Elevated Levels of Soluble Axl (sAxl) Regulates Key Angiogenic Molecules to Induce Placental Endothelial Dysfunction and a Preeclampsia-Like Phenotype.

Preeclampsia (PE), a severe pregnancy-specific syndrome, is characterized by impaired placental angiogenesis. Although the pathogenesis of this condition remains largely unclear, vascular systemic endothelial injury is thought to be the common contributing factor. Soluble Axl (sAxl), a biomarker of endothelial dysfunction, is known to be abnormally increased in a variety of diseases associated with vascular injury. In a previous study, we found that the plasma levels of sAxl were significantly higher in PE with severe features (sPE) than in pregnant women who did not have PE. The current study aimed to further explore the potential role of sAxl in vascular injury in patients with sPE. We found that the upregulation of sAxl in maternal plasma was positively correlated with the plasma levels of sFlt-1 and negatively correlated with placental NO synthase (eNOS) in women with sPE. Furthermore, elevated levels of sAxl suppressed proliferation and endothelial tube formation and promoted cytotoxicity in human umbilical vein endothelial cells (HUVECs) through the downregulation of p-Akt, p-p70S6K, p-mTOR, and Grb2. Subsequently, we established a pregnant rat model with PE-like characteristics by injecting pregnant rats with an adenovirus expressing sAxl. These rats exhibited a typical PE-like phenotype, including increased blood pressure, proteinuria, and fetal growth restriction, along with abnormal placental and fetal renal morphology. In conclusion, our study demonstrated the role of sAxl in systemic vascular injury through the regulation of the expression of key molecules of angiogenesis and described its potential contribution to the development of sPE.

The Regulation of Trophoblastic p53 Homeostasis by the p38-Wip1 Feedback Loop is Disturbed in Placentas from Pregnancies Complicated by Preeclampsia.

BACKGROUND/AIMS: Excessive apoptosis of trophoblasts, induced by sustained hypoxia, leads to abnormal placentation and is strongly linked to pregnancy complications such as preeclampsia (PE). Wild-type p53-induced phosphatase (Wip1) positively regulates cellular survival in tumor cells through the p38 and p53 pathways, but its expression pattern and effects in trophoblasts have yet to be reported. This study clarified the effect of Wip1 on the regulatory mechanism of p53-dependent apoptosis in trophoblasts, and thus increases understanding of the etiology of PE. METHODS: In normal and PE placentas, Wip1 mRNA and protein levels were determined by RT-qPCR and Western blotting respectively, while localization of Wip1 in placental tissues and in HTR8/SVneo cells was determined by immunohistochemistry and immunofluorescence. Two in vitro trophoblastic PE models were established by subjecting HTR8/SVneo cells to either hypoxia intervention in incubator (HII) or simulated ischemic buffer (SIB). Wip1 was suppressed in the aforementioned PE models by specific inhibitor or shRNA, and apoptosis was then assessed by flow cytometry, while further validation was done by measurement of cleaved-caspase 9 expression by Western blotting. The p38 inhibitor SB202190, Mdm2 inhibitor NVP-CGM097, and proteasome inhibitor MG-132 were administered in PE models, either in combination or alone, to determine the regulatory order of the component signal molecules of the feedback loop. The impact of Wip1 on p53-Mdm2 interaction was examined by coimmunoprecipitation. Lastly, the upregulation of the p38-Wip1 loop was confirmed in human placentas from pregnancies complicated by PE, using Western blotting. RESULTS: Wip1 expression was significantly elevated in human PE placentas and in vitro trophoblastic PE models; this is opposite to the pattern observed in tumor cells. Inhibition of Wip1 rescued hypoxia-induced p38 activation, cleavage of caspase 9 and apoptosis but significantly compromised p53-Mdm2 binding, while p-p53Ser15 was increased. Inhibition of Mdm2 degradation resulted in p53 destabilization and p38-Wip1 loop down-regulation, while degradation of the p53-Mdm2 complex resulted in p53 accumulation and p38-Wip1 loop hyperactivation. However, the p53-Mdm2 interaction was found to be more important in the regulation of the p38-Wip1 loop than Mdm2 stability. CONCLUSION: Trophoblastic p53 homeostasis is maintained by the p38-Wip1 feedback regulatory loop in response to hypoxic stress, which is dysregulated in the placentas of pregnancies complicated by PE, and thereby leads to excessive apoptosis.

QSOX1 regulates trophoblastic apoptosis in preeclampsia through hydrogen peroxide production.

Objective: Oxidative stress plays a significant role in the pathogenesis of preeclampsia (PE), by inducing trophoblast cell death and consequent placental dysfunction. Quiescin sulfhydryl oxidase 1 (QSOX1) is upregulated in many types of cancer cells; it promotes disulfide bond formation as well as hydrogen peroxide (H2O2) production. The aims of present study are to investigate the expression pattern of QSOX1 in placentae of pregnancies complicated by PE and the role of QSOX1 in the regulation of trophoblastic function, thus providing in-depth understanding of the putative involvement of QSOX1 in the development of PE. Methods: Human term placenta from normal pregnancies and from pregnancies complicated by PE was collected to measure QSOX1 expression and H2O2 levels. Down-regulation of QSOX1 in HTR-8/SVneo cells was achieved by siRNA interference. An in vitro cellular PE model was generated by hypoxic incubation. Protein expression levels were assessed by Western blotting, and H2O2 levels were determined in the cell culture medium as well as in the cell lysate. Trophoblast apoptosis was evaluated by TUNEL staining. Results: QSOX1 was overexpressed in the PE placenta. Inhibition of QSOX1 expression in HTR-8/SVneo cells attenuated cell apoptosis and intracellular H2O2 levels. Hypoxia-induced QSOX1 expression in HTR-8/SVneo cells and led to apoptosis of HTR-8/SVneo cells, and knock-down of QSOX1 rescued hypoxia-induced trophoblast apoptosis. Conclusions: Hypoxia-induced upregulation of QSOX1 and a consequent elevation in intracellular H2O2 increased apoptosis in placentae of pregnancies complicated by PE.

Anti-NMDA-receptor encephalitis during pregnancy: A case report and literature review.

Anti-N-methyl-d-aspartate receptor (anti-NMDA-R) encephalitis is an autoimmune disorder that was first described by Dr Vitaliani in 2005. In 2007, Dalmau et al. found anti-NMDA-R antibody expressed both in the hippocampus and prefrontal nerve cell membrane, finally proposing the diagnosis of autoimmune anti-NMDA-R encephalitis. Most of the patients are female (91%), with ages ranging from 4 to 76 years. The average age is 23 years, a birth peak age, although anti-NMDA-R encephalitis is rare during pregnancy. The disorder is characterized by prominent psychosis, dyskinesias, seizures, autonomic disturbance, and central hypoventilation. We report a 24-year-old woman hospitalized at 28 gestational weeks with acute-onset psychosis. Over the course of 3 weeks, her mental status worsened until she fell into a coma. Both serum and cerebrospinal fluid anti-NMDA-R antibodies were found to be positive. At cesarean section, a healthy baby boy was born and a wedge-shaped bilateral ovarian resection was performed. Treatment with corticosteroids, intravenous immunoglobulin, and plasmapheresis can lead to improved outcomes for both mother and baby.

Inhibition of nuclear factor-kappa B enhances the tumor growth of ovarian cancer cell line derived from a low-grade papillary serous carcinoma in p53-independent pathway.

BACKGROUND: NF-kB can function as an oncogene or tumor suppressor depending on cancer types. The role of NF-kB in low-grade serous ovarian cancer, however, has never been tested. We sought to elucidate the function of NF-kB in the low-grade serous ovarian cancer. METHODS: The ovarian cancer cell line, HOC-7, derived from a low-grade papillary serous carcinoma. Introduction of a dominant negative mutant, IkBαM, which resulted in decrease of NF-kB function in ovarian cancer cell lines. The transcription ability, tumorigenesis, cell proliferation and apoptosis were observed in derivative cell lines in comparison with parental cells. RESULTS: Western blot analysis indicated increased expression of the anti-apoptotic proteins Bcl-xL and reduced expression of the pro-apoptotic proteins Bax, Bad, and Bid in HOC-7/IĸBαM cell. Further investigations validate this conclusion in KRAS wildtype cell line SKOV3. Interesting, NF-kB can exert its pro-apoptotic effect by activating mitogen-activated protein kinase (MAPK) phosphorylation in SKOV3 ovarian cancer cell, whereas opposite changes detected in p-MEK in HOC-7 ovarian cancer cell, the same as some chemoresistant ovarian cancer cell lines. In vivo animal assay performed on BALB/athymic mice showed that injection of HOC-7 induced subcutaneous tumor growth, which was completely regressed within 7 weeks. In comparison, HOC-7/IĸBαM cells caused sustained tumor growth and abrogated tumor regression, suggesting that knock-down of NF-kB by IĸBαM promoted sustained tumor growth and delayed tumor regression in HOC-7 cells. CONCLUSION: Our results demonstrated that NF-kB may function as a tumor suppressor by facilitating regression of low grade ovarian serous carcinoma through activating pro-apoptotic pathways.

Inconformity of CXCL3 plasma level and placenta expression in preeclampsia and its effect on trophoblast viability and invasion.

As a member of the chemokine family, CXCL3 was previously known to participate in many pathophysiological events. However, whether CXCL3 stimulates trophoblast invasion as a key process of preeclampsia pathogenesis remains largely unknown. Therefore, the aim of this study was to investigate this hypothesis and determine the effect of CXCL3 on the first trimester trophoblast. Seventy gravidas were included in this study. ELISA was used to detect CXCL3 plasma levels on preeclampsia and normal pregnant groups. CXCL3 protein and mRNA levels were detected via Western blot and real-time quantitative PCR analysis after immunolocalized in human placenta. Moreover, the CXCL3 function in HTR-8/Svneo was analyzed via WST-1 assay, flow cytometry and invasion test. The plasma CXCL3 level in preeclampsia was significantly higher than that in normal pregnancy. CXCL3 expression was observed in the cytoplasm of placental trophoblasts and vascular endothelium in all groups without significant difference between maternal and fetal sides. In addition, placenta CXCL3 expression in severe preeclampsia was significantly lower than those in normal and mild PE groups. Moreover, exogenous CXCL3 can promote the proliferation and invasion of HTR-8/Svneo; however, its effect on apoptosis remains unclear. In summary, a significant abnormality of plasma CXCL3 level and placental CXCL3 expression was discovered in severe preeclampsia; CXCL3 had a function in trophoblast invasion, which indicated its participation in shallow implantation. Therefore CXCL3 might be involved in severe preeclampsia pathogenesis.

Arginine supplementation for improving maternal and neonatal outcomes in hypertensive disorder of pregnancy: a systematic review.

OBJECTIVE: This meta-analysis was performed to assess whether arginine supplementation could reduce preeclampsia or eclampsia incidence and improve the outcomes of hypertensive disorders in pregnancy, and to evaluate the safety of L-arginine supplementation. METHODS: The Cochrane Central Register of Controlled Trials (2011), MEDLINE (1980-2011) and Embase (1980-2011) were searched through July 2012, and randomized controlled trials (RCTs) comparing intravenous and/or oral L-arginine supplementation with placebo, or RCTs comparing any treatment with arginine were included. Qualities of RCTs were assessed with the Jadad method. Meta-analyses were performed with fixed- or random-effects models according to heterogeneity of studies. RESULTS: Data from seven RCTs involving 916 patients were enrolled. The meta-analysis showed L-arginine was more effective in reducing preeclampsia or eclampsia incidence (odds ratio 0.384; 95% confidence limits 0.25, 0.58) than the placebo; meanwhile, L-arginine could prolong pregnancy weeks (MD 11.54; 95% CL 5.23, 17.85) than placebo; and its effect on blood pressure was unbalanced (diastolic pressure (MD 4.86; 95% CL 4.19, 5.52) and systolic pressure (MD 3.20; 95% CL -1.54, 7.94)) while the difference in increased neonatal weight (MD 256.24; 95% CL -28.66, 541.13) was not clear. Three of these studies reported some adverse effects, and no teratogenic or lethal effects were noted. CONCLUSION: This study demonstrates L-arginine supplementation is superior to placebo in lowering diastolic pressure and prolonging pregnancy in patients with gestational hypertension with or without proteinuria, but the effect on lowering systolic pressure and increasing neonatal weight was not statistically significant.

Plasma concentrations of sAxl are associated with severe preeclampsia.

OBJECTIVE: Preeclampsia, a multisystem disorder unique to pregnancy, is a major cause of maternal and perinatal mortality and morbidity. Inadequate trophoblast invasion and vascular dysfunction are believed to be involved in preeclampsia. Axl, which interacts with its ligand Gas6, known to regulate cell migration, adhesion, and vascular angiogenesis or homeostasis and vascular network formation, may be implicated in preeclampsia, as preeclampsia is a specific vascular disease. sAxl, a soluble form of Axl, is bound to Gas6 in plasma, which inhibits the activation of the Axl-Gas6 pathway. The aim of this study was to determine the changes and significance of plasma concentrations of sAxl in severe preeclampsia, as well as its correlation with the clinical parameters of severe preeclampsia. DESIGN AND METHODS: Fifty-eight women with severe preeclampsia and 31 healthy pregnant women were included in the study, from April 2012 to October 2012. Plasma sAxl concentrations were detected with an immunosorbent assay (ELISA) kit. RESULTS: Plasma sAxl concentrations were significantly higher in the preeclampsia group (61.52±17.57ng/mL) than in the normal pregnancy group (45.29±15.44ng/mL) (P<0.05). Plasma sAxl concentrations in the severe preeclampsia patients correlated positively with systolic and diastolic blood pressures (r=0.628, P<0.05 vs. r=0.394, P<0.05, respectively) and proteinuria (r=0.583, P<0.05), but inversely with plasma albumin (r=-0.444, P<0.05), gestation of delivery (r=-0.554, P<0.05), and birth weight (r=-0.476, P<0.05). Multiple linear regression analysis indicated that systolic blood pressure and proteinuria were influence factors of plasma sAxl levels (ß1=0.520, P<0.05; ß2=0.461, P<0.05). CONCLUSIONS: Plasma sAxl concentrations were higher in the preeclampsia patients, and plasma sAxl levels were correlated with the clinical parameters of severe preeclampsia. Furthermore, systolic blood pressure and proteinuria might be influence factors of plasma sAxl level.