Spiral artery (SpA) remodelling is essential for a successful pregnancy and is best described by its morphological features; vascular smooth muscle cell separation and loss, vessel dilatation, and ...invasion by extravillous trophoblast cells (EVT). Current opinion holds that EVT fully replace the endothelial cells (EC) of the SpA and take on EC-like characteristics. Placental bed biopsies (6–20 weeks gestation) were immunostained for EC and EVT, showing transient loss of EC. In vessels containing an endovascular EVT plug (n = 28) 77.6 ± 19.3% of the lumen was covered by EC while in vessels without endovascular EVT (n = 100) it was 100 ± 0%.
•In early spiral artery remodelling endothelial cells undergo morphological changes.•In the presence of an endovascular extravillous trophoblast cell plug endothelial cells are absent.•Endovascular extravillous trophoblast cells do not take on endothelial cell like characteristics.•Fully remodelled spiral arteries have an intact endothelium.
In addition to its role in the prevention of neural tube defects, folic acid has many other physiological functions, including cell proliferation, DNA replication, and antioxidant protection. The aim ...of this study was to determine the role that folic acid has in regulating placental trophoblast development. Placental explants from placentae at gestational age 7 wk (n = 3) were cultured in folic acid at concentrations of 10(-6) M, 10(-8) M, and 10(-10) M. Extravillous trophoblast (EVT) invasion was assessed following 6-day culture, and explants were used for immunohistochemical evaluation of proliferation (MKI67) and apoptosis (active caspase 3). In addition, an array was performed on cell culture supernatants to examine a range of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs). Folic acid increased the invasion of EVT cells in this explant model by between 83% and 19% (P = 0.005), and this was associated with increased MKI67 positivity and decreased active caspase 3 positivity; this effect was concentration dependent and showed a biphasic response. In addition, culture in folic acid increased vascular density, as determined by anti-CD31 immunostaining (P = 0.05). The increase in EVT invasion correlated with increased placental explant secretion of MMP2 (P = 0.01), MMP3 (P = 0.01), and MMP9 (P = 0.02). This study demonstrates that folic acid is potentially important in a number of crucial early stages of placental development, including EVT invasion, angiogenesis, and secretion of MMPs, and highlights the need for further studies to address the benefit of longer-term folic acid supplementation throughout pregnancy to prevent pregnancy disorders associated with deficient placental development, including preeclampsia.
STUDY QUESTION
Are alterations in decidual expression of interleukin (IL)-6 and IL-8 associated with sporadic miscarriage?
SUMMARY ANSWER
IL-6 and IL-8 secretion from decidual uterine natural killer ...(uNK) cells and macrophages isolated from women with spontaneous miscarriage was reduced compared with normal controls.
WHAT IS KNOWN ALREADY
Miscarriage is a common gynaecological problem with huge financial and personal implications. Eleven to twenty per cent of all clinically recognized pregnancies are lost before the 20th week of gestation, with miscarriages often being divided into early (≤12 completed weeks from last menstrual period) and late (≥13 weeks). Spiral artery remodelling is a key feature of early pregnancy; failure of this process has been implicated in sporadic miscarriage. The molecular triggers that initiate spiral artery remodelling are not clear, although cytokines such as IL-6 and IL-8 may play a role.
STUDY DESIGN, SIZE, DURATION
This was a laboratory-based study using decidual and placental bed biopsy samples from women with sporadic miscarriage (n = 30) and termination of pregnancy controls (n = 30).
PARTICIPANTS/MATERIALS, SETTING, METHODS
Total adherent decidual cells, CD10+ stromal cells, CD14+ macrophages and CD56+ uNK cells were isolated from decidua from apparently normal pregnancies that were terminated at either 8–10 or 12–14 weeks' gestation. In addition, CD14+ macrophages and CD56+ uNK cells were isolated from decidua from sporadic miscarriage at 8–10 weeks' gestation. Secreted IL-8 was measured in all isolated cell populations, while IL-6 was measured in CD14+ macrophages and CD56+ uNK cells from both sporadic miscarriage and normal controls. Placental bed biopsies were taken from women after sporadic miscarriage or termination of pregnancy at ≤12 completed weeks' or >13 weeks' gestational age, formalin-fixed, paraffin-embedded and immunostained for IL-6, IL-6Rα, GP130, IL-8, CXCR1, CXCR2 and CD13 (aminopeptidase N). Staining intensity for each factor was assessed in extravillous trophoblast cell populations, myometrial and decidual stroma, myometrial and decidual spiral arteries and decidual glandular epithelium. A CPA model was used to assess the potential role of IL-6 and IL-8 in spiral artery remodelling.
MAIN RESULTS AND THE ROLE OF CHANCE
IL-8 was secreted by total adherent decidual cells, CD10+ stromal cells and CD14+ macrophages at both 8–10 and 12–14 weeks' gestation, with CD14+ cells secreting the highest levels. Both CD14+ and CD56+ cells isolated from decidua of early sporadic miscarriage produced lower IL-6 (P = 0.04, P = 0.01, respectively) and IL-8 levels (P = 0.0007, P = 0.002, respectively) compared with normal cases. In addition, altered expression of IL-6, IL-8 and their receptors was observed in various cell types in placental bed (myometrial stroma, glandular epithelium, interstitial extravillous trophoblast cells, vascular smooth muscle cells and endothelial cells) in sporadic miscarriage, particularly from later gestational ages. IL-6 and IL-8 disrupted vascular smooth muscle morphology and organization in an in vitro model of spiral artery remodelling.
LIMITATIONS, REASONS FOR CAUTION
By the nature of sampling at the time of miscarriage, it was not possible to ascertain the cause or effect in the observed alterations of levels of IL-6 and IL-8 in sporadic miscarriage.
WIDER IMPLICATIONS OF THE FINDINGS
Alterations in the expression of IL-6, IL-8 and their receptors may be associated with the aetiology of sporadic miscarriage, especially given the potential role of these cytokines in the regulation of trophoblast invasion and spiral artery remodelling.
STUDY FUNDING/COMPETING INTEREST(S)
This project was supported by funding from Wellbeing of Women (RG1000). The authors have no competing interests to declare.
TRIAL REGISTRATION NUMBER
Not applicable.
The presence of granulated cells within the uterus of many species has been recognised for many years but only recently have these been recognised to be a type of NK cell. Various terms have been ...applied to the cells, including endometrial granulocyte, K cell and, in mouse and rat, granulated metrial gland cell. Although early studies are often based on histology and electron microscopy, these often include important information for current studies. In vitro studies of purified cells have focused particularly on cytotoxicity and cytokine production and roles in the control of trophoblast invasion and spiral artery remodelling in human pregnancy have been proposed. Evidence in mouse has implicated uNK cell production of IFN-γ in vascular remodelling but evidence for such a role for human uNK cells remains to be established. Investigation of uNK cells in human pregnancy is hampered by the lack of availability of tissues from the first half of the second trimester of pregnancy when vascular remodelling occurs and also by possible differences between cells from different regions of decidua. The presence of similar cells in species with no trophoblast invasion into the uterus and epitheliochorial placentation raises the question of whether control of trophoblast invasion by human uNK cells is important in vivo and raises the possibility of another function which is conserved between species.
Alterations in the balance of leucocyte populations in uterine decidua may lead to the generation of an unfavourable cytokine environment that is associated with unsuccessful pregnancy. Single and ...double immunohistochemical labelling was used to examine leucocyte populations in decidua from normal third trimester, foetal growth-restricted and pre-eclamptic pregnancies. Placental bed biopsies from 12 women undergoing elective Caesarean section with no hypertension or foetal growth restriction (FGR), 8 women with FGR without maternal hypertension and 12 women with pre-eclampsia (PE) were used to quantify decidual CD56+ uterine NK cells, CD14+ macrophages, CD3+T-lymphocytes and CD8+ lymphocytes. CD3+CD56+, CD8+CD56+ and CD161+CD3+ double-labelled cells in decidua were compared in PE and control decidua. Decidual CD3+T-lymphocytes (P<0.01), CD8+ cytotoxic T-lymphocytes (P<0.05), CD14+ macrophages (P<0.0001) and CD56+ uterine natural killer (uNK) cells (P=0.01) were decreased in placental bed biopsies from women with PE compared with control third trimester decidua. By contrast, only CD56+ uNK cells were decreased in FGR decidua (P<0.05). Double-positive CD8+CD56+ cells were also decreased in PE compared with control third trimester decidua (P<0.05). The reduction in specific leucocyte subset numbers in PE and uNK cells in FGR suggests that altered local cytokine balance may be important in defective trophoblast invasion and spiral artery transformation in these pathological pregnancies.
BACKGROUND Extravillous trophoblast (EVT) cell invasion of uterine decidua and the inner third of myometrium is critical for successful pregnancy. Many decidual factors are likely to play a role in ...regulating this process. We have previously shown that cytokines, known to be produced by uterine natural killer (uNK) cells, such as TNF-α, TGF-β1 and IFN-γ inhibit EVT invasion. We therefore hypothesized that supernatants from purified uNK cells would inhibit EVT invasion. METHODS AND RESULTS Total unfractionated decidual cell supernatants from 8 to 10 weeks gestation increased EVT invasion from placental villous explants, although uNK cell supernatants from 8 to 10 weeks gestation had no effect. In contrast, both total decidual and uNK cell supernatants from 12 to 14 weeks gestation stimulated EVT invasion. MMP-2, uPA, PAI-1 and PAI-2 levels did not differ under any of the conditions tested, whereas MMP-9 levels were increased in the presence of both total decidual and uNK cell supernatants from both gestational age groups. There was a decrease in the level of EVT apoptosis in the presence of uNK cell supernatant from 12 to 14 weeks, but not 8–10 weeks, gestation. CONCLUSIONS Decidual uNK cell supernatants from 12 to 14 weeks gestational age stimulated EVT invasion, potentially by increasing MMP9 levels and reducing apoptosis. Total decidual cell isolates stimulated EVT invasion at both gestational ages investigated, potentially reflecting the complex nature of these cell culture supernatants.
Histological chorioamnionitis (HCA) is an established marker of ascending infection, a major cause of preterm birth. No studies have characterised the global change in expression of genes involved in ...the toll-like receptor (TLR) signalling pathways in the presence of HCA in the setting of preterm birth (pHCA). Fetal membranes were collected immediately after delivery and underwent histological staging for inflammation to derive 3 groups; term spontaneous labour without HCA (n = 9), preterm birth <34 weeks gestation without HCA (n = 8) and pHCA <34 weeks (n = 12). Profiling arrays ran in triplicate for each group were used to determine the expression of 84 genes associated with TLR signalling and screen for genes of interest (fold change >2; p<0.1). Expression of identified genes was validated individually for all samples, relative to GAPDH, using RT-PCR. Expression of TLR 1, TLR 2, lymphocyte antigen 96, interleukin 8 and Interleukin-1 receptor-associated kinase-like 2 was increased in pHCA (p<0.05). Degree of expression was positively associated with histological staging of both maternal and fetal inflammation (p<0.05). The inflammatory expression profile at the maternal/fetal interface associated with pHCA, a reflection of ascending infection, is extremely heterogeneous suggesting polymicrobial involvement with activation of a common pathway. Antagonism of TLR 1 and TLR 2 signalling in this setting warrants further assessment.
Pathophysiology of heavy menstrual bleeding Hapangama, Dharani K; Bulmer, Judith N
Women's Health,
2016-January-01, 20160100, 2016-Jan, 2016-01-00, 20160101, Letnik:
12, Številka:
1
Journal Article, Book Review
Recenzirano
Odprti dostop
Heavy menstrual bleeding (HMB) is a common gynecological complaint with multiple etiologies and diverse pathophysiological origins. This review discusses HMB with reference to the recently proposed ...PALM-COEIN classification system for abnormal uterine bleeding, initially describing the endometrial events in normal menstruation followed by discussion of the perturbations of normal endometrial shedding that can result in HMB. Our present understanding of the mechanisms of menstrual bleeding as well as many of the pathological aberrations of HMB is incomplete. Further research into the pathophysiology of HMB is urgently needed, as clear knowledge of the mechanisms of this disorder will provide new therapeutic targets to formulate more effective treatments.
Background. In clinical trials, maternal tetanus toxoid (TT) vaccination is effective in protecting newborns against tetanus infection, but inadequate placental transfer of tetanus antibodies may ...contribute to lower-thanexpected rates of protection in routine practice. We studied the effect of placental malaria and maternal human immunodeficiency virus (HIV) infection on placental transfer of antibodies to tetanus. Methods. A total of 704 maternal-cord paired serum samples were tested by ELISA for antibodies to tetanus. The HIV status of all women was determined by an immunoglobulin G antibody-capture particle-adherence test, and placental malaria was determined by placental biopsy. Maternal history of TT vaccination was recorded. Results. Tetanus antibody levels were reduced by 52% (95% confidence interval CI, 30%–67%) in newborns of HIV-infected women and by 48% (95% CI, 26%–62%) in newborns whose mothers had active-chronic or past placental malaria. Thirty-seven mothers (5.3%) and 55 newborns (7.8%) had tetanus antibody levels <0.1 IU/mL (i.e., were seronegative). Mothers' self-reported history of lack of tetanus immunization was the strongest predictor of seronegativity and of tetanus antibody levels in maternal and cord serum. Conclusion. Malarial and HIV infections may hinder efforts to eliminate maternal and neonatal tetanus, making implementation of the current policy for mass vaccination of women of childbearing age an urgent priority.
What is the expression pattern of platelet-derived growth factor BB (PDGF-BB), and its receptors, across the menstrual cycle in healthy control women and those with abnormal uterine ...bleeding–endometrial disorder (AUB-E)?
Immunohistochemical staining for PDGF-BB, platelet-derived growth factor receptor alpha (PDGFRα) and platelet-derived growth factor beta (PDGFRβ) was performed in control and AUB-E endometrium from the proliferative, early, mid- and late secretory phases of the menstrual cycle (n = 5 each group). Control proliferative phase endometrium was cultured in PDGF-BB (0, 10 ng/ml) and vascular maturation assessed (n = 3). Endothelial cell to vascular smooth muscle cell (VSMC) association was assessed after treatment with PDGF-BB (0, 1, 10 ng/ml). Secretion of angiogenic growth factors by endothelial cells or VSMC was determined.
Endothelial cell immunoreactivity for PDGF-BB was reduced in the mid and late secretory phases in AUB-E (P = 0.008). PDGFRα was also reduced in mid secretory phase endothelial cells, proliferative and early secretory phase glandular epithelium in AUB-E (P = 0.008). PDGFRβ expression was not altered. Treatment of proliferative phase endometrium with PDGF-BB (10 ng/ml) reduced the percentage of vessels expressing contractile VSMC markers. PDGF-BB had no effect on angiogenic growth factor secretion by endothelial cells or VSMC in vitro and did not affect their association in an in-vitro endothelial cell–VSMC association assay.
Reduced endothelial cell expression of PDGF-BB in the AUB-E endometrium may contribute to the reduced vascular maturation previously observed in these women.
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