Ulrich Pecks

Interplay between Vascular Endothelial Growth Factor (VEGF) and Nuclear Factor Erythroid 2-related Factor-2 (Nrf2) IMPLICATIONS FOR PREECLAMPSIA

Background: Several studies have suggested that decreasing VEGF levels might result in placental oxidative stress in preeclampsia. Results: VEGF activates Nrf2 in an ERK1/2-dependent manner, protecting against oxidative stress, and, in turn, up-regulates VEGF expression. Conclusion: Reduced VEGF bioavailability may lead to aggregation of oxidative stress and result in preeclampsia. Significance: Nrf2 activation might be considered as an adjunct therapeutic strategy to combat preeclampsia. Several recently published studies have suggested that decreasing VEGF levels result in placental oxidative stress in preeclampsia, although the question as to how decreased VEGF concentrations increase oxidative stress still remains unanswered. Here, we show that VEGF activated Nrf2, the main regulating factor of the intracellular redox balance, in the cytotrophic cell line BeWo. In turn, this activated the production of antioxidative enzymes thioredoxin, thioredoxin reductase, and heme oxygenase-1, which showed a decrease in their expression in the placentas of preeclamptic women. Nevertheless, this activation occurred without oxidative stress stimulus. As a consequence, the activation of Nrf2 protected BeWo cells against H2O2/Fe2+-induced oxidative damage. We further show that VEGF up-regulated the expression of itself. A positive feedback loop was described in which VEGF activated Nrf2 in an ERK1/2-dependent manner; the up-regulation of HO-1 expression by Nrf2 augmented the production of carbon monoxide, which in turn up-regulated VEGF expression. In conclusion, VEGF induces the Nrf2 pathway to protect against oxidative stress and, via a positive feedback loop, to elevate VEGF expression. Therefore, decreased VEGF bioavailability during preeclampsia may result in higher vulnerability to placental oxidative cell damage and a further reduction of VEGF bioavailability, a vicious circle that may end up in preeclampsia.

Maternal and fetal cord blood lipids in intrauterine growth restriction.

Abstract Aim: Small for gestational age neonates (SGA) could be subdivided into two groups according to the underlying causes leading to low birth weight. Intrauterine growth restriction (IUGR) is a pathologic condition with diminished growth velocity and fetal compromised well-being, while non-growth restricted SGA neonates are constitutionally (genetically determined) small. Antenatal sonographic measurements are used to differentiate these two subgroups. Maternal metabolic changes contribute to the pathogenesis of IUGR. A disturbed lipid metabolism and cholesterol supply might affect the fetus, with consequences for fetal programming of cardiovascular diseases. We evaluated fetal serum lipids and hypothesized a more atherogenic lipoprotein profile in IUGR fetuses. Methods: Umbilical cord serum lipids and oxidative modified, low-density lipoprotein (oxLDL) concentrations were measured by colorimetric enzymatic measurements, or by ELISA. Values of IUGR (n=36) and constitutionally small for gestational age neonates (SGA, n=22) were compared with those of healthy, adequate for gestational age, born neonates (CN, n=97). SAS-statistic software was used and two-way ANOVA was adjusted for gestational age at delivery. Results: Fetal high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC) concentrations were found to be lower in the IUGR compared to the CN and SGA groups (HDL-C: P<0.001, TC: P<0.01). Atherogenic indices, including the oxLDL/LDL-C ratio, were increased in the IUGR compared to the CN group (oxLDL/LDL-C ratio: P<0.001). Conclusion: Our results support the hypothesis of a disturbed cholesterol supply in IUGR fetuses. Born SGA has been shown to be a risk factor for developing cardiovascular disease later in life. Since HDL-C has anti-inflammatory properties, a reduced HDL-C during fetal development, and an increase in atherogenic indices, might provide a link to this observation in IUGR fetuses.

Oocyte donation: a risk factor for pregnancy-induced hypertension: a meta-analysis and case series.

BACKGROUND In 2008 and 2009, the authors saw in their institution three women who had undergone oocyte donation and went on to develop severe de novo hypertension before the 26(th) week of gestation, with values above 180/110 mm Hg. Pregnancy was prematurely terminated in these cases because of the acute threat to the mothers life, and none of the three neonates survived. Five further cases with better outcomes were found to have occurred from 2006 to 2010. On the basis of this experience, the authors performed a meta-analysis to determine whether oocyte donation elevates the risk of pregnancy-induced hypertension (PIH). The cases are discussed in detail. METHODS Systematic review of the literature on PIH after oocyte donation, with meta-analysis and calculation of an odds ratio. We also provide a retrospective chart review of our own case series. RESULTS 28 publications were evaluated. The overall rate of PIH in a total of 2308 deliveries after oocyte donation was 22.6%. With the aid of data from 11 studies, the course of pregnancy in a total of 644 oocyte recipients was compared to that in a control group of 2320 women who were not oocyte recipients. The calculated odds ratio for PIH after oocyte donation, compared to conventional reproductive therapy, was 2.57 (95% CI, 1.91-3.47), while the calculated odds ratio for PIH after oocyte donation, compared to other women in the control group, was 6.60 (95% CI, 4.55-9.57). CONCLUSION The data reveal that oocyte donation confers a considerable risk that the recipient will develop PIH. The very early and severe cases of preeclampsia that we report here are rather atypical; similar cases may have occurred elsewhere without finding their way into the relevant literature. The authors recommend close surveillance of pregnancies following allogenic oocyte transplantation by physicians with special expertise in prenatal medicine.

The Evaluation of the Oxidative State of Low-Density Lipoproteins in Intrauterine Growth Restriction and Preeclampsia

Objective. To evaluate the oxidative state of lipoproteins in pregnancies complicated by intrauterine growth restriction (IUGR) in comparison to preeclampsia (PE) and healthy pregnant control subjects (CN). Methods. Maternal serum of 20 PE, 29 IUGR, and 29 gestational age-matched CN were analyzed. Total cholesterol (TC), low-density lipoprotein (LDL)-bound cholesterol (LDL-C), and oxidized LDL (oxLDL) concentration were measured once between 25 and 34 weeks of gestation. Statistical estimates were performed by Students t-test. Results. Serum concentrations of LDL-C and TC were significantly reduced in IUGR [LDL-C: CN – mean = 146 mg/dL, SD = ± 40.1; IUGR – mean = 102 mg/dL, SD = ± 27.3 (p < 0.0001); PE – mean = 130 mg/dL, SD = 38.8 mg/dL; TC: CN – mean = 259/dL, SD = ± 46.8; IUGR – mean = 218 mg/dL, SD = ± 35.0 (p < 0.001); PE – mean = 244 mg/dL, SD = 48.2]. There was no significant difference in oxLDL/LDL-C ratio within the three groups (CN: mean = 0.76, SD = 0.24; IUGR: mean = 0.74, SD = 0.12; PE: mean = 0.77, SD = 0.22). Conclusion. Our results show a lower maternal LDL-C and TC concentration in IUGR pregnancies. These data contribute to the hypothesis of a decreased cholesterol supply to the fetus in IUGR. However, we could not confirm the hypothesis of an altered oxidative state in neither IUGR nor PE.

Multifactorial analysis of affinity-mass spectrometry data from serum protein samples: A strategy to distinguish patients with preeclampsia from matching control individuals

A multifactorial differential analysis of serum proteins using mass spectrometry distinguished samples from pregnant women with severe early-onset preeclampsia (n = 11) from those of control individuals with uneventful pregnancies (n = 13). Serum proteins were fractionated by either their affinities to reversed-phase material coated magnetic beads or by fractionated precipitation. The on-average most abundant ion signals were observed at m/z 9390, 9103, and 8886. The best differentiating ion signals between the two sample groups were found at m/z 13,715, 13,834, and 13,891. The normalized intensities of these ion signals were on-average lower in the preeclampsia group than in the control group. The six ion signal intensities enabled sorting of the individual spectra with high accuracy. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that a protein band migrating just above the 14 kDa marker band contained transthyretin (P02766; Mr (avg.): 13,761). Densitometric analysis of the transthyretin bands showed lower intensities in the preeclampsia samples with respect to those of the controls. Nephelometric analysis of the serum samples determined the mean concentration of transthyretin in the preeclampsia group were lower (0.16 mg/mL; range: 0.13 to 0.20; SD: 0.03) than that in the control group (0.19 mg/mL; range: 0.14 to 0.22; SD: 0.02), substantiating the role of transthyretin concentration differences in the comparison of the two groups. Altogether, our findings support the theory of preeclampsia being a heterogeneous disorder that might be sub-classified by a defined proteome signature in maternal blood using multifactorial analysis of affinity-fractionated serum samples.

Angiogenic factors and acute-phase proteins in serum samples of preeclampsia and HELLP patients: a matched-pair analysis

Objectives: To investigate the serum level distribution of angiogenic markers (PlGF, endoglin, sFlt-1) and acute-phase proteins (SAA, CRP) in patients with HELLP syndrome or preeclampsia (PE) including matched controls. Methods: The matching procedure revealed 46 controls for 23 HELLP cases, and 81 controls for 42 preeclamptic patients. Maternal serum concentrations were determined by immunoassays. Results: SAA and CRP levels were significantly higher in HELLP patients compared with controls. This finding was not observed in preeclamptic subgroup. Pro-angiogenic PlGF is significantly lower in PE and HELLP syndrome. Anti-angiogenic endoglin is significantly higher in PE and HELLP syndrome. The sFlt-1 analysis supports the anti-angiogenic shift in HELLP and preeclamptic patients, but with smaller differences between subgroups. The SAA/PlGF ratio showed the highest ROC value of all tested parameters in discrimination between HELLP and HELLP controls. Conclusions: These findings support the concept that patients with HELLP syndrome have both an anti-angiogenic state and a pronounced inflammatory response, while patients with PE are characterized only by an anti-angiogenic shift.

Fatty acid synthase overexpression: target for therapy and reversal of chemoresistance in ovarian cancer

BackgroundFatty acid synthase (FASN) is crucial to de novo long-chain fatty acid synthesis, needed to meet cancer cells’ increased demands for membrane, energy, and protein production.MethodsWe investigated FASN overexpression as a therapeutic and chemosensitization target in ovarian cancer tissue, cell lines, and primary cell cultures. FASN expression at mRNA and protein levels was determined by quantitative real-time polymerase chain reaction and immunoblotting and immunohistochemistry, respectively. FASN inhibition’s impact on cell viability, apoptosis, and fatty acid metabolism was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide assay, cell death detection enzyme-linked immunosorbent assay, immunoblotting, and 18 F-fluoromethylcholine uptake measurement, respectively.ResultsRelative to that in healthy fallopian tube tissue, tumor tissues had 1.8-fold average FASN protein overexpression; cell lines and primary cultures had 11-fold–100-fold mRNA and protein overexpression. In most samples, the FASN inhibitor cerulenin markedly decreased FASN expression and cell viability and induced apoptosis. Unlike concomitant administration, sequential cerulenin/cisplatin treatment reduced cisplatin’s half maximal inhibitory concentration profoundly (up to 54%) in a cisplatin-resistant cell line, suggesting platinum (re)sensitization. Cisplatin-resistant cells displayed lower 18 F-fluoro-methylcholine uptake than did cisplatin-sensitive cells, suggesting that metabolic imaging might help guide therapy.ConclusionsFASN inhibition induced apoptosis in chemosensitive and platinum-resistant ovarian cancer cells and may reverse cisplatin resistance.

A proteome signature for intrauterine growth restriction derived from multifactorial analysis of mass spectrometry‐based cord blood serum profiling

Intrauterine growth restriction (IUGR) is defined as a condition in which the fetus does not reach its genetically given growth potential, resulting in low birth weight. IUGR is an important cause of perinatal morbidity and mortality, thus contributing substantially to medically indicated preterm birth in order to prevent fetal death. We subjected umbilical cord blood serum samples either belonging to the IUGR group (n = 15) or to the control group (n = 15) to fractionation by affinity chromatography using a bead system with hydrophobic interaction capabilities. So prepared protein mixtures were analyzed by MALDI‐TOF mass spectrometric profiling. The six best differentiating ion signals at m/z 8205, m/z 8766, m/z 13 945, m/z 15 129, m/z 15 308, and m/z 16 001 were collectively assigned as IUGR proteome signature. Separation confidence of our IUGR proteome signature reached a sensitivity of 0.87 and a specificity of 0.93. Assignment of ion signals in the mass spectra to specific proteins was substantiated by SDS‐PAGE in conjunction with peptide mass fingerprint analysis of cord blood serum proteins. One constituent of this proteome signature, apolipoprotein C‐III0, a derivative lacking glycosylation, has been found more abundant in the IUGR cord blood serum samples, irrespective of gestational age. Hence, we suggest apolipoprotein C‐III0 as potential key‐marker of the here proposed IUGR proteome signature, as it is a very low‐density lipoprotein (VLDL) and high‐density lipoprotein (HDL) member and as such involved in triglyceride metabolism that itself is discussed as being of importance in IUGR pathogenesis. Our results indicate that subtle alterations in protein glycosylation need to be considered for improving our understanding of the pathomechanisms in IUGR.

Mass spectrometric profiling of cord blood serum proteomes to distinguish infants with intrauterine growth restriction from those who are small for gestational age and from control individuals.

Intrauterine growth restriction (IUGR) is a multifactorial condition in that the fetus does not reach its genetically given growth potential. Besides its contribution to perinatal mortality, it is a risk factor for cardiovascular and metabolic diseases later in life. The diagnosis is based on antenatal sonography, which allows differentiating between IUGR and fetuses that are small by constitution (small for gestational age [SGA]). Yet, neither a clinical nor a biochemical tool is available to confirm reliably the diagnosis of IUGR postnatally. Recently, we identified umbilical cord blood proteins of the apolipoprotein family by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with differential signal intensities between the IUGR group and a control group. We hypothesized that identified molecules have the potential to generate a proteome profile specific for IUGR. A total of 114 serum samples (42 from the IUGR group, 12 from the SGA group, and 60 from the control group) of the umbilical vein (99 samples) and umbilical artery (15 samples) were analyzed. Sample quality was estimated by determining the abundance of hemoglobin (hemolysis) and CXC-motif chemokines CXCL4 and CXCL7 (platelet activation). Samples passing the quality criteria were forwarded to multiplex apolipoprotein profiling. Assay performance was tested with the sample sets, resulting in a sensitivity of 0.91 and a specificity of 0.85 in the test set with venous blood samples. Arterial cord blood samples followed the trend (sensitivity, 0.67; specificity, 0.85). SGA samples grouped together with the control samples. We conclude that the proteome profiling signature is confirmatory to clinical surveillance with the potential to identify neonates with IUGR postnatally in low-birth weight babies born at uncertain gestational age when antenatal sonography data have not been recorded.

Off-label use of misoprostol for labor induction in Germany: a national survey

OBJECTIVE Misoprostol is safe and effective for labor induction in viable pregnancies. Little is known about the prevalence of off-label use of misoprostol, and the reasons for using or not using misoprostol for labor induction. As such, a national survey was conducted in Germany to assess reliable data about the use of misoprostol in clinical practice. STUDY DESIGN A prospective study was performed in 2013 using a standardized survey questionnaire. All registered departments of obstetrics and gynecology in Germany were targeted. RESULTS Out of 783 questionnaires, 542 (69%) were returned. Three hundred and fifty-five (66%) respondents reported that they use misoprostol for labor induction in viable term pregnancies, and 183 (34%) respondents reported that they never use misoprostol for this indication. The most common reasons given for using misoprostol in labor induction were: effectiveness (40%), good patient acceptance (35%), established/well proven in clinical practice (35%) and cost-effectiveness (32%). The most common reasons given for not using misoprostol were lack of licence (off-label use, 69%) and uncertainty of the legal situation (27%). CONCLUSION Although misoprostol is not licensed in Germany for obstetric indications, the vast majority of respondents (66%) reported that they use misoprostol for labor induction. The main reasons for not using misoprostol for labor induction in Germany are legal concerns rather than lack of scientific evidence. Cost-effective medications with evidence-based effectiveness and safety should be supported by a clear statement from national medical societies.