Search

Introduction Vaginal administration of micronized progesterone (utrogestan capsule, UG) reduces the risk of preterm birth (PTB) in asymptomatic women with a sonographic short cervix at mid-trimester or with a prior history of spontaneous PTB; however, its exact mechanisms remain unclear. We hypothesized that UG limits the inflammatory processes within the gestational tissues and the cervix. Methods Fetal membranes and villous tissues were obtained from normal term placentas from women with cesarean delivery before labor onset. Ectocervical tissues were obtained from premenopausal women undergoing hysterectomies for uterine fibroids. Explant tissue cultures were pretreated with UG for 24 h and then exposed to UG with or without lipopolysaccharide (LPS) for 48 h. Tumor necrosis factor-α, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein-1, interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, IL-13, interferon-γ, tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 levels in tissue homogenates and culture medium were measured by enzyme-linked immunosorbent assays. Real-time quantitative PCR, Western blot, and gelatine zymography were used to measure matrix metalloproteinase (MMP)-9 and MMP-2 mRNA, protein, and activity levels, respectively. Results UG pretreatment did not cause a significant change in basal levels or in LPS-induced production and secretion of cytokines, chemokines, and TIMPs in the three tissues. However, UG pretreatment significantly reduced MMP-9 and MMP-2 expression and activity in fetal membranes stimulated with LPS but not in villous or cervical tissues. Discussion UG pretreatment significantly reduced MMP-9 and MMP-2 expression and activity in fetal membranes stimulated with LPS, suggesting a possible protective mechanism of micronized progesterone in preventing infection-associated PTB.

Introduction Increased endoplasmic reticulum (ER) stress and autophagy have been noted in the placentas of pregnancies complicated by idiopathic intrauterine growth restriction (IUGR); however, the cause of these phenomena remains unclear. We surmised that oxygen-glucose deprivation (OGD) may increase ER stress and autophagy and that mammalian target of rapamycin (mTOR) signaling is involved in regulating placental ER stress and autophagy in pregnancies complicated by IUGR. Methods We obtained placentas from women with normal term pregnancies and pregnancies complicated by IUGR to compare ER stress, mTOR signaling, and levels of autophagy-related proteins between the two groups and used primary cytotrophoblast cells treated with or without salubrinal (an ER stress inhibitor), MHY1485 (an mTOR activator), or rapamycin (an mTOR inhibitor) to investigate the effects of OGD on ER stress, mTOR activity, and autophagy levels in vitro. Results Women with pregnancies complicated by IUGR displayed higher placental ER stress and autophagy levels but lower mTOR activity than women with normal pregnancies. Furthermore, OGD increased ER stress, regulated in development and DNA damage responses-1 (REDD1), phosphorylated tuberous sclerosis complex 2 (TSC2), and autophagy levels and decreased mTOR activity compared to the standard culture condition; however, the salubrinal treatment attenuated these changes. Moreover, the administration of MHY1485 or rapamycin to OGD-treated cells decreased or increased autophagy levels, respectively. Discussion Based on our results, mTOR is a mechanistic link between OGD-induced ER stress and autophagy in cytotrophoblast cells; thus, mTOR plays an essential role in the pathogenesis of pregnancies complicated by IUGR.

To investigate the association between maternal oxidative stress at mid-gestation and subsequent development of pregnancy complications. A total of 503 healthy pregnant women provided their blood and urine samples at 24 to 26 weeks of gestation and were prospectively followed through postpartum. These samples were used to assess a variety of oxidative stress markers, including plasma total antioxidant capacity, 8-isoprostane, erythrocyte glutathione peroxidase and superoxide dismutase activity, and urinary 8-hydroxydeoxyguanosine (8-OHdG). Compared with women with uncomplicated pregnancies, significantly higher plasma 8-isoprostane levels were noted in women who developed preeclampsia (P = .008) and small-for-gestational age infants (P = .002), while higher urinary 8-OHdG concentrations were noted in women who subsequently had low-birth-weight neonates (

Myeloperoxidase (MPO) is a heme protein produced and released by activated neutrophils and monocytes, and increased MPO is considered important in the pathophysiology of cardiovascular diseases (CVD). Accumulating evidence suggests that preeclampsia (PE), idiopathic intrauterine growth restriction (IUGR), and CVD share many similar metabolic disturbances, including an enhanced systemic inflammatory response and endothelial dysfunction. We hypothesized that MPO plays an important role in the development of PE and IUGR. Plasma samples were collected mid-gestation and at delivery from women with normal pregnancies (n = 40) and those who subsequently developed PE (n = 20), IUGR (n = 11) or both (PE + IUGR, n = 8). Placental samples were obtained immediately after delivery from 22 women with normal pregnancies, 19 women with PE, 14 women with IUGR, and 14 women with PE + IUGR. The MPO concentrations were measured using ELISA. Women with PE + IUGR had significantly higher plasma MPO before delivery than normal pregnant women. There was no difference in plasma levels at mid-gestation or the placental concentrations between women with normal pregnancies and those who developed PE, IUGR, or PE + IUGR. Using explants prepared from the placentas of 8 women with normal pregnancies and 8 women with PE, we found no difference in the levels of MPO in the tissue homogenates and culture media between these two groups of women. Together, these results indicate that increased maternal circulating MPO in women with PE + IUGR is likely a result of enhanced systemic inflammation caused by the established disease rather than a primary pathophysiological factor.

Pregnancy is associated with increased oxidative stress, and exaggeration of oxidative damage is considered important in pregnancy complications such as preeclampsia. There is, however, only scattered information regarding the longitudinal change of oxidative stress during pregnancy. We surmised that the placenta is the cause of the increased oxidative stress during pregnancy and hypothesized that the amount of placenta-derived cell-free fetal DNA in maternal plasma is correlated with maternal oxidative stress status. Blood and urine samples were collected at different stages of gestation and 6 to 8 weeks postpartum from 105 women with uncomplicated pregnancies. Additionally, 40 healthy women of reproductive age, but not pregnant, were recruited as controls. All oxidative stress markers, including urinary 8-hydroxydeoxyguanosine (8-OHdG), plasma 8-isoprostane, total antioxidant capacity (TAC), and erythrocyte glutathione peroxidase (GPX) and superoxide dismutase (SOD) activities, were increased in the third trimester, and most of them returned to nonpregnant levels postpartum. Furthermore, the DYS14 gene of the Y chromosome was quantified from plasma samples obtained at 26 to 30 weeks' gestation in 54 women who later delivered a male infant. Significant associations were noted between plasma concentrations of the DYS14 gene and the levels of urinary 8-OHdG and plasma 8-isoprostane, suggesting an association between the breakdown of syncytiotrophoblast and maternal oxidative stress during pregnancy.

BACKGROUND: Autophagy has been reported to be essential for pre-implantation development and embryo survival. However, its role in placental development and regulation of autophagy during pregnancy remain unclear. The aims of this study were to (1) study autophagy by characterizing changes in levels of beclin-1, DRAM, and LC3B in human placenta throughout gestation; (2) determine whether autophagy is involved in regulation of trophoblast invasion in JEG-3 cells (a choriocarcinoma cell line); (3) examine the effects of reduced oxygen and glucose on the autophagic changes; and (4) investigate the effect of reoxygenation and supplementation of glucose after oxygen-glucose deprivation (OGD) on the autophagic changes in primary cytotrophoblasts obtained from normal term pregnancy. METHODOLOGY/PRINCIPAL FINDINGS: An analysis of 40 placental samples representing different gestational stages showed (1) no significant differences in beclin-1, DRAM, and LC3B-II levels in placentas between early and mid-gestation, and late gestation with vaginal delivery; (2) placentas from late gestation with cesarean section had lower levels of LC3B-II compared to early and mid-gestation, and late gestation with vaginal delivery; levels of DRAM were also lower compared to placentas from early and mid-gestation; and (3) using explant cultures, villous tissues from early and late gestation had similar rates of autophagic flux under physiological oxygen concentrations. Knockdown of BECN1, DRAM, and LC3B had no effects on viability and invasion activity of JEG-3 cells. On the other hand, OGD caused a significant increase in the levels of LC3B-II in primary cytotrophoblasts, while re-supplementation of oxygen and glucose reduced these changes. Furthermore, there were differential changes in levels of beclin-1, DRAM, and LC3B-II in response to changes in oxygen and glucose levels. CONCLUSIONS/SIGNIFICANCE: Our results indicate that autophagy is involved in development of the human placenta and that changes in oxygen and glucose levels participate in regulation of autophagic changes in cytotrophoblast cells.

To study oxidative stress differences between women with normal vaginal deliveries (VD) and those with elective cesarean sections without labor (CS), total antioxidant capacity (TAC), erythrocyte glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity, 8-isoprostane, nitrotyrosine and 8-hydroxydeoxyguanosine (8-OHdG) in blood, urine, and placental samples were assessed. The VD group had significantly higher placental 8-isoprostane and 8-OHdG levels as well as greater plasma TAC and 8-OHdG levels and lower erythrocyte SOD activity in umbilical venous blood. Women with VD exhibited differential changes in maternal oxidative stress before and after delivery compared with women with CS. Furthermore, we found that repetitive hypoxia-reoxygenation increased the 8-isoprostane and 8-OHdG levels in villous explants compared with the normoxic controls. Together, these results indicate that labor is associated with increased placental oxidative stress and has an influence on maternal oxidative stress. Therefore, women with VD exhibit different oxidative stress indicators than do those with CS.

BackgroundConcomitant supplementation of vitamins C and E during pregnancy has been reportedly associated with low birth weight, the premature rupture of membranes and fetal loss or perinatal death in women at risk for preeclampsia; however, the cause is unknown. We surmise that hypoxia-reoxygenation (HR) within the intervillous space due to abnormal placentation is the mechanism and hypothesize that concomitant administration of aforementioned vitamin antioxidants detrimentally affects trophoblast cells during HR.Methodology/principal findingsUsing villous explants, concomitant administration of 50 microM of vitamins C and E was observed to reduce apoptotic and autophagic changes in the trophoblast layer at normoxia (8% oxygen) but to cause more prominent apoptosis and autophagy during HR. Furthermore, increased levels of Bcl-2 and Bcl-xL in association with a decrease in the autophagy-related protein LC3-II were noted in cytotrophoblastic cells treated with vitamins C and E under standard culture conditions. In contrast, vitamin treatment decreased Bcl-2 and Bcl-xL as well as increased mitochondrial Bak and cytosolic LC3-II in cytotrophoblasts subjected to HR.Conclusions/significanceOur results indicate that concomitant administration of vitamins C and E has differential effects on the changes of apoptosis, autophagy and the expression of Bcl-2 family of proteins in the trophoblasts between normoxia and HR. These changes may probably lead to the impairment of placental function and suboptimal growth of the fetus.

Ectodomain shedding of epidermal growth factor receptor ligands such as transforming growth factor- alpha (TGF-alpha), heparin-binding epidermal growth factor-like growth factor (HBEGF), and amphiregulin (AREG) is considered to be important during implantation. Tumor necrosis factor-alpha converting enzyme (TACE) has been suggested as the major sheddase for these molecules. The objectives of this study are (1) to characterize the expression of TACE in the human placenta throughout gestation; (2) to determine the association between the expression of TACE with TGF-alpha, HBEGF, and AREG; (3) to ascertain whether TACE mediates TGF-alpha, HBEGF, and AREG shedding; and (4) to examine the effect of hypoxia on the expression of TACE. By analyzing a total of 55 villous samples representing different gestational ages, the authors found that TACE was continuously expressed in the placentas throughout gestation and that the levels of TACE were positively correlated with the levels of TGF-alpha, HBEGF, and AREG. Preadministration of a TACE inhibitor in villous explant cultures or transfection of cytotrophoblastic cells with TACE-specific small interference RNA decreased the shedding of HBEGF and AREG. Moreover, hypoxia (2% O(2)) caused an increase in the levels of TACE mRNA and protein in villous explants and primary cytotrophoblastic cells in vitro. These results indicate that oxygen regulates the expression of TACE and that TACE may be important for placental development during human pregnancy.