A proper placental sampling for syncytin-1 analysis
Syncytin-1 (gene ERVW-1) has been proposed as a marker of pre-eclampsia and malfunctions in placental development. Placenta is heterogeneous tissue, hence the method of biopsy can significantly affect the outcome of analyses. A total of 44 placentae were analyzed by taking 3–30 samples from each. Relative levels of ERVW-1 expression in the placental biopsies were characterized by RT-qPCR. Evaluation of ten biopsies from one placenta individually (not pooling them) is recommended due to the high variability of expression. No significant correlation was found between biopsy localization and level of ERVW-1 expression; therefore, random sampling is recommended. A long cut from the umbilical cord to the edge of the placenta is a convenient approach to placental sampling.
Analysis of predictive factors of pre-eclampsia
Pre-eclampsia is one of the most important causes of pregnant women’s mortality and morbidity in Europe and globally. The study provides an overview of known risk factors and markers and concludes there is no reliable predictor for prediction and stratification of pre-eclampsia risk. It is proposed that mutations of the ERVW-1 gene are investigated as potential predictors to be used in clinical practice either standalone or in multivariable models. A methodology for such investigation including the proposal to develop a multivariable model based on the logistic regression is provided. The methodology is demonstrated and tested on simulation data. The simulation shows a limitation of smallscale studies with a sample smaller than 100 to identify risk factors with low prevalence. The study argues that it is still reasonable to conduct small scale studies because they should be able to identify risk factors with high risk that could improve the accuracy of predictive models.
Analysis of predictive factors of pre-eclampsia
OBJECTIVES: Identification of genetic association between the gene ERVW-1 and preeclampsia.
BACKGROUND: Preeclampsia is a multifactorial disease affecting women during pregnancy and it is one of the main causes of perinatal and maternal morbidity and mortality. The pathophysiology of preeclampsia is very complex and several aspects of the disease have not been elucidated yet. Abnormal placentation frequently occurs during severe preeclampsia. Protein syncytin 1, a product of the ERVW-1 gene, plays a crucial role in the syncytiotrophoblast differentiation and optimal placentation. The syncytin 1 expression is disturbed during preeclampsia. The main focus of this study was the analysis of the ERVW-1 regulatory regions and identification of DNA polymorphisms associated with preeclamptic cases in Slovak population.
METHODS: Regulatory region of gene ERVW-1 was analyzed by sequencing to identify genetic variants.
RESULTS: We identified four DNA variants, namely rs4727276, rs148592540, rs569899772 and rs555416193, in samples of Slovak population.
CONCLUSION: No relation between polymorphisms and preeclampsia was observed, indicating that further investigations with a larger sampling are still required. However, our work represents new original approach in genetic differential diagnosis of preeclampsia with possible useful findings in the future (Tab. 3, Fig. 1, Ref. 34).
Characterization of Genetic Variability and Gene Expression of ERVW-1 in Placentas of Preeclamptic Women
Preeclampsia and associated complications belong to the most frequent causes of mortality and morbidity of both mothers and infants. Preeclampsia has proven multifactorial character with complex pathophysiological background. There are different subtypes of preeclampsia that could be attend by associated syndromes (IUGR, HELLP). These subtypes have significantly diverse clinical features and course of symptoms during gestation. Heritability of preeclampsia varies from 40 % up to 55 % depending on amount of analysed cases and included subtypes of disorder. Nevertheless, preeclampsia has important unknown genetic background. Presumably, the only inducer of disorder that will explain all the pathological aspects leading to preeclampsia and associated syndromes does not exist. Although syncytin-1 is one of the possible major contributors to preeclampsia development. Syncytin-1 is a product of endogenous retroviral element, ERVW-1. Syncytin-1 has pleiotropic functions and its synthesis is the most intense in placenta. Syncytins-1 affects wide variety of processes like regulation of cell cycle, fusion of trophoblast cell and apoptosis, modulation of immune system, etc. Exact function of syncytin-1 in preeclampsia has not been elucidated yet. We proposed hypothesis that variant in sequence of ERVW-1 regulatory region could be responsible for the changes of ERVW-1 expression and this change could be one of the important triggers of pathological processes leading to preeclampsia respectively to transition from mild form of preeclampsia to severe. We introduced and optimized sequencing analysis of ERVW-1 regulatory region and quantification of gene expression level of ERVW-1 in placental tissue. We partially optimized protein quantification of syncytin-1 in placental samples and the optimization will continue during newly started project. We have extended knowledge about sequencing variability of ERVW-1 in Slovak population. Experiments confirmed differences in ERVW-1 and syncytin-1 in physiologically normal and gestational hypertensive samples that include preeclampsia, IUGR and HELLP. Impact and importance of these identified changes have to be tested on a larger amount of samples. Our work have highlighted necessity of strict and accurate classification of the preeclamptic subtypes in cooperation with clinical professionals on sufficient set of patients in the future project.
Optimization of the gene expression analyses of ERVW-1 in placentas of the preeclamptic women
Preeclampsia is a multifactorial disease manifesting in pregnancy. Main symptoms are represented by elevated heart pressure and proteinuria. PE belongs to the most common causes of morbidity and mortality during pregnancy. To this day the scientific community was not able to recognize the primary cause for PE development. However it is very likely that the main factor behind PE is disruption of placenta differentiation. The gene ERVW-1 is a retroviral gene involved in differentiation of placenta and many studies has shown its dysregulation in PE cases. In this diploma work we optimize the methods for analysis of the regulatory region of ERVW-1 in the context of its expression. We find new results and we suggest more effective procedure for analysis of the PE cases.
Pre-eclampsia – second leading cause of death in pregnant women
Pre-eclampsia is hypertensive multisystem disorder affecting women during gravidity or immediately after. It is one of the modt important causes of pregnant women’s mortality and morbidity in Europe and globally. Because of unexplained etiology preeklampsia represents a serious medical problem. This review provides an overview of known risk factors and markers and concludes there is no reliable predictor for prediction and stratification of pre-eclampsia risk.
Monitoring of HERV-W gene polymorphisms in the embryos with symptoms of preeclampsia
HERV-W gene is member of endogenous retroviral elements family. Protein syncytin 1 is product of HERV-W gene and plays crucial role in differentiation of syncytiotrophoblast during pregnancy. Successful differentiation of syncytiotrophoblast differentiation is necessary for optimal placentation in pregnant women. Preeclampsia is one of the major causes of maternal morbidity and mortality, preterm birth, perinatal death, and intrauterine growth restriction worldwide. It is multifactorial disease with heterogeneous set of symptoms. Abnormal placentation frequently occurs during severe preeclampsia, which can have tragic consequences for mother and child. The syncytin 1 expression is disturbed probably on transcription level during preeclampsia. The main aim of graduation thesis is analysis of HERV-W gene and identification of DNA polymorphisms associated with preeclamptic embryos. Theoretical overview is focused on HERV-W gene, regulation of its expression and on blastogenesis. Final part of literary overview deals with pathology of preeclampsia and role of HERV-W in it. Practical part of thesis is focused on sequencing and SSCP analysis of HERV-W regulation regions. Results of our research contributed to extending of knowledge about HERV-W gene and to identification of DNA polymorphisms specific for Slovak population.
Does COVID-19 cause preeclampsia?
COVID-19, a disease induced by virus SARS-CoV-2, is since march of 2020 marked as pandemic. This disease is clinicaly manifesting itself with flu alike symptoms among young patients. More severe (sometimes lethal) course is typical mainly for seniors. Newest research suggests higher risk also for pregnant women. Pregnant women are more susceptible to infection caused by SARS-CoV-2 because of overproduction ACE2 receptor during pregnancy, which this virus uses for cell invasion. Symptoms found in pregnant women positive for COVID-19 are very similar to ones with preeclampsia.
Role of ERVW-1 and syncytin-1 in development of gestational hypertensive diseases
Preeclampsia (PE) is a serious multifactorial disease with onset during pregnancy. Main symptoms of PE are elevated blood pressure and proteinuria. Development of the PE is associated with defective formation of trophoblast and placenta during pregnancy and is the second most common cause of mortality in pregnant women. Despite its high incidence (5 – 8 % of all pregnancies), there is no effective treatment or markers for early diagnosis. One of the factors accountable for healthy placentation is protein called syncytin-1, product of the gene ERVW-1. Main purpose of this work was to compare gene expression of the ERVW-1 between healthy and PE placentas using qPCR and secondly analysis of regulatory region of this gene, identification of any variants and their potential effect on syncytin-1 expression. We successfully managed to optimalize methods used in ERVW-1 gene expression analysis, which will lead to more accurate and reliable results. We also achieved to optimize multiple steps leading to quantitative PCR, that include treating of RNA samples with DNase, reverse transcription and we also introduced a new biopsy protocol to ensure the most reliable results. We were able to identify three variants in our samples using sequence analysis, from which the most common (rs4727276) was found in the regulatory region – URE, what suggest a potential effect on ERVW-1 regulation. Results of our quantitative PCR, where whe analysed nine PE and seven control samples, were against the findings of previous publications that identified reduced gene expression of ERVW-1 in preeclampsia, although the data were not evaluated as statistically significant. Quantitative PCR is widely used and reliable method for measuring of gene expression. However, it meets with multiple challenges in the case of heterogennous tissue like a placenta that are needed to address accordingly.
Role of retroviral protein Syncytin-2 in preeclampsia
Preeklampsia is a major cause of maternal/prenatal morbidity and mortality during pregnancy worldwide. The causes and pathogenic mechanisms of preeclampsia are poorly defined. It seems that genetic predisposition could be an important etiological factor for the development of this disease. Many candidate genes and polymorphisms have been studied in relation to preeclampsia. ERVFRD-1 gene coding syncytin-2 is one of the possible important players in the pathogenesis of this disease.
Pre-eclampsia – second leading casuse of death in pregnant women
Pre-eclampsia is hypertensive multisystem disorder affecting women during gravidity or immediately after. It is one of the most important causes of pregnant women’s mortality and morbidity in Europe and globally. Because of unexplained etiology preeclampsia represents a serious medical problem. This review provides an overview of known risk factors and markers and concludes there is no reliable predictor for prediction and stratification of pre-eclampsia risk.
Elementy HERV a ich funkcia v ľudskom genóme
Nezanedbateľnou súčasťou ľudského genómu sú transponovateľné elementy, ku ktorým sa radia ľudské endogénne retrovirálne elementy (HERV). Neustále sa objavujú nové funkcie elementov HERV v ľudskom organizme, či už fyziologické, alebo patologické a poskytujú unikátny pohľad na interakciu hostiteľskej bunky s pozostatkami zdedených retrovírusových infekcií.
Optimalizácia odberu placentárneho materiálu pre kvantifikáciu expresie génu ERVW-1
Preeklampsia: Ochorenie spôsobené nesprávnou funkciou retrovirálneho elementu?
Preeklampsia (PE) predstavuje závažné ochorenie počas tehotenstva, pre ktoré v dnešnej dobe neexistuje efektívna liečba a ani rýchle a spoľahlivé markery na jej včasnú diagnostiku. Jej hlavné príznaky sú vysoký tlak počas tehotenstva a zvýšený obsah proteínov v moči. PE vzniká predovšetkým nesprávnym formovaním trofoblastu v tehotenstve. Abnormálna diferenciácia trofoblastu je z veľkej miery zapríčinená zníženou expresiou syncytínu-1 kódovaným génom ERVW-1. ERVW-1 je gén patriaci do rodiny endogénnych retrovirálnych elementov (ERV). Expresia týchto sekvencií je bežne v somatických bunkách potlačená, narozdiel od bunkovej línie trofoblastu, kde je jeho expresia výrazne zvýšená. Jeho úloha spočíva predovšetkým v tvorbe mnohojadrového syncýtia, regulácii bunkového cyklu, regulácii apoptózy a imunosupresívnej odpovedi. Všetky tieto úlohy sú nevyhnutné pre správnu tvorbu placenty a deregulácia expresie ERVW-1 prináša komplexné problémy vyúsťujúce do patogenézy PE. Vzhľadom na to, že PE je multisystémové ochorenie, je tiež možné, že tiež možné, že príčiny jej vzniku budú tiež komplexné a polygénne.