In former preeclamptics, a subnormal plasma volume (LPV) predisposes to hemodynamic maladaptation to pregnancy. Here, we assessed the initial cardiovascular response to pregnancy in LPV (n = 20), in former preeclamptics with normal plasma volume (NPV) (n = 35) and in parous controls (CONTR) (n = 9) by echocardiography, blood pressure and heart rate (HR), before pregnancy, and by 5 and 7 weeks amenorrhea. Data analysis was by nonparametric tests. LPV differed from NPV and CONTR, by a consistently lower E/A ratio (ratio of peak mitral flow velocity in early diastole [E] and that during atrial contraction [A]) and an early-pregnancy rise in left atrial diameter (LAD). Both NPV and LPV differed from CONTR by an early-pregnancy rise in HR. The consistently lower E/A ratio together with the early-pregnancy LAD rise in LPV indicate diastolic dysfunction. The early-pregnancy rise in HR suggests sympathetic dominance in the autonomic control of the circulation.
We have previously shown that after exposure to long-term hypoxia, fetal coronary flow is maintained at control levels despite a 25% reduction in cardiac output. We also demonstrated that coronary vascular rings isolated from the long-term hypoxic fetuses and studied in well-oxygenated bath system displayed significantly reduced depolarization-induced contraction strength in response to KCl. To study the mechanism of reduced fetal coronary vascular responses to KCl-induced contractions following exposure to long-term hypoxia, we measured tension and intracellular calcium simultaneously, as well as L-type Ca2+ channel density and sensitivity. Pregnant ewes were housed at altitude (3820 m) for approximately 110 days. At 138 to 141 days of gestation, long-term hypoxic and control animals were killed and fetal and adult left anterior descending coronary artery (LAD) was isolated and studied in a well-oxygenated bath system. Tension and intracellular calcium ([Ca2+]i) were measured simultaneously in response to increasing concentrations of KCl and, in addition, the sensitivity to the calcium channel blocker nifedipine was measured at a half maximal concentration of KCl. We also measured L-type Ca2+ channel density with (+)-[3H]PN200-110. L-type Ca2+ channel density was decreased by ~31% in the long-term hypoxic fetal, but not adult, LAD. Tension in the long-term hypoxic fetal and adult LAD was significantly lower at all concentrations of KCl. [Ca2+]i was lower at rest in both fetal and adult LAD from long-term hypoxic animals and increased to lower levels at all concentrations of KCl. The ratio of tension to [Ca2+]i was also lower at all concentrations of KCl. Sensitivity to nifedipine was unchanged. The reduced L-type Ca2+ channel density and the reduced [Ca2+]i response to KCl, as well as the reduced tension response to [Ca 2+]i, could potentially be involved in the reduction in depolarization-induced contractions in LAD from long-term hypoxic fetuses. In hypoxic adults, reduced [Ca2+]i and reduced tension response to [Ca2+]i may be involved in the lower tension response to KCl-induced contractions.
Allopregnanolone (AP) is a potent GABAergic agonist that suppresses CNS activity, seizure threshold, and excitotoxicity in the adult brain. AP is present in the fetal sheep brain and increases rapidly after asphyxial insult due to increased 5α-reductase type-2 (5αR-2) expression. The aim of this study was to use finasteride to suppress fetal neurosteroid synthesis, and then determine the effect on brain injury, particularly in the hippocampus, of asphyxia induced in utero by brief occlusion of the umbilical cord. Catheters and an inflatable umbilical cord cuff were implanted in fetal sheep at ∼125 days gestation. Five days later the fetuses received either finasteride (20 mg/kg/h) or vehicle (40% hydroxypropyl-β-cyclodextrin) for 2 h. The umbilical cord was occluded (UCO) for 5 min at 30 min after starting the infusion. The fetal brain was obtained 24 h later for examination of activated caspase-3 expression as an index of apoptosis, and to measure AP content. Finasteride treatment alone significantly reduced AP content and increased the number of caspase-3 positive cells in the hippocampus, cerebellum, and the subcallosal bundle, indicating that AP modulates the normal rate of apoptosis in the developing brain. UCO in vehicle and finasteride-treated fetuses produced a similar, marked decrease in O2 saturation (5.8±0.6%), but after finasteride treatment UCO caused a significantly greater increase in the number of caspase-3 positive cells in the hippocampal cornu ammonis 3 (CA3) (57.3±1.6%) compared with the vehicle-treated fetuses. Thus, 5α-reduced steroids such as AP may be protective in reducing cell death following acute fetal asphyxia. Perturbation of normal fetal neurosteroid levels in late gestation (e.g. due to preterm birth, or maternal synthetic steroid treatment to induce fetal lung maturation) could adversely affect brain development and increase its vulnerability to injury.
Tibolone (Tib) exhibits progestagenic activities in addition to its tissue-specific estrogenic activities. The purpose of the current study was to determine the progestagenic actions of Tib and its metabolites using target genes known to be regulated by progestins in human endometrial glandular and stromal cells. Human endometrial glandular and stromal cells were isolated from endometrial tissue fragments and separately incubated with Tib and its metabolites. Real-time polymerase chain reaction (PCR) was used to determine the mRNA content of 17βhydroxy steroid dehydrogenase (17βHSD, type 2) and sulfotransferase (SULT1E1) in endometrial glandular cells, and prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP1) in endometrial stromal cells. In glandular cells, Tib and Δ4-tibolone (Δ4Tib) significantly increased the content of 17βHSD and SULT1E1 mRNA. In stromal cells, Tib and Δ4Tib increased PRL mRNA (∼ 30% of the capacity compared to progesterone) and had little effect on IGFBP1 mRNA. Anti-progestin, RU486, reversed the induction of SULT1E1 and PRL by progesterone or Tib. Also, the two 3 hydroxyl tobolone metabolites, especially 3βOHTib, showed some progestagenic effects. The data showed that Tib and Δ4Tib exhibited clear progestagenic effects in endometrial glandular cells by inducing 17βHSD and SULT1E1, while in stromal cells the response was weaker in the induction of PRL and had little effect on IGFBP1. In addition, the 3βOHTib metabolite expressed progestagenic activity. These disparate effects in two types of cells may be beneficial for maintaining endometrial cells in a quiescent state.
OBJECTIVE:To determine whether the insulin receptor (IR), insulin-like growth factor-I receptor (IGF-IR), and IGF-I are expressed differentially in fibroblasts isolated from normal peritoneal and adhesion tissue before and after 24-hour treatment with increasing glucose concentrations. DESIGN:Prospective experimental study. SETTING:University medical center. PATIENT(S):Primary cultures of fibroblasts established from peritoneal and adhesion tissues of the same patients. INTERVENTION(S):Glucose treatment of the primary cultured fibroblasts for 24 hours with increasing concentrations of glucose (100-850 mg/dL). MAIN OUTCOME MEASURE(S):Real-time polymerase chain reaction was used to measure messenger RNA (mRNA) levels for IR, IGF-IR, and IGF-I. Enzyme-linked immunosorbent assay was used to determine protein levels. RESULT(S):At the normal glycemic level (100 mg/dL), adhesion fibroblasts have significantly higher mRNA levels of the IR (7.96 +/- 0.15 vs. 6.97 +/- 0.16; P<.05), IGF-IR (7.72 +/- 0.22 vs. 6.88 +/- 0.06; P<.05), and IGF-I (7.04 +/- 0.10 vs. 5.92 +/- 0.10; P<.05) when compared with normal fibroblasts, respectively. Data are expressed as log(mRNA/microg RNA). Normal fibroblasts respond to increasing glucose concentrations by increasing the expression levels of the IR, IGF-IR, and IGF-I, whereas adhesion fibroblasts respond by decreasing the expression of the IR, IGF-IR, and IGF-I. CONCLUSION(S):The differential expression of the IR, IGF-IR, and IGF-I in adhesion fibroblasts may contribute to the pathogenesis of fibrosis observed in diabetic patients.
Our objective was to survey training in ET techniques among fellows, its perceived importance, and potential barriers to ET training during fellowship. Although ET training remains an important issue for most fellows and recent graduates, 44% of respondents did not receive this training during their fellowship.
OBJECTIVE:This study tested the hypothesis that the endothelin (ET)/ET receptor (ETR) system in biologic fluids and in the human placenta is altered in delayed miscarriages as compared to apparently normal early pregnancies (reference group).METHODS:Immunoreactive ET (irET) concentrations were measured in plasma, urine, and cervical smears from 57 pregnant women in the weeks 6 to 14 of gestation (46 delayed miscarriages, 11 references) with radioimmunoassay (RIA). ET-1, ETR-A, and ETR-B mRNA, and ETR protein expression were measured in placental tissue of 45 early pregnancies (31 delayed miscarriages, 14 references) using semiquantitative reverse-transcription polymerase chain reaction (RT-PCR) and immunoblotting, respectively.RESULTS:irET levels in plasma, urine, and cervical smears did not differ between groups. Two prevailing ETR-A and ETR-B proteins were found at 45 and 55 kd, and were distributed similarly in delayed miscarriages and references. ETR-A protein and mRNA levels were 54% (P = .009) and threefold (P = .021) higher, respectively, in delayed miscarriages versus references. There was no difference in placental ETR-B and ET-1 mRNA levels between groups.CONCLUSION:Neither irET nor ET-1 mRNA levels differ between delayed miscarriages and normal early pregnancies. Pregnancies at risk for miscarriage cannot be identified by measurement of ET in plasma, urine, or cervical smears. Within the ET/ETR system, ETR-A is selectively up-regulated in placental tissue of delayed miscarriages as compared to normal pregnancies. ETR protein processing is similar in both groups.
OBJECTIVE:The objective of the study was to determine whether the route of administration of estrogen therapy in women with metabolic syndrome (MBS) influences inflammation and coagulation parameters.STUDY DESIGN:Fifty symptomatic postmenopausal women with MBS were randomized to receive 1 mg oral estradiol (oE(2)) or 0.05 mg transdermal E(2) (tE(2)) for 3 months. Measurements were compared with those of 20 healthy premenopausal women and 74 normal postmenopausal women.RESULTS:Compared with both control groups, women with MBS had significantly higher levels of certain inflammation and coagulation markers, which cannot be accounted for based on weight alone. After oE(2), antithrombin III decreased from 104% to 96% (P < .01), the metalloproteinase-9/ tissue inhibitor of metalloproteinase-1 ratio increased (P < .02), and E-selectin decreased from 60 +/- 4.4 to 55 +/- 4.6 ng/mL (P < .05). With tE(2), there were no major changes noted.CONCLUSION:Postmenopausal women with MBS have higher levels of certain coagulation and inflammation markers and different responses to oral compared with transdermal estradiol.
OBJECTIVE:The cell membrane water channel protein aquaporins (AQPs) may be important in regulating the intramembranous (IM) pathway of amniotic fluid (AF) resorption. The objective of the present study was to determine whether aquaporin 3 (AQP3) is expressed in human fetal membranes and to further determine if AQP3 expression in primary human amnion cell culture is regulated by second-messenger cyclic adenosine monophosphate (cAMP).METHODS:AQP3 expression in human fetal membranes of normal term pregnancy was studied by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). To determine the effect of cAMP on AQP3 expression, primary human amnion cell cultures were treated in either heat-inactivated medium alone (control), or heat-inactivated medium containing: (1) SP-cAMP, a membrane-permeable and phosphodiesterase resistant cAMP agonist, or (2) forskolin, an adenylate cyclase stimulator. Total RNA was isolated and multiplex real-time RT-PCR employed for relative quantitation of AQP3 expression.RESULTS:We detected AQP3 expression in placenta, chorion, and amnion using RT-PCR. Using IHC, we identified AQP3 protein expression in placenta syncytiotrophoblasts and cytotrophoblasts, chorion cytotrophoblasts, and amnion epithelia. In primary amnion epithelial cell culture, AQP3 mRNA significantly increased at 2 hours following forskolin or SP-cAMP, remained elevated at 10 hours following forskolin, and returned to baseline levels by 20 hours following treatment.CONCLUSION:This study provides evidence of AQP3 expression in human fetal membranes and demonstrates that AQP3 expression in primary human amnion cell culture is up-regulated by second-messenger cAMP. As AQP3 is permeable to water, urea, and glycerol, modulation of its expression in fetal membranes may contribute to AF homeostasis.
HIV-infected women have high risk for precancerous lesions of the uterine cervix. We studied the prevalence and risk factors of squamous intraepithelial lesions (SIL) among systematically followed HIV-infected women enrolled from a population with low HIV prevalence. The study population consisted of 108 HIV-infected women enrolled between 1989 and 2003 with a mean follow-up 4.4 years. Risk factors of SIL were assessed based on samples collected during 2000–02. The overall rates of atypical glandular cells of uncertain significance (AGUS), atypical squamous cells of uncertain significance (ASCUS), low-grade SIL (LSIL) and high-grade SIL (HSIL) were 4, 24, 15 and 5%, respectively. Reduced CD4-lymphocyte count was associated with an increased prevalence of SIL, whereas duration of HIV infection (< or ≥5 years), use of antiretroviral medication, or HIV viral load (<50 or ≥50 copies/mL) was not. The cumulative risk of developing SIL after 1 and 5 years was 17% (95% confidence interval [CI] 7–27%) and 48% (95% CI 33–63%), respectively. The cumulative risk of SIL was increased among women younger than 31 years ( P = 0.04) as well as in women displaying high initial HIV viral load ( P = 0.01). Our results from a low HIV-incidence population re-emphasize the importance of guidelines for cytologic screening of HIV-seropositive women.
Cation channels comprised of transient receptor potential (TrpC) proteins may play a role in signal-regulated calcium entry and calcium homeostasis in myometrium. The objective of this study was to determine the relative abundance of specific TrpC mRNAs expressed in human myometrium and determine if TrpC mRNA and protein concentrations differ in fundal myometrium before and after the onset of labor. A quantitative real-time polymerase chain reaction (Q-RT-PCR) procedure was developed for determining the concentration of TrpC mRNA expression in immortalized and primary human myometrial cells and myometrial fundus tissues from patients before and after the onset of labor. The corresponding TrpC proteins were detected by Western blot analysis and immu no h istochem is try. hTrpC1, 3, 4, 5, 6, and 7 mRNAs were expressed in two lines of immortalized human myometrial cells and in primary human myocytes. In all of these cells, hTrpC1 and hTrpC4 mRNAs were the most abundant? followed by hTrpC6. A similar distribution was observed in fundal myometrium samples from patients before and after the onset of labor. hTrpC4 mRNA was significantly lower after the onset of labor; there were no significant changes in the concentrations of other TrpC mRNAs. Immuno- h is to chemistry identified hTrpCl, 3, 4, and 6 proteins in myometrial smooth muscle cells. Western blot analysis of myometrial membranes demonstrated no statistically significant changes in hTrpCl, 3, 4 and 6 proteins between samples collected before and after the onset of labor. We have demonstrated that hTrpC1 and hTrpC4 are the most abundant TrpC mRNAs in human myometrium, with TrpC6 being the next most abundant. There was no increase in TrpC mRNA or protein in fundal myometrium with the onset of labor. Nonetheless, these isoforms may play significant roles in signal regulated calcium entry in human myometrium.
BACKGROUND Reproductive outcome studies of couples with a history of recurrent pregnancy loss (RPL) associated with a maternal or paternal carrier of a structural chromosome rearrangement are limited. Correlation of carrier status and cytogenetics of miscarriage specimens is critical to estimate subsequent pregnancy outcome. METHODS Couples found to have a structural chromosome rearrangement were followed prospectively in a tertiary academic centre. Descriptive analysis and subsequent pregnancy outcomes were tabulated and compared to historic controls. RESULTS In 1893 RPL couples, 51 carriers of a structural chromosome rearrangement were identified (2.7%). Overall, this cohort had a total of 273 documented pregnancies. Prior to evaluation, the mean maternal age at the time of delivery or miscarriage was 29.8 years and the live birth rate was 15%. Following evaluation and treatment of concomitant factors, there were 58 monitored pregnancies, with a live birth rate of 71%. Amniocentesis was performed on 22% of the ongoing pregnancies; all were diploid or balanced structural chromosome rearrangements. Thirty-six per cent of the miscarriages were found to have an unbalanced structural chromosome rearrangement. CONCLUSIONS Following evaluation and management of RPL, the live birth rate for carriers of a structural chromosome rearrangement is highly encouraging at 71%, without the addition of assisted reproductive technology.
OBJECTIVE:Intrauterine growth retardation (IUGR) is an important cause of prenatal and neonatal morbidity, and neurologic abnormalities. Although several animal models of IUGR have been developed for scientific investigation, few models approximate the pathophysiology in human fetal growth failure resulting from pregnancy-induced hypertension and preeclampsia. We developed an animal model of IUGR in which fetal growth restriction was induced by administering a synthetic thromboxane A(2) analogue (STA(2)) to the mother.METHODS:Timed pregnant Sprague-Dawley rats were used in this study. STA(2) was delivered into the peritoneal cavity of the pregnant female at a rate of 20 ng/h from day 13 of pregnancy. The effectiveness of this model was evaluated by monitoring the overall growth of the fetuses and neonates and measuring the weight and biochemical composition of individual organs.RESULTS:Fetuses and neonates from the STA(2) group showed a highly significant weight reduction throughout the observation period from day 19 of gestation to postnatal day 7. Weight reduction near and at term exceeded 10% and became more pronounced during the first week after birth. Fetuses on the 20th gestational day exhibited a pattern of growth retardation characteristic of asymmetrical IUGR in which the weight reduction was prominent in the liver with relative sparing of the brain. However, the decrease in brain weight was more than 10%. The protein, DNA, and RNA contents of the liver were lower in the STA(2) group. The protein content of the forebrain and brainstem also decreased significantly in the STA(2) group compared with the control; however, the DNA content of the forebrain was higher in the STA(2) group.CONCLUSIONS:This animal model may mimic human IUGR more closely than previous models because the growth restriction is induced in a truly chronic manner.
Nitric oxide (NO) plays a fundamental role in cervical ripening and it is synthesized in the human cervix. We studied the effect of the dinoprostone on cervical NO release in pregnant women, and we investigated the relationship between cervical NO metabolites, cervical length, and Bishop score. Seventy-seven women underwent induction of labor at ≤37 weeks of gestation, due to post-term pregnancy (23.8%), oligohydramnios (36.3) or preeclampsia (29.9%). Cervicalfluid samples for NO metabolites (NOx), Bishop score, and cervical length were assessed immediately before (time 0 [TO]) and 6 hours after (T6) the local application of dinoprostone, a commercially available prostaglandin E2 (PGE2) analog. The mean patients’ age was 34 ± 3.2 years, mean gestational age at enrollment was 284 ± 9.2 days, and nulliparous represented 31.2%) of the study population. At time 0, Bishop score was less than 4 in 74% (57/77) of the subjects, mean cervical length was 28.6 ± 5.8 mm, mean NOx concentration was 208.6 ± 103.8 μM/mL; 6 hours later, at T6, the mean cervical length decreased to 19.5 ± 8.8 mm, and the mean NOx concentration increased up to 316.7 ± 240.9 μM/mL. Data were unaffected by parity or by regular uterine contraction patterns. A statistically significant positive correlation was found between changes in cervical NOx levels and Bishop score modification (P <.01; r =.494), as well as between the modification of NO metabolites concentration and cervical shortening (P <.01; r =.307). Prostaglandin (PG)-induced cervical ripening is associated with local NO release. NO plays an active role in cervical remodeling since it positively correlates with both cervical shortening and Bishop score increase. NO oxide and PG are the two pathways that, cross activating each other, trigger the cascade of events responsible of cervical ripening.
injury is associated with chorioamnionitis, which is often present without signs of overt infection or fetal compromise. We aimed to determine if prolonged exposure to intrauterine inflammation caused by intra-amniotic infusion of lipopoly saccharide (LPS) would affect the fetal brain. At 80 days of pregnancy ewes bearing singletons had osmotic pumps implanted intra-amniotically to infuse Escherichia coli LPS (055:B5; n = 8) or saline (n = 7) for 28 days. At delivery (110 days), umbilical arterial blood and chorioamnion were assessed for inflammation; cytokine concentrations (interleukin [IL]-6 and IL-8) in amniotic fluid and fetal and maternal plasma were measured. The fetal cerebral hemispheres were examined for gross anatomical changes and the number of activated microglia/macrophages, astrocytes, and oligodendrocytes estimated after immunohistochemical staining. Intra-amniotic administration of LPS caused chorioamnionitis, fetal leucocytosis, and a moderate to extensive infiltration of activated microglia/macrophages in the subcortical white matter in six of eight fetuses; the remaining two fetuses were less affected. Within these focal regions of damage there was an attenuation of astrocytic processes, axonal injury, and a reduction in the number of 2’, 3’ -cyclic nucleotide 3’-phosphodiesterase (CNPase) immunoreactive oligodendrocytes in areas of extensive focal damage. In control fetuses there was mild (3/7) or no infiltration of activated microglia/macrophages in the subcortical white matter. Overall the infiltration of activated microglia/macrophages in the white matter was significantly greater in LPS-expo sed fetuses compared to controls. In regions devoid of injury, the number of oligodendrocytes and astrocytes was not different between groups, nor was there a difference in the volume of cerebral white matter or density of blood vessels within the white matter. Amniotic fluid IL-6 and IL-8, and maternal plasma IL-8 concentrations were significantly increased by LPS infusion. An increase in inflammatory cells and axonal disruption in the subcortical white matter of the fetal brain can accompany chorioamnionitis induced by intra-amniotic administration of LPS, but cystic lesions do not occur. Thus, the effect on the fetal brain is milder than that reported from animal models of acute fetal/intrauterine infection.
Objective: We tested the hypothesis that 02 administration to the mother would increase arterial O-2 tension (PaO2) and cortical tissue O-2 tension (tPO(2)) in both the normoxic control fetus and that acclimatized to high altitude, and that this effect might be greater in the high altitude fetus than that at sea level.Study design: Pregnant ewes were divided into either low-altitude group or high-altitude group (3820 m; maintained from day 30 of gestation to near-term, term = 145 days; n = 6 each). In near-term fetuses we instrumented the cerebral cortex with tissue PO2-laser Doppler flow probes, and placed arterial catheters. With the ewe breathing either air or 50% O-2, we measured fetal arterial and brain tissue PO2 and cerebral blood flow (CBF).Results: In response to maternal O-2 administration, in both low- and high-altitude fetuses, PaO2, O-2 content, and brain tissue PO2 increased significantly. Nonetheless, the fetuses at high altitude showed significantly greater increase in both PaO2 and cerebral tPO(2), than that seen in fetuses at low altitude. In neither group was there a change in CBF or cerebral metabolic rate for O-2,Conclusion: Maternal O-2 administration significantly increased PaO2 and cerebral tPO(2) of the fetus both at low altitude and at high altitude, with this increase being greater in the high altitude animals. We suggest that maternal O-2 administration can have an important effect in ameliorating nonreassuring fetal status, and perhaps be of value in instances of mothers who smoke heavily or with cardiopulmonary disease. (c) 2006 Mosby, Inc. All rights reserved.
OBJECTIVE:Epidemiologic, pathophysiologic, and genetic data suggest a close link between gestational diabetes mellitus (GDM) and type 2 diabetes. Previous studies yielded controversial results on the impact of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1) gene variations on the development of type 2 diabetes mellitus. Therefore, we examined two common single nucleotide polymorphisms (SNP) of this gene in women with GDM.METHODS:We assessed a total of 875 women by oral glucose tolerance testing (OGTT). Two hundred women of this population, 100 patients with an abnormal OGTT and 100 normal controls, were randomly selected. DNA samples isolated from the blood of the control and study groups were analyzed with respect to the SNP Gly482Ser and Thr394Thr of the PGC-1 gene using polymerase chain reaction (PCR) amplification and restriction analysis. Furthermore, a potential interaction between the Gly482Ser and the Thr394Thr variant on the risk of GDM was investigated.RESULTS:Women with GDM were significantly older (32.2 +/-5.5 years vs 29.7 +/- 6.1 years; P = .005), had higher body mass indices (BMI; 28.0 +/- 7.1 kg/m2 vs 25.0 +/- 5.7 kg/m2; P = .002) and displayed higher hemoglobin A1c (HbA1c) values (5.6 +/- 0.9 vs 4.9 +/- 0.5; P <.001). There was no significant difference between the allele distribution of the two polymorphisms in women with and without GDM. No significant associations between the two polymorphisms and BMI or OGTT values were observed. When the different haplotype combinations of the two loci were analyzed for the risk of GDM, no significant association could be found.CONCLUSION:Based on our data, the Gly482Ser and the Thr394Thr polymorphisms of the PGC-1 gene are not associated with the development of GDM.
Due to the extensive use of intracy toplasmic sperm injection (ICSI) in assisted reproduction, not only among couples with severe male factor infertility problems, but to a broader scale, a lot of concern has been raised regarding the safety of the method and its implications in epigenetic control and imprinting dysingulation. This review means to provide a comprehensive report of the published scientific data, outline putative associations between ICSI and epigenetic control, and suggest measures to improve the current state of affairs and reach more scientifically consolidated results. This review was conducted by studying a broad spectrum of articles dealing with the subject of epigenetic control and its relation with ICSI, We tried to view the two subjects as parallel procedures that occur in the organism and by delineating the molecular and biochemical steps that comprise them make suggestions about putative associations between ICSI and epigenetic control. No hard evidence presented at the moment can prove or disapprove ICSTs implications in epigenetic control Nevertheless, we take the view that more comprehensive, long-term, and properly designed studies are imperative to be applied on a large-scale basis. We urge cautiousness, since the welfare of our progeny is what is at stake.
Background: Endogenous steroids are known to be essential for normal brain development. Pre-and postnatal glucocorticoids however, are associated with increased risk for adverse neurological outcome through mechanisms that are not clear, but may lead to alterations of cell structure and function. Objective: The present study tests the hypothesis that prenatal dexamethasone given at critical points in gestation will result in increased neuronal nuclear Ca++-influx, leading to activation of caspase -3 and 9 which triggers the apoptotic pathway and that this mechanism is dependent on gestational age. Design/Methods: Two groups of fetal guinea pigs were studied, at 35 (n=8) and 45 (n=8) days gestation. Saline (Sa), 0.5ml/dose, or dexamethasone (Dx), 0.4mg/kg/dose was injected i.p. into the mother daily x 2 days. Fetal guinea pig brains were harvested at 72 hours post Sa or Dx injection. Nuclei were isolated and ATP-dependent Ca++-influx was determined. Cytosolic caspase-3, and -9 activity was determined. Caspase activity was determined spectrofluorometrically and expressed as nmoles/mg protein/hr. Results: Ca++-influx at 35d was 6.42+/-2.0 (Sa) and 7.42+/-3.4 (Dx), an increase of 16%; at 45d was 5.63+/-2.3 (Sa) and 10.5+/-2.1 (Dx), an increase of 80%. Caspase-3 activity at 35d was 13.3 +/-1.3 (Sa) and 13.9+/-1.9 (Dx); at 45d was 12.8+/-0.8 (Sa) and 9.53+/-1.01 (Dx), a decrease of 25%. Caspase-9 activity at 35d was 3.52+/-0.3 (Sa) and 3.39+/-0.2 (Dx); at 45d was 3.46+/-0.2 (Sa) and 2.49+/-0.2 (Dx), a decrease of 28%. The data show that antenatal Dexamethasone resulted in increased Ca++-influx in neuronal nuclei of fetal guinea pigs without altering caspase-3 or -9 activity. Conclusions: We conclude that Dexamethasone activates neuronal nuclear membrane mechanisms that initiate the apoptotic cascade and increase with gestational age. We speculate that Dexamethasone modifies nuclear membrane mechanisms of Ca++ influx and leads to cellular injury through an apoptotic pathway independent of caspase expression.
