Placental DAPK1 and autophagy marker LC3B-II are dysregulated by TNF-α in a gestational age-dependent manner

Autophagy, a cell-survival process responsible for degradation of protein aggregates and damaged organelles, is increasingly recognized as another mechanism essential for human placentation. A substantial body of experiments suggests inflammation and oxidative stress as the underlying stimuli for altered placental autophagy, giving rise to placenta dysfunction and pregnancy pathologies. Here, the hypothesis is tested whether or not pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-{alpha} are able to influence the expression profile of autophagy genes in human first-trimester villous placenta. Autophagy-focused qPCR arrays identified substantial downregulation of death-associated protein kinase 1 (DAPK1) in first-trimester placental explants in response to IL-6 and TNF-{alpha}, respectively. Immunohistochemistry of placental explants detected considerable DAPK1 staining in placental macrophages, villous cytotrophoblasts and less intense in the syncytiotrophoblast. Both immunohistochemistry and Western blot showed decreased DAPK1 protein in TNF-{alpha}-treated placental explants compared to control. On cellular level, DAPK1 expression decreased in SGHPL-4 trophoblasts in response to TNF-{alpha}. Observed changes in the expression profile of autophagy-related genes were reflected by significantly decreased lipidation of autophagy marker microtubule-associated protein light chain 3 beta (LC3B-II) in first trimester placental explants in response to TNF-{alpha}. Analysis of TNF-{alpha}-treated term placental explants showed decreased DAPK1 protein, whereas in contrast to first-trimester LC3B expression and lipidation increased. Immunohistochemistry of placental tissues from early-onset preeclampsia (PE) showed less DAPK1 staining, when compared to controls. Accordingly, DAPK1 mRNA and protein were decreased in primary trophoblasts isolated from early-onset PE, while LC3B-I and -II were increased. Results from this study suggest that DAPK1, a regulator of apoptosis, autophagy and programmed necrosis, decreases in human placenta in response to elevated maternal TNF-{alpha}, irrespective of gestational age. In contrast, TNF-{alpha} differentially regulates levels of autophagy marker LC3B in human placenta over gestation

Endothelin-1 down-regulates matrix metalloproteinase 14 and 15 expression in human first trimester trophoblasts via endothelin receptor type B

$\textbf{STUDY QUESTION}$: Does endothelin-1 (ET-1) regulate matrix metalloproteinase (MMP) 14 and 15 production and invasion of human first trimester trophoblasts? $\textbf{SUMMARY ANSWER}$: ET-1 in pathophysiological concentrations down-regulates MMP14 and MMP15 expression via endothelin receptor (ETR) type B and decreases trophoblast migration and invasion. $\textbf{WHAT IS KNOWN ALREADY}$: MMP14 and MMP15 are involved in trophoblast invasion. Impairment of invasion has been linked to pregnancy complications such as pre-eclampsia (PE). ET-1 is up-regulated in PE. $\textbf{STUDY DESIGN, SIZE, DURATION}$: $\textit{In vitro}$ study using primary human trophoblasts from 50 first trimester placentas (gestational week 7-12). $\textbf{PARTICIPANTS/MATERIALS, SETTING, METHODS}$: Trophoblasts were cultured in the absence or presence of 10-100 nM ET-1. MMP14 and MMP15 mRNA and protein were quantified by RT-qPCR and Western blotting, respectively. Selective antagonists for ETRA (BQ-123) or ETRB (BQ-788) were used to identify ETR subtypes involved. Functional ET-1 effects were tested in first trimester chorionic villous explants and transwell invasion assays. The roles of tumor necrosis factor (TNF)-α (25 ng/ml) and oxygen (1%) in ET-1 regulation of MMP14 and 15 expression were assessed by Western blotting. $\textbf{MAIN RESULTS AND THE ROLE OF CHANCE}$: ET-1 down-regulated MMP14 and MMP15 mRNA (-21% and -26%, respectively, $\textit{P}$ < 0.05) and protein levels (-18% and -22%, respectively, $\textit{P}$ < 0.05). This effect was mediated via ETRB. ET-1 decreased trophoblast outgrowth in placental explants (-24%, $\textit{P}$ < 0.05) and trophoblast invasion (-26%, $\textit{P}$ ≤ 0.01). TNF-α enhanced ET-1 mediated MMP15 down-regulation (by 10%, $\textit{P}$ < 0.05), whereas hypoxia abolished the effect of ET-1 on both MMPs. $\textbf{LARGE SCALE DATA}$: N/A. $\textbf{LIMITATIONS, REASONS FOR CAUTION}$: Only primary trophoblasts were used in this study. Since trophoblast yield from first trimester placental material is limited, further aspects of MMP14 and 15 regulation could not be characterized. Other anti-invasive factors may be altered by ET-1 in trophoblasts and, thus, contribute to the reduced invasion, but have not been investigated. Oxygen levels similar to those found in the decidua (5-8% O2) were not analyzed in this study. $\textbf{WIDER IMPLICATIONS OF THE FINDINGS}$: ET-1 modifies placental function already during the first trimester of pregnancy, the time-window when the placental changes implicated in PE occur. Thus, our results improve the understanding of the placental mechanisms underlying trophoblast invasion and PE.The study was funded by the Oesterreichische Nationalbank (Anniversary Fund, project number: 14796) and the Herzfelder'sche Familienstiftung (to J.P.; number: 00685). AMM received funding from the Austrian Science Fund FWF (W1241) and the Medical University Graz through the PhD Program Molecular Fundamentals of Inflammation (DK-MOLIN)

Downregulation of p53 drives autophagy during human trophoblast differentiation

The placental barrier is crucial for the supply of nutrients and oxygen to the developing fetus and is maintained by differentiation and fusion of mononucleated cytotrophoblasts into the syncytiotrophoblast, a process only partially understood. Here transcriptome and pathway analyses during differentiation and fusion of cultured trophoblasts yielded p53 signaling as negative upstream regulator and indicated an upregulation of autophagy-related genes. We further showed p53 mRNA and protein levels decreased during trophoblast differentiation. Reciprocally, autophagic flux increased and cytoplasmic LC3B-GFP puncta became more abundant, indicating enhanced autophagic activity. In line, in human first trimester placenta p53 protein mainly localized to the cytotrophoblast, while autophagy marker LC3B as well as late autophagic compartments were predominantly detectable in the syncytiotrophoblast. Importantly, ectopic overexpression of p53 reduced levels of LC3B-II, supporting a negative regulatory role on autophagy in differentiating trophoblasts. This was also shown in primary trophoblasts and human first trimester placental explants, where pharmacological stabilization of p53 decreased LC3B-II levels. In summary our data suggest that differentiation-dependent downregulation of p53 is a prerequisite for activating autophagy in the syncytiotrophoblast

Fetal insulin and IGF-II contribute to gestational diabetes mellitus (GDM) - associated up-regolation of membrane-type matrix metalloproteinase 1 (MT1-MMP) in the human feto placental endothelium

CONTEXT: Gestational diabetes mellitus (GDM)-associated hormonal and metabolic derangements in mother and fetus affect placental development and function. Indeed, in GDM, placentas are characterized by hypervascularization and vascular dysfunction. The membrane-type matrix metalloproteinase 1 (MT1-MMP) is a key player in angiogenesis and vascular expansion. OBJECTIVE: Here, we hypothesized elevated placental MT1-MMP levels in GDM induced by components of the diabetic environment. Therefore, we measured placental MT1-MMP in normal vs. GDM pregnancies, identified potential functional consequences, and investigated the contribution of hyperglycemia and the insulin/IGF axis. DESIGN: Immunohistochemistry identified placental cell types expressing MT1-MMP. MT1-MMP was compared between normal and GDM placentas by immunoblotting. Quantitative PCR of MT1-MMP in primary feto-placental endothelial cells (fpEC) and trophoblasts isolated from both normal and GDM placentas identified the cells contributing to the GDM-associated changes. A putative MT1-MMP role in angiogenesis was determined using blocking antibodies for in vitro angiogenesis assays. Potential GDM-associated factors and signaling pathways inducing MT1-MMP up-regulation in fpEC were identified using kinase inhibitors. RESULTS: Total and active MT1-MMP was increased in GDM placentas (+51 and 54%, respectively, P<0.05) as a result of up-regulated expression in fpEC (2.1-fold, P=0.02). MT1-MMP blocking antibodies reduced in vitro angiogenesis up to 25% (P=0.03). Pathophysiological levels of insulin and IGF-II, but not IGF-I and glucose, stimulated MT1-MMP expression in fpEC by phosphatidylinositol 3-kinase signals relayed through the insulin, but not IGF-I, receptor. CONCLUSIONS: GDM up-regulates MT1-MMP in the feto-placental endothelium, and insulin and IGF-II contribute. This may account for GDM-associated changes in the feto-placental vasculature

Intrauterine growth restriction is associated with alterations in placental lipoprotein receptors and maternal lipoprotein composition

Among other factors, fetal growth requires maternal supply of cholesterol. Cellular cholesterol uptake is mainly mediated by the LDL receptor (LDL-R) and the scavenger receptor family. We hypothesized that expression levels of key receptors of these families were regulated differently in placentas from IUGR pregnancies with varying degrees of severity. Third-trimester placentas from IUGR pregnancies with (IUGR-S) and without (IUGR-M) fetal hemodynamic changes and from control (AGA) pregnancies were studied. LDL-R, LDL-Rrelated protein (LRP-1), and scavenger receptor class B type I (SR-BI) mRNA and protein levels were measured. Cholesterol concentration and composition of lipoproteins were analyzed enzymatically and by lipid electrophoresis, respectively, in maternal and umbilical cord blood. LDL-R mRNA levels in IUGR-M were similar to AGA but lower (P ! 0.05) in IUGR-S. In contrast, LDL-R protein was twofold (IUGR-M) and 1.8-fold (IUGR-S) higher (P ! 0.05) than in the AGA group. LRP-1 mRNA and protein levels were not altered in the IUGR cases. SR-BI mRNA was unchanged in IUGR, but protein levels were lower (P ! 0.05) in IUGR-S than in the other groups. Maternal plasma concentrations of LDL cholesterol were higher (P ! 0.05) in the AGA group (188.5 " 23.6 mg/dl) than in the IUGR-S group (154.2 " 26.1). Electrophoretic mobility of the LDL fraction in maternal plasma demonstrated significant changes in migration toward higher values (AGA 0.95 " 0.06, IUGR-M 1.12 " 0.11, P ! 0.001; IUGR-S 1.28 " 0.20, P # 0.002). We conclude that LDL-R and SR-BI levels are altered in IUGR pregnancies. These differences were associated with changes in LDL, but not HDL, mobility and cholesterol concentration in maternal circulation

The Transcriptional Response in Human Umbilical Vein Endothelial Cells Exposed to Insulin: A Dynamic Gene Expression Approach

BACKGROUND: In diabetes chronic hyperinsulinemia contributes to the instability of the atherosclerotic plaque and stimulates cellular proliferation through the activation of the MAP kinases, which in turn regulate cellular proliferation. However, it is not known whether insulin itself could increase the transcription of specific genes for cellular proliferation in the endothelium. Hence, the characterization of transcriptional modifications in endothelium is an important step for a better understanding of the mechanism of insulin action and the relationship between endothelial cell dysfunction and insulin resistance. METHODOLOGY AND PRINCIPAL FINDINGS: The transcriptional response of endothelial cells in the 440 minutes following insulin stimulation was monitored using microarrays and compared to a control condition. About 1700 genes were selected as differentially expressed based on their treated minus control profile, thus allowing the detection of even small but systematic changes in gene expression. Genes were clustered in 7 groups according to their time expression profile and classified into 15 functional categories that can support the biological effects of insulin, based on Gene Ontology enrichment analysis. In terms of endothelial function, the most prominent processes affected were NADH dehydrogenase activity, N-terminal myristoylation domain binding, nitric-oxide synthase regulator activity and growth factor binding. Pathway-based enrichment analysis revealed "Electron Transport Chain" significantly enriched. Results were validated on genes belonging to "Electron Transport Chain" pathway, using quantitative RT-PCR. CONCLUSIONS: As far as we know, this is the first systematic study in the literature monitoring transcriptional response to insulin in endothelial cells, in a time series microarray experiment. Since chronic hyperinsulinemia contributes to the instability of the atherosclerotic plaque and stimulates cellular proliferation, some of the genes identified in the present work are potential novel candidates in diabetes complications related to endothelial dysfunction

Histopathological placental lesions in mild gestational hyperglycemic and diabetic women

Objective: To investigate and compare the incidence of histopathological placental lesions in mild gestational hyperglycemia, gestational diabetes and overt diabetes at term and preterm gestation.Research design and methods: One-hundred-and-thirty-one placental samples were collected from Diabetes mellitus (DM) positive screened patients. Two diagnostic tests, glycemic profile and 100 g oral glucose tolerance test (OGTT) in parallel identified 4 groups normoglycemic, mild gestational hyperglycemia (MGH), gestational DM (GDM) or overt DM (DM). Placental tissue specimens and sections from 4 groups were obtained by uniform random sampling and stained with hematoxylin-eosin.Results: Placentas from MGH group presented 17 types of histopathological change and higher rates of syncytial nodes and endarteritis. GDM placentas presented only nine types of histopathological change, high rates of dysmaturity, low rates of calcification and no syncytial nodes. Overt DM placentas showed 22 types of histopathological change, 21 of which were present in the preterm period. There were histopathological similarities between MGH and DM placentas, but the former exhibited a higher incidence of endarteritis, which has been described as a post-mortem phenomenon.Conclusion: Our results confirmed that the distinct placental changes associated with DM and MGH depend on gestational period during which the diabetic insult occurs. It may reasonably be inferred that subclinical maternal hyperglycemia during pregnancy, as showed in MGH group, is responsible for increased placental endarteritis, a postmortem lesion in the live fetus

Kisspeptin regulation of genes involved in cell invasion and angiogenesis in first trimester human trophoblast cells

The precise regulation of extravillous trophoblast invasion of the uterine wall is a key process in successful pregnancies. Kisspeptin (KP) has been shown to inhibit cancer cell metastasis and placental trophoblast cell migration. In this study primary cultures of first trimester human trophoblast cells have been utilized in order to study the regulation of invasion and angiogenesis-related genes by KP. Trophoblast cells were isolated from first trimester placenta and their identity was confirmed by immunostaining for cytokeratin-7. Real-time quantitative RT-PCR demonstrated that primary trophoblast cells express higher levels of GPR54 (KP receptor) and KP mRNA than the trophoblast cell line HTR8Svneo. Furthermore, trophoblast cells also expressed higher GPR54 and KP protein levels. Treating primary trophoblast cells with KP induced ERK1/2 phosphorylation, while co-treating the cells with a KP antagonist almost completely blocked the activation of ERK1/2 and demonstrated that KP through its cognate GPR54 receptor can activate ERK1/2 in trophoblast cells. KP reduced the migratory capability of trophoblast cells in a scratch-migration assay. Real-time quantitative RT-PCR demonstrated that KP treatment reduced the expression of matrix metalloproteinase 1, 2, 3, 7, 9, 10, 14 and VEGF-A, and increased the expression of tissue inhibitors of metalloproteinases 1 and 3. These results suggest that KP can inhibit first trimester trophoblast cells invasion via inhibition of cell migration and down regulation of the metalloproteinase system and VEGF-A

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy. Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388. Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16, p<0·0001). Interpretation: Among patients with recent cerebral ischaemia, intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding. Triple antiplatelet therapy should not be used in routine clinical practice