Avancées dans la physiopathologie de la pré-éclampsie : place de la réponse inflammatoire

Systematic review of observational studies of the impact of cardiovascular risk factors on preeclampsia in sub-saharan Africa

BACKGROUND

Maternal mortality is a public health issue, particularly in low- and middle-income countries (LMIC). Sub-Saharan Africa (SSA) is the region most affected worldwide by maternal mortality, and preeclampsia is one of the main causes. We performed a systematic review of observational studies to identify the impact of cardiovascular risk factors on preeclampsia in SSA with a more representative sample.

METHODS

Databases: PubMed and Google Scholar were searched to identify published studies. Studies were included if they reported results on the link between at least one cardiovascular risk factor and preeclampsia. Relevant studies quality was assessed with the Newcastle-Ottawa Scale (NOS). Odds ratios and relative risk (RR) were reported with their confidence intervals.

RESULTS

Twelve articles (8 case-controls, 3 cohorts, 1 cross-sectional) were included in this review, with a total of 24,369 pregnant women. Cardiovascular risk factors such as chronic hypertension, overweight, obesity, diabetes and alcohol were significantly associated with a high risk of preeclampsia. Very few data were available concerning some risk factors. None of the articles reported tobacco consumption as a preeclampsia risk factor. There is a lack of data from French-speaking SSA countries.

CONCLUSION

Cardiovascular risk factors increase the risk of preeclampsia. Our results suggest the need for prospective cohort studies to ascertain this association in order to reduce maternal mortality due to preeclampsia.

Placental Microarray Profiling Reveals Common mRNA and lncRNA Expression Patterns in Preeclampsia and Intrauterine Growth Restriction

Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR) are major contributors to perinatal morbidity and mortality. These pregnancy disorders are associated with placental dysfunction and share similar pathophysiological features. The aim of this study was to compare the placental gene expression profiles including mRNA and lncRNAs from pregnant women from four study groups: PE, IUGR, PE-IUGR, and normal pregnancy (NP). Gene expression microarray analysis was performed on placental tissue obtained at delivery and results were validated using RTq-PCR. Differential gene expression analysis revealed that the largest transcript variation was observed in the IUGR samples compared to NP (n = 461; 314 mRNAs: 252 up-regulated and 62 down-regulated; 133 lncRNAs: 36 up-regulated and 98 down-regulated). We also detected a group of differentially expressed transcripts shared between the PE and IUGR samples compared to NP (n = 39), including 9 lncRNAs with a high correlation degree (p < 0.05). Functional enrichment of these shared transcripts showed that cytokine signaling pathways, protein modification, and regulation of JAK-STAT cascade are over-represented in both placental ischemic diseases. These findings contribute to the molecular characterization of placental ischemia showing common epigenetic regulation implicated in the pathophysiology of PE and IUGR.

Study of Combination of Nanoherbal Andaliman (Zanthoxylum acanthopodium) and Extra Virgin Olive Oil (EVOO) Effects in the Expression of Malondialdehyde (MDA), Heat Shock Protein-70 (HSP70) and Placental Histology of Preeclamptic Rats

Background: Pre-eclampsia (PE) contributes to the second cause of maternal death in Indonesia. Andaliman is a typical spice of the Batak ethnic in Northern Sumatera Province, Indonesia. This study aimed to explore the potential of novel herbal medicine compound of nanoherbal andaliman and extra virgin olive oil (EVOO) as PE treatment. Methods: Nanoherbal andaliman was generated using High-energy Milling (HEM). The treatments were divided into the following five groups: K- (control): pregnant rats; K+: PE model rats; P1: PE model rats + 0.45 g of EVOO/200 g BW on the 13th–19th day of pregnancy; P2: PE model rats + nanoherbal andaliman 100 mg/200 g BW on the 13th– 19th day of pregnancy; and P3: PE model rats + combination of 0.45 EVOO/200 g BW and nanoherbal andaliman 100 mg/200 g BW on the 13th–19th day of pregnancy. Rats were dissected on the 20th day of pregnancy. The observed parameters were blood pressure, proteinuria, malondialdehyde (MDA), Heat Shock Protein-70 HSP-70 and histology of placenta. Results: A significant difference was noticed (p<0.05) in blood pressure, proteinuria, foetal weight, haematocrit, erythrocytes and trophoblastic cells after the administration of combined nanoherbal andaliman and EVOO. No significant differences in placental weight, foetal number, leukocytes, MDA and HSP-70 were found (p>0.05). Conclusion: The combination of nanoherbal andaliman and EVOO decreased systolic blood pressure and induced the expression of MDA and HSP-70, as well as placental histology of pre-eclamptic rats.

Genetic variation of myeloperoxidase gene contributes to preeclampsia: a preliminary association study in Turkish population

OBJECTIVE

To examine MPO gene polymorphisms of women with preeclampsia in Turkish population.

METHODS

Sixty-one preeclamptic and 61 normotensive women without history of preeclampsia in earlier pregnancies were enrolled in this prospective controlled study. MPO mutations were characterized by PCR-RFLP method.

RESULTS

We demonstrated a significant difference in patients with preeclampsia in terms of genotype frequency. Heterozygous carriers of -463A among preeclamptic pregnancies were significantly frequent, whereas rare A/A homozygotes failed to differ from controls.

CONCLUSION

The -463G/A polymorphism of leukocyte MPO could be an intriguing susceptibility factor that modulates an individual's risk of preeclampsia in Turkish population.

HSP70 is associated with endothelial activation in placental vascular diseases

Endothelial cell injury and activation in the placenta are features of placental vascular disease (PVD). While advances in PVD have been made, the pathogenesis of this disease is still unknown. The objective of this study was to pursue potential risk factors and signal transcription pathways involved in PVD pathogenesis. Gene expression in subjects with PVD and with normal pregnancies was compared using a two-channel microarray technique. Higher expression of HSPA6 and HSPA1A was exhibited in PVD subjects. HSPA6 and HSPA1A both encode HSP70, and, therefore, we localized HSP70 expression in placental tissue. Using quantitative polymerase chain reaction (PCR) and Western blot, we observed a significant upregulation of HSP70 in both mRNA and protein levels in placental tissue and microvascular endothelial cells of PVD subjects when compared with normal pregnancies (P< 0.05). HSP70 mRNA and protein expression also correlated negatively with infant birth weight (P< 0.05). HSP70 was expressed mainly in endothelial cells and smooth muscle cells in the placental microvessels. We therefore conclude that HSP70 may mediate endothelial activation and play a role in pathogenesis of PVD.

Redox considerations in female reproductive function and assisted reproduction: from molecular mechanisms to health implications

Physiological levels of reactive oxygen species (ROS) play an important regulatory role through various signaling transduction pathways in folliculogenesis, oocyte maturation, endometrial cycle, luteolysis, implantation, embryogenesis, and pregnancy. Persistent and elevated generation of ROS leads to a disturbance of redox potential that in turn causes oxidative stress (OS). Our literature review captures the role of ROS in modulating a range of physiological functions and pathological processes affecting the female reproductive life span and even thereafter (i.e., menopause). The role of OS in female reproduction is becoming increasingly important, as recent evidence suggest that it plays a part in conditions such as polycystic ovarian disease, endometriosis, spontaneous abortions, preeclampsia, hydatidiform mole, embryopathies, preterm labor, and intrauterine growth retardation. OS has been implicated in different reproductive scenarios and is detrimental to both natural and assisted fertility. Many extrinsic and intrinsic conditions exist in assisted reproduction settings that can be tailored to reduce the toxic effects of ROS. Laboratory personnel should avoid procedures that are known to be deleterious, especially when safer procedures that can prevent OS are available. Although antioxidants such as folate, zinc, and thiols may help enhance fertility, the available data are contentious and must be evaluated in controlled studies with larger populations.

Comparative analysis of the maternal and umbilical interleukin-8 levels in normal pregnancies and in pregnancies complicated by preeclampsia with intrauterine normal growth and intrauterine growth retardation

OBJECTIVES

The aim of this study was to determine the maternal and umbilical cord serum levels of interleukin-8 (IL-8) in pregnancies complicated by preeclampsia with intrauterine normal growth and intrauterine growth retardation (IUGR), and in normotensive pregnancies.

PATIENTS AND METHODS

The study was carried out on 15 patients with singleton pregnancies complicated by preeclampsia with appropriate for gestational age weight infants and 12 pregnant patients with preeclampsia complicated by IUGR. The control group consisted of 10 healthy normotensive delivering patients with singleton uncomplicated pregnancies. Maternal and umbilical serum IL-8 concentrations were estimated using the ELISA method.

RESULTS

There were no statistically significant differences in patient profiles between the groups. Systolic and diastolic blood pressure and mean arterial blood pressure were higher in the study groups in comparison with the control group. Lower birth weight and lower gestational age at birth were observed in the group of patients with preeclampsia complicated by IUGR. Increased maternal and umbilical serum levels of IL-8 were found in both preeclamptic patient groups in comparison with the control group. The umbilical cord blood concentrations of IL-8 in all groups of patients tended to be higher in comparison with the maternal blood.

CONCLUSIONS

It seems that these higher IL-8 concentrations may be associated with apoptosis, inflammation, neutrophil activation, endothelial cell damage and dysfunction, and increased endothelial permeability. They may also participate in an attempt to compensate for the imbalanced apoptosis and vascular resistance. Our findings suggest a possible significant role of IL-8 in the pathogenesis and sequelae of preeclampsia, especially in preeclamptic pregnancies complicated by IUGR.

The role of placental oxidative stress and lipid peroxidation in preeclampsia

Preeclampsia is a complex multisystem disorder exclusively seen in human species that is characterized by hypertension and proteinuria. This disorder has the highest maternal and fetal morbidity and mortality of all pregnancy-related complications. Growing evidence suggests that placental oxidative stress is involved in the etiopathogenesis of preeclampsia. Reduced perfusion as a result of abnormal placentation leads to ischemia reperfusion injury to the placenta. Placental oxidative stress, which results from the ischemia reperfusion injury, is being increasingly reported to be involved in the etiopathogenesis of preeclampsia. It has been proposed as a promoter of lipid peroxidation and the endothelial cell dysfunction that is commonly seen in this condition. Although preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity, there is no consensus regarding causality of lipid peroxidation in preeclampsia. In this article, we address the question of the biologic association of lipid peroxidation and preeclampsia. Lipid peroxidation and leukocyte activation may play a pivotal role in endothelial cell dysfunction. We also review the different factors that have been proposed to cause endothelial cell dysfunction in preeclampsia, trials investigating the role of antioxidant supplementation in preeclampsia, and the lack of consensus among the trials. Additional longitudinal studies are necessary to determine if the various oxidative stress biomarkers estimated early in pregnancy can be narrowed to a single marker for predicting preeclampsia.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall that placental oxidative stress is involved in the etiopathogenesis of preeclampsia, state that placental oxidative stress results from ischemic reperfusion injury, and explain that ischemic reperfusion injury is a promoter of lipid peroxidation and endothelial cell dysfunction seen in preeclampsia.