Inflammatory cytokines patterns in the placenta of pregnancies complicated by HELLP (hemolysis, elevated liver enzyme, and low platelet) syndrome

Circulating inflammatory cytokines and hypertensive disorders of pregnancy: a two-sample Mendelian randomization study

Background

Hypertensive disorders of pregnancy (HDP) pose a significant risk to maternal and fetal well-being; however, the etiology and pathogenesis of HDP remain ambiguous. It is now widely acknowledged that inflammatory response and the immune system are closely related to HDP. Previous research has identified several inflammatory cytokines are associated with HDP. This study applied Mendelian randomization (MR) analysis to further assess causality.

Methods

Patients with HDP who participated in the MR analysis presented with four types of HDP: pre-eclampsia or eclampsia (PE); gestational hypertension (GH); pre-existing hypertension complicating pregnancy, childbirth and the puerperium (EH); and pre-eclampsia or poor fetal growth (PF). A two-sample MR analysis was used to analyze the data in the study. The causal relationship between exposure and outcome was analyzed with inverse variance weighting (IVW), MR Egger, weighted median, weighted mode, and simple mode methods, where IVW was the primary method employed.

Results

Our MR analysis demonstrated a reliable causative effect of Interleukin-9 (IL-9) and macrophage migration inhibitory factor (MIF) on reducing HDP risk, while macrophage inflammatory protein 1-beta (MIP1b), Interleukin-13 (IL-13), and Interleukin-16 (IL-16) were associated with promoting HDP risk.

Conclusions

This study demonstrated that IL-9, MIF, MIP1b, IL-13, and IL-16 may be cytokines associated with the etiology of HDP, and that a number of inflammatory cytokines are probably involved in the progression of HDP. Additionally, our study revealed that these inflammatory cytokines have causal associations with HDP and may likely be potential therapeutic targets for HDP.

Serum syndecan-1 concentration in hemolysis, elevated liver enzymes, and low platelets syndrome: A case report

Background

Hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome occurs in pregnant and postpartum individuals. We observed serum syndecan-1 (SDC-1) levels, which is a component of the glycocalyx, in a patient with HELLP syndrome from admission to the postpartum period and examined their association as reflecting the pathophysiology related to endothelial injury.

Case presentation

A 31-year-old primiparous female patient without a previous medical history at a gestational age of 37 weeks and 6 days was transferred to our hospital the morning after a visit to a previous hospital with headache and nausea. Elevated transaminase, platelet count, and proteinuria were noted. Head magnetic resonance imaging revealed a caudate nucleus hemorrhage and posterior reversible encephalopathy syndrome. After she delivered her newborn through an emergency cesarean section, she was admitted to the intensive care unit. On day 4 post-delivery, the patient’s D-dimer concentration was elevated, and contrast-enhanced computed tomography was performed. The results indicated pulmonary embolism, and heparin administration was initiated. The serum SDC-1 level was highest on day 1 post-delivery and quickly decreased subsequently; however, it remained elevated during the postpartum period. Her condition gradually improved, and she was extubated on day 6 and discharged from the ICU on day 7 post-delivery.

Conclusion

We measured SDC-1 concentration in a patient with HELLP syndrome and found that the clinical course correlated with SDC-1 levels, indicating that SDC-1 is elevated immediately before and after pregnancy termination in patients with HELLP syndrome. Therefore, SDC-1 fluctuations, combined with the elevation of the D-dimer level, may be a potential marker for the early detection of HELLP syndrome and estimation of the syndrome’s severity in the future.

The BPH/5 Mouse Model of Superimposed Preeclampsia Is Not a Model of HELLP Syndrome

Preeclampsia (PE) is a multisystemic disease of pregnancy affecting 2-8% of women worldwide. PE-induced liver disease is a rare but important complication of pregnancy. The pathogenesis of liver dysfunction in PE is poorly understood, but is correlated with dysregulated angiogenic, inflammatory, and hypoxic events in the early phase of placental development. Because BPH/5 mice develop the maternal and fetal hallmarks of PE during pregnancy, we hypothesized that they may also share the clinicopathologic findings of the human PE-associated hemolysis elevated liver transaminases low platelets (HELLP) syndrome. Using this model, we determined that microangiopathic hemolysis, thrombocytopenia, and elevated liver enzymes do not occur in mid to late gestation. Pregnant BPH/5 mice do not develop histologic evidence of hepatic inflammation, but they do have increased microsteatosis scores at preconception and in mid to late gestation that progress to macrosteatosis in a subset of mice in late gestation. The transcriptional upregulation of TNF-α, CXCL-10, and TLR-2 occurs in mid gestation prior to the onset of macrosteatosis. The BPH/5 female mouse is not a model of HELLP syndrome, but may be a model of fatty liver disease associated with pregnancy.

Innate and Adaptive Immune Responses in HELLP Syndrome

Innate and adaptive immune involvement in hemolysis, elevated liver enzymes and low platelet (HELLP) syndrome is an understudied field, although it is of high clinical importance. This syndrome implies a risk of serious morbidity and mortality to both the mother and the fetus during pregnancy. It was proposed that HELLP syndrome occurs in a circulatory inflammatory milieu, that might in turn participate in a complex interplay between the secreted inflammatory immunomodulators and immune cell surface receptors. Meanwhile, reported immune cell attenuation during HELLP may consequently lead to a prolonged immunoactivation and tissue damage. In this regard, learning more about the immune components of this syndrome should widen the understanding of the HELLP pathophysiology and eventually enable development of novel immune-based therapeutics. This review aims to summarize and discuss the recent and previous findings of the innate and adaptive immune responses during HELLP in order to update the current knowledge of the immune involvement in HELLP pathogenesis.

Peripheral Anti-Angiogenic Imbalance during Pregnancy Impairs Myogenic Tone and Increases Cerebral Edema in a Rodent Model of HELLP Syndrome

Using an animal model of hemolysis elevated liver enzymes low platelets (HELLP) that has systemic inflammation and neuroinflammation we wanted to determine if blood brain barrier (BBB) permeability, cerebral edema, vascular tone, and occludin expression were altered in pregnant rats. Anti-angiogenic proteins sFlt-1 and sEng (4.7 and 7 µg/kg/day, respectively) were chronically infused into normal pregnant (NP) rats beginning on gestational day 12 via a mini-osmotic pump. On gestational day 19, blood pressure was measured via a carotid catheter and brains were collected. BBB permeability was assessed in select brain regions from rats infused with 0.5 mg/mL Texas Red Dextran and phenylephrine. Occludin, sFlt-1, and sEng were analyzed via western blot or ELISA. Infusion of sFlt-1 and sEng into NP rats increased hemolysis and liver enzymes, and decreased platelets and led to hypertension. HELLP rats had significant impairment in the myogenic response and increased BBB permeability in the posterior cortex and brainstem. Brain water content in the posterior cortex was increased and sEng protein expression in the brainstem was significantly increased in HELLP rats. The results from this study suggest that a peripheral anti-angiogenic imbalance during pregnancy is associated with decreased myogenic tone, vasogenic edema, and an increase in BBB permeability, but not anti-angiogenic imbalance in the brain.

Dysregulation of the Fas/FasL system in an experimental animal model of HELLP syndrome

INTRODUCTION

Placental FasL is up-regulated in women with HELLP (hemolysis elevated liver enzyme and low platelet) syndrome and has been proposed to contribute to the liver damage seen in these patients.

OBJECTIVE

This study aimed to determine if an experimental rodent model of HELLP also had dysregulation of Fas/FasL compared to normal pregnant (NP) rats. We also set out to determine if blockade of the endothelin system regulated Fas/FasL expression in HELLP rats.

STUDY DESIGN

On gestational day (GD) 12, sEng (7ug/kg) and sFlt-1 (4.7ug/kg) infusion began via mini-osmotic pump into NP rats. On GD19 plasma and tissue were collected and FasL and Fas were measured via enzyme linked immunosorbent assay and gene expression via real-time PCR.

RESULTS

HELLP rats had significantly more circulating and placental FasL compared to NP rats, whereas hepatic FasL was decreased and placental Fas was increased compared to NP rats. Administration of an endothelin A receptor antagonist (ET_A) beginning on GD12 significantly decreased placental expression of Fas in HELLP rats. Liver mRNA transcript of Fas was significantly increased in HELLP rats compared to NP rats.

CONCLUSION

These data suggest that rats in this experimental model of HELLP syndrome have abnormal expression of the Fas/FasL system. Future studies will examine the sources of Fas/FasL dysregulation in this model and if blockade could reduce some of the inflammation and hypertension associated with HELLP syndrome.

Hypertension in an Animal Model of HELLP Syndrome is Associated With Activation of Endothelin 1

Women with hypertensive forms of pregnancy such as hemolysis-elevated liver enzymes-low platelet syndrome have increased circulating endothelin 1; however, the relationship between hypertension and endothelin 1 has not been studied. Using an animal model, we sought to determine whether there was an increased activation/dysfunction of endothelin 1, the effect of endothelin 1 receptor-A blockade on hypertension and other manifestations of hemolysis, elevated liver enzymes, and low platelets syndrome. On gestational day 12, timed-pregnant rats were infused with soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEndoglin; 4.7 and 7 µg/kg) via mini-osmotic pumps for 8 days. A subset of rats were treated with receptor-A antagonist (ABT-627, 5mg/kg) for 8 days. Rats with hemolysis-elevated liver enzymes-low platelet syndrome had significantly increased hypertension (P = .0001), circulating endothelin 1 (P = .03), and a significant 3.3- and 7.2-fold increase in preproendothelin messenger RNA (mRNA) expression in the placenta and liver (P = .01 and .04). Urinary protein:creatinine ratio was significantly increased in these animals (P = .0007), and circulating factors from these rats stimulated a significant increase in endothelial cell secretion of endothelin 1 (P = .001) in an in vitro assay. Blockade of the endothelin 1 receptor A significantly decreased hypertension (P = .001), circulating endothelin 1, and interleukin 17 (P = .004 and .003), placental preproendothelin mRNA expression (P = .016), and urinary protein:creatinine ratio (P = .007) in rats with hemolysis-elevated liver enzymes-low platelet syndrome. Blockade of the endothelin 1 receptor A significantly decreased hemolysis (P = .009), liver enzymes (P = .011), and significantly increased platelet levels (P = .03) and decreased circulating CD4+ and CD8+ T lymphocytes (P = .0004 and .0001) in rats infused with sFlt-1 and sEndoglin. These data support the hypothesis that endothelin 1 activation has a critical role in pathophysiology of as hemolysis-elevated liver enzymes-low platelet syndrome.

Hypertension, inflammation and T lymphocytes are increased in a rat model of HELLP syndrome

OBJECTIVE

An animal model of hemolysis, elevated liver enzymes, low platelet count (HELLP) was used to determine if T lymphocytes accompany hypertension and increased inflammatory cytokines.

METHODS

sFlt-1 (4.7 µg/kg/day) and sEndoglin (7 µg/kg/day) were infused into normal pregnant rats (HELLP rats) for 8 days.

RESULTS

HELLP was associated with increased mean arterial pressure (p = 0.0001), hemolysis (p = 0.044), elevated liver enzymes (p = 0.027), and reduced platelets (p = 0.035). HELLP rats had increased plasma levels of TNFα (p = 0.039), IL-6 (p = 0.038) and IL-17 (p = 0.04). CD4(+) and CD8(+) T lymphocytes were increased.

CONCLUSION

These data support the hypothesis that T cells are associated with hypertension and inflammation.

Depleted mitochondrial DNA content in peripheral blood of women with a history of HELLP syndrome

OBJECTIVE

To test the hypothesis that a quantitative defect of maternal cellular mitochondria would play a role in the pathogenesis of HELLP syndrome.

STUDY DESIGN

Peripheral blood mitochondrial DNA (MtDNA) was measured in 20 non-pregnant women with a history of HELLP syndrome, 40 non-pregnant control subjects who had previous physiologic pregnancies, 59 subjects carrying physiologic pregnancies, seven pregnant women with a history of HELLP syndrome and five women in the active phase of the disease.

MAIN OUTCOME MEASURE

Peripheral blood Mt-DNA.

RESULTS

The median (interquartile range) mtDNA in women with a history of HELLP syndrome, in non-pregnant women who had previous physiologic pregnancies, in subjects carrying physiologic pregnancies, in pregnant women with a history of HELLP syndrome and in women in the active phase of the disease was 115 (81-194), 229 (199-319), 174 (136-211), 101 (82-178) and 92 (39-129) copies per nuclear DNA, respectively. Non-pregnant women with a history of HELLP syndrome had significantly lower levels than non-pregnant controls (p<0.001). Moreover, blood mtDNA was lower in pregnant women with a history of HELLP syndrome and in those in the active phase of the disease when compared to pregnant controls (p=0.002 and p=0.025, respectively).

CONCLUSIONS

Attenuated maternal mitochondrial function may favor HELLP syndrome development.

Seeking the mechanism(s) of action for corticosteroids in HELLP syndrome: SMASH study

INTRODUCTION

Administration of dexamethasone to the hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome patients (10 mg intravenously [IV] every 12 hours) shortens the disease course and reduces maternal morbidity in patients treated at the University of Mississippi Medical Center (UMMC), associated with this severe form of preeclampsia. However, the pathophysiological mechanisms involved with this intervention remain unclear.

OBJECTIVE

We sought to investigate the potential role of IV dexamethasone to restore the imbalance among antiangiogenic and inflammatory factors known to be significantly elevated in women with HELLP syndrome.

STUDY DESIGN

This was a single-center prospective study of women diagnosed with HELLP syndrome who were treated for IV dexamethasone at UMMC. Blood was drawn prior to dexamethasone administration and again 12 and 24 hours after the initial dexamethasone administration. Enzyme-linked immune assays were used to measure circulating inflammatory cytokines and antiangiogenic factors. A repeated-measures analysis of variance was used to analyze the data collected before, after, and during dexamethasone administration.

RESULTS

Seventeen women with HELLP syndrome were enrolled in this study. Dexamethasone significantly decreased evidence of hemolysis (P = .002) and liver enzymes (P = .003), and significantly increased platelets (P = .0001) within 24 hours of administration. Circulating interleukin-6 levels after 24 hours were decreased (P < .001); soluble fms-like tyrosine kinase-1 and soluble endoglin were also significantly decreased by 24 hours after dexamethasone administration (P < .002 and P < .004, respectively). There were no significant differences in circulating levels of placental growth factor (P = .886) due to dexamethasone administration. Angiotensin II receptor autoantibody levels were unchanged by dexamethasone administration.

CONCLUSION

We conclude that 1 important mechanism of dexamethasone administration is to blunt the release of both antiangiogenic and inflammatory factors suggested to play role in the pathophysiology of HELLP syndrome.

Control of extravillous trophoblast function by the eotaxins CCL11, CCL24 and CCL26

STUDY QUESTION

What are the effects of the eotaxin group of chemokines (CCL11, CCL24 and CCL26) on extravillous trophoblast (EVT) functions important during uterine decidual vessel remodelling?

SUMMARY ANSWER

CCL11, CCL24 and CCL26 can regulate EVT migration, invasion and adhesion, highlighting a potential regulatory role for these chemokines during uterine decidual spiral arteriole remodelling in the first trimester of human pregnancy.

WHAT IS KNOWN ALREADY

A successful human pregnancy depends on adequate remodelling of the uterine decidual spiral arterioles, a process carried out by EVT which invade from the placenta. The invasion by EVT into the maternal uterine decidual vessels is regulated by the interaction of many factors including members of the chemokine subfamily of cytokines.

STUDY DESIGN, SIZE, DURATION

This study used the HTR8/SVneo cell line as a model for invasive EVT. All experiments were repeated on at least three separate occasions.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effect of recombinant human CCL11, CCL24 and CCL26 on EVT migration and invasive potential was measured using the xCELLigence real-time system, wound-healing and Matrigel invasion assays, zymography to measure MMP activity and reverse zymography to measure TIMP activity. A commercially available adhesion assay was used to assess EVT adhesion to extracellular matrix proteins.

MAIN RESULTS AND THE ROLE OF CHANCE

All the three eotaxins were found to significantly stimulate migration of the EVT-derived cell line HTR8/SVneo (P < 0.05) with no significant changes in cell number following treatment with each chemokine (P > 0.05). All the three eotaxins significantly increased HTR8/SVneo invasion (P < 0.05) and MMP2 activity (P < 0.05) without any effects on TIMP2 activity (P > 0.05). All the three eotaxins significantly increased HTR8/SVneo cell binding to collagen IV (P < 0.05) and fibronectin (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

This work has been conducted in vitro with a commonly used cell line model of EVT, HTR8/SVneo.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to comprehensively examine the effects of the eotaxin group of chemokines on EVT functions and demonstrates that all the three eotaxins have the ability to regulate EVT functions critical to their role in vessel remodelling. This identifies a new role for the eotaxin group of chemokines during placentation.

Expression of inflammatory cytokines in placentas from pregnancies complicated with preeclampsia and HELLP syndrome

OBJECTIVE

To investigate the expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) in villous trophoblast, syncytial knots and decidua placentas from pregnancies complicated with preeclampsia (PE), Hemolysis, Elevated Liver enzymes and Low Platelet count (HELLP) syndrome and gestational age-matched controls.

METHODS

Study group included 35 placentas from pregnancies complicated with PE and 35 placentas from pregnancies with HELLP syndrome. Control group included 35 placentas from idiopathic preterm labor. Placentas were matched according to the gestational age. Expression of TNF-α, IL-6 and IL-10 was determined by immunohistochemistry and semi-quantitative HSCORE method in villous trophoblast, syncytial knots and decidua. Non-parametric statistics were used for analyses.

RESULTS

There was no difference in the expression of TNF-α, IL-6 and IL-10 in all the studied placental segments between PE, HELLP and gestational age-matched control group. TNF-α (F = 32, 41, p < 0.001), IL-6 (F = 58, 53, p < 0.001) and IL-10 (F = 17, 62, p < 0.001) expression was significantly different in different placental cell types, the highest expression of cytokines was in decidua.

CONCLUSION

There was no difference in cytokine expression in villous trophoblast, syncytial knots and decidua among the studied placental groups. The expression of cytokines was highest in decidua in all the studied placental groups.

Clues to apoptosis pathway involvement in hemolysis, elevated liver enzyme, and low platelet (HELLP) syndrome and intrauterine growth restriction (IUGR)

OBJECTIVE

The neurotrophin family comprises molecules involved in growth, differentiation, survival, regeneration, normal functions of the neuronal system, and in angiogenesis. We have investigated the expression pattern of neurotrophic signaling molecules in pregnancies complicated by elevated liver enzyme, and low platelet (HELLP) syndrome and intrauterine growth restriction (IUGR).

METHODS

Placentas from normal and pathological pregnancies were collected. Macroarray analysis was performed and the data were confirmed by real-time PCR.

RESULTS

Real-time PCR analyses (pathological vs. normal pregnancies) confirmed a significant down-regulation for IL-6, STAT3α, STAT3β, and Bcl-2. The expression of Mcl-1 isoform 1 (long) was significantly increased.

CONCLUSIONS

We suggest that decreased expression of IL-6 could mean that abnormalities in the immunological system function involve inflammatory cytokines other than IL-6 in examined pathological pregnancies. The STAT3α and STAT3β down-regulation lead to a marked reduction of cellular transcriptional activity. Decreased expression of IL-6 is associated with a down-regulation of Bcl-2 but not of Mcl-1 isoform 1, suggesting that these two antiapoptotic proteins may function independently and that Mcl-1 may have a distinct role in controlling apoptotic pathway.

Global gene expression profiling of proliferative phase endometrium reveals distinct functional subdivisions

The human endometrium follows a predictable pattern of development during the proliferative phase. Endometrial thickness increases after day 3 and then plateaus at days 9 to 10 of the menstrual cycle despite continued high serum levels of estrogen. We hypothesized that proliferative phase endometrium undergoes more than simple estrogen responsive growth, rather it is characterized by complex time-dependent functional activities reflected in differential gene expression. Nine endometrial RNA samples from healthy participants were subjected to microarray analysis and 15 samples were used for quantitative real-time polymerase chain reaction. The samples were divided into early, mid, or late proliferative phase. The early proliferative phase showed higher expression of genes including transforming growth factor β2, chemokine (C-C motif) ligand 18 (CCL18), and metallothionein 2A. The mid-proliferative phase was characterized by higher expression of heat shock proteins and implantation-associated genes including Indian hedgehog, secreted frizzled protein 4, and progesterone receptor. In the late proliferative phase, we identified increased angiotensin II receptor, type 2 and large decrease in expression of genes related to natural killer (NK) cell function. We demonstrate a unique gene expression signature at distinct time points within the proliferative phase. The early proliferative phase is characterized by tissue remodeling, angiogenesis, and modulation of inflammation; the mid-proliferative phase is characterized not only by proliferation in response to estrogens but also marks the onset of expression of genes required for endometrial receptivity and a dampening of estrogen responsiveness. In the late proliferative phase, changes in immune function and NK cells predominate. The proliferative phase is not simply a uniform period of estrogen responsive endometrial growth that can be considered as a single experimental time point when evaluating endometrial development; rather the proliferative phase is complex with differing functions and patterns of gene expression.

Decidual-secreted factors alter invasive trophoblast membrane and secreted proteins implying a role for decidual cell regulation of placentation

Inadequate or inappropriate implantation and placentation during the establishment of human pregnancy is thought to lead to first trimester miscarriage, placental insufficiency and other obstetric complications. To create the placental blood supply, specialized cells, the ‘extravillous trophoblast’ (EVT) invade through the differentiated uterine endometrium (the decidua) to engraft and remodel uterine spiral arteries. We hypothesized that decidual factors would regulate EVT function by altering the production of EVT membrane and secreted factors. We used a proteomics approach to identify EVT membrane and secreted proteins regulated by decidual cell factors. Human endometrial stromal cells were decidualized in vitro by treatment with estradiol (10⁻⁸ M), medroxyprogesterone acetate (10⁻⁷ M) and cAMP (0.5 mM) for 14 days. Conditioned media (CM) was collected on day 2 (non-decidualized CM) and 14 (decidualized CM) of treatment. Isolated primary EVT cultured on Matrigel™ were treated with media control, non-decidualized or decidualized CM for 16 h. EVT CM was fractionated for proteins <30 kDa using size-exclusion affinity nanoparticles (SEAN) before trypsin digestion and HPLC-MS/MS. 43 proteins produced by EVT were identified; 14 not previously known to be expressed in the placenta and 12 which had previously been associated with diseases of pregnancy including preeclampsia. Profilin 1, lysosome associated membrane glycoprotein 1 (LAMP1), dipeptidyl peptidase 1 (DPP1/cathepsin C) and annexin A2 expression by interstitial EVT in vivo was validated by immunhistochemistry. Decidual CM regulation in vitro was validated by western blotting: decidualized CM upregulated profilin 1 in EVT CM and non-decidualized CM upregulated annexin A2 in EVT CM and pro-DPP1 in EVT cell lysate. Here, non-decidualized factors induced protease expression by EVT suggesting that non-decidualized factors may induce a pro-inflammatory cascade. Preeclampsia is a pro-inflammatory condition. Overall, we have demonstrated the potential of a proteomics approach to identify novel proteins expressed by EVT and to uncover the mechanisms leading to disease states.

Plasma IL-4, IL-8, IL-12, interferon-γ and CRP levels in pregnant women with preeclampsia, and their relation with severity of disease and fetal birth weight

OBJECTIVE

The aim of the present study was to evaluate the hypothesis that preeclampsia is associated with increased systemic inflammatory responses of Th1-type as well as decreased Th2-type responses compared with normal pregnancy. We also sought to determine whether there was a correlation between these markers with severity of preeclampsia and fetal birth weight.

METHODS

The study population consisted of maternal age, gestational age, and body mass index matched 138 pregnant women; 56 normotensive healthy pregnant women (group 1), 42 women with mild preeclampsia (group 2), 40 women with severe preeclampsia (group 3).

RESULTS

Plasma interleukin (IL)-8 and C-reactive protein (CRP) levels were significantly higher in group 3 than group 1 (p<0.05). Plasma IL-4, IL-12, and interferon (IFN)-γ levels were similar in all groups. Although plasma IL-8 and CRP levels of mild preeclamptic group were higher than control group and lower than severe preeclamptic group, the differences were not statistically significant. There was a positive correlation between IL-12 and fetal birth weight in severe preeclamptic group (p<0.05).

CONCLUSIONS

Elevated maternal serum pro-inflammatory cytokine IL-8 and CRP in severe preeclamptic women compared with normal pregnant women supports the hypothesis that preeclampsia is associated with increased inflammatory responses.

Biochemistry of HELLP syndrome

The HELLP syndrome is a serious complication of pregnancy characterized by hemolysis (H), elevated liver (EL) enzymes, and low platelet (LP) count that occurs in 0.2-0.6% of all pregnancies and in 10-20% of cases with severe preeclampsia and frequently leads to adverse maternal and perinatal outcome. The exact pathobiology of HELLP syndrome has not been clearly defined. As it is considered a form or a complication of severe preeclampsia, it likely has its origin in aberrant placental development and function resulting in ischemia-producing oxidative stress. However, there is still a debate on whether HELLP must be considered a severe form of preeclampsia or a separate disease entity. It can be described as a placenta-induced disease, as is preeclampsia itself, but with a more acute and predominant inflammatory process typically targeting the liver and with a greater activation of the coagulation system. This occurs during a disordered immunologic process and may be due to a genetic predisposition. In this review, we discuss the main biochemical characteristics of HELLP syndrome, particularly focusing on molecular aspects of placental involvement and maternal systemic responses.

Microarray profiling reveals that placental transcriptomes of early-onset HELLP syndrome and preeclampsia are similar

BACKGROUND

The involvement of the placenta in the pathogenesis of preeclampsia and HELLP syndrome is well established, and placental lesions are also similar in these two syndromes. Here we aimed to examine the placental transcriptome and to identify candidate biomarkers in early-onset preeclampsia and HELLP syndrome.

METHODS

Placental specimens were obtained at C-sections from women with early-onset preeclampsia and HELLP syndrome, and from controls who delivered preterm or at term. After histopathological examination, fresh-frozen placental specimens were used for microarray profiling and validation by qRT-PCR. Differential expression was analysed using log-linear models while adjusting for gestational age. Gene ontology and pathway analyses were used to interpret gene expression changes. Tissue microarrays were constructed from paraffin-embedded placental specimens and immunostained.

RESULTS

Placental gene expression was gestational age-dependent among preterm and term controls. Out of the 350 differentially expressed genes in preeclampsia and 554 genes in HELLP syndrome, 224 genes (including LEP, CGB, LHB, INHA, SIGLEC6, PAPPA2, TREM1, and FLT1) changed in the same direction (elevated or reduced) in both syndromes. Many of these encode proteins that have been implicated as biomarkers for preeclampsia. Enrichment analyses revealed similar biological processes, cellular compartments and biological pathways enriched in early-onset preeclampsia and HELLP syndrome; however, some processes and pathways (e.g., cytokine-cytokine receptor interaction) were over-represented only in HELLP syndrome.

CONCLUSION

High-throughput transcriptional and tissue microarray expression profiling revealed that placental transcriptomes of early-onset preeclampsia and HELLP syndrome largely overlap, underlying a potential common cause and pathophysiologic processes in these syndromes. However, gene expression changes may also suggest a more severe placental pathology and pronounced inflammatory response in HELLP syndrome than in preeclampsia.

Evidence of impact of maternal HIV infection on immunoglobulin levels in HIV-exposed uninfected children

HIV infection affects B cell function and is associated with increased immunoglobulin levels, including in HIV-infected pregnant women. It is unknown if maternal HIV infection affects immunoglobulins in their uninfected children. We investigated this using prospective longitudinal data from children born to HIV-infected women enrolled in the European Collaborative Study (ECS). Data from children enrolled in the European Paediatric Hepatitis C Virus Network (EPHN) were used as a comparison group. Associations between infant and maternal factors and child log(10) total IgG, IgM, and IgA levels were quantified in linear regression analyses. A total of 1751 HIV-uninfected (ECS) and 167 HCV-uninfected children (EPHN) were included. HIV-uninfected children had significantly higher IgG, IgM, and IgA levels than HCV-uninfected children up to at least 24 months. Among HIV-exposed uninfected children, IgG levels from birth until 5 years of age were correlated with increased maternal IgG levels. ART exposure in fetal and early neonatal life was associated with lower IgG. These findings indicate alterations in immunoglobulin levels in uninfected children born to HIV-infected women, suggesting that fetal exposure to a chronically activated maternal immune system is associated with an altered humoral response.

Thrombin facilitates invasion of ovarian cancer along peritoneum by inducing monocyte differentiation toward tumor-associated macrophage-like cells

Peritoneal metastasis is a distinct pathologic characteristic of advanced epithelial ovarian cancer (EOC), which is the most deadly disease of the female reproductive tract. The inflammatory environment of the peritoneum in EOC contains abundant macrophages, activated thrombin, and thrombin-associated receptors. However, little is known about the mechanism by which the thrombin-macrophages interaction contributes to tumor invasion and metastasis. We investigated the phenotype and cytokine/chemokine expression of thrombin-treated peripheral blood monocytes (MOs)/macrophages, it was found that the phenotype of MOs was altered toward a TAM-like macrophage CD163(high)IL-10(high)CCL18(high)IL-8(high) after thrombin stimulation. By Matrigel invasion assay, the conditioned medium of thrombin-stimulated MOs accelerated remarkable invasion of ES-2, SKOV3, and HO-8910, which was similar to invasive cell numbers of ascites stimuli (P < 0.05) and higher than MOs medium alone (P < 0.05). IL-8 was proposed as the major chemoattractant mediating EOC invasion based on MOs mRNA and protein expression profiling. It was observed that anti IL-8 monoclonal neutralizing antibody attenuated EOC cell invasion in a concentration-dependent manner. Increased transcriptional activation of NF-kappaB p50/p65 was identified in thrombin-treated MOs. This study provided insight the role of thrombin in the regulation of EOC peritoneal invasion via "educating" MOs.

Heme impairs prostaglandin E2 and TGF-beta production by human mononuclear cells via Cu/Zn superoxide dismutase: insight into the pathogenesis of severe malaria

In many hemolytic disorders, such as malaria, the release of free heme has been involved in the triggering of oxidative stress and tissue damage. Patients presenting with severe forms of malaria commonly have impaired regulatory responses. Although intriguing, there is scarce data about the involvement of heme on the regulation of immune responses. In this study, we investigated the relation of free heme and the suppression of anti-inflammatory mediators such as PGE(2) and TGF-beta in human vivax malaria. Patients with severe disease presented higher hemolysis and higher plasma concentrations of Cu/Zn superoxide dismutase (SOD-1) and lower concentrations of PGE(2) and TGF-beta than those with mild disease. In addition, there was a positive correlation between SOD-1 concentrations and plasma levels of TNF-alpha. During antimalaria treatment, the concentrations of plasma SOD-1 reduced whereas PGE(2) and TGF-beta increased in the individuals severely ill. Using an in vitro model with human mononuclear cells, we demonstrated that the heme effect on the impairment of the production of PGE(2) and TGF-beta partially involves heme binding to CD14 and depends on the production of SOD-1. Aside from furthering the current knowledge about the pathogenesis of vivax malaria, the present results may represent a general mechanism for hemolytic diseases and could be useful for future studies of therapeutic approaches.

The origin of pre-eclampsia: from decidual "hyperoxia" to late hypoxia

Normal gestation implants on a relatively hypoxic deciduas so that trophoblast deeply invades endometrium and angiogenesis seeks for oxygen supply. If implantation occurs before those hypoxic conditions occur, trophoblast invasion is defective, due to the relatively high oxygen tension in the decidual environment, laying the foundations for subsequent pre-eclampsia.