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Storkhead box 1 (STOX1) is a winged helix transcription factor structurally and functionally related to the forkhead family of transcription factors. Recent studies have highlighted its role in the central nervous system and revealed hints in the development of glioma. However, the expression profiles of STOX1, its association with clinicopathological characteristics, and potential functions in glioma remain unknown. In this study, we analyzed three publicly available datasets including CGGA, TCGA, and Rembrandt and revealed a grade-dependent reduction in STOX1 expression in glioma (P < 0.001). Chi-square test demonstrated that low STOX1 expression was significantly associated with older age at initial diagnosis (P < 0.001), less IDH1 mutation (P < 0.001), and advanced WHO grade (P < 0.001). Moreover, multivariate Cox regression analysis showed that STOX1 expression may serve as a novel independent prognostic biomarker in glioma patients. Bioinformatic functional analysis (GSEA) predicted that STOX1 was related to many key cancer pathways including P53 signaling pathway (P < 0.01), DNA replication (P < 0.05), homologous recombination (P < 0.05), and Wnt signaling pathway (P < 0.05). Taken together, these findings suggested that STOX1 may be used as a novel predictive molecular biomarker for glioma grading and overall patient survival. Further investigations on the functional roles and therapeutic value of STOX1 in glioma are warranted.

Preeclampsia (PE) is a high-prevalence pregnancy disease characterized by placental insufficiency, gestational hypertension, and proteinuria. Overexpression of the A isoform of the STOX1 transcription factor (STOX1A) recapitulates PE in mice, and STOX1A overexpressing trophoblasts recapitulate PE patients hallmarks in terms of gene expression and pathophysiology. STOX1 overexpression induces nitroso-redox imbalance and mitochondrial hyper-activation. Here, by a thorough analysis on cell models, we show that STOX1 overexpression in trophoblasts alters inducible nitric oxide synthase (iNOS), nitric oxide (NO) content, the nitroso-redox balance, the antioxidant defense, and mitochondrial function. This is accompanied by specific alterations of the Krebs cycle leading to reduced l-malate content. By increasing NOS coupling using the metabolite tetrahydrobiopterin (BH4) we restore this multi-step pathway in vitro. Moving in vivo on two different rodent models (STOX1 mice and RUPP rats, alike early onset and late onset preeclampsia, respectively), we show by transcriptomics that BH4 directly reverts STOX1-deregulated gene expression including glutathione metabolism, oxidative phosphorylation, cholesterol metabolism, inflammation, lipoprotein metabolism and platelet activation, successfully treating placental hypotrophy, gestational hypertension, proteinuria and heart hypertrophy. In the RUPP rats we show that the major fetal issue of preeclampsia, Intra Uterine Growth Restriction (IUGR), is efficiently corrected. Our work posits on solid bases BH4 as a novel potential therapy for preeclampsia.

Abstract Background Lumbar disc herniation (LDH) is a common musculoskeletal disorder affliction and associated with several genes polymorphism. Storkhead box 1 (STOX1) gene is a transcriptional factor related with several signaling pathways including inflammatory pathway. However, little is known about single‐nucleotide polymorphisms (SNPs) of STOX1 associated with LDH risk. Methods We conducted a case–control study among 508 LDH cases and well‐matched 508 controls, and six candidate SNPs in STOX1 were genotyped by Agena MassARRAY. Chi‐squared test, genetic model, and haploview analysis were used to evaluate associations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression. Results In the allelic model analysis, we found the minor allele “T” of rs7903209 and “A” of rs4472827 were associated with an increased risk of LDH (p = .029, p = .016). Furthermore, in the genotype model analysis, rs7903209 polymorphism was associated with the increased susceptibility of LDH based on dominant (p = .033) and additive model (p = .024); and rs4472827 variant was found to play a harmful role in the LDH risk based on genotype (p = .014), dominant (p = .012), and additive model (p = .015). In the haplotype analysis, the haplotype “GT” in block (rs10998461 and rs10998468) decreased LDH risk (OR = 0.7, 95% CI = 0.52–0.93, p = .016). Functional assessment indicated that rs7903209 and rs4472827 polymorphisms may influence the expression of STOX1. Conclusion Our results provide evidence for polymorphisms of rs7903209 and rs4472827 in STOX1 associated with LDH risk in Chinese Han population.

Recurrent spontaneous abortion (RSA), defined as two or more consecutive pregnancy losses before 12 weeks of gestation with or without previous live births. Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that play important roles in gene expression regulation and trophoblasts function during embryo development. This study aimed to evaluate the function mechanism of circRNAs regulating trophoblasts function in the occurrence and progression RSA. Through overexpression and down-regulation of circ-ZUFSP, we investigated the effect of circ-ZUFSP on the function of trophoblasts and found loss of circ-ZUFSP suppressed trophoblasts migration and invasion in vitro. Moreover, loss of circ-ZUFSP regulated trophoblasts migration and invasion via regulation of miR-203. Furthermore, STOX1 was revealed to a target of miR-203, and down-regulation of STOX1 reversed circ-ZUFSP enhanced cell invasion, suggesting that circ-ZUFSP might regulate STOX1 expression through sponging miR-203 in HTR-8/SVneo cells. In addition, low expression of circ-ZUFSP, STOX1 and high expression of miR-203 were testified in placental tissues of RSA mice. Our study demonstrated a molecular mechanism of circ-ZUFSP regulating trophoblasts migration and invasion, which might provide a novel indicator for early diagnosis and potential treatment of RSA. • Loss of circ-ZUFSP suppressed trophoblasts migration and invasion. • circ-ZUFSP was interacted with miR-203. • Down-regulation of STOX1 reversed circ-ZUFSP enhanced cell invasion. • circ-ZUFSP regulate STOX1 expression through sponging miR-203 in HTR-8/SVneo cells. • Lower expression levels of circ-ZUFSP and STOX1 were testified in placental tissues of RSA mice. [ABSTRACT FROM AUTHOR]

Background: A major cause of preeclampsia is the placental ischemia caused by insufficient trophoblast cells, invading into the spiral artery. Storkhead-box protein 1 (STOX1) is highly associated with preeclampsia. Meanwhile, low-dose aspirin for patients with preeclampsia is effective in reducing the incidence of preeclampsia. The aim of the present study was to explore the underlying mechanism, and the relationship between STOX1 and aspirin in preeclampsia.Methods: The human choriocarcinoma cell line JEG-3 was employed to mimic trophoblast cells and establish a model for trophoblast cells overexpressing STOX1 and knockdown of JEG cell lines, which were treated with aspirin afterwards. Cell counting kit-8 (CCK-8) assay was utilized to estimate cell proliferation and optimal concentration of aspirin for further experiments. Meanwhile, transwell assay was used to detect migration, and flow cytometry was used to measure apoptosis. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting were applied to analyze the expression levels of STOX1 and related genes.Results: Overexpression of STOX1 inhibited proliferation of JEG-3 cells through epidermal growth factor (EGF), vascular EGF (VEGF), and transforming growth factor beta 1 (TGF-β1) proteins, while suppressed migration through MMP2, MMP9, and E-cadherin proteins. In contrast, apoptosis of JEG-3 cells was elevated by STOX1 through Bcl-2, Bax, and Cox-2 proteins. Furthermore, we found that aspirin modulated the expression level of STOX1 and reversed proliferation and migration of STOX1-induced insufficient trophoblast cells.Conclusion: The present study suggested that inhibition of the expression of STOX1 could promote the effects of aspirin in the treatment of preeclampsia. [ABSTRACT FROM AUTHOR]

Preeclampsia (PE), affecting 5-8% of pregnancies, is a common pregnancy disease that has harmful effects on mother and foetus. It has been found that the STOX1 (Storkhead Box 1), which is a transcription factor, carries variants associated with PE. Previous studies showed that, there was a strong relationship between PE and STOX1 variants. Therefore, we hypothesised that variants in the promoter region of the gene may be related to the onset of PE. The aim of this study is to investigate the contribution of STOX1 gene promoter region variants to PE. The blood samples taken from 118 PE patients and 96 healthy pregnant women were analysed by Sanger sequencing method. Sequence analysis results showed that, there is a-922 T > C polymorphism (rs884181) in the promoter region of the STOX1 gene. This polymorphism was found to be statistically significant in individuals with early onset PE ( p  = 0.02) and in PE ( p  = 0.014) compared to the control group.IMPACT STATEMENT What is already known on this subject? As a result of whole-exon studies on the STOX1 gene, polymorphisms were found to disrupt the structure/expression/function of the gene and strengthen its relationship with PE and HELLP syndrome. A previous study by our team found an association between Y153H, the most common polymorphism of STOX1 , and early onset PE. What do the results of this study add? In our study, it was aimed to investigate the effect of genetic modifications in STOX1 gene promoter region on PE through the maternal genotype. Because any change in the promoter region affects the expression level of the gene. Also, for the first time, sequence analysis of the promoter region of STOX1 is investigated in PE. The variations in STOX1 appear to be important in PE especially in Early Onset PE. What are the implications of these findings for clinical practice and/or further research? Although PE is a disease that occurs with pregnancy and shows its effects most during this period, women and children with a history of PE are more prone to various disorders, especially cardiovascular diseases in the following years. Therefore, understanding the pathogenesis of the disease is important for both prevention and treatment process. Variations on STOX1 appear to be important in terms of disease risk.

Nodal, a secreted signaling protein from the TGFβ-super family plays a vital role during early embryonic development. Recently, it was found that maternal decidua-specific Nodal knockout mice show intrauterine growth restriction (IUGR) and preterm birth. As the chromosomal location of NODAL is in the same linkage area as the susceptibility gene STOX1, associated with the familial form of early-onset, IUGR-complicated pre-eclampsia, their potential maternal-fetal interaction was investigated. Pre-eclamptic mothers with children who carried the STOX1 susceptibility allele themselves all carried the NODAL H165R SNP, which causes a 50% reduced activity. Surprisingly, in decidua Nodal knockout mice the fetal placenta showed up-regulation of STOX1 and NODAL expression. Conditioned media of human first trimester decidua and a human endometrial stromal cell line (T-HESC) treated with siRNAs against NODAL or carrying the H165R SNP were also able to induce NODAL and STOX1 expression when added to SGHPL-5 first trimester extravillous trophoblast cells. Finally, a human TGFß-BMP-Signaling-Pathway PCR-Array on decidua and the T-HESC cell line with Nodal knockdown revealed upregulation of Activin-A, which was confirmed in conditioned media by ELISA. We show that maternal decidua Nodal knockdown gives upregulation of NODAL and STOX1 mRNA expression in fetal extravillous trophoblast cells, potentially via upregulation of Activin-A in the maternal decidua. As both Activin-A and Nodal have been implicated in pre-eclampsia, being increased in serum of pre-eclamptic women and upregulated in pre-eclamptic placentas respectively, this interaction at the maternal-fetal interface might play a substantial role in the development of pre-eclampsia.

Implantation of the embryo into the uterus triggers the initiation of hemochorial placentation. The hemochorial placenta facilitates the acquisition of maternal resources required for embryo/fetal growth. Uterine spiral arteries form the nutrient supply line for the placenta and fetus. This vascular conduit undergoes gestation stage-specific remodeling directed by maternal natural killer cells and embryo-derived invasive trophoblast lineages. The placentation site, including remodeling of the uterine spiral arteries, is shaped by environmental challenges. In this review, we discuss the cellular participants controlling pregnancy-dependent uterine spiral artery remodeling and mechanisms responsible for their development and function. [ABSTRACT FROM AUTHOR]

Preterm birth is the leading cause of infant mortality. The mechanisms that instigate preterm birth remain elusive and this makes it difficult to predict or prevent preterm birth. In this study, the authors found that SP-A induced pathological damage to the placenta and promoted preterm birth. Through mechanism, SP-A promoted the expression of STOX1 which further promoted the oxidative stress in the placenta by inhibiting the activities of a series of antioxidant enzymes including SOD, CAT and GSH-Px. SP-A also induced dysregulation of arginine metabolism by inhibiting NOS2 and ARG2. Overexpression of STOX1 aggravated SP-A induced oxidative stress, pathological damage, and preterm birth, whereas knockdown of STOX1 alleviated SP-A induced oxidative stress, pathological damage and preterm birth. The present study uncovers that SP-A induces preterm birth by promoting oxidative stress via upregulating STOX1, which provides new targets for the prediction and prevention of preterm birth., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2022 HCFMUSP. Published by Elsevier España, S.L.U. All rights reserved.)

Preeclampsia (PE) is a high-prevalence pregnancy disease characterized by placental insufficiency, gestational hypertension, and proteinuria. Overexpression of the A isoform of the STOX1 transcription factor (STOX1A) recapitulates PE in mice, and STOX1A overexpressing trophoblasts recapitulate PE patients hallmarks in terms of gene expression and pathophysiology. STOX1 overexpression induces nitroso-redox imbalance and mitochondrial hyper-activation. Here, by a thorough analysis on cell models, we show that STOX1 overexpression in trophoblasts alters inducible nitric oxide synthase (iNOS), nitric oxide (NO) content, the nitroso-redox balance, the antioxidant defense, and mitochondrial function. This is accompanied by specific alterations of the Krebs cycle leading to reduced l-malate content. By increasing NOS coupling using the metabolite tetrahydrobiopterin (BH4) we restore this multi-step pathway in vitro. Moving in vivo on two different rodent models (STOX1 mice and RUPP rats, alike early onset and late onset preeclampsia, respectively), we show by transcriptomics that BH4 directly reverts STOX1-deregulated gene expression including glutathione metabolism, oxidative phosphorylation, cholesterol metabolism, inflammation, lipoprotein metabolism and platelet activation, successfully treating placental hypotrophy, gestational hypertension, proteinuria and heart hypertrophy. In the RUPP rats we show that the major fetal issue of preeclampsia, Intra Uterine Growth Restriction (IUGR), is efficiently corrected. Our work posits on solid bases BH4 as a novel potential therapy for preeclampsia., (Published by Elsevier B.V.)

The article presents a study on the reversal of preeclampsia-like symptoms in mice through aspirin treatment. It notes that mice were subjected to an overexpression of the storkhead box 1 (STOX1) transcription factor to mimic preeclamptic placentas. The female mice have been administered with low doses of aspirin that prevented the onset of hypertension and brought the albumin/creatinine ratio to normal levels. It concludes that the mouse model can serve as a tool to understand PE.

Abstract: Transcriptional activation of CTNNA3, encoding αT-catenin, by the Y153H mutated form of the human STOX1 transcription factor was proposed to be responsible for altered fetal trophoblast invasion into the maternal endometrium during placentation in pre-eclampsia. Here we have generated a mouse model to investigate the in vivo effects of ectopic αT-catenin expression on trophoblast invasion. Histological analysis was used to determine the invasive capacities of trophoblasts from transgenic embryos, as well as proliferation rates of spongiotrophoblasts in the junctional zone. Augmented expression of αT-catenin reduced the number of invading trophoblasts but did not cause embryonic mortality. The, αT-catenin positive cells could still invade into the decidual layer and migrated as deeply as wild-type trophoblasts. Furthermore, the junctional zone is enlarged in placentas of mice overexpressing αT-catenin due to hyperproliferation of the residing spongiotrophoblasts, suggesting a pivotal role of αT-catenin levels in the control of the proliferative versus invasive state of trophoblasts during placentation. Our study provides, for the first time, in vivo data on the effects of increased levels of αT-catenin in the placenta. [Copyright &y& Elsevier]

Pre-eclampsia and late-onset Alzheimer's disease (LOAD) share no clinical features. In contrast to these clinical dissimilarities, striking parallels exist between the (epi)genetic features associated with pre-eclampsia and LOAD for the genes located on 10q22. The parallels in identity between the 10q22 genes involved and active in the organs (placenta, brain) primarily affected in the respective diseases led us to explore, if the pre-eclampsia susceptibility gene STOX1 is functionally involved in LOAD. We demonstrate that isoform A of STOX1 is abundantly expressed in the brain, correlates with severity of disease, and selectively transactivates LRRTM3 in neural cells with increased amyloid-β protein precursor processing. Similar in vitro results were seen in trophoblast. Our data indicate that STOX1 controls a conserved pathway shared between placenta and brain with overexpression in LOAD. [ABSTRACT FROM AUTHOR]

Abstract: Preeclampsia is a common disease of pregnancy, characterized by high blood pressure and proteinuria appearing from the second trimester of gestation. Preeclampsia has been shown to have a strong genetic component. In 2005 a positional cloning project led to the discovery of the STOX1 transcription factor, and mutations of this gene were proposed as causal for preeclampsia in Dutch families. Despite the publication of three contradictory studies, we have shown by analyzing the functional effects of STOX1 that its overexpression in choriocarcinoma cells recapitulates several transcriptomic aspects of preeclampsia. In this review, the current literature is analyzed to evaluate the possible involvement of STOX1 in the pathogenesis of this disease. While preeclampsia obviously cannot be considered as a disease caused by mutation in a single gene, we argue that STOX1 may be at the center of common pathways leading to preeclampsia. [Copyright &y& Elsevier]

The STOX1 gene, identified as a candidate gene for pre-eclampsia in Dutch women, is placentally expressed and subject to imprinting with preferential transmission of the maternal allele. In our study, STOX1-Y153H frequencies were similar in 157 women with pre-eclampsia (65%) and in 157 controls (64%) from the general Dutch population. In an isolated Dutch population, a distortion could not be demonstrated in the transmission of STOX1-Y153H variation from heterozygous mothers to offspring in 50 and 56 families with pregnancies complicated by pre-eclampsia or intrauterine growth restriction, respectively. Our findings do not confirm previous suggestions that STOX1 plays a major role in Dutch women with pre-eclampsia. [ABSTRACT FROM AUTHOR]

• Preeclampsia (PE) is associated with gestational age, systolic and diastolic blood pressure and birth weight. • STOX1 gene Y153H polymorphism is associated with early-onset PE but not with late-onset PE in Turkish population. • STOX1 gene Y153H polymorphism can be identified by RFLP method using Hph I restriction endonuclease. Preeclampsia (PE) is a disease of pregnancy that causes of maternal and prenatal morbidity worldwide. Studies indicate that variations in STOX1 gene may be a direct risk factor to PE but controversial results regarding the relationship of Y153H variation in the second exon of STOX1 gene with PE have been ongoing since 2005. The aim of this study was to identify if there is any correlation between Y153H polymorphisms and PE in Turkish preeclampsia patients. We performed polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) analysis in 500 pregnant women, of whom 373 pregnant women with early onset PE (EOPE) and 500 normal pregnant women. The relationship between STOX1 Y153H polymorphism and EOPE/LOPE was evaluated by statistical analysis. We found that STOX1 Y153H polymorphism is a risk factor for EOPE (p = 0.03). The odds ratio was 1,45 (CI 95% = 1,03–2,05). No relationship between STOX1 Y153H polymorphisms and LOPE (p = 0.13) was found. STOX1 gene Y153H polymorphism is associated with the risk of early onset of pre-eclampsia in a Turkish population. The results provide further evidence of the role of STOX1 in the pathophysiology of this disease. [ABSTRACT FROM AUTHOR]

Background: Lumbar disc herniation (LDH) is a common musculoskeletal disorder affliction and associated with several genes polymorphism. Storkhead box 1 (STOX1) gene is a transcriptional factor related with several signaling pathways including inflammatory pathway. However, little is known about single‐nucleotide polymorphisms (SNPs) of STOX1 associated with LDH risk. Methods: We conducted a case–control study among 508 LDH cases and well‐matched 508 controls, and six candidate SNPs in STOX1 were genotyped by Agena MassARRAY. Chi‐squared test, genetic model, and haploview analysis were used to evaluate associations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression. Results: In the allelic model analysis, we found the minor allele "T" of rs7903209 and "A" of rs4472827 were associated with an increased risk of LDH (p =.029, p =.016). Furthermore, in the genotype model analysis, rs7903209 polymorphism was associated with the increased susceptibility of LDH based on dominant (p =.033) and additive model (p =.024); and rs4472827 variant was found to play a harmful role in the LDH risk based on genotype (p =.014), dominant (p =.012), and additive model (p =.015). In the haplotype analysis, the haplotype "GT" in block (rs10998461 and rs10998468) decreased LDH risk (OR = 0.7, 95% CI = 0.52–0.93, p =.016). Functional assessment indicated that rs7903209 and rs4472827 polymorphisms may influence the expression of STOX1. Conclusion: Our results provide evidence for polymorphisms of rs7903209 and rs4472827 in STOX1 associated with LDH risk in Chinese Han population. [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by the vascular remodeling that also involves proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). Overexpression of Storkhead box (STOX1) regulates genes involved hypoxia, redox balance, nitric oxide, and energy metabolism. In this study, we supposed Stox1 adjusted cells proliferation and migration in PASMCs development and played an important role in the pulmonary arterial vascular remodeling. Hemodynamic assay and Right ventricular morphometric assay were used to check the rat model of PAH. HE staining was used to examine the arterial wall thickness. Masson staining showed that the deposition of collagen was significantly increased in PAH. In addition, Stox1 were assessed by immunofluorescence and immunohistochemistry staining. The effect of Stox1 on PASMCs was assessed by cell counting Kit-8 assay (CCK-8 assay), Scratch-Wound assay, EdU staining assay, Cell cycle analysis and Western blot. Right ventricular systolic pressure (RVSP) and right ventricular were significantly increased in hypoxia group and monocrotaline group compared to control group. The expression of Stox1 was increased in lung tissues in PAH rats. In vitro, the expression of Stox1 was up-regulated with time-dependent manner in hypoxia condition. Meanwhile, Stxo1 promoted the proliferation and migration in hypoxia-treated PASMCs. Moreover, we found that hypoxia promoted the expression of PCNA, Cyclin E and Cyclin A, increased more cells from G 0 /G 1 phase to S phase and induced the activation of AKT proteins, which was significantly attenuated by inhibition of Stox1 expression in PASMCs. These findings indicated that Stox1 induced proliferation of PASMCs and the effect is, at least in part, mediated through AKT signaling pathway. Unlabelled Image • The expression of Stox1 protein was increased in lung tissues in hypoxia-treated and monocrotaline-treated rats. • Inhibition of Stox1supressed the proliferation and migration of PASMCs induced by hypoxia. • Stox1 induced cell cycle arrest in PASMCs. • Stox1 activated AKT signaling pathway in hypoxia PASMCs. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship of STOX1expression and pathogenesis of early onset preeclampsia. Methods: 65 cases of preeclampsia women who delivered in Shanghai Pudong Hospital from October 2015 to June 2018, were recruited, which included 31 cases with early onset preeclampsia (early onset group, gestational week<34 weeks) and 34 patients with late onset preeclampsia (late onset group, gestational week ≥34 weeks). 34 cases women who received caesarean section because of pelvic structural deformities, breech presentation, macrosomia and social factors were included as the control group(gestational week ≥34 weeks) were selected as control group.The expression and localization of STOX1 mRNA and protein in placenta of three groups of maternal were evaluated by immunohistochemistry SP, RT-qPCR and Western blotting. Results: (1) The expression of STOX1 in placenta mainly distributed in the cytoplasm of placental syncytiotrophoblasts, cytotrophoblasts, vascular endothelial and mesenchymal cells, a few in the cell nucleus.The staining intensity of STOX1 in early onset group was significantly stronger than that in late onset group, the staining intensity of the late onset group was similar to that of the control group. The positive expression rates of STOX1protein in early onset group, late onset group and control group were 96.8%(30/31), 70.6%(24/34), 67.6%(23/34) respectively, which was higher in early onset group than that in late onset group( P= 0.005). There was no statistical difference of STOX1 level between the late onset group and the control group( P= 0.793). (2)Relative expression of STOX1 mRNA in early onset group, late onset group and control group were 0.054 3±0.003 5,0.037 5±0.000 7,0.035 2±0.000 4 respectively, which was significantly higher in early onset group than that in late onset group( P< 0.05), while there was no statistical difference between the late onset group and the control group( P> 0.05).(3)Relative expression level of STOX1 protein in early onset group, late onset group and control group were 0.78±0.04,0.59±0.020 and 0.54±0.018 respectively, which is higher in early onset group than that in late onset group( P< 0.05). There was no statistical difference of STOX1 level between the late onset group and the control group( P> 0.05). Conclusions: The pathogenesis of early onset and late onset preeclampsia may be different. Up-regulated expression of STOX1 in placenta may be associated with the pathogenesis of early onset preeclampsia.

Objective: To investigate the expression and significance of STOX1 in different stages of gestation villi and placenta. Methods: Totally 137 cases of normal villi and placenta of pregnant women were collected from the Department of Obstetrics of Shanghai Pudong Hospital from October 1(st) 2015 to February 28(th) 2018, including 64 cases of early pregnancy (early pregnancy group) which consists of 32 cases of 5-7(+6) weeks gestation (early pregnancy group A) and 32 cases of 8-11(+3) weeks gestation (early pregnancy group B), 28 cases of 14-26 weeks gestation(middle pregnancy group) and 45 cases of 37-41 weeks gestation (late pregnancy group). The expression and localization of STOX1 mRNA and protein in placenta were evaluated by RT-qPCR, Western blotting and immunohistochemistry. Results: (1)STOX1 was positively expressed in the cytotrophoblasts and syncytiotrophoblasts as well as interstitial and vascular endothelial cells of all groups. (2)STOX1 mRNA expression in each group was significantly different ( P< 0.05), the lowest was in the early pregnancy group A(0.007 8±0.000 4), which increased along with the progression of gestational age( P< 0.05),and reached the highest level in the third trimester(0.064 4±0.001 3). (3)The protein level of STOX1 in different stages of normal pregnancy was 0.53±0.20 in early pregnancy group A;0.62±0.37 in early pregnancy group B;0.70±0.03 in middle pregnancy group and 0.81±0.04 in late pregnancy group respectively; which was positively related with the progression of gestational age ( P< 0.05). Conclusion: The expressions of STOX1 is gradually increasing along with the normal pregnancy progression, suggesting that it might be involved in proliferation, differentiation and infiltration and (or) apoptosis of trophoblast cells and the development of the placenta.

Preeclampsia (PE) is a serious hypertensive disorder that affects up to 8% of all pregnancies annually. An established risk factor for PE is family history, clearly demonstrating an underlying genetic component to the disorder. To date, numerous genetic studies, using both the candidate gene and genome-wide approach, have been undertaken to tease out the genetic basis of PE and understand its origins. Such studies have identified some promising candidate genes such as STOX1 and ACVR2A. Nevertheless, researchers face ongoing challenges of replicating these genetic associations in different populations and performing the functional validation of identified genetic variants to determine their causality in the disorder. This chapter will review the genetic approaches used in the study of PE, discuss their limitations and possible confounders, and describe current strategies.

Nodal, a secreted signaling protein from the transforming growth factor beta (TGF-β)-super family plays a vital role during early embryonic development. Recently, it was found that maternal decidua-specific Nodal knockout mice show intrauterine growth restriction (IUGR) and preterm birth. The chromosomal location of NODAL is in the same linkage area as the placental (fetal) pre-eclampsia (PE) susceptibility gene STOX1, which is associated with the familial form of early-onset, IUGR-complicated PE. As the STOX1 linkage was originally identified in women being born from a pre-eclamptic pregnancy as well as suffering from PE themselves, the linkage could in part be caused by NODAL, which is why the potential maternal-fetal interaction between STOX1 and NODAL was investigated. In the PE families with the STOX1 susceptibility allele carried by the children born from pre-eclamptic pregnancies, it was found that the pre-eclamptic mothers themselves all carried the NODAL H165R SNP, which causes a 50% reduced activity. Surprisingly, in decidua-specific Nodal knockout mice the fetal placenta showed up-regulation of STOX1 and NODAL expression. Conditioned media of human first trimester decidua and a human endometrial stromal cell line (T-HESC) treated with siRNAs against NODAL or carrying the H165R SNP were also able to induce NODAL and STOX1 expression when added to SGHPL-5 first trimester extravillous trophoblast cells. Finally, a human TGF-β/BMP signaling pathway PCR-array on decidua and the T-HESC cell line with Nodal knockdown revealed upregulation of Activin-A, which was confirmed in conditioned media by ELISA. We show that maternal decidua Nodal knockdown gives upregulation of NODAL and STOX1 mRNA expression in fetal extravillous trophoblast cells, potentially via upregulation of Activin-A in the maternal decidua. As both Activin-A and Nodal have been implicated in PE, being increased in serum of pre-eclamptic women and upregulated in pre-eclamptic placentas respectively, this interaction at the maternal-fetal interface might play a substantial role in the development of PE.