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.
Funding source: Vedecká Grantová Agentúra MŠVVaŠ SR a SAV
Award Identifier / Grant number: VEGA 1/0742/21
Funding source: Agentúra na Podporu Výskumu a Vývoja
Award Identifier / Grant number: APVV-16-0273
Research funding: The authors are supported by the Slovak Research and Development Agency (Grant APVV-16-0273) and by the Ministry of Education (Grant VEGA 1/0742/21).
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: Authors state no conflict of interest.
Informed consent: Informed consent was obtained from all individuals included in this study.
Ethical approval: The study protocol was approved by the Ethics Committee of the Faculty of Medicine, Comenius University, Bratislava.
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