Institute of Molecular Biomedicine, Comenius University, Bratislava, Slovakia.
2nd Department of Gynecology and Obstetrics, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
J Perinat Med. 2021 Mar 26;49(6):755-758. doi: 10.1515/jpm-2020-0526. Print 2021 Jul 27.
It is not clear, which factors affect extracellular DNA (ecDNA) concentrations in healthy women with singleton uncomplicated pregnancies, although deoxyribonucleases (DNases) are hypothesized to be responsible for the cleavage of plasma ecDNA. The aim of this study was to analyze potential determinants of total ecDNA including plasma DNase activity.
Plasma samples were collected from 48 healthy women with singleton uncomplicated pregnancies in the third trimester (gestation week 37). DNA was isolated and quantified using fluorometry and real time PCR. DNase activity was assessed using the single radial enzyme-diffusion method.
Neither ecDNA, nor DNase activity were affected by maternal age or BMI. DNase activity negatively correlated with total plasma ecDNA (r=-0.40, p=0.007). Similar associations were found for ecDNA of nuclear and mitochondrial origin, but not with fetal DNA quantified using Y-targeted PCR in male fetus-bearing pregnancies.
The role of plasma ecDNA of fetal and maternal origin is studied in the pathogenesis of pregnancy-complications. The results indicate that plasma DNase activity could negatively regulate ecDNA concentrations and should, thus, be analyzed in preeclampsia, preterm birth and other ecDNA-related pregnancy complications.
尽管脱氧核糖核酸酶（DNase）被假设负责血浆外源性 DNA（ecDNA）的切割，但目前尚不清楚哪些因素会影响健康单胎无并发症孕妇的血浆 ecDNA 浓度。本研究旨在分析总 ecDNA 的潜在决定因素，包括血浆 DNase 活性。
从第三孕期（妊娠 37 周）的 48 名健康单胎无并发症孕妇中采集血浆样本。使用荧光计和实时 PCR 分离和定量 DNA。使用单径向酶扩散法评估 DNase 活性。
母体年龄或 BMI 均不影响 ecDNA 或 DNase 活性。DNase 活性与总血浆 ecDNA 呈负相关（r=-0.40，p=0.007）。核和线粒体来源的 ecDNA 也存在类似的关联，但在携带男性胎儿的妊娠中使用 Y 靶向 PCR 定量的胎儿 DNA 则没有。
研究了胎儿和母体来源的血浆 ecDNA 在妊娠并发症发病机制中的作用。结果表明，血浆 DNase 活性可能会负调节 ecDNA 浓度，因此应在子痫前期、早产和其他与 ecDNA 相关的妊娠并发症中进行分析。
