| Autor: |
Gardner JJ; Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States., Cushen SC; Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States.; Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, Texas, United States., Oliveira da Silva RN; Lawrence D. Longo, MD Center for Perinatal Biology, Departments of Basic Sciences, Gynecology, and Obstetrics, Loma Linda University School of Medicine, Loma Linda, California, United States., Bradshaw JL; Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States., Hula N; Lawrence D. Longo, MD Center for Perinatal Biology, Departments of Basic Sciences, Gynecology, and Obstetrics, Loma Linda University School of Medicine, Loma Linda, California, United States., Gorham IK; Department of Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, Texas, United States., Tucker SM; Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States., Zhou Z; Department of Population & Community Health, University of North Texas Health Science Center, Fort Worth, Texas, United States., Cunningham RL; Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States., Phillips NR; Department of Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, Texas, United States., Goulopoulou S; Lawrence D. Longo, MD Center for Perinatal Biology, Departments of Basic Sciences, Gynecology, and Obstetrics, Loma Linda University School of Medicine, Loma Linda, California, United States. |
| Abstrakt: |
Circulating cell-free mitochondrial DNA (ccf-mtDNA) is an indicator of cell death, inflammation, and oxidative stress. ccf-mtDNA in pregnancies with placental dysfunction differs from that in healthy pregnancies, and the direction of this difference depends on gestational age and method of mtDNA quantification. Reactive oxygen species (ROS) trigger release of mtDNA, yet it is unknown whether trophoblast cells release mtDNA in response to oxidative stress, a common feature of pregnancies with placental pathology. We hypothesized that oxidative stress would induce cell death and release of mtDNA from trophoblast cells. BeWo cells were treated with antimycin A (10-320 µM) or rotenone (0.2-50 µM) to induce oxidative stress. A multiplex real-time quantitative PCR (qPCR) assay was used to quantify mtDNA and nuclear DNA in membrane-bound, non-membrane-bound, and vesicle-bound forms in cell culture supernatants and cell lysates. Treatment with antimycin A increased ROS ( P < 0.0001), induced cell necrosis ( P = 0.0004) but not apoptosis ( P = 0.6471), and was positively associated with release of membrane-bound and non-membrane-bound mtDNA ( P < 0.0001). Antimycin A increased mtDNA content in exosome-like extracellular vesicles (vesicle-bound form; P = 0.0019) and reduced autophagy marker expression (LC3A/B, P = 0.0002; p62, P < 0.001). Rotenone treatment did not influence mtDNA release or cell death ( P > 0.05). Oxidative stress induces release of mtDNA into the extracellular space and causes nonapoptotic cell death and a reduction in autophagy markers in BeWo cells, an established in vitro model of human trophoblast cells. Intersection between autophagy and necrosis may mediate the release of mtDNA from the placenta in pregnancies exposed to oxidative stress. NEW & NOTEWORTHY This is the first study to test whether trophoblast cells release mitochondrial (mt)DNA in response to oxidative stress and to identify mechanisms of release and biological forms of mtDNA from this cellular type. This research identifies potential cellular mechanisms that can be used in future investigations to establish the source and biomarker potential of circulating mtDNA in preclinical experimental models and humans. |
