Soluble factors released by placental villous tissue: Interleukin-1 is a potential mediator of endothelial dysfunction

miR-218-5p Induces Interleukin-1β and Endovascular Trophoblast Differentiation by Targeting the Transforming Growth Factor β-SMAD2 Pathway

The acquisition of an endovascular trophoblast (enEVT) phenotype is essential for normal placental development and healthy pregnancy. MicroRNAs (miRNAs) are small noncoding RNAs that play critical roles in regulating gene expression. We have recently reported that miR-218-5p promotes enEVT differentiation and spiral artery remodeling in part by targeting transforming growth factor β2 (TGFβ2). We also identified IL1B, which encodes interleukin 1β (IL1β), as one of the most highly upregulated genes by miR-218-5p. In this study, we investigated how miR-218-5p regulates IL1B expression and IL1β secretion and the potential role of IL1β in enEVT differentiation. Using two cell lines derived from extravillous trophoblasts (EVTs), HTR-8/SVneo and Swan 71, we found that stable overexpression of miR-218-5p precursor, mir-218-1, or transient transfection of miR-218-5p mimic, significantly increased IL1B mRNA and IL1β protein levels in cells and conditioned media. We also showed that miR-218-5p directly interacted with SMAD2 3'UTR and reduced SMAD2 at mRNA and protein levels. Knockdown of SMAD2 induced IL1B expression and attenuated the inhibitory effect of TGFβ2 on IL1B expression. On the other hand, overexpression of SMAD2 reduced IL1β levels and blocked the stimulatory effects of miR-218-5p on IL1B expression, trophoblast migration and endothelial-like network formation. In addition, treatment of trophoblasts with IL1β induced the formation of endothelial-like networks and the expression of enEVT markers in a dose-dependent manner. These results suggest that miR-218-5p inhibits the TGFβ/SMAD2 pathway to induce IL1β and enEVT differentiation. Finally, low doses of IL1β also inhibited the expression of miR-218-5p, suggesting the existence of a negative feedback regulatory loop. Taken together, our findings suggest a novel interactive miR-218-5p/TGFβ/SMAD2/IL1β signaling nexus that regulates enEVT differentiation.

Serum Uric Acid Level as a Predictive Biomarker of Gestational Hypertension Severity; A Prospective Observational Case-Control Study

BACKGROUND

Pre-eclampsia poses a significant potential risk of hypertensive disorders during pregnancy, a leading cause of maternal deaths. Hyperuricemia is associated with adverse effects on endothelial function, normal cellular metabolism, and platelet aggregation and adhesion. This study was designed to compare serum urate levels in normotensive pregnant women to those with pregnancy-induced hypertension, and to evaluate its value as a potential predictive marker of hypertension severity during pregnancy.

METHODS

A prospective, observational, case-control study conducted on 100 pregnant women in their third trimester. Pregnant women were classified into two groups (n=50) according to arterial blood pressure measurements: group I had normal blood pressure, and group II had a blood pressure of ≥ 140/90, which was further subdivided according to hypertension severity into IIa (pregnancy- induced hypertension, IIb (mild pre-eclampsia), and IIc (severe pre-eclampsia). Blood samples were obtained on admission. Serum urate, high sensitive C-reactive protein, and interleukin-1β levels, and lipid profile were compared among the groups.

RESULTS

A significant increase in the mean values of serum urate, C-reactive protein, and interleukin- 1β levels was detected in gestational hypertensives. In addition, there was a positive correlation between serum urate levels and C-reactive protein and interleukin-1β, as well as between serum urate levels and hypertension severity.

CONCLUSION

Hyperuricemia and increased C-reactive protein and interleukin-1β serum levels correlate with the severity of pregnancy-induced hypertension, and these biomarkers may play a role in the pathogenesis of pre-eclampsia. Serum urate measurement is sensitive, reliable markers that correlate well with the severity of hypertension in pregnant females with pre-eclampsia.

Adenoviral mediated expression of anti-inflammatory progranulin by placental explants modulates endothelial cell activation by decrease of ICAM-1 expression

INTRODUCTION

Functional disorders of the villous trophoblast may result in preeclampsia through the release of endothelial activating substances. Progranulin is an anti-inflammatory, pro-angiogenic cytokine with TNF-α antagonizing activity. The trophoblastic expression of progranulin is increased during preeclampsia. The aim of the study was to investigate the impact of placental progranulin synthesis on endothelial cell activation.

METHODS

Placental progranulin expression was modified by transduction of an adenoviral vector. Primary isolated human umbilical venous endothelial cells (HUVECs) were incubated with conditioned medium of first trimester placental explants. Functional studies on HUVECs included assays for proliferation, viability, cytotoxicity and analyzes of Intercellular adhesion molecule-1 (ICAM-1) and E-selectin expression.

RESULTS

Placental progranulin expression was more than 10-fold higher by using an adenoviral-mediated overexpression system (Ad.PGRN) compared to control vector (Ad.CTRL) and untreated controls. Incubation of HUVECs with conditioned placental medium revealed a dose-dependent increase of cytotoxicity, reduced cell proliferation and viability and resulted in an increase of ICAM-1 and E-selectin expression. Overexpression of progranulin (Ad.PGRN) antagonized the ICAM-1 expression induced by conditioned medium. However progranulin did not influence the effects on cell proliferation, viability, cytotoxicity and E-selectin expression in HUVECs.

DISCUSSION

Regulation of gene expression in human placental explants is possible by usage of an adenoviral vector system. The increase of endothelial ICAM-1 expression following the incubation with placental conditioned medium was partly reversed by overexpression of placental progranulin. It is suggested that up-regulation of the placental progranulin expression is an endogenous anti-inflammatory mechanism that partially antagonizes the endothelial cell activation during preeclampsia.

Genetic variations in IL1A and IL1RN are associated with the risk of preeclampsia in Chinese Han population

Preeclampsia (PE) is an excessive systemic inflammation response with dysfunction of endothelial. Our study was to investigate the association between genetic variations in IL-1 and the susceptibility to PE in Chinese Han population. 402 PE patients and 554 normal pregnant women of third trimester were enrolled. The polymorphisms of rs315952 in IL1RN and rs17561 in IL1A were genotyped by TaqMan allelic discrimination real-time PCR. Obviously statistic difference of the genotypic frequencies were found in both of IL1RN rs315952 and IL1A rs17561 between cases and controls (for rs315952, P = 0.001; for rs17561, P = 0.021.). For rs315952, the C allele was associated with development of PE (P = 0.003, OR = 1.319, 95%CI 1.099–1.583). Patients with CC or CT genotype were less likely to develop severe PE than patients carrying TT genotype(P< 0.001, OR = 0.24, 95%CI 0.15–0.40). For rs17561, the C allele was the risk factor for predisposition to PE (P = 0.012, OR = 1.496, 95%CI 1.089–2.055). Our results suggest IL1RN and IL1A may involve in the development of PE in Chinese Han population.

The effect of Silymarin on VEGF, VEGFR-1 and IL-1α levels in placental cultures of severe preeclamptic women

OBJECTIVE

The purpose of this study was to evaluate the effects of Silymarin on vascular endothelial growth factor (VEGF), soluble VEGF Receptor-1 (sVEGFR-1) and Interleukin-1 alpha (IL-1α) levels in placental tissue samples of severely preeclamptic women.

MATERIAL AND METHODS

We conducted an in vitro study in Başkent University Faculty of Medicine, Ankara, Turkey between September 2008 and May 2009. A total of 16 placental tissue samples (8 from severe preeclamptic, and 8 from controls) were analysed. Placental samples were incubated, and VEGF, sVEGFR-1, and IL1-α were measured in culture media using an ELISA kit. The effect of Silymarin on these levels was investigated. Descriptive statistics were initially performed, followed by Mann Whitney U-test and Kruskal-Wallis test to compare means between groups. P values less than 0.05 were considered statistically significant.

RESULTS

Eight patients were included in the severe preeclampsia (SP) group, whereas the remaining 8 patients were included in the control group. There were no significant correlations between gestational age and placental VEGF, sVEGFR-1 and IL-1α after 48 or 72 hours of incubation. Basal VEGF levels were lower in the SP group; however, it did not reach statistical significance. sVEGFR-1 and IL-1α levels were also similar between the SP and control groups (p>0.05). After 48 and 72 hours of incubation, sVEGFR-1 levels in Silymarin-added SP and control placental cultures were lower than in the samples without Silymarin addition; however, this difference also did not reach significance.

CONCLUSION

Although we could not demonstrate a significant effect on placental cytokines, considering the role of vasospasm, inflammation, angiogenesis, endothelial cell activation, and oxidative stress in preeclampsia, the potential benefits of Silymarin should be evaluated in future trials with a larger sample size.

Placental secretion of interleukin-1 and interleukin-1 receptor antagonist in preeclampsia: effect of magnesium sulfate

Preeclampsia is a pregnancy-specific disorder characterized by hypertension and systemic endothelial dysfunction. Interleukin (IL)-1β is a possible mediator of maternal endothelial dysfunction in preeclampsia. Serum IL-1β as well as its natural inhibitor IL-1 receptor antagonist (IL-1Ra) were reported to be increased in women with preeclampsia. In the current study, we addressed the role of the placenta in controlling the circulatory levels of IL-1β and its natural inhibitor IL-1Ra in preeclampsia, and the possible effect of magnesium sulfate (MgSO(4)) on these levels. Using an ex vivo placental perfusion system, placentas from preeclamptic (n = 9) and normotensive (n = 6) pregnancies were perfused in presence or absence of MgSO(4). Perfusate samples were collected from the maternal and the fetal circulations of the perfusion system, and IL-1β and IL-1Ra were examined by enzyme-linked immunoassay (ELISA). Preeclamptic placentas secreted higher levels of IL-1β (P < 0.001), and a tendentious higher levels of IL-1Ra, mainly into the maternal circulation, as compared with normotensive placentas, although no differences in IL-1β:IL-1Ra ratio were detected. However, there was only tendentious increase in the secretion levels of IL-1β or IL-1Ra into the fetal circulation of preeclamptic placentas, when compared with normotensive placentas. Administration of MgSO(4) to preeclamptic placentas resulted in an attenuation of the increased secretion of IL-1β into the maternal circulation (P < 0.001), and in a tendentious reduction in IL-1Ra. However, IL-1β:IL-1Ra ratio in preeclamptic placentas was not affected by MgSO(4). Interestingly, exposure of normotensive placenta to MgSO(4) resulted only in increased levels of IL-1Ra in the maternal circulation, without affecting IL-1β levels or IL-1β:IL-1Ra ratio. These findings suggest that the placenta may contribute to the elevation in serum IL-1β and IL-1Ra in preeclampsia by increased secretion of these cytokines into the maternal circulation, and that MgSO(4) is able to attenuate this increased secretion of IL-1β, and possibly IL-1Ra, in preeclampsia.

Etiopathology of chronic tubular, glomerular and renovascular nephropathies: clinical implications

Chronic kidney disease (CKD) comprises a group of pathologies in which the renal excretory function is chronically compromised. Most, but not all, forms of CKD are progressive and irreversible, pathological syndromes that start silently (i.e. no functional alterations are evident), continue through renal dysfunction and ends up in renal failure. At this point, kidney transplant or dialysis (renal replacement therapy, RRT) becomes necessary to prevent death derived from the inability of the kidneys to cleanse the blood and achieve hydroelectrolytic balance. Worldwide, nearly 1.5 million people need RRT, and the incidence of CKD has increased significantly over the last decades. Diabetes and hypertension are among the leading causes of end stage renal disease, although autoimmunity, renal atherosclerosis, certain infections, drugs and toxins, obstruction of the urinary tract, genetic alterations, and other insults may initiate the disease by damaging the glomerular, tubular, vascular or interstitial compartments of the kidneys. In all cases, CKD eventually compromises all these structures and gives rise to a similar phenotype regardless of etiology. This review describes with an integrative approach the pathophysiological process of tubulointerstitial, glomerular and renovascular diseases, and makes emphasis on the key cellular and molecular events involved. It further analyses the key mechanisms leading to a merging phenotype and pathophysiological scenario as etiologically distinct diseases progress. Finally clinical implications and future experimental and therapeutic perspectives are discussed.

Role of placentally produced inflammatory and regulatory cytokines in pregnancy and the etiology of preeclampsia

Human pregnancy is a metabolic and immune challenge for the mother who has to accommodate in her womb a semi-allogeneic fetus whose energy needs increase tremendously with gestation. Recent compelling research has suggested that proper inflammatory changes and oxidative balance are a requisite for successful pregnancy. The placenta is an integral component of this inflammatory response as it actively produces a variety of cytokines and immunomodulatory hormones. In preeclampsia, a life-threatening disorder of pregnancy that is characterized by widespread damage and dysfunction of the maternal endothelium, placental oxidative stress and aberrant cytokine expression induces an exaggerated maternal systemic inflammatory response to pregnancy.

Oxidative stress alters the integrity of cell-free mRNA fragments associated with placenta-derived syncytiotrophoblast microparticles

OBJECTIVES

Cell-free fetal RNA from placental origin is present in the peripheral blood of pregnant women. Therefore, its qualitative analysis might provide insights into the physiological condition of the placenta. Here, we examine whether oxidative stress affects the integrity of placentally derived mRNA in vitro.

METHODS

Placental explants were cultured under normal or oxidative conditions, and the levels of placental and syncytiotrophoblast microparticle associated glyceraldehyde-3-phosphate dehydrogenase 3' versus 5' mRNA fragments were analyzed by real-time reverse-transcriptase polymerase chain reaction.

RESULT

The relative ratio of 3' to 5' mRNA fragments associated with placental microparticles was significantly altered upon culture under oxidative stress.

CONCLUSIONS

Our data suggest that oxidative stress reduces the levels of full-length, particle-associated glyceraldehyde-3-phosphate dehydrogenase mRNA transcripts released by the placenta. Therefore, analysis of the microparticle-coupled mRNA integrity in pregnant women might prove useful to diagnose disorders such as preeclampsia, where placental oxidative stress is involved.

Activated endothelial cells resist displacement by trophoblast in vitro

BACKGROUND

Transformation of the spiral arteries by invading trophoblasts is an essential prerequisite to the development of a healthy fully grown fetus. Reduced transformation of the spiral arteries is a characteristic feature of pregnancies complicated by several diseases of pregnancy including preeclampsia. The aim of this study was to investigate further the hypothesis that spiral artery endothelial cells can contribute to the mechanism of shallow trophoblast invasion.

METHOD

Fluorescently labeled Jar cells were added to monolayers of fluorescently-labeled endothelial cells that had been activated by treatment with TNFalpha, INF gamma or necrotic cell bodies. The ability of the Jars to displace endothelial cells from the monolayers was quantified by measuring the area of Jar cells "islands" formed in the endothelial cell monolayers by confocal microscopy and digital image.

RESULTS

The area of Jar cell islands formed in monolayers of activated endothelial cells was significantly smaller that the area of islands formed in control resting/non-activated endothelial cell monolayers regardless of the activator.

DISCUSSION

This work demonstrates that activated endothelial cells are more resistant to trophoblast displacement than resting endothelial cells and adds weight to the suggestion that endothelial cells could contribute to shallow invasion of the spiral arteries by trophoblasts in diseases such as preeclampsia.

Disturbances in placental immunology: ready for therapeutic interventions?

Recent studies have provided new insight into aberrations in the immunological interplay between mother and fetus and their potential role in the development of recurrent fetal loss and preeclampsia. The action of anti-phospholipid antibodies in recurrent fetal loss is now proposed to involve the complement system, neutrophil activation and the production of TNFalpha by immune bystander cells. A clear involvement of the immune system is emerging in preeclampsia, involving mainly the innate arm, especially neutrophils. The activation of peripheral neutrophils by placentally released inflammatory debris triggers the induction of neutrophil extracellular traps (NETs), which may lead to an occlusion of the intervillous space, thereby further promoting a condition of placental hypoxia. It has, hence, been suggested that new therapeutic strategies be developed, including the possible use of TNFalpha antagonists in cases of recurrent miscarriage. These strategies need to be addressed with caution due to the possible induction of fetal congenital abnormalities.