Our results provide molecular evidence that aberrant global placental gene expression changes in preeclampsia may be due to reduced oxygenation and that these events can successfully be mimicked by in vivo and in vitro models of placental hypoxia.
Elevated expression of soluble vascular endothelial growth factor receptor-1 (sFlt-1) in preeclampsia plays a major role in the pathogenesis of this serious disorder of human pregnancy. Although reduced placental oxygenation is thought to be involved in the pathogenesis of preeclampsia, it is unclear how oxygen regulates placental sFlt-1 expression. The aims herein were to investigate sFlt-1 expression in in vivo and in vitro physiological and pathological models of human placental hypoxia and to understand the role of hypoxia inducible factor-1 (HIF-1) in regulating the expression of this molecule. sFlt-1 expression in placental villi was significantly increased under physiological low oxygen conditions in early first-trimester and in high-altitude placentae, as well as in pathological low oxygen conditions, such as preeclampsia. In high-altitude and in preeclamptic tissue, sFlt-1 localized within villi to perivascular regions, the syncytiotrophoblast layer, and syncytial knots. In first-trimester villous explants, low oxygen, but not hypoxia-reoxygenation (HR), increased sFlt-1 expression. Moreover, exposure of villous explants to dimethyloxalyl-glycin, a pharmacological inhibitor of prolyl-hydroxylases, which mimics hypoxia by increasing HIF-1alpha stability, increased sFlt-1 expression. Conversely, HIF-1alpha knockdown using antisense oligonucleotides, decreased sFlt-1 expression. In conclusion, placental sFlt-1 expression is increased by both physiologically and pathologically low levels of oxygen. This oxygen-induced effect is mediated via the transcription factor HIF-1. Low oxygen levels, as opposed to intermittent oxygen tension (HR) changes, play an important role in regulating sFlt-1 expression in the developing human placenta and hence may contribute to the development of preeclampsia.
Endoglin, a co-receptor for transforming growth factor (TGF)- 1 and - 3 is expressed in the human placenta and plays an important role in the pathogenesis of preeclampsia. Because preeclampsia is associated with hypoxia, and because TGF-3 is overexpressed in preeclamptic pregnancies, we examined the effect of oxygen and TGF-3 on placental endoglin expression and investigated its expression in pathological models of placental hypoxia such as intrauterine growth restriction (IUGR) pregnancies. Endoglin expression was high at 4 to 9 weeks of gestation, when oxygen tension is low, and decreased after 10 weeks, when oxygen tension increases. Exposure of villous explants to low oxygen (3% O 2 ) resulted in elevated expression of both membrane and soluble endoglin compared to standard conditions (20% O 2 ). Moreover, addition of TGF- 3 to villous explants under low oxygen conditions increased the expression of endoglin compared to nontreated explants whereas addition of TGF- 3 -neutralizing antibodies inhibited the low oxygen stimulatory effect on endoglin expression. Endoglin and soluble endoglin expression were significantly increased in placentas of IUGR singletons compared to controls and in the IUGR twin placentas relative to both the control co-twin and the normal twins. These data demonstrate that oxygen regulates the placental expression of endoglin via TGF- 3 . Reduced placental perfusion leading to placental hypoxia might contribute to the increased expression of endoglin in IUGR pregnancies. (Am J
Our aim was to define the association between early onset intra-uterine growth restriction (IUGR) due to placental insufficiency and hypospadias in males. We prospectively studied a cohort of small-for-gestational age (SGA) male infants with hypospadias managed by a multidisciplinary team over a 5-year period. Thirty SGA male infants were diagnosed with hypospadias/abnormal genitalia after birth, and four of them were diagnosed antenatally. Five cases occurred in the smaller pair of discordant IUGR twins, where the larger co-twin had normal male genitalia. Serial ultrasounds demonstrated features of early-onset IUGR in all cases at a median gestational age of 21 weeks (range 14-31weeks). Twenty-one (70%) pregnancies were subsequently complicated by absent/reversed end-diastolic flow in the umbilical arteries indicating severe IUGR, and 17 (57%) women developed severe pre-eclampsia. There were 27 (90%) live births at a median gestational age of 31 weeks (range 27-37); 23 (77%) of the neonates had birth weights <3rd centile. All newborns had normal male karyotypes. In 62% (18/29) the hypospadias was severe. A correlation was found between the severity of the IUGR and the severity of hypospadias as significantly more infants with severe hypospadias were less than the 3rd centile compared to the mild-moderate hypospadias group: 94% (17/18) versus 55% (6/11), respectively (P = 0.02). In conclusion, SGA male newborns with hypospadias exhibit a high rate of early-onset severe IUGR due to placental insufficiency. Early placental development likely influences male external genitalia formation. Careful sonographic evaluation of the genitalia is advised when early-onset placentally mediated IUGR is found.
Aging, independently from the hormonal status, is a major risk factor for cardiovascular morbidity in healthy women. Therefore, we studied the effect of healthy aging on the cardiovascular homeostatic mechanisms in premenopausal and postmenopausal women with similar estrogen levels. Twelve healthy postmenopausal women, confirmed by follicular-stimulating hormone (FSH) and luteal hormone (LH) levels, were compared with 14 normally menstruating women during the early follicular phase (young-EF), to avoid as much as possible the effects of estrogen. Systolic BP was 108 +/- 1.5 vs. 123 +/- 2.5 (P < 0.001), supine norepinephrine was 260 +/- 30 vs. 216 +/- 45 and upright 640 +/- 100 vs. 395 +/- 50 pg/ml (P = 0.05) in young-EF vs. postmenopausal, respectively. Plasma renin activity and aldosterone remained unchanged. Vagal cardiac tone indices decreased significantly with aging (young-EF vs. postmenopausal): high-frequency (HF) band, root mean square successive differences (rMSSD) and proportion of R-R intervals >50 ms (PNN50%) were 620 +/- 140 vs. 270 +/- 70 (P = 0.04), 53 +/- 7 vs. 30 +/- 3 (P = 0.02), and 23 +/- 5 vs. 10 +/- 3 (P = 0.04), respectively. LF to HF ratio was 0.85 +/- 0.17 in young-EF and became 1.5 +/- 0.22 in postmenopausal (P = 0.03). Both arms of the baroreflex, +BRS (29 +/- 5 vs. 13.5 +/- 2.5, P = 0.01) and -BRS (26 +/- 4 vs. 15 +/- 1.5, P = 0.02) decreased with aging. Cardiovascular alpha(1)-adrenoreceptor responsiveness significantly increased and beta-decreased in postmenopausal compared with young EF (P < 0.001, both). The corrected QT intervals (QTc) were similar, whereas corrected JT intervals (JTc) and JTc to QTc ratio were prolonged in the postmenopausal group. We conclude that in young women, parasympathetic control is the main regulator of the cardiovascular system and in postmenopausal women, sympathetic tone dominates. The transition from parasympathetic to sympathetic control may contribute to the increased cardiovascular morbidity with aging.
Abstract-Premenstrual syndrome (PMS) presents with emotional and physical symptoms. Although the emotional symptoms have been extensively studied, the pathophysiology of the fluid-retention symptoms is not currently known. We tested the hypothesis that the fluid regulatory mechanisms are disturbed in PMS. Nine regularly menstruating women with PMS were compared with 9 healthy age-matched women. Hemodynamic parameters and upright plasma volume shift (extrapolated from changes in hematocrit), plasma renin activity (PRA), and plasma aldosterone and sex hormones were measured at different times during the menstrual cycle. During the early follicular and the midluteal phases, the plasma volume shift, supine and upright PRA, and plasma aldosterone were similar in both groups, and none of the participants had edema. Key Words: premenstrual syndrome Ⅲ aldosterone Ⅲ renin Ⅲ edema Ⅲ sex hormones A lmost 75% of women experience premenstrual symptoms at some time during the reproductive phase of their lives, but only Ϸ5% of the affected women perceive distressing or debilitating symptoms. 1-3 Premenstrual syndrome (PMS) displays a cluster of nonspecific symptoms, which can be grouped into 2 classes. The first class is composed of psychological and behavioral symptoms, such as tension, irritability, mood swings, anxiety, and depression. 4,5 The second class refers to the somatic aspect of the syndrome, which can be subdivided into 2 groups. The first subgroup relates to aberrations in volume homeostasis and includes somatic complaints, such as bloatedness, breast tenderness, abdominal swelling, and edema of extremities. 5,6 The second subgroup is related to altered function of the autonomic nervous system and includes dizziness/lightheadedness, palpitations, and disorders of the gastrointestinal system. 5,7 Although there is a vast amount of knowledge about the psychological and psychiatric aspects of PMS, the pathophysiology of its somatic symptoms has been not fully investigated. The cyclic pattern of the symptoms of PMS recalls its relationship with the changing hormonal profile of the menstrual cycle. Symptoms start during the middle-to-late luteal phase and then subside after the onset of menstruation, thereby suggesting a role for ovarian hormones. 8,9 Therefore, we hypothesized that the homeostatic mechanisms that control volume regulation are disturbed in PMS and account for the fluid-related somatic symptoms of the syndrome. Accordingly, the present study was undertaken to shed light on the mechanism of fluid retention in women with PMS. Methods SubjectsIn response to an advertisement in local newspapers, 135 healthy women were interviewed for the study. Eleven women matched our stringent inclusion criteria for PMS, and 9 agreed to participate in the study. They were compared with 9 age-matched women without PMS. All of the participants met the following criteria: they had regular menstrual cycles, were aged between 20 and 45 years, and had a body mass index (BMI) within the reference range (19 to 25 kg/m 2 ). The d...
Our results demonstrate that sFlt-1 expression is increased in severe IUGR placentas with abnormal umbilical artery Doppler of singletons and also in discordant IUGR twins. Reduced placental perfusion may contribute to the increased expression of sFlt-1 in IUGR pregnancies. Our data are compatible with differential sFlt-1 expression in placentas from discordant twins.
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