFD), NaB (200 mg/kg), and HFD + NaB. After six weeks of the experimental procedure, blood samples were collected by cardiac puncture. Data were analyzed and expressed in mean ± SEM and p-values <0.05 were accepted as significant. Data showed that HFD increased lactate dehydrogenase (LD) and free fatty acid (FFA), but not triglyceride (TG) and total cholesterol (TC). It also led to insulin resistance (elevated fasting blood glucose, insulin and homeostasis model assessment for insulin resistance). These effects of HFD were accompanied by increased lipid peroxidation (malondialdehyde and 4-hydroxynonenal). Sodium butyrate significantly decreased circulating nitric oxide (NO) and LD while increasing FFA, TG, insulin resistance, aggravated lipid peroxidation and increased VEGF in HFD rats (P < 0.05). We speculated therefore, that NaB aggravated glucose dysregulation and dyslipidemia, which is accompanied by increased VEGF.

The Imbalance among Oxidative Biomarkers and Antioxidant Defense Systems in Thromboangiitis Obliterans (Winiwarter-Buerger Disease)

(1) Background: Thromboangiitis obliterans or Winiwarter-Buerger disease (WBD), is an inflammatory, thrombotic occlusive, peripheral vascular disease, usually occurring in young smokers. The pathophysiological mechanisms underlying the disease are not clearly understood. The aim of this study is to investigate the imbalance between oxidants and antioxidants occurring in these patients. (2) Patients and Methods: In this cross-sectional study, 22 male patients with WBD and 20 healthy male smoking habit matched control group were included. To evaluate the possible sources of oxidative stress, the antioxidant biomarkers, and the markers of lipid peroxidation and protein oxidation, serum samples were analyzed for total oxidative status (TOS), total antioxidant capacity (TAC), myeloperoxidase (MPO), coenzyme Q10 (CoQ10), superoxide dismutase (SOD), glutathione reductase (GR), malondialdehyde (MDA), and protein carbonyl (PC) activity and/or content. (3) Results: The circulating levels of TOS, TAC, and CoQ10 were significantly higher in WBD patients, with respect to healthy smokers as controls. No significant difference was found among the serum level of PC, total cholesterol, MPO, and GR activity in WBD patients and healthy smoker controls. The activity of SOD and the mean serum level of MDA were significantly lower in WBD patients, with respect to healthy smoker controls. (4) Conclusion: Considerably high levels of oxidative stress were detected in WBD patients, which were greater than the antioxidant capacity. The low level of MDA may be associated with the enzymatic degradation of lipid peroxidation products. High levels of CoQ10 and low levels of SOD may be related to a harmful oxidative cooperation, leading to the vasoconstriction of WBD, representing a promising tool to discern possible different clinical risks of this poorly understood peripheral occlusive disease.

Vascular endothelial growth factor C/A 2578 gene polymorphism and umbilical artery Doppler in preeclamptic women

INTRODUCTION

Preeclampsia is strongly associated with placental hypoperfusion. Genetic factors have an impact on the pathogenesis of preeclampsia. The aim is to assess the association of Vascular Endothelial Growth Factor (C2578A) gene polymorphism with the occurrence and severity of preeclampsia and the umbilical artery Doppler changes among preeclamptic women.

MATERIALS AND METHODS

This case-control study was conducted in clinical and Chemical pathology and Obstetrics departments in Beni- Suef University, Egypt. Two hundred and ninety pregnant women above 20 weeks gestational age until delivery were divided into 2 main groups. The patient group included 145 preeclamptic women who were further sub grouped according to the severity of preeclampsia into 82 severe and 63 mild cases. Control group included 145 normotensive pregnant women. Our primary outcome was detection of VEGF C 2578 A gene mutations by a polymerase chain reaction. A secondary outcome was Doppler changes in the pulsatility index of the umbilical artery compared with VEGF genotypes.

RESULTS

Our study showed that VEGF C 2578 A genotype and alleles frequencies were not related to the occurrence of preeclampsia (p-value 0.513 and 0.549, respectively), odds ratio (95%CI) 1.154 (0.724-1.848). Mild preeclamptic cases showed no significance comparing VEGF genotypes studied and pulsatility index of the umbilical artery. However, severe cases showed p-value < 0.0001.

CONCLUSION

We concluded that VEGF 2578C/A polymorphism had no association with the occurrence of preeclampsia in studied groups, whereas there was a significant relationship among severe cases between CA and CC genotypes and pulsatility index of the umbilical artery.

Serum copper, zinc and lipid peroxidation in pregnant women with preeclampsia in gorgan

The aim of study was to assay serum copper, zinc and lipid peroxidation levels in pregnant women with and without preeclampsia. There were significant differences between systolic, diastolic blood pressures and copper, Cu/Zn ratio and malondialdehyde among two groups. There were significant differences in weight, pre-pregnancy body mass index, systolic, diastolic blood pressures and copper, Cu/Zn ratio and malondialdehyde levels when compared to healthy pregnant women with mild and severe preeclampsia patients. A positive correlation was observed between systolic and diastolic blood pressure and copper, malondialdehyde and Cu/Zn ratio. Copper and malondialdehyde may play a role in the pathophysiology of preeclampsia.

Impaired renal function and increased urinary isoprostane excretion in Ghanaian women with pre-eclampsia

Background

The cause of pre-eclampsia remains largely unknown, but oxidative stress (an imbalance favoring oxidant over antioxidant forces) has been implicated in contributing to the clinical symptoms of hypertension and proteinuria. Assessment of oxidative stress in pre-eclampsia using urinary isoprostane has produced conflicting results, and it is likely that renal function may affect isoprostane excretion. The aim of this study was to determine the role of oxidative stress in the pathophysiology of pre-eclampsia and to assess the effect of renal function on isoprostane excretion in pre-eclampsia in the Ghanaian population.

Methods

This was a case-controlled study, comprising 103 pre-eclamptic women and 107 normal pregnant controls and conducted at the Korle-Bu Teaching Hospital between December 2006 and May 2007. The study participants were enrolled in the study after meeting the inclusion criteria and signing their written informed consent. Oxidative stress was determined by measuring urinary excretion of isoprostane and total antioxidant capacity using an enzyme-linked immunosorbent assay technique. Renal function was assessed by calculating the estimated glomerular filtration rate using the Modification of Diet in Renal Disease formula.

Results

The pre-eclampsia group had significantly (P = 0.0006) higher urinary isoprostane excretion (2.81 ± 0.14 ng/mg creatinine) than the control group (2.01 ± 0.18 ng/mg creatinine) and a significantly (P = 0.0008) lower total antioxidant power (1.68 ± 0.05 mM) than the control group (1.89 ± 0.04 mM). Urinary isoprostane excretion showed a positive correlation with both mean arterial pressure (r = 0.261) and microalbuminuria (r = 0.510) in the pre-eclampsia cases. The pre-eclampsia group had a significantly lower estimated glomerular filtration rate than the control group (P < 0.001), indicating more renal impairment.

Conclusion

The increased urinary excretion of isoprostanes and decreased total antioxidant power in the in pre-eclampsia group suggest increased production of oxidants and depletion and/or reduction of maternal antioxidants. Increased oxidative stress may be important in the pathophysiology of pre-eclampsia by contributing to endothelial dysfunction, proteinuria, and hypertension.

The role of homocysteine, asymmetric dimethylarginine and nitric oxide in pre-eclampsia

Nitric oxide (NO) contributes to vasodilatation that is observed during normal pregnancy. Hyperhomocysteinaemia (HHcy) is a vascular risk factor associated with placental microvascular diseases and pre-eclampsia. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (NOS) has been linked to endothelial dysfunction. Maternal ADMA has been reported to be higher in women with pre-eclampsia and HHcy leads to accumulation of ADMA. The aim of this presented study is to evaluate the alterations of plasma homocysteine, ADMA and NO levels in mild pre-eclampsia. A total of 40 pre-eclamptic women and 40 healthy controls were included into the study. Mean systolic and diastolic blood pressure, mean serum homocysteine and ADMA levels were significantly higher and NO level was lower in patients. Serum homocysteine, ADMA and NO levels found to be correlated among them and with blood pressure. In conclusion, we found that homocysteine and ADMA levels were increased and NO levels decreased in pre-eclampsia.

Magnesium sulfate therapy of preeclampsia: an old tool with new mechanism of action and prospect in management and prophylaxis

A disturbed balance between angiogenic and antiangiogenic growth factors is a highly accepted mechanism in the pathogenesis of pregnancy-induced hypertension and proteinuria, which is clinically known as preeclampsia (PE). We investigated the effect of magnesium sulfate (MgSO4) therapy on vascular endothelial growth factor (VEGF), placental growth factor (PlGF), nitric oxide (NO) metabolites, soluble fm-like tyrosine kinase-1 (sFlt-1) and endoglin levels in PE rats and the effect of this treatment on the feto-maternal outcome. The PE group showed hypertension, proteinuria and decreased number and weight of live pups relative to the control group. This result was associated with increased sFlt-1, VEGF receptor-2 (VEGFR-2), VEGFR-3 and endoglin levels but decreased NO metabolites. MgSO4 therapy ameliorated systolic hypertension and proteinuria and decreased sFlt-1, VEGFR-2, VEGFR-3 and endoglin levels but increased NO metabolites in the treated group. Physiological and biochemical changes and improved pup weight and viability were observed in the treated group. The vasodilator action of MgSO4 and increased NO production are expected to increase placental blood flow and help fetal nutrition and development. Relief of placental ischemia decreases the production of antiangiogenic growth factors and restores the bioavailability of angiogenic factors (PlGF and VEGF). These changes resulted in better fetal outcome and an improved clinical picture of PE. These findings are promising and encourage further study of the mechanism of action of MgSO(4) to support its widespread use in the prevention and management of the etiopathological changes underlying the vast majority of the manifestations and complications of PE.

Cell free expression of hif1α and p21 in maternal peripheral blood as a marker for preeclampsia and fetal growth restriction

Preeclampsia, a severe unpredictable complication of pregnancy, occurs in 6% of pregnancies, usually in the second or third trimester. The specific etiology of preeclampsia remains unclear, although the pathophysiological hallmark of this condition appears to be an inadequate blood supply to the placenta. As a result of the impaired placental blood flow, intrauterine growth restriction (IUGR) and consequential fetal oxidative stress may occur. Consistent with this view, pregnancies complicated by preeclampsia and IUGR are characterized by up-regulation of key transcriptional regulators of the hypoxic response including, hif1α and as well as p53 and its target genes. Recently, the presence of circulating cell-free fetal RNA has been documented in maternal plasma. We speculated that pregnancies complicated by preeclampsia and IUGR, will be associated with an abnormal expression of p53 and/or hif1α related genes in the maternal plasma. Maternal plasma from 113 singleton pregnancies (72 normal and 41 complicated pregnancies) and 19 twins (9 normal and 10 complicated pregnancies) were collected and cell free RNA was extracted. The expression of 18 genes was measured by one step real-time RT-PCR and was analyzed for prevalence of positive/negative expression levels. Results indicate that, among the genes examined, cell free plasma expressions of p21 and hif1α were more prevalent in pregnancies complicated by hypoxia and/or IUGR (p<0.001). To conclude, we present in this manuscript data to support the association between two possible surrogate markers of hypoxia and common complications of pregnancy. More work is needed in order to implement these findings in clinical practice.

Pathological aspects of lipid peroxidation

Lipid peroxidation (LPO) product accumulation in human tissues is a major cause of tissular and cellular dysfunction that plays a major role in ageing and most age-related and oxidative stress-related diseases. The current evidence for the implication of LPO in pathological processes is discussed in this review. New data and literature review are provided evaluating the role of LPO in the pathophysiology of ageing and classically oxidative stress-linked diseases, such as neurodegenerative diseases, diabetes and atherosclerosis (the main cause of cardiovascular complications). Striking evidences implicating LPO in foetal vascular dysfunction occurring in pre-eclampsia, in renal and liver diseases, as well as their role as cause and consequence to cancer development are addressed.

Role of vitamins C and e in regulating antioxidant and pro-oxidant markers in preeclampsia

We compared three groups of pregnant women: placebo with normotensive women, group A which included preeclamptics, and group B which comprised preeclamptics who were supplemented their diets with vitamins C and E. MDA increased from 6.22 ± 2.8 (placebo) to 8.48 ± 1.2 (A) and 8.02 ± 1.8 nmol/gHb (B). NO concentrations were enhanced from 19.3 ± 4.2 (P) to 23.8 ± 6.4 (A) and 24.1 ± 5.4 µmol/L (B). GSH contents were decreased from 10.42 ± 2.81 (P) to 8.02 ± 2.92 (A) and 9.39 ± 1.02 µmol/g Hb (B), whereas GSSG concentrations increased from 0.98 ± 0.28 (P) to 1.24 ± 0.29 (A) and 1.08 ± 0.12 µmol/g Hb (B). SOD activity decreased 23% in A and 14% in B; GRx decreased 27% in A and 5.5% in B; GPx decreased 12% in A and 9.6% in B. Catalase activity, however, increased 27% in A and 29% in B as compared to control. Thus, we conclude that the use of vitamins C and E should be considered for the control of certain important biochemical indices during the development of preeclampsia; however, further studies are needed to develop methods for the prevention of preeclampsia in women at high risk.

The role of antioxidant vitamins in hypertensive disorders of pregnancy

Preeclampsia (PE) is an important and a leading cause of both maternal morbidity and adverse perinatal outcomes. Despite progress in perinatal medicine for patients with an established diagnosis of PE, a therapeutic approach other than termination of pregnancy was unsuccessful. Women predisposed to PE begin pregnancy with a certain degree of endothelial dysfunction, a lesion that precedes shallow placentation. The proposed sequence of events comprises endothelial dysfunction, defective trophoblast invasion, and consequential impaired placental perfusion, immune maladaptation and inflammation. The possible link between these could be oxidative stress by excessive production of reactive oxygen species coupled with inadequate or overwhelmed antioxidant defense mechanisms. These defense mechanisms, involving antioxidant vitamins and enzyme systems, may restrain the extent of damage caused by oxidative stress. Markers of oxidative stress in women with established PE were confirmed. Accordingly, these findings support an expected beneficial effect of antioxidant therapy in the prevention of PE and other pregnancy-related disorders. Numerous studies have been carried out in order to investigate this possible and simple prophylactic and/or therapeutic approach in prevention of oxidative stress and eventual reduction of PE and its perinatal complications. In this review the role of vitamin antioxidants in prevention and treatment of PE is discussed. Despite the logic behind using antioxidant vitamins, the data, thus far, are at best conflicting.

Placental growth factor (PlGF) is a surrogate marker in preeclamptic hypertension

OBJECTIVE

To evaluate plasma levels of angiogenic factors and their association with preeclampsia.

METHODS

Twenty-three women with preeclampsia and nine normotensive pregnant women from the Maternity of Hospital das Clínicas of Belo Horizonte/MG-Brazil were assessed by National High Blood Pressure Education Program Working Group Creteria (NHBPEPWG). The plasma levels of vascular endothelial growth factor (VEGF) and Placental growth factor (PlGF) were determined by ELISA assay.

RESULTS

Plasma concentration of PlGF was 12-fold lower in preeclampsia versus non preeclampsia pregnancies. An inverse correlation was observed between PlGF plasma levels and mean arterial pressure (MAP); a decrease in 1pg/mL of PlGF resulted in 6.18 mm Hg increase in MAP.

CONCLUSION

These results indicate that PlGF is related to MAP in pregnant women.

The immunohistochemical evaluation of VEGF in placenta biopsies of pregnancies complicated by preeclampsia

OBJECTIVE

The study was designed to determine the protein levels of vascular endothelial growth factor (VEGF) in the placenta biopsies of patients with preeclampsia and compare with normal controls.

DESIGN

Prospective cohort study.

METHODS

The placental biopsies were obtained from ten patients with preeclampsia and ten patients of control group at the time of delivery. Avidin-biotin-peroxidase immunohistochemistry was then performed to identify levels of VEGF protein within the tissue and a semi-quantitative method was devised to score the amount of staining present in the sample. Two histopathologists who were blinded to the groups were asked to score each sample for the intensity of staining and the number of cells stained in a randomly selected per high-power fields of each sample. The resulting "H-score" was computed as a product of intensity and percent of cells stained.

RESULTS

The VEGF expression was significantly higher in placenta biopsies of preeclamptic patients compared to that of controls (271.2 +/- 22.65 vs. 201.9 +/- 12.33, P = 0.000).

CONCLUSION

Immunostaining of VEGF is significantly higher in placenta biopsies of patients with preeclampsia.

Vitamin E During Pre‐ and Postnatal Periods

Vitamin E is a fat-soluble nutrient that is extremely important during the early stages of life, from the time of conception to the postnatal development of the infant. The mechanisms involved in its placental and mammary uptake appear to be allowed by the presence of lipoprotein receptors (LDL-receptor, VLDL-receptor, scavenger receptor class B type I) together with lipoprotein lipase at the placental and mammary barriers. In addition, alpha-tocopherol transfer protein has been described as playing an essential role in the selective transfer of RRR-alpha-tocopherol across the placenta. Lower alpha-tocopherol concentrations are found in cord blood as compared to maternal circulation. The ingestion of colostrum which contains very high levels of vitamin E is therefore of utmost importance to supply the newborn with an essential defense against oxygen toxicity. Pregnancy is sometimes associated with complications that may lead to a premature delivery of the baby. Preterm infants are usually facing an oxidative stress that is among others related to a deficiency in alpha-tocopherol, as it accumulates mainly during the third trimester of pregnancy. Despite vitamin E supplementation, preterm infants usually require significantly longer to replenish their serum alpha-tocopherol levels than full-term infants. The use of vitamin E as a therapeutic agent in preeclampsia, which induces high maternal and fetal morbidity and mortality, has been discussed in numerous papers. This disorder is indeed associated with an important oxidative stress in the placenta and maternal circulation. However, the most recent studies did not show a beneficial effect of vitamin E administration in this pathology.

Expression of vascular endothelial growth factor receptor types 1, 2 and 3 in placenta from pregnancies complicated by hypertensive disorders

The aim of the present study was to determine the expression of vascular endothelial growth factor (VEGF) family receptors (VEGFR) in placentas from pregnancies complicated by hypertensive disorders of different clinical severity. Placental tissue from women with gestational hypertension, pre-eclampsia, pre-eclampsia with haemolysis, elevated liver enzymes and low platelets (HELLP syndrome) and normotensive women, as a control group, was examined. Immunohistochemical techniques, reverse transcription–polymerase chain reaction and western blot were used to evaluate receptor expression. In cases with gestational hypertension, as well as in control cases, VEGFR-1 and VEGFR-3 immunoreactivity was detected in all placental components, whereas in placentas from the pre-eclampsia and pre-eclampsia with HELLP syndrome groups, VEGFR-1 and VEGFR-3 immunoreactivity was detected only in some portions of trophoblast and/or some vessels and/or clusters of stromal cells. In the control group, VEGFR-2 immunoreactivity was observed only in the vessels, whereas the hypertensive groups showed VEGF-2 immunoreactivity also in trophoblast and stromal cells. The mRNA levels of the three receptors in the group with gestational hypertension were higher with respect to those in the control group. Placentas from pregnancies with pre-eclampsia showed lowest mRNA expression levels, whereas placentas from women with pre-eclampsia plus HELLP syndrome showed higher mRNA expression levels with respect to the three other groups. Receptor protein levels were lower in pathological cases compared with levles in the control group. These findings demonstrate a dysregulation of placental expression of VEGF family receptors related to the degree of clinical severity of the hypertensive disorder.

The endogenous anti-angiogenic family of splice variants of VEGF, VEGFxxxb, are down-regulated in pre-eclamptic placentae at term

PET (pre-eclamptic toxaemia) has recently been linked with alterations in production of a VEGFR1 [VEGF (vascular endothelial growth factor) receptor 1] splice variant that acts as a circulating inhibitor. We have recently described a family of naturally occurring splice variants of VEGF, termed VEGFxxxb, that also appear to act as inhibitors of conventional VEGFxxx-mediated angiogenesis. To determine whether alteration in splicing of VEGF-VEGFR family members extended beyond VEGFR1, we investigated the effect of pre-eclampsia on placental VEGFxxxb mRNA and protein expression. VEGFxxx and VEGFxxxb mRNA and protein were both found in normal human term placentae. VEGFxxx protein formed the majority of the total VEGF protein (980+/-195 pg/mg), whereas VEGFxxxb (11.5 pg/mg) was found to form a small part of the total VEGF protein expression (1.5+/-0.24%). Evidence for VEGF165b, VEGF121b and VEGF145b expression was found. In pre-eclamptic placentae, there was a significant down-regulation of VEGFxxxb isoforms, but a small up-regulation of VEGFxxx isoforms. In normal placenta VEGFxxxb and VEGFxxx concentrations were positively correlated (r=0.69, P<0.02), whereas in pre-eclamptic placentae, there was a significant negative correlation between VEGFxxxb and VEGFxxx protein expression (r=-0.8, P<0.02), indicating that there was a significant uncoupling of the splicing regulation of the VEGF isoforms. Combined with previous studies showing increased soluble VEGFR1 isoforms in human pre-eclampsia, these data suggest that there may be a common mechanism in pre-eclampsia that involves dysregulation of mRNA splicing of members of the VEGF-VEGFR axis.

Role of anion gap and different electrolytes in hypertension during pregnancy (preeclampsia)

The present study was designed to determine the changes in serum sodium, anion gap, different antioxidants and free radicals in preeclamptic patients and control subjects. Serum sodium, chloride, bicarbonate, calcium, potassium and magnesium were estimated and anion gap was determined in 100 proteinuric hypertensive and 100 normotensive pregnant women. Mean serum sodium, chloride and bicarbonate level (133.26 +/- 13.1, 104.97 +/- 11.37, and 22.01 +/- 4.66 mEq/l, respectively) were significantly higher in proteinuric hypertensive women as compared to controls (125.85 +/- 10.4, 101.90 +/- 6.3, 19.34 +/- 3.21 mEq/l, respectively) whereas anion gap level (6.28 +/- 16.147) was nonsignificantly higher in proteinuric hypertensive as compared to normotensive (4.61 +/- 11.84). Total serum sodium concentration increases in preeclamptic subjects, the exact distribution of serum sodium in various compartments of the body are not clear and correlation of serum sodium and anion gap with proteinuria is also not known. The levels of different antioxidants were decreased in preeclamptic patients as compared to the controls while the level of free radicals elevated in preeclamptic subjects as compared to controls. In our study, anion gap level was found to be rather non-significantly higher in proteinuric hypertensive women as compared to normotensive women.

Pathophysiological basis for the prophylaxis of preeclampsia through early supplementation with antioxidant vitamins

Preeclampsia (PE) is a multisystem disorder that remains a major cause of maternal and foetal morbidity and death. To date, no treatment has been found that prevents the development of the disease. Endothelial dysfunction is considered to underlie its clinical manifestations, such as maternal hypertension, proteinuria, and edema; however, the precise biochemical pathways involved remain unclear. A current hypothesis invokes the occurrence of oxidative stress as pathogenically important, as suggested by the fact that in PE, the placental and circulating levels of lipid peroxidation products (F2-isoprostanes and malondialdehyde [MDA]) are increased and endothelial cells are activated. A potential mechanism for endothelial dysfunction may occur via nuclear transcription factor kappa B (NF-kappaB) activation by oxidative stress. Alternatively, the idea that the antiangiogenic placental soluble fms-like tyrosine kinase 1 factor (sFlt1) is involved in the pathogenesis of this disease is just emerging; however, other pathophysiological events seem to precede its increased production. This review is focused on evidence providing a pathophysiological basis for the beneficial effect of early antioxidant therapy in the prevention of PE, mainly supported by the biological effects of vitamins C and E.

Lipid peroxidation, antioxidant defense, status of trace metals and leptin levels in preeclampsia

OBJECTIVE

To investigate the changes in enzyme activities of erythrocyte superoxide dismutase (SOD), catalase, and placental glutathione peroxidase (GSH-Px), and analyze the levels of serum malondialdehyde (MDA), copper (Cu), zinc (Zn), selenium (Se), leptin and placental MDA and glutathione (GSH).

STUDY DESIGN

Cross-sectional prospective study consisting of 32 preeclamptic (PE) pregnant, 25 non-pregnant (NP) women, 28 healthy pregnant (HP) women. Levels of lipid peroxides in serum and placenta, and activities of SOD, catalase in erythrocyte and placental GSH level, placental GSH-Px activity were measured by spectrophotometric methods. Serum levels of Cu, Zn, Se measured by atomic absorption spectrophotometry. Serum levels of leptin was measured by enzyme immunoassay by using the Cayman chemical kit. One-way analysis of variance and post hoc Tukey-HSD test and Pearson correlation test were used for the statistical analyses.

RESULTS

Serum levels of MDA, Cu, Leptin were markedly higher (P < 0.001); and serum level of Se was markedly lower (P < 0.001) in PE women compared with HP women and NP women. Also, placental MDA level was higher (P < 0.001) and placental GSH-Px activity was lower in PE women compared with HP women. In preeclamptic women erythrocyte catalase activity was markedly increased (P < 0.001), while erythrocyte SOD activity was markedly decreased (P < 0.001) compared to HP women and NP women. Placental GSH level was decreased compared to HP women (P < 0.001). Serum level of Zn was markedly decreased compared to NP women (P < 0.001) but no significant difference was observed in PE pregnant when compared with HP women (P > 0.05). Placental MDA level in PE women had significant negative correlation with serum Se level (r = -0.353, P < 0.05). A negative correlation was found between erythrocyte catalase activity with birth weight (r = -0.528, P < 0.001). Also, there were a significant negative correlation between serum levels of Cu and Se in the preeclamptic women (r = -0.407, P < 0.05).

CONCLUSION

Our data demonstrate that elevation of lipid peroxides together with impaired antioxidant defense mechanisms and status of trace metals and the presence of possible interrelationship and crosstalk between those parameters may be related at least partly to the pathogenesis of preeclampsia. Additionally, lipid peroxides and blood oxidative imbalance could be part of the cytotoxic mechanisms leading to endothelial cell injury.

Angiogenin and vascular endothelial growth factor in pregnancies complicated by preeclampsia

OBJECTIVE

To investigate the role of the angiogenic factors, vascular endothelial growth factor (VEGF) and angiogenin in the pathophysiology of preeclampsia and how their concentrations correlate with the severity of the disease and fetal outcome.

PATIENTS AND METHODS

A prospective study was carried out on 71 pregnant patients with preeclampsia and 20 pregnant normotensive controls. Maternal serum levels of VEGF and angiogenin were determined in all cases by enzyme immunoassay. Assessment of fetal well-being using the Biophysical Profile Score (BPS), umbilical and uterine artery Doppler velocimetry, and infant birthweight were carried out.

RESULTS

Maternal serum VEGF and angiogenin levels were significantly increased in cases of mild and severe preeclampsia compared to controls. Their increase was positively correlated with elevated systolic and diastolic blood pressure, as well as poor BPS, abnormal Doppler velocimetry, and low birthweight.

CONCLUSION

Elevated levels of both VEGF and angiogenin could confirm the existence of vascular reactivity and endothelial disturbance in preeclampsia. Measurement of these angiogenic factors in maternal serum may be a useful as biomarkers for the assessment of the severity of the disease and of fetal outcome.

Aspects of human fetoplacental vasculogenesis and angiogenesis. III. Changes in complicated pregnancies

Patterns of fetoplacental angiogenesis vary not only during the course of a normal pregnancy but also in certain pregnancy pathologies. Here, we review some of the molecular and morphological events which occur in complicated pregnancies. The pregnancy complications are chosen in an attempt to represent the possible different origins (preplacental, uteroplacental, postplacental) of fetal hypoxia. Molecular events focus on reported changes in hypoxia-inducible factors, angiopoietins and the vascular endothelial, basic fibroblast and placenta growth factors and their receptors. Morphological changes focus on patterns of angiogenesis (branching and non-branching) and a consistent set of morphometric descriptors (covering measures of total capillary growth, villous capillarization and capillary size and shape in transverse section). Apart from some uncertainties due to lack of information, or failure to resolve fully the effects of intrauterine growth restriction and pre-eclampsia, alterations in the angiogenic growth factors and morphologies of capillaries and villi in different complicated pregnancies seem to conform reasonably well to those predicted by the fetal hypoxia paradigm. However, it is clear that future studies on the effects of different origins of fetal hypoxia should exercise more care in the choice and interpretation of relevant descriptors and take more account of the parallel effects of possible confounders. In addition, rather than comparing uncomplicated and complicated pregnancies only at term, more information about molecular and morphological events that occur throughout gestation would be extremely valuable. This includes further studies on changes in growth factor receptors, the less-well-documented angiogenic factors (e.g. angiogenin, angiostatin, endostatin) and the associations between endothelial cells and pericytes. A more integrated approach involving also parallel analysis of the effects of erythropoietin and other potential vasoactive factors on the behaviour and morphology of fetal vessels would be beneficial.

VEGF expression in the placenta from pregnancies complicated by hypertensive disorders

OBJECTIVE

To determine the expression of VEGF in the placental tissue from pregnancies complicated by hypertension disorders of different clinical severity.

DESIGN

Prospective cohort study.

SETTING

Polyclinic of Careggi, University of Florence, Italy.

SAMPLE

Placentas from women with gestational hypertension (n= 20), pre-eclampsia (n= 20) and pre-eclampsia with HELLP syndrome (n= 20) and from normotensive women (n= 20), as control group (gestational age comprised between 35 and 38 weeks).

METHODS

An immunohistochemical technique and a quantitative analysis to measure mRNA levels (RT-PCR) were employed.

MAIN OUTCOME MEASURES

Intensity of immunoreactivity and mRNA levels in the placental components. Differences between the data.

RESULTS

VEGF immunoreactivity was observable in all the placental components in the gestational hypertension cases as in the control ones. In the cases with pre-eclampsia and pre-eclampsia with HELLP syndrome, some placental components were not immunoreactive. However, the VEGF positive components of all the pathological groups showed a higher intensity of reactivity with respect to that of the control group. The levels of VEGF mRNA were higher in the gestational hypertension cases and lower in the cases of pre-eclampsia with HELLP syndrome with respect to the control ones; in the cases of pre-eclampsia, the levels were the same as the control ones.

CONCLUSION

The different expression of VEGF in the placenta of the pathological cases is probably related to haemodynamic changes that take place in these disorders, in order to attempt restoration of a normal uteroplacental flow.

Differential expression of vascular endothelial growth factor (VEGF), endocrine gland derived-VEGF, and VEGF receptors in human placentas from normal and preeclamptic pregnancies

Vascular endothelial growth factor (VEGF) is a potent regulator of placental vascular function. Endothelial dysfunction is a key factor associated with preeclampsia. In this study, we examined expression of VEGF, endocrine gland-derived VEGF (EG-VEGF), VEGF receptors 1 and 2 (VEGFR-1 and VEGFR-2), and neuropilin-1 and -2 (NP-1 and NP-2) in human placentas from women with normal and preeclamptic (PE) pregnancies using quantitative or semiquantitative PCR. We found that total VEGF mRNA expression was increased 2.8-fold (P < 0.05), along with increases in mRNA expression of VEGF121, 165, and 189 (P < 0.05; 1.7-, 1.9-, and 1.8-fold, respectively) in PE vs. normal placentas. Expression of VEGFR-1 mRNA, but not EG-VEGF and the other three VEGF receptors studied, was elevated (P < 0.05) 2.7-fold in PE vs. normal placentas. Protein expression of VEGF and its four receptors was determined using Western blot analysis. For VEGF, two major isoforms (VEGF165 and 189) were detected. For VEGFR-1, VEGFR-2, NP-1, and NP-2, one major band was observed at 180, 235, 130, and 130 kDa, respectively. All of these bands were corresponding to their positive controls. Of these five proteins studied, only VEGFR-1 levels were increased (P < 0.05; 1.7-fold) in PE placentas. The expression of VEGF and the four VEGF receptors was confirmed using immunohistochemistry. They were primarily present in syncytiotrophoblasts and endothelial cells of villous capillaries and large vessels. Thus, together with previous reports that VEGFR-1 mediates trophoblast function and inhibits VEGF-induced angiogenesis and endothelium-dependent vasodilation, these data suggest that the increased VEGFR-1 expression may alter VEGF- mediated function on trophoblast and endothelial cells in PE placentas.

Nutritional assessment and support during pregnancy

This article thoroughly updates the authors' previous review of nutritional assessment and support during pregnancy. After briefly reviewing nutrient metabolism and requirements, the authors discuss the nutritional assessment of the pregnant woman and review the nutritional support principles in hyperemesis gravidarum and other conditions that can compromise the nutritional health of mother or fetus.

Vascular endothelial growth factor induced functional and morphologic signs of endothelial dysfunction in isolated arteries from normal pregnant women

OBJECTIVE

The purpose of this study was to determine the effects of vascular endothelial growth factor on basal tone, endothelium-dependent dilatation, permeability, and morphologic features of endothelium in isolated arteries from normal pregnant women. We hypothesized that vascular endothelial growth factor might induce signs of endothelial dysfunction.

STUDY DESIGN

Arteries (approximately 200 microm) were dissected from subcutaneous fat biopsy specimens that were obtained at cesarean delivery and mounted on a pressure arteriograph. Changes in basal tone, dilatation to bradykinin (1 nmol/L to 3 micromol/L) before, during, and after 3 hours of incubation with vascular endothelial growth factor (0.5 or 1 nmol/L), vascular endothelial growth factor (0.5 nmol/L) plus bosentan (a nonselective endothelin receptor A and B antagonist, 1 micromol/L), or vehicle were compared. Scanning electron microscopy was applied for endothelial morphologic features. Permeability to Evans blue dye was evaluated in arteries after incubation with vascular endothelial growth factor, vascular endothelial growth factor plus angiopoietin-1, or vehicle, and in arteries that were obtained from women with preeclampsia.

RESULTS

Basal tone was higher after 60 minutes of incubation with vascular endothelial growth factor (0.5 nmol/L) compared with vehicle (29% +/- 5% [n = 10] vs 10% +/- 4% [n = 7], P =.006). Combination of vascular endothelial growth factor with bosentan failed to increase the tone (n = 4). Bradykinin-mediated dilatation was impaired in arteries that were incubated with vascular endothelial growth factor 0.5 nmol/L (max dilatation: 287% +/- 16% vs 160% +/- 23% [n = 10], P =.0001) or vascular endothelial growth factor 1 nmol/L (max dilatation: 207% +/- 21% vs 88% +/- 4% [n = 3], P =.003). Bradykinin-mediated dilatation was similar after incubation with vehicle (n = 7) or the combination of vascular endothelial growth factor plus bosentan (n = 4). Evans blue dye staining was higher after incubation with vascular endothelial growth factor but was reversed by the addition of angiopoietin-1. Scanning electron microscopy demonstrated the development of intercellular gaps.

CONCLUSION

Vascular endothelial growth factor impaired bradykinin-mediated dilatation and enhanced basal tone and permeability. This might indicate a potential role for vascular endothelial growth factor in the development of endothelial dysfunction in pregnancy. Angiopoietin-1 inhibited the vascular endothelial growth factor-induced vascular leakage, which may have therapeutic implications in preeclampsia.