8-Hydroxy-2-deoxyguanosine staining in placenta is associated with maternal serum uric acid levels and gestational age at diagnosis in pre-eclampsia

Dietary and Antioxidant Vitamins Limit the DNA Damage Mediated by Oxidative Stress in the Mother-Newborn Binomial

During pregnancy, appropriate nutritional support is necessary for the development of the foetus. Maternal nutrition might protect the foetus from toxic agents such as free radicals due to its antioxidant content. In this study, 90 mothers and their children were recruited. DNA damage mediated by oxidative stress (OS) was determined by the levels of 8-hidroxy-2′-deoxyguanosine (8-OHdG) in the plasma of women and umbilical cord blood. The mothers and newborns were categorised into tertiles according to their 8-OHdG levels for further comparison. No relevant clinical differences were observed in each group. A strong correlation was observed in the mother−newborn binomial for 8-OHdG levels (Rho = 0.694, p < 0.001). In the binomial, a lower level of 8-OHdG was associated with higher consumption of calories, carbohydrates, lipids, and vitamin A (p < 0.05). In addition, the levels of 8-OHdG were only significantly lower in newborns from mothers with a higher consumption of vitamin A and E (p < 0.01). These findings were confirmed by a significant negative correlation between the 8-OHdG levels of newborns and the maternal consumption of vitamins A and E, but not C (Rho = −0.445 (p < 0.001), −0.281 (p = 0.007), and −0.120 (p = 0.257), respectively). Multiple regression analysis showed that the 8-OHdG levels in mothers and newborns inversely correlated with vitamin A (β = −1.26 (p = 0.016) and −2.17 (p < 0.001), respectively) and pregestational body mass index (β = −1.04 (p = 0.007) and −0.977 (p = 0.008), respectively). In conclusion, maternal consumption of vitamins A and E, but not C, might protect newborns from DNA damage mediated by OS.

Oxidative nucleic acid damage as a biomarker for preeclampsia

Recent studies have reported that nucleic acid oxidation is elevated in preeclampsia. Furthermore, it is known that products of nucleic acid oxidation are eventually removed through the urine. The aim of this study was to check whether urine can be used as a non-invasive specimen to analyse nucleic acid oxidation in preeclampsia. We carried out a case-control study by enrolling preeclamptic pregnant (n = 31) and normotensive pregnant (n = 31) women. Urine samples from the study participants were collected and the levels of oxidised guanine species (a common product of nucleic acid oxidation) were determined by ELISA method. The urinary levels of oxidised guanine species were significantly higher in the preeclamptic pregnant group compared to the normotensive pregnant group (p = 0.001). The results were also analysed after stratifying the preeclamptic group in terms of severity and gestational age of onset. A significant difference was observed in both mild (p = 0.005) and severe preeclampsia (p = 0.01). However, a significant difference was observed only in the late onset (p = 0.001) and not in the early onset preeclampsia (p = 0.56). The results of this study show that oxidised guanine level is elevated in the urine of preeclamptic pregnant women. IMPACT STATEMENTWhat is already known on this subject? Nucleic acid oxidation is elevated in preeclampsia. However, the utility of urine (a non-invasive specimen) to analyse nucleic acid oxidation is not known.What do the results of this study add? This study shows that the levels of oxidised guanine (a marker of nucleic acid oxidation) are elevated in the urine of preeclamptic women.What are the implications of these findings for clinical practice and/or further research? Urinary levels of oxidised guanine may be developed as a non-invasive biomarker for preeclampsia.

Placental lesions and differential expression of pro-and anti-angiogenic growth mediators and oxidative DNA damage marker in placentae of Ghanaian suboptimal and optimal health status pregnant women who later developed preeclampsia

Background

Angiogenic growth mediators (AGMs) and oxidative stress (OS) both play essential roles in normal placental vascular development and as such, placental alterations in these factors contribute to pre-eclampsia (PE). Suboptimal health status (SHS), an intermediate between health and disease, has been associated with imbalanced AGMs and OS biomarkers. Thus, SHS pregnant women may be at increased risk of developing PE and may present abnormal placental alteration and expression of AGMs and OS compared to optimal health status (OHS) pregnant women. We examined the histopathological morphology, immunohistochemical expression of AGMs antibodies and oxidative DNA damage marker in the placentae of SHS and OHS pregnant women who developed early-onset PE (EO-PE) and late-onset (LO-PE) compared to normotensive pregnancy (NTN-P).

Methods

This nested case-control study recruited 593 singleton normotensive pregnant women at baseline (10–20 weeks gestation) from the Ghanaian Suboptimal Health Status Cohort Study (GHOACS) undertaken at the Komfo Anokye Teaching Hospital, Ghana. Socio-demographic, clinical and obstetrics data were collected, and a validated SHS questionnaire-25 (SHSQ-25) was used in classifying participants into SHS (n = 297) and OHS (n = 296). Participants were followed until the time of PE diagnosis and delivery (32–42 weeks gestation). Blood samples were collected at the two-time points and were assayed for AGMs; soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PIGF), vascular endothelial growth factor-A (VEGF-A), and soluble endoglin (sEng), and OS biomarkers; 8-hydroxydeoxyguanosine (8-OHdG), 8-epiprostaglandinF2-alpha (8- epi-PGF2α) and total antioxidant capacity (TAC) using ELISA. Placental samples were collected for histopathological and immunohistochemical analysis.

Results

Of the 593 pregnant women, 498 comprising 248 SHS and 250 OHS women returned for delivery and were included in the final analysis. Of the 248 SHS women, 56, 97 and 95 developed EO-PE, LO-PE and NTN-P, respectively, whereas 14, 30 and 206 of the 250 OHS mothers developed EO-PE, LO-PE and NTN-P, respectively. At baseline, SHS_NTN pregnant women had a significant imbalance in AGMs and OS biomarkers compared to OHS_NTN pregnant women (p<0.0001). At the time of PE diagnosis, SHS_NTN-P women who developed EO-PE, LO-PE, and NTN-P had lower serum levels of P1GF, VEGF-A and TAC and correspondingly higher levels of sEng, sFlt-1, 8-epiPGF2α, and 8-OHdG than OHS-NTN-P women who developed EO-PE and LO-PE, NTN-P (p<0.0001). A reduced placental size, increased foetal/placental weight ratio, and a significantly higher proportion of fibrinoid necrosis, infarction, villous fibrin, syncytial knots, calcification, chorangiosis, tunica media/vascular wall hypertrophy and chorioamnionitis was associated with the SHS group who developed PE (EO-PE>LO-PE) more than OHS groups who developed PE (EO-PE>LO-PE) when all were compared to NTN-P (p<0.0001). The intensity of antibody expression of PIGF and VEGF-A were significantly reduced, whereas Flt-1, Eng and 8-OHdG were significantly increased in placentae from SHS-pregnant women who developed EO-PE>LO-PE more than OHS- pregnant women who developed EO-PE>LO-PE when all were compared to NTN-P (p<0.0001).

Conclusion

Increased lesions, oxidative DNA damage, and imbalanced expression between pro-and anti-AGMs are associated more with SHS-embodied PE placentae rather than OHS-embodied PE subtypes, thus potentially allowing differential evaluation of PE.

Kisspeptin treatment improves fetal-placental development and blocks placental oxidative damage caused by maternal hypothyroidism in an experimental rat model

Maternal hypothyroidism is associated with fetal growth restriction, placental dysfunction, and reduced kisspeptin/Kiss1R at the maternal-fetal interface. Kisspeptin affects trophoblastic migration and has antioxidant and immunomodulatory activities. This study aimed to evaluate the therapeutic potential of kisspeptin in the fetal-placental dysfunction of hypothyroid Wistar rats. Hypothyroidism was induced by daily administration of propylthiouracil. Kisspeptin-10 (Kp-10) treatment was performed every other day or daily beginning on day 8 of gestation. Feto-placental development, placental histomorphometry, and expression levels of growth factors (VEGF, PLGF, IGF1, IGF2, and GLUT1), hormonal (Dio2) and inflammatory mediators (TNFα, IL10, and IL6), markers of hypoxia (HIF1α) and oxidative damage (8-OHdG), antioxidant enzymes (SOD1, Cat, and GPx1), and endoplasmic reticulum stress mediators (ATF4, GRP78, and CHOP) were evaluated on day 18 of gestation. Daily treatment with Kp-10 increased free T3 and T4 levels and improved fetal weight. Both treatments reestablished the glycogen cell population in the junctional zone. Daily treatment with Kp-10 increased the gene expression levels of Plgf, Igf1, and Glut1 in the placenta of hypothyroid animals, in addition to blocking the increase in 8-OHdG and increasing protein and/or mRNA expression levels of SOD1, Cat, and GPx1. Daily treatment with Kp-10 did not alter the higher protein expression levels of VEGF, HIF1α, IL10, GRP78, and CHOP caused by hypothyroidism in the junctional zone compared to control, nor the lower expression of Dio2 caused by hypothyroidism. However, in the labyrinth zone, this treatment restored the expression of VEGF and IL10 and reduced the GRP78 and CHOP immunostaining. These findings demonstrate that daily treatment with Kp-10 improves fetal development and placental morphology in hypothyroid rats, blocks placental oxidative damage, and increases the expression of growth factors and antioxidant enzymes in the placenta.

The effects of antivenom administrations on the brain tissue of experimentally envenomed pregnant rats and their pups with Androctonus crassicauda scorpion venom during organogenesis period

This study aims to show the changing effects of Androctonus crassicauda venom and A. crasicauda specific antivenom during pregnancy in brain tissue of dams and their pups. Totally, 12 pregnant-Wistar Albino rats were randomly divided into two groups as venom-antivenom administration (n = 6) and control groups (n = 6). In venom-antivenom administration group (VAV), the sublethal dose of A. crassicauda venom dissolved in 1 mL physiological saline solution was subcutaneously (s.c.) injected into pregnant rats during organogenesis period (between 7 and 13 days of pregnancy). Four hours after each venom injection, 1 mL/s.c. dose of the specific anti-venom was administered to rats of VAV group. The rats in control group were given sterile saline solution 1 mL/s.c. In both groups, the fetuses were surgically delivered on the 21st day of pregnancy; dams and pups were sacrificed on postnatal 21 days, and their brain tissues were removed. The brain tissue of dams and their pups were evaluated histopathologically and immunohistochemically. To show the neuronal damages, 8-hydroxy-2-deoxyguanosine (8-OHDG) and amyloid beta precursor protein (ABPP) immunoexpressions were scored in cerebrum, cerebellum, pons and medulla oblongata of brain. To show the neuroprotection, reelin and beta-arrestin immunoexpressions were scored again in the same way. In this context, 8-OHDG immunoexpressions were increased in neocortex, hippocampus and nucleus accumbens when compared with that of control group. Amyloid beta precursor protein was negative in both groups. Reelin and beta-arrestin partly increased in fore and mid brain of VAV group as a reaction against neuronal damages when compared with that of control pups. The authors believe that prompt intervention using anti-venom to scorpion envenomation can partly stop neuronal damages. This neuroprotection may be increased to high and serial doses of anti-venom to save neonatal lives.

Molecular hydrogen ameliorates several characteristics of preeclampsia in the Reduced Uterine Perfusion Pressure (RUPP) rat model

Oxidative stress plays an important role in the pathogenesis of preeclampsia. Recently, molecular hydrogen (H₂) has been shown to have therapeutic potential in various oxidative stress-related diseases. The aim of this study is to investigate the effect of H₂ on preeclampsia. We used the reduced utero-placental perfusion pressure (RUPP) rat model, which has been widely used as a model of preeclampsia. H₂ water (HW) was administered orally ad libitum in RUPP rats from gestational day (GD) 12-19, starting 2 days before RUPP procedure. On GD19, mean arterial pressure (MAP) was measured, and samples were collected. Maternal administration of HW significantly decreased MAP, and increased fetal and placental weight in RUPP rats. The increased levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and diacron reactive oxygen metabolites as a biomarker of reactive oxygen species in maternal blood were decreased by HW administration. However, vascular endothelial growth factor level in maternal blood was increased by HW administration. Proteinuria, and histological findings in kidney were improved by HW administration. In addition, the effects of H₂ on placental villi were examined by using a trophoblast cell line (BeWo) and villous explants from the placental tissue of women with or without preeclampsia. H₂ significantly attenuated hydrogen peroxide-induced sFlt-1 expression, but could not reduce the expression induced by hypoxia in BeWo cells. H₂ significantly attenuated sFlt-1 expression in villous explants from women with preeclampsia, but not affected them from normotensive pregnancy. The prophylactic administration of H₂ attenuated placental ischemia-induced hypertension, angiogenic imbalance, and oxidative stress. These results support the theory that H₂ has a potential benefit in the prevention of preeclampsia.

Pain-reducing anesthesia prevents oxidative stress in human term placenta

Anesthesia is sometimes used for the reduction of maternal pain in normal human term labor, but whether the drugs affect oxidative stress remains unclear. The placenta serves as an interface between the maternal and fetal vasculature. In this study, we immunohistochemically analyzed two markers for oxidative stress, namely 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal–modified proteins (HNE), using placentas from 21 cases of normal tansvaginal delivery (V group), 20 Caesarean sections (C group), and 17 normal transvaginal deliveries with epidural anesthesia (E group). 8-OHdG staining in the nuclei of trophoblasts lining the chorionic villi was significantly stronger in the V group either compared with the C or E group (p<0.001), without significant differences in the C and E groups (p = 0.792). Moderate to intense staining by HNE of the intravascular serum of chorionic villi vasculature was frequently observed in the placentas from the V group, but less frequently of those in either C or E groups (p<0.001), nor the p value comparing the C and E groups was significant (p = 0.128) for HNE staining. Our results suggest that although the role of oxidative stress and its influences on fetal state in the placenta in labor remains unclear, it seems to be lessened by epidural anesthesia.

Oxidative status interactome map: towards novel approaches in experiment planning, data analysis, diagnostics and therapy

Experimental evidence suggests an immense variety of processes associated with and aimed at producing reactive oxygen and/or nitrogen species. Clinical studies implicate an enormous range of pathologies associated with reactive oxygen/nitrogen species metabolism deregulation, particularly oxidative stress. Recent advances in biochemistry, proteomics and molecular biology/biophysics of cells suggest oxidative stress to be an endpoint of complex dysregulation events of conjugated pathways consolidated under the term, proposed here, "oxidative status". The oxidative status concept, in order to allow for novel diagnostic and therapeutic approaches, requires elaboration of a new logic system comprehending all the features, versatility and complexity of cellular pro- and antioxidative components of different nature. We have developed a curated and regularly updated interactive interactome map of human cellular-level oxidative status allowing for systematization of the related most up-to-date experimental data. A total of more than 600 papers were selected for the initial creation of the map. The map comprises more than 300 individual factors with respective interactions, all subdivided hierarchically for logical analysis purposes. The pilot application of the interactome map suggested several points for further development of oxidative status-based technologies.